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Biomedical subjects

M Miyahara

Publications and source records attributed to M Miyahara.

At least 37 records · Page 2Linked to original sources
PubMed2000

Acute myocardial infarction in a patient with anomalous left coronary artery origin and primary antiphospholipid syndrome.

Anomalous left main coronary artery (LMCA) originating from the right coronary sinus and running between the aorta and pulmonary trunk is a rare congenital condition. Although this disease is known to be associated with myocardial infarction and sudden death, the precise mechanism is uncertain. A 14-year-old male with this anomaly developed myocardial infarction during exercise complicated by primary antiphospholipid syndrome. He was admitted to hospital with persistent chest pain and sudden cardiac collapse that occurred while he was running. Cardiac catheterization demonstrated a narrowed segment in the LMCA and impaired blood flow, prompting a diagnosis of extensive anterior myocardial infarction. Emergency bypass surgery was performed using a single saphenous vein graft to the left anterior descending artery. Postoperative angiography showed the presence of an anomalous LMCA arising from the right sinus of Valsalva and running between the great vessels. The aortic samples were pathologically normal. He was discovered to also have primary antiphospholipid syndrome and was discharged without symptoms after warfarin therapy. Complicated primary antiphospholipid syndrome may trigger myocardial infarction in asymptomatic patients with this type of coronary anomaly.

Acute Disease↗
PubMed2000

Aorto-coronary dissection during angioplasty in a patient with myxedema.

A 67-year-old man with overt hypothyroidism and medically controlled hypertension was admitted for coronary angiography because of exertional angina. His triiodothyronine (T3) and thyroxine (T4) levels had been low for 4 years. Although signs and symptoms of hypothyroidism were apparent, his hypercholesterolemia was mild. Coronary angiography revealed an eccentric stenosis in the distal portion of the right coronary artery and it was decided to perform angioplasty because his angina had continued in spite of medication. The dissection appeared at the lesion site after the first nominal inflation, and a subsequent image disclosed a spiral dissection from the dilated site to the aortic sinus and peripheral coronary artery. Although emergency stenting could not prevent the extension near the origin of the brachiocephalic artery, the false lumen thrombosed and then diminished with conservative therapy. Aorto-coronary dissection is potentially life-threatening and has been recently reported as a complication during cardiac catheterization procedures. Chronic hypothyroid insufficiency may be one of the risk factors for this complication.

Aged↗
PubMed2000

Laparoscopic colectomy for Dukes A colon cancer.

The use of laparoscopic surgery to treat colon cancer has been well studied; however, the specific use of laparoscopic colectomy for Dukes A colon cancer has not been evaluated. The data of laparoscopic colectomy were compared with those of conventional open colectomy, and the surgical results of patients who underwent surgery for Dukes A colon cancer were evaluated. Between November 1993 and October 1997, 20 patients underwent laparoscopic colectomy for Dukes A colon cancer. Operation time, blood loss, first passage of flatus, day of resumption of oral intake, length of hospital stay after surgery, and number of dissected lymph nodes were compared between 20 patients who underwent laparoscopic colectomy and 23 patients who underwent conventional open colectomy for Dukes A colon cancer. In patients with laparoscopic colectomy, when compared with those with conventional open colectomy, mean blood loss was less (103 g vs. 318 g), flatus returned more quickly (3.5 days vs. 4.2 days), oral intake resumed earlier (3.7 days vs. 4.7 days), and postoperative hospital stay was shorter (16.4 days vs. 24.6 days). The mean number of dissected lymph nodes was not different between the two groups (9.2 vs. 9.2 for D2 dissection). No patient had port-site metastasis or recurrence during a follow-up period from 13 to 60 months (median, 38 months). Review of the literature and the authors' findings indicated that none of the 142 reported patients had port-site metastasis after laparoscopic colectomy for Dukes A colon cancer. The results indicate that laparoscopic colectomy is safe and useful when applied to patients with Dukes A colon cancer and performed carefully by trained surgeons.

