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Biomedical subjects

S Clements

Publications and source records attributed to S Clements.

At least 19 recordsLinked to original sources
PubMed2001

Inhibition of tendon cell proliferation and matrix glycosaminoglycan synthesis by non-steroidal anti-inflammatory drugs in vitro.

The purpose of this study was to investigate the effects of some commonly used non-steroidal anti-inflammatory drugs (NSAIDs) on human tendon. Explants of human digital flexor and patella tendons were cultured in medium containing pharmacological concentrations of NSAIDs. Cell proliferation was measured by incorporation of 3H-thymidine and glycosaminoglycan synthesis was measured by incorporation of 35S-Sulphate. Diclofenac and aceclofenac had no significant effect either on tendon cell proliferation or glycosaminoglycan synthesis. Indomethacin and naproxen inhibited cell proliferation in patella tendons and inhibited glycosaminoglycan synthesis in both digital flexor and patella tendons. If applicable to the in vivo situation, these NSAIDs should be used with caution in the treatment of pain after tendon injury and surgery.

Adult↗
PubMed2001

96-well plate-based method for total collagen analysis of cell cultures.

Total collagen assays are often laborious and use large quantities of consumables. We have developed a new method of assaying total 3H-proline-labeled collagen from cultured cells. Cells and media are harvested from 96-well plates directly onto fiberglass filtermats and counted in the Wallac 1205 flat-bed scintillation counter (BetaPlate). The assay was validated by comparison with a traditional total collagen assay. The resulting assay provides a rapid one-step method for quantifying collagen synthesis, which, unlike many collagen assays, does not require extensive dialysis or precipitation of proteins.

Carbon Radioisotopes↗
PubMed2000

Internal mammary artery perfusing the Leriche's syndrome.

Two cases of collateral perfusion of a lower extremity, by way of an internal mammary artery, in the presence of Leriche's syndrome are described. The importance of recognizing this condition prior to coronary artery bypass grafting is emphasized.

Aged↗
PubMed1999

What determines geographical variation in rates of acceptance onto renal replacement therapy in England?

OBJECTIVE: To determine the independent effects of need and supply factors on the known geographical variation in acceptance rates onto renal replacement therapy (RRT) in England. METHODS: Data were obtained from all renal units in England on the characteristics of all cases aged 16 years and over, resident in England, who were accepted onto RRT in 1991 and 1992. Of these, 5715 (94.5%) had a valid postcode that could be matched to a census ward. Multilevel modelling using Poisson regression was used. The number of acceptances in each census ward within age bands 16-34, 35-64 and 65+ was the dependent variable. Independent effects modelled were: (1) individual factors (age, sex); (2) census ward need factors--ethnicity (expressed as the percentage of the ward population that was Asian or African-Caribbean), socio-economic deprivation--and supply factors--'access' to the nearest renal unit using crowfly and road travel time and distance, and services available to each ward expressed as number of haemodialysis stations per 100,000 catchment population of the nearest renal unit; (3) district health authority level effects. RESULTS: Age was a major determinant of acceptance, with a 7-fold higher rate in males aged over 64 years compared with younger men. Acceptance rates were lower in females, with a negative age-sex interaction in females aged over 64 years. The percentage of both Asian and African-Caribbean populations per ward was a highly significant positive determinant. Deprivation was also a significant determinant, best represented by a customised index. There was an inverse relation of acceptance with distance, especially road travel time. Other supply side variables had a significant effect though there was no independent district effect. There was some variation in the strength of these relationships by type of area (Greater London, urban and non-urban). CONCLUSIONS: Need and supply factors influence service use as expressed as acceptance onto RRT. Pressure to expand RRT services needs to be aimed at areas with large minority ethnic populations and those living far from existing units.

Adolescent↗
PubMed1999

Doppler velocimetry in the fetus with a single umbilical artery.

OBJECTIVE: To study Doppler velocimetry in fetuses with a single umbilical artery (SUA) as compared to normal. STUDY DESIGN: Private and clinic patients were referred to a perinatal center: 45 with SUA and 124 randomly selected fetuses with a three-vessel cord were studied from 18 to 41 weeks' gestation. Color Doppler flow and energy were utilized to evaluate the umbilical arteries at the fetal abdominal wall as well as the course around the bladder. In addition to Doppler velocimetry, an anatomic survey, estimated fetal weight (EFW) and amniotic fluid index (AFI) were assessed at each examination. RESULTS: Doppler velocimetry in SUA demonstrated indices in the normal range but lower than in normal cords from 26 weeks until near term. Anatomic anomalies were found in 8.9% of SUA as compared to 4.8% for three-vessel cords. Intrauterine growth restriction (IUGR) was seen in four cases of SUA and none in the control group. EFW and AFI for both groups were virtually identical. CONCLUSION: SUA cords theoretically carry a normal blood volume, and the decreased resistance to flow and larger arterial diameter allow this to occur. Anomalies and IUGR are elevated in infants with SUA. Overall, EFW and AFI were the same in both groups of patients.

