Biomedical subjects
Publications and source records attributed to A K Goel.
Alcoholic extracts of 48 identified species of marine flora were screened for a wide range of biological activities. Of these, 3 extracts showed diuretic activity while 2 extracts showed hypotensive effect.
Methanolic and chloroform-methanol extracts of 25 identified species of marine fauna have been screened for a wide range of biological activities. Of these, 2 extracts exhibited diuretic activity, while antibacterial, antiviral, oxytocic and spasmolytic activities, were observed in 1 extract each.
An immunofluorescence assay for direct detection of V. cholerae O1 was developed using polyclonal antibodies raised against outer membrane proteins (OMPs) of V. cholerae O1. Production of OMPs varied with growth media used; maximum production was found in tryptic soy broth. The detection system was specific because no cross-reactivity was observed with other bacteria including V. cholerae O139, E. coli, S. dysenteriae and Salmonella enterica subsp. enterica serovar Typhi. The technique was able to detect 240 CFU/mL of V. cholerae O1 suspended in phosphate-buffered saline. The assay coupled with bacterial enrichment in APW for 6 h detected as few as 5 CFU of V. cholerae in spiked samples. Moreover, a 2-h incubation of enriched bacterial cells in 0.1% yeast extract with 10 ppm nalidixic acid enhanced the bacterial size and helped in morphological identification of V. cholerae. Among 32 potable water samples from afflicted hand pumps and wells collected from a cholera-plagued area 12 were found to be contaminated with V. cholerae by immunofluorescence assay as well as by conventional culture methods. The proposed method could thus be employed in environmental surveillance of V. cholerae O1.
Superovulatory response and embryo production efficacy were investigated in adult (age 2-4 years, average body weight: 27-43 kg) cycling Jakhrana goats (n = 15) under semi-arid environmental conditions of India by administering different superovulatory regimens. Goats were reared under semi-intensive system of management in established farm conditions. To synchronize oestrus, a luteolytic dose of carboprost tromethamine (Upjohn, UK) was administered intramuscularly to all does at the dose rate of 5 microg per kg body weight in a double dose schedule with an interval of 11 days. For superovulation, 750 IU of PMSG (Folligon, Intervet, Boxmeer, Holland) per goat was administered intramuscularly 24 h before administering a second dose of luteolytic agent in five does (treatment 1). FSH (Sigma, St. Louis, MO, USA) 12.50 IU per goat was administered intramuscularly in a decreasing daily dose schedule (2.50, 2.50; 1.875, 1.875; 1.25, 1.25; 0.625, 0.625) at 12 h intervals over four days, initiated 48 h before administering second dose of carboprost tromethamine in 5 does (treatment 2). FSH (Super-Ov, Ausa Intern, USA) was administered at a uniform dose rate of 8.33 units per goat intramuscularly at 24 h intervals over three consecutive days (total dose was 25 units), initiated 48 h before administering a second dose of carboprost tromethamine in 5 does (treatment 3). To synchronize ovulation in responders, human chorionic gonadotrophin (hCG, Chorulon, Intervet) was injected intramuscularly at a dose rate of 500 IU in each goat on the day of oestrus appearance. Goats were laparotomized 72-82 h following the onset of synchronized oestrus and their genitalia were flushed using a standard collection procedure. Variability (p > 0.05) in superovulatory response (number of established corpora lutea) was observed: FSH (Sigma), 11.8 +/- 2.9; FSH (Super-Ov), 11.6 +/- 4.5; PMSG (Intervet), 8.4 +/- 2.3. A similar pattern was reflected in mean embryo and transferable embryo recovery, respectively (p > 0.05): FSH (Sigma), 8.0 +/- 1.8, 5.2 +/- 1.7; FSH (Super-Ov), 6.6 +/- 2.4, 5.4 +/- 2.4; PMSG, 5.8 +/- 1.9, 3.8 +/- 2.2. In PMSG-treated does, comparatively more unfertilized ova or retarded embryos were recovered than in FSH-treated does. The superiority of FSH preparations over PMSG was reflected in terms of total and transferable embryo production (p > 0.05). On average, five transferable embryos (excellent and good quality) were recovered per doe treated with FSH of either source. The mean ova/embryo recovery was satisfactory (55-68%). Results indicated that Jakhrana goats can be superovulated for embryo production using FSH of either source to augment productivity.
Alcoholic extracts of 288 of plant materials from 199 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screening. Biological activities, ranging from moderate to good degree, have been observed in 61 plants extracts. Follow up studies have been carried out in these extracts and some of them have shown moderate degree of activities at this Institute. However, none of the extracts was found to be good enough for further development. Results of the present studies, along with chemical investigations on different species of similar genera which were screened earlier, are also discussed.
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Xanthomonadins are yellow, membrane-bound pigments produced by members of the genus Xanthomonas. We identified an ethyl methanesulfonate-induced Xanthomonas oryzae pv. oryzae mutant (BXO65) that is deficient for xanthomonadin production and virulence on rice, as well as auxotrophic for aromatic amino acids (Pig(-) Vir(-) Aro(-)). Reversion analysis indicated that these multiple phenotypes are due to a single mutation. A genomic library of the wild-type strain was used to isolate a 7.0-kb clone that complements BXO65. By transposon mutagenesis, marker exchange, sequence analysis, and subcloning, the complementing activity was localized to a 849-bp open reading frame (ORF). This ORF is homologous to the aroE gene, which encodes shikimate dehydrogenase in various bacterial species. Shikimate dehydrogenase activity was present in the wild-type strain and the mutant with the complementing clone, whereas no activity was found in BXO65. This clone also complemented an Escherichia coli aroE mutant for prototrophy, indicating that aroE is functionally conserved in X. oryzae pv. oryzae and E. coli. The nucleotide sequence of the 2.9-kb region containing aroE revealed that a putative DNA helicase gene is located adjacent to aroE. Our results indicate that aroE is required for normal levels of virulence and xanthomonadin production in X. oryzae pv. oryzae.
