Direct measurement of the thermal responses of nude resting men in dry environments

Summary Two nude resting men were exposed for two-hour periods to each of 25 dry environments, with air temperatures ranging between 12.8° C and 49.1° C and wind speeds between 0.67 m/sec and 4.94 m/sec. The mean radiant temperature of the surroundings was kept equal to the air temperature. Rates of radiant and convective heat exchange were measured directly, separately and continuously. The men had reached a thermal steady state after 105 min in the warm environments, but not in the cold environments. Graphs are presented to show the effect of ambient temperature and wind speed on the radiation and convection rates attained after 105 min, as well as on metabolic rate, sweat evaporation rate, rectal temperature and mean skin temperature. These graphs revealed some important aspects of the behaviour of man's thermal control system. In particular the physiological conductance increased with increasing ambient temperature and then saturated at an ambient temperature near 35° C. This saturation resulted in a constant difference between rectal temperature and mean skin temperature irrespective of the environmental conditions.Published with the permission of the Chamber of Mines of South Africa.     

Immunohistochemistry of neurone specific enolase with gamma subunit specific anti-peptide monoclonal antibodies.

AIMS--To investigate the application in immunohistochemistry of gamma-subunit specific anti-peptide monoclonal antibodies to human neurone specific enolase (NSE); and to determine their reactivity with formalin fixed, wax embedded sections of normal tissue and neuroendocrine tumours. METHODS--Immunohistochemical staining was performed on sections of formalin fixed, wax embedded tissue with two monoclonal antibodies (NSE-P1 and NSE-P2) raised against different synthetic peptides specific for the gamma subunit of human enolase (neurone specific enolase). RESULTS--Both antibodies gave strong immunostaining in normal tissues and cells known to contain NSE. There was no immunoreactivity in tissues containing either the alpha alpha or beta beta isozymes of enolase. The reactivity of the antibodies with a range of neuroendocrine tumours was also studied and both antibodies gave strong immunostaining of tumour cells in the different tumours. CONCLUSIONS--The use of synthetic peptides from defined regions of a molecule as immunogenes provides antibodies of high specificity. These monoclonal antibodies to NSE are ideally suited for immunohistochemical studies and they should be particularly useful in histopathology as they react with epitopes which are resistant to formalin fixation and wax embedding.     

Social Stigma,HIV/AIDS Knowledge,and Sexual Risk: A Cross‐Cultural Analysis1

The main aim of this study is to evaluate relationships linking social stigma, HIV/AIDS knowledge, and sexual risk among African American (AA) and South African (SA) college students. One major barrier to HIV prevention efforts is the social stigma associated with HIV/AIDS. Based on the Burkholder et al. (1999) findings, persons who engage in greater stigmatization of persons with AIDS (PWA) and gay people are associated with greater sexual behavior risk for HIV/AIDS. The present study attempted to replicate the Burkholder et al. study using African American and South African college students, but the findings were inconsistent with the aforementioned study. AA respondents had higher social stigma of PWA and gays and higher condom self‐efficacy. While SA respondents were less likely to stigmatize PWA and gay persons and had high‐perceived risk of being infected, they reported engaging in high‐risk sexual behavior. The authors discuss the differences that may account for the dissimilar findings.     

Comparison of midazolam and thiopental for rapid sequence anesthetic induction for elective cesarean section

Sixty healthy mothers undergoing elective cesarean section received at random either midazolam 0.2 mg/kg or thiopental 3.5 mg/kg with succinylcholine 1 mg/kg for rapid sequence intravenous anesthetic induction. Maintenance of anesthesia was identical in all patients: 50:50 N2O in oxygen, halothane 0.5% and pancuronium 0.05 mg/kg. Hemodynamic responses were similar, as were the biochemical status of mothers and infants, and maternal to fetal blood gas/acid base gradients. Correlation between maternal arterial and fetal (umbilical venous/arterial) pH, PCO2 and base excess values were statistically better with midazolam. However, 1-min Apgar minus color (A-C) scores less than 5/8 (representing "severe" neonatal depression) were recorded in five infants after midazolam, three of whom required tracheal intubation, and one whose mother was given thiopental. This difference reached statistical significance (P less than 0.05). It is concluded that midazolam is less suitable than thiopental for anesthetic induction in patients undergoing cesarean section.     

