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Biomedical subjects

C A Taylor

Publications and source records attributed to C A Taylor.

At least 73 records · Page 4Linked to original sources
PubMed1989

Cutaneous T cell lymphoma with suppressor phenotype and function.

Cutaneous T cell lymphomas (CTCL) are typically malignancies of postthymic helper T cells which retain helper function when assayed in vitro. We have described a case clinically and morphologically consistent with CTCL, but in which the tumor cells unequivocally had a suppressor T cell phenotype and suppressor function. This case could be differentiated from other varieties of peripheral T cell lymphomas by multiple clinical and laboratory parameters. The increasingly routine use of immune phenotyping in the evaluation of malignant lymphomas will likely result in the identification of additional cases of this entity, which should be studied to assess its clinical and prognostic relationship to the more common helper cell CTCL.

Humans↗
PubMed1988

Glycine-evoked release of [3H]acetylcholine from rat striatal slices is independent of the NMDA receptor.

KCl-, NMDA-, and glycine-evoked release of [3H]acetylcholine was studied in superfused rat striatal slices. KCl-evoked release of [3H]acetylcholine was inhibited by 1.2 mM MgCl2 and 100 microM lidocaine. Similarly, NMDA-evoked release was inhibited by MgCl2 and lidocaine as well as 10 microM CGS 19755, a competitive antagonist at NMDA receptors, and 10 nM MK-801, a noncompetitive antagonist of NMDA-induced responses. Glycine-evoked release was calcium-dependent and was inhibited by 0.1 microM strychnine whereas KCl- and NMDA-evoked release were resistant to strychnine. In addition, lidocaine inhibited the glycine-induced response. Cross-tachyphylaxis was not observed between NMDA- and glycine-evoked release. These results indicate that the strychnine-sensitive, glycine-evoked release of [3H]acetylcholine is independent of the NMDA receptor.

Acetylcholine↗
PubMed1988

Surgical hypothermia.

Induced hypothermia is an interesting and useful adjunct to therapy in many areas of surgery and medicine. To paraphrase Professor Swan (1973), clinical hypothermia 'has a past and some promise for the future'.

Humans↗
PubMed1988

Sodium fluxes modulating neuronal glutamate uptake: differential effects of local anesthetic and anticonvulsant drugs.

Local anesthetics and anticonvulsant drugs were differentiated biochemically by quantitating their effects on aconitine- and ouabain-induced inhibition of L-[3H]glutamate uptake in synaptosomes. Amine local anesthetics reversed the inhibition by both compounds whereas the anticonvulsant drugs such as carbamazepine and diphenylhydantoin reversed the effects of aconitine but not ouabain. These results support the concept that carbamazepine and diphenylhydantoin interact with voltage-sensitive Na channels to block Na conductance whereas the amine local anesthetics are less specific in their actions.

Aconitine↗
PubMed1987

A nonendocytotic mechanism for the selective uptake of high density lipoprotein-associated cholesterol esters.

We have previously described in rats the selective uptake of HDL-associated cholesterol esters (traced by [3H]cholesteryl oleyl ether) in excess of the uptake of HDL-associated apoA-I. In the present studies we show that the mechanism also exists in cultured cells of human and mouse origin as well. This selective uptake represents a net uptake of cholesterol esters and not an isotope exchange, as shown by mass flux studies in adrenal cells. Inhibitors of receptor recycling, chloroquine, monensin, and colchicine, inhibited uptake of apoA-I from HDL by Hep G-2 human hepatoma cells to about the same extent as a reference protein, asialofetuin, but inhibited uptake of the cholesteryl ether tracer much less. Levels of NaN3 which effectively inhibited sucrose pinocytosis inhibited uptake of apoA-I to about the same extent but did not inhibit uptake of the cholesteryl ether at all. Thus, not only receptor recycling, but endocytosis as well, appears not to be involved in selective uptake. This conclusion was supported by studies in which synthetic HDL particles were made to contain two neutral lipid core tracers; one of them, the [3H]cholesteryl ether previously used, was selectively taken up, whereas the other, [14C]sucrose octaoleate, was excluded from selective uptake. Thus, selective uptake cannot involve endocytosis of the entire lipid core, but may involve other specific transfer mechanisms.

Adrenal Cortex Neoplasms↗
PubMed1987

A metabolic comparison of a pure long-chain triglyceride lipid emulsion (LCT) and various medium-chain triglyceride (MCT)-LCT combination emulsions in dogs.

Two 20% lipid emulsions containing mixtures of long-(LCT) and medium-chain triglycerides (MCT) were compared with a 20% LCT lipid emulsion. Beagles were infused with emulsions containing either 100% LCT, 75% LCT-25% MCT, or 50% LCT-50% MCT. The emulsions were part of a total parenteral nutrition (TPN) regimen that included 10% dextrose and 5.5% amino acids. Basic nutritional parameters as well as elimination kinetics were monitored. Plasma linoleic acid, ketone, lactate, pyruvate, insulin, glucose, and carnitine were analyzed. The 75% LCT-25% MCT emulsion offers little advantage over 100% LCT as a metabolic substrate. The 50% LCT-50% MCT combination proved to be a potentially better caloric source due to rapid elimination kinetics, increased ketone production, lack of deposition, and no interference with linoleic acid metabolism.

