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Biomedical subjects

C Williams

Publications and source records attributed to C Williams.

At least 163 records · Page 9Linked to original sources
PubMed1999

Smoking cessation following treatment in a smoke-free Navy Alcohol Rehabilitation program.

The purpose of this study was to examine changes in smoking behavior and attitudes following treatment in the smoke-free Navy Alcohol Rehabilitation program (NARC) and to evaluate changes in staff attitudes toward the smoke-free policy. Consecutive patients (N = 404; 93.8% male) admitted to the NARC between February 1, 1993 and September 30, 1993 were studied, of whom 54.7% were current smokers. Measures included patient surveys administered repeatedly at admission and discharge and at 12 months following the 4-week treatment program. The staff were also administered a survey 2 months before (N = 86) and 6 months after (N = 104) policy implementation. Results indicate that alcohol treatment in a smoke-free environment did not markedly affect the smoking status of patients; the proportion of current smokers at discharge was 54.7%. Significant reductions in cigarettes smoked per day (p < .001) were observed among patients from admission to discharge. However, no statistically significant change in readiness to consider smoking cessation scores was detected. Results indicated no significant change in patient smoking status at 12-month follow-up, although the survey response rate was low (35.1%; N = 142). Six months following implementation of the smoke-free policy, 84.6% of staff indicated that the NARC should remain smoke-free and 84.6% recommended that other alcohol and drug treatment facilities be smoke-free.

Adult↗
PubMed1999

CACP, encoding a secreted proteoglycan, is mutated in camptodactyly-arthropathy-coxa vara-pericarditis syndrome.

Altered growth and function of synoviocytes, the intimal cells which line joint cavities and tendon sheaths, occur in a number of skeletal diseases. Hyperplasia of synoviocytes is found in both rheumatoid arthritis and osteoarthritis, despite differences in the underlying aetiologies of the two disorders. We have studied the autosomal recessive disorder camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP; MIM 208250) to identify biological pathways that lead to synoviocyte hyperplasia, the principal pathological feature of this syndrome. Using a positional-candidate approach, we identified mutations in a gene (CACP) encoding a secreted proteoglycan as the cause of CACP. The CACP protein, which has previously been identified as both 'megakaryocyte stimulating factor precursor' and 'superficial zone protein', contains domains that have homology to somatomedin B, heparin-binding proteins, mucins and haemopexins. In addition to expression in joint synovium and cartilage, CACP is expressed in non-skeletal tissues including liver and pericardium. The similarity of CACP sequence to that of other protein families and the expression of CACP in non-skeletal tissues suggest it may have diverse biological activities.

Amino Acid Sequence↗
PubMed1999

Gender, adolescence and the management of diabetes.

Health professionals view adolescence as a difficult time in which to manage diabetes. Adherence to treatment may be a problem, and there is also an expectation that young people should become independent in self-care. Drawing on data from a qualitative study which interviewed teenagers with diabetes and their mothers, this paper focuses on the ways in which gender and adolescence interact to affect how young people live with diabetes. Key themes explored include: the gendered meanings of diabetes; gendered management strategies; gendered dependencies; and adherence to treatment regimes. Gender was found to have a major impact on how young people managed diabetes. Gender also impacted on the involvement of mothers, with the mothers of sons much more likely to be involved in helping their sons than the mothers of daughters. In discussing some of the implications for health policy, it is suggested that in their ways of managing diabetes, young people should be seen as acting rationally within the confines of their gendered identities. Therefore, a uniform policy which promotes the independence of young people may not always be an appropriate way of working with young people or their families.

Adolescent↗
PubMed1999

Falling by the wayside: a phenomenological exploration of perceived breast-milk inadequacy in lactating women.

