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Biomedical subjects

T Okuno

Publications and source records attributed to T Okuno.

At least 325 records · Page 18Linked to original sources

Chronic encapsulated intracerebral hematoma during infancy: case report.

Chronic encapsulated intracerebral hematoma is a rare condition. Only four cases have been reported. The cause of this condition is unclear. A case of chronic encapsulated intracerebral hematoma in an 1-year-old infant is reported, and the characteristic findings and their causes are discussed with a literature survey.

Cerebral Hemorrhage↗

Relationship of Mallory bodies to intermediate filaments in hepatocytes. A scanning electron microscopy study.

Livers from 12 mice fed griseofulvin for 4 to 6 months were perfused in situ with a detergent solution to extract lipid membranes leaving the cytoskeleton intact. Seven control mice were similarly studied. After 30 to 120 minutes perfusion, liver samples were examined by scanning electron microscopy and transmission electron microscopy. By light microscopy, Mallory bodies (MBs) were observed in pericentral hepatocytes. These were confirmed by transmission electron microscopy. Intermediate filaments (IFs) were observed in close apposition to MBs. Numerous IFs were seen throughout the cytoplasm. The 3-dimensional organization of the cytoskeleton and MBs were clearly visualized by scanning electron microscopy. The IFs were disorganized in the hepatocytes and formed small MBs in griseofulvin-treated mice. In the case of hepatocytes containing large MBs, there was an apparent decrease in the concentration of IFs. Transition forms of dense networks of IFs between the normal cytoskeleton and the MBs were noted in the cytoplasm between small MBs and the nucleus and also at the cell border. The IFs connected to the nucleus and invaded the MBs. The MBs appeared to form as a result of condensation or collapse of the IFs.

Animals↗

[A radiological study of the hip in cerebral palsy in relation to pathogenesis of dislocations].

In recent years it has been reported that dislocation of the hip in cerebral palsy (CP) occurs most frequently in the non-ambulatory patient. This study compares the radiographic anatomy of the hip in CP with normal values and suggests the cause of dislocation. The cases of CP were divided into three groups according to ambulation and dislocation: group 1 consisted of 111 hips in a total of 64 ambulatory children, group 2, 116 hips in 72 non-ambulatory children, and group 3, 37 hips including 13 dislocated hips and 24 subluxated hips in 32 children. Of these 37 hips, patients with a dislocated hip and 3 subluxated hips were ambulatory but the beginning of their independent walking was as late as 5 years of age or even later. The following results were obtained. Femoral antetorsion was markedly increased in CP, and the difference was statistically very significant for all groups 1, 2 and 3 (p less than 0.001, and p less than 0.01 between groups 1 and 2). In CP groups there was no regression with age. Significant increases in femoral inclination were found in CP groups (p less than 0.001). There was, however, no significant differences among groups 1, 2 and 3, and so the degree to which these were the cause for dislocation was less than that of femoral antetorsion. Significant shortness of the femoral neck was noted between groups 1 and 3 (p less than 0.01), with significant regression with age in all CP groups. The mean value of the acetabular index in group 3 was 34.5 +/- 5.9, which was significantly higher than in group 1, and group 2 (p less than 0.001). In groups 2 and 3 there was no regression with age. Thus dislocation and subluxation of the hip in CP can be caused by the increase of antetorsion of the femur and acetabular dysplasia and depend on the ability of walking.

Acetabulum↗

Permeability of the round window membrane.

Cefmetazole sodium, a cephamycin antibiotic, was shown to pass through the round window membrane into the inner ear of the guinea pig. The concentration of the drug in the inner ear fluid indicated that a larger amount of the drug reached the inner ear through the round window membrane than when administered intraperitoneally.

Animals↗

A light and electron microscopic immunohistochemical study of vasoactive intestinal polypeptide- and substance P-containing nerve fibers along the cerebral blood vessels: comparison with aminergic and cholinergic nerve fibers.

