Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 271 records · Page 15Linked to original sources

PubMed1996

Mechanical force regulation of vascular parathyroid hormone-related peptide expression.

Parathyroid hormone-related peptide (PTHrP) was originally identified as a factor responsible for the syndrome of humoral hypercalcemia of malignancy. PTHrP has a vasodilator activity and is produced in vascular smooth muscle. However, the exact physiological role of PTHrP and the regulation of its gene expression in the vascular system have not been understood. We found that the mechanical stretch of rat aortic smooth muscle cells in vitro induced a marked increase in PTHrP expression through a protein kinase C-dependent mechanism. We further examined whether PTHrP expression in blood vessels in vivo is regulated by mechanical forces. Mechanical stretch of isolated aortic strips increased the expression of PTHrP mRNA. The PTHrP mRNA expression levels in aortae from hypertensive 18-week-old spontaneously hypertensive rats (SHR) was twofold higher than age-matched control Wistar-Kyoto (WKY) rats, while the PTHrP mRNA level in the aortae from normotensive 4-week-old SHR was not different from that of age-matched control WKY rats. Moreover, treatment of hypertensive SHR with an angiotensin II type 1 receptor antagonist or hydralazine caused a decrease in PTHrP expression in the aortae with the lowering of blood pressure. These results indicate that the gene expression of the vasoleraxant PTHrP in blood vessels is under the regulation of mechanical forces, and suggest a modulatory role for PTHrP in the regulation of vascular tone.

Animals↗

PubMed1996

[Significance of systemic inflammatory response syndrome at cardiopulmonary bypass].

Systemic Inflammatory Response Syndrome (SIRS) is a new concept of entry criteria for sepsis. This concept, when applied to area of Multiple Organ Failure (MOF), is considered to be a preparatory state for MOF. To study the significance of SIRS state at cardiac surgery, we measured the body temperature, white blood cell count, respiratory rate and heart rate of 18 patients who underwent elective cardiac surgery, from the 1st post-operative day to the 7th post-operative day. We also measured Interleukin-6 and 8 (IL-6 and IL-8) to understand the relationship between the SIRS state and inflammatory cytokines just after cardiopulmonary bypass (CPB), at the 1st, 3rd and 6th postoperative day. The result was as follows: Patients with CPB more than 120 minutes have more frequency and longer duration of SIRS than patients with CPB less than 120 minutes. Serum levels of IL-8 at SIRS state were revealed statistically higher than at non-SIRS case. Duration of SIRS state was related to CPB time and serum levels of IL-6 and IL-8 just after CPB. We concluded that SIRS state is an indication for anti-cytokine therapy to prevent MOF, and it is important to shorten CPB time in order to decrease the duration of SIRS.

Cardiopulmonary Bypass↗

PubMed1996

[Malignant lymphoma of the chest wall in a patient with chronic empyema].

A 76-year-old man presented with the chief complaints of appetite loss and general fatigue. He was admitted with the initial diagnosis of empyema necessitatis, and right thoracic drainage was performed. Nevertheless, the subcutaneous mass in the right side of the chest wall did not shrink, and examination of a specimen obtained by percutaneous needle biopsy resulted in the diagnosis of non-Hodgkin's lymphoma, intermediate lymphocytic type. The patient was treated with Adriamycin, vincristine, prednisolone, and cyclophosphamide, but died of pneumonia and cachexia five months after symptoms first appeared. The diagnosis of intermediate lymphocytic lymphoma, B cell type was made at autopsy. Only 53 cases of malignant lymphoma associated with chronic empyema have been reported in Japan. Surgery was often not done because of the patient's advanced age or poor pulmonary function; diagnosis was often difficult. However, review of the 53 reported cases suggested that resection of the tumor, if possible, would improve the prognosis. Malignant lymphoma should be considered when there is chronic empyema, because such cases are now being reported more frequently.

