Exercise increases the release of atrial natriuretic peptide in heart transplant recipients

Summary It is known that atrial natriuretic peptide (ANP) is synthesized, stored and released from the myocytes of mammalian heart, but the role of cardiac autonomic nerves in triggering the release of ANP has not been fully assessed. We have therefore measured plasma ANP concentrations in the right atrium and the main pulmonary artery, together with pulmonary haemodynamics in 10 heart transplant (HT) recipients who underwent graded submaximal bicycle exercise during right-heart catheterisation.Pulmonary arterial blood samples and haemodynamic measurements were obtained at rest, on peak of exercise, and after ten minutes of recovery. A radioreceptor of -human ANP was used to measure ANP levels. Exercise significantly incresed ANP levels in both the right atrium from 24 pM (resting values) to 48.5 pM, and the main pulmonary artery from 27.1 pM (resting values) to 58.4 pM.We conclude that HT recipients still retain the ability to increase ANP release in response to graded submaximal dynamic exercise, and that the mechanisms underlying ANP release depend on other factors than the integrity of cardiac innervation in man.     

Faecal composition after surgery for Hirschsprung's disease

Diarrhoea and perianal excoriation occur frequently after the endorectal pull-through operation for Hirschsprung's disease. A new method of faecal analysis was performed on 3-day stool collections in 17 postoperative Hirschsprung patients and in 14 normal children, in order to define the faecal abnormality and to establish the cause of perianal excoriation in these patients. Loose stools in postoperative patients were deficient in dry solid content and contained an excess of extractable faecal water. This also had a raised electrolyte concentration, particularly with respect to sodium. Total daily output of faecal water was normal. Formed stools from postoperative patients were also deficient in drysolids but had a normal extractable water content. Excess extractable faecal water, the main abnormality of loose stools in these patients, is the result of abnormal water absorption from the distal colon. Perianal excoriation in these patients is most closely associated with the concentration of sodium in faecal water.     

Rupture of the spleen in erythroblastosis fetalis.

A male infant of 36 weeks' gestation, weighing 3080 g, with erythroblastosis, ruptured spleen, and bilateral suprarenal haemorrhages is described. The infant survived after exchange transfusions and splenectomy.     

Evidence-based policy: rhetoric and reality

Evidence-based policy has been hailed as the current zeitgeist in health care. Its intuitive appeal is clear but its implementation is problematic. This case study demonstrates the practical difficulties of using this approach for purchasing health care. New technologies suffer from limited knowledge about both their long-term benefits and their adverse effects. This undermines attempts to assess effectiveness and efficiency in local populations. Furthermore, the use of evidence should not be assumed to eliminate the need to apply value judgements, which has repercussions for the attainment of equity of access to health care. It is therefore unrealistic to view this approach as a panacea. Rather, evidence-based medicine should contribute to the decision-making process, in conjunction with other considerations such as equity and patient preference.     

Prenatal diagnosis of an intra-abdominal sacrococcygeal teratoma

The prenatal diagnosis of a presacral (type IV) sacrococcygeal teratoma (SCT) is described. The initial ultrasound appearance was suggestive of a lower urinary tract obstruction, but further ultrasonic examination and radiological imaging using contrast medium led to the diagnosis of SCT. This is the first prenatal diagnosis of a totally intra-abdominal SCT.     

Does gender bias exist in the use of specialist health care?

OBJECTIVES: To investigate the evidence for the existence of gender bias (defined as care provided independently of clinical need) in the use of specialist services by critically appraising the literature. METHODS: A computer-assisted search of the bibliographic databases PubMed, Medline, EMBASE, Healthstar and Social Science Citation Index for English language papers published from 1966 until May 1999. In addition, four journals were handsearched and the reference lists of identified papers were explored. Retrospective studies were only used when there were insufficient prospective studies. RESULTS: One hundred and thirty-eight studies were identified covering five major topics: coronary artery disease; renal transplantation; human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS); mental illness; and other (mainly invasive) procedures. The majority (94) examined coronary artery disease. It appears that men are more likely to undergo non-invasive investigations than women, but that subsequent investigation and treatment shows no clear evidence of gender differences. Men are more likely to undergo renal transplantation and, for those with HIV and AIDS, to receive azidothymidine (zidovudine, AZT) than women. There are some indications that disparities in favour of men also occur for those suffering from cardiac arrhythmias and cerebrovascular disease, and for those undergoing vascular surgery, hip replacement and heart transplantation. In contrast, women are more likely to undergo liver transplantation and cataract surgery. Mental health services may be provided differently for men and women. All these findings are limited by a lack of accurate denominator information and insufficient ability to adjust for prognostic factors. CONCLUSIONS: Differences in health care use can be due to demand factors (e.g. differences in the prevalence and severity of disease or in patient preferences), supply factors (particularly clinical judgement), or both. There is a need to examine these explanations thoroughly for gender inequalities in order to ensure that equity (lack of bias) is achieved. There is also a need for higher quality studies if differences are to be attributed conclusively to bias or not.     

