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Biomedical subjects

H Englert

Publications and source records attributed to H Englert.

At least 19 recordsLinked to original sources

Effects of K(ATP) channel modulators on acetylcholine release from guinea-pig isolated atria and small intestine.

The effects of K(ATP) channel blockers (glibenclamide, HMR 1883, HMR 1372) and openers (cromakalim, pinacidil, diazoxide) on the electrically-evoked (5 Hz) release of [(3)H]acetylcholine were studied in isolated guinea-pig atria and myenteric plexus-longitudinal muscle preparations which had been preincubated with [(3)H]choline. Atria: Cromakalim (0.3 microM and 1 microM), pinacidil (10 microM) and diazoxide (30 microM) significantly reduced the stimulation-evoked release of [(3)H]acetylcholine. The inhibition produced by cromakalim and pinacidil was prevented by 1 microM of either HMR 1883, HMR 1372 or glibenclamide. The blockers alone significantly increased the release at concentrations of 30 microM, whereas 1 microM and 10 microM had no effect. Myenteric plexus-longitudinal muscle preparation: The electrically-evoked release of [(3)H]acetylcholine was not affected by K(ATP) channel blockers or openers. In contrast, the contractions of the longitudinal muscle caused by electrical stimulation or by carbachol were strongly inhibited by 1 microM cromakalim which suggests that the relaxant effect of the K(ATP) channel openers is exclusively a direct effect on intestinal smooth muscle. The findings suggest that blockade of activated K(ATP) channels in vagal nerves of guinea-pig atria stimulates acetylcholine release, and that this effect may contribute to the antiarrhythmic actions of K(ATP) channel blockers. By contrast, release of acetylcholine from guinea-pig myenteric plexus is not modulated by K(ATP) channels which suggests heterogeneity of K(ATP) channel distribution in peripheral autonomic nerves.

Acetylcholine↗

Women's health after plastic surgery.

BACKGROUND: Allegations that exposure to endogenous silicone, especially related to breast implants, might be causally related to connective tissue disease originated from case studies. More recent comparative studies have implied no such increased risk. The aims of the present study were to compare the prevalence and/or incidence of autoimmune and connective tissue disorders in a population-based cohort of female Sydney residents stratified by augmentation mammoplasty status. METHODS: In this population-based retrospective cohort study, the health status of female Sydney residents who had augmentation mammoplasty for cosmetic reasons between 1979 and 1983 was compared with that of female Sydney residents who had non-silicone-associated plastic surgery over the same period. Both groups were matched for age (+/- 5 years), year of plastic surgery (+/- 2 years), plastic surgeon, anaesthetist and mode of anaesthesia. Outcome measures comprised rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, sicca symptoms polymyositis/ dermatomyositis, connective tissue disease overlap, digital vasospasm, abnormal nailfold capillaroscopy, elevated antinuclear antibody titre, carpal tunnel syndrome, tendonitis, osteoarthritis, psoriatic arthritis, livedo reticularis, thyroid disease, multiple sclerosis, axillary lymphadenopathy, fibromyalgia and breast carcinoma. RESULTS: There was no difference in the occurrence of connective tissue diseases or connective tissue disease-related parameters, thyroid disorders, fibromyalgia or multiple sclerosis between cohorts. However, axillary adenopathy and low titre positive antinuclear antibody (ANA) occurred with a significantly greater frequency in the exposed cohort (odds ratio (OR) = 3.50, 95% confidence interval (CI) = 2.10-5.84 and OR = 1.29, 95% CI = 1.03-1.62, respectively). Axillary adenopathy correlated with capsular contracture (relative risk (RR) = 2.07, 95% CI = 1.22-3.51) and also the self-reported development of digital vasospasm (RR = 3.20, 95% CI = 1.46-7.03) after breast augmentation. CONCLUSIONS: No association was found between augmentation mammoplasty exposure and various connective tissue diseases and/or their related features. However, axillary adenopathy and low titre ANA were detected more frequently in the exposed cohort. Women with axillary adenopathy were more likely to have breast capsular contracture and report digital vasospasm post-dating surgery. Given comparable frequencies of higher titre ANA of both cohorts, the finding of elevations of low titre ANA is of dubious clinical significance.

