PubMed Health⌕ Search

Biomedical subjects

H Horiguchi

Publications and source records attributed to H Horiguchi.

At least 73 records · Page 4Linked to original sources
PubMed1994

Characterization of high-affinity binding sites for diisopropylfluorophosphate (DFP) from chicken spinal cord membranes.

The delayed neurotoxic organophosphate [3H]diisopropylfluorophosphate ([3H]DFP) binds with high affinity to membrane-bound proteins from the chicken spinal cord. The DFP binding proteins were solubilized from membrane preparations, using a detergent (CHAPS). The protein(s) sites that labeled with a low concentration of [3H]DFP, e.g. 10(-10)-10(-9) M, were defined as the high-affinity binding sites. The density (or concentration) of the high-affinity binding sites in protein(s) was determined by the difference between total and non-specific binding. The high-affinity binding sites were saturable, and the maximal amount of binding sites was estimated at 400 fmol/mg protein. [3H]DFP binding to solubilized proteins was not completely reversible. Concentration-dependent curves suggested that the [3H]DFP binding sites differ from the active sites of acetylcholinesterase, butyrylcholinesterase, and neuropathy target esterase, as well as from muscarinic acetylcholine receptors. The amount of DFP binding sites after a neurotoxic dose of tri-o-cresyl phosphate (TOCP) decreased markedly in membrane preparations from the chicken spinal cord. These results indicate that a TOCP metabolite(s) interacts with the DFP binding sites in vivo. Gel filtration chromatography of the solubilized membranes indicated at least two major high-affinity DFP binding proteins with apparent molecular weights of 300 and 110 kDa. The DFP binding sites corresponding to the 110 kDa protein were insensitive to eserine, a potent anti-cholinesterase agent.

Animals↗
PubMed1994

The interleukin-8 AP-1 and kappa B-like sites are genetic end targets of FK506-sensitive pathway accompanied by calcium mobilization.

FK506, an immunosuppressant, inhibits the production of several cytokines in T lymphocytes. We observed that FK506 suppressed the transcription of a chemotactic cytokine, interleukin-8 (IL-8) in a human T cell line, Jurkat cells, activated by phorbol 12-myristate 13-acetate (PMA) and calcium (Ca2+) ionophore (ionomycin). By deleted and mutated analysis of the IL-8 promoters, the AP-1 and kappa B-like sites were identified as the responsive elements for PMA and ionomycin. FK506 suppressed the transcriptions through the AP-1 or kappa B-like sites induced by PMA plus Ca(2+)-mobilizing agents, but not those induced by Ca(2+)-independent stimuli. In gel retardation analysis, FK506 had little effect on the binding to the AP-1 site of PMA/ionomycin-induced nuclear factors, which were recognized with anti-JunD or c-Fos antibody. In contrast, FK506 or EGTA (Ca2+ chelator) similarly affected the formation of kappa B-like site binding complexes, which were not recognized by any antibodies against the human Rel family proteins (c-Rel, p65, p50, and p49). Furthermore, we confirmed the previous report that FK506 suppressed the PMA/ionomycin-induced activation through authentic kappa B site of immunoglobulin (Ig) gene, to which NF-kappa B binding was also decreased by FK506, indicating that both IL-8 kappa B-like site and Ig kappa B site are FK506-sensitive in spite of the difference of binding factors. Our results indicate that not only the reported IL-2 NF-AT and NFIL-2A sites and Ig kappa B site, but also the IL-8 AP-1 and kappa B-like sites are terminals of FK506-sensitive pathway involving Ca2+ mobilization.

Base Sequence↗
PubMed1994

Hypoproduction of erythropoietin contributes to anemia in chronic cadmium intoxication: clinical study on Itai-itai disease in Japan.

