Association between intraoperative opioid administration and 30-day readmission: a pre-specified analysis of registry data from a healthcare network in New England.

BACKGROUND: The use of intraoperative opioids may influence the rate of postoperative complications. This study evaluated the association between intraoperative opioid dose and the risk of 30-day hospital readmission. METHODS: We conducted a pre-specified analysis of existing registry data for 153 902 surgical cases performed under general anaesthesia at Massachusetts General Hospital and two affiliated medical centres. We examined the association between total intraoperative opioid dose (categorised in quintiles) and 30-day hospital readmission, controlling for several patient-, anaesthetist-, and case-specific factors. RESULTS: Compared with low intraoperative opioid dosing [quintile 1, median (inter-quartile range): 8 (4-9) mg morphine equivalents], exposure to high-dose opioids during surgery [quintile 5: 32 (27-41) equivalents] is an independent predictor of 30-day readmission [odds ratio (OR) 1.15 (95% confidence interval 1.07-1.24); P<0.001]. Ambulatory surgery patients receiving high opioid doses were found to have the greatest adjusted risk of readmission (OR 1.75; P<0.001) with a clear dose-response effect across quintiles (P for trend <0.05), and were more likely to be readmitted early (postoperative days 0-2 vs 3-30; P<0.001). Opioid class modified the association between total opioid dose and readmission, with longer-acting opioids demonstrating a stronger influence (P<0.001). We observed significant practice variability across individual anaesthetists in the utilisation of opioids that could not be explained by patient- and case-specific factors. CONCLUSIONS: High intraoperative opioid dose is a modifiable anaesthetic factor that varies in the practice of individual anaesthetists and affects postoperative outcomes. Conservative standards for intraoperative opioid dosing may reduce the risk of postoperative readmission, particularly in ambulatory surgery.

Association between intraoperative non-depolarising neuromuscular blocking agent dose and 30-day readmission after abdominal surgery.

BACKGROUND: We hypothesised that intraoperative non-depolarising neuromuscular blocking agent (NMBA) dose is associated with 30-day hospital readmission. METHODS: Data from 13,122 adult patients who underwent abdominal surgery under general anaesthesia at a tertiary care hospital were analysed by multivariable regression, to examine the effects of intraoperatively administered NMBA dose on 30-day readmission (primary endpoint), hospital length of stay, and hospital costs. RESULTS: Clinicians used cisatracurium (mean dose [SD] 0.19 mg kg-1 [0.12]), rocuronium (0.83 mg kg-1 [0.53]) and vecuronium (0.14 mg kg-1 [0.07]). Intraoperative administration of NMBAs was dose-dependently associated with higher risk of 30-day hospital readmission (adjusted odds ratio 1.89 [95% Confidence Interval (CI) 1.26-2.84] for 5th quintile vs 1st quintile; P for trend: P<0.001), prolonged hospital length of stay (adjusted incidence rate ratio [aIRR] 1.20 [95% CI 1.11-1.29]; P for trend: P<0.001) and increased hospital costs (aIRR 1.18 [95% CI 1.13-1.24]; P for trend: P<0.001). Admission type (same-day vs inpatient surgery) significantly modified the risk (interaction term: aOR 1.31 [95% CI 1.05-1.63], P=0.02), and the adjusted odds of readmission in patients undergoing ambulatory surgical procedures who received high-dose NMBAs vs low-dose NMBAs amounted to 2.61 [95% CI 1.11-6.17], P for trend: P<0.001. Total intraoperative neostigmine dose increased the risk of 30-day readmission (aOR 1.04 [1.0-1.08], P=0.048). CONCLUSIONS: In a retrospective analysis, high doses of NMBAs given during abdominal surgery was associated with an increased risk of 30-day readmission, particularly in patients undergoing ambulatory surgery.

Comparison of Whole Ovary Cryotreatments for Fertility Preservation.

