Altered blood amino acid distribution in genetically obese mice.

The present study was undertaken to determine whether the alteration in amino acid distribution between the plasma and cellular compartment of the blood, previously described in dietary-obese rats, also occurs in genetically obese mice. The blood concentration of individual amino acids and its distribution between plasma and cells of lean and genetically obese mice (ob/ob) have been measured. The results demonstrated that genetically obese mice showed a decrease (55%, P = 0.0489) of free amino acids in the blood cells. Most amino acids were affected and among the most noteworthy characteristics was the observation that the reduction in concentration was more pronounced for the total concentration of the essential amino acids which was reduced by 76% (P = 0.0112) compared to cells of lean mice. These results suggest that an altered amino acid distribution between plasma and blood cells is a consequence of both diet-induced and genetic obesities.

Should programmes for community-level meningococcal vaccination be considered in Australia? An economic evaluation.

BACKGROUND: Disease due to serogroup C Neisseria meningitidis is life-threatening and potentially preventable by vaccination. In 1999, the UK instigated mass vaccination after a sustained increase in serogroup C meningococcal disease. In the same year, Victoria, Australia experienced a similar change in disease epidemiology. It is timely to undertake an economic evaluation of options for community vaccination in Australia based on local data. METHODS: Cost-effectiveness and cost-benefit analyses of three options for use of polysaccharide vaccine were undertaken for a hypothetical population aged 15--19 years. Baseline analyses assumed 5 years' duration of vaccine protection following a single year of programme implementation. Sensitivity analyses of key variables were performed, including vaccine coverage and effectiveness, case fatality rate and the discount rate. Outcomes included the number of people vaccinated, cases averted, life-years saved and disability-adjusted life-years (DALY) averted. Cost-benefit analysis used lost earnings avoided as a measure of vaccination benefit. RESULTS: Vaccination of people aged 15--19 years in a defined population with a high rate of disease was the most cost-effective option. Compared with no vaccination and assuming 5 years' duration of protection and exclusion of direct cost savings, this resulted in a discounted cost per life-year saved of $23,623, a cost per DALY avoided of $21,097 and benefits exceeding costs in discounted terms. The 'break-even' incidence rate for this option with exclusion of direct cost savings was 14.0/100,000. CONCLUSIONS: Community use of polysaccharide vaccination may be cost effective in Australia under certain conditions. Economic evidence favours use of vaccination in well-defined populations with a high rate of disease. Policy decision-making also requires consideration of non-economic factors, including feasibility of implementation and risk perception by the community.

Responses to cafeteria feeding in mice after the removal of interscapular brown adipose tissue.

Feeding a cafeteria diet to mice resulted in an increased energy intake of approximately 30% and this led to increases in the wet weight, total protein content, and total cytochrome oxidase activity of interscapular and dorso-cervical brown adipose tissue. Surgical removal of interscapular brown adipose tissue, followed by cafeteria feeding, gave rise to an elevation in dorso-cervical brown adipose tissue wet weight, total protein content, and total cytochrome oxidase activity, compared to intact cafeteria-fed mice. Cafeteria feeding with or without the removal of interscapular brown adipose tissue did not lead to significant increases in body weight compared to stock-fed control mice, but both cafeteria-fed groups of mice showed significant elevations in body fat content indicating that the induced hyperphagia led to a relative obesity in the cafeteria-fed groups. The results presented are consistent with an increased thermogenic activity in the brown adipose tissue of cafeteria-fed mice, and the effect of the removal of interscapular brown adipose tissue further indicates the quantitative importance of the tissue in the control of body weight.

BCG vaccination practices in Victoria.

To determine the patterns of usage of bacille Calmette-Guérin (BCG) vaccine in Victoria and assess whether the vaccine was being administered to those in high-risk groups, as identified by the National Health and Medical Research Council, an audit of BCG vaccine unit sales and expenditure, over the past four years was conducted. A postal survey covering all registered Victorian BCG vaccinators inquired about BCG vaccination practices during 1993. Vaccine sales and expenditure had nearly doubled since 1991. The number of registered vaccinators had also increased. The survey response rate was 77 per cent, (228 of 295). Half of the vaccinators were working in general practice, 11 per cent of vaccinators used no set guideline for client selection, 69 per cent vaccinated fewer than 25 people in 1993, 26 per cent had vaccinated neonates (mainly southeast Asian), with few of these vaccinations being carried out in maternity hospitals. Tertiary students and ethnic groups were the most commonly vaccinated groups. Only small amounts of BCG were being given to people outside risk groups, mainly travellers and anxious public. There has been significant increase in numbers of registered vaccinators and use of BCG with much wastage. Application of guidelines was inconsistent and coverage of high-risk groups varied. Despite some selection for vaccination by personal choice, little vaccine appeared to be used in nonrecommended groups. Subsequent changes in practice have resulted, including publicising and clarifying guidelines, reduction in the number of vaccinators, vaccinator upgrading courses, and restructuring of the vaccine ordering system.

Hepatitis B immunisation coverage of infants born to chronic carrier mothers in Victoria.

