Immunological response to cytomegalovirus in congenitally infected neonates

Cytomegalovirus (CMV) is the most common cause of congenital infection worldwide and occurs as a result of transplacental transmission of the virus. The human neonate is highly susceptible to infection due to a combination of immaturity of the immune system and antigenic inexperience. This study uses the in vivo model of congenital CMV to examine both the humoral and cell-mediated immune responses in vertically infected neonates and their mothers. Ten pairs of matched neonates and their mothers were evaluated for specific IgM responses to three immunodominant CMV antigens: pp38 (pUL80a), pp52 (pUL44) and pp150 (pUL32). In contrast to conventional enzyme immunoassay (EIA) testing for CMV-specific IgM, which found five of the mothers and four of the neonates to be positive, Western immunoblotting showed all 10 adults and nine newborns to be positive. Eight mothers and nine newborns had serological evidence of primary infection. All neonates showed a response to pp38, an assembly protein, nine responded to the pp52 immediate early antigen but only four had reactivity to the pp150 tegument associated protein. Of the mothers, eight had pp38 reactivity, 10 showed a response to the pp52 antigen and seven to the pp150 antigen. T cell-mediated immunity was assessed by measuring cytokines using a multiplex microarray assay. Levels of interferon (IFN)-gamma were high in both groups [mean +/- standard error of the mean (s.e.m.): neonates = 657 +/- 238 pg/ml, mothers = 1072 +/- 677 pg/ml, pNS]; however, neonates had significantly higher levels of interleukin (IL)-8 (316 +/- 136 pg/ml versus 48 +/- 28 pg/ml, P < 0.005). Similar levels of IL-2, IL-7, IL-10 and IL-12 were measured in both groups, but levels of IL-1alpha, IL-1beta, IL-4, IL-6 and tumour necrosis factor (TNF)-alpha were either absent or low. In response to CMV, neonates and adults mount a predominant T helper 1 (Th1) response, as evidenced by the presence of IL-2, IL-8, IL-12 and IFN-gamma with concomitant lack of IL-4. These findings suggest that the neonate, when presented with infection in utero, is capable of mounting an individual response; however, the lower IFN-gamma and higher IL-8 levels suggest reduced immune responsiveness when compared to their adult counterparts.

Molecular evidence for infection by HTLV-2 among individuals with negative serological screening tests for HTLV antibodies

Previous serological studies on the Arara do Laranjal Indian group revealed extensive HTLV-2 infections. A collection of 97 new samples from the Arara were found repeatedly negative using three different commercial enzyme immunoassays. Eight samples that exhibited optical density readings close to the cut-off value were re-evaluated using Western blot (GeneLab 2.4, Singapore) assay. One sample was found to be non-reactive, five exhibited indeterminate patterns, one was classified as HTLV, and one was confirmed as HTLV-2. Peripheral blood mononuclear cell DNA of the eight samples were subjected to nested PCR and restriction fragment length polymorphism (RFLP) analysis of the pX and env regions, and nucleotide sequencing of the 5'-LTR region. All produced amplification products of pX, but env could be amplified in only one sample with the commonly used primers. RFLP analysis of the pX region using TaqI confirmed HTLV-2 infection. Nucleotide sequencing of the 5'-LTR region was performed in three samples (HTLV-2, HTLV and indeterminate based on Western blot pattern). Phylogenetic analysis of a 449-nt fragment using the Neighbour-Joining method clearly demonstrated that the three samples clustered within the HTLV-2c molecular subtype. The present study confirms the wide dissemination of the HTLV-2c subtype among linguistically and culturally distinct Amazonian Indian groups, and emphasizes the unique occurrence of infection by this subtype in Brazil. Moreover, it emphasizes the limitation of employing the present serological screening assays in blood banks, epidemiological studies, and the importance of molecular assays in the confirmatory procedures for the primary detection of HTLV-2 infections.

