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Biomedical subjects

K Fukazawa

Publications and source records attributed to K Fukazawa.

At least 55 records · Page 3Linked to original sources
PubMed1992

The immunohistochemical localization of new membrane-associated placental tissue proteins (MP2 A, B, C, D, and E) in human and cynomolgus monkey placentae.

New membrane-associated placental tissue proteins (MP2 A, B, C, D, and E) were investigated by avidin-biotin immunoperoxidase technique in the human and cynomolgus monkey placentae, decidua and umbilical cords. In human early placentae, MP2 A, B, C, and E were localized mainly in the membrane of villous syncytiotrophoblasts and cytotrophoblasts. Histiocytes in the villous stroma were positive for MP2 A, B, D, and E. In human term placentae, obvious positive staining for MP2 A, B, C, and E was observed in the membrane of villous syncytiotrophoblasts, in the amniotic epithelium, and in the umbilical cord sheath. Histiocytes in the villous stroma were positive for MP2 A, B, C, E, and especially for MP2 D. Importantly, MP2 A, C, and E were positive in polymorphonuclear neutrophils, since most of these common antigens are also carcinoma-associated, suggesting clinical usage of MP2 proteins as a new tumor marker. In the cynomolgus monkey placentae, similar immuno-staining results were obtained. The monkey can thus serve as a experimental model for the investigation of the placental proteins.

Amnion↗
PubMed1992

Cytoskeletal architecture of the matrix cell and neuroblast in the neural tube of the chick embryo.

Cytoskeletal architecture of the matrix cell and neuroblast in the wall of midbrain of 4-6 day-old chick embryos was examined by electron microscopy and immunohistochemistry. The matrix cell, the undifferentiated stem cell later producing neurons and glial cells in the central nervous system, is characterized ultrastructurally by abundant free ribosomes and a poorly developed cytomembrane system. A few microtubules running in random directions are observed in the matrix cell body. In the cell processes, microtubules are oriented longitudinally, and linked with each other by cross-bridges, presumably composed of microtubule-associated proteins (MAPs). The cell processes contain abundant cytoplasmic filaments including a large amount of actin filaments which adhere to the plasma membrane of junctional complexes located immediately below the inner surface of the neural tube. In the neuroblast which has been differentiated from the matrix cell, the cytomembranous organelles, especially rough endoplasmic reticulum are markedly better developed than in the matrix cell; microtubules are more numerous in the cell body. The cell process contains many microtubules with cross-bridges and a few intermediate filaments, which are relatively characteristic of the cytoskeleton of the neuroblast. Phalloidin-staining and immunohistochemistry showed that the neuroblast was richer in F-actin, beta-tubulin, MAP1, MAP2, tau, calspectin, and synapsin I than the matrix cell. As the matrix cell differentiates into the neuroblast, both the cytoskeletal and cytomembranous systems proved to develop features, characteristic of a neuron.

Animals↗
PubMed1991

Endocytotic activity of the free floating cells and epithelial cells in the endolymphatic sac: an electron microscopic study.

The fine structure and its functional properties of both free floating cells and epithelial cells in the endolymphatic sac after injections of India ink particles or polystyrene latex beads, 0.24 micron in diameter, into the endolymphatic space, were studied using light and electron microscopy. Twenty-four to 48 hours after injections, these foreign materials had accumulated in the lumen of the endolymphatic sac and a large number of them were ingested into free floating cells, most of which appear to be macrophages. Granular leucocytes taking up the foreign materials into the cytoplasm were also recognized in the sac lumen. A few of these leucocytes passed through the epithelium and migrated to the subepithelial connective tissue, while the others were degenerated and phagocytosed by the free floating cells in the lumen of the sac. In addition to the free floating cells, ink particles, latex beads, and degenerated leucocytes were endocytosed into some of the epithelial cells. As we reported previously, the epithelial cells were clearly classified into two types; type-1 epithelial cells (cytoorganelle-rich cells) and type-2 epithelial cells (filament-rich cells). The foreign materials and degenerated cells were taken up mainly into the type-1 epithelial cells, while the type-2 epithelial cells did not show so marked endocytotic activity in comparison with the type-1 epithelial cells. Thus, it becomes clear that the endolymphatic sac plays an important role in the endocytotic activity for foreign materials and waste products, and both the free floating cells and the type-1 epithelial cells of the sac have strong endocytotic activity.