Aged↗

PubMed1996

[Postoperative immunological capacity after coronary artery bypass grafting in a patient with chronic hemodialysis: comparison with data from patients without chronic hemodialysis].

Recently, coronary artery bypass grafting (CABG) has been performed safely in patients maintained on hemodialysis. However, the postoperative immunological capacity of patients undergoing CABG during chronic hemodialysis has not been fully investigated. Recently we performed CABG in a patient undergoing chronic hemodialysis and measured the immunological parameters. The WBC count, the populations of lymphocytes, OKT 4-positive cells, and OKT 8-positive cells, and NK activity were determined, and the lymphocyte stimulation test (using PHA) was performed before and after cardiopulmonary bypass, then, 1, 3, and 6 days after CABG. We compared these data with those from 17 patients without chronic hemodialysis. The immunological capacity after CABG in the patient with chronic hemodialysis was similar to that of patients without chronic hemodialysis. We suggest that CABG in patients with chronic hemodialysis is a safe operation with regard to the immunological capacity.

Adult↗

PubMed1996

[Prognostic factors of resected pulmonary metastases of osteogenic sarcoma].

From December 1979 to December 1994, 22 patients with osteogenic sarcoma underwent a total of 34 thoracotomies for resection of pulmonary metastases in our department. We did a retrospective study to identify prognostic factors. The tumor doubling time (TDT) calculated for 21 patients before the first (if multiple) resection was not correlated with days of survival after resection of the primary tumor, nor was it correlated with days of survival after the first (if multiple) resection of the pulmonary metastatic tumors. Of the nine patients who underwent at least two thoracotomies, the TDT calculated from X-ray films taken before the second (or later) thoracotomy was significantly shorter than the TDT calculated before the preceding thoracotomy (p < 0.05). The disease-free interval (DFI) after resection of the primary tumor was correlated with the days of survival after that resection (p < 0.001) and also with survival after resection of the pulmonary metastatic tumors (p < 0.01). This DFI of patients who survived at least 2 years from the date of the resection of the primary tumor was significantly longer than in patients who survived less than 2 years from that date (p < 0.05). The most significant prognostic factor was this DFI. The cumulative survival rate was 42.4% at three years and 33.9% at five years, with an operative mortality of 0%.

Adolescent↗

PubMed1996

[An approach to the emergency surgery for arch and/or ascending aortic aneurysm].

The outcome of emergency surgery for the aortic arch aneurysm and/or dissecting aneurysm is worse than that of elective surgery. To decide the future strategy of the emergency surgery for these disease, 11 patients with emergency surgery (= group E: 8 for aortic dissection and 3 for rupture of the aortic arch aneurysm, age; 61 +/- 13 SD) were compared with 12 patients who had elective surgery (= group S: 5 for aortic dissection and 7 for aortic arch aneurysm, age; 69 +/- 3 SD). Ascending aorta replacement was performed in 7 cases in group E v.s. 1 in group S, aortic arch replacement in 2 v.s. 5, ascending aorta and aortic arch replacement in 1 v.s. 4 and patch replacement of the aortic wall in 1 v.s. 2, respectively. Selective cerebral perfusion (SCP) upon the cardiopulmonary bypass (CPB) was used in 45% (5/11) in group E. v.s. in 92% (11/12) in group S, p < 0.05. CPB time, aortic clamp time and SCP time were not significantly different between E group and S group. Postoperative cardiac failure, respiratory failure, renal failure, brain injury and infection occurred at insignificant rates between both groups. Thirty-day and 3-year survivorships were 73% in group E, while in group S they were 92% and 75%, respectively. In group E there were 2 cases which had aortic wall injury due to the aortic clamp used during the surgery. We recommend the use of selective cerebral perfusion and open distal anastomosis in emergency surgery for aortic arch aneurysm and/or Stanford type A aortic dissection.

Aged↗

PubMed1996

The usefulness of MR in establishing the diagnosis of parotid pleomorphic adenoma.

