A prospective multicentre controlled study of Gaoweikang (Chinese multiherb extract-based tincture) used in high-risk HPV infections

OBJECTIVE

The aim of the study was to investigate the safety and antiviral efficacy of a Chinese multiherb extract-based tincture (GWK) on a population of patients with high-risk human papilloma (hrHPV) infections and hrHPV-caused cervical low-grade squamous intraepithelial lesions (LSILs).

PATIENTS AND METHODS

Patients with persistent hrHPV infection were enrolled in Group A, including A1 subjects, who received the intervention, and A2 subjects, who received the control. Patients with hrHPV infection causing cervical LSIL were enrolled in Group B, which included B1 subjects, who received the intervention, and B2 subjects, who served as the control. For Groups A1 and B1, hrHPV was tested at 3 months (M3) and 6 months (M6) after the intervention. The side effects were also analyzed.

RESULTS

At baseline (D0), a total of 99 patients were enrolled in Group A, with 50 subjects in Group A1 and 49 subjects in Group A2. A total of 91 patients were enrolled in Group B, with 45 subjects in Group B1 and 46 subjects in Group B2. There was no significant difference in the characteristics, including average age, age stratification, and HPV genotype. At M6, both Group A1 and Group B1 had a higher hrHPV clearance rate than the control group (A1/A2: 80.0% vs. 20.4%; B1/B2: 64.4% vs. 15.2%, p<0.001). At M6, the effective rates of Group A1 and Group B1 were 84% (42/50) and 68.9% (31/45), respectively. The side effect rates of Groups A1 and B1 were 11.5% (6/52) and 11.1% (5/45), respectively. Most adverse reactions involved local discomfort, including vulvar erythema, vulvar itch, increased vaginal discharge, cervical bleeding, and mild pain in the lower abdomen. Univariate logistic regression analysis showed that the intervention had an OR of 12 (95% CI 4.431-32.50) for clearing persistent HPV infection (p<0.001). For cervical LSIL, the intervention had an OR of 10.1 for clearing persistent HPV infection (95% CI 3.68-27.7) (p<0.001).

CONCLUSIONS

The results of this study suggest that the Chinese multiherb extract-based tincture GWK is safe and well tolerated. Furthermore, this preliminary study showed that this Chinese multiherb extract-based tincture is helpful for promoting HPV clearance in cases of persistent HPV and HPV-induced LSIL.

Study on early markers of death in patients with COVID-19

OBJECTIVE

Coronavirus disease 2019 (COVID-19) was first discovered in December 2019, and since then rapidly spread worldwide. Our study aimed to investigate the early indicators of death in patients suffering from severe and critical COVID-19.

PATIENTS AND METHODS

A retrospective cohort study was conducted on patients with severe and critical COVID-19, admitted to the Seventh Hospital of Wuhan. Clinical information was collected from electronic medical records according to standardized data collection tables. Patients were divided into non-survival and survival groups based on the disease outcome. Using univariate and multivariate logistic regression analysis, and calculating odds ratios (OR) and 95% confidence intervals (CI), independent risk factors for death in severe and critically ill COVID-19 patients were identified.

RESULTS

The median age of 162 patients (57.4% males) was 67.5 years old. Patients in the non-survival group had significantly higher white blood cell count, decreased lymphocyte count, anemia and thrombocytopenia compared to patients in the survival group (p < 0.05). A 28-day mortality rate of the study cohort was 31.5%. Multivariate logistic regression analysis showed that underlying heart disease, lymphocyte count < 1.0 × 109/L, glomerular filtration rate < 66, lactate > 2.2 mmol/L, higher Sequential Organ Failure Assessment (SOFA) score, lower oxygenation index (OR 1.748; 95% CI 1.024-2.984; p=0.041) and higher "multi-lobar infiltration, hypo lymphocytosis, bacterial co-infection, smoking history, hypertension and age" (MuLBSTA) score (OR 1.601; 95% CI 1.062-2.415; p=0.025) were risk factors associated with death in patients with severe and critical COVID-19.

CONCLUSIONS

Underlying heart disease, lymphocyte count, glomerular filtration rate, lactate, oxygenation index, SOFA score, and MuLBSTA score were associated with the risk of death in severe and critical COVID-19 patients.

[The sleep condition and its association with cognitive function of the elderly in six provinces of China]

Objective: To analyze the association between sleep duration and cognitive function of the elderly in six provinces of China. Methods: Based on the cross-sectional survey data of the elderly from the Healthy Ageing Assessment Cohort Study in 2019, 4 644 participants' sociodemographic and economic indicators, lifestyle, prevalence of major chronic diseases, and sleep status, including night-time sleep duration, daytime sleep duration and insomnia, were collected by questionnaires. Cognitive function was evaluated by the Mini-Mental State Examination. Multivariate logistic regression was used to analyze the association between night-time sleep duration, daytime sleep duration and cognitive function. Results: The mean age of 4 644 respondents was (72.3±5.7) years, and 2 111 of them were males (45.5%). The mean total daily sleep time of the elderly was (7.9±1.9) hours, and the proportion of those who slept less than 7.0, 7.0-8.9 and≥9.0 hours was 24.1% (1 119), 42.1% (1 954) and 33.8% (1 571), respectively. The mean sleep time at night was (6.9±1.7) hours. About 23.7% (1 102) of the elderly did not sleep during the day, and the mean duration of the elderly who slept during the day was (78±51) minutes. Among the elderly with insomnia, 47.9% were still satisfied with their sleep quality. The mean value of MMSE score of 4 644 respondents was (24.5±5.3), and the cognitive impairment rate was 28.3% (1 316). The results of multivariate logistic regression model analysis showed that the OR (95%CI) value of the risk of cognitive impairment in older people who did not sleep, slept for 31 to 60 minutes and slept more than one hour was 1.473 (1.139 to 1.904), 1.277 (1.001 to 1.629) and 1.496 (1.160 to 1.928), respectively, compared with those who slept for 1 to 30 minutes during the daytime. Compared with those who slept for 7.0‒8.9 hours at night, the OR (95%CI) value of the risk of cognitive impairment in older people who slept more than 9.0 hours was 1.239 (1.011 to 1.519). Conclusion: The cognitive function is related to sleep duration in the Chinese elderly.

