PubMed Health⌕ Search

Biomedical subjects

N D Carter

Publications and source records attributed to N D Carter.

At least 91 records · Page 5Linked to original sources
PubMed1990

Dystrophin expression and genotypic analysis of two cases of benign X linked myopathy (McLeod's syndrome).

DNA extraction and Southern blot analysis of two cases of McLeod's syndrome showed restriction fragments identical to normal controls using probes from the Xp21 (1-2) region, in contrast to striking deletions found in two other McLeod phenotypes studied in the USA. The McLeod locus is adjacent to Duchenne muscular dystrophy (DMD) and dystrophin immunocytochemistry showed that expression is normal in muscle from the two McLeod cases in spite of the mild DMD-like myopathy.

Blotting, Southern↗
PubMed1989

Plasma membrane potential of lymphocytes from ataxia telangiectasia patients.

The plasma membrane potential of lymphocytes prepared from ataxia telangiectasia (AT) patients and normal subjects was assessed using the optical indicator bis-(3-phenyl-5-oxoisoxazol-4-yl) pentamethineoxonol (oxonol-V). AT lymphocytes had a potential of -46 +/- 9 mV and normal lymphocytes had a potential of -63 +/- 4 mV. The intracellular cation content (Na+ and K+) of AT and normal lymphocytes was similar. AT and normal lymphocytes were both depolarized by extracellular K+ and to a similar extent. This study indicates that one feature characterizing ataxia telangiectasia is a modification of the ability of the lymphocyte cell membrane to sustain a normal membrane potential.

Adolescent↗
PubMed1988

Induction of carbonic anhydrase III mRNA and protein by denervation of rat muscle.

Carbonic anhydrase III (CAIII) protein and mRNA amounts in fast- and slow-twitch rat muscles were examined after resection of the sciatic nerve. Striking changes occur in the fast-twitch anterior tibialis (AT) and extensor digitorum longus (EDL) muscles, where CAIII protein and mRNA are increased several-fold 16 days after denervation. The data suggest that these changes are regulated in part by changes in gene transcription and that they perhaps signal a fast-to-slow fibre type transition in these denervated muscles. AT and EDL show some differences in the effects of denervation, which are suggestive of variation in the timing of denervation-induced responses and/or the CAIII protein/mRNA turnover rates in the two muscles.

Actins↗
PubMed1988

The effects of aging on carbonic anhydrase concentrations in rat liver and skeletal muscle.

The isoenzymes carbonic anhydrase II (CAII) and III (CAIII) have been measured by radioimmunoassay in the livers of male and female rats aged from 21 to 800 days. No sexual dimorphism at 21 days was found, but from 50 to 400 days both isoenzymes show sexual differences. From 600 days onwards, these differences are less apparent. CAIII concentrations in two 'fast' fibre muscles and one 'slow' fibre muscle have been determined. There is no sexual dimorphism in muscle, but a wide variation between individuals was observed. Fast muscles show maximal CAIII levels at 800 days, whereas in slow muscle the concentration of the isoenzyme is declining at this time.

Aging↗
PubMed1988

Characterisation of cDNA clones for rat muscle carbonic anhydrase III.

cDNA clones for rat muscle carbonic anhydrase III have been isolated from a lambda gt-11 library and sequenced. Comparison with human CAIII cDNA showed about 90% homology to rat. The rat clones were used to estimate mRNA from liver and muscle on Northern blots and showed that the sexual dimorphism of CAIII in rat liver relates to a difference in mRNA levels.

Animals↗
PubMed1987

Induction of rat muscle carbonic anhydrase by denervation demonstrated with immunofluorescence.

Immunofluorescence microscopy of carbonic anhydrase III (CA III) was performed on sections of rat anterior tibialis (AT), extensor digitorum longus (EDL) and soleus after denervation. In contralateral control muscles, CAIII was located only in type I fibres whereas following the operation, CAIII was markedly induced in type II fibers of all the muscles, most strikingly in EDL.

Animals↗
PubMed1987

Human milk and preterm formula compared for effects on growth and metabolism.

Metabolic tolerance to a 'premature formula' feed was studied in a group of small immature infants, mean (SD) gestation 27.8 (1.4) weeks. Ten infants weighing 880-1295 g at the time of the study were fed on SMA low birthweight formula for a mean (SD) of 23.5 (5.5) days and were compared with 10 who were fed on expressed breast milk for 25.8 (6.1) days. The infants were well matched for weight, gestation, and postnatal age at the time of the study and were receiving full enteral feeds. They were investigated by balance techniques and plasma sampling on at least two occasions. Ten larger infants weighing 1330-1740 g and being fed on the same formula feed were also studied as an additional control group. Formula fed infants retained more nitrogen and gained weight faster. Plasma phosphorus concentrations were higher in the group fed on the formula feed, and alkaline phosphatase activity was lower. There were no significant differences in plasma concentrations of urea, electrolytes, or albumin or in acid base status. Taurine and arginine concentrations were higher in the group being breast fed, but there were no other significant differences in plasma amino acids, and no toxic concentrations occurred after either feed. The results of this study show that this formula (and presumably other feeds of similar composition) seem to be metabolically safe for the smallest infants.

Anthropometry↗
PubMed1987

Thyroidectomy significantly alters carbonic anhydrase III concentration and fiber distribution in rat muscle.

