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Biomedical subjects

R Roberts

Publications and source records attributed to R Roberts.

At least 109 records · Page 6Linked to original sources
PubMed1999

Do sick newborn infants benefit from participation in a randomized clinical trial?

BACKGROUND: Adult participants in randomized controlled trials often have better outcomes than patients who are eligible but not enrolled. OBJECTIVE: To examine whether newborn infants who were allocated to placebo in an investigational drug trial had better outcomes than infants who were eligible but not randomized (eligible NR). STUDY DESIGN: During a randomized controlled trial of antithrombin therapy in premature infants with respiratory distress syndrome, data were collected prospectively on all 76 infants in the eligible NR group. Study outcomes were compared with those of all 61 infants who were randomized to placebo. The same exogenous surfactant was used in all patients. RESULTS: In the placebo group the mean (SD) birth weight was 1201 (314) g, mean (SD) gestational age was 28.8 (2.3) weeks, and 51% were male. In infants in the eligible NR group, mean (SD) birth weight was 1141 (262) g, mean (SD) gestational age was 28.3 (2. 3) weeks, and 58% were male; 57% of infants in both groups had been exposed to steroids before birth. The median duration of mechanical ventilation was reduced from 6.2 days in the eligible NR group to 4. 8 days in the placebo group (P =.008). There was also a trend toward less frequent and less severe intraventricular hemorrhage in trial participants. CONCLUSIONS: These data are consistent with the hypothesis that sick newborn infants may benefit from participation in a randomized controlled trial.

Antithrombins↗
PubMed1999

Genetics of cardiovascular disease with emphasis on atrial fibrillation.

Cardiology has embraced the techniques of molecular genetics later than other medical disciplines but is now completely submerged in the genetic mapping of cardiac diseases. The techniques of molecular biology, and in particular, their application to the genetics of inherited diseases, have brought the clinician and the scientist together in an unparalleled dependence. The chromosomal mapping of genes responsible for disease requires the identification of families with inherited diseases. This step involves the cooperation of the clinician. In order to continue improving our understanding of the molecular basis, it is imperative to raise the clinician awareness of the role of genetics in cardiac diseases. Arrhythmias can also have a familial origin and it is not generally appreciated that atrial fibrillation could be inherited. In the last two years, we have identified more than 100 families all over the world with individuals affected by the familial form of the disease. With the techniques of genetic mapping we have identified an area on chromosome 10 that carries a gene causing the disease in some of the families and there is ongoing research to identify the specific mutation. The clinician/scientist relationship has just started and the application of the discoveries in molecular genetics will probably have a direct role on how to approach medicine in the future, from prevention of diseases in patients carrying the susceptibility genes to gene therapy in those individuals with the disease.

Atrial Fibrillation↗
PubMed1999

International maternal mortality reduction: outcome of traditional birth attendant education and intervention in Angola.

BACKGROUND: As a result of war and periodic natural disasters, Angola has among the highest infant and maternal mortality rates in the world. In response to the acute health needs of the population, the International Medical Corps (IMC) developed a traditional birth attendant educational course designed to reduce the preventable causes of maternal and infant mortality. METHODS: From 1994 until 1998, Angolan traditional birth attendants (TBAs) participated in an intensive 38-hr training course on prenatal, delivery, and postnatal care. Following the birth of a child, the trained TBAs completed a registration form containing information regarding the health of the mother. Previous studies of Angolan maternal mortality served as historic comparisons. FINDINGS: Complete data including maternal mortality data were available for 19,666 deliveries (83% of total). Fifty five maternal deaths were recorded, which corresponds to a maternal mortality rate of 293 per 100,000 live births. The average historic maternal mortality rate for available comparison groups was 1241 per 100,000 live births. INTERPRETATION: The maternal mortality rate was reduced among women managed by IMC-trained TBAs when compared with historical control data.

Angola↗
PubMed1999

Evolution of the pelvic pouch procedure at one institution: the first 100 cases.

