Search PubMed⌕ Search

Biomedical subjects

S Jeffery

Publications and source records attributed to S Jeffery.

At least 91 records · Page 5Linked to original sources
PubMed1992

Similar prevalence of enteroviral genome within the myocardium from patients with idiopathic dilated cardiomyopathy and controls by the polymerase chain reaction.

OBJECTIVE: To assess the prevalence and significance of enteroviral genome within myocardial biopsy specimens taken from patients with idiopathic dilated cardiomyopathy and from controls. DESIGN: Prospective evaluation of myocardial tissue for the presence of an enteroviral genome by the polymerase chain reaction. SETTING: A tertiary referral centre for patients with idiopathic dilated cardiomyopathy. PATIENTS: Tissue for the study came from 50 consecutive patients with dilated cardiomyopathy, 41 with other forms of heart disease and 34 from coroners' necropsy cases. RESULTS: Enteroviral genome was detected in 6/50 (12%) patients with dilated cardiomyopathy and 13/75 (17%) of the controls (not significant). No differences were seen between dilated cardiomyopathy patients with or without myocardial enteroviral genome in respect of age; duration of symptoms; proportion of patients with a premorbid acute viral illness, excess alcohol consumption, or hypertension; New York Heart Association functional class; measures of left ventricular function; or endomyocardial histology. Within the control group enteroviral genome was detected in 3/15 (20%) patients with ischaemic heart disease, 2/19 (10.5%) with valvar heart disease, 1/5 (20%) with specific heart muscle disease, 0/2 (0%) with congenital heart disease, and 7/34 (20.6%) cases of sudden death. During 2-52 month follow up (mean 22) 15/44 (34%) patients without myocardial enteroviral genome and 2/6 (33%) with myocardial enteroviral genome died suddenly or required orthotopic heart transplantation for progressive heart failure. CONCLUSIONS: These findings do not support the hypothesis that persistent enteroviral infection is of pathogenic or prognostic importance in dilated cardiomyopathy but they are consistent with enterovirus being a common environmental pathogen.

Adolescent↗
PubMed1992

Absence of linkage of Noonan syndrome to the neurofibromatosis type 1 locus.

Eleven families with Noonan syndrome in either two or three generations have been identified. Following the reports of subjects with features of both Noonan syndrome and neurofibromatosis type 1, these pedigrees have been studied using a number of probes at the neurofibromatosis type 1 locus (17q11). A significantly negative lod score was obtained with the intragenic probe NF1-C2, suggesting that the genes for Noonan syndrome and neurofibromatosis type 1 are not contiguous.

Alleles↗
PubMed1991

Renin and atrial natriuretic peptide restriction fragment length polymorphisms: association with ethnicity and blood pressure.

An investigation of restriction fragment length polymorphisms (RFLPs) and association with blood pressure was carried out for the candidate genes coding for renin (REN) and atrial natriuretic peptide (ANP). The relationship between blood pressure, REN and ANP gene RFLPs was tested in a population of black Afro-Caribbean and white European subjects sampled randomly from family practice registers. Upper and lower quintiles for diastolic blood pressure were selected for analysis. Digests of DNA were prepared from leucocytes and RFLPs were determined using Southern blotting analysis with REN and ANP gene probes. There were highly significant ethnic differences found for BglI, Bg/lI and TaqI polymorphisms with 5'REN probe and for BglI polymorphism with an ANP probe. There was also an association between blood pressure and the BglI/REN polymorphism in Afro-Caribbeans but not with any other polymorphisms studied in either ethnic group. The findings show significant ethnic RFLP differences at the gene loci for both renin and ANP and provide evidence for a possible link between variations within or close to the renin gene and elevated blood pressure in Afro-Caribbeans.

Aged↗
PubMed1991

Adult polycystic kidney disease in a kindred of West Indian origin exhibits linkage with the 3'HVR probe on chromosome 16.

In a large pedigree of Caribbean origin with adult polycystic kidney disease, linkage has been established to the 3'HVR probe on chromosome 16. Although there are five different fathers in this pedigree, only one of whom was available for DNA analysis, the polymorphic nature of 3'HVR has enabled gene tracking to be carried out. The same allele cosegregates with the disease in every affected family member.

Adult↗
PubMed1991

Use of probes for ZFY, SRY, and the Y pseudoautosomal boundary in XX males, XX true hermaphrodites, and an XY female.

Three XX males, two XX true hermaphrodites, and an XY female were studied for possible deletions using probes for the recently characterised SRY gene and the pseudoautosomal boundary. The XX males and true hermaphrodites were negative for all three probes, while the XY female was positive. One XX male and one XX true hermaphrodite were sibs. A previous sib pair of an XX male and an XX true hermaphrodite have been shown to be positive for Y chromosomal material near the pseudoautosomal boundary. Thus, both phenotypes can be produced from different mutations, some involving the SRY gene and others not.

