Evaluation of the superiority of subzero nonfreezing storage using isolated rat hepatocytes.
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Biomedical subjects
Publications and source records attributed to K Ota.
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Representational difference analysis of cDNA (cDNA-RDA) is a PCR-based differential cloning method. It involves hybridization of two populations of cDNA with selective amplification of differentially expressed genes. To isolate the differentially expressed genes during renal development, mRNAs from embryonic kidneys at day 13 (E13) and postnatal kidneys from three-week-old (P3) mice were extracted, and double stranded cDNAs prepared. Double stranded cDNAs were digested with DpnII, adaptor-ligated, and amplified by PCR, using adaptor primer to generate "representative amplicons." These reflect the "representation" of most of the cDNA population. The term "amplicons" denotes amplified PCR product. Among the two populations of cDNA, E13 kidney cDNA was used as a "tester," containing target genes, and P3 kidney cDNA as a "driver," driving the process of subtraction, following which, they were subjected to cDNA-RDA under low stringency conditions. During the first round of cDNA-RDA embryonic globin genes were isolated. To competitively eliminate these genes, plasmid DNAs of globin genes were supplemented into driver, and subjected to the second round of cDNA-RDA. This resulted in the isolation of four cDNA clones: H19 gene, mesoderm-specific cDNA, COL2A1 gene, and a novel cDNA. By Northern blot analyses, the H19 gene and mesoderm-specific cDNA exhibited a high degree of developmental regulation, that is, they were abundantly expressed in E13 kidney, and their expression was barely detectable in P3 kidney. The differential developmental regulation of mesoderm-specific cDNA was confirmed by tissue in situ hybridization experiments. The COL2A1 and novel cDNA were rare transcripts in the embryonic Kidney. However, Southern blot analyses of representations indicated their up-regulated expressions in E13 kidneys. The novel gene was differentially expressed in 13-day embryonic lung, and Northern blot analysis revealed an approximately 10 Kb transcript. These results indicate that cDNA-RDA is a sensitive technique to identify rare transcripts with differential expression, and since there is a minimal chance to isolate false positive clones, cDNA-RDA may serve as a powerful tool for delineating up- or down-regulation of the genes involved in various pathological or physiological states of the kidney.
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Tubulointerstitial nephritis antigen (TIN-ag) is an extracellular matrix (ECM) glycoprotein that has been recently isolated and cloned from the rabbit kidney. It is an integral component of the basal lamina, and unlike other basement membrane proteins it is exclusively expressed in the tubular basement membranes (TBMs). Since other ECM glycoproteins have been shown to regulate development of various organ systems, studies were initiated to ascertain its developmental regulation in renal tubulogenesis and glomerulogenesis. Embryonic (day-13 and -17 of gestation), newborn and one-week-old mice kidneys were harvested for expression of TIN-ag as well as cDNA cloning studies. Immunostaining with polyclonal anti-TIN-ag antibody revealed its localization to the basal lamina of ureteric bud branches and epithelial elements of developing nephrons in day-13 embryonic kidneys. Interestingly, it was heavily expressed at the tips of the ureteric bud branches, and was not expressed in the distal convolutions of the S-shaped body stage of the nephrons, the region which forms the future glomerulus. At day-17, TIN-ag expression was less, and the immuno-reactivity was mainly localized to the cortex. In the newborn and one-week-old mice kidneys, the cortical expression of TIN-ag increased progressively, but was absent in the glomeruli. The TIN-ag expression was confined to the cortical TBMs, while absent in the medullary tubules, the latter included segments of the collecting ducts and loop of Henle. Immunoprecipitation studies on [35S]methionine-labeled metanephroi revealed a single band of approximately 58 kDa at day-13, and the incorporated radioactivity decreased at day-17. No high molecular weight isoforms were observed. A partial-length mouse TIN-ag cDNA of approximately 530 bp PCR product was generated, and it had approximately 88% and approximately 93% nucleotide and amino acid sequence homolgy, respectively, with rabbit TIN-ag. Utilizing this cDNA, Northern blot analyses revealed a single transcript of approximately 2 Kb in fetal and postnatal mice kidneys. mRNA expression initially decreased at day-17, and then progressively increased by one week. Utilizing a mouse TIN-ag riboprobe, in situ hybridization studies revealed a generalized diffuse expression of TIN-ag in the epithelial clements of developing nephrons and ureteric bud branches at day-13. Gene expression decreased by day-17, and became confined to the renal cortex, and then progressively increased during the neo- and post-natal periods, but remained absent in the renal medulla and glomeruli. These data indicate that TIN-ag is expressed in the metanephros early in embryonic life in the absence of any detectable isoforms, and it exhibits spatio-temporal characteristics during metanephric development. Being concentrated at the tips of the ureteric bud branches, it is conceivably involved in epithelial:mesenchymal interactions which are highly prevalent during renal organogenesis, and its role in tubulogenesis diverges from glomerulogenesis at the S-shaped body stage of the nephron.
