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Biomedical subjects

A Herring

Publications and source records attributed to A Herring.

At least 19 recordsLinked to original sources
PubMed2006

Correlates of intake of folic acid-containing supplements among pregnant women.

OBJECTIVE: This study describes the timing and correlates of folic acid supplement intake among pregnant women. STUDY DESIGN: Data from 2518 women with estimated delivery dates from 1997 to 2000, collected for the National Birth Defects Prevention Study, a population-based case-control study, were analyzed. Multinomial logistic regression was used to identify correlates of supplement intake. RESULTS: Fifty-three percent of women began taking folic acid supplement during the periconceptional period, 35% during early pregnancy, and 8% during late pregnancy (ie, 3 months before through 1 month after conception, 2-3 months after conception, or more than 3 months after conception, respectively). Women who did not take folic acid supplement periconceptionally tended to be nonwhite, speak Spanish, have low education, be younger than 25 years old, be nulliparous, smoke, have no previous miscarriage and no fertility treatments, begin prenatal care and become aware of their pregnancy after the first trimester, have nonplanned pregnancies, and eat less breakfast cereal. CONCLUSION: This study identifies correlates of folic acid supplement intake, which may contribute to the design of interventions to improve intake during early pregnancy.

Adolescent↗
PubMed2004

The chlamydia screening studies: rationale and design.

BACKGROUND: Screening has been recommended to reduce the prevalence and morbidity associated with genital chlamydia infection in the United Kingdom. METHODS: We describe the rationale and study design of the Chlamydia Screening Studies (ClaSS), a collaborative project designed to evaluate screening outside genitourinary medicine clinics. A non-selective, active screening approach in 16-39 year olds randomly sampled from 27 general practice lists in the Bristol and Birmingham areas formed the basis of interlinked studies: a case-control study was used to investigate factors to improve the targeting of screening; participants with chlamydia were invited to enroll in a randomised controlled trial to evaluate partner notification conducted in primary care; and laboratory based studies were used to assess the best specimens and tests. We also explored psychosocial effects of screening and partner notification and modelled the cost effectiveness of the programme. CONCLUSION: Results from four pilot practices show that mailing of specimens for chlamydia testing is feasible but that it is difficult to achieve high response rates with postal screening. The high prevalence of asymptomatic infection in men suggests that efforts to screen men for chlamydia should be strengthened.

Adolescent↗
PubMed2003

Associations between Mycoplasma genitalium, Chlamydia trachomatis and pelvic inflammatory disease.

OBJECTIVE: To evaluate the association between Mycoplasma genitalium, Chlamydia trachomatis, and pelvic inflammatory disease (PID) METHODS: A case-control methodology was used. Swab eluates were processed using the QIAamp DNA mini kit. Polymerase chain reaction (PCR) for M genitalium was carried out using a real time in-house 16S based assay. An endocervical swab was taken and tested for the presence of C trachomatis (ligase chain reaction, Abbott Laboratories), and a high vaginal swab was taken and tested for the presence of Neisseria gonorrhoeae and bacterial vaginosis. RESULTS: Of the PID cases 13% (6/45) had evidence of M genitalium infection compared to none of the controls (0/37); 27% (12/45) of the cases had C trachomatis infection compared to none of the controls; and 16% (7/45) of cases only had serological evidence of C trachomatis infection compared to 5% (2/37) of controls. Cases were more likely to present with M genitalium and/or C trachomatis than controls (p<0.001). CONCLUSIONS: This study indicates that there may be an association between M genitalium and PID, and that this relation is largely independent of C trachomatis. Future studies need to investigate the pathological basis of the relation between M genitalium and PID using samples from women with PID diagnosed using laparoscopy and endometrial biopsy. Little is known about the epidemiology of M genitalium: large scale epidemiological investigations are needed to determine the prevalence, incidence, and factors associated with this emerging infection.

Adult↗
PubMed2003

Associations between Mycoplasma genitalium, Chlamydia trachomatis, and pelvic inflammatory disease.

OBJECTIVE: To evaluate the association between Mycoplasma genitalium, Chlamydia trachomatis, and pelvic inflammatory disease (PID) METHODS: A case-control methodology was used. Swab eluates were processed using the QIAamp DNA mini kit. Polymerase chain reaction (PCR) for M. genitalium was carried out using a real time in-house 16S based assay. An endocervical swab was taken and tested for the presence of C. trachomatis (ligase chain reaction, Abbott Laboratories), and a high vaginal swab was taken and tested for the presence of Neisseria gonorrhoeae and bacterial vaginosis. RESULTS: Of the PID cases 13% (6/45) had evidence of M. genitalium infection compared to none of the controls (0/37); 27% (12/45) of the cases had C. trachomatis infection compared to none of the controls; and 16% (7/45) of cases only had serological evidence of C. trachomatis infection compared to 5% (2/37) of controls. Cases were more likely to present with M. genitalium and/or C trachomatis than controls (p<0.001). CONCLUSIONS: This study indicates that there may be an association between M. genitalium and PID, and that this relation is largely independent of C. trachomatis. Future studies need to investigate the pathological basis of the relation between M. genitalium and PID using samples from women with PID diagnosed using laparoscopy and endometrial biopsy. Little is known about the epidemiology of M. genitalium: large scale epidemiological investigations are needed to determine the prevalence, incidence, and factors associated with this emerging infection.

