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Biomedical subjects

R Patel

Publications and source records attributed to R Patel.

At least 361 records · Page 20Linked to original sources
PubMed1985

Focal fatty liver lesions in alcoholic liver disease: a broadened spectrum of CT appearances.

The CT examinations of 26 consecutive alcoholic patients with focal fatty infiltration of the liver were analyzed. Five different patterns of focal fatty infiltration were noted. In most alcoholic patients these appearances present no diagnostic problem and further confirmation can be obtained by repeating the CT scan within 1-2 weeks to see if interval resolution occurs following enforced abstinence. In select instances, more invasive and definitive procedures such as superselective angiography or liver biopsy may be necessary to differentiate these findings from other more serious diseases they may closely resemble, such as primary or secondary liver neoplasms.

Adult↗
PubMed1985

A quantitative immunohistochemical study of macroglial cell development in the rat optic nerve: in vivo evidence for two distinct astrocyte lineages.

We have shown previously that three antibodies--anti-galactocerebroside (GC), anti-glial fibrillary acidic protein (GFAP), and the A2B5 monoclonal antibody--can be used to help distinguish three classes of glial cells in the rat optic nerve: oligodendrocytes are GC+, GFAP-, almost all type-1 astrocytes are A2B5-, GFAP+, and almost all type-2 astrocytes are A2B5+, GFAP+. In the present study we have used these antibodies to examine the timing and sequence of the development of the three types of glial cells in vivo. We show that type-1 astrocytes first appear at embryonic Day 16 (E16), oligodendrocytes at birth (E21), and type-2 astrocytes between postnatal Days 7 and 10 (P7-10). Moreover, we demonstrate quantitatively that astrocytes in the optic nerve develop in two waves, with more than 95% of type-1 astrocytes developing before P15 and more than 95% of type-2 astrocytes developing after P15. Finally, we provide indirect evidence that type-2 astrocytes do not develop from type-1 astrocytes in vivo, supporting previous direct evidence that the two types of astrocytes develop from two serologically distinct precursor cells in vitro.

Animals↗
PubMed1984

Gaucher's disease in a black child in South Africa. A case report.

A 7-year-old Black boy presented with massive splenomegaly and a tendency to haemorrhage due to type 1 Gaucher's disease. After splenectomy he became asymptomatic and the haematological parameters returned to normal. Although type 1 Gaucher's disease has been described in adult Blacks, it has not been reported previously in a Black child in southern Africa.

Black or African American↗
PubMed1984

Hybridoma preservation at -70 degrees C: a simple and economical procedure for the short-term storage and individual recovery of hybridomas.

A simple, economical, and time-saving procedure for freezing freshly prepared hybridomas at--70 degrees C is described. The procedure allows for supernatant fluid collection and storage of hybridomas in 96-well flexible polyvinyl microtiter plates. As the plates are sealed, and the plate is relatively soft, individual wells can be removed and cells recovered at the investigator's discretion. Consequently, this procedure allows significant latitude with regard to the time-consuming steps usually associated with hybridoma screening, expansion, and sub-cloning techniques.

Animals↗
PubMed1984

Effects of neonatal transection on glial cell development in the rat optic nerve: evidence that the oligodendrocyte-type 2 astrocyte cell lineage depends on axons for its survival.

We have previously provided evidence that the rat optic nerve contains three types of macroglial cells that develop as two distinct lineages: one lineage comprises type 1 astrocytes, which develop before birth, while the other comprises oligodendrocytes and type 2 astrocytes, which develop after birth from a common, bipotential glial progenitor cell. In the present study we have examined the influence of axons on the development of these two glial cell lineages by cutting the optic nerve at birth so that the retinal ganglion cell axons in the nerve degenerate. Using antibodies to distinguish the different types of glial cells in suspensions and semithin frozen sections of cut and uncut optic nerves, we show that neonatal transection results in a striking decrease in the total number of oligodendrocytes, type 2 astrocytes and their progenitor cells but has much less effect on the number of type 1 astrocytes. Since the [3H]thymidine labelling indices of oligodendrocytes and their progenitor cells were not significantly decreased in cut nerves, our results suggest that the progenitor cells and/or their progeny die in large numbers following neonatal nerve transection. We conclude that axons are required for the survival of cells of the oligodendrocyte-type 2 astrocyte lineage, at least during postnatal development.