The incidence and the risk factors of hemorrhage from gastric fundal varices (FV) have not been fully evaluated. We therefore conducted a retrospective and prospective study to define the incidence and risk factors for such episodes. We investigated 132 patients with cirrhosis and gastric FV. Of these 132 patients, 15 patients had hemorrhagic FV at the time of enrollment. The clinical characteristics were compared between these patients and those without a first hemorrhage from FV. In the patients who had never previously bled, the incidence and risk factors were prospectively investigated. The size of FV was greater and red-spot on the FV were more prevalent in patients with hemorrhagic FV. Child's status was also more severe in these patients. In the 117 patients who had never bled, 34 hemorrhages from FV occurred during the follow-up period. The cumulative risk for such hemorrhage at 1, 3, and 5 years was 16%, 36%, and 44%, respectively. A multiple regression analysis (Cox's model) revealed the size of varices, red-spot on the FV, and Child's status to be statistically significant, as well as independent predictors for hemorrhage from FV. The endoscopic criteria (size of the largest varix and presence of red-spot), as well as the hepatic functional reserve, provide the most essential information for predicting a hemorrhage from FV. An estimation of the probability for hemorrhage from FV based on Cox's model may therefore be beneficial in the clinical management of patients with high-risk FV.
Adult pig pancreatic endocrine cells were harvested by autodigestion without added enzymes. The isolated, crude cells were purified by mono-poly resolving medium (MPRM). The purity of the harvested cells was determined by dithizone staining and the number of pancreatic endocrine cells was counted. A large number of the cells were stained red with dithizone and showed a high viability and a good insulin secretory response to glucose stimulation. The average number of cells purified by MPRM was 3.40 +/- 1.32 x 10(5) cells/g pancreas and the number of dithizone-stained cells was 2.81 +/- 1.09 x 10(5) cells/g pancreas. The insulin secretion from the pancreatic endocrine cells was maintained throughout a 40-day observation period and high glucose stimulation induced an increase in insulin secretion from the cultured cells. In the cells purified by MPRM, light and electron microscopic studies showed the cells to be typical pancreatic endocrine cells. The present purification method using MPRM allowed us quickly to obtain a large amount of adult pig pancreatic endocrine cells from the unpurified preparations. It is thought to be useful for transplantation and biochemical or biological studies of adult pig pancreatic endocrine cells.
Nephrotic syndrome due to focal segmental glomerulosclerosis (FGS) frequently recurs even after renal transplantation and may cause renal allograft failure. From January 1983 though April 1995, 11 adult recipients with primary FGS received 11 kidney transplants at our institution, and 3 of them were treated with pretransplant plasma exchange (PE). Other patients did not receive any preoperative PE, and 4 patients lost their grafts due to recurrent FGS (50%). PE was completed 3 times before the transplantation to prevent posttransplant recurrence of FGS. Two recipients did not have any proteinuria or graft dysfunction without posttransplant PE. One patient had mild proteinuria immediately after transplantation, and histological examination showed recurrent FGS. The patient has been undergoing PE once a month (2 years posttransplant). Her renal function is excellent (sCr 1.2 mg/dl), and her FGS is being well controlled by PE. PE seems to be effective for the prevention of the recurrence of FGS following renal transplantation.
The single neuron activity in the anteroventral region of the third ventricle (AV3V) was extracellularly recorded in urethan and alpha-chloralose anesthetized rats. Electrical stimulation of the medial preoptic area (mPOA) and the paraventricular nucleus (PVN) revealed a reciprocal neural connection between the AV3V and these hypothalamic nuclei with an ipsilateral preponderance. All the AV3V neurons, which were antidromically activated by the stimulation of the mPOA or the PVN, altered their activity after the systemic injection of interleukin (IL)-1beta. On the other hand, only about 60% of the AV3V neurons that showed orthodromic responses were affected by IL-1beta. In seven of nine AV3V neurons that were electrophysiologically identified to send their axons to the mPOA or the PVN, the recombinant human IL-1beta-induced excitation and inhibition were attenuated by a local application of sodium salicylate through multibarreled micropipettes. These results suggest that the AV3V neurons alter their activity in response to the blood-borne IL-1beta, at least in part, through a local synthesis of prostanoids and then send the information to the mPOA and PVN.
