Systematic review with meta-analysis: thiopurines decrease the risk of colorectal neoplasia in patients with inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) have a high risk of developing colorectal neoplasia.

AIM

To investigate whether thiopurines can decrease the risk of developing colorectal neoplasia in patients with ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

We conducted a meta-analysis of 24 observational studies involving 76,999 participants to evaluate the risks of developing colorectal neoplasia in IBD patients receiving thiopurine treatment. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the risks of colorectal neoplasia were calculated using a random-effects model.

RESULTS

The overall pooled estimate revealed a protective effect of thiopurine use on colorectal neoplasia in patients with IBD (OR = 0.63, 95% CI 0.46-0.86). The effect was significant in UC patients (OR = 0.67, 95% CI 0.45-0.98), but was not significant in CD patients (OR = 1.06, 95% CI 0.54-2.09). Thiopurines exposure significantly decreased the risk of colorectal cancer (CRC) (OR = 0.65, 95% CI 0.45-0.96) and advanced colorectal neoplasia (CRC and/or high-grade dysplasia) (OR = 0.62, 95% CI 0.44-0.89), but did not decrease the risk of dysplasia alone (OR = 0.90, 95% CI 0.37-2.21). Tendencies towards the protective effect of thiopurines were distinct in clinic-based studies (OR = 0.59, 95% CI 0.42-0.82) and case-control studies (OR = 0.40, 95% CI 0.26-0.62), but not in population-based studies (OR = 0.95, 95% CI 0.55-1.62) and cohort studies (OR = 0.98, 95% CI 0.81-1.18). Interestingly, studies conducted in Europe (OR = 0.48, 95% CI 0.31-0.77), rather than in North America (OR = 0.91, 95% CI 0.67-1.24), showed the protective effect of thiopurines.

CONCLUSIONS

This meta-analysis revealed an antineoplastic effect of thiopurines on colorectal neoplasia in patients with IBD, particularly amongst patients with UC.

[Application of decision curve on evaluation of MRI predictive model for early assessing pathological complete response to neoadjuvant therapy in breast cancer]

Objective: To construct a dynamic enhanced MR based predictive model for early assessing pathological complete response (pCR) to neoadjuvant therapy in breast cancer, and to evaluate the clinical benefit of the model by using decision curve. Methods: From December 2005 to December 2007, 170 patients with breast cancer treated with neoadjuvant therapy were identified and their MR images before neoadjuvant therapy and at the end of the first cycle of neoadjuvant therapy were collected. Logistic regression model was used to detect independent factors for predicting pCR and construct the predictive model accordingly, then receiver operating characteristic (ROC) curve and decision curve were used to evaluate the predictive model. Results: ΔArea(max) and Δslope(max) were independent predictive factors for pCR, OR=0.942 (95%CI: 0.918-0.967) and 0.961 (95%CI: 0.940-0.987), respectively. The area under ROC curve (AUC) for the constructed model was 0.886 (95%CI: 0.820-0.951). Decision curve showed that in the range of the threshold probability above 0.4, the predictive model presented increased net benefit as the threshold probability increased. Conclusions: The constructed predictive model for pCR is of potential clinical value, with an AUC>0.85. Meanwhile, decision curve analysis indicates the constructed predictive model has net benefit from 3 to 8 percent in the likely range of probability threshold from 80% to 90%.

[High risk factors analysis of stillbirth]

Objective: To explore the high risk factors of stillbirth. Methods: 176 cases of stillbirth were collected in the Obstetrics and Gynecology Hospital of Fudan University from January 1(st), 2010 to December 31(st), 2016. All cases were analyzed retrospectively, including general profile, high risk factors of stillbirth in different years and pregnancy periods. Results: (1) The incidence of stillbirth was 0.178%(176/98 785). Stillbirth occured mostly at 28-28(+6) gestational weeks (10.8%,19/176), and the second peak was 29-29(+6) weeks(10.2%,18/176), while the third common period was 37-37(+6) weeks (9.1%,16/176). After 39 weeks, it maintained at a low level. (2) The top 5 high risk factors of stillbirth were infection (18.2%,32/176), unexplained (13.6%,24/176), hypertention disorders in pregnancy (13.1%, 23/176), umbilical cord torsion (12.5%, 22/176) and fetal malformations (10.2%, 18/176). (3) From 2010 to 2012, the top 3 high risk factors were unexplained, the umbilical cord torsion and infection, while hypertention in pregnancy, infection and fetal malformation became the top 3 high risk factors after 2013. (4) Early stillbirth (20-27(+6) weeks) accounted for 21.6%(38/176); and unexplained (47.4%, 18/38), fetal edema (13.2%, 5/38),infection (13.2%, 5/38), umbilical cord torsion (5.3%, 2/38) were the top 4 high risk factors. Late stillbirth (≥28 weeks) accounted for 78.4%(138/176), with infection (19.6%,27/138), hypertention in pregnancy (15.9%,22/138), umbilical cord torsion (14.5%,20/138) and fetal malformation(12.3%,17/138)being the top 4 high risk factors. Conclusions: More attention should be paid to maternal complications, especially infection and hypertension in pregnancy. Antenatal fetal monitoring, timely termination of pregnancy, standard management of stillbirth and looking for the causes may help reduce the incidence of stillbirth.

