Biomedical subjects
Publications and source records attributed to H Tsuji.
The complete nucleotide sequence of the gene encoding the Salmonella typhimurium methyl viologen-resistant protein, SmvA, similar to QacA (resistance to quaternary ammonium ion) of Staphylococcus aureus, and the surrounding sequences were determined. This indicated that the gene arrangement of S. typhimurium is different from that of Escherichia coli in this region.
Chlorophyll a accumulated when chlorophyllide b was incubated with isolated cucumber etioplasts in the dark. When [14C]chlorophyllide b was used as the substrate for chlorophyll synthesis, [14C]chlorophyll a was formed, showing that chlorophyll a was synthesized from the exogenously added chlorophyllide b, not by light-independent reduction of endogenous protochlorophyllide. The reaction studied showed an optimal pH of 7.5 and required both the soluble and membrane fractions of etioplasts together with ATP. Time course experiments showed that chlorophyll a began to accumulate later than chlorophyll b. Chlorophyllide b esterified with geranylgeraniol accumulated first, but there was little accumulation of chlorophyll a with an unhydrogenated prenyl side chain. No chlorophyllide a was detected during incubation. These observations indicate that esterified chlorophyll b was converted to chlorophyll a. This conversion would play an important role in the use of chlorophyll b for the synthesis of chlorophyll a in the reconstruction of photosystems.
There are conflicting data regarding the impact of serum potassium and magnesium levels on susceptibility to ventricular premature complexes (VPCs) in the clinical setting. The associations of serum potassium and magnesium levels with the prevalence of complex or frequent (> 30/hour, multiform or repetitive) VPCs were examined after adjusting for age, sex, smoking, caffeinated coffee consumption, alcohol consumption, and left ventricular mass in Framingham Offspring Study subjects who were free of clinically apparent heart disease. There were 3,327 eligible subjects (mean age 44 years). Complex or frequent VPCs were present in 183 subjects (5.5%). When age-adjusted prevalences of complex or frequent VPCs were compared among quartiles of serum potassium and magnesium using a trend test, lower potassium (p = 0.002) and lower magnesium (p = 0.010) levels were associated with higher prevalence rates of arrhythmia. In logistic regression analyses that included potassium and magnesium simultaneously, potassium (p = 0.0021) and magnesium (p = 0.0311) levels were inversely associated with the occurrence of complex or frequent VPCs after adjustment for age, sex, smoking, coffee and alcohol consumption, diuretic use, and systolic blood pressure. These associations remained significant after accounting for left ventricular mass. A 1 SD decrement in potassium (0.48 mEq/liter) or magnesium (0.16 mEq/liter) level was associated with a 27% (95% confidence interval 6% to 51%) and a 20% (95% confidence interval 3% to 41%) greater odds of complex or frequent VPCs, respectively. Lower levels of serum potassium and magnesium were concurrently associated with higher prevalence rates of ventricular arrhythmias.
To elucidate the mechanism of alterations of spinal evoked potentials after hypothermia, the effects of systemic and local cooling on conductive spinal evoked potentials were studied in cats. Conductive spinal evoked potentials were recorded from the L1 epidural space after epidural stimulation at the T4 level and during concomitant reduction of body temperature followed by rewarming. On local cooling and rewarming of the stimulating area or the recording area, conductive spinal evoked potentials changes were also analyzed. Systemic cooling provoked an increase in latency, duration, and amplitude as the body temperature decreased. Evoked potentials were not changed by the local cooling of the stimulating area. Thus, the evoked potentials changes of the spinal cord suggest that spinal cord cooling does not influence the stimulus threshold, but may affect the interaction between the amplitude change and the duration in individual spike potentials, and produces changes in temporal dispersion.
The correlation among three variables of late potentials (LPs) obtained by signal-averaged electrocardiography (SAECG) and improvement of ventricular wall motion estimated by echocardiography were studied in 66 patients with a first acute myocardial infarction (MI). Patients with bundle-branch block, intraventricular conduction delay, multi-vessel disease, previous MI, repeat percutaneous transluminal coronary angioplasty (PTCA), or evidence of reinfarction during a 6-month follow-up were excluded. A total of 66 patients was divided into two groups, with (Group 1: n = 27, age 56 +/- 11) or without (Group 2: n = 39, age 61 +/- 10) improvement of ventricular wall motion. Three variables of LPs and ventricular wall motion index (WMI) estimated and scored by echocardiography at admission (WMI 1) and at 6 months after MI (WMI 2) were compared in each group. In Group 1 (WMI 1 vs. WMI 2, p < 0.002), 20 of 27 patients underwent successful angioplasty; in Group 2 (WMI 1 vs. WMI 2, p = NS), 7 of 39 patients had successful emergency angioplasty. There were significant differences in three variables of LPs between the time of admission and at 6 months after MI in Group 1 but not in Group 2. Higher incidence of LPs and greater frequency of successful emergency PTCA were found in Group 1 compared with Group 2. These results suggest that because myocardial ischemia is reversed by successful angioplasty, ventricular wall motion is improved and the arrhythmogenic substrate that generates LPs is stabilized electrically. Stunned or hibernating myocardium may be the arrhythmogenic substrate that generates LPs.