OBJECTIVE: To provide insight into the lived experience of breast feeding, in primiparous women. The main focus was upon women's perceptions related to the adequacy of their breast milk, for the purpose of exclusively nourishing their babies. DESIGN: A longitudinal, phenomenological study involving in-depth, interactive interviews, conducted at 6, 12 and 18 weeks following the birth of the women's babies. PARTICIPANTS AND SETTING: A convenience sample of ten primiparous women were recruited prior to discharge from a maternity unit, in the north of England, in 1998. FINDINGS: Two groups of participants emerged, three who became increasingly confident and empowered by breast feeding and the remaining seven whose confidence progressively diminished, with six of them expressing concern that their breast milk was inadequate. Four major themes related to the participants' perceptions emerged from the analysis: the quest to quantify and visualise breast milk; anxiety regarding the adequacy of their diet; breast feeding as a challenging journey, with most feeling that they had 'fallen by the wayside' (this related partly to inadequate and conflicting advice given by health professionals); and finally, unmet needs for support, nurturing and replenishment in return for 'giving out'. CONCLUSION: Perceived breast-milk inadequacy is underpinned by a complex and synergistic interaction between socio-cultural influences, feeding management, the baby's behaviour, lactation physiology and the woman's psychological state. IMPLICATIONS: Education of midwives and health visitors is required in relation to the needs of breast-feeding mothers within a Western industrialised society. Strong social policy is vital in the UK, to initiate socio-cultural changes, which would enable women who commence breast feeding to perceive it as an empowering and fulfilling experience and not one of 'falling by the wayside'.

Anxiety↗
PubMed1999

The influence of intermittent high-intensity shuttle running and fluid ingestion on the performance of a soccer skill.

The aim of this study was to examine the effect of intermittent high-intensity shuttle running and fluid ingestion on the performance of a soccer skill. Nine semi-professional soccer players volunteered to participate in the study. Their mean (+/- s(x)) age, body mass and maximal oxygen uptake were 20.2+/-0.4 years, 73.2+/-1.8 kg and 59.1+/-1.3 ml x kg(-1) min(-1) respectively. The players were allocated to two randomly assigned trials: ingesting or abstaining from fluid intake during a 90 min intermittent exercise protocol (Loughborough Intermittent Shuttle Test: LIST). This test was designed to simulate the minimum physical demands faced by soccer players during a game. Before and immediately after performance of the test, the players completed a soccer skill test and a mental concentration test. Performance of the soccer skill test after the 'no-fluid' trial deteriorated by 5% (P<0.05), but was maintained during the fluid trial. Mean heart rate, perceived exertion, serum aldosterone, osmolality, sodium and cortisol responses during the test were higher (P<0.05) in the 'no-fluid' trial than in the fluid trial. The results of this study suggest that soccer players should consume fluid throughout a game to help prevent a deterioration in skill performance.

Adult↗
PubMed1999

Muscular soreness following prolonged intermittent high-intensity shuttle running.

The aim of this study was to examine the impact of prolonged intermittent high-intensity shuttle running on soreness and markers of muscle damage. Sixteen males took part in the study, half of whom were assigned to a running group and half to a resting control group. The exercise protocol involved 90 min of intermittent shuttle running and walking (Loughborough Intermittent Shuttle Test: LIST), reflecting the activity pattern found in multiple-sprint sports such as soccer. Immediately after exercise, there was a significant increase (P < 0.05) in serum activities of creatine kinase and aspartate aminotransferase, and values remained above baseline for 48 h (P < 0.05). Median peak activities of creatine kinase and aspartate aminotransferase occurred 24 h post-exercise and were 774 and 43 U x l(-1), respectively. The intensity of general muscle soreness, and in the specific muscles investigated, was greater than baseline for 72 h after the shuttle test (P < 0.05), peaking 24-48 h post-exercise (P < 0.05). Muscle soreness was not correlated with either creatine kinase or aspartate aminotransferase activity. Soreness was most frequently reported in the hamstrings. Neither soreness nor serum enzyme activity changed in the controls over the 4 day observation period. It appears that unaccustomed performance of prolonged intermittent shuttle running produces a significant increase in both soreness and markers of muscle damage.

Adult↗
PubMed1999

The effects of neurocognitive remediation on executive processing in patients with schizophrenia.