Adolescent↗
PubMed1999

The historical roots of high rates of infant death in Aboriginal communities in Canada in the early twentieth century: the case of Fisher River, Manitoba.

Infant mortality is investigated for a period of thirty years at the beginning of the 20th century in the Aboriginal Nations community of Fisher River, Manitoba. Infant mortality rates were generated from parish records of infant burials from the Methodist mission at Fisher River and later archived at the United Church Archives in Winnipeg, Man. The average infant mortality rate (IMR) for the total period (1910-1939) was 249 per 1000 live births, an exceedingly high rate compared to modern IMRs and even higher than those in developing countries today. Acute respiratory infections were found to be the cause of death in the majority of cases. These infectious diseases and high rates of postneonatal infant mortality point to conditions of poverty associated with malnutrition as the major precipitating factor in infant death. Fisher River, like other early 20th century First Nations communities in Canada, experienced socio-economic deprivation because of the decline of the fur trade and the underdevelopment of a reserve economy competing for resources with the Canadian government and Euro-Canadian settlers. These conditions of economic and political marginalization are concluded to be the ultimate causes of high rates of infant mortality and are incorporated in a disease ecology model.

Cause of Death↗
PubMed1999

Protection for nurses during radiotherapy.

Sealed sources of radiation usually take the form of a metal wire implanted locally. These are removed intact and result in little or no residual radioactivity in the patient. An unsealed source of radiation is distributed around the patient's body and radiation will be excreted in the urine, saliva and sweat. Nurses must follow local guidelines to protect themselves from radiation.

Health Knowledge, Attitudes, Practice↗
PubMed1996

Cannabinoid inhibition of adenylate cyclase-mediated signal transduction and interleukin 2 (IL-2) expression in the murine T-cell line, EL4.IL-2.

Cannabinoid receptors negatively regulate adenylate cyclase through a pertussis toxin-sensitive GTP-binding protein. In the present studies, signaling via the adenylate cyclase/cAMP pathway was investigated in the murine thymoma-derived T-cell line, EL4.IL-2. Northern analysis of EL4.IL-2 cells identified the presence of 4-kilobase CB2 but not CB1 receptor-subtype mRNA transcripts. Southern analysis of genomic DNA digests for the CB2 receptor demonstrated identical banding patterns for EL4.IL-2 cells and mouse-derived DNA, both of which were dissimilar to DNA isolated from rat. Treatment of EL4.IL-2 cells with either cannabinol or Delta9-THC disrupted the adenylate cyclase signaling cascade by inhibiting forskolin-stimulated cAMP accumulation which consequently led to a decrease in protein kinase A activity and the binding of transcription factors to a CRE consensus sequence. Likewise, an inhibition of phorbol 12-myristate 13-acetate (PMA)/ionomycin-induced interleukin 2 (IL-2) protein secretion, which correlated to decreased IL-2 gene transcription, was induced by both cannabinol and Delta9-THC. Further, cannabinoid treatment also decreased PMA/ionomycin-induced nuclear factor binding to the AP-1 proximal site of the IL-2 promoter. Conversely, forskolin enhanced PMA/ionomycin-induced AP-1 binding. These findings suggest that inhibition of signal transduction via the adenylate cyclase/cAMP pathway induces T-cell dysfunction which leads to a diminution in IL-2 gene transcription.

Adenylyl Cyclase Inhibitors↗
PubMed1995

Pharmacological characterization of purinoceptor-mediated constriction of submucosal arterioles in guinea pig ileum.

