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S Thomas

Publications and source records attributed to S Thomas.

At least 127 records · Page 7Linked to original sources
PubMed2001

Erectile and ejaculatory dysfunction in a community-based sample of men 50 to 78 years old: prevalence, concern, and relation to sexual activity.

OBJECTIVES: To determine the prevalence rates of erectile and ejaculatory dysfunction, associated bother, and their relation to sexual activity in a population-based sample of elderly men.Methods. Data were collected from 1688 men by way of self-administered questionnaires (including the International Continence Society male sex questionnaire) and measurements at a health center and urology outpatient department. RESULTS: The prevalence of significant erectile dysfunction (ie, erections of severely reduced rigidity or no erections) increased from 3% in men 50 to 54 years old to 26% in men 70 to 78 years old. In the same age strata, the prevalence of significant ejaculatory dysfunction (ie, ejaculations with significantly reduced volume or no ejaculations) increased from 3% to 35%. Pain or discomfort during ejaculation was rare (1%) and independent of age. In general, men were more concerned about erectile dysfunction than about ejaculatory dysfunction. However, most men had no or only little concern about their dysfunction. The percentage of men who reported being sexually active declined with increasing age and was lower in men with erectile and ejaculatory dysfunction and in men without a partner. In sexually active men, 17% to 28% had no normal erections, indicating that with advancing age normal erections are not an absolute prerequisite for a sexually active life. CONCLUSIONS: Erectile and ejaculatory dysfunction are common in elderly men. The results of this study indicate that these conditions are much less of a problem for older men than previously suggested.

Age Distribution↗
PubMed2001

Voided volumes: normal values and relation to lower urinary tract symptoms in elderly men, a community-based study.

OBJECTIVES: To determine the normal values of voided volumes and explore the relation between bladder capacity and lower urinary tract symptoms (LUTS) in elderly men. METHODS: Data were collected from 1688 men 50 to 78 years old recruited from the population of Krimpen aan den IJssel, The Netherlands. Measurements included self-administered questionnaires (including the International Prostate Symptom Score), a 3-day frequency volume chart, transrectal ultrasonography of the prostate, uroflowmetry, and postvoid residual volume determination. RESULTS: The 24-hour voided volumes were independent of age (median 1506 mL; 25th to 75th percentiles 1160 to 1950). The average volume per void and functional bladder capacity (FBC, defined as the largest single voided volume) declined with advancing age. Moreover, FBC was lower in men with a reduced maximum flow rate (less than 15 mL/s) and independent of the postvoid residual volume. Multivariate analyses showed no significant effect of prostate enlargement on the FBC. FBC was strongly related to LUTS: a low FBC coincided with higher International Prostate Symptom Scores. Multivariate logistic regression analyses revealed that the presence of moderate to severe symptoms (International Prostate Symptom Score greater than 7) was independent of prostate volume, but dependent on age, a reduced flow rate, postvoid residual volume, and FBC. CONCLUSIONS: Prospective studies are needed to establish the causal relation between FBC and LUTS. Frequency volume charts are a valid, easy-to-use, noninvasive method to determine FBC as an aspect of urinary tract (dys)function in the evaluation of men with LUTS and to determine treatment options for LUTS.

Age Factors↗
PubMed2001

Complex interactions between autotrophs in shallow marine and freshwater ecosystems: implications for community responses to nutrient stress.

The relative biomass of autotrophs (vascular plants, macroalgae, microphytobenthos, phytoplankton) in shallow aquatic ecosystems is thought to be controlled by nutrient inputs and underwater irradiance. Widely accepted conceptual models indicate that this is the case both in marine and freshwater systems. In this paper we examine four case studies and test whether these models generally apply. We also identify other complex interactions among the autotrophs that may influence ecosystem response to cultural eutrophication. The marine case studies focus on macroalgae and its interactions with sediments and vascular plants. The freshwater case studies focus on interactions between phytoplankton, epiphyton, and benthic microalgae. In Waquoit Bay, MA (estuary), controlled experiments documented that blooms of macroalgae were responsible for the loss of eelgrass beds at nutrient-enriched locations. Macroalgae covered eelgrass and reduced irradiance to the extent that the plants could not maintain net growth. In Hog Island Bay, VA (estuary), a dense lawn of macroalgae covered the bottom sediments. There was reduced sediment-water nitrogen exchange when the algae were actively growing and high nitrogen release during algal senescence. In Lakes Brobo (West Africa) and Okeechobee (FL), there were dramatic seasonal changes in the biomass and phosphorus content of planktonic versus attached algae, and these changes were coupled with changes in water level and abiotic turbidity. Deeper water and/or greater turbidity favored dominance by phytoplankton. In Lake Brobo there also was evidence that phytoplankton growth was stimulated following a die-off of vascular plants. The case studies from Waquoit Bay and Lake Okeechobee support conceptual models of succession from vascular plants to benthic algae to phytoplankton along gradients of increasing nutrients and decreasing under-water irradiance. The case studies from Hog Island Bay and Lake Brobo illustrate additional effects (modified sediment-water nutrient fluxes, allelopathy or nutrient release during plant senescence) that could play a role in ecosystem response to nutrient stress.

