Analysis of crystallite shape in rat incisor enamel

The hydroxyapatite crystallites of mammalian enamel appear as hexagons when seen in cross-sections examined with the transmission electron microscope. Using goniometric transmission electron microscopy, stereo-pair electron micrographs and freeze-fracture replicas, two models have been proposed to explain the hexagonal crystallite profile. The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons. The "rectangular ribbon"model proposes that crystallite profiles are three-dimensional rectangular segments (parallelepipeds), which are contained in the Epon sections and project as opaque hexagons in routine transmission electron micrographs. Morphological observations together with predictions from models indicate that the crystallites in rat incisor enamel are flat ribbons with rectangular cross-sectional profiles. The hexagonal images seen in electron micrographs of thin sections of enamel result from viewing parallelepiped-shaped segments of these crystallites as two-dimensional shadows.     

Ex-addict versus nonaddict counselors' knowledge of clients' drug use

The accuracy of drug counselors' knowledge of their clients' drug use was assessed to determine whether counselor reports might constitute adequate research and evaluation data. Ex-addict paraprofessionals, non-ex-addict paraprofessionals, and degreed professional counselors (N = 82) reported on the drug use by 302 methadone maintenance and drug-free outpatient clients, as did the clients themselves. Counselor nonresponse rates to individual drug category items were acceptably low (less than or equal to 5%) for all but marijuana/hashish and over-the-counter drugs. Counselors' estimates of drug use rates at a group level were relatively accurate. However, reliability coefficients reflecting accuracy on a case-by-case basis were lower than desirable for use in prediction schemes for individual clients. Ex-addicts were overall somewhat more accurate than the other counselor groups.     

Angiotensin II stimulation of renal prostaglandin synthesis elevates circulating prostacyclin in the dog

The ability of the kidney to release prostacyclin (PGI2) under direct stimulation with exogenous angiotensin II was studied in the pentobarbital-anesthetized dog. We assayed for prostacyclin-like activity in systemic arterial blood by continuously monitoring platelet aggregation in vivo and with the blood-bathed bovine coronary artery, which relaxes to prostacyclin. This parallel bioassay allows detection of small amounts of prostacyclin-like activity released into the systemic circulation. Angiotensin II, infused at a rate of 10 or 20 ng/kg/min into the renal artery inhibited latelet aggregation in 8 out of 18 dogs, relaxed the bovine coronary artery in 13 of 16 dogs, and lowered systemic arterial blood pressure 5-10 mm Hg in all but 3 animals. These effects of antiotensin II could be blocked by treating the animal with indomethacin (2 mg/kg, i.v.) and mimicked by administration of exogenous prostacyclin. Infusion of the same dose of angiotensin II (10 or 20 ng/kg/min) intravenously did not release prostacyclin; blood pressure increased during intravenous infusion, and platelet aggregation remained unchaged. These data are consistent with the hypothesis that prostacyclin, of renal origin in these experiments, can act as a circulating hormone. Prostacyclin should not be regarded only as an antiaggregatory substance, but also as a potentially important modulator of blood pressure.     

Incidence, significance and remission of tubal spasm during attempted hysteroscopic tubal sterilization

Four hundred three attempted hysteroscopic tubal sterilizations were performed. Tubal spasm was encountered in 37 cases (9.2%) and prevented bilateral placement of tubal plugs in 16 of those cases. There was some evidence that glucagon was associated with a higher rate of remission and that women using barrier birth control methods experienced a lower incidence of tubal spasm. A number of other factors were found to be unrelated to tubal spasm and its remission.     

The development and preliminary validation of a brief measure of chronic pain impact for use in the general population

From a biopsychosocial perspective, assessing chronic pain's psychological impact should involve at minimum the measurement of pain severity, functional interference, and pain-related emotional burden. This article details the development of a brief instrument, the 15-item Profile of Chronic Pain: Screen (PCP:S), designed to address these three key elements in a national (US) sample of over 2400 individuals recruited via random digit dialing. Retest reliability, internal consistency, and preliminary validity were excellent. The scales also demonstrated minimal social desirability response bias. A series of confirmatory factor analyses on several distinct samples revealed a stable, 3-factor solution reflecting pain severity, interference, and emotional burden. Finally, national norms were developed by gender and three age groups. In view of its strong psychometric properties, the PCP:S has the potential to serve as a brief, cost-effective assessment tool for identifying individuals whose chronic pain merits more detailed psychosocial evaluation.     

Protocol of the animal assisted activity program at a university hospital

Animal-Assisted Activity (AAA) consists in visitation and recreation through contact with animals, aiming at entertainment and improving the interpersonal relationship between patients and staff. Permission for the animals to visit an Institution requires a protocol with rules and safety routines to avoid accidents and zoonoses. The objective of this study is to describe the important points of the protocol to implement the AAA program. The protocol includes: introduction, objectives, inclusion and exclusion criteria for animals, drivers and patients; recommendations to the handlers and the health team, responsibilities of the Nosocomial Infection Control Committee, zoonoses posters, vaccination schedule for dogs and cats, free-informed consent to take part in the program and records with behavioral analysis of the animals. We believe that disclosing the protocol, based on scientific studies, favors the implementation of new programs in institutions considering the lack of national publications.     

Nursing staff absenteeism rates as a personnel management indicator

Absenteeism in nursing is a difficult problem for health organizations; hence it is an indicator that must be monitored. The objective of this study was to analyze the absenteeism rate of nursing professionals in a public hospital. Absenteeism data were collected monthly, from January to July 2008, and calculated by means of an electronic program. The mean absenteeism index for nurses varied from 5.6% to 9.7% for technicians/nursing aides. Sick leaves were the most prevalent reason for absences. The data revealed the major cause of absenteeism and pointed at the need to change policies for hiring nursing professionals, in addition to reviewing the working processes in order to improve the workers' health conditions.