Adult↗
PubMed2000

MLL gene rearrangement in t(9;11) acute myelogenous leukemia with minimal myeloid differentiation (FAB subtype M0).

A 25-year-old man was diagnosed with acute myelogenous leukemia (AML), French-American-British (FAB) subtype M0, based on cytochemical and flow cytometric findings. Cytogenetic analysis revealed the chromosome translocations t(9;11)(p22;q23), and MLL gene rearrangement was identified by Southern blotting. In adult AML, MLL gene rearrangement was initially reported in FAB M4 and M5 cases, and recently in M1 and M2 cases, but was rare in M0 or M3 cases. Because the sensitivity of detecting MLL gene rearrangement by cytogenetic analysis is extremely low compared with Southern blotting analysis, the MLL gene may be involved in substantial numbers of adult AML cases, regardless of FAB subtype.

Adult↗
PubMed1999

Effects of Hydrophobizing Methods of Surfaces on the Interaction in Aqueous Solutions.

The hydrophobic interaction between the surfaces hydrophobized by the adsorption of STAC in a STAC solution (system I) and the interaction between the surfaces hydrophobized by the reaction with OTS in water (system II) were investigated using an atomic force microscope, and their difference was compared. Clear differences of the interaction between systems I and II were found with respect to the force curves and the morphology of the surfactants adsorbed on the surfaces. It is postulated that the hydrophobic interaction for system II is attributable to the cavity bridging between the surfaces, but that for system I it is originated from a different mechanism. It is also implied that the existence of the surfactants in the bulk will play an important role for the hydrophobic interaction. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Nectin/PRR: an immunoglobulin-like cell adhesion molecule recruited to cadherin-based adherens junctions through interaction with Afadin, a PDZ domain-containing protein.

We have isolated a novel actin filament-binding protein, named afadin, localized at cadherin-based cell-cell adherens junctions (AJs) in various tissues and cell lines. Afadin has one PDZ domain, three proline-rich regions, and one actin filament-binding domain. We found here that afadin directly interacted with a family of the immunoglobulin superfamily, which was isolated originally as the poliovirus receptor-related protein (PRR) family consisting of PRR1 and -2, and has been identified recently to be the alphaherpes virus receptor. PRR has a COOH-terminal consensus motif to which the PDZ domain of afadin binds. PRR and afadin were colocalized at cadherin-based cell-cell AJs in various tissues and cell lines. In E-cadherin-expressing EL cells, PRR was recruited to cadherin-based cell-cell AJs through interaction with afadin. PRR showed Ca2+-independent cell-cell adhesion activity. These results indicate that PRR is a cell-cell adhesion molecule of the immunoglobulin superfamily which is recruited to cadherin-based cell-cell AJs through interaction with afadin. We rename PRR as nectin (taken from the Latin word "necto" meaning "to connect").

Alternative Splicing↗
PubMed1999

Different behavior of l-afadin and neurabin-II during the formation and destruction of cell-cell adherens junction.

We have recently isolated two novel actin filament-binding proteins, l-afadin and neurabin-II and shown that they are localized at cell-cell adherens junction (AJ) in epithelial cells. We found here that l-afadin, neurabin-II, ZO-1, and E-cadherin showed similar and different behavior during the formation and destruction of cell-cell AJ in MDCK cells. In MDCK cells, the accumulation of both l-afadin and E-cadherin, but not that of ZO-1, changed in parallel depending on Rac small G protein activity. Dissociation of MDCK cells by culturing the cells at 2 microM Ca2+ caused rapid endocytosis of E-cadherin, but not that of l-afadin or ZO-1. Addition of phorbol 12-myristate 13-acetate to these dissociated cells formed a tight junction-like structure where ZO-1 and l-afadin, but not neurabin-II or E-cadherin, accumulated. We furthermore found that, in non-epithelial EL cells, which expressed E-cadherin and attached to each other, l-afadin, neurabin-II, ZO-1 and E-cadherin were all localized at AJ. In cadherin-deficient L cells, I-afadin was mainly localized at cell-cell contact sites, but ZO-1 was mainly localized at the tip area of cell processes. Neurabin-II did not accumulate at the plasma membrane area. Neither l-afadin nor neurabin-II significantly interacted with alpha-, beta-catenin, E-cadherin, ZO-1 or occludin.

