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Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 451 records · Page 25Linked to original sources
PubMed1997

Serial dynamic magnetic resonance imaging of orbital cavernous hemangioma.

PURPOSE: To assess serial dynamic magnetic resonance imaging after rapid intravenous injection of contrast material as a tool for diagnosing orbital cavernous hemangioma. METHODS: Two patients with orbital cavernous hemangioma were studied. Gadolinium-DTPA, 0.1 mmol/kg, was injected intravenously in 10 seconds. RESULTS: On early imaging after the injection, one small point of enhancement was initially noted, and then the tumor was homogeneously enhanced. The initial enhancement point represented the connecting point of feeding vessels to the lesion. CONCLUSIONS: Dynamic magnetic resonance imaging is useful for diagnosing cavernous hemangioma and for estimating the connecting point of feeding vessels.

Adult↗
PubMed1997

Orbital granular cell tumor developing in the inferior oblique muscle.

PURPOSE: To describe the magnetic resonance imaging and histopathologic features of an orbital granular cell tumor. METHODS: A 43-year-old man was initially examined with slowly progressive vertical diplopia. A firm mass was palpable through the left lower eyelid. Magnetic resonance imaging and histopathologic examinations were performed. RESULTS: Magnetic resonance imaging disclosed a spindle-shaped mass involving the inferior oblique muscle. Histopathologic examination disclosed that the tumor cells, diagnosed as a granular cell tumor, had infiltrated the muscle fibers. CONCLUSION: In the present case, these findings indicate that the granular cell tumor may develop in the inferior oblique muscle.

Adult↗
PubMed1997

Enhanced magnetic resonance imaging in a patient with acute paralysis of the inferior division of the oculomotor nerve.

PURPOSE: To describe the characteristics of enhanced magnetic resonance imaging of the orbit in a patient with acute paralysis of the inferior division of the oculomotor nerve. METHOD: Using a fat-suppression technique, we performed enhanced magnetic resonance imaging of the orbit of a 36-year-old woman with acute paralysis of the inferior division of the left oculomotor nerve. RESULTS: The inferior division of the left oculomotor nerve in the orbit was markedly enhanced, suggesting inflammation of the inferior division of the oculomotor nerve. The severity of paralysis decreased immediately after intravenous corticosteroid (prednisolone acetate) administration. CONCLUSION: These findings suggest that enhanced magnetic resonance imaging with a fat-suppression technique is useful for diagnosing peripheral nerve lesions in the orbit.

Acute Disease↗
PubMed1997

Chronic expanding hematoma in the chest.

We herein report the successful surgical treatment of 2 cases of chronic expanding hematoma in the chest. The first patient, who had undergone thoracoplasty 42 years earlier due to tuberculosis, became aware of a slowly growing mass protruding in the lateral thoracic wall. The second patient, who had tuberculous pleurisy 36 years earlier, was referred to our department because of a slowly expanding intrathoracic mass revealed by a roentgenogram. The tumors, which were encapsulated chronic hematomas, were both surgically resected. These cases are rare because of the development of a very large mass after undergoing treatment for tuberculosis more than 30 years previously.

Aged↗
PubMed1997

Hydroxyl radical scavenging effect of nicaraven in myocardial and coronary endothelial preservation and reperfusion injury.

