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Biomedical subjects

O Yamakawa

Publications and source records attributed to O Yamakawa.

At least 19 recordsLinked to original sources
PubMed2004

Characterization of Acylated Anthocyanins in Callus Induced From Storage Root of Purple-Fleshed Sweet Potato, Ipomoea batatas L.

Four anthocyanins were isolated from a highly pigmented callus induced from the storage root of purple-fleshed sweet potato (Ipomoea batatas L) cultivar Ayamurasaki. The anthocyanins were respectively identified as cyanidin 3- $O$ -(2- $O$ -(6- $O$ -( $E$ )-caffeoyl- $\beta$ -D-glucopyranosyl)- $\beta$ -D-glucopyranoside)-5- $O$ - $\beta$ -D-glucopyranoside, cyanidin 3- $O$ -(2- $O$ -(6- $O$ -( $E$ )- $p$ -coumaroyl- $\beta$ -D-glucopyranosyl)-6- $O$ -( $E$ )-caffeoyl- $\beta$ -D-glucopyranoside)-5- $O$ - $\beta$ -D-glucopyranoside, cyanidin 3- $O$ -(2- $O$ -(6- $O$ -( $E$ )- $p$ -coumaroyl- $\beta$ -D-glucopyranosyl)-6- $O$ -( $E$ )- $p$ -coumaroyl- $\beta$ -D-glucopyranoside)-5- $O$ - $\beta$ -D-glucopyranoside, and peonidin 3- $O$ -(2- $O$ -(6- $O$ -( $E$ )- $p$ -coumaroyl- $\beta$ -D-glucopyranosyl)-6- $O$ -( $E$ )- $p$ -coumaroyl- $\beta$ -D-glucopyranoside)-5- $O$ - $\beta$ -D-glucopyranoside by chemical and spectroscopic analyses. These anthocyanins were examined with respect to the stability in neutral aqueous solution as well as the radical scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. These acylated anthocyanins exhibited both higher stability and higher DPPH radical scavenging activity than corresponding nonacylated cyanidin and peonidin 3- $O$ -sophoroside-5- $O$ -glucosides.

Journal Article↗
PubMed2001

Antimutagenicity of deacylated anthocyanins in purple-fleshed sweetpotato.

The antimutagenicity of the 3-sophoroside-5-glucoside of cyanidin and 3-sophoroside-5-glucoside of peonidin, the anthocyanin derivatives deacylated from the 3-(6,6'-caffeylferulylsophoroside)-5-glucoside of cyanidin (YGM-3) and 3-(6,6'-caffeylferulylsophoroside)-5-glucoside of peonidin (YGM-6) which had been purified from the sweetpotato with purple-colored flesh, was investigated by using Salmonella typhimurium TA 98. A comparison of the antimutagenicity between YGM-3 and YGM-6 and the deacylated derivatives showed that the activity of cyanidin was stronger than that of peonidin. Deacylation of the peonidin-type pigment markedly decreased this antimutagenicity. Caffeic acid showed the strongest antimutagenicity of the constituent organic acids of the anthocyanin pigments, caffeic acid, ferulic acid, and p-hydroxybenzoic acid. These results suggest that the cathecol structure plays an important role in the strong antimutagenicity of anthocyanin pigments.

Acetylation↗
PubMed2000

Anthocyanins in callus induced from purple storage root of Ipomoea batatas L.

Two anthocyanins were isolated from the highly pigmented callus derived from the storage root of purple sweet potato (Ipomoea batatas L.) cultivar 'Ayamurasaki'. One was identified as cyanidin 3-O-sophoroside-5-O-glucoside, and the other as cyanidin 3-O-(2-O-(6-O-(E)-p-coumaroyl-beta-D-glucopyranosyl)-beta-D-glucop yranoside)-5-O-beta-D-glucopyranoside, by chemical and spectroscopic analysis.

