A metropolitan experience with infrainguinal revascularization. Operative risk and late results in northeastern Ohio

Despite being of fundamental importance, the late results of major arterial reconstruction rarely have been documented throughout a large metropolitan area. In this study of 932 patients entered into the computer registry of the Cleveland Vascular Society, 19 surgeons representing 13 community hospitals and referral centers in Cleveland and Akron report the intermediate-term outcome during a mean interval of 35 months after infrainguinal lower extremity revascularization performed in northeastern Ohio from 1978 through 1982. Operative risk (5%), the early amputation rate (7%), and actuarial 5-year survival (48% to 55%) for patients with rest pain or tissue necrosis were significantly worse (p less than 0.05) than comparable figures (0.6%, 0%, and 77%, respectively) for others who underwent procedures for disabling claudication. Although both materials had similar success above the knee, the cumulative 3-year patency rate of autogenous vein bypass to the distal popliteal (69% to 88%; p less than 0.05) and tibioperoneal arteries (43%; 0.05 less than p less than 0.1) was superior to the results of polytetrafluoroethylene grafts (32% to 50% and 19%, respectively). Moreover, polytetrafluoroethylene grafts required reoperations at three times the rate of vein grafts to maintain limb salvage.     

Transient shock and myocardial impairment caused by phaeochromocytoma crisis

A patient admitted to hospital after injury to the abdomen was found to have transient hypertension which was followed by profound hypotension. ST elevation developed and extensive myocardial akinesia was seen at echocardiography, but coronary angiograms at this stage were normal. After treatment with intravenous fluids and dopamine he progressively recovered normal cardiac function. A partly necrotic catecholamine secreting tumour was later removed from the abdomen and it is likely that a kick to the abdomen had damaged the tumour and the consequent release of catecholamine had triggered a phaeochromocytoma crisis.     

Immunocytochemical evidence for an actin-myosin system in lens epithelial cells

Since filamentous actin had been shown earlier to exist in lens epithelial and fiber cells, we inquired whether this could represent a contractile system with myosin and other actin-associated proteins. We resolved this question in freshly removed or organ-cultured rabbit and squirrel lens epithelial whole mounts using immunocytochemical techniques and by immunoblots of extracts separated by electrophoresis. In the former, methods were developed using long fixation times and long incubation in primary antibodies and biotinylated second antibodies visualized by streptavidin immunofluorescence and by diaminobenzidine peroxidase. Myosin was found to be localized along the filamentous rays and at central vertices of polygonal arrays situated at the apices of epithelial cells. It was not clear whether myosin and actin occurred together along the same or adjacent filaments in a bundle. Tubulin and vimentin were found deeper in the cells and were not aligned with actin and myosin filaments. Control lens epithelia treated similarly except for deletion of the primary antibodies showed no staining. As positive controls, pieces of glycerinated sartorius muscle exhibited characteristic cross-banded patterns of actin and myosin when incubated with the same reagents used on the lens epithelium. Denatured extracts of rabbit lens epithelium and of cortical fiber cells separated by electrophoresis and transferred to nitrocellulose paper, stained specifically with the same myosin and tubulin antibodies used in the immunocytochemistry experiments. The molecular weight profile of the myosin polypeptide indicated that lens tissue has myosin II. We conclude that a contractile system exists in lens epithelial and cortical fiber cells, although the function is not understood at this time. We conjecture that the system may act to stabilize lens shape by providing contractile tone.     

Role for interleukin-1 (IL-1) in benzene-induced hematotoxicity: inhibition of conversion of pre-IL-1 alpha to mature cytokine in murine macrophages by hydroquinone and prevention of benzene-induced hematotoxicity in mice by IL-1 alpha