Adult↗

Male systemic sclerosis and occupational silica exposure-a population-based study.

BACKGROUND: The continuing uncertainty about the silica-systemic sclerosis relationship led to the investigation of its role as a disease determinant in a large population-based study of systemic sclerosis. AIMS: To compare the frequency, socioeconomic and educational status, age-specific prevalence and duration of occupational silica exposure in males with and without systemic sclerosis. To assess the temporal relationship between exposure and disease onset. To estimate disease latency. To compare disease characteristics between silica-exposed and non-silica-exposed male cases. METHODS: The study was case-control in design. The exposure variable was occupational silica exposure as assessed by an occupational health officer blinded to case/control status and the outcome variable was systemic sclerosis. The employed instrument comprised either a standardised telephone questionnaire (interviewed cases and controls) or medical records (deceased or living-status-unknown cases). RESULTS: Sixty of 160 cases (37.5%) and 11 of 83 (13.3%) controls had occupational silica exposure (OR=3.93; 1.84-8.54). Comparison of data between 64 interviewed cases and all controls demonstrated initial occupational silica exposure occurring before age 40, comparable educational status but significantly different cumulative socioeconomic status with cases being over-represented in semi-skilled and unskilled occupations. Cross-sectional 'current' occupational data underestimated cumulative silica exposure by more than 50%. Silica exposure uniformly preceded onset of second disease symptoms and disease diagnosis. In most, it also preceded onset of first disease symptoms. Disease latency approximated two decades. No disease features distinguished silica-associated systemic sclerosis from idiopathic systemic sclerosis. The duration of silica exposure in the interviewed silica-exposed cases did not significantly exceed that of silica-exposed controls. CONCLUSIONS: Male systemic sclerosis displays socioeconomic dependence. Silica is a disease determinant in male systemic sclerosis, with disease features including a long latency and clinical characteristics indistinguishable from idiopathic disease. Cross-sectional 'current' occupational data underestimate cumulative occupational silica exposure.

Adolescent↗

Familial risk estimation in systemic sclerosis.

BACKGROUND: Familial systemic sclerosis has been rarely reported. Assumptions have therefore been made implying no familial disease aggregation. This study critically challenges the assumption using a methodical population-based epidemiological approach to quantify the prevalence and characteristics of familial systemic sclerosis. METHODS: In this retrospective cohort study the systemic sclerosis prevalence in first degree family members was compared between 715 systemic sclerosis patients (710 families) and 371 randomly ascertained age and gender group-matched general practice controls (371 families). These data, obtained by telephone questionnaire (living patients) or medical records review (deceased patients and untraceable patients of unknown living status), were validated, where necessary, and expressed in terms of relative risk, absolute risk and population point prevalence. RESULTS: Systemic sclerosis affecting first degree members was validated in ten of 710 families. Reporting of systemic disease in another four more distant family members, and the co-occurrence of systemic and localised disease in three families was also documented. Observed and expected disease subtype concordance was 80% (44-97%) and 68% respectively and the female predominance among familial cases was similar to that for non-familial disease. The risk of disease in a subsequent first degree relative was compared to the risk in an initial first degree family member. Its estimated magnitude was wide (11-158). However, use of population prevalence data to determine the expected number of systemic sclerosis patients in the negative cohorts' families suggests the higher estimate is more realistic. Despite the high magnitude, the absolute disease risk in first degree family members remained low--approximating 1%. The population prevalence of familial systemic sclerosis approximated 1.4/million. CONCLUSIONS: This study substantially increases the otherwise small list of documented instances of familial systemic sclerosis. More importantly, it quantifies the risk for the first time, ranking it as the disease's most powerful determinant identified to date.

