Biomedical subjects

J Fan

Publications and source records attributed to J Fan.

At least 163 records · Page 9Linked to original sources

PubMed1999

Examination of crystalluria in freshly voided urines of recurrent calcium stone formers and normal individuals using a new filter technique.

PURPOSE: We evaluated calcium oxalate (CaOx) and calcium phosphate (CaP) crystalluria in freshly voided urines of normal individuals (controls) and recurrent calcium stone formers (RSF) using a new filter technique. MATERIALS AND METHODS: Chemical analysis of urinary sediment retained by a 0.45 microm. Millipore filter was used to quantitate crystalluria. A CaOx and CaP crystal suspension initially confirmed the reliability of the filter technique. Freshly voided urine samples from 11 controls and 15 RSF were then evaluated. Sediment calcium (S-Ca), oxalate (S-Ox) and phosphate (S-PO4) were compared with routine light microscopy for crystal detection. RESULTS: The recoveries of calcium (Ca) and oxalate (Ox) from the CaOx crystal suspension were 83.8% and 87.5%, respectively. The recoveries of Ca and phosphate (PO4) from the CaP crystal suspension were 97.7% and 89.7%, respectively. The CaOx and CaP crystal volumes (S-Ox and S-PO4) were similar between controls and RSF. However, the sediment to urinary ionic ratios, a parameter indicative of crystal formation under similar levels of supersaturation, was significantly higher in RSF. S-PO4 was 3 to 4 times higher than S-Ox, both in controls and RSF. There was a strong positive correlation between urinary Ox (U-Ox) concentration, and S-Ox and S-Ca concentrations in RSF, but not in controls. There was also a positive correlation between urinary phosphate (U-PO4) and S-PO4 in both groups. A good correlation was also found between the filter technique and standard microscopy for the detection of crystalluria. CONCLUSIONS: We conclude that the filter technique is a simple and sensitive quantitative method to study crystalluria. The predominant crystal type in fresh urines of both controls and RSF appears to be calcium phosphate. The principal difference between crystalluria of RSF and normals is its tendency to form at a lower urinary ionic concentration in RSF, suggesting a higher crystallization inhibitor activity in normal individuals.

Calcium Oxalate↗

PubMed1999

Delayed treatment with diethyl maleate prevents E-selectin expression in human endothelial cells.

BACKGROUND: Polymorphonuclear leukocyte (PMN) infiltration is a significant contributor to tissue damage in many disease states and is known to occur through an orderly set of events. The endothelial cell adhesion molecule E-selectin is involved in the initial rolling of PMNs on the endothelium at sites of inflammation. We have previously shown that the glutathione depleting agent diethyl maleate (DEM) attenuates lung injury in a rodent model of intratracheal LPS stimulation. We hypothesized that DEM might attenuate E-selectin in LPS-treated human umbilical vein endothelial cells as a mechanism underlying this effect. Further, we investigated the role of delayed treatment with DEM on E-selectin expression. METHODS: Human umbilical vein endothelial cells were treated with DEM (100 to 400 mumol/L) before or after LPS stimulation (1 microgram/mL). Surface expression of E-selectin was examined using a cellular enzyme-linked immunosorbent assay. E-selectin mRNA transcripts were detected by Northern blot analysis. Nuclear factor-kappa B (NF-kappa B) activity was detected with gel shift assays. RESULTS: DEM significantly inhibited LPS-induced E-selectin surface expression and mRNA levels in a dose-dependent fashion, with complete inhibition at 250 mumol/L, without affecting cell viability. This inhibitory effect was seen even if DEM was added up to 60 minutes after LPS. DEM inhibited NF-kappa B nuclear translocation in a manner that mirrored protein and mRNA levels. CONCLUSIONS: Delayed treatment with DEM attenuates NF-kappa B nuclear translocation and E-selectin expression in human umbilical vein endothelial cells up to 60 minutes after the onset of LPS stimulation. Thus, DEM may represent an effective intervention for PMN-mediated organ injury even when given after an inflammatory insult.

Cells, Cultured↗

PubMed1999

Role of sex hormones in experimental calcium oxalate nephrolithiasis.

