Biomedical subjects

M Kabra

Publications and source records attributed to M Kabra.

At least 19 recordsLinked to original sources

PubMed2006

Diagnosing and managing cystic fibrosis in the developing world.

Cystic fibrosis (CF), earlier believed to be non existent in non Caucasians, is now a pan ethnic disease, having being reported from various regions of the world over last one decade. Apart from limited resources, the major problems in diagnosis and management of CF in developing countries include: lack of awareness among pediatricians, absence of facilities for diagnosis (sweat chloride estimation and genetic studies), lack of trained manpower for care of specific problems, and non availability of appropriate drugs. Care of children with CF may not be a priority for governments in countries where childhood mortality rates are high, predominantly due to acute infections. An indigenously developed and relatively inexpensive method of sweat collection and chloride estimation using pilocarpine iontophoresis and titration, respectively, may be an alternative to the commercially available costly equipment. Having a team of trained nurse, physiotherapist, and dietician for optimal care of CF patients may not be feasible due to inadequate resources. Training a single person (e.g. nurse) to deliver comprehensive CF care may be a feasible alternative. To overcome problems of non availability of appropriate drugs (enzymes, inhaled antibiotics, DNAse, etc), locally available drugs may be used. Examples include use of hypertonic saline in place of DNAse, enteric coated enzyme tablets in place of enteric coated spherules, etc. Factors that are associated with decreased survival in CF patients from developing countries are age of onset of symptoms <2 months, severe malnutrition at the time of diagnosis, colonization with Pseudomonas at the time of diagnosis and frequency of pneumonia >4 episodes/year. All these factors can be modified except onset of symptoms before 2 months of age, by early diagnosis and appropriate treatment. Many of the above mentioned hurdles have been successfully overcome by us to establish CF services in a resource-limited setting. We conclude that education of pediatricians about the disease, early diagnosis using indigenous technology and aggressive physiotherapy with nutritional management and judicious use of antibiotics can improve the quality of life and survival in CF patients in resource-limited settings.

Anti-Bacterial Agents↗

PubMed2006

Mutations of human TMHS cause recessively inherited non-syndromic hearing loss.

BACKGROUND: Approximately half the cases of prelingual hearing loss are caused by genetic factors. Identification of genes causing deafness is a crucial first step in understanding the normal function of these genes in the auditory system. Recently, a mutant allele of Tmhs was reported to be associated with deafness and circling behaviour in the hurry-scurry mouse. Tmhs encodes a predicted tetraspan protein of unknown function, which is expressed in inner ear hair cells. The human homologue of Tmhs is located on chromosome 6p. OBJECTIVE: To determine the cause of deafness in four consanguineous families segregating recessive deafness linked to markers on chromosome 6p21.1-p22.3 defining a novel DFNB locus. RESULTS: A novel locus for non-syndromic deafness DFNB67 was mapped in an interval of approximately 28.51 cM on human chromosome 6p21.1-p22.3. DNA sequence analysis of TMHS revealed a homozygous frameshift mutation (246delC) and a missense mutation (Y127C) in affected individuals of two families segregating non-syndromic deafness, one of which showed significant evidence of linkage to markers in the DFNB67 interval. The localisation of mTMHS in developing mouse inner ear hair cells was refined and found to be expressed briefly from E16.5 to P3. CONCLUSIONS: These findings establish the importance of TMHS for normal sound transduction in humans.

Alleles↗

PubMed2006

Osteoma cutis in pseudohypoparathyroidism.

Osteoma cutis is the formation of normal bone in the skin. Primary osteoma cutis occurs de novo, whereas the secondary type develops in association with the underlying inflammatory, tumorous or traumatic conditions. Primary osteoma cutis is also associated with Albright's hereditary osteodystrophy (AHO), which can include hypocalcaemic-type pseudohypoparathyroidism (also known as pseudohypoparathyroidism type Ia) or normocalcaemic-type pseudohypoparathyroidism (also known as pseudopseudohypoparathyroidism). We describe a case of osteoma cutis in a 7-year-old boy who had cutaneous, biochemical and phenotypic features of pseudohypoparathyroidism type Ia and AHO.

