Extraction equilibria of uni- and bivalent metal picrates with 15,15-dimethyl-16-crown-5 in benzene/water system.
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Journal Article↗
Biomedical subjects
H Yamada
Publications and source records attributed to H Yamada.
Solvent effect on ion-pair extraction of 2-(2-pyridylazo)-1-naphthol-4-sulfonate anion with solvated hydroxonium ion using alcohols and 1-octanol/octane mixed solvents.
Extraction of 2-(2-pyridylazo)-1-naphthol-4-sulfonate anion with solvated hydroxonium ion was carried out using 14 kinds of alcohols and 1-octanol/octane mixed solvents as a solvent at 25 degrees C. Alcohols are 1-pentanol, 1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol, 3-octanol, 1-nonanol, 2-nonanol, 3-nonanol, 5-nonanol and 1-decanol. Among them, 1-octanol was found to be extremely high in extractability for 2-(2-pyridylazo)-1-naphthol-4-sulfonate anion with hydroxonium cation. The extraction equilibrium for the systems using 1-octanol/octane mixed solvents was analyzed in detail in order to examine the extraction mechanism for these extraction systems. 2-(2-Pyridylazo)-1-naphthol-4-sulfonate anion was found to be extracted with the hydroxonium ion solvated by three 1-octanol molecules as an ion-pair. The extraction and partition constants of the ion-pair of 2-(2-pyridylazo)-1-naphthol-4-sulfonate anion with solvated hydroxonium ion were estimated in the 1-octanol/octane mixed solvent systems.
Journal Article↗
Periodic lateralized epileptiform discharges in influenza B-associated encephalopathy.
An 18-year-old woman presented with coma, hemicomvulsions, and transient periodic lateralized epileptiform discharges (PLEDs). Serological tests were positive for influenza B, and cerebrospinal fluid PCR for herpes simplex virus DNA was negative. Magnetic resonance imaging later showed abnormal signal intensity in the temporal lobe ipsilateral to the PLEDs. Influenza-associated encephalopathy may cause hemiconvulsions and PLEDs, and can mimic herpes simplex encephalitis.
Adolescent↗
Rapidly progressive tabes dorsalis associated with selective IgA deficiency.
Tabes dorsalis is uncommon and progresses slowly from infection to clinical manifestation. We report a rare case of rapidly progressive tabes dorsalis associated with selective IgA deficiency (sIgAD). A 28-year-old man was hospitalized with lightning back pain, nausea, and bladder bowel dysfunction. Serum and cerebrospinal fluid (CSF) revealed high titers of Treponema pallidum antibody, and the serum IgA level was less than 5 mg/dl. Thl-dominant cytokine expression was observed, as is usually seen in neurosyphilis. He was treated with Ceftriaxone and CSF pleocytosis disappeared. We postulate sIgAD influenced the atypical rapid clinical course of tabes dorsalis in this patient.
Adult↗
Ca2+-dependent exocytosis of L-glutamate by alphaTC6, clonal mouse pancreatic alpha-cells.
Pancreatic islet cells express receptors and transporters for L-glutamate and are thus believed to use L-glutamate as an intercellular signaling molecule. However, the mechanism by which L-glutamate appears in the islets is unknown. In the present study, we investigated whether L-glutamate is secreted through exocytosis by alphaTC6 cells (clonal mouse pancreatic alpha-cells). An appreciable amount of L-glutamate was released from cultured cells after the addition of KCl or A23187 in the presence of Ca2+ and 10 mmol/l glucose in the medium. The KCl-induced glutamate release was significantly reduced when assayed in the absence of Ca2+ or when the cells were pretreated with EGTA-AM. The KCl-induced Ca2+-dependent glutamate release was inhibited approximately 40% by voltage-gated Ca2+ channel blockers, such as nifedipine at 20 micromol/l. The degree of KCl-induced Ca2+-dependent glutamate release was correlated with an increase in intracellular [Ca2+], as monitored by fura-2 fluorescence. Botulinum neurotoxin type E inhibited 55% of the KCl-induced Ca2+-dependent glutamate release, followed by specific cleavage of 25 kDa synaptosomal-associated protein. Furthermore, bafilomycin A1, a specific inhibitor of vacuolar H+-ATPase, inhibited 40% of the KCl-induced Ca2+-dependent glutamate release. Immunoelectronmicroscopy with antibodies against synaptophysin, a marker for neuronal synaptic vesicles and endocrine synaptic-like microvesicles, revealed a large number of synaptophysin-positive clear vesicles in cells. Digitonin-permeabilized cells took up L-glutamate only in the presence of MgATP, which is sensitive to bafilomycin A1 or 3,5-di-tert-butyl-4-hydroxybenzylidene-malononitrile (a proton conductor) but insensitive to either oligomycin or vanadate. From these results, it was concluded that alphaTC6 cells accumulate L-glutamate in the synaptophysin-containing vesicles in an ATP-dependent manner and secrete it through a Ca2+-dependent exocytic mechanism. The Ca2+-dependent glutamate release was also triggered when cells were transferred in the medium containing 1 mmol/l glucose, suggesting that low glucose treatment stimulates the release of glutamate. Our results are consistent with the idea that L-glutamate is secreted by alpha-cells through Ca2+-dependent regulated exocytosis.
