[Simultaneous quantitative analysis of four lignanoids in Schisandra chinensis by quantitative analysis of multi-components by single marker].

The aim of the study is to establish a new method of quality evaluation and validate its feasibilities by the simultaneous quantitative assay of four lignanoids in Schisandra chinensis. A new quality evaluation method, quantitative analysis of multi-components by single marker (QAMS), was established and validated with Schisandra chinensis. Four main lignanoids, schisandrin, schisantherin A, deoxyschizandrin and gamma-schizandrin, were selected as analytes and schisandrin as internal reference substance to evaluate the quality. Their contents in 13 different batches of samples, collected from different bathes, were determined by both external standard method and QAMS. The method was evaluated by comparison of the quantitative results between external standard method and QAMS. No significant differences were found in the quantitative results of four lignanoids in 13 batches of S. chinensis determined by external standard method and QAMS. QAMS is feasible for determination of four lignanoids simultaneously when some authentic standard substances were unavailable, and the developed method can be used for quality control of S. chinensis.

Effect of erythromycin on gastric dysmotility and neuroendocrine peptides in rats with diabetes mellitus.

OBJECTIVE: To investigate the effect of erythromycin on the contractive activity of the isolated gastric antrum smooth muscle and somatostatin (SS), vasoactive intestinal peptide (VIP), motilin (MTL), and substance P (SP) in plasma and isolated gastric antrum tissue of diabetes mellitus (DM) rat models. METHODS: Thirty male Sprague-Dawley rats were divided into three groups: control group (n = 10), DM group (n = 10), and erythromycin group (DM models with erythromycin treatment, n = 10). A single dose of streptozotocin (100 mg/kg, dissolved in 0.1 mol/L citric acid buffer, pH4.5) was injected intraperitoneally. After 48 to 72 hours, rats with blood glucose above 16.7 mmol/L and urine glucose level to be (+++) to (++++) over one week were considered successful DM models. The resting tension, mean contractile amplitude and frequency of spontaneous change in isolated longitudinal and circular gastric antrum smooth muscle strips were measured. SS, VIP, MTL, and SP levels in plasma and gastric antrum tissue were measured using radioimmunoassay. RESULTS: (1) In the isolated gastric antrum smooth muscle strips, the gastric motility parameters were lower in DM group than those in control group except circular smooth muscle contractile amplitude and longitudinal smooth muscle contractile frequency. The gastric motility parameters were significantly strengthened in erythromycin group, compared with DM group except longitudinal smooth muscle resting tension (P < 0.01). (2) Plasma SS, VIP, and MTL concentrations in DM group were higher than those in control (P < 0.05), while the SP level decreased (P < 0.05). In the gastric antrum, SS of DM group was significantly higher than that of control group (P < 0.01), while SP and MTL levels were lower than those of control group (P < 0.05 and P < 0.01, respectively). However, the level of VIP in gastric antrum tissue did not change among three groups. The plasma level of SS in erythromycin group was higher than that of DM group (P < 0.05). (3) The blood glucose was lower in erythromycin group than DM group (P < 0.01). CONCLUSIONS: Erythromycin has direct effects on contractive activity of gastric smooth muscle in diabetic rats, but there are few effects on neuroendocrine peptides. Gastric-motility disorders in diabetic rats have a correlation with the changes of neuroendocrine peptide levels in plasma and gastric antrum tissue.

Enhancement of osteopontin expression in HepG2 cells by epidermal growth factor via phosphatidylinositol 3-kinase signaling pathway.

AIM: Osteopontin (OPN) is a phosphorylated glycoprotein with diverse functions including cancer development, progression and metastasis. It is unclear how osteopontin is regulated in HepG2 cells. The aim of this study was to investigate the effect of epidermal growth factor on the expression of osteopontin in HepG2 cells, and to explore the signal transduction pathway mediated this expression. METHODS: Osteopontin expression was detected by RNAase protection assay and Western blot. Wortmannin, a specific inhibitor of PI3K, was used to see if PI3K signal transduction was involved in the induction of osteopontin gene expression. RESULTS: HepG2 cells constitutively expressed low levels of osteopontin. Treatment with epidermal growth factor increased osteopontin mRNA and protein level in a dose- and time-dependent manner. Application of wortmannin caused a dramatic reduction of epidermal growth factor-induced osteopontin expression. CONCLUSION: Osteopontin gene expression can be induced by treatment of HepG2 cells with epidermal growth factor. Epidermal growth factor may regulate osteopontin gene expression through PI3K signaling pathway. Several potential targets in the pathway can be manipulated to block the synthesis of osteopontin and inhibit liver cancer metastasis.