Saturable, specific, high-affinity calcitonin receptors were demonstrated in cultured neoplastic mononuclear spindle cells from a giant-cell tumor of the sacrum of a 38-year-old woman. The receptor was analyzed by autoradiography and 125I-calcitonin binding assay. Binding reversibility of 125I-calcitonin to the cells was not complete and the structural specificity was indicated by the inability of unrelated hormones to compete with calcitonin. The 24,000 receptors/cell and dissociation constant (Kd) of 8.0 x 10(-10) M, calculated from linear Scatchard plots, suggested the existence of a single class of calcitonin binding sites in the neoplastic mononuclear cells. Flow-cytometric analysis in the primary culture showed that mononuclear cells consisted of mononuclear round cells of monocyte/macrophage lineage, which express more calcitonin receptors than neoplastic mononuclear spindle cells. Administration of calcitonin caused morphological and physiological alterations, resulting in involutional or irregular cytoplasmic shapes and inhibition of DNA synthesis in neoplastic mononuclear cells accompanied by the escape phenomenon. Cells preincubated with calcitonin showed a decrease in 125I-calcitonin binding activity, which could account for the escape phenomenon. The decrease in 125I-calcitonin binding was rapid, but the recovery was not observed for 24 h after elimination of calcitonin. This decrease may be caused by the disappearance of residual receptors or by a decrease in calcitonin affinity. The calcitonin-induced morphological changes and the inhibition of DNA synthesis of cells were revealed to be mediated by calcitonin receptors.
We quantified hepatitis C virus RNA in 25 Japanese patients with chronic type C liver disease by competitive reverse transcription-polymerase chain reaction. The amount of the viral RNA in the serum (2 x 10(5)-2 x 10(8) copies/ml) correlated with that in the liver tissue (10(8)-10(11) copies/g) (N = 23, r = 0.727, P < 0.0001). One gram of the infected liver tissue contained 10(2)-10(4) (geometric mean, 10(3), N = 23) times as many copies of the viral RNA as did 1 ml of the serum. Liver tissues of chronic aggressive hepatitis contained significantly higher amounts of the viral RNA than those of chronic persistent hepatitis (P < 0.05). These observations suggested that this method is useful to evaluate viral amount, and the amount of the circulating hepatitis C virus RNA could be used as a marker of the intrahepatic viral amounts, which might contribute to disease activity.
The effects of axial traction stress on intradiscal hydration, solute transport and proteoglycan synthesis were examined in 658 porcine coccygeal intervertebral discs in vitro. Measurements were performed in three tissue fractions: nucleus pulposus, inner and outer annulus fibrosus. At 0.80 MPa traction stress, the equilibrium hydration did not change in the nucleus pulposus. However, in the inner and outer annulus, the equilibrium hydration was reduced, and the change led to an increase of the effective fixed charge density. Diffusion of solute to the nucleus pulposus was significantly suppressed at 0.80 MPa traction stress. The fluid flow of the intervertebral disc tended to be suppressed during the creep recovery process after compression. The proteoglycan synthesis rate in the outer annulus was markedly suppressed by traction stress of 0.80 MPa for 4 h, but not that in the nucleus pulposus. These results suggest that a prolonged excessive axial traction stress induces a decrease in tissue hydration in the annulus fibrosus, and this may lead to an increase in the fractional volume of solid in the matrix and tissue osmotic pressure, resulting in diffusion inhibition of solute and suppression of proteoglycan synthesis. Thus, prolonged and excessive spinal traction may accelerate disc degeneration.
Rapid changes in gene expression were studied during incubation of cucumber (Cucumis sativus L.) cotyledons with cytokinins in darkness. Complementary-DNA clones for mRNAs whose levels decreased within 4 h of treatment with N6-benzyladenine (BA) were isolated by differential hybridization. One of them (CR9) was sequenced. It is 588 bp long, and would encode a protein consisting of 137 amino-acid residues and having a molecular mass of 15 kDa. The sequence shows a high homology with a light-induced gene from rice. Northern blot analysis of the CR9 transcript showed the level of the mRNA (0.7 kb) to decrease tenfold within 4 h of BA treatment, i.e. well before BA-induced cotyledon expansion was observed. The repression became greater with increasing concentration of BA (10(-8)-10(-5) M). The expression of the CR9 gene was repressed specifically by cytokinins (BA, isopentenyladenine and t-zeatin), but not by adenine or 2,4-dichlorophenoxyacetic acid (auxin). The results are discussed in relation to the primary action of cytokinin.
