Thyrotropin controls cyclic nucleotide metabolism of thyroid follicular cells without affecting membrane potential or input resistance.

The action of thyrotropin on the rat thyroid follicular cell has been investigated using continuous transmembrane potential and input resistance recording from individual cells in in vitro preparations. The membrane potential in this study was -68.0 mV +/- 0.6 (mean+/-S.E.). Over a wide range of concentrations (1.5-50 mU/ml), thyrotropin failed to affect membrane potential or input resistance while 20 mU/ml thyrotropin was shown to elicit complex time-dependent changes in tissue levels of both cyclic AMP and cyclic GMP. The present results reveal that thyrotropin-receptor interaction does not affect plasma membrane permeability, but is characterized by complex changes in endogenous cyclic nucleotide metabolism.

Estimates of HIV infection among injecting drug users in Glasgow, 1985-1990.

OBJECTIVE: To use research and surveillance studies in Glasgow (Scotland, UK) to estimate the number of current injectors infected with HIV, the total number of injectors infected up to the end of 1990 and the recent incidence of infection. DESIGN: (A) Prevalence of injecting drug use was estimated using log-linear modelling. (B) Prevalence of HIV infection was determined from voluntary testing of a community-wide sample of injectors. (C) The number of infected current injectors was predicted by combining the distributions generated by (A) and (B). (D) Data on known HIV-positive injectors were used in conjunction with (C) to forecast the cumulative number of infected injectors. RESULTS: The number of current injectors was estimated to be 9400; the prevalence of HIV infection among 447 injectors recruited to the HIV prevalence study during 1990 was 1.1%. From these data, the number of HIV-positive current injectors in 1990 was estimated to be between 52 and 138. Between 1985 and 1990, 110 known HIV-positive injectors were registered or received treatment in Glasgow for HIV-related diseases; the total number of cases estimated to have occurred during this period was between 110 and 300. The incidence of infection in Glasgow during 1990 was likely to have been low in light of the finding that only one case in the prevalence study had not previously been diagnosed HIV-positive. CONCLUSIONS: Linkage of datasets from a variety of sources and studies has enabled the substantial refinement of estimates of the number of injectors and the proportion infected with HIV in Glasgow up to 1990.

Influence of age on the pharmacokinetics and pharmacodynamics of perindopril.

Perindopril is the ester prodrug of the angiotensin converting enzyme inhibitor S-9780. The influence of age on the pharmacokinetics and pharmacodynamics of S-9780 (1 mg administered intravenously) and perindopril (8 mg administered orally) was examined in a double-blind, crossover, acute study in eight young (29 +/- 3 years) and eight elderly (71 +/- 3 years) healthy subjects. Mild headache and light-headedness were the only adverse effects and were more common in the younger subjects. Blood pressure fall was greater in the elderly even after correction for starting blood pressure. Bioavailability of S-9780 was increased in the elderly (35% +/- 17% compared with 19% +/- 7%; p less than 0.025) mainly because of increased conversion rather than absorption. Renal clearance of S-9780 was lower in the elderly (67 +/- 31 ml/min compared with 110 +/- 39 ml/min; p less than 0.03). Dose reduction of approximately 50% is suggested for elderly patients with further adjustment proportional to any preexisting diminished renal function.

Vasoactive intestinal polypeptide does not affect thyroid follicular cell membrane potential or input resistance.

It has been suggested that vasoactive intestinal polypeptide (VIP) has a role as a neurotransmitter and that it participates in the control of hormone release from thyroid follicles. Many hormones and neurotransmitters alter the ionic permeability properties of the plasma membrane of their target cells when they bind to their receptors. Concentrations of VIP able to elicit complex time-dependent changes in rat thyroidal cyclic nucleotide levels did not affect follicular cell membrane potential or input resistance. The suggestion is made that the findings may indicate that Ca2+ is not involved in the initial stages of stimulus-secretion coupling following VIP binding to its receptor on the follicular cell.

Liver abscess in adults: ten years experience in a UK centre.

BACKGROUND: The epidemiology and management of liver abscess (LA) have evolved over time. AIM: To examine our experience over 10 years in a UK teaching centre. DESIGN: Retrospective review of patient records. METHODS: We reviewed the records of all patients aged >16 years discharged from Royal Hallamshire Hospital with a diagnosis of LA between April 1988 and December 1999. RESULTS: There were 69 patients with LA (65 pyogenic, 4 amoebic), giving a crude annual incidence rate of 2.3/100,000/year (18.15/100,000 hospital admissions). Median age was 64 years. Single lesions were found in 41 patients, multiple lesions in 28. Pre-admission, patients were symptomatic for a median 14 days, with the most common symptoms and signs being fever and abdominal pain/tenderness. Pathogens were identified in 74% and predisposing aetiology in 92% of those undergoing investigation. Spread of infection to the liver via the portal venous system was the commonest route of infection (46%), most frequently in patients aged >/=60 years (p=0.019). Abdominal ultrasound (US) was diagnostic for LA in >90% of cases. Treatment with anti-microbial therapy plus interventional radiology was optimal. The case fatality rate was 12.3%, mainly from associated underlying pathology. DISCUSSION: LA is commonly associated with underlying gastrointestinal pathology. Seeking out this underlying aetiology is an integral part of management. We recommend US as the first-line diagnostic tool with guided intervention plus antibiotic(s) as first-line treatment. Prognosis depends chiefly on the underlying pathology.

