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Biomedical subjects

A Steele

Publications and source records attributed to A Steele.

At least 19 recordsLinked to original sources

The anatomic and functional outcomes of defect-specific rectocele repairs.

OBJECTIVE: This study was undertaken to evaluate the anatomic, functional, and quality-of-life effects of site-specific posterior colporrhaphy in the surgical management of rectocele. STUDY DESIGN: In a retrospective observational study 125 patients were studied who had undergone site-specific posterior colporrhaphy between 1995 and 1996, either alone or in conjunction with other pelvic procedures. Physical examination was performed >/=6 months after the operation to assess the anatomic success of the repair. Standardized questionnaires were used to assess quality of life, sexual function, and bowel function. RESULTS: Surgical correction was found at follow-up examination to have been achieved in 82% of eligible patients (73/89). All daily aspects of living improved significantly (P <.05), including ability to do housework (56% improvement or cure), travel (58% improvement or cure), and social activities (60% improvement or cure). Emotional well-being also significantly improved after the operation, as measured by thoughts of embarrassment (57% improvement or cure) or frustration (71% improvement or cure). Sexual function was not affected; however, reports of dyspareunia significantly (P <.04) improved or were cured after the operation in 73% of patients (19/26), worsened in 19% of patients (5/26), and arose de novo in 3 patients. Results showed no other significant differences in vaginal dryness, orgasm ability, sexual desire, sexual frequency, or sexual satisfaction. Bowel symptoms were assessed subjectively and were noted to have significantly improved (P <.008) after the operation. The following improvement or cure rates were obtained: stooling difficulties, 55%; pelvic pain or pressure, 73%; vaginal mass, 74%; and splinting, 65%. CONCLUSION: This study indicates that defect-specific posterior colporrhaphy is equal to or superior to traditional posterior colporrhaphy. This type of repair provides durable anatomic support and is successful in restoring bowel function. It does not detrimentally affect sexual function, may aid in the resumption of sexual activity, and significantly improves quality of life and social aspects of daily living.

Adult

In vitro fracture strength of endodontically treated premolars.

The recent introduction of new bonding agents has led some authors to suggest that certain endodontically treated posterior teeth could be restored with a bonded restoration instead of a full-coverage crown or onlay. To test the fracture resistance of endodontically treated premolars restored with and without bonding agents, we randomly divided 56 intact and caries-free maxillary premolars into seven groups as follows: unaltered teeth; access only; MOD prep and RCT; MOD prep, RCT, and amalgam restoration; MOD prep, RCT, and amalgam with 4-META bonding agent; MOD prep, RCT, and composite resin restoration; and MOD prep, RCT, and composite resin with 4-META bonding agent. The teeth were subjected to compressive fracture tests in a Zwick 1435 Universal Testing Machine. Unaltered teeth and those with access only demonstrated similar fracture strengths. Under the conditions of this study, there was no significant difference in fracture strength between the experimental groups.

Acrylic Resins

Teaching the pelvic organ prolapse quantitation system.

OBJECTIVE: The objective of this study was to determine the ease with which the new Pelvic Organ Prolapse Quantitation system could be learned by residents and medical students. STUDY DESIGN: Standardized multiple-choice tests were administered to 51 obstetric and gynecology residents and medical students from 4 community-based and university-based programs. Parallel pretests and posttests were administered in conjunction with a 17-minute video demonstration of the Pelvic Organ Prolapse Quantitation system and with the addition of a visual memory aid. The posttest was repeated 3 months after the video presentation. RESULTS: The use of a 17-minute video significantly enhanced participants' ability to interpret examination findings when expressed in the terminology of the system (mean improvement in scores 33%, P <.0001). Posttest scores were similar regardless of the type of program or exposure to urogynecology faculty. These scores were maintained at the 3-month retesting. CONCLUSION: The Pelvic Organ Prolapse Quantitation system can be effectively taught by means of a public-domain video presentation.

Audiovisual Aids

Bulimia: a primary care approach.

