Immediate response of 5-methoxytryptophol in the circulation to hypoglycaemic stress induced by insulin.

Pineal indoles have been shown to affect the release of anterior pituitary hormones but details of the interrelationships are lacking. Using a new gas chromatography-mass spectrometry (g.c.-m.s.) assay the concentration of 5-methoxytryptophol (ML) was measured in plasma samples obtained from 16 children undergoing investigation of pituitary function for delayed growth. All the children received an insulin tolerance test (ITT) to study their endocrine response to stress. Some children received luteinizing hormone releasing hormone (LH-RH) and/or thyrotrophin releasing hormone (TRH). The change in concentration of ML during an ITT was similar to the change in concentration of blood sugar; a drop at 20 min followed by a rise at 30 min. This was not significantly altered by the administration of LH-RH or TRH, nor was there a different pattern of response in children who were deficient in growth hormone as opposed to those with idiopathic delayed growth. The fall in concentration of ML with stress may mediate the increased secretion of pituitary hormones. Alternatively, the pineal gland may respond directly to insulin.     

Histochemical demonstration of desialation and desulphation of normal and inflammatory bowel disease rectal mucus by faecal extracts.

Experiments were carried out to assess the susceptibility of normal and inflammatory bowel disease rectal mucus to desulphation and desialation by faecal extracts and by bacterial sialidase. The effects were assessed histochemically using a combined high iron diamine (HID) and alcian blue (AB) stain for sulphomucins and sialomucins. Rectal mucus in biopsies from controls (irritable bowel syndrome) and patients with ulcerative colitis or Crohn's disease was resistant to desialation by Clostridium perfringens sialidase, but susceptible to desialation and desulphation by bacteria-free extracts of normal faeces. Periodic acid-Schiff (PAS) staining of adjacent sections similarly treated showed retention of neutral mucus. One faecal extract selectively desulphated all 42 biopsies, causing the goblet cells to change from HID positive to AB positive, suggesting that most, or all HID positive cells also contain sialomucins. This alters the interpretation of previous histochemical studies. Faecal extracts from patients with active ulcerative colitis (n = 6) had desialating and desulphating effects similar to faecal extracts from normal subjects (n = 6). Ulcerative colitis (n = 21), Crohn's disease (n = 18), and control (irritable bowel syndrome) (n = 17) rectal biopsies all showed similar susceptibility to desulphation by a pooled normal faecal extract, but rectal biopsies from patients with Crohn's disease proved more resistant to desialation than control or ulcerative colitis biopsies (p less than 0.02). These studies imply that colonic mucus undergoes continual desulphation and desialation in vivo as a result of faecal enzyme activity that is probably mainly of bacterial origin. Altered susceptibility of colonic mucus to this may be important in the pathogenesis of colonic disease.     

Dual endothelin‐1 receptor antagonism attenuates platelet‐mediated derangements of blood coagulation in Eisenmenger syndrome

Essentials

• Eisenmenger syndrome is characterised by thrombotic and hemorrhagic risks of unclear aetiology.
• Calibrated automated thrombography was used to assess these coagulation derangements.
• Platelet activity supported abnormalities in procoagulant and anticoagulant pathway function.
• Endothelin‐1 antagonism appeared to ameliorate these derangements.

Summary

Aims

The mechanisms underlying the competing thrombotic and hemorrhagic risks in Eisenmenger syndrome are poorly understood. We aimed to characterize derangements of blood coagulation and to assess the effect of dual endothelin‐1 receptor antagonism in modulating hemostasis in this rare disorder.

Methods

In a 10‐month recruitment period at a tertiary cardiology referral center, during which time there were over 14 000 outpatient consultations, consecutive subjects with Eisenmenger syndrome being considered for macitentan therapy (n = 9) and healthy volunteers (n = 9) were recruited. Plasma thrombin generation in platelet‐rich and platelet‐poor plasma was assessed by calibrated automated thrombography prior to and following therapy.

Results

Median peak plasma thrombin generation was higher in platelet‐rich plasma obtained from Eisenmenger syndrome subjects relative to controls (median peak thrombin [25th–75th percentile]: 228.3 [206.5–258.6] nm vs. 169.9 [164.3–215.8] nm ), suggesting a critical mechanistic role for platelets in supporting abnormal hypercoagulability in Eisenmenger syndrome. Abnormal enhanced sensitivity to the anticoagulant activity of activated protein C was also observed in platelet‐rich plasma in Eisenmenger syndrome, suggesting that derangements of platelet activity may influence the activity of anticoagulant pathways in a manner that might promote bleeding in this disease state. Following 6 months of macitentan therapy, attenuations in the derangements in both procoagulant and anticoagulant pathways were observed.

Conclusions

Abnormal platelet activity contributes to derangements in procoagulant and anticoagulant pathways in Eisenmenger syndrome. Therapies targeting the underlying vascular pathology appear to ameliorate these derangements and may represent a novel strategy for the management of the competing prothrombotic and hemorrhagic tendencies in this disorder.