Africa↗
PubMed2001

The development of a novel technique for predicting the exudate handling properties of modern wound dressings.

Numerous methods have been developed for measuring the absorbency of wound dressings but many are product specific and do not permit comparisons between different dressing types. Existing methods are also of limited value when assessing how a dressing is likely to perform in clinical practice. A new wound model has been developed that overcomes both of these problems. It facilitates direct comparisons between products that are different in structure and composition and provides, perhaps for the first time, a method that may be used to predict the time for which dressings might be expected to remain effective on exuding wounds. The historical background to the introduction of test methods for surgical dressings is briefly reviewed, and the development of the new wound model is described. Some preliminary results that illustrate the potential value of this new technique are also presented.

Absorption↗
PubMed2001

Platelet deposition in stagnation point flow: an analytical and computational simulation.

A mathematical and numerical model is developed for the adhesion of platelets in stagnation point flow. The model provides for a correct representation of the axi-symmetric flow and explicitly uses shear rate to characterise not only the convective transport but also the simple surface reaction mechanism used to model platelet adhesion at the wall surface. Excellent agreement exists between the analytical solution and that obtained by the numerical integration of the full Navier--Stokes equations and decoupled conservation of species equations. It has been shown that for a constant wall reaction rate modelling platelet adhesion the maximum platelet flux occurs at the stagnation point streamline. This is in direct contrast to that found in experiment where the maximum platelet deposition occurs at some distance downstream of the stagnation point. However, if the wall reaction rate is chosen to be dependent on the wall shear stress then the analysis shows that the maximum platelet flux occurs downstream of the stagnation point, providing a more realistic model of experimental evidence. The analytical formulation is applicable to a large number of two-dimensional and axi-symmetrical surface reaction flows where the wall shear stress is known a priori.

Arterial Occlusive Diseases↗
PubMed2001

Detecting deception in children's testimony: factfinders' abilities to reach the truth in open court and closed-circuit trials.

This study examined the influence of closed-circuit television (CCTV) on jurors' abilities to detect deception in children's testimony. Children ages 7-9 individually played games and made a video movie with a male confederate. In the guilty condition, stickers were placed on exposed body parts (i.e., the child's arm, toes, and bellybutton). In the not-guilty and deception conditions, stickers were placed on the child's clothing rather than on bare skin. Approximately 3 weeks later, mock jurors recruited from the community viewed child participants testify either in a traditional courtroom setting or via one-way CCTV. The mock jurors responded to questions about the child witness and the defendant as well as deliberated to reach a verdict. Children in the deception condition were asked to testify as if the stickers had been placed on exposed body parts rather than on their clothing. Predeliberation, jurors were less likely to convict when a child testified in the deception condition as opposed to the guilty condition. These differences disappeared following deliberation. There was no support for the notion that jurors reach the truth better when children testify in open court versus via CCTV. Implications for jurors' abilities to reach the truth are discussed.

Child↗
PubMed2001

Technique of right laparoscopic donor nephrectomy: a single center experience.

