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Biomedical subjects

M James

Publications and source records attributed to M James.

At least 73 records · Page 4Linked to original sources
PubMed1998

Serial transvaginal ultrasonography following McDonald cerclage and repeat suture insertion.

The aim of this study was to explore the hypothesis that serial transvaginal ultrasonography identifies early evidence of suture failure and that repeat cerclage delays delivery. We undertook a review of our policy of transvaginal ultrasonographic cervical surveillance after McDonald cerclage and of repeat suture insertion if persistent cervical effacement developed. Data from 26 pregnancies in 26 women are analyzed. The women had had a total of 57 mid-trimester miscarriages with a median of 2 (1-6) mid-trimester losses per woman. Twelve (46%) of the 26 women developed cervical changes at scan and underwent repeat cerclage. All 14 women who had a single suture inserted progressed to live births but 1 of the 13 women who had repeat cerclage had a mid-trimester miscarriage (p>0.05). The median gestation at delivery for the women who had repeat cerclage was 35 (22-39) weeks compared with 38 (36-40) weeks for those who had a single suture (p>0.05). The median interval from the detection of cervical changes at scan to delivery was 13 (4-19) weeks. Serial transvaginal ultrasonography after cervical cerclage identifies a group of women who are more likely to deliver preterm, and provides an opportunity for intervention (repeat cerclage) which appears to delay delivery by an average of 7 weeks.

Adult↗
PubMed1998

"Can you recommend a sunscreen?": the mysteries explained.

Ratings and tests for the effectiveness of sunscreens are becoming more consistent and scientifically based. This reflects the growing recognition of the health hazards from sunburn and excessive tanning. Health professionals should be aware of the classic six skin types and their susceptibility to burning. As well as Sun Protection Factors (SPFs), long-wave ultra-violet radiation needs to be taken into account. UVA rays cause long-term damage to the skin. No agreed test for UVA protection exists as yet, but some manufacturers have introduced a star rating system for UVA protection. The more UVA stars, the greater the protection. Children's skin is more vulnerable to burning so they need special protection and a high SPF and UVA rating. The first line of defence is avoiding strong sunlight and covering the head and body. Remember that sunscreens need reapplying after swimming. Always follow the manufacturers' directions carefully.

Humans↗
PubMed1998

Holidaying abroad: practical advice for a young family.

Try to tailor your advice to the individual family. Keep it simple and practical. Find out who is going, where and whether the family has any particular health needs. Encourage the family to plan ahead, finding out as much as they can about facilities for young children at their destination. Likely discussion points are vaccinations, infant and toddler feeding, managing the journey, avoiding sunburn and diarrhoea, and contraception. Depending on destination it may be advisable for the family to take some items with them from the UK, e.g. infant formula and feeding equipment, contraceptives, sun protection and insect repellents.

Adult↗
PubMed1997

Maintenance of elevated lead levels in drinking water from occasional use and potential impact on blood leads in children.

The variation in lead concentration was measured by thermal ionisation mass spectrometry isotope dilution in household tap water throughout the day when the plumbing system was not fully flushed. After collection of an initial 125-ml water sample containing 119 micrograms/l and a 2-l sample, 125-ml samples were collected at hourly intervals for 8 h. The concentrations in the hourly samples remained in the range 35-52 micrograms/l compared with 1.7 micrograms/l for fully flushed water. High precision lead isotopic measurements showed that approximately 50% of the lead in these water samples derives from the tap 'housing' compared with the overall household system. A health risk assessment was performed employing the US Environmental Protection Agency Integrated Exposure Uptake Biokinetic Model. Predicted blood lead levels in infants only exceeded the 'levels of concern' of 10 micrograms/dl when 100% of the water consumed contained 100 micrograms Pb/1. It would appear that unless the infant consumed 100% of first flush water at lead concentrations of approximately 100 micrograms/l, the blood lead would not exceed the recommended 'level of concern'. However, if more than 0.51 was consumed in drinks and formulae using first flush water, then the blood lead could easily exceed the recommended level. Likewise, a pregnant mother could be at risk of consuming considerably more than the 0.51/day first flush water of the concentrations measured, or throughout the day, if the system were not fully flushed.

