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Biomedical subjects

G Kumar

Publications and source records attributed to G Kumar.

At least 19 recordsLinked to original sources
PubMed2001

Age estimation using three established methods. A study on Indian population.

Age estimation is an important factor in the identification of an individual in forensic cases. Adult age determination from teeth was carried out using three methods, namely, Johanson method, methods of Kashyap and Koteswar Rao and the average stage of attrition method (ASA). A total of 100 patients were selected. Johanson and Kashyap method uses microscopic measurements, whereas ASA is purely a clinical method. ASA method was found to be the best method. Unsatisfactory results were seen more in Kashyap's technique. In all the three methods overestimates of age were common in mandibular teeth and in teeth taken from female individuals. More studies are needed in Kashyap's method as there are certain difficulties encountered in measuring a few criteria.

Adult↗
PubMed2001

High-throughput genotyping of single nucleotide polymorphisms with rolling circle amplification.

BACKGROUND: Single nucleotide polymorphisms (SNPs) are the foundation of powerful complex trait and pharmacogenomic analyses. The availability of large SNP databases, however, has emphasized a need for inexpensive SNP genotyping methods of commensurate simplicity, robustness, and scalability. We describe a solution-based, microtiter plate method for SNP genotyping of human genomic DNA. The method is based upon allele discrimination by ligation of open circle probes followed by rolling circle amplification of the signal using fluorescent primers. Only the probe with a 3' base complementary to the SNP is circularized by ligation. RESULTS: SNP scoring by ligation was optimized to a 100,000 fold discrimination against probe mismatched to the SNP. The assay was used to genotype 10 SNPs from a set of 192 genomic DNA samples in a high-throughput format. Assay directly from genomic DNA eliminates the need to preamplify the target as done for many other genotyping methods. The sensitivity of the assay was demonstrated by genotyping from 1 ng of genomic DNA. We demonstrate that the assay can detect a single molecule of the circularized probe. CONCLUSIONS: Compatibility with homogeneous formats and the ability to assay small amounts of genomic DNA meets the exacting requirements of automated, high-throughput SNP scoring.

Journal Article↗
PubMed2001

A stress-responsive gene from groundnut, Gdi-15, is homologous to flavonol 3-O-glucosyltransferase involved in anthocyanin biosynthesis.

Stress-tolerant crops are expected to express genes not normally expressed in susceptible crops. We have used desiccation stress coupled with high light intensity to identify groundnut as a relatively tolerant crop. Stress-responsive genes (Gdi, Groundnut Desiccation Induced) were cloned by subtractive hybridisation. The sequence of Gdi-15 shows homology to flavonol 3-O-glucosyltransferases, which are involved in anthocyanin biosynthesis. Gdi-15 transcripts increase markedly in response to stress, suggestive of a role in stress tolerance.

Amino Acid Sequence↗
PubMed2001

Identification of a basolateral sorting signal for the M3 muscarinic acetylcholine receptor in Madin-Darby canine kidney cells.

Muscarinic acetylcholine receptors (mAChRs) can be differentially localized in polarized cells. To identify potential sorting signals that mediate mAChR targeting, we examined the sorting of mAChRs in Madin-Darby canine kidney cells, a widely used model system. Expression of FLAG-tagged mAChRs in polarized Madin-Darby canine kidney cells demonstrated that the M(2) subtype is sorted apically, whereas M(3) is targeted basolaterally. Expression of M(2)/M(3) receptor chimeras revealed that a 21-residue sequence, Ser(271)-Ser(291), from the M(3) third intracellular loop contains a basolateral sorting signal. Substitution of sequences containing the M(3) sorting signal into the homologous regions of M(2) was sufficient to confer basolateral localization to this apical receptor. Sequences containing the M(3) sorting signal also conferred basolateral targeting to M(2) when added to either the third intracellular loop or the C-terminal cytoplasmic tail. Furthermore, addition of a sequence containing the M(3) basolateral sorting signal to the cytoplasmic tail of the interleukin-2 receptor alpha-chain caused significant basolateral targeting of this heterologous apical protein. The results indicate that the M(3) basolateral sorting signal is dominant over apical signals in M(2) and acts in a position-independent manner. The M(3) sorting signal represents a novel basolateral targeting motif for G protein-coupled receptors.

Amino Acid Motifs↗
PubMed2001

Post-traumatic arachnoiditis: an unusual cause of Brown-Sequard syndrome.