Adenosine Triphosphate↗
Development of muscle fatigue assessed by using superposition of evoked and volitional myoelectric potentials.
We studied muscle fatigue development using evoked myoelectrical potentials superimposed on volitional ones. The instantaneous frequency of superim posed M-waves and mean power frequencies of volitional electromyography (EMG) declined during sustained contraction, indicating that fatigue progressed. We divided fatigue into 3 phases, with 20 frames in each fatigue phase, corresponding to one-third of the total sample. The instantaneous frequency of superimposed M-waves and mean power frequencies of volitional EMG were correlated during early intensive isometric voluntary contractions and became increasingly uncorrelated as contraction proceeded. The coefficient between the mean power frequency and instantaneous frequency correlation was also greater at the first peak than at the second peak of the superimposed M-wave, indicating that the motor unit action potential was distorted. Distortion in the motor unit action potential shape depends on elongation of the depolarization zone of muscle fiber, because the superimposed M-wave is a peripheral indicator elicited by electrical stimulation. These results suggest that muscle fatigue develops based on the reduction of the conduction velocity of muscle fiber and on the elongation of the depolarization zone of muscle fiber.
Adult↗
Lymphocyte metallothionein-mRNA as a sensitive biomarker of cadmium exposure.
Human peripheral blood lymphocytes (PBLs) produce metallothioneins (MTs) in response to a variety of heavy metal ions. MTs could therefore be a candidate for a marker that represents the biological effect of heavy metals. Since it is practically difficult to measure MT protein levels in PBLs, we examined if MT-mRNA could serve as a biomarker of heavy metal exposure. It is difficult to obtain RNA from PBLs without degradation, but we found that intact RNA can be prepared by the acid guanidinium thiocyanate-phenol-chloroform extraction method which minimizes nuclease digestion of RNA during purification steps. By Northern blot analysis of RNA isolated by this method from PBLs cultured with or without CdSO4, we demonstrated that MT-mRNA is induced by 0.1 to 0.5 microM CdSO4 in a dose-dependent manner. The blood cadmium levels of exposed humans have been reported to be up to 0.5 microM. This suggests that our assay is able to detect quantitative changes in the PBL MT-mRNA level resulting from in vivo cadmium exposure. Thus, PBL MT-mRNA could be used as a sensitive biomarker reflecting exposure to cadmium, and probably to several other MT-inducing heavy metals.
Cadmium↗
Thymidylate synthase gene expression in primary colorectal cancer and metastatic sites.
Thymidylate synthase (TS) expression has been identified as an important predictor of response to 5-fluorouracil (5-FU). However, there is relatively little information on the heterogeneity of TS mRNA expression between primary and metastatic tumors, as well as differential expression of TS mRNA in metastatic sites. In this study, TS mRNA expression was measured in primary colorectal cancer tumors and various metastatic tumors. The median TS/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA ratio was 0.98 in primary tumors, 0.70 in liver metastases, 1.92 in lymph node metastases, and 3.42 in pulmonary metastases. A significantly higher expression of TS mRNA was observed in pulmonary and lymph node metastases compared with their respective primary tumors. In contrast, TS mRNA expression in hepatic metastases was significantly lower than in primary tumors. Similar results were observed in tumors obtained from the same patient. These results may explain the difference in the clinical response to 5-FU-based chemotherapy between various metastatic sites. The discordant TS expression between primary and metastatic tumors is a critical factor that must be taken into account when TS is being used as a predictive biomarker for the antitumor effect of 5-FU-based chemotherapy.
Adenocarcinoma↗
[The relationship between the categorical perception of facial expressions and semantic distances].
