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Biomedical subjects

M Ohto

Publications and source records attributed to M Ohto.

At least 217 records · Page 12Linked to original sources
PubMed1979

[Laboratory and clinical studies CS-1170 (author's transl)].

CS-1170 is a new antibiotic, a derivative of cephamycin C. In vitro, 50 strains of E. coli and Klebsiella consisting of gentamicin-sensitive isolated from the blood and gentamicin-resistant strains isolated from the urine were inhibited at concentrations from 0.4 to 12.5 mcg/ml of CS-1170, whereas only 2 strain of Klebsiella isolated from the blood had MIC more than 50 mcg/ml of the antibiotic. Moreover, CS-1170 was significantly more effective than cefazolin and cephalothin against these strains. Ten strains of gentamicin-sensitive Serratia isolated from the blood and the 2 gentamicin-resistant strains were inhibited at concentrations from 3.2 to 50 mcg/ml of CS-1170 and only one strain was resistant to this agent. All tested Serratia were resistant to cefazolin and cephalothin. CS-1170 was not effective against Enterobacter. Three cases of biliary tract infections consisting of 2 cases of cholelithiasis and a case of carcinoma of bile duct were treated with 4 g/day dosage of CS-1170. The remarkable effects were obtained in the two cases with cholelithiasis, whereas a case with the carcinoma was treated not so effectively by administration of CS-1170.

Aged↗
PubMed1977

Congenital cystic dilatation of the common bile duct: relationship to anomalous pancreaticobiliary ductal union.

Thirty patients from 15 to 69 years of age with congenital cystic dilatation of the common bile duct were studied. The diagnosis was made by intravenous cholangiography in 70% of the patients and by percutaneous transhepatic cholangiography and/or endoscopic retrograde cholangiopancreatiography in the entire group. Cystic dilatation was also noted in the intraphepatic bile ducts in 12 patients. A union between the common bile and main pancreatic ducts occurred at a high position in 17 of 18 patients in whom both ducts were adequately opacified, forming an abnormally long common channel. One patient with choledochodele had a normal union. The anomalous unions were of two types: the pancreatic duct entering the common duct and the common duct entering the pancreatic duct. The mode of union was correlated with the degree of extrahepatic bile duct dilatation, age of onset, and frequency and severity of symptoms. It is postulated that the congenital anomaly in the union of the two duct systems is the cause of the disease and the congenital choledochocele has a different etiology.

Adolescent↗
PubMed1977

Treatment of carcinoma of the biliary system.

A series of 23 patients with carcinoma at the hilus of the bile duct were studied. Fourteen of the 23 patients underwent surgical resection. Nine of the 14 patients had a curative resection. Six patients are alive after a follow-up period of five to 25 months. The remaining five patients had noncurative resection, and four of them died from metastatic carcinomas during the next 14 months. One patient who had a left hepatic lobectomy is still alive eight months after operation. The other three patients with advanced carcinoma at the hilus of the bile duct were treated by intraoperative radiotherapy. A single dose of 3,000 rads was emitted directly to the tumors. The remaining six patients were treated by drainage procedures only. Four patients with advanced carcinoma of the gallbladder had received radiotherapy. Six of the eight patients who were treated by radiotherapy are alive, although the follow-up period extends to 11 months only.

Adult↗
PubMedDate not supplied

Nonsurgical treatment of hepatocellular carcinoma in cirrhotic patients.

Modern imaging modalities have allowed us to make reliable diagnosis of hepatocellular carcinoma (HCC). Most of HCCs are associated with liver cirrhosis in varying stages of severity and often accompanied by new occurrences of HCC after treatment. Now, newly developed nonsurgical therapeutic modalities are used extensively and achieve good results in terms of anti-tumor effects as well as post-treatment survival.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Enhanced color flow images in small hepatocellular carcinoma.

BACKGROUND: Features of enhanced color flow images in small hepatocellular carcinoma (HCC) are not fully elucidated. The purpose of this study was to clarify the characteristic vascular images in small HCC observed by enhanced color Doppler. METHODS: Enhanced color Doppler using the contrast agent Levovist was performed on 13 patients with HCC smaller than 30 mm. Enhanced color flow appearance was compared with angiographic findings. Time-intensity changes after injection of the contrast agent were analyzed in HCC nodules. RESULTS: Significant improvement in the detection of color flow signals was obtained in small HCC using Levovist, from 33% in precontrast to 92% in postcontrast (p < 0.005). Three patterns of enhanced color flow images, which were related to the angiographic findings, were observed. The time-intensity curve was classified into two types by "time to peak" and "time on plateau" and was associated with the patterns of enhanced images. CONCLUSION: Enhanced color flow imaging promises to be a useful method for evaluating tumor vascularity noninvasively and to contribute to the elucidation of the hemodynamics in small HCC.

