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Biomedical subjects

R Tandon

Publications and source records attributed to R Tandon.

At least 37 records · Page 2Linked to original sources
PubMed2004

Oxidative stress and antioxidants status in peptic ulcer and gastric carcinoma.

Oxidative stress is believed to initiate and aggravate many diseases including peptic ulcers and gastric carcinoma. We observed an increase in rat gastric mucosal lipid peroxidation (LPO) and superoxide dismutase (SOD) and a decrease in catalase (CAT) levels in cold restraint stress-induced gastric ulceration while, in clinical peptic ulceration and gastric carcinoma patients, an increase in serum LPO and a tendency to decrease in SOD and CAT levels were observed. The result thus, indicated a positive correlation between free radical-induced oxidative stress both in gastric and duodenal ulcers and gastric carcinoma.

Animals↗
PubMed2003

The CT triad of malignancy in meningioma--redefinition, with a report of three new cases.

The CT triad of extracranial soft-tissue tumour, underlying osteolysis and an intracranial tumour was reported as a sign of malignancy in meningioma, by Younis and Sawaya in 1992. We report the clinical and CT spectrum of three new cases with a similar triad, confirmed to be malignant meningioma. However, we redefine this sign and suggest that this triad is an unequivocal indicator of malignancy in meningioma, provided metastases have been excluded.

Adult↗
PubMed2003

The second-generation 'atypical' antipsychotics: similar improved efficacy but different neuroendocrine side effects.

The neuroendocrine aspects of schizophrenia generally receive little attention. This is in marked contrast to depressive disorders, where neuroendocrine issues are central to discussions of pathophysiology and treatment. Although the nature of neuroendocrine dysfunction is less well characterized in schizophrenia than in major depression, a number of neuroendocrine abnormalities have been described. Hypercortisolemia has been extensively documented in patients with schizophrenia, particularly during acute exacerbations, with persistent hypercortisolemia being associated with ventricular enlargement and poor outcome. Similarly, abnormalities in thyroid function, the hypothalamo-pituitary-gonadal axis, growth hormone, prolactin, neurotensin, and other neuroendocrine parameters have also been described in schizophrenia. While the precise neuroendocrine profile of schizophrenia is incompletely characterized, the impact of antipsychotic medications employed in its treatment on various endocrine parameters is better understood. Different conventional and atypical antipsychotics variably contribute to hyperprolactinemia, insulin resistance, and other abnormalities. A critical overview of neuroendocrine abnormalities in schizophrenia is provided and the differential impact of different antipsychotics in contributing to neuroendocrine dysfunction is discussed.

Antipsychotic Agents↗
PubMed2003

Efficacy of newer generation antipsychotics in the treatment of schizophrenia.

The advent of the newer 'atypical' antipsychotic medications has revolutionized the pharmacologic treatment of schizophrenia and other psychotic disorders. In contrast to the older conventional antipsychotic agents, atypical medications have a broader spectrum of efficacy (greater efficacy in negative, cognitive, and mood symptoms) and a lower risk of extrapyramidal symptoms (EPS) and tardive dyskinesia. Due to concerns surrounding hematological safety and other adverse effects, clozapine is used principally in patients refractory to treatment with other antipsychotic agents. The other three universally available atypical agents (risperidone, olanzapine, and quetiapine) collectively constitute about 70% of all antipsychotic prescriptions in the USA. Despite the broad popularity of these medications and their rapid adoption in general clinical practice, there are limited data on how they compare to each other with regards to their overall efficacy and also as to their efficacy in specific symptom domains. To address this question, two separate analyses were undertaken. First, all published, short-term, randomized, controlled clinical trials of these agents in schizophrenia and schizoaffective disorder were reviewed and the extent of improvement across these agents was compared. While the amount of improvement with a particular agent across its different studies varied, the average improvement was similar for the agents for all efficacy parameters considered. Secondly, all randomized, controlled clinical trials directly comparing two or more of these agents in patients with schizophrenia or schizoaffective disorder were analyzed. Only three such trials (all industry sponsored) were identified; while there were differences in methodology and small differences in efficacy on a minority of measures on which comparisons were undertaken, the preponderance of data suggested no differences in efficacy. While data thus far do not support assertions of differential efficacy between risperidone, olanzapine, and quetiapine, there are clear differences in their side-effect profiles and these are briefly summarized.

Antipsychotic Agents↗
PubMed2003

Platelet 3H ketanserin binding in tension-type headache.