The majority of laparoscopic donor nephrectomies (LDNs) are limited to the left side due to technical and allograft concerns in using the right. We review our experience with right LDNs. Since June 1997, 15 right LDNs were performed and the records retrospectively reviewed for demographics, operative time, transfusions, complications, and length of stay. Recipient records were also reviewed for delayed graft function, complications, and serum creatinine levels. Overall donor, recipient and graft survivals at 6 months are 100%. Mean operative time was 317 +/- 11.0 min, length of stay was 4.2 +/- 0.2 d, and mean serum creatinine levels at discharge, 1, 3, and 6 months were 1.74 +/- 0.19, 1.59 +/- 0.13, 1.72 +/- 0.13, and 1.68 +/- 0.13 mg/dL, respectively. No transfusions were required. There were no operative or hospital complications. Two recipients (13.3%) experienced delayed graft function, defined as requiring hemodialysis post-transplantation. With hand-assisted laparoscopy, the right laparoscopic donor nephrectomy is safe and allows excellent allograft function.

Adult↗
PubMed2001

Associative learning of likes and dislikes: a review of 25 years of research on human evaluative conditioning.

Evaluative conditioning refers to changes in the liking of a stimulus that are due to the fact that the stimulus has been paired with other, positive or negative stimuli. Although evaluative conditioning appears to be subjected to certain boundary conditions, significant evaluative conditioning effects have been obtained using a large variety of stimuli and procedures. Some data suggest that evaluative conditioning can occur under conditions that do not support other forms of Pavlovian conditioning, and several models have been proposed to account for these differences. In the present article, the authors summarize the available literature, draw conclusions where possible, and provide suggestions for future research.

Association Learning↗
PubMed2001

Important causes of hypoglycaemia in patients with diabetes on peritoneal dialysis.

AIM: Diabetes is now the commonest cause of end-stage renal failure, so there are many diabetic patients receiving dialysis therapy. There are several important ways in which dialysis practice can impinge unfavourably on glucose control. This study focuses on the interaction between maltose-derived metabolites in a new peritoneal dialysis fluid and blood glucose measurements using reagent sticks that depend on the glucose dehydrogenase method. CASE REPORT: We report the cases of three patients, with insulin-treated diabetes and end-stage renal disease treated with peritoneal dialysis, who experienced symptomatic hypoglycaemia with inaccurate glucose readings on reagent strips when converted to icodextrin. CONCLUSION: Careful teamwork between diabetes and renal physicians and specialist nurses is highly desirable to achieve good glucose control in a group of patients at particular risk of microvascular and macrovascular complications.

Adult↗
PubMed2001

Nitric oxide prevents intestinal mitochondrial dysfunction induced by surgical stress.

BACKGROUND: The intestine is highly susceptible to free radical-induced damage and earlier work has shown that surgical stress induces generation of oxygen free radicals in enterocytes, resulting in intestinal damage along with changes in mitochondrial structure and function. Nitric oxide is an important mediator of gastrointestinal function and this study looked at the effect of nitric oxide on surgical stress-induced intestinal mitochondrial alterations. METHODS: Controls and rats pretreated with the nitric oxide donor L-arginine were subjected to surgical stress by opening the abdominal wall and handling the intestine. Enterocytes were isolated, mitochondria prepared and the protection offered by L-arginine against damage due to surgical stress was determined. Protection to structural as well as functional aspects of mitochondria was examined. RESULTS: Mild handling of the intestine affected the enterocyte mitochondrial structure as assessed by lipid composition and electron microscopy. Mitochondria were also functionally impaired with altered calcium flux and decreased respiratory control ratio. Pretreatment with the nitric oxide synthase substrate L-arginine prevented these damaging effects of surgical stress. Protection with arginine was abolished by the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester, indicating the role of nitric oxide. CONCLUSION: Surgical stress in the small intestine can affect enterocyte mitochondrial structure and function. These damaging effects can be prevented by nitric oxide, an important modulator of cellular function.

Animals↗
PubMed2001

Feasibility of day-care open cholecystectomy: evaluation in an inpatient model.

