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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 703 records · Page 39Linked to original sources
PubMed1995

CT and pathological correlation of pulmonary sarcoidosis.

In CT the presence of mediastinal or hilar lymphadenopathies and thickened bronchovascular bundles are landmarks for the diagnosis of pulmonary sarcoidosis. The major CT findings for parenchymal involvement are thickened bronchovascular bundles, large parenchymal nodules, pleural or subpleural nodules, ground-glass opacities, local lung volume loss (distortion of the lung parenchyma), and microscopic and macroscopic honeycombing. The thickened bronchovascular bundles correspond histologically to granulomas, either with or without perigranulomatous fibrosis in the connective tissue sheath around the pulmonary vessels and airways. Conglomerate granulomas are represented on CT by high-attenuation nodules, and the ground-glass opacities are caused by the summation of a number of small granulomas in the interstitium.

Adult↗
PubMed1995

CT of pulmonary tuberculosis.

CT scans in patients with primary tuberculosis commonly show lymphohematogenous spread of the disease, whereas those of postprimary (reactivation) tuberculosis commonly show bronchogenic spread. High-resolution CT (HCRT) is extremely helpful in understanding pathomorphological changes, mode of spread of the disease, and sequential morphological change after antituberculous chemotherapy, and possibly in diagnosing activity of the disease. Centrilobular 2- to 4-mm nodules or branching linear lesions representing intrabronchiolar and peribronchiolar caseation necrosis are the most common findings of early bronchogenic spread of tuberculosis. The 2- to 4-mm centrilobular nodules may coalesce to form 5- to 8-mm nodules or lobular consolidation. Cavitation usually begins at the central portion of a lobule around the bronchioles. Resolution of the tuberculous lesions occurs with antituberculous chemotherapy, resulting in varying degrees of fibrosis, bronchovascular distortion, emphysema, and bronchiectasis. HRCT may show both paracicatricial irregular emphysema and lobular emphysema. CT findings of early miliary dissemination commonly include ground-glass opacification with barely discernible nodules that show discrete miliary nodules thereafter. CT also is useful in the evaluation of long-standing destructive pulmonary lesions and tracheobronchial tuberculosis.

Humans↗
PubMed1995

Nucleosides and nucleotides--CXXXVII. Antitumor phospholipids with 5-fluorouridine as a cytotoxic polar-head: synthesis of 5'-phosphatidyl-5-fluorouridines by phospholipase D-catalyzed transphosphatidylation.

5'-Phosphatidyl-5-fluorouridines, with the same backbone structure as that of natural phospholipids, in which a polar-head group of usual phospholipids is replaced by 5-fluorouridine, were designed to be potent antitumor agents. 5'-Phosphatidyl-5-fluorouridines with a variety of diacyl or dialkyl residues in the glycerol moiety, were synthesized by phospholipase D-catalyzed transphosphatidylation from the corresponding phosphatidylcholine and 5-fluorouridine. These new compounds were evaluated in mice with experimental tumors by ip and po administration. Dipalmitoyl and distearoyl derivatives 1b and 1c had the greatest antitumor activity against both P388 leukemia and Meth A fibrosarcoma in mice.

Animals↗
PubMed1995

Spatiotemporal relationships among early events of fertilization in sea urchin eggs revealed by multiview microscopy.

Four early events of egg fertilization, changes in intracellular calcium concentration and intracellular pH, reorientation of the surface membrane, and the elevation of the fertilization envelope, were imaged in real time and in pairs in single sea urchin eggs. The paired imaging allowed the correlation of the four events spatially and temporally. Three of them propagated as waves starting at the sperm entry site. The earliest was the calcium wave, visualized with fluorescent indicator dyes. After a delay of 10 s there followed a large decrease in the fluorescence polarization of membrane-bound dyes, which we interpret as arising from membrane reorientation as a result of cortical granule exocytosis and microvillar elongation. With a further delay of 15 s the fertilization envelope was seen to rise in transmitted light. All three waves propagated with similar velocities of approximately 10 microns/s, supporting the view that calcium triggers the latter two events. The fluorescence polarization changed in two steps with a clear pause of 10-20 s in between. The second step, which also propagated as wave, reflects either further elongation of microvilli or straightening of irregular microvilli. This second step was abolished by cytochalasin B and was coincident with an increase in cytoplasmic pH, suggesting that pH-induced actin reorganization may play a role. The cytoplasmic alkalinization, imaged with a fluorescent probe, was quite different from the other events in that it took place homogeneously throughout the egg and slowly (over 100 s). Apparently, the alkalinization is not on a direct downstream pathway of calcium origin. An opposing possibility, that the alkalinization may in fact be triggered by the traveling calcium wave, is also discussed.

