Search PubMed⌕ Search

Biomedical subjects

K Kojima

Publications and source records attributed to K Kojima.

At least 379 records · Page 21Linked to original sources

A novel oligosaccharide, xylosyl beta 1-4xylosyl beta 1-(4-methylumbelliferone), synthesized by cultured human skin fibroblasts in the presence of 4-methylumbelliferyl-beta-D-xyloside.

4-Methylumbelliferyl-beta-D-xyloside (Xyl-MU) was added to the medium of cultured human skin fibroblasts. After incubation, the culture medium was pooled, concentrated with a lyophilizer, and dialyzed against distilled water. Then the Xyl-MU derivatives in the diffusate were purified by gel-filtration and HPLC. A novel Xyl-MU derivative was obtained, in addition to the previously reported Xyl-MU derivatives, Xyl-MU-induced glycosaminoglycan (GAG-MU), SA-Gal-Xyl-MU, GlcA-Xyl-MU, Gal-Gal-Xyl-MU, and Gal-Xyl-MU. This Xyl-MU derivative was subjected to carbohydrate composition analysis, enzyme digestion, Smith degradation and ion-spray mass spectrometric analysis, and the results indicated that it was Xyl beta 1-4Xyl beta 1-MU. Although the quantity of Xyl beta 1-4Xyl beta 1-MU synthesized by human skin fibroblasts increased with incubation time, its production was independent of that of the GAG-MU. Xyl-Xyl-MU is different from the intermediates in the regular pathway of GAG-MU biosynthesis initiated by added Xyl-MU, posing an interesting question as to its significance in GAG biosynthesis.

Carbohydrate Sequence↗

Expression of leukemia inhibitory factor in human endometrium and placenta.

Leukemia inhibitory factor (LIF), a cytokine that induces macrophage differentiation in the murine M1 myeloid leukemia cell line, is essential for blastocyst implantation in mice. However, its expression and the role it plays in the human uterus are unknown. To clarify these issues, we examined LIF gene expression in the human uterus by Northern blot hybridization and by a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. Analysis of LIF mRNA showed two hybridization bands, with estimated mRNA sizes of about 4.0-kb pairs and 1.8-kb pairs. LIF mRNA was detected at high levels in endometrial tissue and decidua, but at low levels in the chorionic villus in first trimester and term placenta. In the secretory phase, the endometrial tissue showed higher LIF expression than in the proliferative phase (9.5-fold; p < 0.01). The endometrial tissues were separated into a stroma-enriched fraction (SF) and an epithelium-enriched fraction (EF), and the LIF mRNA levels in each fraction were examined by quantitative RT-PCR. These levels were higher in the EF than in the SF (3.3-fold; p < 0.05). These findings suggest that, in humans, LIF plays a role in uterine function during the menstrual cycle, as well as during pregnancy.

Base Sequence↗

Improved method of preparation of inflated-fixed lung for radiologic-pathologic correlation.

The technique of inflation and fixation of the lung with polyethylene glycol is useful for specimen radiography and radiologic-pathologic correlation, but it is limited by poor histologic staining of the fixed tissue. To improve staining we used formalin to distend and fix the lung before standard fixation with a polyethylene glycol mixture. In this preliminary study, canine and infant lungs, and lungs from three cases of lung cancer were examined. The modified technique provided high-quality staining and satisfactory specimen radiography in all cases except one of the lung cancers; in this case excessive shrinkage occurred and degraded radiographic quality. We conclude that the new method of preparation permits both specimen radiography and high quality staining of the fixed tissue.

Adult↗

Magnetic resonance imaging findings in Japanese encephalitis. White matter lesions.

