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Biomedical subjects

A Gupta

Publications and source records attributed to A Gupta.

At least 217 records · Page 12Linked to original sources
PubMed2001

Diabetic maculopathy and cataract surgery.

Patients with diabetic mellitus have an increased risk of developing cataract. Many such patients have pre-existing diabetic retinopathy at the time of cataract surgery Although more than 90% of the patients who have no pre-existing diabetic retinopathy carry a good visual prognosis and eventually have 20/40 or better visual acuity, nearly one-third of patients with pre-existing retinopathy may show retinopathy progression. Postoperative angiographic macular edema is more common in patients with diabetes but resolves spontaneously in patients with no or minimal diabetic retinopathy. In patients with moderate to severe NPDR or more, clinically significant macular edema tends to persist, may arise de-novo, or even worsen after cataract surgery. Patients with diabetes need a preoperative characterization of their retinopathy and a thorough discussion with the patient about the need for cataract surgery, and the risk of progression of retinopathy is mandated. Currently, early surgery is favored before the development of significant diabetic retinopathy rather than wait for the cataract to become denser. All efforts should be made to stabilize diabetic retinopathy with appropriate laser treatment before cataract surgery. All diabetic patients need close observation for at least 6 months following surgery to intervene with laser photocoagulation as and when required to prevent visual loss from diabetic maculopathy and other consequences of diabetic retinopathy.

Cataract↗
PubMed2001

Postoperative recovery following outpatient pediatric myringotomy: a comparison between sevoflurane and halothane.

STUDY OBJECTIVE: To assess recovery in children undergoing myringotomy and anesthetized using sevoflurane or halothane with special reference to the phenomenon of excitation reported in previous studies. DESIGN: Prospective, randomized, single-blind study. SETTING: Regional (district general) hospital. PATIENTS: 60 healthy, physical status I children (aged 3 to 8 years) presenting for elective outpatient myringotomy. INTERVENTIONS: The children were premedicated with midazolam and paracetamol and randomly allocated to one of two groups: Group H were induced with halothane (0.5% to 5%) and Group S with sevoflurane (1% to 8%). Anesthesia was maintained with oxygen (FIO(2) = 0.33), nitrous oxide, and the study drug. No opioids were administered during surgery. Postoperatively, propofol was given (1 mg/kg) if the child was crying and uncontrollable on the excitation scale for >5 minutes. Total analgesic consumption and side effects were recorded. MEASUREMENTS AND MAIN RESULTS: Postoperatively, the following parameters were recorded: time to eye opening, excitation, pain, time to sit unaided, time to drink water, time to walk, and time to discharge home. No differences were found in the demographic data, duration of anesthesia and operation, time to loss of eyelash reflex, time to waking up, incidence of postoperative excitation (7% and 8% in the sevoflurane and halothane groups respectively), pain, or postoperative nausea and vomiting. The ability to sit and walk, and the time to discharge home (mean 60.4 min vs. 67.1 min, respectively) was similar between the groups. CONCLUSIONS: Although some studies have reported a high incidence of excitation following sevoflurane anaesthesia, we found no differences between halothane and sevoflurane. This finding could be due to the midazolam given as premedication as well as minimal postoperative pain in these children.

Akathisia, Drug-Induced↗
PubMed2001

Ligand-exchange reaction of labile "3 + 1"99mTc(V) complexes with SH group-containing proteins.

The reactivity of labile 3 + 1 mixed-ligand 99mTc complexes of the type [99mTcO(SES)(RS)] with SES being a tridentate dithiol ligand and glutathione or dimethylcysteamine as monodentate ligands RSH towards proteins was investigated in vitro and in vivo. It was found that the complexes undergo reversible transchelation reactions with SH group-containing components of blood such as albumin or haemoglobin. High labelling yields were obtained when 3 + 1 complexes with the tridentate SSS ligand were used. The biodistribution of blood proteins labelled by ligand-exchange reaction with the [99TcO(SSS)] or [99mTcO(SNMeS)] core was studied and compared with the in vivo distribution of the labile 3 + 1 complexes containing glutathione as monodentate ligand.

