Volume 110  ·   Issue 07  ·  1997

OBJECTIVE To search for new putative tumor suppressor genes in colorectal carcinoma. METHODS Subtractive hybridization technologies were applied to screen and select genes, the expression of which was down-regulated in colorectal carcinoma. mRNAs uniquely expressed in normal cells but not in colorectal carcinoma were recovered as cDNA (sub-cDNA) after two rounds of subtractive hybridization with mRNA prepared from colorectal carcinoma. The sub-cDNAs were then used as probes to screen a normal human colon cDNA library constructed in lambda-Zap II phage. The DNAs of positive clones were in vivo excised, and partial DNA sequences were analyzed and compared with DNA sequence database Genbank. RESULTS A total of 46 different clones with an average of about 1 kilobases in transcript size was recovered. Among these 46 down-regulated genes in colorectal carcinoma were genes encoding immunoglobulin (n=32), 40-kDa keratin intermediate filamentous protein or IFP (n=1), major histocompatibility complex-related protein (n=1), unrelated structural proteins (n=10) and gene products yet to be identified (n=2). RNA dotblot hybridizations confirmed that all 46 clones contained genes that were down-regulated and have not been reported before in colorectal carcinoma. CONCLUSIONS The results of this study suggested that the 46 clones were down-regulated in colorectal carcinoma, they should be further studied as new putative tumor suppressor genes and could be used as new tumor markers of colorectal carcinoma.

OBJECTIVE To treat inoperable tracheal stenosis by using nitinol endotracheal stent and to solve some problems facing endotracheal stenting with other kinds of stents. METHODS The stent was made of nitinol wire. It can be deformed to smaller size in iced water. With a self-made introducer, the stent was placed in the location of stenosis. After hot water was injected into the introducer, the stent resumed its original form and anchored there itself. RESULTS Altogether, 5 patients with severe tracheal stenosis received this treatment. Dyspnea was relieved immediately after implantation of stents in all patients. Long-term follow-up also showed satisfactory results. CONCLUSIONS Nitinol stent has some remarkable advantages as compared with other tracheal stents. It can be used as a new endoprosthesis in treating narrowed trachea.

OBJECTIVE To examine the action of ginsenoside Rg1 on the prevention of apoptosis in cultured cortical neurons. METHODS Serum-deprivation was used as a model of apoptosis in cultured cortical neurons. Trypan blue exclusion test was set to examine cell viability. Lactate dehydrogenase release assay was used to investigate neuron injury. Two tests were performed for identification of apoptosis: fluorescence microscopy of cells stained with Hoechst 33 342 and Propidium Iodide; deoxyribonucleic acid (DNA) electrophoresis on agarose gel. RESULTS Rg1 increased the neuron viability, lessened the release of LDH, reduced the morphological changes of nuclei, and decreased the cleavage of DNA. CONCLUSIONS Rg1 can inhibit apoptosis of cultured cortical neurons induced by serum withdrawal. This action of Rg1 is concentration-dependent. The finding may give a clue to elucidate the antiaging activity of Rg1.

OBJECTIVE To investigate the mechanism of endothelin (ET) inflammatory effects on human mesangial cells (HMC). METHODS The following experiments were performed on cultured HMC after ET-1 stimulation: (1) the expression of tumor necrosis factor-α (TNFα), interleukin-1 beta (IL-1 beta), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and endothelin-1 (ET-1) itself messenger ribonucleic acid (mRNA) was determined by Northern Blot analysis; (2) the TNFα concentration was tested with radioimmunoassay; the IL-1 activity was assayed by the enhancement of thymocyte proliferation in response to mitogen; the surface expression of ICAM-1 and VCAM-1 was measured with cell enzyme linked immunoadsorbent assay (ELISA) analysis. RESULTS ET-1 (10-7 mol/L) induced the following changes on HMC: (1) up-regulation of the expression of TNFα mRNA and protein; (2) up-regulation of the expression of ICAM-1 and VCAM-1 mRNA and protein; (3) up-regulation of the expression of ET-1 itself mRNA. However, the expression of IL-1 mRNA and protein was not changed. CONCLUSIONS ET-1 can stimulate HMC to produce TNFα, ICAM-1 and VCAM-1, and thereby induce inflammatory effects. ET-1 can also stimulate HMC to up-regulate the expression of ET-1 itself, so as to amplify inflammatory effects. So, ET-1 is actually an inflammatory mediator and may play an important role in the pathogenesis of glomerulonephritis.

OBJECTIVE To investigate the relationship between angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism and the clinico-pathological manifestations in patients with immunoglobulin nephropathy (IgAN). METHODS A flanking primer pair and an insertion-specific primer pair were used to perform two polymerase chain reactions so as to analyse the insertion/deletion polymorphism of ACE gene. RESULTS There was a significantly higher genotype frequency for DD genotype in IgAN patients. The frequencies for DD genotype were also higher in those patients with hypertension and/or heavy proteinuria and/or severe glomerular sclerosis (P<0.05). CONCLUSIONS We observed a significant association of the deletion polymorphism of ACE gene with renal insufficiency, hypertension and severe glomerular lesions at biopsy. The deletion allele may play a role, at least to some extent, in the deterioration and progression in IgA nephropathy.