The effects of tumor necrosis factor (TNF)-alpha and -beta on the spontaneous firing rate of ventromedial hypothalamic (VMH) neurons were examined in rat brain slice preparations. Of 89 neurons, 36 (40%) showed a decrease in the firing rate to -78.2 +/- 4.0% (n = 36, mean +/- SE) of the preapplication level after a bath application of 20 ng/ml (approximately 1.2 nM) of TNF-alpha. This response to TNF-alpha still persisted in a low-Ca2+, high-Mg2+ medium. Six (7%) of the 89 neurons were excited and 47 (53%) were unaffected by TNF-alpha. The inhibitory responses induced by TNF-alpha were abolished in a solution that contained sodium salicylate (1.9 x 10(-8)M). In contrast, TNF-beta at a dose of 20 ng/ml (approximately 1.1 nM) increased the firing rate to +39.2 +/- 6.5% (n = 11) of the preapplication level in 11 (24.5%) of 45 VMH neurons. Two of the 45 neurons (4.5%) were inhibited and 32 (71%) were unaffected by TNF-beta. The threshold concentration of TNF-alpha to alter the VMH neuron activity was lower than that of TNF-beta. Heat-inactivated TNFs were without effect. These findings suggest that TNF-alpha and -beta act as neuromodulators in the VMH, at least partly through prostaglandin synthesis, and differentially modulate the VMH neuron activity.
Platelet-derived growth factor (PDGF) is an important mitogenic factor for various cells. In order to elucidate the role of PDGF in the development of human glomerulonephritis, we examined the gene and protein expression of the PDGF-B chain (PDGF-B) and PDGF-beta receptor (PDGFR-beta) in renal biopsy specimens from patients with various forms of glomerulonephritis using a nonradioactive in situ hybridization and an immunohistochemical technique. The mRNA expression of PDGF-B and PDGFR-beta was significantly increased in the glomeruli of patients with mesangial proliferative glomerulonephritis (IgA nephropathy, Henoch-Schönlein purpura nephritis, and lupus nephritis) compared with those in normal glomeruli. In cases with increased protein expression of PDGF-B and PDGFR-beta, each mRNA expression was also increased. The degree of glomerular injury was positively correlated with the number of mRNA-positive cells for both PDGF and PDGF receptor. There was also a positive correlation between the number of mRNA-positive cells for PDGF-B and PDGFR-beta. PDGF-B and PDGFR-beta were also expressed on cells of the capillary wall, cellular crescents and infiltrated cells in the interstitium. The results suggest that PDGF acts as an important and common mediator for the development of various forms of human mesangial proliferative glomerulonephritis. Furthermore, PDGF may participate in crescent formation and tubulo-interstitial injury.
The impact of hepatitis B virus (HBV) infection on the outcome of renal transplantation (Tx) has been controversial. To determine the indication of renal Tx in patients infected by HBV, we investigated the long-term outcome of renal transplant patients with hepatitis B surface antigen (HBsAg). We analyzed 980 patients, including 18 HBsAg carriers, who underwent renal Tx and were immunosuppressed with cyclosporin in our institute. Fourteen out of 18 patients (77.8%) showed hepatic dysfunction after an average period of 17.8 months (range 1-65) after Tx. Four out of 14 patients (28.5%) with hepatic dysfunction died of liver failure due to fulminant hepatitis with functioning grafts between 15 and 71 months after Tx. The remaining 10 patients with hepatic dysfunction are alive up to the time of last follow-up; however, 5 of them lost their grafts because of rejection between 44 and 92 months after Tx. Their liver function improved after withdrawal of cyclosporin. Only 4 patients did not develop chronic liver disease and have had functioning grafts for between 44 and 147 months. One patient died of subarachnoid hemorrhage 22 months after Tx. HBe antigen, antibody and HCV antibody status were not related to the occurrence of liver dysfunction after Tx. Four HBV-DNA-positive patients showed deteriorated liver function. Three patients with chronic active hepatitis confirmed by the biopsy were treated with interferon. Interferon improved liver function in 2 patients, however, 1 patient died of liver failure despite interferon therapy. Our data suggested that the presence of HBsAg is often associated with chronic liver disease leading to liver failure regardless of HBe and HCV status after Tx. The indication of renal Tx in patients with HBsAg should be determined carefully giving consideration to these results.
The release of arginine vasopressin (AVP) and atrial natriuretic hormone (ANH) and their involvement in renal water and electrolyte metabolism in primary aldosteronism in humans were studied. An oral acute water load (20 ml/kg body weight) was given to each of 12 patients before and after surgical removal of their aldosterone-producing adenoma(s). Plasma AVP and ANH were measured simultaneously, and renal water and electrolyte metabolism and tubular functions were determined. The same water load was given to seven normal subjects and the same parameters were determined. In the presence of mineralocorticoid excess before the operation, plasma AVP was relatively low compared with plasma osmolality (Posm), but was not suppressed in response to decreases in Posm after the water load. Baseline plasma ANH was high and increased further after the water load; urinary dilution and diuresis both remained normal. After the operation, baseline plasma AVP was normal and decreased in response to the decrease in Posm after the water load, with normal urinary dilution and diuresis. Baseline plasma ANH was normal, and did not increase after the water load. The ratio of urinary K and Na clearances and distal tubular reabsorption of Na increased before the operation. These results suggest that there are perturbations of AVP and ANH release in primary aldosteronism, despite the normal urinary dilution after a water load.
