Interaction of vasopressin and oxytocin with human breast carcinoma cells

The arginine vasopressin and oxytocin content of normal and cancerous human breast tissue were measured using radioimmunoassay. Both peptides were present in amounts greater than that found in the circulation, but no difference between normal and malignant tissues was found. Binding of [3H]oxytocin and [3H]vasopressin were characterized in human breast carcinoma cells (MCF7 cells). Binding of both hormones to MCF7 cells was specific and saturable, the vasopressin receptor found to be of the V1 subtype. Scatchard analyses of the data were linear, indicating a single high affinity, low capacity binding site for each hormone (vasopressin: KD = 47.4 +/- 1.6 nmol/liter, Bmax = 27,300 +/- 6,500 sites/cell; oxytocin: KD = 51.3 +/- 0.4 nmol/liter, Bmax = 87,000 +/- 4,000 sites/cell). The effects of vasopressin and oxytocin on the growth of MCF7 cells were assessed using protein accumulation and cell numbers. Vasopressin at 10-1000 pmol/liter was mitogenic for MCF7 cells, but higher doses (10 nmol/liter) were growth inhibitory. Oxytocin was also mitogenic for MCF7 cells but to a lesser extent than vasopressin. In conclusion, we suggest that vasopressin and possibly oxytocin may be important modulators of the growth of some human breast carcinomas.     

Management of gastroenteritis.

Childhood gastroenteritis remains a common reason for admission to British paediatric units, although the severity of the disease appears to be diminishing in recent years. We studied 215 infants and children with gastroenteritis admitted consecutively to four paediatric units in South Wales in order to determine the severity of the disease, the organisms isolated, the frequency of complications, and the adequacy of management before admission. Stool pathogens were isolated in 125 (58%) patients (viruses in 65, bacteria in 30, and protozoa in 19, with multiple infection found in 11). There was a low incidence of morbidity and complications, but prolonged diarrhoea (postenteritis syndrome) was present in 24 (11%) cases and 77 (36%) had received inappropriate treatment before admission. Contemporary gastroenteritis is thus a relatively mild disease in the acute phase, but management before admission to hospital is often inadequate, and prolonged diarrhoea may be a feature in a considerable number of cases.     

The deep overbite: prevention of trauma

An understanding of the mechanisms by which deep overbite trauma develops will allow interception at an early age of those cases most at risk. Measures may then be taken to prevent progression to the stage where treatment becomes difficult.     

Training of village health workers in Tanzania; a comparison of two approaches

The paper compares the costs of training for two groups of Village Health Workers (VHWs) in Tanzania, where the policy of developing a system based on Primary Health Care principles will require the training of more than 16,000 VHWs during the next decade. In the Kilombero District, one group of VHWs was trained according to the guidelines of the National Programme of the Ministry of Health, and another group followed the training programme of the Kilombero Project, based on the Swiss Tropical Institute Field Laboratory. The training scheme of the Kilombero project cost almost 80% less for one VHW, largely because it depended on on-the-spot training by local staff. The results of a first investigation of the efficacy of the training were encouraging; a long-term evaluation is in progress. The curricula for the two programmes also differed; the Kilombero programme had shorter blocks of theory, interspersed with supervised practical work, and introduced curative medicine earlier in the course. The advantage and disadvantages of the two programmes are discussed, not only in terms of cost but also in terms of their efficacy in training VHWs who will be motivated, efficient and accepted by the community.     

Dairy barns and roll-over protection on farm tractors: Work environment impacts on the adoption of roll-over protective structures

A mailed survey of one group of dairy farmers supports the informal perception that roll-over protective structure (ROPS)-equipped tractors are considered unusable for in-barn tasks. This attitude must be addressed in order to achieve greater use of safety equipment.     

The effectiveness of a media-led intervention to reduce smoking among Vietnamese-American men.

OBJECTIVES: This study evaluated an anti-tobacco campaign targeting Vietnamese men in San Francisco, Calif. METHODS: The intervention included Vietnamese-language media, health education materials, and activities targeting physicians, youth, and businesses. Evaluation involved pretest and posttest cross-sectional telephone surveys and multiple logistic regression analyses designed to identify variables associated with smoking and quitting. RESULTS: At posttest, the odds of being a smoker were significantly lower (odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.68, 0.99), and the odds of being a quitter were significantly higher (OR = 1.65, 95% CI = 1.27, 2.15), in San Francisco than in a comparison community. CONCLUSIONS: Despite modest success, further efforts are needed to reduce smoking among Vietnamese-American men.     

Neuronal nitric oxide synthase mutant mice show smaller infarcts and attenuated apparent diffusion coefficient changes in the peri-infarct zone during focal cerebral ischemia

Diffusion-weighted MRI at 2 T was used to monitor and assess tissue damage after permanent middle cerebral artery occlusion (MCAO) in wild-type (WT) and mice deficient in nitric oxide synthase gene expression (nNOS^?). The ischemic lesion was evaluated 3 h after occlusion and subdivided into the lesion core and peri-infarct zone based on the magnitude of the apparent diffusion coefficient (ADC) change. Infarct volume, measured by using histochemical staining 24 h after MCA occlusion, correlated best with MRI infarct volume as assessed by an ADC threshold of 25% decrease from baseline at 3 h. For ADC thresholds of greater than 25% decrease, lesion size was not significantly different in nNOS^? and WT mice. However, brain tissue showing ADC decreases of 10–25% was significantly smaller in the ipsilateral hemisphere of mutants (27 · 2% and 21 · 2% in WT and nNOS^?, respectively; P < 0.05). These findings occurred independently of infarct volume and are consistent with a smaller peri-infarct zone in nNOS^? mice. We postulate that the smaller peri-infarct zone is a reflection of less severe metabolic disturbance after ischemia in nNOS^? mice, possibly related to diminished production of nitric oxide (NO) or a related product. We conclude that magnetic resonance techniques previously used to assess ischemic damage in larger animals can be extended to the mouse, raising the possibility that the molecular mechanisms leading to ischemic damage can be examined by using genetically engineered mice.     

Sporadic isolates of Escherichia coli O157.H7 investigated by pyrolysis mass spectrometry.

Thirty-six encoded isolates of Escherichia coli. 32 of which were of serotype O157, were examined by pyrolysis mass spectrometry (PyMS). Thirty-one of the serotype O157 isolates possessed the flagellar antigen H7 and produced Verocytotoxin (VT), the other isolate serotyped as H45 and was non-toxigenic. Eighteen of the VT-producing E. coli (VTEC) isolates were from sporadic disease in residents of the Northern Region. Standard principal component (PC) and canonical variate (CV) analysis of the data distinguished only the four non-O157 isolates from the remainder which were indistinguishable by this approach. A similarity matrix based on differences between individual CV means distinguished a further ten isolates. The matrix correctly clustered 2 pairs of isolates from siblings and 4 isolates from an affected family. A further 5 clusters of 3 or more isolates and 6 pairs of isolates were defined. These groupings proved to be homogenous for toxin phenotype but occasionally entrained isolates of dissimilar phage type. However, in general, PyMS-derived clustering of apparently sporadic isolates accorded with geographical locations as determined by postcode. PyMS, which is a quick and high volume capacity phenotypic technique, may be a useful addition to existing methods in the investigation of the epidemiology of sporadic VTEC disease.