Ten patients with Japanese encephalitis diagnosed by serological criteria underwent magnetic resonance imaging (MRI) in axial and coronal sections. In 6, a second MRI study was done. The MRI findings were compared with the clinical outcome. Four patients died within several months of onset, 2 had sequelae such as hemiparesis and dementia, and the remaining 4 had no sequelae. In 9 of 10 patients, either diffuse or patchy white matter lesions were observed bilaterally, together with abnormalities in areas such as the thalamus, basal ganglia, and brainstem. For 3 patients who died or remained demented, the second MRI revealed extensive, diffuse white matter abnormalities. This study indicates that Japanese encephalitis can produce white matter involvement, although gray matter structures such as the thalamus, basal ganglia, and brainstem are more severely affected. The severity of these MRI lesions correlated with the clinical outcome.

Adolescent↗

Antigenicity of the oligosaccharide moiety of the Japanese cedar (Cryptomeria japonica) pollen allergen, Cry jI.

Cry jI, a major allergenic glycoprotein of Cryptomeria japonica (Japanese cedar, Sugi), is the most common pollen allergen in Japan. Carbohydrate analysis and lectin staining indicated that Cry jI possesses the fucose/xylose-containing N-linked oligosaccharide which previously has been found in some plant glycoproteins. Rabbit polyclonal anti-Cry jI IgG antibodies were found to be highly cross-reactive with two other plant glycoproteins which have the same type of oligosaccharides, and the cross-reactivities were completely abolished on chemical deglycosylation of the glycoproteins. Enzyme-linked immunosorbent assay inhibition showed that the majority (up to 70%) of the anti-Cry jI rabbit IgG antibodies recognized the oligosaccharide moiety of Cry jI. The carbohydrate epitopes were found to be only partially involved in the binding of specific IgE antibodies from a pool of human patient sera.

Allergens↗

Progesterone enhances macrophage colony-stimulating factor production in human endometrial stromal cells in vitro.

Increasing evidence suggests that macrophage colony-stimulating factor (M-CSF) is produced in the uterine endometrium and that it plays an important role in the reproductive process. In the present study, using an in vitro decidualization model and human endometrium, we investigated M-CSF messenger RNA (mRNA) expression in human endometrial stromal cells (ESC) by Northern blotting and in situ hybridization. The secreted M-CSF in the culture medium of ESC was measured by enzyme-linked immunosorbent assay. ESC were cultured in the presence of progesterone (P) or estrogen. After a 9-day culture with P, when in vitro decidualization was confirmed by the production of PRL, M-CSF mRNA and protein levels were 3.1 +/- 0.5- and 3.2 +/- 0.8-fold (mean +/- SEM) higher, respectively, than those in cultures without P (P < 0.01). The P-induced increase was dose dependent. On the other hand, estrogen did not increase M-CSF mRNA expression. M-CSF mRNA expression in the first trimester deciduae that expressed PRL mRNA was higher than that in the endometria. By in situ hybridization, ESC as well as epithelial cells were shown to express M-CSF both in vitro and in vivo. These findings indicate that human ESC (decidua cells) express M-CSF mRNA and suggest that they secrete M-CSF in a P-dependent manner during the process of decidualization.

Adult↗

Inhibitory activity on DNA gyrase and intracellular accumulation of quinolones: structure-activity relationship of Q-35 analogs.

Q-35, 1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-(3- methylaminopiperidine-1-yl)-4-oxyquinoline-3-carboxylic acid, has excellent activity against gram-positive bacteria and inhibits S. aureus gyrase at concentrations more than 10-fold lower than those of other quinolones. In this paper, the effect of the C-7 and C-8 substituents of Q-35 on the inhibitory activity of gyrase purified from S. aureus, M. luteus, E. coli, and P. aeruginosa are described. In addition, intracellular accumulation of Q-35 was examined. The 50% inhibitory concentrations (IC50) of Q-35, 8-fluoro- Q-35, and 8-hydro-Q-35 on DNA gyrase purified from S. aureus were 2.5, 7.8, and 68 micrograms/ml, respectively. The IC50 on gyrase from P. aeruginosa were 11, 5.2, and 17 micrograms/ml, respectively. It is concluded that the introduction of a methoxy group into the 8 position of the quinolone leads to greater antibacterial activity against gram-positive bacteria. The concentrations of Q-35 which accumulated in S. aureus and E. coli were almost equal to ciprofloxacin, but in P. aeruginosa, Q-35 was lower than ciprofloxacin.

