Ultrastructural features of the shark brain

The ultrastructural characteristics of elasmobranch central nervous system have not been previously reported. This study presents a general assessment of aldehyde perfused brain and spinal cord in three species of shark: tiger, hammerhead and Atlantic nurse. The same distinct cell types are present in the shark that exist in mammals and similar criteria may be used for their differentiation. Neurons have frequently round nuclei with a prominent nucleoli; cytoplasm is abundant and filled with formed elements; somatic synapses and subsurface cisterns are rare. Astrocytes are smaller, and have less cytoplasm and slightly fewer organelles. Glial fibrils occur, but are not invariably present. Separating astrocytes from neurons is the most difficult identification problem. Oligodendrogliocytes are smaller, and have denser cytoplasm and a dark nucleus. The striking feature of capillary morphology is the presence of an appreciable perivascular space containing collagen; many tortuous evanginations of this space occur into surrounding glial processes which completely invest the capillaries. Astrocyte cell bodies frequently lie immediately next to vessels, and capillaries are occasionally totally surrounded by a single astrocyte process, thus being endocellular. Smaller pericapillary processes may be either astrocytic or ependymal. Dendrites, synapses, axons, and myelin have no obvious special characteristics. Sodium, visualized by precipitation techniques, is prominent in the astroglia and neurons.     

A comparison of five diagnostic systems for childhood schizophrenia and infantile autism

Five diagnostic systems designed to differentiate infantile autism and early childhood schizophrenia were compared by deriving scores on 44 children referred consecutively to the same clinical center. While the autistic scales devised by Rimland, Polan and Spencer, Lotter, and the British Working Party correlated significantly, the degree of correspondence (35%) indicated that several children obtained high autistic scores in one system but low scores in another. The BWP's term schizophrenia has more correspondence with the term autism used by others than with Rimland's schizophrenia. In the DeMyer-Churchill categorical system (early schizophrenia, primary autism, secondary autism, and non-psychotic subnormal), primary autism most resembles Rimland's concept of infantile autism as measured by his E-1 version. All other systems differentiate psychotic from non-psychotic children but do not distinguish any of the psychotic subgroups.This study was supported in part by Public Health Service Grant No. MH05154 and also by LaRue D. Carter Memorial Hospital, State of Indiana, Indianapolis, Ind.The authors wish to thank Dr. Bernard Rimland for providing his scoring key.     

Improving linkages between family physicians and hospitals

Hospitals, as social pillars and hubs of medical activity, can be a great influence and supporter of family physicians and primary healthcare, which will in turn improve the health of their communities. This paper discusses general linkages between family physicians and hospitals and the development of a specific program to enhance these linkages created at a large community hospital in Ontario.     

Optic disk size and optic disk-to-fovea distance in preterm and full-term infants

PURPOSE: Few studies have assessed optic disk and retinal morphology in infants. Here the optic disk and optic disk-to-fovea distance were measured in preterm and full-term infants in vivo. METHODS: Optic disk (OD) dimensions and the center-to-center distance between the OD and the macula were measured using digital imaging in infants undergoing routine ophthalmic examinations. Postmenstrual age of the mother at the time of examination ranged from 32 to 50 weeks. From each image, the OD-to-fovea distance (ODF) and the OD height (ODH) and OD width (ODW) were measured. RESULTS: In 51 retinal images from 51 infants, mean +/- SD values obtained were 4.4 +/- 0.4 mm (ODF), 1.41 +/- 0.1 9 mm (ODH), and 1.05 +/- 0.13 mm (ODW). These dimensions did not change significantly over the age range studied. The mean value for the ratio between ODF and mean OD diameter (ODF/DD) was 3.76. CONCLUSIONS: Results of this in vivo study suggest that though the optic nerve head diameter increases by more than 50%, only limited growth occurs at the highly organized area of the posterior pole from birth to adulthood. This study discusses the finding of a large-angle kappa in infants and the use of a disk macula/disk diameter ratio in the diagnosis of optic nerve hypoplasia.     

