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Biomedical subjects

A Templeton

Publications and source records attributed to A Templeton.

173 records · Page 10Linked to original sources
PubMed1976

Maternal blood-gases, PAo2--Pao2), hysiological shunt and VD/VT in normal pregnancy.

Serial measurements of maternal blood-gases, alveolar-to-arterial oxygen tension difference (PAO2--PaO), calculated pulmonary venous admixture (physiological shunt), deadspace/tidal volume ratio (VD/VT), and respiratory minute volume have been made in a carefully selected group of normal pregnant patients at 12, 24, 32 and 38 weeks of gestation and 5 weeks after delivery. All measurements were made in the semi-recumbent position with a left lateral pelvic tilt. Mean arterial PO2 was consistently greater than 100 mm Hg throughout pregnancy, although the value decreased from 106.4 mm Hg at 12 weeks of gestation to 101.8 mm Hg at the 38th week. Despite this decrease there was no change in (PAO2--PaO2) VD/VT, or percentage shunt with increasing gestation; nor did these values differ significantly from non-pregnant values in the same patients.

Adult↗
PubMedDate not supplied

A prospective study of the relationship between semen quality and fertility in cases of unexplained infertility.

The male partners of 68 couples exhibiting 5.1 +/- 0.3 (SEM) years of unexplained infertility were assessed using the conventional criteria of semen quality, the movement characteristics of the spermatozoa and the outcome of the zona-free hamster egg penetration test. After a follow-up period of 2.3 +/- 0.06 (SEM) years, 25 (37%) of these patients were found to have initiated a pregnancy, thereby permitting an analysis of those aspects of semen quality which most accurately predicted their subsequent fertility. A multivariate discriminant analysis revealed that the conventional semen profile, per se, was not of significant value in discriminating the incidence of pregnancy. However, significant discrimination (P = 0.0173) was obtained when the postcapacitation movement characteristics of the spermatozoa were incorporated into the analysis. The accuracy of this prognosis was further increased if either the duration of infertility or the outcome of the zona-free hamster egg penetration test was taken into consideration. Overall classifications of fertility were then 76.3% and 76.5% accurate, respectively. These results suggest that in vitro assessments of human sperm function are of significant value in evaluating male fertility.

Animals↗
PubMedDate not supplied

Experiences in method development for the analysis of in vitro study solutions for content.

Effects of drugs on the cardiovascular system are required to be assessed as part of safety pharmacology, in particular using the in vitro Human Ether-a-go-go Related Gene Product (HERG) and Purkinje fibre studies and can be used to predict safety margins prior to administration to man. Recent International Conferences on Harmonization (ICH) regulations, draft ICHS7B guidelines, indicate that levels of drug in bath solutions used should be measured if quantitative data are to be obtained for the estimation of safety margins. To accurately measure drug concentrations in bath solutions, a validated analytical method is required. This method is required to be accurate, precise, specific, and robust, and due to the increased potency of new drugs, liquid chromatography with mass spectrometric detection (LC-MS) has become the method of choice. Recent experiences validating methods for the analysis of a wide range of drugs in bath solutions has presented a major issue regarding the solubility of some drugs in bath solutions. This has resulted in the requirement of a different approach to the analysis of, in particular, lipophilic drugs that has in turn highlighted the potential for the significant overestimation of the drug concentration in these bath solutions and therefore inaccurate calculation of safety margins.

Calibration↗
PubMedDate not supplied

A systematic review of the prevalence of Chlamydia trachomatis among European women.

The study aim was to establish by systematic review the prevalence of asymptomatic Chlamydia trachomatis infection of the lower female genital tract in Europe and also to assess the extent and effect of screening. The search process was wide ranging, using the electronic databases Medline, Embase and Aidsline and the Internet using the search engines Netscape and Euro-ferret. Studies published in any language during 1980-2000 were included if they unambiguously reported prevalence of C. trachomatis infection in asymptomatic women, and were assessed qualitatively. From >300 papers which quantified C. trachomatis urogenital infection, only 14 studies met the inclusion criteria: four from the UK, two from Sweden, two from The Netherlands, and one each from Bulgaria, France, Finland, Hungary, Italy and Spain. In only one study had screening taken place. The prevalence of C. trachomatis in unscreened asymptomatic women in Europe ranges from 1.7 to 17% depending upon the setting, context and country. The mode was -6% for women seeking contraception, and 4% for women having cervical smears. In conclusion, this review confirms high prevalence rates of C. trachomatis infection among asymptomatic women in many European settings.

Chlamydia Infections↗
PubMedDate not supplied

HK/LK polymorphism and its genetic determination in Speke's gazelle.

Concentrations of potassium (K) and sodium (Na) were determined in the erythrocytes of 28 members of an interbreeding herd of Speke's gazelle. The distribution of K concentrations and Na/K concentration ratios suggested the presence of the high-K/low-K (HK/LK) polymorphism known in erythrocytes of domestic bovids. The pedigree of the herd of gazelles is known completely, permitting examination of the inheritance of HK/LK polymorphism by overlaying the distribution of phenotypes on the pedigree. Statistical analyses clearly indicate a strong genetic component in the phenotypic variability that is entirely consistent with a single autosomal locus, two-allele mode of inheritance, with the LK allele being dominant. This is the first demonstration of HK/LK polymorphism in a wild bovid species. The evidence indicates that HK/LK polymorphism is of considerable evolutionary age, is of monophyletic origin, and is maintained by selection.

Alleles↗
PubMedDate not supplied

Structure and history of African elephant populations: I. Eastern and southern Africa.

Patterns of restriction site variation within mitochondrial DNA (mtDNA) of 270 individuals were used to examine the current structure of savanna elephant populations and to infer historical patterns of gene flow across eastern and southern Africa. Elephants have a complex population structure characterized by marked subdivision at the continental level (Fst = 0.39; 95% confidence interval 0.19-0.58), and isolation by distance at the regional level. However, phylogeographic analysis revealed evidence of protracted gene flow across the continent. First, one relatively derived haplotype was found at all sampling locations. Second, haplotypes representing exceptionally divergent (up to 8.3%) mitochondrial clades were found to coexist at distant (> 2,000 km) sampling locations. In the few other species characterized by sympatric individuals bearing such divergent haplotypes, all such individuals were found to coexist within limited geographical regions. Accordingly, pronounced mitochondrial divergence within populations is often attributed to ancestral isolation in allopatry, followed by secondary contact. The patterns within elephants do not accord with ancestral isolation in allopatry. Given the exceptional mobility of elephants, a geographical barrier is unlikely to have obstructed gene flow between regions for long enough to produce the observed mitochondrial divergence. Rather, the patterns are consistent with the more parsimonious hypothesis, based on neutral coalescent theory, that gene flow has maintained a sufficiently large effective population size (> 50,000 females) for representatives of clades that diverged at least 4 million years ago to have persisted by chance within a population that was subdivided, but not strictly isolated in allopatry.

Africa, Eastern↗