Animals↗
PubMed1995

Suppurative lesions without prominent epithelioid cell response in abscess-forming granulomatous lymphadenitis.

To clarify the clinicopathological significance of the suppurative lesions without an epithelioid granulomatous response (SLs without Ep) in lymph nodes and their relationship to abscess-forming granulomatous lymphadenitis (AGL) and cat scratch disease (CSD), 10 cases were assessed clinicopathologically and immunohistologically. SLs without Ep were located in the subcapsular sinus, paracortical area and medullary cords, but not in the germinal centers. The microabscesses were surrounded by collections of monocytoid B-lymphocytes (MBLs), histiocytes without epithelioid features, neutrophils, small lymphocytes and small numbers of plasma cells. The majority of the MBLs seen in the SLs without Ep were of the large cell type. The histological triad of toxoplasmic lymphadenitis, i.e., reactive follicular hyperplasia, small clusters of epithelioid cells and aggregates of MBLs, were also seen in all cases. Some of the clinical and pathological findings in our 10 cases were characteristic of CSD, i.e., (1) cat exposure before the lymphadenopathy was in four of the 10 cases, (2) occurrence in autumn and winter months in all cases, (3) typical suppurative granulomas surrounded by palisaded epithelioid cells were in four of the 10 cases, and (4) Warthin-Starry silver stain-positive bacteria were detected in seven of the 10 cases. The results of our study suggest that SLs without Ep are an early stage of CSD.

Abscess↗
PubMed1995

Photic stimulation study of changing the arterial partial pressure level of carbon dioxide.

To investigate the effect of the level of baseline cerebral blood flow (CBF) on local CBF augmentation by activation, we have used positron emission tomography to measure regional CBF (rCBF) in 12 normal volunteers with and without photic stimulation during hypocapnia, normocapnia, and hypercapnia. The increase in rCBF in the primary visual cortex by photic stimulation was 10.8 +/- 3.1, 18.6 +/- 9.3, and 19.5 +/- 6.1 ml 100 ml-1 min-1 in hypo-, normo-, and hypercapnia, respectively. The increase was significantly smaller in hypocapnia than in normocapnia (p < 0.005). The fractional CBF increase caused by the photic stimulation was the same in all breathing conditions. This result indicates that the magnitude of the CBF increase induced by neuronal activity correlates proportionally with the level of baseline CBF.

Adult↗
PubMed1995

Umbilical venous guanosine 3',5'-cyclic phosphate (cGMP) concentration increases in asphyxiated newborns.

Guanosine 3',5'-cyclic phosphate (cGMP) is known to be the second messenger of natriuretic peptides and nitric oxide (NO). To investigate the involvement of natriuretic peptides in the regulation of the feto-placental circulation, specific radioimmunoassays were used to measure the concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cGMP in the umbilical venous plasma of normal and asphyxiated newborns. The plasma concentrations of ANP, BNP and cGMP in asphyxiated newborns were 48.3 +/- 12.9 pm, 24.5 +/- 9.4 pm and 4.4 +/- 1.6 nM (mean +/- s.e.m., n = 10), respectively. These values were significantly higher than those in the normal newborns (17.4 +/- 1.9 pm, 4.7 +/- 1.0 pm, and 0.78 +/- 0.14 nM, respectively). Moreover, the expression of both ANP-A and ANP-B receptor, biologically active receptors for natriuretic peptides, was detected in term human placenta by Northern bolt analysis. The expression of natriuretic peptide receptors was further confirmed by binding assay using [125I]-labelled ANP and solubilized crude membrane preparations of placental tissue. These findings suggest that cGMP is produced in the placenta, at least partly, by the action of ANP and BNP secreted from fetal heart, in pathophysiological conditions such as fetal hypoxia.

Asphyxia Neonatorum↗
PubMed1995

Relationship between lupus anticoagulant (LAC) and pregnancy-induced hypertension.

