Waterborne cryptosporidiosis.

Awareness of the importance of Cryptosporidium as a gastrointestinal parasite of developed countries not only stems from its prevalence in AIDS patients but also from its recent recognition as a possible contaminant of drinking water supplies. The importance of Cryptosporidium to public health has recently been revealed by a series of major epidemics of diarrhoeal disease in the USA and UK. In this review, Huw Smith and Joan Rose document what is known of the causes of some of these outbreaks and explain why this parasite can escape the battery of treatment processes normally used for drinking water supplies in these countries.

Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia.

The association between hyperostosis frontalis interna (HFI), acromegaly and hyperprolactinaemia was investigated. Thirty six acromegalic patients, of whom 19 had hyperprolactinaemia, were compared with 36 randomly-selected, age-sex matched controls. There was a higher prevalence of HFI in the skull X-rays of the acromegalic cohort (P = 0.

Effects of bilateral oophorectomy on lipoprotein metabolism.

The effects of surgical menopause on lipoprotein levels and their time course were studied in 31 premenopausal women who were undergoing hysterectomy and bilateral oophorectomy for non-malignant conditions. Lipoprotein levels were measured before oophorectomy and afterwards at 6 and 12 weeks, then at intervals of 3 months for 18 months. Low density lipoprotein (LDL) cholesterol levels rose significantly (P less than 0.

Factors influencing the responses to calcium antagonists in elderly patients with hypertension and ischaemic heart disease.

The results of a variety of studies that have investigated the effect of age on the pharmacokinetics and pharmacodynamics of calcium antagonist drugs have produced the following conclusions. Primarily, as a result of an age-dependent decline in plasma drug clearance, there is a tendency for elderly patients to have higher plasma drug concentrations than young patients. In terms of pharmacological response, there is good evidence of therapeutic efficacy in both hypertension and ischaemic heart disease, but there is no convincing evidence of any preferential age-related effect, particularly in relation to blood pressure reduction.

Desensitization and down-regulation of brain alpha 2-adrenoceptors by centrally acting antihypertensive drugs.

Rabbits were treated with intravenous clonidine (8 mumol kg-1 day-1), guanabenz (20 mumol kg-1 day-1), rilmenidine (80 mumol kg-1 day-1) or vehicle via osmotic minipumps. After 6 days treatment mean arterial pressure (MAP), pressor responses to intravenous alpha-methyl noradrenaline and depressor responses to intracisternal clonidine were studied, and [3H]-yohimbine binding to forebrain and hindbrain examined in vitro. Clonidine, guanabenz and rilmenidine had similar effects on MAP and caused a similar attenuation of the depressor response to intracisternal clonidine, but only guanabenz attenuated pressor responses to intravenous alpha-methyl noradrenaline.

The relationship between the hypokalaemic response to adrenaline, beta-adrenoceptors, and Na(+)-K+ pumps in skeletal and cardiac muscle membranes in the rabbit.

The hypokalaemic response to adrenaline and the involvement of beta-adrenoceptors and Na(+)-K+ pumps were investigated in control rabbits and animals chronically pretreated with adrenaline. The hypokalaemic response to acute intravenous infusion of adrenaline was significantly reduced when rabbits were chronically pretreated with adrenaline for 10 days. Chronic pretreatment of rabbits with adrenaline significantly reduced the densities for [125I]cyanopindolol and [3H]ouabain binding sites in skeletal muscle and heart.

Hypernatraemic dehydration in patients in a large hospital for the mentally handicapped.

Objective: To determine the prevalence of hypernatraemic dehydration and to assess the hydration and nutritional state of patients in a large hospital for the mentally and physically handicapped; also to assess the efficacy of an intervention programme to reduce the prevalence of hypernatraemic dehydration in the hospital.

Design: Prospective study of patients admitted with hypernatraemic dehydration from a large hospital for mentally and physically handicapped patients (hospital A) to a district general hospital between 1986 and 1988. In 1986 the hydration and nutritional state of a random sample of patients from hospital A was compared with a random sample of patients from a small hospital for the physically and mentally handicapped (hospital B) and with control groups from the community.

Treatment of high blood pressure--the effect on coronary morbidity and mortality.

Established drugs used in the treatment of hypertension have reduced stroke but have had disappointingly little impact on coronary artery disease and its complications. This could be due to inadequate falls in blood pressure (or excessive falls). It is possible that the role of blood pressure in ischaemic heart disease has been over-estimated compared to other risk factors.

An unusual cause of a pulsatile neck swelling: report of a case of cervical aortic arch.

Pulsatile neck swellings are usually related to the carotid vessels and include aneurysms, pseudoaneurysms and tortuous atherosclerotic vessels. A very rare cause of congenital extension of the aortic arch into the neck is described.

Noise levels and exposure patterns to do-it-yourself power tools.

The noise levels produced by a variety of do-it-yourself power tools were measured in a real-life situation. Most of the devices tested produced noise of 100 dB(A) or greater at the user's ear. A questionnaire was issued to 100 males who used these devices.

A clinical and audiological investigation of osteogenesis imperfecta.

Fifty-six patients with osteogenesis imperfecta underwent clinical and audiological assessment. They completed questionnaires regarding their physical and otological disabilities, and attended various centres for audiological testing. It was found that 31 patients had a hearing loss.

An outbreak of waterborne cryptosporidiosis caused by post-treatment contamination.

An outbreak of waterborne cryptosporidiosis affecting 27 persons, diagnosed stool positive, occurred in Ayrshire in April 1988. Twenty-one in 27 confirmed cases required some form of fluid replacement therapy. Local general practitioners indicated a two- to fivefold increase in diarrhoeal disease during the outbreak, and following enquiries made by Environmental Health Officers it became apparent that many hundreds of people had suffered a diarrhoeal illness at that time.

