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Phalloidin, a toxin from the plant Amanita phalloides, irreversibly polymerizes actin filaments and causes cholestasis. Three-dimensional structural changes induced by phalloidin in the bile canaliculi and the intra-acinar localization of these changes were studied in the rat liver by scanning and transmission electron microscopy. After 3 days of treatment, canalicular changes appeared mainly in zones 2 and 3 of Rappaport's acinus, but after 7 days of treatment changes occurred in bile canaliculi of the whole acinus. The changes in the bile canaliculi included tortuosity, saccular dilatation, loss of microvilli, bleb formation and elongation of canalicular side branches. Some side branches extended near to Disse's space, leaving only a thin cytoplasmic rim between the canalicular lumen and Disse's space. Kupffer cells were occasionally situated near such extended bile canaliculi and protruded their processes into the hepatic cord. These results suggest that bile canaliculi in zone 3 are more susceptible to phalloidin toxicity than those in zone 1 and that biliary constituents may leak from such altered bile canaliculi.

Although the identification and characterisation of a participant's lateral profile during quiet standing have not received much research attention, they have the potential to greatly extend our understanding of upright stance stability control. This study further examines limb load asymmetries during quiet bipedal stance. During voluntary frontal-plane weight shifting for 2 min, 300 centre-of-pressure displacements on 14 blindfolded right-handed young adults were recorded. Four biomechanical indices were used to assess postural behaviour. These were the bias of time and the magnitude of the partial ground reaction forces from both legs, and the bias in the number and magnitude of microshifts influencing stability. Our study identifies a significant level of asymmetry in the quiet bipedal stance of right-handed people. This asymmetry is associated with the right-sided bias of the ground reaction force and the angle of inclination to the upright (vertical) centroidal line. We found that the initial lateralisation of the partial ground reaction forces from both feet, as well as the period of ground reaction force bias, are important elements in any clinical tests involving quiet bipedal stance.

Factors influencing the prognosis in gastric cancer treated by curative resection include lymph node metastasis and the extent of invasion of the gastric wall. Lymph node metastasis can be removed surgically, but the extent of invasion is not amenable to external measures. Of these two factors, the extent of wall invasion has the greatest influence on prognosis in cases undergoing curative resection. With lymph node removal of equal extent the prognosis worsens in proportion to the depth of invasion. Further, lymph node metastasis increases with increasing depth of invasion. Metastasis was seen in Group 2 and 3 nodes in more than 60% of cancer with invasion beyond the Tunica muscularis propria (pm), indicating that wide lymph node removal is essential in cancers with deep invasion of the wall. The effects of extended radical operation on the host as illustrated by the indices of total serum protein and albumin levels were no different from those of less extensive resections. It was confirmed that extensive radical resection did not delay postoperative recovery.

Viral nucleoprotein complexes were extracted from nuclei of permissive cells (CV-1) infected with simian virus 40 (SV40) and examined by electron microscopy. SV40 nucleoprotein complexes (SV40 chromatin) showed nucleosomes in linear bead-like arrangements along the extended closed circular DNA. The contour length of the SV40 chromatin was only 1.0-1.8 times shorter than that of viral DNA obtained after deproteinization. The data suggest that the circular DNA in SV40 chromatin can be extended to nearly its full length without detachment of the histone complexes.

We describe here a patient with a recurrent hemangiopericytoma of the superior mediastinum 23 years after an initial complete resection. In the current biopsy specimen, the tumor cells were much more anaplastic than those seen 23 years ago. Although the patient was treated with chemotherapy, which consisted of ifosfamide and epirubicin, the tumor was unresponsive and he died 6 months later from disease progression. Careful long-term follow-up is mandatory for patients with hemangiopericytomas because recurrence with greater malignancy can develop following an extended disease-free interval.

A 61-year-old man, who was diagnosed with superior vena cava syndrome by papillary thyroid carcinoma, was referred to our hospital. A bulky thyroid tumor with tracheal invasion extended from the left neck to the right atrium without distant metastases. The risk of sudden death due to airway occlusion, tumor embolism or obstruction of the tricuspid valve led us to elect surgery. Extended resection of thyroid cancer was performed with cardiopulmonary bypass. Peritoneal dissemination was found via laparotomy. A histological diagnosis of anaplastic carcinoma arising from transformation of papillary carcinoma was made. After the operation, bilateral ureteral occlusion by peritoneal dissemination and multiple lung metastases were detected. The patient died with acute renal failure on postoperative day 12. Intraatrial extension of thyroid cancer is rare, and only 12 cases have been reported in the literature. We present a case of thyroid cancer with intraatrial extension.

