Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 325 records · Page 18Linked to original sources

PubMed1997

Transcatheter arterial embolization-induced bilious pleuritis in a patient with hepatocellular carcinoma.

A 52-year-old man with hepatocellular carcinoma (HCC) was admitted with cough and fever. He had undergone four series of treatments, including transcatheter embolization and chemoembolization with lipiodol and anticancer drugs, over the previous 2 years. Computed tomography demonstrated dilated hepatic ducts, localized necrosis in the right hepatic lobe, and subphrenic abscess. He died of respiratory failure, because of increased effusion of the right pleura, about 3 weeks after admission. Autopsy revealed adhesions in the lower lobes of the right lung, diaphragm, and liver, with granulomas with bile pigment. A fistula was observed from the necrotic regions of the right hepatic lobe to the pleura through the diaphragm. A tumor thrombus in the portal trunk was histologically confirmed as well and moderately differentiated HCC with trabecular arrangement. Direct invasion of HCC with necrotic tissue to the pleura through the diaphragm appeared to have caused the respiratory failure. Although bilious pleuritis is a rare complication of transcatheter arterial embolization (TAE), it should be considered as an adverse effect of TAE in patients with a dilated hepatic duct.

Antineoplastic Agents↗

PubMed1997

Measurement of portal venous flow velocity with an implantable miniature Doppler probe in pig liver transplantation.

Portal venous flow (PVF) was serially monitored after pig liver transplantation (LTX) with the use of an implantable, miniature Doppler probe developed in our laboratory. Throughout the study period, the mean PVF in pigs that underwent LTX was significantly greater than that in pigs that were sham operated. For three animals with early graft failure secondary to primary nonfunction and for six that survived longer than 7 days, the mean PVF on postoperative day (POD) 1 was 18.7 +/- 3.8 cm/s and 41.7 +/- 11.2 cm/s, respectively (P < 0.05). For animals with acute cellular rejection (ACR), the mean PVF was 61.3 +/- 9.9 cm/s on POD 7 and 54.3 +/- 6.38 cm/s on POD 14. These values were significantly higher than those for animals without ACR (P < 0.05). Moreover, the increase in PVF correlated well with the degree of ACR. The actual PVF volume was measured by ex vivo perfusion, which showed a clear correlation with the PVF velocity obtained with the implanted, miniature Doppler probe. We feel that the liver graft requires increased PVF volume after transplantation to facilitate functional recovery from damage to hepatocytes due to preservation-reperfusion injury, and that ACR is also associated with an increased PVF. We conclude that monitoring the PVF in the early postoperative period after LTX is useful in the evaluation of graft function, particularly for predicting primary nonfunction and severity of ACR.

Animals↗

PubMed1997

Isolation of freeze-tolerant laboratory strains of Saccharomyces cerevisiae from proline-analogue-resistant mutants.

Since some amino acids, polyols and sugars in cells are thought to be osmoprotectants, we expected that several amino acids might also contribute to enhancing freeze tolerance in yeast cells. In fact, proline and charged amino acids such as glutamate, arginine and lysine showed a marked cryoprotective activity nearly equivalent to that of glycerol or trehalose, both known as major cryoprotectants for Saccharomyces cerevisiae. To investigate the cryoprotective effect of proline on the freezing stress of yeast, we isolated proline-analogue-resistant mutants derived from a proline-non-utilizing strain of S. cerevisiae. When cultured in liquid minimal medium, many mutants showed a prominent increase, two- to approximately tenfold, in cell viability compared to the parent after freezing in the medium at -20 degrees C for 1 week. Some of the freeze-tolerant mutants were found to accumulate a higher amount of proline, as well as of glutamate and arginine which are involved in proline metabolism. It was also observed that proline-non-utilizer and the freeze-tolerant mutants were able to grow against osmotic stress. These results suggest that the increased flux in the metabolic pathway of specific amino acids such as proline is effective for breeding novel freeze-tolerant yeasts.