Retrograde air embolization in coronary operations

Observations during coronary operations are presented that prove that if the ascending aorta is cross-clamped and suction applied to the left side of the heart or to the aortic root for venting purposes, the pressure rapidly drops in the coronary arterial system and a situation is created in which air may enter through the coronary arteriotomy and pass into the aortic root and the left ventricle. Another mechanism to explain the occurrence of some cases of "iatrogenic" air embolism has also been presented: introduction of air into the ascending aorta while cardioplegic solution is being injected through peripherally attached bypass grafts. Air trapped in these grafts or in the coronary artery itself may propagate proximally as well as distally in the coronary arteries and may reach the aortic root even if the left side of the heart is left unvented. These mechanisms may be responsible for heretofore unexplained cases of "iatrogenic" air embolization. We recommend careful purging of air, which may be present, from the left ventricle and aortic root every time before the aortic cross-clamp is removed during coronary operations.     

Petit mal epilepsy: a review and integration of recent information

Petit mal (absence) epilepsy remains one of the most enigmatic of neurological disorders, and there is no widely accepted theory of its etiology. This review covers some of the current issues concerned with the disorder, including treatment and prognosis, neurochemical research, behavioral and psychophysiological effects of wave-spiked discharges, and EEG studies of seizure control. With respect to treatment, although effective drug therapy (valproic acid, ethosuximide) exists for the "pure" form of absence epilepsy, other forms, in which there is an admixture of grand mal seizures, are less amenable to pharmacotherapy. Moreover, the frequency of fatal hepatic toxicity following valproic acid therapy has been estimated at 1 in 20,000. With respect to prognosis, follow-up studies indicate that many patients do not outgrow the disorder but continue to suffer absence seizures well into adulthood. In recent years, there has been considerable research on the neurochemical basis of absence epilepsy. Current theories, including those that implicate gamma-aminobutyric acid, catecholamines, and "endogenous" epileptogens, are summarized; and requirements for an experimentally induced animal model of absence epilepsy are discussed. The majority of behavioral studies of the disorder have concerned the effects of petit mal-type discharges on sensory and cognitive processes. Some of these studies are reviewed; and recent work bearing on these issues, involving event-related brain potentials, is presented. Our review concludes with a discussion of research aimed at the development of electrophysiologically based approaches to the reduction of seizure frequency in patients with absence epilepsy.     

Associations between Family-Based Stress and Dietary Inflammatory Potential among Families with Preschool-Aged Children

Chronic stress is known to influence dietary choices, and stressed families often report poorer diet quality; however, little is known about how family-based stress is linked with dietary patterns that promote inflammation. This study investigated associations between family-based stress and the inflammatory potential of the diet among preschool-aged children and their parents. Parents (n = 212 mothers, n = 146 fathers) and children (n = 130 girls, n = 123 boys; aged 18 months to 5 years) from 241 families participating in the Guelph Family Health Study were included in the analyses. Parents reported levels of parenting distress, depressive symptoms, household chaos, and family functioning. The inflammatory potential of parents’ and children’s diets was quantified using the Dietary Inflammatory Index (DII^®), adjusted for total energy intake (i.e., the E-DII^TM). E-DII scores were regressed onto family stress using generalized estimating equations to account for shared variance among family clusters. Compared to those in homes with low chaos, parents in chaotic homes had significantly more proinflammatory dietary profiles (β = 0.973; 95% CI: 0.321, 1.624, p = 0.003). Similarly, compared to those in well-functioning families, parents in dysfunctional families had significantly more proinflammatory dietary profiles (β = 0.967; 95% CI: 0.173, 1.761, p = 0.02). No significant associations were found between parents’ E-DII scores and parenting distress or depressive symptoms, nor were any associations found for children’s E-DII scores. Results were not found to differ between males and females. Parents in chaotic or dysfunctional family environments may be at increased risk of chronic disease due to proinflammatory dietary profiles. Children’s dietary inflammatory profiles were not directly associated with family stress; however, indirect connections through family food-related behaviours may exist. Future research should prioritize elucidating these mechanisms.     