Nine eyeballs were enucleated from nine patients with excessive myopia, secondary retinochoroidal atrophy, absolute glaucoma, uveal malignant melanoma, Behcet's disease and sympathetic ophthalmia. The retina and choroid were studied with light and electron microscopes. The results were: In excessive myopia, marked blockade of choriocapillaries was accompanied by progressive retinal degeneration. In secondary retinochoroidal atrophy induced by retrobulbar fibrosis, the choriocapillaries were partially blocked and the retina had markedly degenerated. In Behcet's disease, exudative inflammation was recognized in the choroid extending to the retina and causing retinal detachment, though the choriocapillaries remained morphologically normal. In sympathetic ophthalmia, both the choriocapillaries and the retina remained normal, though marked inflammation was recognized in the outer layer of the choroid. In absolute glaucoma, the fine structures of the choriocapillary were well preserved in spite of bulbar hypertonia. In uveal malignant melanoma, the ultra structure of the choriocapillary near the tumor was well preserved. The choriocapillaries were normal even when the retina had degenerated. Retinal degeneration was recognized when changes such as blockage, disappearance, dilatation and increased permeability were found in the choriocapillaries. Damage to the choriocapillaries might play an important role in inducing and developing retinochoroidal atrophy.

<P>Four cases of femoral neck fracture following avascular necrosis of the femoral head were studied histologically. All four patients were women who had received steroid therapy, three of them for systemic lupus erythematosus and the other for idiopathic thrombocytopenic purpura. Two types of fracture were found according to the site and the mechanism of fracture. One was at the junction between the necrotic bone and the repairing bone, and it can thus be regarded as a stress fracture. The other type of fracture commenced at the superior portion of the junction between the femoral head and neck, which was weak due to the repair reaction. The fracture line extended to the inferior cortex of the femoral neck, as often occurs in the elderly. In one patient, the femoral neck fracture was the first sign of avascular necrosis of the femoral head. </P>

A 56-year-old man was admitted to our department with a chief complaint of lower extremity dysesthesia. He described a dull numbness below the ankle and a dull pain in the nates for the past two years. Although the numbness extended to the thigh, he did not notice any muscular weakness or atrophy. Neurological examination revealed weakness and atrophy in the face, tongue and the proximal portions of all four extremities. Deep tendon reflexes were decreased. A moderate loss of vibratory sensation was noted below the knees. Electromyography showed neurogenic changes. Muscle biopsy revealed both myogenic and neurogenic changes. Sural nerve biopsy revealed a mild reduction of myelinated fibers, particularly the large-diameter fibers. Based on these findings, a diagnosis of bulbospinal muscular atrophy (BSMA) was made. In recent years, there have been some case reports of BSMA with sensory disturbances, or merely with subclinical manifestations of a sensory disturbance. This case is included in the same category as those reports, but it is interesting to note that the sensory disturbance in the lower extremities occurred as the chief complaint of the disease.

The whole body including extended processes of Ito's fat-storing cells was observed by scanning electron microscopy in rat liver injured with lithocholic acid (LCA). Necrotic foci developed in the midlobular zone 48 h after LCA administration. Demonstration of Ito cell bodies around the foci was probably facilitated by easy detachment of hepatocytes from Ito cells. The body and the processes were located mainly between the sinusoidal endothelium and hepatocytes; sometimes they were between hepatocytes. Ito cells often were proximate to collagen fiber bundles and sometimes were attached to them. The cell body was flatly round or elliptic, 7 to 12 micron in diameter. Its surface was finely undulated with microvillous projections about 0.1 micron in length. Branching patterns of the processes resembled a fern-leaf mantling the sinusoidal endothelium. The trunks of the processes were about 2 micron in diameter and 20-30 micron in length. These processes tapered, branching into thinner processes, with the most peripheral being 0.1 micron in diameter. Ito cells and their branching processes likely strengthen sinusoidal walls and control blood flow in the sinusoids.