Abnormalities, Multiple↗
PubMed1998

Semen characteristics and fertility tests required for storage of spermatozoa.

This review addresses critical issues in the selection of semen donors who are very fertile. Traditional semen parameters have been employed and are still used to assess pre- and post-freeze samples in order to discriminate between donors of high and low fecundity. The most predictive factor is the number of motile spermatozoa per straw and the number of motile spermatozoa inseminated. Nevertheless, no absolute standards for fertile samples can be derived from the basic semen examination. The employment of sperm function testing such as the hamster penetration test or computerized motility analysis has been shown to enhance moderately the prediction of fertility of semen samples however, further studies are necessary to determine if these improvements are clinically useful. The need to determine with a high degree of confidence the fecundity of donor semen is enhanced by limitations in the number of pregnancies allowed per donor. The recent publication of league tables in the UK has put extra pressure in clinics to use highly fertile donors. Spermatozoa are also cryostored for patients prior to cancer treatment. With the development of intracytoplasmic sperm injection every sample produced by cancer patients can be stored irrespective of the quality. However, several factors need to be elucidated to maximize the fertility of those patients. The establishment of regional centres in Europe will be a good starting point to deal with many of the issues raised in this review.

Animals↗
PubMed1998

Modelling the spatial distribution of teenage conception rates within Wessex.

This study attempts to determine which factors account for the spatial variation in teenage conception rates within the former Wessex Regional Health Authority and what factors account for the eventual outcomes of these conceptions. Postcoded data on all teenage conceptions from 1991 to 1994 were collected and related to census ward level information and indicators of accessibility to family planning services. The results show that the variation in teenage conception rates and conception outcomes is principally determined by the age of the teenager, deprivation levels, the presence of certain homogeneously distinct groups and the distance to the nearest youth-oriented family planning clinic.

Adolescent↗
PubMed1997

Brain natriuretic peptide is stable in whole blood and can be measured using a simple rapid assay: implications for clinical practice.

OBJECTIVES: To compare the stability of brain natriuretic peptide (BNP) to that of N-terminal atrial natriuretic peptide (NT-ANP) in whole blood and plasma stored under different conditions. To compare a rapid, simple, direct (unextracted) BNP assay to a conventional assay using plasma extraction. DESIGN: Blinded, prospective, comparative study. SETTING: Tertiary referral cardiology department. SUBJECTS: Forty two subjects (24 men, 18 women) comprising 28 patients with left ventricular systolic dysfunction (LVSD) ranging from mild to severe and 14 healthy volunteers. MAIN OUTCOME MEASURES: Stability of NT-ANP and BNP when stored as whole blood or plasma at room temperature over three days. Reproducibility of measurements. RESULTS: BNP was stable in whole blood stored at room temperature for three days; mean change in concentration -7.4% (95% CI 0.6 to -14.8), (direct), -6.3% (5.0 to -16.4), (extracted); whereas a significant decline in BNP concentration was noted in plasma stored at room temperature; -23.2% (-13.7 to -31.6), (direct); -14.4% (-3.2 to -24.3), (extracted). By contrast a small nonsignificant rise in NT-ANP concentration was noted both in whole blood and plasma stored at room temperature for three days; whole blood +8.6% (+22.3 to -3.5), plasma +6.3%, (23.2 to -8.4). The reproducibility of the BNP measurements, and particularly the rapid, direct, measurement, was superior to that for NT-ANP. CONCLUSIONS: BNP is shown to be stable in whole blood for three days and can be measured using a rapid, simple assay. Routine assay of BNP is feasible in ordinary clinical practice and may be of value to general practitioners and hospital based physicians in the diagnosis and management of patients with LVSD. Samples can be sent to a central laboratory without special handling requirements.

Adult↗
PubMed1995

Clinical value of sperm morphology for in-vivo fertility: comparison between World Health Organization criteria of 1987 and 1992.

The World Health Organization (WHO, 1992) has suggested new criteria for scoring sperm morphology. This study compares the clinical value of the new criteria, i.e. classification of a man as fertile or infertile, to those previously established by the WHO (1987). Papanicolaou-stained semen smears from 166 men attending our infertility clinic, whose fertility status was known, were scored using both methods. Using logistic discriminant analysis for compositional data, no difference between these two sets of criteria with respect to predicting pregnancy outcome was observed. The categorization of the abnormalities (head, midpiece, tail) provides no extra clarification. The WHO (1992) cut-off point of 30% for normal forms is not appropriate, as approximately half of the men in the fertile group had a normal sperm morphology below this limit. In conclusion, the present WHO (1992) classification of sperm morphology is of no additional clinical value. Studies on sperm morphology should concentrate on obtaining biological data on, and measurements of, spermatozoa which are functionally active. Only then can the definition of normal be achieved and clinically useful criteria be adopted.