The goal of this study was to compare a traditional slow-freeze method (TF) with an open unidirectional slow freeze cooling system (UF) for whole ovary cryopreservation. Therefore, whole pig ovaries were randomly assigned to (A) fresh control, (B) traditional slow freeze (TF) or (C) unidirectional slow freeze (UF). Ovaries were perfused with 10% DMSO in Krebs-Ringer. For TF, whole ovaries were placed in specimen jars containing 10% DMSO and placed into a specialized container for freezing filled with propan-2-ol. For UF, whole ovaries were placed within a specially designed container containing 10% DMSO and transferred to a specialized freezing machine (CTE 920). Histological evaluation demonstrated intact morphology of follicles in all groups; however, an overall decrease of follicle numbers in TF (46%) and UF (50%) compared to fresh control. Live/dead assay indicated significantly lower populations of live cells in both TF (60%) and UF (58%) compared to fresh tissue (74%). TUNEL assay confirmed a difference in percentage of apoptotic follicles between fresh and TF, but there was no significant difference between fresh and UF. To improve the structural and functional integrity of whole ovaries, further investigation, especially into directional freezing, is needed. Whole ovary cryopreservation could provide opportunities for women facing fertility loss due to chemo- or radiotherapy treatment.

Physiological and behavioural adaptations by big brown bats hibernating in dry rock crevices.

Winter energy stores are finite and factors influencing patterns of activity are important for overwintering energetics and survival. Hibernation patterns (e.g., torpor bout duration and arousal frequency) often depend on microclimate, with more stable hibernacula associated with greater energy savings than less stable hibernacula. We monitored hibernation patterns of individual big brown bats (Eptesicus fuscus; Palisot de Beauvois, 1796) overwintering in rock-crevices that are smaller, drier, and less thermally stable than most known cave hibernacula. While such conditions would be predicted to increase arousal frequency in many hibernators, we did not find support for this. We found that bats were insensitive to changes in hibernacula microclimate (temperature and humidity) while torpid. We also found that the probability of arousal from torpor remained under circadian influence, likely because throughout the winter during arousals, bats commonly exit their hibernacula. We calculated that individuals spend most of their energy on maintaining a torpid body temperature a few degrees above the range of ambient temperatures during steady-state torpor, rather than during arousals as is typical of other small mammalian hibernators. Flight appears to be an important winter activity that may expedite the benefits of euthermic periods and allow for short, physiologically effective arousals. Overall, we found that big brown bats in rock crevices exhibit different hibernation patterns than conspecifics hibernating in buildings and caves.

Mechanisms of apoptosis during reovirus infection.

Reovirus infection has proven to be an excellent experimental system for studying mechanisms of virus-induced pathogenesis. Reoviruses induce apoptosis in a wide variety of cultured cells in vitro and in target tissues in vivo, including the heart and central nervous system. In vivo, viral infection, tissue injury, and apoptosis colocalize, suggesting that apoptosis is a critical mechanism by which disease is triggered in the host. This review examines the mechanisms of reovirus-induced apoptosis and investigates the possibility that inhibition of apoptosis may provide a novel strategy for limiting virus-induced tissue damage following infection.

Anonymous HIV surveillance in Saughton Prison, Edinburgh.

