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Biomedical subjects

G Gopalakrishnan

Publications and source records attributed to G Gopalakrishnan.

At least 19 recordsLinked to original sources
PubMed2006

Bladder-sparing surgery in locally advanced nonurological pelvic malignancy.

INTRODUCTION: The urinary bladder is commonly involved in pelvic malignancy. The incidence of apparent extension into adjacent organs in locally advanced colorectal malignancy is 5-12%. It is not known with other pelvic malignancy. No guidelines are available for its management. Often a dilemma exists between cystectomy and a bladder-sparing procedure. We studied the validity of bladder-sparing surgery (BSS) in locally advanced nonurological pelvic malignancy. METHODS: Hospital records of patients who underwent BSS along with other surgeries (abdomino-perineal resection, anterior resection, anterior exenteration, debulking surgery and total pelvic exenteration) from January 1992 to May 2003 were reviewed. RESULTS: BSS was done in 15 patients. 10 had locally advanced colorectal malignancy, 3 with soft tissue masses of the lateral pelvic wall, 1 had ovarian malignancy and the other had residual mass following radiotherapy and chemotherapy of cancer cervix. In those with locally advanced colorectal malignancy, symptoms suggestive of lower urinary tract involvement were present in 8 (80%). Urine examination and ultrasonography was not helpful in suggesting bladder involvement, unlike CT scan of abdomen and pelvis. Preoperative cystoscopy showed endoscopic evidence of bladder involvement in 7 (87.5%). Bladder was involved supratrigonally in 7. Partial cystectomy was done in 9 patients. The left ureter was involved in 6 patients, and they required ureteric reimplantation. Palliative transurethral resection was done in 1 patient with tumor infiltration at the bladder neck and prostate. 50% patients had bothersome lower urinary tract symptoms at 1 year. One patient died in the immediate postoperative period due to a nonurological cause. Overall 3-year survival rate was 40%. CONCLUSION: Unlike primary bladder cancers these lesions are not multifocal and hence en block conservative bladder-sparing surgery can be offered. Preoperative CT scan or MRI can predict lower urinary tract involvement and help in decision-making by both surgeon and patient. The ultimate decision for bladder sparing is based on intraoperative findings. Sparing the bladder might provide better quality of life by avoiding urinary diversion without altering survival.

Colorectal Neoplasms↗
PubMed2005

HIV in couples in South India; implications for prevention.

We studied HIV prevalence in couples in Chennai, India. In 56% both partners were infected. Among discordant couples, 35 men and seven women were infected. Heterosexual intercourse is the primary risk factor. Concordance was related to sex with commercial sex workers for men and to genital ulcer disease for women. Median CD4 count was 97 cells/mm(3) among concordant men, 222 cells/mm(3) among discordant men. Condom use increased, and frequency of sexual intercourse decreased, among all couples after HIV diagnosis.

Adult↗
PubMed2004

Does failure to visualize the ureter distal to an impacted calculus constitute an impediment to successful lithotripsy?

BACKGROUND: A severe degree of ureteral obstruction is viewed as a predictor of poor outcome in shockwave lithotripsy (SWL). Impacted stones are often considered a contraindication to in-situ SWL. PATIENTS AND METHODS: Impaction in our study was defined as failure to visualize the ureter distal to the calculus with proximal hold-up of contrast for as long as 3 hours on an intravenous urogram (IVU). We evaluated 30 patients with impacted ureteral calculi, who were compared with a second unimpacted group matched for stone size and stone location. The calculi were reorganized into < or =10-mm and >10-mm groups. The results were compared in terms of clearance rates, number of shockwaves, number of sessions, and number of days between the start of SWL and clearance. RESULTS: Between January 1998 and December 2001, 30 impacted stones were treated with lithotripsy. Complete clearance rates in the impacted as well as the non-impacted group were 76.7%. There was no statistical difference in the number of shockwaves, sessions, or time to clearance. The results were poorer in lower-ureteral than upper-ureteral calculi, but this difference did not reach statistical significance. However, the differences between the < or =10-mm and >10-mm stones were statistically significant. CONCLUSION: Impaction on an IVU does not affect the results of lithotripsy.

Humans↗
PubMed2004

Oropharyngeal flora changes in patients with head and neck malignancy post radiotherapy.

Radiotherapy has been recognized as a valuable modality of treatment in the management of head and neck cancers. It can have a direct bactericidal effect on the normal flora of the oropharynx. The objective of this study is to determine the changes in the oropharyngeal flora after external beam radiation. This prospective non randomized control study was performed to aid in identification of organisms involved in sepsis, as well as aid in choosing appropriate antibiotics for surgical procedures in irradiated patient. Forty patients with various head and neck malignancy and thirty control patients were selected. Oropharyngeal swabs were taken prior to radiotherapy, at the end and one month after radiotherapy. A single swab was taken from the control group. A full bacteriological analysis was performed. There was a statistically significant decrease in Alpha Hemolytic Streptococci and Neisseria species post radiotherapy. B Proteus and Candida Albicans showed a statistical significant increase in patients with head and neck cancer post radiotherapy. These changes remained even one month after radiotherapy.

