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Biomedical subjects

H Kobayashi

Publications and source records attributed to H Kobayashi.

At least 361 records · Page 20Linked to original sources
PubMed2000

Effective high-dose chemotherapy combined with CD34+-selected autologous peripheral blood stem cell transplantation in a patient with cutaneous CD30-negative large T cell lymphoma.

Generalized multiple cutaneous tumors developed in a 60-year-old Japanese man. Skin biopsy revealed atypical large T lymphocytes infiltrating the dermis. CD30 staining was negative in the tumor cells. The diagnosis of CD30-negative cutaneous large T cell lymphoma was made. Axial and inguinal lymphadenopathy was present, but there was no evidence of bone marrow involvement. Seven cycles of chemotherapy and local electron beam irradiation were administered and complete remission (CR) was attained. As CD30-negative cutaneous large T cell lymphoma has a poor prognosis despite intensive chemotherapy, high-dose chemotherapy followed by CD34+-selected autologous peripheral blood stem cell transplantation (CD34+-APBSCT) was prescribed. The clinical course after CD34+-selected APBSCT was complicated with CMV infection occurring twice but administration of ganciclovir resolved the symptoms. He has remained in CR for 16 months after CD34+-APBSCT. This appears to be the first case report of CD34+-APBSCT in a patient with CD30-negative cutaneous large T cell lymphoma. Bone Marrow Transplantation (2000) 25, 1315-1317.

Antigens, CD34↗
PubMed2000

Is the morphology of the articular eminence of the temporomandibular joint a predisposing factor for disc displacement?

OBJECTIVES: To test the hypothesis that the morphology of the articular eminence of the TMJ is a predisposing factor for disc displacement. METHODS: MR images of 220 TM joints in 151 patients were studied: 47 joints had no disk displacement (NDD), 81 joints disc displacement with reduction (DDWR) and 92 joints disc displacement without reduction (DDWOR). The shape of the articular eminence of the TMJ was classified into four types, box, sigmoid, flattened and deformed. The prevalence of the box and flattened forms in the three groups of joints was compared. RESULTS: There was no statistically significant difference in the prevalence of the box form between the joints with NDD, DDWR, and DDWOR. On the other hand, the prevalence of the flattened-type was statistically lower in the joints with DDWR (goodness test of fit for chi 2, P < 0.05). CONCLUSIONS: It appears that disc displacement is less likely to be found in joints with a shallow articular eminence.

Analysis of Variance↗
PubMed2000

Flattening of the articular eminence correlates with progressive internal derangement of the temporomandibular joint.

OBJECTIVES: To test the hypothesis that flattening of the slope of the articular eminence occurs with progressive internal derangement (ID) of the TMJ. METHODS: MR images of 170 TMJs in 130 patients with proven disk displacement were studied. The correlation between the prevalence of a flattened articular eminence and radiological stage of ID was analysed. RESULTS: The prevalence of a flattened articular eminence was significantly higher in the joints with advanced ID (Mann-Whitney's U-test, P < 0.05). CONCLUSIONS: It appears that a flattening of the slope of the articular eminence occurs as a result of remodeling or degenerative changes secondary to ID.

Adolescent↗
PubMed2000

Ichthyosis follicularis with alopecia and photophobia in a mother and daughter.

A mother and daughter having ichthyosis follicularis with alopecia and photophobia (IFAP) are reported, with histopathological and electron microscopic findings. We have followed the clinical course of the mother for 26 years since she was 5 years old, and the daughter since birth. They have had almost all the classical and some of the minor symptoms of IFAP, including severe photophobia, extensive non-inflammatory follicular hyperkeratosis, generalized non-scarring alopecia, hyperkeratosis of the extensor aspect of the four extremities, nail deformity and recurrent cheilitis. In addition, their facial appearance greatly resembles that of previously reported patients. A consistent feature in the mother was florid keratotic inflammatory eruptions on the genital region during each of her pregnancies, which rapidly improved after the delivery. Skin biopsy of the genital lesion showed marked acanthosis with dyskeratosis and spongiotic changes. The electron microscopic examination of diseased skin showed damaged desmosomes with spongiosis. No obvious changes were found in normal appearing skin.

