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Biomedical subjects

A Gupta

Publications and source records attributed to A Gupta.

At least 469 records · Page 26Linked to original sources
PubMed1997

Pharmacologic characterization of botulinum toxin for basic science and medicine.

The use of Botulinum neurotoxin (BoNT) is increasing in both clinical and basic science. Clinically, intramuscular injection of nanogram quantities of BoNT is fast becoming the treatment of choice for a spectrum of disorders including movement disorders such as torticollis, blepharospasm, Meige Disease, and hemifacial spasm (Borodic et al., 1991, 1994a; Jankovic and Brin, 1991; Clarke, 1992). Neuroscientists are using BoNTs as tools to develop a better understanding of the mechanisms underlying the neurotransmitter release process. Consequently, our ability to accurately and reliably quantify the biologic activity of botulinum toxin has become more important than ever. The accurate measurement of the pharmacologic activity of BoNTs has become somewhat problematic with the most significant problems occurring with the clinical use of the toxins. The biologic activity of BoNTs has been measured using a variety of techniques including assessment of whole animal responses to in vitro effects on neurotransmitter release. The purpose of this review is to examine the approaches employed to characterize, quantify and investigate the actions of the BoNTs and to provide a guide to aid investigators in determining which of these methods is most appropriate for their particular application or use.

Animals↗
PubMed1997

Retinal ischemia leads to apoptosis which is ameliorated by aurintricarboxylic acid.

Transient retinal ischemia results in a delayed cell death of the inner retinal layers. This study demonstrates that this ischemic cell death occurs, at least in part, through apoptosis. The general endonuclease inhibitor, aurintricarboxylic acid, protected rat retinal cells from ischemic cell damage when administered before the onset of ischemia and, more importantly, when administered 6 hr after the insult. Thus, the demonstration that transient retinal ischemia results in cell damage as a result of apoptosis opens new therapeutic strategies aimed at lessening retinal damage as a result of this process.

Animals↗
PubMed1997

Kinematics of the scaphoid shift test.

Twenty-five uninjured subjects (50 wrists) were examined clinically and fluoroscopically during performance of the scaphoid shift test. Wrists were placed into 3 groups on the basis of the degree of palpable carpal motion that occurred during the clinical examination. Kinematic parameters of rotation and displacement were calculated from digitized images of the carpals at rest and at maximum displacement. On clinical exam, 36% of normal individuals had positive findings on scaphoid shift test. Dorsal displacement of the scaphoid was not significantly associated with positive scaphoid shift test results in these subjects, while total displacement of the scaphoid (the sum of axial and dorsal displacement) was significantly associated with positive test results. The principle confounding factor appeared to be a high degree of displacement that occurred at the capitolunate joint in some individuals, termed a "midcarpal shift." The data demonstrate that despite a high prevalence of positive scaphoid shifts among uninjured individuals, the ability to accurately detect dorsal displacement of the scaphoid using the scaphoid shift test is limited. On the basis of their findings, the authors recommend that positive test results be confirmed fluoroscopically.

Adult↗
PubMed1997

Epilenticular lens implantation versus extracapsular cataract extraction and lens implantation in children.

PURPOSE: To compare the results of epilenticular posterior chamber intraocular lens (IOL) implantation and pars plana lensectomy with those of extracapsular lens aspiration and posterior chamber IOL implantation in eyes with pediatric cataracts. SETTING: Guru Nanak Eye Centre, New Delhi, India. METHODS: Forty eyes with childhood cataract of varied etiology were divided into two groups of 20 eyes each, matched by age, sex, and type of cataract. Group A had epilenticular IOL implantation with pars plana lensectomy. Group B had extracapsular lens aspiration with posterior chamber IOL implantation. Follow-up ranged from 1 to 3 years. RESULTS: All 20 eyes in Group A maintained a clear pupillary axis from the immediate postoperative period to the last follow-up. In Group B, 80% of eyes developed varying degrees of posterior capsule opacification (PCO), which hampered vision. In Group A, 95% of eyes had a visual acuity of 6/12 or better; only 45% of eyes in Group B achieved a visual acuity of 6/60 or better. CONCLUSION: Although patients in both groups had good visual recovery, those having epilenticular IOL implantation with pars plana lensectomy maintained a clear pupillary axis and did not develop PCO, preventing the need for secondary intervention.

Cataract↗
PubMed1997

The effects of midazolam and flumazenil on psychomotor function.

