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Biomedical subjects

H Tsuji

Publications and source records attributed to H Tsuji.

At least 253 records · Page 14Linked to original sources
PubMed1997

[Legionella pneumonia successfully treated despite late diagnosis].

Status asthmaticus developed in a 72-year-old man who was being treated with oral prednisolone for severe persistent asthma. The dosage of prednisolone was increased, and amikacin was injected to treat pneumonia that had developed in the right lung. Progressive pulmonary infiltrates, respiratory compromise, and hypoxemia developed, and the patient eventually required mechanical ventilation. Antibiotic treatment was changed to imipenem/cilastatin, piperacillin, gentamicin, clarithromycin, erythromycin, and minocycline. Liver injury developed. More than one month after the patient was admitted, Legionella pneumonia was diagnosed. Levofloxacin (400 mg/day) was then given orally, in combination with injected imipenem/cilastatin. Liver function did not deteriorate, and the pneumonia resolved. Most diagnoses of Legionnaires' disease are made retrospectively by examination of serum. In this case, antibiotics active against Legionella pneumophila had been used before the diagnosis was established, which probably contributed to the patient's recovery. When aminoglycosides or beta-lactam antibiotics are ineffective, administration of agents effective against Legionnaires' disease should be considered.

Administration, Oral↗
PubMed1997

Angiotensin II increases plasminogen activator inhibitor-1 and tissue factor mRNA expression without changing that of tissue type plasminogen activator or tissue factor pathway inhibitor in cultured rat aortic endothelial cells.

Angiotensin converting enzyme inhibitors (ACE-I) have been reported to prevent the recurrence of cardiovascular events. The mechanism of this decrease, however, can not be completely explained by anti-hypertensive and anti-hypertrophic effects of ACE-I. To investigate the mechanism of this decrease, we studied the regulation of plasminogen activator inhibitor-1 (PAI-1), tissue type plasminogen activator (TPA), tissue factor (TF), and tissue factor pathway inhibitor (TFPI) by angiotensin II (Ang II) in cultured rat aortic endothelial cells. Ang II increased PAI-1 and TF mRNA expression without affecting that of TPA or TFPI. These inductions were accompanied by increases in PAI-1 and TF activities and were inhibited by a type I Ang II receptor antagonist. The results suggest that Ang II decreases the antithrombotic properties of endothelial cells which increases the chance of thrombosis. Thus, inhibition of the renin-angiotensin system may be beneficial to prevent thrombus formation in treatment of ischemic heart disease.

Angiotensin II↗
PubMed1997

Transfection of HepG2 cells with infectious hepatitis C virus genome.

Hepatitis C virus (HCV) represents one of the major causes of acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC) around the world. Our knowledge of the life cycle of HCV, however, is limited. Current studies are hampered by the lack of a reproducible, high-level in vitro replication system of HCV. We sought to establish HCV replication in HepG2 cells by gene transfer of in vitro transcribed HCV RNA. In preliminary experiments, diethylaminoethyl-dextran led to more efficient gene transfer than cationic liposomes (lipofectin, lipofectamine, and DOTAP). Therefore, in subsequent experiments, HepG2 cells were transfected with full-length (9.6-kb) and near-full-length (9.4-kb) HCV RNA using diethylaminoethyl-dextran. Transfection with subgenomic HCV RNA and mock transfection were used as controls. Positive- and negative-strand HCV RNA sequences were detected by reverse transcription polymerase chain reaction (KT-PCR) for 60 days in the infectious HCV RNA transfected HepG2 cells. The presence of negative-strand HCV RNA, presumably representing replicative intermediates, was confirmed by ribonuclease protection assay. The intracellular levels of HCV RNA were measured by quantitative competitive RT-PCR from 10 to 50 days after transfection and were stable over this time period at moderately high levels (10(8) to 10(10) genomes per mg of total RNA). Expression of viral core and nonstructural proteins was detected in the cytoplasm of transfected cells by immunostaining. Virus-like particles measuring 50 to 60 nm in diameter were found by electron microscopy in cytoplasmic vesicles and conditioned media of the cells transfected with infectious HCV RNA but not in cells transfected with truncated HCV RNA. Culture supernatants of infectious HCV RNA transfected HepG2 cells were infectious for Daudi cells for three passages tested. The truncated HCV RNA lacking NS5 and 3' untranslated region (3' UTR) of HCV was replication incompetent. This is the first demonstration of HCV particles in HepG2 cells after transfection with infectious HCV RNA. We conclude that we have established a reproducible HCV replication system in HepG2 cells that can be used to study the life cycle of HCV and to test anti-HCV agents.

