Genetic diversity among Mycobacterium bovis isolates: a preliminary study of strains from animal and human sources

Mycobacterium bovis has the broadest host range of species in the Mycobacterium tuberculosis complex and is responsible for disease in humans and diverse animal species. We report on genotypic differences at multiple loci among 13 isolates derived from a range of human and animal infections. All isolates were classified as M. bovis by phenotypic analysis but could be subdivided into five distinct genotypes based on polymorphisms at the pncA and oxyR loci, the status of the RD5 deletion region, and the spoligotype pattern. These findings suggest the existence of a spectrum of strains with genotypic characteristics between those of M. tuberculosis and M. bovis.

Cutaneous tuberculosis of the penis and sexual transmission of tuberculosis confirmed by molecular typing

A case of culture-positive primary cutaneous Mycobacterium tuberculosis infection of the penis was diagnosed in a male patient; 1 year later, endometrial tuberculosis was diagnosed in the patient's wife. These organisms were confirmed to be indistinguishable by use of molecular techniques.

Estrogen receptor-alpha knockout mice exhibit resistance to the developmental effects of neonatal diethylstilbestrol exposure on the female reproductive tract

Data indicate that estrogen-dependent and -independent pathways are involved in the teratogenic/carcinogenic syndrome that follows developmental exposure to 17beta-estradiol or diethylstilbestrol (DES), a synthetic estrogen. However, the exact role and extent to which each pathway contributes to the resulting pathology remain unknown. We employed the alphaERKO mouse, which lacks estrogen receptor-alpha (ERalpha), to discern the role of ERalpha and estrogen signaling in mediating the effects of neonatal DES exposure. The alphaERKO provides the potential to expose DES actions mediated by the second known ER, ERbeta, and those that are ER-independent. Wild-type and alphaERKO females were treated with vehicle or DES (2 microg/pup/day for Days 1-5) and terminated after 5 days and 2, 4, 8, 12, and 20 months for biochemical and histomorphological analyses. Assays for uterine expression of the genes Hoxa10, Hoxa11, and Wnt7a shortly after treatment indicated significant decreases in DES-treated wild-type but no effect in the alphaERKO. In contrast, the DES effect on uterine expression of Wnt4 and Wnt5a was preserved in both genotypes, suggesting a developmental role for ERbeta. Adult alphaERKO mice exhibited complete resistance to the chronic effects of neonatal DES exposure exhibited in treated wild-type animals, including atrophy, decreased weight, smooth muscle disorganization, and epithelial squamous metaplasia in the uterus; proliferative lesions of the oviduct; and persistent vaginal cornification. Therefore, the lack of DES effects on gene expression and tissue differentiation in the alphaERKO provides unequivocal evidence of an obligatory role for ERalpha in mediating the detrimental actions of neonatal DES exposure in the murine reproductive tract.

The impact of diagnosis by legionella urinary antigen test on the epidemiology and outcomes of Legionnaires' disease

Legionnaires' disease is an uncommon but important cause of life-threatening community-acquired or nosocomial pneumonia. The urinary antigen enzyme immunoassay test, used in Victoria since 1995, now accounts for the majority of initial laboratory notifications (81% in 1999). We review the impact of the test on the disease epidemiology and the public health investigative process. We focus on the major subgroup of cases due to Legionella pneumophila serogroup 1, comparing delays until notification and mortality for urinary antigen detected cases with culture detected cases. The urinary antigen test facilitates a 5-day reduction for the delay between onset of illness and notification. We observed that there was minimal clinical heterogeneity of urinary antigen detected cases whether they were subsequently culture confirmed or not. We encourage clinician use of the urinary antigen test in cases of community-acquired pneumonia where Legionnaires' disease is a possible diagnosis, in conjunction with culture of clinical specimens.

Detection of rpoB mutations in Mycobacterium tuberculosis by biprobe analysis

A biprobe assay utilizing LightCycler technology was developed to detect rifampin resistance-associated gene mutations in the Mycobacterium tuberculosis rpoB gene. Three biprobes detected all mutations present in the 46 rifampin-resistant isolates. Wild-type sequences were correctly identified in each case. The method was reproducible, accurate, and easy to use.

Use of a novel contingency stimulator in Unilateral Spatial Neglect

The trial of a treatment device for Unilateral Spatial Neglect (USN) is reported. A patient who had suffered a right hemisphere stroke that resulted in left sided neglect was studied over a six month period. The study involved the use of a customized electrical device providing stimulation to the neglected hand, triggered by movement of the unaffected side. A battery of neglect measures were performed regularly throughout the study period. Though the results were difficult to interpret, there was no conclusive evidence that the device was effective. The possible reasons for this, the methodological difficulties inherent in studies of this type and suggestions for further studies are discussed.

