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Biomedical subjects

M Taylor

Publications and source records attributed to M Taylor.

At least 523 records · Page 29Linked to original sources
PubMed1988

Proto-oncogenes and embryonic development.

The role of proto-oncogenes in embryonic development was investigated using one of the most characterized vertebrates, the amphibian Xenopus laevis. Genes which belong to the major proto-oncogene families have been detected in Xenopus genome. The developmental control of the myc gene was assayed using a characterized Xenopus myc probe and specific antibodies. The myc gene is highly expressed as a stable maternal mRNA in oocyte, and an unfertilized egg contains 5 X 10(5)-fold the myc RNA content of a proliferative somatic cell. The myc RNA store is evenly distributed in the oocyte and the egg. Fertilization triggers a post-transcriptional control of the gene and the RNA store is progressively degraded to a constitutive value of 10 to 30 myc RNA copies registered per gastrula embryonic cell. The 62K myc protein is accumulated late in oogenesis. This uncoupling of myc expression and cell proliferation appears as a specific developmental regulation of the myc gene, adapted to the series of rapid cell cleavages occurring after fertilization.

Animals↗
PubMed1988

Radiographic signs of union of scaphoid fractures. An analysis of inter-observer agreement and reproducibility.

Inter-observer agreement and reproducibility of opinion were assessed for the radiographic diagnosis of union of scaphoid fractures on films taken 12 weeks after injury. Weighted kappa statistics were used to compare the opinions of eight senior observers reviewing 20 sets of good quality radiographs on two occasions separated by two months. There was poor agreement on whether trabeculae crossed the fracture line, whether there was sclerosis at or near the fracture and on whether the proximal part of the scaphoid was avascular. As a consequence, agreement on union also was poor; it appears that radiographs taken 12 weeks after a scaphoid fracture do not provide reliable and reproducible evidence of healing.

Carpal Bones↗
PubMed1988

Description and recording physical signs in suspected child sexual abuse.

The identification of child sexual abuse may depend on the accurate interpretation of abnormal physical signs. Therefore, it is necessary to have a consistent vocabulary and a full and accurate record of the findings (Report of the Inquiry into Child Abuse in Cleveland 1987). Our suggestions are intended to promote the development of a standard acceptable to all concerned with these problems.

Child↗
PubMed1988

Mannose-mediated targeted immunoadjuvant action of liposomes.

The effect of the ligand mannosylated albumin, covalently coupled to the surface of tetanus toxoid-containing dehydration-rehydration vesicles (DRV), on their adjuvanticity was investigated. Toxoid-containing DRV coated with mannosylated albumin bound in vitro to mouse (BALB/c) peritoneal macrophages selectively and to a greater extent than non-mannosylated DRV. ELISA assays of anti-toxoid IgG1 and IgG2b in the sera of BALB/c mice immunized with various toxoid-containing DRV preparations suggest that mannosylated liposomes are superior in immunoadjuvant action to conventional ones. Such targeted adjuvanticity appears to be influenced by the number of ligand molecules available on the surface of liposomes rather than the number of mannose residues on albumin.

Adjuvants, Immunologic↗
PubMed1988

An evaluation of serum CA 50 levels in cancer using a time-resolved fluoroimmunoassay.

The CA 50 levels in serum samples from 440 patients were estimated using a dissociated enhanced lanthanide immunofluorimetric assay. The distribution was similar to CA 50-RIA assays. Raised levels (greater than 14 U/ml) were present in 95% pancreatic cancer, 68% hepatoma, 54% advanced colorectal cancer, 58% advanced breast cancer and 48% lung cancer. High values were observed in adenocarcinoma of the lung, and were related to tumour mass in small cell lung cancer. CA 50 is independent of CEA. The marker is of considerable potential in pancreatic cancer where the majority of patients express the Can 50 Ag.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1988

Conceptual perspective taking: children's ability to distinguish what they know from what they see.