Bone Neoplasms↗

PubMed2005

Arsenic induced apoptosis in rat liver following repeated 60 days exposure.

BACKGROUND: Accumulation of the wide spread environmental toxin arsenic in liver results in hepatotoxcity. Exposure to arsenite and other arsenicals has been previously shown to induce apoptosis in certain tumor cell lines at low (1-3 microM) concentration. AIM: The present study was focused to elucidate the role of free radicals in arsenic toxicity and to investigate the nature of in vivo sodium arsenite induced cell death in liver. METHODS: Male wistar rats were exposed to arsenite at three different doses of 0.05, 2.5 and 5mg/l for 60 days. Oxidative stress in liver was measured by estimating pro-oxidant and antioxidant activity in liver. Histopathological examination of liver was carried out by light and transmission electron microscopy. Analysis of DNA fragmentation by gel electrophoresis was used to identify apoptosis after the exposure. Terminal deoxy-nucleotidyl transferase mediated dUTP Nick end-labeling (TUNEL) assay was used to qualify and quantify apoptosis. RESULTS: A significant increase in cytochrome-P450 and lipid peroxidation accompanied with a significant alteration in the activity of many of the antioxidants was observed, all suggestive of arsenic induced oxidative stress. Histopathological examination under light and transmission electron microscope suggested a combination of ongoing necrosis and apoptosis. DNA-TUNEL showed an increase in apoptotic cells in liver. Agarose gel electrophoresis of DNA of hepatocytes resulted in a characteristic ladder pattern. CONCLUSION: Chronic arsenic administration induces a specific pattern of apoptosis called post-mitotic apoptosis.

Administration, Oral↗

PubMed2005

Do alpha deletions influence hydroxyurea response in thalassemia intermedia?

Thalassemia intermedia patients show variable phenotypes. Hydroxyurea (HU) may benefit some of the thalassemia intermedia cases (1), however, the parameters influencing the response to HU have not been reported. In this study, the molecular parameters, alpha-globin and beta-globin genotype and the Xmn I polymorphism, were correlated with the HU response. Twenty patients with thalassemia intermedia were given HU (10-20 mg/kg) and responses were evaluated over a one year period. Twelve patients (60%) showed a good response to therapy with a significant increase in Hb and HbF levels and with elimination of the transfusion requirement in four patients. Four out of the twelve (33%) patients were positive for -alpha(3.7) deletions whereas none of the 8 non-responders were positive for alpha deletions. One each of the responders and non-responders were positive for alpha alpha alpha(anti-3.7) triplication. Three (25%) responsive and one non-responsive patients were homozygous for the IVS1-1 (G-->T) mutation. Three of the responsive patients with alpha deletions were also homozygous positive for Xmn I polymorphism. Thus, in addition to acting in synergy with the XmnI polymorphism, alpha deletions may be an independent factor predicting good response to HU in thalassemia intermedia, although this needs to be confirmation in larger studies.

Adolescent↗

PubMed2005

An Indian child with Kindler syndrome resulting from a new homozygous nonsense mutation (C468X) in the KIND1 gene.

Kindler syndrome is an inherited skin condition that presents with blistering followed by photosensitivity and a progressive poikiloderma. The disorder results from mutations in the KIND1 gene, encoding the protein kindlin-1, a recently characterized 677-amino acid protein involved in anchorage of the actin cytoskeleton to the extracellular matrix. We report the clinical features of an 11-year-old boy with Kindler syndrome from a consanguineous Indian family and the identification of a homozygous nonsense mutation (C468X) in exon 12 of the KIND1 gene in his genomic DNA. This mutation has not been described previously but is similar to the 17 previously published KIND1 mutations that are all predicted to lead to loss of kindlin-1 protein expression and function. The clinical features in this boy highlight the relevance of kindlin-1 in skin biology, specifically to epidermal adhesion and response to acute and chronic sun exposure. Delineation of this new pathogenic mutation in KIND1 is also useful for genetic counselling in this family and in assessing carrier status in unaffected family members.

