An experimental model for amoebic abscess production in the cheek pouch of the Syrian golden hamster, Mesocricetus auratus

A new experimental model was developed in hamsters for amoebic abscess caused by Entamoeba histolytica. E. histolytica trophozoites were cultured in a liquid axenic medium, and then injected intradermally into the cheek pouch of the Syrian golden hamster, Mesocricetus auratus. Inoculation consistently resulted in abscess formation at the site in 20 of 22 (91%) study animals. The amoebic nature of the abscesses was confirmed by light microscopy and histopathologic examination. Abscess formation was maximal at day 12 post-inoculation. Potential applications of this simple and reliable model include further elucidation of the pathogenesis of invasive amoebiasis, studies of the host response to amoebae, and in vivo evaluation of chemotherapeutic agents that show in vitro efficacy against E. histolytica.

Leprosy patients with lepromatous disease have an up-regulated IL-8 response that is unlinked to TNF-alpha responses

Tumor necrosis factor (TNF-alpha) in conjunction with interferon-gamma (IFN-gamma) plays an important role in lymphocyte recruitment and granuloma formation in mycobacterial diseases. Lepromatous leprosy infections are typically associated with low to absent T cell responses and the absence of INF-gamma secretion. Chemokines such as IL-8, MCP-1, and MIP-1beta, have also been shown to recruit neutrophils and lymphocytes to the site of mycobacterial infections. We have studied IL-8 expression in relation to TNF-alpha and TGF-beta in monocytes from lepromatous patients (LL) as compared with healthy endemic controls. In endemic controls, no spontaneous expression of IL-8, TNF-alpha, and TGF-beta was observed, but BCG and M. leprae induced activation of all three cytokines. Lepromatous leprosy monocytes spontaneously expressed high levels of IL-8 and TGF-beta but negligible levels of TNF-alpha. A further increase in IL-8 secretion or gene expression by BCG or M. leprae was not significant. BCG, but not M. leprae, was able to stimulate TNF-alpha activation in lepromatous leprosy subjects. TGF-beta responses in LL were parallel to those of IL-8. This suggests a vigorous and active ongoing IL-8 response in lepromatous disease that is independent of TNF-alpha activation. Therefore, in the absence of IFN-gamma and TNF-alpha activation, IL-8 may assume a pivotal role in cell recruitment in leprosy patients with disseminated mycobacterial infections.

IgG1 antimycobacterial antibodies can reverse the inhibitory effect of pentoxifylline on tumour necrosis factor alpha (TNF-alpha) secreted by mycobacterial antigen-stimulated adherent cells

Chronic inflammation associated with cachexia, weight loss, fever and arthralgia is the hallmark of advanced mycobacterial diseases. These symptoms are attributed to the chronic stimulation of tumour necrosis factor (TNF)-alpha. Mycobacterial components directly stimulate adherent cells to secrete TNF-alpha. We have shown recently that IgG1 antimycobacterial antibodies play a role in augmenting TNF-alpha in purified protein derivative (PPD)-stimulated adherent cells from non-BCG-vaccinated donors. We now show that IgG1 antibodies can also augment TNF-alpha expression in stimulated adherent cells obtained from BCG-vaccinated donors and this augmentation is not linked to interleukin (IL)-10 secretion. In addition IgG1 antimycobacterial antibodies can reverse the effect of TNF-alpha blockers such as pentoxifylline and thalidomide. These studies therefore have clinical implications for anti-inflammatory drug treatments which are used increasingly to alleviate symptoms associated with chronic inflammation.

