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Biomedical subjects

J Fan

Publications and source records attributed to J Fan.

At least 199 records · Page 11Linked to original sources
PubMed1998

Role of central IL-1 in regulating peripheral IGF-I during endotoxemia and sepsis.

Inflammatory cytokines may mediate the host response to infection via central nervous system, endocrine, and/or paracrine/autocrine signaling mechanisms. Previous studies have shown that intravenous administration of interleukin (IL)-1 beta alters the concentration of the anabolic hormone insulin-like growth factor (IGF)-I in plasma and various tissues. The purpose of the present study was to determine 1) whether the intracerebroventricular injection of IL-1 beta can influence peripheral IGF-I levels in control animals and 2) whether the central administration of a IL-1 receptor antagonist (IL-1ra) can prevent the changes in peripheral IGF-I induced by endotoxin [lipopolysaccharide (LPS)] or sepsis produced by cecal ligation and puncture. In the first experiment, injection of IL-1 beta (100 ng/rat) decreased IGF-I levels in plasma, liver, and gastrocnemius muscle 28-36% by 1.5 h in conscious fasted rats. IGF-I levels remained reduced at 3 h, but returned to baseline by 6 h. IGF-I content was not altered in soleus, kidney, spleen, intestine, or whole brain after IL-1 beta. In the second series of experiments, LPS injected intravenously decreased IGF-I levels in plasma, liver, and gastrocnemius at 1.5 h, and levels were even further reduced at 3 and 6 h in these tissues (59, 57, and 48%, respectively). Moreover, the IGF-I content was also decreased in soleus (30-35%) and increased in kidney (2- to 3-fold) after LPS. In the third experiment, changes in IGF-I levels in plasma and tissues, similar to those seen in LPS-treated rats, were detected 24 h after induction of peritonitis. Intracerebroventricular infusion of IL-1ra did not alter any of the changes in IGF-I produced by either LPS or sepsis, although it did attenuate the concomitant changes in growth hormone levels. These data suggest that, although central IL-1 beta is capable of modulating peripheral IGF-I levels, central administration of IL-1ra was unable to modulate the changes in peripheral IGF-I in blood and tissues produced by either endotoxemia or peritonitis.

Animals↗
PubMed1998

Improved survival with resection after transcatheter arterial chemoembolization (TACE) for unresectable hepatocellular carcinoma.

AIM: This retrospective study was undertaken to analyze the outcome of hepatic resection in hepatocellular carcinomas (HCCs) that shrunk after transcatheter hepatic arterial chemoembolization (TACE) in 65 patients with unresectable HCCs between June 1987 and September 1996. MATERIALS AND METHODS: Among these 65 patients, the median diameter of the tumor was 9.9 cm (5.6-20.0) prior to the first TACE, after 1-6 times of TACE (median 3) the median tumor diameter reduced to 3.7 cm (1.9-12.5) prior to resection. The duration between the last TACE treatment and sequential resection varied from 1 to 9 months (median 2.5). Serum alpha-fetoprotein (AFP) levels were abnormal in 39 out of the 65 patients. In AFP producing HCCs, the AFP level returned to normal (</=20 microgram/l) in 14 out of 39 patients (35.9%). Hepatic segmentectomy, multiple hepatic segmentectomy or partial hepatic resection were performed in 61 patients, right hemihepatectomy in 1, left trisegmentectomy in 2, and left hemihepatectomy in 1. RESULTS: Tumor necrosis ranged from 40 to 100% and pathologically and complete tumor necrosis occurred in 11 patients (16.9%). Of 14 patients with AFP levels decreased to normal, 10 still had microscopic living tumor foci. The 1-, 3- and 5-year survival rates of the 65 patients were 80.0, 65.0 and 56.0% respectively. CONCLUSION: TACE treatment can provide a chance of tumor resection for those patients with initially judged unresectable HCCs, and liver resection should be performed when the tumor has shrunk to be resectable, even when the AFP level has returned to normal.

Adult↗
PubMed1998

Androgens accelerate thymocyte apoptosis.

