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Biomedical subjects

K Hanada

Publications and source records attributed to K Hanada.

At least 145 records · Page 8Linked to original sources
PubMed1998

Flagellate mushroom (Shiitake) dermatitis and photosensitivity.

Flagellate skin lesions occur in some patients after eating the mushroom Lentinus edodes, and they are called shiitake dermatitis in Japan. We describe a 44-year-old man with such skin lesions on his trunk after eating L. edodes, who developed as well photosensitive skin lesions on exposed areas. Skin phototesting with UVB did not show a decreased minimum erythema dose; UVA irradiation provoked an erythematous lesion with nonspecific histological changes. Analysis of the case histories of 94 Japanese patients with shiitake dermatitis revealed that 44 (47%) also developed dermatitis on the skin exposed to sunlight. UVA photodermatitis has not been emphasized in previous reports. The relationship to bleomycin flagellate dermatitis is discussed.

Adult↗
PubMed1998

Alterations in ultrastructural localization of growth-associated protein-43 (GAP-43) in periodontal Ruffini endings of rat molars during experimental tooth movement.

It is known that orthodontic forces induce discomfort and/or abnormal sensation after application of an orthodontic appliance in patients, suggesting the adaptation of periodontal neural elements to environmental changes. However, no morphological data have been provided. The present study investigated, by immunoelectron microscopy, the localization of growth-associated protein-43 (GAP-43) in periodontal Ruffini endings in rat molars during experimental tooth movement. In the untreated control group, immunoelectron microscopy demonstrated that GAP-43-like immunoreactivity in the Ruffini endings was confined to the Schwann sheaths around the axon terminals, and was in neither the cell bodies of terminal Schwann cells nor the axon terminals themselves. Immunoelectron microscopic observation revealed alterations in the localization of GAP-43-like immunoreactivity in the periodontal Ruffini endings during experimental tooth movement. After 1 day of treatment, the cell bodies of the terminal Schwann cells associated with Ruffini endings appeared to contain immunoreaction products for GAP-43, and retained GAP-43-like immunoreactivity during tooth movement. From 5 to 7 days, a major population of the axoplasm of the periodontal Ruffini endings, which was immunonegative in control, filled the GAP-43 immunoreactions, showing a tendency to decrease in number later, and disappeared completely at 14 days. These findings suggest that orthodontic forces easily induce the remodeling of the mechanoreceptive Ruffini endings as well as the active tissue remodeling in a close relationship. Since the ultrastructural localization of GAP-43-like immunoreactivity was drastically changed in the Ruffini endings during tooth movement, GAP-43 functions as one of the key molecules in the remodeling of mechanoreceptive Ruffini endings during tooth movement.

Acid Phosphatase↗
PubMed1998

Value of MR cholangiopancreatography in evaluating choledochal cysts.

OBJECTIVE: The aim of this retrospective study was to clarify whether MR cholangiopancreatography (MRCP) is a suitable replacement for ERCP in evaluation of the choledochal cyst. MATERIALS AND METHODS: Sixteen patients (six adult and 10 pediatric) with choledochal cysts underwent MRCP using a half-Fourier acquisition single-shot turbo spin-echo sequence. Extent of the cyst, defects within the biliary tree, and presence or absence of the anomalous junction of the pancreaticobiliary duct were evaluated. Findings were compared with those of ERCP. RESULTS: MRCP better defined the proximal biliary tree than did ERCP in two patients. Defects within the biliary tree were diagnosed correctly on MRCP in eight patients; however, two defects within the distal common bile duct were missed in pediatric patients. The presence of the anomalous junction of the pancreaticobiliary duct was revealed accurately by MRCP in all adult patients but was revealed accurately in only four of the 10 pediatric patients. CONCLUSION: MRCP appears to offer diagnostic information that is equivalent to that of ERCP for assessment of choledochal cysts in adults. In pediatric patients, MRCP should not replace ERCP; however, MRCP can play an important role as a noninvasive examination and should be considered a first-choice imaging technique for evaluation of choledochal cysts.

Adult↗
PubMed1998

The use of scanning laser ophthalmoscope microperimetry to detect visual impairment caused by macular photocoagulation.

