A splice variant of trkB and brain-derived neurotrophic factor are co-expressed in retinal pigmented epithelial cells and promote differentiated characteristics

There is evidence suggesting reciprocal trophic interactions between photoreceptors and the retinal pigmented epithelium (RPE), but the factors involved have not been identified. In this study, we investigated the hypothesis that one or more known neurotrophic factors act upon the RPE. Cultured human and freshly isolated bovine RPE cells demonstrated saturable specific binding for [¹²⁵I]labeled BDNF, NT-4/5 and NT-3 with little specific binding for CNTF and none for NGF. Cross-competition experiments showed that BDNF is the preferred ligand and cross-linking of [¹²⁵I]BDNF resulted in a doublet at 160 kd that was increased in RPE cells incubated in all-trans retinoic acid. There was basal phosphorylation of a 145 kd protein recognized by an anti-trk antibody that was increased in RPE cells pulsed with BDNF. RT-PCR with primers spanning the transmembrane domain demonstrated that RPE cells express trkB mRNA lacking a region homologous to exon 9 of chicken trkB, a splice variant that has been demonstrated to preferentially interact with BDNF. Northern blots demonstrated that cultured RPE cells also express mRNA for BDNF. BDNF did not stimulate proliferation or increase survival of RPE cells in serum-free medium, but promoted a differentiated morphology and increased the expression of cellular retinaldehyde binding protein, a marker of the differentiated state in RPE cells. An RPE cell line that spontaneously shows differentiated features showed a high level of BDNF mRNA. These data demonstrate that RPE cells express a short splice variant of trkB whose activation correlates with expression of differentiated characteristics and the cells themselves are capable of producing a ligand for the receptors. Signaling through trkB could play a role in differentiation of RPE cells during development and maintenance of the differentiated state in adult RPE.     

"Death was a blessing" – should it ever be pharmaceutically hastened? British pharmacists'' views

OBJECTIVES: To investigate the views and experiences of British pharmacists in physician-assisted suicide (PAS) and voluntary active euthanasia (VAE) and to examine whether differences in views were associated with personal characteristics. METHOD: A postal questionnaire was mailed to a random sample of 500 registered pharmacists, with addresses in England or Wales, stratified according to sex and community/hospital working environments. MAIN OUTCOME MEASURE: Pharmacists' reports of their views and experiences of PAS and VAE. RESULTS: Completed questionnaires were received from 295 respondents (response rate: 59%). The majority of respondents (83%) reported that at times, a person had the right to choose their own manner of death; 61% and 53% thought that there should be changes in the Law to legalise VAE and PAS, respectively. If it were legal to do so, 63% stated that they would be willing to dispense medication for VAE and 64% for PAS. However, only 45% agreed that the pharmacist should have a role in advising the prescriber on the choice and dose of drugs used. Sex, age, and years registered as a pharmacist were not found to be significantly associated with views on the practices of PAS and VAE. However, pharmacists who reported having a religion were significantly less likely to favour such practices. On comparing the views of community and hospital pharmacists, community pharmacists were significantly less likely than expected to want to be informed about the intended purpose of lethal drugs. CONCLUSION: In this survey, while over half of British pharmacists did not disagree in principle to the legalisation of VAE and/or PAS, they were less supportive of direct involvement in such procedures. Religion was a discriminatory factor associated with negative views of VAE and PAS. The significant minority of pharmacists not wanting to know the purpose of drugs they suspected might be for PAS or VAE is not in accordance with professional accountability, reflecting the complex and sometimes conflicting legal and moral aspects of such practices when deciding upon a course of action.     

Collagen-assisted healing of facial wounds after mohs surgery

Allowing selected full-thickness skin defects to heal by secondary intention offers the advantages of optimal cancer surveillance, simplified wound management, and avoidance of reconstructive procedures with their associated costs and potential complications. The topical use of bovine collagen has been suggested as a method of enhancing wound closure and final cosmetic appearance. This study evaluated the effect of bovine collagen on wound healing in patients undergoing facial Mohs surgery using the fresh-tissue technique. A total of 111 consecutive patients were assigned to a collagen or no-collagen group. Wound care was identical except for the weekly addition of bovine collagen to the wound of patients in the collagen group. Evaluation was at weekly intervals until the wound epithelialized, then bimonthly for at least 6 months. There was no difference in the rate of wound epithelialization or final cosmetic appearance. This study provides no evidence that the topical use of bovine collagen in a facial wound after Mohs surgery enhances wound epithelialization or the final cosmetic appearance.     

Nurse practitioners in primary care III. The southern Ontario randomized trial

A group of nurses who formerly had performed office functions received a special university-based educational program designed to prepare them to assume much of primary care management as nurse practitioners. The associated family physicians would shift their role to general supervision and attention to difficult clinical problems. To test this new form of practice, two complementary randomized trials have been conducted in south-central Ontario. The particular trial reported here was intended to assess the influence of the educational program on the changing roles of the professional personnel. The nurses of 14 family medical practices, with the physicians' support and commitment to participation, applied for the new training. Seven applicants were randomly selected to receive the training and their corresponding practices became the experimental group, while the remaining nurses and practices were retained as controls. During the subsequent year of investigation important changes occurred in professional roles of the experimental group. Nurse practitioners spent more time in clinical activities than conventional office nurses. The shift was not at the expense of time devoted to clinical work by physicians. Doctors delegated more professional activities to nurse practitioners than to conventional nurses. Except for remuneration (affected by legal constraints) job satisfaction among experimental physicians and nurses remained high after one year of experience with the new method.     

Studies of duplex (copper-coated) wires for use in intrauterine devices.

An investigation to develop and study duplex wire for use in IUDs was initiated by the observation that copper wires wound on IUDs occasionally fragmented after prolonged in vivo use. The duplex wires consist of an exposed active copper surface plated onto an inert inner core to maintain structural continuity. Data demonstrated that the dissolution rates as well as surface changes and biological effects are independent of whether stainless steel, Inconnel or Tophet-M was used as the core. Small IUDs can be wound with a duplex wire in a manner identical to that presently used with pure copper to resist fragmentation and to provide contraceptive effects.     

A 2-year longitudinal nutritional survey of 405 Northumberland children initially aged 11.5 years

Children (405), initially of average age 11.5 years, recorded all food and drinks consumed for three consecutive days (with an interview on the fourth day) on five separate occasions over a 2-year period. Food tables (Paul & Southgate, 1978) enabled nutrient intakes to be calculated. The data collected were found to be of high reliability (Hackett et al. 1983). The mean energy intakes showed broad agreement with other recent British dietary surveys but were well below those recorded in the prewar study by Widdowson (1947) and the FAO/WHO (1973) recommended levels. They were slightly below the current Department of Health and Social Security (DHSS; 1979) recommended intakes. Over the 2-year period, the energy intake of the boys increased by 13% compared with an increase of only 7% in the girls. The iron and vitamin A intakes of all groups of children were low compared with current recommendations (DHSS, 1979). This seems to be a result of falling energy intake. Mean calcium intakes were also only marginally in excess of the recommended intake, and those of most of the girls would fall below the recommendation if the proposal to end the fortification of flour (DHSS, 1981) is implemented.