Experimental testing of hypotheses for temperature- and pH-based niche specialization of ammonia oxidizing archaea and bacteria.

Investigation of niche specialization in microbial communities is important in assessing consequences of environmental change for ecosystem processes. Ammonia oxidizing bacteria (AOB) and archaea (AOA) present a convenient model for studying niche specialization. They coexist in most soils and effects of soil characteristics on their relative abundances have been studied extensively. This study integrated published information on the influence of temperature and pH on AOB and AOA into several hypotheses, generating predictions that were tested in soil microcosms. The influence of perturbations in temperature was determined in pH 4.5, 6 and 7.5 soils and perturbations in pH were investigated at 15°C, 25°C and 35°C. AO activities were determined by analysing changes in amoA gene and transcript abundances, stable isotope probing and nitrate production. Experimental data supported major predictions of the effects of temperature and pH, but with several significant discrepancies, some of which may have resulted from experimental limitations. The study also provided evidence for unpredicted activity of AOB in pH 4.5 soil. Other discrepancies highlighted important deficiencies in current knowledge, particularly lack of consideration of niche overlap and the need to consider combinations of factors when assessing the influence of environmental change on microbial communities and their activities.

Improving the rehabilitation of older people after emergency hospital admission.

PURPOSE: Older adults are at risk of functional decline during emergency hospital admissions. This review aims to understand which exercise-based interventions are effective in improving function for older adults who experience unplanned admissions. METHODS: Database searches identified randomised control trials (RCTs) comparing exercise-based interventions with usual hospital care. The primary outcome was functional status measured by activities of daily living (ADL) scores. Secondary outcomes were length of hospital stay (LOS), mortality and readmissions. Sub-group meta-analyses were conducted on interventions delivered in-hospital only compared with interventions provided both in hospital and after discharge. RESULTS: After reviewing 8365 studies, nine were eligible for inclusion. Seven were included in the meta-analysis. Participants from five countries had a mean age of 79 years (1602 participants). Usual care varied considerably and the interventions showed heterogeneity, with different combinations of strengthening, resistance, high-intensity or mobility exercises. There were limited descriptions of exercise intervention delivery and participant adherence. There is low-quality evidence supporting exercise interventions that have both in-hospital and post-discharge components (3 trials, SMD 0.56 (-0.02, 1.13)). Trials involving only in-hospital interventions were inconclusive for functional gains (5 trials, SMD -0.04 (-0.31, 0.22)). CONCLUSIONS: Exercise-based rehabilitation for older patients after emergency hospitalisation improves functional ability if the intervention starts in hospital and continues after discharge. No conclusions can be made regarding the effective exercise 'dose' or content. IMPLICATIONS: Understanding the components of exercise interventions will improve service planning and delivery. Further studies are needed to understand the effective 'dose' and content of exercise for hospitalised older adults.

A new algorithm for the initial evaluation and management of supraventricular tachycardia.

Interpretations by physicians and those generated by electrocardiograph computer softwares have poor ability to recognize different types of supraventricular tachycardia (SVT). Therefore, we developed and tested a new SVT algorithm based on easily identifiable morphological characteristics and a simple dichotomous yes/no format regarding initial electrocardiographic manifestation and response pattern. The algorithm was then tested by medical house staff during the initial evaluation of 50 adult ED and cardiac intensive care unit patients suspected of having SVT. For a wide representation of SVTs, the new algorithm gave an overall diagnostic accuracy rate of 90%. Adenosine use was limited to 54% of the cases. No patient developed hemodynamic instability after algorithm-dictated interventions were carried out. Electrocardiograph computer-generated diagnoses correctly identified the specific type of SVT in 38% of the cases. This study shows the effectiveness of the proposed new algorithm in the rapid bedside evaluation and management of SVTs and confirms that computer-generated diagnoses are unreliable.

Long R-P' paroxysmal supraventricular tachycardia: what is the mechanism?

Deciphering the electrophysiologic mechanism of a long R-P' paroxysmal supraventricular tachycardia typically requires an invasive electrophysiologic study. We present a case where analysis of a simple surface 12-lead ECG was sufficient for the diagnosis.

Estimates of the health risk reductions associated with attainment of alternative particulate matter standards in two U.S. cities.

