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M Ohto

Publications and source records attributed to M Ohto.

At least 163 records · Page 9Linked to original sources
PubMed1989

[Detection of ras gene mutations of pancreatic tumors by polymerase chain reaction and direct sequencing method].

Ras genes (H-,K-,N-ras) are converted to active oncogenes by point mutations occurring in either codon 12, 13 or 61. We analyzed 19 pancreatic tumors (formalin fixed paraffin embedded tissue) of these codons by a method to directly sequence nucleotides around codons 12/13 and 61 of the three ras genes, using polymerase chain reaction and direct sequencing method. Of 19 pancreatic tumors, all 17 duct cell carcinomas involving 2 mucous producing pancreatic cancers had point mutations of the K-ras codon 12, but 2 islet cell tumors had ano point mutation around codons 12, 13, 61 of the three ras genes. Extremely high incidence of ras gene mutation may be relevant to certain pathogenesis of pancreatic cancers.

Base Sequence↗
PubMed1988

Portal hemodynamics in patients with gastric varices. A study in 230 patients with esophageal and/or gastric varices using portal vein catheterization.

The hemodynamic features of gastric varices are not well documented. The purpose of this study was to investigate the nature of hepatofugal collateral veins, their origins, the direction of blood flow in the major veins and collateral veins, and portal venous pressure. To this end, 230 patients, mostly cirrhotic, who had esophageal or gastric varices, or both, demonstrated by endoscopy were investigated by portal vein catheterization. The findings were correlated with endoscopically assessed degrees of varices. Gastric varices were seen in 57% of the patients with varices due to portal hypertension. In most of the patients with advanced gastric varices, esophageal varices were minimal or absent. When patients with gastric varices were compared with those having predominantly esophageal varices, it was found that advanced gastric varices were more frequently supplied by the short and posterior gastric veins, they were almost always associated with large gastrorenal shunts, and portal venous pressure in patients with large gastric varices was lower. Chronic portal systemic encephalopathy was more common in patients with large gastric varices due to hepatofugal flow of superior mesenteric venous blood in the splenic vein than in patients with predominantly esophageal varices. Thus, the hemodynamics in patients with large gastric varices are distinctly different from those in patients with mainly esophageal varices, and such differences seem to account for the differing incidence of chronic encephalopathy and variceal bleeding.

Adult↗
PubMed1988

Pulsed Doppler in the diagnosis of small liver tumours.

Doppler ultrasound detection of the blood flow associated with liver tumours was studied in primary hepatocellular carcinoma as well as in metastatic liver cancer and haemangioma. Doppler signals were detected from 48 of 55 hepatocellular carcinomas (87.3%), seven of 25 metastatic liver cancers (28.0%) and four of 30 haemangiomas (13.3%). The waveforms of Doppler signals were divided into two types: the pulsatile wave, which was detected from hepatocellular carcinoma (in 35 of the 48 with Doppler signals) and metastatic liver cancer (in all seven with positive signals), and the continuous wave, which was seen from hepatocellular carcinoma (41 out of 48) and haemangioma (in all four with signals). In six patients with hepatocellular carcinoma who underwent transcatheter arterial embolization, the pulsatile wave detected before therapy disappeared immediately thereafter and it is possible that this type of wave originates from tumour vessels. In the study of small, hypoechoic, mass lesions appearing in liver cirrhosis, such signals were also demonstrated, even in eight of 10 small hepatocellular carcinomas less than 2 cm in diameter, whilst they were not detected from nine regenerative nodules related to cirrhotic change. In conclusion, the Doppler ultrasound method may be a useful technique in detecting blood flow within liver tumours and may offer the possibility of a differential diagnosis of small tumours.

Adult↗
PubMed1986

Resolution of diffuse granulomatous fibrosis of the liver with antituberculous chemotherapy.

A 71-yr-old man with pulmonary tuberculosis developed jaundice, and an ultrasound examination suggested hepatolithiasis. The liver was markedly enlarged and of stony consistency. Two 2.5-cm biopsy specimens of the liver each disclosed diffuse fibrosis with giant cells; practically no normal parenchyma was seen. Ultrasonography and computed tomography disclosed multiple intrahepatic calcifications, and percutaneous cholangiography revealed stenosis of the right hepatic duct. One year after treatment with antituberculous drugs, liver biopsy specimens taken from the same areas of the liver showed nearly normal histology.

