Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 865 records · Page 48Linked to original sources

PubMed1993

Attenuation of warm ischemic injury of rat lung by inflation with room air--assessment of cellular components and the surfactant in the bronchoalveolar lavage fluid in relation to changes in cellular adenosine triphosphate.

Studies were made on the effects in rat lungs of aerobic and anaerobic conditions on the intracellular levels of adenosine triphosphate and its related metabolites, the releases of intracellular enzymes, and the secretion of pulmonary surfactant. After warm ischemia for 120 min, the ATP content of lungs inflated with air was significantly higher (8.0 +/- 1.2 mumol/g dry weight) than those of deflated lungs and lungs inflated with nitrogen (0.8 +/- 0.7 mumol/g dry weight and 2.0 +/- 0.7 mumol/g dry weight, respectively; P < 0.001). The amounts of intracellular enzymes, such as lactate dehydrogenase, cytosolic and mitochondrial aspartate aminotransferase, and protein in the bronchoalveolar lavage fluid (BALF) of air-inflated lungs were significantly less than those in BALFs of deflated and nitrogen-inflated lungs (P < 0.001). The BALF-contents of dipalmitoyl phosphatidylcholine (DPPC), the main component of alveolar surfactant of aerobic and anaerobic ischemic lung were, however, similar. During 120-min warm ischemia after lavage, air-inflated lungs secreted significantly more DPPC into the alveolar space than nitrogen-inflated lungs did (P < 0.001). We conclude that cell membranes in the lungs are damaged under anaerobic conditions, but that inflation of ischemic lungs with air is effective for protecting them from cell injury and for maintaining the intracellular level of ATP and the ability of the cells to secrete pulmonary surfactant.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1993

Chemical analysis of lipopolysaccharides of Shigella sonnei form II strains expressed by cloned form I antigen genes.

A compositional sugar analysis was carried out on lipopolysaccharide (LPS) from Shigella sonnei form II in which a plasmid with cloned form I antigen genes had been introduced. The recipient form II strains contained galactose, glucose, heptose, glucosamine, and 2-keto-3-deoxyoctonic acid (KDO) (2: 3: 1: 2: 2) in its LPS, while the transformant form I LPS contained, besides these sugars, N-acetyl-L-altrosaminouronic acid as an additional sugar constituent, which is known to be one of the antigenic determinants of form I antigen.

Cloning, Molecular↗

PubMed1993

Effect of 5-fluorouracil and UFT on experimental liver metastasis model of colorectal cancer using mouse colon 26 cells.

Effects of 5-fluorouracil (5-FU) and UFT on an experimental liver metastasis model were compared at equi-effective dosage levels against subcutaneous tumor of mouse colon 26. 5-FU at the dosage level of 40 mg/kg suppressed the subcutaneous tumor growth by 70.0% and 45.0% on day 13 and day 18, respectively, and UFT at 20 mg/kg provided almost equal suppression (63.0% and 48.0%). In the liver metastasis model, 5-FU at 40 mg/kg showed more potent prevention of the formation of metastatic foci (94.9%) than did UFT (60.4%) at 20 mg/kg. 5-FU at 40 mg/kg produced a much higher peak serum level of 5-FU than did UFT at 20 mg/kg and also showed a much higher AUC (area under the curve) level in the portal blood. These results suggest that oral administration of 5-FU might be useful in prevention of liver metastasis of colorectal cancer.

Animals↗

PubMed1993

[Epidemiology of Tsutsugamushi disease and typing of isolated Rickettsia in Chiba Prefecture].

In Chiba Prefecture, the first patient of Tsutsugamushi disease was found in the southern part in the 1950's, but after that no patient was detected until 1982. After 1982, patients have been noticed again, the number of patients has been increasing year by year. The number of serologically confirmed cases was 152 and 157 in 1989 and 1990, respectively with indirect immunofluorescence assay. About 90 percent of the patients were found in November and December, prevalently in the southern part of the prefecture. On the other hand, a few patients were found yearly in a harf of towns and villages in this prefecture. The number of isolated strains of Rickettsia tsutsugamushi from patients was 4, i.e., TR6030, TR6310, TR6311, and TR6324 in 1986 and 3, TR1811, TR1827 and TR1829, in 1991. Six isolates except TR6303 reacted with anti-Kawasaki monoclonal antibody but not with other strain specific monoclonal antibodies. Therefore, these 6 isolates were determined as Kawasaki type strain. An isolate. TR6303, reacted with anti-Kuroki monoclonal antibody at a titer of 1:2560 and anti-Karp monoclonal antibody at a titer of 1:320. This result suggested that the recent Tsutsugamushi disease is mostly caused by Kawasaki types in this prefecture.

