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Biomedical subjects

S G Rao

Publications and source records attributed to S G Rao.

At least 19 recordsLinked to original sources
PubMed2006

Obesity and obstetric anaesthesia.

The prevalence of obesity continues to increase despite preventive strategies. Obese parturients are at increased risk of having either concurrent medical problems or superimposed antenatal diseases such as pre-eclampsia and gestational diabetes. Moreover, they have a tendency to labour abnormally contributing to increased instrumental delivery and Caesarean section. Obesity is a risk factor for anaesthesia related maternal mortality. Morbidly obese women must be considered as high-risk and deserve an anaesthetic consultation during their antenatal care. The significant difficulty in administering epidural analgesia should not preclude their use in labour. A more liberalised use of regional techniques may be a means to further reduce anaesthesia-related maternal mortality in the obese population. The mother's life should not be jeopardised to save a compromised fetus. Prophylactic placement of an epidural catheter when not contraindicated in labouring morbidly obese women would potentially decrease anaesthetic and perinatal complications associated with attempts at emergency provision of regional or general anaesthesia. Early mobilisation, aggressive chest physiotherapy and adequate pain control are essential components of effective postoperative care.

Adolescent↗
PubMed2004

Successful management of isolated ventricular inversion in an adult.

We report a case of isolated ventricular inversion in a 42-year-old woman. This rare congenital cardiac anomaly was corrected by an intraatrial baffle procedure. She also underwent left-sided double-chamber endocardial pacemaker implantation for postoperative tachycardia bradycardia syndrome.

Adult↗
PubMed2001

Mast cells in leprosy skin lesions.

The density and distribution of mast cells was assessed in skin biopsies of 118 untreated leprosy cases and 20 healthy individuals taken as controls. Mast cells were present in only small numbers in the skin biopsies of healthy individuals. Significantly higher mast cell counts were obtained in the skin lesions of indeterminate leprosy (P < 0.01). The mast cell count in the tuberculoid group was significantly lower than that in the lepromatous group (P < 0.05). The lepromatous group also showed increased mast cell degranulation and altered morphology. The mast cell distribution in the skin biopsies of the two groups was, however, similar. The mast cell count in leprosy is probably determined by the pattern of cytokines released by the T lymphocytes. However, the influence of mast cells on the outcome of the disease needs to be evaluated further.

Adolescent↗
PubMed2001

Effect of Caffeine, a xanthine derivative, in the inhibition of experimental lung metastasis induced by B16F10 melanoma cells.

Caffeine, a methyl xanthine derivative, was studied to assess the effect on B16F10 melanoma induced experimental metastasis. Caffeine was administered at a dose of 100 and 50 mg/kg body weight by both routes, to tumour bearing animals. Solid tumour reduction studies with Caffeine showed a significant reduction in tumour volume for 100 mg/kg dose by both oral and i.p. routes. The Caffeine treated metastatic tumour bearing animals significantly (p<0.001) inhibited lung tumour nodules. Serum sialic acid levels and lung hydroxyproline contents in the treated groups were significantly (p<0.001) low, when compared with the untreated control animals. In the present study, our results suggest that Caffeine inhibits solid tumour development and pulmonary experimental metastasis induced by B16F10 melanoma cells, in murine model.

Animals↗
PubMed2000

Destruction and creation of spatial tuning by disinhibition: GABA(A) blockade of prefrontal cortical neurons engaged by working memory.

Local circuit neurons in the dorsolateral prefrontal cortex (dPFC) of monkeys have been implicated in the cellular basis of working memory. To further elucidate the role of inhibition in spatial tuning, we iontophoresed bicuculline methiodide (BMI) onto functionally characterized neurons in the dPFC of monkeys performing an oculomotor delayed response task. This GABA(A) blockade revealed that both putative interneurons and pyramidal cells possess significant inhibitory tone in the awake, behaving monkey. In addition, BMI application primarily resulted in the loss of previously extant spatial tuning in both cell types through reduction of both isodirectional and cross-directional inhibition. This tuning loss occurred in both the sensorimotor and mnemonic phases of the task, although the delay activity of prefrontal neurons appeared to be particularly affected. Finally, application of BMI also created significant spatial tuning in a sizable minority of units that were untuned in the control condition. Visual field analysis of such tuning suggests that it is likely caused by the unmasking of normally suppressed spatially tuned excitatory input. These findings provide the first direct evidence of directional inhibitory modulation of pyramidal cell and interneuron firing in both the mnemonic and sensorimotor phases of the working memory process, and they implicate a further role for GABAergic interneurons in the construction of spatial tuning in prefrontal cortex.