OBJECTIVE: We investigated the efficacy of nicaraven in reducing myocardial as well as coronary endothelial preservation-reperfusion (P/R) injury. METHODS: In experiment I, isolated rat hearts were mounted on a Langendorff (L) apparatus to estimate the baseline cardiac function. Group 1, 8- and 12-h storage in histidine-tryptophan-ketoglutarate (HTK) solution; group 2, 8- and 12-h storage in HTK solution with superoxide dismutase (2.5 x 10(5) U/I) and catalase (2 x 10(5) U/I); group 3, 8- and 12-h storage in HTK solution with nicaraven (10(-3) M). Following storage for 8 and 12 h at 4 degrees C, they were reperfused and post-preservative cardiac function was evaluated. The hearts were then switched back to L-mode and paced at 330 beats/min. Coronary flow (CF) following perfusion with KHB solution containing 5-hydroxytryptamine (5-HT) and nitroglycerin was also measured. In experiment 2, segments of pig coronary artery were suspended in organ chambers and exposed to hydroxyl radicals in the presence or absence of nicaraven. The sensitivity of relaxation response to bradykinin of the prior-exposed rings was measured. RESULTS: The recovery of CF and LV dp/dt following 8 h of storage in group 3 was higher than that in group 1, although there were no significant differences in the other parameters of cardiac functional recovery among the groups. The absolute values of cardiac function following 12 h of storage in groups 1-3 were as follows: 6.6 +/- 2.4, 9.1 +/- 0.8, 15.6 +/- 3.1 ml/min of cardiac output (CO); 1.9 +/- 0.9, 2.3 +/- 0.4, 6.0 +/- 2.3 ml/min of aortic flow (AF); 4.5 +/- 1.3, 6.0 +/- 0.5, 9.5 +/- 0.8 ml/min of CF, respectively. The recovery of CO, AF, CF, SP, MP, and left ventricular (LV) dp/dt were significantly improved in group 3, compared with those in group 1. CF and CO in group 3 were higher than those in group 2.5-HT caused vasoconstriction in all groups, but the vasoconstriction in group 3 was less than in group 1. Prior exposure to FeSO4/H2O2 produced significant endothelial damage as reflected by the right-ward shift of the dose-response curve of bradykinin-induced endothelium-dependent relaxation. In the presence on nicaraven, the dose-response curve recovered to the control level. CONCLUSIONS: Nicaraven may improve coronary endothelial and myocardial function following P/R by its hydroxyl radical scavenging activity.

Animals↗
PubMed1997

Augmented Ca2+ influx is involved in the mechanism of enhanced proliferation of cultured vascular smooth muscle cells from spontaneously diabetic Goto-Kakizaki rats.

To investigate whether augmented calcium influx is involved in the mechanism of the enhanced proliferation of vascular smooth muscle cells (VSMCs) in diabetes, we studied the association between proliferation and cytosolic free calcium concentration ([Ca2+]i) in cultured aortic VSMCs from spontaneously diabetic Goto-Kakizaki (GK) and Wistar rats. Serum, angiotensin II and Bay K 8644, a voltage-dependent Ca2+ channel (VDC) agonist, stimulated the proliferation of VSMCs; the magnitude was greater in VSMCs from GK than Wistar rats. VDC blockers, verapamil and nicardipine, inhibited Bay K 8644-induced cell proliferation, and the difference in the proliferation of VSMCs between GK and Wistar rats disappeared. Angiotensin II-induced proliferation was only partially inhibited by VDC blockers, and enhanced proliferation of GK-VSMCs was still observed. Bay K 8644 and angiotensin II increased [Ca2+]i, and the increase was augmented in GK-VSMCs. Bay K 8644-induced [Ca2+]i increase was completely inhibited by pretreatment with verapamil or removal of extracellular Ca2+, suggesting that VDC is associated with this increase. Although angiotensin II-induced [Ca2+]i increase was not affected by verapamil, removal of extracellular Ca2+ slightly but significantly attenuated angiotensin II-induced [Ca2+]i increase, suggesting that VDC blocker-insensitive receptor-activated Ca2+ influx is involved. These results indicate that augmented Ca2+ influx via VDC and a receptor-activated pathway may be involved in the mechanism of the enhanced proliferation of VSMCs from GK rats.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1997

Functional capacity of the liver after two-thirds partial hepatectomy in the rat.

BACKGROUND: Liver cell proliferation after partial hepatectomy in rats has been thoroughly investigated. Although DNA synthesis and morphologic restoration have been studied in this rat model, the functional capacity of the remnant liver during regeneration has not been elucidated. METHODS: We measured the indocyanine green disappearance rate (ICG-k) and serum aminopyrine (CLamp) in rats at various intervals after two-thirds hepatectomy. Morphologic restoration of the liver after hepatectomy was evaluated on the basis of remnant liver weight, proliferating cell nuclear antigen labeling index, and the DNA content of the regenerating liver. Serial changes in ICG-k and CLamp after two-thirds hepatectomy were compared with the degree of morphologic restoration. RESULTS: ICG-k and CLamp were reduced by one third in rats after two-thirds hepatectomy. Although the rate of restoration of remnant liver weight was steady after hepatectomy, ICG-k and CLamp were lowest about 36 hours after hepatectomy. The restoration of ICG-k was comparable to that of liver weight, but the restoration of CLamp was delayed. CONCLUSIONS: Functional liver capacity was minimal during parenchymal cell mitosis in the regenerating liver. Functional restoration after two-thirds hepatectomy was delayed in comparison with morphologic restoration in rat.