More common than anorexia and less easily detected, bulimia typically begins as an effort to control weight. Although the prognosis is better than that for anorexia nervosa, a number of medical complications can arise related to the mode of purging. Some of these complications can have profound deleterious sequelae if not diagnosed and treated.

Adolescent

Postoperative hyponatremia despite near-isotonic saline infusion: a phenomenon of desalination.

BACKGROUND: It is widely presumed that the development of postoperative hyponatremia (which may be severe) results from administration of hypotonic fluids while antidiuretic hormone is acting. OBJECTIVE: To show that hyponatremia would occur in patients 24 hours after surgery if only near-isotonic solutions are given and to evaluate the mechanisms responsible for hyponatremia in this setting. DESIGN: Prospective cohort study. SETTING: University medical center. PATIENTS: 22 women who were having uncomplicated gynecologic surgery with infusion of near-isotonic solutions only (sodium chloride, 154 mmol/L, or Ringer lactate [sodium, 130 mmol/L, and potassium, 4 mmol/L]). MEASUREMENTS: Plasma electrolyte levels were measured at the time of induction of anesthesia and 24 hours later. Data on the balance of water and electrolytes were obtained for the same 24-hours period. RESULTS: At the time of induction of anesthesia, the plasma sodium concentration was 140 +/- 1 mmol/L; 24 hours later, it decreased in 21 of 22 patients (mean decrease, 4.2 +/- 0.4 mmol/L [P < 0.001]; lowest level, 131 mmol/L in 2 patients). The urine remained hypertonic (peak sodium plus potassium concentration in urine, 294 +/- 9 mmol/L) in all patients for the first 16 hours after induction of anesthesia. CONCLUSIONS: Postoperative hyponatremia occurred within 24 hours of induction of anesthesia when only near-isotonic fluids were infused. Hyponatremia was generally caused by generation of electrolyte-free water during excretion of hypertonic urine-a desalination process. This electrolyte-free water was retained in the body because of the actions of antidiuretic hormone. If the pathophysiology of this hyponatremic state is understood, recommendations for its prevention and treatment can be deduced.

Adult

Trophoblasts express Fas ligand: a proposed mechanism for immune privilege in placenta and maternal invasion.

Cross-linking of Fas (CD95, APO-1) and Fas ligand (FasL; CD95L) induces apoptosis of Fas-bearing cells. Recent evidence suggests that FasL. expression plays an important role in maintenance of immune privilege in murine testis and eye and in tumour escape from immune rejection in colon cancer, melanoma and hepatocellular carcinoma. Bcl-2 is a membrane protein that suppresses apoptosis in response to a variety of stimuli. In this paper we describe abundant expression of FasL protein and mRNA transcripts within the immune privileged environment of the placenta by immunohistochemistry and reverse transcription in-situ polymerase chain reaction methods. The syncytiotrophoblast layer, the main site of feto-maternal interface, and extravillous trophoblasts, demonstrated consistent immunoreactivity for FasL in term placentae. Co-occurrence of Fas and Bcl-2 were detected with a similar pattern of distribution with FasL. The TUNEL method revealed evidence of apoptosis in the placental tissues. We speculate that abundant presence of FasL in the trophoblast contributes to immune privilege in this unique environment, perhaps by fostering apoptosis of activated Fas-expressing lymphocytes of maternal origin. An apoptotic process mediated by FasL may also play a role in placental invasion during implantation and underscores similarities between the trophoblast and neoplastic cells.

Apoptosis

Predictability.

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Humans

Congruence and predictive power of mothers' and teachers' ratings of mastery motivation in children with mental retardation.

The congruence between mothers' and teachers' ratings of mastery motivation among 3-year-old children with mental retardation was investigated. The extent to which maternal and teacher ratings of task persistence at entry to preschool are predictive of observed mastery behaviors at age 5 was tested. Results indicate that mothers rated their children's task persistence behaviors higher than did teachers. Further, once the child's cognitive level and teacher ratings were controlled for statistically, maternal ratings of the child's mastery behaviors were predictive of the child's task mastery performance 2 years subsequent. Implications for educational planning were discussed.