As part of its periodic re-evaluation of particulate matter (PM) standards, the U.S. Environmental Protection Agency estimated the health risk reductions associated with attainment of alternative PM standards in two locations in the United States with relatively complete air quality data: Philadelphia and Los Angeles. PM standards at the time of the analysis were defined for particles of aerodynamic diameter less than or equal to 10 microm, denoted as PM-10. The risk analyses estimated the risk reductions that would be associated with changing from attainment of the PM-10 standards then in place to attainment of alternative standards using an indicator measuring fine particles, defined as those particles of aerodynamic diameter less than or equal to 2.5 microm and denoted as PM-2.5. Annual average PM-2.5 standards of 12.5, 15, and 20 microg/m3 were considered in various combinations with daily PM-2.5 standards of 50 and 65 microg/m3. Attainment of a standard or set of standards was simulated by a proportional rollback of "as is" daily PM concentrations to daily PM concentrations that would just meet the standard(s). The predicted reductions in the incidence of health effects varied from zero, for those alternative standards already being met, to substantial reductions of over 88% of all PM-associated incidence (e.g., in mortality associated with long-term exposures in Los Angeles, under attainment of an annual standard of 12.5 microg/m3). Sensitivity analyses and integrated uncertainty analyses assessed the multiple-source uncertainty surrounding estimates of risk reduction.

Induction of rodent hepatic drug-metabolizing enzyme activities by the novel anticonvulsant remacemide hydrochloride.

Remacemide hydrochloride [FPL 12924AA; 2-amino-N-(1-methyl-1,2-diphenylethyl) acetamide hydrochloride] is being evaluated as a novel neuroprotective treatment for epilepsy and stroke. Preliminary safety evaluation studies in the rat have shown that repeated doses of the compound produce histological and biochemical changes consistent with hepatic enzyme induction. To examine this further, the levels and activities of the major drug metabolizing cytochrome P450 (CYP) subfamilies (CPY1, CYP2, and CYP3) were monitored in microsomal samples from male Sprague-Dawley rats dosed by gavage with FPL 12924AA (250 mg base.kg-1.day-1 for 28 days) or an equivalent volume of vehicle (controls). The interpretation of the findings was aided by comparison with the effects of phenobarbitone (75 mg.kg-1.day-1 ip for 4 days) and beta-naphthoflavone (a single intraperitoneal dose at 80 mg.kg-1.day-1). No significant changes in total hepatic P450 levels (1.44 +/- 0.40 nmol.mg-1 vs. 1.31 +/- 0.19 nmol.mg-1 in controls) or ethoxyresorufin O-deethylase activity (a CYP1A induction probe) were observed after remacemide treatment. The pattern of induction produced by remacemide was very similar to that observed with phenobarbitone. The nonspecific CYP-dependent reaction ethoxycoumarin O-deethylation was induced approximately 2-fold. The specific CYP2B markers pentoxyresorufin O-depentylase and 16 beta-hydroxytestosterone production were both increased markedly by FPL 12924AA (approximately 100- and 20-fold, respectively). 2 beta- and 6 beta-Hydroxytestosterone production were also elevated, indicating the induction of CYP3A1/2. Similar effects on isoform-selective P450-dependent activities were observed in male and female mice treated with remacemide as part of a dose-ranging study.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of a policy of surveillance in stage I testicular seminoma.

PURPOSE: To determine what proportion of patients with Stage I testicular seminoma will be cured with orchidectomy alone. METHODS AND MATERIALS: From August 1984 to December 1991 148 patients with Stage I testicular seminoma were entered on a prospective study of surveillance following orchidectomy. The eligibility criteria included a normal chest X ray, lymphogram, computed tomography (CT) of the abdomen and pelvis, and normal post-orchidectomy tumor markers (AFP and BHCG). Patients were followed with a clinical assessment (markers, chest X ray and CT abdomen and pelvis) at 4 to 6 monthly intervals. RESULTS: With a median follow-up of 47 months (range 7-87 months), the actuarial relapse-free rate was 81% at 5 years. Twenty-three patients have relapsed with a median time to relapse of 15 months (range 2-61 months). Four patients (17%) relapsed at 4 or more years from diagnosis. Twenty-one of the 23 relapses occurred in the paraaortic lymph nodes, one patient relapsed in the mediastinum and ipsilateral inguinal nodes and one patient had an isolated ipsilateral inguinal node relapse. Nineteen patients were treated for relapse with external beam radiation therapy of which three developed a second relapse and were salvaged with chemotherapy. Four patients were treated for first relapse with chemotherapy and one developed a second relapse and died of disease. Age at diagnosis was the only prognostic factor for relapse, with patients age < or = 34 having an actuarial relapse-free rate at 5 years of 70% in contrast to a 91% relapse-free rate in those > 34 years of age. CONCLUSIONS: We recommend that surveillance in Stage I testicular seminoma should only be performed in a study setting until further data regarding the risk of late relapse and the efficacy of salvage chemotherapy is available.

Surveillance after orchidectomy for patients with clinical stage I nonseminomatous testis tumors.