OBJECTIVE: The present study was undertaken to investigate the alterations in platelet 5-HT2 receptor binding in patients with tension-type headache. BACKGROUND: Serotonin (5-HT) has an important but complex role in pain modulation. The involvement of serotonin in tension-type headache has been investigated by studying serotonin in peripheral blood, but results have been inconclusive. There are, however, only a few investigations in which the status of platelet serotonin transporters has been studied by 3H imipramine and 3H paroxetine. The present study was undertaken to investigate alterations in platelet 5-HT2A receptors using 3H ketanserin as a ligand. METHODS: Platelet 3H ketanserin binding was studied in 14 patients with tension-type headache and in 15 healthy controls. The binding characteristics, equilibrium dissociation constant and maximal number of binding sites were determined by Scatchard analysis. RESULTS: There was no change in the equilibrium dissociation constant in the patients with headache as compared to the control group, but subgroup analysis revealed that patients with tension-type headache with a headache index of less than 360 had a significantly lower equilibrium dissociation constant as compared to those with a headache index of more than 360; there was a significant correlation between the equilibrium dissociation constant and the headache index. A significant decrease was observed in the maximal number of binding sites in tension-type headache. No correlation was observed between the maximal number of binding sites and age, duration of illness, or headache intensity. CONCLUSIONS: The findings of the present study show that there is a decrease in the number of binding sites of 5-HT2A receptors in some patients with tension-type headache, suggesting postsynaptic serotonergic dysfunction and the involvement of serotonin in that group.

Binding Sites↗
PubMed2003

Inhibition of anti-CD3 and interleukin-2 stimulated T lymphocyte proliferation by peptidomimetic opioid compound.

In continuation to our earlier studies with peptidomimetic opioid compounds, we have further investigated immunosuppressive properties of one of our peptidomimetic compound (Tyr-NH-CH2-CH2-O-Phe-NH2) using peripheral blood mononuclear cells (PBMCs) of healthy volunteers. Peptidomimetic compound was evaluated for its effect on anti-CD3 and recombinant human interleukin-2 (rhIL-2) stimulated lymphocyte proliferation in vitro and lipopolysaccharide (LPS) induced activation of mitogen activated protein kinase (MAPK, pp42/44) in mouse macrophage cells (RAW 264.7). Our results show the immunosuppressive potential of synthetic peptidomimetic compound. This compound significantly inhibited anti-CD3 and rhIL-2 stimulated lymphocyte proliferation in vitro. However, this peptidomimetic compound did not show any effect on LPS induced MAPK activation. These observations suggest that above peptidomimetic compound has potential to inhibit immune responses mediated by lymphocytes.

Animals↗
PubMed2003

Evaluation of umbilical cord serum therapy for persistent corneal epithelial defects.

AIMS: To evaluate umbilical cord serum therapy as a means of promoting the healing of persistent corneal epithelial defects. METHODS: Umbilical cord serum or autologous serum drops were used to promote the healing of persistent epithelial defects. The study design was a prospective randomised controlled clinical trial. 60 eyes of 59 patients were divided into two groups, 31 in the cord serum group and 29 in the autologous serum control group. Epithelial defects measuring at least 2 mm in linear dimension resistant to conventional medical management were included. Serial measurements of the size of the epithelial defects-namely, two maximum linear dimensions perpendicular to each other, and the area and perimeter was done at start of therapy and follow up days 3, 7, 14, 21. Rate of healing of the epithelial defects were measured as percentage decrease from the baseline parameter at each subsequent follow up. The data were analysed by the non-parametric Wilcoxon rank sum test using STATA 7.0. RESULTS: The median percentage decrease in the size of the epithelial defect was significantly greater in the cord serum group at days 7, 14 and 21 (p<0.05) when measured in terms of the area and perimeter. A greater number of patients showed complete re-epithelialisation with umbilical cord serum (n = 18) than with autologous serum (n = 11) (Pearson chi = 0.19). None of the patients reported any side effects or discomfort with either treatment. CONCLUSIONS: Umbilical cord serum leads to faster healing of the persistent corneal epithelial defects refractory to all medical management compared to autologous serum.

Adult↗
PubMed2003

Keratoplasty for keratomalacia in preschool children.