Salmonella typhimurium infection halts development of type 1 diabetes in NOD mice

Infectious disease has been proposed as an environmental modifier of autoimmunity in both human populations and the NOD mouse. We found that infection of NOD mice with attenuated, but not killed, Salmonella typhimurium can reduce the incidence of type 1 diabetes (T1D), even if infection occurs after the development of a peri-islet pancreatic infiltrate. Functional diabetogenic effector T cells are still present, as demonstrated by the initiation of diabetes in NOD-scid recipients of transferred splenocytes. High levels of IFN-gamma are secreted by splenocytes of infected mice, but there is no evidence of involvement of IL-10 in the protective effect of the infection. Finally, prolonged changes in cell subsets are observed in infected mice involving invariant Valpha14Jalpha281 NuKappaTau and dendritic cells. These data reinforce the idea that prevention of T1D in the NOD mouse cannot be reduced to the simple Th1/Th2 paradigm and that different infections may involve different protective mechanisms.     

Experimental allergic neuritis. Ultrastructure of serum-induced myelin aberrations in peripheral nervous system cultures.

Mature myelinated cultures of mouse dorsal root ganglia (sometimes grown in combination with spinal cord tissue) have been exposed to unheated and heated (complement-inactivated) serum from rabbits with experimental allergic neuritis (EAN). Experimental cultures were examined for periods ranging from several hours to approximately 2 weeks of exposure. Some cultures were exposed to EAN serum for approximately 1 week then returned to normal medium for examination of the reversibility of the lesions. Unheated EAN serum induced demyelination of peripheral nervous system fibers within 96 hours of exposure. Following removal of the EAN serum, affected fibers remyelinated. Heated EAN serum produced a type of myelin swelling identical with that described previously in spinal cord explants exposed to serum from rabbits with experimental allergic encephalomyelitis. The lamellar spacing of the peripheral nervous system meylin was increased to approximately 23 nm. and the normal bifilar intraperiod line was increased to four leaflets. Some hypermyelination was seen. The swelling was incompletely reversible following removal of the heated serum. These findings are discussed in terms of their relevance to immunemediated demyelination and peripheral neuropathy associated with the hypergammaglobulinemic states.     

A Qualitative Study of Women’s Experiences of Communication in Antenatal Care: Identifying Areas for Action

To identify key features of communication across antenatal (prenatal) care that are evaluated positively or negatively by service users. Focus groups and semi-structured interviews were used to explore communication experiences of thirty pregnant women from diverse social and ethnic backgrounds affiliated to a large London hospital. Data were analysed using thematic analysis. Women reported a wide diversity of experiences. From the users’ perspective, constructive communication on the part of health care providers was characterised by an empathic conversational style, openness to questions, allowing sufficient time to talk through any concerns, and pro-active contact by providers (e.g. text message appointment reminders). These features created reassurance, facilitated information exchange, improved appointment attendance and fostered tolerance in stressful situations. Salient features of poor communication were a lack of information provision, especially about the overall arrangement and the purpose of antenatal care, insufficient discussion about possible problems with the pregnancy and discourteous styles of interaction. Poor communication led some women to become assertive to address their needs; others became reluctant to actively engage with providers. General Practitioners need to be better integrated into antenatal care, more information should be provided about the pattern and purpose of the care women receive during pregnancy, and new technologies should be used to facilitate interactions between women and their healthcare providers. Providers require communications training to encourage empathic interactions that promote constructive provider–user relationships and encourage women to engage effectively and access the care they need.