One part of understanding the difference between external reality and mental life involves the ability to differentiate what is seen from what is known. This research investigated the development of children's ability to make the seeing-knowing distinction in the context of conceptual perspective taking. In Experiment 1, 2 developmental levels were found to account for children's performance when asked about a naive observer's knowledge of the identity of objects. At Level 1 (from about 4-6 years of age), children tend to behave as if seeing part of an object is sufficient for someone to share the children's knowledge of the object's identity. Even at 4 years of age, however, children often realize that a small, nondescript part of an object does not provide sufficient information for an observer to know the object's present actions (e.g., that a rabbit is jumping) or nonperceptual information about the object (e.g., that the rabbit has a brother). At Level 2 (after about 6 years of age), children appreciate that someone who shares their visual perspective may not be able to identify the object in view. In Experiment 2, 4- and 6-year-old children were given training designed to make them aware that there may be many interpretations for the same information. 4-year-old children in the training condition performed significantly better on subsequent perspective-taking tasks.

Child↗
PubMed1987

Age-related decreases in the concentration of Met- and Leu-enkephalin and neurotensin in the basal ganglia of rats.

Previous studies using radioimmunoassay procedures have failed to show age-related changes in the concentration of Met- and Leu-enkephalin or neurotensin in rat basal ganglia. In contrast, using a combined high-pressure liquid chromatography (HPLC)-radioimmunoassay (RIA) technique we now report considerable decreases in the levels of these neuropeptides in areas of basal ganglia of 22 months old-compared to 3 months-old male Wistar rats. The concentration of Met-enkephalin was greatly reduced in the striatum and nucleus accumbens, but not in substantia nigra, of old compared to young animals. There was a similarly large decrease in Leu-enkephalin content in striatum of old rats with less marked decreases occurring in both the nucleus accumbens and substantia nigra. Neurotensin levels in the striatum and substantia nigra were greatly reduced in old rats, with a less marked decrease in the nucleus accumbens.

Aging↗
PubMed1987

Interpersonal problem-solving deficits in self-poisoning patients.

Self-poisoning patients (n = 40) were compared with psychiatric patients (n = 40) and nonpatient controls (n = 20) on measures of interpersonal problem-solving skills and locus of control in an effort to determine the importance of these cognitive and personality variables in self-poisoning behavior. The psychiatric and self-poisoning groups showed deficits on measures assessing interpersonal problem solving when compared with nonpatient controls. The self-poisoning group performed below the level of the psychiatric patients on all except one test, on which they performed at the level of the psychiatric group. Locus of control did not differentiate self-poisoning patients from nonpatient controls, and it was concluded that this variable is not an important factor in self-poisoning behavior.

Adolescent↗
PubMed1987

Placental markers of human exposure to polychlorinated biphenyls and polychlorinated dibenzofurans.

Our studies have evaluated biochemical changes in placentae from humans exposed to rice oil contaminated with polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) in Taiwan. Placentae were obtained from nonsmoking women 4 to 5 years after the exposure had occurred. The exposed individuals ingested approximately 1 to 3 g PCBs and 5 mg PCDFs, and many exhibited symptoms characteristic of PCB poisoning. This disease was termed "Yu-Cheng" in Chinese. Based on data from experimental animal models, we examined a number of parameters in placentae from control and exposed women, including arylhydrocarbon hydroxylase (AHH) activity, cytochrome P-450 isozymes, epidermal growth factor (EGF) receptor binding properties and actions, and Ah receptor. We also quantified concentrations of various PCB and PCDF congeners known to be present in the contaminated rice oil. Our results revealed a dramatic elevation in placental AHH activity in samples from PCB/PCDF-exposed women. This increase in enzyme activity was associated with a parallel increase in placental microsomal protein immunochemically related to cytochrome P-450 form 6 [derived from 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced rabbit lung]. No other cytochrome P-450 isozyme was detected in placental preparations, and the form 6 homolog was found only in placentae from exposed women. EGF receptor-mediated autophosphorylation capacity was significantly diminished in PCB/PCDF placentae, but this effect was not associated with changes in plasma membrane EGF receptor binding properties (Kd and Bmax). The EGF receptor autophosphorylation effect correlated well with the decrease in birthweight observed in offspring of exposed women, suggesting that this biochemical event might provide a good marker of effect for the toxic halogenated aromatics.

