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Biomedical subjects

A Taylor

Publications and source records attributed to A Taylor.

At least 91 records · Page 5Linked to original sources
PubMed2003

Cryo-thawed embryos obtained from conception cycles have double the implantation and pregnancy potential of those from unsuccessful cycles.

BACKGROUND: The purpose of this study was to evaluate the influence of fresh IVF/ICSI cycle outcome on the prognosis of the related frozen embryo replacement (FER) cycle. METHODS: 459 FER cycles, involving 2049 cleavage stage embryos with no or up to 10% fragmentation, were performed for which the outcome of the fresh cycle was recorded. The cycles were divided into two groups; group A included cycles in which cryopreserved embryos were obtained from fresh cycles in which conception occurred. Group B were cycles in which cryopreserved embryos originated from unsuccessful fresh cycles. RESULTS: Groups A and B were comparable with respect to mean (+/- SD) age at cryopreservation (33 +/- 3.9 versus 33.2 +/- 4 years, P = not significant), mean number of oocytes retrieved and fertilized normally in the fresh cycle (11 +/- 5.2 versus 11.2 +/- 4.8, P = not significant) and mean age at the cryo-thawed transfer (34.5 +/- 4.2 versus 33.9 +/- 4 years, P = not significant). No significant difference was found between the two groups with regard to mean number of embryos cryopreserved (6.5 +/- 3.9 versus 6.2 +/- 3.6) and subsequently thawed (4.5 +/- 2.5 versus 4.5 +/- 1.8) per cycle and number of cryo-thawed embryos transferred per cycle (2.0 +/- 0.7 versus 2.1 +/- 0.8). However, the implantation rate per transferred embryo in group A was double that in group B (23 versus 11.2%, P < 0.0001). Moreover, the clinical pregnancy and ongoing pregnancy rates per cycle were significantly higher in group A compared with group B (34.8 and 27.3% versus 15.6 and 13.1%, P < 0.0001 and P = 0.0003 respectively). The difference in FER cycle outcome could not be explained by confounding variables. CONCLUSIONS: After thawing, cryopreserved embryos originating from conception IVF/ICSI cycles achieve double the implantation and pregnancy rates of those obtained from unsuccessful cycles.

Adult↗
PubMed2003

Underdiagnosed asthma in South Australia.

BACKGROUND: The prevalence of undiagnosed asthma in the general population and the clinical and demographic characteristics of these patients compared with those with diagnosed asthma are unclear. METHODS: The North West Adelaide Health Survey (NWAHS) is a population household interview survey of adults (age>18 years) in the north western suburbs of Adelaide, South Australia (regional population 0.6 million). Data obtained were weighted to the closest census data to provide population representative estimates. Positive answers to: "Have you ever had asthma?"; "Has it been confirmed by a doctor?"; "Do you still have asthma?" determined current physician diagnosed asthma. A positive bronchodilator response on spirometric testing according to ATS criteria without a physician's diagnosis determined undiagnosed asthma. Other measures included the SF-12 health survey questionnaire, the Selim index of severity of chronic lung disease, skin allergy tests, and demographic data. RESULTS: Of the 3422 individuals interviewed, 2523 (74%) agreed to participate in the clinical assessment. Of these, 292 (11.6%) had asthma, 236 (9.3%) with a doctor's diagnosis of asthma and 56 (2.3%) with undiagnosed asthma defined on spirometric criteria; thus, 19.2% of the total asthma group were undiagnosed. Those undiagnosed were more likely (p<0.05) to be >40 years old, on government benefits, with an income 65 years. Health service use over the previous year was similar for both asthma groups. CONCLUSION: Undiagnosed asthma is common among the Australian population, with a similar clinical spectrum to those with diagnosed asthma.

Adult↗
PubMed2003

Fetal endoscopic telesurgery using an Internet Protocol connection: clinical and technical challenges.

