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Biomedical subjects

K Kojima

Publications and source records attributed to K Kojima.

At least 469 records · Page 26Linked to original sources
PubMed1991

Importance of polymerization initiator systems and interfacial initiation of polymerization in adhesive bonding of resin to dentin.

Although various adhesive resins for dentin have been developed and used clinically, most attention has been directed to adhesion-promoting monomers and pre-treatment agents. The role of polymerization initiator systems in bonding has been overlooked. The purpose of this work was to study the role of initiators from the viewpoint of interfacial initiation of polymerization in dentin bonding. The bond strength between dentin and methyl methacrylate resin was significantly improved by a possible interfacial initiation with (1) the combination of ferric chloride, adsorbed onto dentin, and oxidized tri-n-butylborane (TBBO) and (2) the addition of tertiary butyl peroxymaleic acid (containing a carboxylic acid group, which has an affinity with dentin) to chemically- or light-activated initiator systems.

Acid Etching, Dental↗
PubMed1991

The nephritogenic glycopeptide from rat glomerular basement membrane. X. Synthesis of an N-triglycosyl dipeptide and characteristics of its cis-trans isomers.

Isomers of O-alpha-D-glucopyranosyl-(1----6)-O-beta-D-glucopyranosyl- (1----6)-N-[L-aspart-1-oyl-(L-proline)-4-oyl]-alpha-D-glucopyranos ylamine have been prepared, as models for a derivative possibly present in the glomerular basement membrane of rats, by condensation of the corresponding dipeptide derivative (5) with triglycosylamine (4) in the presence of O,O-diethylcyanophosphonate, followed by deprotection of the trisaccharide-dipeptide derivative. During the deprotection process, cis- and trans-isomers containing proline were separated by silica gel column chromatography and also reversed-phase high performance liquid chromatography.

Amino Acid Sequence↗
PubMed1991

Vasorelaxant and hypotensive effects of tilisolol hydrochloride (N-696) in isolated rat thoracic aorta and pithed rats.

Vasorelaxant and hypotensive effects of tilisolol hydrochloride (N-696) in isolated rat thoracic aorta and pithed rats were investigated. In rat thoracic aorta pre-contracted with KCl (20 mM), tilisolol (10(-5)-10(-3) M) produced concentration-related relaxation, but nadolol and atenolol did not significantly inhibit the responses to 20 mM KCl. The concentration-relaxation curve of tilisolol underwent rightward parallel shifts only to a limited extent in the presence of glibenclamide, a specific antagonist of K+ channel openers. Glibenclamide also shifted the concentration-relaxation curve of cromakalim to the right and in a parallel manner, whereas it did not change that of propranolol. In pithed rats, tilisolol (0.5-2.0 mg/kg, i.v.), but neither nadolol nor atenolol, caused a dose-dependent decrease in diastolic blood pressure and a slight increase in heart rate. Following treatment of the preparation with glibenclamide, the hypotensive effects of tilisolol and cromakalim were antagonized, while that of propranolol was not affected. These results suggest that the vasorelaxant and hypotensive actions of tilisolol involve an opening of K+ channels which can be inhibited by glibenclamide and may also involve additional relaxant mechanisms of action independent of K+ channel opening.

Adrenergic beta-Antagonists↗
PubMed1991

Application of MEN 203 as a polymorphic DNA probe in screening multiple endocrine neoplasia 2a.

Multiple endocrine neoplasia 2a (MEN 2a) is known to be genetically linked to a locus on chromosome 10. The application of polymorphic DNA probes for the region has made it possible to identify carriers of the disease susceptible gene. We performed DNA analysis for a newly found non-Caucasian MEN 2a family using MEN 203 as a probe. Data from DNA analysis of the family members were concordant with the results of conventional endocrinological tests. Furthermore, DNA analysis discriminated four individuals out of fifteen as non-carriers of the gene with a high degree of certainty. The results relieved these people from taking screening tests for years. DNA analysis employing suitable markers such as MEN 203 appears to be useful for a screening program of MEN 2a in Japanese as well as Caucasians.

Aged↗
PubMed1991

[A case of acinar-islet cell tumor of the pancreas body].