Itai-itai disease is a condition caused by long-term exposure of the inhabitants of Toyama prefecture, Japan, to cadmium intoxication. The characteristic clinical features of this disease include renal tubular dysfunction, osteomalacia, and anemia. In order to clarify the pathogenesis of the anemia, the red blood cell count, hemoglobin concentration, hematocrit, serum iron level, total iron-binding capacity, serum ferritin level, serum erythropoietin level, creatinine clearance, fractional excretion of beta 2-microglobulin, and bone marrow morphology were determined in ten patients with Itai-itai disease. Low serum iron or ferritin levels were not observed, and bone marrow aspiration did not reveal any specific hematological disorders. A close relationship was observed between the decrease in the hemoglobin level and the progression of renal dysfunction. Low serum erythropoietin levels were detected despite the presence of severe anemia. These results suggest an important role of renal damage in the anemia which develops in Itai-itai disease.

Aged↗
PubMed1994

Comparative DNA analysis by image cytometry and flow cytometry in non-small cell lung cancer.

To determine whether image cytometry (ICM) is advantageous for clinical DNA analyses of tumor cells, nuclear DNA contents measured by ICM were compared with those by flow cytometry (FCM), using 46 samples of non-small cell lung cancers. ICM was performed on smear specimens of fresh materials (f-ICM) and cell suspensions obtained from paraffin-embedded tumors (p-ICM). The same cell suspensions were also analyzed by FCM (p-FCM). Aneuploid rates/coefficient of variation (CV) of f-ICM, p-ICM, and p-FCM were 76.1/4.90, 71.7/5.01 and 60.9/5.31%, respectively. There was a high correlation in the DNA indices between p-ICM and p-FCM (r = 0.80). In the comparative DNA analysis, there were seven discordant samples. Six of them were estimated as aneuploid by p-ICM, but they were miscounted as diploid or undefinable (impossible) by p-FCM. This was caused by measuring condensed nuclei or debris. All "impossible" samples in p-FCM were squamous cell carcinoma with necrosis. In cell cycle analysis, the S and S+G2/M phase fractions in diploid samples were higher in p-ICM than those in p-FCM (P < 0.005), because the G0/G1 phase (2N) fraction presented by FCM was composed of cancer and non-malignant cells in diploid cancers. In ICM, they can be separately measured by means of morphological selection. These findings indicated that ICM is superior to FCM, especially for the practical DNA measurement of a few cancer cells and in the evaluation of the proliferation rates.

Adult↗
PubMed1994

Clinicopathological study on a case of neuro-Behçet's disease: in special reference to MRI, SPECT and neuropathological findings.

A case of neuro-Behçet's disease with dementia and personality changes is described with magnetic resonance imaging (MRI), single photon emission tomography (SPECT) and neuropathological findings. MRI disclosed high signal areas in the cerebral white matter and the brain stem. SPECT showed a marked reduction of blood flow in the frontal cortex. Neuropathologically, multifocal necrotizing lesions with perivascular lymphocytic infiltration and glial proliferation were detected mainly in the brain stem, namely the midbrain and the pons. From these findings, it is suggested that mental disorders of neuro-Behçet's disease are related to the secondary dysfunction of the frontal cortex due to the damage of the subcortical structures, mainly the brain stem.

Behcet Syndrome↗
PubMed1994

An autopsied case of acute lymphocytic meningoencephalitis with a long clinical course: special reference to CT, MR, SPECT and neuropathological findings.

This report describes the clinico-pathological features of acute lymphocytic meningoencephalitis (ALME) of a patient with a long clinical course of 24 months. The patient rapidly developed a confusional state, occasionally with stupor, various involuntary movements and generalized convulsions followed by fever and headache at the age of 29. Clinical symptoms, except fever and convulsions, had not distinctly improved throughout the clinical course, and cortical atrophy on CT and MR gradually progressed. SPECT revealed a low blood perfusion in the cerebral cortices. Neuropathologically, inflammatory findings were very mild, but nerve cells degenerated prominently. From these clinicopathological findings, it is suggested that chronic degenerative changes followed an acute inflammatory phase.

Adult↗
PubMed1993

Encapsulated type II pneumocyte adenoma: a case report and review of the literature.

