Expression of vascular endothelial growth factor and its receptors in rats with protein-overload nephrosis

Background. Based on the fact that vascular endothelial growth factor (VEGF) increases vascular permeability, it is speculated that VEGF might be involved in the development of proteinuria, although this remains unconfirmed. The production and site of action of VEGF remains unclear in nephrotic renal diseases. Methods. Non-radioactive in situ hybridization was performed to examine the expression of VEGF mRNA and its receptors, flt-1 and KDR/flk-1, in a rat model of nephrosis induced by intraperitoneal injection of bovine serum albumin (BSA). Saline injected rats were served as control animals. Results. Neither morphological changes nor deposition of immunoglobulin or complement were observed in our model. Proteinuria developed, reaching a maximum level in rats injected with BSA for 3 days, followed by persistent proteinuria until day 14. The expression of mRNA for VEGF and the two receptors was markedly upregulated in glomeruli of BSA-induced nephritis compared with the control group. VEGF mRNA was localized in glomerular cells, including cells in mesangium, visceral and parietal epithelial cells. In contrast, flt-1 mRNA and KDR/flk-1 mRNA were expressed on glomerular endothelial cells and cells in mesangium. The ratio of glomerular cells positive for VEGF mRNA and its receptors mRNA increased proportionately with the severity of proteinuria. Immunohistochemistry for ED-1 and proliferating cell nuclear antigen showed no significant increase in infiltrating macrophage or cellular proliferation. Conclusions. Our results suggest that altered glomerular expression of VEGF and its receptors is not associated with proliferation of endothelial cells, but rather with proteinuria in BSA-induced nephritis in rats, VEGF may play a different role in different renal diseases.     

Hepatitis G virus infection from needle-stick injuries in hospital employees

A new RNA virus, hepatitis G virus (HGV) is known to be transmissible by blood transfusion. The aim of this study was to assess whether HGV is an occupational risk to hospital employees as a result of exposure to needle-stick injuries. Among 220 cases of needle-stick injuries, 21 employees were contaminated with HGV. Initially none of the 21 recipients were HGV positive. Fourteen of the 21 recipients were followed up and further tested for HGV RNA and serum antienvelope (E2) specific antibody. None of the 21 recipients exposed to HGV developed liver function abnormalities, but one of the 14 recipients became positive for HGV RNA after the injury. Anti-E2 was negative in all recipients tested. These findings suggest a low clinical risk of occupational exposure to HGV in hospital employees. Nevertheless, HGV is transmissible by needle-stick injury.     

Human erythropoietin stimulates murine megakaryopoiesis in serum-free culture

Recombinant erythropoietin (Epo) was capable of stimulating murine megakaryopoiesis both in serum-containing and serum-free cultures, although a relatively high amount of Epo was necessary to provide sufficient stimulus for colony growth. This observation was further confirmed by experiments using nonadherent, nonphagocytic, and T-cell-depleted marrow cells in which Epo stimulated the growth of single megakaryocytes, as well as clusters or colonies. Total plate analysis revealed that twice as many single megakaryocytes and two-cell aggregates were generated by Epo than generated by pokeweed mitogen-stimulated spleen cell-conditioned medium (PWM-SCM). The number of colonies with four or more cells formed by PWM-SCM, however, was significantly higher than that generated by Epo. These results suggest that in comparison to the factor(s) in PWM-SCM, Epo stimulates the growth of more mature progenitors.     

