Assessment of proximal tubular sodium reabsorption during water diuresis in patients with heart disease

In order to examine the relation between cardiac state and the capacity to excrete a water load, 10 normal subjects and 61 patients with heart disease were studied during water diuresis. Under these conditions, urine flow approximates to the rate of delivery of filtrate, and therefore of sodium, from the proximal tubule of the kidney to the loop of Henle, while free water clearance is a function of distal sodium reabsorption. In 12 patients with complete heart block, ventricular pacing was associated with increased urine flow and free water clearance. Oral propranolol in 3 normal subjects and in 9 patients with intact atrial septa caused a reduction, and oral practolol in 4 normal subjects and 8 patients caused no change. In 6 patients with atrial septal defect, propranolol was without effect. Maximum urine flow correlated with left ventricular end-diastolic pressure but not mean left atrial pressure in 16 patients with chronic rheumatic heart disease. In 7 patients with ischaemic heart disease, maximum urine flow was higher than in those with chronic rheumatic heart disease and similar increase in left ventricular end-diastolic pressure. These results reflect a close relation between proximal tubular sodium reabsorption and cardiac state, and suggest that inappropriate sodium reabsorption at this site may contribute to fluid retention in heart disease.     

A critical investigation into the antibiotic sterilization of heart valve homografts

Waterworth, Pamela M., Lockey, Eunice, Berry, E. M., and Pearce, Helen M. (1974).Thorax, 29, 432-436. A critical investigation into the antibiotic sterilization of heart valve homografts. Sterility tests of homograft heart valves sterilized by antibiotics were found to be invalidated by carry-over of the antibiotics. A method was devised to test the efficacy of different antibiotic mixtures using membrane filters. Fifty-five organisms, including 13 species, were tested, and sterility was achieved with only 35.     

Disodium octaborate tetrahydrate (DOT) application and vacuum cleaning,a combined strategy to control house dust mites

BACKGROUND: The effectiveness of acaricides in homes is controversial. OBJECTIVE: To determine whether disodium octaborate tetrahydrate (DOT) combined with vacuuming lowers dust mite numbers and their allergens in carpets and sofas. METHODS: A 6-month study was carried out with 93 homes, which were randomized into three groups: (i). active, received DOT; (ii). placebo, received water; and (iii). control, received no application. Active and placebo homes were vacuumed weekly. Dust was collected from carpets and sofas at the start of the study and every 2 months thereafter and quantified for live, total mites, and mite allergen levels. RESULTS: At 2 months, live mite numbers in active carpets were 3 +/- 1, in placebo carpets 129 +/- 48, and in control carpets 177 +/- 39 mites/g. The corresponding numbers in sofas were 3 +/- 2, 81 +/- 31, and 134 +/- 45 mites/g, respectively (P < 0.001 active vs placebo and vs. control). Live mites in carpets and sofas remained lower in the active group at 6 months (P < 0.001). Total mites in active carpets decreased from 555 +/- 69 at baseline to 223 +/- 32 mites/g at 6 months (P < 0.001) and mite allergen levels from 1.36 +/- 0.13 to 0.85 +/- 0.16 microg/g (P < 0.001). Total mites in active sofas remained unchanged, but mite allergen levels decreased from 1.48 +/- 0.25 at baseline to 0.7 +/- 0.15 microg/g at month 6 (P < 0.05). CONCLUSION: DOT kills mites in carpets and sofas, and, combined with vacuuming, effectively reduces total mites in carpets and mite allergen levels in carpets and sofas.     

Inequalities in health care provision: the relationship between contemporary policy and contemporary practice in maternity services in England

AIM: The project Addressing Inequalities in Health: new directions in midwifery education and practice (Hart et al. 2001) was commissioned by the English National Board for Nursing, Midwifery and Health Visiting (ENB). Here, we draw on those research findings to consider current midwifery policy and practice in England. BACKGROUND: Little guidance on providing equality of care exists for midwives. The Code of Conduct [United Kingdom Central Council for Nursing, Midwifery and Health Visiting (UKCC) 1992] makes no specific requirement for midwives to address issues of inequalities of health in their practice. Recent policy documents emphasize the need to work towards reducing inequalities and to target practice to 'disadvantaged clients' without giving guidelines on how to identify and care for target groups. METHODS: In-depth studies of midwifery education and service provision were conducted in three very different parts of England. Three months of fieldwork were undertaken at each site, comprising a series of interviews with midwifery educators, managers, students, midwives and service users. Focus groups were also held and observation of classroom sessions and midwifery practice undertaken. Findings. A lack of clear and specific strategies concerning inequalities in health was evident at managerial level. Patchy knowledge of current policy was also evident amongst practising midwives. Specific projects with disadvantaged clients usually resulted from a particular midwife's personal interest or evident local need. All midwives emphasized the importance of 'equality of care'. How this was operationalized varied, and 'individualized' or 'woman-centred' care was assumed to encompass the concept. In the few examples where care was systematically targeted in accordance with policy directives, the midwife's public health role was increased. CONCLUSION: In the absence of a co-ordinated strategic vision driven by managers, practitioners find difficulty in prioritizing care and targeting resources to disadvantaged clients in line with policy directives. Tensions between policy and practice in the care of 'disadvantaged' women clearly exist. Successful implementation of policy at practice level needs: commitment from managers; clarity of purpose in documentation; and provision of specific targets for practitioners. However, the latter should remain flexible enough for the delivery of care to be appropriate and sensitive to individual needs.     

Atrial natriuretic peptide gene transfer by means of intranasal administration attenuates airway reactivity in a mouse model of allergic sensitization

Atrial natriuretic peptide (ANP) is a bronchodilator; however, the short half-life of ANP in vivo limited its therapeutic utility to treat asthma. The efficacy of intranasally administered plasmid DNA-expressing ANP (pANP; amino acid 99-126; Acc. No. XM131840) on the prevention of allergen-induced airway hyperresponsiveness (AHR) was examined in this study by using a mouse model of asthma. Ovalbumin-sensitized mice were treated with pANP versus control plasmids, and AHR was monitored after ovalbumin challenge for 5 weeks on 10-day intervals starting 4 days after gene transfer. Mice administered pANP demonstrated significantly less AHR for 20 days after treatment. The results demonstrate that pANP gene transfer protects against AHR and might be useful in the treatment of asthma.