BACKGROUND: Total extirpation of the colon with pelvic pouch formation, and the avoidance of a permanent stoma, continues to pose a challenge for better results, both technically and functionally. The aims of this study were to investigate the first 100 pelvic ileal-pouch procedures, assessing changes in surgical technique, their relationship to morbidity and long-term outcome, and compare this to the few large international series. METHODS: Between 1984 and 1997, 100 patients had a pelvic J-shaped ileal-pouch formed, 58 two-stage and 42 three-stage procedures. Fifty had a hand-sewn pouch-anal anastomosis and 50 a double-stapled anastomosis. Seventy-three were for ulcerative colitis, five for indeterminate colitis, 20 for familial adenomatous polyposis (FAP), one for multiple primary colorectal cancers, and one for constipation. RESULTS: After a median follow-up of 68 months, 97% of patients still have a functioning pouch. There were two postoperative deaths (one after-pouch formation and one after-stoma closure). Morbidity occurred in 52 patients, including three patients with pouch leaks and three pouch-anal anastomosis leaks (6% leak rate), 27% with a small bowel obstruction (2% early, 20% late, 5% both), a 19% anal stricture rate, and a 9% pouchitis rate. Three pouches have been removed (all for Crohn's disease). Median number of bowel movements per day was six, with 85% of patients reporting a good quality of life. Patients following a double-stapled procedure have less anal seepage and improved continence over those with a hand-sewn ileal pouch-anal anastomosis. CONCLUSIONS: Despite high morbidity rates, pelvic pouch formation provides satisfactory long-term results for patients requiring total proctocolectomy, with functional results and morbidity rates comparable to larger overseas series.

Adenomatous Polyposis Coli↗
PubMed1999

A pre- and postsynaptic modulatory action of 5-HT and the 5-HT2A, 2C receptor agonist DOB on NMDA-evoked responses in the rat medial prefrontal cortex.

Intracellular recordings were made from pyramidal neurons in layers V and VI of the rat medial prefrontal cortex in slice preparations to investigate the effect of the serotonin 5-HT2A,2C receptor agonist (-)-1-2,5-dimethoxy-4-bromophenol-2-aminopropane (DOB) and 5-hydroxytryptamine (5-HT) on N-methyl-D-aspartate (NMDA)-induced responses. Bath application of either DOB or 5-HT [in the presence of antagonists to 5-HT1A, 5-HT3 and gamma-aminobutytric acid (GABA) receptors] produced a concentration-dependent biphasic modulation of the NMDA responses. They facilitated and inhibited NMDA responses at low (</= 1 microM DOB and </= 50 microM 5-HT) and higher concentrations, respectively. Both the facilitating and inhibitory action were blocked by the highly selective 5-HT2A receptor antagonist R-(+)-alpha-(2, 3-dimethoxyphenil)-1-[4-fluorophenylethyl]-4-piperidineme thanol (M100907) and the 5-HT2 receptor antagonist ketanserin, thus indicating that both facilitation and inhibition were mediated by the activation of the 5-HT2A receptor subtype. However, the facilitating, but not inhibitory, action of DOB showed a marked desensitization, suggesting that the facilitation and inhibition of NMDA responses resulted from activation of different 5-HT2A receptor subtypes and/or signal-transduction pathways. Indeed, the selective PKC inhibitor chelerythrine and the Ca2+/CaM-KII inhibitor KN-93 prevented the facilitating and inhibitory action of DOB, respectively. We have generated several lines of evidence to indicate the following scenario. Low concentrations of DOB, at presynaptic nerve terminals, markedly enhance NMDA-induced release of excitatory amino acids (EAAs), which then act upon both NMDA and non-NMDA receptors to elicit inward current. The massive inward current masks the postsynaptic inhibitory action of DOB. At higher concentrations, DOB inhibits the release of EAAs and discloses the postsynaptic inhibitory action.