Freeze-fracture studies of myofiber plasma membrane in X chromosome-linked muscular dystrophy (mdx) mice

Summary The structure of the muscle plasma membrane of extensor digitorum longus muscles of X chromosome-linked muscular dystrophy (mdx) mice was studied by freeze-fracture technique at several time points after birth. The common denominator of the abnormalities was the decreased density of orthogonal arrays throughout all the time points examined. The results demonstrated that the ultrastructural features of the muscle plasma membrane alterations in mdx mice were similar to those in Duchenne dystrophy.Supported by grant (62A-2-20) from National Center of Neurology and Psychiatry (NCNP) of the Ministry of Health and Welfare, Japan     

Primary saphenous venous aneurysms presenting in a child

Venous aneurysms are dilatations of localized venous segments having no connection with varicosities. They are most often found post-traumatically in adults. The case presented here was a rare case of primary saphenous venous aneurysms in an 8-year-old child which were well demonstrated by Tc-99m human serum albumin (HSA) angiography.     

Effects of neuropeptide Y on canine cerebral circulation

The effects of neuropeptide Y (NPY) on the vascular tone of isolated cerebral arteries and vertebral blood flow (VBF) were studied in dogs. NPY elicited a dose-dependent contraction of arteries derived from the brain with ED50 values of 2 nM for the middle cerebral and basilar arteries. Arteries from the neck did not respond to NPY. Intra-arterial administration of NPY as a bolus reduced the VBF dose dependently, with no significant alteration of mean arterial blood pressure and heart rate. The decrease in VBF developed slowly and had a long duration, which was consistent with the observations made in vitro. NPY suppressed the contractile effect of noradrenaline (NA) on isolated cerebral arteries and pretreatment with NPY suppressed the effect of NA on VBF, indicating that NPY contributes to the inhibitory modulation of postsynaptic adrenergic mechanisms. These findings suggest that NPY could have a role in the regulation of cerebral circulation.     

Laser acupuncture therapy for pain and vague complaints in neurosurgery

The value of diode laser acupuncture for pain and other vague neurological complaints has been studied in chronic patients of head trauma and of cerebrovascular disease or neuralgia in head and neck regions. Gallium-Aluminium-Arsenide (Ga-Al-As) diode laser pain attenuator PANALAS-4000 manufactured by Japan Medical Laser Laboratory was used in the following specifications; wave length: 830 nm, power: 20-40 mW, frequency: 5-50 c.p.s., pulse duty: 0.9. The laser acupuncture was applied to some of the representative Chinese meridian points, local pain points and related nerves for 1 to 7 times in a week. It was given in 310 patients in our neurosurgical department. 175 of 227 patients who complained of pain and 12 of 39 patients who complained of numbness showed improvement within 24 hours, another 24 patients with pain and 16 patients with numbness showed improvement after 24 hours. No side effect was noticed. The duration of the effectiveness was about 2 or 3 days. It is very useful to apply the laser acupuncture for pain and vague complaints in neurosurgery.     

Differences in midazolam-induced breathing patterns in healthy volunteers

Sex differences, and the influence of drug dosage and additional upper airway obstruction were studied in midazolam-induced breathing patterns and sedation in 30 healthy volunteers (8 males and 22 females). After administration of 0.1 mg-kg^-1 midazolam (8 male and 8 female subjects), the rib cage (RC) motion increased in 6 males and the abdominal wall (ABD) motion and SaO₂ decreased in all males. In contrast, the RC and ABD motions and SaO₂ decreased in all females. Snoring and loss of consciousness occurred in 7 males and in 2 females. There were significant differences in the RC motion, SaO₂, the incidence of snoring and the sedative state between male and female subjects. A bolus dose of 0.5 mg of flumazenil completely antagonized the sedative effect of midazolam and restored the breathing pattern, whereas it did not completely restore SaO₂. A higher dose (0.2 mg·kg^-1) of midazolam was administered to an additional 8 females. It caused a loss of consciousness in all subjects and increased the RC motion in only one subject. Partial obstruction of the nasal cavity was effected with cotton balls in the remaining 6 females who were sedated with 0.1 mg·kg^-1 midazolam. An increase in the RC motion occurred similar to that observed in males. These findings suggest a difference in midazolam-induced sedation and breathing patterns between male and female subjects with midazolam administration on a mg · kg^-1 basis.