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Biomedical subjects

I Okayasu

Publications and source records attributed to I Okayasu.

At least 145 records · Page 8Linked to original sources
PubMed1986

Chronic manganese poisoning: a neuropathological study with determination of manganese distribution in the brain.

An autopsy case of a 52-year-old man suffering from chronic manganese poisoning (CMP) is reported with determination of the manganese distribution in the brain. The patient had been working in a manganese ore crushing plant since 1965. In 1967 he began to complain of difficulties in walking and diminished libido. Later, he developed various neuropsychiatric symptoms including euphoria, emotional incontinence, masked face, monotonous speech, "cock-walk", increased muscle tone, weakness of upper and lower extremities, tremor of the eye lids, and exaggeration of knee jerks. The major neuropathological change was degeneration of the basal ganglia, in which the pallidum was severely affected. The pallidum disclosed a loss and degeneration of nerve cells, which was especially marked in the medial segment, a prominent decrease of myelinated fibers, and moderate astrocytic proliferation. The substantia nigra was intact. Distribution of manganese in the brain of the present case of CMP was determined using flameless atomic absorption spectrometry and compared with control cases and also a case of Parkinson's disease (PD). There was no significant difference between the control cases and the case of PD in average concentration of manganese and its distribution in the brain. The present case of CMP showed no elevation in average concentration of manganese in the brain. However, there were some changes in its distribution. Thus, the continuance of neurological disorders in CMP is not linked to an elevated manganese concentration itself in the brain. CMP appears to be different from PD in neuropathology and manganese behavior in brain.

Aged↗
PubMed1986

The differences of susceptibility of the target thyroid gland to autoimmune thyroiditis and of antigenicity of thyroid gland for induction of experimental autoimmune thyroiditis.

By using a recently developed method for producing thyroiditis in mice consisting of implantation of a fresh thyroid gland into the peritoneal cavity or under the capsule of the kidney with subsequent injection of lipopolysaccharide, differences were shown in susceptibility of the target thyroid gland to autoimmune destruction and in antigenicity of the thyroid gland for induction of experimental autoimmune thyroiditis. Using recombinant congenic mice, the H-2 haplotypes of the target thyroid gland were found to be as important as those of the immune system in development of autoimmune thyroiditis. On the other hand, the H-2 haplotypes of the thyroid gland are unimportant for induction of autoimmune thyroiditis.

Animals↗
PubMed1986

Hepatocellular carcinoma presenting extrahepatic obstructive jaundice due to bile duct invasion--clinicopathological study of two cases.

Two rare cases of autopsy and surgery presenting extrahepatic biliary obstruction due to intrabile-duct growth of hepatocellular carcinoma were reported. Clinically obstructive jaundice was predominant in comparison with the other symptoms in both cases. In one autopsy case, hepatocellular carcinoma developed in the right lobe of the cirrhotic liver (posthepatitic). It involved the secondary branch of the right hepatic duct and grew into the common hepatic duct. In the other case of surgical operation, hepatocellular carcinoma, which developed in the posterior portion of the right lobe of the cirrhotic liver (posthepatitic), destroyed the posterior wall of the bifurcation of the bilateral hepatic duct and obstructed the common hepatic duct due to the intraductal cancer growth. From the site of the bile duct invasion or permeation by the tumor, two cases were classified into the peripheral (the former case) and proximal (the latter case) types, respectively. Furthermore, as far as obstructive jaundice is clinically concerned, the possibility should be kept in mind that hepatocellular carcinoma may proliferate into the large bile ducts, apart from that of cholangiocarcinoma or cholelithiasis.

Autopsy↗
PubMed1985

Transfer of experimental autoimmune thyroiditis to normal syngeneic mice by injection of mouse thyroglobulin-sensitized T lymphocytes after activation with concanavalin A.

Induction of autoimmune thyroiditis in normal syngeneic CBA/J mice was achieved by injection of 72-hr concanavalin A (Con A)-induced lymphoblasts from donor mice which had been immunized with mouse thyroglobulin (MTg) emulsified with complete Freund's adjuvant (CFA). Injection of lymph node or spleen cells, or frequent injection of serum taken from mice with autoimmune thyroiditis failed to transfer appreciable thyroiditis to recipient mice. Selection by treatment of incubated cells with monoclonal antibody and complement revealed that effector cells in Con A-induced lymphoblast populations for the transfer of autoimmune thyroiditis were Thy-1.2+, Lyt-1.1+, and Lyt-2.1- lymphocytes. These results demonstrate that experimental autoimmune thyroiditis can be adoptively transferred into naive mice by activated Thy-1+, Lyt-2- lymphoblasts.

Animals↗
PubMed1984

Cancer in collagen disease. A statistical analysis by reviewing the Annual of Pathological Autopsy Cases (Nippon Boken Shuho) in Japan.

Cases of systemic lupus erythematosus, systemic sclerosis, periarteritis nodosa, and dermato- and polymyositis autopsied in Japan during a recent, 7-year period (1972-1978) were studied to assess the incidence of cancer as a complication. In comparison with the other three groups, cases of dermato- and polymyositis (DP) showed quite a high incidence of malignancy: 53 of 99 for males (53.5%) and 36 of 139 for females (25.9%). In patients older than 50 years of age cancer was recognized in the autopsies of 65.7% of males and 38.2% of females with DP. The stomach was both the primary site and had the highest incidence of cancers in DP (62.3% males, 27.8% females). It was concluded that DP has a strong association with the development of cancer, particularly gastric carcinoma, in Japan.

Adolescent↗
PubMed1984

A combination of necrosis of autologous thyroid gland and injection of lipopolysaccharide induces autoimmune thyroiditis.