Approaches to cognitive remediation have differed across studies. Most of the larger studies have concentrated on group treatments designed without the benefit of recent laboratory-based studies. The current study describes a randomized trial of an intensive cognitive remediation program involving individual daily sessions of 1 hour for up to 3 months. It targets executive functioning deficits (cognitive flexibility, working memory, and planning) that are known to be problematic in people with schizophrenia. Procedural learning, as well as the principles of errorless learning, targeted reinforcement, and massed practice, was the basis of the intervention. The program was compared with an alternative therapy (intensive occupational therapy) to control for some of the effects of therapeutic contact. Some improvements in cognition followed both therapies. A differential effect in favor of cognitive remediation therapy was found for tests in the cognitive flexibility and the memory subgroups. There was a trend for those receiving atypical antipsychotic medication to benefit more from cognitive remediation for tests of cognitive flexibility. Although there were no consistent changes in symptoms or social functioning between groups, if improvement in cognitive flexibility tasks reached a threshold then there is some evidence that social functioning improved, even over the short duration of the trial. In addition, cognitive remediation differentially improved self-esteem. This study supports the view that cognitive remediation can reduce cognitive deficits and that this reduction may affect social outcome, at least in the short term.

Adult↗
PubMed1999

Large-pore hemodialysis in acute endotoxin shock.

OBJECTIVE: This study was undertaken to test the hypothesis that hemodialysis with a large-pore membrane would improve heart function during acute endotoxin shock. SETTING: Large animal laboratory. DESIGN: Eighteen mongrel dogs were instrumented to measure left ventricular maximum end-systolic elastance (left ventricular maximum elastance at end systole), cardiac output, circumflex artery blood flow, and myocardial mechanical efficiency (CO x MAP/MVO2, where CO is cardiac output, MAP is mean arterial pressure, and MVO2 is myocardial oxygen consumption). Plasma catecholamine concentrations were determined by high-performance liquid chromatography. Endotoxin shock was induced by infusing 5.0 microg/kg/min of Escherichia col 0127:B8 endotoxin in the portal vein for 60 mins, followed by 2.0 microg/kg/min of constant infusion. Control dogs (n = 6) received 4.0 mL/kg/min of saline; hemodialysis dogs (n = 6) underwent venovenous hemodialysis in 50-min intervals using a polysulfone filter (1.2 m2; mean pore size, 0.50 nm; blood flow rate, 400 mL/min; ultrafiltrate, "zero-balanced"); shams (n = 5) were treated identically to hemodialysis dogs, except that no convective dialysis was performed. A fourth group (n = 6) was treated with dopamine (5.0-7.0 microg/kg/min, optimal dose for contractile increase based on dose-response studies). MEASUREMENTS AND MAIN RESULTS: After 2 hrs of treatment, left ventricular maximum elastance at end systole increased and was unchanged in controls (30 +/- 5 mm Hg/mm) and shams (24 +/- 6 mm Hg/mm) compared with basal control. Hemodialysis treatment increased contractility (53 +/- 4 mm Hg/mm), as did dopamine treatment (54 +/- 7 mm Hg/mm). Endotoxin shock reduced mechanical efficiency to 45% of basal control; with hemodialysis treatment, left ventricular efficiency returned to 64% of basal control measurement, compared with 49% with dopamine treatment. During treatment, myocardial glucose uptake was increased with hemodialysis compared with other groups. No difference was observed among groups for left ventricular end-diastolic pressures or dimensions, or catecholamine concentrations. CONCLUSIONS: Large-pore hemodialysis increased left ventricular contractility to a similar degree as dopamine and provided a marginal improvement in myocardial glucose uptake and mechanical efficiency.

Acute Disease↗
PubMed1999

Effect of milk on somatostatin degradation in suckling rat jejunum in vivo.

