Comparison of ethanol versus formalin fixation on preservation of histology and RNA in laser capture microdissected brain tissues

Although RNA can be retrieved from formalin-fixed, paraffin-embedded (FFPE) tissues, the yield is low, and the RNA is fragmented. Recent advances in gene expression profiling underscore the importance of identifying a fixative that preserves histology and mRNA. We demonstrated that, for immersion fixation of brains, 70% ethanol is superior to formalin for mRNA preservation. RNA yield from ethanol-fixed tissues was 70% of the yield from fresh frozen specimens, but only a negligible quantity was recovered from formalin-fixed tissues. RNA from ethanol-fixed brains showed integrity comparable to RNA from fresh frozen tissues, and RT-PCR using RNA from ethanol-fixed tissues was consistently successful. RNA from FFPE tissues composed of low-molecular weight fragments, and their use in RT-PCR failed repeatedly. The yield and quality of RNA from ethanol-fixed brains were unaffected after immersion at 4 degrees C for 2 weeks. In a blinded comparison to FFPE tissues, ethanol-fixed specimens were judged to show comparable histology and superior immunostaining. After laser capture microdissection (LCM), we failed to recover mRNA from FFPE tissues but retrieved mRNA from ethanol-fixed tissues for RT-PCR and cDNA microarray analysis. We conclude that 70% ethanol preserves RNA integrity and is suitable for expression profiling of brain tissues by LCM and cDNA microarray.     

Skeletal differences between black and white men and their relevance to body composition estimates

Skeletal differences exist between closely matched Black and White women, although it is unknown if similar differences also exist between Black and White men after controlling for age, body weight, and stature. The aim of this study was twofold: to test the hypothesis that Black men have greater bone mass, higher bone mineral density, and longer limbs compared to White men of similar age, weight, and height; and second, to establish if ethnic variation in skeletal characteristics has an impact on the models upon which three widely used methods for estimating total body fat are based. Twenty-four healthy Black men were matched by age (±5 years), height (±3 cm), and weight (±2 kg) to 24 healthy White men. Skeletal characteristics and body composition were studied using anatomical and compartment estimates derived by anthropometry, ³H₂O dilution, hydrodensitometry, whole-body ⁴⁰K counting, and dual photon systems. Black men had greater bone mineral mass (P = 0.007), higher bone density (P = 0.054), longer femurs (P = 0.002), longer anthropometric arm and thigh lengths (P = 0.001 and P = 0.002, respectively), lower spine to femur ratio (P = 0.004), and similar spine length (P = 0.271) compared to White men. Total body fat and fat-free body mass (FFM) were estimated in the men using a four-compartment model. Black and White men had similar total body fat, K (TBK), water (TBW), and FFM. Density of FFM and TBK/FFM were also similar between Black and White men, suggesting that current two-compartment hydrodensitometry and TBK models for estimating fat may not require adjustments for ethnicity. The TBW/FFM ratio, which is the main assumed steady-state relation for the two-compartment TBW method of estimating fat, was modestly increased (P = 0.05) in Black men (x? ± SD, 0.744 ± 0.018) compared to White men (0.732 ± 0.021). These results confirm that Black and White men differ significantly in some skeletal characteristics and these differences have implications in the study of both osteoporosis and human body composition. © 1994 Wiley-Liss, Inc.     

Retirement,social support and mental well-being: a couple-level analysis

The European Journal of Health Economics - Social support is increasingly acknowledged as an important resource for promoting well-being. We test whether social support changes around retirement....     

Bone From Blood: Characteristics and Clinical Implications of Circulating Osteogenic Progenitor (COP) Cells

Circulating osteogenic progenitor (COP) cells are a population of cells in the peripheral blood with the capacity for bone formation, as well as broader differentiation into mesoderm-like cells in vitro. Although some of their biological characteristics are documented in vitro, their role in diseases of the musculoskeletal system remains yet to be fully evaluated. In this review, we provide an overview of the role of COP cells in a number of physiological and pathological conditions, as well as identify areas for future research. In addition, we suggest possible areas for clinical utilization in the management of musculoskeletal diseases. © 2020 American Society for Bone and Mineral Research (ASBMR).     

Long-term azithromycin use is not associated with QT prolongation in children with cystic fibrosis

Chronic Azithromycin (AZM) is a common treatment for lung infection. Among adults at risk of cardiac events, AZM use has been associated with cardiovascular harm. We assessed cardiovascular safety of AZM among children with CF, as a secondary analysis of a placebo-controlled, clinical trial, in which study drug was taken thrice-weekly for a planned 18 months. Safety assessments using electrocardiogram (ECG) occurred at study enrollment, and then after 3 weeks and 18 months of participation. Among 221 study participants with a median of 18 months follow-up, increased corrected QT interval (QTc) of ≥30 msec was rare, at 3.4 occurrences per 100 person-years; and incidence of QTc prolongation was no higher in the AZM arm than the placebo arm (1.8 versus 5.4 per 100 person-years). No persons experienced QTc intervals above 500 msec. Long-term chronic AZM use was not associated with increased QT prolongation.     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.     

