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Biomedical subjects

B Patel

Publications and source records attributed to B Patel.

At least 217 records · Page 12Linked to original sources
PubMed1975

Enzymuria in gentamicin-induced kidney damage.

To assess their potential value as early indicators of gentamicin-induced kidney damage, lysosomal hydrolases were measured in the 24-h urines of rats receiving 30 or 60 mg of gentamicin per kg per day for 15 days. Proteinuria, urine osmolality, blood urea nitrogen, and creatinine clearance were also measured. Kidney tissue was examined by both light and electron microscopy. Beta-galactosidase, beta-n-acetyl-hexosaminidase, and alpha-fucosidase were sensitive indicators and were significantly elevated above control values by day 3 at both doses (P < 0.01). Proteinuria, urine osmolality, and tests reflecting glomerular filtration rate were later indicators of nephron damage. Changes by light microscopy were detected on day 5. Necrosis was most prominent in the proximal convoluted tubules on day 10. Electron microscopy revealed numerous cytosomes with myeloid bodies within the proximal tubular epithelium on day 5. Lysosomal enzymuria appears to be an early manifestation of gentamicin nephrotoxicity and may possibly be related to the lysosomal abnormalities seen on electron microscopy.

Animals↗
PubMed1975

Experimental aminoglycoside nephrotoxicity.

The nephrotoxicities of gentamicin and three other experimental aminoglycosides were compared at a single 60 mg. per kilogram per day dose in rats. Renal function, lysosomal enzymuria, and antibiotic concentrations in plasma, urine, and renal tissue were measured at regular intervals throughout the course of treatment. Kidney tissue was examined by light and electron microscopy in animals killed at intervals throughout the period of antibiotic administration. Proteinuria and enzymuria were early indicators of nephron dysfunction, whereas endogenous creatinine clearance declined later in the course of treatment. All animals were killed 24 hours after a previous antibiotic injection and displayed sustained renal tissue antibiotic concentrations which were 5 to 10 times higher than those in serum or urine. When assayed separately, renal cortical tissue had a fivefold greater antibiotic concentration than renal medulla. Light microscopy displayed necrosis of the pars convoluta of the proximal tubule. Electron microscopy revealed appearance of cytosegrosomes with myeloid bodies. It is possible that impaired cytoplasmic degradation of sequestered organelle membranes, resulting from aminoglycoside accumulation, is responsible for the myeloid body formation and subsequent tubular necrosis.

Aminoglycosides↗
PubMedDate not supplied

Toxic properties of the Mycoplasma arthritidis ISR-1 membrane.

Isolated membranes of Mycoplasma arthritidis ISR-1 possess toxic properties for rats, mice and chicken embryos. Reactions are dose-dependent. By intravenous injection of 20 mg of membrane protein, a lethal toxicity syndrome resembling shock is induced in Sprague-Dawley rats of 100 g body weight. Mice of approximately 20-g body weight show the same syndrome by intravenous injection of 15 mg of membrane protein. The lethal toxicity for chicken embryos increases from 10 to 80% after injection of 0.3 to 1.5 mg of membrane protein. The LD50 in chicken embryos was found to be 0.5 mg membrane protein. After administration of 10-15 mg of membrane protein, rats showed an increase in temperature from 38 to 41 degrees C within 5 h. Because of the difficulty in measuring the temperature in mice, loss of body weight was taken as the criterion for toxicity. Body weight was reduced up to 16% within 1 day after intravenous injection of 500 micrograms of membrane protein per g of body weight. For sheep red blood cells, M. arthritidis ISR-1 membranes were haemolytic in concentrations of 4 mg of membrane protein and higher. Intradermal injection of 1 mg of membrane protein into guinea-pigs resulted in red swelling reactions measuring approximately 10 mm in diameter 10 h after injection. For foetal rat skin fibroblasts, M. arthritidis ISR-1 membranes were toxic in concentrations from 1 micrograms (3H-uridine incorporation), 10 micrograms (14C-leucine incorporation) and 100 micrograms (3H-thymidine incorporation) of membrane protein.

Animals↗
PubMedDate not supplied

A comparison of the incidence of nausea after laparoscopic cholecystectomy and diagnostic laparoscopy.

Thirty-four patients undergoing gynecologic diagnostic laparoscopy and 30 patients undergoing laparoscopic cholecystectomies were followed prospectively for nausea and vomiting 24 hours postoperatively. Diagnostic laparoscopy patients had a significantly higher incidence of nausea and vomiting than laparoscopic cholecystectomy patients with similar anesthetic techniques, duration of surgery, and population parameters. All patients had their stomach contents suctioned after induction. While both procedures involve bowel manipulation, patient position and organ manipulation differ: diagnostic laparoscopy involves the Trendelenburg position and laparoscopic cholecystectomy involves the reverse Trendelenburg; diagnostic laparoscopy involves the uterus, ovaries, and fallopian tubes while laparoscopic cholecystectomy involves mainly the gall-bladder and its appendages. These factors may contribute to the differences found in this study.

