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Biomedical subjects

C A Wilson

Publications and source records attributed to C A Wilson.

At least 163 records · Page 9Linked to original sources
PubMed1989

A survey of adolescent dysmenorrhea and premenstrual symptom frequency. A model program for prevention, detection, and treatment.

Eighty-eight female high school adolescents in two separate physical education classes were surveyed for the prevalence of dysmenorrhea and premenstrual symptoms. Each group answered a questionnaire requesting age; presence, severity, and nature of dysmenorrhea and premenstrual symptoms; and course of treatment. Questions were also asked to determine the perceived impact of these symptoms on academic performance, ability to concentrate, study, or take tests, and classes missed. The results showed that the majority of the female adolescents identified dysmenorrhea and premenstrual symptoms as problems that significantly affected their academic performance and were responsible for school absenteeism. Contradictory to common belief, premenstrual symptoms in these adolescents (76 of 88, 86%) were found to be as prevalent as symptoms of dysmenorrhea (80 of 88, 91%), and most of the girls were unaware of the causes and treatments of these symptoms. Subsequently, we designed a model for use by health professionals to educate girls in self-help methods and to screen for and detect these problems.

Absenteeism↗
PubMed1989

Novel variants of human papillomavirus type 2 in warts from immunocompromised individuals.

Twenty cutaneous warts from I8 renal transplant recipients (RTR) and a single wart sample from a patient suffering from Hodgkin's disease were screened for the presence of human papillomavirus (HPV) sequences by Southern blot analysis. Thirteen samples were shown to contain HPV DNA sequences, one was identified as HPV-3, two as HPV-4, six as HPV-2 and four were unidentifiable by restriction digest analysis. HPV-3 was identified in the wart sample from the patient suffering from Hodgkin's disease. In the six samples in which HPV-2 was found, the viral genome showed polymorphism for the PvuII and PstI sites. Two PvuII patterns and one PstI pattern are novel.

Blotting, Southern↗
PubMed1989

Differential involvement of 5-hydroxytryptamine (5HT) in specific hypothalamic areas in the mediation of steroid-induced changes in gonadotrophin release and sexual behaviour in female rats.

Ovariectomised rats were treated with either oestradiol benzoate (OB) alone or OB followed by progesterone (P). The effects of the steroid treatments were noted on plasma LH concentration, lordosis quotient and concentration of 5-hydroxytryptamine (5HT) and 5-hydroxyindole acetic acid (5HIAA) in microdissected hypothalamic areas, i.e. the preoptic area (POA), arcuate nucleus (ARC), median eminence (ME), ventromedial nucleus (VMN), suprachiasmatic nucleus (SCN) and zona incerta (ZI). The ratio of 5HIAA:5HT or parallel changes in the concentrations of 5HT and 5HIAA were taken as indices of 5HT neuronal activity. 5 micrograms OB alone reduced LH release and had no effect on receptivity. This treatment reduced 5HT activity in the SCN and raised it in the ZI. After 5 micrograms OB plus 0.5 mg P, all the rats exhibited an LH surge and full sexual receptivity. 5HT activity was significantly raised in the ME and reduced in the ARC, VMN and ZI. By using submaximal steroid regimes (2 micrograms OB plus 0.05 mg P, or 50 micrograms OB alone) correlations could be made between sexual behaviour, LH release and 5HT activity. There was no correlation between LH release and receptivity indicating that the two functions are controlled by different systems. Correlating 5HT activity in the various sites with the two physiological parameters indicated whether the changes seen after the maximal steroid treatment were concerned with behaviour, LH release or both. The results indicate that the changes seen in the VMN, ARC and ME are correlated with sex behaviour and those in the VMN and ZI with increased LH release.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Insulin-like growth factor I gene expression in the rat ovary is confined to the granulosa cells of developing follicles.