Antigens, Viral↗
PubMed1997

Effects of dibutyryl cyclic adenosine monophosphate on nucleolar organizer regions and epidermal growth factor receptor of Dunn osteosarcoma cells.

We investigated the characteristics of nucleolar organizer regions (NORs) and epidermal growth factor receptor (EGFR) on differentiated Dunn osteosarcoma in response to dibutyryl cyclic adenosine 3',5'-monophosphate (Bt2cAMP). In the presence of 3 mM Bt2cAMP, the mean number of NORs was significantly decreased in 24 hrs and 48 hrs compared with the untreated group. Also, EGFR affinity was decreased and the EGFR number was increased in response to the cellular differentiation by Bt2cAMP. The decrease in EGFR affinity might be considered as an indicator of differentiation or the mature state of the cells. Thus, the present study provides a new clue to support differentiation of osteosarcoma cells from the viewpoint of NORs findings and EGFR analysis as a differentiation marker.

Animals↗
PubMed1997

[Partial splenic embolization for the treatment of liver cirrhosis with hypersplenism: assessment of clinical response and liver function].

We have evaluated the efficacy of partial splenic embolization (SE) in the treatment in 10 cirrhotic patients with marked hypersplenism. The mean infarction rate of the spleen was 84%. The change of spleen size, peripheral blood cell counts and liver function tests after SE were investigated during 3 years, and also 10 cirrhotic patients without SE were followed as control. The residual spleens after SE did not enlarged except 1 case with 65% infarction rate of the spleen. In these cases, the SE led not only to a sustained increase in both platelet and white blood cell counts but also to a significant improvement of hepatic function tests (hepaplastin test, total cholesterol and albumin) during observation period. On the other hand, these parameters tended to decrease in control patients without SE. This study suggests that SE performed with a high infarction rate of spleen is an useful therapy for hypersplenism in cirrhosis.

Adult↗
PubMed1997

[A case of hepatic arterial infusion chemotherapy for multiple liver metastasis from breast cancer].

A 52-year-old woman underwent Auchinclass' operation for breast cancer. The histological type was papillotubular carcinoma. One year and 5 months after operation, multiple liver tumors were found on the CT scan and multiple bone metastasis on MRI. The former were treated by hepatic artery infusion chemotherapy with epirubicin and 5-FU using a subcutaneous implanted pump and the latter by 50 Gy irradiation. The patient began to complain of abdominal pain and discomfort after hepatic artery infusion, so all treatment was discontinued. Six months later the patient died of respiratory failure due to pleural dissemination. No liver mass was detected, and bone metastasis was not changed in section tissues. This suggested that the therapy for a breast cancer patient with distant metastasis must be considered according to the region of recurrence.

Adenocarcinoma↗
PubMed1996

Impact of reduced heart rate variability on risk for cardiac events. The Framingham Heart Study.

BACKGROUND: Although heart rate variability (HRV) is altered in a variety of pathological conditions, the association of reduced HRV with risk for new cardiac events has not been studied in a large community-based population. METHODS AND RESULTS: The first 2 hours of ambulatory ECG recordings obtained on subjects of the Framingham Heart Study who were free of clinically apparent coronary heart disease or congestive heart failure were reprocessed to assess HRV. Five frequency-domain measures and three time-domain measures were obtained. The associations between HRV measures and the incidence of new cardiac events (angina pectroris, myocardial infarction, coronary heart disease death, or congestive heart failure) were assessed with proportional hazards regression analyses. There were 2501 eligible subjects with a mean age of 53 years. During a mean follow-up of 3.5 years, cardiac events occurred in 58 subjects. After adjustment for age, sex, cigarette smoking, diabetes, left ventricular hypertrophy, and other relevant risk factors, all HRV measures except the ratio of low-frequency to high-frequency power were significantly associated with risk for a cardiac event (P = .0016 to .0496). A one-standard deviation decrement in the standard deviation of total normal RR intervals (natural log transformed) was associated with a hazard ratio of 1.47 for new cardiac events (95% confidence interval of 1.16 to 1.86). CONCLUSIONS: The estimation of HRV by ambulatory monitoring offers prognostic information beyond that provided by the evaluation of traditional cardiovascular disease risk factors.

Adult↗
PubMed1996

Determinants of heart rate variability.