Adult↗
PubMed2003

Samaderin B and C from Samadera indica.

Samaderin B, or (1R,2S,5R,5aR,7aS,11S,11aS,11bR,14S)-1,7,7a,11,11a,11b-hexahydro-1,11-dihydroxy-8,11a,14-trimethyl-2H-5a,2,5-(methanoxymetheno)naphth[1,2-d]oxepine-4,6,10(5H)-trione, C(19)H(22)O(7), and samaderin C, or (1R,2S,5R,5aR,7aS,10S,11S,11aS,11bR,14S)-7,7a,10,11,11a,11b-hexahydro-1,10,11-trihydroxy-8,11a,14-trimethyl-2H-5a,2,5-(methanoxymetheno)naphth[1,2-d]oxepine-4,6(1H,5H)-dione, C(19)H(24)O(7), were isolated from the seed kernels of Samadera indica and were shown to exhibit antifeedant activity against Spodoptera litura third-instar larvae. The replacement of the carbonyl group in samaderin B by a hydroxy group in samaderin C causes conformational changes at the substitution site, but the overall conformation is not affected; however, the compounds pack differently in the crystal lattice.

Crystallography, X-Ray↗
PubMed2003

Maternal nutrient restriction during placental growth, programming of fetal adiposity and juvenile blood pressure control.

Epidemiological and experimental studies have demonstrated that maternal undernutrition during pregnancy is associated with abnormal placental growth. In sheep, maternal nutrient restriction over the period of rapid placental growth (30-80 days) restricts placentome growth. Then following adequate nutrition up to term (147 days), placental mass is greater in association with a higher total abundance of the predominant placental glucose transporter-1. The resulting lambs are larger at birth, have heavier kidneys with an increased expression of the glucocorticoid-responsive type 1 angiotensin II receptor. Near to term, these fetuses possess more adipose tissue, the endocrine sensitivity of which is markedly enhanced. For example, the abundance of mRNA for 11beta-hydroxysteroid dehydrogenase type 1, which catalyses the conversion of cortisone to bio-active cortisol is increased. This is associated with a higher abundance of both leptin and glucocorticoid receptor mRNA. At 6 months of age, the juvenile offspring of nutrient restricted ewes have lower resting blood pressure that was positively correlated with plasma cortisol concentration, suggesting their blood pressure could be more strongly driven by circulating cortisol. These offspring also exhibited a greater pressor response to vasoconstrictor challenges, but showed no difference in vasodilatory response. At this age, the kidney weight was similar between groups, but the abundance of cytochrome c in kidney mitochondria was enhanced in lambs born to nutrient restricted ewes that could indicate increased mitochondrial activity. Reduced maternal nutrition during the period of rapid placental growth may therefore contribute to hypertension in later life through physiological and vascular adaptations during fetal life.

Adipose Tissue↗
PubMed2002

8-(2-bromo-3-methoxy-3-methylbutyl)-7-methoxycoumarin.

The title compound, C(16)H(19)BrO(4), is a derivative of osthol, isolated from the seeds of Imperatoria Osthruthium. The structure was solved in space group P-1, with two molecules in the asymmetric unit, and was refined to a final R factor of 0.064. The two molecules in the asymmetric unit differ in the orientation of their brominated substituent group. The benzopyran ring displays aromatic character. The packing of the molecules in the lattice is mainly due to C-H...O hydrogen bonds.

Anti-Inflammatory Agents↗
PubMed2002

Paediatric renal transplantation--a 15 year experience.

OBJECTIVE: To review the outcome of paediatric renal transplantation over a period of 15 years in a developing country. METHODS: This is a retrospective study of 63 children, less than 15 years of age, who underwent living-related renal transplantation in Christian Medical College and Hospital Vellore between 1984 and 1996. RESULTS: The records of 12 patients were not adequate for detailed analysis. Parents were the donors for these children in 84.3% of cases. The most common known cause of end-stage renal disease in these children was reflux nephropathy. Combinations of cyclosporine, azathioprine and prednisolone were used as immunosuppressive drugs. Complications occurred in 16 patients. During the follow-up period, eight patients died and two returned to receiving haemodialysis. Patient survival was 92% at the end of 1 year and 90% at the end of 3 years. Graft survival was 88% and 86% at 1 and 3 years, respectively. CONCLUSION: Our study validates the concept of renal transplantation as optimal therapy with adequate medical, social and functional rehabilitation for children with end-stage renal disease. Our study also indicates that vesicoureteric reflux appears to be underdiagnosed and should be actively pursued to prevent complications.

Adolescent↗
PubMed2001

Insect antifeedant and growth regulating activities of quassinoids from Samadera indica.

Four quassinoids, indaquassin C (1), samaderins C (2), B (3) and A (4), isolated from the seeds and bark of Samadera indica, were tested for insect antifeedant and growth regulatory activities against the tobacco cutworm, Spodoptera litura. Indaquassin C was the most effective antifeedant. Samaderin C increased pupal duration and induced pupal mortality.