Discriminant Analysis↗
PubMed1995

Implementing comprehensive quality control in the andrology laboratory.

Comprehensive quality control procedures were integrated into the routine semen analysis workload of a large university-based andrology laboratory. Methods were chosen to match as far as possible those which have been used successfully for many years in disciplines such as clinical chemistry. Levey-Jennings and cusum charts were plotted in order to monitor the immunobead-binding test for antisperm antibodies and a video-taped control sample for computerized semen analysis. A cryopreserved semen control was also charted. Daily manual sperm counts were plotted against the corresponding computer-assisted semen analysis (CASA) value. Multiple readings of 30 slides were used to monitor morphology assessments. Monthly means for morphology were also calculated regularly. Coefficients of variation were calculated for all variables and were found to be more appropriate for some aspects, such as CASA, than for others, such as morphology, when difference from the previous reading of the same slide was found to be more useful. These integrated quality control procedures had a direct influence on the production of results from the laboratory. Together with a high standard of technician training, comprehensive routine quality control based on repeated analyses of control samples is an effective way of assuring the validity of semen analysis results.

Antibodies↗
PubMed1992

Patient compliance with colorectal cancer screening in general practice.

A randomized controlled trial to test patient compliance with screening for colorectal cancer in association with general practice health checks was carried out in six practices (three urban and three rural). A total of 1588 patients aged 45-64 years were randomized to one of four intervention groups. In the first group patients were posted a Haemoccult test (Kline Beckman) kit. This group was not invited for a health check. In the second group patients were posted the Haemoccult test kit, together with an invitation to attend for a health check. In the third group patients were posted an invitation for a health check, which explained that the patient would be offered the Haemoccult test kit by the nurse at the health check. In the fourth group patients were just invited for a health check. It was found that combining faecal occult blood testing with the health check did not reduce attendance at the health check--43.5% of patients attended when the Haemoccult test kit was offered by the nurse at the health check, 43.6% attended when a test kit was included with the invitation to attend the health check and 42.9% attended when the health check invitation was posted on its own. Overall, compliance with Haemoccult testing was not significantly increased by associating it with a health check (26.2% versus 25.5%) but compliance was higher when the faecal occult blood testing kit was enclosed with the health check invitation than when it was offered at the health check (31.7% versus 20.6%, P less than 0.001). It is easier and cheaper to combine various screening procedures. Although the overall use of the Haemoccult test in the study population was low, there is no reason why the relatively higher compliance rate obtained on posting the test kit with a health check invitation cannot be achieved in previously unscreened populations with higher expected compliance rates. However, faecal occult blood screening for colorectal cancer should not be undertaken on a population basis until its effectiveness in reducing mortality has been proven by randomized trial.

Colonic Neoplasms↗
PubMed1987

And so to beds.

Explore the source record for details and available documents.

Beds↗
PubMed1987

Induction of tissue-specific proline-rich protein multigene families in rat and mouse parotid glands by isoproterenol. Unusual strain differences of proline-rich protein mRNAs.

A dramatic induction of proline-rich protein mRNAs by the beta-agonist isoproterenol in the parotid and submandibular glands of both rats and mice has been demonstrated using Northern and dot-blot hybridizations and cell-free translation. Proline-rich protein mRNAs were either very low or not detectable in glands of control rats and mice. After 4 days of isoproterenol treatment, mRNAs encoding these unusual proteins comprised over 50% of the total glandular mRNAs. A 2-4-fold increase in proline-rich protein mRNAs was observed in rat parotid glands as soon as 4 h after treatment. The rat proline-rich protein multigene family encodes two groups of mRNAs with sizes ranging from 600 to 1100 bases. Cell-free translations gave about 10-12 proline-rich proteins. In glands of isoproterenol-treated mice, major species of proline-rich protein mRNAs were observed at 1050 and 1300 bases for BALB/cJ and DBA/2J mice and at 1100 and 1200 bases for CD-1 and C57BL/6J mice. Cell-free translations showed unusual differences in proteins synthesized from the four strains after isoproterenol treatment. AtT20 cells were transfected with a mouse proline-rich protein gene inserted into the plasmid pUC8 (pUMP2-BE). Transcription of proline-rich protein mRNA was induced by exposing these transfected cells to either isoproterenol or cAMP, plus theophylline.

Animals↗