Pressor responsiveness, age and hypertension.

It has long been accepted that enhanced vascular reactivity is an integral part of the hypertensive state. This study investigates pressor responsiveness to the selective alpha 1-adrenoceptor agonist, phenylephrine, in 62 normotensive and hypertensive subjects aged 20-70 years. Since blood pressure increases with age, it is possible that effects attributed specifically to blood pressure will be confounded by age.

Prediction of response to antihypertensive therapy with enalapril and nifedipine.

We evaluated the usefulness of an integrated concentration-effect modelling technique in predicting the long-term response to antihypertensive therapy with enalapril and nifedipine. Two groups of essential hypertensives were given monotherapy with 20 mg nifedipine twice a day (n = 14) or 20 mg enalapril once a day (n = 13), and were studied following the administration of the drugs and after at least 6 weeks' treatment. For both drugs the predicted responses (predose and 4 h postdose) were in close agreement with the observed responses.

A comparison of fluorescein diacetate and propidium iodide staining and in vitro excystation for determining Giardia intestinalis cyst viability.

The viability of 4 human isolates of Giardia intestinalis cysts using either the fluorogenic vital dyes fluorescein diacetate (FDA) and propidium iodide (PI) or in vitro excystation was assessed. Whereas viable cysts, as defined by in vitro excystation were present in each of the 4 isolates, cysts from only 3 of the 4 isolates took up the vital dyes. FDA consistently over-estimated cyst viability whilst PI under-estimated non-viable cysts when compared with in vitro excystation.

An analysis of staining methods for the detection of Cryptosporidium spp. oocysts in water-related samples.

The ability of five staining techniques, originally developed for the rapid identification of Cryptosporidium spp. oocysts in faecal samples, to detect oocysts in water and water-related samples was assessed. All the stains used (modified Ziehl Neelsen, auramine-phenol (Lempert), Wright-Giemsa, safranin-methylene blue and FITC-labelled monoclonal antibody) stained oocysts after storage in water for 2 months at 4 degrees C (71-89% of control values).

Regulation of beta 1- and beta 2-adrenoceptors following chronic treatment with beta-adrenoceptor antagonists.

The effect of chronic pretreatment of guinea pigs with various beta-adrenoceptor antagonists on the binding characteristics of the radioligand 125I-cyanopindolol (ICYP) and responsiveness of adenylate cyclase to isoprenaline in the gastrocnemius muscle (beta 2-adrenoceptors) and the left ventricle (beta 1-adrenoceptors) were compared. Pretreatment of guinea pigs with propranolol or ICI 118,551 for one week significantly increased the density of the beta 2-adrenoceptors in the gastrocnemius muscle. Atenolol pretreatment for one week did not affect the density of the receptors.

Unrecognized viscus perforation in the elderly.

Thirty-four consecutive patients with unrecognized intra-abdominal perforation were identified from post-mortem records and retrospective analysis was undertaken. The common factors that appeared to contribute to the missed diagnoses included obesity (50%), communication difficulty (33%) and previous abdominal surgery (38%). In addition, symptoms and signs may have been obscured in those patients receiving analgesics (26%), steroids (21%) or non-steroidal anti-inflammatory drug therapy (44%).

Predictability of antihypertensive responsiveness and alpha-adrenoceptor antagonism during prazosin treatment.

This study investigates concentration-effect relationships in nine patients who had essential hypertension treated with prazosin. Antihypertensive responsiveness was determined for each individual patient in terms of millimeters of mercury of blood pressure reduction per nanogram per milliliter of plasma prazosin concentration. The principal findings were that there was significant attenuation of antihypertensive responsiveness, from 11.

Concentration-effect relationships and individual responses to doxazosin in essential hypertension.

1. This study investigates aspects of the pharmacokinetics, pharmacodynamics and concentration-effect relationships in 10 patients with essential hypertension during acute and chronic treatment with doxazosin, an alpha 1-adrenoceptor antagonist. 2.

Pharmacodynamics of amlodipine: hemodynamic effects and antianginal efficacy after atrial pacing.

The hemodynamic effects and antianginal efficacy of 10 mg amlodipine administered intravenously were assessed for 45 minutes in 18 subjects with stable angina pectoris. After amlodipine the heart rate was increased from 75 +/- 12 beats/min to 80 +/- 15 beats/min (p less than 0.05) for at least 15 minutes, with a decrease in systemic vascular resistance of 1091 +/- 205 to 815 +/- 390 dynes/sec/cm5 and a decrease in mean arterial pressure at 30 minutes from 99 +/- 11 to 91 +/- 10 (p less than 0.

Effects of treatment with oestradiol/levonorgestrel on bone, lipoproteins and hormone status in postmenopausal women.

The aim of the study was to investigate the effects of an oestradiol/levonorgestrel regimen, administered parenterally, on bone metabolism, bone density, lipoprotein metabolism and hormone status. Twenty-five women who had undergone a surgical menopause had an oestradiol/levonorgestrel-containing vaginal ring pessary in situ for 6 months. Within the first month there were sustained changes in the biochemical indices of bone metabolism in keeping with a marked reduction in bone turnover and decrease in bone resorption.

Effects of short-term exposure to noradrenaline and adrenaline on adrenoceptor responses.

Adrenaline (0.05 and 1.5 mumol/kg per h) and noradrenaline (0.

Klippel-Feil syndrome and conductive deafness.

The Klippel-Feil syndrome is usually associated with sensorineural deafness and reports of conductive or mixed deafness are rare. Four additional cases are presented in this paper. The middle ear anomalies found in this syndrome are discussed.