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Biomedical subjects

A Srivastava

Publications and source records attributed to A Srivastava.

At least 37 records · Page 2Linked to original sources
PubMed2006

A study of diagnostic yield, technical ease and patient discomfort of low rate repetitive nerve stimulation test in patients with myasthenia gravis.

AIM: The diagnostic yield of repetitive nerve stimulation (RNS) study in different muscles has been evaluated in myasthenia gravis (MG) but there is paucity of comprehensive study on technical ease and patient comfort. In this study we evaluate diagnostic yield of RNS test, technical ease and patient discomfort in 8 different muscles in patients with MG. METHODS: Consecutive patients with MG diagnosed on the basis of clinical evaluation, neostigmine test and/or acetylcholine receptor antibody (AchRAb) assay were subjected to 3 Hz RNS study in abductor digiti minimi (ADM), flexor carpi ulnaris (FCU), anconeus, deltoid, trapezius, serratus anterior (SA), nasalis and tibialis anterior (TA) at rest and 3 min after 30 s exercise. Decrement exceeding 10% was considered abnormal. Patient's discomfort was assessed on a 0-5 scale and technical difficulty by the number of repetitions needed to complete the test or abandonment of test. RESULTS: Thirty-three patients with MG whose age ranged between 16-81 y were evaluated. At the time of RNS study the predominant weakness was ocular in 3, oculobulbar in 13 and limb in 17 patients. The highest diagnostic yield of RNS test was with deltoid and nasalis (78.8% each), followed by trapezius (65.5%). The highest mean patient discomfort score was with deltoid (2.4), followed by nasalis (1.3). The technical difficulty was maximal in deltoid needing 36.4% repetitions followed by SA (33.3%). In oculobulbar group the best yield was in nasalis (92.3%) followed by deltoid (84.6%), and in limb variety deltoid (82.4%) followed by SA (80%) and trapezius (75%). Combining the diagnostic yield, patient comfort and technical ease; the choice of muscle for RNS should be ADM followed by trapezius for patient with predominant limb weakness, nasalis and trapezius in oculobulbar and nasalis in ocular.

Action Potentials↗
PubMed2006

Anti-ulcer activity of Adhatoda vasica Nees.

Adhatoda vasica Nees (Acantheceae), commonly known as Vasaka, is a well-known plant in indigenous systems of medicine and is used for its beneficial effects, particularly in bronchitis. The present investigation was carried out to study the anti-ulcer activity of Adhatoda vasica leaves using two ulcer models (1) Ethanol-induced, and (2) Pylorus ligation plus aspirin-induced models. Adhatoda vasica leaf powder showeda considerable degree of anti-ulcer activity in experimental rats when compared with a control. The highest degree of activity (80%) was observed in the ethanol-induced ulceration model. Results of the study suggest that in addition to its classically established pharmacological activities, the plant also has immense potential as an anti-ulcer agent of great therapeutic relevance.

Administration, Oral↗
PubMed2005

An efficient synthesis of aryloxyphenyl cyclopropyl methanones: a new class of anti-mycobacterial agents.

An efficient, high yield and one-pot synthesis of phenyl cyclopropyl methanones by reaction of different aryl alcohols with 4'-fluoro-4-chloro-butyrophenone in THF/DMF in the presence of NaH/TBAB is reported. Most of the methanones were further reduced to respective alcohols or methylenes. All the compounds were evaluated for their anti-tubercular activities against M. tuberculosis H37Rv in vitro displaying MICs ranging from 25 to 3.125 microg/mL. The most active compounds showed activity against MDR strains and two of them (14 and 16) showed marginal enhancement of MST in mice.

Animals↗
PubMed2005

Marine water quality assessment at Mumbai West Coast.