Lupus anticoagulant (LAC), a serum antiphospholipid autoantibody, is believed to be one of the causes of infertility or fetal loss. The purpose of the present study was to evaluate the role of LAC in the pathogenesis of hypertension during pregnancy. In this study, 20 pregnant women with hypertension were classified into two groups: 14 patients who did not have hypertension before the pregnancy but developed it during the pregnancy (pregnancy-induced hypertension; Group A) and 6 patients who had hypertensive or renal disease before the pregnancy, and developed further hypertension during the pregnancy (pregnancy-aggravated hypertension; Group B). A LAC coagulation assay was performed, and the presence of LAC in each group was compared. All 14 patients in group A were LAC-negative. In contrast, 3 of the 6 patients in group B were LAC-positive, and had clinical autoimmune diseases. The incidence of pregnancy-induced hypertension was also examined in 15 pregnancies from 9 LAC-positive women who had a history of repeated fetal loss but no systemic autoimmune disease (Group C). None of these 15 pregnancies had hypertensive complications, even when they reached term. In the placentas of LAC-positive women, no characteristic changes other than fibrinoid degeneration and microscopic infarction were observed upon histological examination. These results suggest that LAC does not relate with the onset of hypertension during pregnancy.

Adult↗
PubMed1995

Endothelin receptors in the human amnion, chorion laeve, decidua vera and placenta.

The levels of endothelin-1 (ET-1) and the characteristics of endothelin (ET) receptors were investigated in the amnion, chorion laeve, decidua vera and placenta by using a specific radioimmunoassay for ET-1 and a saturation binding assay for ET. ET receptor gene expression in these tissues was also examined by Northern blot analysis. The levels of ET-1-like immunoreactivity (ET-1-LI) in the human amnion, chorion laeve, decidua vera and placenta obtained at elective Caesarean section before labour onset at term (mean +/- s.e.m.) were 1260 +/- 380 (n = 6), 3740 +/- 980 (n = 4), 4550 +/- 780 (n = 4) and 2450 +/- 470 (n = 4) pg g-1 wet weight, respectively. The levels of ET-1-LI in the tissues obtained after spontaneous vaginal deliveries at term did not differ from these. Gel-permeation chromatography and reverse-phase high-performance liquid chromatography revealed that the ET-1-LI in these tissues was mainly composed of ET-1. Scatchard analysis of the saturation binding assay for [125I]-labelled ET-1 and [125I]-labelled ET-3 indicated that high concentrations of both ET-A and ET-B subtypes of receptor were present in membrane fractions from the chorion laeve, decidua vera and placenta. However, in membrane fractions from the amnion, no ET receptors could be detected. These results were confirmed by Northern blot analysis using human ET-A and ET-B receptor cDNA probes. Taken together, these results suggest that the amnion is not the site of action of amniotic ET, and that ET may be involved in the regulation of functions of the chorion laeve or decidua vera.

Amnion↗
PubMed1995

Activation of phospholipase D in cultured human amnion cells.

The regulation of phospholipase D (PLD) activity in the human amniotic membrane was examined using primary cultures of amnion cells. Cultured amnion cells were labelled with [3H]oleic acid, and PLD activity was determined as the amount of [3H]phosphatidylethanol (PEt) produced during incubation in the presence of 0.1% ethanol. PLD activity in cultured amnion cells was activated by addition of arginine vasopressin and oxytocin. PLD activity was also stimulated by treatment was arachidonic acid, the product of phospholipase A2 (PLA2), and phospholipase C (PLC). These results indicate that PLD in amnion cells is activated by substances present in amniotic fluid, and that cross-talk between phospholipases A2, C and D may occur in amnion cells.

Amnion↗
PubMed1995

Dominant role of the second heat shock element in expression of the HSP70-1 gene in rat liver after whole body hyperthermia.

We investigated the regulatory expression of the HSP70-1 gene in rat liver after whole body hyperthermia (rectal temperature of 42 degrees C for 30 min). After heat treatment, HSP70-1 mRNA showed a peak at 1 h, and its protein product began to increase at 3 h. Under these conditions, we identified cis-acting elements involved in the regulatory expression of the HSP70-1 gene by in vivo genomic footprinting. We observed that the second heat shock element (HSE-2; -201 to -178) was clearly protected from methylation by dimethyl sulfate in parallel with the increase in HSP70-1 mRNA. On the contrary, the most proximal HSE-1 (-120 to -101) was protected only slightly. Furthermore, the flanking regions of HSE-2, that is, an NF-kappa B-like element on the upstream side and a GC box on the down-stream side were also protected simultaneously in accordance with the induced expression of the HSP70-1 gene. Gel mobility shift assays with nuclear extracts from rat liver at 30 min after heat treatment showed maximal DNA binding activity equally with oligonucleotides containing HSE-1 and HSE-2, respectively, and also demonstrated the participation of heat shock factor-1 (HSF1) in both cases. These results suggest that, in addition to HSF1, other regulatory factors might be involved in the dominant protection of HSE-2 in the promoter of the HSP70-1 gene in rat liver after whole body hyperthermia.

