Biomedical subjects

T Jin

Publications and source records attributed to T Jin.

At least 109 records · Page 6Linked to original sources

PubMed1992

Inconsistent expression of glycolipid sulfotransferase activity between hepatoma and serum.

Glycolipid sulfotransferase activity in human and rat hepatocellular carcinoma tissues was studied, since an elevated level of the enzyme activity in serum had been demonstrated in cancer patients. The level of the enzyme activity in carcinoma tissues, however, could not be distinguished from that of normal controls. Similar observations were made for rat hepatoma. A higher level of enzyme activity was observed in the female than in the male. Inconsistent expression between hepatoma tissue and serum suggests that humoral factor(s) derived from hepatoma tissue stimulates production of the sulfotransferase, which is released into the blood-stream in the host.

Animals↗

PubMed1992

Cadmium, metallothionein and renal tubular toxicity.

Cadmium-induced nephrotoxicity develops at cadmium concentrations in the renal cortex of 10-300 micrograms/g wet weight. The actual concentration at which it develops depends on a number of factors, e.g., exposure route, chemical species of cadmium administered, rate of administration and simultaneous exposure to other metals. The role of these factors can be explained by a mechanism of cadmium nephrotoxicity in which both extracellular and intracellular metallothionein binding play an essential role. In reindeer used for human food, cadmium was shown to be bound to metallothionein-like proteins. If cadmium bound to such proteins enters the blood plasma via the gastrointestinal tract, this is of special toxicological significance. Metallothionein-bound cadmium in the plasma of experimental animals is efficiently transported to the kidney. Tubular dysfunction in the kidney following a normally tubulotoxic dose of cadmium bound to metallothionein was prevented by preinduction of metallothionein synthesis by small non-toxic doses of cadmium.

Animals↗

PubMed1992

[Clinical evaluation of prostaglandin E1 during anesthesia in non-elderly and elderly patients].

The effects of prostaglandin E1 (PGE1) on blood pressure during anesthesia and the postoperative changes in organ functions were examined and compared in 358 cases. Two hundred and eighty patients were under 64 years of age and 128 patients were over 65 years. It was possible to control blood pressure satisfactorily with PGE1 in both non-elderly and elderly groups. However in the elderly group, it was more difficult to control blood pressure with PGE1 under NLA as compared with enflurane anesthesia. In both groups, urinary flow increased during and after the administration of PGE1, and the livers and kidneys showed neither dysfunction nor deterioration after operation. We had very few incidences of side effects with this drug. PGE1 is also considered safe and useful for elderly people during and after surgery.

Adolescent↗

PubMed1992

Use of immunoadsorbent column chromatography for improved purification of arylsulfatase B from human placenta.

A simple and rapid procedure involving immunoadsorbent column chromatography has been developed for the isolation of lysosomal arylsulfatase B from human placenta. Using this method, we purified the enzyme over 20,000-fold with better recovery (16%) compared to that achieved by the conventional procedure. The enzyme appeared to be homogeneous and had an apparent molecular weight of 58,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions. The purified enzyme migrated as two bands with apparent molecular weights of 43,000 and 8,000 by reductive SDS-PAGE.

Chondro-4-Sulfatase↗

PubMed1991

Elevated serum level of glycolipid sulfotransferase in patients with hepatocellular carcinoma.

Activity of glycolipid sulfotransferase (cerebroside sulfotransferase) in serum was elevated in 21 (33%) of 63 patients with hepatocellular carcinoma (HCC, mean +/- S.E., 349 +/- 32 pmol/ml per h, n = 63, P less than 0.001) compared to healthy subjects (172 +/- 12, n = 85). Ho significant elevation of the sulfotransferase level was observed in liver cirrhosis (219 +/- 28, n = 10) in which many of biochemical HCC markers increase concomitantly. The elevation of sulfotransferase was independent of the production of alpha-fetoprotein and of aminotransferase levels in HCC, providing complementary value for alpha-fetoprotein-negative HCC cases. However, the sulfotransferase levels (234 +/- 21, n = 32, P less than 0.01) in sera from patients with renal cell carcinoma, in whose involved tissues the enzyme was demonstrated to increase markedly, were less than in HCC.

Carcinoma, Hepatocellular↗

PubMed1991

The interaction of the potato-derived chymotrypsin inhibitor with C3H/10T1/2 cells.

Protease inhibitors have been shown to be effective suppressors of carcinogenesis in vitro and in vivo. For example, the potato-derived chymotrypsin inhibitor 1 (CI-1) suppresses radiation transformation of C3H/10T1/2 cells in vitro. In the current study, we have investigated the interaction of CI-1 with C3H/10T1/2 cells. At the concentrations examined, CI-1 was non-toxic and had no effect on the doubling time or saturation density of these cells. This compound was taken up by these cells in a time dependent manner. Analysis of CI-1 from treated cells on a chymotrypsin affinity column revealed that active inhibitor was present in the cells. Additionally, CI-1, as well as the soybean derived Bowman-Birk inhibitor and chymostatin, blocked the cleavage of the peptide substrate Suc-Ala-Ala-Pro-Phe-MCA by intact C3H/10T1/2 cells. We have previously demonstrated that this substrate will reduce the transformation yield following treatment of cells with ionizing radiation. Our results suggest that CI-1 may inhibit transformation of C3H/10T1/2 cells in vitro by inhibiting the activity of Suc-Ala-Ala-Pro-Phe-MCA hydrolyzing activity in these cells.