Thyroidectomy has a dramatic effect on rat muscle, greatly increasing the number of Type I fibers and the concentrations of carbonic anhydrase III (CAIII) in the muscle. Carbonic anhydrase III is not confined to the Type I fibers, as was previously believed, but also occurs in fibers that exhibit a level of ATPase staining less than that of 2A fibers but greater than 2B. These fibers are rare in normal muscle but become numerous after thyroidectomy, when they stain heavily for CAIII.

Adenosine Triphosphatases↗
PubMed1986

Physiological zinc-binding proteins of medium molecular weight in the rat gut.

1. Gel filtration on Sephadex G 75 was used to separate the medium-molecular-weight zinc-binding proteins from the soluble fractions from the duodenal and jejuno-ileal segments of the rat gut at 30 min after the intragastric administration of a tracer dose of 65Zn. These proteins were resolved by ion-exchange chromatography on DEAE cellulose. 2. In both the duodenum and jejuno-ileal segment an appreciable fraction of the total soluble Zn was bound in a protein fraction that resembled metallothionein (MT) in its behaviour on gel filtration. These fractions, however, were not homogeneous, but contained several medium-molecular-weight Zn-binding proteins. In the duodenum, but not in the jejuno-ileal segment, two of these proteins appeared to be the isometallothioneins, ZnMT-I and ZnMT-II. 3. These results suggest a possible role for MT in the binding of newly-absorbed Zn in the duodenal mucosal cells. They also show that gel filtration alone is insufficient for the identification of MT in the intestine.

Animals↗
PubMed1986

Immunocytochemical localization of carbonic anhydrase isozymes I, II, and III in rat skeletal muscle.

Specific antisera were raised against the three carbonic anhydrase (CA) isozymes, CAI, CAII, and CAIII, and were used to determine the fiber distribution of these isozymes in skeletal muscle. Fiber types were determined by ATPase staining, and the CA isozymes were detected using a peroxidase-anti-peroxidase (PAP) technique. All three isozymes were present in type I fibers; CAII and CAIII were exclusive to these fibers, and CAI were also present in some small type 2A fibers.

Actomyosin↗
PubMed1986

Effects of hypophysectomy and growth hormone infusion on rat hepatic carbonic anhydrases.

Rat liver exhibits a reversed sexual dimorphism of its two endogenous soluble carbonic anhydrase (CA) isozymes, CA II and CA III. Normal males have hepatic CA III concentrations ten-twenty times those in the female, while female liver contains two-three times more CA II than the male. Hypophysectomy abolishes this sexual differentiation, having no effect on male liver but producing isozyme concentrations in the female liver similar to those in the male. Infusion of a continuous level of GH into male rats induces a female-like isozyme pattern for both CA II and CA III.

Animals↗
PubMed1985

Fetal plasma carbonic anhydrase III in prenatal diagnosis of Duchenne muscular dystrophy.

Carbonic anhydrase III (CAIII), a skeletal-muscle-specific enzyme which is elevated in the plasma of Duchenne muscular dystrophy (DMD) patients, was measured by radioimmunoassay in fetal plasma in order to evaluate its application to prenatal diagnosis of DMD. Using fetoscopy, pure fetal blood samples were taken at 17-24 weeks gestation from 25 fetuses at risk for DMD and from 78 control fetuses. Care was taken in the handling and storage of all samples. Normal sons were born in eight cases at risk for DMD. The CAIII levels in the infants were not significantly different from those of the control infants. Pregnancies were terminated in the remaining 17 at-risk cases. The CAIII levels in the fetuses were significantly different (p = 0.0034) from those of the control fetuses, although the distributions overlapped. Based on prior maternal risk, seven affected fetuses were expected in the terminated group; five had CAIII levels at or above the 95th centile of the control range. It is suggested that measurement of CAIII achieves partial discrimination between affected fetuses and their normal at-risk brethren.

Carbonic Anhydrases↗
PubMed1985

Evaluation of carrier detection of Duchenne muscular dystrophy using carbonic anhydrase III and creatine kinase.

Carbonic anhydrase III (CAIII) and creatine kinase (CK) were measured in plasma samples from a series of females at-risk as carriers of Duchenne muscular dystrophy and compared with control groups. Both plasma CAIII and CK levels were raised in a proportion of carriers. Although measurement of CAIII and CK was no more successful in identifying carriers than CK alone, CAIII could fulfill a useful confirmatory role, particularly for cases with a marginally elevated CK or where the sample is poorly preserved. The difference between the CK and CAIII results could indicate biochemical heterogeneity in the expression of Duchenne muscular dystrophy.

Carbonic Anhydrases↗
PubMed1985

Rat liver carbonic anhydrase I is not sexually dimorphic but is estrogen repressible.

Carbonic anhydrase (CA) isozymes CAII and CAIII are known to exhibit sexual dimorphism in rat liver, and the levels of these isozymes are affected by sex hormones. In this paper we show that the isozyme CAI is present at low levels in rat liver, with no difference in concentration between male and female rats. Estrogen and diethylstilbestrol reduce CAI levels in both sexes.

Animals↗
PubMed1984

Carbonic anhydrase II isoenzyme in rat liver is under hormonal control.

A specific and sensitive radioimmunoassay for rat carbonic anhydrase II (CAII) was developed. Rat livers were perfused with Ringer's solution and the hepatic CAII was measured. Concentrations of CAII in female liver were significantly higher than those in male liver. Castration increased the concentration in male liver, though not to that in females, and diethylstilboestrol treatment of castrated males gave values higher than those in females.

Animals↗