Animals↗
PubMed1995

Induction of heat shock protein 70 and nucleolin and their intracellular distribution during early stage of liver regeneration.

Our previous work demonstrated a simultaneous induction of Hsp70 and nucleolin mRNA during the prereplicative stage of hepatocytes after partial hepatectomy [Ohmori, H. et al. (1990) Exp. Cell Res. 189, 227-232]. In the present study, changes of intracellular localization of these proteins were examined. Nucleolin, which mainly localized in the nucleus, increased with time and accumulated in the nucleolus around 12-18 h after partial hepatectomy. Hsp70 protein also increased slightly around 6-12 h after the operation. In accordance with this increase, immunohistochemical staining revealed that almost all nuclei of hepatocytes became Hsp70-positive, although Hsp70 was seen to be dispersed throughout the nucleoplasm and nucleolus at all times examined. Next, we isolated a cDNA clone of ribosomal protein (S-17) and examined its behavior. Induction of S-17 mRNA was observed to be essentially similar to that of nucleolin mRNA in regenerating rat liver, although inductions of histone H2A and H4 occurred at a later time, that is, in parallel with DNA synthesis. Furthermore, we observed a simultaneous induction of Hsp70 and nucleolin mRNA by serum-stimulation after serum-depletion in HeLa and IAR-20 (rat) culture cells. These results suggest that the induction of Hsp70, in addition to nucleolin, was not fortuitous but may be involved in the early events of liver regeneration.

Animals↗
PubMed1995

cDNA sequencing and expression of rat mast cell tryptase.

A cDNA encoding rat mast cell tryptase (rMCT) was successfully cloned, and sequenced, from peritoneal cells of Lewis rats infected with Nippostrongylus brasiliensis by the reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends methods. The cDNA was 1,097 base-pairs long, and included 822 base-pairs of an open reading frame. As judged from the deduced amino acid sequence, rMCT is highly homologous to mouse mast cell protease-6, and is considered to be translated as a prepro-enzyme with a 19-amino acid signal peptide, a 10-amino acid activation peptide, and a 245-amino acid mature enzyme. The rMCT mRNA was not detected in peritoneal cells of mast cell-deficient Ws/Ws rats, though it was strongly detected in ones of littermate +/+ and Lewis rats. In addition to in peritoneal mast cells, the rMCT mRNA was detected in the tongue. However, mRNA signals were not detected in the small intestine regardless of N. brasiliensis infection. Nor were mRNA signals detected in RBL2H3 rat basophilic leukemia cells. In the lung, the rMCT mRNA was strongly detected after infection with N. brasiliensis, though it was only faintly detected before infection. These results suggest that the rMCT is basically specific for connective tissue mast cells, but not for mucosal mast cells and that it is up-regulated in the lung during the inflammatory process of a parasitic infection.

Amino Acid Sequence↗
PubMed1995

Efficacy of lansoprazole and amoxicillin in eradicating Helicobacter pylori: evaluation using 13C-UBT and Monoclonal H. pylori antibody testing.

Combination therapy with lansoprazole (LPZ) and amoxicillin (AMPC) was administered to eradicate Helicobacter pylori. Changes in eradication rates were monitored and serum antibody titers, levels of pepsinogens I and II (PI and PII), and gastrin were measured. The 40 subjects were divided into two groups: one group received LPZ 30 mg alone, and the other received LPZ 30 mg and AMPC 1,500 mg concomitantly. AMPC was administered for 2 weeks before completion of LPZ treatment. Maintenance therapy was cimetidine 400 mg. The presence of H. pylori was evaluated using the urea breath test (UBT). The clearance rate was 12.5% and the eradication rate was 0% in the LPZ group, and the corresponding rates in the LPZ with AMPC group were 41.6 and 25.0%, respectively. Serum monoclonal H. pylori antibody titers decreased in patients in whom bacterial eradication had been achieved. Serum PI was significantly reduced in those patients in whom eradication had been achieved. Serum PII and gastrin levels also tended to decrease in patients in whom eradication had been achieved, but no such changes were observed in the other patients. Further research into drug treatment and evaluation methods for bacterial eradication is required.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

Novel colorectal adenocarcinoma-associated 40- and 47-kDa protein antigens recognized by anti-60-kDa heat shock protein antibody.