AIM: To study the results of surgical management of keratomalacia in children. METHODS: A clinical case series of all children with keratomalacia, admitted to an Indian centre during the period from June 2000 to June 2001 is presented. The parameters evaluated were demographic data, systemic associations, and results of medical and surgical intervention. RESULTS: 29 children with keratomalacia ranging from 2 months to 5 years of age (mean 1.8 (SD 1.4) years) were included in the study. All children belonged to families of lower socioeconomic status. 27 patients (93.1%) had not been immunised at all. The systemic diseases precipitating the onset of keratomalacia included measles (41.37%), pneumonia (31.03%), and acute diarrhoea (37.93%). 36 eyes (66.7%) had total corneal melting and 11 (20.3%) eyes had paracentral corneal melting. In 15 eyes (27.8%) an emergency tectonic penetrating keratoplasty was performed of which only five grafts (33.3%) remained clear at a mean follow up of 7.3 (6.8) months (range 3-24 months). Seven eyes underwent optical penetrating keratoplasty, of which four grafts (57.14%) remained clear at a mean follow up of 6.4 (3.6) months (range 3-12 months). None of these could achieve a visual acuity better than 6/60. CONCLUSIONS: Corneal grafting surgery in keratomalacia is associated with poor visual outcome.

Acute Disease↗
PubMed2003

LASIK after retinal detachment surgery.

AIM: To assess the efficacy and safety of laser in situ keratomileusis (LASIK) for correction of myopic refractive errors in eyes which have previously undergone retinal detachment surgery. METHODS: In a prospective, non-comparative case series, 10 eyes of nine patients who had a myopic refractive error and had previously undergone retinal detachment surgery underwent LASIK surgery according to the standard surgical protocol. The surgery could be completed in eight eyes and in two eyes it was aborted intraoperatively. The parameters evaluated included the uncorrected visual acuity, best corrected visual acuity, refraction, detailed fundus evaluation with indirect ophthalmoscope, slit lamp biomicroscopy, and corneal pachymetry. Any intraoperative or postoperative complications were recorded. Follow up visits were scheduled at day 1, 1 week, 1 month, 3 months, and 6 months after LASIK. RESULTS: Eight eyes underwent successful LASIK surgery. The mean spherical equivalent before surgery was -5.436 (SD 1.6) dioptres (D), which was reduced to +0.42 (0.65) D, -0.07 (1.32) D, -0.06 (1.39) D, and -0.06 (0.65) at 1 week, 1 month, 3 months, and 6 months respectively after LASIK. The uncorrected visual acuity improved in all the eyes and the best corrected visual acuity improved or remained same in all the eyes. There was no retinal complication after LASIK. CONCLUSION: LASIK may be used to correct refractive errors in eyes that have undergone retinal detachment surgery. However, scarred conjunctiva in such cases may prevent generation of optimal suction for the microkeratome.

Adult↗
PubMed2003

Causes and temporal trends of blindness and severe visual impairment in children in schools for the blind in North India.

AIMS: To describe the causes of severe visual impairment and blindness (SVI/BL) in children in schools for the blind in north India, and explore temporal trends in the major causes. METHODS: A total of 703 children were examined in 13 blind schools in Delhi. A modified WHO/PBL eye examination record for children with blindness and low vision which included sections on visual acuity, additional non-ocular disabilities, onset of visual loss, the most affected anatomical part of the eye concerning visual impairment, and the aetiological category of the child's disorder based on the timing of insult leading to visual loss was administered in all children. RESULTS: With best correction, 22 (3.1%) were severely visually impaired (visual acuity in the better eye of <6/60) and 628 (89.3%) children were blind (visual acuity in the better eye of <3/60). Anatomical sites of SVI/BL were whole globe in 27.4% children, cornea 21.7%, retina 15.1%, and lens 10.9%. The underlying cause of visual loss was undetermined in 56.5% children (mainly abnormality since birth 42.3% and cataract 8.3%), childhood disorders were responsible in 28.0% (mainly vitamin A deficiency/measles 20.5%), and hereditary factors were identified in 13.4%. Study of temporal trends of SVI/BL by comparing causes in children in three different age groups-5-8 years, 9-12 years, and 13-16 years-suggests that retinal disorders have become more important while childhood onset disorders (particularly vitamin A deficiency) have declined. CONCLUSIONS: Almost half of the children suffered from potentially preventable and/or treatable conditions, with vitamin A deficiency/measles and cataract the leading causes. Retinal disorders seem to be increasing in importance while childhood disorders have declined over a period of 10 years.

Adolescent↗
PubMed2002

Inhibition of antigen specific lymphocyte proliferation and cytokine stimulation by peptidomimetic opioid compound.