Amino Acid Sequence↗

PubMed1988

Role of the 92.5-kilodalton outer membrane protein of Campylobacter jejuni in serological reactions.

Outer membrane proteins from 12 strains of Campylobacter jejuni were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with rabbit antisera prepared against Formalin-treated cell suspensions of three of the strains. The 92.5-kilodalton protein was confirmed to be a minor outer membrane protein and exhibited serological heterogeneity. Serological specificities of the proteins, however, were found not to correlate with serotypic specificities of the strains, as demonstrated by slide agglutination tests with whole-cell suspensions. The results suggested that the 92.5-kilodalton proteins were not likely to be participating antigenic determinants in the immunological reactions that give rise to agglutination of live-cell suspensions in the slide test.

Agglutination Tests↗

PubMed1988

Further studies of swarmer cell differentiation of Proteus mirabilis PM23: a requirement for iron and zinc.

Proteus mirabilis PM23, unlike other motile strains of the species, differentiates in rich fluid media to form nonseptate filaments resembling the swarmer cells formed on solid media. The swarming activity of PM23 is greater than that of the other strains on solid media and it grows faster than another strain, IM47, in differentiation-supporting broth. This faster growth is not exhibited in broth that does not support differentiation. The differentiation of PM23 in brain-heart infusion broth occurs over a wide range of pH and temperature. Inhibitors of swarming on agar plates (p-nitrophenylglycerol and boric acid) and three chelating agents (EDTA, sodium cyanide, and sodium diethyldithiocarbamate) stop differentiation both on plates and in brain-heart infusion broth; however, EGTA is not effective even at 10 mM (10 times the minimum inhibitory concentration of EDTA). The inhibitory mechanisms of p-nitrophenylglycerol and boric acid are different from that of the chelating agents. The timing of EDTA inhibition suggests generation of a "signal" to differentiate after about 2 h growth. Prevention of differentiation by addition of Fe2+ and Zn2+ up to near the time that differentiation should appear suggests that these cations have a crucial involvement in the process of initiation. However, they are not effective as additives in allowing differentiation to occur in defined media or even nutrient broth; the further addition of nucleotides or cAMP was equally ineffective.

Chelating Agents↗

PubMed1987

Influence of cadmium-metallothionein pretreatment on tolerance of rat kidney cortical cells to cadmium toxicity in vitro and in vivo.

Kidney cells were isolated from rats pretreated by daily subcutaneous doses of cadmium metallothionein (CdMT: 0.05-0.2 mg Cd/kg X 5) and from non-pretreated rats. Upon exposure to CdCl2 in vitro (0-200 micrograms Cd/ml), a concentration dependent decrease in viability was observed in the non-pretreated cells, while no such decrease occurred in the pretreated cells indicating that these cells were more resistant to the toxic action of cadmium. There was a higher in vitro uptake of Cd+2 and an increased metallothionein (MT) concentration in the pretreated cells (compared to non-pretreated cells). Subcellular distribution studies revealed that Cd was mainly recovered in the "cytosol" fraction. The higher total cadmium uptake in pretreated cells corresponded to an increase of Cd in "cytosol" and "nuclear" fractions. This observation may be explained by MT-binding of Cd in the cells and is in accordance with a possible protective effect of induced MT in the pretreated cells. In order to assess whether pretreatment-induced tolerance to cadmium toxicity--indicated by the cellular studies--could also be observed in vivo, some whole animal experiments were also performed. A dose-related proteinuria was observed in non-pretreated rats after a single subcutaneous administration of 109Cd-MT at doses of 0.05 and 0.4 mg Cd/kg. Urinary total Cd, 109Cd and MT was also increased in a dose-related fashion. Cadmium concentrations in kidney were dose related and reached 19 micrograms/g wet weight. In contrast, in animals repeatedly pretreated with CdMT according to 1), no proteinuria was observed after administration of the same single doses of 109CdMT. Total Cd. 109Cd and particularly MT-concentrations in urine were lower in such pretreated animals than in in non-pretreated ones in spite of the accumulation of higher tissue concentrations of total Cd (up to 80 micrograms/g). The pretreatment was thus shown to prevent some of the acute nephrotoxicity of CdMT, possibly by means of induction of MT synthesis.

Animals↗

PubMed1987

Resistance to acute nephrotoxicity induced by cadmium-metallothionein dependence on pretreatment with cadmium chloride.