It is unclear why men have a higher incidence of calcium oxalate nephrolithiasis than women. This study examined the role of sex hormones on urinary oxalate excretion and kidney stone formation in an experimental model of urolithiasis. Adult male and female Sprague Dawley rats with different sex hormone modulations were given 0.75% ethylene glycol for 2 wk to induce hyperoxaluria and kidney calcium oxalate crystal deposition. The study groups were: intact male and female rats; castrated male and female rats; intact male or female rats with opposite sex hormone implants; and castrated male and female rats with either testosterone or estradiol implants. Overall, a significant negative correlation between urinary oxalate and plasma estradiol/testosterone ratio was found. None of the estradiol-implanted rats, whether male or female, intact or castrated, developed kidney crystal deposits. The three groups of testosterone-implanted rats had a 43 to 88% rate of kidney calcium oxalate crystal deposition. These results indicate that androgens increase and estrogens decrease urinary oxalate excretion, plasma oxalate concentration, and kidney calcium oxalate crystal deposition. These findings may partly explain why nephrolithiasis is a predominantly male disease.

Animals↗

PubMed1999

Isometric strength measurements in children with arthritis: reliability and relation to function.

OBJECTIVE: To examine the reliability of testing strength in children with juvenile arthritis (JA), and to determine the relationship between strength and function. METHODS: Children with JA were tested for grip and pinch strength (n = 32). Isometric force produced by hip abductors and knee extensors was tested with a hand-held dynamometer (n = 29). Two therapists both performed each of the tests twice so that intrarater and interrater reliability could be examined. Function was measured by means of the Childhood Health Assessment Questionnaire (CHAQ) and performance on a 50-meter run. Reliability was examined with intraclass correlations (ICC). The relationships of strength and function were determined with Pearson and Spearman correlations. RESULTS: All measures demonstrated good intrarater (ICC = 0.92-0.97) and interrater (ICC = 0.80-0.95) reliability. Grip strength and pinch were correlated with the CHAQ (r = -0.45 and -0.33, respectively), while hip abduction and knee extension torque were correlated with rankings on the 50-meter run (rho = -0.34 and -0.38, respectively). CONCLUSION: Isometric strength can be reliably measured in children with arthritis in a clinical setting.

Activities of Daily Living↗

PubMed1999

cDNA cloning and sequencing of MH2 domain of Smad2 from human dental pulp cells.

OBJECTIVE: The purpose of this study was to clone and sequence the cDNA of MH2 domain of Smad2 from human dental pulp cells. METHODS: In this study, total RNA was isolated from primary cultured human dental pulp cells and reverse-transcribed into cDNA. The desired DNA product was obtained by nested PCR with 4 smad2 MH2 domain-specific primers. The segment was inserted into pBluescript II SK vector and the resulting plasmid was transformed into E. coli JM109. The double-strand cDNA of positive clone was sequenced by PE317-A automatic sequencing. RESULTS: cDNA of MH2 domain of Smad2 was obtained from human dental pulp cells. The sequence was consistent with that cloned from a human kidney cDNA library. No mutation was found. CONCLUSION: This study provides the first evidence of expression of smad2 in human dental pulp cells, and indicates that TGF-beta signaling may be mediated by Smad2 in human dental pulp cells. The cDNA cloned in pBluescript/S2MH2 could be used for further functional studies of Smad2 and MH2 domain in dental pulp cells.

Base Sequence↗

PubMed1999

Effects of Kupffer cells stimulated by triglyceride and very low-density lipoprotein on proliferation of rat hepatic stellate cells.