OBJECTIVES: To estimate the prevalence of HIV by anonymous saliva testing in Her Majesty's Prison, Saughton (Saughton Prison), Edinburgh, UK. To elicit linked anonymous risk factor information from which to estimate risk scores for those who had taken an HIV blood test and, among drug injectors, for those who were HIV-1-antibody-positive on saliva testing. SETTING: Saughton Prison on 15 and 16 August 1991; HIV Immunology and Regional Virus Laboratories, Edinburgh, and the Medical Research Council Biostatistics Unit, Cambridge, UK. PARTICIPANTS: Male inmates (378 out of a total of 499) of Saughton Prison. MAIN OUTCOME MEASURES: Answers to a brief questionnaire about age, usual residence, present and past custodial sentences, drug injecting and sexual behaviour prior to and in prison, HIV testing and history of acute hepatitis. HIV-1-antibody status was established by saliva testing. RESULTS: Eighteen per cent of participants were injecting drug users (IDU), of whom approximately one-half (47%) had injected while inside prison. Ninety men (26%), including 40 (14%) of 278 participants who had never injected drugs and 77% of IDU participants, had taken an HIV blood test. Nine per cent of all participants and 35% of IDU participants had had an acute attack of hepatitis. Forty-one (62%) of 66 IDU had been imprisoned five or more times before their current prison sentence. After taking account of region of residence, injecting drug history and acute hepatitis, aspects of sentencing and sexual behaviour were not determinants of those who had been tested for HIV. On the study days, 18 out of 499 (3.6%) participants were known to prison medical officers to be HIV-infected. Following saliva testing, HIV prevalence was 17 out of 375 (4.5%) inmates tested. All 17 had at some time 'taken the blood test for HIV' and all had injected non-medically prescribed drugs. Edinburgh residence, age 26-30 years, have injected in prison and having first injected before 1983 all contributed to the risk score for whether an IDU was HIV-1-antibody-positive on saliva testing. CONCLUSIONS: Documented HIV prevalence in saliva was 4.5%, which--assuming no volunteer bias (as supported by questionnaire returns)--suggests that actual HIV prevalence was 25% greater than revealed to Saughton's prison medical service. All 17 inmates who were HIV-1-antibody-positive on saliva testing had injected non-medically prescribed drugs. The high reported frequency by inmates of injecting in prison highlights the urgent requirement for drug reduction and rehabilitation programmes for injecting inmates. Linked anonymous voluntary HIV testing of saliva can provide valuable information about HIV prevalence for the planning of prison resources and policy.

HIV prevalence and risk factors in university students.

OBJECTIVE: To estimate HIV prevalence and risks in university students. DESIGN: Anonymous self-completion questionnaire and HIV survey with saliva samples. SETTING: University students at matriculation. PARTICIPANTS: All first and third year undergraduates and newly registering postgraduates at the University of Edinburgh, Scotland. MAIN OUTCOME MEASURES: HIV prevalence, sexual behaviour, condom use, drug use. RESULTS: The questionnaire responses were used to classify the 4665 respondents into four groups, ordered by risk of HIV positivity, and a sample of 2041 was selected for testing. All of the top two risk groups were tested (217 and 758 tests, respectively) as well as a random sample of the others. Five positive HIV-antibody tests were detected, all from the highest risk group. This gives an estimated rate of 1.2 per 1000 (95% confidence interval, 0.4-2.9) for all respondents. Only one of the five HIV-positives had been tested for HIV. The factors associated with HIV positivity were residence in Africa, intravenous drug use and male homosexuality. Overall, 74% of respondents reported ever having had sexual intercourse and this rate was the same for men and women. Reported intravenous drug use was very low: 0.5% for men and 0.1% for women. Condom use was more common for partners of short acquaintance, but unrelated to the number of sexual partners in the last year. CONCLUSIONS: There was no evidence of the spread of HIV infection beyond known high-risk groups in this population. This may be a result of relatively low levels of HIV risk-taking behaviour in the majority of respondents.

PIP: In Scotland during 1993-1994, 4665 first and third year undergraduates, newly registering postgraduates, and nongraduating students at the University of Edinburgh completed a questionnaire. Based on responses, the researchers categorized the students into four risk groups. One group consisted of men with male sex partners in the last year, permanent home in Africa, IV non-medically prescribed drug use, ever shared needles or works, ever paid or been paid money for sex, professionally exposed to blood. The second group include those not in the first group but had more than 3 sex partners in the last year, or persons with more than 2 sex partners in the last year and no condom use at last intercourse, or sexual intercourse with a resident of Africa. Persons who were neither in the first two groups nor the fourth group comprised the third group. Persons who never had sex and were not in group one comprised group four. They submitted saliva tests to all students in the top two risk groups and to a random sample of those in the other groups for a total of 2041 students. The researchers aimed to determine HIV prevalence and risk factors. All five HIV seropositive students were from the highest risk group for an overall HIV prevalence rate of 1.2/1000. The HIV prevalence rate for those just in the highest risk group was 22/1000. Only one of these HIV seropositive students had been tested earlier for HIV. HIV infections were limited to persons with a permanent home in Africa, IV drug use, and male homosexual intercourse. All but one HIV seropositive individual were males. 73.7% of all respondents had ever engaged in sexual intercourse. IV drug use was rare (0.5% for men and 0.1% for women). 52% of respondents used a condom during last intercourse. Condom use was associated with short acquaintance of partners. The number of sexual partners in the last year did not affect condom use. These findings indicate that HIV transmission appears to be confined to high risk groups, probably because most students did not practice risky behavior.

