Invasive thymoma with intracaval growth extending and directly invading the right atrium

We report an extremely rare case of an invasive thymoma with intracaval growth extending and directly invading the right atrium. Enbloc excision of the tumor with lobectomy and combined resection of the right atrium, and graft replacement of the superior vena cava were successfully performed during cardiopulmonary bypass. Invasive thymoma with this type of intracaval and intra-atrial progression is extremely rare.     

Neurotoxicity of 1-bromopropane in rats

Neurotoxicity of 1-bromopropane (1-BP) used as an alternative solvent of fluorocarbons was experimentally studied. Eight rats in the experimental group were exposed to 1-BP at 1500 ppm for six hours a day, five days a week for four weeks in an exposure chamber. Another eight rats in the control group were exposed to room air in a similar exposure chamber as those in the experimental group. During the latter half of the fourth week of exposure, all the rats in the experimental group showed a loss of body weight and ataxic gait compared with control rats. At the end of the fourth week, the rats in both groups were perfused through the ascending aorta and fixed. The cerebellum, medulla oblongata, spinal cord and peripheral nerve were processed for histopathological studies. No statistically significant difference in the frequency of axonal degeneration in both peroneal and sural nerves was found between the experimental and control groups. In the cerebellum, the frequency of degeneration of Purkinje cells in both the vermis and hemisphere was higher in the experimental group than in the control group (P < 0.05). There was no significant difference in the frequency of myelin ovoids in the fifth thoracic and in the third cervical posterior columns of the spinal cord between control and experimental groups. There was also no significant difference in the frequency of axonal swelling in the nucleus gracilis of the medulla oblongata between control and experimental groups. Ataxic gait was considered to be induced by degeneration of Purkinje cells in the cerebellum due to 1-BP exposure. However, degenerative findings of nerve fibers in the peripheral nerve, spinal posterior column and nucleus gracilis of the medulla oblongata due to 1-BP exposure were not evident. At the end of the fourth week of exposure, rats in the experimental group showed loss of body weight and markedly decreased motor activities, and it was considered that they would die if we continued the exposure into the fifth week. Therefore, we feel that our experimental schedule should be reconsidered before undertaking any further studies on the peripheral nerve toxicity of 1-BP.     

Peripheral choriovitreal neovascularization in proliferative diabetic retinopathy: histopathologic and ultrastructural study

We describe the histopathologic and ultrastructural evidence of choriovitreal neovascularization in the peripheral fundus of a non-vitrectomized eye with proliferative diabetic retinopathy (PDR). One eye with PDR was surgically enucleated because of neovascular glaucoma and studied with light and electron microscopy. The eye had neovascular membranes at the ora serrata of the peripheral fundus. The newly formed vessels originated from the choroid, passed through Bruch's membrane and the retina, and extended into the vitreous. These vessels had either developing or mature characteristics. The endothelial cells of the developing vessels contained a bulky cytoplasm with many intracytoplasmic filaments, ribosomes and rough endoplasmic reticulum. Budding endothelial cells were frequently found in the developing vessels. The endothelial cells of the mature vessels had attenuated cytoplasm and fenestrations with diaphragms. These observations suggest that choriovitreal neovascularization in the peripheral fundus is one of the features of PDR.     

Iris vessel involvement in iris-nevus syndrome

PURPOSE: To report a case of iris-nevus syndrome accompanied by disruption of the blood-aqueous barrier in the iris which was confirmed angiographically and histopathologically. CASE: The patient was a 39-year-old woman. She noticed blurred vision in the left eye which was diagnosed as left glaucoma. Specular microscopy revealed low endothelial cell density in the left cornea. The left iris showed atrophy with clusters of nodular iris nevus and distorted pupil. The left iridocorneal angle was closed with peripheral anterior synechia. FINDINGS: Indocyanine green iris angiography revealed more vessels on the surface of the left iris than on the right. In fluorescein iris angiography, the dye leaked from the iris vessels in areas where the iris showed advanced atrophy. The trabecular tissue obtained by trabeculectomy from the patient's left eye showed histopathologically a lining of corneal endothelial cells on the surface of the iris. The density of the vessels was high in the iris stroma. Some cells covering the vessel wall showed degeneration with opening of the zonula occludens. Schlemm's canal had narrowed lumina, and the intertrabecular spaces were closed. CONCLUSION: Disruption of the blood-aqueous barrier may occur in iris-nevus syndrome.     

