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Biomedical subjects

S Hague

Publications and source records attributed to S Hague.

At least 19 recordsLinked to original sources

Confirmation of the protective effect of iNOS in an independent cohort of Parkinson disease.

Nitric oxide is a biologic messenger molecule involved in a diverse range of physiologic processes. An exon 22 inducible nitric oxide synthase genotype has recently been reported to be protective against Parkinson disease in a European cohort. The authors confirm the protective effect of this genotype (OR = 0.5, 95% CI 0.27 to 0.93) in an independent Finnish case-control series.

Adult↗

Assessment of a DJ-1 (PARK7) polymorphism in Finnish PD.

Mutations in DJ-1 are a cause of autosomal recessive parkinsonism. Polymorphism of genes implicated in hereditary forms of parkinsonism may be a predisposing factor in sporadic Parkinson's disease (PD). The authors analyzed whether a polymorphism (g.168_185del) within exon 1 of DJ-1 contributes to the risk of sporadic PD in a Finnish case-control series. This gene does not play a major role in the genetic predisposition to PD in this population.

Adult↗

Tamoxifen induction of angiogenic factor expression in endometrium.

Tamoxifen is the current therapy of choice for patients with oestrogen receptor positive breast cancer, and it is currently under evaluation as a prophylactic for women at high risk of developing the disease. However, tamoxifen is also known to induce proliferative changes in the endometrium increasing the risk of developing endometrial hyperplasia, polyps and carcinoma. Angiogenesis is an intimate part of this process. For this reason, we have examined the expression of several well characterized angiogenic factors, namely, acidic and basic fibroblast growth factor, thymidine phosphorylase, vascular endothelial growth factor and adrenomedullin in both normal and tamoxifen exposed pre- and postmenopausal endometrium. Vascular density and endothelial proliferation index were also quantified. We found increased expression of acidic and basic fibroblast growth factor and adrenomedullin after treatment with tamoxifen mainly in premenopausal tissue. Vascular density was significantly increased in pre- but not post-menopausal endometrium (P=0.0018) following tamoxifen treatment. These results support the notion that angiogenesis is integral to the response to tamoxifen exposure, and is a potential target with which to block these side effects of tamoxifen.

Adrenomedullin↗

Protease activated receptor-1 is down regulated by levonorgestrel in endometrial stromal cells.

Progestogens are used clinically for contraception, to control excessive menstrual bleeding and to oppose oestrogen in hormone replacement therapy. The use of intrauterine levonorgestrel (LNG) is however, associated with endometrial atrophy and decidualisation of the stroma. In this study, we aimed to identify genes whose expression is modulated by LNG either alone or in combination with progesterone. Thus endometrial stromal cells were stimulated with progesterone, LNG or LNG and progesterone. Poly-A RNA was isolated and used to probe expression arrays. The expression of a number of genes was altered on exposure to LNG or LNG and progesterone. Alteration of expression patterns was confirmed using semi-quantitative RT-PCR and western blot analysis. In particular, the protease activated receptor-1 (PAR-1) gene that encodes a receptor for thrombin was down regulated. This is the first demonstration that PAR-1 is down regulated by the progestogen LNG in human endometrium. Alteration in the expression levels of this receptor may affect both growth and haemostatic activity within the endometrium and may account for the observed morphological effects seen in users of intrauterine LNG delivery devices.

Down-Regulation↗

Treatment of gustatory hyperlacrimation (crocodile tears) with injection of botulinum toxin into the lacrimal gland.