Action Potentials↗
PubMed2000

Enhancement of anti-metastatic activity of pentoxifylline by encapsulation in conventional liposomes and sterically stabilized liposomes in murine experimental B16F10 melanoma model.

Pentoxifylline has been shown to exhibit anti-metastatic activity by inhibiting homing of B16F10 melanoma cells in the murine experimental metastasis model. In this study, the effect of encapsulation of pentoxifylline in conventional and sterically stabilized liposomes on its anti-metastatic activity in the murine experimental metastasis model was investigated. After a single intravenous dose (10, 20 or 40 mg kg(-1)), pentoxifylline solution, as well as conventional pentoxifylline liposomes, significantly reduced the number of pulmonary nodules compared with the untreated control group. Conventional pentoxifylline liposomes showed significantly higher inhibition (69%) of pulmonary tumour nodule formation at a dose of 20mg kg(-1) as compared with pentoxifylline solution (49%) at the same dose. Encapsulation of pentoxifylline in sterically stabilized liposomes prepared by incorporation of monomethoxypolyethyleneglycol (5000)-cholesteryl ester further enhanced the inhibition of pulmonary nodule formation (77%) at a dose of 20 mg kg(-1) as compared with conventional pentoxifylline liposomes. Overall, the results suggest that encapsulation of pentoxifylline in conventional liposomes enhanced its anti-metastatic activity. Steric stabilization of pentoxifylline liposomes also resulted in a two-fold increase in anti-metastatic activity (at dose of 10 mg kg(-1)) as compared with conventional liposomes.

Animals↗
PubMed1999

Evolving surgical management for ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries.

BACKGROUND: The purpose of this study was to evaluate the results of various surgical modalities that have been evolving for the treatment of ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries. METHODS: From 1993 to May 1997, 14 patients (group 1) were treated with staged unifocalization through thoracotomies and final repair by midsternotomy. From June 1997 to February 1998, 10 patients (group 2) were treated with midsternotomy, single-stage complete unifocalization, and repair. RESULTS: In group 1, 14 patients had 21 procedures (1.5 procedures per patient), of which 3 patients (21%) had final correction. There were two deaths (14%). One patient died of blocked shunt. Another patient who had aneurysmal dilation of homograft tubes that were used for unifocalization died after final repair because of low cardiac output. In group 2, 10 patients had ten surgical procedures for complete unifocalization and 9 of 10 (90%) of them achieved final correction. One patient with low cardiac output in whom we did not close the ventricular septal defect died (10%) of suprasystemic right ventricular pressure. CONCLUSION: In single-stage complete unifocalization, more patients had final correction. It reduces the number of operations and hospitalization and hence is more cost effective than multistaged procedures.

Adolescent↗
PubMed1999

Role of limited posterior thoracotomy for open-heart surgery in the current era.

BACKGROUND: The earliest open-heart operations were performed employing the thoracotomy approach. Over the years, median sternotomy has become the routine way of approaching the heart. However, lately there has been progressive enthusiasm in minimally invasive techniques for accessing the heart. We present our technique of correction of congenital heart defects employing the limited posterior thoracotomy approach. METHODS: From June 1997 to April 1998, 27 patients underwent correction for various intracardiac defects without any mortality. There were 19 ostium secundum defects, with or without other associated anomalies. There were six sinus venosus defects with partial anomalous pulmonary venous connections. Two patients had perimembranous ventricular septal defects, while 2 patients had partial atrioventricular defects. In 2 other patients, pulmonary stenosis was repaired, using pulmonary valvotomy in 1 patient, whereas the other patient required short transannular patch. RESULTS: The median age was 7 years and the median weight was 20 kg. The median skin-to-skin time was 260 minutes. The median bypass time was 63.25 minutes and the median cross-clamp time was 35.0 minutes. All the patients were extubated within 12 hours following surgery and the median ICU stay was 24 hours. Three patients required blood transfusions in the ICU for significant blood loss and the mean chest drainage was 85 cc per 24 hours. None of the patients had phrenic nerve palsies. None of the patients required additional analgesics other than routine ibuprofen or ketorolac tromethamine. Short-term follow-up revealed no functional or physical disability of the thoracic wall and the right arm. All who underwent surgery with this approach were happy with the limited visibility of their scars. CONCLUSIONS: Limited posterior thoracotomy offers a viable alternative for midsternotomy and submammary thoracotomy. It has the advantage of a scar in the back that does not impede the future growth of the breast tissue and the pectoralis major. Our approach does not need any new instruments and hence no contraptions are necessary to perform the operation with this approach. Our results have shown satisfactory short-term results and better cosmesis.