Cohort Studies↗

Systemic sclerosis prevalence and mortality in Sydney 1974-88.

BACKGROUND: Systemic sclerosis prevalence and mortality estimates have demonstrated wide variability. The sole Australian study published to date demonstrated high prevalence rates when compared to overseas estimates. The prevalence and mortality findings reported in this paper derive from a larger study which addressed the distribution and determinants of systemic sclerosis within Sydney. AIMS: To determine systemic sclerosis prevalence and mortality rates within Sydney over 15 years, 1974-88. METHODS: Cases were ascertained from multiple sources including death certificates, hospitals, physicians, vascular surgeons' and dermatologists' private practices, a systemic sclerosis self-help group and private medical laboratories. RESULTS: Overall, 715 cases were identified. Females comprised 77% (95% CI: 74-80) of cases. Disease of the limited subtype accounted for 79% (95% CI: 76-82) of all systemic sclerosis, being relatively more frequent in living than deceased cases, and in females than males. Crude prevalence estimates appeared to rise between 1975 (4.52/100,000 95% CI:3.75-5.29/100,000) and 1988 (8.62/100,000 95% CI:7.64-9.60/100,000) as did estimates of diffuse disease. However, diffuse disease prevalence, when expressed as a proportion of total disease prevalence, showed no significant temporal change. Although crude mortality rates also showed apparent temporal increases (0.24/100,000 in 1975 to 0.80/100,000 in 1988) standardised mortality rates showed less convincing trends (0.41/100,000 in 1976 and 0.40/100,000 in 1988). Death certificate-derived mortality rates provided relatively large underestimates of total mortality. However, these underestimates were relatively constant over time. CONCLUSIONS: This study has demonstrated systemic sclerosis prevalence and mortality rates comparable to overseas estimates, consistently higher prevalence and mortality rates in females than males, proportionally higher rates of diffuse disease in males than females and in deceased cases than living cases, a diffuse: limited disease ratio apparently stable over time, apparently increasing temporal prevalence and mortality rates and, by implication, rising incidence rates. The observed temporal rise in diffuse disease prevalence and the absence of a convincing fall in diffuse disease mortality suggests a rising temporal incidence rate of diffuse disease. Standardised mortality rates demonstrated less consistent trends than did crude mortality rates and failed to demonstrate convincing declines in mortality subsequent to the introduction of ACE inhibitors for management of systemic sclerosis renal disease. Death certificate-derived systemic sclerosis mortality rates considerably and consistently underestimated systemic sclerosis-all cause mortality.

Data Collection↗

Distribution of macrovascular disease in scleroderma.

OBJECTIVE: Macrovascular disease in scleroderma has recently been described in two comparative studies. The aim of this study was to map its anatomical distribution. METHODS: In a retrospective cohort study of 20 scleroderma patients, the results of Doppler studies of arteries in the limbs, neck, and abdomen were compared with those from 20 cohort negative patients. The latter were matched for age, sex, and the presence/absence of hypertension, hyperlipidaemia, smoking, and diabetes status. Arteries were compared quantitatively using a body surface area adjusted measurement of intraluminal diameter, and qualitatively using descriptive characteristics of the arterial walls. The latter were binomially categorised under three non-exclusive headings--thickening, stenosis, and calcification. RESULTS: The ulnar arteries in scleroderma patients were significantly narrower than those of the negative cohort. The arterial walls were also characterised by smooth thickening along their entire length. The characteristics of the other arteries, including those of the lower limbs, were not significantly different from those of the negative cohort. CONCLUSION: The ulnar artery seems to be specifically targeted in patients with scleroderma. Assessment of the ulnar artery should be considered in these patients by means of a modified Allen's test or Doppler sonography especially in the presence of digital gangrene.

Aged↗

Systemic sclerosis in DRw52-positive silica-exposed males: a case report.

