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Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 109 records · Page 6Linked to original sources
PubMed2001

Severe hypercholesterolemia in a double heterozygote for lipoprotein lipase deficiency (LPL(Arita)) and apolipoprotein epsilon4: a report of a family with LPL(Arita).

Although heterozygous lipoprotein lipase (LPL) deficiency is not rare, only part of the phenotypes may have been reported in Japan. Here we describe a Japanese family with LPL(Arita), the most common mutation linked to familial LPL deficiency in Japan, and show for the first time a heterozygote for the mutation who had marked hypercholesterolemia due to increased low-density lipoprotein (LDL) cholesterol. The proband's mother, one of the heterozygotes for LPL(Arita) in the family, had both severe hypercholesterolemia (total cholesterol 306 mg/dl) with an especially increase in LDL-cholesterol and mild hypertriglyceridemia (180 mg/dl). She had normal LDL receptor activity and did not show clear evidence of possible causes of secondary hyperlipidemia. In addition to being heterozygous for LPL deficiency, she was also heterozygous for apo epsilon4. Because the epsilon4 allele is known to be associated with higher LDL-cholesterol, heterozygous apo epsilon4 may be one of causes of her LDL-cholesterol elevation. The other three heterozygotes for LPL(Arita) were moderate drinkers, and all of them had both remarkable hypertriglyceridemia and mild hypercholesterolemia due to increased very-low-density lipoproteins (VLDL). The results suggest that heterozygotes for LPL(Arita) can exhibit various phenotypes of hyperlipidemia, that is, hypertrigliceridemia and/or hypercholesterolemia due to not only increased VLDL but also increased LDL. The phenotypes appear to depend on some other genetic and environmental factors.

Adult↗
PubMed2001

Neurosyphilis showing transient global amnesia-like attacks and magnetic resonance imaging abnormalities mainly in the limbic system.

We report a case of neurosyphilis with transient global amnesia (TGA)-like attacks on the first presentation. MRI abnormalities in bilateral limbic systems, including a few lesions in the basal ganglia and thalamus, were identified. Depression and dementia became apparent, accompanied by a high treponemal antibody titer and mild cortical atrophy. Antisyphilitic therapy brought about mild improvement, and the MRI abnormalities decreased.

Adult↗
PubMed2001

Familial adult onset primary alveolar hypoventilation syndrome.

A 41-year-old man fell into type II respiratory failure after catching a cold, and became dependent on a respirator. Chest radiography showed no abnormalities and the hyperventilation test showed improved arterial blood gas findings. His sleep study showed marked nocturnal desaturation due to hypopnea and apnea with a decrease of thoracic and abdominal movement during sleep. Therefore, we diagnosed him as primary alveolar hypoventilation syndrome (PAH). Seven years previously, his 2-year elder sister had suffered from similar respiratory failure during her second pregnancy and had been diagnosed as PAH. While myopathy was suspected in both cases, attenuation of muscle strength was slight and it appeared not to be the main cause of alveolar hypoventilation. Since medication was not effective in each case, they underwent non-invasive positive pressure ventilation (NIPPV). While sustained mild hypercapnia remained during the daytime, it improved their respiratory failure. To our knowledge, this is the first study of familial adult onset PAH.

Adult↗
PubMed2001

An autopsy case of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes syndrome with chronic renal failure.

A 25-year-old man developed a stroke-like episode. He suffered from renal failure and became dialysis-dependent. His mother was also dialysis-dependent. A3243G point mutation of the mitochondrial tRNA(leu) gene was detected in both of them. The patient was diagnosed with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), and died of a recurrence of stroke-like episodes at the age of 30. Autopsy revealed numerous abnormal mitochondria in the kidneys, but no renal vascular changes. This is the first report of a MELAS case in which the presence of numerous abnormal mitochondria in podocytes and tubules was confirmed by electron microscopy.

Acidosis, Lactic↗
PubMed2001

Pre-treatment with candesartan protects from cerebral ischaemia.

Angiotensin II (Ang II) regulates cerebral blood flow by stimulating cerebral vasoconstriction via AT1-receptors. In adult spontaneously hypertensive rats (SHR), the cerebrovascular autoregulatory curve is shifted to the right, in the direction of higher blood pressures, an indication of excessive cerebrovascular vasoconstriction. A restricted capacity to dilate cerebral blood vessels may be responsible for the enhanced vulnerability to cerebrovascular ischaemia during hypertension. We found that chronic treatment with the AT1-receptor antagonist, candesartan, (0.5 mg/kg/day for 14 days, via osmotic minipumps implanted in the subcutaneous tissue) blocked Ang II binding to AT1-receptors in cerebral blood vessels and in brain areas involved in the regulation of cerebrovascular flow, and increased the ratio of lumen-wall area in the middle cerebral artery. Candesartan treatment normalised the lower part of the autoregulatory curve in SHR, and markedly decreased cerebral ischaemia as a consequence of middle cerebral artery occlusion with reperfusion. Protection from ischaemia is related to arterial remodelling, enhanced compensatory vasodilatation in the peripheral area of ischaemia, decreased reduction in cerebral blood flow following the occlusion of a major cerebral blood vessel, and protection from injury in the periphery of the lesion. Our results indicate that pre-treatment with AT1-antagonists such as candesartan could be of benefit in the prevention and treatment of brain ischaemia.

Angiotensin Receptor Antagonists↗
PubMed2001

The effects of KNK437, a novel inhibitor of heat shock protein synthesis, on the acquisition of thermotolerance in a murine transplantable tumor in vivo.

A newly synthesized reagent, KNK437, has been found specifically to inhibit the synthesis of heat shock proteins in vitro. In this study, we investigated the effects of KNK437 on the synthesis of heat shock proteins and the induction of thermotolerance in transplantable tumors in vivo. SCC VII cells were grown in vivo and transplanted into C3H/He mice. The concentrations of KNK437 in the tumors and the sera of the mice were examined by high-performance liquid chromatography. Hsp72 synthesis was examined by Western immunoblot analysis. The response to hyperthermia was evaluated in terms of the delay in tumor growth. KNK437 had low toxicity in vivo. The concentration of KNK437 in the tumors gradually increased and reached a peak 6 h after i.p. injection. Hsp72 were synthesized 8 h after hyperthermia at 44 degrees C for 10 min, and their synthesis was inhibited by administration of KNK437 6 h before hyperthermia. At a concentration of 200 mg/kg, KNK437 alone showed no antitumor effects and did not increase the thermosensitivity of nontolerant tumors. The same dose of KNK437 enhanced the antitumor effects of fractionated heat treatment at 44 degrees C in a synergistic manner. This study strongly suggests the inhibition of thermotolerance via the inhibition of HSP72 in vivo. The inhibition of thermotolerance by KNK437 may help to improve the efficacy of clinical fractionated hyperthermia.

Animals↗
PubMed2001

Coronary artery bypass grafting in patients with dialysis-dependent renal failure.

The aim of this study was to define short- and long-term results of coronary artery bypass grafting (CABG) in dialysis patients. A retrospective review was carried out on 73 consecutive patients dependent on chronic dialysis who underwent CABG. In 63 isolated CABGs, 9 operations were performed under normal beating heart because of severe atherosclerotic changes in the ascending aorta or carotid arteries. The operative mortality (30 days' mortality) was 4.1%, and causes of death were closely related to cardiopulmonary bypass use. In the last 29 operations after introduction of the beating heart bypass, no hospital deaths occurred. The actual survival rates dropped to 45% at 70 months mainly for noncardiac late death. CABG for dialysis patients as undertaken with an acceptable operative risk. Extended application of beating heart bypass to these patients may produce further positive early results.

Adult↗
PubMed2001

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (5)--Six-month repeated oral dose toxicity study and supplement study in rats].

Cefmatilen hydrochloride hydrate (S-1090) was orally administered to rats at dose levels of 100, 300 and 1000 mg potency/kg once daily for 6 months. All the S-1090 treated groups showed soft feces, reddish-brown feces (due to chelated products of S-1090 or its decomposition products with Fe3+ in the diet), abdominal distention, increased food and water consumption, lower urine pH, and a decrease of white blood cells counts (except for males of the 100 mg potency/kg group). One male in the 300 mg potency/kg group showed mucous feces and marked decrease in body weight, and diet in the middle stage of the administration period. In necropsy of the survivors of all treated groups, marked cecal enlargement was noted. No remarkable changes were observed in the other examination items. From the early stage of the withdrawal period, animals in the 1000 mg potency/kg group showed again soft or mucous feces and a marked decrease in body weight. Of these animals, one male died and another male was sacrificed in a moribund state at about 2 weeks of the withdrawal period. Enterocolitis was observed in these cases. Almost all animals recovered within 3 weeks of withdrawal. A supplemental study of the 6-month toxicity study was conducted to examine the mechanisms of enterocolitis and the changes observable in the 100 or 300 mg potency/kg groups after drug withdrawal. As a reference, cefdinir (CFDN), an oral cephem antibiotic the same as S-1090, was added in the 1000 mg potency/kg group. No deaths occurred in any groups. Decreased intestinal flora were noted in all the groups treated with S-1090 or CFDN at the end of the dosing period. At 2 weeks of the withdrawal period, C. difficile and its D-1 toxin in the cecal contents were highly detected in the S-1090 300 and 1000 mg potency/kg groups and CFDN group. Inflammatory changes in the cecum and colon were observed in these groups. At 4 weeks of the withdrawal period, intestinal flora in the S-1090 groups almost returned to the condition before dosing, but those in the CFDN group were retained highly. Cecal D-1 toxin in the CFDN group was positive and higher than in the S-1090 groups. It was thus considered that the critical condition with enterocolitis resulted from C. difficile, which proliferated more rapidly than the other bacteria and D-1 toxin produced by this bacteria in the withdrawal period. Above changes were commonly observed in the CFDN group. The NOAEL of S-1090 was assessed to be 100 mg potency/kg/day which induced no enteritis.

Administration, Oral↗
PubMed2001

[A case of primary Sjögren's syndrome with acute transverse myelopathy and polyneuropathy as the initial manifestations].

We report a case of primary Sjögren's syndrome with acute transverse myelopathy and polyneuropathy as the initial manifestations. A 72-year-old man developed acute right hemiparesis and his symptoms deteriorated to quadriparesis in four days. A cervical spinal MRI showed an extensive intraparenchymal lesion with high T2-weighted signal intensity, gadolinium enhancement, and cord swelling. An electromyographic study and a sural nerve biopsy showed severe axonal degeneration. The patient complained of thirst and a salivary gland biopsy revealed inflammatory changes, while salivary gland scintigraphy showed diminished secretion. These findings led to a diagnosis of Sjögren's syndrome. Only one case of Sjögren's syndrome with acute transverse myelopathy as the initial manifestation has been reported. In our case, however, polyneuropathy was observed in addition to transverse myelopathy as the initial manifestation. Even if prominent sicca symptoms are absent, all patients with acute transverse myelopathy and polyneuropathy should be carefully examined with considerations of possible presence of Sjögren's syndrome.

Aged↗
PubMed2001

[AML(M7) associated with t(16;21)(p11;q22) showing relapse after unrelated bone marrow transplantation and disappearance of TLS/FUS-ERG mRNA].

A 3-year-old boy with poorly prognostic acute megakaryoblastic leukemia (AML M7) showing t(16;21)(p11;q22) karyotype underwent unrelated bone marrow transplantation (U-BMT) during his first hematological remission. The conditioning regimen consisted of BU, VP-16 and L-PAM. Engraftment was smooth, but the patient developed grade I acute GVHD. During hematological remission before U-BMT, the TLS/FUS-ERG chimeric transcript of t(16;21)(p11;q22) was consistently detectable as minimal residual disease (MRD) by RT-PCR. However, after U-BMT it soon became undetectable. There was no detectable MRD until 7 months after U-BMT, but bone marrow relapse occurred 10 months after U-BMT. We consider that U-BMT is a promising treatment for t(16;21)(p11;q22) AML. However, an intensified conditioning regimen or modification of GVHD prophylaxis is needed.

Bone Marrow Transplantation↗
PubMed2001

[A patient of chronic graft-versus-host disease presenting simultaneously with polymyositis and myasthenia gravis].

We report a patient of polymyositis and myasthenia gravis as manifestations of chronic graft-versus-hot disease (GVHD). A 48-year-old man was diagnosed as having chronic myelogenous leukemia at the age of 42 years, and had bone marrow transplantation (BMT) two years after the onset of the disease. Since he suffered from mild liver dysfunction and cutaneous involvement manifesting chronic GVHD, he was placed on prednisolone and cyclophosphamide. As his condition improved, the prednisolone was gradually tapered. Forty-one months after the BMT, the patient developed muscle pain and muscle weakness. A diagnosis of polymyositis was made from muscle biopsy and laboratory findings. An increase in the prednisolone dose was effective but a few weeks later the patient noticed ptosis and recurrence of muscle weakness. A tensilon test and anti-acetylcholine receptor antibody produced positive results, leading to a diagnosis of myasthenia gravis. Only one case of polymyositis and myasthenia gravis as manifestations of chronic GVHD has been reported, and in our patient both symptoms appeared almost at the same time. Although neuromuscular symptoms as a manifestation of chronic GVHD are rare, all patients receiving BMT should be carefully followed up neurologically to detect neuromuscular complications.

Bone Marrow Transplantation↗
PubMed2000

Coordination control of intramolecular electron transfer in boronate-bridged zinc porphyrin-diimide molecules.

Three sets of dyads, in which a zinc-porphyrin (ZP) electron donor is connected to an aromatic diimide electron acceptor,either pyromellitimide (PI) or naphthalene-1,8:4,5-tetracarboxylic acid diimide (NI), via a boronate-ester bridge, a piperidine bridge, and a 1,3-dioxolane bridge, respectively, were prepared for the purpose of control of intramolecular electron transfer (ET) by acid-base reactions at the connecting bridge. Boronate-ester bridge is a Lewis acidic site and confers a chance to regulate intramolecular ET reaction upon base coordination. This has been demonstrated by suppression of photoinduced ET from ZP to PI or NI in highly electron-pair donating solvents or upon addition of a fluoride anion. To extend this strategy to control of ET-path selectivity, we prepared triad 18, which consists of a ZP donor bearing NI and PI acceptors at similar distances through a boronate-ester bridge and an acetal bridge, respectively. Photoexcitation of 18 in a free form led to intramolecular ET from (1)()ZP preferentially to NI, but the ET path was completely switched toward PI in F(-)-coordinated form without a serious drop in the rate, constituting a novel ET-switching molecular system.

Journal Article↗
PubMed2000

Synthesis of 6-acetamido-5-amino- and -5-guanidino-3, 4-dehydro-N-(2-ethylbutyryl)- 3-piperidinecarboxylic acids related to zanamivir and oseltamivir, inhibitors of influenza virus neuraminidases.

[reaction: see text] 6-Acetamido-5-amino- and -5-guanidino-3, 4-dehydro-N-(2-ethylbutyryl)-3-piperidinecarboxylic acids (8 and 9) have been synthesized starting from natural siastatin B, a bacterial neuraminidase inhibitor isolated from Streptomyces culture in a stereospecific fashion. These compounds are related to zanamivir and oseltamivir, inhibitors of influenza virus neuraminidases.

Acetamides↗
PubMed2000

Ligation of HLA-DR molecules on B cells induces enhanced expression of IgM heavy chain genes in association with Syk activation.

Signals transmitted by class II major histocompatibility complex are important regarding cell function related to antigen presentation. We examined effects of DR-mediated signaling on Ig production from B cells. Cross-linking HLA-DR molecules on B cells by solid-phase anti-HLA-DR monoclonal antibodies, led to an increased production of IgM, without proliferation or apoptosis. This event was accompanied by an enhanced expression of both membrane- and secretory-type IgM heavy chain mRNA. When peptide-pulsed B cells were co-incubated with an HLA-DR-restricted T cell clone treated by the protein synthesis inhibitor emetine, peptide-induced de novo expression of lymphokines and cell-surface molecules on T cells can be neglected. CD40-CD154 interaction was not involved in IgM enhancement, in such a system. The protein-tyrosine kinase inhibitors and the Syk inhibitor piceatannol, but not the Src inhibitor PP2 had a marked inhibitory effect on IgM secretion. Furthermore, ligation of HLA-DR on B cells using the F(ab')2 fragment of anti-DR monoclonal antibody, enhanced Syk activity. Our data suggest that HLA-DR on B cells not only present antigenic peptides to T cells, but also up-regulate IgM production, in association with Syk activation and without the involvement of Src kinases, hence the possible physiological relevance of Src-independent Syk activation.

Animals↗
PubMed2000

Increased phospholipase D2 activity during hypoxia-induced death of PC12 cells: its possible anti-apoptotic role.

During hypoxic incubation (1% O2) of PC12 cells, the PLD activity was transiently increased within 12h, followed by a gradual decrease. In the in vitro assay, the increased PLD activity was independent of GTPgammaS required for PLD1 or of oleic acid for PLD(OA), suggesting the activation of PLD2. The level of PLD2 protein showed no change up to 12h but a gradual decrease after 24 h. Pretreatment of cells with S. chromofuscus PLD resulted in inhibition of hypoxia-induced apoptotic cell death. In contrast, 1-butanol, but not 2-butanol, potentiated cell death. Moreover, the number of apoptotic cells significantly reduced in PC12 cells over-expressing PLD2. These results raise the possibility that PLD2 activation may play an anti-apoptotic role in hypoxia-induced cell death.

1-Butanol↗