Until recently, fetoscopic laser surgery to seal the placental anastomoses that cause severe twin-to-twin transfusion syndrome has been available in only a few centres worldwide. The technique typically takes a long time to learn. We have used a dedicated Internet Protocol (IP) connection for tele-education to assist the introduction of fetoscopic laser surgery to Australia. During the implementation of the international telemedicine link, there were multiple clinical and technical problems, which were eventually overcome. The quality of images and of video-sequences was comparable to that supported by an ISDN connection. Pictures of live surgery performed by an expert in Florida, USA, were transmitted and viewed by a novice team in Brisbane, Australia. The Australian team has performed 19 fetoscopic laser operations to date. Preliminary results are comparable to those from centres that have performed over 100 procedures.

Australia↗
PubMed2003

Anxiety and feelings of medical students conducting their first gynecological examination.

We examined the anxiety of medical students when they conduct their first gynecological examination. The students (226) from two universities completed anonymous questionnaires providing measures of state and trait anxiety and anxiety and confidence feelings, before and after conducting their first bimanual and speculum examination. This took place during a structured, self-directed learning session and involved examination of a professional patient. Students state anxiety was significantly elevated immediately before and fell to below baseline levels after the examination (p < 0.001). Students' reported feelings of increased confidence during the examination (p < 0.001). Students who had personally had a Pap smear test were most anxious before (p < 0.003) but during the examination, students who had experienced a gynecological exam felt less anxious (p < 0.002). The students experiencing the greatest decreases (before to after) in state anxiety were those who had never experienced sexual intercourse (p < 0.005). Most students (96%), particularly those who were more anxious during the examination (p < 0.001) and who experienced a greater decrease in anxiety from before to after the examination (p < 0.008) would recommend this method of learning to other students. In summary, medical students are anxious when they conduct their first gynecological examination, appear to be influenced by their personal experiences and appreciate methods of learning that reduce their anxiety.

Adult↗
PubMed2003

Establishment of a database of diagnosed HCV-infected persons in Scotland.

To provide a comprehensive understanding of the epidemiology of hepatitis C virus (HCV) infection in Scotland, a database of all persons known to have been infected with HCV in Scotland was established. Non-identifying data, held on the computers and requests forms in Scotland's principal and confirmatory HCV testing laboratories, were entered onto a National Database at the Scottish Centre for Infection and Environmental Health. As at December 2001, records from 13,519 persons in Scotland known to have been infected with HCV had been entered on to the database (one in 378 of Scotland's population). Of the 13,519, 69% were male and 90% of the 9,092 for whom risk factor information was available had injected drugs; 37% were from Greater Glasgow. Fifty-six per cent of the 13,519 were diagnosed between 1998 and 2001; 1,727 (23%) of the new diagnoses from 1998 to 2001 were aged under 25 years. The data provide an insight into the epidemiology of HCV infection in Scotland. They support other data, which indicate that the current major risk factor for HCV in the country is injecting drug use.

Adolescent↗
PubMed2002

Increasing the gonadotrophin dose in the course of an in vitro fertilization cycle does not rectify an initial poor response.

OBJECTIVE: To evaluate the value of increasing the gonadotrophin dose after 5 days of controlled ovarian stimulation in IVF patients who show an initial poor response to stimulation. SUBJECTS AND METHODS: We identified all IVF cycles between January 1992 and March 1996 in which ovarian response after 5 days of controlled ovarian hyperstimulation (COH) with 225-300 IU per day of human menopausal gonadotrophins (hMG; Metrodin or Pergonal) was monitored by measurement of serum estradiol concentrations (n=596 patients). According to estradiol concentration, the daily dose of hMG was doubled or increased to 450 IU in 193 patients (group A) or maintained the same in 403 patients (group B). Further cycle monitoring was achieved using serial ultrasound and serum estradiol measurements. RESULTS: The two groups were age-matched. Group A patients experienced a higher cancellation rate despite having a higher mean number of hMG ampoules (59.5 versus 36.2) and a longer duration of stimulation (12.2 versus 10.8 days). They achieved lower levels of serum estradiol on days 9 and 10 of stimulation, produced a lower mean number of oocytes per retrieval (5.8 versus 8.9) and had a lower clinical pregnancy rate per cycle (8.3 versus 23.4%) compared to group B. All differences were statistically significant. CONCLUSION: The poor outcome of cycles with initial low response to COH appears not to be averted by doubling or increasing the hMG dose after 5 days of stimulation.

Adult↗
PubMed2002

The bone formation defect in idiopathic juvenile osteoporosis is surface-specific.