OBJECTIVES: This study sought to examine clinical determinants of heart rate variability and to report normative reference values for eight heart rate variability measures. BACKGROUND: Although the clinical implications of heart rate variability have been described, clinical determinants and normative values of heart rate variability measures have not been studied systematically in a large community-based population. METHODS: The first 2 h of ambulatory electrocardiographic recordings obtained in Framingham Heart Study subjects attending a routine examination were reprocessed for heart rate variability. Recordings with transient or persistent nonsinus rhythm, premature beats > 10% of total beats, < 1-h recording time or processed time < 50% of recorded time were excluded; subjects receiving antiarrhythmic medications also were excluded. Among five frequency domain and three time domain measures that were obtained, low frequency power (0.04 to 0.15 Hz), high frequency power (0.15 to 0.40 Hz) and the standard deviation of total normal RR intervals based on 2-h recordings were selected for the principal analyses. Variables with potential physiologic effects or possible technical influences on heart rate variability measures were chosen for multiple linear regression analysis. Normative values, derived from a subset of healthy subjects, were adjusted for age and heart rate. RESULTS: There were 2,722 eligible subjects with a mean age (+/-SD) of 55 +/- 14 years. Three separate multiple linear regression analyses revealed that higher heart rate, older age, beta-adrenergic blocking agent use, history of myocardial infarction or congestive heart failure, diuretic use, diastolic blood pressure > or = 90 mm Hg, diabetes mellitus, consumption of three or more cups of coffee per day and smoking were associated with lower values of one or more heart rate variability measures, whereas longer processed time, start time in the morning, frequent supraventricular and ventricular premature beats, female gender and systolic blood pressure > or = 160 mm Hg were associated with higher values. Age and heart rate were the major determinants of all three selected heart rate variability measures (partial R2 values 0.125 to 0.389). Normative reference values for all eight heart rate variability measures are presented. CONCLUSIONS: Age and heart rate must be taken into account when assessing heart rate variability.

Adult↗
PubMed1996

Back muscle injury after posterior lumbar spine surgery. Topographic evaluation of intramuscular pressure and blood flow in the porcine back muscle during surgery.

STUDY DESIGN: Intramuscular pressure and blood flow of the back muscles were evaluated topographically during posterior lumbar spine surgery. The topographic damage of the back muscle after surgery was studied. OBJECTIVE: To investigate the relationship between intramuscular pressure or blood flow during posterior lumbar surgery and the back muscle injury after surgery. SUMMARY OF BACKGROUND DATA: Latrogenic back muscle injury in an animal and human model has been reported previously. Changes of intramuscular pressure and blood flow during surgery might be related to the muscle injury. No previous study on this issue has been published. METHODS: The contact pressure between the retractor blade and muscle tissue was monitored in 10 pigs during posterior surgery of the lumbar spine. On one side, intramuscular pressure at 5, 10, and 20 mm lateral to the retractor and on the other side blood flow of the back muscle at 5 and 20 mm during surgery were measured. Histologic changes of the back muscle at 5, 10, and 20 mm to the midline were evaluated 3 hours after surgery. RESULTS: The contact pressure decreased exponentially with time. Intramuscular pressure 5 mm lateral to the retractor was 114 +/- 31 mm Hg and was significantly higher than at 10 mm and 20 mm. Blood flow markedly decreased during surgery and recovered incompletely after releasing the retractor at 5 mm and 20 mm lateral to the retractor. Blood flow at 5 mm was significantly lower than at 20 mm throughout surgery. The muscle damage 3 hours after surgery was more severe near the retractor blade. CONCLUSIONS: The back muscles were exposed to pathophysiologic condition by a retractor during posterior lumbar spine surgery. External compression by a retractor increases intramuscular pressure to levels that impede local muscle blood flow. The muscle degeneration after surgery could be explained by direct mechanical damage and by the increased intramuscular pressure of muscle tissue by the retractor.

Animals↗
PubMed1996

Cloning and sequencing of cDNA encoding 4-aminobenzoate hydroxylase from Agaricus bisporus.

A cDNA clone encoding 4-aminobenzoate hydroxylase (EC 1.14.13.27) has been isolated using a probe prepared by PCR on the basis of partially determined amino acid sequences of the enzyme. The cDNA contained 1380-base pair open reading frame encoding 460 amino acid residues (M(r) 50974), 14-base pair 5'-untranslated region and 123-base pair 3'-untranslated region including a poly(A) tail of 20 nucleotides. All of the partially determined amino acid sequences were shown to be included in the deduced amino acid sequence. Homology analyses showed that the two regions on the enzyme share other flavoproteins such as salicylate hydroxylase and p-hydroxybenzoate hydroxylase.