Anti-Infective Agents↗

[[Projection of household conditions of the elderly in Japan]].

"The household condition of the elderly [in Japan]...was estimated for the years 1975, 1980, 1985 and 1990, and was projected for the years 1995, 2000, 2005 and 2010, using the population census tabulations and the future population by age and sex projected in 1992.... The population aged 65 and over belonging to a 'couple only household' (5,905 thousand) is projected to surpass the population belonging to a 'household with their child' (4,260 thousand) in 2010 for males, while the latter will be...more (6,812 thousand) than the former (5,115 thousand) for females in the same year. The elderly population aged 65 and over in one-person households is projected to increase more remarkably for males than females." (SUMMARY IN ENG)

Adult↗

The first step of experimental study on hybrid trachea: use of cultured fibroblasts with artificial matrix.

Anastomotic stenosis secondary to developing granulation tissue prevents an artificial trachea of non-porous type model from a safe practical use. Taira reported that a non-porous artificial trachea having soft ends for anastomosis works better in this regards apparently by cushioning mechanical stimulations repeatedly applied to the anastomotic rings than most models ever studied have done. We hypothesized that hybridization of soft anastomotic ends of nonporous artificial trachea may further prevent granulation tissue at the anastomoses hopefully by leading epithelial growth earlier onto the inner surface of graft's ends. The graft of our use was made of a 5-cm-long knitted dacron tube with inner coating with silicone rubber covering the entire length but for a 5 mm segment at each end. To date six mongrel dogs have been subjected to test this hypothesis. A piece of subcutaneous tissue was obtained from each dog and prepared for culture of fibroblasts in MEM. These fibroblasts were then suspended in 0.1% collagen with MEM in a container, in which a graft was placed for further culture. Following some 3 weeks of this preparation each graft was implanted to replace a 10-cartilage-ring-long defect of the mediastinal trachea of each donor dog. One dog is enjoying active life 11 months postop, and another 3 months. Four dogs died from anastomotic stenosis 2 to 3 months. Being encouraged by the fact that the anastomotic rings of the long term survivors show bronchoscopically patency more than 40% of cut surface area, and some portion with possible epithelialization without granulation, we will report our further results, along with histological study.

Animals↗

[An application of genetic diagnosis in MEN2a].

Multiple endocrine neoplasia (MEN)2a is known to be genetically linked to a locus on chromosome 10. The application of polymorphic DNA probes (RFLP) for the region made presymptomatic diagnosis possible. The validity and significance of genetic diagnosis has been proved in Caucasian MEN2a families in terms of early diagnosis and cure. In addition, non-carriers of the gene can be discriminated with a high degree of certainty and can be relieved from years of conventional screening program. An example of genetic diagnosis in a Japanese MEN2a family is shown. DNA analysis was done employing MEN203 as a probe. The usefulness of genetic diagnosis was confirmed in Japanese as well as Caucasians. Clinical consideration in carrying DNA analysis and the future of genetic diagnosis is also discussed.

Adult↗

The significant enhancement of fibrinolysis by calcium ion in a cell free system: the shortening of euglobulin clot lysis time by calcium ion.

We investigated the roles of calcium ion (Ca2+) on euglobulin clot lysis time (ECLT) and found that the physiological concentration of Ca2+ significantly (4-5 times) shortened ECLT. The shortening was observed at the concentration of Ca2+ higher than 1.5-2.0 mM. Other divalent cations such as Mg2+, Zn2+ or Mn2+ didn't change ECLT. Anti-tPA antibody or plasminogen activator inhibitor-1 prolonged ECLT in the absence of Ca2+, whereas they had no effect on ECLT shortened by Ca2+. C1 inactivator also had no effect. When barium absorbed plasma was employed, the shortening of ECLT by Ca2+ wasn't observed, whereas it was recovered by the readdition of barium absorbed fraction. When factor X deficient plasma was employed, the shortening of ECLT by Ca2+ was also not observed. Thus, Ca2+ enhances fibrinolysis in a cell free system by a novel pathway in which the presence of factor X is prerequisite.

