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Biomedical subjects

K Kajikawa

Publications and source records attributed to K Kajikawa.

At least 19 recordsLinked to original sources
PubMed1991

Expression of epidermal growth factor in human tissues. Immunohistochemical and biochemical analysis.

The expression of epidermal growth factor (EGF) was examined on various human tissues by radioimmunoassay, immunohistochemistry and Northern blot analysis. Immunoreactive EGF was found in most of the human tissues by radioimmunoassay at various levels. Large quantities of EGF were detected in the kidney and thyroid gland. Immunohistochemically, EGF immunoreactivity was detected mainly in the epithelial cells of the lung, stomach, duodenum, pancreas, kidney, pituitary gland, thyroid gland, mammary gland, ovary, uterus and placenta. Weakly EGF-positive cells were also found in the adrenal gland. The results of EGF-immunostaining were not always consistent with the data from radioimmunoassay. We consider that the amount of EGF measured by radioimmunoassay reflects the density of EGF-positive cells in the tissues and the concentration of EGF in individual EGF-positive cells. Furthermore, EGF mRNA was expressed in the salivary gland, thyroid gland, mammary gland and kidney. It is thus evident that EGF is produced by a variety of human tissues. The kidney expressed exceptionally high levels of EGF mRNA which was about one-tenth of the expression in mouse submandibular gland, suggesting that most of EGF in the urine is produced and secreted by the epithelial cells of renal tubules.

Epidermal Growth Factor↗
PubMed1990

New pyrrolobenzodiazepine antibiotics, RK-1441A and B. II. Isolation and structure.

Antibacteriophage antibiotics, RK-1441A and B, related to neothramycin were isolated from the culture broth of Streptomyces sp. and their structures were deduced from spectroscopic analyses. The structure of RK-1441A was 8,11-dihydroxy-3,7-dimethoxy-5-oxo-1H-pyrrolo[2,1-c:1,4]benzodiazepine. RK-1441B is a tautomeric mixture at C-3 of the structure, 3,8,11-trihydroxy-7-methoxy-5-oxo-1H-pyrrolo[2,1-c:1,4]benzodiazepine.

Anti-Bacterial Agents↗
PubMed1990

New pyrrolobenzodiazepine antibiotics, RK-1441A and B. I. Biological properties.

Streptomyces griseus and bacteriophage B were used for an assay system detecting anti-bacteriophage antibiotics. Streptomyces sp. RK-1441 was found to produce antibacteriophage antibiotics, RK-1441A and B, which are pyrrolo[1,4]benzodiazepine group antibiotics related to neothramycin. Both RK-1441A and B had antibacteriophage activity. The former showed antimicrobial activity on a hypersensitive strain of E. coli for antitumor antibiotics, but the later did not show the activity. Restriction enzyme assay suggested that RK-1441A formed adducts with guanine residues in DNA strands. RK-1441B was not active in vitro, but it might be converted to the active form in host organisms.

Anti-Bacterial Agents↗
PubMed1989

[Clinical evaluation of synthetic hydroxyapatite implants for human periodontal osseous defects. 6 cases studied more than 3 years after the surgery].

We applied of granular hydroxyapatite HAP to periodontal bone defects, for the purpose of restoring the periodontal tissue destroyed by periodontal disease, the subjects were 6 patients (6 regions) with chronic marginal periodontitis who had passed more than 3 years since HAP implantation. After routine periodontal initial treatment, a flap operation was performed, and granular HAP, or a combination of granular and block-like HAP, was implanted into the periodontal bone defect. Clinical parameters were probing depth, clinical attachment level, clinical gingival margin, residual HAP volume and X-ray before operation, at 3, 6, 12 months, and 2, 3, and 4, 6 years after the operation. The results revealed that all measured values showed good results for both granular HAP and the combination of granular and block-like HAP after implantation, and that all cases showed stable results from 12 months on. No remarkable difference was noted between the implanted regions.

