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Author Interviews, Heart Disease, JAMA, University of Pittsburgh / 07.01.2015

Inmaculada Hernandez, PharmD PhD Student, Health Services Research and Policy Deparment of Health Policy and Management Graduate School of Public Health University of Pittsburgh Pittsburgh, PA 15261MedicalResearch.com Interview with: Inmaculada Hernandez, PharmD PhD Student, Health Services Research and Policy Deparment of Health Policy and Management Graduate School of Public Health University of Pittsburgh Pittsburgh, PA 15261 Medical Research: What is the background for this study? What are the main findings? Response: The approval of dabigatran was considered a major contribution to the therapeutic arsenal of anticoagulants since warfarin, whose therapeutic management is complicated, was the only oral anticoagulant approved before 2011. Clinicians therefore considered dabigatran a very promising drug; however, the safety warnings released by the regulatory agencies and the reports of bleeding published in 2011 raised concerns about the safety profile of dabigatran. By the time we initiated our study, the FDA had concluded that dabigatran was associated with similar rates of bleeding than warfarin. However, the results of this observational study were not adjusted by patient characteristics. We therefore compared the risks of bleeding with dabigatran and warfarin adjusting for patient characteristics and using propensity score methods to mitigate selection biases, which observational studies are sensitive to. We found that dabigatran was associated with a higher risk of major bleeding and gastrointestinal bleeding than warfarin. However, the risk of intracranial bleeding was lower with dabigatran. In addition, we found that the increased risk of bleeding with dabigatran was specially higher for African Americans and for patients with chronic kidney disease. (more…)
Author Interviews, JAMA, Mental Health Research, University of Pittsburgh / 06.01.2015

Dr. Brent David MD Academic Chief, Child and Adolescent Psychiatry at Western Psychiatric Institute and Clinic Professor of Psychiatry, Pediatrics & Epidemiology University of Pittsburgh School of Medicine MedicalResearch.com Interview with: Dr. Brent David MD Academic Chief, Child and Adolescent Psychiatry at Western Psychiatric Institute and Clinic Professor of Psychiatry, Pediatrics & Epidemiology University of Pittsburgh School of Medicine Medical Research: What is the background for this study? Dr. David: There are now many studies that show that suicide and suicidal behavior run in families. A family history of suicide increases the risk for suicide attempt and vice versa, so that we believe that the trait that is being passed from parent to child is a tendency to act on suicidal thoughts, resulting in either an attempt or an actual suicide. However, what was not not known was the mechanism by which parents transmitted the risk of suicidal behavior to their children, and what the precursors of suicidal behavior looked like in individuals who were at risk for suicidal behavior, but had not yet engaged in a suicide attempt. Therefore, we conducted a high-risk family study, in which studied the children of parents with mood disorders, about half of whom also had a history of a suicide attempt. Medical Research: What are the main findings? Dr. David: We followed 701 offspring for an average of 5.6 years, and found that those offspring whose parents had made a suicide attempt were almost 5 times more likely to make a suicide attempt themselves, even after accounting for mood disorder in parent and child and past suicidal behavior in the offspring. We found three main pathways by which suicidal behavior was passed from parent to child:
  • Parental mood disorder was transmitted to children, and that was a precursor of a suicide attempt.
  • Parent attempt was related to offspring impulsive aggression, which in turn increased the risk for mood disorder, which then increased the likelihood of a suicide attempt. (We define impulsive aggression as a tendency to response with hostility or aggression to provocation or frustration.
  • Finally, there is a direct path from parent attempt to child attempt, with no precursors or intervening variables.
Implications for clinicians and patients:
  • First, these findings highlight that a parental history of a suicide attempt increases the risk of an attempt in the parent's children. Clinicians who take care of adults who have attempted suicide should make sure that children are assessed as they are at increased risk and that parents know what to look for in the future in order to get their children into needed treatment.
  • Second, the transmission of suicidal behavior from parent to child can be attenuated by preventing the transmission of mood disorder, and of impulsive aggression. There are now evidence based interventions that reduce the likelihood of a child of a depressed parent from developing depression; these treatment involve cognitive behavioral principles and may also involve family interventions. There are now good family-based interventions for impulsive aggression that can attenuate the risk that the child or adolescent will go on to develop a mood disorder, which in turn greatly increases the risk for suicidal behavior.
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Author Interviews, JAMA, Pediatrics, UCSF / 06.01.2015

Yvonne Wu MD Professor of Clinical Neurology and Pediatrics UCSF School of MedicineMedicalResearch.com Interview with: Yvonne Wu MD Professor of Clinical Neurology and Pediatrics UCSF School of Medicine   Medical Research: What is the background for this study? What are the main findings? Dr. Wu: Newborn infants commonly have elevated bilirubin levels, manifested as jaundice, because the body's mechanisms for breaking down bilirubin have not yet fully matured.  Although high bilirubin levels are almost always well tolerated, extremely high bilirubin levels may lead to brain injury, or kernicterus, which in turn can cause a very severe form of cerebral palsy.  When bilirubin levels are extremely high, or when bilirubin levels remain high despite phototherapy, it is recommended that an exchange transfusion be performed to prevent brain injury and cerebral palsy.  The American Academy of Pediatrics (AAP) has published recommendations on when an exchange transfusion should be performed, based on bilirubin level, age of infant and other clinical factors.  However, no previous study had examined the actual risk of cerebral palsy in infants whose bilirubin levels exceeded the exchange transfusion thresholds. Among 500,000 newborns born at Kaiser Permanente Northern California over a 17-year period, we found 1833 who had at least one bilirubin level above the AAP exchange transfusion level.  There were only 3 cases of cerebral palsy due to kernicterus in this group, even though only 42 (2.3%) of them had received exchange transfusions.  All 3 infants had bilirubin levels at least 5 mg/dL above the AAP exchange transfusion threshold and all 3 infants had 2 or more other risk factors for brain damage, including prematurity, sepsis, hypoxia and the hereditary blood disorder G6PD deficiency.  We did not identify any cases of kernicterus among otherwise well term babies, even at bilirubin levels that exceeded the AAP exchange transfusion threshold. (more…)
Author Interviews, JAMA, Mental Health Research, UCSF / 06.01.2015