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To investigate the effect of interventricular septum (IVS) on right ventricular function during exercise, radionuclide angiocardiography was performed in 50 patients with recent myocardial infarction. Twenty-five patients had involvement of IVS according to thallium uptake in IVS (group I), and 25 patients were free of IVS involvement (group II). Although there was no statistical difference between the two groups in right ventricular ejection fraction (EF) at rest (45% +/- 10% vs 48% +/- 8%), patients in group I had significantly lower left ventricular (LV) EF (40% +/- 11% vs 53% +/- 11%, p < 0.01) and larger LV end-diastolic volume (129 +/- 46 vs 106 +/- 31 ml, p < 0.05) than those in group II. All parameters increased significantly during exercise in both groups, but patients in group I had significantly lower exercise right ventricular EF (50% +/- 10% vs 56% +/- 9%, p < 0.05), LVEF (44% +/- 11% vs 56% +/- 13%, p < 0.01), and larger LV end-diastolic volume (155 +/- 44 vs 129 +/- 37 ml, p < 0.05) than those of group II. Significant correlations were observed between right ventricular EF and LV end-diastolic volume at rest and during exercise (r = -0.48, p < 0.05, and r = -0.68, p < 0.01, respectively) in group I, but right ventricular EF correlated with LVEF only at peak exercise (r = 0.65, p < 0.01). In contrast, right ventricular EF did not correlate with any variables at rest or during exercise in group II.(ABSTRACT TRUNCATED AT 250 WORDS)
One hundred twelve patients (102 male and 10 female) underwent sleeve lobectomy for lung cancer from January 1969 to December 1991. Bronchopleural fistula occurred in 6 (5.6%), bronchovascular fistula in 2 (1.8%), pulmonary arterial occlusion in 2 (1.9%), anastomotic stricture or stenosis in 7 (6.3%), and local recurrence in 7 patients (6.3%). Early repair of bronchopleural fistula combined with an omentopexy achieved permanent closure of the fistula. Two patients who underwent a completion pneumonectomy for a pulmonary arterial occlusion died of respiratory failure. Two patients experienced uncontrollable bleeding into the bronchial tree through a bronchovascular fistula and sudden death. Completion pneumonectomy is indicated for a stricture due to scar formation. If pneumonectomy is precluded by poor pulmonary reserve, endoscopic excision using biopsy forceps is an alternative. Endoscopic resection is the treatment of choice for suture granulomas. Complications associated with bronchial or vascular anastomoses are serious and frequently fatal.
BACKGROUND/AIMS: Conventional radiation is almost useless for hepatocellular carcinoma (HCC) because of the severe adverse effects of the irradiation to the accompanying liver cirrhosis. In contrast, the proton beam has Bragg peak, which limits distribution of the beam. The aim of this study was to prove the usefulness of proton irradiation for HCC. METHODS: The proton irradiation was performed in 32 nodular lesions in 24 patients with HCC who had unresectable tumors or serious complications; the proton irradiation was performed either as monotherapy (15 lesions) or as combination therapy to insufficient Lipiodol-targeted chemotherapy (Kodama Co. Ltd., Tokyo, Japan) (17 lesions). The energy was 250 MeV, and 50-87 Gy (76.5 +/- 9.5, mean +/- SD) in total was irradiated for a time period of 17-69 days. RESULTS: After 1 year, size reduction was seen in 12 out of 13 lesions (92%) in the monotherapy group and 9 out of 9 lesions (100%) in the combination therapy group; after 2 years, size reduction was seen 4 out of 5 lesions (80%) in the monotherapy group and 5 out of 5 lesions (100%) in the combination therapy group. Local tumor control has being assured for 2 years of the observation, which is continuing for another 2 years. None of the patients have experienced any serious adverse effects. CONCLUSIONS: These results show that proton irradiation is a new, safe, and effective therapeutic option in cases of HCC, even in patients with unresectable tumors or those with serious complications.
Nuclear DNA contents were measured using a flow cytometry technique in non-small cell lung carcinomas and differences in ploidy patterns were compared between primary lung carcinomas and metastatic lymph nodes. Negative node lung cancer revealed diploidy in 82.6% of the 224 non-small cell lung cancers, in contrast with 19.5% in positive node lung cancer. In multi-stemline cells, a high incidence of nodal involvement was seen when compared with single stemline cells. The more the DNA indices increased, the more the lymph nodes were seen to be extensively involved. Furthermore, intratumoral heterogeneity was evaluated in terms of n-categories. In conclusion, it is suggested that nodal metastasis may be caused by tumor cells with high DNA indices in lung carcinomas, in particular for multi-stemline cells.
