Search PubMed⌕ Search

Biomedical subjects

S Everett

Publications and source records attributed to S Everett.

At least 19 recordsLinked to original sources
PubMed2005

The long sitting screening test in elite cyclists.

Pelvic rotation during cycling is important because it influences aerodynamics, cycling efficiency and the occurrence of overuse injuries. The aim of this study was to determine whether or not pelvic position in long sitting influences pelvic position during cycling. An observational, cross sectional, within-subjects study design was used. Thirty elite international track and road cyclists participated as subjects and two measures were undertaken. In long sitting, a digital inclinometer was positioned on the lumbosacral junction to give a static measure in degrees of sacral inclination (SI) relative to the horizontal. During active cycling, video analysis of reflective surface markers over the anterior superior iliac spine and posterior superior iliac spine was used to give a measure in degrees of anterior pelvic rotation (APR), by the angle between these two landmarks and the horizontal. No significant linear relationship was found between the two testing positions (r = 0.23, p = 0.22).

Adolescent↗
PubMed2004

Changes in chemical signature and host specificity from larval retrieval to full social integration in the myrmecophilous butterfly Maculinea rebeli.

The ant social parasite, Maculinea rebeli shows high levels of host specificity at a regional scale. While 68-88% of caterpillars in the field are adopted by nonhost Myrmica ants, 95-100% of the butterflies emerge from the natural host M. schencki the following year. While retrieval of preadoption caterpillars is specific to the genus Myrmica, it does not explain differential survival with different Myrmica species. We present survival data with host and nonhost Myrmica species suggesting that, with nonhosts (M. sabuleti and M. rubra), survival depends on the physiological state of the colony. We also compared the similarities of the epicuticular surface hydrocarbon signatures of caterpillars that were reared by host and nonhost Myrmica for 3 weeks with those from tending workers. Counterintuitively, the hydrocarbons of postadoption caterpillars were more similar (78%, 73%) to the ant colony profiles of the nonhost species than were caterpillars reared in colonies of M. schencki (42% similarity). However, caterpillars from M. schencki nests that were then isolated for 4 additional days showed unchanged chemical profiles, whereas the similarities of those from nonhost colonies fell to 52 and 56%, respectively. Six compounds, presumably newly synthesized, were detected on the isolated caterpillars that could not have been acquired from M. sabuleti and M. rubra (nor occurred on preadoption caterpillars), five of which were found on the natural host M. schencki. These new compounds may relate to the high rank the caterpillars attain within the hierarchy of M. schencki societies. The same compounds would identify the caterpillars as intruders in non-schencki colonies, where their synthesis appeared to be largely suppressed. The ability to synthesize or suppress additional compounds once adopted explains the pattern of mortalities found among fully integrated caterpillars in Myrmica colonies of different species and physiological states.

Animals↗
PubMed2002

Outcomes at 1 year for the first 200 patients fitted with GyneFix at Margaret Pyke Centre.

The first 200 women to be fitted with GyneFix at the Margaret Pyke Centre, a National Health Service contraception clinic situated in central London, have been followed up at 1 year after insertion. Removals, expulsions and accidental pregnancies in that first year are recorded. Of the cohort, 80% had a known outcome at 12 months. There was one perforation with the inserter tube, leaving 199 women fitted with GyneFix who contributed 2033 woman-months of follow-up time. We recorded 22 early removals, of which 16 were for heavy or irregular bleeding and/or pain, three were because the women wished to conceive and three for other reasons. In addition there were 16 expulsions at intervals ranging from 1 day to 12 months after insertion. Four of the expulsions were unnoticed by the subjects (they were revealed by amenorrhea of pregnancy in two subjects and lost threads in the other two). There were no pregnancies with the GyneFix in situ. The expulsion rate of 8.4% (confidence interval (CI) 5.2-13.4%) and removal rate for bleeding and/or pain of 9.0% (CI 5.6-14.3%) at 12 months recorded in this cohort fall within acceptable ranges for framed intrauterine devices in a population with a large percentage of nulliparous women. However, they are perhaps not as good as had been anticipated for this revolutionary new intrauterine implant. Possible reasons for this are explored.

Adult↗
PubMed1999

The optimal antibiotic combination in a 5-day Helicobacter pylori eradication regimen.

BACKGROUND: Current guidelines for Helicobacter pylori eradication recommend 7 days of a proton-pump inhibitor, clarithromycin (C), and either metronidazole (M) or amoxycillin (A). A shorter course would be cheaper and could be as effective. AIM: This study was designed to investigate the efficacy of three 5-day regimens based on lansoprazole (L). METHODS: 168 dyspepsia patients with H. pylori infection were randomized to receive a 5-day course of either LCM, LAC or CALM, and a 13C-urea breath test was performed after 4 weeks to assess eradication. RESULTS: 160 patients completed the study. Intention-to-treat eradication rates were as follows: LCM 81%, LAC 59%, CALM 88%. LCM and CALM gave significantly better eradication rates than LAC. There was no significant difference in adverse events across the three groups. Logistical regression analysis showed that the specific regimen used and the age of the patient were the only factors influencing eradication outcome. CONCLUSIONS: Five days of CALM yields acceptable eradication rates, and is cheaper than conventional 7-day proton pump inhibitor-triple therapy. It appears to offer good results in metronidazole-resistant strains of H. pylori. A randomized trial comparing 5-day CALM with conventional 7-day therapy is needed before this regimen can be recommended for routine use.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

Evaluation of a three-year urban elementary school tobacco prevention program.