Anthocyanins↗
PubMed1999

Antimutagenicity of sweetpotato (Ipomoea batatas) roots.

Antimutagenicity of the water extracts prepared from the storage roots of four varieties of sweetpotato with different flesh colors was investigated using Salmonella typhimurium TA 98. The extract from the whole roots of the purple-colored Ayamurasaki variety effectively decreased the reverse mutation induced not only by Trp-P-1, Trp-P-2, IQ, B[a]P, and 4-NQO but also by dimethyl sulfoxide extracts of grilled beef. Comparison of the inhibitory activity of the extracts from the normal Ayamurasaki and its anthocyanin-deficient mutant one suggested that the anthocyanin pigment in the flesh decreases the mutagenic activity of the mutagens as heterocyclic amines. Two anthocyanin pigments purified from purple-colored sweet-potato, 3-(6,6'-caffeylferulylsophoroside)-5-glucoside of cyanidin (YGM-3) and peonidin (YGM-6) effectively inhibited the reverse mutation induced by heterocyclic amines, Trp-P-1, Trp-P-2, and IQ in the presence of rat liver microsomal activation systems.

Animals↗
PubMed1996

Cruveilhier-Baumgarten syndrome in which venous hum disappeared following endoscopic variceal sclerotherapy.

We report a case of Cruveihier-Baumgarten syndrome associated with portal vein thrombosis that developed, slowly during a 2-year period after endoscopic variceal sclerotherapy. The thrombosis led to the disappearance of the venous hum and the dilated abdominal wall veins characteristic of this syndrome. A 73-year-old woman was hospitalized for treatment of esophageal varices in April 1988. Her spleen was markedly enlarged, and the histologic findings of her liver were not consistent with hepatic cirrhosis, but with idiopathic portal hypertension. A venous hum was audible in the upper abdomen. Superior mesenteric angiography revealed a porto-systemic shunt vessel under the abdominal wall, originating from the umbilical vein. She was injected four times with a sclerosant, and this brought about disappearance of the esophageal varices. Two years after the first admission, the venous hum was no longer audible, but there was a recurrence of the esophageal varices. More than 2 years later (4 years after the first admission), ultasonographic study, computed tomography, and angiography showed a large thrombus, which completely obstructed the portal vein at the origin of the umbilical vein, and the development of collateral vessels, seen as a "cavernous transformation."

Aged↗
PubMed1996

Detection of K-ras point mutations at codon 12 in pure pancreatic juice for the diagnosis of pancreatic cancer by PCR-RFLP analysis.

The present study was undertaken to detect K-ras point mutations at codon 12 in pure pancreatic juice (PPJ) for the diagnosis of pancreatic cancer (PC) using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. PPJ was collected through a cannula under a duodenal fiberscope from 26 patients with PC and 32 patients with chronic pancreatitis (CP). DNA was extracted from PPJ and was used as the template for PCR. Analysis of PPJ by PCR-RFLP with BstNI revealed that the incidence of K-ras point mutations at codon 12 was 81% (21/26) in patients with PC and 6% (2/32) in those with CP. With reference to the location of PC, the incidence of K-ras mutations was 79% (11/14) in the head, 86% (6/7) in the body, and 80% (4/5) in the tail of the pancreas. The incidence of K-ras mutants was 50% (1/2) in tumor size 1 (TS1; < or = 2.0 cm in size), 71% (5/7) in TS2 (2.1 to < or = 4.0 cm), 89% (8/9) in TS3 (4.1 to < or = 6.0 cm), and 88% (7/8) in TS4 (> 6.1 cm). These results suggested that analysis of K-ras point mutations at codon 12 in PPJ using the PCR-RFLP method is a promising new genetic test for the diagnosis of PC.