Expression of COX-2 proteins in gastric mucosal lesions.

AIM: To investigate the expression of COX-2 proteins in gastric mucosal lesions and to assess the relationship between COX-2 expression and type, pathologic stage, differentiation, or lymph node metastasis in gastric cancer and the relationship between COX-2 expression and H pylori infection in gastric mucosal lesions. METHODS: Thirty patients with gastric carcinoma underwent surgical resection. Samples were taken from tumor site and paracancerous tissues, and ABC immunohistochemical staining was used to detect the expression of COX-2 proteins. H pylori was determined by rapid urea test combined with pathological stating/14C urea breath test. RESULTS: The positive rate and staining intensity of mutant COX-2 gene expression in gastric cancer were significantly higher than those in paracancerous tissues (66.7% vs 26.7%) (P<0.01, P<0.001). There was a significant correlation between COX-2 and pathologic stage or lymph node metastasis type of gastric carcinoma (76.0% vs 20.0%, 79.2% vs 16.7%) (P<0.05). No correlation was found between COX-2 expression and type or grade of differentiation (P>0.05). COX-2 expression of intestinal metaplasia (IM) or dysplasia (DYS) with positive H pylori was significantly higher than that with negative H pylori (50.6% vs 18.1%, 60.0% vs 33.3%) (P<0.05). CONCLUSION: COX-2 overexpression was found in a large proportion of gastric cancer tissues compared with matched non-cancerous tissues and was significantly associated with advanced tumor stage and lymph node metastasis. Overexpression of COX-2 plays an important role in tumor progression of gastric cancer. COX-2 may also play a role in the early development/promotion of gastric carcinoma and is associated with H pylori infection.

Coordinate increase of telomerase activity and c-Myc expression in Helicobacter pylori-associated gastric diseases.

AIM: To detect the telomerase activity and c-Myc expression in gastric diseases and to examine the relation between these values and Helicobacter pylori (H pylori) as a risk factor for gastric cancer. METHODS: One hundred and seventy-one gastric samples were studied to detect telomerase activity using a telomerase polymerase chain reaction enzyme linked immunosorbent assay (PCR-ELISA), and c-Myc expression using immunohistochemistry. RESULTS: The telomerase activity and c-Myc expression were higher in cancers (87.69% and 61.54%) than in noncancerous tissues. They were higher in chronic atrophic gastritis with severe intestinal metaplasia (52.38% and 47.62%) than in chronic atrophic gastritis with mild intestinal metaplasia (13.33% and 16.67%). In chronic atrophic gastritis with severe intestinal metaplasia, the telomerase activity and c-Myc expression were higher in cases with H pylori infection (67.86% and 67.86%) than in those without infection (21.43% and 7.14%). c-Myc expression was higher in gastric cancer with H pylori infection (77.27%) than in that without infection (28.57%). The telomerase activity and c-Myc expression were coordinately up-regulated in H pylori infected gastric cancer and chronic atrophic gastritis with severe intestinal metaplasia. CONCLUSION: H pylori infection may influence both telomerase activity and c-Myc expression in gastric diseases, especially in chronic atrophic gastritis.

Clinical significance of functional constipation categorized by colonic transit time and pelvic floor electromyography.