Adolescent↗
PubMed1991

Immobilization induces carbonic anhydrase III in type II fibers of rat skeletal muscle.

The amount and fiber distribution of carbonic anhydrase III (CA III), a major soluble protein in Type I muscle fibers, were studied during cast immobilization of rat hindlimb with the ankle in plantar or dorsiflexion. The concentration of CA III increased two- (p less than 0.05) and three- (p less than 0.01) fold in the shortened and lengthened tibialis anterior muscle during a 3-weeks immobilization period, respectively. After 6 weeks of immobilization the increase was even greater (p less than 0.001). Concomitantly, the number of CA III positive fibers in the lengthened muscle increased so that almost all fibers were positive. In the soleus muscle no significant change in the CA III concentration was seen. On the basis of actomyosin ATPase staining, the transition of Type IIb fibers towards Type IIa occurred in the tibialis anterior muscle, whereas in the soleus muscle a transformation of Type I fibers towards Type IIa fibers occurred. Therefore, the increase in the muscle CA III concentration seems to be associated with a cell transformation of the muscle towards a more oxidative type.

Animals↗
PubMed1991

Detection of CAIII mRNA in rat skeletal muscle and liver by in situ hybridization.

We carried out a variety of in situ methods of hybridization on rat liver and rat skeletal muscle using 35S-labeled or biotin-labeled rat carbonic anhydrase III (CAIII) cDNA clone. The methods were compared and evaluated. Use of the biotin system produced defined but nonspecific results which were shown not to be due to the biotinylated cDNA probe binding to the mRNA in the muscle sections. This artifact was shown to persist despite various attempts to eliminate it. Alternatively, using 35S-labeled cDNA gave reproducible results which were shown to be consistent with probe binding specifically to mRNA in the muscle section.

Adenosine Triphosphatases↗
PubMed1990

Chronic stimulation-induced effects point to a coordinated expression of carbonic anhydrase III and slow myosin heavy chain in skeletal muscle.

Chronic low-frequency stimulation of rat fast-twitch muscle induces 3.7-fold elevations in cytochrome c oxidase activity, but remains without effect on carbonic anhydrase III (CAIII) mRNA and protein. This is in contrast with the situation in the rabbit where chronic stimulation elicits more than 10-fold elevations in CAIII activity and mRNA content which coincide with an enhanced expression of the slow myosin heavy chain (HCI). Since chronic stimulation of rat muscle does not enhance the expression of HCI, we conclude that CAIII is expressed in parallel with HCI and, therefore, is present only in type I and C fibers.

Animals↗
PubMed1990

The episodic secretory pattern of growth hormone regulates liver carbonic anhydrase III. Studies in normal and mutant growth-hormone-deficient dwarf rats.

Carbonic anhydrase III (CAIII) occurs in male rat liver at concentrations twenty times those in the female, and is sensitive to the pattern of growth hormone (GH) release. Males release GH episodically and have high concentrations of CAIII; females produce GH in a more continuous fashion and have lower CAIII levels. In normal female rats, the endogenous GH secretory pattern was masculinized, either by regular injections of GH-releasing factor (GRF) or by intermittent infusions of somatostatin (90 min on/90 min off). Both treatments induced regular GH pulses and stimulated growth, but only intermittent somatostatin infusions raised CAIII levels (controls, 1.5 +/- 0.5; somatostatin-treated, 9.0 +/- 2.9 micrograms/mg; means +/- S.D.). GRF pulses (4 micrograms every 4 h) did not however raise CAIII levels (controls 1.8 +/- 0.5; GRF-treated 1.4 +/- 0.4 micrograms/mg). Surprisingly, hepatic CAIII is also sexually dimorphic (males, 18.8 +/- 3; females, 2.22 +/- 0.4 micrograms/mg) in a GH-deficient dwarf rat strain which has low plasma GH levels without 3-hourly GH peaks. Intermittent somatostatin infusions in female dwarf rats partially masculinized hepatic CAIII, an effect reduced by co-infusion with GRF. This CAIII response was not secondary to growth induction, since neither somatostatin nor GRF stimulated growth in dwarf rats, and pulses of exogenous GH stimulated growth in female dwarfs without masculinizing CAIII levels. Furthermore, continuous GH infusion in male dwarf rats partially feminized hepatic CAIII levels (to 9.1 +/- 2.4 micrograms/mg), whereas infusions of insulin-like growth factor-1, which induced the same body weight gain, did not affect hepatic CAIII (20.8 +/- 6 micrograms/mg). These results show that hepatic CAIII expression is highly sensitive to the endogenous GH secretory pattern, independent of growth. They also implicate the low basal GH levels between pulses, rather than the peak GH levels, as the primary determinant of the sexually dimorphic hepatic CAIII expression in the rat.