OBJECTIVE: To study the effects of triglyceride, very low-density lipoprotein (VLDL), and Kupffer cell-conditioned medium (KCCM) derived from triglyceride and VLDL treatment on proliferation of rat hepatic stellate cells (HSC). METHODS: HSC and Kupffer cells were isolated and cultured from liver of Wistar rats by in situ perfusion with proteinase and collagenase, and density gradient centrifugation with Nycodenz; HSC and Kupffer cells were identified by immunohistochemistry, endocytosis, and ultrastructure, etc. Kupffer cells were incubated with triglyceride (25 micrograms/ml) and VLDL (25 micrograms/ml) for 24 hours, KCCM were prepared, and MTT colorimetric assay was detected for HSC proliferation. RESULTS: HSC proliferation was 0.1894 +/- 0.0316 (12.5 micrograms/ml), 0.1637 +/- 0.0243 (25 micrograms/ml), 0.1450 +/- 0.0264 (50 micrograms/ml), 0.1212 +/- 0.0275 (100 micrograms/ml), 0.1226 +/- 0.0138 (200 micrograms/ml) and 0.0990 +/- 0.0163 (400 micrograms/ml) in the presence of triglyceride and was 0.1583 +/- 0.0314 (6.25 micrograms/ml), 0.1642 +/- 0.0269 (12.5 micrograms/ml), 0.1834 +/- 0.0498 (25 micrograms/ml), 0.1964 +/- 0.0287 (50 micrograms/ml) and 0.2202 +/- 0.0284 (100 micrograms/ml) in presence of VLDL, respectively. Compared with the control, HSC proliferation at 400 micrograms/ml of triglyceride was lower (P < 0.01), but at 12.5 micrograms/ml of triglyceride and 25, 50, 100 micrograms/ml of VLDL higher (P < 0.05 or 0.01); HSC proliferation was 0.1569 +/- 0.0144, 0.1924 +/- 0.0113 and 0.1871 +/- 0.0116 in the presence of KCCM, KCCM + triglyceride and KCCM + VLDL, respectively. Compared with the control and KCCM, KCCM + triglyceride and KCCM + VLDL might promote HSC proliferation (P < 0.01); there was no statistical significance between KCCM + triglyceride and KCCM + VLDL (P > 0.05); KCCM was greater in HSC proliferation than the control, but there was no significant change (P > 0.05). CONCLUSIONS: Triglyceride, VLDL, and KCCM stimulated by triglyceride and VLDL might promote HSC proliferation and be associated with fatty liver and hepatic fibrogenesis.

Animals↗

PubMed1999

Surgical treatment of hepatocellular carcinoma and related basic research with special reference to recurrence and metastasis.

OBJECTIVE: To summarize the progress of surgical treatment of hepatocellular carcinoma (HCC) and related basic research at the Liver Cancer Institute of Shanghai Medical University in the recent years, with special reference to recurrence and metastasis. METHODS: Published and unpublished update clinical and experimental data in the above-mentioned areas are summarized. RESULTS: Surgical resection has played an important role in improving prognosis of HCC, the 5-year survival were 63.4% for small HCC resection (n = 806), 39.6% for large HCC resection (n = 1061), 64.7% for cytoreduction (using hepatic artery cannulation and ligation) and sequential resection of initially unresectable HCC (n = 93), 56.0% for cytoreduction using transcatheter arterial chemoembolization (TACE) and followed by resection (n = 65), and 22.4% for hepatic resection with removal of tumor thrombi in portal vein (n = 103). Unfortunately, the 5-year recurrent rate after curative resection of HCC was up to 61.5%, which was mainly a result of intrahepatic "metastasis" and multicentric origin of HCC. Clinically, re-resection of subclinical recurrence yielded 56% of 5-year survival (n = 202); prevention of recurrence by transcatheter arterial chemoembolization (TACE) + Interferon, or LAK/IL-2 therapy have decreased 3-year recurrent rate from 33% to 11%-18%. In experimental aspect, metastatic human HCC model in nude mice (LCI-D20) and HCC cell line with metastatic potential (MHCC97) have been established; studies on HCC invasiveness in the molecular level revealed similar results that reported in other solid cancers, and small HCC showed slightly better biological characteristics as compared with large HCC; microvessel density (MVD) that reflecting angiogenesis adversely correlated with 5-year survival of small HCC; experimental interventions using antisense H-ras, bispecific antibody, BB94, as well as anti-angiogenic agents (TNP470, suramin, CAI, heparin, antisense VEGF, etc.) have been demonstrated to inhibit tumor growth and lung metastasis in nude mice model. CONCLUSIONS: Recurrence and metastasis are the major obstacle to further improve prognosis of HCC, studies should be conducted both in clinical and experimental aspects, "HCC invasiveness" will be the major target to be studied, particularly in the molecular level, and anti-angiogenesis will be one of the important approach.

