[Correlation between weight variability and the risk of diabetic nephropathy in patients with type 2 diabetes mellitus].

Objective: To evaluate the relationship between different indexes of weight variability and the risk of diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM). Methods: A retrospective cohort study. The clinical data of 2 180 T2DM patients without DKD who underwent case management at Lee's United Clinic in Taiwan, China from 2002 to 2018 were retrospectively analyzed, including 1 103 females and 1 077 males, with an average age of (64.8±12.4) years. Regular follow-up was conducted for patients for at least 2 years, and their metabolic indexes were monitored annually. BMI variability independent of the mean (BMI-VIM), average yearly mean square successive difference (BMI-ASV), coefficient of variation (BMI-CV) and standard deviation (BMI-SD) were calculated,based on the body mass index (BMI) recorded annually by the patients. Patients were divided into four groups (Q1-Q4) based on the quartiles of the four weight variability indexes. DKD group and non-DKN group(NDKD group) were defined based on the occurrence of DKD at the end of the follow-up. Cox proportional hazards regression models were used to analyze the relationship between the four weight variability indicators and the incidence of DKD. Subgroup analysis was performed by categorizing patients into non-obesity (BMI<28 kg/m2) and obesity groups (BMI≥28 kg/m2) to investigate the impact of the four weight variability indicators on the risk of DKD. Results: After a follow-up of (4.55±2.13) years, 904 patients developed DKD. Compared with the NDKD group, patients in the DKD group had a higher proportion of females, older age, longer duration of diabetes, more insulin users, higher waist-to-hip ratio, higher levels of BMI-VIM, BMI-ASV, BMI-CV, BMI-SD, systolic blood pressure, diastolic blood pressure, and urine albumin-creatinine ratio, a lower proportion of hypoglycemic drugs, estimated glomerular filtration rate, and high-density lipoprotein cholesterol level, with statistically significant differences between the two groups(all P<0.05). Cox proportional hazards regression analysis results revealed that the risk of DKD in T2DM patients increased with the increase in BMI-SD, BMI-CV, BMI-VIM, and BMI-ASV after correcting a series of influencing factors. In the BMI-VIM subgroup, compared with the Q1 group, the risk of DKD in the Q4 group increased by 22.4% [HR=1.224 (95%CI:1.008-1.487), P=0.041]. In the BMI-ASV group, compared with the Q1 group, the risk of DKD in the Q4 group increased by 51.1% [HR=1.511 (95%CI:1.240-1.841), P<0.01]. In the BMI-CV group, compared with the Q1 group, the risk of DKD in the Q4 group increased by 22.2% [HR=1.222 (95%CI:1.006-1.485), P=0.044]. In the BMI-SD subgroup, compared with the Q1 group, the risk of DKD in the Q4 group increased by 22.2% [HR=1.222 (95%CI:1.002-1.490), P=0.048]. Sub-group analysis showed that when the non-obesity group was grouped by BMI-ASV, after correcting a series of influencing factors, compared with the Q1 group, the highest risk of DKD occurred in the Q4 group [HR=1.551 (95%CI:1.228-1.958), P<0.001];when the obesity group was grouped by BMI-ASV, after correcting a series of influencing factors, compared with the Q1 group, the highest risk of DKD occurred in the Q4 group [HR=1.703 (95%CI:1.168-2.485), P=0.006]. Conclusion: Increases in BMI-VIM, BMI-ASV, BMI-CV, and BMI-SD are associated with an increased risk of DKD in T2DM patients.

[Effect of 2-year resistance exercises on cardiovascular disease risk in prediabetes patients].

