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Biomedical subjects

J Eguchi

Publications and source records attributed to J Eguchi.

26 records · Page 2Linked to original sources
PubMed1993

Peritubular endothelial cell proliferation in mice during compensatory renal growth after unilateral nephrectomy.

The proliferation of peritubular endothelial cells during compensatory renal growth (CRG) following unilateral nephrectomy in mice was investigated using a labeling index. The labeling index of peritubular endothelial cells increased 6 h after uninephrectomy and decreased to the normal level within 72 h. Immunohistochemical study revealed that c-myc protein was expressed in the nuclei of both cortical tubular cells and peritubular endothelial cells. Furthermore, intravenous injection of anti-basic fibroblast growth factor (bFGF) neutralizing antibody just after uninephrectomy led to significant inhibition of proliferation of peritubular endothelial cells, but not tubular cells. These results indicate that peritubular endothelial cells proliferate transiently during CRG and that bFGF plays an important role for the growth regulation of that cell in the kidney.

Animals↗
PubMed1993

Transforming growth factor-beta in rat kidney during compensatory renal growth.

Transforming growth factor-beta (TGF-beta) inhibits the DNA synthesis and stimulates the alkaline phosphatase activity of cultured renal cortical tubular cells. When unilateral nephrectomy was performed, TGF-beta activity content gradually decreased in the remaining kidney. An immunohistochemical study of the remaining kidney after uninephrectomy, however, showed that the expression of TGF-beta increased by the third day after uninephrectomy in the proximal tubular cells and an autoradiographic study revealed that TGF-beta expressing tubular cells were different from proliferating cells during compensatory renal growth. These results indicate that the total renal TGF-beta content decreases after uninephrectomy, while the expression of TGF-beta in the proximal tubular cells may increase and act as a brake for compensatory renal hyperplasia.

Adaptation, Physiological↗
PubMed1992

Gene expression and immunohistochemical localization of basic fibroblast growth factor in renal cell carcinoma.

Renal cell carcinoma is known as a neoplastic condition of renal tubular cells and usually shows a hypervascular tumor in angiographic examination. We examined the presence of basic fibroblast growth factor (bFGF) in human renal cell carcinoma. To determine if alterations in bFGF gene expression are present in human renal cell carcinoma, paired samples of normal and neoplastic renal tissue from 6 patients were analyzed for bFGF mRNA content by Northern blot hybridization. In 4 out of 6 patients, tumor tissue expressed bFGF mRNA 2 to 4 times greater than corresponding normal tissue. Two patients showed minimal elevation of tumor bFGF mRNA. The localization of bFGF in the renal cell carcinoma tissue was also examined using immunohistochemical staining, and it was found that bFGF was positively stained at the nuclei of tumor cells and the cell surface. These results suggest that increased expression of bFGF may be associated with neoplastic growth in renal tubular epithelial cells and neovascularization.

Aged↗
PubMed1990

Relationship between ventilation and arterial potassium concentration during incremental exercise and recovery.

The purpose of this study was to compare the relationship of ventilation (VE) with pH, arterial concentrations of potassium [( K+]a), bicarbonate [( HCO3-]a), lactate [( la]a), and acid-base parameters which would affect hyperpnoea during exercise and recovery. To assess this relationship, ten healthy male subjects exercised with intensity increasing as a ramp function of 20 W.min-1 until voluntary exhaustion and they were then allowed a 5-min recovery period. Breath-by-breath gas exchange data, [HCO3-]a, pH, [la]a, [K+]a and blood gases were determined during both exercise and recovery. Using a linear regression method, the VE/[K+]a relationship was analysed during both exercise and recovery. Several interesting results were obtained: a significant relationship between [K+]a and VE was observed during recovery as well as during exercise; the VE at any given values of [K+]a was significantly higher during recovery than during exercise and out of those factors affecting exercise hyperpnoea, only [K+]a had a similar time-course to VE during recovery. Changes in [K+]a during recovery were shown to occur significantly faster than VE with an [K+]a time constant of 70.0 s, SD 16.2 as opposed to 105.5 s, SD 10.0 for VE (P less than 0.01). These results provided further evidence that [K+]a might play an important role as a substance which can stimulate exercise hyperpnoea as has been suggested by other workers. The present study also showed that during recovery [K+]a contributed significantly to the control of VE.