Animals↗
PubMed2001

Identification of the type II Na(+)-Pi cotransporter (Npt2) in the osteoclast and the skeletal phenotype of Npt2-/- mice.

We previously reported that a type II sodium phosphate (Na(+)-Pi) cotransporter (Npt2) protein is expressed in osteoclasts and that Pi limitation decreases osteoclast-mediated bone resorption in vitro. We also demonstrated that mice homozygous for the disrupted Npt2 gene (Npt2-/-) exhibit a unique age-dependent bone phenotype that is associated with significant hypophosphatemia. In the present study, we sought to identify the Npt2 cDNA in mouse osteoclasts and characterize the impact of Npt2 gene ablation on osteoclast function and bone histomorphometry. We demonstrate that the osteoclast Npt2 cDNA sequence is identical to that of the proximal renal tubule and, thus, not an isoform or splice variant thereof. Histomorphometric analysis revealed that, at 25 days of age, Npt2-/- mice exhibited a reduction in osteoclast number and eroded perimeters, relative to wild-type mice. Moreover, although the number of metaphyseal trabeculae was reduced in 25-day-old Npt2-/- mice, trabecular bone volume was normal due to increased trabecular width. At 115 days of age, the decrease in osteoclast index persisted in Npt2-/- mice relative to wild-type littermates. However, mineralizing and osteoblast surfaces and bone formation rates were increased, and, although trabecular number was still reduced, trabecular bone volume was higher than that of wild-type mice. These data demonstrate a link between osteoclast activity and trabecular development in young Npt2-/- mice, and suggest that an age-related adaptation to Npt2 deficiency is apparent in osteoclast and osteoblast function and bone formation.

Animals↗
PubMed2001

Cyclosporin A withdrawal in live related renal transplantation: long-term results.

Cyclosporin A (CsA) withdrawal after 1 yr of stable graft function has been shown to be beneficial in cadaveric renal transplantation. This strategy could be even more suitable for 'immunologically advantaged' grafts as in live related renal transplantation. We report the long-term outcome of patients in a live related transplantation programme undergoing early (between 1989 and 1992) and late (1993 onwards) CsA withdrawal as compared with those on long-term low dose CsA (1993 onwards). Two-hundred and fifty-two patients were divided into three groups based on the following immunosuppressive protocol: group ECyW (n=99), early CsA withdrawal (9 months after transplantation); group LCyW (n=44), late CsA withdrawal (median 16 months, range 13--22 months after transplantation); and group LDCy (n=109), long-term low dose CsA. The median period of follow-up was 66 months after transplantation (range 43--84 months). There was no difference in the actuarial 6-yr patient or graft survival among the three groups. Acute rejection episodes were more frequent in ECyW (54.4%) than in LDCy (31.8%) and LCyW (23.8%) (p=0.001). The risk of developing late (> or =9 months) acute rejection was highest in ECyW 32/99 (32.3%) as compared with LCyW 8/44 (18.4%; p=0.08) and LDCy 8/109 (7.3%; p=0.0001). Of the 32 ECyW patients who developed acute rejection episodes after CsA withdrawal, 13 (40.6%) lost their grafts either due to uncontrolled acute rejection or to chronic rejection. Chronic rejection was higher in ECyW (24%) than in LCyW (11%; p=0.04) and LDCy (17%; p=0.17). Antihypertensive requirement was highest in patients maintained on low dose CsA. Graft function, as measured by serum creatinine levels, was significantly better in LCyW (1.24+/-0.4 mg%) as compared with ECyW (1.49+/-0.5 mg%) and LDCy (1.48+/-0.6 mg%). Early CsA withdrawal after live related renal transplantation is associated with a significant risk of acute rejection and subsequent chronic rejection. Slow withdrawal after 1 yr is safe and more economical than the long-term administration of low dose CsA.

Acute Disease↗
PubMed2001

Effect of lovastatin, an HMG CoA reductase inhibitor, on acute renal allograft rejection.