Animals↗
PubMed1990

Plasma atrial natriuretic peptide after the Fontan procedure and total cavopulmonary connexion.

Plasma atrial natriuretic peptide was measured in 10 children undergoing the Fontan procedure and 3 children undergoing total cavopulmonary connexion. There was no significant difference in pre-operative plasma levels, but post-operative levels were significantly higher 48 hours after cardiopulmonary bypass in the Fontan group. There was no significant difference in plasma arginine vasopressin levels either pre- or post-operatively. Post-operative pleural effusions occurred in only 2 of the 10 patients undergoing the Fontan procedure, but were present in all 3 of those undergoing total cavopulmonary connexion. The release of atrial natriuretic peptide is an appropriate homeostatic response to volume loading and the impairment of this response in the early post-operative period may be of clinical importance.

Arginine Vasopressin↗
PubMed1990

Hormonal manipulation and neonatal imprinting of carbonic anhydrase isozymes in rat liver.

Thyroidectomy has a feminizing effect on the carbonic anhydrase isozymes II and III in male rat liver. These isozymes are known to be sexually differentiated but no treatment so far administered has produced total feminization and this is also true for thyroidectomy. Neonatal castration, however, does produce this result, suggesting the possibility of androgen imprinting for these isozymes during the neonatal period.

Age Factors↗
PubMed1990

Expression of carbonic anhydrase in neisseriae and other heterotrophic bacteria.

A diverse range of heterotrophic bacteria was screened for the presence of carbonic anhydrase (CA) activity, sensitivity to inhibition of growth by acetazolamide (CA inhibitor), and the presence of protein binding monospecific antibody prepared against purified Neisseria sicca CA. CA activity was demonstrated only in strains of N. sicca and N. gonorrhoeae. However, all Neisseria strains, including various isolates of N. meningitidis and N. lactamica, were sensitive to acetazolamide, when grown in air, and showed serological cross-reaction with N. sicca CA. Strains of other genera were resistant to acetazolamide. A number of strains including members of the genera Pseudomonas, Staphylococcus, Streptococcus, Serratia and Proteus also strongly expressed a gene product(s) immunologically related to CA. The presence of CA cross-reacting proteins, which lack hydrase activity, is discussed in relation to the function of the various mammalian CA isoenzymes.

Acetazolamide↗
PubMed1990

Somatostatin and its physiological significance in regulating the episodic secretion of growth hormone in the rat.

Somatostatin (SS) is a powerful inhibitor of growth hormone (GH) secretion both in vitro and in vivo, and is generally regarded as having a negative influence on GH secretion and growth. In the conscious rat, the GH secretory pattern, the response to repeated injections of GH-releasing hormone (GHRH), and the feedback mechanism by which GH regulates its own release are all sexually dimorphic and probably reflect a sexually dimorphic pattern of SS release. Prolonged infusions of SS initially block GHRH-induced GH release but responses begin to break through with time. Withdrawal of SS induces a rebound release of GH in vivo, largely dependent on the release of endogenous GHRH. Prolonged exposure to intermittent infusions of SS in normal female rats produces a paradoxical growth response by inducing regular peaks of GH secretion whereas continuous infusions of SS do not. This response is GH-dependent, and is not due to other effects of SS since intermittent infusions of SS do not increase growth in dwarf rats which are deficient in pituitary GH. The sex differences in GH secretion are also reflected in the expression of several GH-dependent liver enzymes, one of which, carbonic anhydrase III, responds to manipulations of the endogenous secretory pattern by SS in both normal and dwarf rats, and appears to be sensitive to differences in basal, rather than peak, GH levels.

Animals↗
PubMed1990

Plasma concentration of atrial natriuretic peptide in spontaneous atrioventricular re-entrant tachycardias of childhood.

Plasma atrial natriuretic peptide was measured in 13 children between the ages of 1 week and 2 years 9 months during atrioventricular re-entrant tachycardia and 15 minutes after the restoration of sinus rhythm. There was a significant decline in atrial natriuretic peptide during sinus rhythm. Plasma concentrations of the peptide were significantly higher during tachycardia in seven infants under 1 year than in the six older children. The heart rates and the duration of tachycardia were not significantly different in the two age groups. Cardiac failure was present in five of seven children under 18 weeks of age during tachycardia but in none of the older children. The plasma concentration of atrial natriuretic peptide did not significantly correlate with duration of tachycardia or heart rate. If tachycardia occurs in young infants the low functional reserve capacity of the developing heart leads to cardiac failure more frequently and it is likely that this was the cause of the significantly higher plasma concentration of atrial natriuretic peptide in the younger children.

Adenosine↗
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↗
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↗