It has been argued whether the facial expression is recognized categorically or dimensionally. We investigated this issue using three sets of morphed photographic facial images (happiness to anger, surprise, and sadness). Our interest is whether the experimental data of categorical perception can be explained by the dimensional point of view. Experiment 1 examined the facial stimuli generated by FACS. In Experiment 2, subjects were asked to discriminate some pairs of faces and to categorize the emotion shown one at a time. The discrimination accuracy between categories was better than that within each category. In Experiment 3, subjects were asked to rate those stimuli following the semantic differential technique. Then we examined the relationship between the discrimination accuracy obtained in Experiment 2 and the semantic distances obtained in Experiment 3, defined by Euclidean distances between pairs of stimuli in the factor space that was constituted two factors interpreted as "pleasantness" and "activities". Discrimination accuracy within each category increased as a function of the semantic distances, whereas discrimination accuracy between categories remained high irrespective of the different semantic distances.
Adolescent↗
Potent antimalarial activities of polyether antibiotic, X-206.
In the course of our screening program to discover antimalarial antibiotics, which are active against drug resistant Plasmodium falciparum in vitro and rodents infected with P. berghei in vivo, from the culture broth of microorganisms, we found a selective and potent active substance produced by an actinomycete strain K99-0413. It was identified as a known polyether antibiotic, X-206. We also compared the in vitro antimalarial activities and cytotoxicities of 12 known polyethers with X-206. Among them, X-206 showed the most selective and potent inhibitory effect against both drug resistant and sensitive strains of P. falciparum. Comparison of biological activities and ion-affinities of the above antibiotics suggests that monovalent cations play an important biological role for the intracellular growth of P. falciparum in parasitized erythrocytes. Moreover, X-206 showed potent in vivo antimalarial activity on the rodent model, though the therapeutic window was narrow compared with its selective toxicity in vitro. These observations are the first report of antimalarial activity of X-206.
Actinomycetales↗
[Endometriosis-adenomyosis mouse model induced by transvaginal pituitary transplantation].
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Animals↗
Response of native and denatured hen lysozyme to high pressure studied by (15)N/(1)H NMR spectroscopy.
High-pressure (15)N/(1)H NMR techniques were used to characterize the conformational fluctuations of hen lysozyme, in its native state and when denatured in 8 M urea, over the pressure range 30--2000 bar. Most (1)H and (15)N signals of native lysozyme show reversible shifts to low field with increasing pressure, the average pressure shifts being 0.069 +/- 0.101 p.p.m. ((1)H) and 0.51 +/- 0.36 p.p.m. ((15)N). The shifts indicate that the hydrogen bonds formed to carbonyl groups or water molecules by the backbone amides are, on average, shortened by approximately 0.02 A as a result of pressure. In native lysozyme, six residues in the beta domain or at the alpha/beta domain interface have anomalously large nonlinear (15)N and (1)H chemical-shift changes. All these residues lie close to water-containing cavities, suggesting that there are conformational changes involving these cavities, or the water molecules within them, at high pressure. The pressure-induced (1)H and (15)N shifts for lysozyme denatured in 8 M urea are much more uniform than those for native lysozyme, with average backbone amide shifts of 0.081 +/- 0.029 p.p.m. ((1)H) and 0.57 +/- 0.14 p.p.m. ((15)N). The results show that overall there are no significant variations in the local conformational properties of denatured lysozyme with pressure, although larger shifts in the vicinity of a persistent hydrophobic cluster indicate that interactions in this part of the sequence may rearrange. NMR diffusion measurements demonstrate that the effective hydrodynamic radius of denatured lysozyme, and hence the global properties of the denatured ensemble, do not change detectably at high pressure.
Animals↗
[A case of autoimmune pancreatitis observed from local enlargement to the diffuse swelling of the pancreas in its long clinical course].
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Autoimmune Diseases↗
[A case of renal cell carcinoma diagnosed by MAG3 scintigraphy because of moderate renal dysfunction].
An 84-year-old man presented at our hospital with complaints of severe gross hematuria and lower right abdominal pain. A right renal mass was detected by ultrasound sonography and plain computerized tomography (CT) scan, but an exact diagnosis was not obtained. Because the patient presented with moderate renal dysfunction and severe gross hematuria, we were unable to perform imaging studies using contrast material or ureteroscopic instruments. Finally, mercaptoacetylglycyl-glycylglycine (MAG3) scintigraphy and magnetic resonance imaging (MRI) demonstrated renal cell carcinoma, and we performed transarterial embolization (TAE) therapy using ethanol and gel foam. Based on their efficacy and noninvasiveness, we conclude that MAG3 scintigraphy and MRI are the optimal modalities for imaging in patients with renal dysfunction.
Aged↗
[Sclerosing Sertoli cell tumor of the testis: a case report].