3-Hydroxy-3-methyl glutaryl coenzyme A (HMG CoA) reductase inhibitors are established anti-lipidemic agents. They also exert immunomodulatory effects. Two recent reports suggest that pravastatin may be useful in decreasing the incidence and severity of acute rejections (ARs) in heart and kidney transplant recipients. We undertook this prospective, randomized, placebo-controlled, double blind trial to investigate the effect of lovastatin on acute renal allograft rejection. Sixty-five consecutive, one-haplotype-matched, living related first renal transplant recipients were randomized to receive either lovastatin 20 mg/d or placebo for 3 months, in addition to cyclosporine, azathioprine, and steroids. Lipid levels, AR episodes, and liver and muscle enzymes were followed for 3 months post-transplant. At the end of the study period, lovastatin had successfully controlled lipid levels. However, there was no effect on AR episodes (15.15% in the treatment group vs. 18.75% in the placebo group).

Adult↗
PubMed2001

High incidence of pruritus after large doses of hydroxyethyl starch (HES) infusions.

BACKGROUND: There are several studies indicating a correlation between treatment with hydroxyethyl starch (HES) and pruritus. In order to see whether there is a possible dose-response relationship between HES and pruritus, we retrospectively studied 50 patients who had received HES in varying doses (cumulative dose 500-19500 ml) as hemodilution therapy after subarachnoid hemorrhage. METHODS: Of 50 consecutive patients, 6 were excluded due to severe neurological sequelae. A questionnaire was sent to the remaining 44 patients at 6 months (5-12 months) median (range) after the end of HES treatment. RESULTS: We received answers from 37 patients, of whom 54% reported pruritus. On average pruritus lasted for 15 weeks. There was significantly more pruritus in patients who received more than 5000 ml of HES versus those who received less than 5000 ml (P=0.023). Pruritus had a delayed onset and appeared as pruritic crises lasting for 2-30 min. It had a patchy distribution in most patients and no predilected locations. In 4 patients (20%) the pruritus lasted longer than 21 weeks. CONCLUSION: Our study indicates that there is a dose-dependency for the incidence of HES-induced pruritus, and that in some cases the pruritus may be severe and long-lasting.

Blood Volume↗
PubMed2001

Mucor endophthalmitis.

PURPOSE: To report on a case of type 2 diabetes, with eyelid gangrene and endophthalmitis as a presenting manifestation of rhino-orbito-cerebral mucormycosis. RESULTS: CECT head showed proptosis, mucosal thickening in the ethmoid sinus and hypodense lesions in the frontal and occipital lobes. Vitreous tap showed right angle branched aseptate hyphae consistent with mucormycosis. CONCLUSIONS: A diabetic patient presenting with sudden loss of vision, eyelid gangrene and endophthalmitis, involvement by an angio-invasive fungus-like mucormycosis is an important consideration.

Anti-Bacterial Agents↗
PubMed2001

Isolation of primary HIV-1 that target CD8+ T lymphocytes using CD8 as a receptor.

HIV-1 use CD4 receptors to infect their primary targets, CD4+ cells, whereas CD8+ cells have a protective role against HIV-1. We recently isolated HIV-1-producing CD8+ clones from two AIDS patients. Here we show that although HIV-1 produced by CD8+ cells maintained the ability to infect CD4+ cells, these viruses were able to infect CD8+ cells independent of CD4. Evidence indicates that these viruses used CD8 as a receptor to infect CD8+ cells. First, expression of CD8 was downmodulated after infection. Second, anti-CD8 antibodies blocked viral entry and replication in CD8+ cells. Finally, resistant cells became susceptible after expression of CD8. Although these viruses used CXCR4 to enter CD4+ cells, it seems that infection of CD8+ cells was independent of CXCR4 or CCR5 co-receptors. Novel changes were observed in envelope sequences of CD8-tropic viruses. These results provide initial evidence that HIV-1 can mutate to infect CD8+ cells using CD8 as a receptor.

Amino Acid Sequence↗
PubMed2001

Quantification of static and dynamic supraglottic activity.