Autoimmune thyroiditis was induced in CBA/J female mice by a newly developed method consisting of intraperitoneal implantation of one whole syngeneic thyroid gland with subsequent intravenous injection of lipopolysaccharide (LPS). The best timing for intravenous injection of LPS after intraperitoneal implantation of the thyroid tissue was 6 hr. Intraperitoneal injection of serum (but not spleen cells) taken from the mice which received implantation of one whole syngeneic thyroid gland alone, with simultaneous intravenous injection of LPS, induced autoimmune thyroiditis in the normal syngeneic mice. Furthermore, intraperitoneal injection of the medium in which one whole syngeneic thyroid gland was incubated at 37 degrees C for 10 hr, with simultaneous intravenous injection of LPS, also induced autoimmune thyroiditis in the normal syngeneic mice. Instead of intraperitoneal implantation of one whole syngeneic thyroid gland, implantation of either one lobe of autologous thyroid under the capsule of the kidney, with subsequent intravenous injection of LPS induced autoimmune thyroiditis in both intact and implanted thyroids. It is suggested that combined effects of leakage of tissue antigen originating from the necrotized tissue into the circulation and polyclonal activation by subsequent injection of LPS induced an autoimmune response.

Animals↗
PubMed1984

Histopathological and morphometrical study of the human epididymis and testis.

Histopathological and morphometrical observations of the epididymis and testis were performed on 159 autopsy cases and 3 surgical materials of orchiectomy. The serum values of testosterone, FSH, LH, and values of intratesticular testosterone were measured in a certain number of the cases. Concerning the epididymis, increasing arteriosclerotic change was observed in the older epididymis. A high incidence of hyalinization of small arteries and arterioles was found in the younger epididymis. Eosinophilic microbodies were seen in the epithelial nuclei of the ductus epididymidis with high incidence in the older age groups. They were thought to be a catabolic compound containing phospholipids and protein resulting from cell degeneration of the mucosal epithelium. The diameter of the ductus epididymidis decreased with age. Inflammatory changes and ensued periductal sclerosis were found in the efferent duct area with an extremely high incidence. Serum values of testosterone correlated with both the age and morphological scoring calculated on the basis of either clusters or individual Leydig cells. Furthermore, testicular volume was inversely correlated with age.

Adult↗
PubMed1983

The difference of susceptibility of target thyroid gland to autoimmune thyroiditis induced by a combination of implantation of thyroid gland and injection of lipopolysaccharide.

Autoimmune thyroiditis was induced in CBA/J mice by a newly developed method consisting of a combination of implantation of one whole syngeneic thyroid gland under the capsule of the kidney and subsequent injection of lipopolysaccharide (LPS) intravenously 6 hr after implantation. This procedure was repeated once, a week later. With this method the implanted thyroid gland, after becoming necrotic due to circulatory disturbance and regenerating, also developed definite thyroiditis, quite similar to that of the intact thyroid gland on Day 49. With respect to the H-2 haplotype of the mice, both intact and implanted thyroid glands of CBA/J (H-2k) and C3H/He (H-2k) mice showed severe thyroiditis, whereas those of BALB/c (H-2d) and C57BL/6 (H-2b) mice developed mild inflammation. With a combination of implantation of thyroid glands derived from parental good (CBA/J) or poor responder (BALB/c) mice and subsequent injection of LPS into (good X poor responder) (CBA/J X BALB/c)F1 hybrid mice, it was found that the genetic background of the target thyroid tissue itself has a strong influence on susceptibility.

Animals↗
PubMed1982

Experimental study on the drainage of so-called intravenous fat pigment from the liver. Long-term observation with histologic, enzyme-histochemical and electron microscopic analysis.

The drainage and decrease of so-called intravenous fat pigment (i.v. fat pigment), which was a lipoid-pigment complex and deposited in the reticuloendothelial system after repeated infusions of Intrafat (intravenous fat emulsion), was observed in the liver of the rabbit by histological, histochemical and electron microscopic methods. As a result, the i.v. fat pigment was mainly found in Kupffer cells immediately after the repeated injections of Intrafat. After then, depending on the period when no injection were given, it decreased gradually and disappeared finally from Kupffer cells. On the other hand, in the interstitium of Glisson's sheath, many phagocytes, extremely swollen and laden with i.v. fat pigment, appeared during the postinfusion period. Furthermore, these phagocytes laden with i.v. fat pigment were found in Glisson's sheath for a long period, although they showed a tendency of decrease. Histochemical and electron microscopic characteristics, quite similar to those of Kupffer cells, suggested that these phagocytes corresponded to the extremely swollen histiocytes or macrophages having some role in the drainage or the metabolism of the i.v. fat pigment.

Animals↗
PubMed1981

Argyrophil cells in adenomas of familial polyposis coli.

The presence of argyrophil cell was demonstrated in the adenomas of familial polyposis coli (FPC) with the Sevier-Munger method. Usually, argyrophil cells were distributed sparsely near the base of the crypts, rather close to the normal mucosa. But, adenomas with severe or moderate dysplasia did not contain argyrophil cells. The frequency of argyrophil cells in the adenoma was remarkably higher in the sigmoid than in the ascending colon. Because this phenomenon was found both in the non-adenomatous mucosal crypts of FPC and of normal control cases, it is conceivable that the appearance of the argyrophil cells in the adenomas of FPC is affected by the structural arrangement of the original non-tumorous mucosa, as a background. Furthermore, a tendency, that many argyrophil cells were located within the adenomas, was observed in one of the seven families examined. It showed that the argyrophil cell which is thought to be one of the elements constituting the adenoma might actively participate in the growth of the adenoma.

Adenoma↗