OBJECTIVE To observe the safety and cardiovascular stability of on-line hemofiltration (HF) or hemodiafiltration (HDF) and evaluate the clinical effectiveness of one HF or HDF session in addition to two hemodialysis (HD) sessions weekly. METHODS Forty patients were randomly divided into four groups: group predilutional (PRD) HF (filtration rate: 259-333 ml/min) group predilutional HDF (filtration rate: 167 ml/min) group postdilutional (POD) HDF (filtration rate: 83 ml/min) and group bicarbonate HD. The reduction rate of parathyroid hormone (PTH), β2-microglobulin (β2MG), α1-microglobulin (α1MG) and KT/V in the initial treatment of every month was observed, and the incidence of hypotension and pyretic reaction during each treatment was evaluated. RESULTS After 4-month observation, the KT/V for Group POD HDF is better than that for the other three groups, and for Group PRD HDF is better than that for Group HF and HD. Serum level of PTH and β2MG was not decreased after every treatment in Group HD, and so was serum level of α1MG in all groups. Significant removal of PTH and β2MG was observed in Group HF, PRD HDF and POD HDF. The monthly serum level of β2MG and KT/V were stable in all groups, but the monthly serum level of PTH tended to be decreased in Group HF, PRD, HDF, and POD HDF. The incidence of pyretic reaction in HF or HDF was the same as in HD. Although the ultrafiltration volume was significantly higher during HF or PRD HDF than during HD, the incidence of hypotension in HF or PRD HDF was similar to that in HD. CONCLUSIONS On-line HF or HDF proved to be a safe and reliable method. POD HDF mode seems to have the best KT/V, HF or PRD HDF offers a better choice for preventing intradialytic hypotension. One HF or HDF session in addition to two HD sessions weekly is similarly effective to decrease the serum level of PTH and the proof of the clinical effectiveness of such a therapy awaits a long-term observation.

OBJECTIVE To investigate the nitric oxide (NO)-dependent 3', 5'-cyclic guanosine monophosphate (cGMP) stimulation or inhibition in isolated glomeruli and inner medullary collecting duct (IMCD) cells from normal and diabetic rats for elucidating the probable role of NO in diabetic nephropathy. METHODS Glomeruli and IMCD cells were obtained from anesthetized diabetic rats, 2 weeks after streptozotocin-induction, and normal rats, and incubated for 10 minutes under basal state or adding different drugs. cGMP was measured by radioimmunoassay. RESULTS Diabetic glomeruli had a higher generation of cGMP under basal state but failed to further response of L-arginine, which was contrary to the glomeruli from normal rats. NG-monomethyl-L-arginine prevented the elevation of cGMP after L-arginine stimulation in normal rats but not in diabetic rats. Acetylcholine produced a concentration-dependent of cGMP accumulation in the glomeruli of both groups, but the extent was relatively smaller in diabetic than in normal. A similar tendency was also observed in sodium nitroprusside treated glomeruli. However the cGMP increment in response to atrial natriuretic peptide was identical in the two groups. For the IMCD cells, neither the difference of basal cGMP nor those responses related to acetylcholine or sodium nitroprusside could be observed. But the attenuated response to L-arginine also existed in diabetic IMCD cells. CONCLUSIONS Both diabetic glomeruli and IMCD cells have an abnormal NO metabolism, which may account in part for the disturbance of renal hemodynamics.

OBJECTIVE To examine the relationship between P-selectin expression and human glomerulonephritis. METHODS P-selectin expression was investigated in renal biopsies of glomerulonephritis patients (n=133) by immunohistochemical and in situ hybridization analyses. They were divided into three groups based on the degrees of cells proliferation or sclerosis. Group I: histological lesions in glomeruli are mild (n=23); Group II: glomerular cells proliferation is prominent (n=91); Group III: glomerular sclerosis is severe (n=19). The Kruskal-Wallis test, Chisquare test and Spearman's correlation were used in our study. RESULTS In normal controls, renal P-selectin expression was negative (n=10). In glomerulonephritis, the up-regulated P-selectin expression on tubular epithelium was significantly higher than that on glomeruli and interstitium (P<0.01). P-selectin was expressed predominantly on platelets in glomeruli, and glomerular P-selectin expression was more significantly up-regulated in Group II than in Group I or Group III (P<0.05; and P<0.01, respectively). There were strong correlations between the degree of tubulointerstitial lesions and the expression of P-selectin on tubular epithelium or within interstitium (rs=0.395 and rs=0.337, P<0.01). Furthermore, P-selectin messenger RNA (mRNA) signals were also detected in the cytoplasm of glomerulus, tubular epithelial cells, interstitium and vascular endothelium. CONCLUSIONS P-selectin might mediate intraglomerular platelets aggregation, activation and leukocyte accumulation in the early stages of human proliferative glomerulonephritis. The up-regulation of P-selectin in interstitium was associated with interstitial fibrosis and tubular atrophy and may contribute to the progression of glomerulonephritis.