Brown-Sequard syndrome (BSS) is a unilateral cord injury characterised by an ipsilateral motor deficit with contralateral pain and temperature hypoaesthesia. Although there are a variety of causes, the majority of cases are generally of neoplastic origin or are traumatic in origin. We describe a rare cause of Brown-Sequard syndrome as a result of post-traumatic arachnoiditis. Magnetic resonance imaging with the use of thin-slice high-resolution constructive interference in steady state (CISS) and T2-weighted spin-echo sequence were used to demonstrate the cause and appearance of the lesion in the spinal canal and was useful in the assessment and management of the patient. This case illustrates the usefulness of the CISS sequence in MRI for elucidating arachnoiditis.

Adult↗
PubMed2001

BMI does not accurately predict overweight in Asian Indians in northern India.

Asian Indians are at high risk for the development of atherosclerosis and related complications, possibly initiated by higher body fat (BF). The present study attempted to establish appropriate cut-off levels of the BMI for defining overweight, considering percentage BF in healthy Asian Indians in northern India as the standard. A total of 123 healthy volunteers (eighty-six males aged 18--75 years and thirty-seven females aged 20--69 years) participated in the study. Clinical examination and anthropometric measurements were performed, and percentage BF was calculated. BMI for males was 21.4 (sd 3.7) kg/m(2) and for females was 23.3 (sd 5.5) kg/m(2). Percentage BF was 21.3 (sd 7.6) in males and 35.4 (sd 5.0) in females. A comparison of BF data among Caucasians, Blacks, Polynesians and Asian ethnic groups (e.g. immigrant Chinese) revealed conspicuous differences. Receiver operating characteristic (ROC) curve analysis showed a low sensitivity and negative predictive value of the conventional cut-off value of the BMI (25 kg/m(2)) in identifying subjects with overweight as compared to the cut-off value based on percentage BF (males >25, females >30). This observation is particularly obvious in females, resulting in substantial misclassification. Based on the ROC curve, a lower cut-off value of the BMI (21.5 kg/m(2) for males and 19.0 kg/m(2) for females) displayed the optimal sensitivity and specificity, and less misclassification in identification of subjects with high percentage BF. Furthermore, a novel obesity variable, BF:BMI, was tested and should prove useful for interethnic comparison of body composition. In the northern Indian population, the conventional cut-off level of the BMI underestimates overweight and obesity when percentage BF is used as the standard to define overweight. These preliminary findings, if confirmed in a larger number of subjects and with the use of instruments having a higher accuracy of BF assessment, would be crucial for planning and the prevention and treatment of various obesity-related metabolic diseases in the Asian Indian population.

Adult↗
PubMed2001

Screening for major depressive disorders in adolescent psychiatric inpatients with the mood modules from the Primary Care Evaluation of Mental Disorders and the Patient Health Questionnaire.

The mood modules from the Primary Care Evaluation of Mental Disorders (PRIME-MD) and the Patient Health Questionnaire (PHQ) were administered to 17 (52%) female and 16 (48%) male adolescent (13-17 years old) psychiatric inpatients. The internal consistencies of both were good (KR-20 for PRIME-MD=.80, Cronbach coefficient alpha for Patient Health Questionnaire=.85). The correlation between the PRIME-MD and Patient Health Questionnaire total scores was .87 (p<.001), and the point-biserial correlation of both questionnaires' total scores with being diagnosed with a Major Depressive Disorder was .54 (p<.001). Both mood modules appeared to be equally effective in screening for a Major Depressive Disorder.

Adolescent↗
PubMed2001

Evidence for the construct validities of the Beck Youth Inventories with child psychiatric outpatients.

To provide further information about the construct validities of the Beck Youth Inventories of Emotional and Social Impairment, these inventories were administered to 35 female and 65 male outpatients whose ages ranged from 7 to 12 years and who were diagnosed with various psychiatric disorders. The Children's Depression Inventory was also administered, and the children were rated by a parent with the Conners' Parent Rating Scale-Revised: Short Form. The scores on the former inventory were more positively correlated with the scores on the Beck Youth Depression Inventory (r =.81, p<.001) than with scores on the four other Beck Youth Inventories, and those on the Conners Oppositional scale were comparably correlated with the scores on the Beck Youth Disruptive Behavior (r=.49, p<.001) and Anger (r=.41, p<.001) Inventories. These latter correlations were higher than those for scores on the Oppositional scale with the scores on the three other Beck scales.

Affective Symptoms↗
PubMed2001

A case report of primary hyperparathyroidism with severe bony involvement and nephrolithiasis.