Vasoactive intestinal polypeptide (VIP)- and substance P-containing nerve fibers were observed in the cerebral blood vessels using an immunohistochemical technique. VIP-containing nerve fibers distributed in a spiral pattern, similar to that of muscle cells. Under electron microscopic observation, VIP-immunoreactive terminals lay close to a muscle cell in the inner layer of the adventitia. In contrast, substance P-containing nerve fibers showed a meshwork pattern in the outer layer of the adventitia. Using both acetylcholinesterase (AChE) staining and VIP immunohistochemistry, AChE-positive and VIP-immunoreactive nerve fibers revealed almost the same distribution in the same specimen. The present data suggest that VIP-containing nerve fibers may play a role in the smooth muscle control of the blood vessels, whereas substance P-containing nerve fibers may not take part in muscle control.

Animals↗

Pathology of acute hepatitis A in humans. Comparison with acute hepatitis B.

Little is known about the pathologic characteristics of viral hepatitis A in humans. The authors compared the histologic features in liver biopsy specimens taken within 30 days of the onset of illness from 15 patients with hepatitis A and 14 patients with acute hepatitis B. In both hepatitis A and B, liver cell damage and necrosis were diffusely located, with accentuation in the centrilobular and midzonal areas in which ballooning degeneration and variation in cytoplasmic staining quality were observed frequently. One case of epidemic hepatitis A showed prominent periportal liver cell necrosis with inconspicuous centrilobular liver cell alterations. Kupffer cell mobilization was mild in hepatitis A, but more striking in hepatitis B. The portal inflammation was more pronounced and rich in plasma cells in hepatitis A than in hepatitis B. In summary, there were no major differences in the pathologic features of acute hepatitis A and B as sampled within 30 days of the onset of illness.

Acute Disease↗

Systemic rhabdomyosarcoma with diffuse bone marrow involvement. Case report of an unusual presentation.

Rhabdomyosarcoma presenting as a systemic disease is rare. This report concerns a 12-year-old girl who came to medical attention for what was thought to be a hematologic malignancy. Diffuse lytic bone lesions and large primitive cells in the bone marrow exhibiting erythrophagocytosis supported this diagnosis. During the course of the disease, a soft tissue mass in the region of the left ankle was removed and was a typical alveolar rhabdomyosarcoma. Retrospective review of the marrow, including electron microscopy, demonstrated that the primitive marrow cells were probably rhabdomyoblasts as well. The clinical course was a rapid downhill one in which lytic bone lesions and hypercalcemia were prominent. Although rhabdomyosarcoma eventually may disseminate, initial widespread disease without a clinically apparent primary can be a diagnostic dilemma. This clinical presentation, in combination with the recognized aggressiveness of the alveolar histologic subtype, identifies a rare subgroup of patients with rapidly fatal disease.

Ankle↗

[Feulgen-DNA cytofluorometry of the liver cell carcinomas].

Twenty-four autopsy cases of liver cell carcinomas were investigated by Feulgen-DNA cytofluorometry (NIKON SPM-RF 1-D) on paraffin-embedded tissue materials. The methods employed for tissue preparation and cytofluorometry were previously reported by us. The ploidy pattern based on cytofluorometry of the liver cell carcinomas exhibited wide DNA content distributions, in which many S phase cells having intermediate DNA content values ranging from diploid level to various, higher ploidy levels were included. From the comparative studies on both the histopathological findings and the ploidy pattern of the liver cell carcinomas, it was indicated that the peak value of the DNA content distribution was shifted from the diploid to the tetraploid level with the increasing appearance of the polyploid cells, and also that the degree of polyploidization appeared to correspond to the extent of the histological malignancy.

Adult↗

[Peptidergic innervation of the cerebral blood vessels--an immunohistochemical study].

By an immunohistochemical technique, vasoactive polypeptide (VIP)-and substance P-containing nerve fibers are observed in the cerebral blood vessels. VIP-containing nerve fibers distribute in a spiral pattern, similar to the muscle cell distribution pattern. Under an electron microscopic observation, VIP-immunoreactive terminals lie just near to a muscle cell in the inner layer of the adventitia. In contrast, substance P-containing nerve fibers show a meshwork pattern in the outer layer of the adventitia. In combination of acetylcholinesterase (AChE) staining and VIP immunohistochemistry, AChE-positive and VIP-immunoreactive nerve fibers reveal almost same distribution in the same specimen. The present data suggest that VIP-containing nerve fibers may play a role of smooth muscle control of the blood vessels, while substance P-containing nerve fibers may not take part in muscle control.

Animals↗