Biomedical subjects
Publications and source records attributed to A Kumar.
Primary osteosarcoma of the skull is rare. Osteosarcoma arising from the sellar region is extremely uncommon. The case of a 38-year-old man with osteosarcoma of the sella is described, and the literature is reviewed. The patient was treated with surgery followed by aggressive chemotherapy and radiotherapy. Currently he is in remission at 12 months.
BACKGROUND: Enterobacter aerogenes, a Gram-negative bacterium, is an important, although infrequent, cause of nosocomial bacteremia in the hospitalized pediatric and neonatal population. Enterobacter aerogenes was isolated for the first time in our neonatal intensive care unit (NICU) from blood culture of a 5-day-old neonate; 12 more cases were discovered in the next 70 days. The present report summarizes the clinico-bacteriological spectrum and outcome of the affected neonates. Efforts made to find the source of infection and curb the outbreak are also presented. METHODS AND RESULTS: Thirteen newborns, including seven preterms, acquired E. aerogenes septicemia. Perinatal risk factors were present in all the neonates. The mean birthweight of affected infants was 1880 +/- 540 g. Symptoms appeared at a mean age of 3.5 +/- 1.5 days (range 3-8 days). The clinical presentation was indistinguishable from septicemia caused by other Gram-negative organisms. Complications encountered included sclerema, bleeding diathesis, meningitis and shock. The organism, isolated from blood in all and from the cerebrospinal fluid in two cases, was found to be resistant to all antibiotics in the first five cases, but turned sensitive to gentamicin, cefotaxime and amikacin during the latter half of the epidemic. The bacterium in the last case (no. 13) was again found to be resistant to all the antibiotics. Overall mortality was 46.2%; the mean interval between onset of symptoms and death being 2.3 +/- 1.8 days. The organism was traced to the rubber pipe attached to a foot-operated suction machine in the NICU. The neonatal unit was temporarily closed, fumigated and reopened with strict instructions to follow proper hand washing protocol and ensure cohort nursing of infected infants. CONCLUSIONS: Enterobacter aerogenes is capable of causing nosocomial outbreaks of septicemia in NICU. Low birthweight infants with associated perinatal risk factors appear to be predisposed. The sensitivity patterns of the isolates highlight the capability of E. aerogenes to acquire or lose resistance to antibiotics rapidly during treatment. A high mortality rate coupled with a short interval between onset of symptoms and death, suggested high virulence of the strain.
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We surveyed the clerkship administrators of pediatrics, family medicine, and internal medicine at U.S. medical schools, and of pediatrics at Canadian medical schools to determine what rewards and incentives are being offered to nonsalaried faculty for office-based teaching. Monetary payment was offered by 13% to 22% of the programs. Nonmonetary rewards like educational opportunities were offered by 70% to 89%; academic appointments by 90% to 95%; special recognition events by 62% to 79%; and appreciation letters by 74% to 84% of programs. Only 3 of 338 responders offered no rewards or incentives.
The mononuclear cells exert a paracrine influence on the ovarian function, including steroidogenesis. This study examines the ability of the conditioned medium from the cultures of splenic mononuclear cells, obtained during various phases of the ovarian cycle, on progesterone accumulation by the granulosa cells in the culture medium. Female Wistar rats, aged twenty-five days, were made pseudopregnant by an injection of pregnant mare's serum gonadotropin. The splenic mononuclear cells were isolated at follicular phase, early luteal phase, mid luteal phase and late luteal phase and cultured for 48 h. The ammonium sulphate precipitated fraction of the conditioned medium was added to the granulosa cells obtained from immature rats treated with diethylstillboestrol. The granulosa cells were cultured for 48 h, and the progesterone accumulated in the medium was assayed. The conditioned medium from the cultures of the mononuclear cells obtained during follicular phase and late luteal phase inhibited FSH-induced progesterone secretion, whereas conditioned medium obtained from mid luteal phase mononuclear cells enhanced the effect of FSH. The stimulatory effect of db-cAMP on progesterone accumulation in the culture medium is inhibited by conditioned medium obtained from all the phases of the ovarian cycle. This study demonstrates a cyclicity in the behaviour of the splenic mononuclear cells on ovarian steroidogenesis, suggesting a bi-directional paracrine and/or endocrine relationship between ovary and the mononuclear cells.