A 13-week dietary toxicity and toxicokinetic study with l-theanine in rats

This study was conducted to evaluate the safety of l-theanine (Suntheanine) when administered as a dietary admixture to male and female Crl:CD (SD)GS BR rats at concentrations providing doses of 0, 1500, 3000 or 4000 mg/kg bw/day for 13 weeks. The study design was consistent with OECD Guideline 408 and USFDA Redbook II (1993) and GLP. There were no consistent, statistically significant treatment-related adverse effects on behavior, morbidity, mortality, body weight, food consumption and efficiency, clinical chemistry, hematology, or urinalysis. There were no consistent treatment-related adverse effects in gross pathology, organ weights or ratios or histopathology. The increased incidence of renal tubular cell adenomas in high-dose females only were not consistent with the characteristics of a renal carcinogen (due to early onset and low number of animals affected) but were more consistent with a genetic predisposition than with direct organ toxicity. The no-observed-adverse-effect-level (NOAEL) was 4000 mg/kg bw/day, the highest dose tested.

Using cohort studies to estimate mortality among injecting drug users that is not attributable to AIDS

BACKGROUND

Injecting drug use (IDU) and associated mortality appear to be increasing in many parts of the world. IDU is an important factor in HIV transmission. In estimating AIDS mortality attributable to IDU, it is important to take account of premature mortality rates from other causes to ensure that AIDS related mortality among injecting drug users (IDUs) is not overestimated. The current review provides estimates of the excess non-AIDS mortality among IDUs.

METHOD

Searches were conducted with Medline, PsycINFO, and the Web of Science. The authors also searched reference lists of identified papers and an earlier literature review by English et al (1995). Crude mortality rates (CMRs) were derived from data on the number of deaths, period of follow up, and number of participants. In estimating the all-cause mortality, two rates were calculated: one that included all cohort studies identified in the search, and one that only included studies that reported on AIDS deaths in their cohort. This provided lower and upper mortality rates, respectively.

RESULTS

The current paper derived weighted mortality rates based upon cohort studies that included 179 885 participants, 1,219,422 person-years of observation, and 16,593 deaths. The weighted crude AIDS mortality rate from studies that reported AIDS deaths was approximately 0.78% per annum. The median estimated non-AIDS mortality rate was 1.08% per annum.

CONCLUSIONS

Illicit drug users have a greatly increased risk of premature death and mortality due to AIDS forms a significant part of that increased risk; it is, however, only part of that risk. Future work needs to examine mortality rates among IDUs in developing countries, and collect data on the relation between HIV and increased mortality due to all causes among this group.

Investigation of SO2, HCl and NOx, control from waste incinerators using a novel additive in a pilot scale reactor

A pilot scale experimental investigation of the use of a novel additive, calcium magnesium acetate, for the simultaneous control of SO2, HCl and NOx has been carried out. The pilot scale reactor simulated the furnace and flue gas conditions of a typical large scale waste incinerator and was a vertical 4m high reactor operated at 80 kW. The calcium magnesium acetate was added as a wet spray to the reactor at temperatures above 750 degrees C. The influence of the calcium magnesium acetate dose rate was investigated on the simultaneous removal of SO2, HCl and NOx. Maximum reductions were achieved at a Ca/S ratio (or Ca/Cl ratio) of 2.5 and were, 70% for SO2, 45% for HCl and 18% for NOx for each of the pollutant gases respectively.

Molecular epidemiology of norovirus strains circulating in Ireland from 2003 to 2004

Since 2002, the burden of norovirus (NoV) infection in Ireland has increased. Outbreaks in institutional settings are the most common causing widespread disruption to health service delivery. This is the first national study of NoV in the Republic of Ireland and its aim was to identify the major NoV strains circulating in Ireland over a 13-month period between November 2003 and November 2004, inclusive. A prospective study screened faecal samples (n = 478) for NoV RNA. Positive samples (n = 116) were further analysed by a second PCR, targeted to the orf1/orf2 junction of the virus. Phylogenetic analysis was based on sequence alignments of this domain. GII/4 viruses represented 92.2% of sequences, 2.7% were GII/2, GII/3 and GGIIB cluster-like strains. The remaining 5.2% were of GI origin. NoV was detectable throughout the study period, although two peaks of infection were observed. The majority of infections were caused by a range of closely related GII/4 NoV strains.