Bone Resorption↗
PubMed1984

The fine structure of psammoma bodies in meningocytic whorls.

Psammoma bodies within meningocytic whorls in five cases of meningioma were examined by electron microscopy. The cells comprising the meningocytic whorls showed the conventional ultrastructural features of meningothelial cells with interdigitations and interconnections by means of junctional complexes. In some whorls, collagen fibers, elastic fibers, microfibrils, as well as finely reticulated material were observed. Calcified foci of various sizes were seen within many of these whorls. Extracellular matrix vesicles, with or without hydroxyapatite crystals, were occasionally noted at the periphery of extracellular psammoma bodies in the whorl. Furthermore, many small aggregates of crystals were present adjacent and parallel to the collagen and elastic fibers in the meningocytic whorls. Substantial amounts of collagen fibers were also observed within the large psammoma bodies. These findings suggest that the matrix vesicles, presumably produced by the meningothelial cell, may serve as the initial nidi of calcification of psammoma bodies as originally suggested by Lipper et al. Collagen fibers as well as elastic fibers in the whorls may also play an important role in orienting apatite crystal deposition during the growth of extracellular psammoma bodies and serve as early sites of calcification.

Adult↗
PubMed1984

Secretory granules in benign and malignant glucagonomas of the pancreas.

Two cases of glucagonoma, one benign and the other malignant, was presented. Benign glucagonoma in a 29-year-old man with multiple endocrine neoplasia type 1 was composed largely of tumor cells with secretory granules ranging from 139 to 417 nm in diameter identical to A cell granules. There were a few tumor cells which contained no A cell granules but smaller granules of approximately 166 nm diameter similar to those of pancreatic polypeptide containing cells. Radioimmunoassay of the tumor extract showed 319 micrograms/g wet weight of glucagon and 0.72 microgram/g wet weight of pancreatic polypeptide. Malignant glucagonoma in a 34-year-old man was a massive tumor of 7 X 6 X 5 cm replacing the tail and body of the pancreas with multiple metastases. The tumor contained 0.2 microgram/g wet weight of glucagon and 0.065 microgram/g wet weight of vasoactive intestinal peptide. The electron microscopic examination revealed that the tumor cells had variable numbers of atypical secretory granules measuring 110 to 200 nm in diameter different from A cell granules. An analysis of plasma glucagon by the gel filtration technique showed the heterogeneity of glucagon molecules indicating the presence of large glucagon. Atypical secretory granules in malignant glucagonoma were considered to represent immature granules containing the precursor or intermediate of glucagon.

Adenoma, Islet Cell↗
PubMed1984

Mucoepidermoid carcinoma of the liver.

An autopsy case of mucoepidermoid carcinoma of the liver associated with congenital cysts in a 78-year-old man was reported. The liver weighed 1,900 g, and there was a massive tumor of 11 X 10 X 6.5 cm in the left lobe with multiple sero-mucinous cysts. Histologically, the tumor cells consisted of four types of cells: mucus-secreting cells, squamous cells, intermediate cells, and oxyphilic cells. The variety of tumor cells quite resembled that of mucoepidermoid carcinoma of the salivary gland. The sero-mucinous cysts were lined with a single layer of cuboidal or columnar cells and were not communicated with the biliary ducts. Part of the cysts with benign lining cells was in continuity with tumor cells of the intermediate type. Discussion was made on the histogenesis of hepatic mucoepidermoid carcinoma in particular emphasis on the association of the congenital cysts.

Aged↗
PubMed1984

Central pontine myelinolysis with extrapontine lesions.

An autopsy case of central pontine myelinolysis (CPM) was reported. The patient, a 48-year-old man, with a long history of alcoholic intake appeared in a hospital with the diagnosis of alcoholic hepatitis and the neurologic symptoms of delirium tremens. During the hospital course he fell into "locked in" with concomitant development of marked hyponatremia (92 mEq/1). An autopsy revealed typical CPM and the extra-pontine myelinolytic lesions distributed symmetrically in the thalami, subthalamic nuclei, and lateral geniculate bodies. Spongiosis was also found in the deep layer of the cerebral cortex and in the putamen. It was suggested that CPM occur in close association with marked hyponatremia and the extrapontine involvement be likely to manifest in the deep layer of the cerebral cortex, putamen, thalamus, and lateral geniculate body, where the myelin cylinders form an interlacing network embedding large neurons and oligodendrocytes.