Aminopyrine↗
PubMed1997

Silver-stained nucleolar organizer regions in adenocarcinoma of the cervix--a light and electron microscopic study.

An increase in the number of Ag-NORs has been described as a possible marker for histopathological cancer diagnosis. The ultrastructural correlation of the reaction, however, has never been elucidated. In tissue samples of the endocervix of the uterus, we compared the ultrastructural configuration of Ag-NORs with the number of Ag-NORs dots. Light microscopic studies showed that the number of Ag-NORs in adenocarcinoma cells significantly increased, but the relation to the bromodeoxyuridine labeling index was not determined. By electron microscopy, Ag-NORs were only observed in the nucleoli and the nuclear bodies of nuclei. Ag-NORs were localized on all components of the nucleolar structure, but the dense fibrillar component was the predominant site in several cases. The nuclear bodies were exclusively found in adenocarcinoma cells and were argyrophilic. A spotted distribution of Ag-NORs was often found in the nucleoli of adenocarcinoma cells that showed an increased Ag-NOR count. The number of Ag-NORs was attributed not only to the number of nucleoli and nuclear bodies in a nucleus but also to the speckled distribution of silver deposits in a nucleolus. These results imply that the Ag-NOR count is a more definitive indicator of a hyperactive state of the cells than the combined number of nucleoli and nuclear bodies in adenocarcinoma of the uterine cervix.

Adenocarcinoma↗
PubMed1997

Brain-derived neurotrophic factor gene expression in the developing zebrafish.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family of polypeptides that includes NGF, NT-3, NT-4/5 and NT-6. Although neurotrophins are known to be expressed in teleost fishes little is known about their functions in the development of these vertebrates. We are therefore studying BDNF in the zebrafish, Danio rerio. The structure of zebrafish BDNF mRNA was established using PCR and cDNA cloning. The encoded BDNF was 91% identical to mammalian BDNF. Southern blot analysis revealed a unique BDNF gene. Northern blot analysis detected two heterogeneous populations of BDNF transcripts centered at 1.6 and 2 kb. BDNF transcripts were first measurable 24 h post-fertilization (pf). Their abundance relative to total transcripts increased 6-fold between 1 day and 3 days pf and again 2-fold by 7 days pf. In situ hybridization analyses of 4-day-old larvae revealed BDNF transcripts in the retina, brain, otic vesicle, pectoral fin and the hair cells of the neuromast. The early onset and cellular sites of expression suggest that BDNF functions in nervous system and fin development in the zebrafish.

Aging↗
PubMed1997

Modulation of c-fms proto-oncogene in an ovarian carcinoma cell line by a hammerhead ribozyme.

Co-expression of macrophage colony-stimulating factor (M-CSF) and its receptor (c-fms) is often found in ovarian epithelial carcinoma, suggesting the existence of autocrine regulation of cell growth by M-CSF. To block this autocrine loop, we have developed hammerhead ribozymes against c-fms mRNA. As target sites of the ribozyme, we chose the GUC sequence in codon 18 and codon 27 of c-fms mRNA. Two kinds of ribozymes were able to cleave an artificial c-fms RNA substrate in a cell-free system, although the ribozyme against codon 18 was much more efficient than that against codon 27. We next constructed an expression vector carrying a ribozyme sequence that targeted the GUC sequence in codon 18 of c-fms mRNA. It was introduced into TYK-nu cells that expressed M-CSF and its receptor. Its transfectant showed a reduced growth potential. The expression levels of c-fms protein and mRNA in the transfectant were clearly decreased with the expression of ribozyme RNA compared with that of an untransfected control or a transfectant with the vector without the ribozyme sequence. These results suggest that the ribozyme against GUC in codon 18 of c-fms mRNA is a promising tool for blocking the autocrine loop of M-CSF in ovarian epithelial carcinoma.