Amino Acids↗

PubMed1997

Potentially multicentric hepatocellular carcinoma: clinicopathologic characteristics and postoperative prognosis.

When multiple hepatic tumors are present, it is sometimes difficult to distinguish between metastatic and multicentric hepatocellular carcinoma (HCC). To identify the important clinicopathologic features of multicentric HCC, we evaluated the clinical characteristics of patients with multicentric HCC and examined the usefulness of surgical treatment in those patients. A total of 99 patients with multiple HCCs were classified into one of the following two groups according to whether their tumors were multicentric or metastatic: Group MO consisted of 18 patients with tumors thought to have developed synchronously from multicentric origins. Group IM consisted of 64 patients with intrahepatic metastases. In this study 18% of the patients with multiple HCCs were thought to have presented with multicentric tumors. This study revealed that synchronous multicentric HCCs often affected multiple segments of the liver and responded relatively well to partial hepatectomy of individual tumor-affected areas. To appropriately treat potentially multicentric HCC, it is important to understand the histopathologic characteristics of multicentric HCC and diagnose during preoperative and intraoperative ultra-sonography, so surgical treatment may be useful.

Carcinoma, Hepatocellular↗

PubMed1997

Pulmonary metal distribution in urban dwellers.

To clarify the factors influencing the concentrations and distribution of metal elements in the lung, we analyzed the following 8 metals in the 5 lung lobes of 17 autopsied urban dwellers by flame or flameless atomic absorption spectrometry: aluminum (Al), cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), manganese (Mn), copper (Cu), and Zinc (Zn). The arithmetic mean value (in micrograms of metal per gram of dry weight) calculated for five lobar metal concentrations in each subject ranged from 80 to 681 for Al, from 0.34 to 3.41 for Cd, from 0.41 to 12.7 for Cr, from 0.22 to 1.93 for Ni, from 0.15 to 1.47 for Pb, from 0.64 to 2.36 for Mn, from 2.84 to 7.24 for Cu, and from 40.7 to 77.6 for Zn. The eight metals were classifiable into two groups on the basis of the interindividual and interlobar concentration variations. The first group, consisting of Cu and Zn, was characterized by smaller interindividual variations (co-efficient of variation, CV < 30%) and smaller inter lobar variations (mean CV < 15%). Their levels were not affected significantly by sex, smoking habits, or possible occupational exposure to metal-containing dust. In contrast, the second group, consisting of Al, Cd, Cr, Ni, Pb, and Mn, exhibited larger interindividual variations (CV > 45%) and larger interlobar variations (mean CV > 25%). Concentrations of these metals, except for Cd, tended to be higher in the upper lobes than in the lower lobes. The concentrations of Al and Cr were significantly higher in men than in women. Smoking significantly elevated the levels of Cr, Cd, Ni, and Pb, and the concentrations of Al, Cr, Ni, and Mn were higher in subjects with possible occupational exposure to metal-containing dust than in those without such exposure. However, the interlobar distribution patterns of the metals did not seem to be influenced by sex, smoking habits, or occupational exposure to metal-containing dust.

Adult↗

PubMed1997

Hepatic resection for hepatocellular carcinoma.

BACKGROUND: The significance of pTNM staging of hepatocellular carcinoma (HCC) as a prognostic factor after hepatic resection was evaluated. PATIENTS AND METHODS: The prognoses were analyzed in 262 patients treated with hepatic resection for HCC. RESULTS: As a whole, the pTNM stages correlated well with the survival rates. The survival rates of stage I and II patients were significantly higher than those of stages III and IV. However, there was no significant difference in survivals between stage I and II, and between stage III and IV-A. The survival rates of the patients treated with segmentectomy or lobectomy in stages I and II were significantly higher than those with subsegmentectomy or smaller resection. Multivariate analysis revealed that tumor size greater than 2 cm, multiple gross tumors, surgical margin less than 1 cm, and Child C classification were independently significant factors of poor survival. CONCLUSIONS: The results of hepatic resection for HCC should be stratified by pTNM staging and by Child classification of hepatic function before comparison.