Base Sequence↗

PubMed2005

Cord blood analysis for prenatal diagnosis of thalassemia major and hemophilia A.

Beta thalassemia and Hemophilia A are common genetic disorders for which prenatal diagnosis (PND) is an accepted option. Our aim was to evaluate cord blood analysis as a method for PND of these disorders. Cord blood samples at 18-26 weeks gestation from nine mothers with previous thalassemia major child and five families with previous hemophilia A were studied. In the former; HbF, HbA2 and HbF were determined by high performance liquid chromatography (HPLC) and in latter; Factor VIII and IX assays were done by one stage method. In HPLC studies for thalassemia, three out of nine fetuses were affected, five were carriers and one was normal. In hemophilia PND samples, 2 out of five fetuses were affected. Thus, HPLC and factor VIII assay in cord blood are feasible alternatives for PND in Beta thalassemia and hemophilia A respectively, especially when DNA analysis is uninformative or there are financial constraints.

Female↗

PubMed2004

Can throat swab after physiotherapy replace sputum for identification of microbial pathogens in children with cystic fibrosis?

OBJECTIVE: To compare cultures throat swab after physiotherapy with results of sputum culture in identification of lower airway pathogens in children with cystic fibrosis. METHODS: 387 samples of sputum cough swabs, throat swab and throat swab after physiotherapy were collected from 48 patients of cystic fibrosis and cultured for aerobic bacteria. The results of cultures of cough swabs, throat swab and throat swab after physiotherapy were compared with results of sputum culture. RESULTS: There was good concordance between culture results of sputum and other methods. Over all concordance was 70%, 81% and 92% with cough swab, throat swab and throat swab after physiotherapy. Sensitivity for isolation of Pseudomonas aeruginosa by throat swab, cough swab and throat swab after physiotherapy was 40%, 42% and 82% respectively. Specificity for isolation of Pseudomonas by throat swab, cough swab and throat swab after physiotherapy was 99%, 100% and 99% respectively. Sensitivity for isolation of Staphylococcus aureus by throat swab, cough swab and throat swab after physiotherapy was 57%, 50% and 100% respectively. Specificity for isolation of Staphylococcus by throat swab, cough swab and throat swab after physiotherapy was 99% for all these methods. CONCLUSION: It is concluded that throat swab after physiotherapy in a child with CF can be used reliably for identification of lower airway pathogens.

Child↗

PubMed2004

Novel missense mutation in the coagulation factor IX catalytic domain associated with severe haemophilia B--Factor IXDelhi.

Factor IX is a vitamin K-dependent serine protease, which exists as a zymogen in the blood. On activation to factor IXa, by factor XIa or tissue factor-factor VIIa complex, it forms tenase complex with factor VIIIa, in the presence of Ca2+. This tenase complex enzymatically converts factor X to factor Xa, thereby bringing about the coagulation cascade. Mutations in factor IX gene have been shown to cause haemophilia B, which is inherited as an X-linked recessive disorder. Herein we report a novel missense mutation at the nucleotide position 30829-T > A in the exon 8 of factor IX gene. This transversion leads to the substitution of histidine 236 to glutamine. This resulting abnormal protein has been named factor IXDelhi. Molecular modelling was performed to predict the molecular pathology of this mutation. We predict that this change in the catalytic domain may affect the surface loop that accommodates Ca2+, thereby leading to severe bleeding disorder.

Catalytic Domain↗

PubMed2003

Prenatal diagnosis in hemophilia A using factor VIII gene polymorphism--Indian experience.