In recent past, Mumbai Municipal corporation was not able to keep pace with required infrastructural facilities due to unprecedented population growth. Sewage disposal is one of the major issues, which needed immediate attention because huge quantity of sewage with only preliminary treatment is disposed into the nearby coastal areas and has deteriorated the water quality of the near coastal region. World Bank assisted Bombay Sewage Disposal Project (BSDP) undertaken by the Municipal Corporation of Bruhan Mumbai (MCBM) envisaged sewage discharges through marine outfalls at Worli and Bandra and treatment by aerated lagoons for other areas before disposal in creeks. During BSDP programme, studies were undertaken on water quality assessment along the west coast of Mumbai before and after commissioning of the Worli outfall. A pre- and post-commissioning water quality database for selected parameters was generated for near shore as well as west coast region up to 5 km seaward distance to assess the efficacy of the Worli outfall and delineate the areas affected around diffuser location of the outfall due to sewage disposal. This paper presents observations of the coastal studies at Mumbai and the impact zone of Worli outfall.

Bathing Beaches↗
PubMed2005

Synthesis and antitubercular activities of bis-glycosylated diamino alcohols.

Conjugate addition of diamines to glycosyl olefinic esters 1a and 1b followed by reduction of resulting bis-glycosyl beta-amino esters (2-7 and 14-19) with lithium aluminium hydride led to the respective glycosyl amino alcohols (8-13 and 20-25) in moderate to good yields. All the compounds were evaluated for antitubercular activity against Mycobacterium tuberculosis H(37)Ra and H(37)Rv. Few of the compounds exhibited antitubercular activity with MIC as low as 6.25-3.12microg/mL in virulent and avirulent strains. Compound 13 was found to be active against MDR strain and showed mild protection in mice.

Amino Alcohols↗
PubMed2005

Six novel mutations including triple heterozygosity for Phe31Ser, 514delT and 516T-->G factor X gene mutations are responsible for congenital factor X deficiency in patients of Nepali and Indian origin.

Factor X (FX) deficiency is a rare (1 : 100000) autosomal recessive disorder caused by heterogeneous mutations in FX gene. We have studied the molecular basis this disease in six Indian and one Nepali patients. Diagnosis was confirmed by measuring the FX coagulant activity (FX: C) using a PT based assay. Six of them had a FX: C of < 1% and one patient had 24% coagulant activity. Mutations were identified in all the seven patients. These included eight (88.8%) missense and one frame-shift (11.2%) mutations of which six were novel. Three of the novel mutations, a Phe31Ser affecting 'Gla' domain and 514delT and 516T-->G mutations affecting Cys132 in 'connecting region' were identified in a triple compound heterozygous state in a Nepali patient presenting with a severe phenotype. Two other novel mutations, Gly133Arg, may affect the disulphide bridge between Cys132-Cys302 in the connecting region while Gly223Arg may perturb the catalytic triad (His236, Asp282 and Ser379). The other novel mutation, Ser354Arg, involves the replacement of a small-buried residue by a large basic aminoacid and is likely to have steric or electrostatic effects in the pocket involving Lys351-Arg347-Lys414 that contributes to the core epitope of FXa for binding to FVa. Three previously reported mutations, Thr318Met; Gly323Ser; Gly366Ser were also identified. This is the first report of the molecular basis of FX deficiency in patients from the Indian subcontinent.

Arginine↗
PubMed2005

Air pollution and heat exposure study in the workplace in a glass manufacturing unit in India.

Air pollution in the workplace environment due to industrial operation have been found to cause serious occupational health hazard. Similarly, heat stress is still most neglected occupational hazard in the tropical and subtropical countries like India. The hot climate augments the heat exposure close to sources like furnaces. In this study an attempt is made to assess air pollution and heat exposure levels to workers in the workplace environment in glass manufacturing unit located in the State of Gujarat, India. Samples for workplace air quality were collected for SPM, SO(2), NO(2) and CO(2) at eight locations. Results of workplace air quality showed 8-hourly average concentrations of SPM: 165-9118 microg/m(3), SO(2): 6-9 microg/m(3) and NO(2): 5-42 microg/m(3), which were below the threshold limit values of workplace environment. The level of CO(2) in workplace air of the plant was found to be in the range 827-2886 microg/m(3), which was below TLV but much higher than the normal concentration for CO(2) in the air (585 mg/m(3)). Indoor heat exposure was studied near the furnace and at various locations in an industrial complex for glass manufacturing. The heat exposure parameters including the air temperature, the wet bulb temperature, and the globe parameters were measured. The Wet Bulb Globe Temperature (WBGT), an indicator of heat, exceeded ACGIH TLVs limits most of the time at all the locations in workplace areas. The recommended duration of work and rest have also been estimated.