Base Sequence↗
PubMed1997

Epitope specificity of IgE antibodies to a major allergen (Cry j 1) of Japanese cedar pollen in sera of humans and monkeys with pollinosis.

Japanese cedar (Cryptomeria japonica) pollinosis has been reported to occur naturally in Japanese monkeys (Macaca fuscata) as well as humans. Using monoclonal antibodies (mAb) specific to Cry j 1, a major allergen in Japanese cedar pollen, we identified five independent epitopes (EP-1 to EP-5) on the molecule. The epitopes recognized by IgE antibodies in the sera of humans and monkeys with the pollinosis were analysed by an IgE enzyme-linked immunosorbent assay inhibition method with these mAb. In human patients, the mAb to EP-1 strongly blocked the binding of IgE antibodies in all patients' sera to Cry j 1. The reaction patterns of IgE antibodies in monkeys, however, varied among the troops of monkeys. In some troops, the mAb to EP-1 showed a blocking pattern similar to that for human patients. In other troops, mAb to EP-4 and EP-5 blocked binding of IgE. These results indicate that some, but not all, monkeys have antibody responses to the major allergen similar to those of humans.

Allergens↗
PubMed1997

Accessory lobe of the liver mimicking a mass in the left adrenal gland. A case report.

An accessory lobe of the liver is a rare anomaly which we have diagnosed in a patient by CT. The lesion appeared as a soft-tissue-density mass with the same density as the liver and attached to the liver. Radionuclide liver scintigraphy helped to confirm the diagnosis. The object of this report is to draw attention to this rare entity since it can cause diagnostic confusion.

Adrenal Gland Neoplasms↗
PubMed1997

The role of N-terminal glycosylation in the human oxytocin receptor.

The human oxytocin receptor includes three N-glycosylation sites in its extracellular N-terminal domain. We have established permanent cell-lines in which the gene for the human oxytocin receptor (OTR) has been introduced into HeLa cells. These cells differ by the disruption of one or more of the N-terminal N-glycosylation sites by site-directed mutagenesis of the transfected OTR constructs. The binding capacity of each transfectant, calculated per mg membrane protein, was 5-17 times higher than that of human term myometrium. The pharmacological characteristics of the transfected wild-type OTR are very similar to those of native myometrial OTR. The mutation of N-glycosylation sites (Asn-X-Ser/Thr), namely OTR-D8N15N26 (Asn8-->Asp8), -N8D15N26(Asn15-->Asp15), -N8D15D26(Asn15-->Asp15, Asn26-->Asp26) and -D8N15D26 (Asn8-->Asp8, Asn26-->Asp26) appear to affect neither their dissociation constant (Kd), nor the affinities for various oxytocin related ligands. As a high level of cell surface binding was retained for each clone, receptor trafficking appears to be normal. This suggests that the full glycosylation of OTR observed in vivo is not essential for its activity. These results indicate also that these cell lines may prove very useful for pharmacological screening of oxytocin related products.

Gene Transfer Techniques↗
PubMed1997

Structural feature of the major but not cytokine-inducing molecular species of lipoteichoic acid.

Previously, lipoteichoic acid (LTA) of Enterococcus hirae was found to exhibit definite cytokine-inducing activity but synthetic specimens which share the fundamental structural principles proposed for LTA had no corresponding activity. We also showed recently that several minor components totally less than 5% of the LTA fraction from E. hirae ATCC 9790 possessed the activity, whereas the major component (over 90%) did not [Suda, Y., Tochio, H., Kawano, K., Takada, H., Yoshida, T., Kotani, S., and Kusumoto, S. (1995) FEMS Immun. Med. Microbiol. 12, 97-112]. In the present study, the structure of the major component of LTA was studied in an attempt to elucidate the reason for the lack of the activity in the synthetic compounds. The major component of the LTA was first digested by hydrofluoric acid hydrolysis to cleave phosphodiester linkages present. The hydrolysis products were separated and characterized by means of NMR and MS. The linkage positions of the original phosphodiesters were determined from the NMR spectra of an alkali-treated product without hydrofluoric acid degradation. The compound was proved to consist of 1,3-linked poly(glycerophosphate) and a lipid anchor, Glc(alpha1-2)Glc(alpha1-3)acyl(2)Gro, the former being linked to the 6-position of the distal glucose of the latter. The 2-position of the glycerol residues in the glycerophosphate part were substituted by oligoglucose esterified partially with alanine. The gross structure elucidated here thus coincides with the previous conclusion described by Fischer [Fischer, W. (1990) in Glycolipids, Phosphoglycolipids and Sulfoglycolipids (Kates, M., ed.) pp. 123 234, Plenum Press, New York]. Thus, the molecular species with this so-called "LTA structure" is not responsible for the cytokine-inducing activity.

