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.     

Evaluation of three substitutes for Percoll in sperm isolation by density gradient centrifugation

Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by gradient centrifugation for use in assisted reproductive procedures. Efficacy was assessed in terms of percentages of sperm recovery, sperm vitality and motility, normal sperm morphology and normal sperm chromatin condensation. No significant difference was found in the recovery of spermatozoa for men with both normal sperm counts and oligozoospermia, between PVP-coated and silane-coated particle solutions. Iodixanol had significantly lower sperm recovery compared to the other products. Sperm vitality, progressive motility, normal morphology and normal chromatin condensation did not differ significantly between any of the sperm isolation products.      

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.     

Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation

The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN , with the exception of the first, fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis inthe group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.      

Nucleolin Promotes Homologous DNA Pairing in vitro

We purified to near homogeneity a previously identified 100 kDa mammalian homologous DNA pairing protein. The purified 100 kDa protein also catalyzed high levels of cell-free homologous DNA recombination activity. This ATP-dependent activity was capable of forming conservative recombinant products between two circular, double-stranded DNA molecules. We were unable to detect any DNA polymerase, DNA ligase, or 5' or 3' exonuclease activity associated with this purified material. The purified 100 kDa protein bound silver nitrate as well as a monoclonal antibody specific for nucleolin. A recombinant protein comprised of the Escherichia coli maltos-ebinding protein fused to the carboxyl-terminal two-thirds of human nucleolin possessed homologous DNA pairing activity. These data indicate that the 100 kDa homologous DNA pairing protein is nucleolin. The observation that nucleolin can carry out homologous DNA strand pairing in vitro raises the prospect that it may function similarly in vivo.