Dr. Georges Naasan MD Neurologist, Clinical Instructor UCSF Memory and Aging CenterMedicalResearch.com Interview with: Dr. Georges Naasan MD Neurologist, Clinical Instructor UCSF Memory and Aging Center Medical Research: What is the background for this study? What are the main findings? Dr. Naasan: Degenerative diseases of the brain can lead to dysfunction in judgment, emotional processing, social decorum and self-awareness. In turn, such dysfunctions may result in criminal behavior that appears for the first time in middle-aged adults or even later in life. We studied 2397 patients from the Memory and Aging Center at UCSF and found 204 (8.5%) that had a criminal behavior as part of their illness. The large majority of these patients were patients with a specific type of neurodegenerative disease called behavioral variant of frontotemporal dementia, followed by a group of people with a disease called semantic variant of primary progressive aphasia. People with Alzheimer's disease, a disease that does not usually interrupt the functions mentioned above, were the least likely to exhibit criminal behavior. The common manifestation of criminal behaviors in people with the behavioral variant frontotemporal dementia included theft, sexual advances trespassing and public urination in contrast to people with Alzheimer's disease who, when such behaviors were present, primarily committed traffic violations often secondary to cognitive impairment. (more…)
Author Interviews, HIV, Johns Hopkins, Kidney Disease / 06.01.2015

Alison G Abraham PhD Associate Scientist Department of Epidemiology Johns Hopkins Bloomberg School of Public HealthMedicalResearch.com Interview with: Alison G Abraham PhD Associate Scientist Department of Epidemiology Johns Hopkins Bloomberg School of Public Health Medical Research: What was the motivation for this study? Dr. Abraham: HIV-infected individuals are at higher risk for kidney dysfunction compared to the general population.  Prior to effective antiretroviral therapy, very aggressive forms of kidney disease were described primarily among black HIV-infected individuals.  While effective therapy and increasing viral suppression rates have made HIV-associated nephropathy rare, some of these same drugs have nephrotoxic effects.  In addition, the reduction in AIDS and mortality has led to HIV-infected individuals living long enough to experience age-related chronic diseases, which are also risk factors for kidney disease and end-stage renal disease.  Thus we wanted to know how these competing forces were affecting end-stage renal disease risk in the well-treated HIV-infected North American population over time.  Are we seeing more ESRD as a result of nephrotoxic drugs and chronic disease, or less ESRD as a result of better viral suppression and large reductions in HIV-associated nephropathy? Medical Research: What are the main findings? Dr. Abraham: We found that end stage renal disease rates have been steadily falling over the past 10 years coincident with notable improvements in viral suppression prevalence.  However a large racial discrepancy in ESRD risk has persisted even though HIV-associated nephropathy cases are now rare.  While ESRD cases among blacks in our study tended to have higher viral loads and lower CD4 counts compared to non-black ESRD cases, suggesting less effective HIV treatment, we found that the racial discrepancy in ESRD risk persisted even among the well-suppressed subset, i.e. those who had undetectable viral loads for 90% of their follow-up time. (more…)
Author Interviews, Brigham & Women's - Harvard, JAMA, Nutrition / 05.01.2015

Qi Sun, MD ScD Assistant Professor of Medicine Channing Division of Network Medicine Brigham and Women's Hospital and Harvard Medical School Assistant Professor Department of Nutrition, Harvard School of Public Health 665 Huntington Avenue, Boston, MA 02115MedicalResearch.com Interview with: Qi Sun, MD ScD Assistant Professor of Medicine Channing Division of Network Medicine Brigham and Women’s Hospital and Harvard Medical School, Assistant Professor, Department of Nutrition Harvard School of Public Health Boston, MA 02115 Medical Research: What is the background for this study? What are the main findings? Dr. Sun: While we know whole grains are beneficial for reducing the risk of some major chronic diseases, such as heart disease and diabetes, evidence regarding whether whole grains are also able to lower mortality is sparse. We therefore want to answer this important research question in the current analysis. Using data collected from two prospective cohort studies consisted of more than 100 thousand US men and women, we found that whole grain intake was significantly associated with lower total mortality and lower cardiovascular mortality, but not cancer mortality. For every serving (28 grams) of whole grain intake per day, the total mortality is reduced by 5% and cardiovascular mortality by 9%. (more…)
Author Interviews, Case Western, Genetic Research / 05.01.2015

Michael A. Weiss, MD, PhD The Cowan-Blum Professor and Chairman of the Department of Biochemistry Distinguished Research Professor andMedicalResearch.com Interview with: Michael A. Weiss, MD, PhD The Cowan-Blum Professor and Chairman of the Department of Biochemistry Distinguished Research Professor and Professor of Medicine in the Endocrine Division at the Case Western Reserve School of Medicine in Cleveland, Ohio. Joseph Racca Researcher and graduate student Department of BiochemistryJoseph Racca Researcher and graduate student Department of Biochemistry Case Western Reserve School of Medicine in Cleveland, Ohio. Medical Research: What is the background for this study? What are the main findings? Response: The function of the gene responsible for male differentiation, sex-determining region of the Y chromosome (SRY), was first demonstrated in transgenic mouse models by P. Koopman, R. Lovell-Badge and colleagues in the early 1990s. These findings were corroborated by identification of mutations in human SRY that are associated with human sex reversal: XY, 46 gonadal dysgenesis leading to somatic sex reversal (Swyer’s Syndrome). Such mutations may occur spontaneously in spermatogenesis or be inherited. The characterization of the molecular defects associated with these mutations has unmasked novel biological and biochemical activities of SRY. More broadly, such studies have also increased our understanding of an entire family of related transcription factors (Sry-box related; SOX), which broadly function in metazoan development (from worms, fish and flies to mammals). Within human SRY, the majority of clinical mutations occur in the region of the protein responsible for specific DNA binding and DNA bending, the primary molecular actions of SRY at target genes. Our study bridges structure (i.e., protein folding and stability) and function (i.e., transcriptional activation of target genes and related cell-biological processes such as trafficking and proteosomal degradation). In our current study, we highlighted the importance of a structural scaffold in human SRY, specifically a key single amino acid that buttresses the unique L-shape structure of this domain. The mutation of interest represents a “perfect storm” leading to deleterious effects on multiple activities, including specific DNA binding, cellular localization, and both protein and cellular stability (lifetime), among other properties, together leading to sex reversal and cancer (gonadoblastoma) in the proband patient. Our integrated multi-disciplinary approach allowed us to characterize these various facets of SRY in the context of its biological site of action: the pre-Sertoli cell in an embryonic gonadal ridge just prior to its morphological differentiation into a testis. We are grateful to Prof. Patricia K. Donahoe (Harvard Medical School and the Massachusetts General Hospital), who generously provided this micro-dissected pre-Sertoli cell line. (more…)
Author Interviews, Breast Cancer, Mayo Clinic, NEJM / 03.01.2015