Alkaloids↗
PubMed1999

A randomized controlled trial comparing plasma removal with white cell reduction to prevent reactions to platelets.

BACKGROUND: Recent data suggest that most reactions to platelets are caused by white cell (WBC)-derived cytokines that accumulate in the plasma portion of the component during storage. On the basis of this theory, the effectiveness of two interventions to prevent reactions, poststorage WBC reduction and plasma depletion, were compared. STUDY DESIGN: A multiple crossover design was used, in which platelet components for transfusion to a patient randomly were WBC reduced after storage, or the plasma supernatant was removed. Adults >17 years of age, with a hematologic disease requiring platelet transfusion support, were eligible for the study. Patients were assessed for signs and symptoms characteristic of a reaction during, immediately after, and 1 hour after transfusion. Reactions were graded as mild, moderate, or severe. Interleukin 6 levels were also measured in the transfused platelet components. RESULTS: There were 380 analyzable platelet transfusions to 30 patients. The frequency of reactions was 25.8 percent (48/186) in the transfusions of poststorage WBC-reduced platelets and 17.0 percent (33/194) in the transfusions of plasma-depleted platelets (p<0.008). The severity of the reaction was graded by the patient. Severe reactions occurred more frequently in connection with poststorage WBC-reduced platelets than with plasma-depleted platelets: 33.4 percent (16/48) versus 18.2 percent (6/33), respectively (p = 0.048). Regression analysis identified interleukin 6 as the most significant of the evaluated factors in its correlation with the risk of reaction. CONCLUSION: Plasma removal is more effective than poststorage WBC reduction in preventing reactions, especially severe reactions to platelets.

Adolescent↗
PubMed1999

The effects of economic circumstances on British students' mental and physical health.

Three-hundred sixty British university students completed a questionnaire providing information on demographic characteristics, financial circumstances, smoking, and drug and alcohol use. A 14-item inventory of physical symptoms, the short form 36 health survey (SF-36), and the General Health Questionnaire (GHQ-12) were used to assess their physical and psychological well-being. Except for physical functioning, all subscales of the SF-36 and the GHQ indicated levels of health significantly below population norms matched for age and sex. Poorer mental health was related to longer working hours outside the university and difficulty in paying bills. Students who had considered abandoning study for financial reasons had poorer mental health, lower levels of social functioning and vitality, and poorer physical health as indicated by variables on the SF-36. They were also heavier smokers. Students' personal debt was significantly associated with their knowing people involved in prostitution, crime, or drug dealing to help support themselves financially.

Adult↗
PubMed1999

Variations in self-reported health by occupational grade in the British Post Office: the Q-health project.

Between 1995 and 1998 a national sample of 58,501 (42,885 males, 15,616 females) Post Office employees (29%) completed and returned a postal questionnaire survey providing information on demographic characteristics, physical and psychological health, health and lifestyles and health screening behaviour. Response rates by occupational grade were as follows: manual (male 69.3%, females 43.6%); clerical (male = 11.8%, female, 42.3%); middle management (males 15.5%, females 10.7%) and senior management (males 3.4%, females 3.3%). A number of differences in health status occurred with occupational grade. Angina, high blood pressure, obesity, smoking, arthritis, disability, GP consultations and abnormal smears were all more prevalent in lower occupational grades. Height, job satisfaction, seat belt use and breast self-examination were also lower in lower status jobs. Some findings were unexpected: GHQ scores indicated better mental health in lower grades, whilst knowledge and frequency of testicular self-examination and attendance for mammograms were higher in lower grades. Self-reports for asthma, diabetes and family history of bowel cancer were also greater in higher grades. These findings are considered in terms of response bias, health selection, the psychosocial work environment, occupational health interventions and the nature, meaning and organization of social position within the Post Office.

Administrative Personnel↗
PubMed1999

Molecular biology and atrial fibrillation.