PURPOSE: To establish the efficacy and safety of botulinum toxin in the treatment of Crocodile Tear Syndrome and record any possible complications. METHODS: Four patients with unilateral aberrant VII cranial nerve regeneration following an episode of facial paralysis consented to be included in this study after a comprehensive explanation of the procedure and possible complications was given. On average, an injection of 20 units of botulinum toxin type A (Dysport) was given to the affected lacrimal gland. The effect was assessed with a Schirmer's test during taste stimulation. Careful recording of the duration of the effect and the presence of any local or systemic complications was made. RESULTS: All patients reported a partial or complete disappearance of the reflex hyperlacrimation following treatment. Schirmer's tests during taste stimulation documented a significant decrease in tear secretion. The onset of effect of the botulinum toxin was typically 24-48 h after the initial injection and lasted 4-5 months. One patient had a mild increase in his preexisting upper lid ptosis, but no other local or systemic side effects were experienced. CONCLUSIONS: The injection of botulinum toxin type A into the affected lacrimal glands of patients with gusto-lacrimal reflex is a simple, effective and safe treatment.

Adult↗

In-vivo angiogenesis and progestogens.

BACKGROUND: Progestogens are used clinically for contraception, to control excessive menstrual bleeding, and to prevent estrogen-induced endometrial hyperplasia. A significant problem with progestogen-only methods of contraception is the induction of breakthrough bleeding. METHODS: The effects of different progestogens on angiogenesis were examined using two approaches. The mouse sponge angiogenesis assay employed direct delivery of the dose ranges achieved therapeutically. The angiogenic response to long-term intrauterine levonorgestrel exposure, compared with unexposed premenopausal endometrium, was also studied. RESULTS: In the mouse sponge assay, norethisterone and medroxyprogesterone acetate stimulated angiogenesis at all doses, but was dose-dependent for levonorgestrel and nomegestrol. Levonorgestrel stimulated angiogenesis in the dose range 100 pmol/l to 10 nmol/l, but not at higher doses. In contrast, nomegestrol acetate stimulated angiogenesis at high, but not low, doses. Expression of acidic and basic fibroblast growth factors, thymidine phosphorylase, vascular endothelial growth factor and adrenomedullin were unaltered in levonorgestrel-exposed endometrium compared with premenopausal controls. Vascular density was increased but endothelial proliferation reduced in levonorgestrel-exposed endometrium. CONCLUSIONS: This is the first report of the direct effects of a wide range of doses of different progestogens on angiogenesis; results suggest that vascular targeting may be an effective strategy to deal with progestogen-induced abnormal bleeding.

Administration, Intravaginal↗

Adrenomedullin inhibits hypoxic cell death by upregulation of Bcl-2 in endometrial cancer cells: a possible promotion mechanism for tumour growth.

Regions of hypoxia are a common feature of solid tumours. When tumour cells are exposed to hypoxic stress, transcription of a battery of genes is initiated. The angiogenic factor adrenomedullin (ADM) is a hypoxia regulated gene. ADM is thought to act through the G protein-coupled receptor calcitonin receptor-like receptor (CRLR), with specificity being conferred by the receptor associated modifying protein 2 (RAMP2). Here we report for the first time that ADM treated or stably transfected Ishikawa cells overexpressing ADM show increased resistance to hypoxia induced apoptosis. These cells also show an upregulation of the oncoprotein Bcl-2, which is protective against hypoxic cell death when transiently transfected into Ishikawa cells. Since Ishikawa cells express the putative ADM-receptor CRLR-RAMP2 the production and secretion of ADM with the consecutive upregulation of Bcl-2 could establish an autocrine/paracrine mechanism rescuing malignant cells from hypoxic cell death. These results, taken together with our previous findings that ADM is an angiogenic factor which is upregulated by the nonsteroidal antiestrogen tamoxifen (TAM) in endometrial cells, implicate this peptide as a promoter of tumour growth and a possible target for anticancer strategies.

Adrenomedullin↗

Expression of the hypoxically regulated angiogenic factor adrenomedullin correlates with uterine leiomyoma vascular density.