OBJECTIVE To investigate the biocompatibility of dialyzer reuse. METHODS Twenty-two hemodialysis patients were randomized into cuprophan (CU, 7), polymethylmethacrylate (PMMA, 7) and polysulphone (PS, 8) membrane groups to observe IL-1β, TNF-α, IL-6 gene expression and their plasma levels by using themselves as control with enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. RESULTS Plasma levels of interlukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) were 14.07±3.32 pg/ml, 67.41±19.79 pg/ml, 83.67±40.34 pg/ml; 12.80±3.01 pg/ml, 49.65±9.75 pg/ml, 33.36±12.14 pg/ml and 14.41±3.16 pg/ml, 80.56±23.22 pg/ml, 48.14±16.01 pg/ml, respectively, after patients dialyzed with CU, PMMA and PS membranes. Plasma cytokine levels decreased after reuse compared with those before reuse in each group. But no significant difference was found between them (P>0.05); the levels of IL-1β, TNF-α, IL-6 gene expression after reuse were 5.61±0.33, 2.11±0.12, 5.04±0.19%; 2.43±0.19, 1.29±0.11, 3.48±0.20% and 2.48±0.20, 1.24±0.11, 3.22±0.20% respectively by in situ hybridization, and 0.92±0.07, 0.63±0.05, 0.53±0.05; 0.61±0.06, 0.47±0.04, 0.37±0.03 and 0.59±0.05, 0.44±0.04, 0.38±0.03 by RT-PCR, respectively. After reuse there was significant decrease as compared with that before reuse (P<0.001, P<0.005 and P<0.05, respectively). CONCLUSIONS This suggested reprocessing dialyzer with formaldehyde reduced cytokine release and gene expression in peripheral blood mononuclear cells and enhanced dialyzer biocompatibility. It would be beneficial to reduce the dialysis cost and may reduce the complication related to a long term hemodialysis.

OBJECTIVE To investigate the prognosis of lupus nephritis (LN) and its influencing factors in patients with lupus nephritis in China. METHODS A retrospective study was carried out in 86 patients followed up for at least 5 years. Clinical features, serological and immunological tests were investigated. Renal biopsies were performed at the beginning of the study and repeated in some cases during the follow-up period. All the 86 patients had serum creatinine (Scr) level less than 132.6 μmol/L at the initial presentation and were divided into three groups according to the level of Scr at the end of the study. Group Ⅰ: the patients with normal renal function (Scr<132.6 μmol/L); Group Ⅱ: the patients with mild-moderate renal insufficiency (132.6 μmol/L≤SCR≤530.4 μmol/L); Group Ⅲ: the patients with end stage renal failure (ESRF) (Scr≥530.4 μmol/L). RESULTS Forty-seven patients reached clinical remission with normal renal function, 11 had with stabilization of renal function, although the systemic lupus erythematosis (SLE) activity relapsed repeatedly, while 28 subjects developed renal insufficiency after 60-170 (mean 88.12±28.23) months of observation. ESRF rate was 11.6% in this group of patients. Eight patients died (2 died of infections and 6 died of ESRF) during the follow-up period. At the beginning of the study the rates of hypertension, persistent anemia and hematuria in Group Ⅱ were 50%, 70%, and 70% respectively, being much higher than those in Group Ⅰ. The calculation of AI and CI in 60 patients revealed that there were 65% of patients with AI≥7 and 70% of patients with CI≥3 in Groups Ⅱ and Ⅲ, while in Group Ⅰ there were only 32% of patients with AI≥7 and 19% of patients with CI≥3. Sixteen cases had pathologic class changed in 48 repeated biopsies. Seven cases changed to Class Ⅳ, 5 to Class Ⅱ, 3 to Class Ⅴ from other classes and one to class Ⅲ from Class Ⅱ. CONCLUSIONS Factors associated with the development of renal insufficiency in these lupus patients included hypertension, anemia and hematuria. Renal biopsy evaluation offered additional prognostic information and showed that patients with severe active and chronic histologic changes were at risk for developing renal insufficiency. During the clinical course, the renal classification of LN changed in certain patients, thus the histologic classification of renal morphology at initial presentation did not fully predict the outcome. Renal involvement is very common in systemic lupus erythematosis (SLE) patients. Lupus nephritis (LN) is the most common form of secondary renal disease in China. It has various and unpredictable clinical features. The risks associated with its treatment have challenged investigators to detect the factors which may influence the survival rate of patients with LN and to develop the rational approaches to therapy. Decades of intensive investigation at many centers around the world had underscored the predictive value of demographic, clinical and laboratory data prior to treatment. Controversies still existed due to the difference in environment, race and the selection criteria of patients as well as the method used to evaluate the outcome. There are still some factors which are thought to have an impact on the prognosis of LN. Most of the articles on the prognosis of patients with LN were reported from Europe and America either about Caucasian or African-American patients. The prognosis of LN and its influence in Chinese patients need more elucidation.

Over the past 40 years, the enormous new knowledge about pathogenesis, immuno-pathology, pathophysiology and progression of renal diseases has been accumulated from basic laboratory researches. In the 1990's, nephrologists have been more exciting and collaborating with basic scientists to understand the cellular and molecular mechanisms of these diseases.