Humans↗

PubMed1993

Serotype-specific amplification of Rickettsia tsutsugamushi DNA by nested polymerase chain reaction.

Polymerase chain reaction (PCR) with nested primer pairs was used to diagnose scrub typhus and identify the Rickettsia tsutsugamushi serotype. The primer pairs used for PCR were designed on the basis of the nucleotide sequence of the gene that encodes the 56-kDa antigen. Serotype-specific primers were used in the second PCR amplification. Five serovariants, the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of R. tsutsugamushi, were identified by nested PCR. In addition, the serotype identified by PCR with DNA from blood clots was the same as that of the strain isolated from five patients with scrub typhus. These findings indicate that this method is useful for diagnosis and identification of the rickettsial serotype in infected patients.

Base Sequence↗

PubMed1993

Effect of granulocyte-macrophage colony-stimulating factor on chemotherapy-induced granulocytopenia in patients with malignancies.

To investigate the effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on cytotoxic chemotherapy-induced granulocytopenia, we performed an open nonrandomized clinical trial in 46 patients with malignancies receiving cytotoxic chemotherapy regimen. Twenty-six patients who received two cycles of the identical chemotherapy regimen and had granulocytopenia less than 1 x 10(9) cells/l after the first cycle of chemotherapy were eligible for this study. They received 60, 125 or 250 micrograms/m2/day of rhGM-CSF randomly. The nadirs of peripheral granulocytes demonstrated significantly much higher levels in all dosages studied than those of control cycles. The duration of granulocytopenia was shortened with rhGM-CSF support. Such granulocyte recovery appeared in parallel with increasing dosages of GM-CSF, thus, infections with febrile episodes were reduced. Toxicity of rhGM-CSF was generally well tolerated.

Adult↗

PubMed1993

Phase II study of recombinant human granulocyte-macrophage colony-stimulating factor in myelodysplastic syndrome and aplastic anemia.

As phase II study, we treated 18 patients with myelodysplastic syndrome (MDS) and 37 patients with aplastic anemia (AA) with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) for 14-28 days. Administration of rhGM-CSF resulted in a dose-dependent increase in circulating granulocyte counts, which was statistically significant in patients with AA. There were no consistent changes in monocyte and lymphocyte counts. Although no increase in both thrombocyte and erythrocyte counts was detected in the majority of the patients, a response of both lineages to rhGM-CSF, in addition to granulocyte lineage, was observed in 3 patients. Drug-associated adverse events developed in 28 patients (51%). The most frequent adverse event was fever. In general, the treatment with rhGM-CSF was well tolerated. The results suggest that rhGM-CSF is effective for patients with MDS and AA.

Adolescent↗

PubMed1993

A novel metabolite of 3,4-methylenedioxyamphetamine (MDA): formation of 3-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline and its pharmacological effect.

In 3,4-methylenedioxyamphetamine (MDA)-treated rat brain and urine, 3-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline (3Me6,7MDTIQ) was detected as a new metabolite. The content of 3Me6,7MDTIQ in (R)-MDA-treated rat was significantly higher than that in (S)-MDA-treated brain and urine. This result suggests that this metabolism of MDA contains stereoselective pathways. The pharmacological effects of 3Me6,7MDTIQ on behavior differed from those of MDA. The ambulation score of 3Me6,7MDTIQ was significantly decreased compared to the control, and the rearing score of 3Me6,7MDTIQ was moderately decreased compared to the control in an open-field test.

3,4-Methylenedioxyamphetamine↗

PubMed1993

Frequency analysis of QRS complex with bundle branch block in patients with and without sustained ventricular tachycardia.

To distinguish patients with bundle branch block (BBB) and sustained ventricular tachycardia (s-VT) from patients with BBB but without s-VT, a frequency analysis of the QRS complex was performed in 71 patients. Frequency analysis of the QRS complex of patients with left bundle branch block (LBBB) showed that patients with s-VT had significantly larger areas and area ratios between 50 and 100 Hz in the X lead than patients without s-VT (area: -0.905 +/- 0.231 vs -1.195 +/- 0.286. area ratio: -0.783 +/- 0.230 vs -1.125 +/- 0.310; P < 0.05). The area and area ratios from 100 to 200 Hz in the Z lead were also larger in patients with s-VT. The highest predictive accuracy using the area ratio from 50 to 100 Hz in the X lead was 86%, with a sensitivity and specificity of 83% and 88%, respectively. In cases with LBBB, time domain analysis showed no significant difference between patients with s-VT and those without s-VT. Frequency analysis of the QRS complex may be useful for distinguishing LBBB patients with s-VT from those without s-VT.