Child, Preschool

Hyponatremia in the rat in the absence of positive water balance.

The purpose of this report is to determine the mechanisms that lead to hyponatremia when isotonic saline was the only fluid infused into rats given antidiuretic hormone (ADH), and what might minimize the degree of this hyponatremia. Normal rats were deprived of food and water for the 24-hr study period. They received an infusion of isotonic saline to expand their extracellular fluid (ECF) volume with and without exogenous ADH administration (N = 8 in each of the four groups). Similar studies were also carried out in 32 rats fed a low electrolyte diet for 72 hr before the experiment. An additional control group was fed the low electrolyte diet supplemented with sodium (Na), potassium (K), and chloride (Cl). Hyponatremia developed over 24 hr in rats fed their usual diet if treated with ADH and isotonic saline (fall, 13 +/- 2 mM, P < 0.01). The hyponatremia was caused by negative balance for Na + K salts. Hyponatremia did not develop after the saline + ADH treatment if rats were pretreated for 3 days with a low electrolyte diet. Two factors were required to develop this hyponatremia--generation of electrolyte-free water as a result of the excretion of a large quantity of Na + K salts at a high concentration in the urine, and prevention of the excretion of this electrolyte-free water by ADH. Increasing the avidity for Na reabsorption by the kidney prevented this type of hyponatremia from developing.

Animals

Erythrocyte Na(+)-H+ exchanger kinetics and Na(+)-Li+ countertransport activity in essential hypertensive patients.

The authors measured Na(+)-H+ exchanger kinetics together with Na(+)-Li+ countertransport V(max) in the erythrocytes of 21 subjects with essential hypertension and 16 normotensive control subjects. Na(+)-H+ exchange V(max) appeared to be increased in patients with essential hypertension, while the Na(+)-H+ exchanger affinity for intracellular proton sites (K50%) proved to be unchanged and the index of cooperativity among intracellular proton binding sites as measured by Hill's coefficient (Hill's n) decreased as compared with normotensive control subjects. Na(+)-Li+ countertransport V(max) appeared to be higher in patients with essential hypertension than in control subjects. The authors were unable to find any correlations between Na(+)-H+ exchanger kinetic parameters and metabolic variables such as parameters of insulin resistance and plasma lipids. On the basis of the data obtained, erythrocyte Na(+)-H+ exchanger activity was found to be abnormal in two kinetic variables in essential hypertensive patients and showed no simple linear correlations with the main variables of glucose metabolism, plasma lipids, renin or aldosterone.

Adult

Tuberculin testing in two Liverpool social clubs: the effects of a tuberculosis outbreak on background positivity.

BACKGROUND: Tuberculin testing remains the standard method for assessing infection due to tuberculosis in the UK. However, there are no data on the incidence of tuberculin positivity among the general adult population in the UK and consequently interpretation of Heaf test results is often difficult. METHODS: During the investigation of an outbreak of tuberculosis in a Liverpool social club 198 members were interviewed and Heaf tested and 171 members of a second social club in Liverpool were similarly screened as a control group. Comparisons between the results from the two populations provided both an estimate of baseline Heaf test positivity in indigenous white adults from a British inner city population, and a measure of the effect on this baseline of recent exposure to tuberculosis. RESULTS: In both club populations the proportion of positive Heaf tests increased with age. Independent of age, the tuberculosis exposed population had a higher proportion of positive Heaf grade results (40.9%) than those in the control group (26.9%). Multivariate analysis confirmed both the differences in Heaf results between clubs and between age groups but identified no other behavioural or medical factors which affected Heaf test results. CONCLUSIONS: Heaf test positivity increases with age at least up to 54 years, and recent exposure to tuberculosis increases the proportion of positive Heaf tests in each age group. Interpretation of positive Heaf tests when assessing the effects of a tuberculosis outbreak should take account of background levels of Heaf positivity.

Adolescent

Can a severe degree of ketoacidosis develop overnight?

