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Biomedical subjects

M Hickey

Publications and source records attributed to M Hickey.

At least 37 records · Page 2Linked to original sources

Endometrial bleeding in hormone replacement therapy users: preliminary findings regarding the role of matrix metalloproteinase 9 (MMP-9) and tissue inhibitors of MMPs.

OBJECTIVE: To establish the effect of hormone replacement therapy (HRT) on the expression of matrix metalloproteinase 9 (MMP-9) and the tissue inhibitor of MMPs, TIMP-1, in the endometrium of postmenopausal and perimenopausal women. DESIGN: Prospective observational study. SETTING: United Kingdom teaching hospital. PATIENT(S): Thirty-one perimenopausal and postmenopausal HRT recipients, with a control group of eight postmenopausal women not undergoing HRT. INTERVENTION(S): Prospective record of bleeding patterns and endometrial biopsy. MAIN OUTCOME MEASURE(S): Endometrial histology, bleeding patterns, MMP-9, and TIMP-1 expression. RESULT(S): MMP-9 and TIMP-1 are expressed in benign postmenopausal endometrium. Expression of both molecules is reduced in HRT recipients compared with non-HRT recipients. CONCLUSION(S): Exposure to HRT appears to alter endometrial expression of MMP-9 and TIMP-1 and also the local balance between these molecules. This alteration may promote breakdown of the endometrial extracellular matrix and blood vessels and hence bleeding.

Base Sequence↗

Abnormalities in muscle function during gait in relation to the level of lumbar disc herniation.

STUDY DESIGN: A comparison between gait in patients undergoing surgery for L4 and L5 lumbar disc herniations and that in an age- and weight-matched control group. OBJECTIVES: To study whether changes in the moments produced at the ankle and knee joints during walking reflect the neurologic level of a herniated nucleus pulposus. SUMMARY OF BACKGROUND DATA: Lumbar herniated discs often cause muscle weakness, reduced motor function, and change in walking capacity. The specific effects of a disc herniation on muscle function during gait is poorly documented. METHODS: Conventional physical examination and kinetic analysis of gait were performed on 16 patients who subsequently underwent surgery for herniated discs (eight with L4-L5 and eight with L5-S1 disc herniations) and 16 healthy control subjects. The three components of the external moment at the ankle and knee were computed. The peak magnitudes of specific components of the external moments were compared with those of the control group. RESULTS: Reduced external ankle plantar flexion moment, indicating a decreased function of the ankle dorsiflexors, was found in patients with herniated nucleus pulposus of both L4-L5 and L5-S1. Reduced external ankle dorsiflexion moment, indicating a decreased function of the ankle plantar flexors, was found only in patients with a lesion to the L5-S1 disc, but not in those with herniations at L4-L5. CONCLUSIONS: Preoperative gait analysis identified functional deficits of the muscles about the ankle and foot that relate to the level of the herniation. Kinetic measurements can assist in understanding the functional limitations associated with specific levels of a herniation.

Adult↗

Progestogens versus oestrogens and progestogens for irregular uterine bleeding associated with anovulation.

BACKGROUND: Dysfunctional uterine bleeding (DUB) is "excessively heavy, prolonged or frequent bleeding of uterine origin which is not due to pregnancy or to recognizable pelvic or systemic disease". Anovulation may be inferred from a number of observations but in the normal clinical situation, anovulation is often assumed when a woman presents with heavy, prolonged or frequent bleeding, particularly in those at the extremes of reproductive life and in women known to have the polycystic ovarian syndrome. Menstrual bleeding that is irregular or excessive is usually poorly tolerated by the majority of women. Changes in the length of the menstrual cycle generally imply disturbances of the hypothalamo-pituitary-ovarian (HPO) axis. In anovulatory DUB with acyclic (irregular) oestrogen production there will be no progesterone withdrawal from oestrogen primed endometrium and so cycles are irregular. Prolonged oestrogen stimulation may cause a build up of endometrium with erratic bleeding as it breaks down and is expelled. This is the rationale for using cyclical progestogens during the second half of the menstrual cycle in order to provoke a regular withdrawal bleed. Continuous progestogen is intended to induce endometrial atrophy and hence to prevent oestrogen-stimulated endometrial proliferation. Progestogens, and oestrogens and progestogens in combination are already widely used in the management of irregular or excessive bleeding due to DUB, but the regime, dose and type of progestogen used varies widely with little consensus about the optimum treatment approach. OBJECTIVES: To determine the effectiveness and acceptability of progestogens alone, and oestrogens and progestogens in combination in the management of irregular bleeding associated with anovulation. SEARCH STRATEGY: The search strategy of the Menstrual Disorders Group was used to identify all randomised trials of progestogens alone or in combination with oestrogens in the management of irregular menstrual bleeding associated with anovulation. In addition a search of the Cochrane Controlled Trials Register was undertaken. SELECTION CRITERIA: All randomised controlled trials of progestogens (via any route) alone or in combination with oestrogens in the treatment of irregular bleeding associated with anovulation. DATA COLLECTION AND ANALYSIS: Study quality assessment and data extraction were carried out independently by two reviewers. Both reviewers were experts in the content matter. MAIN RESULTS: No randomised trials were identified which compared progestogens with oestrogens and progestogens in the management of irregular bleeding associated with anovulation. Only one small, non-randomised study compared two progestogen regimes in the management of heavy and irregular bleeding in subjects with confirmed anovulation. One randomised study compared the effects of two progestogens on endometrial histology in subjects with a variety of menstrual symptoms, half of whom had cystic glandular hyperplasia. No studies were found which compared progestogens with oestrogens and progestogens in combination or with placebo in the management of irregular bleeding associated with anovulation. REVIEWER'S CONCLUSIONS: There is a paucity of randomised studies relating to the use of progestogens and of oestrogens and progestogens in combination in the treatment of irregular bleeding associated with anovulation. Further research is needed to establish the role of these treatments in the management of this common gynaecological problem.