PURPOSE: This study was designed to determine the proportion of patients with clinical stage I nonseminomatous germ cell tumors of the testis (NSGCTT) managed with surveillance after orchidectomy who have more advanced disease and, therefore, require further treatment, the time to progression, the sites of progression, and the efficacy of treatment delayed until progression was recognized. PATIENTS AND METHODS: One hundred five patients were observed prospectively without further treatment after orchidectomy and full clinical staging. Treatment was given immediately upon detection of marker-positive, clinical, or radiologic evidence of disease. RESULTS: Thirty-seven patients (35.2%) have required further therapy for disease progression, occurring from 2 to 21 months after diagnosis. Thirty-six patients have been successfully treated. Overall, 104 patients (99%) remain alive and free of disease at 12 to 121 months after orchidectomy. Progression occurred in the retroperitoneum in 25 of 37 patients who developed further disease on surveillance. The presence of vascular invasion in the primary tumor was predictive of an increased risk of progression. CONCLUSION: Surveillance is a valid alternative to immediate retroperitoneal lymph node dissection in patients with clinical stage I NSGCTT but should be recommended only under the close supervision of physicians experienced in the diagnosis and treatment of testicular cancer.

Significance and value of immunohistochemical localization of pregnancy specific proteins in feto-maternal tissue throughout pregnancy.

Tissue from 50 cases of products of conception and placenta at different gestational ages from as early as 12 d post ovulation up to 40 wk were examined by immunoperoxidase technique for localization of HCG, HPL, SP1, and PAPP-A. HCG was localized in the cytoplasm of syncytiotrophoblast (ST) with strong intensity in the 12-d blastocyst and remained strong until 8 to 10 wk. It then gradually decreased, becoming almost negative in term placenta. HCG was also seen in the cytoplasm of intermediate trophoblast (IT) at the implantation site but with variability in staining. HPL and SP1 appeared later than HCG in ST, and the intensity of staining increased rapidly to strongly positive by wk 8. They remained strong until full term. IT stained strongly positive with HPL throughout pregnancy, and some were different from the HCG positive ones. ST were constantly negative for PAPP-A throughout pregnancy. The latter, however, was definitely seen in the cytoplasm of cytotrophoblast (CT) of early blastocyst, the superficial epithelium of the endometrium adjacent to the implantation site, in many decidual cells around the implantation site and in the amniotic membrane epithelium.

Necropsy study of mountaineering accidents in Scotland.

One hundred and twenty one people died in mountaineering accidents in Scotland between July 1978 and December 1983. Necropsies were carried out on 42, which form the basis of this report. In 21 cases head injury was major fatality factor, but in 11 of these there were also serious chest injuries. Focal brain damage (haematomas, contusions, or lacerations) was more common (n = 21) than diffuse brain damage (n = 18). Over half of the victims with severe head injury had few other injuries and would probably have survived had the head injury been prevented. Spinal injuries usually occurred with other major injuries. Chest injuries were common, being serious in 18 cases, but abdominal injuries were uncommon. Four climbers with only minor injuries died of hypothermia.

The use of scientific information in setting ambient air standards.

The Clean Air Act, as amended in 1977, requires periodic review and revision of all national ambient air quality standards (NAAQS) to insure that they are based on the latest scientific information. This article presents an overview of how EPA currently reviews and establishes NAAQS. The role of scientific information and expertise in the process is illustrated by a review of several key issues faced in the development of the proposed revisions to the carbon monoxide NAAQS. Finally, a risk analysis framework being developed within EPA's Office of Air Quality Planning and Standards for possible future use in NAAQS reviews is described. The principal objective of the risk analysis framework is to provide more formal treatment of uncertainties in the scientific data base.

Colitis cystica profunda.

The clinical, pathologic and radiologic features of colitis cystica profunda (CCP) in a 60-year-old woman are presented. This benign lesion, although rare, is usually misdiagnosed and consequently treated as a carcinoma. It should be included in the differential diagnosis of submucosal rectal lesions.

Chemotherapy sensitivity testing in human tumours.

We have attempted to establish in vitro growth in a consecutive series of 245 malignant tumours submitted for routine histopathology. Initially, three disaggregation procedures were used: mechanical separation, digestion by trypsin, and digestion by collagenase. The resulting cell fractions had varying success rates in establishing growth. Abundant epithelial cell growth was achieved in monolayer culture in 63 tumours, and the sensitivity of the cells to cytotoxic agents was tested. There was no indiscriminate cytotoxic effect, and each tumour type varied in its sensitivity from one patient's lesion to another. While testing of all solid tumours is not possible with present-day techniques, we believe that the employment of in vitro sensitivity testing as a routine procedure may be possible in the future if a suitable system giving correlation between in vitro and in vivo sensitivity can be developed.