Public-private partnership organizations in health care: cooperative strategies and models

Value-adding partnerships have emerged as a preferred strategy of private health care providers to achieve high-quality, low-cost provider status. This same strategy can be applied by public sector providers through the creation of public-private partnership organizations (3POs). Strategies to build 3POs between local governments and their medical communities currently under development are outlined. The conceptual and practical aspects of implementing 3POs are presented.     

Endocrine-metabolic response to abdominal aortic surgery: A randomized trial of general anesthesia versus general plus epidural anesthesia

The influence of epidural anesthesia on the endocrine-metabolic response following abdominal aortic reconstruction was studied in a prospective randomized trial. Cortisol and catecholamine responses and nitrogen balance were measured in two groups of five patients receiving general anesthesia only (group 1) or general anesthesia combined with epidural bupivacaine (group 2). The study lasted from preoperatively until the first postoperative day. At 2100 hours on the day of surgery serum cortisol concentrations were higher in group 1 than in group 2 (1.41 versus 0.82 mol/L; p<0.01). Likewise the total perioperative hypercortisolemia, expressed as the area under the curve, was significantly higher in group 1 (11.7 versus 5.7 mol/L/hr, p<0.01). Intraoperative urinary excretion of epinephrine and postoperative norepinephrine excretion were significantly higher in group 1 than in group 2. Urinary excretion of free cortisol and cumulative nitrogen balance were not different between the groups. Although the number of patients was limited and the sensory nerve block level was not measured perioperatively, this study suggests that epidural anesthesia attenuates the stress response to aortic surgery.

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Resumen Se diseñó un ensayo clínico prospectivo y randomizado con el fin de estudiar el efecto de la anestesia epidural sobre la respuesta endocrino-metabolica luego de una reconstrucción aórtica abdominal. Se determinaron la respuesta de cortisol y catecolaminas y el balance de nitrógeno en dos grupos de 5 pacientes que recibieron anestesia general solamente (Grupo 1) o anestesia general combinada con bupivacaína epidural (Grupo 2). El estudio se realizó en el periodo comprendido entre la fase preoperatoria hasta el primer día postoperatorio. A las 21:00 horas del mismo día de la cirugía las concentraciones séricas de cortisol resultaron más altas en el Grupo 1 que en el Grupo 2 (1.41 versus 0.82 micromol/l, p<0.01). Igualmente, la hipercortisolemia total perioperatoria apareció más alta en el Grupo 1 (11.7 versus 5.7 micromol/l^* hora, p<0.01). La excreción urinaria intraoperatoria de epinefrina y la excreción postoperatoria de norepinefrina aparecieron significativamente más altas en el Grupo 1 que en el Grupo 2. No se registraron diferencias en la excreción urinaria de cortisol libre ni en el balance acumulado de nitrógeno. Aunque el número de pacientes fue limitado y el nivel del bloqueo sensorial no fue determinado perioperatoriamente, el presente estudio sugiere que la anestesia epidural atenúa la respuesta de estrés en la cirugia aórtica.

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Résumé Dans une étude prospective et randomisée, l'influence de l'anesthésie péridurale sur la résponse métabolique endocrinienne a été étudiée dans la période préopératoire immédiate jusqu'au premier jour postopératoire après la chirurgie de l'aorte abdominale. On a mesuré les résponses en catécholamines et l'équilibre azoté chez cinq patients ayant eu une anesthésie générale seule (groupe 1) et cinq patients ayant une anesthésie générale combinée avec une anesthésie péridurale par la bupivacaïne (groupe 2). A 21H00 le jour de l'intervention,. la concentration en cortisol était plus haute dans le groupe 1 par rapport au groupe 2 (1.41 vs 0.82 micromol/l, p<0.01). De même, l'hypercortisolémie périopératoire totale, exprimée par la surface sous la courbe, était significativement plus élevée dans le groupe 1 (11.7 vs 5.7 micromol/l heure, p<0.01). L'excrétion urinaire peropératoire d'épinéphrine et l'excrétion postopératoire de la norépinéphrine étaient significativement plus élevées dans le groupe 1 par rapport au groupe 2. L'excrétion urinaire du cortisol libre et l'équilibre azoté tout au long de l'étude n'étaient pas très différents. Bien que le nombre de patients était limité et que le niveau supérieur de l'anesthésie n'ait pas été mesuré en périopératoire, les résultats de cette étude suggèrent que l'anesthésie péridurale atténue la réponse au stress dans la chirurgie de l'aorte abdominale.