Animals↗
PubMed1991

Cellular localization of rat Isk protein in the stria vascularis by immunohistochemical observation.

A novel rat membrane protein, termed Isk protein, that exhibits a voltage-dependent potassium channel activity was first reported through molecular cloning combined with an electrophysiological assay (Takumi et al., 1988). In the present study, we made an attempt to identify the cellular localization of the rat Isk protein in the stria vascularis using two types of antibodies that specifically react with the distinct parts of the rat Isk protein. Immunohistochemical analysis showed that the rat Isk protein was present only on the endolymphatic surface of the marginal cell. The possibility that the Isk protein is involved in potassium permeation in the luminal membrane of the marginal cell will be also discussed.

Amino Acid Sequence↗
PubMed1991

Vascular permeability of the stria vascularis in experimental endolymphatic hydrops.

Vascular permeability of the stria vascularis was morphologically examined in hydrops animals, using the tracer method of horseradish peroxidase (HRP). The reaction product of HRP was observed in the capillary of the stria vascularis, not outside of it. The finding suggests that the vascular permeability of the stria vascularis is unchanged in Kimura's hydrops model.

Animals↗
PubMed1991

Transport of HRP through Reissner's membrane in experimental endolymphatic hydrops.

Unilateral endolymphatic hydrops was produced in guinea pigs by cauterization of the endolymphatic sac. Measurements of compound action potential (CAP), cochlear microphonics (CM) and negative summating potential (-SP) confirmed endolymphatic hydrops three months after surgery. In both control and hydropic ears, reaction product of HRP was observed only on the perilymphatic surface of the epithelial cells of Reissner's membrane after 10 min perfusion, while it was observed on both the endolymphatic and perilymphatic surfaces after 30 min perfusion. Epithelial tight junctions were not stained and labelled pinocytotic vesicles were observed in the epithelial cells. These findings suggest that the transport of HRP through Reissner's membrane is unchanged in endolymphatic hydrops and that the epithelial junctions are tight regardless of the distension of Reissner's membrane.

Animals↗
PubMed1990

A novel Bacillus subtilis gene involved in negative control of sporulation and degradative-enzyme production.

We have cloned a 2.5-kilobase fragment of the Bacillus subtilis genomic DNA which caused the reduction of extracellular and cell-associated protease levels when present in high copy number. This fragment, in multicopy, was also responsible for reduced levels of alpha-amylase, levansucrase, alkaline phosphatase, and sporulation inhibition. The gene relevant to this pleiotropic phenotype is referred to as pai. By DNA sequencing, two open reading frames--ORF1 and ORF2, encoding polypeptides of 172 and 207 amino acid residues, respectively--were found. These open reading frames seemed to form an operon. Deletion analysis revealed that an entire region for ORF1 and ORF2 was necessary for the pai phenotype. In addition, it was observed that the presence of the pai gene, in multicopy, caused overproduction of two proteins (molecular masses, 21 and 24 kilodaltons [kDa]). Analyses of the N-terminal amino acid sequences of these two proteins suggested that they were products of ORF1 and ORF2. Disruption of the pai gene at ORF1 in the genomic DNA resulted in the release of repression on protease synthesis and sporulation in glucose-enriched (2%) medium. The mutant carrying insertional disruption at ORF2 could not be constructed, suggesting that the ORF2 product, the 24-kDa protein, is essential for growth. The 21-kDa protein contains a helix-turn-helix domain observed in other DNA-binding proteins. Chromosomal mapping of pai indicated that this gene is located close to thr-5. These results suggest that the pai gene is a novel transcriptional-regulation gene involved in glucose repression.

Alkaline Phosphatase↗
PubMed1990

[Diagnosis: tumor marker].