Adult↗
PubMedDate not supplied

Androgen deprivation induces selective outgrowth of aggressive hormone-refractory prostate cancer clones expressing distinct cellular and molecular properties not present in parental androgen-dependent cancer cells.

PURPOSE: The mechanism of progression of human prostate cancer (CaP) cells under androgen ablation therapy remains unclear. To study the alternative pathways of CaP cell growth under conditions of androgen deprivation, androgen-independent CaP variants were selected and expanded from an androgen-dependent CaP line via an in vitro androgen deprivation treatment. Cellular and molecular properties of these androgen-independent variants were characterized both in vitro and in vivo and compared with those of their parental androgen-dependent cells. METHODS: Androgen deprivation treatment of an androgen-dependent CaP cell line, LNCaP, was carried out by replacing culture medium with RPMI 1640 medium plus 10% charcoal-stripped serum. Cells that survived through the androgen deprivation treatment were harvested and expanded in the androgen-deficient culture medium and were designated CL-1. The CL-1 cells were also recultured in androgen-containing medium and designated CL-2. The growth (cell cycle analysis, 3H-thymidine incorporation assay, growth expansion, and colonization efficiency), expression of CaP-associated markers (semiquantitative reverse transcriptase polymerase chain reaction), interaction with endothelial and bone marrow stromal cells, sensitivity to anticancer agents and radiation (growth inhibition), and tumorigenicity of CL-1 and CL-2 cells were determined and compared with these characteristics in parental LNCaP cells. RESULTS: CL-1 and CL-2 cells are fast-growing cells when compared with parental LNCaP cells. They were capable of potentiating the growth of endothelial and bone marrow stromal cells in co-culture experiments and acquired significant resistance to radiation and to anticancer cytotoxic agents (Taxol paclitaxel, vinblastine, and etoposide). In contrast to the poorly tumorigenic parental LNCaP cells, CL-1 and CL-2 lines proved highly tumorigenic, exhibiting invasive and metastatic characteristics in intact and castrated mice or in female mice within a short period of 3 to 4 weeks. No growth supplements (e.g., Matrigel) were needed. When transfected with the green fluorescence protein (GFP) gene and transplanted orthotopically in the accessory sex gland, extensive metastatic disease from the primary CL tumor could be identified in bone, lymph nodes, lung, liver, spleen, kidney, and brain. Semiquantitative reverse transcriptase polymerase chain reaction analysis revealed a markedly distinct molecular expression profile in the CL lines: overexpression of basic fibroblast growth factor, interleukin-6, interleukin-8, vascular endothelial growth factor, transforming growth factor-beta, epidermal growth factor receptor, caveolin, and bcl-2 messenger RNAs and marked down-regulation of E-cadherin, p-53, and pentaerythritol tetranitrate. CONCLUSIONS: Early administration of hormonal therapy after failure of first-line treatment is associated with a profound clonal selection of aggressive AI variants, such as CL-1 and CL-2 lines. These tumor lines, with their parental counterparts, can serve as valuable tools for studying the cellular and molecular mechanisms of CaP progression and metastasis under hormonal therapy. CL-1 and CL-2 offer a unique and reproducible model for the evaluation of drug sensitivity and for other therapeutic modalities for advanced prostate cancer.

Androgens↗
PubMedDate not supplied

Outcome in ambulatory status immediately following hip fracture surgery in the acute setting: a comparison of nursing home residents and community older adults.

OBJECTIVE: To compare the ambulatory status following hip fracture surgery in the acute setting between older adults from long-term care facilities (LTCF) and the community. SETTING: A 650-bed, urban, inner city, university-affiliated teaching hospital. METHODS: One hundred forty hip fracture patients (60-97 years) from long-term care facilities and the community were examined. Ambulatory status before and after surgery was categorized four ways based on the degree of independence in ambulation: A1 = independent ambulation (with or without an assisting device), A2 = assistance of another person required, A3 = predominant use of a wheelchair, and A4 = bed-bound. Change in ambulatory status was designated as "moderate" if the deterioration was one status level only (A1 to A2, A2 to A3, and A3 to A4) or "major" if the deterioration was more than one status level (A1 to A3/A4 or A2 to A4). Additional variables such as age, sex, risk factors, length of stay, history of drug use, and laboratory results also were examined. RESULTS: Hip fracture patients from LTCF were older (P = 0.0160) and had more overall risk factors for hip fracture (P = 0.0039) than community patients. They also had higher rates of dementia (P < 0.000), arrhythmia (P = 0.025), delirium (P = 0.0016) and anxiolytics use (P = 0.019) than patients from the community. On admission, LTCF patients had lower serum calcium (P = 0.0003), phosphorus (P = 0.0210), and albumin (P = 0.0004) than community patients. Before hospitalization they also were less ambulatory (P = 0.002) than community patients. Post surgery, ambulatory status declined in both groups. However, a "major" change (decline) in ambulatory status occurred more often in LTCF patients (P = 0.001). CONCLUSIONS: A greater decline in ambulatory status is seen in patients from LTCF than in community patients, immediately following hip fracture surgery. Compared with community patients, LTCF patients are also older, sicker (higher total risk score) and have an increased risk for a decline in functional status.

Journal Article↗