The longitudinal study compared effects of varying amounts of tobacco instruction (one, two, and three years) on the knowledge, attitudes, and behavioral intentions of urban elementary students. A three-year, fourth-through-sixth grade tobacco prevention curriculum was developed based on the Centers for Disease Control and Prevention's Guidelines for School Health Programs to Prevent Tobacco Use and Addiction. The curriculum comprised five, 45-minute lessons per year. The same trained instructor taught the curriculum all three years. Six intervention schools were taught the curriculum, and two control schools were not. A 49-item questionnaire was used to assess tobacco knowledge, attitudes, and behavioral intentions. The experimental group's posttest knowledge and attitude scores were significantly higher than the control group's posttest scores. No significant differences occurred in posttest behavioral intention scores between the control and intervention groups.

Adolescent↗
PubMed1998

Clinical and histological associations of cagA and vacA genotypes in Helicobacter pylori gastritis.

AIMS: To determine the relation among the cytotoxin associated gene (cagA) and vacuolating cytotoxin gene (vacA) status of Helicobacter pylori isolates, the associated clinical diseases, and the severity and pattern of chronic gastritis. METHODS: Helicobacter pylori was cultured from gastric biopsies obtained from dyspeptic patients. DNA was extracted from the isolates and the cagA and vacA status determined by the polymerase chain reaction (PCR). The prevalence of the different cagA and vacA genotypes in three clinical groups, duodenal ulcer, gastric ulcer, and non-ulcer dyspepsia was compared. The histological features in sections from two antral and two corpus biopsies were graded by one blinded observer. The grades were compared with age and sex matched groups with different cagA and vacA genotypes, and with duodenal ulcers, or non-ulcer dyspepsia. RESULTS: Isolates from 161 patients were included. One hundred and nine (68%) harboured a cagA+ strain and 143 (89%) harboured a vacA s1 strain. The prevalence of cagA+ strains in duodenal ulcer patients (94%) was highly significantly greater than in those with non-ulcer dyspepsia (56%). However, of the patients infected with a cagA+ strain, almost equal numbers had non-ulcer dyspepsia or peptic ulceration. Chronic inflammation, polymorph activity, surface epithelial degeneration, atrophy, and intestinal metaplasia were all significantly more severe in the cagA+ than in the cagA- group, whereas only corpus epithelial degeneration was significantly more severe in the vacA s1 group compared with the vacA s2 group. Patients infected with cagA+ strains were almost four times more likely to have antral intestinal metaplasia than cagA- patients. An antral predominant gastritis was present in duodenal ulcer patients compared with matched non-ulcer dyspepsia patients, but this was not attributable to cagA or vacA status. CONCLUSIONS: Helicobacter pylori strains showing cagA positively and the vacA s1 genotype are associated with more severe gastritis but these virulence factors do not appear to determine the overall pattern. The pattern is closely linked to clinical disease. Therefore, it is likely that the nature of the disease complicating chronic infection is determined by host and environmental factors, while bacterial factors determine the magnitude of the risk of developing such disease.

Adolescent↗
PubMed1995

Vaginal thrush: how can we help our clients?

Vaginal thrush is a common fungal infection. Recurrent infections occur in about 10% of women. It is important to complete the course of treatment (often clotrimazole (Canesten) pessaries) to eradicate the fungus. A partner who shows symptoms should also be diagnosed and treated. With recurrent thrush, test for diabetes. Simple self-help measures may be helpful, as may attention to personal hygiene. Postmenopausal women are often susceptible because of reduced vaginal lubrication. A vaginal jelly can be helpful.

Candidiasis, Vulvovaginal↗
PubMed1994

African-American adults' perceptions of guns and violence.

This study examined African-American adults' perceptions of guns and violence. Through a mall intercept type study, 347 adults, ages 20 to 75, responded to a 54-item questionnaire. One third of the respondents claimed they owned one or more types of guns, three fourths had personally known someone who had been shot, more than one third had actually seen someone shot, and one third had a gun pulled on them. While the vast majority (84%) believed guns are too easy to obtain, the majority (62%) also believed that having a gun at home would help protect them. There were no significant differences in perceptions of guns based on age, gender, level of education, or socioeconomic status. The results of this study tend to substantiate the concern and fear of personal harm that African Americans have to contend with on a regular basis. The results also suggest the need for some form of educational intervention and gun safety training in order to help reduce the risk of death and injury among African Americans.