Three groups of rats (B-D) were given various daily doses of CdCl2 (0.5-2 mg Cd/kg) continuously or in intervals during time periods of 1-8 weeks. Another group of animals (A) were kept untreated. At the end of the period, selected subgroups of groups A-D were given a single subcutaneous injection of 109Cd-metallothionein (109CdMT) 0.05 or 0.4 mg Cd/kg ("challenge dose"). Subsequently, urinary creatinine, protein, Cd, 109Cd and MT and kidney cortex Cd, 109Cd and MT were determined. In group A (no long term pretreatment), an increased proteinuria was observed after the rats had received the lower of the challenge doses of 109CdMT, and an even greater increase after the higher challenge dose of 109CdMT. No such increase appeared in group B, C and D (repeatedly pretreated with CdCl2) at either of the challenge doses. Higher metallothionein concentrations in kidney cortex observed in the pretreated groups constitute a plausible explanation of the protective effects of pretreatment against the development of increased proteinuria after challenge dosing. It is likely that increasing Cd concentrations, gradually accumulating in the renal cortex (22-226 micrograms/g wet wt.) as a result of the pretreatment, served to induce the synthesis of metallothionein in the renal cortical cells, thus making them resistant to the challenge from 109CdMT.

Acute Disease↗

PubMed1987

Urease activity related to the growth and differentiation of swarmer cells of Proteus mirabilis.

Urease activity was measured using whole cells of both long (swarming) and short (nonswarming) populations of Proteus mirabilis from casein hydrolysate agar (CHA) and broth (CHB) cultures, and from brain heart infusion broth (BHIB) cultures. Urease is a constitutive enzyme for both long and short cells, but its activity was tremendously increased when urea was incorporated into the media. Urease production was also affected by culture age and media used. Before exponential phase, urease activity was very low, and it increased to its highest point after about 4 h in BHIB and 8 h in both CHA and CHB cultures at 37 degrees C. Long cells had higher urease activity than did short cells when grown on CHA, and was also expressed by two different strains cultured in BHIB. Strain PM23, in BHIB, was able to form long cells (swarming cells) to a maximum proportion after about 4 h, but strain IM47 could not differentiate in any of the liquid media. The former had more urease when swarming differentiation was initiated. PM23 grew relatively faster than IM47 when the former began to differentiate, but this fast growth could not be observed when nutrient broth or minimal medium was used. These observations suggest that long or swarming cells are "faster growing" rather than "nongrowing bacteria".

Kinetics↗

PubMed1986

Uptake of cadmium in isolated kidney cells--influence of binding form and in vivo pretreatment.

Uptake of cadmium as 109CdCl2, 109Cd-cysteine, 109Cd-albumin and 109Cd-metallothionein was studied in isolated kidney cells from rat. Cd as 109CdCl2 and 109Cd-albumin was taken up at similar rates. The uptake of cadmium as 109Cd-cysteine was greater and that of 109Cd-metallothionein lower compared with that of the other substances. These observations were made on non-pretreated cells. In cells taken from rats pretreated with CdCl2 in vivo, the uptake of cadmium as 109CdCl2, 109Cd-cysteine and 109Cd-albumin was lower than in cells from non-pretreated rats. However, the uptake of 109Cd-metallothionein was considerably enhanced in pretreated cells. In pretreated kidney cells the decreased uptake of Cd (as Cd-albumin) might be related to protection of the kidney against acute Cd toxicity and increased uptake of metallothionein-Cd might contribute to the explanation of renal damage in long-term Cd exposure.

Albumins↗

PubMed1986

Cadmium toxicity in kidney cells. Resistance induced by short term pretreatment in vitro and in vivo.

Epithelial cells from the kidney were freshly isolated from rats pretreated by daily subcutaneous doses of CdCl2 in vivo (0.5-2 mg Cd/kg X 5). Such cells were incubated in vitro in media with different concentrations of cadmium chloride (0-200 micrograms Cd/ml). There was no inhibition of cell growth in such cells. However, in cells isolated from non-treated rats, in vitro exposure to the same concentrations of CdCl2 caused a dose dependent decrease in viability. When cells, isolated from non-treated rats were pretreated in vitro with CdCl2 (10 micrograms/ml) and subsequently exposed to cadmium chloride (0-200 micrograms/ml), a protective effect was observed, which was similar to the one observed in cells isolated from animals pretreated with CdCl2. The concentration of metallothionein in the cells treated with cadmium was increased. A lower uptake of cadmium chloride, in vitro has been observed in kidney cells pretreated in vivo or in vitro compared to nonpretreated cells. Subcellular distribution studies indicate that Cd-distribution was similar in pretreated and non-pretreated cells, but concentrations were generally lower in the pretreated cells. The decreased uptake of Cd by pretreated kidney cells is a sign of Cd-interference with cellular function. These changes are suggested as a contributing mechanism to the prevention of acute toxic effects of cadmium on the kidney.

Animals↗

PubMed1986