Objective: To investigate the effect of a 2-year resistance and aerobic training on reducing the risk of cardiovascular disease in patients with prediabetes. Methods: A total of 248 patients with prediabetes were enrolled from Chinese and Western Medicine Hospital Affiliated to Nanjing University of Chinese Medicine from January to April 2014, and Danyang People's Hospital and The First Affiliated Hospital of Guangxi Medical University from May to December 2014.Based on random number table method, the patients were divided into 3 groups: the resistance training group (RT group, 82 cases), the aerobic training group (AT group, 83 cases) and control group (83 cases). Participants in the RT group and the AT group underwent a total of 24 months of exercise training. Changes in indicators (blood glucose,blood lipid, etc.) at baseline and the end of 12 and 24 months among the groups were compared. Results: After intervention, glycosylated hemoglobin (HbA1c), low density lipoprotein cholesterol (LDL-C), blood pressure and homeostasis model 2 insulin resistance index (HOMA2-IR) in the RT and AT groups tended to decrease, and the steady state model 2 ß cell function index (HOMA2-ß) tended to increase. At the end of 24 months, HbA1c [5.80 (5.43, 6.20) %, 5.70 (5.50, 6.00)% vs. 6.20 (5.70, 6.60) %, all P ≤ 0.01], LDL-C [3.07 (2.69, 3.58) mmol/L, 2.97 (2.62, 3.95) mmol/L vs. 3.21(2.54, 3.78) mmol/L, all P<0.05] and HOMA2-IR [0.96 (0.82, 1.47), 1.20 (0.99, 1.43) vs. 1.34 (1.09, 1.51), all P<0.05] were significantly decreased in the RT and AT groups than in the control group. In addition, HOMA2-ß [84.50 (60.55, 107.33), 93.00 (78.60, 119.75) vs. 53.40 (37.70, 80.40), all P = 0.001] was significantly increased in the AT and RT groups compared with that in the control group. There were no significant differences in triglyceride (TG) and high-density lipoproteincholesterol (HDL-C) levels between the training groups and the control group (all P>0.05). After adjusting for age, sex and blood pressure, the cardiovascular risk of prediabetes was significantly reduced in RT (P =0.017) and AT groups (P =0.018). The Cox regression analyses showed that both the resistance training (HR=0.419, 95%CI =0.415-0.942, P=0.037) and the aerobic training (HR=0.310, 95%CI=0.447-0.866, P=0.026) were protective factors for cardiovascular disease in prediabetic patients after adjustment of age, sex, statins, body mass index and waist-to-hip ratio, which reduced the risks of cardiovascular disease in prediabetic patients by 58.1% and 69.0%, respectively. Conclusions: Two years of aerobic and resistance training interventions have obvious advantages on glycemic and insulin resistance control in prediabetes patients. The resistance training can reduce the risk of cardiovascular disease, and it is, thus, recommended for prediabetic patients without obvious exercise contraindications.

[Effect of intervention programs regarding community "5+1" staged diabetes target management on patients with type 2 diabetes mellitus].

Objective: To analyze the effect of intervention programs and influencing factors regarding the community "5+1" staged diabetes target management on patients with type 2 diabetes mellitus (T2DM) and to provide evidence for improving the quality of life (QOL). Methods: A total of 12 community health service centers from Shanxi province, Jiangsu province, and Ningxia Hui autonomous region were selected as intervention group and control group, by stratified cluster sampling method. "5+1" model was used in intervention groups and basic public health services model was applied in control groups for this two-year follow-up. Data was collected through a questionnaire on demographic and disease-related information, while the QOL was measured with SF-36. Multiple linear regression and conducted by SAS 9.4. Results: A total of 2 467 subjects were included at baseline and 1 924 had completed a two-year-long management service. After intervention programs being implemented, the net effect of PCS score between the intervention and the control groups was 13.6, with the net effect of MCS score as 29.8. Results from the multiple linear regression showed that the main factors affecting PCS scores included age, type of medical insurance, baseline PCS score and regions of residency. Main factors related to MCS score included age, type of medical insurance, baseline MCS score, hypertension, and region of residency. Conclusion: Community "5+1" staged diabetes target management model presented favorable effect of improving the QOL on T2DM patients.

Detection of hand-foot-mouth disease and its spatial-temporal Epidemiological characteristics with GIS platform.

