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Biomedical subjects

H Kawamura

Publications and source records attributed to H Kawamura.

At least 199 records · Page 11Linked to original sources
PubMed1994

A novel type of B-cell mitogen isolated from juzen-taiho-to (TJ-48), a Japanese traditional medicine.

Juzen-taiho-to (TJ-48), a Japanese traditional medicine, is known to have various immunological activities including the induction of B-cell proliferation. We investigated the properties of the pectic polysaccharide fraction of TJ-48 (F-5-2) which is most active in the proliferation of spleen cells. To an extent equal to that of TJ-48, F-5-2 induced the proliferation of B-cells, particularly those holding both sIgM and sIgD. The proliferation induced by F-5-2 was T-cell independent and macrophage dependent. The macrophages could be substituted for a soluble factor(s) secreted from the macrophages but not for IL-1. Generally, B-cell mitogens are known to induce the proliferation of B-cells and subsequently differentiation into plasma cells. However, although F-5-2 induced the B-cell differentiation, it arrested their development in the intermediate stage of the B-cell differentiation. The B-cells induced by F-5-2 produced IgM antibody in response to IL-6 and an antigen (SRBC) but not IgG antibody. F-5-2 induced the expression of IL-6R not only on IgM+ and IgG+ B-cells but also on IgD+ B-cells. These results suggest that F-5-2 is a new type of B-cell mitogen.

Animals↗
PubMed1994

Spontaneous hemarthrosis of the knee in the elderly: etiology and treatment.

The etiology of spontaneous hemarthrosis of the knee in elderly patients with osteoarthritis is still unknown. This report discusses six cases, one that was managed with conservative measures and five in which arthroscopic evaluation and treatment were performed. These patients were elderly individuals whose chief complaint was knee pain and swelling about the joint, without an obvious history of trauma. Each of the five operative patients underwent arthroscopic surgery after repeated hemorrhage into the joint that did not respond to serial aspirations of large amounts of blood and immobilization, using a knee immobilizer. The roentgenograms of each involved knee demonstrated lateral compartment osteoarthritis. Arthroscopic examination revealed a degenerative flap tear of the posterior horn of the lateral meniscus in the five operative cases. These patients underwent arthroscopic resection of the injured lateral meniscus and did not experience a recurrence of the hemarthrosis. The origin of the bleeding was most likely from the peripheral arteries of the posterior horn of the lateral meniscus.

Aged↗
PubMed1994

Fallout radioactivity in soil and food samples in the Ukraine: measurements of iodine, plutonium, cesium, and strontium isotopes.

To estimate the level and distribution of fallout attributable to the 26 April 1986 Chernobyl nuclear power station accident in the Ukraine, we sampled several kinds of substances at Korosten, Zhitomir and at Katyuzhanka, Vishgorod, Kiev in the Ukraine, and measured the radioactivity of 137Cs, 134Cs, 90Sr, 129I, 238Pu, 239,240Pu, and the density of 127I (stable). The substances investigated were soil, dry milk, wheat, rye, drinking water, and mushrooms. Except for the mushrooms collected, which were sampled at Katyuzhanka, Vishgorod, and at Kiev, all substances were at Korosten, Zhitomir. The activity of 137Cs, 134Cs, 90Sr, 238Pu, and 239,240Pu were all higher in soil and mushrooms than in the other four substances. The activity of 137Cs was 960 and 1,210 Bq kg-1 in the two soil samples and 6,110 Bq kg-1 in the mushrooms. The activity of 134Cs was approximately 15% of 137Cs in the two soil samples while < 3% of 137Cs in the mushrooms. The activity concentration level of 90Sr as compared to 137Cs concentration was 15-31% in food samples other than mushrooms but only 1.9% in mushrooms and 1.4 and 1.2% in the two soil samples. The radioactivity ratios, 238Pu: 239,240Pu and 239,240Pu: 137Cs, suggested that the proportion of cesium radioisotopes and 239,240Pu in the soil attributable to the Chernobyl accident was approximately 100% and 10-20%, respectively, while approximately 100% of 239,240Pu in the mushrooms was attributable to the accident. The activity of 129I was small but the ratio of 129I: 127I in the two soil samples was 4.3 x 10(-8) and 1.0 x 10(-7), which is approximately 10 times larger than that in the global fallout. These results suggest that the areas where the soil was sampled are iodine-deficient and were contaminated slightly by the Chernobyl accident.

Accidents↗
PubMed1994

Cancer mortality in low radon spa area.

