Relative mutagenicities of gaseous nitrogen oxides in the supF gene of pSP189

Gaseous nitric oxide (NO), an environmental pollutant found in cigarette smoke and diesel exhaust, has been shown to generate mutations in aerobic in vitro assays. The objective of this study was to identify which oxides of nitrogen, formed in the gaseous phase from NO, possess mutagenic activity. Samples of the plasmid pSP189, in 1 M HEPES buffer, pH 7.4, were exposed to preparations of nitrogen dioxide (NO2), dinitrogen trioxide (N2O3) or an air control. The gas mixtures were formed in a gas-tight syringe and were then introduced into 1 l flasks. The plasmid solution was introduced immediately afterwards. Transformation of Escherichia coli strain MBM7070 with the treated plasmids allowed analysis of mutation frequencies and the types of mutations induced in the target supF gene. The mutation frequency resulting from NO2 exposure was not different from that of the control. However, N2O3 produced a substantial number of mutations. The mutation frequency and the types of mutations were found to depend on the length of time that the gases were allowed to incubate in the syringe prior to introduction into the 1 l flasks (mutation frequency was maximal at approximately 2 min). The most prevalent mutations were AT-->GC transitions (68%), followed by GC-->AT transitions (30%), similar to previous findings when pure NO was bubbled through pSP189 solutions. These results suggest that it is N2O3, rather than NO2, that is the most likely source of mutagenic potential from gaseous nitrogen oxides.      

Rheumatoid arthritis: similarity of radiographic abnormalities in men and women

To test the hypothesis that there are significant differences in the radiographic appearance of rheumatoid arthritis between men and women, the authors blindly evaluated bilateral hand and wrist radiographs in 32 men with definite rheumatoid arthritis and 32 age- and disease duration-matched women (mean age, 56.4 years; mean disease duration, 10.5 years). Radiographically, disease distribution and severity were identical in these matched groups. Superimposed osteoarthritis was frequent in both groups and related to age. Ill-defined bone proliferation was present in 13 of 64 hands in both groups. Cystic changes and well-defined erosions were present in 12 of 64 male hands and six of 64 female hands, but this difference was not statistically significant. In women, presence of cysts and bone proliferation was related to disease duration, whereas men exhibited these atypical features independent of disease duration. There was no statistically significant difference in the frequencies of typical and atypical features of rheumatoid arthritis between the two sexes, and the authors postulate that previously reported differences relate to patient selection and lack of adequate matching.     

Relationship between the development of blindness in Churg-Strauss syndrome and anti-myeloperoxidase antibodies

Occular involvement is infrequent and blindness rare in Churg-Strauss syndrome. We describe a patient with Churg-Strauss syndrome who presented with blindness. This was associated with the appearance of circulating autoantibodies to myeloperoxidase.      

Early diagnosis of nonviable pregnancy with endovaginal US

The mean diameter of the gestation sac and the presence or absence of a yolk sac or embryo and/or cardiac pulsations on endovaginal ultrasound (US) images were correlated with normal and abnormal outcomes of pregnancy. Sixty-two patients who were less than 10 weeks pregnant (menstrual age) underwent endovaginal US. In 59 patients with gestation sacs greater than or equal to 8 mm, the absence of a yolk sac predicted a nonviable pregnancy with a sensitivity of 67% and a specificity of 100%. In 35 patients with gestation sacs greater than or equal to 16 mm, the absence of an embryo predicted a nonviable pregnancy with a sensitivity of 50% and a specificity of 100%. When the absence of cardiac pulsations was added to the latter group of patients, the sensitivity was 100% and the specificity was 100%. The combination of these criteria (gestation sac size; demonstration of yolk sac, embryo and/or cardiac pulsations) enabled the early (less than 10 weeks menstrual age) diagnosis of a nonviable pregnancy with endovaginal US.     

A clinical and immunologic study of blood transfusion and postoperative bacterial infection in spinal surgery

Allogeneic blood transfusion has been implicated as an independent risk factor for postoperative bacterial infection in clinical and animal studies. The association among transfusion, quantitative immunologic factors, and infection was examined in 102 patients undergoing 109 spinal fusion procedures. In 60 procedures, patients received autologous blood only; in 24 procedures, they received at least 1 unit of allogeneic blood, and in 25 procedures, they received no transfusions. Twenty-two patients developed bacterial infections, in 8 cases while in hospital and in 14 cases after discharge. Univariate analysis revealed that patients who received any allogeneic blood and those who received no allogeneic blood differed significantly in the rate of hospital-acquired infection (20.8 vs. 3.5%), length of stay (12.3 vs. 9.7 days), days of fever greater than or equal to 38 degrees C (4.0 vs. 2.9), days on antibiotics (3.9 vs. 2.5), duration of surgery (309 vs. 231 min), blood loss (1343 vs. 887 mL), surgeon, and postoperative drop in natural killer (NK) cells (-174 vs. -42/microL). Multivariate logistic and linear regressions revealed that the number of allogeneic units transfused was the only significant predictor of in-hospital infection (p = 0.016) or days on antibiotics and length of stay. None of the clinical, surgical, or transfusion variables was significantly associated with posthospital infection, although a significantly greater drop in NK cells had occurred in patients who developed infection (p = 0.0035). These data strongly implicate allogeneic transfusion as a risk factor for in-hospital postoperative bacterial infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detailed per-oral small bowel examination vs. enteroclysis. Part I: Expenditures and radiation exposure

Time involved, patient reaction, and radiation exposure were compared for 25 patients undergoing a per-oral small bowel series and 18 having enteroclysis. For the per-oral study, mean room time was 17 minutes and fluoroscopy time was 4 minutes; for enteroclysis, mean room time was 44 minutes and fluoroscopy time was 22 minutes. Side effects were categorized as mild to moderate in two thirds of patients having enteroclysis, whereas they were minimal in 20% of those having the per-oral examination. Radiation exposure was five times greater for enteroclysis. These factors should be considered along with the age of the patient, indications for the examination, and the accuracy of the technique when planning a study of the small bowel.