The effects of a carbonated carbohydrate drink on gastric emptying, gastrointestinal distress, and exercise performance.

To determine the effect of a carbonated carbohydrate (CHO) drink on gastric function and exercise performance, eight male cyclists completed four 120-min bouts of cycling. Each bout consisted of a 105-min ride at 70% VO2max followed by a 15-min self-paced performance ride. During each trial, one of four test solutions was ingested: carbonated CHO (C-10%), noncarbonated CHO (NC-10%), carbonated non-CHO (C), and noncarbonated non-CHO (NC). Following the performance ride, the subjects had their stomach contents removed by aspiration. There were no significant differences in gastric emptying (GE) except for Trial C-10%, which averaged 13.3% less than NC. However, there was no difference in the perception of gastrointestinal comfort between this trial and any other. Average power output during the performance ride was not significantly different between carbonated and noncarbonated trials, or between CHO-fed and no-CHO trials; however, the subjects worked at a greater intensity when fed CHO. Finally, acid base status did not change when a carbonated drink was ingested. This indicates that adding carbonation to a sport drink does not significantly alter gastric function, the perception of GI comfort, or exercise performance.     

Dopaminergic transmission and the sleep-wakefulness continuum in man

Modulation of dopaminergic transmission on daytime alertness and performance and on nocturnal sleep were studied in man using 30, 60 and 90 mg pemoline, a dopamimetic drug, and 2, 4 and 6 mg pimozide, a dopamine receptor antagonist. Pemoline lengthened daytime sleep latencies and improved attention, and increased wakefulness during nocturnal sleep. Rapid eye movement (REM) sleep was reduced with 90 mg pemoline, but this was due entirely to increased wakefulness. Pimozide had little effect on overnight sleep, but increased the tendency to fall asleep and impaired performance during the day. These studies suggest that the effects of certain drugs which modulate the activity of neurotransmitters, involved in the control of sleep and wakefulness, may be related to the inherent level of activity of the central nervous system. Modulation of the dopaminergic system can have a profound influence on the manifestation of wakefulness and vigilance, but is unlikely to modify directly the elaboration of REM sleep in man.     

Prevalence of mental illness and its impact on the use of home care and nursing homes: a population-based study of older adults in Manitoba.

OBJECTIVES: To determine the prevalence of mental illness in older adults and its effect on home care and personal care home (PCH) use. METHODS: Using nonidentifying administrative records (fiscal years 1997-1998 to 2001-2002) from the Population Health Research Data Repository housed at the Manitoba Centre for Health Policy, we determined the 5-year period prevalence for individuals aged 55 years and over (119 539 men and 145 752 women) for 3 mental illness categories: cumulative mental disorders (those having a diagnosis of depression, anxiety disorder, personality disorder, schizophrenia, and [or] substance abuse), any mental illness, and dementia. We calculated age-specific and age-adjusted rates of home care and PCH use and the prevalence of mental illness in PCH residents. RESULTS: From the group aged 55 to 59 years to the group aged 90 years or older, the prevalence of mental illness increased with the population's age. The prevalence of any mental illness rose from 32.4% to 45.0% in men and from 42.6% to 51.9% in women, and dementia prevalence rose from 2.0% to 33.6% in men and from 1.3% to 40.3% in women. The age-adjusted annual rates of open home care cases per 1000 population aged 55 and older varied by mental illness grouping (no mental disorder, 57 for men and 91 for women; cumulative mental disorders, 162 for men and 191 for women; dementia, 300 for men and 338 for women). The age-adjusted rates of PCH use per 1000 population aged 75 years and older also varied by mental illness grouping (no mental disorder, 53 for men and 78 for women; cumulative mental disorders, 305 for men and 373 for women; dementia, 542 for men and 669 for women). Among patients admitted to (or resident in) a PCH in 2002-2003, 74.6% (87.1%) had a mental illness, and 46.0% (69.0%) had dementia. CONCLUSIONS: Mental illness affects the use of home care and nursing homes profoundly. Individuals with dementia used home care at 3 times the rate of those having no mental illness diagnosis, and they used PCHs at 8 times the rate.     

Colonization with methicillin-resistant Staphylococcus aureus after liver transplantation.