Adult↗
PubMed1997

Inhibition of bovine nasal cartilage degradation by selective matrix metalloproteinase inhibitors.

N-terminal analysis of aggrecan fragments lost from bovine nasal cartilage cultured in the presence of recombinant human interleukin 1alpha revealed a predominant ARGSVIL sequence with an additional ADLEX sequence. Production of the ARGSVIL-containing fragments has been attributed to the action of a putative proteinase, aggrecanase. The minor sequence (ADLEX) corresponds to a new reported cleavage product; comparison of this sequence with the available partial sequence of bovine aggrecan indicates that this is the product of a cleavage occurring towards the C-terminus of the protein. Matrix metalloproteinase (MMP) inhibitors inhibited aggrecan loss from bovine nasal explants incubated in the presence of recombinant human interleukin 1alpha. A strong correlation between inhibition of aggrecan metabolism and inhibition of stromelysin 1 (MMP 3) (r=0.93) suggests a role for stromelysin or a stromelysin-like enzyme in cartilage aggrecan metabolism. However, the compounds were approx. 1/1000 as potent in inhibiting aggrecan loss from the cartilage explants as they were in inhibiting stromelysin. There was little or no correlation between inhibition of aggrecan metabolism and inhibition of gelatinase B (MMP 9) or inhibition of collagenase 1 (MMP 1). Studies with collagenase inhibitors with a range of potencies showed a correlation between inhibition of collagenase activity and inhibition of collagen degradation in the cartilage explant assay. This indicates that in interleukin 1alpha-driven bovine nasal cartilage destruction, stromelysin (or a closely related enzyme) is involved in aggrecan metabolism, whereas collagenase is principally responsible for collagen degradation.

Aggrecans↗
PubMed1997

The molecular basis for cross-reaction of an anti-dystrophin antibody with alpha-actinin.

The epitope recognised by the anti-dystrophin monoclonal antibodies MANDYS141 and MANDYS142 has been characterised using a phage display peptide library and a bacteriophage lambda cDNA library. Using a phage display library of random 15-mer peptides, the epitope recognised by the two antibodies was identified as EEXF. A lambda gt11 clone obtained by screening a human muscle cDNA library was shown to contain part of the out-of-frame human mitochondrial succinyl CoA synthetase (alpha-subunit) cDNA sequence which contains the sequence EEPL, suggesting a minimum requirement of EEXF/L for antibody binding. The sequence EEDF is located in the helical rod region of dystrophin and the N-terminal domain of alpha-actinin; this may explain why native dystrophin is not detected, since the alpha-helical, coiled-coil folding of the rod region of dystrophin may obscure the epitope in the native protein. The antibody cross-reaction between dystrophin and alpha-actinin is likely to be fortuitous and not due to any structural homology that exists between these two members of the spectrin superfamily.

Actinin↗
PubMed1997

Single session effects of treatment components within a specialized inpatient posttraumatic stress disorder program.

This study examined the potential contributions of individual treatment components within one inpatient posttraumatic stress disorders (PTSD) program. Fifteen treatment components were assessed by a self-report instrument administered to a cohort of veterans just before and immediately after each session approximately halfway through the program. Components with an external focus, action modality, and, secondarily, little Vietnam content were associated with more improvement than components with an internal focus, verbal modality, or high Vietnam content. Improvement was greatest in veterans with fewer PTSD symptoms. Short-term improvement was not correlated with veterans' ratings at discharge of component effectiveness. These results were later confirmed on a second cohort. This study supports the potential roles of distraction and physical release, as opposed to exploratory verbal discussion, in the treatment of chronic combat-related PTSD.

Adult↗
PubMed1997

Detection of glove puncture and skin contamination during caesarean section.