Association between obesity phenotypes and incident hypertension among Chinese adults: a prospective cohort study

OBJECTIVES

To explore the association between obesity phenotype and the risk of hypertension among Chinese adults.

STUDY DESIGN

A prospective cohort study.

METHODS

Two waves of data were collected in 2009 and 2011 by the China Health Nutrition Survey. According to International Diabetes Federation and Chinese obesity criteria, participants were divided into four groups: metabolically healthy non-overweight/obesity (MHNO), metabolically healthy overweight/obesity (MHO), metabolically abnormal non-overweight/obesity (MANO), and metabolically abnormal overweight/obesity (MAO). Logistic regression model was performed to estimate the risk of hypertension with obesity phenotype.

RESULTS

Among a total of 4604 adults aged 18-65 years at baseline, 467 developed hypertension during the 2-year follow-up period. After adjusting for several potential confounders, significantly increased risks for hypertension were found for participants in MHO (odd ratio [OR]: 1.78, 95% confidence interval [CI]: 1.39-2.27), MANO (OR: 1.71, 95% CI: 1.02-2.86), and MAO (OR: 3.35, 95% CI: 2.54-4.42) group compared with the MHNO group.

CONCLUSION

Metabolically abnormal individuals, regardless of their body weight status, showed significantly higher risks for hypertension compared with healthy non-overweight/obese group. Furthermore, MHO individuals had significantly increased risk of incident hypertension.

[The role of autophagy in the curcumin induced proliferation in human laryngeal cancer Hep2 cell]

Objective:The aim of this study is to study the effect of 3-methyladenine (3-MA) on the autophagy and apoptosis of human laryngeal cancer Hep 2 cells induced by curcumin. Method:The proliferation of human laryngeal cancer Hep2 cells was observed by MTT assay. The autophagy level was detected by AO acridine orange staining. Annexin VFITC/PI double staining was used to detect the apoptosis of Hep2 cells. The expression of LC3, Beclin1, Bcl-2 and Bax protein were detected by Western blot. Result:MTT assay showed that curcumin inhibited the proliferation of Hep2 cells in a dose/time dependent manner. The apoptosis rate of curcumin combined with 3-MA increased (P<0.05). Acridine orange staining showed that 3-MA combined with curcumin could significantly reduce the autophagy level of laryngeal carcinoma Hep2 cells. The expression of Bcl-2, Bclin-1 and LC3 Ⅱ was decreased, while the expression of Bax protein was increased (P<0.05). Conclusion:Curcumin can induce apoptosis of Hep 2 cells and induce the development of protective autophagy. The inhibitory effect of curcumin on the apoptosis of laryngeal carcinoma Hep2 cell line was significantly enhanced by 3-MA.

[Reference ranges of gestational weight gain in Chinese population on the incidence of macrosomia: a multi-center cross-sectional survey]

Objective: To investigate the influence of gestational weight gain (GWG) on the incidence of macrosomia, and to establish the reference ranges of GWG based on the incidence of macrosomia. Methods: A multicenter, cross-sectional study was conducted. Totally, 112 485 women were recruited from 39 hospitals in 14 provinces in China. Totally, 61 149 cases were eligible with singleton pregnancies and non-premature deliveries. The associations of pre-pregnancy body mass index (BMI), GWG, newborn gender and gestational diabetes with macrosomia were analyzed with logistic regression. The normal GWG ranges were calculated in all maternal BMI subgroups, based on the normal incidence of macrosomia was set as the range of 5.0% to 10.0%. Results: In this study, the incidence of macrosomia was 7.46% (4 563/611 149). The macrosociam was positive related with maternal height, delivery week, pre-pregnancy BMI, GWG, gestational diabetes, primipara, and male babies significantly (P<0.05), based on unadjusted and adjusted logestic regression. The normal range of GWG 20.0-25.0, 10.0-20.0, 0-10.0 and 0-5.0 kg in subgroups of underweight (pre-pregnancy BMI<18.5 kg/m(2)), normal (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)) and obese (≥30.0 kg/m(2)), respectively. Conclusion: The reference range of GWG in China based on the incidence of macrosomia is established.

