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Biomedical subjects

A Gupta

Publications and source records attributed to A Gupta.

At least 379 records · Page 21Linked to original sources
PubMed1999

Spontaneous apoptosis in peripheral blood mononuclear cells of leprosy patients: role of cytokines.

Peripheral blood mononuclear cells from leprosy patients underwent spontaneous apoptosis upon culture for 24 h. The apoptosis was inhibited by anti-TNFalpha antibodies and to a certain extent by anti-IL-1alpha and IL-6, thus showing that T(H)2-type cytokines (mainly TNFalpha) are responsible for inducing apoptosis. This cytokine-mediated apoptosis could be inhibited by ionomycin and zinc, thereby suggesting that these metal ions can be used to decrease the levels of these inflammatory cytokines in various diseases.

Antibodies↗
PubMed1999

Mercury resistance in Bacillus cereus RC607: transcriptional organization and two new open reading frames.

The chromosomal mercury resistance determinant of Bacillus cereus RC607 confers resistance to inorganic mercury and to organomercurials. The order of genes in the completed mercury resistance determinant is operator-promoter 1 (O/P1) merR1 merT open reading frame 3 (ORF3) ORF4 merA O/P2 merR2 merB2 merB1. The previously undetermined 1-kb DNA sequence between the merA and merB1 genes includes two significant ORFs, whose predicted protein products are homologous with MerR (the transcriptional regulator) and MerB (the organomercurial lyase enzyme). Two transcriptional start sites (promoters), O/P1 at the beginning of the determinant and O/P2 immediately upstream of the sixth ORF, the newly identified merR2, were mapped by reverse transcriptase (RT) primer extension. A long 6.3-kb mRNA traversing all eight ORFs was shown by RT-PCR. Growth sensitivity measurements in liquid media and cellular mercury volatization assays characterized inducibility and differences in functional activity in B. cereus RC607 and after cloning of the mer determinant into plasmids in Escherichia coli.

Amino Acid Sequence↗
PubMed1999

The Ununited Scaphoid:Prognostic Factors in Delayed and Nonunions of the Scaphoid.

This study attempts to classify scaphoid nonunions, identify the prognostic indicators of scaphoid nonunions and report the clinical, functional and radiographic results of scaphoid nonunions treated by Herbert screw and bone grafting. The patient population included 51 scaphoid nonunions in 50 patients treated by Herbert screw with or without bone graft. Group I was patients with delayed union; Group II was stable nonunions, Group IIIA consisted of unstable nonunions without DISI; Group IIIB included unstable nonunions with DISI deformity. Although the overall union rate was 84%, 87% stable nonunions (Groups I and II) united compared to only 60% unstable (Groups IIIA and B). This was statistically significant using the Chi-square test at p < 0.05. Thus, delayed unions and stable nonunions unite readily but unstable and displaced nonunions have significantly lower rates of union even after Herbert screw and bone grafting.

Journal Article↗
PubMed1999

Distal Interphalangeal Joint Arthrodesis Using Intramedullary and Interosseous Fixation.

Multiple fixation techniques have been developed for distal interphalangeal (DIP) joint arthrodesis. Delayed and nonunion rates varying from 0% to 20% have been reported. The senior author has refined a technique for DIP joint arthrodesis by using an intramedullary Kirschner wire and an interosseous wire for fusion of the DIP joint and interphalangeal (IP) joint of the thumb. In 24 joint arthrodeses in 19 patients, the nonunion rate was 4%, and the minor complication rate was 12%. The advantages of this technique include the absence of protruding hardware that would necessitate removal; consistency in achieving osteosynthesis, with a low nonunion rate; and technical simplicity.

Journal Article↗
PubMed1999

Acute pulmonary embolism: diagnosis with MR angiography.