PURPOSE: To assess the usefulness of MR findings in establishing a specific diagnosis of parotid pleomorphic adenoma. METHODS: T1-weighted and T2-weighted MR images with and without contrast enhancement were obtained in 82 patients with parotid tumors. Imaging findings in the 38 patients in whom surgery subsequently revealed pleomorphic adenomas were compared with findings in the 44 patients who had other types of tumor. Specifically, the homogeneity, signal intensity, contrast enhancement, capsule thickness, lobulation, adenopathy, and infiltration of adjacent fat were compared among the different types of tumor. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: A low-signal capsule on T2-weighted images and a lobulated contour characterized most pleomorphic adenomas. The sensitivity of the first finding for pleomorphic adenoma was 82%; specificity, 85%; positive predictive value, 82%; and negative predictive value, 84%. For the second finding, the sensitivity was 53%; specificity, 84%; positive predictive value, 74%; and negative predictive value, 67%. CONCLUSION: None of the signs evaluated had perfect sensitivity and specificity. The MR findings of a complete capsule, lobulated contour, or high T2 signal intensity have a high predictive value for the diagnosis of pleomorphic adenoma.

Adenoma, Pleomorphic↗

PubMed1996

[Contralateral lung contusion].

A 47-year-old man was admitted to the emergency room in November 1994 with left-sided chest pain. Two days before admission, he had fallen two meters and hit the left side of his chest. A chest roentgenogram showed patchy infiltrative shadows and a pleural effusion confined to the right lung field. Bloody fluid was obtained from the right B3b by bronchoalveolar lavage. Specimens obtained from the right lung by transbronchial lung biopsy revealed deposition of hemosiderin and precipitation of fibrin, which were consistent with lung contusion. The abnormal shadows on the chest roentgenogram disappeared spontaneously within one week. Review of the literature suggests that contra coup pulmonary contusion is rare, and that the mechanism might involve injury of small vessels by high-speed vibration of the contralateral part of the mediastinum.

Accidents, Occupational↗

PubMed1996

[Fundamental study of lung-cancer screening by helical CT: second report: evaluation of CT images using normal volunteers].

In order to examine the use of helical computed tomography (CT) in lung cancer screening, we evaluated the effects of tube current and table feed speed on image quality. CT images of normal volunteers, which were scanned under various tube currents (150mA, 100mA, 50mA) and various table feed speeds (15mm/sec, 20mm/sec, 25mm/sec, 30mm/sec), were visually evaluated by experienced diagnostic radiologists. The images were not affected by decreasing the milliamperage. However, as table feed speed increased, images were evaluated as significantly worse. Particularly, since the degradation of the images scanned at greater than 25mm/sec was remarkable, they were judged to be unacceptable for detection of the abnormality. In conclusion, a tube current of less than 50mA and table feed speed of less than 20mm/sec are suitable in the application of helical CT for lung cancer screening.

Adult↗

PubMed1996

[A case report of open heart surgery in an infant with MNMS caused by femoral arterial cannulation during cardiopulmonary bypass].

We report a case of myonephropathic metabolic syndrome (MNMS) and compartment syndrome caused by femoral arterial cannulation during long-term cardiopulmonary bypass. A boy who had been diagnosed with truncus arteriosus type 1 and who subsequently underwent a Rastelli operation at age 3 months had a second Rastelli operation at age 6 years due to graft stenosis (pressure gradient 82 mmHg between RV and PA). MNMS and compartment syndrome occurred postoperatively due to long-term femoral arterial cannulation during cardiopulmonary bypass. However, acute renal failure was successfully managed with CAPD. The patient recovered from acute renal failure 40 days postoperatively. CAPD is considered useful for postoperative acute renal failure in infants. We conclude that retrograde insertion of the cannula should be changed to anterograde insertion at an earlier time, or else the cannula should be inserted via the prosthetic graft.