Adult↗
PubMed1987

Acute blasticidin S poisoning.

Blasticidin S is an effective fungicidal aminocylonucleoside antibiotic against a rice blast disease. We presented the first 4 reported cases of acute poisoning from ingesting blasticidin S for suicidal attempts. Three of the patients were fatal. The symptoms observed in the patients included vomiting immediately after ingestion and severe, persistent, watery diarrhea. The toxic effects of blasticidin S were noted in ectodermal tissues including the skin, conjunctiva, cornea, and intestine. Massive loss of intestinal fluid resulted in progressively pronounced hypotension associated with tachycardia. The treatment of choice for the poisoning consists of intravenous fluid administration and the management of body water and electrolyte balance.

Adult↗
PubMed1985

Oxidation of biological membranes and its inhibition. Free radical chain oxidation of erythrocyte ghost membranes by oxygen.

The oxidation of human and rat erythrocyte ghost membranes by molecular oxygen has been performed in an aqueous suspension at 37 degrees C. A constant rate of oxygen uptake was observed in the presence of radical initiator. alpha-Tocopherol in the membrane suppressed the oxidation and the induction period was clearly observed. alpha-Tocopherol decreased linearly during the induction period and when it was depleted the induction period was over and a rapid oxidation started. The rate of oxidation was proportional to the square root of the rate of initial radical generation. The kinetic chain length, the ratio of the rate of propagation to that of initiation, was long, ranging from 7 to 100. These results indicate that the erythrocyte ghost membranes are oxidized by a free radical chain mechanism by molecular oxygen. Among the fatty acids of membrane lipids, polyunsaturated fatty acids were oxidized exclusively. Proteins as well as polyunsaturated fatty acids were oxidized and the formation of the high- and low-molecular-weight proteins and the decrease of protein bands were observed on gel electrophoresis.

Amidines↗
PubMedDate not supplied

NF-kappa B and I-kappa B overexpression in articular chondrocytes with progression of type II collagen-induced arthritis in DBA/1 mouse knees.

OBJECTIVE: To investigate the roles of NF-kappa B and I-kappa B in chondrocytes in the cartilage destruction of mouse collagen-induced arthritis. METHODS: DBA/1 mice were immunized with bovine type II collagen (C II) emulsified with Freund's incomplete adjuvant. Histological abnormalities in the mouse knees were evaluated in sections stained with hematoxylin and eosin, or toluidine blue. Immunostaining using anti-NF-kappa B and anti-I-kappa B antibodies was performed to observe the expression and nuclear shift of NF-kappa B and I-kappa B in articular chondrocytes. RESULTS: Loss of metachromasia of perichondrial cartilage was found in 8 out of 10 knees of the mice at 5 weeks, and in all 10 knees at 7 weeks after C II-immunization. The mean percentage of NF-kappa B-positive chondrocytes at 3, 5 and 7 weeks and in the control was 33.6 +/- 7.6, 54.9 +/- 2.7, 75.9 +/- 1.0 and 27.9 +/- 3.8%, respectively. The mean percentage of NF-kappa B-positive nuclei was 9.1 +/- 0.7, 19.5 +/- 3.7, 47.5 +/- 3.0 and 8.6 +/- 0.1%, respectively. NF-kappa B-positive chondrocytes significantly increased from 3 to 7 weeks in a time-dependent manner (p < 0.0001). The percentage of I-kappa B-positive chondrocytes at 3, 5 and 7 weeks and in the control was 15.5 +/- 1.7, 41.1 +/- 2.5, 51.2 +/- 5.7 and 12.1 +/- 2.1%, respectively. I-kappa B-positive chondrocytes significantly increased from 3 to 5 weeks (p < 0.005). CONCLUSION: These findings suggest that nuclear shift of NF-kappa B localization causes cartilage destruction in the early stage of arthritis in DBA/1 mice immunized with C II.

Animals↗