PURPOSE: This clinical study was to evaluate changes of evoked spinal cord potentials (ESCPs) elicited by direct spinal cord stimulation and to determine their relation to spinal cord ischemia during aortic aneurysm surgery. METHODS: We monitored descending ESCPs from the thoracic spinal cord and lumbar enlargement after cervical spinal cord stimulation (thoracic descending ESCP and lumbar descending ESCP), and segmental ESCP at lumbar enlargement elicited by bilateral tibial nerve stimulation in 22 aortic aneurysm surgical operations. RESULTS: ESCP changes were classified into three types: (1) decrease of amplitude in lumbar descending ESCP and segmental ESCP; (2) decrease of amplitude in segmental ESCP alone; (3) decrease of amplitude in all ESCPs. The late negative waves of both lumbar descending ESCP and segmental ESCP were more sensitive than other components of ESCPs. Postoperative paraplegia occurred in the two cases that showed persistent diminution of amplitude in the late negative waves. Segmental ESCP was less reliable than lumbar descending ESCP, because it depended entirely on the adequate perfusion of the lower extremities. CONCLUSIONS: Lumbar descending ESCP was the best method for the spinal cord ischemia during aortic aneurysm surgery. Spinal cord ischemia could be detected by diminution in the amplitude of the late negative wave of lumbar descending ESCP. The recovery amplitude of the late negative wave after declamping correlated with the neurologic outcome.
Disseminated intravascular coagulation (DIC) is one of the most critical complications of malignant diseases. It is conventionally diagnosed by a decrease in platelets and an increase in fibrin/fibrinogen degradation products (FDP). Recently, an immunological assay was developed that can directly quantify the amount of soluble fibrin (SF) formed in the blood. This study examined this assay system in the diagnosis of DIC and found that it is a good indicator of both fibrin formation and of DIC. Plasma levels of SF correlated well with the DIC score, which is determined according to the 'DIC Scoring Guideline' proposed by the DIC Study Group under the Japanese Ministry of Public Welfare in 1988. It also correlated well with the serum levels of FDP. Normal values of plasma SF ranged between 0 and 9.50 micrograms/ml. Interestingly, values of SF in females tended to increase with age, for reasons that are not yet determined.
A modular ceramic spacer system was developed and used for vertebral body replacement in 21 patients with metastatic spine tumor in cervical (n = 10 cases), thoracic (n = 9), and lumbar spines (n = 2). All cases of cervical and lumbar spinal tumors underwent simultaneous use of a ceramic spacer and plate-screw fixation, and eight patients received additional posterior interventions in the thoracic spine. Postoperative radiation therapy was performed in all cases except two, which involved prostatic carcinoma. Complete or moderate pain relief was obtained in 19 patients, and 17 patients were able to walk after surgery. The average bed rest period was 11 days. Radiologically, a clear zone at the spacer-vertebral body interfaces and migration of the spacer was observed in four cases and one case, respectively. However, satisfactory pain relief and stabilization of the spine was obtained in an average follow-up time of 22.3 months. In all four autopsy specimens studied, the ceramic spacer showed firm connection with the vertebral body. This modular ceramic spacer system facilitates a relatively easy procedure, maintenance of spinal stability, early ambulation, and no interference with local radiation therapy.
BACKGROUND: Late potentials and left ventricular remodeling are important factors in the prognosis of acute myocardial infarction. However, the relationship between late potentials and ventricular remodelling has not been fully evaluated. METHODS: We evaluated clinical characteristics, coronary angiographic findings and radionuclide angiographic measures about 1 month after an acute myocardial infarction in patients with and without late potentials. RESULTS: Although the left ventricular ejection fraction of patients with late potentials was not different from that of patients without late potentials, the left ventricular end-diastolic volume of patients with late potentials was larger than that of patients without late potentials (P < 0.05). There was a significant positive correlation between the left ventricular end-diastolic volume and the filtered QRS duration (r = 0.53, P < 0.001). The root mean square of the voltage in the terminal 40 ms and the low-amplitude signal duration of < 40 microV in the terminal QRS sequence were also correlated with the left ventricular end-diastolic volume (r = 0.40, P < 0.02, and r = 0.39, P < 0.02, respectively). Patency of the infarct-related vessel in the late phase of an acute myocardial infarction was an important factor associated with the occurrence of late potentials (P < 0.01). CONCLUSION: A larger left ventricular end-diastolic volume in patients with late potentials might be associated with left ventricular remodeling during the first month after an acute myocardial infarction.