Infants born to HBsAg- (hepatitis B surface antigen) carrier mothers are highly likely to become chronic hepatitis B (HB) carriers themselves unless their status is recognised at birth and they are immunised with three doses of HB vaccine, the first within 48 hours of birth, concurrent with hepatitis B immune globulin (HBIG). This study was designed to determine how many infants born in Victoria to carrier mothers completed three doses of HB vaccine. We sent the names of all infants of HBsAg-carrier mothers notified in Victoria between 1.7.91 and 30.6.92 to the appropriate local government immunisation providers and requested information on how many doses of HB vaccine, DTP (diphtheria-tetanus-pertussis) or CDT (combined diphtheria-tetanus), and OPV (oral polio vaccine) they had received. The HBsAg-carrier prevalence of women giving birth in Victoria in 1991-92 was at least 0.52%. Of the 336 infants notified, 239 (71.1%) were recorded in local government records. Of these 239, 90.8% received at least two doses and 80.8% received at least three doses of hepatitis B vaccine. There was no significant difference in the number who received three doses of HB vaccine compared with three doses of DTP or CDT vaccine. Of the entire cohort of 336, only 57.4% were documented as being completely immunised against hepatitis B. HB immunisation coverage for these infants needs to be improved. The high rate of loss to follow-up, especially between the maternity hospital and the community, is disturbing. Mechanisms for intensive prospective follow-up of these infants should be developed to prevent loss to follow-up and to encourage full immunisation against HB. Improving HB immunisation coverage of infants in high HBsAg-prevalence ethnic groups and introduction of universal infant HB immunisation may lead to increased coverage of infants of carriers by serving as back-up mechanisms for those lost to follow-up.

Hepatitis B immunisation rates among infants in ethnic groups with high prevalences of hepatitis B surface antigen carriers.

To determine hepatitis B immunisation rates in infants from ethnic groups with hepatitis B surface antigen chronic carrier prevalence over 5 per cent, a questionnaire was sent to all Maternal and Child Health Centres in Victoria, requesting information on the hepatitis B and diphtheria-tetanus-pertussis (DTP) or combined diphtheria-tetanus (CDT) immunisation status for all infants born between 1 July 1992 and 30 June 1993 and at risk of hepatitis B infection because of maternal ethnicity. We received data on 3611 of 5744 infants (62.9 per cent) in targeted ethnic groups. Of these, 12.8 per cent had not received hepatitis B vaccine, and 81.6 per cent, 76.8 per cent and 64.0 per cent had received at least one, two and three doses respectively, while 84 per cent had received at least three doses of DTP vaccine and/or CDT vaccine. Coverage with DTP or CDT was higher than for hepatitis B vaccine (P < 0.001), and coverage was better in areas with a higher percentage of infants in high-prevalence ethnic groups (P < 0.001). Changes in the program in Victoria in terms of timing of the first dose of vaccine plus greater attention to follow-up may lead to improved hepatitis B immunisation rates among infants in targeted ethnic groups. Adoption of universal infant hepatitis B immunisation, by increasing familiarity with hepatitis B vaccine, is likely to be the best way to increase immunisation coverage for these infants.

The pattern of postoperative analgesic administration in non-English speaking Asian women following caesarean section.

A survey of postoperative analgesic administration to non-English speaking Asian women following Caesarean section has shown significant differences when compared to English speaking Caucasian women. The main differences demonstrated were that analgesia was utilised for a shorter period (mean of 16 hours) and that a smaller number of doses were given to the Asian group.

Immunising the population. Are we succeeding?

While diseases such as diphtheria and poliomyelitis have disappeared in this country, other vaccine preventable diseases such as measles, pertussis and rubella are quite common and result in epidemics from time to time. There are some groups in the community with particularly low coverage with specific vaccines and they need extra attention. Immunisation providers need to identify the barriers to achieving high coverage rates and adopt measures to overcome these barriers.

Influenza surveillance in general practice.

This paper describes a survey of influenza conducted in general practice from July to October 1990. The study demonstrates how interested general practitioners can be involved in community based surveillance for the early detection of influenza outbreaks.

Tuberculosis. The old and the new.

BACKGROUND: The overall incidence of tuberculosis (TB) in the general Australian population is low and has been stable over the past 10 years. The incidence is, however, much higher in certain subgroups of the population and these include overseas-born people (especially from countries in Asia) and Aboriginal and Torres Strait Islander populations. Other groups regarded as at increased risk of TB are nursing home residents, the homeless, prison populations and immunosuppressed patients, especially those who are HIV positive. OBJECTIVE: Patients regarded as high risk should be investigated promptly if they present with signs or symptoms suggestive of TB. DISCUSSION: The best method of preventing the transmission of TB and preventing the emergence of drug resistant strains of the organism are by ensuring that sputum smear positive patients are isolated till non-infectious; that any patient with TB receives prompt and adequate treatment; that all patients with TB comply with a full course of treatment till cured: and that contact tracing is undertaken to detect newly infected patients so as to offer chemoprophylaxis and to detect previously unrecognised cases.

Low mannose-binding lectin complement activation function is associated with predisposition to Legionnaires' disease.