The aim of this study is to investigate the main category of hand-foot-mouth (HFM) virus and analyze the distribution characteristics and susceptible population of HFM disease in China. Infants who have had HFM disease for less than 7 days were selected from the First Affiliated Hospital of Guangxi Medical University, Guangxi, China. Various specimens were collected from the infants, and EV71 and CA16 nucleic acid detections were performed using fluorescence quantitative assay. The positive results of the specimens were compared to determine the components of the pathogen. Moreover, the data of the target cases were analyzed based on Geographic Information System (GIS) to obtain the spatial-temporal epidemiological features of HFM disease in China. The detection rate of HFM virus in the throat swab, feces, bleb fluid and cerebrospinal fluid were 75%, 81.13%, 85.71% and 25%, respectively, indicating that the detection rate of virus in the bleb fluid was the highest. When the detection was based on more than one specimen, it was found that the positive rate was higher compared to detection based on a single specimen. The positive detection rate of EV71 in the target specimens was significantly higher than that of CA16 and mixed infection. Moreover, CA16 infection was usually accompanied by EV71 infection. As to spatial-temporal distribution, hand-foot-month disease broke out in the South of China in April, then spread to the north, and diminished in July. There was a notable difference in the number of cases between different provinces. EV71 and CA16 are the main viruses inducing HFM disease, especially EV71. Fluorescence quantitative polymerase chain reaction with high sensitivity can be used to detect the copy number of viruses, which is applicable to the early diagnosis of HFM disease. The incidence of HFM disease is notably different according to the influence of time, geographical space, gender and the living conditions of the children. Early diagnosis and treatment based on scientific methods are needed to reduce the incidence of severe diseases and avoid death.

[Effect of perioperative multi-day low dose ketamine infusion on prevention of postmastectomy pain syndrome].

Objective: To investigate the effects of multi-day low dose ketamine infusion for postmastectomy pain syndrome (PMPS) after breast cancer surgery. Methods: This study was a prospective randomized controlled trial. From June 2015 to May 2016 in Affiliated Yiwu Hospital of Wenzhou Medical University, 66 patients with breast cancer surgery were randomly divided into control group (group C) and ketamine group (group K). Patients in group K were infused with 0.5 mg/kg of ketamine mixed in 250 ml of 0.9% normal saline in 1 h daily for 7 days. Patients in group C were infused the same dose of 0.9% normal saline. Anesthesia induction in both groups were given intravenous midazolam, sufentanil, propofol, vecuronium and intermittent positive pressure ventilation after tracheal intubation, anesthesia was maintained with propofol and remifentanil. After awakening, all patients were monitored in postanesthesia care unit (PACU) and given patient-controlled intravenous analgesia(PCIA). Pain scores were assessed using visual analogue scales (VAS) during PACU, 4 h, 24 h and 2-5 d after surgery, simultaneously analgesic requirement were recorded. Patients were evaluated Hospital Anxiety and Depression Scale (HADS) 5 d after surgery . The patients were followed up for 6 months. At 3 m, 6 m after surgery, the incidence of PMPS, the level of pain, pain site and HADS scale were assessed. Results: The VAS score uring PACU, 4 h, 24 h and 2-5 d after surgery in group K( (2.5±0.8), (2.4±0.5), (2.4±0.5), (2.0±0.4), (1.5±0.5), (1.0±0.4), 1(1), respectively) was lower than those in group C ((2.9±1.0), (2.9±0.6), (2.6±0.5), (2.3±0.5), (1.8±0.6), (1.5±0.5), 1(0), respectively). There was statistically difference between the two groups (all P<0.05). The consumption of analgesics required at each time postoperation in group K were also lower than that of group C(all P<0.05). Followed up for 6 months, 2 lost in group C, 1 lost in group K. The incidence of PMPS in group K at 3 months and 6 months after surgery was significantly lower(25% and 22%) than that in group C(52% and 45%)(χ(2)=4.729, 3.842, all P<0.05). There were no significant difference in pain level and site between two groups of PMPS patients (all P>0.05). There were no significant difference of HADS scale preoperative and 5 d after surgery between two groups (all P>0.05); and HADS scale in group K at 3 m and 6 m after surgery was significantly lower than that in group C(all P<0.05). Conclusion: Perioperative continuous multi-day low dose ketamine infusion can effectively reduce the incidence of PMPS after breast cancer surgery.

[Effect of intravenous infusion with lidocaine on rapid recovery of laparoscopic cholecystectomy].