Chronic exposure of humans to benzene (BZ), a myelotoxin, causes aplastic anemia and acute leukemia. The stromal macrophage that produces interleukin-1 (IL-1), a cytokine essential for hematopoiesis, is a target of BZ's toxicity. Monocyte dysfunction and decreased IL-1 production have been shown to be involved in aplastic anemia in humans. Hydroquinone (HQ), a toxic bone marrow (BM) metabolite of BZ, causes time- and concentration-dependent inhibition of processing of the 34-Kd pre-interleukin-1 alpha (IL-1 alpha) to the 17-Kd mature cytokine in murine P388D1 macrophages and BM stromal macrophages, as measured by Western immunoblots of cell lysate proteins using a polyclonal rabbit antimurine IL-1 alpha antibody. HQ over a 10-fold concentration range had no effect on the lipopolysaccharide (LPS)-induced production of pre- IL-1 alpha precursor or on cell viability or DNA and protein synthesis. Stromal macrophages obtained from the femoral BM of C57Bl/6 mice exposed to BZ (600 or 800 mg/kg body weight) for 2 days were incapable of processing the 34-Kd pre-IL-1 alpha to the mature 17-Kd cytokine when stimulated in culture with LPS. Stromal macrophages from mice coadministered BZ and indomethacin, a prostaglandin H synthase (PHS) inhibitor that has been shown to prevent BZ-induced myelotoxic and genotoxic effects in mice when coadministered with benzene were able to convert the pre-IL-1 alpha to mature cytokine. Administration of recombinant murine IL-1 alpha (rMuIL-1 alpha) to mice before a dose of BZ that causes severe depression of BM cellularity completely prevents BM depression, most probably by bypassing the inability of the stromal macrophage in BZ-treated animals to process pre-IL-1 alpha to the mature cytokine.     

Validity of the Maslach Burnout Inventory for family practice physicians

This study assesses the utility of Maslach's concept of burnout for family practice physicians. Maslach Burnout Inventory (MBI) subscale correlations for the 67 residents in this sample are compared with Maslach's normative sample. The residents scored in the moderate to high range on the MBI subscales. MBI interscale correlations were similar to the pattern reported by Maslach. Significant correlations between job satisfaction and five of the six MBI subscales suggest that the construct of burnout has considerable psychological import for these physicians. The validity of the emotional exhaustion subscale is demonstrated by significant correlations with self-assessed burnout, job satisfaction, and faculty assessments of resident burnout. Independent observers were most sensitive to residents' emotional exhaustion and less likely to assess accurately the less visible aspects of burnout related to depersonalization and lack of achievement, which suggests the usefulness of multiple measures for assessing the burnout phenomenon.     

<Emphasis Type="Italic">TCF7L2</Emphasis>variant genotypes and type 2 diabetes risk in Brazil: significant association,but not a significant tool for risk stratification in the general population

Background  

Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population.     

Direct evidence for the involvement of carbohydrate sequences in human sperm-zona pellucida binding

Several lines of evidence indicate that mammalian fertilization is initiated via a binding process that is dependent upon the recognition of oligosaccharide sequences associated with zona pellucida (ZP) glycoproteins. Here, specific chemical and enzymatic methods were employed to modify human ZP and to test their effects on sperm binding in the hemizona assay system (HZA). Periodate oxidation of human ZP under very mild conditions (10 min, 0 degrees C, 1 mM sodium m- periodate) that attacks only terminal sialic acid resulted in a 30% loss of human sperm binding in the HZA [hemizona index (HZI) = 70.2 +/- 10.9, n = 22; P < 0.05]. Periodate oxidation under mild conditions (1 h, 23 degrees C, 10 mM sodium m-periodate) caused a 40% decrease in binding (HZI = 60.8 +/- 10.3; n = 24; P< 0.01). Treatment of human ZP with neuraminidase caused a substantial increase in sperm binding to human ZP (HZI = 297 +/- 45, n = 22; P < 0.01). These findings indicate that there are sialic acid dependent binding sites coexisting with binding sites that are obscured by sialic acid. To determine the periodate sensitivity of these obscured sites, hemizona were first digested with neuraminidase and subsequently subjected to mild periodate oxidation. The combined enzymatic and chemical treatments caused a 79% decrease in sperm binding compared to control hemizona (HZI = 20.7 +/- 4.4, n = 16; P < 0.001). Human sperm-ZP interaction was also increased by digestion of human ZP with endo-beta-galactosidase (HZI = 710 +/- 232, n = 14; P < 0.01), indicating that potential binding sites for spermatozoa are also obscured by lactosaminoglycan sequences. These studies support a definitive role for the involvement of ZP-associated glycans in the binding of human spermatozoa to oocytes.