Mechanisms of androgen-induced thymic involution are largely undefined. We have found that significant decreases in thymic size occur 2-4 h after a dose of testosterone is administered to castrated male mice. This rapid rate of change suggests a role for androgen-induced apoptosis in modulating the size and composition of the thymus. Using thymic organ cultures to define these effects of androgens, we found that dihydrotestosterone treatment of thymus tissues from females or from castrated males results in enhancement of thymocyte apoptosis. Intact (androgen-replete) or testicular feminization, Tfm/Y (androgen-resistant) mice failed to show apoptotic change with androgen treatment, although the apoptotic response to glucocorticoids was present, suggesting a requirement for a functional androgen receptor. Acceleration of thymocyte apoptosis by androgens may mediate processes of thymocyte selection, with the potential to impart gender-specific characteristics on the peripheral T cell repertoire.

Animals↗
PubMed1998

[A follow-up study on renal tubular dysfunction in women living in the cadmium-polluted Jinzu River basin in Toyama, Japan. Part 1. Changes in the level of exposure to cadmium after soil replacement of polluted paddy fields and the related effects on the prognosis of renal tubular dysfunction].

A follow-up study on renal tubular dysfunction was carried out on 193 female inhabitants of the cadmium (Cd)-polluted Jinzu River basin and 40 reference subjects living in an adjacent area in 1994-95. They were 54 to 70 years old when the initial examination was conducted in 1983-84. In the Cd-polluted Jinzu River basin, extensive reclamation of polluted rice fields has been conducted since 1979; as a result, the average Cd concentrations in polished rice consumed by the subjects in the 1994-95 study (0.12 ppm in 1994, 0.14 ppm in 1995) were significantly lower than those in the 1983-84 study (0.26 ppm in 1983, 0.29 ppm in 1984). The average Cd levels in urine in the follow-up study (7.5 micrograms/g Cr. in 1994, 7.7 micrograms/g Cr. in 1995) were also significantly lower than those in the initial study (13.5 micrograms/g Cr. in 1983, 13.3 micrograms/g Cr. in 1984). However, the mean values for urinary excretion of beta 2-microglobulin (beta 2-m) (3.9 mg/g Cr. in 1994, 3.7 mg/g Cr. in 1995) and glucose (203 mg/g Cr. in 1994, 251 mg/g Cr. in 1995) in the follow-up study were significantly higher than those obtained at the initial examination (2.0 mg/g Cr. and 125 mg/g Cr. in 1983 and 1.1 mg/g Cr. and 78 mg/g Cr. in 1984 for beta 2-m and glucose excretion, respectively). The magnitude of increase in urinary excretion of beta 2-m and glucose in inhabitants of the Cd-polluted area was significantly higher than that of the inhabitants of the reference area. Moreover, an increase was observed in the prevalence of renal tubular dysfunction determined by urinary beta 2-m exceeding 10 mg/g creatinine and urinary glucose exceeding 150 mg/g creatinine only among inhabitants of the Cd-polluted area; it is noteworthy that 31 new cases of renal tubular dysfunction were observed in the follow-up study. These results indicate that renal tubular dysfunction among inhabitants of the Cd-polluted Jinzu River basin is irreversible and progressive, and many new cases of renal tubular dysfunction were also noted over a period of 11 years, despite the fact that Cd exposure had decreased over the past 11 years.

Aged↗
PubMed1998

Hepatic lipase.

Hepatic lipase (HL) is an important enzyme that is involved in the metabolism of chylomicrons, intermediate density lipoproteins, and high density lipoproteins. HL may affect the liver uptake of remnant lipoproteins by modifying their compositions. HL also participates in the reverse cholesterol transport, thereby influencing the process of atherosclerosis. Several new functions of HL have recently been revealed. In this article, we review some of the recent progress based on studies using transgenic animals, with an emphasis on HL functions in remnant metabolism and atherosclerosis.

Animals↗
PubMed1998

[Damage effects of asbestos and cigarette smoke solution on human embryo lung cell DNA].