Adult↗

Aerobic training in a patient with nonsevere aplastic anemia: a case report.

This case report examined whether a 26-year-old man with a 5-year history of nonsevere aplastic anemia could perform aerobic training and whether exercise was beneficial. Testing was performed at baseline and at 8 and 16 weeks and included complete blood tests, graded exercise tests with breath-by-breath gas analyses, and health status assessment with the Medical Outcomes Survey SF-12 health survey. Training consisted of treadmill walking for 25 minutes, 3 days a week for 16 weeks, at 75% of maximal heart rate. The patient successfully completed 16 weeks of training and had no adverse effects from testing or training. Training did not produce changes in disease-related measures (hematologic values) or impairment measures (cardiopulmonary measures of fitness). The mental component of the SF-12 improved from below 2 standard deviations from the population mean to within 1 standard deviation of the population mean. The benefits of aerobic training for this person with aplastic anemia were that he showed that he could participate in aerobic-type activities and that training appeared to improve his mental health.

Adult↗

Clinical implications of disturbances of uterine vascular morphology and function.

Menstrual disturbances are one of the most common problems presenting to the gynaecologist. In order for the endometrium to bleed, vessels must break down. Disruption in the regulation of endometrial vascular growth and function has been found in association with spontaneous and sex steroid-induced disturbances of menstrual bleeding. Although circulating oestrogens and progestogens influence the endometrial vessels, this effect appears to be indirect, and regulation is primarily via local factors. Deficient vasoconstriction and haemostasis with excessive fibrinolysis is seen in menorrhagia. Breakthrough bleeding in users of progestogen-only contraceptives is associated with increased superficial vascular fragility and disruptions in the supporting basement membrane. Blood vessels in uterine fibroids are abnormal in distribution and appearance. Adenomyosis is also commonly associated with menstrual disturbance, and alterations in vascular distribution suggest altered angiogenesis. Successful human embryo implantation requires endometrial vascular breakdown. Excessive thrombosis associated with the antiphospholipid syndrome may interfere with this re-modelling and compromise implantation. Arteriovenous malformations are a rare but important cause of excessive or irregular vaginal bleeding. Abundant vessels with abnormal morphology, associated with aberrant angiogenesis can be seen, and embolization of these vessels may be an effective conservative treatment. Improved understanding of the regulation of the uterine vasculature is likely to lead to targeted therapies to prevent unscheduled vascular breakdown and to control menstrual disturbance at an endometrial level.

Arteriovenous Malformations↗

The measurement of endometrial perfusion in norplant users: a pilot study.

The use of progestogens without oestrogen is commonly associated with irregular menstrual bleeding. Oestrogens and progestogens are both thought to influence endometrial perfusion; changes in endometrial perfusion may contribute to vascular fragility and breakdown. In this study, endometrial perfusion was measured using laser-Doppler fluxmetry in women in the secretory phase of the menstrual cycle before and 4-6 weeks after insertion of the low-dose long-acting levonorgestrel contraceptive implant system, Norplant. Endometrial perfusion was also measured in women exposed to Norplant for up to 19 months. There was no significant difference between endometrial perfusion in control cycles (27.2 flux units +/- 5.5, SEM) and at 4-6 weeks after Norplant insertion (16.3 flux units +/- 5.0), a time when irregular bleeding and spotting are common. Endometrial perfusion was no different from controls after longer periods of Norplant exposure (35.7 flux units +/- 7.2). No direct relationships between endometrial perfusion and plasma concentrations of ovarian steroid hormones were demonstrated. Short-term endometrial vasomotion was largely abolished during Norplant exposure.