BACKGROUND AND OBJECTIVE: To demonstrate the effectiveness of scanning laser ophthalmoscope (SLO) microperimetry in detecting retinal sensitivity and in describing areas of unstable fixation following photocoagulation therapy. PATIENTS AND METHODS: Two patients with iatrogenic vision loss resulting from photocoagulation therapy underwent a fundus examination, SLO microperimetry, and fluorescein angiography. One patient also underwent indocyanine green angiography. RESULTS: Two types of visual acuity decrease--sudden-onset and late-onset--were demonstrated following macular photocoagulation, the former resulting from incorrect identification of the fixation point, and the latter from enlarging photocoagulation scars placed in close proximity to the fovea. In one case, SLO microperimetry detected dense scotoma corresponding to the patient's symptoms and an unstable fixation point. In the other case, different retinal sensitivities were found in the photocoagulation scars. No differences were found with fluorescein angiography or indocyanine green angiography. CONCLUSION: SLO microperimetry might be effective for quantitative assessment of retinal sensitivity in photocoagulation scars and for detecting fixation points and determining their stability.

Diabetic Retinopathy↗
PubMed1997

Age-related decline in humoral immunity caused by the selective loss of TH cells and decline in cellular immunity caused by the impaired migration of inflammatory cells without a loss of TDTH cells in SAMP1 mice.

We investigated the cellular basis of the age-related decline in antibody (Ab) and delayed-type hypersensitivity (DTH) responses to sheep red blood cells (SRBC) in vivo in short-lived senescence-accelerated mouse (SAM) P1. In SAMP1 mice, age-related decreases in CD4+ T cells in the peripheral blood occurred earlier than in control mice and occurred in parallel with the age-related decline in Ab and DTH responses. In addition, the involution of the thymus was faster. The injection of thymic T cells from young mice before sensitization completely restored the Ab responses in aged SAMP1 mice. These data suggest that the age-related decline in Ab response is due to the age-related early loss of helper-T (TH) cells. On the other hand, the local transfer of spleen cells from sensitized aged donors into the footpads of naive syngeneic recipients evoked strong DTH responses, demonstrating the existence of DTH-mediating T (TDTH) cells in the spleens of aged SAMP1 mice. Moreover, the local injection of naive spleen cells from young donors, together with the antigen, into the footpads caused DTH responses in sensitized aged recipients. These findings indicate that TDTH cells were induced and were able to migrate and function as effector cells in aged mice. When naive spleen cells from aged donors were injected locally into the footpad, they restored the DTH response in aged mice, but this effect did not work if the cells were injected intravenously. This demonstrates that the inflammatory cells of the aged mice were able to work at the local site, but could not migrate there. The intravenous injection of naive spleen cells from young donors restored the DTH response in aged mice, suggesting that the endothelial cells of aged mice were not impaired and permitted the inflammatory cells to migrate into the extravascular tissues. Thus, although the age-related decline of the Ab and DTH responses occur in parallel, we found different effects of aging on TH and TDTH cells in SAMP1 mice. Furthermore, our data suggest that the reason for the low DTH response in aged SAMP1 mice is not the loss of TDTH cells, but rather the impaired migration of inflammatory cells into the local site.

Aging↗
PubMed1997

A mammalian homolog of the yeast LCB1 encodes a component of serine palmitoyltransferase, the enzyme catalyzing the first step in sphingolipid synthesis.

Serine palmitoyltransferase (SPT; EC 2.3.1.50) catalyzes the initial step dedicated to sphingolipid biosynthesis and is thought to be a key enzyme for regulating cellular sphingolipid content. For SPT activity, the yeast Saccharomyces cerevisiae requires two genes, LCB1 and LCB2. We isolated mammalian LCB1 cDNA homologs from mouse and Chinese hamster ovary (CHO) cells and an LCB2 cDNA homolog from CHO cells. The mammalian LCB1 proteins are predicted to have about 35% amino acid identity to the yeast Lcb1 protein, whereas the CHO LCB2 protein is predicted to have about 40% amino acid identity to the yeast Lcb2 protein. Northern blot analysis of mRNA isolated from various mouse tissues revealed that the tissue distribution of both LCB1 and LCB2 messengers followed a similar pattern. Transfection of an SPT-defective CHO mutant strain with a CHO LCB1-expressing plasmid restored both SPT activity and de novo sphingolipid synthesis to the wild type levels, whereas transfection of the mutant strain with a CHO LCB2-expressing plasmid did not exhibit any recovery effects, indicating that the SPT defect in the mutant cells is specifically complemented by the CHO LCB1 homolog. Furthermore, when the SPT-defective mutant cells were transfected with a plasmid encoding a His6-tagged CHO LCB1 protein, SPT activity bound to a Ni2+-immobilized resin. These results indicate that the CHO LCB1 homolog encodes a component of SPT.

Acyltransferases↗
PubMed1997

Inhibitory effect on curcumin on mammalian phospholipase D activity.