The heterogeneous nature of the mutations, the size, and the complexity of the factor VIII gene makes direct mutation analysis in hemophilia A families in India an option that is not very feasible and practical. Thus, carrier screening and prenatal diagnosis of hemophilia A often depends on haplotype analysis using restriction fragment length polymorphisms (RFLP) and short tandem repeat (STR) markers to track the defective factor VIII gene within a family. The main objective of this present study was to assess the utility of using polymerase chain reaction (PCR)-based five polymorphic markers: four intragenic Hind III, Bcl I, intron 13, and intron 22 STRs and one extragenic marker St14 in prenatal diagnosis. Forty-one chorionic villus samples (CVS) were studied from 41 families with a history of hemophilia A. PCR and RFLP were used for screening. Intron 22 STR showed the highest informativeness (60.9%), followed by Hind III (51.2%), Bcl I (46.3%), & intron 13 STR (51.2%); the extragenic marker St14 (VNTR) was informative in 46.3% of families. Linkage analysis, with the combined use of these five PCR-based polymorphic markers, gives good informativeness of 87.8% in the Indian population. Of the 41 CVS tested, 21 were found to be male fetuses and of these 13 were found likely to be affected with hemophilia A. Only in 12.2% of the families were none of the markers informative.

Chorionic Villi↗

PubMed2003

A case of dextrocardia, radial ray malformation and renal anomaly.

A 12-year-old boy is described with bilateral radial club hands, scoliosis, hypospadias, isolated dextrocardia, hypoplastic ribs, an ectopic kidney and spina bifida occulta. Although some of the clinical features of this patient are seen in VATER association and sacrococcygeal dysgenesis, the presence of dextrocardia, facial dysmorphism, radial, renal and vertebral anomalies preclude these diagnoses.

Abnormalities, Multiple↗

PubMed2003

Origins and frequencies of SLC26A4 (PDS) mutations in east and south Asians: global implications for the epidemiology of deafness.

Recessive mutations of SLC26A4 (PDS) are a common cause of Pendred syndrome and non-syndromic deafness in western populations. Although south and east Asia contain nearly one half of the global population, the origins and frequencies of SLC26A4 mutations in these regions are unknown. We PCR amplified and sequenced seven exons of SLC26A4 to detect selected mutations in 274 deaf probands from Korea, China, and Mongolia. A total of nine different mutations of SLC26A4 were detected among 15 (5.5%) of the 274 probands. Five mutations were novel and the other four had seldom, if ever, been identified outside east Asia. To identify mutations in south Asians, 212 Pakistani and 106 Indian families with three or more affected offspring of consanguineous matings were analysed for cosegregation of recessive deafness with short tandem repeat markers linked to SLC26A4. All 21 SLC26A4 exons were PCR amplified and sequenced in families segregating SLC26A4 linked deafness. Eleven mutant alleles of SLC26A4 were identified among 17 (5.4%) of the 318 families, and all 11 alleles were novel. SLC26A4 linked haplotypes on chromosomes with recurrent mutations were consistent with founder effects. Our observation of a diverse allelic series unique to each ethnic group indicates that mutational events at SLC26A4 are common and account for approximately 5% of recessive deafness in south Asians and other populations.

Asia, Southeastern↗

PubMed2002

An indigenously developed method for sweat collection and estimation of chloride for diagnosis of cystic fibrosis.

An indigenously developed method for sweat collection and titration method for estimation of chloride was validated. The mean difference in estimated chloride value from the known strength of saline in 50 samples was -1.04 +/- 4.13 mEq/L (95% CI: -0.07 to 2.28). The mean difference in the estimated chloride values between two observers when the test was performed on known strengths of saline solution was -2.5 +/- 4.24 mEq/L (95% CI: -3.67 to 1.33). The inter observer variability between two observers when the test was performed on sweat samples obtained from 50 individuals was -1.12 +/- 4.34 mEq/L (95% CI: -2.23 to 0.8 ). Sweat weight of more than 100 mg could be collected in first attempt in 602 of 757 (80%) patient with an average sweat weight of 230 mg. This inexpensive method of sweat collection and chloride estimation has acceptable accuracy and repeatability and can be used in resource poor setting for making a diagnosis of cystic fibrosis.

Cystic Fibrosis↗

PubMed2001

Factor IX gene polymorphisms in Indian population.