Adult↗

Superficial endometrial vascular fragility in Norplant users and in women with ovulatory dysfunctional uterine bleeding.

The aim of this study was to develop an objective test for superficial endometrial vascular fragility at hysteroscopy, and to apply this test to women using Norplant((R)) for contraception and to women with ovulatory dysfunctional uterine bleeding (DUB). A prospective observational study was carried out in 34 Norplant users and 20 women with menorrhagia due to ovulatory DUB. Superficial endometrial vascular fragility was assessed at hysteroscopy by observing the source and extent of frank and subepithelial bleeding during controlled collapse and redistension of the uterine cavity. Superficial endometrial blood vessels were more fragile in Norplant users compared to women with DUB (chi(2) = 11.60, P = 0.02). Superficial endometrial petechiae (chi(2) = 37.9, P < 0.0001) and ecchymoses (chi(2) = 42.2, P = 0.0001) were more frequently observed in the Norplant users than in the menorrhagia group. In Norplant users, superficial endometrial vascular fragility was increased in those with frequent bleeding or spotting during the past 30 days (chi(2) = 6.15, P = 0.01), and in those who were examined during a bleeding episode (chi(2) = 5.3, P = 0.02). Fragility was increased in the menorrhagia group during the perimenstrual period (days 24 to 05; chi(2) = 12.83, P = 0.01). There was no obvious relationship between subepithelial bleeding and circulating concentrations of oestradiol and progesterone.

Adult↗

A functional model for progestogen-induced breakthrough bleeding.

During the past 5 years, a number of important advances have been made in our understanding of the mechanisms of sex steroid-induced breakthrough bleeding (BTB). These observations suggest that superficial endometrial vascular fragility may be the mechanism underlying BTB, and molecular changes in the microvasculature as well as hysteroscopic observations have supported this hypothesis. This paper aims to present a unified picture of our current understanding of BTB, particularly that associated with progestogens, to indicate current gaps in our knowledge and possible directions for future research.

Endometrium↗

The structure of endometrial microvessels.

Recent studies have provided substantial evidence to highlight abnormalities in the structure of endometrial microvessels in users of progestogen-only contraception. Structural changes alone are unlikely to lead to breakthrough bleeding, but appear to be associated with a reduction in vessel integrity, and may reflect alterations in the control and growth of endometrial microvessels in those exposed to exogenous progestogens. In users of low-dose progestogens, immunohistochemical studies have demonstrated changes in superficial endometrial vascular morphology, density and in endometrial migratory cell populations. In Norplant users the endometrial endothelial basal lamina is deficient in the initial months of exposure, when bleeding problems are most common. The basal lamina refers to the very thin structure consisting mostly of collagen IV and laminin seen underlying endothelial and epithelial cells at the electron microscope level. In addition, hysteroscopic studies have demonstrated increased fragility of superficial vessels. Changes in endometrial microvascular anatomy associated with normal menstruation have been reviewed, and are compared with those seen following contraceptive steroid exposure. Likely mechanisms of breakthrough bleeding such as increased superficial vascular fragility and the possible alterations in endometrial vascular structure leading to this are discussed.

Endometrium↗

Disturbances of endometrial bleeding with hormone replacement therapy.

Breakthrough bleeding is a common problem in postmenopausal women taking hormone replacement therapy (HRT) and is often the single most important factor deterring women from continuing to use HRT, or from starting it in the first place. The mechanisms which underlie this unscheduled bleeding are poorly understood. The benefits of HRT in terms of longevity and quality of life are becoming increasingly apparent, and a greater understanding of why this bleeding occurs and how we can prevent or treat it, will undoubtedly enable more women to reap the potential considerable benefits of long-term oestrogen and progestogen replacement. What sets postmenopausal women apart from their counterparts in the mid-reproductive years is the increased likelihood of endometrial adenocarcinoma in which unscheduled bleeding is the presenting symptom. Therefore, spontaneous postmenopausal bleeding must always be appropriately evaluated. Hence, the occurrence of unscheduled bleeding with HRT may provide a dilemma with diagnosis as well as a challenge to acceptability. Combined HRT regimens tend to be predominantly progestogenic, and there is increasing evidence to suggest that some of the vascular changes seen in women taking long-term, low-dose progestogen-only contraceptives may also occur in women taking HRT.