     

Mechanism of complement activation after coronary artery occlusion: evidence that myocardial ischemia in dogs causes release of constituents of myocardial subcellular origin that complex with human C1q in vivo

To evaluate whether ischemic myocardium releases molecules that react with the first component of complement, we studied cardiac lymph from eight dogs before and at intervals after coronary artery occlusion and reperfusion. Before occlusion, the dogs were injected intravenously with radiolabeled human C1q. Labeled C1q could be detected in the cardiac lymph within minutes following injection. Rabbit antisera, prepared against substances precipitated from postreprefusion cardiac lymph by anti-human C1q, also reacted with specific constituents of isolated cardiac sarcoplasmic reticulum and mitochondria. To evaluate whether mitochondria are the source of these C1q-binding proteins, we isolated intramyofibrillar and subsarcolemmal mitochondria from canine heart and incubated sonicates of these with purified C1q, immobilized on nitrocellulose. Molecules bound to the immobilized C1q were removed with 0.1% sodium dodecyl sulfate, fractionated under reducing conditions by polyacrylamide gel electrophoresis, and transferred electrophoretically to nitrocellulose paper. Antisera prepared against postreperfusion lymph reacted with a 31,000-32,000-dalton protein in these nitrocellulose paper replicas. Since this protein originates from mitochondria, binds to C1q, and is recognized by antibodies made against postreperfusion lymph, this protein is likely to be one of the subcellular constituents that, upon release from ischemic cells, activates the complement cascade. To evaluate the clinical relevance of these observations, we tested sera from 53 patients obtained 48-72 hours after hospitalization for suspected myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sexually transmitted infections and use of sexual health services among young Australian women: women's health Australia study

Our objective was to examine associations between self-reported sexually transmitted infections (STIs) and sociodemographic, lifestyle, health status, health service use and quality of life factors among young Australian women; and their use of family planning and sexual health clinics and associations with health, demographic and psychosocial factors. The study sample comprised 14,762 women aged 18-23 years who participated in the mailed baseline survey for the Australian Longitudinal Study on Women's Health, conducted in 1996. The main outcome measures are self report of ever being diagnosed by a doctor with an STI, including chlamydia, genital herpes, genital warts or other STIs, and use of family planning and sexual health clinics. The self-reported incidence of STI was 1.7% for chlamydia, 1.1% genital herpes, 3.1% genital warts, and 2.1% other STIs. There was a large number of demographic, health behaviour, psychosocial and health service use factors significantly and independently associated with reports of having had each STI. Factors independently associated with use of family planning clinic included unemployment, current smoking, having had a Pap smear less than 2 years ago, not having ancillary health insurance, having consulted a hospital doctor and having higher stress and life events score. Factors independently associated with use of a sexual health clinic included younger age, lower occupation status, being a current or ex-smoker, being a binge drinker, having had a Pap smear, having consulted a hospital doctor, having poorer mental health and having higher life events score. This study reports interesting correlates of having an STI among young Australian women aged 18-23. The longitudinal nature of this study provides the opportunity to explore the long-term health and gynaecological outcomes of having STIs during young adulthood.     

Diabetes mellitus: subclinical cardiovascular disease and risk of incident cardiovascular disease and all-cause mortality

Previously diagnosed diabetes mellitus, newly diagnosed diabetes mellitus, and impaired glucose tolerance are important determinants of the risk of clinical cardiovascular disease (CVD). We have evaluated the relation of patients with subclinical CVD, diabetes, and impaired glucose tolerance and "normal" subjects and the risk of clinical CVD in the Cardiovascular Health Study. Diabetes (1343), impaired glucose tolerance (1433), and normal (2421) were defined by World Health Organization criteria at baseline in 1989 to 1990. The average follow-up was 6.4 years (mean age 73 years). Diabetics had a higher prevalence of clinical and subclinical CVD at baseline. Compared with diabetes in the absence of subclinical disease, the presence of subclinical CVD and diabetes was associated with significant increased adjusted relative risk of death (1.5, CI 0.93 to 2.41), relative risk of incident coronary heart disease (1.99, CI 1.25 to 3.19), and incident myocardial infarction (1.93, CI 0.96 to 3.91). The risk of clinical events was greater for participants with a history of diabetes compared with newly diagnosed diabetics at baseline. Compared with nondiabetic nonhypertensive subjects without subclinical disease, patients with a combination of diabetes, hypertension, and subclinical disease had a 12-fold increased risk of stroke. Fasting blood glucose levels were a weak predictor of incident coronary heart disease as were most other risk factors. Subclinical CVD was the primary determinant of clinical CVD among diabetics in the Cardiovascular Health Study.     

Between and within subject variation of the first phase insulin response to intravenous glucose

Summary Eight normal subjects underwent two intravenous glucose tolerance tests to determine the between and within subject variation of the first phase insulin response. Variability was represented by the coefficient of variation. The between subject variation for the incremental 0–10 min insulin area was 58%, and the within subject variation was 22% (median value), range 3–55%. The variation of the first phase response expressed in four different ways was compared. The total and incremental (above fasting levels) 0–10 min areas provided less variable results (variation 52 and 58%) than the 1+3 min insulin levels (variation 72%) or mean of the incremental 3–5 min insulin levels (variation 66%). The ratio of the incremental 0–10 min insulin to glucose areas was as variable (variation 53%) as the insulin responses alone. The variability of insulin responses to intravenous glucose severely limits their value as early predictors of B-cell failure.