Metabotropic glutamate receptor mRNA expression in the schizophrenic thalamus.

BACKGROUND: The central role that the thalamus plays in information processing and sensory integration suggests that its dysfunction may be a factor in the pathophysiology of schizophrenia. Glutamate is a key neurotransmitter in thalamic function, and although all aspects of thalamic glutamate neurotransmission have not been elucidated, transcripts encoding members of each family of the glutamate receptors have been identified in the thalamus. Recently, activation of group II metabotropic glutamate receptors (mGluRs) was demonstrated in rats to ameliorate the behavioral effects associated with exposure to phencyclidine, an uncompetitive NMDA receptor antagonist that can induce psychotic symptoms, suggesting the possibility of mGluR abnormalities in schizophrenia. We investigated whether expression of thalamic mGluR mRNA is altered in this illness. METHODS: We examined the expression of the transcripts encoding the mGluR1, 2, 3, 4, 5, 7, and 8 receptors in postmortem thalamic tissue samples from elderly schizophrenic and control subjects, using in situ hybridization. We identified six thalamic nuclei in each section (anterior, dorsomedial, lateral dorsal, central medial, reticular, and nuclei of the ventral tier). RESULTS: There were no differences between elderly schizophrenic and control subjects in the expression of mGluR1, 2, 3, 4, 5, 7, or 8 transcript levels in any of these six thalamic nuclei. CONCLUSIONS: mGluR mRNA expression is not abnormal in the thalamus of patients with schizophrenia. The modulatory roles proposed for mGluRs, and the potentially important relationship between mGluRs and NMDA receptors, suggest that mGluRs may be involved in the pathophysiology of schizophrenia, but this is not detectable at this level of gene expression.

Multifocal motor neuropathy with conduction block: is it a distinct clinical entity?

We studied 169 patients with motor neuron disease. Seventeen showed abnormal amplitude reduction of the compound muscle action potential. Ten had focal loss of both amplitude and area across a specific segment (conduction block). Eight of the 10 had slowing of conduction across that segment. Nine were men and had prominent hand involvement. Six had probable or definite upper motor neuron signs. Five of the 10 showed immunologic abnormalities (elevated GM1 antibody titers or paraproteinemia), and eight had had symptoms for more than 4 years. Seven of the 17 patients showed loss of amplitude without corresponding loss of area and focal slowing of conduction (temporal dispersion). Five of the seven were men, five had prominent hand involvement, and five had definite or probable upper motor neuron signs. Two had immunologic abnormalities, and ony one had had symptoms for longer than 4 years. Among 152 patients with no abnormality of conduction, 64% wee men, hands were dominantly involved in 34%, upper motor neuron signs were definite or probable in 72%, and 3% had immunologic abnormalities. None had symptoms for more than 4 years. Because there were so many exceptions, we could not define a unique syndrome by criteria involving conduction block, GM1 antibodies, or lack of upper motor neuron signs. The clinical syndrome associated with multifocal conduction block seemed uniform, however, and patients with conduction block had slower progression if there were no upper motor neuron signs.

Quantitative analysis of myocardial perfusion changes with transmyocardial laser revascularization.