[Single-center experience of robot-assisted laparoscopic nephron-sparing surgery for giant renal hamartoma]

The clinical data of 22 patients with giant renal hamartoma in Zhejiang Provincial People's Hospital who underwent robot-assisted laparoscopic nephron-sparing surgery from October 2014 to January 2020 were retrospectively analyzed. All the patients successfully completed the operation. The operation time and renal artery occlusion time was (179±34) min and (19.8±2.5) min, respectively. The intraoperative blood loss was (117±62) ml, and the postoperative hospital stay was (9.0±1.5) d. All cases were confirmed as renal angiomyolipoma by postoperative pathology. No urine leakage, postoperative bleeding and other complications occurred. Postoperative telephone follow-up was performed for 6 to 52 months, and no tumor recurrence on the surgical side was reported.

[Correlation analysis between decreased cerebral perfusion measured from arterial spin labeling and cerebrovascular events in patients with bilateral moyamoya angiography]

Objective: To explore the correlation between decreased cerebral perfusion measured from arterial spin labeling and cerebrovascular events in patients with bilateral moyamoya angiography (MMA). Methods: Twenty-seven consecutive cases with bilateral MMA, who were admitted to the neurosurgery department of Nanjing Drum Tower Hospital from April to November 2020, were included in this retrospective study. Among them, 10 were males and 17 were females, aged 35-66 (55±9) years. These patients all presented with unilateral cerebral hemisphere cerebral infarction or cerebral hemorrhage. The Wilcoxon paired signed-rank test was used to qualitatively analyze the differences in the Arterial Transit Artifact (ATA) of the bilateral cerebral hemispheres. The mean gray value, the kurtosis and skewness of gray distribution curve of bilateral cerebral hemispheres on cerebral blood flow (CBF) images with post labeling delay (PLD) of 1.5 s and 2.5 s were quantitative calculated. The relationship between ASL and cerebrovascular event was determined using binary logistics regression analysis. Results: No significant difference was observed in ATA between bilateral hemispheres on CBF images with PLDs of 1.5 s and 2.5 s (P>0.05). On the CBF images with a PLD of 1.5 s, the mean gray value of the cerebral hemisphere on the lesion side (17.50±5.88) was markly lower than that on the non-lesion side (20.80±5.51) (P<0.001), the kurtosis and skewness of gray distribution were significantly different between bilateral cerebral hemispheres (P<0.05);On the CBF images with a PLD of 2.5 s, the mean gray value and the skewness of the gray distribution on the lesion side of the cerebral hemisphere were statistically different from those on the non-lesion side (P<0.05), while the difference in kurtosis was not statistically significant between bilateral cerebral hemispheres (P>0.05). Multivariate regression analysis showed that the reduction of gray value on the side of the lesion was independently associated to the occurrence of the cerebrovascular events (OR_PLD1.5=0.192, 95%CI:0.047-0.783;OR_PLD2.5=0.175, 95%CI:0.050-0.615). Conclusion: The decreased perfusion detected by ASL is independently associated with cerebrovascular events in patients with MMA.

MiRNA-300 suppresses proliferation, migration and invasion of non-small cell lung cancer via targeting ETS1

OBJECTIVE

To elucidate the biological function of microRNA-300 (miRNA-300) in influencing the progression of non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The relative level of miRNA-300 in NSCLC tissues and cells was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The influences of miRNA-300 on the proliferative, migratory, and invasive potentials of A549 cells were assessed. The binding relationship between miRNA-300 and ETS1 was verified by the Dual-Luciferase Reporter Gene Assay. Finally, the regulatory effect of the interactive miRNA-300 and ETS1 on the progression of NSCLC was identified.

RESULTS

MiRNA-300 was downregulated in NSCLC tissues and cells. The overexpression of miRNA-300 suppressed A549 cells to proliferate, migrate, and invade. MiRNA-300 could bind to ETS1 3'UTR and suppress its level in A549 cells. Notably, the knockdown of miRNA-300 could reverse the regulatory role of ETS1 in the cellular behaviors of NSCLC.

CONCLUSIONS

MiRNA-300 suppresses NSCLC to proliferate, migrate, and invade by targeting ETS1.

Effects of progesterone therapy on serum sclerostin levels in healthy menopausal women: a 3-month randomized, placebo-controlled clinical trial

Sclerostin, a natural hormone made in bone, suppresses bone formation. Sclerostin is also decreased by estrogen. Progesterone, estrogen's menstrual partner, stimulates bone formation. It is unclear whether progesterone influences sclerostin. This study showed that progesterone did not change sclerostin using serum remaining from a randomized progesterone hot flush therapy trial.

INTRODUCTION

Progesterone and sclerostin are both endogenous hormones acting through osteoblast-origin cells and promote or suppress bone formation, respectively. Estradiol suppresses sclerostin, but progesterone, its menstrual cycle partner hormone, has unclear sclerostin relationships. We postulated that progesterone therapy would influence serum sclerostin levels.

METHODS

We obtained sclerostin levels for an ethics-approved post hoc analysis. Fasting sclerostin was measured in all remaining sera from a previous 12-week randomized controlled trial (RCT) of oral micronized progesterone (progesterone) for menopausal (> 1 year after last flow) vasomotor symptoms (VMS). Women in the RCT took 300 mg progesterone at bedtime or placebo (1:1) in a trial showing progesterone significantly decreased VMS.

RESULTS

Participants were healthy menopausal, primarily Caucasian (91.2%) community-dwelling women (± SD), 55.2 ± 4.6 years old with BMI 24.9 ± 2.9 kg/m². The baseline sclerostin level in 60 women was 28.41 ± 10.47 pmol/L. Baseline sclerostin was not correlated with the run-in VMS score (r = 0.143, P = 0.294). Paired baseline and 12-week RCT data for 52 women showed serum sclerostin levels did not change related to experimental therapy (P = 0.504). Changes in final sclerostin values adjusted for baseline were progesterone (- 1.07 ± 7.96 pmol/L) and placebo (- 2.64 ± 8.70 pmol/L). In observational data (n = 60), baseline sclerostin levels correlated with the General Framingham Cardiovascular (CVD) Risk score (r = - 0.398, P = 0.003) and self-reported health by SF-36 quality of life instrument (QoL, r = - 0.331, P = 0.016).

CONCLUSION

Physiological oral micronized progesterone did not stimulate nor suppress serum sclerostin levels based on post hoc analysis of RCT data. Exploratory results, however, showed sclerostin negatively correlated with CVD risk and QoL. ClinicalTrials.gov #NCT0146469.

[Risk factors associated with prolonged postoperative length of stay of patients with gastric cancer]

Objective: To investigate the risk factors of prolonged postoperative length of stay (LOS) in patients with gastric cancer. Methods: A retrospective study was performed on 2033 patients who underwent curative surgery in Department of Pancreatic-gastric, Cancer Hospital, Chinese Academy of Medical Sciences. Eightieth percentile of postoperative hospital stay for all patients was taken as the cutoff, the patients were divided into the normal group (1 532 patients) and the extended group (501 patients). Logistic regression model was used to determine the risk factors related to prolonged postoperative LOS in gastric cancer. Results: A total of 417 cases with postoperative complications were recruited in extended group. The five highest complications accounting for prolonged LOS were: abdominal infection in 69 cases (13.77%), pleural effusion in 60 cases (11.98%), anastomotic leakage in 43 cases (8.58%), poor wound healing in 34 cases (6.79%), and bleeding in 25 cases (4.99%). Logistic regression analysis showed that age (OR=1.348, P=0.013), surgical procedure (OR=2.712, P<0.001), extent of resection (OR=2.035, P<0.001), degree of incision healing(OR=4.867, P<0.001), and perioperative blood transfusion (OR=1.711, P<0.001) were independent risk factors for prolonged postoperative LOS. Conclusions: The most common complication associated with prolonged postoperative LOS for gastric cancer patients is abdominal infection. Age, surgical procedure, extent of resection, degree of incision healing, and perioperative blood transfusion are the independent risk factors for prolonged postoperative LOS.

Observation of Dynamical Quantum Phase Transitions with Correspondence in an Excited State Phase Diagram

Dynamical quantum phase transitions are closely related to equilibrium quantum phase transitions for ground states. Here, we report an experimental observation of a dynamical quantum phase transition in a spinor condensate with correspondence in an excited state phase diagram, instead of the ground state one. We observe that the quench dynamics exhibits a nonanalytical change with respect to a parameter in the final Hamiltonian in the absence of a corresponding phase transition for the ground state there. We make a connection between this singular point and a phase transition point for the highest energy level in a subspace with zero spin magnetization of a Hamiltonian. We further show the existence of dynamical phase transitions for finite magnetization corresponding to the phase transition of the highest energy level in the subspace with the same magnetization. Our results open a door for using dynamical phase transitions as a tool to probe physics at higher energy eigenlevels of many-body Hamiltonians.

[A retrospective comparative study of continuous pumping for home enteral nutrition after esophagectomy]

Objective: To discuss the effect and safety of continuous pumping for home enteral nutrition after esophagectomy. Methods: The current study retrospectively analyzed the esophageal cancer patients who underwent transthoracic esophagectomy between January 2017 and November 2017 at First Department of Thoracic Surgery, Peking University Cancer Hospital and Institute. There were totally 108 cases, including 88 males and 20 females, with an average age of 62 years. The patients were divided into pump feeding group (n=56) and traditional tube feeding group (n=52). The postoperative short-term safety, weight maintenance, enteral nutrition tolerance and nutritional support complete rate of the 2 groups were compared by χ(2) test, Fisher exact test and t test, respectively. Results: Compared with traditional tube feeding group, the patient safety in pumping feeding group was significantly better, with complications within 2 months after discharge were 11/52 and 4/56 respectively (χ(2)=2.393, P=0.035); the weight maintenance was significantly better, the weight loss within 4 weeks after discharge were 3.90 kg and 0.13 kg, respectively (t=7.720, P=0.000); the general enteral complications were significantly lower (26/52 vs. 5/56, χ(2)=22.225, P=0.000), the nutritional support complete rate was significantly higher (23/52 vs. 55/56, χ(2)=39.167, P=0.000). Conclusions: Continuous pump feeding enteral nutrition support after discharge postoperatively could help improve patient safety after discharge, which is better for weight maintenance of the patients. Pump feeding could also enhance tolerability of tube feeding and ensure the effective accomplishment of nutritional support.

[Assessing the consistency of methods to measure travel behavior related to exposure to air pollution]

Objective: To compare diary-reported trips and Global Positioning System (GPS) recording trips and identify the reasons for the discrepancies between two methods. Methods: The survey was conducted in Jiangning district in Nanjing city during July to September and November to December, 2015. Both the diary records and GPS method were used to investigate the travel behavior of 33 retired adults for 5 consecutive days. The GPS traces were display in Google Earth and then split into trips to compare with the diary records according to time and location. χ(2) test was used to analyze the influence of trip characteristics on misreporting rates of each method. Results: A total of 1 087 trips in the survey can be compared between the diary (n=909) and the GPS method (n=912). 7.3% (79/1 087) of the trips were only recorded by GPS method, and 11.8% (128/1 087) were only reported in the diary. Of the remaining 880 trips recorded by the both methods, 86.7% (763/880) matched each other, while 13.3% (117/880) did not. For the matched trips, the difference between the trip durations recorded by diary and GPS method was 2.0 (quartile was 6.0) minutes and the diary method overestimated about 25.0% trip durations when compared with the GPS method. The accuracy rates were 84.8%(903/1 065) and 86.9%(925/1 065) for diary and GPS method, respectively. Both methods were more likely to misreport the trip under 5 minutes. The misreporting rates of diary method for trips under 5 minutes were 6.8 times higher than trips over 30 minutes (21.7% vs 3.2%). The reporting accuracy was also significantly different among trips by different travel mode (P<0.05) for both methods, diary method had the lowest accuracy in reporting vehicles recorders (69.3%, 133/192), while GPS method was more accuracy in both biking (91.9%, 136/148) and vehicles recorders(89.6%, 172/192). The main reasons for misreporting by diary method were forgetting or unwilling to record and failing to record trips according to travel mode, while forgetting to carry GPS device, bad GPS signal and failing to locate the position were the main reasons for misreporting by GPS method. Conclusion: The majority of the trips reported in diary and GPS method are well consistent with each other. Both of the methods should be used simultaneously in the survey of time-activity pattern to improve the data quality.

[Analysis of relationship between (18)F-FDG PET/CT SUVmax of esophageal squamous cell carcinoma before treatment and postoperative survival]

Objective: To evaluate the value of (18)F-FDG PET/CT in predicting long-term survival of esophageal squamous cell carcinoma(ESCC) before initial treatment. Methods: A total of 167 ESCC patients were retrospectively analyzed who underwent surgery between January 2010 and December 2014 in prospective database of Peking University Cancer Hospital Thoracic Surgery Department One, all cases were included according to inclusion and exclusion criteria.The relationship between SUVmax of the primary tumor and patients' age, gender, tumor location, tumor differentiation, tumor regression grade as well as long term survival were compared. Results: The median follow-up time of the 167 cases was 46.9 months(ranging from 30.5 to 86.2 months), with 1 year and 3 years postoperatively being 95.1% and 68.4%, respectively.The SUVmax of the tumor was positively correlated with cT(P<0.01), cN(P=0.033), cTNM(P=0.002) and pTNM(P=0.003)of the tumor.Patients with SUVmax ≤6 obtained a survival significantly better compared with patients with SUVmax>6, the 3 years OS were 83.4 % vs 65.6% (P=0.02) , and DFS were 82.4% vs 55.4%(P=0.006), respectively.The multivariate regression analysis demonstrated that the SUVmax>6 before treatment was the independent prognostic factor for OS (HR=3, 95%CI 1.050-8.568) and DFS (HR=3.971, 95% CI 1.408-11.200) of the ESCC patients. Conclusions: The higher the (18)F-FDG PET/CT SUVmax of the ESCC primary tumor, the poorer survival of the patients. Therefore, SUVmax could be used as an indicator to predict long term survival of the ESCC patients before treatment.

Effects of caloric restriction on peroxisome proliferator-activated receptors and positive transcription elongation factor b expression in obese rats

OBJECTIVE

To investigate the effect of caloric restriction (CR) on expressions of peroxisome proliferators-activated receptors (PPARs) and positive transcription elongation factor b (P-TEFb) (including cyclin-dependent kinase 9 (CDK9) and cyclin T1) protein in visceral adipose tissue of obese rats.

MATERIALS AND METHODS

Obese rats were induced by high-fat diet for 8 weeks. Then they were divided into three groups: Model (n=5), 50% Calorie Restricted (50% CR, n=5), Intermittent Fasting (IF) (eight cycles of 3-d fasting and 3-d refeeding, n=6) for 8 weeks. Biochemical parameters were measured. Protein and mRNA expression of Cdk9, cyclin T1 and PPARs were qualified in visceral adipose tissue.

RESULTS

A significant decline in fasting plasma glucose (FPG), homeostatic model assessment of insulin resistance (HOMA-IR), body weight, and visceral fat weight was observed in 50% CR group. The IF group exhibited a significant decrease in FPG, HOMA-IR, visceral fat weight. Both 50% CR and IF down-regulated mRNA and protein expression of PPARγ and Cdk9, cyclin T1 and up-regulated mRNA and protein expression of PPARβ.

CONCLUSIONS

These results suggest that the effects of 50% CR and IF on HOMA-IR, body weight, visceral fat weight, P-TEFb and PPARγ expression may be related to their protective potential on obesity.

[Short-term outcome of sacral neuromodulation on refractory interstitial cystitis/pelvic pain syndrome]

Objective: To summarize the initial experiences of applying sacral neuromodulation (SNM) for refractory interstitial cystitis/pelvic pain syndrome (IC/PPS). Methods: From January 2013 to August 2016, 26 patients with refractory IC/PPS (including 5 males and 21 females) treated with SNM were recruited in Beijing Chaoyang Hospital and Hebei Yanda Hospital in this retrospective study. The data before operation, after implantation of stage Ⅰ tined lead, and during short-term follow-up after implantation of stage Ⅱ implanted pulse generator (IPG) were compared in order to observe the improvement of relevant symptoms, and to summarize the effectiveness and safety of SNM for IC/PPS. Results: All the 26 patients received stage Ⅰ tined lead implantation under local anesthesia, of whom 7 patients finally had the tined lead removed under local anesthesia because of poor testing effects. And 19 patients chose embedding of IPG at the end of stageⅠ, with the conversion rate from stage Ⅰto stage Ⅱ being 73.1%. The mean follow-up time after stage Ⅱ was 12.1 months. The data at the end of follow-up compared with those before treatment were: voiding frequency in 24 hours 24.3±9.6 vs 13.5±5.7, nocturia 4.6±2.2 vs 2.7±1.5, average voiding amount (109.4 ±45.3)vs(172.6±61.6) ml, O'leary-sant scale score 26.0±3.1 vs 17.0±3.8, quality of life (QOL) score 5.7±0.4 vs 3.3±1.3, sex rating 5.4±1.4 vs 2.9±1.6, and Numeric Pain Intensity Scale 8.4±1.7 vs 3.9±1.2 (all P<0.05). During the follow-up period for the 19 patients, 11 showed symptoms relieve without recurrence, 5 patients had slightly symptoms recurrence and 3 patients had severe recurrence of pelvic pain and frequent urination. About 42.1%(8/19) patients received reprogramming, the average reprogramming rate being 1.73/person. And 84.2% (16/19) patients had symptoms improvement greater than 50% after stage Ⅱ IPG implantation. Conclusions: SNM is an effective, safe and minimally invasive procedure for refractory IC/PPS. IC/PPS is a good indication for SNM with a high conversion rate from stage Ⅰ to stage Ⅱ. Patients should be followed up regularly after operation, and reprogramming should be arranged according to the degree of symptom improvement.

Association between the abdominal obesity anthropometric indicators and metabolic disorders in a Chinese population

BACKGROUND

Obesity has become a major health problem in contemporary society and it is closely related to many chronic diseases, so it is an important issue for measuring adiposity accurately and predicting its future. Prevention and treatment of overweight and obesity has become one of the key prevention and treatment of metabolic disorders.

OBJECTIVE

In this study, we compared the ability of the four anthropometric indicators (body mass index, waist circumstance, waist-height ratio, waist-to-hip ratio) to identify metabolic disorders (hypertension, hyperlipidaemia, hyperglycemia and hyperuricemia) by receiver operating characteristic (ROC) curve analyses and to provide evidence for clinical practice.

METHODS

In this large scale cross-sectional study, 13,275 Han adults (including 7595 males and 5680 females) received physical examination between January, 2009 and January, 2010 in Xuanwu Hospital of Capital Medical University were investigated by the means of questionnaire, Meanwhile, the physical examination and serological results were recorded. A package known as Statistical Package for Social Scientist (SPSS) was employed to analyse the responses while t-test, one-way analysis of variance (ANOVA), ROC analysis and chi-square statistical methods were used to test the hypotheses.

RESULTS

WC, WHtR, WHR and BMI were all significantly (P < 0.001) correlated with all metabolic risk factors regardless of gender. And the area under the curve (AUC) of WHtR was significantly greater than that of WC, BMI or WHR in the prediction of hypertension, hyperlipidaemia, hyperglycemia and hyperuricemia.

CONCLUSION

Our data show that WHtR was the best predictor of various metabolic disorders. The diagnostic value in descending order was WHtR > WHR > WC > BMI. Therefore we recommend WHtR in assessment of obese patients, in order to better assess the risks of their metabolic diseases.

Construction of the mammalian expressing vector pEGFP-N1-P53 and its expression successful in chicken fibroblast cells and blastoderm

The enhanced green fluorescent protein (EGFP) pEGFP-N1-P53 eukaryotic expression vector, which contains the human tumor suppressor p53, was constructed and transfected into chicken fibroblast cells and stage-X blastoderm to analyze the transfection efficiency. The complementary DNA of the human p53 gene was cloned by reverse transcription-polymerase chain reaction from human peripheral blood and inserted into the pEGFP-N1 vector by HindIII and BamHI double digestion. The pEGFP-N1-P53 vector was transfected into chicken embryo fibroblasts by Lipofectamine 2000 liposomes, and the transfection efficiency was analyzed by fluorescence microscope after 36 h of transfection. The stage-X blastoderm was also transfected by blastoderm injection using Lipofectamine 2000 liposomes at room temperature after 12-24 h; then hatching occurred until seventh day, and the transfection efficiency was analyzed by fluorescence microscope in the dead embryo. A total of 90 hatching eggs were transfected by the pEGFP-N1-P53 vector, and 20 chicken embryos expressed the reporter gene, which indicated that recombinant pEGFP-N1-P53 could be transfected and expressed in stage-X blastoderm by liposomes. Chicken embryo fibroblasts were transfected and expressed the reporter gene. The pEGFP-N1-P53 vector was constructed successfully and could be transfected and expressed in chicken embryo fibroblasts and stage-X blastoderms efficiently.

Characterization ofD-Aminoacylase fromAlcaligenes denitrificansDA181

The D-aminoacylase produced by Alcaligenes denitrificans DA181 was a new type of aminoacylase which had both high stereospecificity and specific activity. The molecular weight and isoelectric point of this enzyme were 58,000 and 4.4, respectively. The apparent Km and kcat values of this enzyme for N-acetyl-D-methionine were estimated to be 0.48 mM and 6.24 x 10(4) min-1, respectively. The optimum temperature was 45 degrees C. The enzyme was stable up to 55 degrees C for 1 hr in the presence of 0.2 mg/ml bovine serum albumin. The enzyme was stable in the pH range of 6.0 to 11.0 with an optimum pH of 7.5. This enzyme contained about 2.1 g atom of zinc per mole of enzyme. Enzyme activity was inhibited by incubation with EDTA. The inhibition by EDTA was fully reversed by Co2+ and partially by Zn2+.

Altered expression of survivin, Fas and FasL contributed to cervical cancer development and metastasis

OBJECTIVE

To evaluate the expression of apoptosis-related genes and their correlation with prognosis in cervical cancer patients.

MATERIALS AND METHODS

The expressions of Survivin, Fas and FasL in tissues of cervical cancer, cervical intraepithelial neoplasia (CIN), chronic cervicitis and normal cervix wer detected by immunohistochemical staining, and the relationship between the expression of Survivin, Fas and FasL and clinical pathologic characteristics of cervical cancer was correlation analysis.

RESULTS

The positive expression rates of Survivin and FasL in cervical cancer tissues were significantly higher than those in tissues of normal cervix, chronic cervicitis and CIN (p < 0.05), but lower positive expression rate of Fas was observed in cervical cancer tissues when compared with that in normal cervix, chronic cervicitis and CIN tissues (p < 0.05). The expression of Survivin was significantly correlated with clinical staging and lymph node metastases of cervical cancer (p < 0.05). The expression of FasL was correlated with lymph node metastases, clinical staging and pathological grading of cervical cancer (p < 0.05). The expression of Survivin was negatively correlated with that of Fas (r = -0.517, p < 0.01), but positively correlated with that of FasL (r = 0.381, p < 0.01) in tissues of cervical cancer.

CONCLUSIONS

The up-regulated expression of Survivin and FasL and down-regulated expression of Fas may be involved in the carcinogenesis and development of cervical cancer. The expression of FasL may be one of the prediction indexes for disease progression and prognosis in cervical cancer.

The effect of candesartan on the pharmacokinetics of enalaprilat in nephrotic rats

BACKGROUND AND OBJECTIVES

The adverse reactions in combination of angiotensin-converting enzyme inhibitors (ACEIs) and Ang II receptor blockers (ARBs) were severer than that in monotherapy for patients with nephropathy. The effect of candesartan on pharmacokinetics of enalaprilat in nephrotic rats was investigated to make references for the clinical therapy in patients with nephropathy to avoid related adverse effects.

MATERIALS AND METHODS

Nephrotic rats were prepared by adriamycin injection. Control group and one nephrotic group received enalapril alone, another nephrotic group received enalapril and candesartan simultaneously. Blood samples were drawn at time points after a single oral administration. The concentration of enalaprilat was determined using LC-MS/MS.

RESULTS

Compared with control group and nephrotic group received enalapril alone respectively, Tmax of enalaprilat in nephrotic group received both enalapril and candesartan cilexetil prolonged about 21.43% and 6.224%, respectively; AUC(0-t) increased by 185.3% and 60.63%, respectively; Cmax increased by 219.4% and 56.64%, respectively; t1/2 increased by 163.7% and 30.05%, respectively; CL/F reduced by 65.12% and 40.78%, respectively. There were no significant differences of the V1/F of enalaprilat between three groups. The CL/F and t1/2 of enalaprilat showed significant correlations with serum creatinine (Scr) respectively (r = -0.7502; r = 0.5626).

DISCUSSION

The combination with candesartan in nephrotic rats significantly changed the pharmacokinetics of enalaprilat, showing increased accumulation and decreased elimination. In view of these findings, we should lower dosage and prolong dosing interval for nephrotic patients in the combination of enalapril and candesartan.

Diblock and triblock copolymer thin films on a substrate with controlled selectivity

Using self-consistent field theory (SCFT), morphology development in symmetric linear ABC triblock copolymer films on neutral and selective substrates has been studied, and it is compared with the triblock copolymer morphologies in bulk. In particular, the effects of the substrate preferable to B (interior) block on nanopattern formation of the copolymer films are of our central interest. Here, we report various nanopatterns with tunable square morphologies. The domain patterns are much more diverse than those parallel to the substrate with substrate selectivity for end-block or those vertical to the substrate without substrate selectivity. Furthermore, in order to figure out an economical and efficient way to fabricate useful passive pattern transfer layers, which have potential applications in microelectronic processes and ultrahigh density storage media, we propose a two-step strategy and scrutinize the conditions for generating square symmetries using cylinder-forming or lamella-forming AB diblock copolymers deposited on substrates created from ABC triblock copolymer films. It is found that a thinner film with weak incompatibility can produce square patterns.

Oriental HLA-A*11:90 detected in a Taiwanese cord blood sample and the haplotype in association with A*11:90 allele

We report here an HLA-A allele, A*11:90, found in a Taiwanese cord blood sample using DNA sequence-based typing (SBT) protocol after observing an anomalous reaction pattern in a sequence-specific oligonucleotide (SSO) typing exercise. The sequence of A*11:90 is identical to A*11:01:01, the most predominant A*11 variant in Taiwanese, in exon 2 but differs from A*11:01:01 in exon 3 by two nucleotide substitutions at codon 163 (c.487C>G and c.488G>A), resulting R163E. In comparison with the sequence of A*11:02:01, the second most predominant subtype of A*11 in Taiwanese A*11:90 has one nucleotide difference at codon 19 (c.55A>G) in exon 2 resulting K19E and two nucleotides variations at codon 163 (c.487C>G and c.488G>A) in exon 3 resulting R163E. HLA-A*11:90-B*40:02-DRB1*11:01 is the deduced probable HLA haplotype in association with A*11:90. The generation of A*11:90 is thought to involve a DNA recombination event between alleles A*11:01:01 and A*80:01 where A*80:01 donated a fragment of the DNA sequence (from n.t. 487 to n.t. 497) to the recipient sequence of A*11:01:01.

Anti-inflammatory and analgesic activities of Chaenomeles speciosa fractions in laboratory animals

The prescription of current existing anti-inflammatory drugs is hampered by their adverse effects over time. Botanical extracts are thought to be a potential source of a natural anti-inflammatory property with fewer adverse effects. Chaenomeles speciosa has long been used as an herbal medicine for treatment of various diseases such as rheumatoid arthritis, prosopalgia, and hepatitis. Until now there have been no reports on the specific anti-inflammatory fractions of extract of C. speciosa (ECS). In the present study the anti-inflammatory activities of different fractions of ECS were evaluated using carrageenan-induced paw edema in rats. The 10% ethanol fraction (C3) was found to have stronger anti-inflammatory effects compared with other fractions at the same dose. We also found that chlorogenic acid was one of the active constituents responsible for the anti-inflammatory effect using bioassay-guided fractionation by means of high-performance liquid chromatography. Compared with controls, fraction C3 demonstrated significant anti-inflammatory activity in the xylene-induced ear edema test (P < .01), acetic acid-induced peritoneal capillary permeability test, and the cotton pellet granuloma test in mice or rats (P < .01); it also showed marked analgesic activity in the acetic acid-induced abdominal contraction test and formalin-induced paw licking test in mice and rats (P < .05 or .01). However, fraction C3 showed no significant effect in the hot plate test in mice. These findings justify the use of the C. speciosa for treating pain and inflammation. These results support the proposal of C. speciosa fraction C3 as a potential anti-inflammatory agent.

Deep Impact: observations from a worldwide Earth-based campaign

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

Mathematical modelling of MSW incineration on a travelling bed

The rising popularity of incineration of municipal solid waste (MSW) calls for detailed mathematical modelling and understanding of the incineration process. In this paper, governing equations for mass, momentum and heat transfer for both solid and gaseous phases in a moving bed in a solid-waste incineration furnace are described and relevant sub-models are presented. The burning rates of volatile hydrocarbons in the moving bed of solids are limited not only by the reaction kinetics but also the mixing of the volatile fuels with the under-fire air. The mixing rate is averaged across a computation cell and correlated to a number of parameters including local void fraction of the bed, gas velocity and a length scale comparable to the particle size in the bed. A correlation equation is also included to calculate the mixing in the freeboard area immediately next to the bed surface. A small-scale fixed bed waste incinerator was built and test runs were made in which total mass loss from the bed, temperature and gas composition at different locations along the bed height were measured. A 2-D bed-modelling program (FLIC) was developed which incorporates the various sub-process models and solves the governing equations for both gases and solids. Thermal and chemical processes are mainly confined within a layer about 5-9 times in thickness of the averaged particle size in the burning bed. For a large part of the burning process, the total mass loss rate was constant until the solid waste was totally dried out and a period of highly rising CO emission followed. The maximum bed temperature was around 1200 K. The whole burning process ended within 60 min. Big fluctuations in species concentration were observed due to channelling and subsequent 'catastrophic' changes in the local bed conditions. Reasonably good agreement between modelling and measurements has been achieved. Yet the modelling work is complicated by the channelling phenomenon in the bed. Numerical simulations without consideration of the channelling effect produced very good agreement with experiments concerning the total mass loss, but significant discrepancy exists for temperature and gas composition profiles. Transient phenomena such as the breaking of waste particles and the "catastrophic" creation of new burning channels occurring during waste incineration is a vital area requiring further investigation at the fundamental level. The underlying theory of bed behaviour must be extended to include these transient events.

Functional signal peptides bind a soluble N-terminal fragment of SecA and inhibit its ATPase activity

The selective recognition of pre-secretory proteins by SecA is essential to the process of protein export from Escherichia coli, yet very little is known about the requirements for recognition and the mode of binding of precursors to SecA. The major reason for this is the lack of a soluble system suitable for biophysical study of the SecA-precursor complex. Complicating the development of such a system is the likelihood that SecA interacts with the precursor in a high affinity, productive manner only when it is activated by binding to membrane and SecYEG. A critical aspect of the precursor/SecA interaction is that it is regulated by various SecA ligands (nucleotide, lipid, SecYEG) to facilitate the release of the precursor, most likely in a stepwise fashion, for translocation. Several recent reports show that functions of SecA can be studied using separated domains. Using this approach, we have isolated a proteolytically generated N-terminal fragment of SecA, which is stably folded, has high ATPase activity, and represents an activated version of SecA. We report here that this fragment, termed SecA64, binds signal peptides with significantly higher affinity than does SecA. Moreover, the ATPase activity of SecA64 is inhibited by signal peptides to an extent that correlates with the ability of these signal peptides to inhibit either SecA translocation ATPase or in vitro protein translocation, arguing that the interaction with SecA64 is functionally significant. Thus, SecA64 offers a soluble, well defined system to study the mode of recognition of signal peptides by SecA and the regulation of signal peptide release.

[Inhibition of transmembrane K(+) currents in mammalian ventricular myocytes by antiarrhythmic agent RP62719]

The effect of RP62719 on the inward rectifier K(+) current (I(K1)),transient outward K(+) current (I(to)) and delayed outward K(+) current (I(K)) in isolated cardiac myocytes was determined using the whole cell patch clamp technique in guinea pig and dog. RP62719 decreased I(K1) with an inhibitory concentration 50 (IC(50) ) of 5.0+/-1.0 micromol/L at -100 mV in guinea pig ventricular cells. In dog ventricular myocytes, RP62719 inhibited Ito by 84+/-4.4% with an IC(50) of 1.2+/-0.51 micromol/L at +40 mV. In guinea pig ventricular cells, RP62719 decreased I(K): I(Kstep) by 50.0+/-8.3%%and I(Ktail) by 56.0+/-4.9% at +40 mV, respectively. RP62719 inhibited I(Kstep) with an IC(50) of 4.2+/-0.8 micromol/L and I(Ktail) with an IC(50) of 3.3+/-0.75 micromol/L. Thus it is suggested that the ionic mechanism of antiarrhymic effect by RP62719 may be due to its inhibition of I(K1),I(to) and I(K).

Differential translocation of protein precursors across SecY-deficient membranes of Escherichia coli: SecY is not obligatorily required for translocation of certain secretory proteins in vitro

SecY, a component of the protein translocation system in Escherichia coli, was depleted at a nonpermissive temperature in a strain which had a temperature-sensitive polar effect on the expression of its secY. Membrane vesicles prepared from these cells, when grown at the nonpermissive temperature, contained about 5% SecY and similarly low levels of SecG. As expected, translocation of alkaline phosphatase precursors across these SecY-deficient membranes was severely impaired and appeared to be directly related to the decrease of SecY amounts. However, despite such a dramatic reduction in SecY and SecG levels, these membranes exhibited 50 to 70% of the wild-type translocation activity, including the processing of the signal peptide, of OmpA precursor (proOmpA). This translocation activity in SecY-deficient membranes was still SecA and ATP dependent and was not unique to proOmpA, as lipoprotein and lambda receptor protein precursors were also transported efficiently. Membranes that were reconstituted from these SecY-depleted membranes contained undetectable amounts of SecY yet were also shown to possess substantial translocation activity for proOmpA. These results indicate that the requirement of SecY for translocation is not obligatory for all secretory proteins and may depend on the nature of precursors. Consequently, it is unlikely that SecY is the essential core channel through which all precursors traverse across membranes; rather, SecY probably contributes to efficiency and specificity.

SecE-depleted membranes of Escherichia coli are active. SecE is not obligatorily required for the in vitro translocation of certain protein precursors

Membrane vesicles were prepared from Escherichia coli cells in which SecE was depleted to 2% of wild-type membranes. SecE depletion had pleiotropic effects; SecD, SecF, SecG, and SecY were decreased 4-6-fold, whereas SecA was increased about 16-fold over that of wild-type membranes. These membranes were substantially active in the in vitro translocation of proOmpA, which was mediated by the SecA pathway since it was inhibited by azide. Similar substantial translocation activities were observed for proLamB and proLpp in the SecE-depleted membranes. However, the translocation of proPhoA was more severely impaired. These data indicate that SecE may enhance but is not obligatorily required for the translocation of at least certain precursors, and suggest that the effects of the SecE depletion on protein translocation may be precursor-dependent.

Influence of column type and chromatographic conditions on the ion-exchange chromatography of immunoglobulins

Immunoglobulins are often purified by affinity chromatography. However, this technique is costly, can result in poor resolution for subclasses (or is only group specific), and leads to possible leaching of contaminants into the purified products. Ion-exchange chromatography has shown great potential and has found an increased usage in the purification of immunoglobulins. The aim of this study is to further understand the separation mechanism with emphasis on the influence of column type and chromatographic conditions on the peak shape, selectivity and changes in the elution patterns. Included are strong cation-exchange, strong anion-exchange and weak anion-exchange columns. Five immunoglobulin G antibodies were used as test probes. Some sera and ascites were also used in the study. Among the chromatographic conditions examined were mobile phase pH, buffer type, buffer concentration, gradient rate, and column temperature. Significant differences in the chromatographic behavior (elution pattern, peak shape and selectivity) of the test samples are discussed in regard to the column type and the chromatographic conditions.

Purification and characterization of L-aminoacylase from Alcaligenes denitrificans DA181

The L-aminoacylase produced intracellularly by Alcaligenes denitrificans DA181 was purified to homogeneity. This enzyme had an apparent molecular weight of 80,000, and was composed of two subunits of identical molecular weight. Its isoelectric point was pH 5.1. The optimal reaction temperature and pH were 65 degrees C and 8.0, respectively. This enzyme showed specificity toward N-acetyl-derivative of hydrophobic L-amino acids with N-acetyl-L-valine as the favored substrate, followed by N-acetyl-L-alanine.

Depression of neuronal protein synthesis initiation by protein tyrosine kinase inhibitors

Growth factors stimulate cellular protein synthesis, but the intracellular signaling mechanisms that regulate initiation of mRNA translation in neurons have not been clarified. A rate-limiting step in the initiation of protein synthesis is the formation of the ternary complex among GTP, eukaryotic initiation factor 2 (eIF-2), and the initiator tRNA. Here we report that genistein, a specific tyrosine kinase inhibitor, decreases tyrosine kinase activity and the content of phosphotyrosine proteins in cultured primary cortical neurons. Genistein inhibits protein synthesis by > 80% in a dose-dependent manner (10-80 micrograms/ml) and concurrently decreases ternary complex formation by 60%. At the doses investigated, genistein depresses tyrosine kinase activity and concomitantly stimulates PKC activity. We propose that a protein tyrosine kinase participates in the initiation of protein synthesis in neurons, by affecting the activity of eIF-2 directly or through a protein kinase cascade.

Heat-shock inhibits protein synthesis and eIF-2 activity in cultured cortical neurons

Stress, such as heat-shock, hypoxia and hypoglycemia, inhibits the initiation of protein synthesis. The effects of heat-shock on protein synthesis, eucaryotic initiation factor 2 (eIF-2) activity, protein kinase C (PKC), and casein kinase II (CKII) activities were studied in primary cortical neuronal cultures. In neurons exposed to heat-shock at 44 degrees C for 20 min, protein synthesis is inhibited by more than 80%, and is accompanied by a 60% decrease in eIF-2 activity. Steady state PKC and CK II activities were not affected by heat-shock. Vanadate (200 microM), a protein phosphotyrosine phosphatase inhibitor, partially prevented the depression of eIF-2 activity during heat-shock, and increased CKII activity by 90%. In contrast, staurosporine (62nM), a protein kinase C inhibitor, did not affect eIF-2 activity. We conclude that heat-shock causes a change in the phosphorylation/dephosphorylation of regulatory proteins leading to a depressed eIF-2 activity and protein synthesis in neurons.

Effects of acute hypoxia on intracranial dynamics in unanesthetized goats

The effects of acute hypoxia on intracranial dynamics were studied in six unanesthetized goats that were subjected to hypobaric hypoxia at a simulated 4,000-m high altitude for 2 h. Another six nonhypoxic goats served as control group for cerebral water content (CWC). In this study, we measured cerebral blood flow (CBF) by electromagnetic flowmeter, intracranial pressure (ICP) through an intraventricular catheter, and CWC by a wet-to-dry weight technique for a given volume of brain tissue. Intracranial compliance was calculated from a pressure-volume index derived from the change in intraventricular pressure after a subarachnoid injection of saline. During acute hypoxia CBF increased from 146.0 +/- 10.60 to 185.3 +/- 7.83 ml x min-1.100 g-1, ICP increased from 15.4 +/- 1.82 to 27.4 +/- 3.84 cmH2O, and CWC increased from 78.7 +/- 0.30 to 79.5 +/- 0.16%, but intracranial compliance decreased from 0.65 +/- 0.28 to 0.36 +/- 0.19 ml/cmH2O. The data suggest that acute hypoxia results in a significant disturbance of intracranial dynamics, which may be one of the important pathophysiological mechanisms of high-altitude cerebral edema and acute mountain sickness.

Fimbriated stationary phases for proteins

This paper describes synthetic procedures for preparing fimbriated stationary phases on poly(styrene-divinylbenzene) (PS-DVB) packing materials. The synthesis consists of a five-step procedure in which the order in which the steps are carried out may be varied. These steps are (i) polymerization of monomers to form an amphiphilic copolymer or oligomer, (ii) adsorption of either monomers, or polymer onto the PS-DVB surface, (iii) solvent induction of functional group orientation at the PS-DVB-polymer interface and polymer-water interface, (iv) a cross-linking reaction that forms a hydrophilic surface layer, and (v) derivatization of the surface layer with stationary phase.

Factors affecting the separation and loading capacity of proteins in preparative gradient elution high-performance liquid chromatography

The optimum conditions for the purification of proteins by gradient elution in reversed-phase liquid chromatography were studied, with emphasis on the column length. Because of the strong dependence of the retention of proteins on the mobile phase composition, very short columns can be used successfully to perform analytical separations. A similar conclusion is extended to preparative separations. Columns with different lengths and diameters were used. The dependence of the loading capacity for touching band separation on the column length, diameter and volume was studied, in addition to the regeneration time between successive runs, the starting mobile phase composition and the necessary column efficiency.

Coated hydrophilic polystyrene-based packing materials

A very hydrophilic high-performance liquid chromatographic base support was created from microparticulate, macroporous poly(styrene-divinylbenzene) beads. An organic monomer containing cross-linking functionalities was coated on the poly(styrene-divinylbenzene), followed by a catalyzed cross-linking reaction. The coatings formed contain only stable chemical bonds (e.g., C-C, C-O-C), and easily-derivatized hydroxyl moieties. This coated base support was evaluated for hydrophilicity, chemical stability, solvent compatibility, rigidity, and irreversible adsorption. Derivatives of the coated base support were made and applied in various modes of chromatography.

Purification and Characterization of d -Aminoacylase from Alcaligenes faecalis DA1

A d -aminoacylase from Alcaligenes faecalis DA1 has been purified to homogeneity by a simple purification procedure with two columns, Fractogel DEAE-650 and HW-50. The specific activity of the purified enzyme was found to be 580 U/mg of protein with N -acetyl- dl -methionine as the reaction substrate. The apparent molecular weight and isoelectric point of this enzyme were determined to be 55,000 and 5.4, respectively.

Flow-through particles for the high-performance liquid chromatographic separation of biomolecules: perfusion chromatography

This paper reports a new technique for reducing resistance to stagnant mobile phase mass transfer without sacrificing high adsorbent capacity or necessitating extremely high pressure operation. The technique involves the flow of liquid through a porous chromatographic particle, and has thus been termed "perfusion chromatography". This is accomplished with 6000-8000 A pores which transect the particle. Data from electron microscopy, column efficiency, frontal analysis and theoretical modelling all suggest that mobile phase will flow through these large pores. In this manner, solutes enter the interior of the particles through a combination of convective and diffusional transport, with convection dominating for Peclet numbers greater than one. The implications of flow through particles on bandspreading, resolution and dynamic loading capacity are examined. It is shown that the rate of solute transport is strongly coupled to mobile phase velocity such that bandspreading, resolution of proteins and dynamic loading capacity are unaffected by increases in mobile phase velocity up to several thousand centimeters per hour. The surface area of this very large-pore diameter material is enhanced by using a network of smaller, 500-1500 A interconnecting pores between the throughpores. Scanning electron micrographs show that the pore network is continuous and that no point in the matrix is more than 5000-10,000 A from a through-pore. As a consequence, diffusional path lengths are minimized and the large porous particles take on the transport characteristics of much smaller particles but with a fraction of the pressure drop. Capacity and resolution studies show that these materials bind and separate an amount of protein equivalent to that of conventional high-performance liquid chromatography as well as low performance agarose-based media at greater than 10-100 times higher mobile phase velocity with no loss in resolution.

Specificity of alkaline elastase Bacillus on the oxidized insulin A- and B-chains

The substrate specificity of alkaline elastase Bacillus from alkalophilic Bacillus sp. Ya-B was investigated using oxidized insulin A- and B-chains. Under time-limited cleavage, the initial cleavage site of the enzyme on the oxidized insulin A-chain and B-chain was at the leucine13-tyrosine14 bond and the leucine15-tyrosine16 bond, respectively. When the cleavage was completed, three major cleavage sites and three minor cleavage sites on the A-chain, and five major cleavage sites and four minor cleavage sites on the B-chain were found. However, most of the peptides produced after complete hydrolysis of the A- or B-chain by the enzyme were composed of four to six amino acid residues. The results suggest that this enzyme cleaves the oxidized insulin A- and B-chains in a block-cutting manner.

High-speed and high-performance size-exclusion chromatography of proteins on a new hydrophilic polystyrene-based resin

High-performance size-exclusion chromatography of some standard proteins, peptides and amino acids on a new hydrophilic packing material obtained by chemical transformation of a cross-linked polystyrene-divinylbenzene copolymer was studied. Columns filled with 4 and 7 micron particles were compared. The influence of the concentration of acetonitrile, isopropanol and trifluoroacetic acid in the mobile phase on the chromatographic performance was investigated. A good linear calibration graph covering the molecular weight range from 200 to 700,000, was obtained under the optimal conditions. The packing material can be used for separations, for molecular weight determinations and for the pre-fractionation of proteins. The high rigidity of the packing material allows relatively high pressures to be used and therefore fast separations to be achieved. The packing material was applied to the chromatography of proteins from beer, bones and milk.