Curcumin, the major yellow pigment of turmeric (Curcuma longa), has strong anti-carcinogenic and anti-inflammatory activities. We examined the effects of curcumin on enzyme activities of the following phospholipases in a cell-free system: G protein-mediated phospholipase D (PLD), phosphatidylinositol-specific phospholipase C, and phospholipase A2 from mouse macrophage-like cell line J774.1 cells, sphingomyelinase from bovine brain, and phosphatidylcholine-phospholipase C from Bacillus cereus. Curcumin inhibited several types of phospholipases, most effectively PLD among those tested. It also inhibited 12-O-tetradecanoylphorbol-13-acetate-induced PLD activation in intact J774.1 cells in a dose-dependent manner. These results suggest that the anti-inflammatory and anti-carcinogenic action of curcumin is partly due to the inhibition of PLD.

Animals↗
PubMed1997

Calretinin-like immunoreactivity in the Ruffini endings, slowly adapting mechanoreceptors, of the periodontal ligament of the rat incisor.

The distribution and ultrastructural localization of calretinin (CR)-like immunoreactivity (-LI) were investigated in the lingual periodontal ligament of rat incisors. Some thick nerve fibers within the nerve bundle displayed CR-LI; these CR-like immunoreactive (-IR) nerve fibers entered the alveolar half of the lingual periodontal ligament of the incisor where dendritic terminal arborization was exhibited. Thin and beaded CR-IR nerve fibers were rarely observed in the periodontal ligament. Observations of adjacent sections immunostained with protein gene-product 9.5 (PGP 9.5) revealed that most, if not all, PGP 9.5-IR nerve terminals showing a dendritic arborization expressed CR-LI. Immunoelectron microscopic observations showed that electron-opaque immunoreaction products were localized in the axoplasm of the axon terminals, except for the mitochondria, which were surrounded by Schwann sheaths and multiple-layered basal lamina. Neither cell bodies, the cytoplasmic extension of terminal Schwann cells, nor other cellular elements such as periodontal fibroblasts exhibited CR-LI. The present findings suggest that Ruffini endings, an essential mechanoreceptor in the periodontal ligament and categorized as a slowly adapting mechanoreceptor, express CR-LI, and that CR may participate in the Ca2+ homeostasis against external stimuli in the periodontal Ruffini endings.

Animals↗
PubMed1997

Involvement of diacylglycerol production in activation of nuclear factor kappaB by a CD14-mediated lipopolysaccharide stimulus.

Exposure of Chinese hamster CHO-K1 transfectant cells expressing mouse CD14 (CHO/CD14 cells) to lipopolysaccharide (LPS) induced rapid elevation of the cellular diacylglycerol (DAG) and choline/phosphocholine levels and nuclear translocation of nuclear factor kappaB (NFkappaB). When cells were incubated with short-chain DAG analogues or bacterial phospholipase C, NFkappaB activation occurred even without the LPS stimulus. Treatment of CHO/CD14 cells with tricyclo[5.2.1.0(2.6)]decyl-(9[8])xanthogenate (D609), an inhibitor of phosphatidylcholine-specific phospholipase C and phospholipase D, almost completely inhibited not only the LPS-dependent production of DAG and choline/phosphocholine but also the LPS-dependent NFkappaB activation. In contrast, treatment of cells with 1-(6-{[3-methoxyoestra-1,3, 5(10)-trien-17beta-yl]-1H-pyrrole-2,5-dione (U73122), an inhibitor of phosphatidylinositol-specific phospholipase C in vitro, did not affect the LPS-dependent activation of NFkappaB. Production of DAG and activation of NFkappaB after the LPS stimulus were observed in mouse macrophage-like J774.1 cells, and this response to LPS by J774. 1 cells was also inhibited by D609. These results suggest that the production of DAG from phosphatidylcholine was upstream of NFkappaB activation in response to a CD14-mediated LPS stimulus.

Animals↗
PubMed1997

Immunocytochemical detection of p53 protein as an adjunct in cytologic diagnosis from pancreatic duct brushings in mucin-producing tumors of the pancreas.