We have previously shown that idiopathic juvenile osteoporosis (IJO) is characterized by a decreased cancellous bone volume and a very low bone formation rate on cancellous surfaces. Whether IJO similarly affects cortical bone is unknown. We therefore compared tetracycline double-labeled transfixing iliac-crest bone biopsies from eight children with typical clinical features of IJO (six girls; age 10-12 years) and from nine children (four girls; age 9-12 years) without metabolic bone disease. No differences in intracortical remodeling activity were detected. Both structural parameters reflecting intracortical remodeling (cortical porosity, active canal diameter, and quiescent canal diameter) and bone surface-based metabolic parameters (osteoid, osteoblast, mineralizing, osteoclast and eroded surfaces, and bone formation rate) were similar in IJO patients and controls (p > 0.2 each, t-test). Although the internal cortex of the biopsy was thinner in IJO patients than in controls (660 +/- 170 microm vs. 980 +/- 320 microm; p = 0.02), there was no difference in the width of the external cortex (p = 0.36). In growing children, both cortices exhibit an external modeling drift. Therefore, the difference in internal cortical width point to a decreased modeling activity on the endocortical surface of the internal cortex. In fact, bone formation rate on this surface was 48% lower in IJO patients than in controls (82 +/- 45 microm(3)/microm(2) per year vs. 159 +/- 162 microm(3)/microm(2) per year). However, this difference did not achieve statistical significance (p = 0.21) due to the high variability of bone formation rate on modeling surfaces. The disturbance of bone remodeling in IJO is limited to cancellous bone, but there may be a modeling defect affecting the internal cortex. Thus, the process causing IJO appears to mainly affect bone surfaces that are in contact with the bone marrow cavity.

Bone Remodeling↗
PubMed2002

Prevalence of hepatitis C among injectors in Scotland 1989-2000: declining trends among young injectors halt in the late 1990s.

We previously reported a continual decline in anti-HCV prevalence among young injectors from Glasgow and Lothian between 1990 and 1997. The original study was extended to ascertain if the anti-HCV prevalence among injectors from Glasgow, Lothian, Tayside and Grampian had changed since 1997. Residual sera from injectors who had undergone attributable anti-HIV testing were tested anonymously for anti-HCV. In all four regions, no significant changes in prevalence were found among those aged < 25 years during the late 1990s (Glasgow 1997-9/00: 43%-41%; Lothian 1997-9: 13%-17%; Tayside 1997-9: 45%-35%; Grampian 1996-9: 28%-29%). Among those aged > or = 25 years, significant decreases in prevalence were only observed in Glasgow (1997-9/00: 79%-72%, P = 0.03) and Lothian (1997-9: 54%-45%, P = 0.05). The findings highlight that existing harm reduction measures, acknowledged as having helped to reduce the spread of HCV, are not sufficient to bring this epidemic under control and reduce transmission to sporadic levels.

Adolescent↗
PubMed2002

Monitoring hepatitis C virus infection among injecting drug users in the European Union: a review of the literature.

Hepatitis C virus (HCV) among injecting drug users (IDUs) is one of the European Union's (EU) major public health problems. This review examines the current state of knowledge regarding HCV among IDUs in EU countries. Studies published between January 1990 and December 2000, were identified through a computerized search (MEDLINE and EMBASE). Ninety-eight studies have reported prevalence for HCV among groups of IDUs in all EU countries except Luxembourg. The prevalence of anti-HCV ranged from 30 to 98%. Incidence rates ranged from 6.2 to 39.3 per 100 person years. This review provides a comprehensive examination of HCV infection among IDUs in the countries of the EU, and quite clearly demonstrates that the quality and epidemiological relevance of the studies published varies widely. Thus, the reported data may not reflect accurately the current or recent past prevalence of HCV among IDUs in the EU. A strategic approach to the surveillance of HCV among IDUs in the EU, utilizing robust and consistent methods, is required urgently.

Adult↗
PubMed2002

A comparison of some metabolic effects of N-methylaspartate stereoisomers, glutamate and depolarization: a multinuclear MRS study.

