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Biomedical subjects

M Yoshida

Publications and source records attributed to M Yoshida.

At least 1,135 records · Page 63Linked to original sources
PubMed1996

Selenium administration to a ten-year-old patient receiving long-term total parenteral nutrition (TPN)--changes in selenium concentration in the blood and hair.

Muscle pain in the lower limbs occurred in a child with short bowel syndrome who has been receiving longterm total parenteral nutrition (TPN). Biochemical parameters revealed that the plasma and erythrocyte selenium concentrations were below the normal range for children and intravenous injection of selenium prepared from selenious acid was started at a dose of 100 micrograms per day. Muscle pain in the lower limbs disappeared one month afterwards. At this point in time, the elevation of the plasma selenium concentration was noted but the erythrocyte selenium concentration remained low. When administration was suspended due to catheter-induced fever five months later, the whole blood selenium concentration decreased again and the symptoms recurred. Accordingly, the dose of selenium was increased to 200 micrograms/day. Subsequently, the blood selenium concentration recovered to the normal range for children. After the dose increase to 200 micrograms/day, concentrations in hair samples collected at every centimeter distance from the root end were determined. The selenium concentration at the root end was found to be higher than the normal range for children, indicating that this was an excessive dose case. Although the dose was decreased from 200 micrograms/day to 120 micrograms/day, the plasma and erythrocyte selenium levels did not go down. Furthermore, the selenium level in the hair reached a plateau, and no recurrence of symptoms was observed. The above results indicate the usefulness of monitoring the selenium concentration in hair in addition to determining the blood selenium level and GSH-Px activity in administering selenium to children undergoing TPN.

Adolescent↗
PubMed1996

Magnetic resonance images in patients with acute traumatic injury of the temporomandibular joint: a preliminary report.

Condylar or subcondylar fractures are severe traumatic lesions of the temporomandibular joint (TMJ) but the damage to the intracapsular soft tissues is not fully defined. In this study, twelve joints in ten patients with condylar and subcondylar fractures of the TMJ between two and twelve days after injury, were examined by magnetic resonance imaging to evaluate the damage to the intracapsular soft tissues in the acute phase. The joint capsule and the retrodiscal tissue were both swollen and showed increased signal intensity. Tears were recognized in the capsule of the eight joints and in the retrodiscal tissue of six joints. All discs were displaced in an anteromedial direction along with the fractured condylar fragments, but tear (rupture) was not recognized. In all cases, high signal intensity was seen in the joint spaces, and haemarthrosis was recognized in six joints during open reduction surgery.

Acute Disease↗
PubMed1996

Disposition characteristics of plasmid DNA in the single-pass rat liver perfusion system.

PURPOSE: To define the hepatic uptake mechanism of a plasmid DNA, we quantitated the uptake of pCAT (plasmid DNA encoding chloramphenicol acetyltransferase reporter gene fused to simian virus 40 promoter), a model plasmid, after a single pass through the perfused rat liver using albumin- and erythrocyte-free Krebs-Ringer bicarbonate buffer (pH 7.4). METHODS: [32P]pCAT was introduced momentarily into this system from the portal vein as a bolus input or constant infusion mode, and the outflow patterns and hepatic uptake were evaluated using statistical moment analysis. RESULTS: The venous outflow samples had electrophoretic bands similar to that of the standard pCAT, suggesting that the plasmid is fairly stable in the perfusate during liver perfusion. In bolus experiments, pCAT was largely taken up by the liver and the uptake was decreased with increase in injected dose. Statistical moment analysis against outflow patterns demonstrated that the apparent volume of distribution of pCAT was greater than that of human serum albumin, indicating a significant reversible interaction with the tissues. The results of collagenase perfusion experiments suggest that the hepatic accumulation of pCAT occurred preferentially in the nonparenchymal cells (NPC). The amount of total recovery in the liver decreased substantially by preceding administration of polyinosinic acid, dextran sulfate, succinylated bovine serum albumin, but not by polycytidylic acid. This suggests that pCAT is taken up by the liver via scavenger receptors for polyanions on the NPC. In constant infusion experiments, the presence of 2,4-dinitrophenol and NH4Cl caused a significant increase in the outflow concentration of [32P]pCAT and decrease by half in the total hepatic recovery than that of plasmid DNA administered alone, suggesting that plasmid DNA may undergo internalization by the NPC. CONCLUSIONS: The liver plays an important role in the elimination of plasmid DNA and a successful delivery system will be required to avoid its recognition by the scavenger receptors on the liver NPC.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1996

A phase II study of cisplatin, vindesine and continuously infused 5-fluorouracil in the treatment of advanced non-small-cell lung cancer. Osaka Lung Cancer Chemotherapy Study Group.