BACKGROUND: In cases of mucin-producing tumor (MPT) of the pancreas, a new clinical entity of pancreatic tumor, it has been reported to be difficult to distinguish adenoma from carcinoma preoperatively. This observation caused the authors to develop a new method of p53 immunocytochemistry using cytologic samples obtained by endoscopic retrograde pancreatic duct brushing (ERPDB). METHODS: Fifteen cases of MPT (9 with carcinoma and 6 with adenoma) were examined. In all cases, histologic diagnosis was determined by surgery or autopsy. A wire with a small brush was pushed into the dilatated pancreatic duct detected by endoscopic retrograde pancreatography (ERP). Specimens obtained by brushing were prepared on slides and subsequently fixed with ethanol. Papanicolaou staining and p53 immunocytochemistry were performed simultaneously. The ability of conventional cytology to distinguish adenoma from carcinoma was compared with that of p53 immunocytochemistry. RESULTS: Five of 9 cases (56%) with carcinoma of MPT were correctly diagnosed by Papanicolaou staining. Two of four cases, classified as benign by Papanicolaou staining, expressed p53 protein. Overall, 7 of 9 cases (78%) with carcinoma MPT were correctly diagnosed by Papanicolaou staining associated with p53 immunocytochemistry. In the cases with adenoma MPT, all cases were classified as benign by Papanicolaou staining and no case positive for p53 protein was encountered. CONCLUSIONS: These results suggest that p53 immunocytochemistry as an adjunct in cytologic diagnosis using ERPDB may contribute to differentiating adenoma from carcinoma MPT of the pancreas preoperatively.

Adenocarcinoma, Mucinous↗
PubMed1997

Immunohistochemical localization of calbindin D28k in the periodontal Ruffini endings of rat incisors.

It was examined whether calbindin D28k (CB) might be located in the rat incisor periodontal Ruffini ending, an essential mechanoreceptor in periodontal ligament, by light- and electron-microscopic immunohistochemistry. Some thick nerve fibers showing CB-like immunoreactivity (LI) entered the lingual half of the periodontal ligament of the incisor and showed the dendritic terminal arborization. Electron-dense immunoreaction products indicating CB-LI were distributed diffusely in axoplasm of the axon terminals, no mitochondria, however, were not labeled. Neither cell bodies nor cytoplasmic extensions of the terminal Schwann cells exhibited CB-LI. CB was presumed to be involved in the maintenance of Ca2+ homeostasis in the mechano-electric transduction in mechanoreceptors in the periodontal ligament.

Animals↗
PubMed1997

Activation of MAP kinase cascade induced by human pancreatic phospholipase A2 in a human pancreatic cancer cell line.

We have found that the growth of human pancreatic cancer cells MIAPaCa-2, induced by human pancreatic phospholipase A2 group I (hPLA2-I), is mediated via its specific receptor but not via its catalytic property. The present study showed that the activation of mitogen-activated protein kinase (MAPK) cascade in MIAPaCa-2 cells is induced by hPLA2-I: this digestive enzyme induced phosphorylation of MEK1/2, p44/42 MAPK and ATF-2, and the phosphorylation in the MAPK cascade was inhibited after the cells were pre-incubated with a selective inhibitor of MEK, PD98059. In addition, this inhibitor dose-dependently blocked the hPLA2-I-induced MIAPaCa-2 proliferation, suggesting that activation of the MAPK cascade is essential for the hPLA2-I-induced MIAPaCa-2 proliferation.

Activating Transcription Factor 2↗
PubMed1997

RecQ DNA helicase is a suppressor of illegitimate recombination in Escherichia coli.

Bloom syndrome and Werner syndrome are genetic disorders in which an increased rate of chromosomal abnormality is observed. The genes responsible for these diseases, BLM and WRN, have been cloned and identified as homologs of the Escherichia coli recQ genes. We studied the effect of recQ mutations on illegitimate recombination, which is an aberrant biological event related to the chromosomal abnormality in humans, and found that a variety of recQ mutations increased spontaneous illegitimate recombination by 20- to 300-fold and increased UV light-induced illegitimate recombination by 10- to 100-fold. Most lambda bio or lambda pro transducing phages are formed by the recombination events at several hot spots, which are enhanced by the recQ mutation. The analysis of nucleotide sequences at the recombination junction in the transducing phages indicates that recombination at the hot spot sites as well as the non-hot spot sites takes place between short homologous sequences. Enhancement of the recombination in the recQ mutants also occurs in the recA, recBC sbcBC, or recBC sbcA backgrounds, indicating that these recombination events are mediated by none of the known recombination pathways, RecBC, RecF, and RecE. We therefore concluded that the RecQ function suppresses illegitimate recombination that depends on short homologous regions. We discuss a model, based on the 3'-to-5' helicase activity of RecQ, to explain the role of this protein as a suppressor of illegitimate recombination.

Adenosine Triphosphatases↗
PubMed1997

Involvement of heparan sulfate proteoglycans in the binding step for phagocytosis of latex beads by Chinese hamster ovary cells.