An unusual benign lung neoplasm, a papillary adenoma of type II pneumocytes, was resected from a 26-year-old man who showed no clinical symptoms. The tumor was 2.0 cm in diameter and was localized in the subpleural region of S7 of the right lung; the cut surface showed a spherical medullary mass encapsulated by a thin layer of connective tissue. Histologically, there were cuboidal to columnar epithelial cells with a little nuclear atypia showing a monotonous papillary pattern with a delicate stroma in most parts of the tumor. There was neither capsular invasion nor metastasis of tumor cells. Nuclear DNA analysis of the tumor cells showed a diploid pattern and a low S-phase fraction. The immunohistochemical study revealed that most tumor cells contained a large amount of surfactant apoprotein in the cytoplasm. Osmiophilic lamellar bodies characteristic of type II pneumocytes were frequently found by electron microscopy. These findings indicate that this was a benign adenoma of the lung arising from type II pneumocytes.

Adenoma↗
PubMed1993

[Abnormalities of calcium, phosphorous and vitamin D metabolism with proximal renal tubular dysfunction in subjects environmentally exposed to cadmium].

Calcium, phosphorus and vitamin D metabolism were examined in 21 male and 13 female subjects with renal tubular dysfunction in the cadmium-polluted Jinzu River basin in Toyama prefecture, Japan. Multiple proximal renal tubular dysfunction was detected in all subjects showing increased FE beta 2-m and FFua, generalized aminoaciduria and renal glucosuria. Reduced ability of tubular reabsorption of phosphate resulted in hypophosphatemia in 31% of the women. Despite decreased tubular reabsorption of calcium, the level of serum calcium remained normal in all subjects. Serum 1,25-dihydroxyvitamin-D [1,25(OH)2D], which is produced in the proximal tubules through 1 alpha-hydroxylation from 25-hydroxyvitamin-D [25OHD], was normal or increased to more than 60pg/ml. The serum level of 1,25(OH)2D was inversely related to creatinine clearance in both the men (p < 0.05) and women (p < 0.01). Serum iPTH was slightly increased to more than 0.9 mg/ml, whereas the levels of other hormones, including 25OHD, calcitonin, thyroxine (T4) and triiodothyronine (T3) were normal. The serum alkaline phosphatase activity and serum osteocalcin concentration were significantly increased compared to those of controls in both sexes. Bone loss detected by the measurement of bone density was prominent in female subjects. These results support the hypothesis that the serum phosphate concentration is more important than the serum concentration of 1,25(OH)2D for abnormalities of bone metabolism in cadmium-induced renal tubular dysfunction.

Aged↗
PubMed1993

Cadmium induces interleukin-8 production in human peripheral blood mononuclear cells with the concomitant generation of superoxide radicals.

Acute or chronic exposure to cadmium (Cd) causes severe organ damages with the infiltration of leukocytes, neutrophils in particular occurring in the acute phase. Interleukin-8 (IL-8), a novel neutrophil chemotactic and activating cytokine, is produced by various types of cells in response to a wide variety of inflammatory stimuli. The administration of an antibody against IL-8 has been shown to inhibit neutrophil infiltration in several animal models, indicating a causal relationship between IL-8 and neutrophil infiltration. Hence, in this study we investigated whether Cd induced IL-8 production in human peripheral blood mononuclear cells (PBMC). Cd, over a wide range of concentrations, did induce human PBMC to produce large amounts of bioactive IL-8, the maximal induction being observed at 10(-4) M. The production was inhibited specifically by a metal chelating agent, ethylenediaminetetraacetic acid (EDTA). Steady level of IL-8 mRNA increased within 30 min after the addition of Cd and reached a maximal level at 2 h, decreasing thereafter. A protein synthesis inhibitor, cycloheximide, failed to inhibit IL-8 mRNA accumulation, indicating that new protein synthesis was not required for IL-8 mRNA induction. Concomitantly with the induction of IL-8, within 10 min Cd generated reactive oxygen intermediates (ROI) in human PBMC. A radical scavenger, N-acetyl-L-cysteine (NAC), inhibited both IL-8 production and the generation of ROI, implying the possible involvement of ROI in IL-8 production. This notion was also supported by our findings that a superoxide generating agent, paraquat, induced IL-8 production in human PBMC and that NAC blocked this paraquat-induced IL-8 production.