Fifty-two previously untreated patients with advanced non-small-cell lung cancer (NSCLC) were treated on a 14 day cycle with cisplatin (60 mg m-2 i.v.) and vindesine (3 mg m-2 i.v.) on day 1, followed by a 3 day continuous infusion of 5-fluorouracil (800 mg m-2 day-1) starting on day 8. An overall response rate of 40.4% was observed in 47 evaluable patients, which included one complete response and 18 partial responses. Responses were achieved in 61.1% of stage 3 patients and 27.6% of stage 4 patients. The median progression-free interval was 19.3 weeks, and median survival time was 41.6 weeks (47.1 weeks for patients with stage 3 disease and 38.7 weeks for those with stage 4 disease). Toxicity was well tolerated. Gastrointestinal and renal toxicities did not exceed WHO grade 2. Grade 3 or 4 leucopenia and anaemia occurred in nine (19%) and four (9%) patients respectively, but only grade 2 thrombocytopenia was observed. Phlebitis at the infusion site was observed in 24 patients (53%). This treatment programme achieved a response rate similar to other active combination regimens for the treatment of advanced NSCLC, and was less toxic.

Adenocarcinoma↗
PubMed1996

Tretinoin induces bone marrow collagenous fibrosis in acute promyelocytic leukaemia: new adverse, but reversible effect.

In 11/13 acute promyelocytic leukaemia (APL) cases treated with tretinoin (RA) we observed RA-induced inaspirable collagenous fibrosis of the bone marrow. To study the mechanism of RA on collagen production, we cultured a human bone marrow derived stromal cell line and an osteoblastic cell line with RA in vitro. 10(-7) and 10(-6)M of RA stimulated collagen production. Clinical and experimental observation may be important to understand this adverse effect of RA as it is useful in cancer chemoprevention as well as treatment for APL. This adverse effect is spontaneously reversible after stopping RA or following chemotherapy.

Adult↗
PubMed1996

An aggressive nasal lymphoma accompanied by high levels of soluble Fas ligand.

Fas ligand (FasL), either in the membrane bound form or soluble form, has cytotoxic activity against Fas-expressing cells. We report a case of nasal lymphoma accompanied by liver damage and pancytopenia. The serum level of soluble FasL (sFasL) was very high on admission, but rapidly decreased to normal levels after chemotherapy for lymphoma. Liver damage and pancytopenia also improved with the decrease in serum sFasL. Since Fas is expressed on both hepatocytes and haemopoietic cells, these facts suggest that FasL was expressed on lymphoma cells and directly associated with pathogenesis of liver damage and pancytopenia through its cytotoxic activity.

Enzyme-Linked Immunosorbent Assay↗
PubMed1996

Heat shock-enhanced T cell apoptosis with heat shock protein 70 on T cell surface in multicentric Castleman's disease.

We report here that T cells from patients with multicentric Castleman's disease (MCD) are sensitive to hyperthermia. T cells from two of three patients with MCD revealed DNA ladder formation and chromatin condensation following heat shock (30 min at 41.5 degrees C). Peripheral blood mononuclear cells (PBMC) from the same MCD patients exhibited high levels of spontaneous apoptosis after 72 h in culture and elevated apoptosis after heat shock, as evaluated by a quantitative flow cytometric assay. Heat shock protein 70 (hsp70) was detected on the cell surface of T cells in all three patients after heat shock. Furthermore, hsp70 was detected on T cells in the two MCD patients with apoptosis even in the absence of heat shock. T cells from normal samples did not show either heat-shock-induced expression of cell-surface hsp70 or apoptosis. Thus, heat shock treatment augmented hsp70 expression on the cell surface of T cells and enhanced apoptosis. Our studies suggest that hyperthermia may influence the clinical course of MCD.

Antigens, Surface↗
PubMed1996

Leukocyte adhesion to vascular endothelium induces E-selectin linkage to the actin cytoskeleton.