MedicalResearch.com Interview with: Dr. Lynn C. Hartmann MD Professor of Oncology, Mayo Clinic Associate Director for Education of the Mayo Clinic Cancer Center. Medical Research: What is the background for this study? What are the main findings? Dr. Hartmann: Women with atypical hyperplasia of the breast – which is defined via breast biopsy that was done to evaluate findings on a mammogram or a palpable concern – have been considered a “high risk” group of women, but the extent of their risk has not been clearly defined. As a consequence, practice guidelines for high-risk women (eg for screening MRI) do not include them. Mayo Clinic has developed a cohort of women with atypical hyperplasia who have been followed long-term for later breast cancers and we show that their risk of developing breast cancer is about 30% at 25 years of follow-up. This same level of risk was confirmed in the other large cohort of women with atypical hyperplasia, based at Vanderbilt University (Nashville Breast Cohort). This level of risk meets the current criterion for screening MRI and should also encourage the use of anti-estrogen drugs, such as tamoxifen, which have already been shown to be efficacious in this population of women. Medical Research: What should clinicians and patients take away from your report? Dr. Hartmann: There are about 100,000 US women each year diagnosed with atypical hyperplasia via breast biopsy. Although strictly speaking, atypical hyperplasia is a benign finding, it is associated with a sizable risk of a later breast cancer. Physicians from numerous disciplines care for women with high-risk benign breast issues, including gynecologists, family physicians, internists, surgeons and oncologists. These practitioners, and the patients themselves, need information about the absolute risk of breast cancer occurring over time after a diagnosis of atypical hyperplasia. This information is provided in the NEJM report. Also, current guidelines should be updated to include this high-risk population and specifics about their absolute risk, and that the risk level qualifies these patients for screening MRI. Moreover, from the standpoint of risk reduction, four previously conducted breast cancer prevention trials included women with atypical hyperplasia. These trials used hormonal therapies (anti-estrogens) and showed that, in women with atypical hyperplasia, the use of such medications could lower the risk of a later breast cancer by 50% or more. Yet, other research has shown that women are quite reluctant to take such medications, primarily because of fear of side effects. In the NEJM report, we detail specific numbers of side effects that actually occurred in women who used these anti-estrogens (as opposed to the number of side effects seen in women taking placebo) and show that most of the side effects occurred quite uncommonly. Thus, we hope that the combination of information provided in this report on (i) actual risks of breast cancer and (ii) actual risks of side effects will help patients and practitioners make informed decisions on the best treatment approaches for women with atypical hyperplasia. Medical Research: What recommendations do you have for future research as a result of this study? Dr. Hartmann: First, women with atypical hyperplasia should be included in future prospective trials of novel imaging strategies (they were not included in trials of MRI, which had been limited to women with hereditary risk). Second, efforts should continue to predict which women with atypical hyperplasia are at highest risk, especially in the first 5-10 years after their biopsy, so they can be cared for optimally. Our research team, and others, continue to study the underlying molecular pathways that drive the progression from atypical hyperplasia to cancer; identifying such processes would not only aid in risk prediction but also identify driving pathways that could be blocked pharmaceutically. Citation: upcoming NEJM publication discussing: Women with Atypical Hyperplasia are at Higher Risk of Breast Cancer MedicalResearch.com Interview with: Dr. Lynn C. Hartmann MD Professor of Oncology, Mayo Clinic Associate Director for Education of the Mayo Clinic Cancer Center. Medical Research: What is the background for this study? What are the main findings? Dr. Hartmann: Women with atypical hyperplasia of the breast – which is defined via breast biopsy that was done to evaluate findings on a mammogram or a palpable concern  – have been considered a “high risk” group of women, but the extent of their risk has not been clearly defined.  As a consequence, practice guidelines for high-risk women (eg for screening MRI) do not include them.  Mayo Clinic has developed a cohort of women with atypical hyperplasia who have been followed long-term for later breast cancers and we show that their risk of developing breast cancer is about 30% at 25 years of follow-up.  This same level of risk was confirmed in the other large cohort of women with atypical hyperplasia, based at Vanderbilt University (Nashville Breast Cohort).  This level of risk meets the current criterion for screening MRI and should also encourage the use of anti-estrogen drugs, such as tamoxifen, which have already been shown to be efficacious in this population of women. (more…)
Author Interviews, Journal Clinical Oncology, Lung Cancer, Radiation Therapy, UT Southwestern / 03.01.2015