For estimating supraglottic compression in disordered voice production, categorical rating scales of true vocal fold coverage by supraglottic structures are the current standard. Quantification of change in the position of supraglottic structures compared to no supraglottic activity would be a better method for distinguishing between and within voice-disordered groups. This study developed a method for quantifying static supraglottic activity and extent of false vocal fold (FVF) motion during dynamic supraglottic activity. Twelve control participants and 12 individuals with voice disorders (6 with complaints of vocal fatigue and 6 with vocal fold nodules) were enrolled in the study. These individuals participated in a transnasal fiberoptic laryngeal examination in which various speech tasks were recorded. Single-frame images were selected to represent the positions of minimum and maximum supraglottic compression for each speech task. Two individuals rated these single-frame images using a categorical rating scale. Two other individuals measured the anterior-to-posterior (A-P) distance, vocal fold length, and vocal fold area. A-P and FVF compression were derived from these three measures. Reliability was demonstrated between judges for the ratings and between and within judges for the measures. Significant differences in normalized static supraglottic compression measures corresponded to the rating scale categories. Significant differences in normalized dynamic supraglottic compression measures corresponded to the differences in category ratings between minimum and maximum compression. Using the normalized measures, the voice-disordered groups demonstrated significantly greater static A-P compression (t test, p < .03) than did the control participants. These results suggest that static supraglottic activity may be diagnostic of voice disorder. Normalized dynamic FVF compression ratios were not significantly different between groups. This supports a previous hypothesis that dynamic supraglottic activity serves as an articulatory function at the level of the larynx and is part of the linguistic/phonemic system, rather than evidence of disordered laryngeal function.

Adult↗
PubMed2001

Effect of laparoscopy on immune function.

BACKGROUND: Laparoscopic surgery is believed to lessen surgical trauma and so cause less disturbance of immune function. This may contribute to the rapid recovery noted after many laparoscopic operations. Preservation of both systemic and intraperitoneal immunity is particularly important in surgery for sepsis or cancer and so an understanding of the impact of laparoscopy on immune function is relevant. METHODS: Literature on immunological changes following laparoscopy and open surgery was identified from Medline, along with cross-referencing from the reference lists of major articles on the subject. RESULTS AND DISCUSSION: Despite a few contradictory reports, systemic immunity appears to be better preserved after laparoscopic surgery than after open surgery. However, the local intraperitoneal immune system behaves in a particular way when exposed to carbon dioxide pneumoperitoneum; suppression of intraperitoneal cell-mediated immunity has been demonstrated in a number of studies. This feature may be clinically important and should be acknowledged when considering laparoscopic surgery in patients with malignancy or sepsis.

Acute-Phase Reaction↗
PubMed2001

Prognostic factors for persistent distal renal tubular acidosis after surgery for posterior urethral valve.

Risk factors, including age at presentation, age at surgery, time between presentation and surgery, urodynamic abnormalities, and vesicoureteric reflux, were prospectively studied for the development of distal renal tubular acidosis (DRTA) before surgery and persistent DRTA after surgery in 24 boys with posterior urethral valve (PUV) with normal serum creatinine levels. DRTA was persistent in 11 of 17 boys (65%) at the end of follow-up after intervention. For the development of DRTA before surgery, only a longer time between presentation and surgery (intervening period) turned out to be a significant risk factor on multivariate analysis (beta = -0.13; P = 0.04). Boys with persistent DRTA after surgery had older age at presentation (P = 0.03), older age at surgery (P = 0.001), a longer intervening period (P = 0.0007), and bilateral or severe unilateral reflux (P = 0.04) before surgery. On univariate logistic regression, age at surgery (beta = -0.07; P = 0.04) and intervening period (beta = -0.13; P = 0.02) were found to be significant risk factors for persistent DRTA, but on multivariate analysis, only intervening period was found to be significant (beta = -0.13; P = 0.02). A delay in intervention after noticing voiding symptoms can predict a high incidence of DRTA before intervention and persistent DRTA after surgery in boys with PUV.

Acidosis, Renal Tubular↗
PubMed2001

Metastatic pattern of CC531 colon carcinoma cells in the abdominal cavity: an experimental model of peritoneal carcinomatosis in rats.