Adolescent↗
PubMed1999

Isodirectional tuning of adjacent interneurons and pyramidal cells during working memory: evidence for microcolumnar organization in PFC.

Studies on the cellular mechanisms of working memory demonstrated that neurons in dorsolateral prefrontal cortex (dPFC) exhibit directionally tuned activity during an oculomotor delayed response. To determine the particular contributions of pyramidal cells and interneurons to spatial tuning in dPFC, we examined both individually and in pairs the tuning properties of regular-spiking (RS) and fast-spiking (FS) units that represent putative pyramidal cells and interneurons, respectively. Our main finding is that FS units possess spatially tuned sensory, motor, and delay activity (i. e., "memory fields") similar to those found in RS units. Furthermore, when recorded simultaneously at the same site, the majority of neighboring neurons, whether FS or RS, displayed isodirectional tuning, i.e., they shared very similar tuning angles for the sensory and delay phases of the task. As the trial entered the response phase of the task, many FS units shifted their direction of tuning and became cross-directional to adjacent RS units by the end of the trial. These results establish that a large part of inhibition in prefrontal cortex is spatially oriented rather than being untuned and simply regulating the threshold response of pyramidal cell output. Moreover, the isodirectional tuning between adjacent neurons supports a functional microcolumnar organization in dPFC for spatial memory fields similar to that found in other areas of cortex for sensory receptive fields.

Action Potentials↗
PubMed1999

Effect of Hepatogard--an indigenous formulation on dexamethasone induced antihealing effects in male albino rats.

Hepatogard, is a multi-ingredient phytopharmaceutical product containing crude powders of eleven plants. Its effect on the different parameters of wound healing was assessed alone and in the presence of dexamethasone. The parameters chosen for the study were the breaking strength of incised wound, breaking strength of granulation tissue and hydroxyproline content. The result showed that Hepatogard increased the breaking strength of granulation tissue but not of incised wound. It reversed the dexamethasone induced decrease in breaking strength in both incised wound and granulation tissue. Even though it had no effect of its own on hydroxyproline concentration, it reversed the dexamethasone induced decrease in the hydroxyproline content of granulation tissue. Thus, Hepatogard has the potential for antagonizing the antihealing effect of steroids in patients receiving steroid therapy.

Animals↗
PubMed1999

Expansion of haematopoietic stem cells in vitro: a challenge to stem cell biologists.

Expansion of haematopoietic stem cells from various sources has gained importance so as to provide a clinically potential graft, which shows ideal growth kinetics, resulting in reduction of the period of neutropenia and thrombocytopenia in any autologous or allogenic transplant setting. Expansion also facilitates transduction of genes for gene therapy. This review examines the various means employed to achieve the expansion of stem cells, and the criteria used to score the extent of expansion based on how stem cells are identified. It tries to analyse the ideal manner in which expansion should be carried out, with emphasis that expansion should not be at the expense of loss of stemness. It also attempts to judge the roles played by the stromal elements and cytokines, which are both part of the complex microenvironment, which in vivo has a strict regulation on haematopoiesis.

Animals↗
PubMed1998

Expression of the cell adhesion molecule E-cadherin by the human bone marrow stromal cells and its probable role in CD34(+) stem cell adhesion.

Bone marrow stroma is the physical basis of the haematopoietic microenvironment and regulates several key features of stem cell proliferation and differentiation. It plays a crucial role in maintaining haematopoietic homeostasis. Earlier studies have shown that this is achieved through interactions with the extracellular matrix and specific molecules called the cell adhesion molecules (CAMs). In this paper, we show that E-cadherin, a cell adhesion molecule which plays a crucial role in cell-cell aggregation during development, is also present in the bone marrow stroma. The expression of the CAM can also be demonstrated on a subset of CD34(+)stem cells. Stromal expression of E-cadherin is decreased when treated with lymphokine mixture, phytohaemagglutinin-treated-leukocyte-conditioned medium (PHA-LCM). This is the reverse of ICAM-I expression, which increases with PHA-LCM treatment. E-cadherin shows homotypic and homophilic interaction and its presence on a subset of CD34(+)cells leads to speculation on whether this CAM has a role in adherence of primitive stem cells to the marrow stroma.

Antigens, CD34↗
PubMed1998

Gastric teratoma in an infant--a case report.

Gastric teratoma is an extremely rare tumour. We report a gastric teratoma in a four month old male infant who presented with a large abdominal mass. There is no evidence of recurrence 1 1/2 years after the tumour was excised. Our case is an addition to the few cases reported in the World literature.

Humans↗