BACKGROUND: Open cholecystectomy is still a fairly frequently performed operation worldwide, and is used where laparoscopic surgery has failed or is contraindicated, and where some surgeons do not operate laparoscopically for technical reasons. In developing countries laparoscopic cholecystectomy is costly and is available only in a few centres. The present study was conducted to assess the feasibility of day-care open cholecystectomy using an inpatient model. METHODS: Thirty patients were subjected to open cholecystectomy. Intraoperative nasogastric decompression and local wound infiltration with 0.25% bupivacaine was carried out. Postoperatively patients were encouraged to be ambulant, pass urine and start oral fluids. Intravenous fluids and parenteral medication were stopped at 8 p.m. when patients were assessed for feasibility for discharge. All patients were reassessed the next morning for any adverse effects that could have occurred had the patients been discharged on the evening of surgery. RESULTS: Prospectively, 73.3% of patients were considered to be dischargeable on the evening of surgery; but on reassessment the next morning, retrospectively, 93.3% of patients were actually dischargeable on the evening of surgery. A total of 76.6% of patients was actually discharged within 24 h of surgery. No patient required readmission. On follow up there were no complications that could be attributable to early discharge. A total of 83.3% of patients approved of day-care open cholecystectomy. CONCLUSIONS: Day-care open cholecystectomy is safe and feasible. In developing countries, where the use of laparoscopic surgery is limited due to resource constraints, day-care open cholecystectomy can lead to substantial savings in health-care resources.

Adult↗
PubMed2001

Correlates for erectile and ejaculatory dysfunction in older Dutch men: a community-based study.

OBJECTIVES: We estimated correlates for erectile dysfunction (ED) (defined as a report of erections of severely reduced rigidity or no erections) and ejaculatory dysfunction (EjD) (defined as a report of ejaculations with significantly reduced volume or no ejaculations) in a large community sample of older men. DESIGN: A community-based study. SETTING: Krimpen aan den IJssel, a municipality near Rotterdam, The Netherlands. PARTICIPANTS: A total of 1,688 (50% of the eligible) men age 50 to 78. MEASUREMENTS: Presence of ED and EjD (International Continence Society sex questionnaire), urinary tract symptoms (international prostate symptom score), prostate enlargement (transrectal ultrasonography), urinary flow obstruction (uroflowmetry), obesity (body mass index), chronic obstructive pulmonary disease (COPD), diabetes mellitus, and cardiovascular problems. Determined marital status, educational level, and smoking and drinking habits. Population attributable risk (PAR) was estimated for correlates that yielded from multiple logistic regression models on ED and EjD. RESULTS: Multiple logistic regression analyses yielded the following correlates for significant ED: age, smoking, obesity, urinary tract symptoms, and treatment for cardiovascular problems and COPD. Age, erectile function, urinary symptoms, and previous prostate operations proved to be correlates for significant EjD. Urinary symptoms and obesity have the highest PAR for ED, whereas decreased erectile function has the highest PAR for EjD. CONCLUSIONS: Age, obesity, and urinary tract symptoms are the most-important correlates of significant ED in the population. Cardiac problems, COPD, and smoking are other independent correlates. Significant EjD is largely related to age, decreased erectile function, and previous prostate surgery.

Aged↗
PubMed2001

Clinical decisions using the National Triage Scale: how important is postgraduate education?

Triage is the formal nursing assessment of all patients who present to an Emergency Department (ED). The National Triage Scale (NTS) is used in most Australian EDs. Triage decision making involves the allocation of every patients presenting to an ED to one of the five NTS categories. The NTS directly relates a triage category to illness or injury severity and need for emergency care. Triage nurses' decisions not only have the potential to impact on the health outcomes of ED patients, they are also used, in part, to evaluate ED performance and allocate components of ED funding. This study was a correlational study that used survey methods. Triage decisions were classified as 'expected triage', 'overtriage' or 'undertriage' decisions. Participant's qualifications were allocated to five categories: 'nil'; 'emergency nursing'; 'critical care nursing'; 'midwifery'; and 'tertiary' qualifications. There was no correlation between triage decisions and length of experience in emergency nursing or triage. 'Expected triage' decisions were more common when the predicted triage category was Category 3 (P < 0.001) and 'overtriage' decisions were less common when the predicted triage category was Category 2 (P < 0.0010). The frequency of 'undertriage' decisions decreased significantly when the predicted triage category was Category 3 (P < 0.001) or Category 4 (P < 0.001). There was no correlation between triage decisions and qualifications in the 'nil', 'emergency nursing' or 'critical care nursing' categories. A midwifery qualification demonstrated a positive correlation with 'expected triage' decisions (P = 0.048) and a negative correlation with 'undertriage' decisions (P = 0.012). There was also a positive correlation between a tertiary qualification and 'expected triage' decisions (P = 0.012).

Clinical Competence↗
PubMed2001

Nasolabial flaps in oral reconstruction: an analysis of 224 cases.