Intraocular pressure and pulsatile ocular blood flow after retrobulbar and peribulbar anaesthesia

AIMS

This study investigated the effect of peribulbar and retrobulbar local anaesthesia on intraocular pressure (IOP) and pulsatile ocular blood flow (POBF), as such anaesthetic techniques may adversely affect these parameters.

METHODS

20 eyes of 20 patients who were to undergo phacoemulsification cataract surgery were prospectively randomised to receive peribulbar or retrobulbar anaesthesia. The OBF tonometer (OBF Labs, Wiltshire, UK) was used to simultaneously measure IOP and POBF before anaesthesia and 1 minute and 10 minutes after anaesthesia. Between group comparisons of age, baseline IOP, and baseline POBF were performed using the non-parametric Mann-Whitney test. Within group comparisons of IOP and POBF measured preanaesthesia and post-anaesthesia were performed using the non-parametric Wilcoxon signed ranks test for both groups.

RESULTS

There was no statistically significant IOP increase post-anaesthesia in either group. In the group receiving peribulbar anaesthesia, there was a significant reduction in POBF initially post-anaesthesia which recovered after 10 minutes. In the group receiving retrobulbar anaesthesia, there was a persistent statistically significant reduction in POBF.

CONCLUSIONS

Retrobulbar and peribulbar injections have little effect on IOP. Ocular compression is not needed for IOP reduction when using local anaesthesia for cataract surgery. Conversely, POBF falls, at least for a short time, when anaesthesia for ophthalmic surgery is administered via a retrobulbar route or a peribulbar route. This reduction may be mediated by pharmacologically altered orbital vascular tone. It may be safer to use other anaesthetic techniques in patients with ocular vascular compromise.

Natural history of cervical human papillomavirus infection in young women: a longitudinal cohort study

BACKGROUND

Laboratory and epidemiological research suggests an association between human papillomavirus (HPV) and cervical intraepithelial neoplasia (CIN). We studied the natural history of incident cervical HPV infection and its relation to the development of CIN.

METHODS

We recruited 2011 women aged 15-19 years who had recently become sexually active. We took a cervical smear every 6 months and stored samples for virological analysis. We immediately referred all women with any cytological abnormality for colposcopic assessment, but postponed treatment until there was histological evidence of progression to high-grade CIN.

FINDINGS

In 1075 women who were cytologically normal and HPV negative at recruitment, the cumulative risk at 3 years of any HPV infection was 44% (95% CI 40-48): HPV 16 was the most common type. The cumulative risk at 3 years of detecting an HPV type not present in the first positive sample was 26% (20-32). 246 women had an abnormal smear during follow-up, of whom 28 progressed to high-grade CIN. The risk of high-grade CIN was greatest in women who tested positive for HPV 16 (risk ratio 8.5 [3.7-19.2]); this risk was maximum 6-12 months after first detection of HPV 16. All HPV types under consideration were associated with cytologically abnormal smears. Although abnormality was significantly less likely to be associated with low-viral-load samples, the cumulative risk at 3 years of a high-viral-load sample after a low-viral-load sample was 45% (95% CI 35-56). Five women who progressed to high-grade CIN consistently tested negative for HPV.

INTERPRETATION

Our findings suggest that attempts to exploit the association between cervical neoplasia and HPV infection to improve effectiveness of cervical screening programmes might be undermined by the limited inferences that can be drawn from the characterisation of a woman's HPV status at a single point in time, and the short lead time gained by its detection.

Environmental mycobacteria in northern Malawi: implications for the epidemiology of tuberculosis and leprosy

More than 36000 individuals living in rural Malawi were skin tested with antigens derived from 12 different species of environmental mycobacteria. Most were simultaneously tested with RT23 tuberculin, and all were followed up for both tuberculosis and leprosy incidence. Skin test results indicated widespread sensitivity to the environmental antigens, in particular to Mycobacterium scrofulaceum, M. intracellulare and one strain of M. fortuitum. Individuals with evidence of exposure to 'fast growers' (i.e. with induration to antigens from fast growers which exceeded their sensitivity to tuberculin), but not those exposed to 'slow growers', were at reduced risk of contracting both tuberculosis and leprosy, compared to individuals whose indurations to the environmental antigen were less than that to tuberculin. This evidence for cross protection from natural exposure to certain environmental mycobacteria may explain geographic distributions of mycobacterial disease and has important implications for the mechanisms and measurement of protection by mycobacterial vaccines.