Adult↗
PubMed2000

Subcorneal pustular dermatosis type of IgA pemphigus: demonstration of autoantibodies to desmocollin-1 and clinical review.

We describe a 40-year-old Japanese man with a 3-year history of vesiculopustular lesions resembling subcorneal pustular dermatosis. Histopathology showed subcorneal pustules containing a few acantholytic cells, and direct immunofluorescence disclosed IgA deposition in the intercellular space of the upper epidermis. Circulating IgA autoantibodies of very low titre were also demonstrated by indirect immunofluorescence. A novel cDNA transfection technique clearly detected IgA autoantibodies reactive with human desmocollin-1. Combined therapy with dapsone and etretinate improved the skin lesions. We review the clinical features of 49 patients in the literature who presented with vesiculopustular lesions and intraepidermal IgA deposition.

Adult↗
PubMed2000

Combined cutaneous hamartoma encompassing benign melanocytic naevus, vellus hair cyst and epidermoid cyst.

We describe a combined cutaneous hamartoma in a 57-year-old man, which comprised a vellus hair cyst, an epidermoid cyst and an intradermal melanocytic naevus in a single facial tumour. The vellus hair cyst was filled with keratinous material with unusual slit-like lacunae. While numerous cases of epidermoid cyst have been reported in association with an intradermal melanocytic naevus, our case is a rare example of a lesion combining several hamartomatous elements.

Cysts↗
PubMed2000

Development and fine structure of the yolk nucleus of previtellogenic oocytes in the medaka Oryzias latipes.

The development and fine structure of yolk nuclei in the cytoplasm of previtellogenic oocytes were examined by electron microscopy during several stages of oogenesis in the medaka, Oryzias latipes. Shortly after oogenesis starts, oocytes 20-30 microm in diameter have much electron-dense (basophilic) cytoplasm, within which a continuous or discontinuous, irregular ring-shaped lower electron-dense area of flocculent appearance (LF) begins to emerge around the nucleus. The yolk nucleus is first recognized within an LF area as a few fragments of dense granular thread measuring 20-25 nm in width. The threads consist of two rows of very dense granules resembling ribosomes or ribonucleoprotein (RNP)-like particles in size and electron density. These thread-like fragments gradually increase in number and length until they assemble into a compact, spherical mass of complicated networks. Analysis of serial sections suggests that the yolk nucleus is a complicated mass of numerous, small deformed vacuoles composed of a single lamella with double layers of ribosomes or RNP-like granules, rather than a mass of granular threads. When oocytes develop to greater than 100 microm in diameter, the yolk nucleus begins to fragment before dispersing throughout the surrounding cytoplasm, concomitantly with the disappearance of LF areas. At this stage of oogenesis, a restricted region of the granulosa cell layer adjacent to the yolk nucleus becomes somewhat columnar in morphology, fixing the vegetal pole region of the oocyte.

Animals↗
PubMed2000

Autoimmune pancreatitis detected as a mass in the tail of the pancreas.

A mass in the tail of the pancreas was detected in a 62-year-old male patient who had hypergammaglobulinaemia, and was positive for antinuclear antigen and anti-SS-A antibody. Endoscopic retrograde pancreatography revealed focal irregular narrowing of the main pancreatic duct in the tail of the pancreas. Dynamic computed tomography showed swelling of the pancreatic tail, which was enhanced on delayed phase. Autoimmune pancreatitis was suspected and corticosteroid therapy was commenced. This led to significant resolution of the pancreatic stricture. It is important to recognize this clinical entity as corticosteroid therapy may avoid unnecessary surgery.

Autoantibodies↗
PubMed2000

Psittacosis with increased gammadelta T cells in bronchoalveolar lavage fluid.

Experience with two cases of psittacosis is described here in which the number of gammadelta T cell receptor-positive T lymphocytes (gammadelta T cell) in the bronchoalveolar lavage fluid was markedly increased (25.1 and 66.9%) and CD8+ T cells were also increased with reversal of the CD4/CD8 ratio. These values improved to the normal range along with recovery of their radiographical findings. The present findings suggest that gammadelta T cells may play an important role in protection from lung injury caused by Chlamydia psittaci infection.