Risk factors for neonatal mortality in low-income population subgroups in Karachi, Pakistan

This paper assesses the risk factors for neonatal mortality (0-28 days of life) for full-term singleton live births. The study sample comprised 1,011 ever-married women who were residents of four multi-ethnic, multi-religious low-income areas of Karachi, Pakistan during 1995. The analysis sample was restricted to 4,488 live births to 912 women. Results showed that 4.8% (n = 217) of all births ended in death in the neonatal period, and 76% (n = 164) of these neonatal deaths occurred in the first week of life. While neonatal mortality rates had declined appreciably over time, a large proportion of neonatal deaths were clustered in a small group of women. The univariate analysis showed a statistically significant association between a number of maternal-level parameters (e.g., mother's age at birth, level of formal education, employment status, religious affiliation, and consanguinity) and child-level parameters (e.g., birth order, birth interval, survival status of the preceding child, sex of the neonate, year of death). At the multivariate level, consanguinity, birth order and year of death were found to be statistically significant risk factors for neonatal mortality analyses despite adjustment for death clustering. The study highlights the importance of inbreeding as a determinant of early offspring death, and points to the need for better understanding of why deaths are clustered in certain families. Given the widespread practice of close cousin marriages in Pakistan across all socio-economic groups, there is a need to validate the findings in less economically disadvantaged population subgroups within the country.

The effect of mycobacterial virulence and viability on MAP kinase signalling and TNF alpha production by human monocytes

SETTING

The success of Mycobacterium tuberculosis as a human pathogen depends on its ability to tolerate and perhaps manipulate host defense mechanisms.

OBJECTIVE

To determine the induction of tumour necrosis factor-alpha (TNF alpha), a central mediator of immunity, by human monocytes infected with virulent M. tuberculosis, M. leprae and attenuated M. bovis BCG.

DESIGN

Mycobacteria-induced cellular activation pathways of TNF alpha production was investigated using an inhibitor of protein tyrosine kinase (PTKs) and an inhibitor of mitogen-activated protein (MAP) kinases.

RESULTS

TNF alpha production was significantly lower during infection with virulent M. tuberculosis than with BCG and this differential response was independent of mycobacterial viability. TNF alpha production involved the PTK and MAP kinase pathways. Reduced TNF alpha induction by M. tuberculosis was associated with a reduction in the extent and duration of phosphorylation of extracellular-signal regulated kinases (ERK 1/2). Infection with M. leprae triggered low and transient ERK 1/2 activation as well as low TNF alpha production.

CONCLUSION

Maintenance of the differential response in both live and heat-killed preparations suggests that the reduced TNF alpha response associated with virulent mycobacteria is due to differences in the presence of components capable of triggering host pattern recognition receptors, rather than events associated with phagosome trafficking or the active release of intracellular modulators.

Breast cancer and the uptake of mammography screening services by women with intellectual disabilities

BACKGROUND

It is estimated that approximately 50% of women in Australia with intellectual disability will live to 70 years of age and as a result many will fall within the age group at highest risk for breast cancer (50-69 years).

METHODS

Subjects were identified through the Western Australia Disability Services database. To determine the number of women diagnosed with breast cancer during the period 1982-2000, individual records (n = 2,370) were linked to the Western Australia Cancer Registry and the Mammography Screening Registry.

RESULTS

The incidence of breast cancer among women with intellectual disability was 64.0 per 100,000 person-years, by comparison with 146.7 per 100,000 person-years in the general population. The uptake of breast cancer screening was examined in a subgroup of 380 women, 34.7% of whom had used mammographic screening, as opposed to 54.6% screening uptake in the general population. Failure to use screening services was highest in women who were unmarried, and was positively associated with severity of intellectual disability, presence of physical disabilities, and urban residence.

CONCLUSIONS

The lower incidence of breast cancer in women with intellectual disability may in part be attributable to decreased life expectancy, but it also appears to reflect significant under utilization of the readily available screening services.

Comparative survival advantage of males with Down syndrome

In virtually all countries life expectancy is longer in females than in males. A multigeneration, population-based dataset was used to investigate whether a gender-specific difference in life expectancy could be determined in a large cohort (n = 1,332) of people with Down syndrome resident in Western Australia. Contrary to the established pattern of longevity in the general population, and in most people with intellectual disability, males with Down syndrome had a significantly greater life expectancy than females with the same disorder. The reasons for this atypical finding are discussed in terms of the patterns of morbidity experienced by people with Down syndrome, especially at early and late stages of their lifespan.