Rhizobium strains nodulating green gram [Vigna radiata (L.) Wilczek] were found to produce bacteriocin on modified Bergersen's medium and inhibited the growth of homologous Rhizobium strains. Four bacteriocin producing and four bacteriocin non-producing strains were compared for their effect on nodulation, in planta nitrogenase activity and plant dry weight of green gram. The bacteriocin producers formed more nodules in comparison to non-bacteriocin producers. However, the symbiotic effectiveness of bacteriocin producers was less in terms of plant dry weight in comparison to non-bacteriocin producers.
BACKGROUND: Management of the pancreatic stump after pancreaticoduodenectomy (PD) is still a matter of debate. Pancreaticojejunostomy (PJ) is used commonly but is associated with a significant incidence of pancreatic leaks. Pancreaticogastrostomy (PG) is an alternative that has been reported to be safer. METHODS: The study is a retrospective analysis of all patients having PD for ampullary carcinoma in one surgical unit at All India Institute of Medical Sciences over 18 years, with PG being the only drainage procedure for the pancreatic stump. RESULTS: Among 125 patients having PD for ampullary carcinoma, overall morbidity rate was 28%, mortality rate was 4.8%, with no cases of leakage from the pancreaticogastrostomy. CONCLUSIONS: In world literature (including the current series), the leakage rate of PG is 2.5% (14 of 553) with only 2 deaths (2 of 14) due to leakage from PG. Our large experience and these data conclusively prove the safety of pancreaticogastrostomy, which should be the drainage procedure of choice for the pancreatic stump following pancreaticoduodenectomy.
Ascites due to congestive heart failure (CHF) is characteristically serous in gross appearance. Although hemorrhage into ascites commonly indicates a malignant or inflammatory cause, cirrhosis of the liver is a well known cause of bloody ascites. We report a case of hemorrhagic ascites due to biventricular congestive heart failure in which workup for other causes was negative and hemorrhage cleared after 4 months. In as much as the mechanism of ascites is similar in both cirrhosis and CHF, we propose that a similar mechanism could cause bleeding into ascites in CHF.
At the Institute Rotary Cancer Hospital, AIIMS, New Delhi, 246 patients of breast cancer were operated on from June 1993 to June 1996; 82 suitable patients were discharged within 48 h (short stay surgery, SSS) after surgery and 164 were discharged after 48 h (conventional stay surgery, CSS). After discharge, patients of both groups were followed in the outpatient clinic until the removal of sutures and drains. There was no mortality or readmission for a complication in either group. Mean post-operative hospital stay was 1.5 days in the SSS group, and 3.3 days in the CSS group. There was no statistically significant difference in the incidence of post-operative complications like wound infection (4.8% vs 4.2%), flap necrosis (6% vs 5.4%), seroma (14% vs 19%), and the average number of hospital visits (3.42 vs 3.2) in SSS and CSS groups, respectively. Patient acceptance of early discharge was good except in the day care group. The study supports the safety and feasibility of short stay surgery for breast cancer in certain circumstances for properly selected patients.
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Methanolic extracts of 31 botanically identified species of marine flora, collected from Gujarat Coast, have been screened for a wide range of biological activities. Of these, 3 extracts showed anti-implantation, 2 had antiviral, 2 showed hypotensive, 1 had anti-inflammatory while 12 extracts showed diuretic activities. The antiviral activity; against EMCV, was confirmed in one alga. The active principles and results of these studies are reported.
Over a 7-year period from 1987 to 1993, 41 male breast cancer patients were seen in the breast cancer clinic of the Institute Rotary Cancer Hospital (IRCH) at the All India Institute of Medical Sciences (AIIMS). Their mean age was 54.2 years; and duration of symptoms ranged from 1 to 84 months with a mean of 15.1 months. Breast lump was the commonest presenting symptom. Fine needle aspiration cytology (FNAC) was the commonest diagnostic procedure. The TNM stage distribution was stage I, 5; stage II, 13; stage III, 17; and stage IV, 6. Radical mastectomy (25/36) was the commonest surgical procedure. Locoregional radiotherapy was given in 15 patients. Thirty patients received systemic adjuvant therapy (chemotherapy or tamoxifen, or a combination of the two). Local or distant recurrence occurred in 8 patients (8/31, 28.3%). Actuarial overall and disease-free survival was 100% and 80.1% at 2 years and 91.7% and 66.7% at 4 years, respectively. On univariate analysis, axillary lymph node status and age were found to affect disease-free survival significantly. Advanced stage of disease at presentation is common in Indian patients and will continue to influence treatment policies. Neoadjuvant chemotherapy needs to be evaluated for locally advanced tumors to improve outcome. Multicentric studies are necessary to define the relative roles of tamoxifen and chemotherapy for adjuvant treatment.
Alcoholics extracts of 266 botanically identified plant materials from 222 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screenings. Biological activities have been observed in 89 extracts. Follow-up studies have been carried out in some plants with confirmed activity. The active principles and results of these studies are reported.
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