Acute Kidney Injury↗

PubMed1996

[Reconstruction of right ventricular outflow tract-pulmonary artery utilizing autologous tissue in extreme tetralogy of Fallot after coil embolization for major aortopulmonary collateral artery: report of a case].

We report a successful surgical treatment for tetralogy of Fallot with pulmonary atresia. A 18-year-old girl was admitted because of increasing exertional dyspnea and cyanosis. She had undergone bilateral classical Blalock-Taussing shunt. Prior to the correction, two major aortopulmonary collateral arteries were embolized using steel coils. Under cardiopulmonary bypass, posterior wall of the pulmonary artery was anastomosed directly to the cranial margin of the ventriculotomy for a floor made of autologous tissue. The roof was reconstructed using a patch with a monocusp. The patient is in a good postoperative condition. A coil embolization is useful and this reconstruction utilizing autologous tissue could prevent a late stenosis of the reconstructed pulmonary artery tract.

Adolescent↗

PubMed1996

[Usefulness of scheduled IABP for CABG].

We examined the usefulness of intra-aortic balloon pumping (IABP) before the coronary arterial bypass grafting (IABP) before the coronary arterial bypass grafting (CABG) in patients with severe ischemic heart disease. Left main trunk (LMT) disease, unstable angina and low ejection fraction (less than 40%) were indications for scheduled IABP. Eleven patients underwent IABP before CABG surgery (the scheduled IABP group), and five patients didn't before CABG surgery (the unscheduled IAPB group). Analysis comprised the duration of IABP and mortality. There were no significant differences between the two groups in age, pre-operational cardiac index, ejection fraction, aorta clamp time or total perfusion time. IABP application times were significantly longer in the unscheduled IABP group than in the scheduled IABP group (p < 0.05). No death occurred in the scheduled group, but three patients in the unscheduled group died (p < 0.05). No complications were observed due to IABP in any patient of either group. We conclude that scheduled IABP is useful for patients with severe ischemic heart disease.

Aged↗

PubMed1996

[Flap of the musculus latissimus dorsi to prevent alveolar air leakage from sectional plane of the lung after resection of metastatic pulmonary and chest wall tumor].

Alveolar air leakage after pulmonary resection usually heals with adequate pleural drainage, but must be more actively treated if leakage may be severe. If left untreated, the postresection space can lead to empyema. We used a muscle flap to prevent alveolar air leakage from a large sectional plane of the lung resected because of metastases in the lung and chest wall. A 48-year-old man complained of pain and a mass on the right side of his back. He had undergone resection and chemotherapy for clear cell sarcoma that originated on the back of the left hand when 43 years of age, wedge resection of the right lower lobe of the lung for a metastatic pulmonary tumor at 46 years, and lobectomy of the same lobe for a recurrence of the metastatic pulmonary tumor at 47 years. The diagnosis was of a metastatic tumor to the right chest wall with peripheral pulmonary tumors of the right upper and middle lobes. Resection of the chest wall and the lung including the tumors was done. Much air leakage from the extensive sectional plane of the right upper and middle lobes was seen intraoperatively, and this plane was therefore covered with a flap of the musculus latissimus dorsi. Chest tubes were removed on day 7 postoperatively when air leakage was no longer seen. Subcutaneous emphysema, which appeared on day 14 postoperatively, required redrainage of the pleural air space, but pleurodesis was effective. Use of a muscle flap was simple and effective for covering of a sectional plane of the lung, and should be considered when alveolar air leakage may be extensive.

Humans↗

PubMed1996

[Helical CT for lung-cancer screening: fourth report. Detectability of pulmonary lesions].