Roles of myofibroblasts in prostaglandin E2-stimulated intestinal epithelial proliferation and angiogenesis

Prostaglandins (PG) are produced throughout the gastrointestinal tract and are critical mediators for a complex array of physiologic and pathophysiologic processes in the intestine. Intestinal myofibroblasts, which express cyclooxygenase (COX) and generate PGE(2), play important roles in intestinal epithelial proliferation, differentiation, inflammation, and neoplasia through secreting growth factors and cytokines. Here, we show that PGE(2) activated human intestinal subepithelial myofibroblasts (18Co) through Gs protein-coupled E-prostanoid receptors and the cyclic AMP/protein kinase A pathway. 18Co cells and primary colonic myofibroblast isolates expressed a number of growth factors; several of them were dramatically regulated by PGE(2). An epidermal growth factor-like growth factor, amphiregulin (AR), which was not expressed by untreated cells, was strongly induced by PGE(2). Expression of vascular endothelial growth factor A (VEGFA) was rapidly increased by PGE(2) exposure. Hepatocyte growth factor (HGF) was elevated in PGE(2)-treated myofibroblasts at both mRNA and protein levels. Thus, PGE(2)-activated myofibroblasts promoted the proliferation and migration of intestinal epithelial cells, which were attenuated by neutralizing antibodies to AR and HGF, respectively. Moreover, in the presence of PGE(2), myofibroblasts strongly stimulated the migration and tubular formation of vascular endothelial cells. Neutralizing antibody to VEGFA inhibited the observed stimulation of migration. These results suggest that myofibroblast-generated growth factors are important mediators for PGE(2)-induced intestinal epithelial proliferation and angiogenesis, which play critical roles in intestinal homeostasis, inflammation, and neoplasia.     

A phase II study of weekly paclitaxel/estramustine/carboplatin in hormone-refractory prostate cancer

Purpose

The objective of this phase II study was to determine the response rate in patients with hormone-refractory prostate cancer given paclitaxel/estramustine/carboplatin for weeks 1, 2, and 3 of a 4-week cycle.

Patients and Methods

Eighty-four patients were registered into the trial. Paclitaxel 80 mg/m² and carboplatin area under the curve of 2 were administered intravenously on days 2, 9, and 16, and oral estramustine 280 mg 3 times daily was given on days 1-3, 8-10, and 15-17 for 6 cycles. Eastern Cooperative Oncology Group performance status 0, 1, and 2 was 46%, 41%, and 13%, respectively, and median age was 70 years (range, 53-82 years), with 58 patients (69%) aged > 65 years. The majority of patients (83%) were white. Fifteen patients (18%) had received previous chemotherapy, 61 patients (73%) had undergone previous surgery, and 51 patients (61%) had received previous external-beam radiation therapy.

Results

Intent-to-treat analysis revealed a ≥ 50% prostate-specific antigen decrease rate of 61%. Median survival was 15.3 months. The most frequent grade ≥ 3 toxicities included fatigue (11%), nausea (10%), neutropenia (9%), anemia (6%), and vomiting (6%).

Conclusion

Paclitaxel/estramustine/carboplatin administered in a weekly regimen is highly effective in the treatment of hormone-refractory prostate cancer and can be administered with reasonable safety in an outpatient setting.     

Establishment of a Varicose Vein Center in a Tertiary Vascular Surgery Practice: Urban Versus Rural Differences

We examined changes in practice patterns after the establishment of a varicose vein center (VVC) within two tertiary university vascular surgery practices and compared differences between urban (U) and rural (R) sites. Practice patterns for the treatment of VVs were compared 3 years before (period 1) and 3 years after (period 2) the formation of a U-VVC and an R-VVC in 2001. Both VVCs were part of similar-sized tertiary vascular surgery practices. Evaluation was specific to VVs, reticular veins, and telangiectasias. Prior to U-VVC, there were 338 office visits, six office procedures, and 114 hospital procedures. After U-VVC, there were 624, 120, and 312, respectively. Prior to R-VVC, there were 85 office visits, five office procedures, and 69 hospital procedures. After R-VVC, there were 528, 163, and 303, respectively. In period 1 for U-VVC and R-VVC, VVC relative value unit (RVU) generation as a percent of total practice RVUs was 1.0% and 0.7%, respectively. In period 2 for U-VVC and R-VVC, VVC RVU generation as a percent of total practice RVUs was 2.6% and 2.5%, respectively. In an effort to provide more coordinated treatment for patients with VVs, establishing a VVC within a tertiary academic vascular surgery practice can lead to rapid expansion of clinical volume by increased office visits, office procedures, and hospital procedures. Clinical demand for evaluation and treatment of VVs showed little variation between R-VVC and U-VVC.Presented at the Winter Meeting of the Peripheral Vascular Surgery Society, Park City, UT, January 27, 2006.