The electrophysiological properties of the resting thyroid follicular cell.

Glass microelectrodes have been useful in the study of the electrical properties of the resting thyroid follicular cell membrane. The resting transmembrane potential (RMP) has probably been underestimated in earlier work, possible as a result of leak artefacts, and it is clear that in most species the RMP is certainly greater than -60 mV. The ratio of membrane Na+ permeability to K+ permeability (PNa/PK) is of the order of 0.07 to 0.08, and Cl- is possibly (although not definitely) distributed in a passive fashion across the cell membrane, indicating that the transmembrane K+ gradient is the most important factor in the generation of the RMP. The existence of an electrogenic sodium pump in the follicular cell membrane has been demonstrated: the pump contributes about -2 mV to the RMP under control conditions. Follicular cells are completely electrically coupled, the basic coupled cellular unit probably being equivalent to the individual thyroid follicle, and the specific membrane resistance and specific membrane capacitance have been calculated to be 5 k omega. cm2 and 3.6 microF/cm2 respectively.

The electrophysiological properties of the parathyroid cell: results of a study employing Sprague-Dawley rats and a review of the literature.

The present work indicates that the parathyroid cell of the Sprague-Dawley rat has a resting transmembrane potential of -30.5 +/- 4.1 mV. In a review of data obtained by earlier studies using other species, it was clear that in general the parathyroid cell transmembrane potential lies between -20 mV and -45 mV, that the transmembrane K+ concentration gradient is the principal factor in determining the magnitude of the membrane potential in the resting state, and that in most species a reduction in the extracellular Ca++ leads to cellular hyperpolarization. Detailed data on cellular input resistance in intact parathyroid tissue is not as yet available; however, indirect evidence exists that direct communication of the type described between other gland cells is present between parathyroid cells, a phenomenon which allows the passage of current to flow between adjacent cells via specialised connecting structures such as gap junctions.

Hypothyroidism and anaemia.

Hypothyroidism can lead to a wide variety of anaemic disorders, and numerous mechanisms are involved in the pathogenesis of these anaemias. Attention to the haematological status of hypothyroid patients is correspondingly important.

Automated exchange transfusion for life-threatening plasmodium falciparum malaria--lessons relating to prophylaxis and treatment.

We report a case of traveller to Kenya who contracted severe plasmodium falciparum malaria complicated by disseminated intravascular coagulation and acute renal failure. She had taken no antimalarial prophylaxis in view of concerns in the media regarding the adverse effects of mefloquine. There was a protracted delay before the diagnosis of malaria was made. Clinical recovery occurred following treatment with intravenous quinine, haemofiltration and manual/automated red-cell exchange transfusions. Automated red-cell exchange transfusion resulted in a marked decrease in the parasitaemia, before a response to quinine therapy would have been anticipated, leading to a successful outcome thereafter. In conjunction with other groups we therefore feel that exchange transfusions should be considered in seriously ill patients with falciparum malaria, multiorgan complications and parasitaemias greater than 10%.

Comparison of four survey methods designed to estimate the prevalence of HIV among female prostitutes who inject drugs.

In Glasgow, during the period January 1990 to December 1992, 4 different methods were used to determine HIV prevalence among female prostitutes who inject drugs: the surveillance of prostitutes undergoing voluntary named tests, an unlinked anonymous survey of prostitutes attending a health care drop-in centre, a community-wide voluntary anonymous survey of injecting drug users including female prostitutes, and a voluntary anonymous survey of female prostitutes recruited in Glasgow's red-light area. HIV prevalence varied from 1.2 to 4.7% though overlapping confidence intervals indicated no significant differences. A comparison of each approach leads the authors to suggest that the former 2 methods which are relatively inexpensive should be conducted, if possible, on high risk groups such as prostitutes and injecting drug users on a continuous basis. If these indicate HIV rates which are stable and less than 5%, implementation of more sophisticated voluntary anonymous approaches need only be done every 3 to 4 years. However, if rates are unstable and/or greater than 5% then such surveys should be initiated more frequently, perhaps biannually.

Low and stable prevalence of HIV among drug injectors in Glasgow.