Amino Acid Sequence↗
PubMed1999

Magnetic Effect on Ion-Exchange Kinetics.

Effects of magnetic exposure on an ion-exchange process are investigated, employing ion-exchange resins. The electrolyte solution, resin suspension, and water are mixed in a container, and the mass transfer coefficient is determined by measuring the change of the ionic concentration in the bulk. Two methods of magnetic exposure are performed: case (1) in which only the electrolyte solution is exposed to the magnetic field and case (2) in which only the resin suspension is exposed to the magnetic field. The following features are found in both cases: (i) the film mass transfer rate reduces by about 5% when the exposure time is greater than 25 min, (ii) the magnetic effect is reduced by adding the alcohol, (iii) the magnetic effect remains for about 3 days but disappears after 6 days, and (iv) the magnetic effect is observable in the solutions of structure-disordering ions, but not in the solutions of structure-ordering ions. As for the temperature dependence, the magnetic effect decreases with temperature in case (1) but it stays constant in case (2). It is postulated that the magnetic effects are attributable to the stabilization of water molecules around the structure-ordering ion and those on the resin surface. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Evaluation of Interaction Forces between Macroparticles in Simple Fluids by Molecular Dynamics Simulation.

The present article provides the description of the solvation forces between large spheres in a fluid. The molecular dynamics (MD) method was applied to the relatively simple systems in which a pair of structureless macroparticles, either solvophobic or solvophilic, is immersed in a simple fluid of two types, either a soft-sphere or a Lennard-Jones fluid. When a pair of solvophobic macroparticles was in the attractive Lennard-Jones fluid, no dense layer of the solvent particles formed near the surface of the macroparticles and the strong attractive forces were induced between them. In the other combinations of macroparticles and fluids, the dense layers formed and the solvation forces oscillated, exhibiting the attraction and repulsion, whose periodic distance was about the diameter of solvent particles. Our results agreed well with those of the other simulation and theoretical studies with respect to the solvent density profile near a macroparticle and the force-distance profile between macroparticles. The benefit of our approach would be the simplicity in specifying or finding the bulk condition that is in equilibrium with the thin film of molecules between large surfaces. The present method can be applied straightforward to macroparticles immersed in mixtures and complex fluids described by the bead-spring model, to which the conventional grand canonical ensemble Monte Carlo (GCEMC) method is hardly accessible. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

HLA-A33 and -B44 and susceptibility to postherpetic neuralgia (PHN).

HLA class I and class II alleles of 32 Japanese patients with postherpetic neuralgia (PHN) and 136 healthy controls were analyzed by serological (class I) and DNA (class II) typing for any significance in the susceptibility to varicella-zoster virus (VZV). We recognized positive associations of the development of PHN with the HLA class I antigens HLA-A33 and -B44, and the HLA-A33-B44 haplotype. This haplotype is tightly linked to DRB1*1302 in a Japanese healthy population. However, no significant association between PHN and HLA class II alleles was observed with no linkage of the HLA haplotype HLA-A33-B44 to HLA-DRB1*1302 in the patients with PHN. These findings suggest that HLA class I gene may genetically control the immune response against VZV in the pathogenesis of PHN.

Aged↗
PubMed1999

Follow-up of clinical efficacy of iontophoresis therapy for postherpetic neuralgia (PHN).