The changing survival profile of people with Down's syndrome: implications for genetic counselling

Cohort studies have indicated that the survival of individuals with Down's syndrome has dramatically increased over the past 50 years. Early childhood survival in particular has shown major improvement, due largely to advances in cardiac surgery and in general health management. The present study was based on a continuous cohort of 1332 people with Down's syndrome in Western Australia, registered for intellectual disability services between 1953 and 2000. Their life expectancy was 58.6 years, 25% lived to 62.9 years, and the oldest living person is 73 years of age. Life expectancy for males was greater than females by 3.3 years. The substantial increase in survival across the study period means that the life expectancy of people with Down's syndrome is approaching that of the general population, but accompanied by a range of significant mid-life health problems. The findings are of relevance to all developed countries and have considerable implications in terms of the counselling information provided to families at risk of having a child with Down's syndrome.

Cerebral involvement in benign tertian malaria

Although Plasmodium vivax usually causes benign uncomplicated malaria, it can occasionally result in severe disease with life-threatening, end-organ involvement generally seen with falciparum malaria. We report a case of cerebral malaria caused by P. vivax and review the literature on this subject.

The influence of intellectual disability on life expectancy

BACKGROUND

To date, relatively few representative data have been available to health planners and advocacy groups on the life expectancy of people with intellectual disability. A study of trends in the survival profiles of people with intellectual disability was undertaken to assist in the planning of appropriate medical and support services.

METHODS

Since 1953, the Disability Services Commission of Western Australia has maintained a database of persons diagnosed with intellectual disability. The database was used to calculate survival probabilities on a total of 8724 individuals, 7562 of whom were still alive at the time of sampling in December 2000.

RESULTS

Kaplan-Meier survival plots showed a strong negative association between severity of intellectual disability and survival, with median life expectancies of 74.0, 67.6, and 58.6 years for people with mild, moderate, and severe levels of handicap. Significant negative associations also were observed with male gender, Indigenous Australian parentage, and individuals diagnosed with a specific genetic disorder.

CONCLUSIONS

The findings indicate a major and expanding increase in the service requirements of this aging, intellectually disabled population during the past two generations.

Human T cell responses to peptides of the Mycobacterium leprae 45-kD serine-rich antigen

In order to identify T cell epitopes within the Mycobacterium leprae 45-kD serine-rich antigen, we analysed responses to overlapping 17-mer peptides encompassing the whole antigen in non-exposed UK controls, Pakistani leprosy patients and tuberculosis patients in both the United Kingdom and Pakistan. This antigen has been described as M. leprae-specific, although it has a hypothetical homologue in M. tuberculosis. Human peripheral blood mononuclear cells were stimulated with peptide for 5 days and IFN-gamma measured in supernatants by ELISA. Some peptides were recognized more frequently by T cells from tuberculoid leprosy patients than those from UK controls, suggesting that such T cell epitopes might have diagnostic potential, while other peptides induced greater responses among UK control subjects. Short-term cell lines confirmed that these assays detected specific T cell recognition of these peptides. However, many tuberculosis patients also recognized these potentially specific peptides suggesting that there could be a true homologue present in M. tuberculosis.

Does inbreeding lead to decreased human fertility?

In most Western countries there is a widespread belief, fostered in part by historical prejudice and religious proscription, that inbreeding in human populations causes a reduction in fertility. Support for this belief has been claimed in HLA-based studies, with increased rates of fetal losses suggested in HLA-compatible unions. To critically assess the overall status of fertility in consanguineous unions, data on 30 populations resident in six countries were collated from a systematic review of the literature. The mean numbers of live births were then compared in four consanguinity test categories, ranging from second cousin to uncle-niece/double first cousin, and corresponding non-consanguineous reference groups. Linear regressions indicated a positive association between consanguinity and fertility at all levels of inbreeding, attaining statistical significance at first cousin level (p < 0.0001). The results were, however, subject to a number of potential limitations, in particular lack of control for important socio-demographic variables. To overcome this problem, data on first cousin marriages were abstracted from the National Family and Health Survey conducted in India during 1992-1993. Multivariate analysis showed that fertility in first cousin unions was positively influenced by a number of variables, including illiteracy, earlier age at marriage and lower contraceptive uptake, but the most important of these parameters were duration of marriage and reproductive compensation. In net terms, consanguinity was not found to be associated either with a significant positive or negative effect on fertility.