Atrial fibrillation remains one of the most challenging arrhythmias in cardiology. Despite the overall advance in the treatment of patients with cardiac dysrhythmias with the introduction of radiofrequency ablation, therapeutic options in atrial fibrillation have remained largely unchanged and aimed at controlling the heart rate and anticoagulation. New surgical and ablation compartmentalization techniques are being developed that are promising, but to date these techniques are still extremely laborious and available only to a handful of patients. Advances in genetics and molecular biology will likely give new insights into the development of the disease. Molecular biology research is presently focused into two main fields: 1) identification of the genes that cause familial forms of the disease, and 2) altered gene expression during the disease state. These studies are aimed at identifying not only the triggering factors in the acute form but also those that prolong the arrhythmia and convert it into a chronic form.

Animals↗
PubMed1999

Evisceration after abdominal stab wounds: is laparotomy required?

OBJECTIVES: To determine the incidence of intra-abdominal injury requiring laparotomy after an abdominal stab wound with evisceration. To identify clinical signs that increase the likelihood of an intra-abdominal injury in the presence of such a wound. METHODS: Information was collected prospectively over an 8-year period on all patients who presented to our urban level I trauma center with an abdominal stab wound and evisceration. This information included which organ eviscerated, presence of other indications for laparotomy, organs injured, and postoperative complications. All comparisons used the Fisher's exact chi2. RESULTS: A total of 81 patients were admitted with evisceration after an abdominal stab wound. Sixty-one patients (75%) had eviscerated omentum, 18 patients (22%) had eviscerated small bowel, and 2 patients (2%) had eviscerated colon. Sixty-two patients (76%) had evisceration as the sole indication for laparotomy, the remaining 19 patients (24%) had another indication such as hypotension or peritonitis. Overall, 63 patients (78%) had an intra-abdominal injury that required repair. This was true regardless of organ eviscerated (omentum = 77% vs. viscus = 80%, not significant) or clinical presentation (no other indication = 76% vs. another indication = 84%, not significant). CONCLUSION: The majority of patients who present with an evisceration after a stab wound to the abdomen require a laparotomy. This is true regardless of what has eviscerated or the presence of other clinical indications to operate. Evisceration should continue to prompt operative intervention.

Abdominal Injuries↗
PubMed1999

A transgenic rabbit model for human hypertrophic cardiomyopathy.

Certain mutations in genes for sarcomeric proteins cause hypertrophic cardiomyopathy (HCM). We have developed a transgenic rabbit model for HCM caused by a common point mutation in the beta-myosin heavy chain (MyHC) gene, R400Q. Wild-type and mutant human beta-MyHC cDNAs were cloned 3' to a 7-kb murine beta-MyHC promoter. We injected purified transgenes into fertilized zygotes to generate two lines each of the wild-type and mutant transgenic rabbits. Expression of transgene mRNA and protein were confirmed by Northern blotting and 2-dimensional gel electrophoresis followed by immunoblotting, respectively. Animals carrying the mutant transgene showed substantial myocyte disarray and a 3-fold increase in interstitial collagen expression in their myocardia. Mean septal thicknesses were comparable between rabbits carrying the wild type transgene and their nontransgenic littermates (NLMs) but were significantly increased in the mutant transgenic animals. Posterior wall thickness and left ventricular mass were also increased, but dimensions and systolic function were normal. Premature death was more common in mutant than in wild-type transgenic rabbits or in NLMs. Thus, cardiac expression of beta-MyHC-Q(403) in transgenic rabbits induced hypertrophy, myocyte and myofibrillar disarray, interstitial fibrosis, and premature death, phenotypes observed in humans patients with HCM due to beta-MyHC-Q(403).

Animals↗
PubMed1999

Health-related correlates of gambling on the British National Lottery.

