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Biomedical subjects

D Barlow

Publications and source records attributed to D Barlow.

At least 37 records · Page 2Linked to original sources
PubMed1999

Today's treatments: how do you choose?

OBJECTIVE: To provide a view on how the clinician can select appropriate treatment when managing individual patients with endometriosis. METHODS: Review of randomized controlled trials and personal experience. RESULTS: The main determinants of therapy choice are personal experience and patient acceptability. Placebo-controlled trial results support the use of naproxen, dydrogesterone, danazol and leuprolide for pain relief. Laser laparoscopy is more effective than expectant management for pain relief. In direct comparisons, oral contraceptives, Zoladex, danazol, gestrinone, nafarelin and leuprolide have similar efficacies in relieving pain, but have different side-effect profiles. In controlled trials, only laser laparoscopy was shown to improve fertility in minimal/mild disease. The physiological response of bone metabolism to GnRH agonist therapy should be seen in context and the place of add-back regimens understood. The general medical history of the patient must be considered when choosing therapy. CONCLUSIONS: The clinician must provide the patient with appropriate information on the treatment options to allow her to make an informed choice.

Endometriosis↗
PubMed1999

Serologic evidence of human herpesvirus 8 transmission by homosexual but not heterosexual sex.

Epidemiologic studies link Kaposi's sarcoma with a sexually transmitted agent. Human herpesvirus 8 (HHV-8) is likely to be that agent, but routes of transmission are poorly described. A seroepidemiologic study was conducted to determine whether HHV-8 is transmitted sexually between heterosexuals. Sera from 2718 patients attending a sexually transmitted disease (STD) clinic were tested for antibodies to HHV-8 and herpes simplex virus type 2 (HSV-2). Information on sex partners in the previous 12 months and past STDs were obtained by questionnaire. Relationships between possible risk factors and HHV-8 infection were assessed by logistic regression. Overall, seroprevalence of HHV-8 was 7.3%. Independent risk factors for HHV-8 in the whole group were homo/bisexuality and birth in Africa and, among homo/bisexual men, a history of syphilis and HSV-2 and human immunodeficiency virus seropositivity. Among heterosexuals there was no evidence for sexual transmission; the only independent risk factor for HHV-8 seropositivity was birth in Africa.

Adolescent↗
PubMed1999

Extremes of body mass do not adversely affect the outcome of superovulation and in-vitro fertilization.

The effect of extremes of body mass on ovulation is well recognized by clinicians. However, the effect of obesity and extreme underweight on the outcome of in-vitro fertilization (IVF) cycles has received relatively little attention. In a retrospective nested case-control study we examined the effect of the extremes of body mass index (BMI) on IVF-embryo transfer outcome at a university-based IVF unit. A total of 333 patients were included in the study; 76 obese patients (BMI > 27.9) with 152 controls, and 35 underweight patients (BMI < 19) with 70 controls. The patients were matched with their controls in age +/- 1 year, day 3 follicle stimulating hormone (FSH) concentration, daily dose of gonadotrophin (+/- 37.25 IU), gonadotrophin preparation and the year of treatment. The following parameters were compared between the study and control groups: duration of administration and dose of gonadotrophin, number of follicles aspirated, number of eggs, fertilization rate, number of embryos, serum oestradiol concentration on human chorionic gonadotrophin (HCG) day (peak oestradiol), clinical pregnancy rate, implantation rate, miscarriage rate, and incidence of ovarian hyperstimulation syndrome. Apart from a significantly lower peak oestradiol concentration (P = 0.009) in the obese patients, they and the underweight patients were not significantly different from their normal controls. The extremes of body mass index do not adversely affect the outcome of IVF-embryo transfer treatment. However, the obese patients had lower peak oestradiol concentrations than their normal controls despite receiving similar gonadotrophin doses.

Abortion, Spontaneous↗
PubMed1999

Poor responders to ovulation induction: is proceeding to in-vitro fertilization worthwhile?