Chinese hamster ovary (CHO) K1 cells, typical nonprofessional phagocytes, exhibited intense phagocytosis of latex beads when incubated under serum-free conditions. Under the serum-free conditions, the recognition mechanism of latex beads by cells was investigated. Exogenous heparin and heparan sulfate but not chondroitin sulfate effectively inhibited the binding of latex beads to cells. The binding of latex beads to cells was also inhibited by treatment of cells with heparitinase more effectively than by treatment of cells with chondroitinase. Furthermore, CHO mutant cells defective in biosyntheses of both heparan sulfate and chondroitin sulfate proteoglycans almost completely lacked binding activity of latex beads. Another mutant, which is deficient in heparan sulfate proteoglycans but rather overproduces chondroitin sulfate proteoglycans, also showed lower binding activity, compared with wild-type cells. Coculture of these proteoglycan-less mutants and the wild-type cells did not restore the binding activity of the mutant cells, suggesting that membrane-bound rather than secretory proteoglycans were responsible for the binding of latex beads. These results indicated that heparan sulfate proteoglycans at the cell surface were involved in the binding step for phagocytosis of latex beads by CHO cells.

Animals↗
PubMed1997

Stimulation of bone formation by intraosseous application of recombinant basic fibroblast growth factor in normal and ovariectomized rabbits.

The effect on intraosseous bone formation of a single local injection of recombinant human basic fibroblast growth factor into the distal femur was examined in normal and ovariectomized rabbits. In normal rabbits, basic fibroblast growth factor increased bone mineral density around the injected site in a dose-dependent manner at 4 weeks, with significant effects at concentrations of 400 micrograms and greater. Doses of 400 and 1,600 micrograms of basic fibroblast growth factor increased bone mineral density by 8 and 9%, respectively, compared with the opposite control femur. Histological examination showed that basic fibroblast growth factor (400 micrograms) induced the proliferation or recruitment of undifferentiated mesenchymal cells around the existing trabeculae at 3 days after the injection. For the first 2 weeks, osteoid formation was strongly stimulated, and this was followed by mineral apposition for another 2 weeks, at which time the femurs were harvested. Consequently, basic fibroblast growth factor stimulated intraosseous bone formation at 4 weeks. We speculate that the direct action of basic fibroblast growth factor on bone formation may be to stimulate proliferation or recruitment of minimally differentiated mesenchymal cells and to initiate the cascade of events in later stages of bone formation. In ovariectomized rabbits, basic fibroblast growth factor (400 micrograms) also increased bone mineral density, histomorphometrical bone formation markers, and trabecular connectivity to levels similar to those in rabbits who had received sham operations.

Animals↗
PubMed1997

A case of Sjögren's syndrome associated with Sweet's syndrome.

We report a case of Sjögren's syndrome whose clinical course had been indolent until the patient presented with Sweet's syndrome (acute febrile neutrophilic dermatosis). This patient showed renal failure and renal tubular acidosis. Sweet's syndrome resolved within 3 weeks without corticosteroid therapy. Renal biopsy findings were consistent with interstitial nephritis. His renal manifestations responded to corticosteroid therapy and the renal function remained stable during 6 years follow-up without recurrence of Sweet's syndrome. Although close association of both syndromes is already known, in our case Sjögren's syndrome may have been exacerbated by occurrence of Sweet's syndrome.

Acute Kidney Injury↗
PubMed1997

Complete nucleotide sequence and genome organization of sweet potato feathery mottle virus (S strain) genomic RNA: the large coding region of the P1 gene.

The complete nucleotide sequence of a sweet potato feathery mottle virus severe strain (SPFMV-S) genomic RNA was determined from overlapping cDNA clones and by directly sequencing viral RNA. The viral RNA genome is 10,820 nucleotides long, excluding the poly(A) tail and contains one open reading frame (ORF) starting at nucleotide 118 and ending at 10,599, potentially encoding a polyprotein of 3,493 amino acids (Mr 393,800). The ORF was followed by a 3' untranslated region of 221 nucleotides. The deduced polyprotein includes P1 (74K), HC-Pro (52K), P3 (46K), 6K1, CI (72K), 6K2, NIa-VPg (22K), NIa-Pro (28K), NIb (60K) and coat (35K) proteins, after an analysis of protein cleavage sites analogous to other potyvirus polyproteins. The polyprotein had a high level of amino acid identity with those of other potyviruses, except in the regions of P1 and P3. The P1 of SPFMV-S RNA has 664 amino acid residues, and is the largest and least similar to those of other potyviruses. HC-Pro and CI show high identity with those of other potyviruses. P3 has relatively low identity, however, the length of P3 was within the range of variability among other potyviruses. The 6K1 protein between P3 and C1 is also highly similar to those of other potyviruses. This is the first report on the complete nucleotide sequence of the sweet potato-infecting virus.

Genome, Viral↗