The aims of this paper were to describe clinical and laboratory details of 4 siblings, of whom 2 have systemic sclerosis and to describe this family in the context of reported cases of familial systemic sclerosis. The proband and his affected male sibling share the tissue typing antigens: HLA11, B57, DR13, DRw52,- and DQ2,6. Both were concordant for gender, silica exposure, marital status, migration history and antinuclear factor status but discordant for systemic sclerosis subtype, age at disease onset and ENA status. One non-affected sibling had no disease despite concordance for gender, HLA status, silica exposure, marital status, and migration history.

Age Factors↗

Simultaneous recording of ATP-sensitive K+ current and intracellular Ca2+ in anoxic rat ventricular myocytes. Effects of glibenclamide.

We investigated the temporal relationship between the adenosine triphosphate-sensitive K current (KATP current), hypoxic shortening and Ca accumulation in cardiomyocytes exposed to anoxia or metabolic inhibition. Whole-cell, patch-clamp experiments were performed with nonstimulated isolated rat heart ventricular muscle cells loaded with the Ca-sensitive fluorescent dye 1-[2-(5-carboxyoxazol-2-yl)-6-aminobenzofuran-5-oxy]-2-(2'- amino-5'-methylphenoxy) ethane-N,N,N',N'-tetraacetic acid (fura-2) via the patch pipette. After approximately 8 min anoxia, the KATP current started to rise and reached a maximum of 21.3 +/- 3.7 nA (n = 5, recorded at 0 mV clamp potential) within 1-3 min. At that time hypoxic contracture also occurred. Resting cytoplasmic free calcium (Cai) did not change significantly before hypoxic shortening. After hypoxic contracture, the KATP current decreased and Cai started to rise, reaching about 1 micromol/l. The presence of glibenclamide (10 micromol/l) in the bath reduced the anoxia-induced KATP current by more than 50%, but did not significantly influence the time dependence of current, hypoxic shortening and Cai, or the magnitude of Cai. Metabolic inhibition with 1.5 mmol/l CN resulted in KATP current increase and hypoxic shortening, occurring somewhat earlier than under anoxia, but all other parameters were comparable. In non-patch-clamped cells loaded with fura-2 AM ester and field-stimulated with 1 Hz, 1 micronol/l glibenclamide had no significant effect on the magnitude of the Cai increase caused by exposure of the cells to 1.5 mmol/l CN-. After CN- wash-out in non-patch-clamped cells, Cai declined, oscillated and finally returned to control values. It can be concluded that glibenclamide inhibits anoxia-induced KATP currents only partially and has no significant effect on anoxia-induced rise in resting Cai.

Adenosine Triphosphate↗

Scleroderma and silicone gel breast prostheses--the Sydney study revisited.

BACKGROUND: Silicone augmentation mammoplasty has been postulated as a cause of environmentally-induced scleroderma. While representing a small proportion of all alleged causes of scleroderma, the issue has huge social, ethical and medicolegal ramifications. The hypothesis, however, has been recently questioned in results of comparative studies. We have previously reported no association between augmentation mammoplasty and scleroderma. However, all information was self-reported including augmentation mammoplasty status, and the prosthesis type was not identified. In addition, data were not available from untraceable cases. The current study addresses these issues. AIMS: To validate self-reported augmentation mammoplasty status, re-analyse rates of exposure to silicone gel breast prostheses in 556 scleroderma patients and 289 general practice controls and evaluate whether silicone gel breast prostheses are causally linked to scleroderma. METHODS: Study design-population-based case-control study; Cases-scleroderma patients resident in Sydney for at least six consecutive months between 1974-1988; Controls-patients from 29 randomly selected Sydney general practices, age- and gender-group-matched with cases. Validation of augmentation mammoplasty exposure was ascertained from the general medical practitioner of each interviewed case and control, or from the medical records of each deceased or untraceable case. Validation of the date of surgery and prosthesis type was from the relevant plastic surgeon. For each augmentation mammoplasty-positive case, validation of both the date and nature of the scleroderma onset was from the patient's medical records. Controls were given a "control date' for disease onset to adjust for duration of potential exposure. RESULTS: Validation of augmentation mammoplasty status was possible in 252 (87.2%) living controls, and 532 (95.7%) cases, of whom 287 were living. Self-reported augmentation mammoplasty status was highly reliable in living non-senile cases (kappa = 1), and living validated controls (kappa = 0.86). No association was identified between silicone gel augmentation mammoplasty and scleroderma with unadjusted odds ratios of 1.33 (95% CI: 0.26-6.71), and 1.00 (95% CI: 0.16-6.16) following adjustment for potential confounders of age, socioeconomic status and ethnicity. CONCLUSIONS: This validates the self-reported augmentation mammoplasty status previously reported and does not support the hypothesis that silicone gel augmentation mammoplasty is an environmental inducer of scleroderma in females.