OBJECTIVE: Functional constipation (FC) is a common gastrointestinal disorder, the incidence of which is increasing each year with the changes in life style and diet, and the age of patients is becoming younger. Correct categorization will guide the treatment of FC and in the present study colonic transit time (CTT) and pelvic floor electromyography (PFE) were evaluated for their clinical significance in categorizing FC. METHODS: Thirty-two cases of FC diagnosed by Rome II criteria with a duration of 6 months to 30 years were enrolled. Radio-opaque markers were used to detect CTT, the transit index (TI) and colonic evacuation rate; PFE was used to observe whether there was any paradoxical movement between the pelvic floor and abdominal muscles. RESULTS: Colonic transit time was recorded in 32 patients: 20 had outlet obstruction constipation and 12 had slow transit type. In the outlet obstruction type, PFE showed varying degrees of paradoxical movement between the muscles, whereas in the slow transit type, only 4 cases showed it. CONCLUSION: Functional constipation can be categorized by CTT and PFE, which are simple, painless and feasible to perform.

[Coordinated expression of c-Myc and telomerase activity in Helicobacter pylori infected gastric diseases].

OBJECTIVE: To detect the telomerase activity and c-Myc expression in gastric diseases and to examine the relation between these values and Helicobacter pylori (Hp) as a risk factor for gastric cancer. METHODS: 171 gastric samples were studied to detect telomerase activity with telomerase polymerase chain reaction enzyme linked immunosorbent assay and c-Myc expression using immunohistochemistry. RESULTS: Telomerase activity and c-Myc expression were higher in cancers (87.7% and 61.5%) than in noncancerous tissues. Telomerase activity and c-Myc expression were higher in chronic atrophic gastritis with moderate or severe intestinal metaplasia (52.4% and 47.6%) than in chronic atrophic gastritis with mild intestinal metaplasia (13.3% and 16.7%). In chronic atrophic gastritis with moderate or severe intestinal metaplasia, telomerase activity and c-Myc expression were higher in cases with Hp infection (67.9% and 67.9%) than in these without infection (21.4% and 7.1%). c-Myc expression was higher in gastric cancer with Hp infection (77.3%) than that without infection (28.6%). Telomerase activity and c-Myc expression were coordinately up-regulated in Hp infected gastric cancer and chronic atrophic gastritis with moderate or severe intestinal metaplasia. CONCLUSIONS: Hp infection may influence both c-Myc expression and telomerase activity in gastric diseases, especially in chronic atrophic gastritis. c-Myc and telomerase co-expressed in gastric cancer and chronic atrophic gastritis with moderate or severe intestinal metaplasia.

[EGF/PI3K signaling pathway regulates the expression of osteopontin in liver cancer HepG2 cells].

OBJECTIVE: To investigate the effect of epidermal growth factor (EGF) on the expression of osteopontin (OPN) in liver cancer HepG2 cells. METHODS: Human liver caner cells of HepG2 line were cultured in medium without bovine serum. EGF was added. Another cells were pretreated with specific phosphatidylinositol 3 (PI3) inhibitor Wortmannin and then added with EGF. HepG2 cell were collected. RNase prote4ction assay and Western blotting were used to examine the expression of OPN in the HepG2 cells. RESULTS: HepG2 cells cultured in the bovine serum free medium expressed very low level of OPN. EGF increased the expression of OPN mRNA and protein in a dose- and time-dependent manners. Pretreatment of Wortmannin significantly reduced the EGF-induced OPN expression. CONCLUSION: EGF increases the OPN expression, possibly through PI3 signaling pathway. It is possible to block the synthesis of OPN through manipulating several target genes, thus inhibiting the metastasis of liver cancer.

Multiple genetic alterations and behavior of cellular biology in gastric cancer and other gastric mucosal lesions:H.pylori infection, histological types and staging.

