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Biomedical subjects

G Smith

Publications and source records attributed to G Smith.

At least 55 records · Page 3Linked to original sources
PubMed2004

Surveillance of sexually transmitted infections in the West Midlands using anonymised individual patient datasets from genitourinary medicine clinics.

Sexually transmitted infections (STIs) declined in the UK during the 1980s and early 1990s but have increased substantially since 1995. Within the overall increase there are important differences in the epidemiology of these infections. The current, aggregate system of STI data collection in the UK provides limited demographic information and is unable to fully explain these differences. More useful information can be obtained using an enhanced surveillance system that collects disaggregate, anonymised, individual patient data including ethnic group and truncated postcode of residence. Such a system has been set up in the West Midlands NHS region. The methodology of the project is described here along with the findings to date. These findings confirm that the burden of STIs disproportionately affects young persons, men who have sex with men, black ethnic minority groups and those living in urban areas. Identifying the groups at greatest risk in this way enables interventions to be more usefully targeted.

Adolescent↗
PubMed2003

Pharmacological profile of the cyclic nociceptin/orphanin FQ analogues c[Cys10,14]N/OFQ(1-14)NH2 and c[Nphe1,Cys10,14]N/OFQ(1-14)NH2.

In this study we describe the activity of two cyclic nociceptin/orphanin FQ (N/OFQ) peptides; c[Cys(10,14)]N/OFQ(1-14)NH(2) (c[Cys(10,14)]) and its [Nphe(1)] derivative c[Nphe(1),Cys(10,14)]N/OFQ(1-14)NH(2) (c[Nphe(1),Cys(10,14)]) in native rat and mouse and recombinant human N/OFQ receptors (NOP). Cyclisation may protect the peptide from metabolic degradation. In competition binding studies of rat, mouse and human NOP the following rank order pK(i) was obtained: N/OFQ(1-13)NH(2)(reference agonist)>N/OFQ=c[Cys(10,14)]>>c[Nphe(1)Cys(10,14)]. In GTPgamma(35)S studies of Chinese hamster ovary cells expressing human NOP (CHO(hNOP)) c[Cys(10,14)] (pEC(50) 8.29) and N/OFQ(1-13)NH(2) (pEC(50) 8.57) were full agonists whilst c[Nphe(1)Cys(10,14)] alone was inactive. Following 30 min pre-incubation c[Nphe(1)Cys(10,14)] competitively antagonised the effects of N/OFQ(1-13)NH(2) with a pA(2) and slope factor of 6.92 and 1.01 respectively. In cAMP assays c[Cys(10,14)] (pEC(50) 9.29, E(max) 102% inhibition of the forskolin stimulated response), N/OFQ(1-13)NH(2) (pEC(50) 10.16, E(max) 103% inhibition) and c[Nphe(1)Cys(10,14)] (~80% inhibition at 10 microM) displayed agonist activity. In the mouse vas deferens c[Cys(10,14)] (pEC(50) 6.82, E(max) 89% inhibition of electrically evoked contractions) and N/OFQ(1-13)NH(2) (pEC(50) 7.47, E(max) 93% inhibition) were full agonists whilst c[Nphe(1)Cys(10,14)] alone was inactive. c[Nphe(1)Cys(10,14)] (10 microM) competitively antagonised the effects of N/OFQ(1-13)NH(2) with a pK(B) of 5.66. In a crude attempt to assess metabolic stability, c[Cys(10,14)] was incubated with rat brain membranes and then the supernatant assayed for remaining peptide. Following 60 min incubation 64% of the 1 nM added peptide was metabolised (compared with 54% for N/OFQ-NH(2)). In summary, we report that c[Cys(10,14)] is a full agonist with a small reduction in potency but no improvement in stability whilst c[Nphe(1)Cys(10,14)] displays tissue (antagonist in the vas deferens) and assay (antagonist in the GTPgamma(35)S assay and agonist in cAMP assay) dependent activity.

Animals↗
PubMed2003

Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2.

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.

Journal Article↗
PubMed2003

Laparoscopic management of large paraesophageal hiatal hernia.