Uterine leiomyomas are the most prevalent benign tumor type in women of reproductive age and are one of the most common indications for hysterectomy. The expression of five angiogenic factors, adrenomedullin (ADM), vascular endothelial growth factor (VEGF), acidic fibroblast growth factor, basic fibroblast growth factor, and platelet-derived endothelial cell growth factor/thymidine phosphorylase, were examined in 91 uteri collected throughout the menstrual cycle; 52 of which contained leiomyomata, and the remainder were normal controls. The microvascular density and endothelial proliferative indices were then determined for each of the uterine sections. ADM and VEGF were the most widely expressed angiogenic factors in the leiomyomas. Furthermore, the expression of ADM and VEGF in the endometrium and myometrium was up-regulated in leiomyoma-bearing uteri compared with controls. Although acidic fibroblast growth factor and basic fibroblast growth factor were expressed in leiomyomas and endometrium in all of the uterine samples examined, they were only expressed in the myometrium of leiomyomata-bearing uteri. Endothelial proliferation in leiomyomas was statistically greater than that of the myometrium and endometrium, both within and between uteri (P < 0.05). The vascular density in the myometrium but not the endometrium was significantly increased in leiomyoma-containing uteri (P < 0.05). Expression of ADM alone correlated directly with vascular density and endothelial cell proliferation index in leiomyomas and myometrium and may account for the high vascularity found in leiomyomas and the myometrium of leiomyoma-bearing uteri. As such, ADM is identified as a novel target for antiangiogenic therapy of these benign, clinically problematic uterine tumors.

Adrenomedullin↗

Regulation of endometrial angiogenesis.

Bleeding problems are the most common reason for discontinuation of hormone replacement therapy. Human endometrium undergoes the unique process of benign angiogenesis under the control of ovarian steroids during reproductive life and it is presumed that similar processes occur when women take hormone replacement therapy. The key players in endometrial growth and angiogenesis are vascular endothelial growth factor, thymidine phosphorylase and adrenomedullin. Regulation of these angiogenic factors is described.

Adrenomedullin↗

PCR display identifies tamoxifen induction of the novel angiogenic factor adrenomedullin by a non estrogenic mechanism in the human endometrium.

Tamoxifen is currently the most widely used drug for the treatment of breast cancer, but there now exists considerable evidence that tamoxifen can also induce endometrial hyperplasia in pre menopausal women. We have used PCR differential display on primary human endometrial isolates in an attempt to identify genes induced by tamoxifen but not estrogen. Eight such differentially expressed bands were cloned and sequenced, one of which was found to be the peptide adrenomedullin. We have shown that adrenomedullin is a novel growth factor for endothelial cells and is angiogenic in vivo in the chick chorioallantoic membrane assay. Immunohistochemical analysis of endometrial sections have shown that while macrophages in the endometrium express adrenomedullin at a low level, endometrial macrophages of women receiving tamoxifen strongly express adrenomedullin (P=0.008). We postulate that endometrial induction of the angiogenic factor adrenomedullin by tamoxifen is part of the mechanism by which tamoxifen results in endometrial hyperplasia.

Adrenomedullin↗

Multifocal choroiditis: clinicopathologic correlation.

Many of the white dot syndromes are considered to have a granulomatous pathogenesis. The histopathologic characteristics of this case of multifocal choroiditis seen within 15 months of apparent clinical onset show that the white dot lesions were nongranulomatous perivascular choroidal infiltrates, consisting mainly of B lymphocytes. Early choroidal neovascularization was also seen.