Sympathetic nerve stimulation causes a constriction of submucosal arterioles that is mediated by ATP acting at P2 receptors. In the present study, we examined the P2 receptor subtype mediating this response. A computer-assisted video monitoring system measured drug-induced changes in arteriolar diameter (resting diameter approximately 40-80 microns) in pieces of submucosa in vitro. The rank-order potency for vasoconstriction caused by several ATP analogs was alpha,beta-methylene ATP (alpha,beta-MeATP) > beta,gamma-methylene ATP = 2-methylthioATP > ATP > ADP. Constrictions caused by alpha,beta-MeATP were competitively antagonized by suramin (KB = 3.2 microM) and were noncompetitively blocked by pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (KB = 0.5 microM). Norepinephrine-induced constrictions were not affected by suramin (100 microM) or by pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (3 microM). Extracellular solutions with 0 added calcium prevented constrictions caused by alpha,beta-MeATP (0.1-1.0 microM), but not those caused by norepinephrine (3 and 10 microM). Nifedipine (0.3 and 1 microM) reduced constrictions caused by 40 and 60 mM extracellular potassium chloride, but not those caused by alpha,beta MeATP. These data indicate that P2X receptors mediate constriction of submucosal arterioles. P2X-mediated vasoconstriction is dependent on extracellular calcium, but calcium entry through nifedipine-sensitive calcium channels does not contribute to P2X-mediated vasoconstriction.

Adenosine Triphosphate↗
PubMed1993

Accuracy tests of tooth formation age estimations for human skeletal remains.

Estimations of age from tooth formation standards for a large (n = 282) sample of subadult skeletal remains from a 19th century historic cemetery sample were analyzed. The standards of Moorrees et al. (1963a,b) for the permanent and deciduous teeth, and Anderson et al. (1976) for the formation of permanent dentition were employed in a variety of combinations to calculate mean dental ages. Tests of accuracy and bias were made on a small sample (n = 17) of personally identified individuals, and age of attainment scores were compared to age of prediction scores for each individual. The resulting dental age distributions for the skeletal sample were compared to documented burial records for the cemetery to determine the representativeness of the skeletal sample. These comparisons showed little difference between age of attainment versus age of prediction methodologies. The standards of Moorrees et al. (1963a,b) were observed to provide the most accurate estimates of age with a standard deviation of one-half year. The standards of Anderson et al. (1976), while easier to use and more extensive, are problematic in that the original reference sample begins at three years of age, while the sample used by Moorrees and colleagues begins at birth. The skeletal age distributions compare well to the overall chronological age distribution for the cemetery. These results affirm that tooth formation age estimates for subadult skeletal remains from archaeological or forensic samples provide accurate assessments of age at both the individual and population level.

Adolescent↗
PubMed1989

Immunoblotting analysis of the reaction of wildebeest, sheep and cattle sera with the structural antigens of alcelaphine herpesvirus-1 (malignant catarrhal fever virus).

Malignant catarrhal fever (MCF) is a disease of cattle and some other ruminants caused by alcelaphine herpesvirus-1 (AHV-1), a virus of wildebeest. The disease also occurs in the absence of wildebeest and is then thought to be caused by a viral agent harboured by the sheep. The structural proteins of AHV-1 have been used as antigens for the immunoblotting analysis of sera from wildebeest, sheep and cattle infected by either AHV-1 or the "sheep-associated" form of the disease. Wildebeest sera showed a uniform response reacting strongly with six polypeptides. Sheep sera also gave positive results but individual sera reacted with varying subsets of the antigens recognized by wildebeest. These results support the earlier suggestion that sheep harbour a herpesvirus related to AHV-1. A bovine serum from a case of MCF caused by AHV-1 also reacted only with a subset of the six wildebeest-reactive polypeptides. Sera from cattle affected with the "sheep-associated" form of the disease gave reactions in only two of the eight cases tested; both positive sera reacted to a few polypeptides only.

Animals↗
PubMed1989

14C triolein breath test: an assessment in the elderly.

14C triolein breath tests are highly sensitive in detecting fat malabsorption in adults, but experience in the elderly is sparse. We have evaluated 48 'normal' subjects over the age of 65 years and compared the results with those of 46 normal subjects under 65 from a previous study. Results were calculated as eight hour cumulative values and expressed as percentages of the administered dose. Reference ranges have been calculated separately for the following age groups: 65 years or less (201 to 460), 66 to 75 (182 to 405) and over 75 (141 to 336). A clear age related decline in eight hour cumulative values was noted. The values fell by 23% between the ages of 17 and 65 years and by 25% between the ages of 65 and 87 years. Pancreatic insufficiency or bacterial colonisation of the small bowel is unlikely, but delayed intestinal absorption or the effects of slower metabolic rate cannot be excluded. This test is simple and practicable in the elderly and the study emphasises the importance of age in the interpretation of results.

Aged↗
PubMed1975

Gastric emptying following vagotomy and antrectomy and proximal gastric vagotomy.

Gastric emptying of solid meals labelled with 129Cs was studied in patients for up to one year after vagotomy and antrectomy or after proximal gastric vagotomy. Significant delay was found one month after vagotomy and antrectomy but this had returned to normal by six months. No delay was found after proximal gastric vagotomy. The effect of posture on gastric emptying was also studied in the same subjects. No significant differences were found between gastric emptying in the supine or sitting positions after solid meals.

Duodenal Ulcer↗