Animals↗
PubMed2001

Maternal nutritional manipulation of placental growth and glucose transporter 1 (GLUT-1) abundance in sheep.

Glucose transporter 1 (GLUT-1) is the predominant glucose transporter in the placenta but the extent to which its abundance is nutritionally regulated is unknown. This study investigated the effects of restricted maternal nutrition between day 28 and day 80 of gestation followed by re-feeding to either meet or to exceed the total energy requirements on placental size and GLUT-1 abundance at mid-gestation (that is, day 80) and near to term (that is, days 140-145 of gestation; term = 147 days). Singleton bearing ewes either consumed 8.7-9.9 MJ day(-1) of metabolizable energy (that is, well fed) or 3.2-3.8 MJ day(-1) of metabolizable energy (that is, nutrient restricted) from day 28 to day 80 of gestation, after which stage they consumed either 6.5-7.5 MJ day(-1) (that is, adequately fed) or 8.0-10.9 MJ day(-1) (that is, well fed) of metabolizable energy until near to term. In all ewes, at both sampling dates, the abundance of GLUT-1 was higher in the maternal component than in the fetal component of the placenta. Immunohistochemistry confirmed that GLUT-1 was located in the maternal uterine syncytium. At day 80 of gestation, placental mass was lower (P < 0.05) in the nutrient restricted group, but there was no difference in the abundance of GLUT-1 between the nutrient restricted group and the well fed group. At near term, placental mass was greater (P < 0.05) in ewes that were nutrient restricted during early to mid-gestation and then adequately fed up to term compared with ewes that were well fed during early to mid-gestation. This increase was associated with a higher (P < 0.05) abundance of total placental GLUT-1 and a larger fetus. There was no effect of previous nutrient restriction on placental mass, fetal weight or GLUT-1 abundance at term, when ewes were well fed in the second half of gestation. In conclusion, maternal nutrient restriction between early to mid-gestation alters placental growth but has no effect on placental GLUT-1 abundance. Increasing maternal feed intake to meet calculated energy requirements in previously nutrient restricted ewes during the second half of gestation, increases placental mass and fetal weight, and the abundance of GLUT-1, an adaptation not observed if maternal food intake is increased above requirements.

Analysis of Variance↗
PubMed2000

Effect of Feronia limonia on mosquito larvae.

Bioassay guided fractionation of the acetone extract of Feronia limonia dried leaves afforded a potent mosquito larvicide, identified as n-hexadecanoic acid and found to be effective against fourth instar larvae of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti, with LC50 of 129.24, 79.58 and 57.23 ppm, respectively.

Animals↗
PubMed2000

Antifungal activity of some tetranortriterpenoids.

Natural tetranortriterpenoids such as cedrelone from Toona ciliata, azadiradione from Azadirachta indica, limonin, limonol and nomilinic acid from Citrus medica, along with some cedrelone derivatives were tested for their antifungal activity against Puccinia arachidis, a groundnut rust pathogen. Results show that cedrelone was the most effective in reducing rust pustule emergence. Replacement of functional groups or modification of the A or the B ring in cedrelone reduced the effectiveness indicating the importance of specific structural features for activity.

Antifungal Agents↗
PubMed2000

Photooxidation of cedrelone, a tetranortriterpenoid from Toona ciliata.

Cedrelone, a tetranortriterpenoid on photolysis by UV light yields a true photooxidation product 3 [14 beta,15beta,22beta,23beta-diepoxy-6-hydroxy-1,5, 20(22)-meliatriene-2,7,21-trione] whose structure is well established by NMR studies and confirmed by X-ray crystallography, along with product 4 [14 beta,15beta-epoxy-6,23-dihydroxy-1,5,20(22)-meliatriene-2,7, 21-trione]. Addition of rose bengal increases the rate of photooxidation whereas DABCO decreases rate of photolysis proving the involvement of singlet oxygen in the photooxygenation. Both the photoproducts exhibited antifeedant activity.

Crystallography, X-Ray↗
PubMed1999

Eosinophilic cystitis--not that uncommon!

The clinical presentation, radiological manifestations and response to therapy of seven cases of biopsy-proven eosinophilic cystitis seen over an 8-year period were evaluated retrospectively. All of the five men and two women had symptoms of dysuria and frequency, with haematuria in two cases. One developed acute painful retention. The urine was sterile in all. Radiological findings included bladder mass lesions and upper tract dilatation. Cystoscopy showed papillary, erythematous and ulcerative mucosal lesions, and in one instance a large mass lesion. The various procedures carried out were cold cup biopsies, transurethral resections, or fulgration of lesions and partial cystectomy. Medical therapy included non-steroidal anti-inflammatory drugs and prophylactic antibiotics to cover the procedures carried out. There was excellent symptomatic improvement in all patients. This is the largest single-centre experience reported, and is unusual as the majority of the patients in this series were men.

Adult↗