(Immuno)affinity chromatography: a versatile tool for fast and selective purification, concentration, isolation and analysis

Today, thanks to the availability of tailor made biomolecules with the desired biological functions, separations based upon (immuno)affinity techniques are more and more common in a large field of applications. By using the high selectivity of biomolecules (antibodies, receptors, specific proteins), this technique offers the possibility of isolating compounds from complex samples with a selectivity which cannot be achieved by other chromatographic methods. In order to succeed, however, the solid phase support for the immobilisation of the ligand of interest plays a prominent role. For this reason, numerous supports have already been introduced while research on new materials with additional advantages is continued. Here, a new solid phase support will be discussed for (immuno)affinity applications. This material demonstrates low non-specific adsorption and high ligand accessibility, which enables an enhanced selectivity and capacity. Because the material is available in large quantities and exhibits superb mechanical and physical stability, selective isolations have been performed on analytical as well as preparative scale. To demonstrate the potential of this new support, several applications will be presented. Based upon immunoaffinity, two applications for the determination of oestradiol in serum respectively vitamin B12 in fermentation broth will be presented. Regarding affinity chromatography, an enzyme reactor in which the enzyme glucose oxidase is immobilised on the new material, is made for the detection of glucose by Flow Injection Analysis and electrochemical detection. Next, to isolate, identify and test components on their xeno-oestrogenic activity, an affinity column is produced in which human oestrogen receptor is covalently coupled. Several components are screened on their biological activity and the results obtained will be presented here.

Recombinant expression analysis of natural and synthetic bovine alpha-casein in Escherichia coli

As a prelude to developing a yeast-based fermentation process for the production of phenylalanine-free alpha-casein as a foodstuff for patients suffering from phenylketonuria, we cloned the gene encoding bovine alpha-casein. We synthesised a modified gene sequence encoding the same, but devoid of phenylalanine codons and with a codon bias similar to that of naturally occurring highly expressed genes in Saccharomyces cerevisiae. The results show that both gene sequences are readily expressed in Escherichia coli when cloned in an E. coli bacteriophage T7 promoter-driven plasmid vector. In this host, the natural and synthetic casein proteins were produced at levels equating to 18.0% and 7.6% of the cell's soluble protein, respectively.

Mycobacterium elephantis sp. nov., a rapidly growing non-chromogenic Mycobacterium isolated from an elephant

A strain isolated from a lung abscess in an elephant that died from chronic respiratory disease was found to have properties consistent with its classification in the genus Mycobacterium. An almost complete sequence of the 165 rDNA of the strain was determined following the cloning and sequencing of the amplified gene. The sequence was aligned with those available on mycobacteria and phylogenetic trees inferred by using three tree-making algorithms. The organism, which formed a distinct phyletic line within the evolutionary radiation occupied by rapidly growing mycobacteria, was readily distinguished from members of validly described species of rapidly growing mycobacteria on the basis of its mycolic acid pattern and by a number of other phenotypic features, notably its ability to grow at higher temperatures. The type strain is Mycobacterium elephantis DSM 44368T.

Trends in antituberculosis drug resistance in Karonga District, Malawi, 1986-1998

SETTING

Karonga District, Malawi.

OBJECTIVES

To examine long term trends in initial and acquired resistance to antituberculosis drugs in a rural area of Africa.

DESIGN

Monitoring of all patients with culture-confirmed tuberculosis 1986-1998.

RESULTS

Initial drug resistance results were available for 1121 patients. The proportion resistant to any of the first line drugs (streptomycin, isoniazid, rifampicin or ethambutol) was 9.6%, and to isoniazid 7.2%. Initial resistance to at least isoniazid and rifampicin (multidrug resistance) was seen in only six patients. No initial resistance to ethambutol was found. There was no significant change in initial drug resistance over time. Overall, 22/120 (18%) patients with previous treatment were resistant to at least one drug; only one had multidrug resistance. Acquired resistance decreased over the period of the study. There were no associations between age, sex or human immunodeficiency virus (HIV) status and initial or acquired drug resistance.

CONCLUSIONS

Changes in acquired resistance may reflect the recent performance of a control programme more quickly than those in initial resistance. It is encouraging that acquired resistance decreased and levels of multidrug resistance were low despite more than a decade of use of rifampicin. The lack of association between HIV and drug resistance confirms findings elsewhere in Africa.

Legionnaires' disease outbreak: Victoria's largest identified outbreak

This paper describes and analyses some aspects of an outbreak of Legionnaires' disease in Victoria, commencing in late October 1998. In all, 18 cases caused by Legionella pneumophila serogroup 1 were notified within 10 days making this the largest outbreak in Victoria reported to that date. All cases had epidemiological links to an industrial estate in a northern Melbourne suburb. Extensive environmental sampling revealed Legionella bacteria in five cooling towers. Molecular sub-typing techniques were used to compare clinical and environmental isolates. Isolates from one tower had a pulsed-field gel electrophoresis pattern that was indistinguishable from clinical isolates from eight cases. Control of outbreaks caused by Legionella bacteria requires rapid, coordinated responses to linked cases of disease. The Legionella urinary antigen test facilitated a rapid public health response, and culture and molecular sub-typing of clinical specimens assisted in developing epidemiological links.