Base Sequence↗
PubMed1992

[Analysis of pedestrian injuries in traffic accidents: impact point, injury portion, and injury severity].

We conducted in-depth case studies of traffic accidents involving 118 pedestrians, who were struck by the fronts of bonnet-type cars. The data were reviewed in order to correlate injury severity with pedestrian age, and area of body contact, contact surface of vehicle or the local environment, and impact speed. It was found that head injuries caused by impacts against the top surface of car bonnets and leg injuries caused by front bumpers both showed high incidence rates. Both head and leg injuries caused by striking the vehicle were more severe than those caused by striking the road surface. In cases of impact between the head and the solid portion of the vehicle, such as the A-pillar, or in cases of secondary impact between the head and underhood solid structures such as shock tower, injuries tended to be more severe. The location of head impact varied according to the stature of the pedestrians.

Accidents, Traffic↗
PubMed1992

[Neonatal tuberous sclerosis: report of a case studied by cranial MRI].

We reported longitudinal cranial MRI studies of a neonate with tuberous sclerosis who presented convulsive seizures on the first day after birth. Cortical tubers were not detected on MRI performed at the age of 1 month, but became evident at 18 months after birth. This finding might reflect the pathological difference between the amount of myelin around the cortical tuber and other white matter lesions, which increased with age. A heterotopic islet was shown as partially stratiform appearance on MRI. This result suggests that the structure of the heterotopic islet might be heterogeneous.

Brain↗
PubMed1992

[Quantitative DNA image cytometry by color image analyzer].

We developed a new method to analyze DNA quantitatively by a color image analyzer. A microscopic image of the nucleus stained with Feulgen's reaction, is taken by a CCD color camera and inputted in a color image analyzer. DNA quantity can be calculated directly from the RGB components of the color image instead of the monochrome image taken through band-pass filter, which is specific for the absorption of Feulgen's stain. It takes about 10 minutes to measure 500 nuclei by this method and its accuracy is almost the same as flow cytometry (CV = 3%). The nuclear color image can also be analyzed morphometrically. This method can select tumor cells in a usual cytologic specimen and measure their DNA contents.

Cytophotometry↗
PubMed1991

Pulmonary blastoma with a topographic transition from blastic to more differentiated areas. An immunohistochemical assessment of its embryonic nature using stage-specific embryonic antigens.

In order to investigate the probable embryonic nature of pulmonary blastoma, immunohistochemical studies were performed using stage-specific embryonic antigens (Ley, Lex, sialyl Lex-i) in case of pulmonary blastoma with a very wide spectrum of morphological features. The tumour presented a topographic transition from primitive blastic and embryonic areas to more differentiated areas showing diverse differentiation. Blastic areas composed of extremely immature cells were found in most peripheral parts of the tumour. Inside the blastic areas there were "embryonic" areas which morphologically resembled human embryo lungs in the pseudoglandular and canalicular stages. Most central parts of the tumour showed more differentiated features including chondrosarcomatous, leiomyosarcomatous and rhabdomyosarcomatous elements and the common type of adenocarcinomatous element. Electron microscopic observation suggested the blastic and embryonic nature of these immature cell elements. Ley was expressed in the blastic and pseudoglandular areas. Lex was expressed in the canalicular areas. These antigens were not expressed in the more differentiated areas. The topographic gradient in the tumour of morphology and antigen expression from the peripheral blastic areas to the central more differentiated areas suggests that the primitive cells gradually differentiated into more mature cells of various directions as the tumour grew in size.

Antigens↗
PubMed1991

Expression of MHC class II antigens in human lung cancer cells.

