Biomedical subjects

Ning Dai

Publications and source records attributed to Ning Dai.

10 recordsLinked to original sources

PubMed2006

Mechanisms of the in vivo inhibition of calcification of bioprosthetic porcine aortic valve cusps and aortic wall with triglycidylamine/mercapto bisphosphonate.

Heart valve replacements fabricated from glutaraldehyde (Glut)-crosslinked heterograft materials, porcine aortic valves or bovine pericardium, have been widely used in cardiac surgery to treat heart valve disease. However, these bioprosthetic heart valves often fail in long-term clinical implants due to pathologic calcification of the bioprosthetic leaflets, and for stentless porcine aortic valve bioprostheses, bioprosthetic aortic wall calcification also typically occurs. Previous use of the epoxide-based crosslinker, triglycidyl amine (TGA), on cardiac bioprosthetic valve materials demonstrated superior biocompatibility, mechanics, and calcification resistance for porcine aortic valve cusps (but not porcine aortic wall) and bovine pericardium, vs. Glut-prepared controls. However, TGA preparation did not completely prevent long-term calcification of cusps or pericardium. Herein we report further mechanistic investigations of an added therapeutic component to this system, 2-mercaptoethylidene-1,1-bisphosphonic acid (MABP), a custom synthesized thiol bisphosphonate, which has previously been shown in a preliminary report to prevent bioprosthetic heterograft biomaterial calcification when used in combination with initial TGA crosslinking for 7 days. In the present studies, we have further investigated the effectiveness of MABP in experiments that examined: (1) The use of MABP after optimal TGA crosslinking, in order to avoid any competitive interference of MABP-reactions with TGA during crosslinking; (2) Furthermore, recognizing the importance of alkaline phosphatase (ALP) in the formation of dystrophic calcific nodules, we have investigated the hypothesis that the mechanism by which MABP primarily functions is through the reduction of ALP activity. Results from cell-free model systems, cell culture studies, and rat subcutaneous implants, show that materials functionalized with MABP after TGA crosslinking have reduced ALP activity, and in vivo have no significant calcification in long-term implant studies. It is concluded that bioprosthetic heart valves prepared in this fashion are compelling alternatives for Glut-prepared bioprostheses.

Alkaline Phosphatase↗

PubMed2005

Improved capsule endoscopy after bowel preparation.

BACKGROUND: The diagnostic yield of capsule endoscopy depends on the quality of visualization of the small-bowel wall and complete passage through the small bowel. This study examined the effect of bowel preparation on the volume of intestinal content and on small-bowel transit. METHODS: Sixty-one consecutive patients (34 men, 27 women; mean age 56 years, range 17-88 years) were enrolled in the study. Although not randomized, 33 patients received a bowel preparation, and 28 had no preparation. Gastric emptying, small-bowel transit time, overall preparation assessment, and bowel-wall visualization were evaluated by 3 investigators who were unaware of whether the patient had undergone bowel preparation. RESULTS: Small-bowel transit time was significantly shorter in patients with bowel preparation (median 213 minutes: 95% CI[190, 267]) than in those without preparation (median 253 minutes: 95% CI[228, 307]) (p <0.01). The capsule reached the cecum in 97% of patients in the bowel-preparation group, compared with 76% in the nonpreparation group (p=0.02). Bowel preparation improved the quality of visualization significantly; this effect was more pronounced in the distal small bowel. CONCLUSIONS: This study demonstrated that bowel preparation accelerates small-bowel capsule transit and leads to a higher rate of complete capsule endoscopy. Visualization of the small bowel was improved by bowel preparation. Bowel preparation before capsule endoscopy is recommended.

Adolescent↗

PubMed2004

Irritable bowel syndrome consulters in Zhejiang province: the symptoms pattern, predominant bowel habit subgroups and quality of life.

AIM: To investigate the pattern of symptoms, predominant bowel habits and quality of life (QOL) by the Chinese version of the SF-36 in irritable bowel syndrome (IBS) consulters in Zhejiang province. METHODS: From January 2001 to January 2002, 662 Roma II criteria-positive IBS patients were enrolled by gastroenterologists in 10 hospitals from Digestive Disease Center of Zhejiang (DDCZ). Patients were classified into constipation predominant IBS (IBS-C), diarrhea predominant IBS (IBS-D) and alternating constipation and diarrhea IBS (IBS-A) according to the predominant bowel habits. All patients were evaluated for the demographic checklists, IBS bowel symptoms, extra-colonic symptoms, and QOL by Chinese version of the SF-36 questionnaire. RESULTS: (1) Besides abdominal pain, the predominant colonic symptoms were in order of altered stool form, abnormalities of stool passage, abdominal distension and passage of mucus in IBS patients. Also, IBS subjects reported generalized body discomfort and psychosocial problems including dyspeptic symptoms, poor appetite, heartburn, headache, back pain, difficulty with urination, fatigue, anxiety and depression. (2) IBS-C and IBS-A are more common among female patients, whereas male patients experienced more cases of IBS-D. In regards to the IBS symptoms, there were significant differences among IBS subgroups. Abdominal pain (frequency > or =2 days per week and duration > or =1 hour per day) was frequent in IBS-A patients (P=0.010 and 0.027, respectively), IBS-D patients more frequently experienced the passage of mucus, dyspeptic symptoms and anxiety (P=0.000, 0.014 and 0.015, respectively). (3) IBS patients experienced significant impairment in QOL, decrements in QOL were most pronounced in vitality, general health, mental health, and bodily pain. Compared with the general population (adjusted for gender and age), IBS patients scored significantly lower on all SF-scales (P<0.001), except for physical function scale (P=0.149). (4) QOL was impaired in all subgroups, particularly in scales of vitality, general health and mental health. Compared with IBS-D, QOL in IBS-C scored significantly lower on physical function, role physical, general health, role emotional, and mental health scales (P=0.037, 0.040, 0.039, 0.005 and 0.026, respectively). CONCLUSION: Besides colonic symptoms, IBS could cause generalized body discomfort and psychosocial problems. The IBS subgroups based on predominant bowel habits are helpful to identify clinical distinction of the IBS. QOL is significantly impaired in IBS patients. The Chinese version of the SF-36 health survey scales may be a useful measurement of IBS patients.