BACKGROUND: Somatostatin-14 is present in breast milk, and intact somatostatin-14 has been recovered from gastric lumen of infants. Studies have shown that somatostatin-14 is metabolized in the intestinal luminal contents in vitro, which could be prevented by the presence of breast milk. In this study, the effect of milk on stability of somatostatin-14 in suckling rat jejunum in vivo was examined. METHODS: 125I-Somatostatin-14[Tyr 11] was administered to the isolated jejunal loops in anesthetized suckling rats in the absence or presence of milk, fractions of milk, or known protease-peptidase inhibitors. Structural integrity of 125I-somatostatin-14[Tyr 11] recovered from tissues at different intervals was analyzed by gel filtration and high-performance liquid chromatography. RESULTS: Radioactivity rapidly disappeared from the jejunal lumen with a 50% clearance achieved by 1.2 minutes. Gel filtration and high-performance liquid chromatography analyses showed that 125I-somatostatin- 14[Tyr 11] was rapidly degraded into smaller fragments. At 1 minute, jejunal luminal radioactivity was eluted in a major peak with retention time of 42.4 minutes, along with other minor peaks (retention time, 5.6, 8.0, 10.4, and 14.4 minutes); only a trace amount of intact 125I-somatostatin-14[Tyr 11] (retention time, 44.8 minutes) was present. Coadministration of rat's milk or its soluble fraction increased the level of intact 125I-somatostatin-14[Tyr 11] in the jejunal lumen and jejunal tissue. Presence of rat's milk-casein or peptidase inhibitors (bestatin, phosphoramidon, or Bowman-Birk inhibitor), however, failed to increase the level of intact 125I-somatostatin-14[Tyr 11]. CONCLUSION: These results suggest that somatostatin-14 is rapidly degraded in the jejunal lumen of suckling rats, and that milk-borne peptidase inhibitors prevent this somatostatin-14 degradation.

Animals↗
PubMed1999

Influence of high and low glycemic index meals on endurance running capacity.

PURPOSE: The purpose of this study was to examine the effect of high and low glycemic index (GI) carbohydrate (CHO) pre-exercise meals on endurance running capacity. METHODS: Eight active subjects (five male and three female) ran on a treadmill at approximately 70% VO2max to exhaustion on two occasions separated by 7 d. Three hours before the run after an overnight fast, each subject was given in a single-blind, random order, isoenergetic meal of 850+/-21 kcal (mean+/-SEM; 67% carbohydrate, 30% protein, and 3% fat) containing either high (HGI) or low (LGI) GI carbohydrate foods providing 2.0 g CHO.kg(-1) body weight. RESULTS: Ingestion of the HGI meal resulted in a 580% and 330% greater incremental area under the 3-h blood glucose and serum insulin response curves, respectively. Performance times were not different between the HGI and LGI trials (113+/-4 min and 111+/-5 min, respectively). During the first 80 min of exercise in the LGI trial, CHO oxidation was 12% lower and fat oxidation was 118% higher than in the HGI trial. Although serum insulin concentrations did not differ between trials, blood glucose at 20 min into exercise in the HGI trial was lower than that during the LGI trial at the same time (3.6+/-0.3 mmol.L(-1) vs 4.3+/-0.3 mmol.L(-1); P < 0.05). During exercise, plasma glycerol and serum free fatty acid concentrations were lower in the HGI trial than in the LGI trial. CONCLUSIONS: This results demonstrate that although there is a relative shift in substrate utilization from CHO to fat when a low GI meal is ingested before exercise compared with that for a high GI meal, there is no difference in endurance running capacity.

Adult↗
PubMed1999

Carbohydrate-electrolyte ingestion during intermittent high-intensity running.

PURPOSE: The purpose of this study was to examine the effects of ingesting a carbohydrate-electrolyte beverage or a noncarbohydrate placebo on muscle glycogen utilization during 90 min of intermittent high-intensity running. METHODS: Six trained games players (age 24.6 +/- 2.2 yr; height 179.6 +/- 1.9 cm; body mass 74.5 +/- 2.0 kg; VO2max 56.3 +/- 1.3 mL x kg(-1) x min(-1); mean +/- SEM) performed two exercise trials, 7 d apart. The subjects were university soccer, hockey, or rugby players. On each occasion, they completed six 15-min periods of intermittent running, consisting of maximal sprinting, interspersed with less intense periods of running and walking. During each trial, subjects consumed either a 6.9% carbohydrate-electrolyte solution (CHO-E: the CHO trial) or a noncarbohydrate placebo (the CON trial) immediately before exercise (5 mL x kg(-1) BM) and after every 15 min of exercise thereafter (2 mL x kg(-1) BM). Drinks were administered in a double-blind, counter-balanced order, and the total volume of fluid consumed during each trial was 1114 +/- 30 mL. Needle biopsy samples were obtained from the vastus lateralis muscle before and after 90 min of exercise. Venous blood samples were collected from an antecubital vein at rest and every 30 min during exercise. RESULTS: Muscle glycogen utilization in mixed muscle samples was lower (P < 0.05) during CHO [192.5 +/- 26.3 mmol glucosyl units (kg x DM(-1))] than CON [245.3 +/- 22.9 mmol glucosyl units (kg x DM(-1))]. Single fiber analysis on the biopsy samples of the subjects during the CON trial showed a greater glycogen utilization in the Type II fibers compared with Type I fibers during this type of exercise [Type I: 182.2 +/- 34.5 vs Type II: 287.4 +/- 41.2 mmol glucosyl units (kg x DM(-1)); P < 0.05). After 30 min of exercise, blood lactate was significantly greater (P < 0.05) and serum insulin concentration lower (P < 0.05) in CON. CONCLUSIONS: In summary, when trained games players ingested a carbohydrate-electrolyte beverage, muscle glycogen utilization was reduced by 22% when compared with a control condition.