OBJECTIVE: To study the combined damage effects of asbestos and cigarette solution on human embryo lung cell (HEL) DNA. METHODS: Unscheduled DNA synthesis (UDS) assay was used. Repair and synthesis on DNA in HEL treated with asbestos and/or cigarette smoke was studied. RESULTS: It showed that UDS in HEL could be induced by exposure to asbestos or cigarette smoke only with a significant dose-response relationship, and the amounts of [3H]-TdR incorporation in cells treated with combination of asbestos and cigarette smoke was significantly higher than their sum in cells treated with asbestos or cigarette only. CONCLUSION: There is a synergistic damage effect of asbestos and cigarette on DNA of HEL. In addition, dimethyl sulfoxide (DMSO), a scavenger of .OH, can partly inhibit [3H]-TdR incorporation caused by asbestos. And .OH plays certain role in damage to DNA of cells caused by asbestos.

Asbestos, Serpentine↗
PubMed1998

[Comparison of changes in oncogene of human embryo lung cells before and after chemical modification for chrysotile].

OBJECTIVE: To seek for a suitable chamical agent for surface modification of chrysotile. METHODS: The effects of aluminum citrate, mixed rare earth and sodium selenite on c-Ha-ras oncogene and P21ras protein in the transformation of human embryo lung cells caused by chrysotile were studied. RESULTS: The transcription level of c-Ha-ras oncogene and the content of P21ras in those exposed to chrysotile were significantly higher than those in the controls. The transcription level of c-Ha-ras oncogene and the content of P21ras in those exposed to chrysotile treated in advance with three kinds of chemicals mentioned above were significantly lower than those in untreated. CONCLUSION: Treatment of chrysotile with three kinds of above-mentioned chemicals in advance could reduce its carcinogenecity in human beings.

Aluminum Compounds↗
PubMed1998

[Analysis of amino acids, vitamins and inorganic elements in Dictyophora indusiata].

Fifteen amino acids(total content: 13.37 mg.100 ml-1), 12 inorganic elements(Zn 37.3 micrograms.g-1, Mn 56.9 micrograms.g-1, Cr 4.88 micrograms.g-1, Fe 370 micrograms.g-1, Se 0.81 microgram.g-1, Cu 28.2 micrograms.g-1, Co 0.78 microgram.g-1, Ni 2.09 micrograms.g-1, etc.), and vitamin E(73.2 micrograms.g-1) in Dictyophora indusiata were determined. Seven amino acids, including valine 0.61, leucine 1.04, isoleucine 0.66, threonine 0.74, methionine 0.20, lysine 0.52, and pheuylalanine 0.64(mg.100 mg-1), were found to be essential. The possible medical significance of Dictyophora indusiata is discussed.

Amino Acids↗
PubMed1998

[An experimental study of the formation of osteoclast-like cell in rat bone marrow culture].

OBJECTIVES: To set up a culture method of osteoclast-like cell (OLC) formation in rat bone marrow and to investigate the effects of 1,25(OH)2D3 and osteoblasts on the formation of OLC. METHODS: The culture of bone marrow from 4-week old rats were studied for the formation of OLC. The culture was divided into four groups: group A, only bone marrow culture as control; group B, bone marrow and osteoblast (from the crania of newborn rats) coculture; group C, bone marrow culture with 1,25(OH)2D3(final concentration 10(-8) mol/L); group D, bone marrow and osteoblast coculture with 1,25(OH)2D3. After 7 days of culture, the number of OLC which was recognized as tartrate resistant acid phosphatase (TRACP) (+) multinucleated cell, the cellular TRACP and the resorption pits on bone slice were examined. RESULTS: No OLC was present at the beginning of the bone marrow culture in any groups. OLC still failed to be detected in group A by the end of culture, and a few of OLCs could be found out in group B and C. The number of OLC in group D was more than that in the other groups (P < 0.01). The cellular TRACP in group A was lower than that in the other groups, and the cellular TRACP activity in group B and C was lower than that in group D (P < 0.01). In group D, several smaller resorption pits on The bone slice were observed. CONCLUSION: The formation of OLC requires 1,25(OH)2D3 and coculture with osteoblasts favors the formation of OLC in bone marrow culture.

Animals↗
PubMed1998

[10-Hydroxycamptothecin induces apoptosis in human T24 urinary bladder cancer cells].