Hemophilia B is an X-linked, recessive disorder of hemostasis, caused by a defect in coagulation factor IX. To date, several restriction fragment length polymorphisms (RFLPs) have been identified within the gene for human factor IX. The incidence of these RFLPs differs significantly in different populations. In the present study, we analyzed the heterozygosity frequency and the allele frequency of three common intra- and extragenic polymorphic sites of the factor IX gene in Indian population. The main objective was to test the informativeness of two intragenic markers Dde I and Xmn I and one extragenic marker Hha I for carrier detection and prenatal diagnosis. The method used was polymerase chain reaction (PCR) and RFLP, which is economical yet simple to perform. In Indian population Dde I marker showed an informativeness of 69.0% followed by 38.0% for Hha I and 23.0% for Xmn I. The cumulative informativeness of these three markers was found to be 80 to 82%. A comparison of the heterozygosity rates of these three markers with the other ethnic groups showed that Indian population had almost similar pattern with the Caucasians and American blacks but differed significantly from the Orientals including Japanese, Chinese and Malays.

Deoxyribonucleases, Type II Site-Specific↗

PubMed2001

Mitochondrial myopathy presenting as ataxia with dilated cardiomyopathy.

Mitochondrial disorders are multisystem diseases with very heterogeneous clinical manifestations. Common cardiac features include cardiomyopathy and conduction defects. We report a five-year-old boy who presented with signs of congestive cardiac failure and was diagnosed to have dilated cardiomyopathy. Six months later, he developed progressively worsening ataxia, hypotonia, other cerebellar signs, hearing loss, severe sensory peripheral neuropathy and lactic acidosis. Electronmicroscopy of skeletal muscle biopsy was consistent with mitochondrial myopathy.

Ataxia↗

PubMed2001

Adhalin deficiency: an unusual cause of muscular dystrophy.

Childhood muscular dystrophies have a wide clinical spectrum, motor disability and are variably inherited. Although the phenotype may appear similar they may represent distinct genetic entities. Advances in immunohistochemistry, gene deletion and linkage studies have enabled precise characterization. We report a family with an early onset weakness and calf pseudo hypertrophy in 2 male sibs with an usually mild course. Deletion screening was negative for 24 exons of the DMD gene in both. Muscle immunohistochemistry revealed normal dystrophin I and II staining but complete absence for adhalin, a dystrophin associated glycoprotein. Classifying them as adhalinopathy. Severe childhood autosomal recessive muscular dystrophies (SCARMD) result from mutation in the sarcoglycan complex (59). Adhalinopathy is now used to describe SCARMD. The adhalinopathy described in our patients is the first report from India.

Biopsy, Needle↗

PubMed2001

Congenital adrenal hyperplasia presenting as hematuria and acute renal faliure.

We present a neonate who presented with hematuria and acute renal failure. Classical 21 hydroxylase deficiency was diagnosed on the basis of features of salt wasting, response to treatment with corticosteroids and mineralocorticoids and a positive ACTH stimulation test. Renal vein thrombosis secondary to hemoconcentration due to salt wasting was attributed as the cause of hematuria. Follow-up revealed clinical improvement and normalization of renal parameters. This is the first report of congenital adrenal hyperplasia presenting as hematuria and renal failure to the best of our knowledge.

Acute Kidney Injury↗

PubMed2001

Congenital myotonic dystrophy.

Myotonic muscular dystrophy is the most frequent autosomal muscular dystrophy affecting adults and children. It affects multiple organ systems and is probably the best example of variable expressivity in a human disease. This article presents a patient with congenital myotonic dystrophy who had facial dysmorphism, hypotonia, talipes, feeding and respiratory difficulties in the neonatal period and later presented to us with developmental delay and had percussion myotonia. His mother had clinical and electrophysiological features of myotonia. Expansion of unstable CTG trinucleotide repeat in the myotonic protein kinase gene was demonstrated in both. The identification of this molecular defect allows its specific diagnosis in relation to other neuromuscular disorders as well as accurate prenatal diagnosis.

Child, Preschool↗