Adult↗

Adenosine triphosphate-dependent K currents activated by metabolic inhibition in rat ventricular myocytes differ from those elicited by the channel opener rilmakalim.

Adenosine triphosphate (ATP) dependent potassium channels (KATP channels) in heart ventricular muscle cells can be activated by depletion of intracellular ATP stores as well as by channel openers. In the present study we examined whether properties of KATP channels are dependent on the mode of activation. Whole-cell and single-channel currents were investigated by use of the patch-clamp technique in isolated ventricular rat myocytes. The channel opener rilmakalim dose dependently activated whole-cell currents [concentration for half-maximal activation (EC50) = 1.1 microM, Hill coefficient = 3.1, saturation concentration 10 microM]. Metabolic inhibition with 2-deoxy-D-glucose (10 mmol/l) also activated KATP currents after a time lag of several minutes. These currents were about two-fold higher than the rilmakalim-activated currents (rilmakalim-activated current 3.9 +/- 0.2 nA, 2-deoxy-D-glucose-activated current 8.1 +/- 0.9 nA; both recorded at 0 mV clamp potential). While the rilmakalim-activated current could be blocked completely and with high affinity by the sulphonylurea glibenclamide [concentration for half-maximal inhibition (IC50) = 8 nM, Hill coefficient = 0.7] the 2-deoxy-D-glucose-activated current could only be blocked partially (by maximally 46%) and higher glibenclamide concentrations were needed (IC50 = 480 nM, Hill coefficient = 0.8). The partial loss of blocking efficiency after metabolic inhibition was not restricted to glibenclamide but was also observed with the sulfonylureas glimepiride and HB 985, as well as with the non-sulfonylureas HOE 511 and 5-hydroxy-decanoate. Single-channel studies were in accordance with these whole-cell experiments. Both rilmakalim and metabolic inhibition with the uncoupler carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) activated single channels in the attached mode, where the number of current levels was significantly higher in the case of FCCP. Rilmakalim-activated channels were completely blocked by 10 microM glibenclamide, whereas several single-channel levels appeared in the presence of 100 microM glibenclamide after metabolic inhibition. In conclusion, after metabolic inhibition the amplitude of the activated KATP current is about twice as high as under saturating concentrations of the opener rilmakalim. Moreover, channels activated by metabolic inhibition lost part of their sensitivity to known channel blockers.

Adenosine Triphosphate↗

Immunogenetic analysis of 5 families with multicase occurrence of scleroderma and/or related variants.