Adult↗

PubMed1993

Nonpharmacologic treatment of common atrial flutter guided by transient entrainment.

We attempted nonpharmacologic treatment for common atrial flutter in 7 patients, with direct current catheter ablation (CA) in 5 cases and cryoablation in 2 cases under the guidance of transient entrainment. Transient entrainment during common atrial flutter by pacing from the mid or low lateral right atrium (LLRA) revealed a long conduction time between the LLRA and the orifice of the coronary sinus (CSo) (73% to 121% of flutter cycle length). In 2 cases, fragmented electrograms were recorded at the low right atrial septum with durations of 150 msec and 155 msec, respectively. Because these fragmented electrograms were transiently entrained by rapid atrial pacing in the same manner as other atrial electrograms and were recorded in an area of long conduction, we believe that fragmented electrograms represent critical slow conduction. In 5 cases, CA was directed at this area. Three cases were successfully treated with 3 to 4 DC shocks of 100 J (follow up periods of 11.3, 4.5 and 3 months). Two cases which received 1 to 2 DC shocks of 100 J had recurrence of atrial flutter 6 and 4.7 months later, respectively. Two cases which showed atrial septal defect received surgical treatment. They were successfully treated with extended cryoablation in this same area (follow up periods of 26 and 9.2 months). In conclusion, extended ablation of an area of fragmented electrograms using transient entrainment may be an effective treatment for common atrial flutter.

Aged↗

PubMed1993

Mutational analysis of the amino acid residues essential for the cis and trans cleavage activity of the potato virus Y 50-kDa protease.

To examine the proteolytic activities of various truncated derivatives of the potato virus Y (PVY) 50-kDa protease, the derivatives were expressed in Escherichia coli in polyprotein forms fused with coat protein (CP). For the intermolecular cleavage reaction, the truncated proteases were expressed together with the substrate protein containing the polymerase-CP junction. The activity was evaluated by the amount of the mature CP released from the precursor by the intra- and intermolecular cleavage occurring in E. coli. By this experiment, we identified the moiety responsible for the proteolytic activity of the 50-kDa protease to be a 26-kDa polypeptide mapped to the C-terminal half of the protease. Introduction of His234-->Tyr, Asp269-->Asn, or Cys339-->Gly substitution in the putative catalytic triad of the protease abolished its activity. However, the mutated protease with Cys339-->Ser replacement retained a reduced proteolytic activity.

Amino Acid Sequence↗

PubMed1993

Cleavage of potato virus Y polyprotein in Escherichia coli depending on the proteolytic activity of viral protease.

We have cloned a 5-kb cDNA corresponding to the 3'-half of genomic RNA of potato virus Y (PVY), the type member of plant potyvirus. Based on its nucleotide sequence, the cDNA was presumed to encode PVY protease responsible for the self-processing of polyprotein precursor expressed from PVY genome. To test its proteolytic activity, the cDNA was modified so as to express the protease-polymerase-coat protein (CP) portion of PVY polyprotein in Escherichia coli. By Western blotting analysis of the cell extract of E. coli expressing the polyprotein, mature CP was detected. A large deletion in the polymerase-coding region did not affect the emergence of mature CP, but a small deletion in the putative protease region resulted in disappearance of mature CP and appearance of the intact polyprotein. These results indicated that the polyprotein expressed in E. coli was cleaved depending on the proteolytic activity of PVY protease.

Amino Acid Sequence↗

PubMed1993

An occurrence of equine transport pneumonia caused by mixed infection with Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus.

An acute death occurred in a racehorse with pneumonia after long-distance transportation in December, 1990. Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus were isolated from the lung at high rate. Specific antigens of these bacteria were also demonstrated immunohistologically in the pneumonic lesion. These findings indicated that the disease is equine transport pneumonia caused by a mixed infection of the three bacterial species. This is the first report on the isolation of P. caballi and S. suis from a racehorse in Japan.

Animals↗

PubMed1993

The growth of mouse hybridoma cells between Peyer's patch lymphocyte and myeloma cell in the gastrointestinal tract. A model for human multiple lymphomatous polyposis of the gastrointestinal tract.

To elucidate the mechanism of multiple lesions in human primary lymphoma or multiple lymphomatous polyposis of the gastrointestinal tract, we developed a experimental model utilizing mouse hybridoma cells. Syngeneic mice were immunized with human hemoglobin via gastric intubation and a hybridoma clone (13c) between the Peyer's patch cell and mouse myeloma cell was obtained. The 13c cells were infused into normal syngeneic mice through a lateral tail vein. About 2 months after injection mice were sacrificed and their viscera were scrutinized histologically. All 11 mice receiving 13c showed multiple tumors at the colon, microscopic massive invasions at the small intestine, and scattered invasions at Peyer's patch, mesenteric lymph nodes and the spleen, exhibiting the similar distribution patterns as in human multiple lymphomatous polyposis of the gastrointestinal tract. ME-1 or MU-1 cells (hybridomas between P3 and mouse spleen cell) were distributed at the liver, spleen and paraaortic lymph nodes. Such migration patterns of 13c cells and their adherence to vessel walls suggest that multiple invasions may be lymphocyte homing receptor-mediated phenomena.