Animals↗
PubMed1987

Vector competence of Culex (Melanoconion) taeniopus for allopatric and epizootic Venezuelan equine encephalomyelitis viruses.

The vector competence of Culex (Melanoconion) taeniopus was examined in the laboratory for "enzootic" allopatric and "epizootic" strains of Venezuelan equine encephalomyelitis viruses of hemagglutination inhibition subtypes I, II, III, and IV. Following bloodmeals from viremic hamsters, and extrinsic incubation of 20-22 days, mosquitoes were allowed to refeed for transmission attempts. Infection rates never exceeded 50% with oral doses of less than 10(4) chick embryo cell culture plaque forming units (CECPFU), and approached 100% only after ingestion of greater than or equal to 10(5.5) PFU. Transmission was achieved for some "epizootic" subtype IABC and "enzootic" subtype ID strains after bloodmeals containing greater than or equal to 10(3.4) CECPFU; subtypes II, III, and IV were never transmitted despite oral doses up to 10(5.0) CECPFU. These data contrast sharply with those reported previously for sympatric "enzootic" subtype IE Middle American Venezuelan encephalitis viruses.

Animals↗
PubMed1986

Laboratory vector competence of Culex (Melanoconion) cedecei for sympatric and allopatric Venezuelan equine encephalomyelitis viruses.

Laboratory vector competence of Culex (Melanoconion) cedecei was examined for Venezuelan equine encephalomyelitis (VEE) viruses. Colonized adult female mosquitoes originating from a southern Florida population were given bloodmeals from viremic hamsters circulating various titers of 3 hemagglutination inhibition (HI) subtypes of VEE viruses. Following extrinsic incubation of about 3 weeks, mosquitoes were allowed to refeed on uninfected hamsters for transmission trials. Cx. cedecei was highly efficient in becoming infected with and transmitting its sympatric, HI subtype II "Everglades" virus. With bloodmeal titers of 10(0.9) chick embryo cell culture (CEC) plaque forming units (PFU), the infection rate was 9% and transmission occurred following extrinsic incubation. Infection rates were greater than or equal to 80% with oral doses of greater than or equal to 10(1.8), and all infected mosquitoes were capable of transmission following incubation. Cx. cedecei was also highly sensitive to infection with allopatric HI subtype IE Middle American VEE virus isolates. Infection rates were greater than or equal to 50% with bloodmeal titers undetectable by CEC assay. Rates were 100% with oral doses of greater than or equal to 10(0.8) CECPFU. Transmission rates were 100% in all experiments. Similar results were obtained with HI subtype IAB "epizootic" VEE virus isolates from the 1969 Middle American outbreak. Infection rates were 100% with oral doses of greater than or equal to 10(1.2), and transmission rates were 100% after extrinsic incubation. Comparisons with laboratory vector competence of the Middle American enzootic VEE virus vector, Culex (Melanoconion) taeniopus, are discussed.

Animals↗
PubMed1985

Role of insulin and dexamethasone in the expression of bioactivity in rat hepatocytes cultured in a serum-free defined medium.

Previously, we described primary cultures of rat liver cells in a serum-free multihormone defined medium (Am. J. Physiol. 243: E132-E151, 1982). This cell preparation exhibits marked insulin-dependent syntheses of protein, glycogen and lipids (hereafter collectively referred to as "bioactivity" for brevity). In the present studies, the role of different hormones in the expression of insulin's bioactivity was investigated. Hepatocytes from fasted rats, previously maintained in the multihormone glucagon-supplemented medium, were first cultured in the defined medium without the hormones and, subsequently, tested for bioactivity by replacing the missing hormones singly or in combination. Of all the hormones tested (testosterone, estradiol, thyroxine, glucocorticoid steroid and insulin), only insulin, dexamethasone and thyroxine when present individually in the culture medium, showed slight bioactivity (glycogenesis); however, insulin and dexamethasone, when present together, further increased each bioactivity, protein (1.3-fold), glycogen (8-fold) and lipid (1.6-fold) syntheses. The determination of apparent binding parameters of insulin specific receptors using Scatchard plots showed that insulin exposure caused a decrease in receptor concentration (Ro), dexamethasone exposure caused an increase in affinity (Kd), and, compared to insulin alone, treatment with insulin plus dexamethasone increased receptor concentration with no change in apparent affinity. Insulin induced a consistently small, but statistically significant, increase in the average specific activity of the protein-disulfide interchange enzyme, glutathione-insulin transhydrogenase (GIT), with equal distribution between its nonlatent ("readily available") and latent ("cryptic") forms. However, when dexamethasone was present along with insulin, the distribution of GIT was significantly greater in the latent form than in the nonlatent form. Examination by scanning and transmission microscopy showed clear differences, both in the cell surface and intracellular morphology, in the hepatocytes exposed to different hormonal milieu.

Animals↗
PubMed1985

Localization of glutathione-insulin transhydrogenase (protein-disulfide interchange enzyme) in pancreas using immunocytochemistry, immunodiffusion, and enzymatic activity assay techniques.