Cohort trends in age of initiation to heroin use

This paper examines gender differences and trends over time in the age of initiation to heroin use. Data from two large surveys: the Sydney component of the ANAIDUS, conducted in 1989, and the ASHIDU, conducted in 1994, were used to examine this issue. Together, these studies contained information on 1,292 individuals who identified themselves as heroin users. Results indicated that, while there were no significant gender differences in age of initiation to heroin use, there was a significant (p < 0.001) time trend in the mean age at which heroin was first used. Specifically, the mean age of first heroin use among individuals born during the interval 1940-1949 was 20.5 years while among those born during 1970-1979 the mean age of first heroin use was 16.5 years. These findings were confirmed by analyses of the National Household Survey. Further analysis of the ASHIDU data indicated that younger age of initiation to heroin use was associated with polydrug use, overdose and crime after the effects of duration of heroin use had been statistically controlled. These findings suggest that there has been both an increase in the willingness of young people to experiment with heroin and an increased availability of the drug over this time. In combination with evidence that there has been an increase in the amount of heroin being imported into Australia, and an increased demand for treatment for opiate dependence, these data suggest that Australia is experiencing an increase in the use of heroin, particularly among youth.

Cannabis use and psychosis

This paper reviews evidence on two hypotheses about the relationship between cannabis use and psychosis. The first hypothesis is that heavy cannabis use may cause a "cannabis psychosis"-a psychosis that would not occur in the absence of cannabis use, the symptoms of which are preceded by heavy cannabis use and remit after abstinence. The second hypothesis is that cannabis use may precipitate schizophrenia, or exacerbate its symptoms. Evaluation of these hypotheses requires evidence of an association between cannabis use and psychosis, that is unlikely to be due to chance, in which cannabis use precedes psychosis, and in which we can exclude the hypothesis that the relationship is due to other factors, such as other drug use, or a personal vulnerability to psychosis. There is some clinical support for the first hypothesis. If these disorders exist they seem to be rare, because they require very high doses of THC, the prolonged use of highly potent forms of cannabis, or a pre-existing (but as yet unspecified) vulnerability. There is more support for the second hypothesis, in that a large prospective study has shown a linear relationship between the frequency with which cannabis has been used by age 18 and the risks over the subsequent 15 years of a diagnosis of schizophrenia. It is still unclear whether this means that cannabis use precipitates schizophrenia, whether it is a form of "self-medication", or whether the association is due to the use of other drugs, such as amphetamines, which heavy cannabis users are more likely to use. There is stronger evidence that cannabis use can exacerbate the symptoms of schizophrenia. Mental health services should identify patients with schizophrenia who use alcohol, cannabis and other drugs and advise them to abstain or to greatly reduce their drug use.

A case of late postpartum seizures after epidural analgesia

We present the case of a 29-year-old female who in her third pregnancy developed seizures seven days postpartum. The only symptoms preceding the seizures were headache and visual disturbance. There was no evidence of preeclampsia antepartum or postpartum. All clinical investigations were normal including computerised tomography, magnetic resonance imaging and lumbar puncture. All symptoms resolved within 24 h of the first seizure. In this case report we highlight the difficulties in establishing the cause of postpartum seizures.

Updated European recommendations for the clinical use of HIV drug resistance testing