Adult↗
PubMed1999

Persistence of self in advanced Alzheimer's disease.

PURPOSE: To determine if evidence of the persistence of a sense of self or personal identity could be found in people in the middle and late stages of Alzheimer's disease. The theme of diminishing self pervades both the popular and professional literature on Alzheimer's disease. DESIGN: Qualitative using conversational analysis. The purposive sample was 23 residents of two urban nursing homes in the southeastern United States who were in the middle and late stages of Alzheimer's disease. Their mean Mini-Mental State examination score was 10.65. Nineteen subjects were women, four were men in this 1993-1997 study. METHODS: Analysis of 45 conversations lasting 30 minutes with nursing home residents with a diagnosis of probable Alzheimer's disease. Use of the first person indexical and other evidence, such as awareness and reactions to the changes that had taken place, in support of and counter to the notion of persistence of self, were sought in conversational analysis. FINDINGS: Respondents used the first person indexical frequently, freely, and coherently. Evidence was also present that participants were aware of their cognitive changes. Many struggled to provide an explanation, but none mentioned Alzheimer's disease. CONCLUSIONS: Evidence suggests the persistence of awareness of self into the middle and late stages of Alzheimer's disease. Failure to recognize the continuing awareness of self and the human experience of the person in the middle and late stages can lead to task-oriented care and low expectations for therapeutic interventions. The bafflement noted in respondents suggests that people should be told their diagnosis and offered an explanation of what this diagnosis means.

Alzheimer Disease↗
PubMed1999

The role of COX-2 in intestinal cancer.

Cyclooxygenase (COX), the key regulatory enzyme for prostaglandin synthesis is transcribed from two distinct genes. COX-1 is expressed constitutively in most tissues, and COX-2 is induced by a wide variety of stimuli and was initially identified as an immediate-early growth response gene. In addition, COX-2 expression is markedly increased in 85-90% of human colorectal adenocarcinomas, whereas COX-1 levels remain unchanged. Several epidemiological studies have reported a 40-50% reduction in the risk of developing colorectal cancer in persons who chronically take such nonsteroidal anti-inflammatory drugs (NSAIDs) as aspirin, which are classic inhibitors of cyclooxygenase. Genetic evidence also supports a role for COX-2, since mice null for COX-2 have an 86% reduction in tumor multiplicity in a background containing a mutated APC allele. These results strongly suggest that COX-2 contributes to the development of intestinal tumors and that inhibition of COX is chemo-preventative.

Animals↗
PubMed1999

Generation of neutralizing human monoclonal antibodies against parvovirus B19 proteins.

Infections caused by human parvovirus B19 are known to be controlled mainly by neutralizing antibodies. To analyze the immune reaction against parvovirus B19 proteins, four cell lines secreting human immunoglobulin G monoclonal antibodies (MAbs) were generated from two healthy donors and one human immunodeficiency virus type 1-seropositive individual with high serum titers against parvovirus. One MAb is specific for nonstructural protein NS1 (MAb 1424), two MAbs are specific for the unique region of minor capsid protein VP1 (MAbs 1418-1 and 1418-16), and one MAb is directed to major capsid protein VP2 (MAb 860-55D). Two MAbs, 1418-1 and 1418-16, which were generated from the same individual have identity in the cDNA sequences encoding the variable domains, with the exception of four base pairs resulting in only one amino acid change in the light chain. The NS1- and VP1-specific MAbs interact with linear epitopes, whereas the recognized epitope in VP2 is conformational. The MAbs specific for the structural proteins display strong virus-neutralizing activity. The VP1- and VP2-specific MAbs have the capacity to neutralize 50% of infectious parvovirus B19 in vitro at 0.08 and 0.73 microgram/ml, respectively, demonstrating the importance of such antibodies in the clearance of B19 viremia. The NS1-specific MAb mediated weak neutralizing activity and required 47.7 micrograms/ml for 50% neutralization. The human MAbs with potent neutralizing activity could be used for immunotherapy of chronically B19 virus-infected individuals and acutely infected pregnant women. Furthermore, the knowledge gained regarding epitopes which induce strongly neutralizing antibodies may be important for vaccine development.