Angiogenesis Inhibitors↗

PubMed1999

[Intercellular adhesion molecule-1 expression in experimental liver fibrosis].

OBJECTIVE: To explore the role of intercellular adhesion molecule-1 (ICAM-1) in experimental liver fibrosis. METHODS: Experimental liver fibrosis models of rats were induced by high fat diet, low fat diet plus ethanol, high fat diet plus ethanol, and carbon tetrachloride subcutaneous injection respectively. At sacrifice, liver pathologic changes were studied and ICAM-1 expression was evaluated with immunohistochemistry by using a monoclonal antibody. RESULTS: ICAM-1 expression was observed in the hepatocellular membrane; ICAM-1 positive hepatocytes were localized in zones of portal tract with focal necrosis and inflammatory damage. Staining for ICAM-1 was associated with the degree of liver inflammation and fibrosis. In the different models, the intensity of ICAM-1 expression was different; It ranged in an increasing order from high fat diet, low fat diet plus ethanol, high fat diet plus ethanol, and carbon tetrachloride model. The strongest reactivity for ICAM-1 was seen in carbon tetrachloride model (P < 0.05), the difference was significant as compared with the other models. However, there was no significant difference among the three other models (P > 0.05). CONCLUSION: Upregulation of ICAM-1 expression in experimental liver fibrosis may be related with liver fibrogenesis.

Animals↗

PubMed1999

[Effects of Kupffer cells stimulated by triglyceride and very low-density lipoprotein on proliferation of rat hepatic stellate cells].

OBJECTIVE: To study the effects of Kupffer cell-conditioned medium (KCCM) derived from triglyceride and very low-density lipoprotein (VLDL) treatment on proliferation of rat hepatic stellate cells (HSC). METHODS: HSC and Kupffer cells were isolated from liver of Wistar rats by in situ perfusion with pronase and collagenase and density gradient centrifugation with Nycodenz and then cultured. KCCM was prepared and MTT colorimetric assay was used to detect HSC proliferation. RESULTS: HSC and Kupffer cells were isolated successfully with high purity. 12.5 mg/L of triglyceride and 25 - 100 mg/L of VLDL promoted HSC proliferation (P < 0.05 or 0.01); KCCM + triglyceride and KCCM + VLDL might promote HSC proliferation as compared with a control group (P < 0.01). There was no significant difference between KCCM + triglyceride and KCCM + VLDL (P > 0.05). CONCLUSION: The technique for isolation of HSC and Kupffer cells described here is simple and reliable. Triglyceride, VLDL and KCCM stimulated by them may promote HSC proliferation and be associated with fatty liver and hepatic fibrogenesis.

Animals↗

PubMed1999

[Hepatic resection with removal of tumor thrombi for hepatocellular carcinoma with tumor thrombi in portal vein and curative analysis].

OBJECTIVE: To study the therapeutic effects of surgical treatment for hepatocellular carcinoma (HCC) with tumor thrombi in the main trunk or the first branch of the portal vein (PVTT) and factors affecting prognosis. METHODS: 111 HCC patients with PVTT underwent hepatic resection with removal of tumor thrombi in the first left or the right branch of the portal vein or removal of tumor thrombi by direct opening of the main trunk of the portal vein. Hepatic artery infusion and/or portal vein infusion were performed after hepatic resection with removal of tumor thrombi for HCC with PVTT in 22 of the patients. Among 111 patients, 32 received postoperative transhepatic arterial chemoembolization and/or portal vein chemotherapy. Conservative treatment and surgical exploration or hepatic artery ligation (HAL) and infusion (HAI) and/or portal vein infusion (PVI) were performed in other 14 and 20 HCC patients with PVTT, respectively. RESULTS: The 1-, 2-, 3-, 4- and 5- year survival rates were 61.7%, 36.2%, 32.3%, 24.4% and 22.4% in the resected group, respectively, whereas 14 HCC patients with PVTT treated conservatively died in three months and the 1-, 2- year survival rates were 6.0% and 0 in the 20 patients with surgical exploration or HAL and HAI and/or PVI respectively. CONCLUSIONS: Hepatic resection with removal of tumor thrombi for HCC with PVTT should be encouraged for the prolongation of life span and quality of life.