PURPOSE: To prospectively evaluate pulmonary magnetic (MR) angiography as a diagnostic examination for acute pulmonary embolism (PE). MATERIALS AND METHODS: Thirty-six consecutive patients (19 women, 17 men; age range, 28-84 years) underwent pulmonary digital subtraction angiography (DSA) and pulmonary MR angiography. MR angiograms were obtained during suspended respiration and the pulmonary arterial phase of gadolinium-based contrast medium injection. A steady-state gradient-recalled-echo sequence with free induction decay sampling was used. DSA studies were interpreted for the presence of acute PE by two independent radiologists; an adjudicator made the final decision on discordant interpretations. RESULTS: By using DSA, a total of 19 acute pulmonary emboli were depicted in 13 patients. Prospectively, 13 of these emboli were depicted by using MR angiography. MR angiography missed six emboli: Four required the DSA adjudicator to make the decision, and one was in a patient whose MR angiogram was acquired during breathing. Four of these six emboli were small subsegmental emboli, and two were segmental. CONCLUSION: Performed without pulmonary arterial catheterization, iodinated contrast media, or ionizing radiation, pulmonary MR angiography had a high accuracy for depicting lobar and segmental emboli, but was unable to depict four of five subsegmental emboli.

Acute Disease↗
PubMed1999

Functional impairment of blood-brain barrier following pesticide exposure during early development in rats.

1. The effect of certain pesticides on the functional integrity of the developing blood-brain barrier (BBB) was studied following single and repeated exposure, and after subsequent withdrawal in rats. 2. Ten-day-old rat pups exposed orally to quinalphos (QP, organophosphate), cypermethrin (CM, pyrethroid) and lindane (LD, organochlorine) at a dose of 1/50th of LD50, showed a significant increase in the brain uptake index (BUI) for a micromolecular tracer, sodium fluorescein (SF), by 97, 37 and 72%, respectively, after 2 h. Residual increases in the BUI were found even after 3 days of the single treatment of QP (28%) and LD (23%). 3. Repeated exposure for 8 days (postnatal days (PND) 10-17) with QP, CM and LD increased the BBB permeability by 130, 80 and 50%, respectively. Recovery from these changes was complete in QP and LD-treated animals after 13 days (PND 18-30) of withdrawal. However, CM showed persistent effects that were normalized only after 43 days (PND 18-60) of withdrawal. 4. A single dose reduced to 1/100th of LD50 also increased BUI in 10-day-old rat pups following QP (20%) and CM (28%) exposure at 2 h. 5. An age-dependent effect of these pesticides was evident from the study showing higher magnitude of BUI changes in 10-day-old rats as compared to that in 15-day-old rats. Furthermore, adult rats did not show any effect on BBB permeability even at a higher dose (1/25th of LD50) of these pesticides given alone or in combination with piperonyl butoxide (600 mg/kg, i.p.) for 3 consecutive days. 6. This study showed that developing BBB is highly vulnerable to single or repeated exposure of certain pesticides. The observed persistent effects during brain development even after withdrawal of the treatment may produce some neurological dysfunction at later life as well.

Administration, Oral↗
PubMed1999

One day old infant with acyanotic congenital heart disease: critical aortic stenosis.

Congenital aortic stenosis accounts for about 5% of cardiac malformations recognized in childhood. It belongs to the category of acyanotic congenital heart disease. These lesions produce a load on the heart because of left ventricular outflow tract obstruction. Severe aortic stenosis in the newborn period (critical aortic stenosis) presents with signs of left sided heart failure (pulmonary edema, poor perfusion), right sided heart failure (hepatomegaly, peripheral edema) and may progress rapidly to total circulatory collapse. We present a case of an infant with critical aortic stenosis presenting with cyanosis, who was entirely dependent on ductal patency for systemic output. When oxygen was given, the ductus started to close, with a worsening of the left sided output and subsequent acidosis. With the right to left shunt across the ductus, the baby was cyanotic and dependent on prostaglandin to keep the ductus open. There was minimal flow across the aortic valve because of the stenosis and extremely poor left ventricular function prior to surgery. After relief of the aortic valvular obstruction, there was finally good antegrade flow across the aortic valve, terminating cyanosis.

Adult↗
PubMed1999

Simplified gene-fragment phage display system for epitope mapping.