A great variety of therapies have been attempted for PHN, including pharmacotherapy and physical therapy. However, there has been no decisive treatment, and reports of the clinical efficacy of all available therapies have been rather controversial. Almost all studies conducted so far have looked only at short-term therapeutic efficacy, and only a few investigators have conducted long-term observations or studies on long-term outcome. We followed up the clinical efficacy of iontophoresis therapy using lidocaine and methylprednisolone in 197 PHN patients. Monitoring conducted for an average of 4 years after completion of the treatment showed that pain remained unchanged or improved compared to pain observed upon completion of the treatment in 90.4% of patients. Although 42.6% of patients were still continuing some treatment, 90.9% were found to be able to take care of themselves. Findings obtained were reviewed and discussed from various viewpoints. Our findings showed that iontophoresis therapy is not only effective at the end of the treatment, but its efficacy is maintained over a long period of time, indicating that it is clinically very useful for the treatment of PHN.

Adult↗
PubMed1999

Successful treatment of cytomegalovirus colitis with ganciclovir in a patient with adult T cell leukemia lymphoma: case report.

An 84-year-old patient with adult T cell leukemia lymphoma (ATLL) developed diarrhea on day 5 of chemotherapy and was diagnosed with cytomegalovirus (CMV) colitis. Sigmoidoscopy revealed multiple superficial erosions surrounded by a flare. Computed tomography (CT) and ultrasonogram of the abdomen revealed marked thickening of the colonic mucosa. There were 186 CMV antigen-positive leukocytes per 31,000 white blood cells (WBC). A colonic biopsy specimen showed typical CMV nuclear inclusions. Immunohistological study of the specimen was positive for CMV antigen. Administration of ganciclovir (DHPG) 500 mg/day for 14 days improved the diarrhea and other symptoms. On day 30 of the chemotherapy, the patient developed diarrhea again but was diagnosed with pseudomembranous colitis instead of CMV colitis. At that time, CMV antigenemia and a histologic study for CMV were negative. The stool was positive for Clostridium difficile toxin antigen. ATLL patients are believed to be immunocompromised hosts and often develop opportunistic infections such as CMV infection. Most suffer from CMV pneumonia at the end of their course of therapy. Few gastrointestinal (GI) CMV infections are seen in ATLL patients and details of CMV colitis have never been reported. When an ATLL patient develops diarrhea that barely responds to conventional therapy, CMV colitis and pseudomembranous colitis should be listed in the differential diagnosis.

Aged↗
PubMed1999

[Nutcracker phenomenon treated with left renal vein transposition: a case report].

Herein is reported a case of the nutcracker phenomenon with severe gross hematuria which was surgically treated. A 14-year-old boy had been suffering from left flank pain and recurrent gross hematuria causing urinary retention with blood clots. Radiological images including three-dimensional computed tomography (CT) and angiography disclosed the nutcracker phenomenon with left renal venous hypertension. Since the aforementioned symptoms could not be managed conservatively, he underwent transposition of the left renal vein at 5.5 cm caudal from the original position. Postoperative course was uneventful and the patient has had no further hematuria after the surgery.

Adolescent↗
PubMed1998

Hepatocyte injury in tyrosinemia type 1 is induced by fumarylacetoacetate and is inhibited by caspase inhibitors.

Tyrosinemia type 1, caused by mutations in the fumarylacetoacetate hydrolase gene (Fah), is characterized by severe liver injury. We earlier developed a tyrosinemic mouse model with two genetic defects, Fah and 4-hydroxyphenylpyruvate dioxygenase (Hpd) deficiencies. Apoptosis of hepatocytes was induced and an acute onset of liver failure occurred after administration of homogentisic acid (HGA), the intermediate metabolite between the enzymes HPD and FAH. Cytochrome c was released from mitochondria prior to liver failure in the Fah-/- Hpd-/- double-mutant mice after the administration of HGA. In a cell-free system, the addition of fumarylacetoacetate induced the release of cytochrome c from the mitochondria. We also found that caspase inhibitors were highly effective in preventing the liver failure induced by HGA in the double-mutant mice. Therefore, fumarylacetoacetate apparently induces the release of cytochrome c, which in turn triggers activation of the caspase cascade in hepatocytes of subjects with hereditary tyrosinemia type 1.