Air Pollutants, Occupational↗
PubMed2005

Synthesis and antimycobacterial activities of glycosylated amino alcohols and amines.

Reduction of glycosyl beta-amino esters (6-14 and 25-30) with lithium aluminum hydride resulted in glycosyl amino alcohols (15-23 and 31-36) in good yields. However, reductive amination of glycosyl aldehydes (1-3) with different amines in presence of sodium borohydride resulted in good to moderate yields of glycosyl amines (37-41). All the compounds were evaluated for antitubercular activity against Mycobacterium tuberculosis H37Ra and H37Rv. Compounds 18, 21, 35 and 36 exhibited antitubercular activities with MIC ranging from 6.25 to 3.12 microg ml(-1).

Amines↗
PubMed2005

Fludarabine-based conditioning for allogeneic stem cell transplantation for multiply transfused patients with Fanconi's anemia.

A fludarabine-based protocol (fludarabine (25 mg/m(2)/day x 6 days), cyclophosphamide (10 mg/kg/day x 2 days) and ATG (ATGAM 10 mg/kg/day x 4 days)) was used in four multiply transfused Fanconi's anemia (FA) patients aged 5-15 years to reduce rejection during allogeneic bone marrow transplantation (BMT). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mini methotrexate. The graft source was G-CSF-stimulated bone marrow or peripheral blood stem cells (PBSC) in two patients each. All patients engrafted with median time to ANC>500/mm(3) being 14 days (range: 12-17) and unsupported platelet count >20 ,000/mm(3) being 13 days (range: 11-18). One patient had secondary graft rejection on day 56 and expired on day 69 due to fungal pneumonia. One patient who developed acute myeloid leukemia on day 56 underwent successful induction with cytosine and daunorubicin followed by peripheral blood stem cell (PBSC) rescue on day 70 and is presently in remission with complete donor chimerism and grade I GVHD. At a median follow-up of 13 months (range: 4-21), three patients (75%) are well with complete donor chimerism. Addition of fludarabine to the conditioning regimen for BMT in FA can provide additional immunosuppression for engraftment without increasing toxicity.

Adolescent↗
PubMed2005

Pre-transplant reduction of isohaemagglutinin titres by donor group plasma infusion does not reduce the incidence of pure red cell aplasia in major ABO-mismatched transplants.

Major ABO incompatibility in stem cell transplant recipients has been associated with pure red cell aplasia (PRCA). Reduction of incompatible isohaemagglutinin titres pre-transplant by various methods has been thought to reduce the incidence of PRCA. Our data suggest that pre-transplant reduction of incompatible isohaemagglutinin titres by donor group plasma infusion does not reduce the incidence of PRCA. We also failed to find any relationship between pre-transplant ABO isohaemagglutinin titre and the risk of developing PRCA.

ABO Blood-Group System↗
PubMed2005

Randomized trial of two different conditioning regimens for bone marrow transplantation in thalassemia--the role of busulfan pharmacokinetics in determining outcome.

In total, 94 patients with homozygous beta thalassemia were randomized to two different conditioning regimens: busulfan 600 mg/m2 + cyclophosphamide 200 mg/kg or busulfan 16 mg/kg + cyclophosphamide 200 mg/kg and antilymphocyte globulin (47 in each group), for bone marrow transplantation, to see whether increased myeloablation or increased immunosuppression would reduce rejection. Busulfan pharmacokinetics in determining outcome was evaluated. There was no significant difference in engraftment, graft-versus-host disease, rejection, and overall and disease-free survival in the two groups. Systemic exposure to busulfan was significantly higher in the 600 mg/m2 group, but in both groups there was a wide interindividual variation in the busulfan kinetics. Six patients rejected the graft, two in the busulfan 600 mg group and four in busulfan 16 mg group (P = 0.677 CI -0.17, 0.07), but in five patients (pharmacokinetic data not available in one patient) who rejected the graft busulfan first dose trough level (C(min)-1) was below 150 ng/ml while it was above this level in the 66 of 68 patients with successful engraftment (P < or = 0.001). This randomized trial shows that rejection is influenced by busulfan levels and suggests that monitoring of busulfan levels and dose adjustment based on first-dose kinetics may reduce the risk of rejection.

