Population dynamics of Aeromonas spp. in an urban river watershed

Density of Aeromonas spp. at one site in the Buffalo River and at four sites on its upstream tributaries was followed from June 1992-June 1993. Membrane filtration counts of Aeromonas during the summer ranged between 18 and 4000 ml-1, which were one to two logs higher than faecal coliform and faecal streptococci densities. Aeromonas spp. in the Buffalo River, and faecal coliforms, faecal streptococci, and the heterotrophic plate count throughout the watershed, increased by approximately one log during summer rainstorms. However, Aeromonas spp. increased only by a factor of two during rainstorms at the upstream sites. Aeromonas spp. showed a strong positive correlation with both indicator bacteria and total suspended solids at the upstream sites during the summer but not the winter. Correlations between Aeromonas and indicator bacteria remained strong in the Buffalo River during the winter, signifying that different conditions exist in the Buffalo River and its upstream tributaries. The strong correlation between Aeromonas spp. and indicator bacteria in the Buffalo River suggest that, in the absence of media capable of the quantitative recovery of potentially pathogenic aeromonads, standard faecal coliform analyses may adequately assess public health risks from Aeromonas spp. in an urban river used for recreational purposes.     

Use of extendable total femoral replacements in children with malignant bone tumors

Although rarely required, extendable reconstruction devices for replacing the entire femur offer children with malignant bone tumors the opportunity of a nearly normal development by overcoming an expected leg length discrepancy. Femoral integrity can be restored, allowing most patients to walk without the use of aids. There are no data available to provide evidence regarding long term results and morbidity in such patients. Six patients (range 2-12 years of age), three with osteogenic osteosarcoma and three with Ewing's sarcoma, were treated between 1988 and 1996 with custom made Stanmore extendable prosthetic total femoral replacements. One patient died 12 months after surgery because of complications relating to pulmonary metastasis. The remaining five patients were observed between 2.7 and 8.9 years (average, 5 years). No tumor recurrence has been recorded and no amputation has been performed. All surviving patients underwent an average of 9.4 operative procedures (range, 4-16 procedures) including 6.4 extension procedures (range, 3-10 procedures), and one prosthetic revision (range, 0-3 procedures). Five revisions in two patients were necessary because of infection, loosening of the prosthesis, mismatch between femoral head and acetabulum, or full extension of the extending mechanism. The functional results were measured in accordance with the Musculoskeletal Tumor Society rating score, with an average result of 77.3%. Total femoral replacement in a growing individual achieves good functional results yet has various risks for an uncertain outcome. Careful selection of the patient and realistic appraisal of the long term prospects are essential for successful treatment.     

Diuretic-based treatment and cardiovascular events in patients with mild renal dysfunction enrolled in the systolic hypertension in the elderly program

BACKGROUND: It is expected that the treatment of hypertension in patients with renal disease decreases the risk of cardiovascular events, but the evidence in these patients is lacking. OBJECTIVE: To assess the effect of diuretic-based treatment on cardiovascular events in patients with isolated systolic hypertension and renal dysfunction. METHODS: A total of 4336 persons aged 60 years and older with systolic blood pressures of 160 mm Hg and higher and diastolic blood pressures of less than 90 mm Hg were randomly assigned to receive either placebo or chlorthalidone (12.5-25.0 mg/d), with the addition of atenolol (25-50 mg/d) or reserpine (0.05-0.10 mg/d) if needed, and observed for 5 years. The risk of first-occurring cardiovascular events, including stroke, transient ischemic attack, myocardial infarction, heart failure, coronary artery bypass surgery, angioplasty, aneurysm, endarterectomy, sudden death, or rapid death, was stratified according to baseline serum creatinine levels (35.4-84.0, 84.1-101.6, 101.7-119.3, and 119.4-212.2 micromol/L [0.4-0.9, 1.0-1.1, 1.2-1.3, and 1.4-2.4 mg/dL]). RESULTS: Systolic blood pressure reduction was not affected by baseline serum creatinine levels. Active treatment did not affect the risk of serum creatinine levels becoming elevated during follow-up. The risk of hypokalemia with active treatment decreased significantly with increasing baseline serum creatinine levels. In the 4 baseline serum creatinine groups, the relative risk (95% confidence interval) of cardiovascular events developing with active treatment was 0.73 (0.54-0.97), 0.63 (0.49-0.82), 0.62 (0.44-0.87), and 0.59 (0.38-0.91). The results were similar for the outcomes of stroke or coronary artery events and in analyses stratified by sex or age. CONCLUSION: Diuretic-based treatment of patients with isolated systolic hypertension prevents the development of cardiovascular events in older persons with mild renal dysfunction.     

Processing and analyzing the mouse temporal bone to identify gross, cellular and subcellular pathology

A technique has been developed for preparing the mouse temporal bone for histopathological examination: first, as a whole mount to detect any gross malformations of the bony or membranous labyrinths; second, in dissected segments to localize damage in the different sensory organs and to quantify sensory- and supporting-cell losses; and finally, in semi-thick and thin sections to identify and characterize subcellular pathology. Examples are given of the successful application of this technique to mice with very different inner-ear problems, including those with an abnormally short cochlear spiral, a defective lateral semicircular canal, abnormal otoliths over the saccular macula, an increased susceptibility to noise damage and those which lack fibroblast growth factor receptor 3.     