AIM:To investigate the expression of multiple genes and the behavior of cellular biology in gastric cancer (GC) and other gastric mucosal lesions and their relations to Helicobacter pylori (H. pylori) infection, tumor staging and histological subtypes.METHODS:Three hundred and twenty seven specimens of gastric mucosa obtained via endoscopy or surgical resection, and ABC immunohistochemical staining were used to detect the expression of p53, p16, Bcl-2 and COX-2 proteins.H. pylori was determined by rapid urea test combined with patholo-gical staining or 14 Curea breath test. Cellular image analysis was performed in 66 patients with intestinal metaplasia (IM) and/or dysplasia (Dys). In 30 of them, both cancer and the paracancerous tissues were obtained at the time of surgery. Histolo-gical pattern, tumor staging, lymph node metastasis, grading of differentiation and other clinical data were studied in the medical records.RESULTS:p16 expression of IM or Dys was significantly lower in positive H. pylori chronic atrophic gastritis (CAG) than those with negative H. pylori (CAG: 54.8% vs 88.0%, IM:34.4% vs 69.6%, Dys: 23.8% vs 53.6%, all P < 0.05), Bcl-2 or COX-2 expression of IM or Dys in positive H. pylori cases was signi-ficantly higher than that without H. pylori (Bcl-2: 68.8% vs 23.9%, 90.5% vs 60.7%; COX-2: 50.0% vs 10.8%, 61.8% vs 17.8%; all P <0.05). The mean number of most parame-ters of cellular image analysis in positive H. pylori group was significantly higher than that in negative H. pylori group (Ellipser: 53 plus minus 14, 40 plus minus 12&mgr;m, Area(1): 748 plus minus 572, 302 plus minus 202&mgr;m(2), Area(2): 3050 plus minus 1661, 1681 plus minus 1990&mgr;m(2), all P< 0.05; Ellipseb: 79 plus minus 23, 58 plus minus 15&mgr;m, Ratio-1: 22% plus minus5%,13% plus minus4%,Ratio-2:79% plus minus17%,53% plus minus20%,all P<0.01). There was significant correl-ation between Bcl-2 and histologic pattern of gastric carcinoma, and between COX-2 and tumor staging or lymph node metasta sis (Bcl-2: 75.0% vs16.7%; COX-2: 76.0% vs 20.0%, 79.2% vs 16.7%; all P< 0.05).CONCLUSION:p16, Bcl-2, and COX-2 but not p53 gene may play a role in the early genesis/progression of gastric carcinoma and are associated with H. pylori infection. p53 gene is relatively late event in gastric tumorigenesis and mainly relates to its progression. There is more cellular-biological behavior of malignant tumor in gastric mucosal lesions with H. pylori infec-tion. Aberrant Bcl-2 protein expression appears to be preferentially associated with the intestinal type cancer. COX-2 seems to be related to tumor staging and lymph node metastasis.

[A randomized controlled Multi-center clinical trial on mosapride in the treatment of functional dyspepsia].

OBJECTIVE: To evaluate the effectiveness and safety of mosapride on treatment of functional dyspepsia. METHODS: Randomized controlled clinical trial was conducted and patients suffered from functional dyspepsia were included. 5 mg mosapride was given three times daily for 4 weeks in the treatment group. 10 mg domperidone was given three times daily for 4 weeks as control. Changes on symptom score, gastric empty or new occurring events were included as outcomes. RESULTS: 231 patients suffered from functional dyspepsia were selected by inclusion and exclusion criteria from August 15 to Oct 22, 1999. Of these, 108 (46.8%) were males, versus 123 (53.2%) females and 118 (51.2%) in the treatment group and 113 (48.9%) as controls. 222 (96.1%) patients were followed up. Results showed that the total efficacy rates in early satiety and abdominal distension were 84.5% and 90.1% in mosapride after the 2 weeks of treatment. Mosapride seemed to be more effective in improving symptoms of belching and heartburn than that in controls (P < 0.05). In 4 weeks, the total efficacy in improving symptoms of abdominal distention and belching showed more effective in mosapride than that in controls (P < 0.05). Decrease of symptoms score was more in mosapride than that in controls (P < 0.05). Mosapride was less effective in controls in improving the gastric empty in terms of proportion (46.2% vs. 25.9%, P = 0.020) and range (46.2% vs. 24.0%, P = 0.003). Side effects would include diarrhea, constipation, headache, dizziness, insomnia, skin scare and the like. There was no significant difference between the two groups (9.6% in mosapride vs. 14.0% in controls). CONCLUSION: Mosapride was safe and effective in improving the symptoms and gastric empty of functional dyspepsia.