The concentration of angiotensins I and II in blood from the pulmonary artery and left ventricle of man

The concentrations of angiotensin I (AI) and II (AII) were determined by radioimmunoassay in blood from the main pulmonary artery (MPA) and left ventricule (LV) of ten subjects with rheumatic valvular heart disease. The levels of AI were consistently higher in MPA plasma (21.8+/-2.4 pmol/1) than in LV plasma (14.7+/-2.0 pmol/1), paired t, P less than 0.001. The levels of AII were consistently lower in MPA plasma (21.8+/-4.7 pmol/1) than in LV plasma (33.8+/-7.2 pmol/1), paired t, P less than 0.001. The AII antiserum cross-reacted with three metabolites of the hormone, [des-Asp1]angiotensin II, [des-(Asp1, Arg2)angiotensin II [des-(Asp1, Arg2 Val,3]angiotensin II. To characterize the nature of circulating AII immunoreactive material, paper chromatography was used to separate AII from its immunoreactive metabolites. The results showed that 84-100% of the AII immunoreactive material from both MPA and LV plasma chromatographed with the mobility of authentic angiotensin II. The mean pulmonary conversion of endogenous AI was 33+/-4.8% and the net extraction of AII by peripheral tissues was 33+/-4.1%.     

The future of clinical communication in an electronic environment

Computer technologies, particularly electronic computer networks, can enhance nurses' abilities to initiate, facilitate, and sustain interpersonal contact with patients. Computer networks are electronic links between remote sites and as such provide a pathway for communication between nurses and patients. In an innovative project known as the ComputerLink, a team of nurses used an electronic network to provide information, communication, and decision support to homebound persons and their caregivers. This experiment allowed exploration of the unspoken language of nursing and provides direction for considering how nursing therapeutics can capitalize on the benefits of the electronic network.     

Risk factors for a medically inappropriate admission to a Department of Internal Medicine

OBJECTIVE: To identify patient- and admission-related risk factors for a medically inappropriate admission to a department of internal medicine. METHODS: Cross-sectional study of a systematic sample of 500 admissions to the department of internal medicine of an urban teaching hospital. The appropriateness of each admission and reasons for inappropriate admissions were assessed using the Appropriateness Evaluation Protocol. Risk factors included the time (day of week and holidays) and manner (through emergency department or direct admission) of admission, patient age and sex, health status of patient and spouse, living arrangements, formal home care services, and informal support from family or friends. RESULTS: Overall, 76 (15.2%) hospital admissions were rated as medically inappropriate by the Appropriateness Evaluation Protocol. In multivariate analysis, the likelihood of an inappropriate admission was increased by better physical functioning of the patient (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.1-2.1 [for 1 SD in Physical Functioning scores]), lower mental health status of the patient's spouse (OR, 2.6; 95% CI, 1.3-5.6), receipt of informal help from family or friends (OR, 3.3; 95% CI, 1.5-7.2), and hospitalization by one's physician (OR, 3.6; 95% CI, 1.7-7.5). Receiving formal adult home care was not associated with inappropriateness of hospitalization. CONCLUSIONS: Inappropriate admissions to internal medicine wards are determined by a mix of factors, including the patient's health and social environment. In addition, the private practitioners' discretionary ability to hospitalize their patients directly may also favor medically inappropriate admissions.     

Differential responses of granulosa cells from small and large follicles to follicle stimulating hormone (FSH) during the menstrual cycle and acyclicity: effects of tumour necrosis factor-alpha