Adolescent↗
PubMed1987

Hexose transport regulation in cultured fibroblasts derived from normal and type II diabetic patients.

The kinetics of saturable and nonsaturable sugar transport were studied in normal and Type II diabetic cultured skin fibroblasts under fast or slowly growing conditions. The Km of hexose transport for fast and slow-growing normal fibroblasts was 1.38 +/- 0.3 and 0.88 +/- 0.12 mM, respectively, while those of the diabetic fibroblasts were 1.57 +/- 0.29 and 0.8 +/- 0.19 mM, respectively. The respective transport Vmax for normal and diabetic fast-growing cells was 13.9 +/- 0.8 and 12.95 +/- 2.4 nmoles 2-DG/mg protein/min. For slowly growing cells of both groups, a transport Vmax of 11.5 +/- 2.4 and 11.3 +/- 1.7 nmoles 2-DG/mg protein/min was obtained. No significant differences were observed in the Km or Vmax of hexose transport under these various growth conditions between normal and diabetic cell cultures. Nonsaturable sugar uptake as determined by L-glucose or cytochalasin B inhibited 2-DG uptake was variable, but no significant differences were observed between the normal and Type II diabetic cells. The activation energies for saturable and nonsaturable sugar uptake were not different among the two donor groups. Insulin stimulation of hexose transport was studied in the presence and absence of dexamethasone (5 X 10(-6) M) at varying insulin concentrations. No difference was observed in the amount of insulin necessary to obtain a maximum stimulatory response (approximately 33 nM insulin in both groups). Also, the insulin concentration required to achieve a one-half maximal response was not significantly different in the donor groups (i.e., 3.53 +/- 0.6 nM for normals and 3.98 +/- 1.1 nM for diabetics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Inheritance of human-erythrocyte Gerbich blood group antigens.

The blood group-antigenic determinant Gerbich was first described greater than 25 years ago, but its mode of inheritance has not been established. We performed protein immunoblotting by means of anti-beta sialoglycoprotein (SGP) and anti-gamma SGP reagents. The anti-beta SGP was a monoclonal antibody that reacts with normal beta SGP and with the abnormal beta-related SGPs associated with Gerbich and Yus types of Ge-negative red cells. In the families studied, we have shown that the products of the Ge alleles are inherited in an autosomal codominant manner.

Alleles↗
PubMed1987

The basal cell naevus syndrome.

The basal cell naevus syndrome, classically described as a triad of multiple basal cell carcinomas, odontogenic keratocysts of the jaws and skeletal anomalies, is well known by oral and plastic surgeons and dermatologists. This paper describes the clinical features in a series of 60 patients, and highlights some problems of diagnosis and management.

Adolescent↗
PubMed1986

The regulation of phosphofructokinase in epimastigote Trypanosoma cruzi.

Glycosomal (microbody)-enriched fractions prepared from epimastigote Trypanosoma cruzi were used as a partially purified source of phosphofructokinase. D-Fructose 6-phosphate showed sigmoidal kinetics at pH 7.0, but hyperbolic kinetics at pH 8.0. Various adenosine nucleotides were positive effectors; 5'-AMP was the most powerful. ATP showed hyperbolic kinetics under all conditions tested. Several described inhibitors and activators of mammalian phosphofructokinase were without significant effect on the trypanosomal enzyme; the absence of effect of D-fructose 2,6-bisphosphate is of particular note.

Adenosine Diphosphate↗