Surgical specimens of lung cancers were examined immunopathologically for the expression of major histocompatibility complex class II (MHC-II) antigens in the tumor cells and their relationship to the lymphocytic infiltration. A lymphocytic infiltrate was frequently observed in the tumor tissue, though its intensity differed among the various histological types. MHC-II antigens were often demonstrated in tumors with a lymphocytic infiltrate. They were detected predominantly in the cytoplasm of tumor cells and to a lesser extent on the cell membranes. The emergence of the MHC-II-positive tumor cells was closely related to a local infiltration by lymphocytes including interferon-gamma (IFN-gamma)-producing T-cells. On the basis of the histological findings, an in vitro experiment was carried out. Four types of lung cancer cells were incubated with recombinant IFN-gamma in order to induce MHC-II antigens. MHC-II antigens (HLA-DR as well as HLA-DQ and HLA-DP antigens) were elicited in three cancer cell lines depending on the concentration of IFN-gamma. Immunoelectron microscopic study revealed that they were expressed on the surface of the cell membrane, though to a lesser extent than in the cytoplasm. It was considered that MHC-II antigens could be induced in some tumor cells in the immunological environment where IFN-gamma was secreted from T-cells and concentrated locally.

HLA-DQ Antigens↗
PubMed1991

[Five years' experience with new medical examiner's system in Tsukuba].

Medical examiner's system has been authorized by the act of Autopsy and preservation of corpses and the government ordinance for medical examiner's system since 1949 in Japan, and introduced only in five large cities (Tokyo metropolis, Osaka, Kobe, Yokohama, Nagoya). Recently in Ibaraki Prefecture, new forensic medical service system (Tsukuba Medical Examiner's office) was instituted. This new system is not authorized by the government ordinance, but authorized by the regional ordinance of Ibaraki prefectural governor, therefore this system is enforce only in Ibaraki prefecture. In our new system, medical examiner does not have discretionary power to order an autopsy, and family have a right to reject it, therefore an autopsy rate is very low (about 2%). One hundred and forty four autopsies have been conducted under this system. Ninety four of 144 autopsy cases (67%) were dead from sickness or natural death, in remaining 50 cases manner of death was accidental, suicidal or undetermined. The medical examiner does not conduct autopsies for criminal investigation or homicide cases in Ibaraki prefecture. These autopsies are conducted at the department of legal medicine, University of Tsukuba.

Autopsy↗
PubMed1991

Postmortem determination of the biological distribution of formic acid in methanol intoxication.

Two 25-year-old men were fatally intoxicated with methanol. The formic acid levels in their blood, urine, and organs were determined postmortem by headspace gas chromatography. The postmortem concentrations of formic acid in the two patients were the following: 0.32 and 0.23 mg/mL in blood, 2.27 and 0.47 mg/mL in urine, 0.11 and 1.17 mg/g in the brain, 0.54 and 0.51 mg/g in the liver, and 0.13 and 1.19 mg/g in the kidneys. The total amounts of formic acid in the gastric contents were 108 and 23.2 mg.

Adult↗
PubMed1990

Sudden death due to right ventricular cardiomyopathy.

A 21-year-old man died suddenly at a small party. He had had no clinical signs of cardiac disease except for a slightly abnormal electrocardiogram (occasional premature ventricular contractions) since he was 15 years of age. Autopsy examination revealed cardiomegaly (469 g), with right atrial and ventricular dilatation. The right ventricular myocardium was massively replaced with adipose tissue, and there was one isolated fatty lesion in the right side of the ventricular septum. There were no congenital malformations such as a septal defect or valvular deformity. Histologically, muscular fibers remaining in the right ventricular wall showed neither degenerative nor inflammatory changes. An isolated lesion of the ventricular septum consisted of almost complete replacement of the muscle bundles with adipose tissue. Such a pathologic condition has recently been termed right ventricular cardiomyopathy. Postmortem examination is necessary to make a definite diagnosis of the disease, because in most adult cases of the disease, sudden death occurs before there have been any critical signs.

Adult↗