Objective: To investigate the effect of intravenous infusion with lidocaine on rapid recovery of laparoscopic cholecystectomy. Methods: This study was a prospective randomized controlled trial. From February to August 2016 in Affiliated Yiwu Hospital of Wenzhou Medical University, 60 patients scheduled for laparoscopic cholecystectomy under general anesthesia were involved and randomly divided into control group (n=30) and lidocaine group (n=30). Patients in lidocaine group received lidocaine 1.5 mg/kg intravenously before induction and followed by 2.0 mg·kg(-1)·h(-1) to the end of surgery. Patients in control group received equal volumes of saline intravenously. Anesthesia induction in both groups were given intravenous midazolam 0.03 mg/kg, sufentanil 0.2 µg/kg, propofol 2.0 mg/kg and cisatracuium 0.2 mg/kg. Anesthesia was maintained with propofol 0.05-0.20 mg·kg(-1)·min(-1) and remifentanil 0.1-0.5 µg·kg(-1)·min(-1) for laryngeal mask airway which bispectral index (BIS) value maintained at 40-60. BIS, heart rate(HR) and mean arterial pressure(MAP) were recorded before anesthesia induction, before and immediately after laryngeal mask implantation, intraoperative 30 min and anesthesia awake. Pain scores were assessed using visual analogue scales (VAS) at postoperation immediately, 30 min during postanesthesia care unit (PACU), 2, 6, 12, and 24 h after surgery. The time of PACU retention, postoperative ambulation, first intestine venting and discharge were recorded. The dosage of propofol and remifentanil, the frequency of sufentanil used, the incidence of postoperative nausea and vomiting were also recorded. Patient satisfaction was evaluated by using Simple Restoration Quality Score (QoR-9). Results: BIS values before and after laryngeal mask implantation in lidocaine group were 50.50±3.47 and 54.63±1.25 respectively, which was lower than those in control group(54.30±4.78, 55.80±2.33; t=3.542, 2.423, all P<0.05). The VAS score at postoperation immediately, PACU 30 min, postoperative 2, 6, 12 h in lidocaine group were 2.76±0.97, 2.37±0.93, 2.10±1.12, 1.76±0.97, 1.20±0.76 respectively, which was lower than those in control group (3.83±1.34, 3.27±1.26, 3.06±1.20, 2.63±0.88, 1.90±0.84; t=3.528, 3.154, 3.217, 3.603, 3.372, all P<0.05 ). The frequency of additional sufentanil at postoperation immediately and PACU 30 min in lidocaine group was 5(17%), 3(10%), which were less than those in control group(12(40%), 9(30%); χ(2)=4.022, 3.950, all P<0.05). The dosage of propofol and remifentanil in lidocaine group were (4.33±0.75) mg·kg(-1)·h(-1) and (9.00±1.66) µg·kg(-1)·h(-1) respectively, which were less than those in control group ((5.20±1.39) mg·kg(-1)·h(-1) and (10.43±2.20) µg·kg(-1)·h(-1;) t= 2.982, 2.842, all P<0.05). The time of PACU retention, postoperative ambulation and first intestine venting were (39.90 ± 8.06) min, (11.93±1.68) h and (10.16±1.05) h respectively in lidocaine group, which were shorter than those in control group ((48.23±10.04) min, (13.16±1.58) h and (11.13±1.30) h; t=3.514, 2.931, 3.156, all P<0.05). The QoR-9 score in lidocaine group was 15.60±1.07, which was higher than that in control group(14.73±0.74, t=-3.649, P<0.05). There was no significant difference in the incidence of postoperative nausea/vomiting and the discharge time between two groups (all P>0.05). Conclusion: Intravenous infusion of lidocaine can effectively reduce the dosages of propofol and remifentanil, postoperative early VAS score, postoperative ambulation time and first intestine venting time which could improve the satisfaction of patients.

[A clinical analysis of insulin antibody in type 2 diabetic patients].

