Effect of fixatives and tissue processing on the content and integrity of nucleic acids

Clinical and molecular medicines are undergoing a revolution based on the accelerated advances in biotechnology such as DNA microarrays and proteomics. Answers to fundamental questions such as how does the DNA sequence differ between individuals and what makes one individual more prone for a certain disease are eagerly being sought in this postgenomic era. Several government and nonprofit organizations provide the researchers access to human tissues for molecular studies. The tissues procured by the different organizations may differ with respect to fixation and processing parameters that may affect significantly the molecular profile of the tissues. It is imperative that a prospective investigator be aware of the potential contributing factors before designing a project. The purpose of this review is to provide an overview of the methods of human tissue acquisition, fixation, and preservation. In addition, the parameters of procurement and fixation that affect the quality of the tissues at the molecular level are discussed.     

Consolidation radiation after complete remission in Hodgkin's disease following six cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy: is there a need?

PURPOSE: Combined modality treatment using multidrug chemotherapy (CTh) and radiotherapy (RT) is currently considered the standard of care in early stage Hodgkin's disease. Its role in advanced stages, however, continues to be debated. This study was aimed at evaluating the role of consolidation radiation in patients achieving a complete remission after six cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy using event-free survival (EFS) and overall survival (OS) as primary end points. PATIENTS AND METHODS: Two hundred and fifty-one patients with Hodgkin's disease attending the lymphoma clinic at the Tata Memorial Hospital (Mumbai, India) from 1993 to 1996 received induction chemotherapy with six cycles of ABVD after initial staging evaluation. A total of 179 of 251 patients (71%) achieved a complete remission after six cycles of ABVD chemotherapy and constituted the randomized population. Patients were randomly assigned to receive either consolidation radiation or no further therapy. RESULTS: With a median follow-up of 63 months, the 8-year EFS and OS in the CTh-alone arm were 76% and 89%, respectively, as compared with 88% and 100% in the CTh+RT arm (P =.01; P =.002). Addition of RT improved EFS and OS in patients with age < 15 years (P =.02; P =.04), B symptoms (P =.03; P =.006), advanced stage (P =.03; P =.006), and bulky disease (P =.04; P =.19). CONCLUSION: Our study suggests that the addition of consolidation radiation helps improve the EFS and OS in patients achieving a complete remission after six cycles of ABVD chemotherapy, particularly in the younger age group and in patients with B symptoms and bulky and advanced disease.     

Door to balloon time in patients presenting with acute ST elevation myocardial infarction and time factors influencing it; an observational study from a tertiary care teaching hospital in India

The objective of this prospective observational study was to assess the door-to-balloon time (D2B), in acute ST-segment elevation myocardial infarction (STEMI) patients and the time factors influencing it. The following timeframes were measured during the study: ED to ECG time, ED to coronary care unit time (ED2CCU), consent time, post-consent to balloon time (POSTCONSENT2B) and D2B. Effective D2B was 54 ± 12.2 min. Of the dependent variables, D2B had a strong positive correlation (ρ = 0.903) with consent time. This study sheds light on consent time a previously unrecognized entity as a significantly influencing factor for the D2B time.     

Salivary Epithelial Cells as Model to Study Immune Response Against Cutaneous Pathogens

The human skin not only provides passive protection as a physical barrier against external injury, but also mediates active surveillance via epidermal cell surface receptors that recognize and respond to potential invaders. Primary keratinocytes and immortalized cell lines, the commonly used sources to investigate immune responses of cutaneous epithelium are often difficult to obtain and/or potentially exhibit changes in cellular genetic make‐up. Here we investigated the possibility of using salivary epithelial cells (SEC) to evaluate the host response to cutaneous microbes. Elevated secretion of IFN‐γ and IL‐12 was observed in the SEC stimulated with Staphylococcus aureus, a transient pathogen of the skin, as mono species biofilm as compared to SEC stimulated with a commensal microbe, the Staphylococcus epidermidis. Co‐culture of the SEC with both microbes as dual species biofilm elicited maximum cytokine response. Stimulation with S. aureus alone but not with S. epidermidis alone induced maximum toll‐like receptor‐2 (TLR‐2) expression in the SEC. Exposure to dual species biofilm induced a sustained upregulation of TLR‐2 in the SEC for up to an hour. The data support novel application of the SEC as efficient biospecimen that may be used to investigate personalized response to cutaneous microflora.     