We have examined functions of the cytoplasmic domain of E-selectin, an inducible endothelial transmembrane protein, especially its ability to associate with the cytoskeleton during leukocyte adhesion. Confocal microscopy of interleukin-1 beta (IL-1 beta)-activated human umbilical vein endothelial cells (HUVEC) visualized clustering of E-selectin molecules in the vicinity of leukocyte-endothelial cell attachment sites. A detergent based extraction and Western blotting procedure demonstrated an association of E-selectin with the insoluble (cytoskeletal) fraction of endothelial monolayers that correlated with adhesion of leukocytes via an E-selectin-dependent mechanism. A mutant form of E-selectin lacking the cytoplasmic domain (tailless E-selectin) was expressed in COS-7 cell and supported leukocyte attachment (in a nonstatic adhesion assay) in a fashion similar to the native E-selectin molecule, but failed to become associated with the cytoskeletal fraction. To identify the cytoskeletal components that associate with the cytoplasmic domain of E-selectin, paramagnetic beads coated with the adhesion-blocking anti-E-selectin monoclonal antibody H18/7 were incubated with IL-1 beta-activated HUVEC, and then subjected to detergent extraction and magnetic separation. Certain actin-associated proteins, including alpha-actinin, vinculin, filamin, paxillin, as well as focal adhesion kinase (FAK), were copurified by this procedure, however talin was not. When a mechanical stress was applied to H18/7-coated ferromagnetic beads bound to the surface of IL-1 beta-activated HUVEC, using a magnetical twisting cytometer, the observed resistance to the applied stress was inhibited by cytochalasin D, thus demonstrating transmembrane cytoskeletal mechanical linkage. COS-7 cells transfected with the tailless E-selectin failed to show resistance to the twisting stress. Taken together, these data indicate that leukocyte adhesion to cytokine-activated HUVEC induces transmembrane cytoskeletal linkage of E-selectin through its cytoplasmic domain, a process which may have important implications for cell-cell signaling as well as mechanical anchoring during leukocyte-endothelial adhesive interactions.

Actins↗
PubMed1996

Uptake characteristics of oligonucleotides in the isolated rat liver perfusion system.

The objective of this study was to examine the hepatic disposition characteristics of 20-mer model phosphodiester oligonucleotide (PO) and its partially phosphorothioated (PS3) and fully phosphorothioated (PS) derivatives in the single-pass isolated rat liver perfusion system. [32P]-labeled oligonucleotides were momentarily introduced into this system through the portal vein as a bolus input mode, and the venous outflow patterns were evaluated using statistical moment analysis. The apparent volumes of distribution of these oligonucleotides were greater than those of reference substances for vascular space (erythrocytes) and extracellular space (human serum albumin), indicating a significant interaction between oligonucleotides and the liver. Significant hepatic uptake of oligonucleotides was also observed. About 20%, 36%, and 52% of the injected dose (3 micrograms/rat) was taken up by the liver during a single passage after bolus injection of PO, PS3, and PS, respectively. In the case of PS injection, slow efflux from the liver was observed in the latter phase of perfusion. This suggests that the hepatic uptake process of these oligonucleotides greatly depended on their types. The results of collagenase perfusion experiments suggest that PS3 oligonucleotides were taken up by both liver parenchymal and nonparenchymal cells. The amount of total recovery in the liver decreased substantially by coadministration of polyinosinic acid, dextran sulfate, polycytidic acid and 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid. This suggests that PS3 was taken up by the liver as an anionic molecule in a nonspecific manner.

Animals↗
PubMed1996

The heterogeneous interaction of substoichiometric TNP-ATP and F1-ATPase from Escherichia coli.