We describe a simple and efficient system for epitope mapping by cloning random gene fragments into a specially designed gIIIp-based phage display vector. DNA encoding the antigen of interest is PCR-amplified and partially digested with DNaseI to generate 50-150-bp-long fragments, which are polished with T4 DNA polymerase and dephosphorylated. These fragments are cloned at the 5' end of the gIII after linearizing the vector with SmaI/SrfI, and the ligation is carried out in the presence of restriction enzyme SrfI. The restriction enzyme in the ligation reaction recuts the self-ligated vector but not the recombinants, since ligation with foreign fragments destroys the enzyme recognition site. Dephosphorylation of inserts prevents their chimerization and ensures ligation of single insert per vector molecule. Thus, using the above strategy, which prevents self-ligation of both the insert and the vector, the overall cloning efficiency and, thereby the library size, is improved more than 10-fold compared to the standard blunt-end, ligation-based methods for making similar libraries. The library is further enriched by a single-step infection of E. coli by phages obtained from primary transformants. This step eliminates all the phages that carry insert that are not in-frame with gIIIp and therefore do not display gIIIp. We have shown the utility of the above system in constructing a glutathione-S-transferase (GST) gene-fragment library in phages and identifying the epitope recognized by a monoclonal antibody against GST.

Amino Acid Sequence↗
PubMed1999

RT-PCR: characterization of long multi-gene operons and multiple transcript gene clusters in bacteria.

Reverse transcription (RT)-PCR is a valuable tool widely used for analysis of gene expression. In bacteria, RT-PCR is helpful beyond standard protocols of northern blot RNA/DNA hybridization (to identify transcripts) and primer extension (to locate their start points), as these methods have been difficult with transcripts that are low in abundance or unstable, similar to long multi-gene operons. In this report, RT-PCR is adapted to analyze transcripts that form long multi-gene operons--where they start and where they stop. The transcripts can also be semiquantitated to follow the expression of genes under different growth conditions. Examples using RT-PCR are presented with two different multi-gene systems for metal cation resistance to silver and mercury ions. The silver resistance system [9 open reading frames (ORFs); 12.5 kb] is shown by RT-PCR to synthesize three nonoverlapping messenger RNAs that are transcribed divergently. In the mercury resistance system (8 ORFs; 6.3 kb), all the genes are transcribed in the same orientation, and two promoter sites produce overlapping transcripts. For RT-PCR, reverse transcriptase enzyme is used to synthesize first-strand cDNA that is used as a template for PCR amplification of single-gene products, from the beginning, middle or end of long multi-gene, multi-transcript gene clusters.

Bacillus cereus↗
PubMed1999

Hyperthyroidism due to papillary carcinoma of the thyroid--a case report.

A rare case of papillary carcinoma of the thyroid producing hyperthyroidism is presented. A young patients presented seven years after a thyroid operation with metastatic disease in the cervical lymph nodes and a history of deteriorating vision in the left eye. He also had a lesion in the base of the skull which could not be established to be metastasis from the thyroid cancer. There was clinical and biochemical evidence of hyperthyroidism. Radionuclide scan revealed uptake in the residual thyroid tissue and patchy uptake by the cervical lymph nodes. The patient underwent a complete thyroidectomy and radical neck dissection of the left side and 'berry-picking' of the lymph nodes on the right side. Although the patient became euthyroid post-operatively, his general condition deteriorated and he rapidly lost vision in both eyes before any ablative therapy could be instituted for the tumour in the base of the skull. The patient was lost to follow-up.

Adult↗
PubMed1999

Spectrum of cystic variants of Wilm's tumour: cystic nephroma (multilocular cyst) and cystic partially differentiated nephroma--a report of four cases.

Two cases of cystic nephroma (multilocular cyst of the kidney), and one case each of cystic partially differentiated nephroblastoma (CPDN) and rhabdomyomatous Wilms' tumour are described. All were male and in the pediatric age group. Grossly tumours were unilateral, unicentric and multiloculated. The need for proper designation of these lesions is highlighted because of difference in the treatment and prognosis of these tumours.

Child, Preschool↗
PubMed1999

Adaptation of cytochrome-b5 reductase activity and methaemoglobinaemia in areas with a high nitrate concentration in drinking-water.