We report here a case of sclerosing Sertoli cell tumor of the testis. A 21-year-old male, who complained of right testicular pain, visited a Jikei University affiliated hospital on May 30th, 1999. A small nodule with a diameter of 6 to 7 mm was palpable on the central surface of the right testis. No tumor markers for testicular cancer, such as hCG-beta and alfa-fetoprotein, were elevated. However, ultrasound revealed a hypoechoic mass with increased blood flow. Therefore, we performed right high orchiectomy under the diagnosis of right testicular cancer. Pathological diagnosis of this tumor was sclerosing Sertoli cell tumor. Neither recurrence nor metastasis has been found for 12 months postoperatively.
Adult↗
Effects of a highly toxic coplanar polychlorinated biphenyl, 3,3',4,4',5-pentachlorobiphenyl on intermediary metabolism: reduced triose phosphate content in rat liver cytosol.
The effects of a highly toxic coplanar polychlorinated biphenyl, 3,3',4,4',5-pentachlorobiphenyl (PenCB), on triose phosphate metabolizing enzymes were studied. Male Wistar rats received 25 mg/kg PenCB, i.p. At this dose the compound provokes a wasting syndrome. The activity of triose phosphate metabolizing enzymes, glyceraldehyde-3-phosphate dehydrogenase, triose phosphate isomerase, glycerokinase, transaldolase and transketolase were significantly reduced by PenCB treatment to 50%, 60%, 50%, 70% and 40% of free-fed controls, respectively. An inhibition study with pyrazol, a specific inhibitor of alcohol dehydrogenase (ADH), showed that ADH makes about a 30% contribution to the formation of glycerol-3-phosphate from glyceraldehyde-3-phosphate. Our current study revealed that PenCB suppresses ADH at the protein expression level. The reduced formation of glycerol-3-phosphate from glyceraldehyde dehydrogenase by PenCB could be due to the suppression of ADH. The triose phosphate content in the liver cytosol of PenCB-treated rats was significantly lower than in free-fed controls. The suppression of triose phosphate metabolism could be a cause of the wasting syndrome provoked by highly toxic coplanar PCB.
Animals↗
[Suppression of stress proteins, GRP78, GRP94, calreticulin and calnexin in liver endoplasmic reticulum of rat treated with a highly toxic coplanar PCB].
The present study was addressed on the effect of 3,3',4,4',5-pentachlorobiphenyl (PenCB) to the expression of molecular chaperon proteins, glucose regulated protein (GRP) 78, GRP94, calreticulin and calnexin in liver endoplasmic reticulum of rat by treatment with acute exposure. Male Wistar rats received PenCB in corn oil at once a dose of 10 mg/kg i.p., then at 5 days after treatment the microsomes were prepared. Free-fed and pair-fed control groups were given the vehicle. The microsomal proteins were separated on SDS-PAGE, transferred to membrane and blotted using antibody towards respective chaperone proteins. The protein levels of GRP78, GRP94, calreticulin and calnexin were significantly decreased with the acute exposure. In addition, albumin level in the microsomes was also significantly reduced by the PenCB treatment. The transferrin level was significantly higher than pair-fed but not from free-fed group. These chaperone proteins have important physiological functions against synthesized and/or denatured proteins, which include assembling, folding of proteins. PenCB-treatment may alter the extent of biosynthesis of secretory protein such as albumin through the decreasing levels of chaperone proteins in endoplasmic reticulum. Interestingly, reduced GRP78 protein level by PenCB was not due to decreased mRNA level. Our results suggested that a part of the toxicity of PenCB is associated to significant decrease of the chaperone proteins in the endoplasmic reticulum.
Animals↗
[Nontuberculous atypical mycobacterial infection with progressive pancytopenia in a patient with myelodysplastic syndrome].
We describe a patient with myelodysplastic syndrome (MDS) who developed disseminated infection due to nontuberculous mycobacteria (NTM). A 64-year-old man was admitted because of persistent fever that had been unresponsive to antibiotics. Bone marrow aspiration specimens showed myelodysplasia (RA), but the origin of the fever was unclear. Cytopenia worsened to a level that required transfusion of red blood cells and platelets. Repeated bone marrow examination revealed hypoplasia with hemophagocytosis. Several weeks later, photochromogenic NTM was isolated from bone marrow specimens, sputum and broncho-alveolar lavage (BAL) fluid which had been obtained on admission. Antituberculosis treatment with clarithromycin markedly improved the patient's general condition and hematological abnormalities. Three months after resolution of the NTM infection, the peripheral blood monocyte count increased, the fever recurred, and the patient suddenly died of myocardial infarction. Disseminated infection with NTM has gained attention as a frequent complication of AIDS, and NTM can also be one of the pathogens causing disseminated infection in patients with MDS. In the present case, infection with mycobacteria that normally would have been digested by macrophages and would not have caused disseminated infection in a healthy individual, was probably related to the clinical features including high fever, severe pancytopenia and hemophagocytosis.
Disease Progression↗