Combined carcinoma of the pancreas is very rare. The case of pancreatic tumor featuring both acinar cell and islet cell tumors presented, may be only the fifth case of acinar-islet cell tumor in the world. A 34-year-old-woman visited our hospital complaining of weight loss (8 kg/6 months). A clearly demarcated pancreatic tumor was visualized by ultrasonography, body CT and MRI. Class 3 cells were extracted via ultrasonography guided fine-needle biopsy. Tumor was enucleated on October 5, 1988. Histologic appearance of the tumor by light microscopy was consistent with that of both acinar cell and islet cell tumors. Electron microscopy revealed two distinct populations of zymogen and neuroendocrine granules. The patient is doing well 1 year and 7 months postoperatively with no evidence of liver metastasis or recurrence. This case is significant in terms of the close histogenic relationship between pancreatic exocrine and endocrine components.

Adenoma, Islet Cell↗
PubMed1991

Mechanisms of inhibitions of DNA polymerase gamma by nucleotide analogues having anti-HIV activities.

Inhibition mechanisms of 5'-triphosphates of 3'-azido-3'-deoxythymidine (AZT-TP) and 3'-deoxythymidine (ddTTP) on extensively purified DNA polymerase gamma from bovine testes were examined by analysis of the products synthesized on singly primed M13mp18 single-stranded DNA or synthetic oligonucleotide template-primer in the presence of analogues. The results indicate that AZT-TP inhibits DNA polymerase gamma in competition with dTTP but is not incorporated into DNA, whereas ddTTP is incorporated into DNA and causes chain termination.

Animals↗
PubMed1991

[A case of Sjögren's syndrome with malignant lymphoma].

A case of a 62-year-old female with Sjögren's syndrome (SjS) who developed a malignant lymphoma (ML) is reported. The patient who became blind at 32 years of age due to retinitis, began to complain of sicca syndrome (dry eye and dry mouth) and polyarthralgia at 40 years of age. A rapidly progressive subcutaneous mass was noted in the right anterior chest wall at 62 years of age. The surgically resected mass was diagnosed histologically as ML, diffuse, large cell type. Immunohistological study was done. Almost all of the lymphocytes infiltrated around ductules of a small salivary gland biopsied 6 years earlier were B-cells (MB-1; +, Mx-Pan B; +, IgG k; +). Only a small number of them were evaluated as T-cells (UCHL-1; +). The ML tumor was studied as a B-cell lymphoma which did not produce immunoglobulins (MB-1; +, Mx-Pan B; +). The patient was treated with a CHOP-B protocol and radiation without exacerbation. In recent reports of this association, helper T-cells were dominant in the lymphocytes infiltrated in the salivary gland in the early stage when ML did not develop yet. In this case, B-cells were dominant in the small salivary gland in contrast to the former reports. It is interesting that there was a difference in the character of the infiltrating lymphocytes.

Female↗
PubMed1990

[Thin-section computed tomography of the normal minor fissure].

The minor fissure was studied with thin computed tomographic (CT) sections (2 mm thickness, 3 mm interval) in 50 patients. It showed high density line or area in all patients. In nine patients CT sections were not obtained through the all region of the minor fissure. Of other 41 patients the fissure was complete in 12 (29%), slightly incomplete in 18 (44%), half incomplete in 7 (17%), and considerably incomplete in 4 (10%). The upper surface of the middle lobe appeared to be upwardly convex in all 50 patients. The location of the highest portion of the minor fissure was hilar in 12 (24%) of 50 patients, medial 1 (2%), anterior 0 (0%), lateral 8 (16%), posterior 3 (6%), dorsal 10 (20%), central 12 (24%), others 2 (4%), and indeterminate 2 (4%). The minor fissure was higher medially than laterally in 22 (44%) patients, and higher posteriorly than anteriorly in 40 (80%) patients. The lowest portion of the minor fissure was anterior in 20 (40%) patients, lateral in 4 (8%), and posterior 3 (6%). The anterior vein of the anterior segment of the right upper lobe (V3b) came in contact with the minor fissure in 20 (40%) patients. In 18 (90%) of these 20 patients minor fissure medial to V3b was incomplete partially. Three dimensional reconstruction image of the minor fissure improved understanding of the anatomy. Familiarity with the anatomic detail of the minor fissure and with variations in the relationships of the upper and middle lobes is useful in localization or extension of a lesion.

Adult↗
PubMed1990

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis.

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis (JE) was performed. Neurologically dementia, forced laughing, tetraplegia and parkinsonism were observed as sequelae. In the CT and MR scans about 3 years after the onset of JE, low-density areas (LDAs) or abnormal signal intensities had remained in the thalamus and basal ganglia. The abnormalities were also found in the brain stem. When the main lesions shown by CT and MRI were compared with those of the acute stage, T2-weighted MRI clearly revealed multiple small areas with high signal intensities, although those in the acute stage had shown diffuse abnormal signals. These findings may be useful in helping to identify JE a long time after the onset.

Brain↗