Adult↗
PubMed1992

Thrombus with infection in total artificial heart animals.

From January 1980 to December 1990, several types of total artificial hearts were implanted into 378 animals. In a retrospective study of these animals, 147 (39%) were found to have thrombus with infection (T&I). The criteria for diagnosis was thrombus formation in the artificial heart and a positive blood culture. The most common pathogen isolated from T&I animals was Pseudomonas species. Concurrent skin lesions and contamination from the pressure lines may be the primary sources of infection, but bacterial translocation from the intestine is another possible route. The main pathological findings at necropsies of artificial heart animals with T&I were associated with sepsis, congestive heart failure, infected thrombus, thromboembolism, and multiple organ infarctions. Most thrombi appeared to have originated from valve junctions and connectors. On the basis of these observations, a possible mechanism for pathogenesis of T&I has been proposed. The results suggest that design improvements and surface modifications to reduce thrombosis are important factors that should be carefully considered. Similarly, it is important to eliminate the route of entry of pathogenic microorganisms. These findings imply that bacterial interaction with thrombus, device related bacterial colonization, and host immunomodulation and gut barrier function following artificial heart implantation need further investigation.

Animals↗
PubMed1987

Anogenital ratio: measure of fetal virilization in premature and full-term newborn infants.

To provide normative data, we measured anogenital distances in 115 infants of 25 to 42 weeks gestational age and 10 pregnant women, including anus to fourchette (AF), anus to base of the clitoris (AC), and fourchette to base of the clitoris (FC). All infant measurements showed positive and significant correlations with body surface area, weight, length, and gestational age (P less than 0.001). However, the anogenital ratio (AF/AC) followed a normal distribution and did not correlate with any of the anthropometric variables or age. Mean (+/- SD) value in infants was 0.37 +/- 0.07, and in adults, 0.36 +/- 0.07. An anogenital ratio greater than 0.50 falls outside the 95% confidence limits, suggests labioscrotal fusion, and indicates a need for further evaluation. Because it is independent of body size and gestational age, the anogenital ratio should be useful in diagnosing androgen-induced labioscrotal fusion in both premature and full-term female infants.

Adult↗
PubMed1984

Meal-stimulated gastric acid secretion in infants.

Basal acid output and meal-stimulated acid output were measured in newborn infants after nasogastric infusion of 5% glucose and elemental formula, respectively. In six older infants (age range 6 to 31 months), basal acid output was 0.067 +/- 0.017 mmol/kg/hr and maximal acid output was 0.200 +/- 0.028 mmol/kg/hr. Meal-stimulated acid output in four of six older infants was 0.149 +/- 0.038 mmol/kg/hr. In eight healthy newborn infants basal acid output was 0.038 +/- 0.008 mmol/kg/hr; meal-stimulated acid output was 0.064 +/- 0.011 mmol/kg/hr (P less than 0.01). The time course of the secretory response to the elemental formula was as described previously after a protein meal in adults: the rate of acid secretion increased after 20 minutes and remained greater than the basal rate through the remainder of the 90 minute test period. These results demonstrate that in human newborn infants a mixed meal containing protein hydrolysate induces an acid secretory response that is qualitatively similar to but weaker than the response in older infants and adults.

Basal Metabolism↗
PubMed1984

A comparison of mydriatic eyedrops in low-weight infants.

The pupils of neonates often need to be dilated to examine the retina for retinopathy of prematurity and other disorders. It is known that low-weight infants (less than 1600 grams) are susceptible to systemic hypertension when 10% or 2.5% phenylephrine eye drops are used. To find the safest and best commercially available mydriatic agent in neonates, 30 low-weight infants were divided evenly into three groups. The drops tested were cyclopentolate 0.5% alone, cyclopentolate 0.5% plus mydriacyl 0.5%, and a combination drop of phenylephrine 1% and cyclopentolate 0.2%. There was no clinically significant effect of any of the drops on systolic blood pressure or pulse rate. The cyclopentolate and phenylephrine combination dilated the pupils by a mean of 2.8 mm which was statistically greater than the other groups (P less than 0.01) and had a longer duration of maximal dilation than the other drops (P less than 0.05).

Blood Pressure↗
PubMed1982

Phagocyte chemotaxis in the perinatal period.

Cross-sectional and limited sequential studies of neutrophil and monocyte chemotaxis were done using cells isolated from cord blood and peripheral blood of 2- to 6-day-old neonates and infants at 4 and 6 months of age. These studies show that cord blood phagocyte chemotaxis is comparable to adult values, whereas phagocyte chemotaxis at 2-6 days of age is significantly lower than adult (P less than 0.01) or cord (P less 0.01) chemotaxis values. At 6 months of age, phagocyte chemotaxis is still low compared to adult values (P less than 0.01).

Adult↗