Adult↗

PubMed1999

[Detection of apoptosis exposed to 10-hydroxycamptothecin in T24 human urinary bladder cancer cells].

OBJECTIVE: To study whether 10-hydroxycamptothecin (HPT) can induce apoptosis in bladder cancer cell and establish methods for detecting apoptotic cells. METHODS: Human urinary bladder cancer cell line (T24) was exposed in vitro to different concentrations of 10-hydroxycamptothein for various lengths of time. Flow cytometry, Hochest 33258 and Hematoxylin staining were used to determine the induction of apoptosis after use of HPT. DNA gel analysis was also carried out to detect DNA fragmentation. RESULTS: Cell shrinage, nuclear fragmentation and condensed chromosomes showed that apoptosis can be induced by HPT within the concentration of 0.01 - 10 microg/ml. The flow cytometry analysis showed that the percentage of apoptotic cells were related to the concentration and the time of induction. T24 cell line exposed to HPT experienced internucleosomal DNA fragmentation by producing a typical ladder pattern on agarose gel electrophoresis. The detection of minimum exposure time for HPT-induced apoptosis in T24 cells showed that 3 hours of exposure to HPT were enough to trigger internucleosomal DNA fragmentation. Compared to Hochest 33258 staining, Hematoxylin staining was more easy, rapid and accurate to detect apoptosis. CONCLUSIONS: The induction of apoptosis exposed to HPT in T24 human urinary bladder cancer cells is a good model for further studying urinary bladder cancer. Hematoxylin staining is a useful method for detecting apoptosis.

Antineoplastic Agents, Phytogenic↗

PubMed1999

[The relationship of lung function and heart function of RHD patients in different period].

OBJECTIVE: To investigate the relationship of heart function and lung function in RHD patients. METHODS: We compared heart posterior-anterior film, lung function test results, PaO(2) and O(2) Sat of blood gas analysis before and after motion before operation, early postoperation, late postoperation, according to heart function and cardiothoracic ratio in 98 RHD patients. RESULTS: With worsening of heart function and enlargement of cardiothoracic ratio, lung function worsened too. PaO(2) and O(2) Sat did not change apparently. The lung function of early postoperation did not improve significantly. The lung function improved gradually with better heart function and shortening of heart in later postoperation. But small air way obstruction and diffuse function and function residue volume changed slowly. CONCLUSIONS: Heart function affects the lung function directly. They were positively correlated.

Adolescent↗

PubMed1999

[Effects of cigarette smoke solution and chrysotile on proliferation activity of human embryo lung cells].

OBJECTIVE: To study the separate and combined effects of cigarette smoke solution and chrysotile on cell proliferation activity. METHODS: Human embryo lung (HEL)fibroblasts were cultivated with cigarette smoke solution and chrysotile separately or in combination at varied concentrations for certain times, and cell proliferation was observed with [(3)H] TdR incorporation. RESULTS: Cigarette smoke solution and chrysotile could enhance cell proliferation at lower doses, both separately or in combination, but inhibit it at higher doses. Lower dose of cigarette smoke solution and chrysotile in combination could enhance cell proliferation synergistically, but higher doses could only do additively. CONCLUSION: Cigarette smoke solution and chrysotile could affect HEL cell proliferation separately or in combination, with an enhancing or inhibiting effect, which depended on their doses.

Asbestos, Serpentine↗

PubMed1999

[Effects of vitamin A deficiency on the development and growth of rat embryos].

Effects of vitamin A deficiency on the development and growth of rat embryos were studied. Serious vitamin A deficiency markedly reduce body weight, body length and tail length, and induce incomplete development of skeleton and induce pathological change of brain and kidney of rat fetus. It was concluded that the development and growth of the embryos was affected and the brain and the kidney of fetus were damaged in serious vitamin A deficient rats.

Animals↗

PubMed1999

Expression of Plasmodium falciparum-infected erythrocyte membrane protein from cerebral malaria patients.