Adult↗
PubMed1995

Measurement of serum PSP/reg-protein concentration in various diseases with a newly developed enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay, based on two monoclonal antibodies (Hreg1-1 and Hreg101-1) specific for pancreatic stone protein (PSP)/reg-protein, was developed to determine the concentration of this protein in serum from individuals with various diseases. The serum concentration of PSP/reg-protein was significantly higher in patients with various pancreatic diseases than in normal controls, and was also significantly higher in patients with acute pancreatitis or chronic relapsing pancreatitis than in patients with chronic pancreatitis. Furthermore, the serum PSP/reg-protein concentration was also significantly increased in liver cirrhosis, choledocholithiasis, and various cancers of the digestive system, and was extremely high in all patients tested with chronic renal failure. A significant correlation was apparent between the serum concentration of PSP/reg-protein and elastase-I in 68 patients with chronic pancreatitis or pancreatic cancer. Whereas only 7 of these patients showed a normal serum PSP/reg-protein concentration and a significantly increased elastase-I concentration, 15 of these patients showed a significantly increased serum PSP/reg-protein concentration and a normal serum elastase-I concentration. These results indicate that the serum PSP/reg-protein concentration may reflect pancreatic damage, especially in acute pancreatitis, and may be a sensitive a marker for such damage as elastase-1, although false positivity was apparent in renal failure and in some patients with hepatic dysfunction or digestive system malignancies.

Antibodies, Monoclonal↗
PubMed1994

Serum levels of c-erbB-2 protein in digestive diseases.

The clinical significance of the measurement of c-erbB-2 oncogene product was evaluated. The subjects consisted of 404 patients, including 248 with cancer of the digestive organs and 128 with benign digestive diseases. Serum c-erbB-2 protein levels were measured by sandwich immunoenzyme assay. The positive rates of c-erbB-2 protein, at a cut-off value of 17.0 U/ml, were, for cancers: hepatocellular carcinoma 61.6%, biliary tract cancer 54.8%, pancreatic cancer 25.0%, esophageal cancer 33.3%, gastric cancer 16.9%, and colorectal cancer 5.0%. For benign digestive diseases, the rates were: liver cirrhosis 63.3%, chronic hepatitis 43.2%, acute hepatitis 42.9%, other liver diseases 42.8%, cholelithiasis 30.0%, and chronic pancreatitis 0%. Serum c-erbB-2 protein levels were significantly correlated with the markers of hepatic functional reserve, the indocyanine green retention rate and the hepaplastin test. These findings suggest that serum c-erbB-2 protein levels are greatly influenced by liver dysfunction and that their clinical usefulness as a serum tumor marker is questionable.

Adult↗
PubMed1994

Endoscopic ultrasonography in the diagnosis of extraluminal compressions mimicking gastric submucosal tumors.

We evaluated the diagnostic usefulness of endoscopic ultrasonography (EUS) in 19 patients with extragastric compression. In these 19 cases, the causes of the compression were normal organs or structures in 16 cases (splenic artery 7, spleen 5, normal pancreas two, gall-bladder one, colon one) and extraluminal tumors in three cases (two hepatic hemangiomas, one neurogenic tumor of the omentum minor). In 12 of these 19 cases, the site of the submucosal compression was located in the upper part of the stomach. All three tumors were confirmed by other procedures, and in the remaining 16 patients with compression by normal organs or structures, negative follow-up results (mean: 14 months) supported the absence of a true submucosal tumor. EUS was 100% accurate in the differentiation of an extragastric compression from a submucosal tumor, and in the identification of the compressing organ. EUS was also far superior to other procedures, such as ultrasonography and CT. It significantly shortens the diagnostic procedure, especially in patients with compressions by normal extraluminal structures, making other diagnostic modalities unnecessary.

Adult↗
PubMed1994

[Clinical usefulness of tumor markers associated with pancreatic cancer].