Consanguinity and early mortality in the Muslim populations of India and Pakistan

Empirical information from studies conducted in Pakistan has indicated a high level of offspring mortality that can be attributed to parental consanguinity even when non-biological variables are controlled. However, with the exception of some small and geographically restricted studies, few comparable data are available on the influence of inbreeding in child survival among the Muslim population of India, which numbers between 100 and 120 million. The present study compares deaths during the first 5 years of life among the offspring of first cousin (F = 0.0625) and non-consanguineous unions (F = 0), using data collected in the 1992-1993 Indian National Family Health Survey (NFHS) and the 1990-1991 Pakistan Demographic and Health Survey (PDHS). The focus was on determinants of mortality in live-born children to age 5 years. In both countries, bivariate analyses indicated that mortality was significantly increased in the offspring of first cousin unions during the neonatal and post-neonatal, total infant, and under-5 year periods. The findings were confirmed by multivariate regression, which incorporated control for a range of biological and demographic factors.

Neuro-ophthalmic features in pediatric tubercular meningoencephalitis

PURPOSE

To examine the neuro-ophthalmic profile in childhood tubercular meningoencephalitis and assess its prognostic importance.

METHODS

One hundred consecutive patients with tubercular meningoencephalitis underwent evaluation for optic nerve functions, supra- and infranuclear oculomotor involvement, and raised intracranial tension. Patients underwent follow-up for 9 months.

RESULTS

In 100 patients with tubercular meningoencephalitis, 67 had neuro-ophthalmic features. Common findings were retrobulbar neuritis (32) and gaze palsy (20). Others, in decreasing prevalence, were third and sixth nerve palsy, conjugate deviation, primary optic atrophy, and complete ophthalmoplegia. Raised intracranial tension was associated with neuro-ophthalmic features in 53 of 67 patients (P<.05). Complete ophthalmoplegia was significantly associated with mortality on logistic regression analysis (relative risk, 6.35; P=.012). By 6 months, 56% of patients with retrobulbar neuritis progressed to optic atrophy.

CONCLUSION

Neuro-ophthalmic features, in association with raised intracranial tension, often are a part of pediatric tubercular meningoencephalitis presentation. The type of neuro-ophthalmic features may have prognostic value. Optic nerve involvement is the most common finding in tubercular meningoencephalitis.

Treatment of tibial diaphyseal fractures with closed flexible intramedullary ender nails: 39 fractures followed for a period of two to seven years

OBJECTIVE

To assess the efficacy of flexible intramedullary Ender nails for the treatment of tibial diaphyseal.

MATERIALS AND METHODS

This is a retrospective review of patients treated with the Ender Nail for both open and closed tibial shaft fractures. Between January 1989 and December 1994, 43 fractures were treated with these nails. The configuration of each fracture was determined using the Orthopedic Trauma Association classification and the extent of soft tissue damage was assessed using the Gustilo and Anderson's classification. Four patients were excluded from the study due to inadequate follow-up. There were 27 closed and 12 open fractures.

RESULTS

The average time to union in 34 out of 39 fractures was 17 weeks. Delayed union and malunion occurred in two patients each and superficial wound infection in 1 patient. Nonunion occurred in 5 fractures that were all located in the distal 1/3 of the tibial diaphysis. We attribute this high rate of non-union to a poor rotational control on the distal fragment by these nails.

CONCLUSIONS

The Ender nails provide effective fixation for the OTA stable class of tibial fractures, where they produce good axial and rotational stability by virtue of their three-point fixation. Rotational and angular stability should be improved by a supplementary cast immobilization for fractures with unstable configuration and those located in the distal third of the diaphysis.

Pericardial effusion as a cause of morbidity in patients on maintenance hemodialysis: is it preventable?