Adenosine Diphosphate↗
PubMed1996

Vanadate triggers the transition from chromosome condensation to decondensation in a mitotic mutant (tsTM13) inactivation of p34cdc2/H1 kinase and dephosphorylation of mitosis-specific histone H3.

At the nonpermissive temperature (39 degrees C), chromosomes remain condensed in a temperature-sensitive cell mutant (tsTM13) arrested in the late stage of mitosis. Highly increased activity of histone H1 kinase, hyperphosphorylation of histone H1, and mitosis-specific histone H3 phosphorylation are maintained, even in telophase. In the present study, the defect of chromosome decondensation in tsTM13 cells was found to be partially normalized by a tyrosine phosphatase inhibitor, vanadate, with induction of chromosome decondensation and the formation of multinucleated cells. In the presence of vanadate, the H1 kinase activity dropped to near normal levels and the amount of the inactive from of p34cdc2 protein phosphorylated at a tyrosine residue was increased. H1 and H3 were also extensively de- phosphorylated, the latter being tightly associated with chromosome decondensation. Serine/threonine-protein phosphatase in late mitosis of the mutant works normally at 39 degrees C. The results indicate that (a) the genetic defect in the mutant may be involved in the control mechanism of the p34cdc2/H1 kinase activity in the late M phase rather than the phosphatase, (b) normalization of the defect of the mutant by vanadate results from inactivation of H1 kinase, and (c) late mitosis-specific events (p34cdc2/H1 kinase inactivation, mitosis-specific dephosphorylation of histone H1 and H3) are closely operating with chromosome decondensation.

CDC2 Protein Kinase↗
PubMed1996

Heterogeneous structure of the polyubiquitin gene UbC of HeLa S3 cells.

The nucleotide sequence of the polyubiquitin gene UbC of HeLa S3 cells and its upstream region was determined and characterized. Recognition sequences for the transcription factors HSF, NF kappa B, AP-1(c-jun), NF-IL6 and Sp1 were found in the upstream control region, a result consistent with the observation of a distinct regulatory response for the UbC gene compared with that of another polyubiquitin gene UbB. Employing a PCR procedure to amplify the entire coding region from genomic DNA, we found a heterogeneity in the repeat number (eight and nine repeats) of the ubiquitin coding units, which resulted from an apparent deletion of either the seventh or the eighth unit in the predominant nine-ubiquitin-unit coding gene. In addition, by comparison with the nucleotide sequence of the UbC gene of human leukocytes previously determined, we found a significant number of nucleotide discrepancies. However, these discrepancies could be substantially reduced by realigning the units so that the first and second ubiquitin units of the sequence determined here are translocated to the boundary between the eighth and the ninth units.

Base Sequence↗
PubMed1996

Dose-volume histogram analysis of high dose rate intracavitary brachytherapy for uterine cervix cancer.

PURPOSE: We retrospectively analyzed the relationship between dose distribution and local control using a dose-volume histogram (DVH) in patients with cancer of the uterine cervix treated by definitive radiotherapy including intracavitary brachytherapy. METHODS AND MATERIALS: Twenty-five patients with squamous cell carcinoma of the uterine cervix who underwent definitive radiotherapy between August 1987 and April 1994 were selected for the present study. They included 15 patients with local control and 10 patients with local recurrence. In principle, these patients were treated with 50 Gy of external beam pelvic radiotherapy and a point A dose of 24 Gy, in four fractions, of intracavitary brachytherapy. The DVHs of tumor volumes were calculated by superimposing three-dimensional (3D) dose distributions on computed tomography (CT) images taken before brachytherapy. RESULTS: Differential DVHs revealed a tendency for the portion of the total tumor volume to which the delivered dose was low to be larger in patients with local recurrence. The tumor volumes and the absolute dose volumes of which the absorbed dose was less than 24 Gy [DV (< 24 Gy)] were significantly larger in patients with local recurrence than those in local control patients (p = 0.02 and 0.03, respectively). The percent DV (<24 Gy) was not significantly different in the two groups. In patients with larger tumor volume, the absolute DV (<24 Gy) was also larger and a strong linear correlation was noted between them. CONCLUSIONS: The analysis of dose distribution of brachytherapy using DVH was useful to evaluate the quality of dose distribution quantitatively. The absolute dose volume was considered more important than the percent dose volume for evaluation of the clinical outcome. Our study suggested that unfavorable dose distribution for the tumor volume in brachytherapy was one of the reasons of poor local control in patients with large tumor volume.