STUDY OBJECTIVE: To determine the effects of midazolam and its antagonism with flumazenil on psychomotor function as assessed by the perceptive accuracy test (PAT) and choice reaction time (CRT). DESIGN: Double-blind, cross-over, randomized, placebo-controlled study. SETTING: Department of Anaesthesiology, University Hospital, Linköping, Sweden. SUBJECTS: 11 healthy volunteers (6 females, 5 males, mean age 32 years). INTERVENTIONS: Midazolam 0.1 mg/kg (Group MH), midazolam 0.035 mg/kg (Group ML), or placebo (Group PL) were injected intravenously (IV) in a cross-over design. Flumazenil 0.5 mg was injected after 60 minutes. Plasma concentrations of midazolam were measured at 3, 30, 60 and 75 minutes. MEASUREMENTS AND MAIN RESULTS: Baseline values were first obtained on psychomotor tests including the PAT and CRT. These tests were then repeated 30 and 60 minutes after the IV injection of midazolam or placebo, and repeated 15 and 30 minutes following the injection of flumazenil. A dose-dependent effect of midazolam was seen on the PAT and CRT. Flumazenil completely reversed the psychomotor effects of midazolam in Group ML at 60 minutes but not in Group MH, and this action was clearly detected by the PAT. Psychomotor tests had returned to baseline values when the plasma concentration of midazolam was below 33 ng/ml. A marked inter-individual variation was seen on the PAT, CRT, and in the correlation between the plasma concentration and the results on the PAT. CONCLUSIONS: There was a dose-dependent deterioration in psychomotor performance in subjects given midazolam. The PAT was sensitive in the detection of these residual effects, but a large inter-individual variation in the psychomotor effects of midazolam was evident that could be due to pharmacodynamic and pharmacokinetic variability between individuals. Flumazenil in a dose of 0.5 mg IV completely reversed the effects of low-dose, but not high-dose, midazolam.

Adjuvants, Anesthesia↗
PubMed1997

Traumatic first rib fracture: is angiography necessary? A review of 730 cases.

The two most common sites of first rib fracture were at the subclavian sulcus and in the neck of the first rib, posteriorly. Five distinct mechanisms for rib fracture were identified and included: (i) posteriorly directed trauma to the upper thorax or shoulder girdle; (ii) a direct blow to the sternum and anterior chest wall; (iii) a blow fracturing the clavicle; (iv) a strong sudden contraction of the scalenus anticus muscle; and (v) radiographic findings of a first rib fracture without history of trauma. Isolated first rib fracture regardless of mechanism of injury, results in a low incidence of major vascular injury (mean 3%), although with fracture displacement, the incidence is higher. First rib fracture associated with concomitant head, thoracic, abdominal, or long bone trauma was associated with vascular injury in 24% of cases. According to this review, specific indications for subclavian artery and aortic arch arteriography in patients with traumatic first rib fracture include widened mediastinum on chest radiography, upper-extremity pulse deficit, posteriorly displaced first rib fracture, subclavian groove fracture anteriorly, brachial plexus injury and expanding hematoma.

Angiography↗
PubMed1997

A new high molecular weight agglutinin from garlic (Allium sativum).

Erythrocyte agglutination by lectins from Allium sativum was inhibited only by mannose of the sugars tested. However, asialofetuin was more effective inhibitor of agglutination as compared to mannose. This led to the use of an asialofetuin-silica affinity column to isolate agglutinins of 110 and 25 kDa (ASA110 and ASA25). While ASA25 is a dimeric protein comprising of subunits of 12.5 and 13.0 kDa, ASA110 is a glycoprotein of two identical subunits of 47 kDa. ASA110 revealed to have a high content of aspartic acid, glycine, leucine and serine but low content of cysteine and methionine. It contains 14 residues of neutral sugars in addition to 43 residues of hexosamines per mole of lectin and requires metal ions for its functional conformation. Serological cross-reactions with other species showed some common epitopes of ASA110 and ASA25 present in A. porrum, A. ascalonicum, Narcissus alba, PHA and Con A but not in A. cepa. ASA110 with CHO cells indicated it to be weakly cytotoxic with LD50 of 160 microg/ml.

Amino Acids↗
PubMed1997

Acute renal failure in the elderly: a demographic and clinical study of patients in eastern India.

A total of 638 patients with acute renal failure (ARF) of diverse etiology were studied over a period of 9 years (July 1985-Dec, 1994) of which 96 (15%) patients were classified as elderly ARF with mean age of 72.5 years. Medical causes accounted for 80% of geriatric ARF while 20% patients, had ARF of surgical origin. Decreased renal perfusion resulting from gastroenteritis was the predominant (52.8%) cause of ARF in the medical group. Nephrotoxic ARF and ARF due to F. malaria were seen in 10 and 7 patients respectively. Obstructive uropathy was observed in 12 patients in surgical group and in remaining 8 patients ARF developed following various surgical procedures. ARF in association with multiorgan failure was not observed in our study. Mortality was seen in 24 patients (25%). The causes of mortality were GI bleed (6), peripheral circulatory failure (5), hyperkalemia (4) and sepsis (4). Thus medical ARF remains the major cause of acute renal failure in elderly patients in our study in contrast to ARF associated with multiorgan failure and surgery in developed countries.

Acute Kidney Injury↗
PubMed1997

Programmed cell death (apoptosis) in cord blood lymphocytes.