[Risk factors for acute rejection in living-donor kidney transplant recipients in China: a subgroup analysis of a multi-center, registry study]

Objective: To evaluate pre-and early post-transplantation risk factors for acute rejection(AR) in kidney recipients. Methods: This subgroup analysis of a multi-center registry study was conducted on living-donor kidney transplant recipients in China with 10 years of follow-up. This study analyzed 1 255 recipients including 921 males(73.4%) and with a mean age of (33±10)years. Data from patients were first analyzed with univariate analysis and then multivariate analysis was used for finding out the potential risk factors of AR. Results: A total of 106(8.4%) patients were suspected with AR after kidney transplantation, while 1 149 patients were considered as non-AR. Multivariable analysis demonstrated a significant influence of recipient age and cold ischemia time(CIT) on the occurrence of AR(OR: 0.956, 95% CI: 0.923-0.990; OR: 1.006, 95% CI: 1.002-1.011, respectively). The frequency of severe infection was significantly higher in the AR group than non-AR group(38.7% vs 10.8%; P<0.000 1). The occurrence of new-onset diabetes mellitus and tumors was similar in the two groups. Conclusions: Recipient age and CIT are risk factors for AR after living-donor kidney transplantation. Reducing CIT and intensive management of younger recipient could benefit kidney transplant patients.

[Seasonality of clustering of fever and diarrhea in Beijing, 2009-2015]

Objective: To understand the seasonal distribution of the clustering of fever and diarrhea. Methods: Concentration degree and circular distribution methods were used to analyze the seasonal distribution of the clustering of fever and diarrhea in Beijing from 2009 to 2015. The information were collected from the Infectious Disease Surveillance Information System of Beijing. Results: The M values of the clustering of fever and diarrhea were 0.57 and 0.47. Circular distribution results showed that the clustering of fever and diarrhea angle dispersion index R values were 0.57 and 0.46 respectively, the sample average angle of Rayleigh' s test Z values were 414.14, 148.09 respectively (all P<0.01). The clustering of fever and diarrhea had seasonality. The incidence peak of fever was on October 13, and the epidemic period was during August 13-December 14. The incidence peak of diarrhea was on July 31, and the epidemic period was during May 20-October 11. Conclusion: The clustering of fever had obvious seasonality in Beijing, which mainly occurred in autumn and winter. The cluster of diarrhea had certain seasonality, which mainly occurred in summer and autumn.

The Cold Hardiness of Phrynocephalus erythrurus, the Lizard Living at Highest Altitude in the World

BACKGROUND

Phrynocephalus erythrurus living at Qinghai-Tibet Plateau, is believed to be the highest lizard in the world, but we know little about how these lizards cope with very low temperatures in winter.

OBJECTIVE

The aim of this study was to find the difference of the lizards before and after cold acclimatization.

MATERIALS AND METHODS

In this study the limit of supercooling and inoculative freezing, the concentration of four organic osmolytes, and the activity of lactate dehydrogenase in the plasma were measured in samples shortly after capture and in other samples after 7~8 weeks of acclimatization at 2~4 degree C.

RESULTS

Animals acquired an ability to undergo deeper supercooling and inoculative freezing through the course of acclimatization. We find no regular changes of the four organic osmolytes after the acclimatization.

CONCLUSION

We think that this species of lizard is partly freeze-tolerant and conclude that it uses supercooling to survive in winter.

[The sex difference of speech evoked auditory brainstem responses in children and young adults]

OBJECTIVE

The aim of this study was to compare the sex difference of the speech-ABR in young adults and school age children.

METHODS

Speech-ABR of eighty normal hearing subjects including twenty four school-age children(12 girls and boys, age from 6 to 12 years old) and fifty six young adults(male 29, female 27, age from 20 to 34 years old) were recorded. The speech syllable /da/ as stimulus sound was transmitted to right ear by insert earphones in speech-ABR test.

RESULTS

① Females had a shorter latency than males in transient response (waves V, A and O) and sustained response (waves D, E and F) of speech-ABR (P<0.05, respectively). The amplitudes of transient response (waves V and A) and sustained response (waves D, E and F) in females were also significantly larger than those in males (P<0.05, respectively), except for amplitude of peak O (P>0.05). The V/A slope in females was significantly steeper than that in males[(-0.43±0.13)vs(-0.25±0.08), P<0.01]. ②The amplitude and latency of speech-ABR in transient response (waves V, A and O) and sustained response (waves D, E and F) were not significantly different between boys and girls. Only the V/A slope in girls was significantly steeper than that in boys [(-0.46±0.12)vs(-0.35±0.15), P<0.05]. ③The latency of speech-ABR was significantly prolonged in young men when compared with boys in both transient response (waves V, A and O) (P<0.05, respectively) and sustained response (waves D and F, P<0.05, respectively), except for wave E (P>0.05). The amplitude of speech-ABR showed a statistically significant decrease (P<0.05, respectively) only in wave A, D and F. Contrarily, the decrease in response amplitudes of waves V, E and O were not statistically significant (P>0.05, respectively). The V/A slope was steeper in boys than in young men, which was statistically significant (P<0.05). ④ In girls and young women, peak latency and magnitude of speech-ABR showed similar characteristics. No significant differences were found in either transient response or sustained response. The V/A slope between girls and young women was similar without significant difference (P>0.05).