The nasolabial flap is a simple option for the reconstruction of selected oral defects. Though its use in floor-of-mouth reconstruction has been described, other uses in the oral cavity have not been studied extensively. We present a series of 224 oral malignancies where the nasolabial flap was used for reconstruction after surgical excision.

Adolescent↗
PubMed2001

Insulin-like growth factor I accelerates gastric ulcer healing by stimulating cell proliferation and by inhibiting gastric acid secretion.

BACKGROUND: Given the importance of Insulin-Like Growth Factor I (IGF-I) to intestinal maintenance and the presence of IGF-I in salivary glands, we hypothesized that IGF-I participates in the healing of gastric ulcers. The aim of the study was to determine: 1) whether IGF-I applied locally would support gastric ulcer healing by increasing cell proliferation and 2) the effect of IGF-I on gastric acid secretion. METHODS: Gastric ulcers were induced with a cryoprobe. Immediately thereafter, IGF-I (0.4, 4.0 and 40 microg) or vehicle was infiltrated perifocally. In another group, animals received a daily dose of 40 micromol omeprazole subcutaneously. Ulcer healing was evaluated by ulcer size and histological examination at 7 days. Pentagastrin-stimulated gastric acid secretion was evaluated in conscious rats with gastric fistula, after IGF-I (400 microg) had been injected intravenously. RESULTS: IGF-I significantly reduced ulcer size, but only at low doses (0.4 microg/kg body weight (BW), P = 0.008; 4 microg/kg BW, P = 0.001). This effect was similar to omeprazole treatment. Histological examination after IGF-I administration showed increased cell proliferation, increased IGF-I content and down-regulated IGF-I receptors. The secretory studies demonstrated a significant decrease in gastric acid secretion 30 min after IGF-I bolus injection (IGF-I: 53 +/- 11 microEq; vehicle: 116 +/- 5 microEq; P=0.001), which lasted for more than 1 h. CONCLUSION: IGF-I stimulates gastric ulcer healing, stimulating cell proliferation and inhibiting gastric acid secretion.

Animals↗
PubMed2001

Cross-cultural evaluation of two drinking assessment instruments: alcohol timeline followback and inventory of drinking situations.

This article describes the psychometric characteristics of two major assessment instruments used in a World Health Organization (WHO) clinical trial: (a) Alcohol Timeline Followback (TLFB, which assesses daily drinking patterns), and (b) Inventory of Drinking Situations (IDS, which assesses antecedents to "heavy" drinking). Clients (N = 308) were outpatient alcohol abusers from four countries (Australia, Canada, Mexico, and Sweden). Generally, the Alcohol TLFB and IDS were shown to be reliable and valid with outpatient alcohol abusers in four countries, and in three languages. These results suggest that the Alcohol TLFB and the IDS can be used in clinical and research settings with Swedish-, Spanish-, and English-speaking alcohol abusers.

Adult↗
PubMed2001

Loss of NF1 alleles distinguish sporadic from NF1-associated pilocytic astrocytomas.

Pilocytic astrocytomas classified as WHO grade I typically arise in childhood and upon complete surgical removal carry a favorable prognosis. Children with neurofibromatosis 1 (NF1) have a vastly increased risk for pilocytic astrocytomas, especially for those of the optic nerve. Using 4 intragenic NF1 microsatellite markers, we examined losses of NF1 alleles on the long arm of chromosome 17 in 12 NF1-associated and 25 sporadic pilocytic astrocytomas. The TP53 gene region on the short arm of chromosome 17 was also examined in these tumors using 3 markers. Loss of 1 NF1 allele was detected in 11 of 12 (92%) informative NF1-associated pilocytic astrocytomas. In contrast, only 1 of 24 informative (4%) sporadic pilocytic astrocytomas exhibited allelic loss in the NF1 region. Among the 11 NF1-associated tumors with NF1 loss, 5 had also lost alleles on 17p. The high rate of NF1 allele loss in NF1-associated pilocytic astrocytomas suggests a tumor initiating or promoting action of the NF1 gene in these patients. On the other hand, the much lower rate of NF1-allele loss in sporadic pilocytic astrocytomas argues for only minor importance of NF1 in that patient group. The present data support different mechanisms in the formation of NF1-associated and sporadic pilocytic astrocytomas.

Adolescent↗