OBJECTIVE: To investigate the relative contribution of the major histocompatibility (MHC) gene complex in the etiopathogenesis of familial scleroderma and/or its variants, in 5 Australian families, each with 2 affected members. METHODS: Affected individuals and consenting first degree relatives were examined and had blood collected for histocompatibility leukocyte (HLA) class I, class II antigen, and complement C4 typing. An antinuclear (ANA) profile screen on each family member was performed. RESULTS: Family 1, had 2 affected siblings (scleroderma, CREST), each anticentromere positive (> 1/640 titer), with identical HLA haplotypes. A brother, who was HLA identical to his affected sisters was clinically normal and ANA negative. In Family 2, there were no HLA haplotype similarities between the 2 sisters affected with diffuse scleroderma. Both were ANA positive (> 1/640). A 3rd sister was HLA identical to the proband but was clinically normal and ANA negative. In Family 3, affected siblings (CREST, morphea) had identical HLA haplotypes. In Family 4, both mother (CREST) and one of her 2 daughters (scleroderma) had anticentromere antibodies (1/2560). The unaffected daughter, not sharing either of her sister's haplotypes, was normal and ANA negative. In Family 5, 2 sisters (CREST, CREST) were HLA identical. CONCLUSION: A female predominance in familial scleroderma was observed. There was no common HLA haplotype between different families affected with scleroderma or its disease variants. Within families (except in one case, where the possibility of crossover exists or a question of paternity) affected siblings shared both HLA haplotypes. The development of disease was not totally accounted for by HLA genes, since family members with the same HLA haplotypes as the proband, were not affected. It appears that genes within the MHC complex are required but are not sufficient for the development of systemic sclerosis.

Adolescent↗

Limited scleroderma is associated with increased prevalence of macrovascular disease.

Microvascular involvement in scleroderma is well recognized. Macrovascular disease is not. OBJECTIVE. To test the hypothesis that the prevalence of macrovascular disease is increased in patients with limited scleroderma (systemic sclerosis, lSSc). METHODS. A retrospective cohort study design was employed in which the prevalence of macrovascular disease in all female patients from specified hospitals (1974-90) with lSSc of at least 5 years' duration was compared and contrasted with that in a comparable group of controls. Each control was matched to one lSSc case by sex; age (+/- 5 yrs); number of inpatient admissions (+/- 2); year of last hospital admission (+/- 2 yrs), history of hypertension, cigarette smoking and diabetes mellitus, and medical record number most closely approximating the case. The distribution of vascular disease was assessed in the peripheral, coronary, and cerebral arterial territories. RESULTS. Peripheral macrovascular disease (PVD) occurred in 18 (58%) of the lSSC patients and only 3 (9.6%) of the controls (RR = 6.0; 95% CI 2.0-18). Of the 18 lSSc cases, 8 had PVD documented angiographically, 4 by arterial Doppler ultrasound, and 6 had absent peripheral pulses. Five of these required subsequent partial limb amputation. Two of the 3 controls with PVD had absent peripheral pulses, and 1 had an angiographically documented abdominal aortic aneurysm. No control required limb amputation. There was no significant difference in the prevalence of coronary artery or cerebrovascular disease between the groups. CONCLUSION. The prevalence of peripheral large vessel occlusive disease is increased in lSSC and associated with severe morbidity.

Adult↗

Large vessel occlusive disease associated with CREST syndrome and scleroderma.

OBJECTIVES: To report the cases of three patients with CREST syndrome and one patient with diffuse scleroderma who had severe macrovascular disease and only minimal vascular risk factors. METHODS: The medical histories, physical examinations, and results of clinical investigations were reviewed in four patients. RESULTS: These four patients had severe morbidity from macrovascular disease of the arms and legs in the presence of minimal underlying vascular risk factors. These patients represent 11% of the women with scleroderma seen at our hospital since 1974. This is a greater than threefold increase above the expected proportion of symptomatic vascular disease seen in population studies. In the patients with CREST syndrome, large vessel disease was first seen more than 10 years after the onset of Raynaud's phenomenon, which was the first manifestation of the disease. A pathological specimen of the ulnar artery from one patient showed severe luminal narrowing by an acellular material with no evidence of atheroma. CONCLUSIONS: These cases suggest an association of both the CREST syndrome and scleroderma with macrovascular disease.

Aged↗

Reproductive function prior to disease onset in women with scleroderma.