Exposure of guinea pig brain slices to low concentrations (10 microM) of NMDA caused decreases in PCr and ATP within 30 min, with a slower decrease in NAA and increase in lactate, both detectable after 1 h. Exposure to NMDA for over 1 h or at higher concentrations caused further increases in lactate and decreases in NAA, with no further change in PCr or ATP. The L-isomer, NMLA, and the racemic mixture, NMDLA, caused similar changes in lactate and NAA, but both produced greater decreases in the energy state than NMDA, similar to those caused by prolonged exposure to glutamate. MK-801 prevented the changes in the energy state caused by NMDA, but not those caused by NMLA or by glutamate. The results are compared to previous studies on depolarization and discussed in terms of the role of the NMDA sub-type of glutamate receptor in the excitotoxic hypothesis of neuronal degeneration.

Adenosine Triphosphate↗
PubMed2002

Lead poisoning: case studies.

Early clinical features of lead toxicity are non-specific and an occupational history is particularly valuable. Lead in the body comprises 2% in the blood (t1/2 35 days) and 95% in bone and dentine (t1/2 20-30 years). Blood lead may remain elevated for years after cessation from long exposure, due to redistribution from bone. Blood lead concentration is the most widely used marker for inorganic lead exposure. Zinc protoporphyrin (ZPP) concentration in blood usefully reflects lead exposure over the prior 3 months. Symptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) or in any event >3.8 micromol l-1 (80 microg dl-1) should receive sodium calciumedetate i.v., followed by succimer by mouth for 19 days. Asymptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) may be treated with succimer alone. Sodium calciumedetate should be given with dimercaprol to treat lead encephalopathy.

Acute Disease↗
PubMed2002

The management of persistent and recurrent chronic anal fissures.

There are numerous definitive reviews concerning aetiology and management of acute and chronic anal fissures. The problem of persistence and recurrence after surgical and nonsurgical therapy has not been specifically addressed and there is little evidence-based guidance for the management of this difficult group of patients. A review of the literature with particular reference to persistence and recurrence of chronic anal fissures is presented and an algorithm of management incorporating evidence-based data is suggested.

Journal Article↗
PubMed2002

The human tuftelin gene and the expression of tuftelin in mineralizing and nonmineralizing tissues.

Tuftelin has been suggested to play an important role during the development and mineralization of enamel, but its precise function is still unclear. This article reviews major milestones in the discovery, structural characterization, expression, localization, and conservation of tuftelin in different vertebrate species. It focuses on the structure of the human tuftelin gene, which has recently been deciphered [12]. It describes the exon-intron organization, sizes and structure, the promoter structure, and the newly discovered alternatively spliced human tooth-bud tuftelin mRNA transcripts. It also examines information on the structural motifs in the human-derived tuftelin protein and how they relate to tuftelin from other species. It reviews our recent results on the transcription of tuftelin mRNA and protein expression in several nonmineralizing soft tissues, using reverse-transcription polymerase chain reaction (RT-PCR) followed by DNA cloning and sequencing, indirect immunohistochemistry, immunohistochemistry combined with confocal microscopy, and in situ hybridization. These results and earlier Northern blot results show that tuftelin, in addition to being expressed in the developing and mineralizing tooth, is also expressed in several nonmineralizing soft tissues, suggesting that tuftelin has a universal function and/or a multifunctional role.

Alternative Splicing↗
PubMed2002

Randomized comparison of the quality of realtime fetal ultrasound images transmitted by ISDN and by IP videoconferencing.

We compared the quality of realtime fetal ultrasound images transmitted using ISDN and IP networks. Four experienced obstetric ultrasound specialists viewed standard recordings in a randomized trial and rated the appearance of 30 fetal anatomical landmarks, each on a seven-point scale. A total of 12 evaluations were performed for various combinations of bandwidths (128, 384 or 768 kbit/s) and networks (ISDN or IP). The intraobserver coefficient of variation was 2.9%, 5.0%, 12.7% and 14.7% for the four observers. The mean overall ratings by each of the four observers were 4.6, 4.8, 5.0 and 5.3, respectively (a rating of 4 indicated satisfactory visualization and 7 indicated as good as the original recording). Analysis of variance showed that there were no significant interobserver variations nor significant differences in the mean scores for the different types of videoconferencing machines used. The most significant variable affecting the mean score was the bandwidth used. For ISDN, the mean score was 3.7 at 128 kbit/s, which was significantly worse than the mean score of 4.9 at 384 kbit/s, which was in turn significantly worse than the mean score of 5.9 at 768 kbit/s. The mean score for transmission using IP was about 0.5 points lower than that using ISDN across all the different bandwidths, but the differences were not significant. It appears that IP transmission in a private (non-shared) network is an acceptable alternative to ISDN for fetal tele-ultrasound and one deserving further study.