The detectability of various abnormal findings in helical screening CT(HSCT) with low-dose and single-breath-hold scanning of the lung was examined using conventional CT as a gold standard. In 75 patients, HSCT was obtained with scanning parameters of 120kVp, 50 mA, 10 mm-collimation. 20 mm/second and 1 sec/rotation. Conventional CT was obtained with 150 mA and 10 mm-slice contiguous scanning HSCT depicted 141 of 159 focal lesions in nodules and masses (65 of 69 lesions more than 5mm in size), 44 of 47 in infiltrative lesions, 11 of 11 in reticular lesions and 23 of 39 in bullae and blebs. There were only 3 false positive lesions in nodule and mass. Sensitivity, specificity and accuracy of HSCT for diffuse lesions were 100% (11/11), 95% (61/64) and 96% (72/75) for fibrotic change and 75% (9/12), 100% (63/63) and 96% (72/75) for emphysematous change, respectively. Since the detectability of HSCT was good for abnormal findings, showing increased attenuation in comparison with the lung parenchyma, it was considered to be a promising method for lung-cancer screening.

Adult↗

PubMed1995

[Application of molecular biology to occupational health field--the frequency of gene polymorphism of cytochrome P450 1A1 and glutathione S-transferase M1 in patients with lung, oral and urothelial cancer].

A polymorphism in exon 7 of the cytochrome P450 1A1 (CYP1A1) and A homozygous gene deletion at the glutathione S-transferase M1 (GSTM1) locus of genomic DNA isolated from peripheral blood were investigated for its relationship with lung, oral and urothelial cancer using the polymerase chain reaction (PCR) technique. As for the CYP 1A1 Val/Val genotype, 5 of 88 healthy controls (5.6%), 1 of 33 lung cancer patients (3.0%, P > 0.05, odds ratio 0.52, 95% confidence interval 0.21-17.3 with Ile/Ile Ile/Val type as base line), 4 of 32 oral cancer patients (12.4% P > 0.05, odds ratio, 2.37, 95% confidence interval 0.60-9.30) and 4 of 85 urothelial cancer patients (4.8% P > 0.05], odds ratio, 0.82, 95% confidence interval 0.21-3.16) were CYP 1A1 Val/Val types. The frequency of GSTM1 deletion genotype was 39.8% in the healthy controls and 45.5%, 50.0% and 61.2% in lung cancer, oral cancer and urothelial cancer patients, respectively. The frequency of GSTM deletion genotype was statistically increased in urothelial cancer patients (P < 0.05, odds ratio 2.38, 95% confidence interval 1.28-4.34). The odds ratio of combined genotypes of CYP1A1 Val/Val and GSTM1 deletion was 1.42 (95% confidence interval 0.12-16.8), 3.64 (95% confidence interval 0.47-27.9), 1.02 (95% confidence interval 0.14-7.53) in lung cancer, oral cancer and urothelial cancer patients, respectively. Thus, the GSTM1 deletion genotype as a host factor predisposing to urothelial cancer was proved in this study.

Adult↗

PubMed1995

The effect of cross-linking of the two heads of porcine aorta smooth muscle myosin on its conformation and enzymic activity.

The two heads of porcine aorta smooth muscle myosin can be cross-linked by a disulfide bridge between the two 17-kDa essential light chains with 5,5'-dithiobis(2-nitrobenzoic acid) [Katoh, T., Tanahashi, K., Hasegawa, Y. & Morita, F. (1995) Eur. J. Biochem. 227, 459-465]. When the cross-linked myosin sample was visualized by rotary shadowing, the two heads of myosin molecules appeared predominantly to adhere to each other. The cross-linking of dephosphorylated myosin in the presence of ATP was greatly inhibited by a decrease in the concentration of NaCl from 0.4 M to 0.15 M, suggesting that the cross-linking of the two heads was suppressed in 10S myosin. However, the fraction of dephosphorylated myosin in a filamentous state at 0.1 M NaCl in the presence of 1 mM ATP was increased from 33% to 83% by the cross-linking. The cross-linking of the two heads might inhibit the formation of the 10S conformation, leading to the increase in the fraction of filamentous myosin. The filaments of the cross-linked myosin sample were visualized by electron microscopy and appeared morphologically similar to those of uncross-linked myosin. The ATPase activity of the cross-linked dephosphorylated myosin sample was more than three times as high as that of an uncross-linked control. The increase in the activity may be related to the increase in the fraction of filamentous myosin caused by the cross-linking. The ATPase activity of dephosphorylated myosin in the presence of actin was increased more than twofold by the cross-linking, but the activity of phosphorylated myosin was affected only slightly. The degree of phosphorylation-dependent regulation of actin-activated ATPase activity decreased with an increase in the degree of cross-linking and was extrapolated to zero at 100% cross-linking. Superprecipitation of acto-cross-linked dephosphorylated myosin was activated, while that of acto-cross-linked phosphorylated myosin was inhibited only slightly. These results suggest that the freedom of each head in myosin molecules may be required to keep the ATPase activity and superprecipitation of acto-dephosphorylated myosin low but not for keeping these activity levels high in acto-phosphorylated myosin.

