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Biomedical subjects

H Ray

Publications and source records attributed to H Ray.

15 recordsLinked to original sources
PubMed2004

Metabolism of lipids in human white adipocyte.

Adipose tissue is considered as the body's largest storage organ for energy in the form of triacylglycerols, which are mobilized through lipolysis process, to provide fuel to other organs and to deliver substrates to liver for gluconeogenesis (glycerol) and lipoprotein synthesis (free fatty acids). The release of glycerol and free fatty acids from human adipose tissue is mainly dependent on hormone-sensitive lipase which is intensively regulated by hormones and agents, such as insulin (inhibition of lipolysis) and catecholamines (stimulation of lipolysis). A special attention is paid to the recently discovered perilipins which could regulate the activity of the lipase hormono-sensible. Most of the plasma triacylglycerols are provided by dietary lipids, secreted from the intestine in the form of chylomicron or from the liver in the form of VLDL. Released into circulation as non-esterified fatty acids by lipoprotein lipase, those are taken up by adipose tissue via specific plasma fatty acid transporters (CD36, FATP, FABPpm) and used for triacylglycerol synthesis. A small part of triacylglycerols is synthesized into adipocytes from carbohydrates (lipogenesis) but its regulation is still debated in human. Physiological factors such as dieting/fasting regulate all these metabolic pathways, which are also modified in pathological conditions e.g. obesity.

Adipocytes↗
PubMed1991

Sperm immobilizing effect of triterpene saponins from Acacia auriculiformis.

A mixture of two partially triterpenoid saponins (Tg), isolated from Acacia auriculiformis was tested for sperm immobilizing activity by using in vitro system. The lowest concentration (ED) required for an obvious immobilization of human sperm by using a modified Sander-Cramer test was found to be 0.35 mg/ml in physiological saline. The ability of the compound as a sperm immobilizing agent was compared with that of Triton X-100 and found to be more potent. Cervical mucus penetration test was also performed and the ED successfully prevented sperm entry in human cervical mucus. Supra-vital staining with eosin-nigrosin indicated death of the treated sperm. Electron microscopic study of Tg-treated sperm showed plasma membrane disintegration and dissolution of acrosomal cap which is presumably the cause for the spermicidal effect of the saponins. No permanent lesion was observed after application of 1.25 mg/ml Tg solution in physiological saline to the eye of rabbits for ten consecutive days.

Acacia↗
PubMed1991

A new glass ionomer root canal sealer.

Various physical characteristics of a new glass ionomer root canal sealer were tested. These included setting time, ease of delivery to the root canal, adaptability and adhesion to the dentinal wall of the root canal, and radiopacity. Scanning electron micrographs and electron microprobe analyses were made. The characteristics were compared with those of Grossman's sealer. The results indicated that, with respect to the properties tested, the glass ionomer sealer was superior to Grossman's sealer.

Adhesiveness↗
PubMed1987

Characterization and expression of a cloned tetracycline resistance determinant from Campylobacter jejuni plasmid pUA466.

A tetracycline resistance (Tcr) determinant previously cloned from the Campylobacter jejuni plasmid pUA466 (D. E. Taylor, J. Bacteriol. 165:1037-1039, 1986) was localized by restriction endonuclease mapping, subcloning, and Tn1000 insertion mutagenesis to a 2-kilobase region consisting of 1.8- and 0.2-kilobase HincII fragments. Tcr encoded by the cloned fragment (pUOA1) was expressed constitutively in Escherichia coli. A protein with an apparent molecular weight of 68,000 encoded by pUOA1 was produced in an in vitro transcription-translation system and in minicells. Tn1000 insertions which resulted in inactivation of Tcr expression also resulted in an alteration in the 68,000-molecular-weight protein. Some mutants specified a truncated protein, whereas others completely lost the ability to specify the protein. The protein which appears to be involved in the expression of Tcr specified by C. jejuni plasmids is of approximately the same molecular weight as the protein specified by the streptococcal class M determinant. This finding is consistent with our previous results which indicate that homology exists between the Tcr determinant from C. jejuni and a 5-kilobase HincII probe derived from the streptococcal class M determinant.

Bacterial Proteins↗
PubMed1981

3-(4-hydroxy phenyl)-2-propenoic acid - a reproductive inhibitor in male rat.

Oral administration of 3-(4-hydroxy phenyl)-2-propenoic acid, at a dose of 50 mg/kg body weight/day (reported antiprolactin dose in rat) for 56 days, to adult male rat produces complete loss of libido, significant decrease in weight of testis and accessory sex organs, decrease in fructose content of coagulating gland and reduction in acid phosphatase activity in prostate. All these effects can be reversed by exogenous prolactin (500 micrograms/rat/day) plus testosterone propionate (200 micrograms/rat/day), but not by prolactin or testosterone alone, when administered along with the test compound for the last 28 days. Inhibitory influence of the compound over the reproductive organs is believed to be attributed primarily to the antiprolactin nature of the compound and secondarily to the significant (P less than 0.01) fall in plasma testosterone level caused by the compound.

Acid Phosphatase↗
PubMedDate not supplied

Drawing specimens for coagulation testing: is a second tube necessary?

Three recent studies discussed the possibility that the National Committee for Clinical Laboratory Standards (NCCLS) recommendations that the coagulation specimen should be the second or third tube collected are unnecessary. However, only one reagent/instrument was used in each study. Our protocol differed from the previous studies because we performed the assays on three different reagent/instrument systems on the same samples. Our study used photo-optic, mechanical, and nephelometric systems of clot detection. After obtaining informed consent, we obtained two blue-stoppered tubes of blood from 95 subjects: 15 normal patients and 80 patients currently on coumadin therapy. No discard tube was drawn for coagulation testing. A prothrombin time with an international normalized ratio and an activated partial thromboplastin time, were performed on each tube. Laboratory One used a MLA 1600C (Hemoliance) with Thromboplastin DS (Pacific-Hemostasis, ISI of 1.11) and APTT-LS (Pacific-Hemostasis). Laboratory Two used an STA (Diagnostica-Stago) with Neoplastine CI+ (Diagnostica-Stago, ISI of 1.14) and PTT-LT (Diagnostica-Stago). Laboratory Three used an ACL 300 with Plastinex (Biodata, ISI of 1.67) and Actin FSL (Dade Behring). No clinical or statistically significant differences were seen between the first or second tubes on any of the three reagent/instrument combinations in the PT in seconds, international normalized ratio reporting, or APTT results. Our results indicate that the NCCLS guidelines for obtaining a second tube when performing coagulation testing should be considered for elimination when new revisions are published.

Anticoagulants↗