MedicalResearch.com Interview with: Dr. Puneeth Iyengar, MD, PhD. Assistant Professor Director of Clinical Research Dept of Radiation Oncology Co-leader, Thoracic Disease Oriented Team Harold Simmons Cancer Center UT Southwestern Medical Center  Dallas, TX Medical Research: What is the background for this study? What are the main findings? Response: Stage IV Non-small cell lung cancer (NSCLC) remains a disease of limited survival, in the range of one year for a majority of patients who historically have gone on to receive systemic therapy only. Disease in this patient population most often recurs in the sites of original gross disease. With greater understanding of the biology and patterns of failure that occur in stage IV NSCLC, it is becomingly increasingly obvious that there are subsets of patients, those with limited sites of metastatic disease, who may benefit with more aggressive local therapy in addition to systemic agents to effectuate longer progression free survival (PFS) and potentially overall survival (OS). Since failures of treatment occur most commonly in original gross deposits, local non-invasive therapy in the form of stereotactic body radiation therapy (SBRT) may offer a means to curtail the recurrences, perhaps as a way to shift the time to and patterns of failure. To address these concepts, a multi institutional single arm phase II study was conducted at UT Southwestern Medical Center in Dallas and University of Colorado Medical Center. Twenty-four patients with limited metastatic NSCLC (fewer than or equal to six sites of disease including the primary) who had progressed through at least one systemic therapy regimen were treated with SBRT to all sites of gross disease and the EGFR inhibitor erlotinib with progression free survival the primary end point. The results of the study were very significant, with a PFS in this study cohort of 14.7 months, compared to historical ranges of 2-4 months, and an OS of 20.4 months, compared to historical ranges of 6-9 months for this same patient population. The SBRT treatments were found to be very safe and efficacious – only 3 out of 47 measurable lesions irradiated recurred with a concomitant shift in failure patterns from local to distant sites. As importantly, EGFR status was evaluated in 13 patient tumors, with none harboring the most common mutations. One could, therefore, predict that with a mutation enriched population, the combination of EGFR inhibitor and SBRT may have offered even greater PFS and OS benefits. Our observations also suggest that the SBRT treatments probably contributed the most to the dramatic PFS and OS outcomes. These findings were published in the Journal of Clinical Oncology in the December 1, 2014 print issue with an accompanying editorial. (more…)
Author Interviews, Brigham & Women's - Harvard, Diabetes, JAMA / 02.01.2015

Seth A. Berkowitz, MD, MPH Division of General Internal Medicine Massachusetts General Hospital, BostonMedicalResearch.com Interview with: Seth A. Berkowitz, MD, MPH Division of General Internal Medicine Massachusetts General Hospital, Boston Medical Research: What is the background for this study? What are the main findings? Dr. Berkowitz: Prior studies had looked the association between single unmet basic material needs and diabetes control, but hadn't necessarily looked at multiple things people may not be able to afford, which more closely mirrors real-life. Also, prior studies had been done in a 'pre-Affordable Care Act' setting, while, by being in Massachusetts, our study was conducted in a setting of near-universal healthcare coverage that is similar to what the rest of the US is moving towards. We found that difficulties meeting basic material needs, such as difficulties affording food, known as food insecurity, and having financial barriers to taking medications, called cost-related medication underuse, are associated with worse diabetes control and increased use of costly health services in diabetes patients, despite near-universal health insurance coverage (more…)
Author Interviews, Erasmus, NEJM, Stroke / 02.01.2015

Diederik Dippel MD, PhD Senior Consultant in Neurology Erasmus MC University Medical Center Rotterdam The NetherlandsMedicalResearch.com Interview with: Diederik Dippel MD, PhD Senior Consultant in Neurology Erasmus MC University Medical Center Rotterdam The Netherlands Medical Research: What is the background for this study? What are the main findings? Dr. Dippel: MR CLEAN is the first randomized clinical trial to show that intra-arterial treatment of ischemic stroke to get the clot out, really works. It leads to more recovery and less handicap. Previous studies had shown that intra-arterial treatment leads to recanalization, but the final proof that the treatment leads to recovery more often than standard treatment was lacking. With standard treatment, less than 1 out of 5 recovers without handicap, but with this new treatment, this will be 1 out of 3. The treatment did not lead to more complications than standard treatment. The rate of symptomatic intracranial hemorrhage was similar in both arms. Our study differs from previous, neutral trials.
  • First, we required patients to have an intracranial arterial occlusion confirmed by neuro-imaging.
  • Second, we used third generation thrombectomy devices, such as retrievable stents in most of the cases.
  • Third, our trial was conducted in a country with a very good infrastructure, which allowed rapid transfer to intervention centers, which are spread throughout the country. Our rate of iv tPA in Dutch hospitals is over 11% on average.
  • Last, all intervention centers participated, and almost no patients were treated outside the trial. Moreover, reimbursement of the treatment was conditional on participation in the trial. (more…)
Annals Thoracic Surgery, Author Interviews, Heart Disease, Surgical Research, Yale / 02.01.2015

Karthik Murugiah MBBS Fellow in Cardiovascular Medicine Yale School of Medicine Center for Outcomes Research and Evaluation (CORE) New Haven, CT 06510MedicalResearch.com Interview with: Karthik Murugiah MBBS Fellow in Cardiovascular Medicine Yale School of Medicine Center for Outcomes Research and Evaluation (CORE) New Haven, CT 06510 Medical Research: What is the background for this study? What are the main findings? Response: Aortic valve disease is common among older people and frequently requires valve replacement. 1-year survival after open surgical aortic valve replacement is high (9 in 10 survive the year after surgery). Our study focuses on the experience of these survivors in terms of the need for hospitalization during the year after surgery. Among patients >65 years of age enrolled in Medicare who underwent surgical replacement of their aortic valve and survived at least one year, 3 in 5 were free from hospitalization during that year. Both, the rates of hospitalization and the average total number of days spent in the hospital in the year following surgery have been decreasing all through the last decade (1999 to 2010). (more…)
Author Interviews, Cancer Research, PNAS, UCSD / 31.12.2014