Computer Communication Networks↗
PubMed2002

Medical students' opinions of chaperone use during gynecological and anorectal examinations.

The opinions of medical students on chaperone use during physical examinations of the male and female was studied. The students (157) had conducted their first gynecological or first anorectal and prostate examination. Fifty-one percent of students were female, 56% younger than 25 years of age, and 77% males and 73% females had experienced sexual intercourse. Data on the use of a chaperone during vaginal, anorectal, breast and musculoskeletal examinations when conducted by doctors and by students was collected by anonymous questionnaires. Most students feel a chaperone is necessary when students-in-training conduct vaginal (94%), anorectal (94%) or breast (89%) examinations. Fewer students feel a chaperone is necessary when doctors rather than students conduct vaginal (41%), anorectal (22%) and breast (25%) examinations. Students were significantly more likely to feel a chaperone was necessary when a doctor of the opposite sex conducts vaginal (58%) and anorectal (34%) examinations, compared to a doctor of the same sex. Students who were male, 25 years or older or had not experienced sexual intercourse were significantly more likely to favour doctors using chaperones. The differences in responses of students of differing age, gender and sexual experience should be considered and discussed when students are learning invasive physical examinations.

Adult↗
PubMed2002

Renovascular hypertension: nuclear medicine techniques.

Angiotensin converting enzyme inhibition (ACEI) renography is the only imaging examination that tests directly for the presence of renovascular hypertension (RVH); other imaging examinations test for the presence of renal artery stenosis (RAS). The goals of ACEI renography are two-fold: 1) to detect those patients with hypertension who have renal artery stenosis as the cause of their hypertension and who would benefit from revascularization, and 2) to determine which hypertensive patients do not have renovascular hypertension and obviate the expense and risk of angiography and, potentially, revascularization. This review summarizes general components of renal scintigraphy (pretest voiding, hydration, patient position, relative uptake, time to peak height of the renogram curve, 20 min/max ratio, postvoid images, quality control) as well as those components specific to ACEI renography (choice of radiopharmaceutical, choice of ACE inhibitor, angiotensin II receptor blockers, diuretics, parenchymal mean transit time, monitoring of blood pressure, 1 versus 2 day protocols and omission of the baseline study). ACEI renography is highly accurate in patients with suspected RVH who have normal or near normal renal function. In this patient population, the sensitivity and specificity of ACEI renography for renovascular hypertension exceed 90%; angiography as an initial approach is not cost effective. Data from 10 studies evaluating cure or improvement in blood pressure in 291 patients undergoing revascularization showed the mean positive predictive value of ACEI renography to be 92%. When azotemic patients present with suspected RVH, as many as 50% of patients may have an intermediate probability ACEI renogram and the sensitivity of detecting RVH falls to approximately 80% even when intermediate and high probability tests are combined.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

Alzheimer disease is not associated with polymorphisms in the angiotensinogen and renin genes.

Hypertension has been implicated as a risk factor for Alzheimer disease (AD) and dementia in epidemiological studies of humans. It is thus possible that there are common genetic determinants for hypertension and AD. Epidemiological, clinical, and experimental data suggest that the renin-angiotensin-aldosterone system is a critical regulator of blood pressure. The presence of an MboI site in an RFLP in the renin gene and the Thr at the Met/Thr polymorphism at codon 235 (M235T) of the angiotensinogen gene have been reported to be associated with hypertension. These variants were studied in autopsy-confirmed AD cases and matched controls from the U.K. While no association was detected with the renin polymorphism, a weak deleterious effect was observed in cases homozygous for the angiotensinogen Thr allele. However, this association was not observed in a French cohort of clinically diagnosed AD cases and controls, suggesting that the initial observation was a type I error. Thus, these polymorphisms are unlikely to be associated with AD risk.

Aged↗