We have reviewed the clinical usefulness of tumor markers in gynecologic malignancy. In cervical squamous cell carcinoma. SCC and CEA showed increase in frequency of elevated cases according to the clinical stages (FIGO), and the frequency was significantly higher in recurrent cases than in patients with no evidence of disease. In endometrial carcinoma, presently, no specific tumor marker has been found. The diagnostic efficiency of CA 125, CA 19-9 and TPA were 25.2, 23.8 and 32.6, respectively. Further investigation must be necessary to establish markers sensitive enough. In primary ovarian malignancy, combination assay might be much more useful than single assay. The most effective combinations were TPA/CA 125/Ferritin in serous cystadenocarcinoma, and CEA/CA 19-9/TPA in mucinous cystadenocarcinoma. In the monitoring of the disease, it seems to be essential to select suitable combination of markers in each case. In addition, recently, multivariate analysis systems, such as CAMPAS (computer-aided multivariate and pattern analysis system), have become available.

Biomarkers, Tumor↗
PubMed1989

[Clinical results of endourologic technique for upper urinary calculi].

Between May, 1985 and September, 1987, percutaneous nephrolithotripsy (PNL) and transurethral ureterolithotripsy (TUL) have been performed at our hospital and five affiliated hospitals. We report on the therapeutic results of 216 cases treated during this period. PNL and TUL were performed 168 times on 120 patients (119 males and 41 females) and 57 times on 56 patients (35 males and 21 females), respectively. Rate of success with PNL was 80.7% (103/130) for renal calculus, 85.7% (18/21) for upper ureteral calculus, and 47.1% (8/17) for middle-lower ureteral calculus. Rate of success with TUL was 57.9% (33/57). Of these, cases of ureteral lower edge calculus showed the lowest rate of success, being 33.3% (2/6). Complications of the cases undergoing PNL and TUL were: ureteral damage in 13; hemorrhage in 6; renal pelvic damage in 4; ureteral lower edge stenosis in 3; pyrexia in 3; cardiac insufficiency in 2 and retention of perfusate in posterior peritoneal cavity, pneumonia and renal insufficiency in 1 case each.

Adolescent↗
PubMed1989

[Congenital stomatocytosis associated with aplastic anemia].

A seven year-old boy with hereditary stomatocytosis complicated with aplastic anemia was reported. He was admitted to our hospital because of pale and general fatigue. On physical examination, he had severe anemia, petechiae, but no hepatosplenomegaly. Peripheral blood cell count revealed pancytopenia; RBC 103 X 10(4)/microliters, Hb 3.5 g/dl, Ret 21%, WBC 1,200/microliters, Pl 1.3 X 10(4)/microliters, and bone marrow revealed markedly hypocellular marrow. Red cell morphology demonstrated stomatocytosis. Red cell life span (51Cr T1/2) was 12 days, Coombs' test and Ham's test were negative. Indirect bilirubin was 1.1 mg/dl and marked decrease of haptoglobin was found. Family studies showed that his father and sister had stomatocytosis on peripheral blood examination, but no anemia. The patient had severe anemia because of complicated aplastic anemia. Congenital stomatocytosis with aplastic anemia is extremely rare. The authors are interested in a possible relationship between hereditary stomatocytosis and aplastic anemia although the precise mechanism remains to be elucidated.

Anemia, Aplastic↗
PubMed1987

[Clinical evaluation of cisplatin in children with malignant solid tumors. Pediatric Cisplatin Study Group].

A cooperative multicenter clinical study on cisplatin in children with malignant solid tumors was conducted in seventeen institutions. Of 63 children entered into the study, 18 patients were treated with cisplatin alone, 33 with a VCAP regimen (VCR, CPA, ADM and CDDP) and 12 with other combination regimens. The numbers of evaluable patients were 14, 27 and 7, respectively. Response rates for neuroblastoma were 37.5% (3/8) with cisplatin alone and 79.2% (19/24) for the VCAP regimen. Major adverse effects were gastrointestinal symptoms, bone marrow suppression and renal impairment. Hearing difficulty, electrolyte imbalance and transient elevation of transaminase were also observed. However, these adverse effects were within a tolerable range of severity. The results of this study demonstrate that cisplatin is a useful drug in the treatment of neuroblastoma.

Adrenal Gland Neoplasms↗