Predictors of Treatment Outcomes in ANCA-Associated Vasculitis with Severe Kidney Failure

Background and objectives

In ANCA-associated GN, severe renal dysfunction portends a poor prognosis for renal recovery and patient survival. This study evaluated the prognostic factors affecting renal and patient outcomes in patients presenting with severe kidney failure to guide immunosuppressive therapy.

Design, setting, participants, & measurements

This study retrospectively evaluated clinical and histopathologic characteristics of 155 patients who underwent biopsy between October 1985 and February 2011 (median eGFR at presentation, 7.1 ml/min per 1.73 m²; 87% required hemodialysis), all treated with immunosuppressive medications. Three outcomes of interest were measured: patient survival, renal survival, and treatment response (defined as dialysis-free survival without active vasculitis by 4 months after biopsy). Competing risk, Cox, and logistic regression analyses were conducted for each outcome measure.

Results

Within 4 months after biopsy, treatment response was attained in 51% of patients, 35% remained on dialysis, and 14% died. In a competing risk analysis, estimated cumulative incidence rates of ESRD and disease-related mortality were 26% and 17% at 1 year and 32% and 28% at 5 years, respectively. Cyclophosphamide therapy and treatment response by 4 months were independently associated with patient and renal survival, adjusting for the percentage of normal glomeruli, histopathologic chronicity index score, and baseline clinical characteristics. Only 5% of patients still dialysis dependent at 4 months subsequently recovered renal function. Low chronicity index score (odds ratio [OR], 1.16; 95% confidence interval [95% CI], 1.04 to 1.30, per unit decrease) and baseline eGFR>10 ml/min per 1.73 m² (OR, 2.77; 95% CI, 1.09 to 7.01) were significantly associated with treatment response by 4 months. Among cyclophosphamide-treated patients, the likelihood of treatment response was >14% even with highest chronicity index score and eGFR<10 ml/min per 1.73 m².

Conclusions

Although low baseline renal function and severe renal scarring are associated with lower treatment response rate, no “futility” threshold could be identified. Conversely, continued immunosuppressive therapy beyond 4 months is unlikely to benefit patients who remain dialysis dependent.     

Prevalence and correlates of alcohol use disorders in the Singapore Mental Health Survey

Aims To establish the prevalence, correlates, comorbidity and treatment gap of alcohol use disorders in the Singapore resident population. Design The Singapore Mental Health Study is a cross‐sectional epidemiological survey. Setting A nationally representative survey of the resident (citizens and permanent residents) population in Singapore. Participants A total of 6616 Singaporean adults aged 18 years and older. Measurements The diagnoses were established using the World Mental Health Composite International Diagnostic Interview (WMH‐CIDI) diagnostic modules for life‐time and 12‐month prevalence of selected mental illnesses including alcohol use disorders. Findings The life‐time prevalence of alcohol abuse and alcohol dependence was 3.1% and 0.5%, while the 12‐month prevalence of alcohol abuse and alcohol dependence was 0.5% and 0.3%, respectively. The life‐time and 12‐month prevalence of alcohol use disorders was 3.6% and 0.8%, respectively. Those with alcohol use disorder had significantly higher odds of having major depressive disorder [odds ratio (OR) 3.1] and nicotine dependence (OR 4.5). Compared to the rest of the population, those with an alcohol use disorder had significantly higher odds of having gastric ulcers (OR 3.0), respiratory conditions (OR 2.1) and chronic pain (OR 2.1). Only one in five of those with alcohol use disorder had ever sought treatment. Conclusions The prevalence of alcohol use disorders is relatively low in the Singapore adult population. Comorbidity with mental and physical disorders is significant, emphasizing the need to screen people with alcohol use disorders for these comorbidities.