This study was conducted to evaluate the relationship between serum insulin levels and the production of insulin antibody (IA) in type 2 diabetes (T2DM). A total of 647 T2DM were included. Among them, 20.9% patients were IA positive, who were elder and had a longer duration, lower BMI, a higher positive rate of glutamic acid decarboxylase antibody(GADAb) and higher serum insulin levels during an insulin secretion test. More patients were treated with insulin in IA positive group than in IA negative group (65.9% vs 41.0%, P=0.000). Fasting serum insulin level was associated with occurrence of IA in all patients (OR=1.02, P=0.001) and insulin treated patients (OR=1.033, P=0.002). The cut-off point of fasting serum insulin level for predicting IA positive was 17.87 mIU/L (sensitivity 55.1%, specificity 89.0%). Exogenous insulin use is associated with the presence of IA. Fasting serum insulin level can be used as a predictor for the production of IA in insulin-treated patients.

Cardiovascular risk and events in 17 low-,middle-, and high-income countries

BACKGROUNDMore than 80% of deaths from cardiovascular disease are estimated to occur inlow-income and middle-income countries, but the reasons are unknown.METHODSWe enrolled 156,424 persons from 628 urban and rural communities in 17 countries(3 high-income, 10 middle-income, and 4 low-income countries) and assessedtheir cardiovascular risk using the INTERHEART Risk Score, a validated score forquantifying risk-factor burden without the use of laboratory testing (with higherscores indicating greater risk-factor burden). Participants were followed for incidentcardiovascular disease and death for a mean of 4.1 years.RESULTSThe mean INTERHEART Risk Score was highest in high-income countries, intermediatein middle-income countries, and lowest in low-income countries (P<0.001).However, the rates of major cardiovascular events (death from cardiovascularcauses, myocardial infarction, stroke, or heart failure) were lower in high-incomecountries than in middle- and low-income countries (3.99 events per 1000 personyearsvs. 5.38 and 6.43 events per 1000 person-years, respectively; P<0.001). Casefatality rates were also lowest in high-income countries (6.5%, 15.9%, and 17.3%in high-, middle-, and low-income countries, respectively; P = 0.01). Urban communitieshad a higher risk-factor burden than rural communities but lower ratesof cardiovascular events (4.83 vs. 6.25 events per 1000 person-years, P<0.001) andcase fatality rates (13.52% vs. 17.25%, P<0.001). The use of preventive medicationsand revascularization procedures was significantly more common in high-incomecountries than in middle- or low-income countries (P<0.001).CONCLUSIONSAlthough the risk-factor burden was lowest in low-income countries, the rates ofmajor cardiovascular disease and death were substantially higher in low-incomecountries than in high-income countries. The high burden of risk factors in highincome...

Rabbit-specific ventricular model of cardiac electrophysiological function including specialized conduction system.

The function of the ventricular specialized conduction system in the heart is to ensure the coordinated electrical activation of the ventricles. It is therefore critical to the overall function of the heart, and has also been implicated as an important player in various diseases, including lethal ventricular arrhythmias such as ventricular fibrillation and drug-induced torsades de pointes. However, current ventricular models of electrophysiology usually ignore, or include highly simplified representations of the specialized conduction system. Here, we describe the development of an image-based, species-consistent, anatomically-detailed model of rabbit ventricular electrophysiology that incorporates a detailed description of the free-running part of the specialized conduction system. Techniques used for the construction of the geometrical model of the specialized conduction system from a magnetic resonance dataset and integration of the system model into a ventricular anatomical model, developed from the same dataset, are described. Computer simulations of rabbit ventricular electrophysiology are conducted using the novel anatomical model and rabbit-specific membrane kinetics to investigate the importance of the components and properties of the conduction system in determining ventricular function under physiological conditions. Simulation results are compared to panoramic optical mapping experiments for model validation and results interpretation. Full access is provided to the anatomical models developed in this study.

Delayed gastric emptying is related to cardiovascular autonomic neuropathy in Chinese patients with type 2 diabetes.

