The use of cadaver models to diagnose rib fractures: A pilot study

Background

In the emergency department, rib fractures are a common finding in patients who sustain chest trauma. Rib fractures may be a sign of significant, underlying pathology, especially in the elderly patients where rib fractures are associated with significant morbidity and mortality. To date, no studies have evaluated the ability of ultrasound to detect rib fractures using cadaver models and subsequently use this model as a teaching tool.

Age-dependent sensitivity to unprotected cardiac ischemia: the senescent myocardium.

Six young, sexually mature sheep and seven senescent sheep (aged 0.75 +/- 0.11 years and 7.1 +/- 0.45 years) were instrumented with sonomicrometric crystals and micromanometers to assess global left ventricular mechanics while preload was varied during right heart bypass both before and 30 minutes after 15 minutes of global normothermic ischemia. Left ventricular weight and end-diastolic volume were not significantly different between age groups when indexed to body weight. Contractility was quantitated by the slope of the linear preload-recruitable stroke work relationship and diastolic mechanics by an exponential end-diastolic pressure versus volume function generated over physiologic cardiac workloads. Postischemic systolic functional recovery was markedly worse in the older group (22.7% +/- 10.7% versus 54.2% +/- 9.5%, old versus young, p less than 0.05). However, diastolic stiffness was not changed in either group postischemically. These data demonstrate that the senescent myocardium is less tolerant of ischemia and may require specific intraoperative myocardial management strategies to preserve global pump function.     

Coexisting Endogenous and Exogenous Llpold Pneumonia and Pulmonary Alveolar Proteinosis in a Patient with Neurodevelopmental Disease

We report a unique case of coexistingexogenous lipoid pneumonia, endogenous lipoid pneumonia (EU), and pulmonary alveolar proteinosis (PAP) in a 5-year-old patient with severe neurodevelop mental disease. The patient presented with gastroesophageal reflux and presumed chronic lung disease resulting from recurrent aspiration pneumonias and succumbed to respiratory failure. The autopsy showed lipid-laden macrophages and periodic acid-SchiJf9ositive granular matm'al i n alveolar spaces and multilamellated structures within both alveolar macrophages and extracellular debris.

These findings were similar to those in previous reports of coexisting E I P and PAP in the setting of gastroesophageal refux [I] . However, the present case diJfered by the presence of scattered large osmiophilic extracellular lipid vacuob. Besides strengthening the association between EIP and PAP and their relationship to gastroesophageal refux, this case suggests that t h q may arise together with exogenous lipoid pneumonia, through related mechanisms, in the setting of neurodevelopmental disease.     

Mapping the social and physical contexts of physical activity across adolescence using ecological momentary assessment

BACKGROUND: Research has sought to understand how environmental factors influence adolescent physical activity, yet little is known about where and with whom adolescents are physically active. PURPOSE: This study used electronic ecological momentary assessment (e.EMA) to map the social and physical contexts of exercise and walking across adolescence. Differences in physical activity contexts by gender, grade in school, day of the week, and season were examined. METHODS: Twice a year between 9th and 12th grade, 502 adolescents (51% female) of mixed ethnicity (55% White) participated in 4-day e.EMA intervals (Thursday-Sunday) where their primary activity (e.g., exercise, TV, homework), social company (e.g., friends, family, class), and physical location (e.g., home, school, outdoors) were assessed every 30 (+/-10) min during waking hours. RESULTS: Overall, greater proportions of exercise and walking were reported with friends, outdoors, and at school. However, boys were more likely to report exercising and walking in outdoor locations than girls. Exercising with classmates, family, and at school decreased across high school. Walking with family, friends, and outdoors also decreased. On weekdays compared to weekends, students reported a greater proportion of their exercise and walking at school. Students were more likely to report exercising and walking outdoors in the fall and the spring than in the winter. CONCLUSION: e.EMA showed that the social and physical contexts of adolescent exercise and walking vary as a function of gender, grade in school, day of the week, and season. Understanding the contexts of physical activity during the high school years can be helpful in designing interventions during adolescence.     

Juvenile Rheumatoid Arthritis: Benefits from Massage Theraphy

Studied children with mild to moderate juvenile rheumatoid arthritiswho were massaged by their parents 15 minutes a day for 30 days(and a control group engaged in relaxation therapy). The children'sanxiety and stress hormone (cortisol) levels were immediatelydecreased by the massage, and over the 30-day period their paindecreased on self-reports, parent reports, and their physician'sassessment of pain (both the incidence and severity) and pain-limitingactivities     

Area postrema-lesions increase operant responding to sucrose in rats

Rats with lesions of the area postrema (APX) are known to exhibit an enhanced intake of highly palatable foods such as sweetened condensed milk and cookies. These observations suggest the possibility that APX rats find these foods more rewarding and will work harder to obtain these foods. Sham and APX rats were tested on fixed ratio (FR) and progressive ratio (PR) schedules. APX rats consistently pressed more times to receive sucrose solution and attained both FR 3 and FR 5 criteria significantly faster than sham-lesioned control rats. Furthermore, rats with APX had significantly higher break points than sham-lesioned control rats on a progressive ratio schedule. These results support the hypothesis that rats with lesions of the area postrema will consistently work harder to obtain a highly palatable food reward.     

Enduring effects of prenatal cocaine exposure on selective attention and reactivity to errors: evidence from an animal model

Adult Long-Evans rats, exposed prenatally to 1 of 4 doses of cocaine (0.0,0.5,1.0, or 3.0 mg/kg iv), were tested on a 3-choice visual attention task with an olfactory distractor presented unpredictably on one third of the trials. The performance of all 3 cocaine-exposed groups was significantly more disrupted than that of controls by the presentation of distractors. Results demonstrate that prenatal cocaine exposure increases susceptibility to distractors, using a task specifically designed to measure this function. In addition, the present study revealed that individuals exposed to cocaine in utero exhibit greater performance disruption after an error than controls, in certain types of tasks. Both areas of dysfunction, impaired selective attention and impaired arousal regulation, have important functional consequences in humans, possibly affecting the school performance and social development of cocaine-exposed children.     

Pharmacological disintegration of lipid rafts decreases specific tetramer binding and disrupts the CD3 complex and CD8 heterodimer in human cytotoxic T lymphocytes

Accumulating evidence strongly supports the role of lipid rafts in the regulation of T-lymphocyte activation, but the organization and molecular composition of these cholesterol- and sphingolipid-rich membrane microdomains in different subsets of T cells remain poorly investigated. Here, we show that pharmacological disruption of lipid rafts in human CD8+ cytotoxic T-lymphocyte (CTL) clones disturbs the integrity of CD3 complex and CD8 heterodimer, without affecting the reactivity with T-cell receptor (TCR)-specific antibodies. This demonstrates that interaction with completely assembled CD3 complex is not required for the stable expression of TCR at the cell surface. The effect of raft disruption on CD3 and CD8 expression correlates with failure to bind specific tetrameric complexes by a proportion of surface TCR molecules. However, the interaction of specific tetramer with the rest of surface TCR pools appears to be unaffected, demonstrating that TCR-signalling complexes may differ in their requirement for cholesterol to stably maintain their composition and to rearrange for efficient tetramer binding. Together with previously published data, our results support the existence of molecular and/or structural heterogeneity of lipid rafts that may play an important role in controlling distinct functional properties of T-cell subsets.