OBJECTIVE

Cardiovascular diseases are the cause for 45% mortality and 20% morbidity in hemodialysis (HD) patients. Pericardial effusion (PE) accounts for 03-04% of all deaths in HD patients as a result of tamponade, arrhythmias or heart failure. This study aims to find out the prevailance and precipitating factors for PE in hemodialysis patients.

PATIENTS AND METHODS

Fifty-five patients were identified for echo-cardiographic assessment on the basis of signs and symptoms suggestive of PE i.e., hypotension during dialysis, dyspnea, globular heart in chest x-ray, raised JVP, soft heart sounds and low voltage ECG. A matched controlled group of 55 patients for age, sex, dialysis schedule, cause of ESRD and dialysis bath, was also studied echocardiographically.

RESULTS

Pericardial Effusion was detected in 12 patients (10.9%), 10 (83.3%) were on 2/week and only two on 3/week dialysis. Of these 75% were non-compliant in fluid intake and 58.3% were irregular in treatment. The morbidity of PE in study group (18.2%) is significantly higher as compared to controls (3.6%) (P = < 0.05). No correlation was found between development of PE and high iPTH and low albumin levels. Ten patients with mild PE responded to vigorous dialysis. Two patients developed cardiac tamponade needing pericardiocentesis.

CONCLUSION

We have identified 2/week dialysis (inadequate dialysis dose), acetate bath and fluid and dialysis non-compliance as factors contributing to development of PE in HD patients.

Effect of the disulfide bridge and the C-terminal extension on the oligomerization of the amyloid peptide ABri implicated in familial British dementia

Familial British dementia (FBD) is a rare neurodegenerative disorder and shares features with Alzheimer's disease, including amyloid plaque deposits, neurofibrillary tangles, neuronal loss, and progressive dementia. Immunohistochemical and biochemical analysis of plaques and vascular amyloid of FBD brains revealed that a 4 kDa peptide named ABri is the main component of the highly insoluble amyloid deposits. In FBD patients, the ABri peptide is produced as a result of a point mutation in the usual stop codon of the BRI gene. This mutation produces a BRI precursor protein 11 amino acids longer than the wild-type protein. Mutant and wild-type precursor proteins both undergo furin cleavage between residues 243 and 244, producing a peptide of 34 amino acids in the case of ABri and 23 amino acids in the case of the wild-type (WT) peptide. Here we demonstrate that the intramolecular disulfide bond in ABri and the C-terminal extension are required to elongate initially formed dimers to oligomers and fibrils. In contrast, the shorter WT peptide did not aggregate under the same conditions. Conformational analyses indicate that the disulfide bond and the C-terminal extension of ABri are required for the formation of beta-sheet structure. Soluble nonfibrillar ABri oligomers were observed prior to the appearance of mature fibrils. A molecular model of ABri containing three beta-strands, and two beta-hairpins annealed by a disulfide bond, has been constructed, and predicts a hydrophobic surface which is instrumental in promoting oligomerization.

Tropical pulmonary eosinophilia and filariasis in Pakistan

Filariasis is a major health problem in South Asia, particularly India, Sri Lanka and Bangladesh. Pakistan was presumed to be not affected. We report for the first time confirmed cases of tropical pulmonary eosinophilia (TPE) in indigenous patients as a result of infection with Wuchereria bancrofti. Following clinical examination, total leukocyte and eosinophil counts were recorded. Parasitological examinations included blood for microfilariae and stool and urine for eggs of intestinal parasites. Total immunoglobulin (Ig) E and specific antifilarial IgG were measured. Suspected cases of TPE were treated with diethylcarbamazine, 6 mg/kg for four weeks and were followed up to 2 and 4 weeks after treatment. Four persons fulfilled the criteria for TPE. Their response to treatment was marked with clinical improvement, reduction in eosinophil count and reduced titers of specific antifilarial antibodies. Two persons had W. bancrofti antigen in their sera confirmed by filariasis antigen detection test. Tropical pulmonary eosinophilia due to Wuchereria. bancrofti, although rare, is present in Pakistan.