Adult↗
PubMed2000

Protein kinase C-alpha and -epsilon down-regulate cell surface sodium channels via differential mechanisms in adrenal chromaffin cells.

In cultured bovine adrenal chromaffin cells, our [3H]saxitoxin ([3H]STX) binding, immunoblot, and northern blot analyses specified protein kinase C (PKC) isoform-specific posttranscriptional and posttranslational mechanisms that direct down-regulation of cell surface Na channels. Immunoblot analysis showed that among 11 PKC isoforms, adrenal chromaffin cells contained only conventional (c)PKC-alpha, novel (n)PKC-epsilon, and atypical (a)PKC-zeta. Treatment of adrenal chromaffin cells with 100 nM 12-O-tetradecanoylphorbol 13-acetate (TPA) or 100 nM phorbol 12,13-dibutyrate (PDBu) caused a rapid (<15 min) and sustained (>15 h) translocation of PKC-alpha and -epsilon (but not -zeta) from cytosol to membranes, whereas a biologically inactive 4alpha-TPA had no effect. Thymeleatoxin (TMX), an activator of cPKC, produced similar membrane association of only PKC-alpha at 100 nM, with the potency of TMX being comparable with those of TPA and PDBu. Treatment with either 100 nM TPA or 100 nM TMX reduced cell surface [3H]STX binding to a comparable extent at 3, 6, and 12 h, whereas TPA lowered the binding to a greater extent than TMX at 15, 18, and 24 h; at 15 h, Gö6976, a specific inhibitor of cPKC, completely blocked TMX-induced decrease of [3H]STX binding while preventing by merely 57% TPA-induced decrease of [3H]STX binding. Treatment with 100 nM TPA lowered the Na channel alpha-subunit mRNA level between 3 and 12 h, with its maximum 52% fall at 6 h, and it was accompanied by a subsequent 61 % rise of the beta1-subunit mRNA level at 24 h. Gö6976 failed to prevent TPA-induced reduction of the alpha-subunit mRNA level; TMX did not change the alpha- and beta1-subunit mRNA levels throughout the 24-h treatment. Brefeldin A, an inhibitor of vesicular exit from the trans-Golgi network, augmented TPA- and TMX-induced decrease of [3H]STX binding at 1 and 3 h. Our previous and present studies suggest that PKC down-regulates cell surface Na channels without altering the allosteric gating of Na channels via PKC isoform-specific mechanisms; cPKC-alpha promotes Na channel internalization, whereas nPKC-epsilon decreases the alpha-subunit mRNA level by shortening the half-life of alpha-subunit mRNA without changing its gene transcription.

Adrenal Glands↗
PubMed2000

Involvement of phosphatidylcholine-specific phospholipase C in thromboxane A2-induced activation of mitogen-activated protein kinase in astrocytoma cells.

Thromboxane A2 (TXA2) receptor-mediated signal transduction was investigated in 1321N1 human astrocytoma cells. 9,11-Epithio-11,12-methano-TXA2 (STA2), a TXA2 receptor agonist, induced Ca2+ mobilization and phosphoinositide hydrolysis in a concentration-dependent manner. These responses were inhibited by treatment with U73122, an inhibitor of phosphatidylinositol-specific phospholipase C, or by culturing in 0.5% fetal calf serum containing 0.5 mM dibutyryladenosine 3',5'-cyclic monophosphate (dbcAMP) for 2 days. However, the dbcAMP treatment augmented the TXA2 receptor-mediated phosphorylation of mitogen-activated protein kinase (MAPK). These results were confirmed by a functional MAPK assay measuring the incorporation of 32P into the MAPK substrate peptide. The TXA2 receptor-mediated MAPK activation was inhibited by SQ29548, a TXA2 receptor antagonist, and GF109203X, an inhibitor of protein kinase C. Although U73122 did not inhibit or only slightly inhibited the activation of MAPK, D-609, an inhibitor of phosphatidylcholine-specific phospholipase C, potently attenuated the activation in a concentration-dependent manner. Furthermore, STA2 accelerated the release of [3H]choline metabolites from the cells prelabeled with [3H]choline chloride. This release was inhibited by treatment with D-609. These results suggest that phosphatidylcholine-specific phospholipase C and protein kinase C, but not phosphatidylinositol-specific phospholipase C, are involved in TXA2 receptor-mediated MAPK activation in 1321N1 human astrocytoma cells.