Negative signaling in B cells causes reduced Ras activity by reducing Shc-Grb2 interactions

To elucidate the molecular basis for inhibition of B cell proliferation and differentiation by the Fc receptor for IgG (Fc(gamma)RII), we compared the signaling events in B cells stimulated by cross-linking surface Ig alone (positive signaling), or by co-cross-linking surface Ig and Fc(gamma)RII (negative signaling). Both modes of stimulation induced tyrosine kinase activation. Positive signaling induced activation of Ras, Raf-1 kinase, and mitogen-activated protein kinase; these events were significantly attenuated during negative signaling. Since Ras is activated by SOS and Vav, two known guanine nucleotide exchange factors, activation events associated with these molecules using the two different stimuli were examined. Results of these experiments indicated that tyrosine phosphorylation of Vav did not change upon co-cross-linking. In contrast, the association of Shc and Grb2 was abrogated under negative and induced under positive signaling conditions. Concomitantly, Shc was observed to associate with a tyrosine-phosphorylated 145-kDa protein, previously identified as Src homology 2-containing inositol phosphatase, only under conditions of negative signaling. Based on these results, we hypothesize that negative signaling via the Fc(gamma)RII in B cells is at least partly the result of a block in Ras activation, and that SOS, but not Vav, is the major guanine nucleotide exchange factor in B cells for Ras activation.     

The value of physical examination in the diagnosis of patients with blunt abdominal trauma: a retrospective study

Between 1 January 1993 and 1 January 1994, 204 consecutive patients with possible blunt abdominal injury were analysed retrospectively. All patients underwent a standardized diagnostic approach on admission to the emergency room. Abdominal ultrasound (AUS) was performed in all cases. If there was evidence of intra-abdominal injury on physical examination or AUS, without signs of persistent hypovolaemia after initial assessment, contrast-enhanced computed tomographic scanning (CECT) of the abdomen was carried out without exception. Physical examination was equivocal in 13 and 3 per cent, respectively, of patients with 'isolated' abdominal trauma (N = 23) or with fractures of lower ribs 7-12 as a sole diagnosis (N = 30). In multiple injury patients (N = 95) or those with suspected 'isolated' head injury (N = 56), these figures reached 45 and 84 per cent, respectively. AUS (N = 204) revealed intra-abdominal injury in 20 per cent of patients, and CECT (N = 43) resulted in additional information in 49 per cent. Patients with 'isolated' head injury showed 9 per cent abnormalities on abdominal evaluation versus 32 per cent in multiple injury patients. In lower rib fractures (7-12) in multiple injury patients abdominal injury was diagnosed in 67 per cent of the cases. We conclude that: (1) negative findings following reliable physical examination of patients with 'isolated' head injury show very high values (NPV 100 per cent), but reliable physical examination is very infrequent (16 per cent); (2) NPV in lower rib fractures due to low energy impact is very high (100 per cent), with a reliable physical examination in most patients (97 per cent); (3) in patients with isolated abdominal trauma 87 per cent have a reliable physical examination with a moderately high NPV (71 per cent); (4) almost half the multiple injury patients have an unequivocal physical examination (45 per cent), with a high NPV following reliable physical examination for abdominal injury (85 per cent); (5) abdominal ultrasonography should be the first step in the radiological assessment of all patients with possible blunt abdominal injury; (6) in multiply injured patients with fractures of their lower ribs (7-12) due to high energy impact the incidence of abdominal injury is very high and CECT might be indicated even in the case of normal AUS findings.     

Granulomatous glomerulonephritis in intravenous drug users: a report of three cases in oxycodone addicts

Various well-documented renal lesions are associated with intravenous drug use; however, intraglomerular mesangial granulomas have not been previously described. We report three patients who developed an unusual granulomatous glomerulonephritis and interstitial nephritis after intravenous injection of oxycodone, derived from suppositories. Granulomas were seen in an intraglomerular mesangial and also interstitial location. In both sites, the granulomas were associated with filamentous material, presumably derived from a component of the suppositories. This material was periodic acid-Schiff-positive, but negative with Congo red and silver stains. Ultrastructurally, the filamentous material was seen within the mesangial granulomas and also in a subendothelial location, suggesting derivation from the circulation with subsequent transport across the basement membrane and accumulation in the mesangium, where a granulomatous reaction was elicited. All patients developed a degree of renal failure; two of the patients require hemodialysis 20 and 30 months after presentation.     

Genetic and population perspectives on life events and depression

Population comparisons of epidemiological surveys using the same investigator-based measures suggest that large differences are possible in the experience of clinically relevant depression and of life events capable of provoking such episodes. It is argued that, given the great majority of onsets in the various populations were provoked by a life event, the differences in the experience of depression are likely to have been largely the result of psychosocial factors. Moreover, this interpretation would still be likely to hold even if heritability (h2) coefficients for depression within the component populations were substantial. The same argument would hold for the interpretation of the across-population differences in the experience of life events. New material concerning the differing experience across populations of humiliation/entrapment events, known to be particularly depressogenic, is also presented and the implications of the findings for future aetiological research discussed.     

Myelodysplastic syndromes (MDS): prognostic factors and scoring systems

OBJECTIVE: To evaluate the score systems of Cassano and Sanz and suggest a new one. DESIGN: Case series. LOCATION: Teaching hospitals: EPM UNIFESP and Faculdade de Medicina de Botucatu. PARTICIPANTS: 59 patients diagnosed from 1979 to 1992. INTERVENTION: Evaluation of clinical-laboratorial data. MEASUREMENT: Statistical comparison, uni and multivariate analysis and actuarial survival curves. RESULTS: Cassano's system divided the patients into high and low risk (p = 0.0966) while Sanz's gave high, intermediate and low risk (p = 0.0108). The univariate analysis showed hemoglobin, WBC count, E/M ratio, liver size and blast percentage in BM as statistically significant. The multivariate analysis showed blast percentage in BM (p = 0.004) and Hb (p = 0.050) as significant. Our system, considering the multivariate analysis data, divided the patients into high, intermediate and low risk (p = 0.0038). CONCLUSIONS: Sanz's system was more functional than Cassano's, while ours showed predictive survival value and ease of use in clinical practice.