BACKGROUND: Large paraesophageal hernias (POHs) predominantly occur in the elderly population. Early repair is recommended to avoid the risks associated with gastric volvulus. METHODS: Data were collected prospectively during an 8-year period. Laparoscopic repair of POHs initially included circumcision of the sac and mesh hiatal repair. Sac excision and suture hiatal repair were later adopted. A fundoplication was also included, initially as a selective procedure. RESULTS: Fifty-three patients with large POHs were treated by one surgeon. All had attempted laparoscopic repair, with four conversions to an open procedure. Symptomatic hernia recurrence occurred in five patients (9%). The 21 patients who had sac excision, hiatal repair, and fundoplication have remained free of symptomatic recurrence. The postoperative morbidity rate was 13%, with one death. CONCLUSIONS: Laparoscopic repair of large POHs remains feasible. We advocate complete sac excision, hiatal repair, fundoplication, and gastropexy to prevent early recurrence.

Aged↗
PubMed2003

High resolution spectroscopy of the 12Lambda B hypernucleus produced by the (e,e'K+) reaction.

High-energy, cw electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the potential of the (e,e'K+) reaction for hypernuclear spectroscopy. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed energy resolution was found to be approximately 900 keV for the (12)(Lambda)B spectrum, and is substantially better than any previous hypernuclear experiment using magnetic spectrometers. The positions of the major excitations are found to be in agreement with a theoretical prediction and with a previous binding energy measurement, but additional structure is also observed in the core excited region, underlining the future promise of this technique.

Journal Article↗
PubMed2003

Spatial parasite transmission, drug resistance, and the spread of rare genes.

The transmission of many parasitic worms involves aggregated movement between hosts of "packets" of infectious larvae. We use a generic metapopulation model to show that this aggregation naturally promotes the preferential spread of rare recessive genes, compared with the expectations of traditional nonspatial models. A more biologically realistic model also demonstrates that this effect could explain the rapid observed spread of recessive or weakly dominant drug-resistant genotypes in nematode parasites of sheep. This promotion of a recessive trait arises from a novel mechanism of inbreeding arising from the metapopulation dynamics of transmission.

Animals↗
PubMed2003

Mild cognitive impairment in the oldest old.

BACKGROUND: No data exist on whether the syndrome of amnestic mild cognitive impairment occurs in the oldest old, or if the relationships for functional status and neuropsychometric performance based on clinical diagnosis hold true in this age group. DESIGN/METHODS: The authors performed comprehensive neurologic evaluations, neuropsychometric testing, and functional assessments on a sample of 90- to 100-year-old residents of Rochester, MN. Subjects were diagnosed as normal or with amnestic mild cognitive impairment (MCI) or dementia according to well-accepted criteria. Data on the following measures were collected and analyzed: Record of Independent Living (ROIL), Mini-Mental State Examination (MMSE), Dementia Rating Scale (DRS), Trailmaking Test (TMT), and modified version of the Free and Cued Selective Reminding Test (FCSRT). RESULTS: Data on 111 subjects (56 normal, 13 MCI, and 42 dementia) were analyzed. On the ROIL, functional capacity to carry out activities of daily living was worse for patients with dementia compared to patients with MCI and normal subjects, but did not differ between MCI and normal subjects. Scores on the MMSE, DRS, and TMT-A were worse in the dementia group compared to the normal group, and in the dementia group compared to MCI, but scores on these measures for normal subjects compared to patients with MCI were not different. Scores on the FCSRT and memory subtest of the DRS showed differences among all three groups. CONCLUSION: In spite of the advanced age of the cohort, the relationship between cognitive and functional performance and clinical diagnosis follows patterns previously described in younger samples of normal subjects, subjects with amnestic mild cognitive impairment, and subjects with dementia.

Age Distribution↗
PubMed2003

Prevalence of urinary catheterization in UK nursing homes.

A postal questionnaire survey was undertaken in registered nursing homes in three different health districts in England: Gloucestershire, North Staffordshire and Leeds. Nursing homes may be registered as general nursing or mental health homes. If homes also have provision for residential beds these are defined as dual registered homes. Overall, 9% (438/4900) of residents, with an equal male:female split, had urinary catheters. There was no significant difference in the overall urinary catheterization rate in the three districts (P=0.9). There was a wide range of urinary catheterization prevalence between homes, with some homes of all three categories having no catheterized residents and several with a prevalence of over 40%. The wide range of prevalence may be due to differences in residents' underlying medical conditions or to differences in attitudes towards urinary catheterization by nursing home staff. Almost all homes (114/124, 92%) stated they had an infection control policy, but 31% (38/124) did not have a written policy on urinary catheter care. In view of the potential for morbidity, infection control policies should include a section on the care of urinary catheters and this should form part of the continuing training of nursing home staff.

