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Biomedical subjects

K Shigeta

Publications and source records attributed to K Shigeta.

50 records · Page 3Linked to original sources
PubMed1986

Quantitative and qualitative characterization of human cancer-associated serum glycoprotein antigens expressing fucosyl or sialyl-fucosyl type 2 chain polylactosamine.

The quantity of tumor-associated antigens carrying type 2 chain polylactosamines with four types of fucosyl determinants, LeX (X-hapten), poly-LeX, sialyl LeX, and LeY (Y-hapten), present in sera of patients with various malignant and non-malignant disorders, as well as the qualitative chemical properties of the carrier molecules in sera, have been investigated using four monoclonal antibodies, each of which defines one of these determinants. The following findings are of particular importance: the serum levels of LeX defined by antibody FH2 and poly-LeX defined by ACFH18 in patients with cancer were occasionally high (incidence about 10%); however, the majority of patients did not show elevated levels; the serum level of the antigen, defined by monoclonal antibody FH6 (termed sialyl LeX-i since this determinant is carried by i antigen), was significantly high in patients with cancers originating from organs from which adenocarcinomas often develop. For example, among various types of lung cancer, only adenocarcinoma but not squamous cell carcinoma, small cell carcinoma, or large cell carcinoma showed a high level of sialyl LeX-i antigen in sera. The incidence of high antigen levels in sera of patients with adenocarcinomas of lung was as high as 76% of the observed cases; the serum level of Ley (Y-hapten) was frequently high in patients with hepatoma (incidence, 34%); sialyl LeX-i antigen was separated on gel filtration as a glycoprotein with an average molecular weight greater than 10(6). It was characterized by its susceptibility to basehydrolysis, Pronase digestion, and sialidase and endo-beta-galactosidase treatment and is assumed to be a high molecular weight mucin-type glycoprotein; sialyl LeX-i antigen expressed in sera of patients with cancer was soluble in perchloric acid, while the same antigen in sera of patients with noncancerous diseases and normal subjects was mostly insoluble in perchloric acid. LeX, a poly-LeX, and essentially all LeY antigens in sera of patients with cancer were perchloric acid-insoluble.

Antibodies, Monoclonal↗
PubMed1984

Fragmentation of a 70000-dalton calpastatin molecule upon its complex formation with calpain.

Homogenously purified porcine calpain I (Mr 112000), a low-Ca2+-requiring form of Ca2+-dependent cysteine proteinase [EC 3.4.22.17], was coupled to Sepharose 4B gel as an active form. It was used as a ligand to calpastatin (Mr 70000), calpain-specific inhibitor protein, for an affinity chromatography. Only in the presence of Ca2+, calpastatin bound to calpain-Sepharose, but the interaction resulted in rather extensive fragmentation of a calpastatin molecule into several peptides of Mr 14000 to 70000, which still retain inhibitory activities against calpain. Fragmentation was demonstrated both by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and by high-performance liquid chromatography in the presence of 6 M guanidine-HCl.

Animals↗
PubMed1980

Clinical implications of alpha-fetoprotein in liver cirrhosis: five-year follow-up study.

The level of alpha-fetoprotein (AFP) was estimated by radioimmunoassay or passive hemagglutination method in a series of 159 patients with liver cirrhosis, and the incidence of serum hepatitis B antigen, histopathologic features of the liver, incidence of development of hepatocellular carcinoma (HCC) and mortality in AFP-positive cases were studied. Approximately 40 per cent of the patients had an AFP level higher than 20 ng/per ml, and all the elevations of AFP over 100 ng per ml were transient. In contrast, patients who developed HCC during the course of the disease always exhibited an increasing value of AFP. The seropositivity for AFP was significantly related to the presence of serum hepatitis B surface antigen and also to liver cell dysplasia as well as to thickening of the liver cell plates. As compared with a group of AFP-negative cases, the AFP-positive group showed a higher incidence of development of HCC and poorer prognosis over a five-year follow-up period. The data obtained suggested that increased AFP-production in patients with liver cirrhosis might reflect, largely an abnormal or altered liver cell regeneration, probably associated with hepatitis B virus, and that patients with transiently elevated AFP values might be at greater risk for the development of HCC.

Carcinoma, Hepatocellular↗
PubMed1977

Carcino-fetal proteins and gastric cancer: the site of alpha-fetoprotein synthesis in gastric cancer.

Although several investigators have reported serum alpha-fetoprotein positive gastric cancer with or without metastasis to the liver, its site of production is still unclear. We studied on the site of alpha-fetoprotein synthesis in our cases which showed remarkably high level of serum alpha-fetoprotein, and clarified the presence of alpha-fetoprotein producing gastric cancer by means of direct immunofluorescent technique. However, we also knew the hepatocytes adjacent ot the metastatic lesions could also synthesize alpha-fetoprotein, although these hepatocytes were not known whether under regeneration or degeneration. Through this study, the other carcinofetal proteins such as carcino-placental alkaline phosphatase and CEA were examined using the sera or tumor tissues. Our results will support the idea that cancer is the disease of cell differentiation.

Adenocarcinoma↗
PubMedDate not supplied

Sonographic detection of diffuse peripheral nerve hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy is an autoimmune disease characterized by recurrent demyelination and remyelination with resultant thickening of the peripheral nerves. We report a case in which sonography was instrumental in demonstrating diffuse peripheral nerve hypertrophy. On sonography, both brachial plexuses were found to be diffusely hypertrophic and hypoechoic. Similar findings were noted for the median, sciatic, and femoral nerves. The brachial plexus findings were confirmed by MRI.

Adult↗
PubMedDate not supplied

Temporomandibular disorders: MR assessment of inflammatory changes in the posterior disk attachment during the menstrual cycle.

PURPOSE: Our goal was to correlate the menstrual cycle with joint pain, MR evidence of the disk, and posterior disk attachment in patients with temporomandibular disorders. METHOD: Forty-two women underwent MRI involving conventional T1-and T2-weighted gadolinium-enhanced fat-suppressed SE imaging sequences. RESULTS: There was a strong statistical difference in the degree of joint pain between proliferated phase and secretory phase groups (p < 0.005). Joint pain had a tendency to increase at the secretory phase. Significantly less contrast enhancement of the posterior disk attachment was observed in the proliferated phase than in the secretory phase (p < 0.001) or menstrual phase (p < 0.01). In addition, anterior disk displacement without reduction of the temporomandibular joint was closely associated with joint pain. CONCLUSION: Our results suggest that positional changes of the disk and the menstrual cycle may play a role in the degree of joint pain and inflammatory pathology of the posterior disk attachment.

Adolescent↗