MedicalResearch.com Interview with: Annie Samraj and Ajit Varki MDDr. Annie Samraj MD Postdoc Fellow Varki Lab and Ajit VAjit Varki MD Distinguished Professor of Medicine and Cellular & Molecular Medicine Co-Director, Center for Academic Research and Training in Anthropogeny (CARTA) Co-Director, Glycobiology Research and Training Center (GRTC) University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0687.arki MD Distinguished Professor of Medicine and Cellular & Molecular Medicine , Co-Director, Center for Academic Research and Training in Anthropogeny, Co-Director, Glycobiology Research and Training Center University of California, San Diego, La Jolla, CA Medical Research: What is the background for this study? What are the main findings? Dr. Varki: For the past decade, there has been increasing evidence that people who consume red meat (beef, pork, lamb) are at a higher risk for certain kinds of cancers. Although red meat is a high quality source of protein, iron and vitamins, too much consumption may be harmful to humans. While there are other hypotheses under consideration, we focused on a non-human sugar molecule called Neu5Gc in red meat that could explain the link to cancer risk. We extensively studied various foods and concluded that red meat (particularly beef) is rich in Neu5Gc. In contrast poultry, fish steaks and hen eggs have little or no Neu5Gc. From previous studies, we knew that animal-derived Neu5Gc could be incorporated into human tissues. In this study, we hypothesized that eating red meat could lead to inflammation if the body’s immune system targets the foreign Neu5Gc. Chronic inflammation is also known to instigate or promote tumor progression. To test this hypothesis, we used mice engineered to be similar to humans in that they lacked Neu5Gc, and also produced antibodies against it. When these mice were fed Neu5Gc, they developed systemic inflammation. Tumor formation increased fivefold and Neu5Gc accumulated in the tumors, proving the hypothesis. None of the various control groups of mice showed this effect. (more…)
Annals Internal Medicine, Author Interviews, Colon Cancer, Race/Ethnic Diversity, University of Pennsylvania / 30.12.2014

Jeffrey H. Silber, M.D., Ph.D. The Nancy Abramson Wolfson Endowed Chair in Health Services Research Director, Center for Outcomes Research The Children's Hospital of Philadelphia Professor of Pediatrics, Anesthesiology & Critical Care The Perelman School of Medicine Professor of Health Care Management, The Wharton SchoolMedicalResearch.com Interview with: Jeffrey H. Silber, M.D., Ph.D. The Nancy Abramson Wolfson Endowed Chair in Health Services Research Director, Center for Outcomes Research The Children's Hospital of Philadelphia Professor of Pediatrics, Anesthesiology & Critical Care The Perelman School of Medicine Professor of Health Care Management, The Wharton School The University of Pennsylvania  Philadelphia, PA 19104 Medical Research: What is the background for this study? What are the main findings? Response: Differences in colon cancer survival by race is a well recognized problem among Medicare beneficiaries. We wanted to determine to what extent the racial disparity in survival is due to a racial disparity in presentation characteristics at diagnosis (such as advanced stage and the presence of chronic diseases) versus a disparity in subsequent treatment by surgeons and oncologists. To answer this question, we compared black colon cancer patients to three matched white groups: (1) “Demographics” match controlling age, sex, diagnosis year, and Survey, Epidemiology, and End Results (SEER) site; (2) “Presentation” match controlling demographics plus comorbidities and tumor characteristics including stage and grade; and (3) “Treatment” match including presentation variables plus details of surgery, radiation and chemotherapy. We studied Medicare patients 65 years of age and older diagnosed between 1991-2005 in the SEER-Medicare database. There were 7,677 black patients and 3 sets of 7,677 matched white controls. We found that difference in 5-year survival (black-white) was 9.9% in the demographics match. This disparity remained unchanged between 1991-2005. After matching on presentation characteristics, this difference fell to 4.9%. Finally, after additionally matching on treatment, this same difference hardly changed, moving to only 4.3%. So the disparity in survival attributed to treatment differences comprised only an absolute 0.6% of the overall 9.9% survival disparity. (more…)
Author Interviews, Breast Cancer, Johns Hopkins, Journal Clinical Oncology, Leukemia / 28.12.2014

MedicalResearch.com Interview with: Dr. Judy Karp, Dr. Antonio Wolff and  Dr. Kala Visvanathan Breast Cancer Program Johns Hopkins Sidney Kimmel Comprehensive Cancer Center Baltimore, MD 21287 Medical Research: What is the background for this study? What are the main findings? Response: The background for this study was the clinical observation from the Johns Hopkins Leukemia Program that a significant number of women with newly diagnosed acute myeloid leukemia had a personal history for breast and/or ovarian cancers.  This observation led to our examination of the large NCCN breast cancer database in a multidisciplinary and multi-institutional study.  The overarching finding in our study is that the risk of developing some form of leukemia following chemotherapy with or without radiation therapy, while small, continues to increase over at least 10 years without a plateau and is roughly twice what we thought it to be from previous breast cancer studies. (more…)
Aging, Author Interviews, Nature, Scripps / 27.12.2014

Paul Schimmel, Ph.D. Professor The Skaggs Institute for Chemical Biology, The Scripps Laboratories for tRNA Synthetase Research Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, California MedicalResearch.com Interview with: Paul Schimmel, Ph.D. Professor The Skaggs Institute for Chemical Biology, The Scripps Laboratories for tRNA Synthetase Research Department of Molecular and Cell Biology, The Scripps Research Institute, La Jolla, California Medical Research: What is the background for this study? What are the main findings? Dr. Schimmel: Resveratrol (RSV) is thought to provide health benefits by activating a protective stress response. In the paper we described a new, previously missed mechanism for its action. This mechanism is activated at much lower concentrations of resveratrol than previously described or imagined. Consequently, other mechanisms, which appear to act at higher concentrations of resveratrol, are layered over a preexisting foundation set by the newly revealed mechanism. (more…)
Author Interviews, Surgical Research, University Texas, Weight Research / 27.12.2014