In most European countries, HIV drug resistance testing has become a routine clinical tool. However, its practical implementation in a clinical context is demanding. The European HIV Drug Resistance Panel was established to make recommendations to clinicians and virologists on this topic and to propose quality control measures. The panel recommends resistance testing for the following indications: i) drug-naive patients with acute or recent infection; ii) therapy failure, including suboptimal treatment response, when treatment change is considered; iii) pregnant HIV-1-infected women and paediatric patients with detectable viral load when treatment initiation or change is considered; and iv) genotype source patient when post-exposure prophylaxis is considered. In addition, for drug-naive patients with chronic infection in whom treatment is to be started, the panel suggests that resistance testing should be strongly considered and recommends testing the earliest sample for drug resistance if suspicion of resistance is high or prevalence of resistance in this population exceeds 10%. The panel does not favour genotyping over phenotype, however it is anticipated that genotyping will be used more often because of its greater accessibility, lower cost and faster turnaround time. For the interpretation of resistance data, clinically validated systems should be used to the greatest extent possible. It is mandatory that laboratories performing HIV resistance tests take regular part in quality assurance programs. Similarly, it is necessary that HIV clinicians and virologists take part in continuous education and meet regularly to discuss problematic clinical cases. Indeed, resistance test results should be used in the context of all other clinically relevant information for predicting therapy response. The panel also encourages the timely collection of epidemiological information to estimate the impact of transmission of resistant HIV and the prevalence of HIV-1 non-B subtypes in the different European countries.

Updated European Recommendations for the Clinical Use of HIV Drug Resistance Testing

In most European countries, HIV drug resistance testing has become a routine clinical tool. However, its practical implementation in a clinical context is demanding. The European HIV Drug Resistance Panel was established to make recommendations to clinicians and virologists on this topic and to propose quality control measures. The panel recommends resistance testing for the following indications: i) drug-naive patients with acute or recent infection; ii) therapy failure, including suboptimal treatment response, when treatment change is considered; iii) pregnant HIV-1-infected women and paediatric patients with detectable viral load when treatment initiation or change is considered; and iv) genotype source patient when post-exposure prophylaxis is considered. In addition, for drug-naive patients with chronic infection in whom treatment is to be started, the panel suggests that resistance testing should be strongly considered and recommends testing the earliest sample for drug resistance if suspicion of resistance is high or prevalence of resistance in this population exceeds 10%. The panel does not favour genotyping over phenotype, however it is anticipated that genotyping will be used more often because of its greater accessibility, lower cost and faster turnaround time. For the interpretation of resistance data, clinically validated systems should be used to the greatest extent possible. It is mandatory that laboratories performing HIV resistance tests take regular part in quality assurance programs. Similarly, it is necessary that HIV clinicians and virologists take part in continuous education and meet regularly to discuss problematic clinical cases. Indeed, resistance test results should be used in the context of all other clinically relevant information for predicting therapy response. The panel also encourages the timely collection of epidemiological information to estimate the impact of transmission of resistant HIV and the prevalence of HIV-1 non-B subtypes in the different European countries.

Ethical issues in using a cocaine vaccine to treat and prevent cocaine abuse and dependence

A "cocaine vaccine" is a promising immunotherapeutic approach to treating cocaine dependence which induces the immune system to form antibodies that prevent cocaine from crossing the blood brain barrier to act on receptor sites in the brain. Studies in rats show that cocaine antibodies block cocaine from reaching the brain and prevent the reinstatement of cocaine self administration. A successful phase 1 trial of a human cocaine vaccine has been reported. The most promising application of a cocaine vaccine is to prevent relapse to dependence in abstinent users who voluntarily enter treatment. Any use of a vaccine to treat cocaine addicts under legal coercion raises major ethical issues. If this is done at all, it should be carefully trialled first, and only after considerable clinical experience has been obtained in using the vaccine to treat voluntary patients. There will need to be an informed community debate about what role, if any, a cocaine vaccine may have as a way of preventing cocaine addiction in children and adolescents.

Prescription drug utilization following patient co-payment changes in Australia

In November 1990 major patient co-payment changes were introduced into the Pharmaceutical Benefits Scheme (PBS), which accounts for around 90% of all community prescriptions in Australia. Interrupted time series analyses were performed to assess the impact of these co-payment changes on the prescription levels of defined groups of 'discretionary' and 'essential' drugs for both the general community and for a subgroup comprising elderly returned servicemen and women. While the co-payment changes themselves had a significant immediate effect on lowering the use of both categories of drugs, the effects were substantially larger for the 'discretionary' groups in both cases. Notably there was a clear post-intervention trend for increased prescriptions of 'essential' drugs after the initial decline, which was not evident for the 'discretionary' drugs. The introduction of programmes to compensate high risk groups in Australia may have enabled the co-payment to become a more selective policy instrument than has been shown in other settings.