The in vivo intraovarian synthesis of insulin-like growth factor-I (IGF-I) has been studied in the rat by Northern blot, dot blot hybridization, and in situ hybridization histochemistry. Ovarian IGF-I mRNA transcript sizes (7.0 kilobases (kb), 1.6 kb, and a group from 0.4-0.9 kb) were similar to those in liver and other tissues. The proportion of ovarian IGF-I to tubulin messenger RNA (mRNA) was increased to 176% of control values by treatment with diethylstilbestrol, while the ratio in liver was decreased to 64.4%. In situ hybridization identifies the major in vivo site of IGF-I synthesis in the ovary as the granulosa cells of developing follicles. IGF-I mRNA was present in the granulosa cells of developing preantral and antral follicles, but was not seen in atretic follicles or corpora lutea. In preovulatory follicles high levels of IGF-I mRNA were confined to the antral cell layers and to the cells of the cumulus oophorus. High levels of tubulin gene expression within follicles were seen in a similar distribution to that for IGF-I but 80-90% of corpora lutea also strongly expressed the tubulin gene. Interstitial cells, including thecal cells, express the tubulin gene at low levels but do not express the IGF-I gene. The distribution of IGF-I mRNA is the same as that previously observed for mitotically active granulosa cells, and therefore offers strong support for the view that IGF-I in the ovary acts by an autocrine-paracrine mechanism to promote granulosa cell replication.

Animals↗
PubMed1988

Optic disk neovascularization and retinal vessel diameter in diabetic retinopathy.

We measured retinal vessel diameter before and after panretinal photocoagulation in 59 eyes with diabetic retinopathy and moderate to severe optic disk neovascularization. Treatment significantly reduced mean arteriolar and venular diameter. The diameter of the retinal arterioles after treatment correlated significantly with the amount of regression in disk neovascularization. Eyes with large diameter vessels after treatment usually had little or no regression of proliferative retinopathy, whereas regression was more frequently seen in eyes with smaller diameter vessels after treatment.

Arterioles↗
PubMed1988

Changes in dopamine activity in the zona incerta (ZI) over the rat oestrous cycle and the effect of lesions of the ZI on cyclicity: further evidence that the incerto-hypothalamic tract has a stimulatory role in the control of LH release.

Previous results indicate that the dopaminergic system in the anterior medial zona incerta (ZI) exerts a stimulatory effect on LH release. In this report changes in dopamine (DA) turnover in the ZI, preoptic area (POA) and arcuate/median eminence area (ARC/ME) (as assessed by the rate of decline in DA concentration after alpha-methyl-p-tyrosine) have been noted each afternoon (16.00-18.00 h) of the 4 days of the oestrous cycle and also on the morning (9.00-11.00 h) of proestrus (P) and second day of dioestrus (D2). Over the time of the preovulatory LH surge on P, a significant rise in DA turnover was observed in the ZI. As this area contains components of the dopaminergic incerto-hypothalamic (I-H) tract, this study provides evidence to implicate the I-H tract in the physiological stimulation of the preovulatory surge of LH on proestrus. Selective destruction of DA nerve terminals (with 6-hydroxydopamine plus desmethylimipramine) and the various cell bodies (with ibotenic acid) in the ZI both induced a period of dioestrus (9-11 days). The similarity of effect of these two types of lesion indicate that the DA nerve terminals in the ZI stimulate a stimulatory pathway ultimately to induce LH release.

Animals↗
PubMed1988

Acute posterior multifocal placoid pigment epitheliopathy and cerebral vasculitis.

Four cases of suspected cerebral vasculitis have been described in association with acute posterior multifocal placoid pigment epitheliopathy, but none was confirmed histopathologically. We describe a patient who developed fatal cerebral vasculitis after placoid pigment epitheliopathy. Histopathologic data revealed a focal granulomatous inflammation of medium-sized arteries in the leptomeninges. Multinucleated giant cells were a conspicuous part of the inflammatory reaction. The cause of both placoid pigment epitheliopathy and cerebral vasculitis remains obscure.

Acute Disease↗
PubMed1988

The effect of selective D1 and D2 dopaminergic agents on sexual receptivity in the female rat.

A number of dopaminergic drugs was tested for their effect on female sexual receptivity in ovariectomised plus adrenalectomised rats primed with oestradiol benzoate. The selective D1 agonist (SKF 38393 5-40 mg/kg) and D1 antagonist (SCH 23390 0.1-10 mg/kg) had no significant effect on sexual behaviour. The results of administration of mixed dopaminergic agents (DOPA, 10-50 mg/kg with benserazide or 100-200 mg/kg alone and haloperidol 0.01-1.0 mg/kg) and selective D2 dopaminergic agents (LY 171555 2.5-800 micrograms/kg, BHT 920 0.01-1.0 mg/kg and sulpiride 5-80 mg/kg) indicate that a central dopaminergic system has an inhibitory control on female sexual activity exerted through D2 receptors. Any stimulatory effects of the exogenous agonists were probably due to an action on presynaptic D2 receptors. The predominance of the D2 pre- and post-synaptic receptor activity appears to be influenced by the sexual receptivity of the animal.