Recently lower mortality for cancers of all sites was reported among inhabitants in the Misasa spa area, where there is a high radon background. To clarify the effects of radon exposure on cancer mortality, the effects of a hot spring itself on cancer mortality was investigated in the Beppu spa area, which has only a low radon background, and adjacent control areas. For females, the mortalities for cancers of all sites, liver and lung were higher in Beppu than those for all Japan on the basis of the standardized mortality ratio (SMR), while the SMR for all cancers was lower in adjacent areas. For the male inhabitants in both areas the cancer mortalities of all sites were not significantly different from those of all Japan. When we directly compared the most typical spa areas in Beppu and an adjacent control area, a Poisson regression analysis did not show that the relative risk of dying from cancer of all sites was decreased in the spa areas. These results are thus consistent with the view that the lower cancer mortality in the Misasa spa area might be related to exposure to low levels of radon.

Adult↗
PubMed1994

Transcription stimulation of the adenovirus type 12 E1a gene in vitro by the 266-amino-acid E1A protein.

We previously showed that the 13S but not the 12S mRNA product of the E1a gene of the highly oncogenic type 12 adenovirus (Ad12) stimulates the expression of its own gene. In this study, the mechanism for the autoregulation of the Ad12 E1a gene was investigated in vitro. The 266-amino-acid E1A protein of Ad12 was synthesized in yeast cells and purified as a 57-kDa polypeptide. The purified Ad12 E1A protein stimulated transcription from the proximal promoter of its own gene but had almost no effect on that from the distal promoter. A 35-bp upstream region including a TATA box for the proximal promoter seemed to be sufficient for transcription stimulation by the E1A protein. The Ad12 E1A protein formed a complex with a TATA box-binding protein (TBP), as does the E1A protein of nononcogenic Ad serotypes. Moreover, the E1A protein significantly reduced the binding of TBP to a TATA sequence, while it did not affect the DNA-binding activity of nuclear factor I, a stimulatory protein of the distal transcription of the Ad12 E1a gene. These results suggest that the 13S mRNA product of the Ad12 E1a gene regulates the transcription of its own gene by modulating the activity of TBP.

Adenovirus E1A Proteins↗
PubMed1994

An image-guided stereotactic system for neurosurgical operations.

A new simulation system utilizing digital images (CT/MRI/SPECT) and an ultrasound/laser navigation system has been developed for image-guided surgery. Preoperative CT/MRI imaging does not always indicate the actual location of the lesion during intracranial operation, because the lesion may be displaced or distorted by operative procedures or CSF flowout. The authors developed an image integration system including an intraoperative ultrasonogram, which provides accurate information not only on the location of the deep-seated lesions but also surrounding anatomical structures during operation. The rationale of the system is to coordinate the three-dimensional axes of each image with the aid of a stereotactic subframe. Our simulation system has two ways. One simulation system works on a SUN workstation. At the preoperative simulation study: the entry point on the brain surface and the access route to the lesion are decided on from the three-dimensional CT/MRI images on the computer display. Then the configuration of the lesion from the operative view is displayed as an expected ultrasound image by reconstructing the CT and/or SPECT image. Another simulation system (HyperCAS) works on the HyperCard of a MacIntosh. The target point, the entry point and the trajectory are decided on and the three-dimensional location of these points is measured from serial CT images on the LCD display. At the time of operation, stereotactic craniotomy is performed using the laser navigator. The extent of the lesion at every depth in the surgical process is predicted from these images, and the access route to the lesion is easily corrected with the intraoperative ultrasound navigator.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Simulation↗
PubMed1994

Purines. LXII. Both enantiomers of N6-(1,3-dimethyl-2-butenyl)adenine and their 9-beta-D-ribofuranosides: synthesis and cytokinin activity.

Both enantiomers [(1'R)-6 and (1'S)-6] of N6-(1,3-dimethyl-2-butenyl)adenine and their 9-beta-D-ribofuranosides [(1"R)-16 and (1"S)-16] have been synthesized for the first time from both enantiomers of alanine (15) in nine steps. These aglycones and nucleosides, together with N6-(3-methyl-2-butenyl)adenine (5) and its 9-beta-D-ribofuranoside (18) as well as 9-beta-D-ribofuranosyl-cis-zeatin (20) and 9-(2-deoxy-beta-D-ribofuranosyl)-cis-zeatin (19), were tested for cytokinin activity in the tobacco callus bioassay. The order of their activity was 5 > (1'R)-6 > (1"R)-16 approximately 18 > (1'S)-6 > (1"S)-16 > 20 > 19. The bioassay results are compared with those obtained previously for the derivatives modified analogously in the N6-substituent in the cis- and trans-zeatin series.

Adenine↗
PubMed1994

Detection of the antibodies against porcine cytomegalovirus from whole blood collected on the blood sampling paper.