Calcium↗
PubMed2000

Up-regulation of cell surface insulin receptor by protein kinase C-alpha in adrenal chromaffin cells: involvement of transcriptional and translational events.

Our previous study showed that treatment of cultured bovine adrenal chromaffin cells with phorbol 12, 13-dibutyrate (PDBu) or 12-O-tetradecanoylphorbol 13-acetate (TPA) caused a rapid (<15 min) and persistent (>15 h) translocation of both conventional (c) protein kinase C-alpha (PKC-alpha) and novel PKC-epsilon (but not atypical PKC-zeta) from cytosol to membranes, whereas thymeleatoxin (TMX) increased the similar but selective membrane association of only cPKC-alpha. In the present study, chronic (>/=12 h) treatment of chromaffin cells with PDBu raised cell surface (125)I-insulin binding without altering the K(D) value; it developed in a concentration (EC(50) = 1.9 nM)-and time (t(1/2) = 14.6 h)-dependent manner, reaching its maximum 115% increase at 48 h. Either TPA (30 nM) or TMX (EC(50) = 6.4 nM) also increased (125)I-insulin binding by 97 or 88%, whereas the biologically inactive 4alpha-TPA had no effect. The increasing effect of PDBu (30 nM for 24 h) on (125)I-insulin binding was significantly blocked, even when H7, an inhibitor of PKC, was added at 8 h after the initiation of PDBu treatment. Concurrent treatment with brefeldin A, an inhibitor of vesicular transport from the trans-Golgi network, cycloheximide, an inhibitor of protein synthesis, or 5,6-dichlorobenzimidazole riboside, an inhibitor of RNA synthesis, abolished the PDBu-induced increment of (125)I-insulin binding. Western blot analysis, using antibody against the beta-subunit of the insulin receptor, showed that treatment with PDBu (30 nM) or TMX (EC(50) = 2.3 nM) increased levels of insulin receptor precursor (approximately 190 kDa; t(1/2) = 7.1 h) and insulin receptor beta-subunit (t(1/2) = 15.4 h), causing their almost maximum 52 and 59% rises, respectively, at 24 h. Northern blot analysis revealed that PDBu or TMX increased levels of insulin receptor mRNAs by approximately 35% as soon as 3 h, producing its monophasic peak approximately 76% increases at 24 h. All of these increasing effects of PDBu and TMX on (125)I-insulin binding and insulin receptor beta-subunit and insulin receptor mRNA levels were entirely prevented by simultaneous treatment with Gö6976, a selective inhibitor of cPKC. These results suggest that long-term activation of cPKC-alpha up-regulates the density of the cell surface insulin receptor via transcriptional/translational events.

Adrenal Medulla↗
PubMed2000

Tubed latissimus dorsi musculocutaneous flaps for esophageal replacement in puppies: long-term follow-up.

PURPOSE: The aim of this study was to show that a tubed latissimus dorsi musculocutaneous flap (tubed LDMCF) may be useful for treating circumferential esophageal defects. METHODS: A segment of esophagus 3 vertebrae long was excised through a right thoracotomy in each of 6 puppies, and a tubed LDMCF was interposed between the cut ends of esophagus. The puppies were sacrificed after a mean follow-up period of 6.6 years. The tubed LDMCF was examined histologically. Functional integrity was assessed using barium meal and endoscopy before sacrifice. RESULTS: All puppies survived and grew normally on a normal diet, although 4 vomited occasionally. There was smooth passage of barium through the tubed LDMCF without stenosis, although endoscopy showed regrowth of hair. Histologically, no metaplasia, dysplasia, or malignancy was observed in any tubed LDMCF. CONCLUSIONS: The tubed LDMCF is technically safe, obviates the necessity for laparotomy, and long-term follow-up would suggest that it is histologically stable. Thus, it could become an alternative procedure for bridging esophageal defects.

Animals↗