We tested in a retrospective study the hypothesis that women with scleroderma have an increased risk, before disease presentation, of problems in pregnancy. Reproductive history, as reported from a validated postal questionnaire, was obtained from 204 women with scleroderma [mean year of birth (yob) 1942] and compared to that reported by 233 women with primary Raynaud's phenomenon (mean yob 1948) and 189 healthy women from a population register (mean yob 1950). Only pregnancies occurring before symptom onset in the scleroderma group were considered for analysis. All analyses were adjusted for job, social class, age at first pregnancy, smoking habit, and where relevant, parity. The results are expressed as odds ratios (OR) [with 95% confidence limits (CL)] giving the risk of developing scleroderma, with previous exposure to each of the specific reproductive variables analyzed, relative to the 2 comparison groups. The women with scleroderma were more likely than the population women to have had a delay in conception (> or = 12 months): OR 2.6 (1.1, 5.7) or be infertile: OR 2.3 (0.7, 7.2). These differences were not apparent when the scleroderma group was compared to the women with Raynaud's: OR's 0.7 and 1.1, respectively. Similarly there was a greater self report of maternal ill health in pregnancy in the group with scleroderma compared to the population women: OR 2.1 (1.2, 3.5) but not compared to the women with Raynaud's: OR 1.0 (0.7, 1.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

A double blind, randomised, multicentre comparison of two doses of intravenous iloprost in the treatment of Raynaud's phenomenon secondary to connective tissue diseases.

OBJECTIVE: To compare low (0.5 ng/kg/min) and standard dose (2 ng/kg/min) iloprost (a stable carbacyclin analogue of prostacyclin) in patients with Raynaud's phenomenon secondary to connective tissue disorders. DESIGN: Double blind, random allocation, three six hour infusions on consecutive days. Follow up period eight weeks. SETTING: Rheumatology units, five teaching hospitals. PATIENTS: 55 Patients with Raynaud's phenomenon (greater than seven attacks per week), 32 secondary to well documented classical progressive systemic sclerosis (American Rheumatism Association criteria), 11 CREST syndrome, 5 mixed connective tissue disease, 1 rheumatoid arthritis, 1 Sjögren's syndrome, 1 childhood dermatomyositis, and 4 abnormal nailfold capillaroscopy and antibody profiles but no definite diagnosis. INTERVENTIONS: All other treatment for Raynaud's phenomenon was discontinued two weeks before entry. 28 Patients were randomly allocated to receive the low dose, 27 the standard dose. Differing dilutions allowed infusion rates to be started at 10 ml/h with increments of 10 ml/h every 15 minutes until infusion rates reached 0.5 ng/kg/min and 2 ng/kg/min respectively. MAIN OUTCOME MEASURE(s)--Reduction in frequency, duration, and severity of attacks of Raynaud's phenomenon. Assessment of ulcer and ischaemic lesion healing. RESULTS: Both dosage regimens were equally effective in reducing severity, frequency, and duration of Raynaud's attacks. Ulcer healing occurred to similar degree in both treatment groups (standard dose 44%, low dose 39%). Low dose was associated with significantly fewer side effects. CONCLUSIONS: Both dosage regimens reduce severity of Raynaud's phenomenon and encourage ulcer healing. Low dose was associated with fewer side effects and was better tolerated by the patients.

Adult↗

Binding of loop diuretics to their renal receptors: use as a screening model for potential diuretic activity.

Loop diuretics of the benzoic acid and aryloxyacetic acid families inhibit Na+K+Cl- cotransport. The ranking order of potencies measured in the thick ascending limb of Henle's loop and the ranking order of affinities for [3H]piretanide receptors on renal plasma membranes are the same. Potencies and affinities correlate well (correlation coefficient r = 0.959 for the medulla and r = 0.951 for the cortex). Therefore, measurement of [3H]piretanide binding is proposed to facilitate screening for loop diuretic action.

Animals↗