BACKGROUND AND STUDY AIMS: Delayed gastric emptying (DGE) is the commonest gastrointestinal (GI) complication in type 2 diabetes. We aimed to evaluate the association between DGE and cardiovascular autonomic neuropathy (CAN) in type 2 diabetes. PATIENTS AND METHODS: A total of 71 Chinese patients (39 men and 32 women, aged 60-90 years) and 30 controls (12 men and 18 women, aged 50-79 years) were studied in Nanjing, China. The gastric emptying was assessed by 13C-octanoic acid breath test (OBT) and gastric emptying ultrasonography (GEU). Cardiovascular autonomic neuropathy (CAN) was assessed by a scoring system being validated before. RESULTS: The diabetic patients, except for a higher plasma glucose level, had similar characteristics compared to the non-diabetic controls. Diabetic patients had higher incidence of DGE and CAN than controls (48.5% vs. 10.7%, p = 0.001). Among diabetic patients with DGE (n = 27), 18 (66.7%) had CAN and 9 (33.3%) did not. Corresponding figures for those without DGE (n = 39) were 14 (35.9%) and 25 (64.1%), respectively (p = 0.014). Diabetes was independently associated with the risk of DGE with odd ratio (95% CI) of 15.6 (1.92, 127.06) (p = 0.010). The presence of diabetes or CAN was independently associated with the half gastric emptying time after adjusting for age, gender, plasma glucose and blood pressure. CONCLUSIONS: We found a much prolonged gastric emptying time in Chinese patients with type 2 diabetes as compared to non-diabetic controls. There was a high rate of CAN in diabetic patients, and it was associated with gastric emptying.

Development and characterization of potent and specific peptide inhibitors of p60c-src protein tyrosine kinase using pseudosubstrate-based inhibitor design approach.

The cytoplasmic protein p60c-src, an ubiquitous non-receptor protein tyrosine kinase (PTK) is a potential anticancer target as it is over-expressed and/or constitutively active in several cancer types. In addition, the phenotype of c-src knock-out mice is consistent with osteopetrosis, which suggests that inhibitors against this enzyme may also be therapeutic for osteoporosis. Using a known peptide substrate for c-src, MIYKYYF, as a template, we have developed a series of pseudosubstrate-based peptide inhibitors. Structure-activity relationship studies have been performed on one of these inhibitors, CIYKYYF. In a kinase assay using YIYGSFK as the substrate, CIYKYY has been demonstrated to inhibit p60c-src, with an IC50 of 0.6 microm. Further truncation has led to the determination that even the smaller peptide, CIYK, is a moderately potent inhibitor with IC50 of 15 microm. Some improvement in inhibitory potency (IC50 = 11.8 microm) has been observed with the replacement of Tyr3 in CIYK with beta-phenylalanine (beta-Phe). The tetrapeptide CI(beta-Phe)K will be used as a lead compound for future development of peptidomimetics and small molecule inhibitors that have the capacity to penetrate the plasma membrane of intact cells.

A comparison of the effect of three sedatives on esophageal sphincters in cats.

BACKGROUND/AIMS: Children 5 years old and younger often require sedation for esophageal motility studies (EMS). At our institution, an intramuscular cocktail of meperidine, promethazine and chlorpromazine (MPC) has been used as the standard sedative for young children undergoing EMS. Administering the intramuscular sedative may, however, be more traumatic to the child than the procedure. Moreover, its effect on esophageal motility is not known and prolonged sedation is common. The aim of this study was to determine the effects of MPC and two orally-administered sedatives on esophageal sphincter function, using the cat model, with a goal to identify a potentially suitable orally-administered sedative for use in young children requiring sedation for EMS. METHODS: We measured upper (UESP) and lower (LESP) esophageal sphincter pressures in 25 cats initially without sedation, and then following sedation with midazolam, chloral hydrate and MPC. The results were compared. RESULTS: All three sedatives significantly decreased LESP compared to the control (p<0.05). Midazolam decreased LESP the most; however, the difference from the other sedatives did not reach statistical significance. All three sedatives decreased UESP, compared to control, but the differences were not statistically significant. Of the two oral sedatives, chloral hydrate had the least effect on the esophageal sphincters although its effect was not statistically different from that of midazolam. CONCLUSIONS: Ethically appropriate studies are needed to determine which oral sedative would be most beneficial for use in sedating children undergoing esophageal motility studies. Until studies can be done, the choice between chloral hydrate and midazolam should be based on the experience and comfort of the attending physician with regard to the potential side effects of the medications.

Prevalence of immunoglobulin G to Helicobacter pylori among endoscopy nurses/technicians.