Adult↗

PubMed1997

Effects of wrapping tightness on acute cardiac function in dynamic cardiomyoplasty.

BACKGROUND: It has not been clarified how tightly the heart should be wrapped for maximal augmentation of cardiac function in cardiomyoplasty. METHODS: Hearts in acute failure induced by propranolol were wrapped with the left latissimus dorsi muscle, loosely (loose CMP), moderately (moderate CMP), and tightly (tight CMP) in each of 5 pigs. To measure the pressure between the latissimus dorsi muscle and the left ventricle (LV), a Millar pressure catheter with a latex balloon was placed on the anterior wall of the LV. Left ventricular wall tension was calculated according to Laplace's law, using the difference between the LV pressure and the balloon pressure. RESULTS: In the loose CMP, moderate CMP, and tight CMP groups, the mean balloon pressures during unassisted beats were 8.2, 10.4, and 13.2 mm Hg, respectively. During unassisted beats, the mean LV wall tension values were 38,683, 29,938 (p < 0.05 versus loose CMP), and 26,652 (p < 0.05 versus loose CMP) dynes/cm, respectively, the peak LV pressures were 76.8, 73.8, and 65 (p < 0.05 versus loose CMP) mm Hg, respectively, and the stroke volumes were 12.8, 9.2, and 8.5 (p < 0.05 versus loose CMP) mL, respectively. During assisted beats, the mean LV wall tension values were 20,059, 11,290, and 7,893 (p < 0.05 versus loose CMP) dynes/cm, respectively, the peak LV pressures were 94.1, 98.1, and 92.0 mm Hg, respectively, and the stroke volumes were 13.8, 11.6, and 9.4 (p < 0.05 versus loose CMP) mL, respectively. CONCLUSIONS: During unassisted beats, tight CMP (13 mm Hg) had the advantage of diminishing LV wall tension, but the disadvantage of diminishing LV pressure and stroke volume, compared with loose CMP (8 mm Hg). Moderate CMP (10 mm Hg), however, had the advantage of diminishing LV wall tension without a decrease in LV pressure and stroke volume.

Animals↗

PubMed1997

Biochemical and morphological changes in the liver during isolated liver perfusion with double bypass using automatic blood pumps.

Isolated organ perfusion is used in clinical practice for chemotherapy in adults with malignant tumors. However, it has not been performed in children because of the size mismatch with the adult circuits. The authors have previously studied isolated liver perfusion in small animals using the self-regulating extracorporeal membrane oxygenation circuit. The present study was designed to investigate the biochemical and morphological changes in the liver during isolated liver perfusion with double bypass using automatic blood pumps. Isolated liver perfusion was performed with bypass between the hepatic and portal veins in seven weanling Yorkshire swine weighing 8.2 to 12.2 kg, at a flow rate of 20 mL/min/kg for up to 4 hours. Venous blood from the intestine and lower body was bypassed to the superior vena cava. As a result, perfusate glutamic pyruvic transaminase and lactate concentrations did not change during liver perfusion. On gross inspection, the surface of the liver was mottled. Microscopically, normal histology of the hepatic parenchyma and portal tract structures was preserved. Transmission electron microscopy showed no gross structural abnormalities in most of the hepatocytes for up to 4 hours. However, swelling of the mitochondria and smooth endoplasmic reticulum was seen occasionally in a very small number of the hepatocytes after more than 3 hours of perfusion. Glycogen granules decreased with time in some animals. Isolated liver perfusion at 20 mL/min/kg of perfusion flow can be performed safely for up to 4 hours with nearly intact hepatocellular function and morphology.

Alanine Transaminase↗

PubMed1997