The National Lottery has been estimated as being played by 65% of the adult British population. This study investigated whether higher average weekly spending on the Lottery is associated with various health-related variables. Results from a survey of 482 British adults (mean age = 33.3 yr.), consisting of 107 students and 375 people in employment, indicated that those who spent more on the Lottery had significantly poorer social functioning (Social Functioning scale of the SF-36 Health Survey), higher weekly alcohol and cigarette consumption, and lower frequency of social support (Emotional and Social Interaction scales of the Medical Outcomes Study Social Support Survey). By contrast, higher lottery spending was not associated with poorer general mental health (General Health Questionnaire). Manual workers spent over twice the weekly amount on the Lottery compared to nonmanual workers. Consumption of alcohol and cigarettes was lower than recently published UK norms. Results suggest that higher Lottery spending among the general adult population possibly may be linked specifically to restrictions in social activity. The association of Lottery spending with alcohol and cigarette use among a sample whose consumption was relatively low appears to require explanation within psychological theories of addiction. The over-all pattern of results is discussed in relation both to addiction theory and to the Lottery's widespread appeal and availability.

Adult↗
PubMed1999

Bridging the theory-practice gap.

In New Zealand, there is a festering debate over a "theory-practice gap" in nursing. Joint appointments may be a potential solution to this issue. Joint appointments refer to a variety of arrangements whereby concurrent employment occurs within an educational institution and a clinical setting. Advantages for the appointees include job satisfaction and professional growth. Clinical credibility for nurse educators enables improved facilitation of student learning. In clinical areas, benefits in patient care are associated with the marrying of academic rigour with clinical practice. Some appointees assist with staff development, act as consultants on nursing issues and undertake research. Disadvantages in the concept focus on role conflict, i.e. incongruity between the roles and role ambiguity, i.e. lack of clarity concerning expectations. Success depends upon the personal attributes of appointees; realistic expectations; flexibility to allow the concept to evolve; and support from colleagues and management. This research describes a case study of a joint appointment between a nurse lecturer and a staff nurse in an acute forensic psychiatry unit. Advantages, disadvantages and reasons for success are discussed in relation to the literature findings. (See p15-15) The discussion focuses on the need to develop research methodology to further clarify potential benefits and advantages.

Clinical Competence↗
PubMed1998

Echocardiography-guided ethanol septal reduction for hypertrophic obstructive cardiomyopathy.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction is frequently responsible for symptoms in hypertrophic obstructive cardiomyopathy (HOCM). Medical therapy is often not sufficient to control these symptoms, and surgical myotomy-myomectomy is required. METHODS AND RESULTS: We enrolled 33 symptomatic patients with HOCM and obstruction (>/=40 mm Hg gradient at rest or >/=60 mm Hg dobutamine-provoked). By contrast echocardiography, the bulging septum was localized and infarcted by injection of 2 to 5 mL of absolute ethanol into the septal artery(ies) supplying the hypertrophied area. Baseline echocardiograms with Doppler, myocardial perfusion tomograms, and treadmill exercise or pharmacological testing were compared with those at 6 weeks and 6 months. The mean rise in creatine kinase was 1964+/-796 U. All patients experienced symptomatic relief; NYHA class decreased from 3. 0+/-0.5 to 0.9+/-0.6 (P<0.001). Exercise time increased from 286+/-193 to 421+/-181 seconds (P=0.03). The resting and dobutamine-provoked gradient decreased from 49+/-33 and 96+/-34 mm Hg to 9+/-19 (P<0.001) and 24+/-31 mm Hg (P<0.001), respectively. Echocardiograms repeated at 6 weeks after the procedure showed a 28% reduction in septal thickness and 17% reduction in left ventricular mass. Myocardial perfusion imaging showed a "septal amputation pattern," with scarring in the upper and middle septal areas. Complete heart block developed in 11 patients, who then required permanent pacemaker implantation. CONCLUSIONS: Echocardiography-guided ethanol septal reduction in patients with HOCM is a safe, minimally invasive procedure that provides symptomatic relief with improved hemodynamic and left ventricular parameters.

Adult↗