Animals↗
PubMed1988

Behavioral effects in adulthood of serotonin depletion by P-chlorophenylalanine given neonatally to male rats.

The effect in male rats of depletion of brain 5HT over days 1-7 or 8-16 after birth, by daily administration of 100 mg/kg PCPA was noted on various behaviors after the animals had reached adulthood. Treatment over days 1-7 had little or no effect, but over days 8-16 induced the following behavioral changes: In the elevated plus-maze, the treated group spent longer on the open arms, indicating a lower level of anxiety. In a test for sexual orientation, the treated animals were more sexually oriented toward the female stimulus and they showed a reduction in pendulum movements (a fear-related parameter); however their sexual performance with a receptive female was not different from the controls. The animals were also tested as residents in a resident-intruder paradigm for their social and agonistic activity. The treatment induced an increase in offensive activity confined to the high intensity elements and a parallel decrease in defensive activity. These results can be interpreted in terms of an increased reactivity to environmental and social cues and a decreased anxiety.

Animals↗
PubMed1988

Experimental ischemia induces cell mitosis in the adult rat retina.

Experimental occlusion of the central retinal vessels in albino rats followed by reperfusion for 2 or 4 days resulted in a highly active proliferative response. Mitotic figures were produced in retinal vascular cells, presumed Müller cells, retinal pigment epithelial cells, and possibly other cell populations in the retina. A large number of mitoses were observed in 60-100% of 50 experimental eyes with 2, 4 or 6 hr of experimental ischemia and 2 or 4 days of reperfusion and in none of the 37 control eyes. Autoradiography demonstrated 3H-thymidine uptake in the retina and in vascular cells on a trypsin digest preparation of the retina. Retinal ischemia followed by reperfusion leads to mitosis of retinal cells. This suggests a causal relationship in proliferative retinopathies where ischemia and cell proliferation coincide.

Animals↗
PubMed1987

Management of increased intraocular pressure after cataract extraction.

We measured the change in intraocular pressure prospectively after extracapsular cataract extraction in 80 eyes after treatment with either pilocarpine gel, pilocarpine 4% solution, timolol 0.5% solution, or placebo. Intraocular pressure, pupil size, and anterior chamber cellular reaction were measured in a masked fashion on the first day after surgery. A significant increase in intraocular pressure was found in all groups postoperatively when compared with baseline values (P less than .001). Eyes treated with pilocarpine gel had an average intraocular pressure increase of 4.2 +/- 2.1 mm Hg (mean +/- 1 S.E.), eyes treated with pilocarpine 4% eyedrops had an average increase of 9.8 +/- 2.8 mm Hg, and eyes treated with timolol demonstrated an intraocular pressure increase of 8.25 +/- 3.19. The intraocular pressure in untreated eyes (controls) increased by an average of 12.9 +/- 2.7 mm Hg. Only the difference in intraocular pressure change between the eyes treated with pilocarpine gel and control eyes was statistically significant (P = .025). Postsurgical intraocular pressure exceeding 25 mm Hg was observed in three of 20 pilocarpine gel treated eyes (15%) and 11 of 20 control eyes (55%). Pilocarpine treatment was not associated with noticeable changes in intraocular inflammatory response, nor were significant ocular or systemic adverse reactions observed. A single administration of pilocarpine gel is effective in reducing increased intraocular pressure for the first 24 hours after extracapsular cataract extraction.

Cataract Extraction↗
PubMed1987

Yeast phosphoglycerate kinase: investigation of catalytic function by site-directed mutagenesis.

A salt link buried in the domain interface of phosphoglycerate kinase has been implicated as being important in controlling the conformational transition from the open, or substrate-binding, to the closed, or catalytically competent, form of the enzyme. The residues contributing to the salt link are remote from the active site, but are connected to the substrate-binding sites through strands of beta-sheet. It has been suggested that these residues may also mediate sulphate and anion activation. These assumptions have been tested by examining the properties of a site-directed mutant (histidine-388----glutamine-388). The expression and overall structural integrity of the mutant, produced in yeast from a multicopy plasmid, remains essentially unaltered from the wild-type enzyme. However, the mutant enzyme has a kcat. reduced by 5-fold. The Km for ATP is lowered by 3-fold, and the Km for 3-phosphoglycerate is unaffected. The effects of sulphate on activity over a wide range of substrate concentrations appear to be the same for both the mutant and wild-type enzymes. These results lead to a reappraisal of the mechanistic role of the inter-domain histidine-glutamate interaction, as well as a refinement of the kinetic model of the enzyme.