The purpose of this study was to compare the prevalence of Helicobacter pylori (HP) seropositivity among gastroenterology nurses and technicians with that of the general population. Nurses attending the 1996 Indiana Society of Gastroenterology Nurses and Associates Spring and Fall Education Courses were asked to complete a checklist regarding employment, current symptoms, and use of universal precautions, and to have 3 ml blood drawn. These 138 blood specimens as well as 112 serum samples from generally age- and sex-matched blood donors (representing the general population) underwent qualitative HP antibody testing. Results showed that the prevalence of seropositivity for immunoglobulin G (IgG) antibody for HP among the gastroenterology nurses and technicians was 19 of 138 (13.8%), which was less than that of the blood donor control group, whose seropositivity was 20 of 112 (17.9%). However, this difference failed to reach statistical significance. Seropositivity tended to increase with age, but there was no association between clinical symptomatology and seropositivity. Likewise, there was no difference in seropositivity between nurses assisting with endoscopic procedures for more than 10 years and those assisting for less than 10 years. Although the differences were not significant, these findings refute those of an earlier study in which the researchers found 122 gastroendoscopists and endoscopy nurses significantly more likely to be positive for HP antibodies. Therefore, the findings reported here provide important information.

A Lewis(y) epitope mimicking peptide induces anti-Lewis(y) immune responses in rabbits and mice.

Lewis(y) carbohydrate antigens are abundant on the surface of many carcinomas. Mab B3 directed against this carbohydrate antigen has been used to make an immunotoxin that is very cytotoxic to cancer cells expressing the Lewis(y) antigen. Mab B3 was also used to screen a phage-displayed peptide library and identified a peptide mimicking the Lewis(y) epitope. In this report, we demonstrate that the Lewis(y) epitope-mimicking peptide induces anti-Lewis(y)immune responses in both rabbits and mice. In addition, Lewis(y) antigens induce anti-peptide immune responses. These results indicate that carbohydrate-mimicking peptides provide a novel strategy to elicit immune responses for tumor-associated carbohydrates.

Comparison of five PCR methods for detection of Helicobacter pylori DNA in gastric tissues.

Five different PCR methods for the detection of Helicobacter pylori were evaluated. The results of this study indicate that of the five PCR methods examined, the ureC (glmM) gene PCR is the most sensitive and specific for the detection of H. pylori in gastric biopsy specimens.

Discovery of a novel series of potent and selective substrate-based inhibitors of p60c-src protein tyrosine kinase: conformational and topographical constraints in peptide design.

On the basis of the efficient substrate for p60c-src protein tyrosine kinase (PTK) YIYGSFK-NH2 (1) (Km = 55 microM) obtained by combinatorial methods, we have designed and synthesized a series of conformationally and topographically constrained substrate-based peptide inhibitors of this enzyme, which showed IC50 values in the low-micromolar range (1-3 microM). A "rotamer scan" was performed by introducing the four stereoisomers of beta-Me(2')Nal in the postulated interaction site of the peptide inhibitor 23(IC50 = 1.6 microM). This substitution led to selective and potent inhibitors of p60c-src PTK; however, no substantial difference in potency was observed among them. This and the results of the "stereochemical scan" performed at residues 2 and 7 of 3 (peptides 19-21), which form the disulfide bond, may suggest that the enzyme active site does not have rigid topographic requirements and thus is able to achieve important conformational changes to bind the ligand as long as the pharmacophore pattern in the inhibitor is conserved. Two new potent iodo-containing nonphosphorylatable tyrosine analogues were also incorporated into our lead inhibitory sequence 23, producing the most potent inhibitors for p60c-src PTK identified thus far in our studies. Compounds 29 and 30 exhibit IC50 values of 0.13 and 0.54 microM, respectively. Peptide 29 is 420-fold more potent than the parent peptide 1. Selectivity studies of peptides 23-30 toward p60c-src, Lyn, and Lck PTK showed in general high Lyn/Src and moderate Lck/Src selectivity ratios. We found that the chi1 space constraints of the specialized amino acids, introduced at position 3 of the peptide lead 23, were not as important as the configuration of the Calpha of that residue to recognize the subtle chemical environment surrounding the active site of Src and Lck PTK, as reflected on the obtained Lck/Src selectivity ratios.