The first HIV-positive diagnosis among injecting drug users (IDU) in Glasgow was made in 1985. By the end of 1987 prevalence among IDU receiving voluntary attributable tests was 4.8%. Since 1990, an annual cross-sectional survey of HIV prevalence and risk behaviours among 500 current Glasgow IDU has provided a more representative sample. Anonymously-tested saliva samples obtained from respondents revealed prevalence rates of 1.8%, 1.2% and 1.0% in 1990, 1991 and 1992 respectively. Since 1987 a wide range of measures aimed at reducing HIV-related risk behaviour among IDU has been introduced and maintained in Glasgow. Against this background, there is evidence that IDU in the city have reduced their risk behaviours. The findings reported here suggest that implementing harm-reduction measures when prevalence is low may inhibit the rapid dissemination of HIV.

Successful treatment of molluscum contagiosum with topical imiquimod in a severely immunocompromised HIV-positive patient.

Molluscum contagiosum is a common viral infection in the immuno-compromised HIV-positive patient where it is often severe and affecting the face and neck. It is frequently resistant to conventional, locally destructive therapies. Anecdotal evidence suggests that the immunomodulatory drug imiquimod might be a valid therapeutic option in this group of patients. We report the case of a severely immunocompromised HIV-positive patient with resistant facial molluscum contagiosum lesions that responded to topical imiquimod. The response to therapy and the possible implications for pathogenesis are discussed.

Honeymoon malaria and "herbal" therapy: A case report.

A marked rise in the number of cases of malaria in the UK contracted in east Africa has been reported in 1998. This may be explained by the "Lariam"-media hype, poor understanding, poverty of health education, or increase in travel to more exotic destinations. European centers have experienced changes in the pattern of imported malaria and constant up-dates are essential. However even the best informed may still acquire malaria.

Two simultaneous cases of Cyclospora cayatensis enteritis returning from the Dominican Republic.

According to the "International Passenger Survey," published in 1996 by the Office of Trading Standards, 534,000 British people traveled to the Caribbean area (personal communication, ABTA, 1998). The Dominican Republic, the eastern end of a large Caribbean island, has become in recent years one of the most popular destinations for UK holidaymakers as well as for travelers from many other countries. Cyclospora cayatensis has been firmly identified as a cause of gastroenteritis among international travelers,1 including human immunodeficiency virus (HIV)-positive individuals,2 but it has not been previously reported in the literature in British individuals returning from this increasingly popular vacation destination.

'Now and Again It Really Hits Me': The Impact of an HIV-positive Diagnosis upon Psychosocial Well- being.

Quantitative and qualitative data were gathered from a sample of 66 seropositive and 67 seronegative men and women about the impact of an HIV diagnosis upon psychosocial well-being. No significant differences between seropositives and seronegatives were found on any of the psychosocial measures except hopelessness. Nor was there significant variation by disease progression (but this may be due to the restricted size of the sample). The qualitative data are used to illustrate these findings and explore their meaning. It is concluded that, with the exception of a hopeless future orientation, psychosocial disturbance of seropositives tends to be episodic and short-lived and thereby difficult to measure.

The Koebner phenomenon in anaphylactoid purpura.

The Koebner phenomenon, often a feature of psoriasis, lichen planus, warts, and erythema multiforme, is documented in a patient with anaphylactoid purpura.

Domiciliary nebulized pentamidine for secondary prophylaxis against Pneumocystis carinii pneumonia.

The viability of a programme for delivering aerosolized pentamidine within the patient's home setting for the secondary prophylaxis of Pneumocystis carinii pneumonia (PCP) has been explored with seven homosexual AIDS patients, the major objectives being the assessment of the safety and acceptability of the treatment and the discovery of the most suitable care setting (home, ward, outpatient clinic) for the administration of therapy. It is concluded that a domiciliary prophylaxis programme is a viable alternative.

Direct intercellular communication in health and disease: an overview.

Direct intercellular communication (cell to cell coupling) is a mechanism for the local transit of information between cells and supplements the endocrine and nervous systems. Electrophysiological, biochemical, histological and cell culture techniques have established the widespread existence of coupling in mammalian tissues, and the importance of the gap junction has been recognised. Information is carried in the form of ions and small molecules between cells, and sensitive apparatus exists within each cell for controlling the permeability of the junctional membrane. The system may be important in the control and co-ordination of cellular metabolism and growth in the embryo and in adult tissues. Disorders of direct intercellular communication may be important in the pathogenesis of some diseases, in particular cancer.

The last public execution in Glasgow: the case of Dr Edward Pritchard, M.D.

Dr Edward Pritchard, a Glasgow medical practitioner, was the last person to be executed in public in Glasgow. In a famous trial of the time, he was condemned to death for murdering his wife and his mother-in-law, and he was hanged on Glasgow Green in 1865. An account of Dr Pritchard's life, his trial and his death is given here, together with a reference to the medical examination which was carried out on Pritchard's remains when his grave was exhumed in 1910.

Metolazone and axillary vein thrombosis.

The usage of powerful diuretics, such as metolazone, may lead to thrombotic complications.