Opsonizing antibodies (IgG1) up-regulate monocyte proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and IL-6 but not anti-inflammatory cytokine IL-10 in mycobacterial antigen-stimulated monocytes-implications for pathogenesis

Cachexia is one of the prominent features of advanced tuberculosis (TB) seen in association with increased expression of the monokine TNF-alpha. Several mycobacterial proteins, including PPD, stimulate TNF-alpha secretion from monocytes. Host factors that may play a role in cytokine expression from monocytes remain largely unknown. One such factor is the opsonizing antibodies. Monocytes have high-affinity receptors (FcgammaI and FcgammaIII) for IgG1 and IgG3 antibodies that mediate antigen uptake. We have reported selective up-regulation of IgG1 (which bind to Fcgamma receptors) in advanced TB and have recently shown the ability of PPD-specific IgG1 antibodies to augment TNF-alpha expression in PPD-stimulated monocytes. These observations have now been extended to other cytokines with semipurified fractions from secreted antigens of Mycobacterium tuberculosis (containing 30 kD and 58 kD) that were devoid of lipids, glycolipids and carbohydrates. In the presence of heat-inactivated TB plasma containing known amounts of antigen-specific IgG1 antibodies, these fractions induced significantly increased TNF-alpha, IL-6 and IL-10 secretion. Absorption of IgG1 with Protein 'A' removed the augmenting activity for TNF-alpha and IL-6 secretion from the TB plasma samples. In the case of IL-10, removal of IgG1 resulted in increased rather than decreased IL-10 secretion. These results suggest a possible pathogenic role for antibodies in TB by enhancing proinflammatory and blocking down-regulatory cytokines such as IL-10 cytokines during the chronic phase of TB.

Diagnostic assays for leprosy based on T-cell epitopes

To date, only a limited number of antigens have been described as specific for Mycobacterium leprae, and in many cases, homologues have subsequently been shown to exist in mycobacteria such as M. avium and M. intracellulare. A Leprosy Synthetic Peptide Skin Test Initiative was established by the Steering Committee on the Immunology of Mycobacteria of the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, to investigate the potential of synthetic peptides that encode T-cell epitopes as diagnostic tools, which could be used to develop a skin-test reagent specific for leprosy. Such M. leprae-specific peptides should have unique amino acid sequences, or significant sequence-dissimilarity from those in other mycobacteria. Synthetic peptides, 15 amino acids long, were synthesised from 33 genes or open reading frames within the M. leprae genome. Tuberculoid leprosy patients from four leprosy-endemic countries, Brazil, Ethiopia, Nepal and Pakistan, were tested as subjects known to have been infected with M. leprae, and to make good T-cell responses to antigens of M. leprae; UK blood donors were used as non-exposed or non-infected subjects. Peptides inducing potentially specific responses in leprosy patients and not in UK controls, and those inducing cross-reaction responses, present in both leprosy patients and non-exposed, non-infected controls, were identified. A difference from the equivalent M. tuberculosis sequence of five or more amino acid residues did not, by itself, identify peptides that were M. leprae-specific, suggesting that many of these peptides may have homologues in environmental mycobacteria. To date, this approach has identified a number of peptides with greater than 90% specificity and 19-47% sensitivity, which are undergoing further specificity-testing. Such peptides would have great potential as T-cell reagents with which to monitor exposure to M. leprae within communities, formulated either as skin-test reagents, or as antigens for tests in vitro.

The role of Tc-99m HMPAO functional brain imaging in detection of cerebral radionecrosis

BACKGROUND

Cerebral radionecrosis is a possible complication of brain radiation therapy in patients with primary or metastatic tumors. This retrospective study evaluated the role of Tc-99m hexamethyl propyleneamine oxime (HMPAO) scintigraphy in monitoring the effects of radiation on the brain.