Insulin-dependent diabetes mellitus in poor control, alcohol intake associated with extracellular fluid volume contraction, or hypoglycemia may each lead to an increased rate of production of ketoacids. Generally, several days of illness are required before ketoacidosis becomes severe. Two clinical examples are presented to suggest that a severe degree of ketoacidosis may develop over a short period of time, literally overnight. In both examples, there was the ingestion of a modest amount of ethanol. From a quantitative analysis of factors that may influence the rate of production and removal of ketoacids, the following were deduced. Contributing factors to the very rapid development of maximal ketoacidosis could include the absence of a lag period for the conversion of ethanol to acetyl-coenzyme A in the liver and an impaired ability of the brain and kidneys to oxidize ketoacids, especially if these ketoacids are produced very rapidly and/or if less metabolic work is performed by these organs. In special settings, ketoacidosis may develop more rapidly than is generally appreciated.

Adult

Nurses' knowledge and beliefs about AIDS: comparing nurses in hospital, community and hospice settings.

The literature reports an ongoing debate amongst nurses regarding the risk of contracting human immunodeficiency virus (HIV) through routine nursing care. An emotionally charged dilemma appears to exist for many nurses regarding what they perceive as conflict between professional obligation and personal risk. This study investigates nurses' beliefs, knowledge and perceptions of risk of contracting HIV while implementing their nursing care. The study focuses on qualified nurses in the hospice, hospital and community settings. No other similar comparative study that also focuses on hospice nurses has been identified. This quantitative study was implemented within Northern Ireland, by way of a respondent-administered questionnaire. The study's sample consisted of 45 qualified nurses and a response rate of 93% (42 respondents) was achieved. Analysis of the data involved the use of descriptive and correlational statistics. Overall findings indicated that many nurses, but particularly those who work in the hospital and community settings, hold negative and biased beliefs, and have inadequate knowledge and misguided perceptions regarding their risk of contracting HIV through the implementation of routine nursing care of clients. Many of those nurses readily admit their lack of knowledge. On the whole, hospice nurses appear more knowledgeable and exhibit a more positive approach to AIDS clients, and appear less fearful than do nurses in the other two settings. Implications for hospital management, for nurse education, for nurses themselves and for clients are discussed. This study should be seen as a springboard for future research within Northern Ireland.

Acquired Immunodeficiency Syndrome

A molecular epidemiological study of porcine rotaviruses.

Diarrhoea in the piglet can lead to stunted growth and neonatal death, with important implications for the pig farmer. During 1993, a pilot study was initiated to monitor the epidemiology of rotavirus infection in piglets with diarrhoea. Bimonthly diarrhoeal faecal specimens were collected from scouring piglets less than 6 weeks of age on a pig farm in the Northern Transvaal. The stool specimens were examined by a commercial enzyme-linked immunosorbent assay (Rotavirus EIA, IDL, Jerusalem). In total, rotavirus antigen was detected in 24% of the litters by the ELISA, which is directed at the group A rotavirus antigen. Rotavirus was found to occur throughout the year and predominantly in piglets 4 weeks old. Polyacrylamide electrophoretic analysis of the viral RNA genomes showed the presence of four distinct strains of Group A rotaviruses circulating on this farm. This study highlights the natural diversity of rotavirus strains circulating on a single farm and may indicate the importance of rotavirus infection in piglets with diarrhoea in South Africa.

Age Factors

The visual prognosis following HLA-matched keratoplasty for high-risk patients.

We report the clinical details of 30 HLA-matched corneal grafts with a mean follow-up of 29 months. Few of the patients were immunologically naive as almost all had received previous unmatched grafts. The two-year survival rate was 77%, comparable with other series. A majority of patients obtained good vision, and this was statistically superior to a recent large series. Almost all remained on their topical medication indefinitely. The contralateral visual acuity was surprisingly good, but there are few published data for comparison. We were unable to document an enhanced prognosis with a higher degree of HLA-A, B or DR match, possibly because of the small numbers.

Adult