Measures that can be taken to reduce exposure to potentially infected body fluids are of particular relevance in obstetric and gynaecological surgery due to high rates of glove puncture and relatively higher prevalence of human immunodeficiency virus seropositivity in the obstetric age group. We describe the use of a simple electronic device that alarms following puncture of surgical gloves or the creation of a fluid bridge between surgeon and patient. Further exposure to potentially infected body fluids is thus prevented. This present study was performed in the context of caesarean section, but the application of the technique to gynaecological procedures is appropriate.

Cesarean Section↗
PubMed1997

Cardiac baroreceptor sensitivity is impaired after acute stroke.

BACKGROUND AND PURPOSE: The blood pressure (BP) fall and increased BP variability after acute stroke have been previously described. The underlying pathophysiological mechanisms producing these findings are unclear but may include abnormalities of cardiac baroreceptor reflex arc and/or changes in sympathetic nervous system activity. To date, evidence of impaired cardiac baroreceptor sensitivity (BRS) after stroke is limited to patients with chronic disease as determined by invasive methodology. Therefore, it was proposed to assess cardiac BRS and sympathovagal balance with the use of novel noninvasive techniques after acute stroke. METHODS: Thirty-seven acute stroke patients underwent simultaneous surface electrocardiographic and noninvasive beat-to-beat BP recording. Cardiac BRS was assessed by power spectral analysis techniques, and sympathovagal balance was determined from the ratio of the low- to high-frequency powers for pulse interval variability. The responses were compared with a control group matched for age, sex, and BP. RESULTS: Median cardiac BRS was significantly lower in stroke patients than in control subjects (high-frequency alpha-index, 4.89 versus 6.50 ms/mm Hg; P = .007; combined alpha-index, 4.65 versus 5.46 ms/mm Hg; P = .02). Median normalized high- but not low-frequency power of systolic BP variability was significantly greater in stroke patients (11.0 versus 6.7 normalized units; P < .001), probably reflecting differences in the mechanical effects of respiration on BP in stroke patients. No significant differences were observed in the power spectrum of pulse interval variability between stroke patients and control subjects. Patients with tight hemisphere strokes, however, had a significant reduction in median high-frequency pulse interval power compared with patients with left hemisphere strokes (8 versus 20 normalized units; P = .03), which may reflect a change in sympathovagal balance in favor of increased sympathetic tone in this group. CONCLUSIONS: The impairment of cardiac BRS may be important in explaining the increased BP variability after stroke. There was no significant difference in surrogate measures of sympathovagal activity between acute stroke patients and control subjects, but right hemisphere stroke patients had a significant alteration in the sympathovagal balance of pulse interval variability compared with left hemisphere stroke patients. This sympathetic predominance in right hemisphere strokes may be important in the development of cardiac arrhythmias after stroke. The prognostic implications of these findings need to be further explored.

Acute Disease↗
PubMed1996

Cloning of cDNA encoding human rapsyn and mapping of the RAPSN gene locus to chromosome 11p11.2-p11.1.

We have isolated and sequenced cDNA clones for the human 43-kDa acetylcholine receptor-associated protein rapsyn. The cDNA encodes a 412-amino-acid protein that has a predicted molecular mass of 46,330 Da and shows 96% sequence identity with mouse rapsyn. Analysis of PCR amplifications, first from somatic cell hybrids and subsequently from radiation hybrids, localizes the human RAPSN gene locus to chromosome 11p11.2-p11.1 in close proximity to ACP2.

Amino Acid Sequence↗
PubMed1996

The ATM gene and susceptibility to breast cancer: analysis of 38 breast tumors reveals no evidence for mutation.