METHODS

Ninety-eight patients (41 female, 57 male) with a mean age of 51 years (range, 16-82 years) underwent 128 sets of single-photon emission computed tomography studies. TI-201 and Tc-99m HMPAO single-photon emission computed tomography studies were performed for tumor localization and evaluation of the effect of radiation on the cerebral cortex. Thirty concomitant neuropsychological tests and 96 anatomic imaging (computed tomography/magnetic resonance imaging) were performed. The average radiation dose was 52 Gy delivered as 1.8 to 2 Gy/fraction. Thirty-two patients received an average dose of 160 mCi of I-125 EGFr concomitantly. The average follow-up period was 34 months. Abnormalities away from the tumor site were interpreted as positive on HMPAO studies, neuropsychological testing, or anatomic imaging; otherwise, they were classified as negative.

RESULTS

There were 10/45 (22%) and 75/83 (90%) abnormal HMPAO study results before and after radiation therapy. The HMPAO studies compared with neuropsychological testing showed 3/13 (23%) and 14/17 (82%) concordant abnormalities in addition to tumor site in patients pre- versus postradiation therapy. There was better concordance of HMPAO and anatomic imaging in 22/30 (76%) patients versus 24/67 (36%) patients before radiation therapy. HMPAO imaging after radiation therapy revealed significantly more perfusion abnormalities. There were significant differences between all of the aforementioned parameters. CONCLUSION Tc-99m HMPAO imaging is useful in the evaluation of the effects of radiation therapy on the brain and is highly concordant with neuropsychological testing. It is superior to anatomic studies in identifying radiation-induced changes.

Sociodemographic correlates of consanguineous marriage in the Muslim population of India

Using data derived from the 1992-1993 National Family Health Survey, the sociodemographic characteristics of consanguineous marriage were determined in the Muslim population of India. In this nationally representative sample of 8436 women, consanguineous marriages accounted for 22.0% of the total. No differences between the consanguineous and non-consanguineous groups were observed in terms of mean age at marriage or mean age at cohabitation. The study confirmed the negative association between consanguineous marriage and maternal education but also indicated that women in consanguineous unions were more likely to be employed, albeit mainly in agricultural work on behalf of the family. Consanguineous couples more frequently lived in smaller towns and in an extended family environment. Somewhat conflicting results were obtained with indicators of socioeconomic status, but the overall picture suggested that consanguineous households had greater access to consumer goods because of their larger number of co-resident persons.

A postgenomic approach to identification of Mycobacterium leprae-specific peptides as T-cell reagents

To identify Mycobacterium leprae-specific human T-cell epitopes, which could be used to distinguish exposure to M. leprae from exposure to Mycobacterium tuberculosis or to environmental mycobacteria or from immune responses following Mycobacterium bovis BCG vaccination, 15-mer synthetic peptides were synthesized based on data from the M. leprae genome, each peptide containing three or more predicted HLA-DR binding motifs. Eighty-one peptides from 33 genes were tested for their ability to induce T-cell responses, using peripheral blood mononuclear cells (PBMC) from tuberculoid leprosy patients (n = 59) and healthy leprosy contacts (n = 53) from Brazil, Ethiopia, Nepal, and Pakistan and 20 United Kingdom blood bank donors. Gamma interferon (IFN-gamma) secretion proved more sensitive for detection of PBMC responses to peptides than did lymphocyte proliferation. Many of the peptides giving the strongest responses in leprosy donors compared to subjects from the United Kingdom, where leprosy is not endemic, have identical, or almost identical, sequences in M. leprae and M. tuberculosis and would not be suitable as diagnostic tools. Most of the peptides recognized by United Kingdom donors showed promiscuous recognition by subjects expressing differing HLA-DR types. The majority of the novel T-cell epitopes identified came from proteins not previously recognized as immune targets, many of which are cytosolic enzymes. Fifteen of the tested peptides had > or =5 of 15 amino acid mismatches between the equivalent M. leprae and M. tuberculosis sequences; of these, eight gave specificities of > or =90% (percentage of United Kingdom donors who were nonresponders for IFN-gamma secretion), with sensitivities (percentage of responders) ranging from 19 to 47% for tuberculoid leprosy patients and 21 to 64% for healthy leprosy contacts. A pool of such peptides, formulated as a skin test reagent, could be used to monitor exposure to leprosy or as an aid to early diagnosis.