Antilymphocyte Serum↗
PubMed2005

Statistical shape analysis: clustering, learning, and testing.

Using a differential-geometric treatment of planar shapes, we present tools for: 1) hierarchical clustering of imaged objects according to the shapes of their boundaries, 2) learning of probability models for clusters of shapes, and 3) testing of newly observed shapes under competing probability models. Clustering at any level of hierarchy is performed using a mimimum variance type criterion criterion and a Markov process. Statistical means of clusters provide shapes to be clustered at the next higher level, thus building a hierarchy of shapes. Using finite-dimensional approximations of spaces tangent to the shape space at sample means, we (implicitly) impose probability models on the shape space, and results are illustrated via random sampling and classification (hypothesis testing). Together, hierarchical clustering and hypothesis testing provide an efficient framework for shape retrieval. Examples are presented using shapes and images from ETH, Surrey, and AMCOM databases.

Algorithms↗
PubMed2005

Identification of factor VIII gene mutations in 101 patients with haemophilia A: mutation analysis by inversion screening and multiplex PCR and CSGE and molecular modelling of 10 novel missense substitutions.

Haemophilia A (HA) is an X-linked bleeding disorder caused by diverse mutations in the human coagulation factor VIII (FVIII) gene. We have analysed DNA from 109 unrelated Indian patients with HA for their FVIII gene defects. Among these patients 89 (82%) had severe (FVIII:C <1%) HA, 11 (10%) had moderate (FVIII:C 1-5%) HA and nine (8%) had mild (FVIII:C 5-30%) HA. These patients were first screened for the common intron 22 and intron 1 inversions. Inversion negative samples were screened for point mutations by a multiplex PCR and conformation sensitive gel electrophoresis strategy. Mutations were identified in 101 of the 109 patients. These included two (2%) intron 1 and 51 (51%) intron 22 inversions, four (4%) gross deletions and 44 (43%) point mutations. Twenty-nine novel causative mutations, including 11 missense, seven frameshift, five nonsense mutations, three splice site defects and three gross deletions were detected. Ten of the novel missense mutations were studied by molecular modelling. Two different (Thr2253Pro and Pro1392fs) mutations were seen in four unrelated families and FVIII gene haplotyping suggested a common founder effect. Seven of these 109 patients had inhibitors. Among them, four had intron 22 inversions, one had a novel gross deletion (delexon 2-9) and one a nonsense mutation (Trp1535Stop). In one of these patients, no mutation could be identified in the FVIII gene. A Thr2253Pro novel mutation and an intron 22 inversion were identified in two female haemophiliacs. The data from this study suggests that the spectrum of gene defects in Indian patients with HA is as heterogeneous as reported in other populations.

Amino Acid Substitution↗
PubMed2005

Functional Independence Score in Haemophilia: a new performance-based instrument to measure disability.

Morbidity in haemophilia has been described predominantly in terms of musculoskeletal dysfunction and assessed by the clinical and radiological joint scores. These scores document changes in a particular joint, but do not reflect the impact of these changes on the individual in terms of his overall musculoskeletal function. Several self-assessment instruments have been used to measure musculoskeletal function but none have been specifically validated for use in haemophilia. In order to objectively assess musculoskeletal function of patients with haemophilia, we developed Functional Independence Score in Hemophilia (FISH), a performance-based instrument. FISH measures the patient's independence in performing seven activities under three categories: self-care (grooming and eating, bathing and dressing), transfers (chair and floor) and mobility (walking and step climbing). Each function is graded from 1 to 4 depending on the amount of assistance needed in performing the function. We evaluated 35 patients who were over 10 years old and had had at least three major bleeds per year. All subjects were scored for clinical (World Federation of Hemophilia, WFH score) and radiological changes (Pettersson's score). Functional independence of the patient was assessed using the Stanford Health Assessment Questionnaire (HAQ) and the FISH. Correlation of the FISH score was modest with both the WFH clinical score (r = -0.68) and the radiological score (r = -0.44). While there was good correlation between FISH and HAQ (r = -0.90), FISH had better internal consistency than HAQ (Cronbach's alpha 0.83 vs. 0.66). FISH appears to be a promising disease-specific instrument for assessing overall musculoskeletal function in haemophilia. It requires evaluation in different patient populations.

