Biodegradable controlled-release microsphere systems made with the biocompatible biodegradable polyester excipient poly(DL-lactide-co-glycolide) constitute an exciting new technology for drug delivery to the central nervous system (CNS). Implantable controlled-release microspheres containing dopamine (DA) or norepinephrine (NE) provide a novel means to compare DA- or NE -induced restitution of function in unilateral 6-hydroxydopamine lesioned rats. A suspension of 3 microL of DA- or NE-containing microspheres or empty microspheres was implanted in 2 sites of the DA denervated striatum of rats previously unilaterally lesioned with 6-hydroxydopamine. Contralateral-rotational behavior induced by apomorphine was used as an index of lesion success and, following implantation of the microspheres, also as an index of functional recovery. Interestingly, both DA- and NE-microsphere-implanted rats displayed a 30-50% reduction in the number of apomorphine-induced rotations up to 8 wk postimplantation. Rats implanted with empty microspheres did not demonstrate significant changes in contralateral rotational behavior. Behavioral studies following implantation of a mixture of DA and NE microspheres revealed an 80% decrease in the number of apomorphine induced rotations up to 4 wk. On conclusion of the studies, immunocytochemical examination revealed growth of DA and tyrosine hydroxylase immunoreactive fibers in the striatum of DA and NE microsphere-implanted rats. Functional behavior appeared to correlate with the degree of fiber growth. Preliminary electron microscopic studies showed signs of axonal sprouting in the vicinity of the implanted microspheres. No growth was noted in rats implanted with empty microspheres. This report reviews the abilities of both microencapsulated NE and DA to assure functional recovery and to promote DA fiber (re)growth in parkinsonian rats. This novel means to deliver these substances to the central nervous system could be of therapeutic usefulness in Parkinson's disease.

Animals↗

PubMedDate not supplied

Dopamine fiber growth induction by implantation of synthetic dopamine-containing microspheres in rats with experimental hemi-parkinsonism.

Injectable local drug delivery formulations-so-called microspheres have recently been developed, in which drugs are microencapsulated within biocompatible and biodegradable copolymer excipients like poly[DL-lactide-co-glycolide]. In view of its potential therapeutical usefulness, we have studied the microsphere methodology as a means to substitute for experimentally induced subnormal levels of endogenous dopamine (DA). Administration of 6-hydroxydopamine (6-OH-DA) unilaterally in the medial forebrain bundle of rats results in an up-regulation of postsynaptic receptors in the denervated striatum, functionally manifested as contralateral rotational behavior after apomorphine. DA microspheres were implanted in the denervated striatum. The majority of the rats displayed an attenuation of the contralateral rotational behavior induced by apomorphine up to 8 wk postimplantation. Immunocytochemical observations unexpectedly demonstrated growth of DA and tyrosine hydroxylase immunoreactive fibers in the denervated striatum. Interestingly, there was an apparent correlation between functional recovery and the degree of growth of DA fibers. The present results suggest that implantation of DA microspheres may promote DA fiber growth and extended recovery of surviving DA neurons, and, therefore, could be of therapeutic usefulness in Parkinson's disease.

Animals↗

PubMedDate not supplied

Ultrastructural and Immunological methods in diagnostic pathology in a community hospital.

Five unusual tumors and one case of glomerulonephritis were examined by light microscopy, immunochemical methods, and electron microscopy in order to arrive at a correct diagnosis. We propose that these techniques can be used in community hospitals for selected cases in order to classify certain types of tumors, identify the primary site of some metastatic tumors, and help in the precise classification of some autoimmune diseases.

Adult↗

PubMedDate not supplied

Ultrasonographic measurement of gastrointestinal wall thickness and the ultrasonographic appearance of the ileocolic region in healthy cats.

Ultrasound evaluation was performed on 11 healthy cats to determine wall thickness measurements for the stomach, duodenum, jejunum, ileum, and colon and to characterize the appearance of the ileocolic region. The terminal ileum had a characteristic "wagon wheel" appearance on cross-sectional images. Gastrointestinal wall thickness measurements were as follows: gastric fundus (mean, 2.0 mm; 95% confidence interval [CI], 1.7 to 2.2 mm), pylorus (mean, 2.1 mm; 95% CI, 1.9 to 2.4 mm), duodenum (mean, 2.2 mm; 95% CI, 2.0 to 2.4 mm), jejunum (mean, 2.3 mm; 95% CI, 2.1 to 2.5 mm), ileum (mean, 2.8 mm; 95% CI, 2.5 to 3.2 mm), and colon (mean, 1.5 mm; 95% CI, 1.4 to 1.7 mm).

Animals↗

PubMedDate not supplied

Are black nurses an endangered species?

In the late 1980s it was feared that black nurses in Britain were a dying species. There was a belief that young people of minority ethnic descent were being deterred from choosing nursing as a career owing to the discrimination, disadvantage and harassment experienced by their parents as health service workers. Anecdotal evidence and limited statistical evidence suggested that the number of black applicants to preregistration training in nursing and midwifery was lower than would be expected when compared with the representation of the minority ethnic groups in the population as a whole. Nevertheless, the evidential base has, to date, been limited. Using the most comprehensive data set available, this paper presents an analysis of the national pattern of applications from members of minority ethnic groups to preregistration nursing and midwifery training. The evidence indicates complex patterns of under- and, in some cases, over-representation of black and Asian minority ethnic groups.

Black or African American↗

PubMedDate not supplied

Nursing in the new millennium: vision, activism, and the role of the media.

Explore the source record for details and available documents.

Forecasting↗

PubMedDate not supplied

Patient Self-Determination Act. On behalf of the patient.

Explore the source record for details and available documents.

Decision Making↗