Transmyocardial laser revascularization (TLR) is a technique of creating left ventricular transmural channels in patients with refractory angina. We aimed to measure perfusion changes quantitatively using technetium-99m methoxyisobutyl isonitrile. Perfusion scans were performed on 94 TLRs and in 94 control patients at rest and during exercise at assessment, and 3-, 6-, and 12-month follow-up. A serial set of scans allowed direct comparison of each patient over all visits. Bull's-eyes were divided into 5 anatomic regions and a 20-region model. Severity values were calculated for rest, stress, and each cardiac region using a threshold of 1 for analysis. Higher scores indicated greater severity of ischemia and lower perfusion. At 3-month follow-up, the severity was significantly worse during TLR than in control patients both during stress (0.172 +/- 0.003 and 0.161 +/- 0.003, respectively, p = 0.007) and at rest (0.170 +/- 0.003 and 0.158 +/- 0.003, respectively, p = 0.002). At 6 months, severity during stress was 0.176 +/- 0.003 with TLR and 0.162 +/- 0.003 in controls (p = 0.001), with no significant difference at rest. At 12 months, there was no significant difference between TLR and control groups at stress and rest. Regional severity deteriorates during TLR compared with control patients anteriorly (p = 0.001, p = 0.0016, p = 0.005 at 3, 6, and 12 months), apically (p = 0.005, p = 0.0046, p = 0.032, respectively), and laterally (p <0.0001, p = 0.001, p = 0.002, respectively). An apparent improvement is observed in the inferoseptal region at 6- and 12-month follow-up-an area not lasered. Thus, TLR appears to produce deterioration in resting myocardial perfusion in lasered regions, and improvement in nonlasered regions, with no difference in exercise-induced myocardial ischemia compared with that in control patients.

Genetic heterogeneity of HIV type 1 subtypes in Kimpese, rural Democratic Republic of Congo.

A relatively low and stable seroprevalence of HIV-1 was previously reported among pregnant women attending for antenatal care between 1988 and 1993 in Kimpese, a rural town in the Democratic Republic of Congo (DRC, formerly Zaire). To characterize the HIV-1 subtypes circulating in this area, we have examined a 330-bp fragment of the p17 region of the gag gene of HIV-1 strains obtained from 70 patients (55 mothers, 15 children), of whom 61 were epidemiologically unlinked. Phylogenetic analyses revealed the existence of at least seven HIV-1 subtypes within the Kimpese region. Among the 61 epidemiologically unlinked patients, subtype A was predominant and found in 29 (47.5%) individuals. Other subtypes cocirculating in this rural part of DRC include subtypes C (1.6%), D (9.8%), F (3.2%), G (6.5%), H (21.3%), and J (4.9%). Sequences from four patients did not cluster with any of the currently documented HIV-1 subtypes, in analyses of fragments of both the gag (247 to 330 bp, 197 bp, and 310 bp) and env (340 bp) genes. Overall, comparisons of the gag(p17) gene regions revealed high pairwise divergences (mean, 19.9%; range, 1 to 46%). This level of gag(p17) gene variation in the DRC is considerably greater than previously appreciated. These results are relevant for the molecular epidemiology of HIV-1 in Africa and for the design of a future vaccine against HIV-1 in this region.

Stacked inspiratory spirometry reduces pulmonary shunt in patients after coronary artery bypass.

Atelectasis is a major factor in postoperative morbidity for patients undergoing cardiopulmonary surgery. We evaluated the effectiveness of stacked inspiratory spirometry (STIS) in 17 patients status postcoronary artery bypass graft in a nonrandomized fashion. We measured pulmonary shunt as an endpoint, and compared the magnitudes before and after the STIS maneuver. Our results showed an 8.66 percent reduction in pulmonary shunt (p < 0.05). The reduction in shunt was modest; however, repetitive maneuvers might result in greater improvement.

Anticardiolipin antibodies and pregnancy outcome in women with human immunodeficiency virus infection.