Expression of 40- and 47-kDa proteins recognized by anti-60-kDa heat shock protein antibody was investigated in colorectal adenocarcinoma tissue. In all cases of colorectal adenocarcinoma tissue (n = 9), 40- and 47-kDa proteins were detected by immunoblot analysis. However, expression of these two proteins was extremely low or was not expressed in control tissue. There was no correlation between the quantity of these two bands and histologic type or the location of the tumors. Our results first demonstrate the accumulation of structurally altered 60-kDa heat shock protein-associated antigens in carcinoma tissue and suggest that these two proteins could be a possible candidate for tumor-specific 60-kDa heat shock protein-related protein antigens.

Adenocarcinoma↗
PubMed1995

Altered cardiovascular responses to purinergic A2 stimulation in the nucleus tractus solitarius of spontaneously hypertensive rats.

OBJECTIVE: To investigate the cardiovascular effects of adenosine A2 receptor stimulation in the nucleus tractus solitarius and whether these effects are altered in hypertension. DESIGN AND METHODS: Ten- or 11-week-old spontaneously hypertensive rats (SHR) or Wistar-Kyoto (WKY) rats were anaesthetized with urethane. Adenosine (100 ng) or adenosine A2 agonist (2-octynyladenosine, 5 ng) were micro-injected (50 nl) into the nucleus tractus solitarius. Blood pressure and heart rate were measured from a femoral artery. Sympathetic nerve activity was recorded from the abdominal splanchnic nerve. RESULTS: Blood pressure, heart rate and sympathetic nerve activity were consistently decreased after the micro-injection of adenosine into normotensive rats. Changes from the baseline in blood pressure, heart rate and sympathetic nerve activity were significantly smaller in SHR than in WKY rats (blood pressure: SHR -5.6 +/- 2.1% versus WKY rats -20.0 +/- 2.1%; heart rate: SHR -5.4 +/- 0.88% versus WKY rats -9.2 +/- 2.3%; sympathetic nerve activity: SHR -5.5 +/- 1.1% versus WKY rats -21 +/- 2.8%). Micro-injection of an A2 agonist into the nucleus tractus solitarius also decreased blood pressure and heart rate, and those responses were not inhibited by pretreatment with an adenosine A1-specific antagonist. The response induced by micro-injection of A2 agonist into the nucleus tractus solitarius was significantly smaller in SHR than in WKY rats, whereas the changes in heart rate did not differ statistically (blood pressure: -23.4 +/- 4.7% versus -10.8 +/- 2.1%; heart rate: -12.1 +/- 1.2% versus -13.6 +/- 2.1%). CONCLUSION: The present results suggest that stimulation of adenosine A2 receptors in the nucleus tractus solitarius decreases both blood pressure and inhibitory sympathetic nerve activity and that those inhibitory responses to adenosine in the nucleus tractus solitarius are deranged in SHR.

Adenosine↗
PubMed1995

Causative allergens of allergic rhinitis in Japan with special reference to silkworm moth allergen.

To determine the importance of silkworm moth allergens, we tested 267 patients with allergic rhinitis with CAP-RAST, a new assay system for detecting specific IgE in sera. We used the following allergen sources: house-dust mite, Candida, Alternaria, cat dander, orchard grass, ragweed, mugwort, Japanese hops, Japanese cedar, Japanese cypress, cotton, silk, larval chironomid midge, adult chironomid midge, and silkworm moth. As expected, the highest positive rate of reaction, as determined by CAP-RAST, was 73.8% for Japanese cedar, followed by 53.2% for mite and 50.6% for Japanese cypress. Although the positive rate for silkworm moth was not as high as for cedar pollen, one-third of patients had specific IgE against silkworm moth. The positive rate of reaction to silkworm moth was much higher than that to chironomid. It was interesting to note that the patients reported had not been documented as having frequent contact with silkworm moth allergen. Correlations between silkworm moth and silk, and silkworm moth and chironomid midge were found to be significant (P < 0.001). Silkworm moth allergen showed the third highest reaction rate in patients with severe symptoms. These results suggest that silkworm moth allergen should be considered to be important in patients with allergic rhinitis in Japan.

Adolescent↗