An epidemiological investigation was undertaken in India to assess the prevalence of methaemoglobinaemia in areas with high nitrate concentration in drinking-water and the possible association with an adaptation of cytochrome-b5 reductase. Five areas were selected, with average nitrate ion concentrations in drinking-water of 26, 45, 95, 222 and 459 mg/l. These areas were visited and house schedules were prepared in accordance with a statistically designed protocol. A sample of 10% of the total population was selected in each of the areas, matched for age and weight, giving a total of 178 persons in five age groups. For each subject, a detailed history was documented, a medical examination was conducted and blood samples were taken to determine methaemoglobin level and cytochrome-b5 reductase activity. Collected data were subjected to statistical analysis to test for a possible relationship between nitrate concentration, cytochrome-b5 reductase activity and methaemoglobinaemia. High nitrate concentrations caused methaemoglobinaemia in infants and adults. The reserve of cytochrome-b5 reductase activity (i.e. the enzyme activity not currently being used, but which is available when needed; for example, under conditions of increased nitrate ingestion) and its adaptation with increasing water nitrate concentration to reduce methaemoglobin were more pronounced in children and adolescents.

Adolescent↗
PubMed1999

99Tcm-citrate: a new bone imaging radiopharmaceutical.

99Tcm-citrate has been shown to incorporate irreversibly in the skeleton with a biodistribution different to that on a conventional bone scan. The aims of this study were to confirm the bone-imaging properties of 99Tcm-citrate, to identify the variabilities influencing its skeletal uptake, to compare its uptake in bone with that of 99Tcm-MDP and to assess its possible role in bone scintigraphy. Appropriate animal and human studies (n = 45) were conducted. The 3 h lesion-to-bone ratio of 99Tcm-citrate was compared with that of 99Tcm-MDP in more than 150 lesions, including osteoblastic sites (Group A), lesions undergoing treatment or healing (Group B), and degenerative or old healed lesions (Group C). The uptake ratio was classified as concordant (< 20% variation), mildly discordant (20-50% variation) or significantly discordant (> 50% variation). Animal experiments showed most bone uptake of 99Tcm-citrate when prepared at a pH of 6.0-6.5. The two radiopharmaceuticals appeared to compete for bone uptake, suggesting related but different sites of bone accumulation. The 99Tcm-citrate/99Tcm-MDP uptake ratio in Group A was concordant (mean +/- S.D. = 0.92 +/- 0.15), while Group C lesions had a significantly lower 99Tcm-citrate/99Tcm-MDP uptake ratio (0.34 +/- 0.24, P < 0.01). A comparison of Group B lesions showed wide variation in intensity and area of involvement in many lesions (uptake ratio < 0.5 or > 1.5 in 13 of 30 sites). We conclude that 99Tcm-citrate has a different site of bone localization than phosphonates, possibly in the organic matrix. Although its skeletal uptake is lower than that of 99Tcm-MDP, it may have better specificity in differentiating osteoblastic from degenerated or healed bony lesions, and therefore be useful in predicting healing of bone secondaries, fractures or osteomyelitic lesions.

Adult↗
PubMed1999

Evaluation of thyroid hormones in chronic renal failure.

When chronic renal failure becomes advanced, the serum levels of most hormones are altered because of several interplaying mechanisms. This study was carried out to evaluate the level of total thyroxine (T4), triiodothyronine (T3) and thyrotropin (TSH) in 96 clinically euthyriod patient with chronic renal failure and 25 healthy individual as control. The patients were grouped into two groups, 62 patient on conservative management and 34 patients on chronic haemodialysis. The patient of both groups showed significant decrease in total T3 and T4 level as compared to normal control. Serum TSH level were similar in both groups as well as in control and were with in normal limit except 3 patients on conservative management which showed TSH level above normal chronic haemodialysis did not have positive effect in alteration of serum T3, T4 and TSH level.

Adult↗
PubMed1999

Outbreak of cholera in arid zone of Bikaner.

Bikaner being an arid zone was more or less unaffected by cholera until 1994 when an outbreak of clinical cholera occurred. We isolated 64 Vibrio cholerae strains out of 475 stool samples received (isolation rate 13.47%). All the Vibrio strains belonged to biotype El Tor serotype Ogawa. Low isolation rate was probably related to the poor transportation and medical facilities available at remote areas and indiscriminate and irrational use of antibiotics. The antimicrobial susceptibility testing of the isolates has not shown significant resistance against commonly used antimicrobials.

Cholera↗