AIM: To provide theoretical evidence for studying the molecular pathogenesis of human cerebral malaria. METHODS: The expressions of Plasmodium falciparum erythrocyte membrane protein 1(PfEMP1) on the surface of parasitized erythrocyte (PE) specimens from 19 cases of cerebral malaria patients in Yunnan Province were quantitatively analyzed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique. 43 patients of falciparum malaria, 9 patients of vivax malaria and 6 healthy controls were also investigated. RESULTS: The expressions of higher molecular mass (Mr) 260-320 kDa forms of PfEMP1 were found on PE from cerebral malaria patients. By contrast, the expression of PfEMP1 and P. vivax erythrocyte membrane protein (PvEMP1) on PE from falciparum malaria patients and vivax malaria patients had a PfEMP1 with Mr 240 kDa and a PvEMP1 with Mr 180 kDa band, respectively. Healthy controls expressed an EMP of Mr 140 kDa. CONCLUSION: The binding of 260-320 kDa PfEMP1 proteins expressed on PE from cerebral malaria patients to diverse receptor molecules on the endothelial cell(EC) of the cerebral microvessels such as CD36, thrombospondin (TSP), intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), endothelial leukocyte adhesion molecule 1(ELAM-1) and chondroitin sulfate A (CSA) might be the molecular basis for the pathogenesis of cerebral malaria.

Adolescent↗

PubMed1998

Immunomodulatory effects of hypertonic resuscitation on the development of lung inflammation following hemorrhagic shock.

Hypertonic resuscitation fluids are known to be effective in restoring circulating volume in the hypovolemic trauma patient. Previous studies have suggested that hypertonicity might exert effects on immune cells leading to an altered host response. The present studies evaluated the effect of hypertonic resuscitation on the development of lung injury in a hemorrhagic shock model in which antecedent shock primes for increased lung neutrophil sequestration in response to intratracheal LPS. Resuscitation with hypertonic saline significantly reduced albumin leak, bronchoalveolar lavage fluid neutrophil counts, and the degree of histopathologic injury compared with resuscitation with Ringer's lactate. Both in vivo and in vitro data suggest that this beneficial effect may be related to altered adhesion molecule expression by the neutrophil. Specifically, hypertonicity induced shedding of L-selectin and prevented LPS-stimulated expression and activation of CD11b, both of which might contribute to reduced sequestration in the lung. Impaired up-regulation of lung ICAM-1 may have also participated, although ex vivo studies suggest that alterations in neutrophils were sufficient to account for the effect. Lung cytokine-induced neutrophil chemoattractant did not differ between animals resuscitated with hypertonic saline vs Ringer's lactate. Considered together, these studies demonstrate a possible novel approach to inhibiting organ injury in disease processes characterized by neutrophil-mediated damage.

Adjuvants, Immunologic↗

PubMed1998

Generation, identification, and evaluation of expressed sequence tags from different developmental stages of the Asian blood fluke Schistosoma japonicum.

Here we report 658 expressed sequence tags (ESTs) generated from the 5'-termini of clones randomly selected from directional cDNA libraries constructed from mRNAs from three developmental stages of Schistosoma japonicum. Putative identifications were assigned to 46. 2% of the ESTs; 6.4% were previously known from S. japonicum, 5.6% were previously known from S. mansoni, 34.2% were known from other organisms, and the remaining 53.8% may represent S. japonicum-specific genes. These 658 ESTs appeared to be derived from 457 unique genes, which together represent 2 to 3% of the 15,000 to 20,000 genes predicted to occur in the schistosome genome.

Animals↗

PubMed1998

Genome sequence of an obligate intracellular pathogen of humans: Chlamydia trachomatis.

Analysis of the 1,042,519-base pair Chlamydia trachomatis genome revealed unexpected features related to the complex biology of chlamydiae. Although chlamydiae lack many biosynthetic capabilities, they retain functions for performing key steps and interconversions of metabolites obtained from their mammalian host cells. Numerous potential virulence-associated proteins also were characterized. Several eukaryotic chromatin-associated domain proteins were identified, suggesting a eukaryotic-like mechanism for chlamydial nucleoid condensation and decondensation. The phylogenetic mosaic of chlamydial genes, including a large number of genes with phylogenetic origins from eukaryotes, implies a complex evolution for adaptation to obligate intracellular parasitism.

Aerobiosis↗