Biomedical subjects
Publications and source records attributed to M A Shapiro.
Recombination at the immunoglobulin kappa light chain locus creates a complete variable region gene and its reciprocal product. The results presented here show that reciprocal products may be substrates for secondary recombination and that at least one V kappa group rearranges by inversion.
We have previously reported that a segment of DNA from a murine plasmacytoma comprises DNA from three chromosomes, the immunoglobulin kappa light-chain locus on chromosome 6, the S mu locus on chromosome 12, and a region on chromosome 15. We now report that the reciprocal product contains DNA from only the kappa locus and chromosome 15 and not from S mu. We conclude that a complex series of events, including both a transposition of DNA and a translocation between chromosomes, generated these imperfect reciprocal products.
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Studies were run in parallel to compare the broth microdilution method and the chocolate agar dilution method for testing antibiotic susceptibility of Neisseria gonorrhoeae. Six clinically relevant drugs were tested against 23 clinical isolates of N. gonorrhoeae, including several penicillinase-producing, as well as multiply resistant, strains. Results showed that the MIC obtained by the two methods were not significantly different. The microdilution method appears to be a more sensitive system for discriminating penicillinase activity. The microdilution system is a more expedient method for screening new antibacterial agents and is more readily adaptable to new automated equipment.
The most common cyanobacterium contaminating drinking water systems in southwestern Pennsylvania is Schizothrix calcicola. Lipoplysaccharides (LPS) were isolated from this species by hot phenol-water extraction. The polysaccharide moiety was composed of glucosamine, galactose, glucose, mannose, xylose and rhamnose. The lipid A part contained beta-hydroxylauric, myristic, pentadecanoic, palmitic, beta-hydroxypalmitic, stearic, oleic, and linoleic acids. In contrast to many LPS isolated from Enterobacteriaceae, the dominant component was not beta-hydroxymyristic but beta-hydroxypalmitic acid. The LPS induced Limulus lysate gelation and Schwartzman reaction but was nontoxic to mice. The identity of LPS was verified by alkali and lysozyme treatment. The results suggest that S. calcicola is one of the principal sources of endotoxins in water systems using open finished-water reservoirs.
Free transplants of hair-bearing scalp as "plugs" or "strips" are an adequate treatment for male alopecia. Cooling the grafts eliminates hematoma and infection and allows successful take and growth of larger plugs. However the result of grafting wide hairstrips is unreliable.
Analysis of 78 observations (including 6 of the author's own) of primary malignant vascular tumours of the lung, showed that these tumours had no characteristic clinicoroentgenological features; in this connection the question of their preoperative cytological diagnosis is of importance. The retrospective collations of cytological and histological data in 8 patients made it possible to establish criteria of cytological diagnosis of similar tumours. For the first time in the Soviet literature a suggestion was put forward that basing on the data of cytological investigations it is possible in a number of cases to give a detailed verification of tumours of the lung with presumable indication to hemangioendothelioma, angiosarcoma, or hemangiopericytoma. Metastases of malignant vascular tumours of other localizations in the lung are of analogous cytological pattern. correct diagnosis of primary of metastatic tumour can be made only if all the complex of clinico-roentgenological and cytological data are taken into account.
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PURPOSE: To determine whether more inferior vena cava (IVC) filters were used after interventional radiologic placement methods became available, and if so, whether this increase could be due to expansion of indications. PATIENTS AND METHODS: A retrospective analysis of the number of filters placed, the method of placement used, the indications for placement, and patient survival was performed during the 3 years before and the 3 years after 1989, the first year filters were placed percutaneously at the authors' institution. RESULTS: From 1986 through 1988, 35 filters were all placed by surgeons in the operating room. From 1990 through 1992, 201 filters were all placed by radiologists in the special procedures suite. In the surgery group, 13 of 35 filters (37%) were placed for contraindications to anticoagulation therapy, 12 (34%) were placed for complications of anticoagulation, and nine (26%) were placed for recurrent thromboembolic disease despite anticoagulation. One filter was placed because of a free-floating thrombus in the IVC. In the radiology group, 98 of 161 patients (60%) underwent placement for contraindications to anticoagulation, 25 (16%) experienced complications of anticoagulation, 28 (17%) experienced recurrent thromboembolic disease, and nine (6%) had a free-floating thrombus. The 6-month survival in patients treated before 1989 was 80% versus 43% after 1989. CONCLUSION: At the authors' institution, filters are now placed exclusively by interventional radiologists. The overall indications for placement remain unchanged. The increase in utilization appears primarily related to more frequent placement in severely ill patients who may not experience considerably improved survival but may benefit from a substantial reduction in the risk of hemorrhagic complications.
Mortality experience was determined over a 13-year period (1960-72) for sample populations in two small Pennsylvania communities with widely different air pollution levels. The sample populations had been the subject of a Public Health Service study at the beginning of the period and air quality measurements were made at that time. The influence of smoking on mortality was clearly evident. A relationship was suggested between mortality rate and length of residence in the polluted community (age-adjusted), but not in the control community. The hypothesis is suggested that immigrants to a polluted area are a self-selected, unusually healthy group. While the small population size precluded definitive conclusions on the influence of air pollution on mortality, it appears that those with over 20 years exposure to air pollution in the polluted community (151 mug/m3 suspended particulate, 3.7 mg/100 cm2/day sulfation rate) have about one-tenth the excess mortality of those smoking one pack of cigarettes a day in the control community (109 mug/m3, 0.6 mg/100 cm2/day). The data are consistent with the hypothesis that the effects of smoking and air pollution are additive.
The in-vitro antigonococcal activity of enoxacin was measured by a broth microdilution method. Comparisons were made with five clinically relevant marketed drugs against 23 clinical isolates of Neisseria gonorrhoeae, including several penicillinase producers as well as multiply resistant strains. Results showed that enoxacin possessed potent activity against all organisms tested, with MIC values ranging from less than or equal to 0.013 to 0.05 micrograms/ml.