Immunohistochemical and ultrastructural analysis of dysplastic epithelium of human ocular surface: basement membrane and intermediate filament.

PURPOSE: The dysplastic corneal epithelium is characterized by the abnormal proliferation of epithelial cells. The phenotypes of these cells have not been elucidated. We investigated whether such epithelium expresses the phenotypes of corneal or conjunctival epithelial cells. METHODS: The corneas and conjunctivae from four normal subjects and from one patient with epithelial dysplasia of the central cornea were immunostained for IV and VII collagens and for cytokeratins. Monoclonal antibodies against collagen IV reacted to the [alpha1(IV)]2alpha2(IV) or alpha5(IV) molecule. Anti-cytokeratin antibodies were used to define epithelial cell types. The ultrastructure of the basement membrane (BM) of each specimen also was examined. RESULTS: Type VII collagen immunoreactivity was detected in all the specimens of epithelial BM. The anti-collagen IV [alpha1(IV)]2alpha2(IV) antibody labeled the conjunctival BMs, not the BMs of the corneal epithelia, of each subject. The normal corneal epithelial BM, not the BM of the conjunctival or dysplastic corneal epithelium, was immunolabeled with anti-alpha5(IV) antibody. The pattern of cytokeratin expression in the corneal epithelial dysplasia resembled that seen in the normal conjunctivae. Small breaks in the BM of dysplastic corneal epithelium were ultrastructurally revealed. The number of hemidesmosomes in the dysplastic corneal epithelium was decreased as compared with that in the normal BM. CONCLUSION: The composition of collagen types within the BM and the cellular phenotype of the dysplastic epithelium in the cornea resembled those of conjunctival epithelium, not of the cornea.     

Inhibition of P-selectin attenuates neutrophil-mediated myocardial dysfunction in isolated rat heart

The expression of P-selectin on postischemic endothelium after reperfusion has been shown to trigger neutrophil attachment and the subsequent inflammatory responses. Extensive studies have demonstrated that P-selectin is involved in the progression of neutrophil-mediated myocardial infarction and no-reflow phenomenon. In the present study, we examined the effects of selectin inhibitors, sialyl Lewis X-oligosaccharide and anti-P-selectin monoclonal antibody, PB1.3 on neutrophil-dependent left ventricular dysfunction in isolated rat heart. The hearts were subjected to global ischemia for 20 min and then reperfused for 45 min with rat plasma in the presence of human neutrophils during the first 5 min of the reperfusion. Left ventricular developed pressure and other parameters of the left ventricular function deteriorated throughout the reperfusion period in a neutrophil-dependent manner. In contrast, the coronary flow was reduced early on (< 15 min) but recovered to the level in the hearts reperfused with no neutrophils 45 min after the reperfusion. We examined the effects of selectin inhibitors under experimental conditions in which the hearts were perfused with 30 million neutrophils. The treatment with sialyl Lewis X-oligosaccharide at a dose of 0.3 mg/min resulted in amelioration of left ventricular developed pressure to 57.2 +/- 14%, compared to 26.1 +/- 4.3% in the saline-treated group (P < 0.05). Similarly, the treatment with mouse anti-human P-selectin monoclonal antibody (IgG1) PB1.3 at a dose of 0.6 mg/min resulted in the prominent recovery of left ventricular developed pressure after 45 min of reperfusion (59.9 +/- 9.3% vs. 26.1 +/- 4.3% in the saline-treated group, P < 0.05). PB1.3 also attenuated the elevation of left ventricular end-diastolic pressure compared to that of the saline-treated group during the reperfusion period. Moreover, the treatment with PB1.3 ameliorated the recovery of coronary flow until 10 min after the reperfusion and the recovery of coronary flow 10 min after the reperfusion was 55.2 +/- 9.2%, as compared to 28.2 +/- 7.7% in saline-treated hearts (P < 0.05). To our knowledge, this is the first direct demonstration that the specific inhibition of P-selectin results in the inhibition of neutrophil-mediated left ventricular dysfunction or myocardial stunning.     