A 'poor response' in the context of in-vitro fertilization (IVF) can be defined as failure to produce an adequate number of mature follicles, and/or a peak oestradiol concentration less than a defined minimum. The cut-off points implied in this definition vary between different centres. Many opt to cancel the IVF cycle when their defined minimum concentrations are not reached despite the lack of evidence of improved outcome in subsequent cycles. Patients attending the Oxford Fertility Unit who are 'poor responders' have always been given the option of continuing with treatment. The first cycles of IVF in 124 patients, with normal day 3 follicle stimulating hormone (FSH), who produced less than five follicles within a 2 year period were studied. The patients were divided into three groups according to the number of follicles produced: A (one or two follicles; n = 33), B (three follicles; n = 33) and C (four follicles; n = 58). The three groups were similar in age, day 3 FSH, total gonadotrophin dose, duration of stimulation, peak oestradiol concentration, oocyte yield, fertilization rate and the clinical pregnancy rate. However, group A had a significantly higher oestradiol concentration per follicle (P < 0.001). The clinical pregnancy rate/cycle in the three groups was comparable to our overall rate in the study period (25.5%). This paper suggests that poor responders with a normal day 3 FSH may still achieve a pregnancy rate similar to that of normal responders.

Adult↗
PubMed1999

Implantation versus infiltration: the Sampson versus the endometriotic disease theory.

It has been assumed that endometriosis is a progressive disease, with growth and development of lesions being inevitable once the disease has started. The implantation and the metaplasia theories describe the mechanism of initiation of endometriotic lesions, but do not explain the different clinical manifestations of endometriosis. To explain the variable expression, growth and development of lesions into severe disease, a new endometriotic disease theory is proposed. This theory suggests that progression of endometriosis to endometriotic disease is considered similar to the onset and progression of a benign tumour. In this theory, the most important factor in the development of endometriotic disease is not the initial implantation/metaplasia, but cellular changes such as mutations. According to this theory, endometriotic disease develops from endometriotic cells that have 'escaped' the influence of protective and regulatory factors in the peritoneal fluid.

Animals↗
PubMed1999

Marketing environment dynamics and implications for pricing strategies: the case of home health care.

This research reviews the factors affecting the pricing or rate schedules of home health care agencies. A large number of factors affect costs and thus rate structures. The major factors include reimbursement structures with accompanying discount structures, administrative burdens, and risks. Channel issues include bargaining power, competition, and size. Staffing issues affect pricing and product through the provider level, productivity, and quality outcomes. Physician and patient issues include quality concerns and choices. These factors are discussed in light of overall marketing strategy and the interaction of pricing with other marketing controllables such as product, place/distribution, and promotion. Economic and accounting principles are also reviewed with consideration to understanding direct and indirect costs in order to enable negotiators to effectively price health care services.

Accounting↗
PubMed1998

Superovulation with a high gonadotropin dose for in vitro fertilization: is it effective?

PURPOSE: Our purpose was to investigate the effect on the ovarian response of increasing the gonadotropin dose. METHODS: We analyzed retrospectively the in vitro fertilization data for patients who had two cycles of treatment, with a higher dose in cycle 2. The patients were stratified according to age, ovarian response, and gonadotropin dose in the first cycle. The main outcome measure was the number of follicles, eggs, and embryos and the peak estradiol (E2) level. RESULTS: The study included 244 patients. Patients in both age groups (n = 118, < or = 33 years; n = 126, > 33 years), low (n = 66) and intermediate (n = 145) responders, and patients who received < 225 IU follicle-stimulating hormone (n = 175) in cycle 1 had a better response in cycle 2. However, the high responders (n = 33) and those who received 225 or 300 IU follicle-stimulating hormone (n = 69) in cycle 1 showed a similar response in both cycles, except for a significantly higher E2 level in cycle 2. CONCLUSIONS: Our results indicate that exceeding a daily dose of 300 IU is unrewarding.

Adult↗
PubMed1998

Evidence from human oocytes for a genetic bottleneck in an mtDNA disease.

We have examined oocytes from a patient with Kearn-Sayre syndrome caused by mtDNA rearrangements. In mtDNA diseases, mutant and wild-type mtDNA frequently coexist in affected individuals (the condition of heteroplasmy). The proportion of mutant mtDNA transmitted from mother to offspring is variable because of a genetic bottleneck, and the "dose" of mutant mtDNA received influences the severity of the phenotype. The feasibility of prenatal diagnosis is critically dependent on the nature and timing of this bottleneck. Significant levels of rearranged mtDNA were detectable in the majority of the patient's oocytes, by use of multiplex PCR, with wide variation, in the levels of mutant and wild-type molecules, between individual oocytes. We also used length variation in a homopolymeric C tract, which is often heteroplasmic in normal controls, to identify founder subpopulations of mtDNAs in this patient's oocytes. We present direct evidence that the number of segregating units (n) is three to five orders of magnitude less than the number of mitochondria in the human female oocyte. In some cases, the best estimate of n may correspond to a single mitochondrion, if it is assumed that intergenerational transmission of mtDNA can be treated as a single sampling event. The bottleneck appears to contribute a major component of the variable transmission from mother to oocyte, in this patient and in a control. That this bottleneck had occurred by the time that oocytes were mature advances the prospects for prenatal diagnosis of mtDNA diseases.