Amino Acid Sequence↗
PubMed1999

SL1 trans splicing and 3'-end formation in a novel class of Caenorhabditis elegans operon.

Many Caenorhabditis elegans genes exist in operons in which polycistronic precursors are processed by cleavage at the 3' ends of upstream genes and trans splicing 100 to 400 nucleotides away, at the 5' ends of downstream genes, to generate monocistronic messages. Of the two spliced leaders, SL1 is trans spliced to the 5' ends of upstream genes, whereas SL2 is reserved for downstream genes in operons. However, there are isolated examples of what appears to be a different sort of operon, in which trans splicing is exclusively to SL1 and there is no intercistronic region; the polyadenylation signal is only a few base pairs upstream of the trans-splice site. We have analyzed the processing of an operon of this type by inserting the central part of mes-6/cks-1 into an SL2-type operon. In this novel context, cks-1 is trans spliced only to SL1, and mes-6 3'-end formation occurs normally, demonstrating that this unique mode of processing is indeed intrinsic to this kind of operon, which we herein designate "SL1-type." An exceptionally long polypyrimidine tract found in the 3' untranslated regions of the three known SL1-type operons is shown to be required for the accumulation of both upstream and downstream mRNAs. Mutations of the trans-splice and poly(A) signals indicate that the two processes are independent and in competition, presumably due to their close proximity, raising the possibility that production of upstream and downstream mRNAs is mutually exclusive.

Animals↗
PubMed1999

Psychosocial predictors of cigarette smoking among adolescents living in public housing developments.

BACKGROUND: Adolescents residing in low-income public housing developments in inner-city regions may be particularly vulnerable to a variety of risk factors associated with cigarette smoking. OBJECTIVE: To elucidate the aetiology of cigarette smoking among adolescents living in public housing developments. DESIGN, SETTING, AND SUBJECTS: We examined predictors of smoking from four domains: background characteristics, social influences, behavioural control, and psychosocial characteristics using a sample of seventh graders (mean age 12.9 years) who reside in public housing developments in New York City (n = 624). The addresses of participants in a larger investigation of the aetiology and prevention of smoking were checked to determine if they lived in one of 335 public housing developments in New York City. All participants living in public housing developments were included in the current study. MAIN OUTCOME MEASURES: African-American and Hispanic students completed questionnaires about their cigarette use, social pressures to smoke, smoking attitudes, smoking knowledge, and smoking resistance skills. Students also provided information on demographic and behavioural control (such as church and school attendance). RESULTS: Logistic regression analyses indicated that social influences from friends and family members predicted smoking. Psychosocial characteristics such as advertising resistance skills, anti-smoking attitudes, and refusal skills lowered the odds of smoking. CONCLUSIONS: These findings suggest that smoking prevention approaches targeted at these young people should increase their awareness of social pressures to smoke, correct misperceptions about the prevalence of smoking among friends, and teach relevant psychosocial skills.

Adolescent↗
PubMed1999

Recurrent acute life-threatening events and lactic acidosis caused by chronic carbon monoxide poisoning in an infant.

Acute severe carbon monoxide poisoning is usually easy to recognize and diagnose. However, chronic or less severe exposure may produce more subtle symptoms. We report on a 31/2-year-old girl who was admitted to the hospital several times with acute, life-threatening events, acidosis, and flu-like symptoms. The diagnosis was elusive, but after careful questioning of family members and a home visit, chronic carbon monoxide poisoning was diagnosed.

Acidosis, Lactic↗