Marginal transfer of ReoPro (Abciximab) compared with immunoglobulin G (F105), inulin and water in the perfused human placenta in vitro

ReoPro (Abciximab), a Fab fragment of a human-murine chimeric monoclonal antibody, binds to glycoprotein IIb/IIIa receptors on human platelets and inhibits platelet aggregation. Can ReoPro transit the human placenta since it does not have an Fc (domain) as does IgG? This question was addressed using an in vitro term human placental lobular dual perfusion model. ReoPro, along with 3H(2)O, inulin or 125I-F105 human IgG(1), were added to the maternal reservoir for 6 or >12 h, ReoPro was equivalent to, or exceeded, clinically relevant plasma concentrations (0.3-3 microg/ml). 3H(2)O rapidly appeared in the fetal circuit, while fetal 14C-inulin never equilibrated with the maternal inulin. After 6 h, 125I-F105 was present with fetal/maternal percentages-0.55 per cent. ReoPro was not detectable (<3.9 ng/ml) in the fetal circuit during or at the end of any perfusion. Using immunohistochemistry, ReoPro was only detected attached to maternal and fetal platelets, and to the trophoblastic surface of the placental villi. Only pharmaceutically insignificant amounts of ReoPro were detected in the fetal circuit, which demonstrates a barrier capacity of the human term placenta for this Fab fragment compared with IgG.

Respiratory health effects of cannabis: position statement of the Thoracic Society of Australia and New Zealand

Both the gaseous and the particulate phases of tobacco and cannabis smoke contain a similar range of harmful chemicals. However, differing patterns of inhalation mean that smoking a 'joint' of cannabis results in exposure to significantly greater amounts of combusted material than with a tobacco cigarette. The histopathological effects of cannabis smoke exposure include changes consistent with acute and chronic bronchitis. Cellular dysplasia has also been observed, suggesting that, like tobacco smoke, cannabis exposure has the potential to cause malignancy. These features are consistent with the clinical presentation. Symptoms of cough and early morning sputum production are common (20-25%) even in young individuals who smoke cannabis alone. Almost all studies indicate that the effects of cannabis and tobacco smoking are additive and independent. Public health education should dispel the myth that cannabis smoking is relatively safe by highlighting that the adverse respiratory effects of smoking cannabis are similar to those of smoking tobacco, even although it remains to be confirmed that smoking cannabis alone leads to the development of chronic lung disease.

Botulism as a cause of respiratory failure in injecting drug users

BACKGROUND

Wound botulism occurs as a consequence of inoculation of Clostridium botulinum spores into a wound.

AIM

To describe such a case of wound botulism.

RESULTS

A 23-year-old drug-injecting user presented with bulbar symptoms and progressive signs over a three-day period. The diagnosis of botulism was suspected and was treated with large doses of penicillin and botulinum antitoxin. The diagnosis was confirmed by the presence of serum botulinum toxin A.

CONCLUSION

Physicians should be aware of the association of botulism in injecting drug users, particularly in Ireland.

Physiological interpretation of electrical impedance epigastrography measurements

Measurement of the electrical impedance of the gastric region is carried out with the epigastrograph. This generates and applies alternating current around the abdominal area and measures the potential difference in order to determine the impedance externally, via electrodes. The change of epigastric impedance for a subject, given a meal after fasting, depends on the conductivity of the meal compared to the stomach and surrounding tissues. Typically a conductive meal has conductivity >7 mS cm(-1), non-conductive <2 mS cm(-1) and neutral about 4.5 mS cm(-1). Half-emptying times (T50s) from gastric emptying studies in volunteers using three test meals of 450 ml volume were obtained and found to be shorter than expected from the literature. The meals were a 10% glucose solution and two milk shakes of energy 1,300 kJ and 2,850 kJ, respectively. These electrical impedance epigastrography (EIE) measurements were carried out with scintigraphy. The T50 values of the latter were significantly longer. The direct comparison of the normalized experimental data obtained by both methods led to the concept that EIE measurements are mainly influenced by gastric secretion. Thus the EIE trace of a 'neutral' meal suggests the hypothesis that the volume of the meal is not the significant factor but is influenced by gastric acid secretions. Physiology of the gastric mucosa during the digestion of a meal and intragastric pH values also suggests this. Gastric function studies using EIE measurements may therefore reflect gastric ionic concentration rather than the volume of the contents of the stomach. In turn this could lead to the development of a non-invasive method for the continuous recording of gastric acid secretions.