Cord blood lymphocytes are functionally immature and have deficient immune responses. In order to determine whether the process of programmed cell death is distinct between cord blood and peripheral blood lymphocytes, we analyzed the expression of fas and bax (apoptosis promoting genes) and bcl-2 and bcl-xL (apoptosis inhibiting genes) at protein or mRNA levels using flow cytometry and quantitative PCR methods, respectively. The susceptibility of T cell subsets from cord blood and adult peripheral blood to undergo apoptosis following restimulation with anti-CD3 or anti-Fas monoclonal antibodies was also studied. We observed that cord blood T cell subsets expressed lower levels of Fas and Bcl-2, a low bcl-2/bax ratio, and higher bcl-xL compared to peripheral blood. Additionally, upon primary stimulation with anti-CD3, cord blood T cell subsets were more resistant to apoptosis compared to peripheral blood. In contrast, rechallenge of previously stimulated lymphocytes with anti-CD3 monoclonal antibody triggered apoptosis in a larger proportion of T cells from cord blood as compared to peripheral blood, whereas the number of T cells undergoing anti-Fas-induced programmed cell death were lower in cord blood compared to peripheral blood.

Adult↗
PubMed1997

Congenital Y-type urethro-perineal fistula.

A case of congenital fistula between the prostatic urethra and the perineal skin in a ten-months-old male child is reported. The fistula was lined by squamous epithelium. The precise embryological origin of this fistulous communication remains controversial. We believe that this anomaly is distinct from the congenital H-type urethro-anorectal fistula.

Cutaneous Fistula↗
PubMed1997

Vertical transmission of HIV in New York State: a basis for statewide testing of newborns.

Infants (n = 313) of HIV-infected mothers were enrolled (mean age 1.9 weeks, range 0-8 weeks) in a 3-year prospective study of vertical transmission. Fifty-six infants (17.9%) had laboratory and clinical evidence of HIV infection. Polymerase chain reaction (PCR) provided early and reliable identification of infected infants. Thirty-one of the 56 infected infants had specimens submitted when the infants were 4 weeks of age or less and 30 (97%) tested PCR positive. This percentage increased to 100% by 8 weeks of age when 51 of the 56 infected infants had specimens tested for that time period. Immune complex dissociation (ICD) antigen testing was a sensitive method for diagnosis of infection but only in infants older than 1 month. p24 antigen testing, although free of false positives, is less sensitive than either of the other methods. Among surrogate markers of HIV infection, elevation of soluble CD8 levels precedes an increase in immunoglobulin levels or a decline in CD4 T lymphocytes. Vertical transmission is significantly lower in Central and Western New York State than other regions. Transmission is significantly higher in low birthweight babies and in infants whose mothers have CD4 counts < 500. This study provided the basis for establishing a Pediatric HIV PCR Testing Service for the early diagnosis of HIV infection in neonates.

Blotting, Western↗
PubMed1997

Immunolocalization of acidic and basic fibroblast growth factors in porcine uterine and conceptus tissues.

Immunohistochemical techniques were used to localize acidic and basic fibroblast growth factor (FGF) polypeptides in porcine uterine and conceptus tissues collected on Days 10 through 14 of gestation, which is the peri-implantation period, and in uterine tissues collected on the same days of the estrous cycle. Our results demonstrate differential expression of acidic and basic FGF (aFGF, bFGF) in porcine uterine and conceptus tissues. Localization of these peptides in the uterus of cycling and pregnant pigs was different from that reported for other species, suggesting species-specific roles for FGFs in early pregnancy. Increases in both cytoplasmic and nuclear bFGF immunostaining were detected in uterine luminal and glandular epithelial cells from Days 10 to 14 of gestation but not in the uterine epithelium of cycling pigs. Acidic FGF immunostaining was not detected in luminal or glandular epithelium of either cycling or pregnant uterine tissue; however, differential stromal staining was observed. Uterine tissues collected from pigs on Days 10-14 of the estrous cycle had diffuse aFGF immunostaining throughout the stroma. During early pregnancy, however, intense aFGF immunostaining was concentrated around the glandular epithelial and below the luminal epithelial cells as gestation progressed. Basic FGF, but not aFGF, was detected in porcine conceptuses collected during the peri-implantation period (Days 10-14 of gestation). Although both acidic and basic FGF belong to the same family of proteins, results of the present study indicate that they likely play different roles in uterine function and conceptus development in pigs.

Animals↗
PubMed1997

A case of nondigitalis cardiac glycoside toxicity.

A case is presented of cardiac glycoside poisoning in a 1-year-old patient from the plant Nerium oleander (common oleander). The patient had bradycardia, vomiting, altered level of consciousness, and no history of ingestion. Antibody-based digoxin assays may cross-react with other cardiac glycosides nonquantitatively. Chromatographic techniques can be used in the specific diagnosis.

Animals↗