The unreliability of clinical measures of muscle tone: implications for stroke therapy

BACKGROUND

the central tenet of the neurofacilitatory approach to stroke therapy is that muscle tone needs to be normal before normal movement can occur. A reliable clinical measure of the full spectrum of muscle tone is needed to test: (i) the purported relationship between muscle tone, other motor impairments and disability, and (ii) the effectiveness of stroke therapy to restore movement.

AIM

the purpose of the study was to test the inter-rater reliability of clinical categorization of muscle tone (spastic/normal/flaccid) and also a visual analogue scale with anchor points of 'lowest tone possible' (score 0) and 'highest tone possible' (score 100).

METHODS

four independent raters assessed tone of elbow flexors and knee extensors of 14 stroke rehabilitation inpatients using the categorical scale. Six independent raters assessed tone of elbow flexors and knee extensors of 25 chronic stroke patients and two healthy volunteers using the visual analogue scale. All assessment orders were randomized.

RESULTS

both scales were unreliable, with K coefficients for the categorical scale ranging from -0.046 to 0.56 for the categorical scale, and intra-class correlation coefficients for the visual analogue scale of 0.595 for elbow flexors and 0.451 for knee extensors. Assessment order effects for the visual analogue scale were non-significant for elbow flexors (P= 0.545) and knee extensors (P= 0.911).

CONCLUSIONS

these results, and those of earlier studies, suggest that clinical measures of muscle tone are consistently unreliable. Systematic investigation of the therapy rationale for planning and evaluating treatment is required before relevant clinical measures can be developed.

A study of infection in elderly nursing/residential home and community-based residents

It is commonly believed that patients admitted to hospital from nursing homes/residential homes (NHRH) with infections are less likely to respond to treatment and have a higher fatality rate than counterparts admitted from their own homes ('the Community'). It is also believed that NHRH's harbour a reservoir of unusual and resistant organisms. These preconceptions may influence how these patients are managed. A database of 10593 sequential admissions to a Geriatric Medical unit over a three-year period was used to identify NHRH and community populations with a principal diagnosis of infection. They were investigated using the Department of Microbiology's database. The admission rate in the NHRH group was twice that of the community group. There were no significant differences in length of stay (LOS) [16 +/- 2 vs 17 +/- 2 days (s.e.m.)], or mean survival time (ST)(61 days (37-84) vs 48 days (25-72): 95% confidence intervals) between the two groups. Subgroups of the NHRH group did have significantly different survival times. Fatality rate was not significantly different between the NHRH (40%) or Community (35%) groups. Both the NHRH and community group underwent very similar levels of investigation (189 vs 200 investigations performed). The types and frequencies of pathogen seen in the two groups were very similar.

Activity against Mycobacterium tuberculosis of alkaloid constituents of Angostura bark, Galipea officinalis

The activity of an ethanolic extract of Galipea officinalis bark against Mycobacterium tuberculosis was shown to reside mainly in the basic alkaloidal fraction although the major part of the alkaloids present were in the neutral fraction. Six alkaloids were isolated from the bark including two other alkaloids not previously reported from G. officinalis and a new quinoline named allocuspareine, whose structure was determined by spectroscopic methods. 1H- and 13C-NMR spectral data for three of these compounds are reported for the first time. Isolation and testing of fractions and individual alkaloids against ten strains of M. tuberculosis showed that all the alkaloids possessed some activity but that the unidentified most polar basic fraction exhibited the greatest effect.

Religion, community service, and identity in American youth

The role of religion in identity development has, for many years, been a relatively neglected topic in psychology. To demonstrate the importance of religion to the formation of identity, this paper presents evidence connecting community service and religiousness in American youth. Data are reviewed that show (1) youth are heavily involved in volunteer service; (2) many youth view religion as important and those who do so are more likely to do service than youth who do not believe that religion is important in their lives; (3) involvement in church-sponsored service makes it more likely that youth will adopt the religious rationale in which service is couched; and (4) youth who do church-sponsored service are neither service "nerds" nor single-issue tunnel-visioned adolescents. These data from nationally representative samples strengthen the case that the many contemporary youth who take religion seriously are vibrantly engaged in their schooling, in the betterment of communities, and the development of identities which presage healthy lives.

Culturally sensitive care in a forensic setting

In the forensic service there is a disproportionate number of ethnic minority patients. Providing culturally sensitive care has not been given a high priority within formal nurse education in the past. This article describes a training programme for nurses working in a forensic service aimed at promoting culturally sensitive care. The programme included methods of raising awareness, motivation and interest in training on this subject.