Abdominal Pain↗

PubMed2003

The effect of famotidine on gastroesophageal and duodeno-gastro-esophageal refluxes in critically ill patients.

AIM: To investigate the effect of famotidine on gastroesophageal reflux (GER) and duodeno-gastro-esophageal reflux (DGER) and to explore it's possible mechanisms. To identify the relevant factors of the reflux. METHODS: Nineteen critically ill patients were consecutively enrolled in the study. Dynamic 24 hours monitoring of GER and DGER before and after administration of famotidine was performed. The parameters of gastric residual volume, multiple organ disorder syndrome (MODS) score, acute physiology and chronic health evaluation II (APACHE II) score and PEEP were recorded. Paired t test; Wilcoxon signed ranks test and Univariate analysis with Spearman's rank correlation were applied to analyse the data. RESULTS: Statistical significance of longest acid reflux, reflux time of pH<4 and fraction time of acid reflux was observed in ten critically ill patients before and after administration. P value is 0.037, 0.005, 0.005 respectively. Significance change of all bile reflux parameters was observed before and after administration. P value is 0.007,0.024, 0.005, 0.007, 0.005. GER has positive correlation with APACHE II score and gastric residual volume with correlation coefficient of 0.720, 0.932 respectively. CONCLUSION: GER and DGER are much improved after the administration of famotidine. GER is correlated with APACHE II score and gastric residual volume.

Adult↗

PubMed2003

[Correlation of rdxA gene mutation and metronidazole resistance of Helicobacter pylori].

OBJECTIVE: To demonstrate the correlation of rdxA gene mutation and metronidazole (MTZ) resistance of H.pylori isolates in the local area. METHODS: Clinical strains of H.pylori were isolated from gastric biopsy of patients. Resistance to metronidazole of the isolates was determined by using diffusion test and two fold dilution test. Genome DNAs of the isolates were prepared for PCR to detect rdxA gene. The target amplification products were sequenced after T-A cloning. The sequences were compared with the reported sequences from Hp26695 and 134 other strains of H.pylori. RESULTS: MTZ resistance rate was 76.1% in 21 clinical isolates. The target fragment 886 bp in length containing rdxA gene could be successfully amplified. In comparison with the reported corresponding sequence of H.pylori stain 26695, homologies of the nucleotide sequences from the amplification products were 90.1% approximate, equals 95.1%. Mutations caused by base insertion/deletion and substitution in the MTZ resistance isolates were found. Among these mutations, two types of insertion mutations have not been reported in literatures. No same mutations were present in the MTZ sensitive isolates. CONCLUSION: The rdxA gene mutation may play an important role in MTZ resistance of H.pylori.

Amino Acid Sequence↗

PubMed2003

[Dual cell seeding to improve cell retention on polytetrafluoroethylene grafts].

OBJECTIVE: To improve cell retention on the graft with dual cell seeding technique, adding a layer of smooth muscle cells (SMCs) between the graft and endothelial cells (ECs). METHODS: Polytetrafluoroethylene (PTFE) grafts pretreated with fibronectin were seeded with SMC followed by ECs one day later and exposure to an in vitro flow system. The number of ECs on grafts was counted under microscope. RESULTS: After exposure to the flow for 1 hour, 61% of the ECs lost when the ECs were seeded alone, whereas only 27% of the ECs lost when the ECs were seeded on the top of SMCs. Preconditioning of a cell seeded graft in a low rate flow did not improve cell retention when late exposure to a higher rate flow. CONCLUSION: This in vitro study indicates that using SMCs as a media layer between ECs and graft surface can improve the retention of seeded ECs on PTFE graft.

Blood Vessel Prosthesis↗

PubMed2003

[Effects of Chinese herbal compound on the expression of hepatocyte cytochrome P450IIE1 in rats with alcoholic fatty liver].