Taylor S. Riall, MD, PhD Professor, John Sealy Distinguished Chair in Clinical Research Department of Surgery, University of Texas Medical Branch, Galveston, TXMedicalResearch.com Interview with: Taylor S. Riall, MD, PhD Professor, John Sealy Distinguished Chair in Clinical Research Department of Surgery, University of Texas Medical Branch, Galveston, TX Medical Research: What is the background for this study? What are the main findings? Dr. Riall: In patients who have symptoms related their gallstones – most commonly sharp right upper quadrant abdominal pain (often associated with fatty meals), nausea, and vomiting - the current recommendation is to remove the gallbladder (perform cholecystectomy). However, in older patients there are multiple factors that make this decision difficult. Older patients have more associated medical problems (like diabetes, heart disease, etc.) making elective surgery higher risk. On the flip side, older patients are at higher risk of developing complications from their gallstones, and once they do, their mortality (death from gallbladder disease) and complications increase substantially. In recent study of Medicare beneficiaries with symptomatic gallstones, we found that fewer than 25% underwent elective removal of the gallbladder after an initial episode of pain or symptoms related to their gallbladder. We then developed a model that predicted the likelihood of these same patients requiring emergent gallstone-related complications if they did not have their gallbladder removed electively. This information prompted the current study. We sought to determine if the patients getting their gallbladders removed were the ones at highest risk for complications. Similar to the previous study, we found that only 22% of Medicare beneficiaries in this study (a different population) underwent elective gallbladder removal. We divided patients into three groups based on our risk prediction model – those with <30% risk, 30-60% risk, and >60% risk of requiring acute gallstone-related hospitalization. Please note that while we call the <30% risk group “low” risk, a 17% chance of hospitalization is actually a significant risk – much higher than seen in other medical conditions for which surgery or other interventions may be considered.
  • First, our model worked well – the ACTUAL hospitalization rate was 17%, 45%, and 69% in the two years after the first symptoms.
  • Second, whether patients had their gallbladder removed seemed unrelated to risk. 22% of patients in the lowest risk group, 21% in the middle risk group, and 23% in highest risk group had their gallbladder removed. Even more striking, in the healthiest patients – those with no medical problems and no reason not to perform elective surgery - cholecystectomy rates actually decreased with increasing risk of emergent admission. Cholecystectomy was performed in 34% of patients in the low risk group, 25% of patients in the moderate risk group, and 26% of patients in the highest risk group.
  • In addition, fewer than 10% of patients who didn’t have their gallbladder removed were ever seen by a surgeon, suggesting that this decision is being made at the level of the primary care or emergency physician and not necessarily patient choice.
(more…)
Author Interviews, Hearing Loss, HIV, JAMA, UCSD / 27.12.2014

dr-peter-torre Dr. Peter Torre III PhD Associate Professor, Audiology Director, Recreational Noise Exposure and Hearing Lab San Diego State UniversityMedicalResearch.com Interview with: Dr. Peter Torre III PhD Associate Professor, Audiology Director, Recreational Noise Exposure and Hearing Lab San Diego State University Medical Research: What is the background for this study? What are the main findings? Dr. Torre: The primary purpose of our study was to evaluate hearing sensitivity in HIV+ and HIV- adults. And subsequently, in HIV+ adults only, to examine whether HIV disease variables or treatment was associated with hearing sensitivity. The main findings were that HIV+ adult had poorer hearing for both the lower and higher frequencies compared with HIV- adults, although we did not find any significant associations between HIV variables and treatment variables with hearing loss. (more…)
Author Interviews, Blood Pressure - Hypertension, Case Western, Dermatology, JAMA, Weight Research / 26.12.2014

Dr. Jonathan L. Silverberg MD PhD MPH Assistant Professor in Dermatology, Medical Social Sciences and Preventive Medicine Northwestern University, Chicago, IllinoisMedicalResearch.com Interview with: Dr. Jonathan L. Silverberg MD PhD MPH Assistant Professor in Dermatology, Medical Social Sciences and Preventive Medicine Northwestern University, Chicago, Illinois Medical Research: What is the background for this study? Dr. Silverberg: Previous studies found associations between obesity and atopic dermatitis (AD). However, little was known about the association between AD and metabolic risk factors, such as central obesity and high blood pressure. (more…)
Author Interviews, Heart Disease, NYU / 26.12.2014

Dr. Glenn I. Fishman MD Professor; William Goldring Professor of Medicine Vice Chair Research Dept of Medicine Director of the Leon H. Charney Division of Cardiology NYU LangoneMedicalResearch.com Interview with: Dr. Glenn I. Fishman MD Professor; William Goldring Professor of Medicine Vice Chair Research Dept of Medicine Director of the Leon H. Charney Division of Cardiology NYU Langone Medical Research: What is the background for this study? What are the main findings? Dr. Fishman: Sudden cardiac arrest (SCA) due to life-threatening ventricular arrhythmias is one of the leading causes of death in the US. Conditions that predispose to SCA can be acquired, as in atherosclerotic coronary artery disease, or inherited in the form of mutated cardiac ion channels, i.e. ion channelopathies. Mutations in the SCN5A cardiac sodium channel gene have been linked to progressive cardiac conduction disorders as well as atrial and ventricular arrhythmias. Understanding the mechanistic basis for lethal arrhythmias in cardiac sodium channelopathy patients has been limited in part due to the lack of adequate model systems that replicate human physiology. To address this limitation, we have developed the first genetically modified porcine model of an inherited channelopathy. A mutation in the SCN5A gene first identified in a child with the arrhythmic condition Brugada syndrome was introduced into the pig genome. Mutant pig hearts displayed conduction abnormalities and ventricular fibrillation bearing striking resemblance to the human condition. (more…)
Author Interviews, Case Western, Nature, Neurological Disorders / 26.12.2014

Bradley T. Lang, PhD Researcher, Jerry Silver Lab Department of Neurosciences Case Western Reserve University School of MedicineMedicalResearch.com Interview with: Bradley T. Lang, PhD Researcher, Jerry Silver Lab Department of Neurosciences Case Western Reserve University School of Medicine Medical Research: What is the background for this study? What are the main findings? Dr. Lang: In the late 1980’s, Jerry Silver, PhD, discovered the presence of chondroitin sulfate proteoglycans in the developing nervous system, which form barriers to prevent aberrant growth. He has been building on this finding for more than 30 years, attempting to understand why the adult spinal cord is incapable of regenerating, or why axons don’t grow where they don’t. He has found that the glial scar, which surrounds the site of neural trauma, is incredibly rich in proteoglycans, which prevent regeneration in the spinal cord. In 2009 we collaborated with a group at Harvard to discover the very first receptor for chondroitin sulfate proteoglycans, protein tyrosine phosphatase-sigma, or PTPsigma. Medical Research: What are the main findings? Dr. Lang: The findings in this paper are twofold. We first describe a novel mechanism of regeneration failure, where regenerating axons become stabilized within a gradient of chondroitin sulfate proteoglycan, completely preventing motility. This finding helps explain why axons persist in the vicinity of the glial scar after injury indefinitely, with little to no regeneration potential—they are simply embedded within the scar. We were able to model this interaction in a petri dish to screen for drugs that were capable of promoting motility. The second finding in the manuscript is the discovery and characterization of a novel peptide therapeutic that binds to the receptor for chondroitin sulfate proteoglycans and releases inhibition. Most importantly, this drug was given systemically, similar to a daily insulin injection, avoiding complications due to direct nervous system infusion/injection. After several weeks of treatment (which began 1 day after injury), rats with severe spinal cord injury regained coordinated locomotion, bladder control, and/or balance. In total, 21/26 treated animals regained some function. (more…)
Author Interviews, Genetic Research, Neurological Disorders, PNAS, Scripps / 26.12.2014