Abnormal anticardiolipin antibodies are associated with adverse pregnancy outcome in the general obstetric population. We studied 55 pregnancies in women infected with human immunodeficiency virus type 1 (HIV-1) to examine two hypotheses: that a substantial proportion of these women would have raised anticardiolipin antibodies, and that the affected pregnancies would be more likely to be complicated by preterm delivery and intrauterine growth retardation. Blood was taken at the initial antenatal visit, and was also taken from 15 HIV-seronegative intravenous (IV) drug users and 20 controls with no drug history. The reference for immunoglobulin G class antibodies to cardiolipin was calculated from 50 healthy young adults, and the upper limit of normal was defined as 4 standard deviations above the mean for this reference series. Twenty-four percent of the infected women, but none of the HIV-seronegative IV drug users and none of the control group, had raised anticardiolipin antibodies. There was no statistically significant relationship with birth weight, standardized birth weight, length, gestation, occipitofrontal circumference, or adverse pregnancy outcome. No women gave a history of thromboembolism or recurrent abortion, and in no pregnancy was there clinically apparent thromboembolism. We conclude that abnormal anticardiolipin antibodies provoked by HIV infection are common, but probably have a narrow specificity for cardiolipin, are unrelated to phospholipid antibody syndrome, and cannot explain adverse pregnancy outcome in HIV-infected women.

Prevalence of hepatitis C in prisons: WASH-C surveillance linked to self-reported risk behaviours.

We used cross-sectional willing anonymous salivary hepatitis C (WASH-C) surveillance linked to self-completed risk-factor questionnaires to estimate the prevalence of salivary hepatitis C antibodies (HepCAbS) in five Scottish prisons from 1994 to 1996. Of 2121 available inmates, 1864 (88%) participated and 1532/1864 (82%) stored samples were suitable for testing. Overall 311/1532 (20.3%, prevalence 95% CI 18.3-22.3%) were HepCAbS-positive: 265/536 (49%, 95% CI 45-54%) injector-inmates but only 27/899 (3%, 95% CI 2-4%) non-injector-inmates. Among injectors, HepCAbS positivity was only slightly higher (p = 0.03) in those who had injected inside prison (53%, 162/305) than in those who had not (44%, 98/224). Those who began injecting in 1992-96 were much less likely to be HepCAbS-positive than those who started pre-1992 (31%, 35/114 vs. 55%, 230/422; p < 0.001). Even with injectors who began in 1992-96 but had never injected inside prison, the prevalence of hepatitis C carriage was 17/63 (95% CI 16-38%). The prevalence and potential transmissibility of hepatitis C in injector-inmates are both high. Promoting 'off injecting' before 'off drugs' (both inside and outside prison), methadone prescription during short incarcerations, alternatives to prison, and support of HepCAbS-positive inmates in becoming eligible for treatment, all warrant urgent consideration.

The involvement of the anterior cingulate cortex in blood pressure control.

The visceromotor nature of the rat anterior cingulate cortex was investigated by electrically stimulating this area in both anesthetized and awake animals. Initial studies demonstrated that electrical stimulation of any division of the anterior cingulate cortex elicits a significant fall in blood pressure in the sodium pentobarbital-anesthetized rat. Depressor responses were greatest (up to 50% decreases) following stimulation of the ventral third of the anterior cingulate cortex. Heart rate was not altered by cingulate cortex stimulation. In the awake animal, stimulation of previously identified depressor sites in the rostral third of the pregenual cingulate cortex elicited pressor responses. In contrast, stimulation of the caudal third of this cortex elicited depressor responses, and stimulation of the middle third elicited biphasic (pressor followed by depressor) responses. These results indicate that the anterior cingulate cortex is a visceromotor region which may provide a cortical output for the regulation of blood pressure responses associated with learning and or stress.

The impact of chronic hepatitis C virus infection on HIV disease and progression in intravenous drug users.