Acetoacetates↗
PubMed1998

Frabin, a novel FGD1-related actin filament-binding protein capable of changing cell shape and activating c-Jun N-terminal kinase.

We purified from rat brain a novel F-actin-binding protein with a Mr of about 105,000 (p105), which was estimated by SDS-polyacrylamide gel electrophoresis. We cloned its cDNA from a rat brain cDNA library and characterized it. p105 was a protein of 766 amino acids and showed a calculated Mr of 86,449. p105 consisted of one F-actin-binding domain at the N-terminal region, one Dbl homology domain and one pleckstrin homology domain at the middle region, and one cysteine-rich domain at the C-terminal region. This domain organization of p105 was similar to that of FGD1, which has been determined to be the genetic locus responsible for faciogenital dysplasia or Aarskog-Scott syndrome. We therefore named p105 frabin (FGD1-related F-actin-binding protein). Frabin bound along the sides of F-actin and showed F-actin-cross-linking activity. Overexpression of frabin in Swiss 3T3 cells and COS7 cells induced cell shape change and c-Jun N-terminal kinase activation, respectively, as described for FGD1. Because FGD1 has been shown to serve as a GDP/GTP exchange protein for Cdc42 small G protein, it is likely that frabin is a direct linker between Cdc42 and the actin cytoskeleton.

Actins↗
PubMed1998

T cell epitopes in Japanese cedar (Cryptomeria japonica) pollen allergens: choice of major T cell epitopes in Cry j 1 and Cry j 2 toward design of the peptide-based immunotherapeutics for the management of Japanese cedar pollinosis.

Japanese cedar pollinosis is caused by exposure to Japanese cedar (Cryptomeria japonica) pollen, of which two components, Cry j 1 and Cry j 2, are believed to be the major allergens. T cell lines specific to either Cry j 1 or rCry j 2 were reactive to various portions of each panel of overlapping peptides derived from Cry j 1 or Cry j 2. Two peptides, p211-225 and p108-120, from among six major T cell epitopes identified in Cry j 1 sequence, and three peptides, p182-200, p344-355, and p66-80, from among five in Cry j 2, were chosen to design an artificial polypeptide (named Cry-consensus) based on a difference among the types of the restriction molecules capable of presenting these peptides. After construction of a DNA encoding these peptides in order, Cry-consensus was expressed in Escherichia coli. Five of six T cell epitopes, except for Cry j 2 p344-355, in Cry-consensus were recognized by the T cell clones specific to each peptide. PBMC from allergic patients induced higher proliferation under stimulation from Cry-consensus than individual peptides. Eighty-eight percent of the PBMC (15 of 17) showed proliferation under the Cry-consensus stimulation. Thus, several major T cell epitopes from Cry j 1 and Cry j 2 can be chosen in the design of peptide-based immunotherapeutics for the management of Japanese cedar pollinosis in subjects having various types of HLA class II molecules.

Adult↗
PubMed1998

New method for determining prognosis of patients with psoriasis (E-PAP).

We developed a new method for evaluating clinical symptoms of psoriasis during the observation period, by adding a parameter of time (the number of days) to the psoriasis area and severity index (PASI). This method was named the evaluation for prognosis with averaged PASI (E-PAP). Using this method, we assessed 14 cases to determine the following items: (1) clinical symptoms during the observation period; (2) clinical effects of treatments; (3) patient's satisfaction with treatments; and (4) necessity for additional and/or alternate treatments. We evaluated the usefulness of E-PAP in determining the prognosis of patients with psoriasis by comparing the uninterrupted monotherapy and intermittent therapy with cyclosporin A (Cys A). Although there were no differences in Cys A dosages after remission as well as adverse reactions between the two groups, the E-PAP value was significantly different between them. These results suggest that this method may be useful for determining the prognosis of patients with psoriasis.

Antirheumatic Agents↗