OBJECTIVE: To study the emechanisms of 10-Hydroxycamptothecine (HPT) inhibiting human urinary bladder cancer. METHODS: Using flow cytometry, electron microscopy and fluorescence microscopy, we studied the effects of HPT on human T24 urinary bladder cancer cells. RESULTS: HPT at 0.005 mg/L inhibited T24 bladder cancer cells by preventing the cells from S phase to G2/M phase and did not induce apoptosis. The apoptotic cells were induced by HPT at the concentration of 0.01-0.10 mg/L. CONCLUSION: HPT can inhibit human T24 urinary bladder cancer cells and induced apoptosis at some concentrations. The induction of apoptosis is a very important mechanism of 10-Hydroxycamptothecine to treat urinary bladder cancer cells.

Antineoplastic Agents, Phytogenic↗
PubMed1998

[Retrograde partial hepatectomy: report of 11 patients].

OBJECTIVE: To study a new approach to hepatectomy for liver tumors resected difficulty by typical method. METHOD: The operative order is retrograde as compared with typical hepatectomy, namely, transection of the liver is performed first, isolating adhesions between the tumor and the diaphragm or partial invaded phrenectomy is performed second, and then after cutting corresponding ligaments, liver tumor is removed. If the surrounding organs were invaded or adhered by tumor too tightly to be separated. They were resected with the tumor. RESULT: The approach was used in 11 patients with malignant tumors of liver from June 1994 to January 1996. Operation time was 192 min (150 - 250 min) and estimated blood loss during operation was 1460 ml (800 - 4, 200 ml). No operative mortality was found and all of the patients recovered uneventfully. CONCLUSION: The retrograde partial hepatectomy is a good method for resection of liver tumors resected difficulty by typical hepatectomy.

Adult↗
PubMed1998

[Determination of impurities in tantalum by ICP-AES].

The spectral and non-spectral inteferences of tantalum to the determination of Al, Ca, Cr, Cu, Fe, Mg, Mn, Mo, Nb, Ni, Pb, Sn and Ti by ICP-AES were studied. The non-spectral inteference can be eliminated by optimizing operating conditions. Three methods for correction of spectral inteferences were evaluated. The proposed method was used for the determination of impurities in synthetic samples with satisfactory results.

English Abstract↗
PubMed1998

Modulation of the insulin-like growth factor system by chronic alcohol feeding.

Insulin-like growth factor (IGF)-I is a potent anabolic agent that plays an important role in regulating muscle protein balance. Alterations in one or more of the various components of the IGF system may be in part responsible for the muscle wasting that accompanies chronic alcohol consumption. The purpose of the present study was to characterize changes in the growth hormone-IGF axis produced by chronic alcohol consumption in rats. After 8 weeks of alcohol feeding, the IGF-I concentration was decreased in plasma (31%) as well as in the liver and skeletal muscle (40-50%), compared with pair-fed control animals. In addition, alcohol consumption decreased IGF-I mRNA abundance in liver and muscle (approximately 50%). IGF-I content in duodenum and kidney, however, was not altered by alcohol feeding. Concomitantly, the relative concentration of IGF binding protein (IGFBP)-1 was increased in plasma, liver, and muscle of alcohol-fed rats, compared with control values. In contrast, no changes in the plasma concentrations of IGFBP-2, -3, or -4 were detected in alcohol-fed rats at this time point Previous studies have indicated that elevations in glucocorticoids or decreases in insulin or growth hormone might be responsible for the decrease in IGF-I and/or the increase in IGFBP-1 in other catabolic conditions. However, there was no difference in the plasma concentrations of these hormones between alcohol-fed and control animals in this study. These data indicate that chronic alcohol feeding in rats decreases IGF-I and increases IGFBP-1 in the circulation and in skeletal muscle and that these changes appear to be independent of changes in classical hormonal regulators of the IGF system. The observed alterations in the IGF system are consistent with a reduction in the anabolic actions of IGF-I induced by chronic alcohol consumption.

Alcoholism↗
PubMed1997

Androgens alter B cell development in normal male mice.