Brachytherapy↗
PubMed1996

Direct and indirect activation of human corticospinal neurons by transcranial magnetic and electrical stimulation.

Corticospinal volleys and surface electromyographic (EMG) responses evoked by magnetic and electrical transcranial stimulation were recorded simultaneously in three conscious human subjects. For magnetic stimulation, the figure-of-eight coil was held on the hand motor area either with the induced current through the brain flowing in a postero-anterior direction (P-A stimulation) or in a latero-medial direction (L-M stimulation). For electrical stimulation, the anode was placed 7 cm lateral to the vertex and cathode at the vertex (anodal stimulation). The P-A stimulation that was generally used preferentially evoked I waves, whereas the L-M and anodal stimulation preferentially evoked D wave. The results suggested that the mode of activation by transcranial magnetic stimulation altered, depending on its current direction, and the difference between P-M magnetic and electrical stimulation can be explained by the context of the D and I hypothesis.

Aged↗
PubMed1996

Hyperthermia induces apoptosis in malignant fibrous histiocytoma cells in vitro.

The effect of mild hyperthermia on a cultured rat malignant fibrous histiocytoma (MFH) cell line, MFH-2NR, was investigated. MFH cells in log-phase (growing phase) were heated at 41 degrees-44 degrees C for 1 hr. Hyperthermic treatment at 41 degrees C did not substantially affect cell proliferation and treatment at 44 degrees C caused necrosis. After hypothermic treatment at 42 degrees or 43 degrees C, proliferation of MFH cells was arrested and morphological changes characteristic of apoptosis, cell shrinkage accompanying apoptotic bodies and chromatin condensation, became apparent. Hyperthermia-induced apoptosis was further confirmed by terminal deoxynucleotidyl transferase staining and a ladder pattern on agarose gel electrophoresis. Flow cytometric analysis indicated that the population in the G1 phase of the cell cycle significantly decreased with a concomitant increase in apoptotic cells, indicating that apoptosis might occur mainly in the G1 phase population.

Animals↗
PubMed1996

Back muscle injury after posterior lumbar spine surgery. A histologic and enzymatic analysis.

STUDY DESIGN: Back muscle injury after posterior lumbar surgery was studied by muscle histology and serum creatine phosphokinase MM isoenzyme activity. OBJECTIVES: To investigate intraoperative factors influencing the magnitude of back muscle injury after posterior lumbar surgery. SUMMARY OF BACKGROUND DATA: The authors previously have reported iatrogenic back muscle injury in an animal model and in humans. Serious injury of the back muscle has been shown by short-term and long-term follow-up evaluation. METHODS: The retraction pressure was monitored, and the retraction pressure-time products were calculated in 24 patients. Early histologic changes of multifidus muscle, which were taken at completion of surgery, and serum creatine phosphokinase MM isoenzyme activity changes were examined. RESULTS: The magnitude of back muscle injury was significant as the pressure-time product increased. Creatine phosphokinase MM isoenzyme activity increased after surgery and reached a plateau 1 day after surgery, followed by recovery to the normal value 1 week after surgery. Creatine phosphokinase MM isoenzyme activity tended to be high in cases with multilevel exposure and with high pressure-time product. CONCLUSIONS: Back muscle injury occurs in all patients who underwent posterior lumbar surgery, and these injuries are related to the retraction pressure, time, and extent of exposure.

Adult↗
PubMed1996

Sustained ventricular tachycardias associated with myotonic dystrophy.

Patients with myotonic dystrophy are reported to have a higher frequency of sudden death than the general population. Although causes of sudden death in myotonic dystrophy are suggested to be due to conduction of defects progressing, the HV interval cannot predict whether conduction system disease would develop or progress. We report two cases of myotonic dystrophy complicated with sustained monomorphic ventricular tachycardias (VT), which can cause sudden death. In Case No. 1, although the patient was treated successfully for sustained VT with verapamil in electrophysiologic studies, another sustained VT was confirmed 2 years later. In Case No. 2, the patient showed decreased left ventricular ejection fraction and late potentials, and induced sustained VT that was identical to clinically documented VT. Although VT is believed to be rare in patients with myotonic dystrophy, these cases suggest that VT is a possible cause of sudden death.

Adult↗