Evidence of patient-to-patient transmission of hepatitis C virus through contaminated intravenous anaesthetic ampoules.

Two separate cases of acute hepatitis C virus (HCV) infection following medical procedures, arthroscopy and colonoscopy, are reported. In both episodes, patient risk factors were reviewed, and staff and other patients' sera were tested for HCV antibodies and RNA. HCV RNA positive samples were genotyped, sequenced, and subjected to phylogenetic analysis. No risk factors for HCV infection were identified for either case except for medical procedures. HCV RNA positive patients were identified preceding both cases on the respective theatre lists. HCV infection in a second low risk patient was also identified. Nucleic acid sequencing and phylogenetic analysis of HCV from the two putative source patients and the three recipient patients demonstrated a high degree of relatedness respectively. The results suggest that patient-to-patient transmission occurred in both episodes via contamination of intravenous anaesthetic ampoules with HCV used on multiple patients. Injectable medication ampoules should not be used for more than one patient.

Measles outbreak in young adults in Victoria, 1999.

OBJECTIVES: To describe an outbreak of measles in Victoria. DESIGN: Case series with cases identified through enhanced passive surveillance and outbreak-related active surveillance. SETTING: State of Victoria, 1999. MAIN OUTCOME MEASURES: Number of cases; epidemiological links and patterns of transmission; patient demographic features and vaccination status; complications. RESULTS: 75 cases were identified (74 laboratory-confirmed; and one epidemiologically linked to a laboratory-confirmed case), with onset between 11 February and 2 May 1999. The first case was in a 21-year-old woman who had recently holidayed in Bali and worked at a large cinema complex in Melbourne. Sixteen cases occurred in people who had contact with the index case at the cinema on one evening. The outbreak spread to regional Victoria and South Australia. Median age of patients was 22 years; 64 (85%) were born between 1968 and 1981, with only one patient in the age group targeted by the primary school component of the 1998 Australian Measles Control Campaign; this child had not been vaccinated. More than a third of patients (28) were hospitalised (total, 97 inpatient days), and five were healthcare workers. CONCLUSIONS: This outbreak was caused by international importation of measles virus. It highlights the change in epidemiology of measles in Australia, from a disease of childhood to one predominantly affecting young adults. A strong two-dose childhood vaccination program, vigilant surveillance, and rapid response to outbreaks will continue to be the basis of measles control, but better protection for young adults should be considered.

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.

Influenza vaccination in Victoria, 1992.

OBJECTIVES: To determine the rates and patterns of vaccination against influenza in the Victorian population. Further, to determine rates of vaccination against influenza in residents of Victorian nursing homes and hostels. DESIGN: Between May and June of 1992 we conducted a telephone survey of 537 systematically selected Victorian residents. We obtained information on age, sex, vaccination status, and level of risk for the complications of influenza. We conducted a separate postal survey of 143 randomly selected Victorian nursing homes and hostels to establish rates of vaccination within these institutions. PARTICIPANTS: Residents of Victoria listed in the White Pages telephone directories in both metropolitan and rural areas. We made calls during working hours to both residential and business numbers, and spoke to the first person who answered the telephone. Participants in the nursing home survey were the matrons or directors of nursing of randomly chosen facilities in the State, who filled out questionnaires relating to their residents. RESULTS: The vaccination rate against influenza in the whole population was 13.3%. This and all other figures quoted are adjusted for age, unless otherwise specified. There was a significant difference in vaccination rates between rural (9%) and metropolitan (16%) areas (P < 0.05). Using the National Health and Medical Research Council (NHMRC) guidelines, 29% of the population had at least one indication for vaccination. Of people at low risk for complications of influenza, 7.8% were vaccinated. Of people with one or more specific indications for vaccination, 29.4% were vaccinated. Vaccination rates increased with increasing number of indications and with increasing age, approaching 45% in people over 65 years and 50% in people with three or more indications for vaccination. The postal survey of nursing homes and hostels revealed that a mean of 52% of residents per facility were vaccinated against influenza. This figure varied between 45% in rural facilities and 53% in metropolitan facilities. CONCLUSIONS: We estimate that 550,000 doses of influenza vaccine were used in Victoria in 1992. Approximately 50% of these were given to people at low risk for complications of influenza. These findings highlight the need to target high risk groups for vaccination, reassure the general public, and educate health care professionals.

Adrenalectomy reverses the impaired pyrogenic responses to interleukin-beta in obese Zucker rats.

Interleukin-1 is an important endogenous pyrogen which stimulates thermogenesis in normal animals by a central action which is dependent on release of corticotrophin releasing factor (CRF). Central injection of murine recombinant interleukin-1 beta (IL-1 beta, 5 ng) in conscious lean (+/?) Zucker rats produced significant increases in resting oxygen consumption (VO2, 26 per cent), colonic temperature (1.3 degrees C) and thermogenic activity (mitochondrial GDP binding) of brown adipose tissue (BAT, 24 per cent). In contrast, genetically obese (fa/fa) Zucker rats showed nonsignificant changes in VO2 (4 per cent), temperature (0.5 degrees C) and BAT activity (0 per cent). Bilateral surgical adrenalectomy (ADX) dramatically enhanced the effects of IL-1 beta on VO2 (45 per cent) body temperature (1.8 degrees C) and BAT activity (44 per cent) in obese mutants, but only slightly increased responses in lean rats. These data suggest that impaired responses to IL-1 beta in obese mutants may be due to inhibitory actions of glucocorticoids on either prostaglandin synthesis or CRF release within the hypothalamus.