In sequel to our preliminary observations with peptidomimetic opioid compounds, we have further investigated immunomodulatory activity of one peptidomimetic compound (Tyr-NH-CH2-CH2-O-Phe-NH2) with peripheral blood mononuclear cells (PBMCs) of healthy volunteers/tuberculosis patients. This peptidomimetic compound was evaluated for its effect on purified protein derivative (PPD) stimulated lymphocyte proliferation in vitro, production of Th1 and Th2 cytokines by ELISA and ribonuclease protection assay. Our study shows the immunosuppressive potential of above synthetic peptidomimetic compound. This compound inhibited PPD stimulated human lymphocyte proliferation and this inhibition was reversed by opioid receptor antagonist, naloxone. Its immunosuppressive effect was further demonstrated by inhibition of interleukin-9 (IL-9), IL-10 but failed to influence IL-2, IL-15 and interferon-y (IFN-gamma) in PPD stimulated human PBMCs.

Animals↗
PubMed2002

A pilot study on observations on CD4 & CD8 counts in healthy HIV seronegative individuals.

BACKGROUND & OBJECTIVES: CD4 T lymphocyte count is used to measure the progression of HIV infection and is recommended as part of the standard care of HIV infected person. Information on reference CD4 counts and CD4:CD8 ratio in healthy individuals is lacking in India. Therefore the present study was undertaken to obtain base-line data on CD4 counts and CD4:CD8 ratio of healthy population from north India and to assess the feasibility of using the values as reference in an extended larger study. METHODS: In this pilot study 84 HIV negative healthy volunteers (56 males, 28 females) in the age group of 20-59 yr and who were willing to participate in the study were enrolled after proper counseling. Blood specimens were collected from each subject and processed for anti-HIV antibodies for exclusion of HIV. CD4 and CD8 counts of the samples were performed by fluorescence activated cell sorting (FACS). RESULTS: The mean +/- SD of the absolute numbers of CD4 and CD8 lymphocytes/microliter was 763.6 +/- 226 and 547.5 +/- 190 in males and 797.9 +/- 263 and 567.7 +/- 250 in females. The range of the CD4 and CD8 counts was 365-1328 and 264-991 in males and 415-1257 and 224-1126 in females respectively. The mean +/- SD of the CD4:CD8 ratio was 1.47 +/- 0.42 in males and 1.52 +/- 0.45 in females. INTERPRETATION & CONCLUSION: The results of this study showed that there is wide variability in CD4 count in our population, as is seen in studies reported from other parts of India. A large multicentric study could define the normal range for CD4 and CD8 counts and CD4:CD8 ratio in the Indian population.

Adult↗
PubMed2001

Hippocampus and amygdala in schizophrenia: assessment of the relationship of neuroanatomy to psychopathology.

The hippocampus and amygdala are believed to be involved in the pathology of schizophrenia. In this study, we attempted to replicate the reported bilateral volume reduction of the hippocampus and amygdala and to study the relationship of the volumes of these structures to the symptoms of schizophrenia. The hippocampus-amygdala complex (HAC) was manually traced on 3-mm coronal T(1)-weighted MRIs, resampled into 1-mm coronal slices, from 20 male patients with schizophrenia and 20 age-matched male controls. The complex was divided into three parts: anterior one-third representing the amygdala and middle and posterior thirds representing the anterior and posterior halves of the hippocampus. Positive and negative symptoms and severity of hallucinations and thought disorder (conceptual disorganization) were quantified using the Brief Psychiatric Rating Scale (BPRS). None of the above structures, controlled for brain volume, differed significantly in patients compared with normal controls. When the relationship between volumes and symptoms was examined, the left HAC was found to inversely correlate with thought disorder and negative symptoms. Specifically, significant inverse correlations were found between (i) left amygdala and thought disorder, (ii) left hippocampus and negative symptoms, and (iii) left anterior and posterior hippocampus volumes and positive and negative symptoms, respectively. Our findings further support the role of the HAC in the pathophysiology of schizophrenia and suggest unique associations between individual structures and specific symptoms of the illness.

Adult↗
PubMed2001

Prevalence of cavum septum pellucidum in schizophrenia studied with MRI.

OBJECTIVE: To study the prevalence of cavum septum pellucidum (CSP), a midline developmental anomaly, in patients with schizophrenia. METHODS: Three-millimeter coronal T1 weighted MRI images of 43 normal controls and 73 patients with schizophrenia were examined. The images were resampled into 1-mm slices and CSP was measured by the number of slices in which it appeared. RESULTS: Patients had significantly higher incidence of CSP (Fisher's exact test 0.042; one-sided). Eighteen (41.9%) of the controls and 44 (60.3%) of patients had a CSP, and one of 46 controls and three of 73 patients had a large CSP of six slices or more. There was no relationship between the presence or size of CSP and regional brain volumes or volumes of hippocampus-amygdala complex, caudate, superior temporal gyrus or ventricular CSF. CONCLUSION: Higher incidence of CSP may reflect a neurodevelopmental disturbance in schizophrenia.

Adult↗