Alcoholism↗
PubMed1984

Repair of the mouse synovial membrane after chemical synovectomy with osmium tetroxide.

Repair of the synovium of the mouse knee joint following intra-articular injection with osmium tetroxide has been studied by light and electron microscopy. Within a first few days after osmium tetroxide injection complete necrosis of the synovial intima and inflammatory response in the subintimal connective tissue occurred. The resurfacing of the denuded synovium was performed by proliferation of immature synovioblasts which appeared to be derived from mesenchymal cells in the transition zone. The synovial intima completely restored the original structure, while repair of the subintimal tissue was accomplished by a scarring.

Animals↗
PubMed1983

Diagnostic aspect of spindle-cell sarcomas by electron microscopy.

Spindle-cell sarcomas in the somatic soft tissue and soft parts, including fibrosarcoma, leiomyosarcoma, malignant fibrous histiocytoma (MFH), and malignant schwannoma were examined by electron microscopy in order to delineate the most reliable cellular features for their diagnosis. Fibrosarcoma consisted largely of fibroblastic cells and leiomyosarcoma cells were packed in forming small cell groups with constant junctional complexes of nexus and zonula adherens types. MFH showed variable cellular features containing the cells with myofibroblastic and histiocytic differentiation. Malignant schwannoma was characterized by tumor cells having slender cytoplasmic processes with overlapping or interdigitation and thick basement membrane. These ultrastructural features were contributory to the differential diagnosis of the sarcomas examined.

Adult↗
PubMed1983

An ultrastructural study on periductal elastosis in human breast tumors.

An ultrastructural study on elastosis of human breast tumors was made with special attention to the periductal elastosis and the cell responsible for elastic fiber formation. The elastosis was found prominently in scirrhous type of duct carcinoma. In the area of mild periductal elastosis, the elastic fibers with many microfibrils and a tiny central elastin were seen around the periductal fibroblasts which were characterized by attenuated cytoplasms with aggregates of microfilaments and slightly developed rough endoplasmic reticulum. With the thickening of the periductal wall, such an area was replaced by abundant mature elastic fibers with peripheral microfibrils and a few intervening ordinary fibroblasts. Therefore, it was suggested that the periductal fibroblasts which transformed into ordinary fibroblasts during the development of elastosis were primarily concerned with the elastic fiber formation. In the interlobular tissue in which both fibroblasts and myofibroblasts were present, the elastic fibers were larger than those of the periductal area and had less microfibrils in their periphery. The relationship between microfibrils and elastin during the early elastosis, maturation process of the elastic fibers, and cell modulation of the fibroblasts in the breast elastosis were discussed.

Adenofibroma↗
PubMed1983

An autopsy case of rheumatoid arthritis with an involvement of the cardiac conduction system.

A case of rheumatoid arthritis with an involvement of the cardiac conduction system was described. The patient was a 65-year-old man who had a 15-year history of classical rheumatoid arthritis combined with an advanced atrioventricular (AV) block resulting in Adams-Stokes seizure. Prior to the occurrence of the AV block, a complete right bundle branch block with a left axis deviation and a first-degree AV block were found on an electrocardiogram (ECG). The histological examination of the conduction system according to the serial sectioning method disclosed that the branching portion of the His bundle and anterior fascicle of the left bundle branch were replaced by the scarring tissue and that the penetrating portion of the His bundle, the AV node and the right bundle branch had rheumatoid granulomatous lesions. The extent and localization of the lesions in the conduction system were well correlated with the findings on the ECG.

Adams-Stokes Syndrome↗