The interactions of substoichiometric TNP-ATP and F1-ATPase from Escherichia coli (EF1) were examined and compared with those in the case of mitochondrial F1-ATPase (MF1) and F1-ATPase from thermophilic Bacillus PS3 (TF1). EF1 hydrolyzed substoichiometric TNP-ATP faster than TF1 or MF1, although some 20% of the TNP-ATP remained unhydrolyzed even in the presence of excess chase ATP. The affinity of the catalytic site of EF1 for the product, TNP-ADP, was weaker than that of TF1 or MF1, and the TNP-ADP was readily released upon addition of excess ATP. The amplitude of the difference absorption spectrum induced by binding of TNP-AT(D)P to EF1 was smaller than that of MF1 or TF1 under similar experimental conditions. When an excess amount of TNP-ATP was added to EF1 and the change of the difference spectrum was measured, the shape of the difference spectrum of the ATP-replaceable fraction was very similar to that in the case of binding of TNP-ATP to the isolated beta subunit of TF1, indicating that the rapidly replaceable fraction of bound TNP-ATP was actually at the catalytic site and most of the non-replaceable portion was bound at noncatalytic sites. Weaker affinity of the catalytic site for TNP-ATP may account for the heterogeneous binding and hydrolysis under the conditions described in this paper.

Adenosine Triphosphate↗
PubMed1996

Electron microscopic observations of aberrant capsids of pseudorabies virus.

Interactions between four strains of pseudorabies virus (PrV) and seven kinds of cell lines were examined. Three kinds of cells (SKL, CPK and PK-15) were especially infected with PrV at an MOI of about 10 PFC/cell. At sequential intervals after infection, cells of these types were collected for electron microscopic observations and the infectious doses of culture fluids were assayed. Developmental features of PrV were found to be very similar to those of herpes simplex virus (HSV), with the slight difference that PrV developed a little earlier and more vigorously than did HSV. At the late stage of infection, aberrant capsids of PrV were observed frequently in the nucleus of SKL but rarely in the nuclei of CPK and PK-15. The titer of infectious virus produced by SKL was much larger than that produced by CPK and PK-15. Immuno-electron microscopic examination using a monoclonal antibody against the major capsid protein of PrV clearly demonstrated that the complete and aberrant capsids have a common epitope. The mechanism of the formation of aberrant capsids is discussed.

Animals↗
PubMed1996

Family history-related risk of gastric cancer in Japan: a hospital-based case-control study.

In Japan, there have been a few reports on the familiar factors of gastric cancer (GC) and on the GC risk related to family history (FH) at other cancer sites. We analyzed the association between GC occurrence and a positive FH of cancer of the stomach and of other sites in a hospital-based case-control study. The subjects included cases histologically confirmed as incident cancer of the stomach (n = 136; 86 male and 50 female patients) and sex and age (+/- 1 year)-matched controls. GC risk was high when a subject had a parental history of GC [Mantel-Haenszel odds ratio adjusted for sex and age (OR)=2.3; 95% confidence interval (95% CI):1.1-5.0]. GC risk was almost unity for a cancer FH of any other cancer site, even among closer relatives, suggesting little or no contribution to GC occurrence. The familial occurrence of GC found in this study suggests the existence of a genetic susceptibility to cancer of the stomach. Further, females tended to show higher GC risks than males, when reporting an affected mother (OR=6.0; 95% CI:1.1-31.4 and OR= 1.4; 95% CI:0.4-4.8, respectively), whereas males showed a slightly higher risk than females when reporting an affected father (OR=2.4; 95% CI:0.8-7.5 and OR=2.3; 95% CI:0.4-15.6, respectively). This suggests a possible gender difference in how environmental factors influence GC occurrence. The development of gastric tumors seems to be due to a complex and unknown interaction between environmental and genetic factors.

Aged↗
PubMed1996

Diagnosis of renovascular hypertension by echo-Doppler velocimetry.

A 13 year old boy suffering hypertension was examined for peripheral plasma renin, angiotensin-I, angiotensin-II and aldosterone. All data were within the normal range. The Captopril test and renal scintigraphy (both with and without Captopril) also showed normal patterns. Echo-Doppler velocimetry of the renal artery revealed that left renal arterial peak flow velocity was fast (3.4 m/s). The patient was therefore diagnosed with left renal arterial stenosis. Angiography demonstrated the duplex of the left renal artery and stenosis of the left lower renal artery. Percutaneous transluminal angioplasty was successfully performed.

Adolescent↗
PubMed1996

Application of a new perchloric acid treatment method to measure endotoxin in both amniotic fluid and cord blood by an endotoxin-specific chromogenic Limulus test in intra-amniotic infection.