Animals↗
PubMed1984

Detection of primary antimitochondrial activity of drugs in cultured mammalian cells utilizing glutamine as the carbon source.

Growth of guinea-pig keratocytes (GPK) proceeded normally in standard medium in which glutamine (mitochondrial substrate) replaced glucose as the carbon and energy source. Cells in the glucose-free glutamine cultures were much more sensitive to the toxic and growth-inhibiting effects of the antimitochondrial drugs ethidium bromide, chloramphenicol and oligomycin than cells in glucose-containing cultures. In the latter, cells continued to proliferate in the presence of these drugs after 2-3 days incubation, but in the non-fermenting cells growth was arrested within 24 h and there was more than 95% cell death after 2 days. Cycloheximide, a general inhibitor of protein synthesis in eukaryotic cells, showed no selective inhibition of growth and glutamine and glucose cultures were equally affected. The system appears to be useful for the detection of primary antimitochondrial activity of drugs in general.

Animals↗
PubMed1984

Nonsurgical removal of a kinked right coronary catheter.

Cardiac catheterization is a commonly performed procedure affording valuable data. Catheter related complications such as catheter knotting, fracture, and collapse have been reported. Occasionally surgery is needed to extricate an entrapped catheter when nonsurgical means are unsuccessful. We describe a case of kinking of a right coronary catheter during transfemoral coronary arteriography, so that the catheter could not be withdrawn. A simple, nontraumatic method facilitated removal of the kinked catheter and permitted completion of the procedure, obviating the need for surgery.

Angina, Unstable↗
PubMed1983

Epoxidation of short-chain alkenes by resting-cell suspensions of propane-grown bacteria.

Sixteen new cultures of propane-utilizing bacteria were isolated from lake water from Warinanco Park, Linden, N.J. and from lake and soil samples from Bayway Refinery, Linden, N.J. In addition, 19 known cultures obtained from culture collections were also found to be able to grow on propane as the sole carbon and energy source. In addition to their ability to oxidize n-alkanes, resting-cell suspensions of both new cultures and known cultures grown on propane oxidize short-chain alkenes to their corresponding 1,2-epoxides. Among the substrate alkenes, propylene was oxidized at the highest rate. In contrast to the case with methylotrophic bacteria, the product epoxides are further metabolized. Propane and other gaseous n-alkanes inhibit the epoxidation of propylene. The optimum conditions for in vivo epoxidation are described. Results from inhibition studies indicate that a propane monooxygenase system catalyzes both the epoxidation and hydroxylation reactions. Experiments with cell-free extracts show that both hydroxylation and epoxidation activities are located in the soluble fraction obtained after 80,000 x g centrifugation.

Journal Article↗
PubMed1983

Production of Methyl Ketones from Secondary Alcohols by Cell Suspensions of C(2) to C(4)n-Alkane-Grown Bacteria.

Nineteen new C(2) to C(4)n-alkane-grown cultures were isolated from lake water from Warinanco Park, Linden, N.J., and from lake and soil samples from Bayway Refinery, Linden, N.J. Fifteen known liquid alkane-utilizing cultures were also found to be able to grow on C(2) to C(4)n-alkanes. Cell suspensions of these C(2) to C(4)n-alkane-grown bacteria oxidized 2-alcohols (2-propanol, 2-butanol, 2-pentanol, and 2-hexanol) to their corresponding methyl ketones. The product methyl ketones accumulated extracellularly. Cells grown on 1-propanol or 2-propanol oxidized both primary and secondary alcohols. In addition, the activity for production of methyl ketones from secondary alcohols was found in cells grown on either alkanes, alcohols, or alkylamines, indicating that the enzyme(s) responsible for this reaction is constitutive. The optimum conditions for in vivo methyl ketone formation from secondary alcohols were compared among selected strains: Brevibacterium sp. strain CRL56, Nocardia paraffinica ATCC 21198, and Pseudomonas fluorescens NRRL B-1244. The rates for the oxidation of secondary alcohols were linear for the first 3 h of incubation. Among secondary alcohols, 2-propanol and 2-butanol were oxidized at the highest rate. A pH around 8.0 to 9.0 was found to be the optimum for acetone or 2-butanone formation from 2-alcohols. The temperature optimum for the production of acetone or 2-butanone from 2-propanol or 2-butanol was rather high at 60 degrees C, indicating that the enzyme involved in the reaction is relatively thermally stable. Metal-chelating agents inhibit the production of methyl ketones, suggesting the involvement of a metal(s) in the oxidation of secondary alcohols. Secondary alcohol dehydrogenase activity was found in the cell-free soluble fraction; this activity requires a cofactor, specifically NAD. Propane monooxygenase activity was also found in the cell-free soluble fraction. It is a nonspecific enzyme catalyzing both terminal and subterminal oxidation of n-alkanes.