Elizabeth A. Thomas, Ph.D. Associate Professor Department of Molecular and Cellular Neuroscience The Scripps Research InstituteMedicalResearch.com Interview with: Elizabeth A. Thomas, Ph.D. Associate Professor Department of Molecular and Cellular Neuroscience The Scripps Research Institute   Medical Research: What is the background for this study? What are the main findings? Response: Increasing evidence has demonstrated that epigenetic factors can profoundly influence gene expression, and in turn, influence resistance or susceptibility to disease.  Epigenetic drugs, such as histone deacetylase (HDAC) inhibitors, are finding their way into clinical practice, and are being proposed for therapeutic use in several neurological disorders.  Our previous studies have shown that selective HDAC inhibitors can cause beneficial effects in mouse models of Huntington’s disease, improving symptoms, and reducing severity of the disease.  Our current studies show that one such compound can alter DNA methylation, an epigenetic mark that can be inherited, leading to changes in gene expression that are seen in the parent mouse exposed directly to the drug, as well as in offspring from the drug-treated male mice.  Concurrent with these changes, we observed that offspring from drug-treated males shown improved disease symptoms, showing a delay in disease onset and a reduction of motor and cognitive symptoms that included improved performance in tests of balance, speed and memory. These finding have significant implications for human health as they enforce the concept that ancestral drug exposure may be a major molecular factor that can affect disease outcome in a subsequent generation.  One exciting aspect of our study is that the parental drug treatment made the offspring better, not worse, like other compounds known to cause transgenerational effects. (more…)
Author Interviews, JAMA, Obstructive Sleep Apnea, Pediatrics, University Texas, UT Southwestern / 26.12.2014

Ron B. Mitchell, MD Professor of Otolaryngology and Pediatrics William Beckner Distinguished Chair in Otolaryngology Chief of Pediatric Otolaryngology UT Southwestern and Children's Medical Center Dallas ENT Clinic Dallas, TX 75207MedicalResearch.com Interview with: Ron B. Mitchell, MD Professor of Otolaryngology and Pediatrics William Beckner Distinguished Chair in Otolaryngology Chief of Pediatric Otolaryngology UT Southwestern and Children's Medical Center Dallas ENT Clinic Dallas, TX 75207 Medical Research: What is the background for this study? What are the main findings? Dr. Mitchell: The “gold standard” for the diagnosis of and quantification of obstructive sleep apnea (OSA) is polysomnography (PSG or a ‘sleep study’). However, the majorities of T&A procedures are done without PSG and are based on a clinical diagnosis. This is because PSG is expensive, requires overnight observation and is often unavailable. It is important to diagnose and quantify OSA as it allows for surgical planning and predicts the need and type of treatment after surgery. We used data from the Childhood Adenotonsillectomy (CHAT) study; a large multicenter trial (RCT), to look at the ability of clinical parameters to predict the severity of obstructive sleep apnea in children scheduled for a T&A. The main findings of the study are that certain clinical parameters such as obesity and African American race as well as high scores on certain validated questionnaires (such as the pediatric sleep questionnaire- PSQ) are associated, but cannot predict OSA severity. PSG remains the only way to measure objectively the severity of OSA. (more…)
Author Interviews, Brigham & Women's - Harvard, Exercise - Fitness, Weight Research / 26.12.2014

Rania Mekary, MS, Ph.D. Harvard School of Public Health Nutrition Department Boston, Ma 02115MedicalResearch.com Interview with: Rania Mekary, MS, Ph.D. Harvard School of Public Health Nutrition Department Boston, Ma 02115   Medical Research: What is the background for this study? What are the main findings? Dr. Mekar: Findings on weight training and waist circumference (WC) change have been controversial.  Moreover, a lot of people focus on aerobic and only aerobic workout... They are not to be blamed because aerobic workout (e.g. jogging) relies mostly on fat as a source of energy while anaerobic workout (e.g. resistance) relies mostly on carbohydrates. Our study, however, showed that resistance training over the long-term was the most inversely associated with waistline change (aka abdominal fat), even more than aerobic exercise. We also justified physiologically why it is the case... It has to do with the greater Excess Post-exercise Oxygen Consumption (EPOC) as compared with aerobic training and also to the muscle adaptation and its increase in mitochondria which leads to more lipid oxidation upon engaging in anaerobic workout over the long-term. (more…)
Author Interviews, HIV, Nature, UCLA / 22.12.2014