Numerous articles and several reviews have been published on the role of antioxidants, and diet and lifestyle modifications in cancer prevention. However, the potential role of these factors in the management of human cancer have been largely ignored. Extensive in vitro studies and limited in vivo studies have revealed that individual antioxidants such as vitamin A (retinoids), vitamin E (primarily alpha-tocopheryl succinate), vitamin C (primarily sodium ascorbate) and carotenoids (primarily polar carotenoids) induce cell differentiation and growth inhibition to various degrees in rodent and human cancer cells by complex mechanisms. The proposed mechanisms for these effects include inhibition of protein kinase C activity, prostaglandin E1-stimulated adenylate cyclase activity, expression of c-myc, H-ras, and a transcription factor (E2F), and induction of transforming growth factor-beta and p21 genes. Furthermore, antioxidant vitamins individually or in combination enhance the growth-inhibitory effects of x-irradiation, chemotherapeutic agents, hyperthermia, and biological response modifiers on tumor cells, primarily in vitro. These vitamins, individually, also reduce the toxicity of several standard tumor therapeutic agents on normal cells. Low fat and high fiber diets can further enhance the efficacy of standard cancer therapeutic agents; the proposed mechanisms for these effects include the production of increased levels of butyric acid and binding of potential mutagens in the gastrointestinal tract by high fiber and reduced levels of growth promoting agents such as prostaglandins, certain fatty acids and estrogen by low fat. We propose, therefore, a working hypothesis that multiple antioxidant vitamin supplements together with diet and lifestyle modifications may improve the efficacy of standard and experimental cancer therapies.
Platelet factor-3 (PF(3)) availability and platelet aggregation to ADP (4 micromol/l) and adrenaline (1.2 micromol/l) were evaluated in patients being treated with 5-fluorouracil (5-FU) for gastrointestinal malignancy. It produced a significant reduction in platelet aggregation and platelet factor-3 (PF(3)) availability ( P < 0.001) without being associated with thrombocytopenia. The changes in platelet aggregation occurred during the first week of chemotherapy and continued with subsequent courses. This acquired abnormality may be responsible for a haemorrhagic diathesis even without obvious thrombocytopenia. Study of platelet function is important and may be considered to assess the haematological toxicity in patients being treated with systemic 5-FU therapy.
A method based on pseudoaffinity chromatography has been developed for the separation of lactate dehydrogenase (LDH), pyruvate kinase (PK) and aldolase from rabbit muscle extract using cross-linked guar (CLG) and cross-linked pectin (CLP) as the matrices, and dyes as the ligands. Screening of several dyes revealed that dyes No. 1014 and No. 1015, immobilized on CLG and CLP displayed a higher affinity for LDH and PK. Aldolase was not retained on any of the dye columns. It was observed that 1014-CLP and 1014-CLG columns retained 90% and 55% LDH activities, respectively, whereas 1015-CLP and 1015-CLG retained 83% LDH and 72% PK. A coupled-column system comprising 1014-CLP and 1015-CLP or 1014-CLG and 1015-CLG could separate LDH, PK, and aldolase from a mixture of these enzymes, as well as from rabbit muscle extract. Enzymes were found to be homogeneous on polyacrylamide gel electrophoresis. The method has been found to be simple and economical.
OBJECTIVE: Endopyelotomy is a well-accepted modality of treatment for pelviureteral junction (PUJ) obstruction, but the time period of stenting is debatable. The present study was aimed at evaluating the optimum duration and effectiveness of splinting after endopyelotomy. PATIENTS AND METHODS: Twenty-nine consecutive patients with primary PUJ obstruction were randomized to have an external splint (for economic reasons) for 2 weeks or 4 weeks. Thirteen patients in each group were available for evaluation. The groups were comparable in age, sex, symptoms, and preoperative glomerular filtration rate (GFR). All patients underwent antegrade endopyelotomy with placement of an 8F-12F polyethylene splint across the PUJ. A nephrostogram was performed after removal of splint at 2 or 4 weeks. Nondraining units were managed by putting in a 6F double-J stent for 6 weeks and considered failures. Patients were evaluated at 3, 6, and 12 months for symptomatic improvement, change in GFR, and drainage pattern on a diuretic renogram. RESULTS: At 1 year, a nonobstructed curve pattern was seen in 70% and improvement in GFR in 54% of the patients in the 2-weeks group, whereas in the 4-weeks group, these values were 54% and 39%, respectively. All patients in the 4-weeks group and 90% of those in the 2-weeks group were symptom free at 1 year of follow-up. Morbidity in terms of tube-related complications was comparable. CONCLUSION: Two weeks of splinting is as effective as 4 weeks in the successful outcome of endopyelotomy.