Actomyosin↗

PubMed1995

Intraoperative microwave tissue coagulation as treatment for patients with nonresectable hepatocellular carcinoma.

BACKGROUND: The microwave tissue coagulator (2450 MHz) has been used clinically in the treatment of hepatocellular carcinoma (HCC) to transection of the liver parenchyma and has proven an excellent method for hemostasis. There are, however, few reports on the application of this coagulator to the induction of tumor necrosis. METHODS: Microwave tissue coagulation (MTC) was applied at laparotomy in eight patients with nonresectable multiple HCCs. All patients were treated with a combination of resection or intrahepato-arterial chemotherapy and MTC. A total of 222 bouts of MTC were applied to 21 tumors, the largest of which was 65 mm in largest dimension. The monopolar needle electrode was inserted directly into the tumor and the procedure was repeated at approximately 5 mm intervals. RESULTS: Levels of alpha-fetoprotein in serum were found to have decreased in all patients one month after surgery with MTC. Contrast-enhanced computerized tomography (CT) showed the complete absence of blood flow in all tumors subjected to MTC. Needle biopsy one month after MTC confirmed tumor necrosis in all cases. All patients are alive at the time of this report, with the longest survival period being 24 months. In three of eight patients, new tumors were confirmed by angiographic CT at sites separate from the treated tumors. MTC resulted in fewer adverse effects on liver function and less extensive inflammatory reactions than liver resection. CONCLUSION: Intraoperative MTC appears to be an effective method for inducing local tumor necrosis, and may be of use in combination with palliative surgery for multiple HCC when radical liver resection is not feasible.

Aged↗

PubMed1995

Porcine aorta smooth-muscle myosin contains three species made of different combinations of two 17-kDa essential light-chain isoforms.

Porcine aorta myosin was reacted with a bifunctional cross-linking reagent, N,N'-o-phenylenedimaleimide. The 17-kDa essential light chain (LC17) in each myosin head was intramolecularly cross-linked within a single myosin molecule. The 34-kDa cross-linked LC17 dimer was isolated and its peptide map, after lysylendopeptidase digestion, was obtained by reverse-phase HPLC. Based on the amino acid compositions of peptide fragments, the N-terminal Cys residues of LC17 subunits were assigned to be cross-linked to each other. To study the distribution of two LC17 isoforms, LC17nm and LC17gi [Hasegawa, Y., Ueda, Y., Watanabe, M. & Morita, F. (1992) J. Biochem. 111, 798-803], aorta myosin was reacted with 5,5'-dithiobis(2-nitrobenzoic acid) (Nbs2). The LC17 dimer cross-linked with Nbs2 was resolved into three distinct bands on urea/PAGE using a 4% acrylamide gel. Densitometric analysis of the three band intensities showed that three pairs of LC17 isoforms in aorta myosin are present in the ratio of LC17nm-LC17nm/LC17nm-LC17gi/C17gi-LC17g i = 22:46:32. This ratio is consistent with the random combination of two LC17 isoforms with myosin heavy chains.

Animals↗