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Neo red cell (NRC) was derived from outdated human red cells. The following experimental work has been done in order to investigate if NRC is valid for organ preservation. Hearts were obtained from male Lewis rat (250-350 g body weight). Heart transplantation was performed as Ono-Lindsey's method after 1, 3, 6, 12 and 24 hours simple cold storage. Rats were divided into two groups. Group 1; original NRC as preservation solution, Group 2; modified NRC (NRC suspended with UW solution) as preservation solution. After 1, 3, and 6 hour cold ischemic storage, the transplanted hearts in both groups showed contraction immediately after declamping the aorta and the pulmonary artery. After 12 and 24 hour preservation, the transplanted hearts in group 2 showed contraction. Myocardial ATP levels after 6, 12, 24 hours cold storage compared with 0 hour were 62.3%, 28.3%, 32.8% in group 1 respectively. On the contrary, myocardial ATP levels were 87.2%, 57.6%, 52.2% in group 2 respectively. After 24 hour preservation, pathological change was not remarkable between the two groups. Results of the prolonged preservation time and the myocardial ATP changes suggest that there is a possibility for effective use of NRC not only as blood substitute but also organ preservation solution.
The expression of MHC class II molecules is normally restricted to antigen presenting cells. Aberrant expression of class II molecules, however, was detected in the thyrocytes of autoimmune thyroid diseases. We attempted to regulate the expression of HLA-DR molecules in thyroid carcinoma cells by expressing the exogenous poly(ADP-ribose) synthetase gene. We transfected a metal inducible expression plasmid capable of expressing poly(ADP-ribose) synthetase gene into thyroid carcinoma 8505C cells and the transformants, treated with metal and IFN-gamma, were separated by Magnetic Cell Separation. The activity of the synthetase was increased in the HLA-DR-enriched transformants as compared with that in control or the HLA-DR+ transformants. RNA blot analysis and flow cytometric analysis revealed that the IFN-gamma-inducible expression of HLA-DR molecules was depressed by the induction of exogenous poly(ADP-ribose) synthetase gene. This result indicates that HLA-DR expression was correlated with the level of poly(ADP-ribose) synthetase in human thyroid carcinoma cells. Furthermore we examined the level of poly(ADP-ribose) synthetase in patients with autoimmune thyroid diseases. We observed a significant decrease in poly(ADP-ribose) synthetase in the patients. Taken together with the previous observation, the decrease in poly(ADP-ribose) synthetase is closely linked to the aberrant expression of HLA-DR molecules in some autoimmune thyroid diseases.
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A phase I study with TUT-7, a new anthracycline antitumor antibiotic, was conducted in 35 malignant tumor patients at 11 institutions nationwide. The study was initiated with a single dose at 100 mg/body which was equivalent to 2n, then the dose as escalated up to 700 mg/body in accordance with the modified Fibonacci's scheme. The dose limiting factor (DLF) was considered to be leukopenia, and maximum tolerated dose (MTD) was 700 mg/ body. The consecutive days dosing study subsequently conducted started with 25 mg/body/day, and the dose level was escalated up to 150 mg /body/day. TUT-7 was orally administered for seven (7) to fourteen (14) consecutive days in principle. It was considered that DLF was leukopenia and MTD was 100 mg/body/day for consecutive days dosing. The study indicated that serum drug concentrations reached their plateaus on the 5th day after initiation of TUT-7 treatment and the accumulation of this compound was low. With these findings, a regimen with a dose of 100 mg/body/day orally administered for 14 consecutive days was recommended for early phase II studies.
An early Phase II study with TUT-7 (menogaril), a new anthracycline antitumor antibiotic, was conducted in patients with various malignant tumors at 81 departments of 65 institutions nationwide. One course of TUT-7 treatment consisted of seven (7) or fourteen (14) consecutive days of administration at 75 or 100 mg/body/day with two-week drug withdrawal; at least two courses of treatment were given in principle. Among the 165 patients registered, 145 patients were eligible and 128 patients were evaluable for antitumor efficacy. In 11 patients with malignant lymphoma, one (1) had CR and five (5) had PR (54.5%); in three (3) patients with prostate cancer, one (1) had PR (33.3%); and in 12 patients with uterine cervical cancer, two (2) had PR (16.7%). Adverse drug reactions frequently observed were digestive organ disorders (anorexia and nausea/vomiting) and malaise. The abnormality in laboratory tests observed frequently was myelosuppression (leukopenia and neutropenia).