Heterozygosity for ataxia-telangiectasia (A-T), a cancer-prone recessive syndrome, has been associated with an increased risk of breast cancer. The gene for A-T (ATM) is located at chromosomal region 11q22-q23, a region of frequent loss of constitutional heterozygosity in breast and other tumors. Loss of constitutional heterozygosity at 1lq22-q23 was found in 47% of informative cases in the series of primary tumors analyzed in this study. To investigate the role of ATM in breast cancer, we have determined the complete genomic organization of the gene, developed an exon-scanning PCR single-strand conformation polymorphism (PCR-SSCP) assay for mutation detection of ATM, and screened 38 consecutive breast tumors for mutations using both genomic DNA- and cDNA-based assays. In addition to common ATM polymorphisms detected both in the coding sequence and in flanking introns, seven unique SSCP alleles were identified in six tumor DNAs. Sequence analysis of these alleles revealed rive nucleotide substitutions that were predicted to change the encoded amino acid. However, PCR-SSCP and nucleotide sequencing analysis of the paired blood samples and of an extended sample size of a total of 224 chromosomes indicated that these SSCP patterns represent constitutional rare polymorphisms with a frequency between 0.005 and 0.023. Because the majority of A-T mutations are null mutations and none of the ATM alleles found in breast cancer samples would lead to the truncation of the translation product, we conclude that, in this initial sample of sporadic breast cancer patients, there was no evidence for an increased number of A-T carriers. In addition, because no somatic mutations were found, our study rules out the ATM gene as the frequently altered tumor suppressor gene at 11q23.

Ataxia Telangiectasia↗
PubMed1996

Crystal structure of the yeast cell-cycle control protein, p13suc1, in a strand-exchanged dimer.

BACKGROUND: p13(suc1) from fission yeast is a member of the CDC28 kinase specific (CKS) class of cell-cycle control proteins, that includes CKS1 from budding yeast and the human homologues CksHs1 and CksHs2. p13(suc1) participates in the regulation of p34(cdc2), a cyclin-dependent kinase controlling the G1-S and the G2-M transitions of the cell cycle. The CKS proteins are believed to exert their regulatory activity by binding to the kinase, in which case their function may be governed by their conformation or oligomerization state. Previously determined X-ray structures of p13(suc1), CksHs1 and CksHs2 show that these proteins share a common fold but adopt different oligomeric states. Monomeric forms of p13(suc1) and CksHs1 have been solved. In addition, CksHs2 and p13(suc1) have been observed by X-ray crystallography in assemblies of strand-exchanged dimers. Analysis of various assemblies of the CKS proteins, as found in different crystal forms, should help to clarify their role in cell-cycle control. RESULTS: We report the X-ray crystal structure of p13(suc1) to 1.95 A resolution in space group C2221. It is present in the crystals as a strand-exchanged dimer. The overall monomeric fold is preserved in each lobe of the dimer but a single beta-strand (Ile94-Asp102) is exchanged between the central beta-sheets of each molecule. CONCLUSIONS: Strand exchange, which has been observed for p13(suc1) in two different space groups, and for CksHs2, is now confirmed to be an intrinsic feature of the CKS family. A switch between levels of assembly may serve to coordinate the function of the CKS proteins in cell-cycle control.

Amino Acid Sequence↗
PubMed1996

Genetic mapping of two blood pressure quantitative trait loci on rat chromosome 1.

A genetic map for rat chromosome 1 was constructed using 66 microsatellite markers typed on either or both of two populations derived from inbred Dahl salt-sensitive (S) rats: F2(LEW x S) n = 151, and F2(WKY x S) n = 159. These populations had been raised on a high salt (8% NaCl) diet. Systolic blood pressure and heart weight were found to be genetically linked to two separate regions on rat chromosome 1 in the F2(LEW x S) population. One region was centered around the anonymous SA locus and accounted for 24 mmHg of blood pressure. The other region was 55 cM from the SA locus centered around a cluster of cytochromes P450 loci, and accounted for 30 mmHg of blood pressure. Since blood pressure and heart weight were highly correlated these same regions were also linked to heart weight. These results were cross-specific as linkage of these chromosome 1 regions to blood pressure and heart weight was not observed in several other F2 populations derived by crossing S and other normotensive control strains. This is presumably due to different alleles and/or different genetic backgrounds in the various populations. The SA region of chromosome 1 was found to influence body weight in F2(LEW x S) rats. Combining the present data with our previously published data on the F2(LEW x S) population showed that four separate quantitative trait loci with additive effects accounted for 106 mmHg and 38% of the total variance of blood pressure and for 506 mg and 34% of the total variance of heart wt.

Animals↗