Aged↗
PubMed1986

Natural history of minute hepatocellular carcinoma smaller than three centimeters complicating cirrhosis. A study in 22 patients.

Twenty-two patients with cirrhosis and minute hepatocellular carcinoma less than 3 cm in diameter were followed for periods of 6-37 mo without specific treatment. The survival curve drawn by the Kaplan-Meier method showed a 1-yr survival of 90.7%, a 2-yr survival of 55.0%, and a 3-yr survival of 12.8%. The ultrasonic patterns of these masses in the liver were correlated with the size and showed a tendency to change from a low echo pattern to a low periphery and, finally, to a massive pattern. The growth speed calculated from the doubling time for tumor volume varied considerably from case to case with an average of 6.5 +/- 5.7 mo; it also changed in some cases during the observation period. Serum alpha-fetoprotein levels were generally low, rarely assisted in diagnosis, but tended to increase when the mass attained a diameter of greater than 3 cm; sudden acceleration in the rate of increase in alpha-fetoprotein level often coincided with a change of ultrasonic pattern to the massive one.

Aged↗
PubMed1986

Diagnosis of small hepatocellular carcinoma: correlation of MR imaging and tumor histologic studies.

Magnetic resonance (MR) images of the liver were used to study 43 patients with relatively small hepatocellular carcinomas (HCCs) and 36 with other hepatic mass lesions. In 27 HCC patients, histologic findings were available. All focal lesions detectable by CT without contrast media were delineated with greater contrast by MR imaging. The rate of detection depended on tumor size, being 97.5% for HCCs greater than 2 cm in the longest axis and 33.3% for those less than 2 cm. MR imaging demonstrated the ring sign characteristic of encapsulated HCC twice as frequently as CT scans. Inversion recovery (IR) images depicted the internal structure of the HCC better than T2-weighted spin-echo images. Lesions were classified into four patterns of intensity: low, iso, high, and mixed. The latter three were relatively characteristic of HCC and related closely with steatosis of cancer tissue. HCCs with fibrosis tended to have long T1 values; those with steatosis had short T1 values. T1 and T2 relaxation times were useful in the differential diagnosis.

Adult↗
PubMed1986

Accuracy of angiography in the diagnosis of small hepatocellular carcinoma.

Conventional hepatic arteriography combined with superselective infusion arteriography was carried out in 51 patients with hepatocellular carcinoma smaller than 5 cm, and angiograms of varying phases were analyzed. In cancers smaller than 40 mm, particularly in those smaller than 20 mm, so-called tumor stain in the capillary phase was the only abnormality seen in most but not all cases. Within a tumor stain, there were unstained areas in most cases and histologic examination in resected specimens showed them to be due to either necrosis, fibrosis, or fatty changes. Homogeneity and shape of the stain seemed to be related to growth speed and invasiveness of the cancer. Although overall diagnostic value of angiography for small hepatocellular carcinoma was high, super-superselective infusion hepatic arteriography produced nodular stains in 7 of 11 control cases of nonalcoholic cirrhosis without cancer, making difficult the differential diagnosis between stains due to tumors and those due to hyperplastic nodules of cirrhosis.

Adult↗
PubMed1986

[Treatment of hepatocellular carcinoma by alcohol injection into the tumor and irradiation of the tumor].

Small hepatocellular carcinoma has come to be diagnosed by imaging modalities recently progressed. However, in patients with the carcinoma surgery is often contraindicated due to liver dysfunction. From such reason intratumor alcohol injection therapy has been developed and the efficacy has been clearly demonstrated in hepato cellular carcinoma with tumor under 3 cm is diameter. While in radiation therapy has been effective in that with tumor up to 10 cm in diameter. In treatment of hepatocellular carcinoma, it is important to choose a therapeutic method by considering the degrees of cancer progress and liver dysfunction.

Administration, Topical↗
PubMed1986

[Ultrasound diagnosis of hepatocellular carcinoma].

Nowadays, ultrasound has been widely used in clinical practice of gastroenterology. A recently developed ultrasound apparatus with a higher resolution of image and less artifacts makes it possible to find out a small HCC sized about 1.0 cm. Moreover, a new convex type of probe with a wide field of view enables us to detect a small HCC locating in the upper part of the right lobe which has been done with difficulty before. Early diagnosis of HCC by detecting a small mass lesion will be carried out reliably by a modern ultrasound modality.

Carcinoma, Hepatocellular↗