Adult↗

Linkage and association of insulin gene VNTR regulatory polymorphism with polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting up to 10% of women of reproductive age. Women with anovulatory PCOS have hyperinsulinaemia, insulin resistance, and dyslipidaemia, and the syndrome is associated with greatly increased risks of non-insulin-dependent diabetes mellitus and cardiovascular disease and it often clusters in families. The VNTR (variable number of tandem repeats) locus upstream of the insulin gene (INS) regulates insulin expression. We have studied INS VNTR as a candidate genetic locus for susceptibility to PCOS. METHODS: We evaluated linkage of PCOS to the INS VNTR locus on chromosome 11p15.5 in 17 families with several cases, and looked for an association between VNTR and PCOS in two additional clinic populations. VNTR genotypes were designated I/I, I/III, and III/III and linkage disequilibrium mapping was used to test the primary role of the VNTR. FINDINGS: In a group of PCOS/male pattern baldness families, we obtained positive evidence for linkage to 11p15.5 (p = 0.002). The INS VNTR III/III genotype was associated with an increased risk of PCOS in two independent case-control studies (odds ratios 8.20 [p = 0.005] and 5.70 [p = 0.043]). Multilocus linkage disequilibrium mapping suggests that VNTR itself is the predisposing locus. INTERPRETATION: Mapping of susceptibility to PCOS to the INS VNTR implies that PCOS is due, in part, to an inherited alteration in insulin production. The data suggest a mechanistic link between type 2 diabetes and PCOS, which is a risk factor for diabetes later in life.

Alleles↗

Motion detection deficits in infantile esotropia without nystagmus.

PURPOSE: To investigate whether adults with infantile strabismus but without latent nystagmus have abnormalities of horizontal motion detection. METHODS: Eleven adult subjects with infantile esotropia but without latent nystagmus and 15 control subjects were required to detect the onset of motion and drift direction of a sinusoidal, spatial frequency grating that moved with linearly increasing velocity. The grating was presented monocularly in paracentral vision at an eccentricity of 16.5 degrees with a field size of 18 degrees. The contrast of the grating was just above contrast threshold for visibility. RESULTS: The mean velocity threshold for detection of motion was raised significantly in the patient group compared with the control group. Nine of the 11 subjects with infantile esotropia demonstrated directional asymmetry for the detection of motion. Thresholds were elevated more often when the grating was moving nasally in the squinting eye and temporally in the nonsquinting eye, and raised thresholds were more prevalent in the squinting eye. CONCLUSIONS: The findings indicate that in infantile esotropia, the presence of motion perception deficits are not always associated with the development of latent nystagmus. The predominance of nasally directed motion deficits in the squinting eye and temporally directed motion deficits in the nonsquinting eye was unexpected and may have been caused by abnormal development of cortical motion processing.

Adult↗

Blepharoplasty and ptosis.

Recent advances in local anesthetic techniques have led to suggestions that buffered solutions for infiltration increase patient comfort. The use of an eutectic mixture of local anesthetics cream has however proved to be disappointing. The use of monopolar electrocautery, carbon dioxide lasers, and high-frequency radio wave electrosection provide the surgeon with new modes of cutting and coagulation. Lower lid blepharoplasty via a conjunctival approach may avoid many of the complications of the anterior approach. Such complications may also be minimized by careful preoperative planning and frequently the inclusion of a lateral canthopexy in the surgical procedure. The lid height after anterior and posterior levator resection can now be set more accurately with adjustable suture techniques. A new technique combining a superior tarsectomy with levator resection is described. A range of materials for brow suspension are now available. Autogenous fascia lata remains the material of choice when available.

Anesthesia, Local↗

Collaborative research: benefits and guidelines.

Several benefits of collaborative research and guidelines for strengthening collaborative mechanisms have been described here, but the impetus for research and development of competent research teams must come from health professionals themselves. The literature makes it apparent that allied health professionals need to devote a considerable amount of energy and resources to develop a knowledge base for the health-related professions, similar to those in medicine and the biological sciences. Research projects, particularly collaborative ones, can make significant contributions to the body of professional knowledge, the knowledge-generation process, the health care practitioner, and the patient. The results of research should not be judged successful until its ultimate goal (ie, impact on patients and practice) has been measured. In collaborative research, relationships should be based on systems thinking, making networking into a scientific approach--a true partnership approach--which is crucial in dealing with the problems of health care today.

Allied Health Occupations↗