Aged↗
PubMed2003

Audit of scope and culture techniques applied to samples for the diagnosis of Mycobacterium bovis by hospital laboratories in England and Wales.

This audit examines the ability of English and Welsh laboratories to diagnose Mycobacterium bovis infection. All 164 clinical laboratories submitting samples to the PHLS Mycobacterium Reference Unit and Regional Centres for Mycobacteriology were surveyed. Twenty per cent of responding centres did not use a pyruvate-containing medium or incubate for the minimum recommended period of 8 weeks. This study demonstrates the potential for the underdiagnosis of M. bovis infection in England and Wales. Possible reasons for underdiagnosis are discussed together with strategies to optimize recovery of M. bovis.

Culture Media↗
PubMed2003

Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips.

Tear production was evaluated in 39 horses and 29 ponies using Schirmer tear test strips to determine whether diurnal or weekly fluctuations occur, whether location of strip placement has an effect, if values are the same for both eyes in an animal and whether sex, age, stabling vs. pasture and winter vs. summer had an effect. There was no test in which the raw score was less than 10 mm, although there were many occasions where tear wetting exceeded 35 mm. Analysis of the raw (continuous) scores by linear regression provided no evidence that signalment, housing or season or location of strip placement affected results. The distribution of tear test scores for a 'population' of eyes did not differ when the right eye was compared with the left eye or when the same eye was compared at different times on the same day. Individual test wetting values for opposing eyes measured at the same time, and also wetting values for the same eye measured at different times on the same day sometimes differed substantially. In winter maximum tear wetting exceeded 35 mm more frequently in the STT I than in the STT II even in housed horses and ponies, but there was no consistent significant difference. There appears to be wide variability in the STT I in normal horses and ponies.

Animals↗
PubMed2003

The streak retinoscopy pupil reflex in the presence of astigmatism.

Computer simulation is being increasingly used as a teaching tool. Having developed a computer-generated virtual focimeter, we are now in the process of developing a computer-generated virtual streak retinoscope to teach the principles of retinoscopy and the effect of residual refractive error and mirror movement on the pupil reflex. One of the important requirements was to provide as accurate a simulation as possible for the completely general case of an astigmatic patient and a streak in any orientation being moved also in any orientation. This required a thorough understanding of the optical theory of the retinoscope and equations that describe the behaviour of the pupil reflex. We have taken this opportunity to review the optics of the streak retinoscope and derive equations for the behaviour of the pupil streak reflex.

Astigmatism↗
PubMed2003

Analgesic effects of parecoxib following total abdominal hysterectomy.

BACKGROUND: Forty-eight ASA I-II patients undergoing total abdominal hysterectomy (TAH) were studied in a double blind, randomized placebo controlled trial of parecoxib for postoperative analgesia. METHODS: All patients were given propofol 2-4 mg kg(-1) i.v., a non-depolarizing muscle relaxant, morphine 10 mg i.v. and prochlorperazine 12.5 mg i.m. intraoperatively. Their lungs were ventilated with nitrous oxide and isoflurane 1-1.5% in oxygen. Morphine was self-administered for postoperative analgesia via a patient controlled analgesia (PCA) device. Patients were allocated randomly to receive either parecoxib 40 mg i.v. or normal saline on induction of anaesthesia. RESULTS: Twelve patients did not complete the study. Of the remaining 36 patients, there was no significant difference between the treatment groups in age, weight, ASA status, duration of surgery, or intraoperative dose of morphine. However, mean (95% CI) 24 h morphine consumption of 54 (42-65) mg in the parecoxib group was significantly (P=0.04) lower than that of 72 (58-86) mg in the placebo group. Pain intensity scores on sitting up were significantly lower (P=0.02) in the parecoxib group compared with placebo. There was no significant difference between the treatment groups in pain intensity scores at rest and on deep inspiration, or in nausea, total number of vomiting episodes, median number of rescue antiemetic doses, and sedation scores. CONCLUSIONS: Parecoxib 40 mg i.v. may be recommended in patients having TAH as it provides morphine-sparing analgesia.