DNA Primers↗
PubMed1998

Do gastrointestinal symptoms vary with the menstrual cycle?

This systematic review presents both the physiological and symptom-based studies which have explored gastrointestinal variation across the menstrual cycle. Understanding this variation may be helpful in identifying the origin of pelvic pain, particularly as the symptoms associated with causes, such as endometriosis, also vary across the cycle. One-third of otherwise asymptomatic women may experience gastrointestinal symptoms at the time of menstruation, and almost 50% of women with irritable bowel syndrome report a perimenstrual increase in symptoms.

Abdominal Pain↗
PubMed1998

The use and cost of HIV service provision in England in 1996. National Prospective Monitoring System (NPMS) Steering Group and NPMS Working Party on Costs.

OBJECTIVE: The aim of the study was to measure the use and estimate the cost of HIV service provision in England. DESIGN AND SETTING: Standardised activity and case-severity data were collected prospectively in 10 English HIV clinics (5 London and 5 non-London sites) for the periods 1 January 1996 to 30 June 1996 and 1 July 1996 to 31 December 1996 and linked to unit cost data. In total, 5440 patients with HIV infection attended during the first 6 months and 5708 during the second 6 months in 1996. MAIN OUTCOME MEASURES AND RESULTS: The mean number of inpatient days per patient-year for patients with AIDS was 19.7 [95% confidence interval (CI): 13.7 to 25.7] for January to June and 20.8 (95% CI: 15.3 to 26.4) for July to December 1996. The mean number of outpatient visits for asymptomatic patients with HIV infection was 14.8 (95% CI: 11.9 to 17.6) and 13.3 (95% CI: 10.8 to 15.7) for the respective periods and 16.1 (95% CI: 13.21 to 18.97) and 15.7 (95% CI: 11.2 to 20.2), respectively, for patients with symptomatic non-AIDS (i.e. symptomatic patients with HIV infection but without AIDS-defining conditions). Substantial centre-to-centre variation was observed, suggesting that many clinics can continue the shift from an inpatient- to an outpatient-based service. Cost estimates per patient-year for HIV service provision for 1996 varied from 4695 Pounds (95% CI: 3769 Pounds to 5648 Pounds) for asymptomatic patients, to 7605 Pounds (95% CI: 6273 Pounds to 8909 Pounds) for symptomatic non-AIDS patients to 20,358 Pounds (95% CI: 17,681 Pounds to 23,206 Pounds) for patients with AIDS. CONCLUSIONS: Different combinations of antiretroviral therapy affect the cost estimates of HIV service provision differently. Anticipated reduction in inpatient-related activity through the increased use of combination antiretroviral therapy will further shift service provision from an inpatient- to outpatient-based service and reduce costs per patient-year. The extent and duration of such effects are currently unknown. The long term effects of combination treatment on the morbidity and mortality patterns of individuals infected with HIV are also currently unknown, as are their implications on the use and cost of HIV service provision. Multicentre databases like the National Prospective Monitoring System (NPMS) will provide healthcare professionals with information to improve existing services and anticipate the impact of new developments.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Gonorrhoea in inner London: results of a cross sectional study.

OBJECTIVES: To estimate population based incidence rates of gonorrhoea in an inner London area and examine relations with age, ethnic group, and socioeconomic deprivation. DESIGN: Cross sectional study. SETTING: 11 departments of genitourinary medicine in south and central London. SUBJECTS: 1978 first episodes of gonorrhoea diagnosed in 1994 and 1995 in residents of 73 electoral wards in the boroughs of Lambeth, Southwark, and Lewisham who attended any of the departments of genitourinary medicine. MAIN OUTCOME MEASURES: Yearly age, sex, and ethnic group specific rates of gonorrhoea per 100,000 population aged 15-59 years; rate ratios for the effects of age and ethnic group on gonorrhoea rates in women and men before and after adjustment for confounding factors. RESULTS: Overall incidence rates of gonorrhoea in residents of Lambeth, Southwark, and Lewisham were 138.3 cases yearly per 100,000 women and 291.9 cases yearly per 100,000 men aged 15-59 years. At all ages gonorrhoea rates were higher in non-white minority ethnic groups. Rate ratios for the effect of age adjusted for ethnic group and underprivilege were 15.2 (95% confidence interval 11.6 to 19.7) for women and 2.0 (1.7 to 2.5) for men aged 15-19 years compared with those over 30. After deprivation score and age were taken into account, women from black minority groups were 10.5 (8.6 to 12.8) times as likely and men 11.0 (9.7 to 12.6) times as likely as white people to experience gonorrhoea. CONCLUSIONS: Gonorrhoea rates in Lambeth, Southwark, and Lewisham in 1994-5 were six to seven times higher than for England and Wales one year earlier. The presentation of national trends thus hides the disproportionate contribution of ongoing endemic transmission in the study area. Teenage women and young adult men, particularly those from black minority ethnic groups, are the most heavily affected, even when socioeconomic underprivilege is taken into account. There is urgent need for resources for culturally appropriate research and effective intervention to prevent gonococcal infections and their long term sequelae in this population.