Innate immune system deficiency may predispose to severe infections such as Legionnaires' disease. We have investigated the role of mannose-binding lectin (MBL) deficiency in the Melbourne Aquarium Legionnaires' disease outbreak. Serum samples from patients and controls that were exposed but shown to be uninfected from the Melbourne Aquarium Legionnaires' disease outbreak were tested for MBL function (C4 deposition) and level (mannan-binding). MBL function was lower in Legionnaires' disease cases than in age- and sex-matched uninfected, exposed controls. The frequency of MBL deficiency with C4 deposition < 0.2 U/microl was significantly higher in Legionnaires' disease cases than in controls. This also applied to Legionnaires' disease cases requiring hospital care. There was no difference in MBL mannan-binding levels between Legionnaires' disease patients and controls. There was no significant interval change in MBL function or level after a mean of 46 days. MBL complement activation functional deficiency appears to predispose to Legionnaires' disease.

A pre-induction test dose for suxamethonium.

A two-part experimental and clinical study was conducted to determine the effects of administration of a pre-induction dose of suxamethonium, and to see whether the symptoms produced could form the basis of a test dose, to determine sensitivity to suxamethonium prior to administration of a full intubation dose. Suxamethonium was shown to produce distinctive clinical features characterised by signs of both extraocular muscle contraction and paresis, manifest by symptoms of eye and eyelid heaviness without generalised paresis. The dose response was determined in individuals with normal plasma cholinesterase, to a test dose of suxamethonium chloride of between 20 and 1 micrograms/kg. Individuals with abnormal plasma cholinesterase were shown to exhibit sensitivity to these low doses and were easily distinguished from those with normal enzyme. A protocol is suggested which can conveniently establish, prior to induction, those individuals with a reduced ability to hydrolyse suxamethonium.

Continuous suxamethonium infusion for microlaryngeal surgery.

The suxamethonium infusion requirements to maintain a 100% neuromuscular block in patients undergoing microlaryngeal surgery were determined. Anaesthesia was maintained with halothane and the neuromuscular block monitored with a peripheral nerve stimulator delivering train-of-four stimuli. Suxamethonium requirements varied directly with time in a linear manner and the onset and recovery time of the block increased with time. No difficulties in recovery were observed when the duration of infusion was less than l h, even when the nature of the block had altered to the non-depolarizing type. A good correlation was observed between neuromuscular block as indicated by peripheral nerve stimulation and laryngeal muscle paralysis.

Patient feedback on the anaesthetist's performance during the pre-operative visit.

A questionnaire was devised from guidelines published by the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland for the conduct of the pre-operative interview and conduct of anaesthesia. The responses to the questionnaire formed the basis of an accumulative record of patient feedback on individual anaesthetist's performance and used as one component of annual appraisal. The median "desired answer" and "overall dissatisfaction" percentages, and the "desired : undesired answer" ratio for consultants and non-training grade doctors from 835 patients at a large Acute District General Hospital were 92%, 0.6% and 12:1, respectively.

An analysis of thirty years of contributions to the British anaesthetic literature (1953-1982).

A thirty-year review of the two major British anaesthetic journals, Anaesthesia and the British Journal of Anaesthesia, was undertaken. Overseas contributors accounted for 30% of the total articles published, with North America providing the greatest proportion. The remainder of the contributions came from the United Kingdom. The British contributions were analysed for content and origin. The North West Thames Region with 9%, contributed the single largest percentage of the British articles. There was a marked difference in the Regional contributions, not invariably linked to the size of the Authority or the number of University Departments. Over the thirty-year period there was a progressive increase in the number of published articles and an increase in the proportion of overseas contributors.

Veno-venous extra-corporeal membrane oxygenation.

A case of post-traumatic respiratory insufficiency is presented in whom a prolonged period of veno-venous membrane oxygenation was utilised in an effort to provide life support and allow resolution of pulmonary damage. Stabilisation of respiratory function was achieved. Withdrawal of support was required because of surgical haemorrhage while the patient was fully heparinised. Respiratory function deteriorated and the patient died 4 days after discontinuing membrane oxygenation. The procedure was undertaken in the Intensive Care Unit of a District General Hospital where cardiopulmonary bypass facilities are not normally available.

Possible expression of the obese gene in the brown adipose tissue of lean heterozygote littermates of the genetically obese (ob/ob) mouse.

Lean littermates of the genetically obese (ob/ob) mouse of confirmed genotype, +/+ wildtype or ob/+ heterozygous, were fed either stock diet or a high-energy 'cafeteria' diet. Body weights food consumption, and weights and metabolic parameters of the interscapular and dorso-cervical brown adipose tissue sites were examined. Both genotypes showed similar characteristics of food intake and body weight gain on the cafeteria diet. The ob/+ brown adipose tissue was, however, different from the +/+ in that the GDP binding to the mitochondria was lower and the cytoplasmic density of the mitochondria in the tissue was higher in both stock and cafeteria fed groups. It is suggested that the decreased GDP binding is partly compensated for by an increase in the mitochondrial content of the brown adipose tissue of the ob/+ mice, thus normalizing the total thermogenic capacity and allowing the maintenance of lean body weight despite a slight expression of the obese gene in the thermogenic pathway.