OBJECTIVE: It is unclear whether co-infection with hepatitis C virus (HCV) can influence HIV related morbidity or mortality, either by accelerating HIV-related disease progression, or by contributing to end stage liver disease. The aim of this study was to examine the effect of HCV infection on the severity and progression of HIV disease in a cohort of Edinburgh intravenous drug users (IDUs). METHODS: In 240 (47%) out of 508 patients in the Edinburgh IDU cohort both HIV seroconversion dates and anti-HCV serology were available. Demographic variables and HIV-related progression between anti-HCV positive and anti-HCV negative groups were compared. Parameters assessed included clinical endpoints (time of development of significant symptoms attributable to HIV (CDC stage IV), time of development of AIDS, and time of death) and immunological endpoints (time of CD4+ counts dropping below 200/mm3, 100/mm3 and 50/mm3). RESULTS: Two hundred and two out of 240 patients (84%) had positive anti-HCV serology. There was no significant difference in the frequency of clinical and immunological endpoints between the anti-HCV positive and negative groups. Progression analysis from HIV seroconversion to HIV related clinical endpoints indicated that anti-HCV serology was not a significant factor influencing the rate of HIV progression (relative risks (RR) for anti-HCV positive group: seroconversion to CDC IV, 1.01; seroconversion to AIDS, 1.05; seroconversion to death, 0.90). Likewise, HCV serostatus did not significantly affect progression to immunological endpoints (RR for anti-HCV positive group: seroconversion to CD4+ < 200/mm3, 1.04; seroconversion to CD4+ < 100/mm3, 1.13; seroconversion to CD4+ < 50/mm3, 0.97. Overall mortality from end stage liver failure was 4% in HCV-seropositive patients without AIDS. This suggests that HCV has had a clinically (though not statistically) significant impact on overall survival in this cohort. CONCLUSIONS: This study demonstrates that HCV co-infection does not influence the rate of progression to either clinical or immunological endpoints in our population of HIV-infected drug users. Further data are required to assess the effect of HIV on thge progression of HCV-related liver disease.

Measles, mumps and rubella immunisation in children at risk of infection with human immunodeficiency virus.

A retrospective serological study of 81 children at risk of HIV (II HIV-infected, 70 HIV-negative) was performed to assess susceptibility to measles, mumps and rubella and response to measles, mumps and rubella (MMR) immunisation. There was no difference in the initial serological response between the HIV-infected and HIV-negative children. Repeat serology should be performed on HIV-infected children as during follow-up antibodies may be lost. Reimmunisation should be considered for the seronegative.

Reduced concentrations of IgG antibodies to Pneumocystis carinii in HIV-infected patients during active Pneumocystis carinii infection and the possibility of passive immunisation.

The relationship between Pneumocystis carinii antibody concentrations and acute Pneumocystis infection was investigated by testing sequential samples of serum from HIV antibody-positive patients with respiratory symptoms and HIV-negative immunocompromised patients by means of an indirect immunofluorescence assay for specific IgG antibodies to P. carinii. Loss of circulating antibody at the time of active Pneumocystis infection was observed in five patients with proven infection. Three others showed recovery of antibody coinciding with treatment and clinical recovery from infection. Concentrations of specific IgG antibody against P. carinii were measured in 40 blood donors and in six different batches of an intravenous immunoglobulin (IV Ig) preparation. Titres greater than 128 were found in the IV Ig batches examined. The use of IV Ig, either alone or in conjunction with other therapeutic agents, should therefore be considered in patients suffering from acute infection with P. carinii.

The epidemiology of HIV infection in Edinburgh related to the injecting of drugs: an historical perspective and new insight regarding the past incidence of HIV infection derived from retrospective HIV antibody testing of stored samples of serum.

The pattern of sudden explosive outbreaks of HIV infection among drug users has been seen in several countries but is as yet incompletely understood. The epidemic of injecting drugs in Edinburgh was associated with at least four overlapping epidemics of blood-borne viruses (hepatitis B, C, D and HIV). Only hepatitis B was initially recognized, being followed by HIV and latterly hepatitis C. Retrospective HIV testing of stored samples of serum from clinically diagnosed patients with HIV has allowed the HIV epidemic to be delineated and more accurate seroconversion dates identified for most of the patients. There is evidence to suggest that the explosive drug-related Edinburgh HIV epidemic may have been self-terminating and that the epidemic in male drug users preceded that in female drug users by around 3 months. We suggest that the self-terminating nature of this epidemic may have been related to changes in drug injecting behaviour or to varying infectivity of the virus. This latter possibility should be explored in future studies of HIV transmission.