Endotoxin in both amniotic fluid and cord blood was measured to detect intra-amniotic fetal infection. Both amniotic fluid and cord blood plasma were pretreated by a perchloric acid treatment, and the endotoxin level was measured by Endospecy test. Cut off values for endotoxin in amniotic fluid and cord blood were 8.5 pg/mL and 7.6 pg/mL, respectively. Escherichia coli intra-amniotic infection caused respiratory distress syndrome (RDS)-mimicking pneumonia. Abnormally high values of endotoxin in both amniotic fluid and cord blood were detected. Intra-amniotic infection caused by Gram-positive bacteria (group B streptococci, Enterococcus fecalis) was shown to be endotoxin negative in both amniotic fluid and cord blood. In cases of negative amniotic fluid culture, measurement of the value of endotoxin in the amniotic fluid is useful in identifying intra-amniotic fetal infection.

Amniotic Fluid↗
PubMed1996

Effect of cyclosporin A on isolated rabbit bladder and urethral smooth muscle.

BACKGROUND: The effects of Cyclosporin A (CsA) on vascular smooth muscle inducing hypertension have been established. However, there is no information available concerning the effects of CsA on urinary smooth muscle. Therefore, the effects of CsA were investigated on the bladder and urethral smooth muscle in rabbits. METHODS: CsA (10 mg/kg/day, intravenously) was given to rabbits for 14 days. Rabbit bladder and urethral smooth muscles were then isolated and evaluated using a muscle bath technique. RESULTS: 10(-10)-5 x 10(-6)M CsA alone had no direct effect on bladder or urethral smooth muscles. The Emax (maximum contractile response) and ED50 values for acetylcholine-induced contractions and the Emax (maximum relaxation response) for isoproterenol-induced relaxation in bladder smooth muscles were not significantly different between CsA-treated and control groups. The ED50 for isoproterenol-induced relaxation was significantly lower in the CsA group (P < 0.05). The Emax for phenylephrine- and clonidine-induced contractions in urethral smooth muscle was significantly higher in the CsA-treated group (P < 0.05). The ratio of the maximum response of the urethral smooth muscle to phenylephrine and clonidine in Ca+2-free solution to the normal solution in the CsA group (13.42% and 4.40%, respectively) was significantly higher than the maximal response ratios in the control group (6.34% and 3.00%, respectively; P < 0.05). CONCLUSIONS: CsA treatment augments the relaxation response of the bladder to isoproterenol and the contractile response of the urethra to phenylephrine and clonidine. In addition, CsA increases the filling of intracellular stores of releasable Ca+2, and also increases the permeability of Ca+2 in rabbit urethral smooth muscle. Thus, it is suggested that CsA may cause a urinary disturbance in patients treated with CsA via increased urethral resistance.

Acetylcholine↗
PubMed1996

Subcapsular hematoma and hypertension following percutaneous needle biopsy of a transplanted kidney.

Percutaneous needle biopsy of a transplanted kidney is indicated as a diagnostic procedure in the evaluation of unexplained deteriorated renal function after renal transplantation. This procedure is not always without complications. We report a case of a subcapsular hematoma and hypertension following a percutaneous needle biopsy of a transplanted kidney. The cause of hypertension in this patient and the management of the subcapsular hematoma are discussed.

Adult↗
PubMed1996

Modulation by nitric oxide and prostaglandin of the renal vascular response to angiotensin II (3-8).

1. The aim of this study was to investigate the renal vascular response to angiotensin II (3-8) (AIV). The effect of the nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) or the cyclooxygenase inhibitor, indomethacin on the AIV-induced response was examined in anaesthetized spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). 2. Intrarenal infusion of AIV produced a biphasic vasoconstrictor response. The vasoconstriction developed rapidly to reach a maximum followed by a partial recovery to a sustained lesser level of vasoconstriction. The initial maximum response was enhanced by L-NAME but not affected by indomethacin treatment. The simultaneous administration of L-NAME and indomethacin prevented the partial recovery resulting in a greater sustained level of constriction. 3. A stable vasoconstriction of relatively constant magnitude was observed with angiotensin II (AII) infusion. The AII vasoconstriction was enhanced by L-NAME but not changed by indomethacin. The combination of these inhibitors further enhanced the AII-induced vasoconstriction in WKY, but not in SHR. 4. Pretreatment with the AII receptor antagonist, losartan, inhibited the vasoconstriction induced by AIV and AII. 5. These results suggest that nitric oxide and prostaglandins may modulate the renal vascular response to AIV.

Angiotensin II↗