Amino Acid Sequence↗
PubMed1987

Comparative studies of prosthetic materials in the left atrium of the dog.

To assess the healing process of various intracardiac prosthetic graft materials, we inserted autologous left atrium (control), autologous pericardium (AP), bovine pericardium (BP), polytetrafluoroethylene (PTEE) and woven Dacron (WD) patches into excised defects in the left atrial wall of 15 dogs. Two patches were implanted into each heart utilizing six patches for each material. Three months after graft placement, histological examination revealed chronic inflammation and fibrosis for all materials. Dense connective tissue surrounded the grafts in which fibrosis was most prominent. Cartilage formation occurred in 11 grafts: 5 BP, 4 PTFE, 1 control and 1 AP site. This change was not evident with WD. The extent of cartilage formation was greatest in BP. Bone formation occurred in 3 BP sites. 2 PTFE and 1 control site. Quantitative calcium concentrations were similar for all of the grafts without bone formation. Calcium concentrations at sites with bone formation averaged 15.13 mg/g +/- 6.39 mg/g compared to 0.939 +/- 0.419 for sites without bone formation (p less than 0.0001). We conclude that while inflammation, fibrosis and connective tissue thickening occur with healing of all graft materials, cartilage and bone formation differ with respect to the material employed.

Animals↗
PubMed1987

Dopaminergic neurones in the zona incerta exert a stimulatory control on gonadotrophin release via D1 dopamine receptors.

The zona incerta (ZI) is a site of dopamine nerve terminals and part of the incertohypothalamic tract (I-H). Previous findings indicate that dopamine in the ZI has a stimulatory control on the release of luteinizing hormone (LH) and occurrence of ovulation. The effect of acute administration into anaesthetised rats of selective D1 and D2 dopamine agonists and antagonists injected into the ZI on plasma luteinizing hormone (LH) and on the occurrence of ovulation has now been investigated. It was found that bilateral injections on the day of pro-oestrus of a selective D1 antagonist, Sch 23390, inhibited ovulation at 10 micrograms/side/rat. Unilateral injections of a selective D1 agonist, SKF 38393, at 10 micrograms/rat stimulated a significant rise in plasma LH concentration in ovariectomised oestrogen-primed rats, and this was partially reversed by systemic pre-treatment with Sch 23390. The selective D2 agonist, LY 171555, and D2 antagonists, sulpiride and domperidone, had no effect on plasma LH levels or ovulation. This indicates that D1 receptors (but not D2 receptors) in the ZI are involved in the control of gonadotrophin release and may have a physiological function in reproductive processes.

Animals↗
PubMed1987

The role of the hypothalamic beta-adrenergic system in controlling the LH rise in short-term castrated rats.

Intraventricular infusions of adrenaline and various pharmacological agents acting on beta-adrenergic receptor subtypes were carried out in rats orchidectomized 16 h previously. Infusions (10 microliter) of solutions containing the drugs were administered under anaesthesia induced with alphaxalone and alphadolone. Levels of LH were measured in plasma collected immediately before and at predetermined intervals after the infusion. The acute rise in LH levels after castration was increased still further by isoprenaline (a mixed beta 1- and beta 2-agonist), fenoterol (a beta 2-agonist) and atenolol (a beta 1-antagonist). In contrast, prenalterol (a beta 1-agonist) and (2RS,3RS)-3-isopropylamino-1-(7-methylindan-4-yloxy)++ +butan-2-ol (ICI 118,551) (a selective beta 2-antagonist) were inhibitory to LH release. Adrenaline itself, salbutamol (another selective beta 2-agonist), propranolol (a mixed beta-antagonist) and metoprolol (a beta 1-antagonist) did not significantly alter plasma LH concentrations at the doses administered. The stimulatory effect of isoprenaline on LH release was partially reduced when given together with ICI 118,551, but was not affected when administered simultaneously with atenolol. The inhibitory effect of ICI 118,551 was, however, prevented by concomitant administration with fenoterol, as was that of prenalterol when infused with atenolol. The results suggest that the hypothalamic mediation of the short-term changes in LH release in response to castration is exerted, at least in part, through the activation of a beta 2-stimulatory component and the suppression of a beta 1-inhibitory component.

Adrenergic beta-Agonists↗