Aged↗
PubMedDate not supplied

Noninvasive quantitation of liver iron in dogs with hemochromatosis using dual-energy CT scanning.

The concentration of iron deposited in the livers of two dogs with experimentally induced iron overload was determined by use of dual energy computerized tomographic (CT) scanning. A phantom was constructed, containing known amounts of iron-dextran solutions. CT scans of the phantoms, at 80 and 120 kVp, corrected for the response of water, showed a linear relationship between known iron concentrations and difference in CT number at the two scanning energies, with a change of 24 H units per 1000 mg% iron. Using the graph of this linear relationship, the amount of iron in dog liver was predicted, compared with the amount of iron measured from biopsy specimens, and analyzed by neutron activation analysis. A close correlation existed between predicted liver iron and measured iron concentration (r = 0.99). Dual-energy CT scanning appears to provide an accurate, noninvasive method of quantitating liver iron.

Animals↗
PubMedDate not supplied

Diagnosis of small hepatocellular carcinoma by computed tomography: correlation of CT findings and histopathology.

The diagnostic value of computed tomography (CT) scans in small hepatocellular carcinoma (HCC) (less than 5 cm) was studied in 82 patients. Dynamic scan was also made in 66 of them. Combined unenhanced and enhanced scans detected 87% of the lesions greater than 2 cm, but the detection rate was only 25% for lesions less than 1.5 cm. Diagnostic failure was due to isodensity of the mass and to technical artefacts. Diagnosis of the surrounding capsule and internal septa (partition) and demonstration of the typical pattern of density enhancement by dynamic scan proved useful in differentiating HCC from secondary cancers. On unenhanced CT, the density of the interior was subject to the histological changes of tumour such as bleeding, necrosis and fatty metamorphosis. Similarly, enhanced CT showed density changes suggestive of these histological changes. Dynamic scan proved particularly useful for lesions less than 3 cm because the typical density enhancement was frequently demonstrated in the arterial phase. It was concluded that unenhanced CT combined with dynamic scan has a high diagnostic value in small HCC and reflects histological changes.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Percutaneous ethanol injection for the treatment of small hepatocellular carcinoma. Study of 95 patients.

Percutaneous ethanol injection (PEI) was applied to 120 lesions in 95 patients with hepatocellular carcinomas (HCC) smaller than 3 cm in the past 6 years. All main target tumours, in 67 patients who had been followed by sonography for more than 6 months after PEI, decreased in size; 28 tumours (41.8%) became undetectable and have remained so until now. The 1-, 2-, 3-, 4- and 5-year survival rates calculated by the Kaplan-Meier method were 93%, 81%, 65%, 52% and 28% respectively. These survival rates were better than those of patients with HCC smaller than 3 cm who did not receive anticancer treatment (P less than 0.01). The survival of patients of the Child's A or Child's B status was better than that of those with Child's C disease. Recurrence occurred in areas within the liver different from the original lesion in 34% in one year, 61% in two years and 66% in three years after PEI. PEI was then repeated in 61% of such patients.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Amino acid residues of core region of hepatitis B virus. Asymptomatic carriers versus patients with liver disease.

Recent molecular biological studies have shown that mutations of hepatitis B virus (HBV) genes may have an important role in the pathogenesis of HBV-induced liver diseases. It has been suggested that the core antigen of HBV could be an immunologic target of cytotoxic T lymphocytes. In this study, nucleotide sequences encoding 183 amino acid residues of the core region of HBV were analysed in 4 asymptomatic healthy carriers and in 5 patients with chronic liver disease, in whom serum aminotransferase levels were fluctuating. A cluster of amino acid substitutions were found from codon 87 to 97 of the core region of HBV in all 5 patients with liver diseases. Such changes were not found in any of the asymptomatic carriers. These data suggest that the peptide sequence spanning 11 amino acid residues in this particular region may play an important role in the pathogenesis of B-viral liver disease, and could be an immunologic target of cytotoxic T lymphocytes.

Adult↗
PubMedDate not supplied

Extrahepatic portal vein obstruction in adults detected by ultrasound with frequent lack of portal hypertension signs.