OBJECTIVE: To study the effect of Chinese herbal compound (CHC) on the expression of hepatocyte cytochrome P450IIE1 in rat model of alcoholic fatty liver (AFL). METHODS: The AFL rats models were established by administering the drinking water with 40%(v/v) ethanol, and the changes of pathology in liver and hepatocyte P450IIE1 expression, as well as the contents of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), vitamin E (VitE) in liver were detected and compared with those in the control group. RESULTS: Fatty degeneration in liver recovered normally in the CHC-treated group. Immunohistochemical and in situ hybridization examination showed that CHC could inhibit the hepatocyte cytochrome P450IIE1 expression markedly, and restore the contents of MDA, SOD, GSH, VitE to nearly normal range. CONCLUSION: CHC can prevent AFL through inhibiting the hepatocyte cytochrome P450IIE1 expression markedly

Animals↗

PubMed2002

[Virtual colonoscopy in diagnosis of colorectal neoplasia]

OBJECTIVE: To evaluate the value of virtual colonoscopy in diagnosis of colorectal neoplasia. METHODS: Virtual colonoscopy was performed in 29 patients with colorectal neoplasia confirmed by colonoscopy. The results were compared with colonoscopy for each case. RESULTS: Virtual colonoscopy was successfully performed in each patient without any complications. All colorectal carcinomas detected by colonoscopy were identified by virtual colonoscopy. Twenty-five polyps were detected with colonoscopy, whereas only 16 identified by virtual colonoscopy. Compared with the results of colonoscopy, detection rate of polyps greater than 1.0 cm between 0.5 approximate, equals 0.9 cm and less than 0.5 cm in size was 90.0% 62.5% and 28.6% respectively. CONCLUSION: Virtual colonoscopy is fast, minimal invasive and well tolerated. This technique is a valuable clinical method in diagnosis of colorectal cancer and polyps larger than 0.5 cm in size.

Journal Article↗

PubMed2002

[Life quality of patients after cholecystectomy].

OBJECTIVE: To evaluate the quality of life in patients who underwent laparoscopic and open cholecystectomy for chronic cholecystolithiasis. METHODS: A prospective survey was made on 25 patients receiving laparoscopic cholecystectomy (LC group) and 26 patients receiving open cholecystectomy (OC group). The quality of life was measured with the gastrointestinal quality of life index (GLQI) preoperatively, and at 2, 5, 10 and 16 weeks after the operation. RESULTS: The mean preoperative GLQI scores of all dimensions of the quality of life were 112.5 and 110.3 in the LC and OC groups respectively. In the LC group, the quality of life was not considerably reduced at 2 weeks after operation, with a mean GLQI score of 110. There was a significant improvement both in total mean score and in the aspects of symptomatology, emotional and physiological status from 5 to 16 weeks after LC operation. In the OC group, the GLQI score reduced to 102.0 at 2 weeks after surgery (P < 0.05). There were significant reductions in the aspects of symptomatology, physiological and social status as well. The GLQI scores reached to the preoperative level of 115.6 at 10 weeks after the operation (P > 0.05). The patients experienced significant improvements of GLQI at 16 weeks after OC operation (P < 0.01 or P < 0.05). The LC group showed better GLQI scores than did the OC group for up to 10 weeks postoperatively (P < 0.05). CONCLUSIONS: LC is betler or more rapidly than OC is improving the quality of life postoperatively. The assessment of the quality of life is valuable for measuring the outcome of surgical treatment.

Adult↗

PubMedDate not supplied

Quality of life and cost-effectiveness of combined therapy for reflux esophagitis.

OBJECTIVE: To evaluate clinical, Quality of Life (QoL) and medical cost outcomes in patients with symptomatic reflux esophagitis (RE) receiving different "triple combination therapy". METHODS: A multicenter medical effectiveness trial conducted in 10 hospitals of 5 regions in Zhejiang Province. 248 patient-volunteers were assigned to 8 weeks of "triple combination therapy" with Lansoprazole plus Cisapride and Sucralfate or Ranitidine plus Cisapride and Sucralfate. Main outcomes assessment included symptoms scale scores, RE severity, QoL at baseline and 8 weeks. Medical cost data were collected with cost analysis questionnaire. RESULTS: (1) More Lansoprazole group patients noted RE symptoms resolution than Ranitidine group (92.3% vs 78.4%, P<0.01). There was no striking difference between two groups in RE healing rate (90.8% vs 82.9%, P>0.05). (2) RE significantly impaired QoL of patients (P<0.001). Compared with Ranitidine group, QoL in Lansoprazole group had significant improvement (rate of "good" QoL 64.5% vs 45.6%, P<0.01). (3) There was close correlation between symptomic effectiveness and QoL rating scale in both the Lansoprazole and Ranitidine group (P<0.01, r=0.235 and 0.353 respectively). There were no statistical difference of medical cost between the two groups (P>0.05). CONCLUSION: RE significantly impaired QoL of patients. "Triple combination therapies" can significantly improve RE symptoms and QoL. Lansoprazole combination therapy was more cost-effective than Ranitidine combination group.

2-Pyridinylmethylsulfinylbenzimidazoles↗