Local convection enhanced delivery of IL4-Pseudomonas exotoxin (NBI-3001) for treatment of patients with recurrent malignant glioma

PURPOSE

This was an open-label, dose-escalation trial of intratumoral administration of IL-4 Pseudomonas Exotoxin (NBI-3001) in patients with recurrent malignant glioma.

PATIENTS AND METHODS

A total of 31 patients with histologically verified supratentorial grade 3 and 4 astrocytoma were studied. Of these, twenty-five patients were diagnosed with glioblastoma multiforme (GBM) while six were diagnosed with anaplastic astrocytoma (AA). Patients were over 18 years of age and had Karnofsky performance scores > or = 60. Patients were assigned to one of four dose groups in a dose-escalation fashion: 6 microg/ml x 40 ml, 9 microg/ml x 40 ml, 15 microg/ml x 40 ml, or 9 microg/ml x 100 ml of NBI-3001 administered intratumorally via stereotactically placed catheters. Patients were followed with serial MRI scans and clinical assessments every four weeks for the first 16 weeks and then every eight weeks until week 26.

RESULTS

No drug-related systemic toxicity, as evident by lack of hematological or serum chemical changes, was apparent in any patients; treatment-related adverse effects were limited to the central nervous system. No deaths were attributable to treatment. Drug-related Grade 3 or 4 toxicity was seen in 39% of patients in all dose groups and 22% of patients at the maximum tolerated dose of 6 microg/ml x 40 ml. The overall median survival was 8.2 months with a median survival of 5.8 months for the GBM patients. Six-month survival was 52% and 48%, respectively. Gadolinium-enhanced magnetic resonance imaging of the brain showed areas of decreased signal intensity within the tumor consistent with tumor necrosis following treatment in many patients.

CONCLUSIONS

NBI-3001 appears to have an acceptable safety and toxicity profile when administered intratumorally in patients with recurrent malignant glioma.

Carditis: all Helicobacter pylori or is there a role for gastro-oesophageal reflux?

BACKGROUND

Recent epidemiological studies have reported a threefold increase in the incidence of adenocarcinoma of the lower oesophagus and gastro-oesophageal junction (cardia). There are conflicting reports available implicating both gastro-oesophageal reflux disease and Helicobacter pylori infection in the aetiology of carditis and cardia intestinal metaplasia, despite strong evidence to show that these two conditions are, if anything, inversely related. We aimed to determine the prevalence of carditis and cardia intestinal metaplasia in dyspeptic subjects and also their association with H. pylori infection and gastro-oesophageal reflux disease.

METHOD

Histological samples from the gastric cardia were obtained from dyspeptic subjects. H. pylori status was assessed based on histological, microbiological and rapid urease testing. Gastro-oesophageal disease was diagnosed on the basis of histological evidence and/or erosive oesophagitis. Patient demographics were recorded. Cardia intestinal metaplasia (CIM), when present, was subgrouped as complete or incomplete.

RESULTS

Overall, 276 subjects were enrolled; 163 (59%) had carditis and 36 (13%) CIM. H. pylori infection and gastro-oesophageal reflux disease occurred in 64 (23%) and 150 (54%), respectively. H. pylori infection was strongly associated with carditis and CIM (P<0.001 and P<0.01). Older age and male gender were also associated with inflammation and intestinal metaplasia of the cardia. Gastro-oesophageal reflux was not associated with either entity.

CONCLUSION

Carditis and CIM occur frequently. Both conditions are strongly associated with H. pylori infection, older age and male gender. There was no association with gastro-oesophageal reflux disease.