David Gerberry PhD Center for Biomedical Modeling, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CaliforniaMedicalResearch.com Interview with: David Gerberry PhD Assistant Professor Department of Mathematics and Computer Science Xavier University, Cincinnati, Ohio   Medical Research: What is the background for this study? What are the main findings? Response: In an attempt to control the spread of HIV, governments in sub-Saharan Africa are considering providing antiretroviral drugs to people who do not have the virus but are at risk for becoming infected. Such drugs are known as pre-exposure prophylaxis, or PrEP.  Given the cost of PrEP, an important question is how to maximize the impact of interventions given a fixed level of prevention resources. A common strategy is to target resources to the individuals that are at the highest risk for infection.  This group of people is often referred to as the "core group" and can be thought of as sex workers, clients of sex workers and other individuals that are at very high risk for infection.  While targeting this core group is ideal and would result in the most cost-effectiveness interventions, being able to identify these individuals is difficult in practice and they are often unwilling to participate in the intervention; take pre-exposure prophylaxis or change their behavior for example.  From a mathematical perspective it is also very difficult to quantify their increased level of risk.  For example, is a sex worker at 5 times, 25 times, 100 times or 1000 times the risk for HIV infection?  Without this quantification, it is impossible to estimate the cost-effectiveness of a targeted strategy. In our work, we build an intervention strategy based on geographical targeting.  This takes advantage of the fact that HIV incidence is much higher in certain geographical locations than others.  Therefore, individuals in these areas are at increased risk for HIV infection.  Most importantly, such an intervention is feasible because reliable data exists across much of sub-Saharan Africa for the severity of the HIV epidemic in different regions.  To illustrate our ideas we used mathematical modeling to consider resource allocation in South Africa and found that targeting the provinces with highest HIV incidence would prevent 40% more infections than a plan that ignored geographic variation while using the same amount of resources. (more…)
Author Interviews, Critical Care - Intensive Care - ICUs, Kidney Disease, University of Pittsburgh / 22.12.2014

MedicalResearch.com Interview with: Florentina E. Sileanu BS Center for Critical Care Nephrology and Clinical Research, Investigation, and Systems Modeling of Acute Illness Center Departments of Critical Care Medicine and Department of Biostatistics, University of Pittsburgh Graduate School of Public Health and Dr. John A. Kellum, MD, MCCM Professor of Medicine, Bioengineering and Clinical & Translational Science Vice Chair for Research Center for Critical Care Nephrology, University of Pittsburgh School of Medicine Pittsburgh, PA Medical Research: What is the background for this study? What are the main findings? Response: Acute Kidney Injury (AKI) affects millions of Americans each year resulting in increased short and long-term complications including need for dialysis and death. Many trials recruiting subjects at risk for AKI have focused on those with other (e.g. cardiovascular and respiratory) organ failures because these patients are at highest for AKI. However, patients without these conditions might not be at low-risk for AKI. We explored whether Acute Kidney Injury occurring as a single organ failure or occurring before other organ failures would be associated with the same outcomes as in sicker patients. Using a large, academic medical center database, with records from July 2000 through October 2008, we identified a "low-risk" cohort as patients without cardiovascular and respiratory organ failures defined as not receiving vasopressor support or mechanical ventilation within the first 24 hours of ICU admission. We were able to show that low-risk patients have a substantial likelihood of developing AKI and that the relative impact on mortality of AKI is actually greater for low-risk patients (OR, 2.99; 95% 2.62-3.41) than for high-risk patients (OR, 1.19; 95% 1.09-1.3). (more…)
Author Interviews, Pediatrics, Toxin Research, University Texas / 21.12.2014

Ying Xu Assistant Professor, Ph.D. Department of Civil, Architectural and Environmental Engineering University of Texas, AustinMedicalResearch.com Interview with: Ying Xu Assistant Professor, Ph.D. Department of Civil, Architectural and Environmental Engineering University of Texas, Austin Medical Research: What is the background for this study? What are the main findings? Response: Phthalates have been widely used as plasticizers to enhance the flexibility of polyvinyl chloride (PVC) products.  They are ubiquitous and persistent indoor pollutants and may result in profound and irreversible changes in the development of human reproductive tract. In this study, we found that the emissions of phthalates and phthalate alternatives increase significantly with increasing temperature.  We developed an emission model and validated the model via chamber experiments.  Further analysis showed that, in infant sleep microenvironments, an increase in the temperature of mattress can cause a significant increase in emission of phthalates from the mattress cover and make the concentration in breathing zone about four times higher than that in the room, resulting in potentially high exposure.  In residential homes, an increase in the temperature from 25 to 35 ºC can elevate the gas-phase concentration of phthalates by more than a factor of 10, but the total airborne concentration may not increase that much for less volatile compounds. (more…)
Author Interviews, Endocrinology, JCEM, Menopause, UCLA / 20.12.2014

Carolyn J. Crandall, MD, MS Professor of Medicine David Geffen School of Medicine at University of California, Los Angeles UCLA Medicine/GIM Los Angeles, CA 90024MedicalResearch.com Interview with: Carolyn J. Crandall, MD, MS Professor of Medicine David Geffen School of Medicine UCLA Medicine/GIM Los Angeles, California 90024 Medical Research: What is the background for this study? What are the main findings? Dr. Crandall: In a large group of postmenopausal women aged 50-79, we found that women who reporting having hot flashes at baseline had increased risk of hip fracture during the subsequent 8 years of observation, nearly double the risk compared with women who did not have hot flashes at baseline. (more…)
Author Interviews, Brigham & Women's - Harvard, Psychological Science, Surgical Research / 20.12.2014

Brian I. Labow, MD Director, Adolescent Breast Clinic Assistant in Surgery Assistant Professor of Surgery Harvard Medical School PrimaryMedicalResearch.com Interview with: Brian I. Labow, MD Director, Adolescent Breast Clinic Assistant in Surgery Assistant Professor of Surgery Harvard Medical School Primary   Medical Research: What is the background for this study? What are the main findings? Dr. Labow:  This study is part of our larger Adolescent Breast Disorder Study, in which we examine the impact of several breast disorders on adolescent girls and boys and measure the effect of treatment. In this present study we have found breast asymmetry, defined as having at least 1 cup size difference between breasts, can have a significant impact on the psychological wellbeing of adolescent girls.  Validated surveys were given to adolescent girls with breast asymmetry, macromastia (enlarged breasts), and healthy unaffected girls between the ages of 12-21 to assess a wide array of health domains. Girls with breast asymmetry had noted deficits in psychological wellbeing and self-esteem when compared to healthy girls of the same age.  These impairments were similar to those of girls with macromastia, a condition known to have significant negative mental health effects. Interestingly, these negative psychological outcomes did not vary by patient’s age or severity of breast asymmetry. Older and younger adolescents were negatively impacted similarly, as were those with lesser and greater degrees of breast asymmetry. (more…)