Activities of Daily Living↗
PubMed2005

Molecular genetics of hereditary prothrombin deficiency in Indian patients: identification of a novel Ala362 --> Thr (Prothrombin Vellore 1) mutation.

Prothrombin deficiency is a rare (1:200 000) autosomal recessive disorder caused by diverse mutations in prothrombin gene. We have studied the molecular basis of this disorder in four unrelated Indian patients. The diagnosis was based on prolonged prothrombin (PT) and activated partial thromboplastin times and low factor II coagulant activity (FII: C) measured using a PT based assay. FII: C levels ranged between 4.7% and 17.5%. Mutations were identified in all the four patients. Five different causative mutations including four (80%) missense and an in-frame deletion (20%) were identified. One of them was a novel, Ala362 --> Thr amino acid change affecting 'B' chain of -thrombin. This mutation was present in a compound heterozygous state with a previously reported Arg-1 --> Gln missense change affecting pro-peptide cleavage site. Ala362 --> Thr occurred at a codon, evolutionarily conserved in all the 24 different prothrombins or its related serine proteases studied. Molecular modeling of this mutation was found to cause a conformational change around the region involving a catalytic triad residue His363 and a cysteine residue at codon 364. The FII: C level in this patient was 17.5%. Three other previously reported mutations were also detected in the homozygous state: Arg271 --> Cys in Kringle-2 region, a Glu309 --> Lys in "A" chain of -thrombin and an in-frame deletion of 3 bp (AAG) leading to Del Lys301/302 in "A" chain of -thrombin. This is the first report of the molecular basis of prothrombin deficiency in Indian patients and we suggest the eponym 'Prothrombin Vellore 1' for Ala362 --> Thr mutation.

Adult↗
PubMed2005

Three novel beta-propeller mutations causing Glanzmann thrombasthenia result in production of normally stable pro-alphaIIb, but variably impaired progression of pro-alphaIIbbeta3 from endoplasmic reticulum to Golgi.

BACKGROUND: Glanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder characterized by lack of platelet aggregation in response to most physiological agonists and caused by either a lack or dysfunction of the platelet integrin alpha(IIb)beta3 (glycoprotein IIb/IIIa). OBJECTIVES: To determine the molecular basis of GT and characterize the mutations by in vitro expression studies. PATIENTS: We studied three unrelated patients from southern India whose diagnosis was consistent with GT. RESULTS: Immunoprecipitation of the cell lysates and immunoblotting showed no detectable mature alpha(IIb) in the G128S mutant, in contrast to 6% and 33% of the normal amount of mature alpha(IIb) in the S287L and G357S mutants, respectively. Pulse-chase analysis demonstrated pro-alpha(IIb) in the mutants comparable with the normal pro-alpha(IIb), but no conversion to mature alpha(IIb) in the G128S mutant, and only trace conversion to mature alpha(IIb) in the S287L and G357S mutants. The disappearance of pro-alpha(IIb) in the three mutants was similar to that in cells expressing normal alpha(IIb)beta3 or alpha(IIb) only. All three mutants demonstrated pro-alpha(IIb)beta3 complexes and co-localized with an ER marker by immunofluorescence. The G128S mutant showed no co-localization with a Golgi marker, and the other two mutants showed minimal and moderate co-localization with the Golgi marker. CONCLUSIONS: These three beta-propeller mutations do not affect the production of pro-alpha(IIb), its ability to complex with beta3, or its stability, but do cause variable defects in transport of pro-alpha(IIb)beta3 complexes from the endoplasmic reticulum to the Golgi.

Adult↗