Cytochemical characteristics of neurons in the trigeminal mesencephalic nucleus of hatchling chicks

The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100β. Calbindin D28k and S-100β appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, γ-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse.     

Cardiac atrophy in women following bed rest

Both chronic microgravity exposure and long‐duration bed rest induce cardiac atrophy, which leads to reduced standing stroke volume and orthostatic intolerance. However, despite the fact that women appear to be more susceptible to post‐spaceflight presyncope and orthostatic hypotension than male astronauts, most previous high‐resolution studies of cardiac morphology following microgravity have been performed only in men. Because female athletes have less physiological hypertrophy than male athletes, we reasoned that they also might have altered physiological cardiac atrophy after bed rest. Magnetic resonance imaging was performed in 24 healthy young women (32.1±4 years) to measure left ventricular (LV) and right ventricular (RV) mass, volumes, and morphology accurately before and after 60 days of 6° head‐down tilt (HDT) bed rest. Subjects were matched and then randomly assigned to sedentary bed rest (controls, n=8) or two treatment groups consisting of (1) exercise training using supine treadmill running within lower body negative pressure plus resistive training (n=8), or (2) protein (0.45 g/kg/day increase) plus branched‐chain amino acid (BCAA) (7.2 g/day) supplementation (n=8). After sedentary bed rest without nutritional supplementation, there were significant reductions in LV (96±26–77±25 mL; P=0.03) and RV volumes (104±33–86±25 mL; P=0.02), LV (2.2±0.2–2.0±0.2 g/kg; P=0.003) and RV masses (0.8±0.1–0.6±0.1 g/kg; P<0.001), and the length of the major axis of the LV (90±6–84±7 mm. P<0.001), similar to what has been observed previously in men (8.0%; Perhonen M.A., Franco F., Lane L.D., Buckey J.C., Blomqvist Zerwekh J.E., Peshock R.M., Weatherall P.T., Levine B.D. J Appl Physiol 2001: 91: 645–653). In contrast, there were no significant reductions in LV or RV volumes in the exercise‐trained group, and the length of the major axis was preserved. Moreover, there were significant increases in LV (1.9±0.4–2.3±0.3 g/kg; P<0.001) and RV masses (0.7±0.1–0.8±0.2 g/kg; P=0.002), as well as mean wall thickness (9±2–11±1 mm; P=0.02). The interaction between sedentary and exercise LV and RV masses was highly significant (P<0.0001). Protein and BCAA supplementation led to an intermediate phenotype with no change in LV or RV mass after bed rest, but there remained a significant reduction in LV volume (103±14–80±16 mL; P=0.02) and major‐axis length (91±5–88±7 mm; P=0.003). All subjects lost an equivalent amount of body mass (3.4±0.2 kg control; 3.1±0.04 kg exercise; 2.8±0.1 kg protein). Cardiac atrophy occurs in women similar to men following sedentary 60 days HDT bed rest. However, exercise training and, to a lesser extent, protein supplementation may be potential countermeasures to the cardiac atrophy associated with chronic unloading conditions such as in spaceflight and prolonged bed rest.     

Physician-Patient Communication in the Urban Clinical Setting

Improving communication between doctor and patient can help meet the objective of providing high-quality, cost-effective, accessible health care. The benefits of effective communication are considerable. Studies indicate that good physician-patient communication can improve diagnostic accuracy and treatment adherence, increase the satisfaction of doctor and patient, and thereby reduce the risk of malpractice suits. Communication in the urban clinical setting comes with a unique set of difficulties. The sociocultural differences between doctor and patient tend to be more pronounced, the interactions with patients more short-term, and the resulting medical encounters of a more impersonal nature. Physicians and patients frequently differ on role expectations for one another. It is nevertheless possible to effect successful communication in the urban medical environment and strengthen the partnership—the “social system”—that exists between doctor and patient. The Miles Institute for Health Care Communication has developed a model, known as the ABCDE approach, that may help facilitate communication in the urban setting. In this article the techniques of the ABCDE model are summarized and a case study is used to show how these techniques might be applied.     

Incidence of spontaneous hearing threshold shifts during modern concert performances.