Journal Article↗
PubMed1982

Immunogenetic studies in essential hypertension among black patients. I. Correlative studies of serum autoantibody formation.

Serum antinuclear antibody (ANA) and HLA phenotype frequency were studied in 100 black subjects with essential hypertension and 100 normotensive black controls matched for age and sex. 11% of hypertensive individuals had a positive serum ANA test compared with 2% of controls (p less than 0.01). Among the hypertensive patients, positive serum ANA test was seen exclusively in patients who were receiving treatment with methyldopa. Although ANA also correlated with hypertensive vascular damage as assessed by retinal and EKG abnormalities, this was believed to have been due to the higher dose of methyldopa that may have been required to treat hypertension in these more severe cases. A statistically significant correlation of HLA-A11 and HLA-B12 with hypertension was observed, but only studied when uncorrected for the number of HLA specificities. It was concluded that autoantibody formation in essential hypertension is most likely to have been a consequence of antihypertensive drug therapy. In addition, further studies using larger number of patients and controls might more clearly establish the question of whether or not HLA is associated with essential hypertension.

Adult↗
PubMed1982

Iron deficiency and anemia among Indian women in Fiji.

In June 1979, 245 Hindu and 240 Moslem women of childbearing age (14-45 yr) living in a semi-rural area north of Lautoka were tested for anemia and for iron-deficiency. Ninety-six (39%) of the 245 Hindu women and 77 (32%) of the 240 Moslem women were anemic according to World Health Organization criteria. Most of the cases of anemia were due to iron-deficiency. The prevalence of anemia did not change significantly with advancing age or increasing parity. Hookworm ova were found on examination of a single specimen of feces in 27 (14%) of 195 Hindu and 50 (24%) of 209 Moslem women. The presence of hookworm did not correlate with anemia. The red cell folate level was less than 160 micrograms/l in 117 (24%) of 478 women and the serum vitamin B12 level was less than 100 ng/l in 47 (10%) of 476 women. Subnormal levels of these vitamins did not correlate with anemia. The serum ferritin was determined to assess tissue iron stores. Two-hundred-and-twenty-four (46%) of 484 Indian women tested had serum ferritin values of less than 10 microgram/l; 400 (83%) had ferritin values of less than 26 microgram/l. The high prevalence of iron deficiency appears to be due predominantly to dietary factors.

Adolescent↗
PubMed1981

Relative value of computed tomography and ultrasonography in the assessment of renal angiomyolipoma.

Imaging studies on six patients with known angiomyolipomas were reviewed to determine the contribution of each imaging modality to the preoperative diagnosis. A spectrum of clinical presentations from asymptomatic patients with tuberous sclerosis to acutely ill patients with flank pain and hypotension was included. Findings varied from multiple, small, bilateral intrarenal masses to single larger masses with extrarenal components. Computed tomography (CT) identified fat containing masses in all cases. Ultrasound showed hyperechoic masses in all four cases in which it was utilized. In addition, CT allowed diagnosis of associated hematomas and additional angiomyolipomas not seen on other studies. Ultrasound provided a noninvasive follow-up method without the use of ionizing radiation.

Adult↗