Most of the recently developed tumor antigens detected by monoclonal antibodies are sugar chains and frequently associated with blood group substance. By immunohistochemical studies, we evaluated mainly the clinical usefulness and significance of the serum assay of CA-50 classified as a type 1 sugar chain, sialyl SSEA-1 as a type 2 sugar chain, and ST-439 with an undetermined structure, as well as their clinicopathological significance. In addition, the value of measurement of CA19-9, ST-439, and SLX in pure pancreatic juice (PPJ) was investigated. Furthermore, the clinical usefulness of K-ras mutation at codon 12 (KRM) in PPJ was studied. The incidence of serum CA19-9 among tumor markers was highest in pancreatic cancer (81%), but relatively high in benign diseases. On the other hand, both serological and immunohistological studies showed that sialyl SSEA-1 and ST-439 were highly specific for the tumor, whereas they appeared in serum or tumor less frequently than CA19-9 or CA-50 carrying the type 1 sugar chain. The accuracy of the tumor markers (CA19-9, sialyl SSEA-1, and ST-439) for pancreatic cancer, was almost equal (77% to 80%) and higher than that of CEA (69%). However, a highly positive correlation between sialyl SSEA-1 and ST-439 was revealed as well as among type 1 sugar chains in malignant diseases. Therefore, we conclude that the combination assay with CA19-9 or a similar tumor marker, sialyl SSEA-1 or ST-439, and CEA would be appropriate for the screening of pancreatic cancer. When the cut off value was set as the M + 2SD of the controls, significantly elevated concentrations of CA19-9 in PPJ were found in the secretory phase in 90% of the patients with pancreatic cancer (PC) and 66% of the patients with chronic pancreatitis (CP). Although increased concentrations of CA19-9 in PPJ have no cancer specificity, measurement of CA19-9 in PPJ can be used as a sensitive marker for some pancreatic disorders. On the other hand, concentrations of ST-439 and SLX in PPJ were significantly increased only in PC, and their incidences were 50% and 40%, respectively. They have a high tumor-specificity, but their incidences were not as high as initially expected.(ABSTRACT TRUNCATED AT 400 WORDS)

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

The immunohistochemical evaluation of PSP/reg-protein in normal and diseased human pancreatic tissues.

In order to elucidate the characteristics of reg-protein, which is identical to pancreatic stone protein (PSP/reg-protein), and the relationship between the generation and evolution of chronic pancreatitis and the expression of PSP/reg-protein in the pancreas, we investigated the expression of PSP/reg-protein in normal and diseased human pancreatic tissues by immunohistochemistry. The PSP/reg-protein was expressed in all cases with normal pancreas or chronic pancreatitis, and in 70.6% of cases with pancreatic cancer. This protein was present in the cytoplasm of acinar cells and, in some cases, in the intraluminal contents of ductules in nonmalignant tissues. From the view of distribution and cellular localization, PSP/reg-protein was expressed more broadly and densely in chronic pancreatitis with mild to moderate injury than in the normal pancreas. However, the protein was less expressed in severely damaged chronic pancreatitis tissue, such as calcifying pancreatitis, than in the normal pancreas. These findings suggest that mild to moderate injury to pancreatic tissue may stimulate the synthesis of PSP/reg-protein, whereas more severe injury tends to depress it.

Calcium-Binding Proteins↗
PubMed1993

Biliary papillomatosis with the point mutation of K-ras gene arising in congenital choledochal cyst.

Biliary papillomatosis is a rare entity. A case of biliary papillomatosis associated with congenital choledochal cyst and intrahepatic gallstones is reported here. Percutaneous transhepatic cholangioscopy revealed multiple papillary lesions of the right intrahepatic duct and the common bile duct. Microscopically, the papillary mucosal lesion showed papillary proliferations of bile duct epithelial cells with mild atypia. Furthermore, a point mutation at codon 12 of the K-ras oncogene was found in the papillary lesion. To the best of our knowledge, this is the first case of biliary papillomatosis arising in congenital choledochal cyst. Although the pathogenesis of biliary papillomatosis in our case was unclear, biliary irritation associated with choledochal cyst may be related to biliary papillomatosis with point mutation at codon 12 of K-ras gene.