The fertilizing ability of human epididymal sperm

Purpose: Membrane cofactor protein (MCP), CD46, whose primary function is to protect host cells from homologous complement, has been presumed to serve as a sperm adhesion molecule for oocytes. The purpose of this study was to clarify the relationship between the properties of MCP expressed on epididymal sperm and their fertilizing ability in a recently developed strategy for assisted reproduction. Methods: We collected ejaculated sperm from normal subjects and epididymal sperm from vasectomized subjects and patients with congenital absence of the vas deferens. Western blotting and cofactor activity assay were performed to investigated the structural and functional properties of MCP. Results: Epididymal spermatozoa which showed a reduced fertilizing ability tended to react poorly with antibodies against MCP and also showed low cofactor activity, indicating weak complement regulatory activity compared to that of ejaculated spermatozoa. Conclusions: MCP is sufficiently expressed in ejaculated sperm in men with a normally developed epididymis but is diminished in epididymal sperm from men with congenital or acquired obstruction of the vas deferens.     

Immunolocalization of prolyl 4-hydroxylase in fibroblasts cultured from Tenon's capsule of humans

Background: The excessive accumulation of extracellular matrix (ECM) with the repopulation of fibroblasts may lead to an unsuccessful outcome of glaucoma filtering surgery. We examined the immunolocalization of ECM components and prolyl 4-hydroxylase, an enzyme involved in collagen biosynthesis, in cultured Tenon's capsule fibroblasts (TCFs) of humans to evaluate the production of ECM in the cells. Methods: We used light microscopy to evaluate the immunolocalization of prolyl 4-hydroxylase and ECM components, collagen types I, III, and IV, cellular fibronectin, and laminin in TCFs. Ultrastructural localization of the enzyme was also evaluated by electron microscopy. Results: Immunoreactivity with monoclonal antibodies against the and subunits of the enzyme or with the polyclonal antibody against it was detected in the cytoplasm of the cells in a fine granular pattern, indicating its localization in the indoplasmic reticulum (ER). Immunoreactivity for the enzyme was detected in the cisternae of the ER on electron microscopy. Types I and III collagen reactivities were also observed in the cytoplasm in a fine granular pattern. T reactivity was present diffusely on the cell surface. The distribution of laminin reactivity in the cytoplasm resembled that of types I and III collagen. Cellular fibronectin reactivity was observed in the ECM in a reticular pattern. Conclusion: Prolyl 4-hydroxylase was located in the cisternae of the ER. TCFs produced a variety of ECM components in vitro. The results provide insight into the fibrotic process during scar formation at the site of a bleb following filtering surgery.     

Electron microscopical and immunohistochemical studies on the induction of "Qi" employing needling manipulation.

During a sparrow-pecking and twisting-needle manipulation to the acupoints BL 23, 24 and 25 for an induction of "Qi", it was found that some transparent materials were binding to the needles after removed from the volunteer's skin. Electron-microscopical analysis of the transparent materials revealed that they corresponded to the injured fascia made up of collagen fibers, elastic fibers, fibroblasts, adipocytes and mast cells. Rarely were nerve fiber-like structures observed in the materials. Immunohistochemically, calcitonin gene-related peptide-positive nerve fibers could be demonstrated in the acupoint BL 24 associated fascia. A possible functional relationship between the needle manipulation and the induction of Qi-sensation is discussed along with the acupoint tissue constitution.