The usefulness of blood sampling paper for the detection of antibodies against porcine cytomegalovirus (PCMV) by enzyme-linked immunosorbent assay (ELISA) was examined. The PCMV antibody titer of whole blood collected on the paper agreed with that of serum and the absorbances of the corresponding samples were well correlated (r = 0.88). Blood was collected from 26 piglets in the field on the blood sampling paper and ELISA was performed. The maternal PCMV antibody of these piglets decreased during the 8 weeks after birth and IgM antibody against PCMV was detected in four piglets.

Aging↗
PubMed1994

Glucose effectiveness in two subtypes within impaired glucose tolerance. A minimal model analysis.

To clarify the event that is involved in the pathogenesis of impaired glucose tolerance (IGT), we studied 15 individuals with IGT and 15 subjects with normal tolerance using the minimal model approach. Our IGT subjects were characterized by normal insulin secretory responses to oral glucose and mild impairments in insulin sensitivity (SI) and glucose effectiveness (SG) at basal and zero insulin. Next, we classified our IGT subjects into two subpopulations: one with normal insulin sensitivity (SI: 0.92 +/- 0.11 x 10(-4) min-1.pmol/l-1 and the other with insulin resistance (SI:0.31 +/- 0.06 x 10(-4)min-1.pmol/l-1, P < 0.05). The populations did not differ with respect to body mass index and fasting plasma glucose level. Basal plasma insulin level was higher in the insulin-resistant group (84.8 +/- 23.3 pmol/l) than in the insulin-sensitive group (48.7 +/- 6.8 pmol/l), but the difference was not statistically significant. The absolute insulin secretory responses to oral glucose were significantly higher in the resistant group (83,205 +/- 17,787 pmol/l x min) than in the sensitive group (24,727 +/- 3,591 pmol/l x min, P < 0.01), whose absolute responses were similar to those of normal control subjects (24,576 +/- 2,767 pmol/l x min). No significant difference was observed in SG between the resistant (0.016 +/- 0.002 min-1) and sensitive (0.013 +/- 0.002 min-1, P > 0.05) type of IGT, but SG was significantly type of IGT, but SG was significantly decreased in both groups compared with normal control subjects (0.023 +/- 0.002 min-1, P < 0.05-0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Effect of calcium antagonist (benidipine) and alpha 1 blocker (urapidil) on renal hemodynamic responses to two acute environmental stresses in spontaneously hypertensive rats (SHR)].

Renal hemodynamic responses were studied in spontaneously hypertensive rats (SHR) and Wistar-Kyoto Rats (WKY) to two acute stresses: environmental stress (foot shock (FS) and air jet (AS)). The effects of calcium channel blocker (benidipine) and alpha 1 blocker (urapidil) on these responses were studied using an ultrasonic pulsed Doppler flowmeter. The increments in mean arterial pressure (MAP) and renal vascular resistance (RVR) were greater in SHR during both stresses. On the other hand, the decrease in the renal blood flow (RBF) with these stresses almost disappeared with renal denervation. These renal hemodynamic responses in SHR disappeared with alpha 1 blocker (urapidil), but not with calcium channel blocker (benidipine). The sympathetic nervous system became hyperactive in SHR under environmental stress, Which induced specific renal hemodynamic change. These results suggest that investigations on essential hypertension should focus on clarifying not only systemic hypertensive reaction, but also changes in renal hemodynamics. Furthermore, it is necessary for antihypertensive therapy to take these hemodynamic changes into consideration.

Acute Disease↗
PubMed1994

[Duplication of the inferior vena cava with left renal cell carcinoma].

A case of duplication of the inferior vena cava (IVC) with left renal cell carcinoma is presented, and the clinical and radiological significance is discussed. Although computed tomographic (CT) scanning, inferior venacavography and renal venography revealed a sufficient amount of anatomical information, an accidental rupture to the inferior vena cava occurred during the procedure. The patient subsequently required 7 units of blood, and suffered acute hepatitis two months following the blood transfusion. However, no recurrences of renal cell carcinoma and hepatitis have been observed four year after the procedure.

Carcinoma, Renal Cell↗
PubMed1993

Phosphorylation of NF-I in vitro by cdc2 kinase.

Nuclear factor I (NF-I) was purified to near homogeneity from Ehrlich ascites tumor cells. Mouse NF-I consisted of two peptides with relative molecular masses of 53 and 55 kDa and bound to the authentic NF-I site of the adenovirus DNA with no significant affinity with the CCAAT box. The purified protein was efficiently phosphorylated in a reaction containing immunoprecipitates with an anti-cdc2 kinase antibody. This phosphorylation was abolished when a synthetic peptide containing the consensus phosphorylation site by cdc2 kinase was added in excess to the reaction. These findings indicate that mouse NF-I is phosphorylated in vitro by the cdc2 protein kinase.

Animals↗