The localization of the protein-disulfide interchange enzyme, glutathione-insulin transhydrogenase (GIT), in rat and mouse pancreas was studied by protein A-gold immunocytochemistry, immunodiffusion, and assay of enzymatic activity. Immunocytochemistry on tissue sections using antibody to GIT and protein A-gold complex indicated the presence of GIT in alpha and beta cells in islets as well as acinar cells. The beta cells in obese (ob/ob) hyperinsulinemic mice showed increased GIT immunoreactivity. In both alpha and beta cells, GIT immunoreactive sites were associated predominantly with secretory granules. In pancreas from rats injected with glibenclamide, the degranulated beta cells contained GIT immunoreactive sites on the cisternal surface of the rough endoplasmic reticulum (RER). In acinar cells, the RER, Golgi elements, condensing vacuoles, and zymogen granules possessed GIT immunoreactive sites as did mitochondria. Immunocytochemistry on sections of isolated subcellular fractions showed that GIT was associated with different membranes. The enzymatic activity of GIT was found in the following order: Golgi elements greater than mitochondria greater than microsomes greater than zymogen granules greater than cytosol. In Ouchterlony immunodiffusion tests, each subcellular fraction showed a precipitin band which was continuous with that of purified GIT, a result indicating the presence of immunologically identical GIT in all fractions.

Animals↗
PubMed1983

A radioiodinated, intracellularly trapped ligand for determining the sites of plasma protein degradation in vivo.

We recently developed a general method for determining tissue sites of degradation of plasma proteins in vivo that made use of covalently attached radioactive sucrose. On degradation of the protein, the sucrose remained trapped in the cells as a cumulative marker of protein degradation. The method described here depends on the same principles, but uses an adduct of cellobiose and tyramine that is radioiodinated to high specific radioactivity and then covalently attached to protein. Use of the radioiodinated ligand increases the sensitivity of the method at least 100-fold and allows simplified tissue analysis. Proteins derivatized with the radioiodinated ligand were recognized as underivatized proteins both in vitro and in vivo. On degradation of derivatized low-density lipoprotein, the rate of leakage from cultured fibroblasts was only 5% during 24 h. Similarly, on injection of labelled proteins into rats and rabbits, urinary excretion of the label was in all cases less than 10% of total labelled catabolic products recovered 24 h after injection. Examination of the tissue contents of label at two times after injection of labelled asialofetuin or apolipoprotein A1 in rats, and asialotransferrin in rabbits showed that the label did not detectably redistribute between tissues after initial uptake and catabolism; a significant leakage from liver was quantitatively accounted for by label appearing in gut contents and faeces. A simple double-label method was devised to provide a correction for intact protein in trapped plasma, the extravascular spaces, and within cells. By using this method it becomes unnecessary to fractionate tissue samples.

Animals↗
PubMed1983

Addictive behaviors and life problems before and after behavioral treatment of problem drinkers.

The broader impact of a behavioral self-control training intervention focusing on the reduction of alcohol consumption was examined in a sample of 93 problem drinkers (55 male). Individual life problems were assessed via the method of goal attainment scaling before and after treatment and at 3-6 months, 12 months and 24 months following termination. Alcohol and drug use, smoking and weight were also evaluated. At intake, women were more likely than men to be unmarried, married to a problem drinking spouse, or taking psychoactive prescription medication but less likely to be using illicit drugs, smoking or gambling . For both men and women negative emotional states and family discord headed the list of current life problems. Although intervention focused primarily on drinking behavior, the majority of other life problems also showed improvement at all follow-up points. Remission of life problems was associated with decreased alcohol consumption. Body weight tended to increase slightly after treatment but typically returned to or below baseline by later follow-ups. Overall rates of drug use and smoking showed little change; however, smoking cessation was associated with successful control or cessation of alcohol use and relapse to smoking coincided with unremitted drinking. Implications for treatment are considered.

Adult↗
PubMed1982

The genetics of malignant hyperthermia: evidence for heterogeneity.

Study of phenotype and familial distribution of malignant hyperthermia (MH) suggests heterogeneity with MH possibly being a symptom of several disorders. Review of all reported family studies supports the concept of heterogeneity with autosomal dominant inheritance in about one-half of the families. There is no strong evidence for other mendelian patterns of inheritance, but sporadic and possibly multifactorially determined cases are common. MH is also seen in other musculoskeletal disorders. We report 12 Wisconsin families with MH and outline a preliminary approach to the counseling of MH patients and their families.

Bone Diseases↗
PubMed1982

Demographic disaggregation in the construction of regional econometric models: a statistical evaluation.

"A cohort-component method is used to construct historical annual age/sex disaggregations of total population. In econometric models of six substate areas [in the United States], regressions are estimated with and without the disaggregated data for five model variables expected to be dependent on the size of particular population subgroups. Statistical tests are performed to determine significant differences in residual variance of estimation with and without the disaggregated data. Although age/sex population projections may be a desired model output per se, the results indicate that the population subgroup data generally do not improve estimation of other model variables." (summary in FRE, ITA, JPN, )

Age Distribution↗