Alkaline Phosphatase↗
PubMed1997

Haplotypic diversity of DQA1*03 and *05 subtypes differing at amino acid residue 160 encoded in the third exon in 2215 Japanese individuals.

We analyzed the frequencies and haplotypes of DQA1*03 and *05 subtypes, DQA1*03011 or DQA1*0302 and DQA1*0501 or DQA1*0503, respectively, differing only at codon 160 in the non-polymorphic third exon of the DQA1 gene. Of these, 1,862 and 337 individuals selected as DQA1*03- and DQA1*05-positive samples, respectively among 2,215 unrelated Japanese were typed for their nucleotide variation at residue 160 using PCR-SSP. As observed in other populations, all the samples carrying DQA1*03011 (Gene Frequency, GF: 7.8%) were found to share DQB1*0302, whereas those carrying DQA1*0302 (GF: 44.3%) were associated with a variety of DQB1 alleles including DQB1*0302. Both of the DQA1-DQB1 haplotypes with DQA1*03011 and DQA1*0302 carrying DRB1*0406, DQA1*03011-DQB1*0302 and DQA1*0302-DQB1*0302, showed a strong linkage disequilibrium with B62 (p < 0.001, p < 0.05). These results suggested that DQA1*03011 was generated from a single amino acid change at residue 160 in the DQA1*0302-DQB1*0302 haplotype. However, none of the haplotypes with two different DQA1*03 subtypes carrying DRB1*0403,*0405,*0802 and *0901 showed a linkage disequilibrium with any common B-locus antigens, revealing extensive haplotypic diversity of the DQA1*03 group. For example, DRB1*0802 haplotypes showed linkage disequilibria with two different B-locus antigens, B35 and B61 depending on the presence of DQA1*03011 and DQA1*0302, respectively. The GFs of DQA1*0501 and *0503 were 5.1% and 2.7%, respectively. The DQA1*05 associated haplotypes in the DR52-antigen group with DQB1*0301 were divided into two groups, depending on the bimorphism at residue 160. Such a high degree of haplotypic diversity in association with DRB1 and B alleles observed in the DQA1*03 and *05 groups related to amino acid variation at residue 160, which may affect biological function such as the interaction between CD4 and HLA-DQ molecules, seems to reflect selective pressure in the evolutionary process of HLA antigens.

Alleles↗
PubMed1997

Malignant fibrous histiocytoma of the cecum: report of a case and review of the literature.

Malignant fibrous histiocytoma (MFH) of the gastrointestinal tract is extremely rare. Here we report a case of MFH of the cecum and review other cases of large bowel MFH in the literature. A 64-year-old man had a large tumor mass in the cecum associated with multiple small peritoneal implants. Histologically, most of the lesion showed inflammatory pseudotumor-like appearance; that is, a mixed proliferation of fibroblasts and myofibroblasts loosely arranged in sweeping fascicles or whorled structures and an admixture of chronic inflammatory cell infiltrate. The myofibroblastic nature of the spindle-shaped cells was confirmed by their immunohistochemical and ultrastructural findings. In addition, there was atypical histiocytic cells infiltrate in some areas and marked lymphatic involvement and lymph node metastasis by such histiocytic cells. These features were interpreted as MFH, although it had to be distinguished from inflammatory fibrosarcoma and leiomyosarcoma. The differential diagnosis is discussed here.

Actins↗