Extrahepatic portal vein obstruction (EHPO) was seen in 54 adult patients at the Chiba University Hospital and affiliated hospitals from 1978 to 1991. They were classified according to the background disease (Group A, unknown aetiology; Group B, benign disease; Group C, malignant disease). Among the initial symptoms and signs, abdominal pain was the most frequent in Group A (37%), and symptoms attributable to the primary disease in Groups B (44%) and C (75%). Definite or probable diagnosis was made in 45 of the 54 patients (81.8%) by ultrasound (US) examination carried out because of these symptoms and signs. Signs of portal hypertension were observed in 67% of patients; oesophageal varices were seen in 60%. Extrahepatic portal vein obstruction without portal hypertension signs was characterized by thick extensive hepatopetal collaterals or patency of some intrahepatic portal veins. Extrahepatic portal vein obstruction patients without portal hypertension remained free of its signs for more than 3 years of follow up and, in fact, EHPO without portal hypertension signs was a common occurrence. Emphasis is made on the diagnostic value of US examination which was useful in identifying the relation of clinical manifestation of EHPO to pathophysiology, and on the frequent lack of portal hypertension signs in this disease.

Constriction, Pathologic↗
PubMedDate not supplied

An early gallstone clearance following repeat piezoelectric lithotripsy.

Piezoelectric extracorporeal litotripsy was performed in 128 symptomatic patients with radiolucent gall-bladder stones to assess the significance of disintegration in fragment clearance. Up to 10 repeat lithotripsy sessions were scheduled to achieve a fragment target size of < 3 mm. Fragmentation assessed by the size of the largest fragments after the last session was graded into three classes. I: sludge-like disintegration, 18%; II: < 3 mm (mean +/- s.d., 1.7 +/- 0.5 mm), 56%; and III: > or = 3 mm (3.3 +/- 0.6), 26%. All patients were initially subjected to lithotripsy alone. Bile acid dissolution therapy was started only when ultrasonography failed to show the evidence of decrease in the < 3 mm fragments during a 1 month follow up. Finally, 69 patients (54%) were treated by lithotripsy alone, and the remaining 59 received additional dissolution therapy at a mean period of 2.5 months after the initial lithotripsy. The rate of complete clearance in class I, II and III patients was 91, 42 and 10% at 6 months and 100, 68 and 49% at 18 months, respectively. Significant differences were noted between the three fragmentation grades (I vs II, III, P < 0.0001; II vs III, P < 0.02). The patients with complete clearance within 6 months were seen only in those treated by lithotripsy alone, while the majority (87%) of patients with complete clearance during the later period were seen in those treated by additional dissolution therapy. We conclude that a high degree of fragmentation appears to lead stones to an earlier period clearance, and reduce the need for dissolution therapy.

Actuarial Analysis↗
PubMedDate not supplied

Infection of human hepatocyte cell lines with hepatitis C virus in vitro.

Hepatocyte related cell lines, namely human embryonic hepatocyte cell line (WRL68) and hepatoblastoma cell line (Hep G2), were tested for their ability to support hepatitis C virus (HCV) replication in vitro. The replicative intermediate of the minus strand HCV RNA was newly transcribed from the inoculated virus, and was stable in WRL68 cells over a period of 62 days. HCV RNA detected in the culture medium at 62 days after infection suggested a long period of virus secretion from this cell line. In Hep G2, transcription of the minus strand HCV RNA was also detected until 39 days after infection, but transcription and secretion of viral progeny could not be demonstrated. Although HCV infection of WRL68 was not high, this cell line might prove to be a useful tool for studying HCV replication in vitro.

Base Sequence↗
PubMedDate not supplied

Aflatoxin and p53 abnormality in duck hepatocellular carcinoma.

Recent studies have revealed that a point mutation at codon 249 in the p53 gene predominates in hepatocellular carcinoma (HCC) cases from Southern Africa and China, where infection with hepatitis B virus (HBV) and contamination of aflatoxin B1 in food are risk factors for HCC. This unique mutation from G to T at the third base in codon 249 observed in human HCC cases is suggested to be linked to aflatoxin exposure. Six ducks with HCC, five of which were fed a diet containing aflatoxin B1 for 1-2 years, were analysed for the presence of point mutations at this codon of the p53 gene by polymerase chain reaction and direct nucleotide sequencing. None of the six ducks with HCC showed the change at this codon regardless of duck hepatitis B virus infection. This suggests that aflatoxin B1 itself might not be involved in the unique mutation at codon 249 in hepatocarcinogenesis, or that other factors coincident with aflatoxin may be responsible for this unique mutation.

Aflatoxin B1↗