Adenocarcinoma↗

A longitudinal study of changes in endometrial microvascular density in Norplant implant users.

This study aimed to investigate the effects of the subdermal levonorgestrel contraceptive implant Norplant on endometrial vascular density at different durations of exposure, and the relationship between endometrial histology, vascular density, and bleeding patterns. A prospective controlled trial of Norplant implant users compared endometrial vascular density in biopsies taken before and after Norplant implant insertion. A total of 34 women with regular menstrual cycles requesting long-term contraception were recruited at the Sydney Centre for Reproductive Health Research, Australia. A significant increase in mean endometrial microvascular density was observed from as early as 3 weeks after insertion of Norplant implants. Vascular density was increased from a control secretory phase value of 189.6 (7.0 vessels/mm2 (+/- SEM) to 253.80 +/- 7 vessels/mm2 at 2-13 weeks of Norplant implant exposure (t ratio = 2.08, p = 0.01) and 212.7 +/- 12.9 vessels/mm2 at 14-42 weeks of exposure (t ratio = 2.03, p = 0.02). In those with atrophic endometrium, or in whom myometrium and basalis only were found in biopsies (20 of 66, 30%), mean endometrial vascular density was increased at 273.1 +/- 16.1 vessels/mm2 compared with 210.9 +/- 11.7 vessels/mm2 in other histological groups (F ratio = 9.74, p = 0.0028). Bleeding and spotting in the previous 30 days were less common in those with this histological appearance at a mean of 4.95 days compared with 8.22 days. This is the first study to assess endometrial vascular density in the early months of Norplant implant use. The findings suggest that the endometrial vasculature is profoundly altered in the early months of Norplant implant exposure when bleeding problems are most common.

Adolescent↗

Changes in vascular basement membrane in the endometrium of Norplant users.

Progestogen-only contraception is almost invariably associated with changes in menstrual bleeding patterns. Changes in the endometrial vasculature, and in particular an increase in vascular fragility, may contribute to this bleeding. In this study, endometrial vascular density and endothelial cell basement membrane components were examined using immunohistochemistry before and after insertion of Norplant. Endometrial vascular density was increased from a mean (+/- SEM) of 189.6 +/- 7.0 vessels/mm2 during the control cycle to 253.9 +/- 80.7 vessels/mm2 at 2-13 weeks of Norplant exposure, and to 212.7 +/- 12.9 vessels/mm2 at 14-42 weeks. During the control cycle, a mean of 161.4 +/- 4.5 vessels/mm2 stained for collagen IV (85% of all vessels), while at 2-13 weeks, 144.5 +/- 13.0 vessels/mm2 stained for collagen IV (57% of all vessels) (t ratio = 2.08, P = 0.0057). By 14-42 weeks, 71% of vessels (151.0 +/- 9.8) vessels/mm2 were surrounded by collagen IV. This was not significantly different from control values (t ratio = 2.03). Endometrial vascular laminin was also reduced following Norplant insertion, from a mean of 176.0 +/- 4.2 vessels/mm2 in the control cycle (93% of vessels), to 156.3 +/- 6.7 vessels/mm2 at 2-13 weeks of exposure (57% of vessels) (t ratio = 2.08, P = 0.01). By 14-42 weeks of exposure to Norplant, 162.5 +/- 9 vessels/mm2 (76%) stained for laminin. This was not significantly different from control values (t ratio = 2.04). Endometrial vascular heparan sulphate proteoglycan (HSPG) was reduced from 58.6 +/- 3.0 vessels/mm2 during the control cycle (31% of vessels) to 43.6 +/- 5.6 vessels/mm2 (only 17% of vessels) at 2-13 weeks (t ratio = 2.08, P = 0.025). At 14-42 weeks, only 19% of vessels stained for HSPG (41.3 +/- 5.8 vessels/mm2; t ratio = 2.04, P = 0.009).

Adolescent↗

Variations in vaginal epithelial surface appearance determined by colposcopic inspection in healthy, sexually active women.