Adult↗
PubMed2003

Investigation of interaction between N-acetyltransferase 2 and heterocyclic amines as potential risk factors for colorectal cancer.

Fast N-acetyltransferase 2 (NAT2) acetylators may be at increased risk of colorectal cancer through the activation of carcinogenic heterocyclic amines (HA), which are produced by meat cooked at high temperatures and are found in cigarette smoke. A study of 500 incident colorectal cancer cases and population controls, matched for age, sex and general practitioner, was conducted in the UK to investigate this hypothesis. Usual meat intake and lifetime smoking habits were estimated using a detailed questionnaire administered by interview. Subjects also indicated how well cooked they ate their meat. Subjects were classified as fast or slow NAT2 acetylators on the basis of NAT2 genotype. Complete genotype data were available on 433 matched pairs. The risk of colorectal cancer showed a steady increase with meat intake, rising to an odds ratio of 1.51 [95% confidence interval (1.03, 2.23)] for the highest versus the lowest quartile, after adjustment for total energy intake, and this was even more pronounced for red meat [odds ratio 1.97 (1.30, 2.98)]. However, this effect was not influenced by the preference for well-done meat. Smoking was also associated with an increased risk [odds ratio 1.47 (1.10, 1.98) for ever- versus never-smokers]. In both cases and controls approximately 40% of subjects were classified as fast acetylators, and the risks associated with (red) meat intake and smoking did not vary with NAT2 status. This study provides no support for the hypothesis that fast NAT2 acetylators are at increased risk of colorectal cancer, even if exposed to high levels of HA from well-cooked meat or smoking.

Aged↗
PubMed2003

Antibiotics and surgery for vesicoureteric reflux: a meta-analysis of randomised controlled trials.

AIMS: To evaluate the benefits and harms of treatments for vesicoureteric reflux in children. METHODS: Meta-analyses of randomised controlled trials using a random effects model. Main outcome measures were incidence of urinary tract infection (UTI), new or progressive renal damage, renal growth, hypertension, and glomerular filtration rate. RESULTS: Eight trials involving 859 evaluable children comparing long term antibiotics with surgical correction of reflux (VUR) and antibiotics (seven trials) and antibiotics compared with no treatment (one trial) were identified. Risk of UTI by 1-2 and 5 years was not significantly different between surgical and medical groups (relative risk (RR) by 2 years 1.07; 95% confidence interval (CI) 0.55 to 2.09, RR by 5 years 0.99; 95% CI 0.79 to 1.26). Combined treatment resulted in a 60% reduction in febrile UTI by 5 years (RR 0.43; 95% CI 0.27 to 0.70) but no concomitant significant reduction in risk of new or progressive renal damage at 5 years (RR 1.05; 95% CI 0.85 to 1.29). In one small study no significant differences in risk for UTI or renal damage were found between antibiotic prophylaxis and no treatment. CONCLUSION: It is uncertain whether the identification and treatment of children with VUR confers clinically important benefit. The additional benefit of surgery over antibiotics alone is small at best. Assuming a UTI rate of 20% for children with VUR on antibiotics for five years, nine reimplantations would be required to prevent one febrile UTI, with no reduction in the number of children developing any UTI or renal damage.

Adolescent↗
PubMed2003

Elevated results in a vitamin B12 assay when using serum separator blood collection tubes.

BACKGROUND: In the light of apparently spurious serum vitamin B(12) results in some patients, the effect of serum separator sample tubes on serum vitamin B(12) values, assayed by the Bayer Centaur analyser, was examined. METHOD: Results of parallel assays of serum vitamin B(12) in plain (non-gel) serum tubes and serum separator gel tubes were compared. Serum in previously centrifuged gel tubes was mixed in the tube and the effect of that mixing on assay results quantitated. A limited investigation of the effect of tube cap type was also carried out. RESULTS: Serum vitamin B(12) concentration was 54% higher in samples taken into serum separator tubes after re-mixing the serum in the original tube. This effect could be abolished by re-centrifugation. CONCLUSIONS: Use of serum separator tubes may be associated with spuriously elevated serum vitamin B(12) concentrations in the Bayer Centaur assay. Laboratories receiving samples for vitamin B(12) assay in serum separator tubes that have already been centrifuged should either re-centrifuge the tubes, or aliquot and re-centrifuge serum from the tubes prior to vitamin B(12) assay.

Artifacts↗