Multiscale relationships between fibronectin structure and functional properties.

Cell behavior is tightly coupled to the properties of the extracellular matrix (ECM) to which they attach. Fibronectin (Fn) forms a supermolecular, fibrillar component of the ECM that is prominent during development, wound healing and the progression of numerous diseases. This indicates that Fn has an important function in controlling cell behavior during dynamic events in vivo. The multiscale architecture of Fn molecules assembled into these fibers determines the ligand density of cell adhesion sites on the surface of the Fn fiber, Fn fiber porosity for cell signaling molecules such as growth factors, the mechanical stiffness of the Fn matrix and the adhesivity of Fn for its numerous soluble ligands. These parameters are altered by mechanical strain applied to the ECM. Recent efforts have attempted to link the molecular properties of Fn with bulk properties of Fn matrix fibers. Studies of isolated Fn fibers have helped to characterize the fiber's material properties and, in combination with models of Fn molecular behavior in the fibers, have begun to provide insights into the Fn molecular arrangement and intermolecular adhesions within the fibers. A review of these studies allows the development of an understanding of the mechanobiological functions of Fn.

Problem-based learning in a competency-based world.

This article addresses the needed shift in nursing education from an information-driven approach in teaching to a process that promotes higher level thinking and clinical judgement. Strengths and weaknesses of problem-based learning and competency-based education in nursing are presented. Whereas the former focuses on critical thinking and clinical judgement, the latter's emphasis is on clinical competency. The appropriateness of the philosophies in both academic and practice settings is discussed.

The expert witness: defending the profession or prosecuting your peers.

The use of CRNAs as expert witnesses in court cases is well-established. The CRNA who acts as a legal consultant or an expert witness is not retained merely to pontificate in the courtroom based on their considerable experience and expertise. The CRNA will undertake many roles in the process of assisting the attorney including those of (1) record reviewer and data analyst, (2) researcher and retriever, (3) synthesizer, and (4) teacher. Beyond these roles is the philosophical premise that the person best suited to evaluate the competence of a nurse anesthetist is another nurse anesthetist. Poor practitioners who are a danger to the public ought to be held accountable for their failings, whereas excellent practitioners who are mistakenly accused of negligence ought to be defended. Although challenging and time consuming, the role of the legal consultant and expert witness is rewarding in both financial and personal satisfaction terms. The role and functions of the CRNA who takes on the challenges of appearing as an expert witness or legal consultant is explored. The fine points of medical malpractice is not discussed, except as a cursory overview. The goal is to provide the practicing CRNA with the basic tools needed for these roles.

Teacher self-efficacy in new nurse educators.

The purpose of this study was to determine the variables that influence teacher self-efficacy in faculty with five or fewer years of teaching experience. Specifically, the relationship between formal educational courses and teacher self-efficacy in the teaching domains of course preparation, instructor behavior, evaluation and examination, and clinical teaching were examined. Findings showed that the 346 new nurse educators in this study had a strong sense of teacher self-efficacy. Results of multiple regression analysis indicated that formal education courses, teaching experience in nursing, and other teaching experience influenced the level of teacher self-efficacy. This study has implications for the mentoring of new faculty in the teaching role.

Clinical pathways: a tool to evaluate clinical learning.

Clinical pathways are a means by which an instructor can objectively and effectively evaluate student learning and progress toward clinical outcomes. An advantage to use of pathways in one-time experiences is that the pathway serves as a criterion-based frame of reference for both student and instructor, since the criteria are the same as for other clinical experiences in that course. The faculty member thus has an objective measure of student learning and performance, and the student always knows the measure on which she or he will be evaluated. Clinical pathways are limited to brief experiences and are not designed to show professional growth and progress in learning over time. A pathway could be designed, however, to appraise critical thinking and professional behaviors associated with spontaneous incidents, such as a problem patient. Nurse educators can use pathways as a creative means to address student responses in a variety of situations.

AANA journal course: update for nurse anesthetists--anesthetic considerations for the burn patient.

The anesthetic management of a burn trauma patient requires practitioners to have a solid understanding of the pathophysiology of the burn wound, the phases of burn trauma management, and the anesthetic implications for each phase. This article addresses anesthetic considerations during the acute, surgical, and reconstructive phases of care of the burn victim. An overview of the effects of thermal injury on the body systems is presented. Surgical considerations include preoperative evaluation, preparation, and transport, as well as fluid and temperature monitoring. Anesthetic drugs and temperature monitoring. Anesthetic drugs and techniques are discussed, with consideration given to the special concerns of burn patients. The unique features of electrical injuries are described since these bring an added dimension to anesthesia management.

Teaching strategies for critical thinking.

Critical thinking is a phase that is being heard frequently in nursing education. Nurse educators are encouraged to teach students to think critically because of the higher-order thinking skills that are required in our complex health care delivery system. The challenge to educators is the selection, development, and implementation of appropriate teaching strategies. This article describes a variety of strategies for teaching critical thinking within the context of nursing.

Perspectives on academic dishonesty.

Academic dishonest behaviors, such as lying, cheating, and plagiarism, are destructive and must be recognized and addressed early in the development of professional nurses. Faculty must be concerned with the relationship between student integrity in the classroom and clinical or professional behaviors. The authors discuss student motivation and attitudes toward unethical practices, faculty responses, and responsibilities when these incidents arise, and strategies for preventing academic dishonesty.

Pathogenesis of the impaired gall bladder contraction of coeliac disease.