A total of 107 sexually active women, aged 18-35 years, was recruited through family planning clinics in four centres in different countries. Each woman underwent two or three gentle but thorough and systematic vaginal inspections using a consistent technique with colposcopic magnification over a 4-6 month period to look for changes in vaginal and cervical appearance which might be related to sexual intercourse, tampon use, contraceptive method used, cigarette smoking or other environmental factors. Obvious changes in appearance were photographed at x10 magnification. These 'appearances' or 'conditions' were classified according to a modification of the recommendations of a workshop sponsored by the World Health Organization, the Population Council and the Conrad Program. Most of these alterations in the appearance of the vaginal epithelium were judged to be of such minor clinical importance that they have been termed 'conditions' or 'changes in appearance' rather than 'lesions'. In all, 56 'conditions' or 'appearances' were noted in 314 inspections, the commonest being petechiae (53.6%). Potentially significant conditions justifying the term 'lesions' (three microulcerations, two ecchymoses, five abrasions and one mucosal tear; 3.5% of inspections) usually healed spontaneously and disappeared rapidly. The incidence of these conditions was highest when the inspections followed intercourse in the previous 24 h (25.2 versus 14.2%; P < 0.0008), or tampon use (32.4 versus 15.9%; P < 0. 0001). These processes may be regarded as a reflection of regular minor trauma to the vaginal epithelium.

Adolescent↗

Effect of computerized physician order entry and a team intervention on prevention of serious medication errors.

CONTEXT: Adverse drug events (ADEs) are a significant and costly cause of injury during hospitalization. OBJECTIVES: To evaluate the efficacy of 2 interventions for preventing nonintercepted serious medication errors, defined as those that either resulted in or had potential to result in an ADE and were not intercepted before reaching the patient. DESIGN: Before-after comparison between phase 1 (baseline) and phase 2 (after intervention was implemented) and, within phase 2, a randomized comparison between physician computer order entry (POE) and the combination of POE plus a team intervention. SETTING: Large tertiary care hospital. PARTICIPANTS: For the comparison of phase 1 and 2, all patients admitted to a stratified random sample of 6 medical and surgical units in a tertiary care hospital over a 6-month period, and for the randomized comparison during phase 2, all patients admitted to the same units and 2 randomly selected additional units over a subsequent 9-month period. INTERVENTIONS: A physician computer order entry system (POE) for all units and a team-based intervention that included changing the role of pharmacists, implemented for half the units. MAIN OUTCOME MEASURE: Nonintercepted serious medication errors. RESULTS: Comparing identical units between phases 1 and 2, nonintercepted serious medication errors decreased 55%, from 10.7 events per 1000 patient-days to 4.86 events per 1000 (P=.01). The decline occurred for all stages of the medication-use process. Preventable ADEs declined 17% from 4.69 to 3.88 (P=.37), while nonintercepted potential ADEs declined 84% from 5.99 to 0.98 per 1000 patient-days (P=.002). When POE-only was compared with the POE plus team intervention combined, the team intervention conferred no additional benefit over POE. CONCLUSIONS: Physician computer order entry decreased the rate of nonintercepted serious medication errors by more than half, although this decrease was larger for potential ADEs than for errors that actually resulted in an ADE.

Clinical Pharmacy Information Systems↗

Effects of oral combined hormone replacement therapy on plasma lipids and lipoproteins.

Hormone replacement therapy has been shown to decrease the risk of coronary heart disease (CHD) in menopausal women. In this cross-sectional study, we addressed the following question: What effects would combined oral hormone replacement therapy have on plasma lipid and lipoprotein profiles independent of the other known CHD risk factors? We analyzed the plasma lipoproteins of two groups of menopausal women who were randomly selected from a large database of individuals. One group (n = 10) was not taking any hormone replacement therapy (NO HRT), while the second group (n = 8) was taking a daily dose of 0.625 mg conjugated estrogen and 2.5 mg medroxyprogesterone orally (PremPro, Wyeth-Ayerst, Philadelphia, PA) for at least 6 months (HRT). The two groups were not different in age, body weight, percent body fat, body mass index (BMI), waist to hip ratio, blood pressure, or insulin and glucose levels. High-density lipoprotein (HDL)-cholesterol was significantly higher (P < .05) in the HRT group. The total cholesterol (TC) to HDL-cholesterol ratio was significantly lower for HRT versus NO HRT (P < .05). Apolipoprotein (apo) A-1, the apo A-1/B ratio, and lecithin:cholesterol acyltransferase (LCAT) activity were significantly higher in HRT (P < .05). Lipoprotein subclass profiles measured by nuclear magnetic resonance (NMR) spectroscopy showed an increase in larger HDL subpopulations (H3 and H4) in HRT (P < .05), which are considered antiatherogenic. No differences were seen in the cholesterol concentration or size of low-density lipoprotein (LDL) subpopulations in HRT compared with NO HRT. These results indicate that the combined estrogen and progesterone treatment leads to beneficial effects on plasma lipoproteins. The beneficial effects include (1) increases in HDL-cholesterol and predominance of HDL2, (2) no adverse effects on LDL subpopulation distribution, and (3) increases in apo A-1 levels and LCAT activity, which indicate an improvement in reverse cholesterol transport.

Administration, Oral↗