OBJECTIVES: Concerts have long periods of intense sound with short break intervals. Hearing concerns are well known to performers; concertgoers largely ignore them. Preperformance and postperformance audiograms were compared to assess hearing threshold shifts with and without earplugs. METHODS: A prospective, randomized study in which 29 volunteers attended 3 concerts, encompassing 3 music genres. Audiograms, seating location, sound intensity, and earplug-use data were collected. Data were analyzed to determine frequency test-retest variability. RESULTS: Sound levels averaged 99.8 dBA, and the maximum was 125.6 dBA. Sixty-four percent (9/14) of participants without earplugs showed significant threshold shifts compared with 27% (4/15) of those using earplugs. No significant differences existed between music genres or seating location. CONCLUSIONS: This study showed a high incidence of threshold shifts in unprotected concertgoers. Sound levels exceeded all Occupational Safety and Health Act rules despite standardized sound systems. A significant reduction in threshold shifts was seen with the use of earplugs. EBM rating: A-1b.     

Crohn's disease of the upper gastrointestinal tract

Involvement of the upper gastrointestinal tract by Crohn's disease is being recognized with increasing frequency. Gastroduodenal disease is more common, although esophageal disease is now noted infrequently as well. There is nearly always concomitant involvement of the small bowel or colon. Initial phases of the disease are manifested as superficial inflammatory changes of the mucosa but can progress to scarring and stenosis. Optimum double-contrast technique is necessary to detect these early lesions.     

Effects of antihypertensive medications on vitality and well-being

The effects of captopril, methyldopa, and propranolol were assessed for sense of well-being and vitality among 626 men with mild to moderate hypertension in a multicenter, randomized, double-blind clinical trial. After a 24-week treatment period, patients taking captopril, compared with patients taking methyldopa and propranolol, scored significantly higher on measures of well-being and vitality. In addition, patients on captopril had more favorable results in being able to keep up with their work and in not feeling tired or sleepy at work. The effects of each of the drugs manifested themselves at different periods. For example, the negative effects of methyldopa on vitality were evident by week 8, whereas the negative effects did not become manifest for propranolol until week 24. On the other hand, a steady progressive improvement in vitality scores was evident at week 8 and at week 24 for patients on captopril. The findings of the study also suggest that the effects of the treatment drugs were most marked in patients who had had previous antihypertensive medications and who were on single-drug therapy during the course of the clinical trial. Further, the differences between patients taking captopril and those on methyldopa and propranolol appear to be obscured by the addition of a diuretic. The findings of the study may guide the physician in orienting his or her patient and in planning and implementing a therapeutic regimen.     

Family counseling and legal issues in Alzheimer's disease

Caring for a patient with Alzheimer's disease produces significant stress and morbidity in the caregiver. This article reviews the existing evidence on caregiver burden in Alzheimer's disease and elaborates on the counseling and legal options that can be exercised by them. By availing of existing supports and planning ahead, caregivers can decrease burden levels and deliver more effective care to the patient.     

Pediatric resident performance. The reliability and validity of rating forms.

A large pediatric residency program conducted an extensive analysis of the reliability and validity of the rating forms used to evaluate the pediatric residents enrolled in the program. Analyses were conducted on groups of residents who took the Pediatric In-Training Program (PITE) from 1977 through 1981. An average of 7.1 faculty members rated each resident on a standard form. The data indicate that although the reliability of individual ratings is very low, several factors achieved acceptable levels of reliability when aggregated. The first-year rating of history-taking ability correlated significantly with the PITE but ratings for more advanced residents did not correlate with PITE scores, mostly because of ceiling effects.     

Familial pheochromocytomas with unusual associations.

Pheochromocytoma occurs in a familial pattern in approximately 10% of patients. Although most familial pheochromocytomas are an expression of the genetic abnormality of neuroectodermal dysplasia or the genetic syndrome of multiple endocrine neoplasia, some familial pheochromocytomas occur without associated disease. Two patients with familial pheochromocytoma are described. One had an extraadrenal tumor, producing severe renal artery stenosis and in whose family pheochromocytomas were found in three successive generations. A second had multiple pheochromocytomas associated with von Hippel-Lindau disease and a family member with multiple endocrine neoplasia type 2. The combinations and permutations of these genetic entities form discrete syndromes, with other peculiar interrelationships, pathologically related to an aberration in the migration, growth, and differentiation of the neural crest cells, and emphasizing their common neuroectodermal origin. The unique features that characterize the familial pheochromocytomas and cause diagnostic and therapeutic challenges are reviewed.