We have investigated the possibility that the abnormally decreased gall bladder contraction after meals in patients with coeliac disease might result in part from an abnormality in the gall bladder response to endogenous cholecystokinetic hormones--for example, cholecystokinin and motilin--rather than solely from decreased secretion of such hormones. Eight patients with untreated coeliac disease and nine controls received intravenous infusions of the pure synthetic cholecystokinin analogue caerulein, 2-16 ng/kg/hour. Gall bladder emptying was measured on a minute-by-minute basis using 99mTc-HIDA scans. In the patients with coeliac disease, gall bladder emptying was greatly decreased (34.6 +/- 9.9 v 61.5 +/- 7.5% at 60 minutes, p less than 0.02), and a much greater dose of caerulein was needed to initiate gall bladder contraction (3.80 +/- 1.08 v 1.49 +/- 0.56 ng/kg, p less than 0.02). These results suggest that the abnormal gall bladder contraction in coeliac disease is not simply because of impaired release of cholecystokinin. Although mechanical factors secondary to the increased gall bladder size in patients with coeliac disease might to some extent account for the findings, the alternative explanation is that the gall bladder muscle is for some reason resistant to the action of cholecystokinetic agents. A similar phenomenon affecting the pancreas might contribute to the abnormally decreased pancreatic secretion found in coeliac disease.

Multifocal gastric carcinoid tumours, achlorhydria, and hypergastrinaemia.

Multiple polypoidal carcinoid tumours of the stomach were found in 5 patients with achlorhydria (4 of whom had pernicious anaemia) as a result of autoimmune atrophic gastritis. The tumours were small (nearly all less than 1 cm diameter) and appeared to grow very slowly, if at all; no significant enlargement or complications were seen during periods of observation of up to 6 years. No extragastric hormonal syndromes were identified. They differed from the carcinoid tumours usually found in the intestinal tract by being composed of argyrophil (not argentaffin) cells of the enterochromaffin-like (ECL) type. Fasting plasma levels of gastrin, which is believed to be trophic to ECL cells, were very high in all patients. Thus, chronic hyperplasia of gastric ECL cells (as a result of hypergastrinaemia) may have been responsible for development of the tumours. Long-term, uninterrupted achlorhydria produced by potent inhibitors of gastric acid secretion might therefore predispose to carcinoid tumours of the stomach.

Antidiarrhoeal agents. Clinical pharmacology and therapeutic use.

Diarrhoea is common and may be disabling, and in developed countries is responsible for more days lost from work than more socially acceptable conditions such as heart disease. Acute diarrhoea in the form of infantile gastroenteritis contributes to the deaths of more children than any other single condition in the world. This review describes the pathophysiological mechanisms and the treatments available for the more common types of diarrhoea in developed countries. Proper treatment depends on an understanding of the underlying pathological abnormality.

Campylobacter enteritis in Chelmsford.

During one year, out of 1829 faecal specimens examined at the Chelmsford Public Health Laboratory, campylobacters were isolated from 109 (6%), 21 of the positive cultures were from hospital in-patients and 3 were from hospital staff. The remaining 85 isolates were from specimens sent in by general practitioners. The authors' figures show a marked season variation with most of the infections occurring from June to September. The highest incidence (36%) was in the 20 to 30 age group, 99% of patients had diarrhoea, usually watery, occasionally explosive, and 9% had visible blood in their stools. Eighteen per cent. of patients had abdominal pain, 5 of the 21 hospital in-patients underwent abdominal surgery. Fifty-nine faecal specimens were examined microscopically and 30 of these had blood and pus cells or pus cells alone. Three patients had rectal biopsies showing a nonspecific colitis, 11 patients had recently been abroad.

Defective platelet function following the administration of penicillin compounds.

Platelet function and blood coagulation were studied in five human volunteers receiving penicillin-G in incremental doses of 1.2--48 million U/day, in six volunteers receiving ampicillin in incremental doses of 60--300 mg/kg/day (4--20 g/day), and in six volunteers receiving methicillin in incremental doses of 60--300 mg/kg/day. Coagulation tests remained normal in all 17 volunteers. However, ADP-induced platelet aggregation became abnormal in every subject except one receiving ampicillin and one receiving methicillin. Defective aggregation occurred with predictability with the following doses: penicillin-G, 24 million U/day; ampicillin, 300 mg/kg/day; methicillin, 300 mg/kg/day. All volunteers given penicillin-G and all given ampicillin experienced dose-related prolongation of bleeding time which did not occur with methicillin. Striking prolongation of bleeding time occurred only with penicillin-G in doses of 48 million U/day. Other tests of platelet function including clot retraction, platelet factor 3 availability, and collagen-induced or epinephrine-induced aggregation remained normal during the administration of these drugs. Measurement of intracellular adenine nucleotides revealed that the ADP and ATP content of platelets was unaffected. It appears that at least one mechanism by which the penicillin compounds alter platelet behavior is by interfering with activation of these cells by ADP.

Enzyme formation in higher plant tissue : A protein inhibitor of invertase synthesis secreted by tissue slices of plant storage organs.

Ageing slices of artichoke tuber or carrot root produced a substance, characterised as a protein, which when added to freshly cut slices inhibited invertase development. For maximum effect, it was necessary to expose the tissue to inhibitor immediately on excision, and this resulted in a slower rate of enzyme production and a lower final level. We suggest that there is an interaction between gibberellin, whose production is initiated by wounding, and the inhibitor. Bacterial infection was not the cause of the results obtained.