Animals↗

PubMed1993

The incidence of vertical transmission of hepatitis C virus.

This study was undertaken to clarify the incidence of the vertical transmission of hepatitis C virus (HCV). During the third trimester, 2015 pregnant women were examined as to anti-HCV antibodies. Anti-HCV antibody seropositive women were examined for HCV-RNA in peripheral blood at labor and in breast milk. Their offspring were also examined for HCV-RNA in umbilical cord blood and peripheral blood one week after birth and during subsequent outpatient visits. The following results were obtained: (1) Twelve of the 2015 pregnant women (0.6%) were seropositive for anti-HCV antibodies; (2) Seven of the twelve women (58%) seropositive for anti-HCV antibodies were also seropositive for HCV-RNA; (3) Three newborns of the seven HCV-RNA seropositive women (43%) were found to have HCV-RNA in the cord blood; (4) In the three newborns HCV-RNA had disappeared from the peripheral blood within one month after birth; (5) Two of the seven HCV-RNA seropositive women (29%) had HCV-RNA positive breast milk; (6) The possibility of infection via breast milk was shown in one infant at ten months after birth. Based on these results, it is indicated that HCV vertical transmission is possible in more than half of the HCV-RNA seropositive mothers. However, because of the disappearance of HCV from the infants' peripheral blood, further following study is needed.

Base Sequence↗

PubMed1993

Gastric non-Hodgkin's lymphoma associated with Behçet's disease.

The first case of primary gastric lymphoma associated with Behçet's disease is reported. A 43-year-old woman, who had been treated for Behçet's disease for 15 years, was diagnosed as low-grade and small lymphocytic malignant lymphoma of the stomach. Although the patient had been treated for Behçet's disease, chemotherapy was performed and a complete remission of gastric lymphoma was achieved. The literature regarding the association of malignant diseases with Behçet's disease is briefly reviewed.

Adult↗

PubMed1993

Granulomatous angiitis of the central nervous system--case report.

A 22-year-old male presented with granulomatous angiitis manifesting as headache. Computed tomography (CT) demonstrated a low-density area and ring-like enhancement in the right frontoparietal region. Steroid therapy caused rapid improvement in the signs and symptoms. Withdrawal of steroid was followed by recurrence of the headache and low-density area. The steroid treatment was resumed until he became asymptomatic 3 months after admission. He was followed up as an outpatient once every 2 weeks. One month after discharge, he complained of mild headache, and CT again demonstrated a mild increase in the low-density area. He was followed up continuously without steroid treatment. Two months after discharge, he suddenly lost consciousness, and CT demonstrated multiple intracerebral hematomas in the bilateral parietal regions. Removal of an intracerebral hematoma in the right parietal region and external decompression were carried out, but he died 3 days later. Histological examination of tissues from the right parietal cortex and leptomeninges demonstrated granulomatous inflammation with several giant cells in the vessels of the cerebral cortex and leptomeninges.

Adult↗

PubMed1993

Ganglionic neurons in vagal and laryngeal nerves projecting to larynx, and their peptidergic features in the cat.

The distribution of cell clusters in the cervical vagal nerve (CVN), superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN), and the peptidergic features of their ganglionic neurons projecting to the larynx, were investigated in the cat using a combination of retrograde tracing by wheat germ agglutinin (WGA) and immunocytochemistry. In the CVN, a few medium sized cell clusters at a level caudal to the nodose ganglion, and some small cell clusters along the course of the vagus, were found. In the SLN and RLN, some medium sized ganglia were located close to the laryngeal framework and a few small groups of cells occupied more rostral parts. Some neurons of the cell clusters in the CVN and most of the ganglionic cells in the SLN and RLN exhibited WGA-immunoreactive (IR) cells, which projected to the larynx. In these WGA-positive ganglionic neurons, many cells showed vasoactive intestinal polypeptide-IR neurons, some neuropeptide Y-IR, and a few substance P-IR and calcitonin gene-related peptide-IR cells were also identified. The present findings indicate that neurons of the cell clusters in the laryngeal nerves, particularly those in the vicinity of the laryngeal framework, project to the larynx and may be autonomic.

Animals↗