Aged↗
PubMed1993

Diagnostic significance of cancer-associated carbohydrate antigen (CA19-9) concentrations in pancreatic juice: analysis in pure pancreatic juice collected by endoscopic aspiration and immunohistochemical study in chronic pancreatitis.

This study evaluated the diagnostic significance of concentrations of the cancer-associated carbohydrate antigen CA19-9 in pure pancreatic juice (PPJ) collected by endoscopic cannulation. We also attempted to elucidate the features and source of the increased CA19-9 concentration found in the pancreatic juice of patients with chronic pancreatitis (CP) by means of immunohistochemical staining. The mean output as well as the mean concentration of CA19-9 in each of the four fractions collected was highest in patients with pancreatic cancer (PC) and also was elevated significantly in patients with CP compared with controls. However, CA19-9 concentrations were not elevated in patients with cholecystolithiasis. When the cutoff value was set as the mean concentration + 2SD of the controls, significantly elevated concentrations of CA19-9 were found in the third fraction (secretory phase) in 90% of the patients with PC and 66% of the patients with CP. Immunohistochemical staining revealed that CA19-9 was expressed more widely in the ductal cells of CP tissues than in those of normal pancreatic (NP) tissues, with CP tissue showing more CA19-9-positive ductal cells per area than NP tissues. In NP tissue, CA19-9 was localized to the apical surface and supranuclear regions (apical type) in all the ductal cells stained by the antigen, while approximately 50% of cases with CP exhibited a cytoplasmic pattern showing a loss of polarity of the antigen expression. Moreover, this cellular localization pattern was more pronounced in the small ducts that had proliferated and aggregated following the destruction of lobules in CP.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

Identification of K-ras oncogene mutations in the pure pancreatic juice of patients with ductal pancreatic cancers.

Pancreatic cancer is detected on the basis of morphological changes delineated by means of various image-diagnostic methods. However, differentiation between chronic pancreatitis and pancreatic cancer, especially at the early stage, is not always simple when based upon the morphological changes alone. Therefore, we attempted to elucidate K-ras mutations in the sediment of pure pancreatic juice (PPJ) containing exfoliated ductal pancreatic cancer cells. PPJ was collected endoscopically from 20 patients with pancreatic cancer (PC) and 18 patients with chronic pancreatitis (CP). Polymerase chain reaction and allele specific oligonucleotide dot blot hybridization for K-ras mutations were performed with the DNA extracted from these samples. A K-ras mutation at codon 12 was identified in the PPJ of 11/20 (55%) of the patients with PC. On the other hand, the same mutation was not identified in the PPJ of any patient with CP. Moreover, K-ras mutations at codons 13 and 61 were not recognized in the PPJ of any patient with either PC or CP. These findings suggested that the presence of a K-ras mutation at codon 12 in PPJ would be useful in confirming the diagnosis of PC.

Adult↗
PubMed1993

[Availability of determination of serum anti-Helicobacter pylori IgG antibody in diagnosis of Helicobacter pylori infection].

We studied on clinical availability of determination of serum anti-Helicobacter pylori (HP) IgG antibody in diagnosis of HP infection compared with bacterial culture. The population of this study consisted of patients who underwent endoscopic examination in our hospital. Detection and quantification of HP were made by the culture of biopsy specimens taken from the antrum and the body of the stomach. And, simultaneously, serum anti-HP antibody (HP-Ab) was measured by ELISA. The levels of HP-Ab in culture positive patients, 40.6 +/- 33.7U, are significantly higher than that of culture negative patients, 10.6 +/- 9.1U. Sensitivity and specificity in diagnosis of HP infection using determination of serum HP-Ab were 96.2% and 60.0% respectively. Significant correlation was found between the levels of serum HP-Ab and the amounts of HP bacilli in the biopsy specimen taken from body of the stomach.

Aged↗