This study determined effects of follicle stimulating hormone (FSH) alone and in combination with tumour necrosis factor (TNF), on granulosa cells from small (5-10 mm diameter) and large (>10-25 mm) follicles during follicular and luteal phases of the cycle and during periods of acyclicity. Granulosa cells were collected from ovaries of premenopausal women undergoing oophorectomy. The cells were cultured with human FSH (2 ng/ml) and testosterone (1 microM) in the presence or absence of human TNF-alpha (20 ng/ml). Media were removed at 48 and 96 h after culture and progesterone, oestradiol and cAMP in media were measured by radioimmunoassays. FSH stimulated the accumulation of oestradiol from granulosa cells of small follicles during the follicular and luteal phases but not during acyclicity; and TNF reduced oestradiol accumulation in the presence of FSH. Interestingly, in granulosa cells from small follicles, progesterone and cAMP secretion increased in response to FSH and neither was affected by TNF. Thus, TNF specifically inhibited the conversion of testosterone to oestradiol in granulosa cells from small follicles. FSH stimulated oestradiol production by granulosa cells of large follicles obtained only during the follicular phase of the cycle and TNF inhibited the FSH-induced oestradiol secretion. Granulosa cells obtained from large follicles during the luteal phase and during acyclicity did not accumulate oestradiol in response to FSH. However, FSH increased progesterone and cAMP secretion by granulosa cells obtained from large follicles during the follicular and luteal phases. During the luteal phase alone, TNF in combination with FSH increased progesterone accumulation above that of FSH alone. FSH did not increase progesterone, oestradiol or cAMP secretion by granulosa cells obtained from large follicles during acyclicity. Thus, FSH increases progesterone, oestradiol and cAMP secretion by granulosa cells of small follicles during the follicular and luteal phases and TNF appears to inhibit FSH-induced oestradiol secretion specifically in those cells. In large follicles, FSH-stimulated granulosa cell secretion of oestradiol is limited to the follicular phase and this effect can be inhibited by TNF. In addition, when granulosa cells of large follicles do not increase oestradiol secretion in response to FSH, TNF stimulates progesterone secretion.     

The ability of the rat to metabolize myristoyl-methionine: an acylamino acid with potentially useful antibacterial properties

Two experiments with Sprague Dawley rats tested their ability to hydrolyse myristoyl-methionine (M-M) into myristic acid and L-methionine (M). In the first experiment, lasting for 3 days. male rats were orally administered [9,10-3H]myristoyl-L-[35S]methionine. The recovery of radioactivity was approximately 90% for both isotopes; 19% of the administered 3H was recovered in the urine and 16% in the faeces, while the recovered 35S activity was 13 and 12%, respectively. The balance of the radioactivity was found among the tissues, organs and blood. In the second experiment, male and female rats received soybean-based diets which were supplemented with either 0.305% M-M or 0.2% M (both diets contained equal amounts of M) for periods up to 4 weeks. The growth rate of the rats receiving the 0.305% M-M diets was slightly slower than that for the rats on the 0.2% M diet, but the difference was not statistically significant (P > 0.05). The M-M rats had a transitory decrease in feed consumption, suggesting that palatability may have contributed to the growth difference and that a somewhat greater amount of M-M was necessary for the rat to attain the same growth rate as that produced by 0.2% M. When the amount of dietary M-M was increased to 3.05% M-M, a greater reduction in feed consumption and body weight gain was observed. This latter diet was an initial attempt to study the potential toxicity of M-M. None of the haematological, clinical chemistry or organ weight data suggested that M-M was overtly toxic per se, but longer-term feeding studies are needed to evaluate the potential toxicity of M-M more fully.     

Longitudinal changes in lung function associated with aspects of swine-confinement exposure

Several aspects of swine-confinement farming appear to be leading to adverse respiratory effects. This study was set up in a longitudinal design to study the association between certain characteristics of farms or the way they are run and a decline in lung function. A cohort of 171 pig farmers was observed for 3 years. Lung function was measured. Exposure to farm characteristics was determined at the start of the observation period, using data from standardized farm surveys and from diaries kept by the participants. Mean decline in lung function was 73 mL/year for forced expiratory volume in 1 second (FEV1) and 55 mL/year for forced vital capacity (FVC). A longitudinal decline in FEV1 was significantly associated with the use of quaternary ammonium compounds as disinfectants (an additional 43 mL/year) and also with the use of an automated dry feeding system (an additional 28 mL/year). The association with the use of wood shavings as bedding material was not statistically significant. The impact of these characteristics in a longitudinal study provides stronger evidence for causal inference than that shown in previous cross-sectional designs. This may be useful in promoting preventive measures.