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.

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.

The effect of interscapular brown adipose tissue removal on body-weight and cold response in the mouse.

1. The removal of the interscapular brown adipose tissue (IBAT) led to an increase in body-weight of normal, lean mice as compared to anaesthetized controls. 2. No significant difference in food consumption could be detected between the two groups of mice over the period of the experiment. 3. Fat extraction of the whole carcasses with chloroform:methanol showed a statistically significant increase in fat content in the animals without IBAT. 4. There was no apparent failure in the operated animals to sustain core temperature when exposed to a cold stress situation (4 degrees for 24 h). 5. There was no difference in the wet weight, protein content or cytochrome oxidase content of the dorso-cervical brown adipose tissue (DCBAT) between operated and control mice. This is indicative of a lack of proliferation of other brown adipose tissue sites in the operated mice in response to the removal of the IBAT. 6. It is suggested that brown adipose tissue is implicated in dietary thermogenesis in the mouse.

Comparative and developmental studies on 4-hydroxy-2-oxoglutarate aldolase and hydroxyproline oxidase.

1. In rats, liver 4-hydroxy-2-oxoglutarate aldolase and hydroxyproline oxidase activities are maximal in the suckling period. 2. Liver activities for 4-hydroxy-2-oxoglutarate aldolase, alanine-glyoxylate aminotransferase, serine-pyruvate aminotransferase and serine dehydratase, but not hydroxyproline oxidase, are increased in rats on a high-fat, carbohydrate-free diet. 3. It is suggested that 4-hydroxy-2-oxoglutarate may be a significant source of glyoxylate for glycine and hence glucose formation. 4. Mammalian liver hydroxyproline oxidase activity is higher in carnivorous species; necessary, perhaps, to metabolise a relatively large influx of hydroxyproline on a flesh diet.

Effects of insulin on lipolysis and lipogenesis in adipocytes from genetically obese (ob/ob) mice.

A method for the preparation of isolated adipocytes from obese mice is described. Similar yields of adipocytes (50--60%), as judged by several criteria, are obtained from obese mice and lean controls. Few fat-globules and no free nuclei were observed in cell preparations, which are metabolically active, respond to hormonal control and appear to be representative of intact adipose tissue. Noradrenaline-stimulated lipolysis was inhibited by insulin, equally in adipocytes from lean and obese mice. Inhibition in obese cells required exogenous glucose, and the insulin dose--response curve was shifted to the right. Basal lipogenesis from glucose was higher in adipocytes from obese mice, and the stimulatory effect of insulin was greater in cells from obese mice compared with lean controls. A rightward shift in the insulin dose--response curve was again observed with cells from obese animals. This suggests that adipose tissue from obese mice is insulin-sensitive at the high blood insulin concentrations found in vivo. The resistance of obese mice to the hypoglycaemic effect of exogenous insulin and their impaired tolerance to glucose loading appear to be associated with an impaired insulin response by muscle rather than by adipose tissue.

L-serine dehydratase and L-serine-pyruvate aminotransferase activities in different animal species.

1. A rough inverse correlation between liver serine dehydratase activity and species body size was observed with mammals. This was not found for glutamate, malate or lactate dehydrogenase, fumarase or aspartate-2-oxoglutarate aminotransferase. Serine dehydratase (and certain liver aminotransferases showing a similar species-size dependence) may have a role in the stimulation of heat production. 2. Cold-exposed rats showed a 3-4 fold increase in serine dehydratase activity. 3. No liver serine dehydratase was measurable in amphibia. 4. In mammals high liver serine-pyruvate aminotransferase is associated with a flesh-eating dietary habit. High activity was found in amphibia and goldfish. A gluconeogenic role is suggested.

Increased liver L-serine-pyruvate aminotransferase activity under gluconeogenic conditions.

Rat liver l-serine-pyruvate aminotransferase activity exceeds markedly the normal adult value (a) in the neonatal period, (b) after glucagon injection and (c) after alloxan injection, observations that reinforce the suggestion from comparative findings that the aminotransferase has a role in gluconeogenesis. Some findings, however, argue in favour of l-serine dehydratase as the enzyme of gluconeogenesis from l-serine.

The subcellular distribution of rat liver L-alanine-glyoxylate aminotransferase in relation to a pathway for glucose formation involving glyoxylate.

1. The distribution of l-alanine-glyoxylate aminotransferase activity between subcellular fractions prepared from rat liver homogenates was investigated. The greater part of the homogenate activity (about 80%) was recovered in the ;total-particles' fraction sedimented by high-speed centrifugation and the remainder in the cytosol fraction. 2. Subfractionation of the particles by differential sedimentation and on sucrose density gradients revealed a specific association between the aminotransferase and the mitochondrial enzymes glutamate dehydrogenase and rhodanese. 3. The aminotransferase activities in the cytosol and the mitochondria are due to isoenzymes. The solubilized mitochondrial enzyme has a pH optimum of 8.6, an apparent K(m) of 0.24mm with respect to glyoxylate and is inhibited by glyoxylate at concentrations above 5mm. The cytosol aminotransferase shows no distinct pH optimum (over the range 7.0-9.0) and has an apparent K(m) of 1.11mm with respect to glyoxylate; there is no evidence of inhibition by glyoxylate. 4. The mitochondrial location of the bulk of the rat liver l-alanine-glyoxylate aminotransferase activity is discussed in relation to a pathway for gluconeogenesis involving glyoxylate.