INTRODUCTION: Although the majority of patients with primary hyperparathyroidism have a relatively asymptomatic benign disorder, there are patients who have a more aggressive disorder. CLINICAL PICTURE: We report a case of primary hyperparathyroidism presenting during pregnancy complicated by antepartum haemorrhage and severe prematurity. The diagnosis was made postpartum, when her problems rapidly progressed to result in severe neuromuscular weakness, bilateral pathological hip fractures as well as nephrolithiasis. TREATMENT: Surgical parathyroidectomy was performed. The underlying lesion was a large solitary parathyroid adenoma with cystic elements. CONCLUSION: Primary hyperparathyroidism is not an innocuous disease and can result in severe morbidity if left untreated.

Adenoma↗
PubMed2000

Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties.

An enzymatic method to graft hexyloxyphenol onto the biopolymer chitosan was studied. The method employs tyrosinase to convert the phenol into a reactive o-quinone, which undergoes subsequent nonenzymatic reaction with chitosan. Reactions were conducted under heterogeneous conditions using chitosan films and also under homogeneous conditions using aqueous methanolic mixtures capable of dissolving both hexyloxyphenol and chitosan. Tyrosinase was shown to catalyze the oxidation of hexyloxyphenol in such aqueous methanolic solutions. Chemical evidence for covalent grafting onto chitosan was provided by three independent spectroscopic approaches. Specifically, enzymatic modification resulted in (1) the appearance of broad absorbance in the 350-nm region of the UV/vis spectra for chitosan films; (2) changes in the NH bending and stretching regions of chitosan's IR spectra; and (3) a base-soluble material with (1)H-NMR signals characteristic of both chitosan and the alkyl groups of hexyloxyphenol. Hexyloxyphenol modification resulted in dramatic changes in chitosan's functional properties. On the basis of contact angle measurements, heterogeneous modification of a chitosan film yielded a hydrophobic surface. Homogeneously modified chitosan offered rheological properties characteristic of associating water-soluble polymers.

Chitin↗
PubMed2000

Scale for identification of "at risk" families for underfive deaths.

India currently has an infant mortality rate (IMR) of 73 and aims to reach 60 per 1000 live births by 2000 A.D. The "at risk" approach which has been traditionally used for Maternal and Child Health services could help to reduce costs. The main objective of the study was to identity socio-demographic "risk factors" at family level for underfive deaths and assess the validity and efficiency of a risk index scale for this purpose. A computerised database on about 71,000 individuals in 28 villages in Ballabgarh Block exists since 1987. All the underfive deaths in the study area during the period 1991-95 were compared with age and sex matched controls on socio-demographic variables. All variables which were found significant at 10% level were taken in for logistic regression. The variables found significant were used to construct a ten point scale. This scaling system was applied to all the families with an underfive child during the two year period 1996-97. Validity and efficiency of this approach was calculated. A total of 849 cases and their age and sex matched controls were studied. The variables which were significantly associated with risk of underfive deaths were: not received measles vaccine (2.19; 1.58-3.04), history of sibling death (2.03; 1.19-3.45), maternal illiteracy (1.86; 1.23-2.81), never used a contraceptive (1.59; 1.17-2.14), having more than 4 children (1.46; 1.04-2.05). About 40% of houses were labelled as high risk. The sensitivity and specificity were around 60%. The improvement in efficiency by the risk approach was 33%. Risk approach is helpful in identifying families who are at greater risk of having underfive deaths. It results in a modest increase in the efficiency of services.

Case-Control Studies↗
PubMed2000

Chitosan based water-resistant adhesive. Analogy to mussel glue.

Using analogies from nature, we investigated the possibility that tyrosinase-catalyzed reactions of 3,4-dihydroxyphenethylamine (dopamine) could confer water-resistant adhesive properties to semidilute solutions of the polysaccharide chitosan. Rheological measurements showed that the tyrosinase-catalyzed, and subsequent uncatalyzed, reactions lead to substantial increases in the viscosity of the chitosan solutions. Samples from these high-viscosity modified-chitosans were spread onto dry glass slides, the slides were lapped and clipped together either in air or after being submerged in water, and the bound slides were held under water for several hours. Adhesive shear strengths of over 400 kPa were observed for these modified chitosan samples, while control chitosan solutions conferred no adhesive strength (i.e., the glass slides separated in the absence of measurable forces). High viscosities and water-resistant adhesive strengths were also observed when semidilute chitosan solutions were treated with the known cross-linking agent, glutaraldehyde. Further studies indicate a relationship between the increased viscosities and water-resistant adhesion. These results demonstrate that the renewable biopolymer chitosan can be converted into a water-resistant adhesive.

Adhesives↗