Reelin expression is upregulated following ocular tissue injury

Purpose Reelin is important in the guidance of neuronal stem cells in the central nervous system during normal development. We wished to determine whether reelin is expressed in the retina and cornea after injury. Methods Mice underwent laceration of their retina as well as corneal epithelial debridement. The mice were sacrificed at 3 days, and eyes were fixed and stained for reelin expression and reelin messenger ribonucleic acid (mRNA). Results In normal eyes, reelin was expressed only at very low levels in the ganglion cell layer of the retina and the endothelial cell layer of the cornea. In injured eyes, there was marked expression in reelin immunoreactivity in the retina and cornea. Reelin gene expression was seen in the retina and cornea. Conclusions Reelin is expressed during normal retinogenesis. This study shows that reelin is also upregulated following injury to the retina and cornea. The expression of reelin following injury suggests that reelin may play an important role in regulating stem cell trafficking in neuronal and nonneuronal tissues following injury similar to its role in normal organogenesis. For consideration of publication in Graefe’s Archive for Clinical and Experimental Ophthalmology.     

Experimental study on "delay" phenomenon in relation to flap width and ischaemia

The present investigation was designed to clarify what induces circulatory enhancement in the delay procedure. Two different sizes of a bipedicle flap were prepared in rats and the blood flow was measured at the centre of the flaps. The delay effect, that is, elongation of the survival length, was significantly less in the wide flap than in the narrow flap, though the two flap groups had almost identical levels of central ischaemia when averaged for each group. On the basis of ischaemic level, the flaps, regardless of size, were classified into two groups: more and less ischaemic than the mean. The delay effects noted in the more ischaemic flaps were not significantly different from those in the less ischaemic flaps. These results indicate that flap width has more influence on the delay effect than the degree of ischaemia.     

Repair of subglottic stenosis with a free perichondrial graft

A case of tracheal stenosis was reconstructed, after trough formation, with a chondromucosal flap which was developed by submucous perichondrial grafting. At the first stage, a free perichondrial graft from the pinna was transplanted into the buccal submucosal layer. About 10 months later, when sufficient neocartilage had formed, the chondromucosal composite graft was transferred from the buccal region to the paratracheal subcutaneous region with the mucosa facing deeply. Finally, 4 weeks later the tracheal trough was closed with a composite rotation flap which incorporated the skin, neocartilage and mucosa. The postoperative course was uneventful and a wide tracheal lumen with a firm framework and mucous lining was confirmed by both fibrescopic and radiographic examination.     

A case-control study of breast cancer among Japanese women: with special reference to family history and reproductive and dietary factors

Summary To study the effects of family history and reproductive, anthropometric, and dietary factors on the risk of breast cancer among low risk populations, we conducted a hospital-based case-control study involving 908 patients with breast cancer and their matched controls, in Japan. A positive family history of breast cancer significantly increased the risk of breast cancer (odds ratio = 1.52, 95% confidence interval: 1.14–2.03). The risk further increased with increasing number of family members affected. Obesity, single marital status, fewer births, a late childbirth, and less consumption of green-yellow vegetables and dairy products were also associated with an increased risk of breast cancer. These associations were independent in multivariate analyses. There was no increase in risk associated with consumption of high fat foods. When analyzed by menopausal status, the association with family history of breast cancer, especially in the first degree of relatives, was more evident for premenopausal breast cancer. The associations with obesity and lower consumption of dairy products were more pronounced for postmenopausal breast cancer, while those with lower parity and single marital status were stronger for premenopausal breast cancer.     

Independent regulation of activation and inactivation phases in non-contractile Ca transients by nicotinic receptor at the mouse neuromuscular junction

Non-contractile Ca²⁺ mobilization (not accompanied by muscle contraction) occurs by the prolonged activation of nicotinic acetylcholine receptor in mouse diaphragm muscles treated with anticholinesterase. To elucidate the regulation properties of non-contractile Ca²⁺ mobilization by nicotinic receptor, the modes of action of competitive and depolarizing neurmuscular blockers were investigated. (+)-Tubocurarine (0.07–0.1 μM), pancuronium (0.05 μM) and -bungarotoxin (0.03–0.06 μM) decreased decay time (T₂, duration of inactivation phase) without changes in rise time (T₁, duration of activation phase) of non-contractile Ca²⁺ transients. These competitive antagonists also suppressed their peak amplitude at higher concentrations than those affectingT₂. Contractile Ca²⁺ transients were not inhibited by these antagonists at the concentrations used. Decamethonium (1 μM), a depolarizing blocker, suppressed the peak amplitude of non-contractile Ca²⁺ transients without affecting their duration. In contrast, succinylcholine (0.3 μM) suppressed both peak amplitude andT₁ without changingT₂, presumably via the receptor desentization. Succinylcholine but not decamthonium inhibited contractile Ca²⁺ transients at the concentrations used. These results demonstrate that the activation and inactivation phase in non-contractile Ca²⁺ transients are independently regulated by nicotinic acetylcholine receptor.     

Calretinin is differentially localized in magnocellular oxytocin neurons of the rat hypothalamus. A double-labeling immunofluorescence study

By use of a double-labeling immunofluorescence method with a confocal laser scanning microscope, we have examined whether a calcium-binding protein, calretinin, is localized in magnocellular oxytocin and vasopressin neurons of the rat hypothalamus. In the supraoptic nucleus, all oxytocin-labeled cells were stained for calretinin. However, in the magnocellular part of the paraventricular nucleus, almost all oxytocin-stained cells were devoid of calretinin immunoreactivity. All vasopressin-positive cells of both the supraoptic nucleus and the magnocellular part of the paraventricular nucleus lacked calretinin immunoreactivity. No calretinin immunoreactivity was found in oxytocin-labeled cells of the the anterior commissural nucleus or in vasopressin-labeled cells of the suprachiasmatic nucleus. We previously showed that another calcium-binding protein, calbindin-D28k, was localized in magnocellular oxytocin neurons of the supraoptic nucleus but not in those of the paraventricular nucleus. These findings suggest that, in general, magnocellular oxytocin neurons of the supraoptic nucleus and those of the paraventricular nucleus can be chemically distinguished, that is, the former contain both calretinin and calbindin-D28k but the latter lack the two calcium-binding proteins.     

Local muscimol disinhibits mesolimbic dopaminergic activity as examined by brain microdialysis and Fos immunohistochemistry

Infusion of muscimol (5×10⁻⁵ M, 60 min) into the nucleus accumbens (NAC) through a dialysis membrane caused a significant increase in extracellular dopamine (DA) and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC). Fos-like immunoreactivity induced by intra-NAC infusion of muscimol was seen ipsilaterally in many accumbofugal target areas, but no Fos-positive neurons were seen in the vicinity of the dialysis membrane in the NAC. Sequential staining of Fos and tyrosine hydroxylase (TH) immunoreactivities revealed that a portion of A10 dopaminergic neurons were double-labelled. These results suggest that muscimol in the NAC disinhibits mesolimbic DA neuronal activity possibly through activity of the accumbofugal GABA neuron system.