Adolescent↗
PubMed1997

Psychological effects of continuation versus discontinuation of hormone replacement therapy by estrogen implants: a placebo-controlled study.

There is conflicting evidence regarding the effects of hormone replacement therapy (HRT) with estrogens on psychological and psychiatric symptoms of menopause. Forty women already attending a menopause clinic for continuing HRT by estrogen implants were studied in a randomized, double-blind, placebo-controlled study of estrogen reimplantation versus implantation of a placebo preparation. Assessment included self rating with visual analog scales, standardized psychological and menopause rating scales (Hospital Anxiety and Depression Scale, Self-Concept Questionnaire, Cognitive Failures Questionnaire, Greene Menopause Index), and interview with the Present State Examination. No difference in outcome with regard to either psychological or psychiatric symptoms was found 2 months after entry to the study between the women who received an active implant and those who received a placebo implant, in spite of the former group having a significant rise in estradiol levels. The only effect of HRT on physical symptoms was a nonsignificant reduction in flushes. Psychiatric morbidity of the study population was high with nearly half being "psychiatric cases" according to the Present State Examination at both initial assessment and follow-up. At entry to the study nearly all the women had levels of estradiol in the premenopausal range and four had supraphysiological levels. It appears likely that women were returning requesting a new implant because of symptoms related to nonhormonal factors. Women receiving continuing HRT for menopausal symptoms should be reassessed both for hormonal status and current psychosocial factors when they present with recurrent symptoms, especially those of a psychological or psychiatric nature.

Adult↗
PubMed1997

Infertility treatment and multiple birth rates in Britain, 1938-94.

Trends in multiple birth rates are thought to have been substantially affected by subfertility treatments in the last 25 years, but there are few quantitative assessments of this. This paper examines trends in twin and higher multiple birth rates separately in Scotland, England and Wales and compares their course with corresponding multiple birth rates in the Oxford Record Linkage Study area, where the proportions following subfertility treatment are documented. National data on prescriptions for subfertility treatments reinforce the view that they have had a major effect on the trends, and currently perhaps 60% of triplet and higher order births and 15% of twins follow their use in Britain.

Birth Rate↗
PubMed1997

Uterine cavity assessment prior to in vitro fertilization: comparison of transvaginal scanning, saline contrast hysterosonography and hysteroscopy.

A total of 44 patients undergoing in vitro fertilization (IVF) and requiring uterine cavity assessment agreed to have both saline contrast hysterosonography (SCHS) and hysteroscopy. SCHS was performed following a baseline transvaginal scan by injection of saline into the uterine cavity during continuous scanning. Hysteroscopy was performed with a flexible fiberscope with a 3.6-mm outer diameter; 38 of 44 women (86%) underwent both procedures. Hysteroscopy diagnosed intrauterine abnormalities in 16 women. SCHS was in complete agreement in 13 of 16 cases. As a screening test for any cavity abnormality, SCHS had a 87.5% sensitivity, 100% specificity, 100% positive predictive value and 91.6% negative predictive value. In 14 women, an abnormal uterine cavity was apparent on transvaginal scanning (TVS). However, TVS, unlike SCHS, could not (1) confidently diagnose submucosal fibroids in the presence of a uterus with multiple fibroids; (2) distinguish between a hyperplastic endometrium and a large polyp; or (3) differentiate between an arcuate and a septate uterus. In addition, ovarian pathology was diagnosed on TVS in five women: endometrioma (n = 1), complex cysts (n = 2) and polycystic ovaries (n = 2). SCHS is a simple, accurate, well-tolerated procedure that can be performed within a fertility unit, avoiding invasive and expensive diagnostic hysteroscopy. Significant findings can be treated by operative hysteroscopy prior to commencing an IVF treatment cycle.

Adult↗