BACKGROUND: Peritoneal spread of tumour cells is a major source of morbidity and mortality in patients with colorectal cancer. In order to develop strategies to prevent intraperitoneal dissemination and to treat peritoneal carcinomatosis, the spread of tumour cells in the peritoneal cavity was studied. METHODS: Two million CC531 colon carcinoma cells were administered intraperitoneally in five groups of eight rats. The rats were killed after 1, 2, 4 and 8 hours and 3, 7, 14 and 21 days. After inspection of the abdominal cavity, samples of blood and ascites were taken. Liver, spleen, omentum, mesentery, diaphragm, parathymic lymph nodes and lungs were removed for histology and immunohistochemistry. RESULTS: No abnormalities were seen in the abdominal cavity until day 3. Subsequently the peritoneum and omentum became thickened and after 21 days all rats had haemorrhagic ascites and peritoneal carcinomatosis. The abdominal fluid contained tumour cells at all stages. The number of tumour cells decreased in the first 8 hours, and increased thereafter. At microscopy the peritoneum was completely covered by tumour cells after 3 days. Tumour cells concentrated in the milky spots (MS) of the omentum within 4 hours. The size of the MS increased as a result of an increase in number of tumour cells and macrophages. After 7--21 days the MS were completely replaced by tumour cells and new MS were formed. In the diaphragm tumour cells invaded the lymphatic lacunae after 8 h, and obliterated these after 3--7 days. Also invasion of the muscle fibres was seen after 3 days. Microscopically no tumour cells were found in blood, liver, spleen, parathymic nodes and lung. CONCLUSION: After intraperitoneal administration of CC531 colon carcinoma cells, tumour cells spread throughout the abdominal cavity, and concentrate in the milky spots of the greater omentum, the paracolic gutters, the subhepatic and subphrenic spaces and in the lymphatic lacunae of the diaphragm.

Animals↗
PubMed2001

Cervical cerclage in the second trimester of pregnancy: a historical cohort study.

OBJECTIVE: The purpose of this study was to compare second-trimester transvaginal cervical cerclage with conservative management on duration of pregnancy and perinatal outcome in patients with early or advanced cervical changes. STUDY DESIGN: A historical cohort analysis was performed. Maternal and neonatal records between 1995 and 1999 were retrospectively reviewed for women presenting between 18 and 27 weeks of gestation with early cervical changes (length <3 cm, dilatation <2 cm, funneling of fetal membranes shown by transvaginal ultrasonography) (group 1, n = 31) and for women with advanced cervical effacement and dilatation (cervical dilatation > or =2 cm but < or =5 cm, fetal membranes visible) (group 2, n = 39). In each group, patients who underwent Shirodkar or McDonald cerclage were compared with patients treated conservatively with bed rest. Both groups also received multifactorial treatment with tocolytic agents, broad-spectrum antibiotics, and indomethacin. Outcome variables were analyzed for statistical significance by parametric and nonparametric methods. RESULTS: Regardless of treatment method, patients with early cervical changes (group 1) were given a diagnosis earlier and delivered later in pregnancy compared with their counterparts who had advanced cervical changes (group 2) (P <.05). In both patients who underwent cerclage and those treated conservatively, the mean birth weight among surviving infants was higher and the mean neonatal intensive care unit stay was shorter in group 1 than in group 2 (P <.02). However, duration of maternal hospital stay and neonatal survival rates were not different. In both groups 1 and 2, the interval from treatment to delivery, the mean gestational age at delivery, and mean birth weight were increased, whereas neonatal intensive care unit stay was decreased by cerclage treatment (P <.05). In group 1, a higher percentage of patients treated with cerclage received antibiotics and indomethacin than did control subjects (P <.01), whereas in group 2, the use of multifactorial treatment was not different (P =.5). The duration of maternal hospital stay and neonatal survival did not differ significantly among patients treated conservatively or with cerclage. CONCLUSIONS: Diagnosis of premature cervical changes by ultrasonography was correlated with treatment earlier in gestation and with a favorable impact on perinatal outcome in both patients treated with cerclage and those treated conservatively. Cervical cerclage was associated with an improved perinatal outcome (in comparison with conservative therapy) in women with early cervical changes detected by ultrasonography and in patients with advanced cervical dilatation and visible membranes. However, the apparent therapeutic effect of cerclage in patients with mild cervical incompetence may be due in part to an increased use of antibiotics and indomethacin in conjunction with cerclage.

Adult↗