Williams syndrome (WS) is considered a contiguous gene syndrome, with most patients having a 1.5-Mb deletion of chromosome 7q11.23 containing the elastin gene and flanking genes. Studies of the frequency, extent, and origin of these deletions are ongoing in many labs to discover ultimately the molecular and pathogenetic basis for WS. An analysis of 9 sporadic WS families with typical phenotypes was performed by genotyping polymorphisms in the region. This study revealed deletions in all 9 patients, with one showing a novel deletion extending much further centromeric than any other WS deletions yet reported.
Diagnosis of systemic amyloidosis by fine-needle aspiration biopsy of abdominal fat is well established. A complete diagnosis now must include determination of the chemical type of amyloid. Microextracts of amyloid proteins from 11 Congo red-positive aspirate samples were analyzed with immunochemical methods. There was correspondence of the results obtained by immunohistologic and Western blotting analyses in 3 of 4 specimens with kappa light chain amyloid, 5 of 6 with lambda amyloid, and 1 with amyloid A. The method provides rapid and reliable diagnostic information necessary for classification of the chemical type of amyloid required for initiation of specific modes of therapy, with little discomfort to the patient.
The aim of the present study was to examine the cellular basis of the involvement of oestradiol and progesterone in blastocyst implantation in the primate. To this end, the cellular distribution of receptors for oestradiol (ER) and progesterone (PR) in fetal trophoblast cells and in endometrial compartments of timed lacunar (pre-villous) and villous stages of placentation in primary implantation sites collected on days 13-22 of gestation were investigated in rhesus monkeys. Both in pre-villous stage tissue and in villous stage tissue, cytotrophoblast cells and syncytiotrophoblast cells and other trophoblast derived cells were PR positive, while they were generally ER negative. Maternal endometrial cells were ER negative, while epithelial cells, stromal cells and vascular endothelial cells in maternal endometrium showed heterogeneous staining patterns for PR depending on their relative location; these patterns, however, correlated well with glandular hyperplasia and differentiation, stromal-decidual transformation and vascular response seen during blastocyst implantation.
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PURPOSE: To compare the effectiveness of deep lamellar keratoplasty (DLK) with that of penetrating keratoplasty (PKP) in cases of corneal lesions not involving the endothelium. METHODS: Forty-eight eyes with leukomatous corneal opacity (n = 33), keratoconus with apical scarring (n = 6), granular corneal dystrophy (n = 5), lattice corneal dystrophy (n = 2), and multiple corneal foreign bodies (n = 2) in an age group varying from 16 to 53 years underwent DLK (n = 24) and PKP (n = 24) by utilizing B and (B+ and A) grade M-K preserved donor tissue, respectively. The patients were followed up closely, and the graft clarity, visual achievement, astigmatism and endothelial cell count were evaluated at repeated occasions up to 1 year. RESULTS: Astigmatism of <3 diopters (D) and > or = 5D was obtained in 19 eyes and one eye, respectively, after DLK at 6 months, whereas six eyes of the PKP group had astigmatism <3D, and 12 eyes had > or = 5D at the end of 6 months. The same at 1 year was observed in 20 and one eye in the DLK and eight and five eyes of the PKP group. Astigmatism of > or = 5D at the end of 6 months in both the groups showed highly significant changes (p < 0.001). Best corrected visual acuity of 6/18 or more was achieved in 18 and 12 eyes at 6 months after DLK and PKP, respectively, which were statistically highly significant (p < 0.001), whereas at 1 year, it was seen in 17 and 15 eyes of the DLK and PKP groups, respectively, which was nonsignificant. The mean endothelial cell count was 2,233.3+/-64.453 cells/mm2 and 2,219.6+/-102.48 cells/mm2 at 6 months and I year, respectively, after DLK, which was nonsignificant. The mean cell count of the donor eyes used for PKP was 2,191+/-52.164 cells/mm2, 1,902.8+/-70.346 cells/mm2 at 6 months, and 1,579.0+/-80.24 cells/mm2 at 1 year. All the values showed highly significant changes (p < 0.001). Further, the graft clarity of > or = 3+ was achieved in 20 and 18 eyes at 6 months postoperatively in the DLK and PKP groups, whereas the same was observed in 19 and 13 eyes of both the groups, respectively, at 1-year follow-up. CONCLUSION: DLK is a promising procedure and should be practiced more frequently for corneal pathology not involving the endothelium.