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infection after orthotopic liver transplantation (OLT). Colonization with MRSA is associated with a higher risk of infection. Previous studies have shown a high prevalence of MRSA colonization among OLT candidates. However, the risk of colonization with MRSA after OLT is still unclear. The objective of this study was to estimate the incidence and the factors associated with colonization with MRSA after OLT. This was a prospective cohort study including patients submitted to OLT between the years 2000 and 2002. Surveillance cultures of nasal swab specimens were performed within the 1st 72 hours of hospital admission and, subsequently, on weeks 2, 6, 13, and 26. Patients whose baseline cultures revealed nasal carriage of MRSA were excluded. A total of 60 patients were included in the study. The median follow-up was 72 days. A total of 9 patients (15%) became colonized. In multiple logistic regression analyses, the use of a urinary catheter for > or =5 days (P = .006), postoperative bleeding at the surgical site (P = .009), and preoperative use of fluoroquinolones (P = .08) were associated with a higher risk of colonization. Patients without any of these risk factors did not become colonized. In conclusion, nasal carriage of MRSA is frequently acquired after OLT. Periodic postoperative screening for MRSA carriage should be an integral component in programs designed to reduce nosocomial MRSA transmission in these patients. Further studies are needed to set up and validate a predictive model that could allow targeting postoperative screening to high-risk OLT recipients.     

Gender differences in condom-related behaviors and attitudes among Mexican adolescents living on the U.S.-Mexico border.

Adolescents are at increasing risk for HIV infection in Mexico. Research on gender differences in risk behaviors and determinants is needed to develop effective HIV prevention interventions targeting Mexican adolescents. This study examined gender differences in the likelihood of unprotected sex and theoretical correlates among high school students in the border city of Tijuana. Three hundred seventy high-school students completed a face-to-face interview and a self-administered survey. Differences in sexual initiation, condom use, intentions to use condoms in the future, and attitudes towards condoms in this population were assessed. Although male students initiated sexual practices earlier than females, females were more likely to have unprotected sex. Females perceived themselves as more likely to avoid unprotected sex in the future and held more favorable attitudes about condoms. The results suggest that stereotypical gender roles and communication barriers place Tijuana female high school students at higher risk for HIV infection than their male peers.     

Avoidance of Nitrous Oxide for Patients Undergoing Major Surgery: A Randomized Controlled Trial

Background: Nitrous oxide is widely used in anesthesia, often administered at an inspired concentration around 70%. Although nitrous oxide interferes with vitamin B12, folate metabolism, and deoxyribonucleic acid synthesis and prevents the use of high inspired oxygen concentrations, the consequences of these effects are unclear.

Methods: Patients having major surgery expected to last at least 2 h were randomly assigned to nitrous oxide-free (80% oxygen, 20% nitrogen) or nitrous oxide-based (70% N2O, 30% oxygen) anesthesia. Patients and observers were blind to group identity. The primary endpoint was duration of hospital stay. Secondary endpoints included duration of intensive care stay and postoperative complications; the latter included severe nausea and vomiting, and the following major complications: pneumonia, pneumothorax, pulmonary embolism, wound infection, myocardial infarction, venous thromboembolism, stroke, awareness, and death within 30 days of surgery.

Results: Of 3,187 eligible patients, 2,050 consenting patients were recruited. Patients in the nitrous oxide-free group had significantly lower rates of major complications (odds ratio, 0.71; 95% confidence interval, 0.56-0.89; P = 0.003) and severe nausea and vomiting (odds ratio, 0.40; 95% confidence interval, 0.31-0.51; P < 0.001), but median duration of hospital stay did not differ substantially between groups (7.0 vs. 7.1 days; P = 0.06). Among patients admitted to the intensive care unit postoperatively, those in the nitrous oxide-free group were more likely to be discharged from the unit on any given day than those in the nitrous oxide group (hazard ratio, 1.35; 95% confidence interval, 1.05-1.73; P = 0.02).     

The relations among putative biorisk markers in schizotypal adolescents: minor physical anomalies, movement abnormalities, and salivary cortisol.

BACKGROUND: Evidence suggests that prenatal insult may play a role in the etiology of psychotic disorders. Minor physical anomalies (MPA) are an indicator of abnormal fetal development and are elevated in individuals at genetic and behavioral risk for psychosis. Yet, there has been little empirical research on the relationships between MPAs and other neurobiological risk indicators. We hypothesized that the frequency of MPAs (an external marker of prenatal central nervous system [CNS] disruption) would be associated with two other biomarkers suggestive of disruptions in fetal neurodevelopment: movement abnormalities (an indicator of striatal abnormalities) and heightened cortisol secretion (an indicator of hypothalamic-pituitary-adrenal [HPA]/hippocampal function). METHODS: Participants with schizotypal personality disorder (SPD; n = 39) and both normal (n = 47) and other personality disorders (n = 28) control subjects were administered structured diagnostic interviews and assessed for MPAs, movement abnormalities, and salivary cortisol. RESULTS: Schizotypal personality disorder participants showed significantly greater MPAs and movement abnormalities and higher cortisol than both the normal and other personality disorders groups. Hierarchical linear regression analyses revealed that higher rates of MPAs were linked with greater movement abnormalities and salivary cortisol. CONCLUSIONS: The findings suggest that MPAs serve as a marker of neurodevelopmental abnormalities that affect striatal and hippocampal regions.