Castration of normal male mice leads to splenic enlargement and expansion of the B cell population. Since the spleen does not express receptors for androgens, these changes are most likely mediated by effects of androgens on other target organs. Two potential sites of androgen-mediated effects on B cells are evaluated in these studies: thymus and bone marrow. We first confirmed other findings indicating that castration of normal male mice results in expansion in the numbers of bone marrow B cells and then extended these observations by showing that these changes were reversible following androgen replacement. B cell expansion in castrate marrow and spleen was not altered by prior thymectomy, suggesting that thymic androgen receptors are not involved in the observed effects. Androgen receptors were found to be present in both immature B cells and marrow stromal cells by immunoblotting and ligand binding assays. The results suggest a direct modulatory role for androgens on B cells within the bone marrow compartment.

Androgens↗
PubMed1997

Cloning, chromosome localization, expression, and characterization of an Src homology 2 and pleckstrin homology domain-containing insulin receptor binding protein hGrb10gamma.

hGrb10alpha (previously named Grb-IR) is a Src-homology 2 domain-containing protein that binds with high affinity to the tyrosine-phosphorylated insulin receptor and insulin-like growth factor-1 receptor. At least two isoforms of human Grb10, (hGrb10alpha and hGrb10beta), which differ in the pleckstrin homology (PH) domain and the N-terminal sequence, have previously been identified in insulin target tissues such as human skeletal muscle and fat cells. Here we report the cloning of the third isoform of the hGrb10 family (hGrb10gamma) from human skeletal muscle and its localization to human chromosome 7. We have also determined the human chromosome localization of Grb7 to 17q21-q22 and Grb14 to chromosome 2. hGrb10gamma contains an intact PH domain and an N-terminal sequence that is present in hGrb10alpha but absent in hGrb10beta. RNase protection assays and Western blot analysis showed that hGrb10alpha and hGrb10gamma are differentially expressed in insulin target cells including skeletal muscle, liver, and adipocyte cells. hGrb10gamma is also expressed in HeLa cells and various breast cancer cell lines. The protein bound with high affinity to the insulin receptor in cells, and the interaction was dependent on the tyrosine phosphorylation of the receptor. hGrb10gamma also underwent insulin-stimulated membrane translocation and serine phosphorylation. hGrb10gamma phosphorylation was inhibited by PD98059, a specific inhibitor of mitogen-activated protein kinase kinase, and wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase. Taken together, our data suggest that hGrb10 isoforms are potential downstream signaling components of the insulin receptor tyrosine kinase and that the PH domain may play an important role in the involvement of these isoforms in signal transduction pathways initiated by insulin and other growth factors.

Amino Acid Sequence↗
PubMed1997

A new member of the transmembrane 4 superfamily (TM4SF) of proteins from schistosomes, expressed by larval and adult Schistosoma japonicum.

The transmembrane 4 superfamily (TM4SF) comprises an assemblage of surface antigens from mammalian cells and from the human blood flukes. Member proteins of the TM4SF are characterized by the presence of four hydrophobic domains, which are presumed to be membrane-spanning, and specific conserved motifs. The Sm23 group of TM4SF, which includes Sm23, Sj23, and Sh23 from blood flukes, shows potential as immunodiagnostic and vaccine target antigens for use in controlling human schistosomiasis. Here we describe a cDNA from miracidia and adult Schistosoma japonicum parasites which apparently encodes a new member of the TM4SF. The deduced polypeptide, termed Sj25/TM4, has substantial amino acid homology to Sm23 from Schistosoma mansoni although it is not a species homologue of Sm23. Sj25/TM4 is predicted to span the cell membrane four times, with its NH2- and COOH-termini embedded in the cytoplasm, and to have two extracellular hydrophilic loops, one of which may be N-glycosylated. This topology is characteristic of TM4SF proteins; in addition, Sj25/TM4 contains the sequence motifs conserved in the TM4SF. Southern hybridization analysis demonstrated that Sj25/TM4 and Sj23 are encoded by genes at separate loci and, further, showed interstrain variation at the locus encoding Sj25/TM4 in Chinese and Philippine isolates of S. japonicum.

Amino Acid Sequence↗