Absorption↗

[Etiology and management of esophageal varices].

The most common etiogenic disease of portal hypertension that we experience is liver cirrhosis, which accounts for 84% of all cases. In patients with portal hypertension, congestion by portal blood due to cirrhosis causes a rise in portal pressure and development of collateral circulation between the portal system and the postcaval system is observed. Esophageal varices are associated with higher mortality than any other symptom of portal hypertension and are an important consideration in treatment. When emergency endoscopic examination and diagnosis show esophageal variceal bleeding, the varices must be constricted directly using a Sengstaken-Brakemor tube. If hemostasis is maintained, medical and surgical procedures can be performed after the recovery of body strength. Endoscopic Injection Sclerotherapy (EIS) has recently been widely carried out to prevent variceal bleeding and its application is increasing. However, treatment with EIS alone is not sufficient in terms of long-term efficacy, and surgical treatment is effective, especially in patients with gastric varices or splenomegaly. For Child A and B groups, both with good liver function, non-shunting operation, especially, the SUGIURA procedure, shows a marked effectiveness on varices. For group Child C, EIS is selected. The newly-developed Transjuglar Intrahepatic Portasystemic Shunt (TIPS), is being used, recently. For hepatic insufficiency, liver transplantation is expected to be one of the method for future treatment. Cirrhosis is also commonly accompanied by hepatoma, and this must be taken into consideration in treatment.

Catheterization↗

[The association between body mass index and self-assessed symptoms among young women].

Attitudes and behaviours of young women toward dieting and the relationship between body mass index (BMI) and subjective symptoms were studied by a questionnaire survey applied to all the students of a two-year women's college in Sapporo, Hokkaido. The response rate was 96% to yield a total of 608 subjects. 1) Young women showed excessive thinness-oriented attitudes. 2) Over 30 percent of the women reported irregular menstruation, neck pain, fatigue and oversensitiveness to cold. 3) Those who reported oversensitiveness to cold, wearied eyes or stomachache had significantly lower average BMI than those who did not. 4) A U-shaped relationship, with a higher prevalence of complaints of these three symptoms with a low BMI, was shown. Considering these findings, it appears that being excessively thin is related to symptoms and young women's thinness-oriented attitudes are unhealthful.

Adolescent↗

[Reoperation for valvular heart disease: its operative procedure and result].

From April, 1983 to March, 1993, 63 patients (pts) underwent reoperations of valvular heart disease at Tokyo Medical and Dental University Hospital, of which 44 pts had undergone closed mitral commissurotomy (CMC), open aortic or mitral commissurotomy (OAC or OMC) or valvuloplasty, and 17 pts had undergone aortic or mitral valve replacement (AVR or MVR). Valve replacement was performed in 59 pts (mechanical valve replacement; 42 pts, porcine valve replacement; 12 pts), and 2 pts received OMC due to restenosis after CMC. Preoperative diagnosis included restenosis after CMC, OMC or valvuloplasty in 43 pts, bioprosthetic dysfunction after MVR in 10 pts, perivalvular leakage after AVR in 1 pt, valve detachment after AVR in 4 pts (Beçhet 3 pts, infective endocarditis 1 pts). Valve replacement or valvuloplasty was done for another valves in addition to the previously operated valve in 44 pts (72.1%), especially for tricuspid valve. Restenosis after CMC, occurred at 20.6 years after surgery, and restenosis after OMC and valvuloplasty at 13.1 years. Bioprosthetic dysfunction after MVR occurred at 8.5 years. Valve dysfunction of the mechanical valve was not observed. The early operative mortality after reoperations was 11.5% (7 pts) in this series. And 3 pts (4.9%) died in the late follow-up due to cancer in 1 pt and congestive heart failure in 2 pts. A first choice of mechanical valve for redo valve replacement for aortic/mitral valve, and modified AVR using composite graft and proximal double fixation to the fragile annulus seemed to be satisfactory to accomplish better operative results.

Adolescent↗