Risk of Gastrointestinal Bleeding With Extended Use of Nonsteroidal Anti-Inflammatory Drug Analgesia After Joint Arthroplasty

BackgroundChronic nonsteroidal anti-inflammatory drug (NSAID) use is associated with gastrointestinal bleeding via inhibition of endogenous mucosal protection and platelet aggregation. This study aimed to determine whether extended NSAIDs after joint arthroplasty is associated with increased risk of gastrointestinal bleeding.MethodsThis was a retrospective study examining 28,794 adults who underwent joint arthroplasty by one of 50 surgeons from 2016 to 2018. Episodes of gastrointestinal bleeding within 90 days postoperatively were identified prospectively. Postoperative medications were reported directly by patients with electronic questionnaires. The primary analysis was performed using binary logistic regression.ResultsA total of 74 (0.26%) episodes of gastrointestinal bleeding occurred within 90 days (median 8 days) postoperatively. Of 5086 patients with complete data included in the primary analysis, 59.6% had used NSAIDs with median duration of 2 weeks (interquartile range, 0-6 weeks). Patients with gastrointestinal bleeding were significantly older (71.3 vs 67.0 years), required longer hospitalizations (2.1 vs 1.5 days), and more commonly had a history of peptic ulcers (10.8% vs 0.9%). However, there was no positive association between NSAID use and gastrointestinal bleeding. In fact, the odds of gastrointestinal bleeding were lower in patients taking NSAIDs. Gastrointestinal bleeding was associated with anticoagulants, antiplatelet agents, and, to a lesser extent, aspirin.ConclusionNSAIDs were not associated with gastrointestinal bleeding and may be prescribed safely for a majority of patients after joint arthroplasty. The greatest odds of gastrointestinal bleeding occurred in patients with peptic ulcer disease and those who received antiplatelet and anticoagulation agents. Increasing age and bilateral surgery were also associated with gastrointestinal bleeding.Level of EvidenceLevel III.     

Tezacaftor/ivacaftor in people with cystic fibrosis who stopped lumacaftor/ivacaftor due to respiratory adverse events

BackgroundIncreased rates of respiratory adverse events have been observed in people ≥12 years of age with cystic fibrosis homozygous for the Phe508del-CFTR mutation treated with lumacaftor/ivacaftor, particularly in those with percent predicted forced expiratory volume in 1 s (ppFEV₁) of <40%. We evaluated the safety, tolerability, and efficacy of tezacaftor/ivacaftor in people with cystic fibrosis homozygous for Phe508del-CFTR who discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms.MethodsParticipants ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV₁ of ≥25% and ≤90% were randomized 1:1 and treated with tezacaftor/ivacaftor or placebo for 56 days.ResultsOf 97 participants, 94 (96.9%) completed the study. The primary endpoint was incidence of predefined respiratory adverse events of special interest (chest discomfort, dyspnea, respiration abnormal, asthma, bronchial hyperreactivity, bronchospasm, and wheezing): tezacaftor/ivacaftor, 14.0%; placebo, 21.3%. The adverse events were mild or moderate in severity. None were serious or led to treatment interruption or discontinuation. Overall, the discontinuation rate was similar between groups. The mean (SD) ppFEV₁ at baseline was 44.6% (16.1%) with tezacaftor/ivacaftor and 48.0% (18.1%) with placebo. The posterior mean difference in absolute change in ppFEV₁ from baseline to the average value of days 28 and 56 was 2.7 percentage points with tezacaftor/ivacaftor vs placebo.ConclusionsTezacaftor/ivacaftor was generally safe, well tolerated, and efficacious in people ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV₁ of ≥25% and ≤90% who previously discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms.