Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 343 records · Page 19Linked to original sources

PubMed1999

Iron chelator deferoxamine reduces preneoplastic lesions in liver induced by choline-deficient L-amino acid-defined diet in rats.

The aim of this study was to investigate whether an iron chelator, deferoxamine (DFO) can prevent lipid peroxidation, resulting in reduced liver injury as well as reducing preneoplastic lesions induced by a choline-deficient L-amino acid-defined (CDAA) diet. CDAA diet administration resulted in an increased serum ALT level (367 +/- 58) after two weeks, but simultaneous DFO treatment for two weeks reduced this elevation of ALT as well as malondialdehyde (MDA) production in the liver. Feeding rats a CDAA diet for 12 weeks led to the development of severe liver fibrosis and preneoplastic lesions detected as enzyme-altered lesions. DFO treatment prevented the expression of activated stellate cells, resulting in the reduction of liver fibrosis as well as reducing the development of preneoplastic lesions. These results indicate that iron chelation can reduce the development of preneoplastic lesions in a CDAA diet model.

Alanine Transaminase↗

PubMed1999

Prevention of B220+ T cell expansion and prolongation of lifespan induced by Lactobacillus casei in MRL/lpr mice.

We examined the therapeutic effect of heat-killed Lactobacillus casei (LC) on MRL/lpr mice. Ingestion of a diet containing 0.05% (w/w) LC from the weaning period prolonged the lifespan and tended to reduce the proportion of B220+ T cells in the spleen and mesenteric lymph nodes (MLN) of MRL/lpr mice. When LC was intraperitoneally injected once a week after the age of 8 weeks, I-A- macrophages accumulated in the spleen as well as the peritoneum and macrophage progenitors increased in the bone marrow. Moreover, the amount of IL-6 mRNA in peritoneal macrophages was reduced by LC injection. Splenocytes from LC-injected MRL/lpr mice exhibited lower proliferative responses to mitogens than those from control MRL/lpr mice and the increase in number of B220+ T cells in the spleen and MLN was prevented by LC injection. However, LC injection affected neither expression of interferon-gamma (IFN-gamma) and IL-4 mRNAs nor proliferative capacities of splenic T cells. Our findings demonstrate that LC injection accelerates macrophage recruitment and prevents the expansion of B220+ T cells without affecting the functions of T cells in MRL/lpr mice. These immunological modulations induced by LC may lead to prolongation of the lifespan of MRL/lpr mice.

Administration, Oral↗

PubMed1999

Two-dimensional electrophoresis of Malassezia allergens for atopic dermatitis and isolation of Mal f 4 homologs with mitochondrial malate dehydrogenase.

The yeast Malassezia furfur is a natural inhabitant of the human skin microflora that induces an allergic reaction in atopic dermatitis. To identify allergens of M. furfur, we separated a crude preparation of M. furfur antigens as discrete spots by 2-D PAGE and detected IgE-binding proteins using sera of atopic dermatitis patients. We identified the known allergens, Mal f 2 and Mal f 3, and determined N-terminal amino acid sequences of six new IgE-binding proteins including Mal f 4. The cDNA and genomic DNA encoding Mal f 4 were cloned and sequenced. The gene was mitochondrial malate dehydrogenase and encoded Mal f 4 composed of 315 amino acids and a signal sequence of 27 amino acids. We purified Mal f 4, which had a molecular mass of 35 kDa from a membrane fraction of a lysate of cultured cells. Thirty of 36 M. furfur-allergic atopic dermatitis patients (83.3%) had elevated serum levels of IgE to purified Mal f 4, indicating that Mal f 4 is a major allergen. There was a significant correlation of the Phadebas RAST unit values of Mal f 4 and the crude antigen, but not between Mal f 4 and the known allergen Mal f 2.

Allergens↗

PubMed1999

Malignant fibrous histiocytoma of the spermatic cord: a case report.

We present a case of malignant fibrous histiocytoma of the spermatic cord. An 86-year-old man was admitted to the hospital with a right painless scrotal mass. Under the diagnosis of a testicular tumor, right radical orchiectomy was performed. Grossly, the tumor firmly adhered to the spermatic cord. The right testis and epididymis were normal. The histologic diagnosis was malignant fibrous histiocytoma. There was local recurrence 2 months after surgery. The recurrent tumor was resected with the surrounding soft tissue, but the patient died 5 months after the initial operation.

Aged↗

PubMed1999

Hamartoma of the urinary bladder.

BACKGROUND: Hamartomas of the urinary bladder are extremely rare. We report on a case in a 58-year-old female who presented with the chief complaint of pain on urination. METHODS/RESULTS: Cystoscopy revealed a solid tumor on the left posterior wall of the bladder. Transurethral resection of the tumor failed to provide a definitive pathological diagnosis of the tumor. Thus, we performed partial cystectomy. The pathological diagnosis was hamartoma arising from the urinary bladder. CONCLUSION: This is the ninth case diagnosed as urinary bladder hamartoma to be reported in the literature.

Cystoscopy↗

PubMed1999

Protein-bound acrolein: a novel marker of oxidative stress in Alzheimer's disease.

Several lines of evidence support the role of oxidative stress, including increased lipid peroxidation, in the pathogenesis of Alzheimer's disease (AD). Lipid peroxidation generates various reactive aldehydes, such as 4-hydroxynonenal (HNE), which have been detected immunochemically in AD, particularly in neurofibrillary tangles, one of the major diagnostic lesions in AD brains. A recent study demonstrated that acrolein, the most reactive among the alpha,beta-unsaturated aldehyde products of lipid peroxidation, could be rapidly incorporated into proteins, generating a carbonyl derivative, a marker of oxidative stress to proteins. The current studies used an antibody raised against acrolein-modified keyhole limpet hemocyanin (KLH) to test whether acrolein modification of proteins occurs in AD. Double immunofluorescence revealed strong acrolein-KLH immunoreactivity in more than half of all paired helical filament (PHF)-1-labeled neurofibrillary tangles in AD cases. Acrolein-KLH immunoreactivity was also evident in a few neurons lacking PHF-1-positive neurofibrillary tangles. Light acrolein-KLH immunoreactivity occurred in dystrophic neurites surrounding the amyloid-beta core, which itself lacked acrolein-KLH staining. The pattern of acrolein-KLH immunostaining was similar to that of HNE. Control brains did not contain any acrolein-KLH-immunoreactive structures. The current results suggest that protein-bound acrolein is a powerful marker of oxidative damage to protein and support the hypothesis that lipid peroxidation and oxidative damage to protein may play a crucial role in the formation of neurofibrillary tangles and to neuronal death in AD.

Acrolein↗

PubMed1999

Expression of PRAD1/cyclin D1, retinoblastoma gene products, and Ki67 in parathyroid hyperplasia caused by chronic renal failure versus primary adenoma.

BACKGROUND: In primary hyperparathyroidism, certain genetic abnormalities responsible for parathyroid tumorigenesis are proposed, and it has been reported that the overexpression of PRAD1/cyclin D1 induced by a DNA rearrangement of the parathyroid hormone (PTH) gene is one of the genetic disorders in a number of primary parathyroid adenomas. However, in secondary hyperparathyroidism caused by uremia, the mechanism of monoclonal proliferation in nodular parathyroid hyperplasia is not well understood. To elucidate the mechanism, we examined the expression of PRAD1/cyclin D1, retinoblastoma gene products, and Ki67 in primary adenoma and secondary hyperplasia. METHODS: In adenomas (N = 15) and associated glands (N = 7) with normal histology obtained from patients with primary hyperparathyroidism and in diffuse (N = 14), multinodular (N = 58), and single nodular (N = 28) glands from patients who underwent parathyroidectomy for renal hyperparathyroidism, the expression of these cell cycle regulators was evaluated by immunohistochemical technique. A labeling index was used to define the proportion of cells with positive nuclear staining by each antibody. RESULTS: In 6 out of 15 (40%) primary adenomas, PRAD1/cyclin D1 was overexpressed (a labeling index of more than 500), possibly because of the PTH gene rearrangement, but not in secondary hyperplasia, including single nodular glands. Compared with diffuse hyperplasia, nodular hyperplasia showed a significantly higher expression of PRAD1/cyclin D1 (P < 0.05), retinoblastoma gene products (P < 0.05), and Ki67 (P < 0.05). However, no statistically significant correlation between the expression of PRAD1/cyclin D1 and that of Ki67 was observed in both primary adenoma and secondary hyperplasia. CONCLUSIONS: These results suggest that in secondary hyperplasia caused by uremia, at least remarkable overexpression of PRAD1/cyclin D1 induced by PTH gene rearrangement may be not the major genetic abnormality responsible for tumorigenesis. Heterogenous genetic changes seem to contribute to monoclonal proliferation of parathyroid cells induced by the expression of PRAD1/cyclin D1 or by some other mechanism independent of the amplification of the proto-oncogene.

Adenoma↗

PubMed1999

A novel 18-amino acid deletion in apolipoprotein E associated with lipoprotein glomerulopathy.

BACKGROUND: Lipoprotein glomerulopathy (LPG) is a novel disease characterized by proteinuria, lipoprotein thrombi in glomeruli, and an increased concentration of plasma apolipoprotein (apo) E. Previous studies have shown that a genetic disorder of apo E may be associated with the genesis of this disease. METHODS: An apo E mutation was analyzed in a 57-year-old Japanese male with LPG and systemic atherosclerotic complications. Apo E phenotypes were analyzed by isoelectric focusing and immunoblotting. Apo E genotypes were determined by restriction fragment isotyping with HhaI. Polymerase chain reaction (PCR) products of apo E coding region exons 3 and 4 were cloned into pT7Blue-T-vector and were sequenced. RESULTS: A novel apo E mutation was identified in this patient and his family. There was a discrepancy between an apo E phenotype (E1/3) and genotype (E3/3). Sequence analysis showed a 54 bp deletion in exon 4 of the apo E gene, causing the 18-amino acid deletion (Gln 156-Gly 173-->0). This deletion mutation was further confirmed by the detection of a short fragment of PCR-amplified DNA using polyacrylamide gel electrophoresis. The patient was a heterozygote with apo E1, and this mutation was determined to be the structural basis for the apo E1 phenotype. One of two daughters was a heterozygous carrier of apo E1, although she did not have proteinuria or atherosclerotic diseases. CONCLUSIONS: Apo E1 (Gln 156-Gly 173-->0) is a novel mutation of apo E that may be etiologically related to LPG and to the development of atherosclerosis. The result of this family study suggests that the occurrence of LPG may involve other genetic or environmental factors.

Adult↗

PubMed1999

The effect of combination therapy with interferon and cryofiltration on mesangial proliferative glomerulonephritis originating from mixed cryoglobulinemia in chronic hepatitis C virus infection.

Cryofiltration, which has developed from double filtration plasmapheresis (DFPP) with a cooling unit, is an on-line technique to remove cryoglobulin. We report on a patient who suffered from progressive edema and renal insufficiency caused by cryoglobulinemic membranoproliferative glomerulonephritis (MPGN), probably due to chronic hepatitis C virus (HCV) infection. To remove cryoglobulins and terminate the HCV infection, we utilized combination therapy with cryofiltration and interferon-alpha injection with corticosteroids. Interferon-alpha was capable of decreasing proteinuria but not diminishing cryoglobulin. Additional cryofiltration could remove cryoglobulin to an undetectable level. This combination therapy was partially successful to reduce proteinuria and prevent the progressive deterioration of renal function. The major adverse effects of this therapy were bleeding and myelosuppression. We conclude that this combination therapy may be effective and should be considered as treatment for cryoglobulinemic MPGN.

Aged↗

PubMed1999

Encephalopathy in suckling mice infected with Kasba (Chuzan) virus.

Kasba (Chuzan) virus (an orbivirus), strain K-47, produced encephalopathy with severe necrosis in suckling mice inoculated intracerebrally. On day 3 after inoculation with 10(3)TCID50, the mice showed severe focal encephalomalacia and meningitis. On day 4, necrosis had spread to the midbrain, cerebellum and spinal cord. From one day after inoculation, virus was recovered from the brain and the titre rose over the next 3 days. Immunohistochemical examination demonstrated viral antigens in the cytoplasm of both degenerate and intact neurons, and ependymal cells in or around necrotic lesions. The study indicated that the virus has an affinity for immature nerve cells in the brains of suckling mice and causes primary encephalomalacia. Since the lesions resembled those of the hydranencephaly-cerebellar hypoplasia syndrome in calves (Chuzan disease), the system described should prove useful in studies on pathogenesis.

Animals↗

PubMed1999

Expression of c-yes oncogene product in various animal tissues and spontaneous canine tumours.

An immunohistochemical study of various visceral organs of normal adult dogs, cats, pigs, horses, cows, and chickens (five of each species) and of 185 spontaneous canine tumours was carried out using paraffin wax sections and a commercially available antibody to the human c- yes oncogene product. Among the adult normal tissues of six animal species, epithelial cells of the proximal and distal renal tubules, the myocardium, hepatocytes, cerebellar Purkinje cells and adrenal cortical cells were positive for c- yes product. Among the foetal tissues of dogs and chickens, a positive reaction was observed on canine chorionic villi cells and chick yolk sac surface epithelium, and on epithelial cells of the renal tubules, hepatocytes and the myocardium. These findings suggest that the c- yes proto-oncogene may play a physiological role in the cell growth and metabolism of these adult and foetal tissues. Of the 185 tumours tested, 59 (31.9 per cent) expressed the c- yes oncogene product. The c- yes -positive tumours accounted for 44.4 per cent (12/27) of the skin tumours, 5.5 per cent (1/18) of the round cell tumours, 35. 7 per cent (10/28) of the soft tissue tumours, 21.4 per cent (3/14) of the testicular tumours, 29.1 per cent (23/79) of the mammary tumours, and 52.6 per cent (10/19) of the other tumours types. Expression of the c- yes oncogene appeared to be common in spontaneously arising canine tumours, and the degree of expression varied considerably by tumour type.

Animals↗

PubMed1999

Postoperative delirium and plasma melatonin.

The molecular mechanisms of postoperative delirium are not understood in detail yet. This condition is similar to cases of mental symptoms in interferon therapy or hemodialysis. We propose that postoperative delirium is caused by a deficiency of serotonin, an important neurotransmitter, and review the evidence supporting our hypothesis. The serotonin deficiency results from a decrease in tryptophan, the serotonin precursor, and from an increase in melatonin, a serotonin metabolite. Our hypothesis may be applicable to the mechanisms of mental symptoms in interferon therapy and hemodialysis. In addition, we discuss to the relationship between homeostasis and biorhythms because postoperative delirium may be a dysrhythmia.

Delirium↗

PubMed1999

Effects of amlodipine on native cardiac Na+ channels and cloned alpha-subunits of cardiac Na+ channels.

The inhibitory effects of amlodipine besilate (CAS 11470-99-6) on the native Na+ current (INa) and cloned human cardiac Na+ channel alpha subunit (hH1) were studied by whole cell patch clamp techniques. Amlodipine produced tonic block of INa in a concentration- and holding potential (HP)-dependent manner with hyperpolarization of H infinity. Amlodipine produced phasic blockade of INa, which was dependent on HP and pulse duration. Amlodipine produced tonic blockade of hH1 in a concentration-dependent manner with 1 : 1 stoichiometry, and phasic blockade of hH1 which was dependent on the pulse duration. Amlodipine blocked INa in a voltage- and frequency-dependent manner via affinity to the resting as well as inactivated conformations of the alpha subunit.

Algorithms↗

PubMed1999

Antiemetic efficacy of granisetron: a randomized crossover study in patients receiving cisplatin-containing intraarterial chemotherapy.

BACKGROUND: Cisplatin (CDDP) is one of the most active chemotherapeutic agents but is among the most emetogenic drugs. The emetic side-effects of CDDP-containing intraarterial chemotherapy have not been evaluated in a prospective randomized trial and the efficacy of serotonin antagonists in preventing the emesis associated with this method of CDDP administration has not been assessed. METHODS: CDDP 50 mg/m2 and methotrexate 30 mg/m2 were administered every 3 weeks through intraarterial catheters placed in the bilateral internal iliac arteries. Patients were classified into two groups: granisetron treatment group (group G) and no treatment group (group NG) with the first course of chemotherapy, crossing over with the second course. The patients in group G received granisetron 40 micrograms/kg by intravenous infusion. RESULTS: Although intraarterial CDDP administration produced less emesis than intravenous CDDP administration, at the same concentration, gastrointestinal toxicity is still the most unpleasant side-effect for patients. Granisetron administration significantly reduced nausea and vomiting during the acute emetic phase (an evaluation of treatment as very effective and effective was made in 89% in group G and 33% in group NG (P < 0.001). Complete control of emesis was achieved in 68 and 18% of patients in groups G and NG, respectively (P < 0.0001). CONCLUSION: A single prophylactic infusion of granisetron was effective in preventing the nausea and vomiting associated with intraarterial CDDP-containing therapy.

Adolescent↗

PubMed1999

Identification of carboxyl residues in pepstatin-insensitive carboxyl proteinase from Pseudomonas sp. 101 that participate in catalysis and substrate binding.

Pseudomonas carboxyl proteinase (PCP), isolated from Pseudomonas sp. 101, is the first example from a prokaryote of unique carboxyl proteinases [EC 3.4.23.33] which are insensitive to aspartic proteinase inhibitors, such as pepstatin, diazoacetyl-DL-norleucine methylester, and 1,2-epoxy-3(p-nitrophenoxy)propane. To identify the catalytic residue(s) of PCP, chemical modification was carried out using carboxyl residue-specific reagents, carbodiimides. PCP was inactivated effectively by N,N'-dicyclohexylcarbodiimide (DCCD) with pseudo-first-order kinetics. For the inactivation, 0.7 mol DCCD was involved per 1 mol PCP. The effects of pH and methanol on the inactivation showed that two carboxyl residues (Asp and/or Glu) were involved in the reaction. The inactivation by DCCD was prevented by a competitive inhibitor, tyrostatin, or a synthetic substrate in a concentration-dependent manner. Based on these data, differential labeling of PCP with DCCD was carried out: Firstly, PCP was treated with cold DCCD in the presence of tyrostatin. After removal of the tyrostatin, which covered the substrate binding site, by dialysis, the PCP was treated with [14C]DCCD to label carboxyl residue(s) essential for its function. Two labeled peptides were isolated by HPLC from a trypsin digest of cold- and [14C]DCCD modified PCP. On analysis of their amino acid sequences, it was revealed that the [14C]DCCD was bound to Asp140 and Glu222 of PCP, respectively. Based on these data, it was strongly suggested that Asp140 and Glu222 of PCP were involved in its catalytic function or substrate binding.

Amino Acid Sequence↗

PubMed1999

Formation of 4-hydroxy-2-nonenal-modified proteins and 3-nitro-L-tyrosine in rat island skin flaps during and after ischemia.

4-Hydroxy-2-nonenal (HNE)-modified proteins and 3-nitro-L-tyrosine were evaluated as a specific marker of reactive oxygen species (ROS)- and nitric oxide (NO)-mediated peroxynitrite-induced tissue injuries in ischemic and reperfused skin flap by Western blot analysis. Specimens were taken from island skin flaps of rats during the following three conditions: ischemia only, 5 hours of ischemia and reperfusion, and 10 hours of ischemia and reperfusion. HNE-modified proteins and 3-nitro-L-tyrosine increased with ischemic time (3, 6, and 10 hours postischemia). In the reperfused skin flap after both 5 and 10 hours of ischemia, HNE-modified proteins and 3-nitro-L-tyrosine were increased 3 hours postreperfusion, and they reached a maximum 6 hours after reperfusion. HNE-modified proteins and 3-nitro-L-tyrosine 1 hour postreperfusion were higher with 10 hours ischemia-reperfusion than with 5 hours ischemia-reperfusion. These results indicate (1) that ROS- and NO-induced peroxynitrite-mediated cytotoxicity in ischemic flaps is dependent on the ischemic period and (2) that ROS- and NO-induced peroxynitrite-mediated cytotoxicity occurs during an early stage of reperfusion if the ischemic period is long.

Aldehydes↗

PubMed1999

Oxidative stress is associated with region-specific neuronal death during thiamine deficiency.

Thiamine deficiency (TD) is a model of chronic impairment of oxidative metabolism and selective neuronal loss. TD leads to region-specific neuronal death and elevation of inducible nitric oxide synthase (iNOS) in macrophages/microglia in mouse brain. Identification of the initial site of neuronal death in the submedial thalamic nucleus allowed us to test the role of iNOS and oxidative stress in TD-induced neuronal death. The pattern of neuronal loss, which begins after 9 days of TD, overlapped with induction of the oxidative stress marker heme oxygenase-1 (HO-1) in microglia. Neuronal death and microglial HO-1 induction spread to engulf the whole thalamus after 11 days of TD. As in past studies, reactive iron and ferritin accumulated in microglia beginning on day 10. The lipid peroxidation product, 4-hydroxynonenal (HNE) accumulated in the remaining thalamic neurons only after 11 days of TD. These responses were not likely mediated by iNOS because HO-1 induction and HNE accumulation were comparable in iNOS knockout mice and wild-type controls. These results show that region and cell specific oxidative stress is associated with selective neurodegeneration during TD. Thus, TD is a useful model to help elucidate neuron-microglial interaction in neurodegenerative diseases associated with oxidative stress.

Aldehydes↗

PubMed1999

Argyrophilic nucleolar organizer region in proliferating cell has a predictive value for local recurrence in superficial bladder tumor.

PURPOSE: It has been shown in many carcinomas that the proliferation rate and number of argyrophilic nucleolar organizer regions (AgNOR) are associated with tumor aggressiveness. However, in bladder tumor the significance of the correlation between the number of AgNOR and tumor behavior remains controversial. Therefore, it would be helpful if a new technique could be developed that would allow for more accurate AgNOR counting in association with tumor behavior. We established the simultaneous staining technique of AgNOR with Ki-67 labeling to reveal the significance of AgNOR count in superficial bladder tumor. MATERIALS AND METHODS: A total of 50 paraffin sections of superficial bladder tumor were stained with AgNOR and Ki-67 (MIB-1). The numbers of AgNORs in proliferating (MIB-1 positive) or resting (MIB-1 negative) cells were counted from a total of 100 nuclei. Correlations between MIB-1 associated AgNOR count and clinicopathological parameters were statistically analyzed. RESULTS: The AgNOR count in proliferating cells was significantly higher than that in resting cells (p<0.01), and the count significantly increased with tumor grade (p<0.01). Based on recurrence-free survival analyses the local recurrence rate was significantly higher in patients with high proliferating cell NOR but not for those with resting or whole cells. However, no AgNOR score helped to select patients at high risk for disease progression. CONCLUSIONS: Proliferating cell NOR had a predictive value for local recurrence in patients with superficial bladder tumor.

Adult↗