Application of "one-bead one-compound" combinatorial library methods in signal transduction research.

Using a "split-synthesis" solid phase synthetic approach, bead libraries can be generated such that each bead displays only one chemical entity. This "one-bead one-compound" combinatorial library can then be assayed for specific biological properties using either a solid-phase on-bead binding or functional assay, or a releasable solution phase assay. Positive compound-beads can then be isolated for structure determination. Various assay systems to screen such a "one-bead one-compound" library are described. We have used this combinatorial library method to discover peptides that bind to the cell surface immunoglobulins of murine lymphoma cells. Such peptides, when presented in an oligomeric form to a lymphoma cell are able to induce signal transduction. Additionally, we have also applied the "one-bead one-compound" combinatory library approach to elucidate peptide substrate motifs for protein tyrosine kinases. Multiple distinct peptide motifs were identified for p60(c-src) protein tyrosine kinase. Using the identified peptide substrates as templates, potent and highly specific pseudosubstrate-based peptide inhibitors were developed.

Potent pseudosubstrate-based peptide inhibitors for p60(c-src) protein tyrosine kinase.

We recently reported the identification of GIYWHHY as an efficient and specific substrate for p60(c-src) protein tyrosine kinase (PTK) by screening a secondary random peptide library (Q. Lou et al., Bioorg. Med. Chem., 4: 677-682, 1996). Based on the primary structure of GIYWHHY, we designed and synthesized several pseudosubstrate-based peptide inhibitors. Some of these peptide inhibitors are highly potent and specific with IC50 in the low micromolar range. Because both YIYGSFK and GIYWHHY are efficient and specific substrates for p60(c-src) PTK, chimeric branched peptides based on these two sequences were synthesized. These branched peptides inhibit p60(c-src) PTK with high potency, indicating that the enzyme-active site of p60(c-src) PTK can accommodate more than a linear motif. This may explain why seemingly several peptides with very different linear structures can all be phosphorylated by this enzyme.

Rapid and effective method for preparation of fecal specimens for PCR assays.

We have developed a novel method for the preparation of fecal specimens for PCR assays. Approximately 100 mg of solid stool or 200 microliters of liquid fecal sample was thoroughly suspended in 1 ml of water. Fecal debris was removed by low-speed centrifugation (2,800 x g for 2 min). The supernatant was then boiled for 10 min in a water bath and further clarified by high-speed centrifugation (12,000 x g for 5 min). Fifty microliters of the clarified supernatant was then purified by Sepharose CL-6B spin column chromatography, and a portion of the purified supernatant was used for PCR. By this method, stools containing enterotoxigenic Escherichia coli H10407 were amplified by colonization factor antigen I fimbrial gene PCR, with a sensitivity of 100 organisms per reaction. The method was also effective for processing stool specimens for Clostridium difficile toxin A and B gene PCRs. This method is rapid, effective, and simple to perform and will improve the applications of PCR to stool specimens for diagnostic purposes.

Evaluation of 16S rRNA gene PCR with primers Hp1 and Hp2 for detection of Helicobacter pylori.

The PCR primer set Hp1-Hp2, which amplifies a 109-bp fragment of the 16S rRNA gene of Helicobacter pylori, has been widely used for the detection of H. pylori in clinical specimens. We have examined 34 stool samples and 50 human tissue samples from H. pylori-infected and uninfected patients, five human leukocyte samples, and one human cell line by this PCR method. All of these specimens produced a 109-bp PCR product. When Escherichia coli DNA was used as the template, several nonspecific bands, but not the 109-bp band, were observed. No PCR products were generated when DNA samples from five different fungi were used as templates. These results indicate that this 109-bp PCR product was amplified from the human genome. The 109-bp PCR product generated from various clinical specimens also hybridized with the probe pHp, corresponding to a region internal to the PCR product of Hp1-Hp2. We conclude that the 16S rRNA gene PCR with the primer set Hp1-Hp2 is not specific and cannot be used to detect H. pylori in clinical specimens.