CONCLUSIONS

The female adults have shorter wave latency and larger amplitude of speech-ABR than males, which suggests that females have better speech encoding in brainstem. There are few differences between female and girls in wave latency and amplitude. The speech encoding in brainstem in young men tends to become worse than in boys. It implies that the increase of androgen might weaken the ability of the speech encoding in brainstem.

Development of Reverse Transcription Loop-Mediated Isothermal Amplification for Rapid Detection of Batai Virus in Cattle and Mosquitoes

Batai virus (BATV) is an arthropod-borne single-stranded RNA virus belonging to the genus Orthobunyavirus of the family Bunyaviridae that is primarily transmitted by mosquitoes. Methods for detecting BATV are currently limited to serological surveillance, virus isolation, and conventional reverse transcription-polymerase chain reaction (RT-PCR) assay. In this study, we sought to develop a BATV detection assay that needs no specialized equipment and is highly specific, sensitive, and simple. We first developed and optimized a reverse transcription loop-mediated isothermal amplification (RT-LAMP) for rapid detection of BATV that uses two pairs of primers to amplify a conserved region of the BATV M gene. The optimal reaction conditions for this RT-LAMP BATV detection assay were 40 min at 65°C. The amplification products could be visualized directly for color changes. This RT-LAMP method has a detection limit of 2.86 copies/μL and a sensitivity that was approximately 10- and 100-fold greater than real-time and conventional RT-PCR, respectively. RT-LAMP for BATV detection showed no cross-reactivity with other viruses and its sensitivity was validated with cattle blood and mosquito specimens. Our results suggest that this RT-LAMP method was simpler and faster than conventional RT-PCR or real-time RT-PCR. Moreover, RT-LAMP represents a potential tool to test for BATV in clinical and mosquito samples, especially in rural areas of China. This method also shows promise as a diagnostic tool due to its rapid and sensitive detection without the need for sophisticated equipment or complicated protocols.

Synthesis and structure of a new scorpionate-dithio carboxyl oxovanadium complex and an organic dithio carboxyl compound

A new complex of oxovanadium(IV), V(2)O(2)[(HB(pz)(3))(2)(pyrro)(2) (1) and a dimer-dithio carboxyl compound (C(5)H(8)NS(2))(2) (2) have been synthesized by the reaction of VOSO(4).nH(2)O with NaHB(pz)(3) and pyrrolidine dithio carboxylic acid ammonium salt. They were characterized by element analysis, IR spectra, UV-vis spectra and X-ray diffraction. Structural analyses of 1 and 2 gave the following parameters: 1, triclinic, P-1, a=7.732(4)A, b=14.285(8)A, c=17.802(9)A, alpha=101.314(8) degrees , beta=92.682(9) degrees , gamma=92.228(9) degrees , V=1923.6(18)A(3), and Z=4; 2, monoclinic, C2/c, a=13.857(2)A, b=10.4213(18)A, c=9.436(2)A, beta=97.099(2), V=1352.1(4)A(3), and Z=4. In complex 1, vanadium atom adopts a distorted tetragonal bipyramid structure, which is typical for oxovanadium(IV) complexes. Compound 2 is a dimer-dithio carboxyl compound with S-S bond. In addition, thermal analysis was performed for analyzing the stabilization of the complexes.

Unbalanced translocation in an adult patient with premature ovarian failure and mental retardation detected by spectral karyotyping and array-comparative genomic hybridization

BACKGROUND

There are only three cases of unbalanced translocation (X;1) reported in childhood in the literature, while no such phenotypic information is available in adults.

MATERIALS AND METHODS

To delineate the phenotype-genotype relationship of unbalanced translocation (X;1) in adulthood, we reported here a 20-year-old female with an unbalanced translocation (X;1) which was determined by spectral karyotyping, array-comparative genomic hybridization and subtelomeric fluorescence in situ hybridization (FISH).

RESULTS

The phenotype of partial trisomy 1 and partial monosomy X of the present case was much attenuated, including premature ovarian failure, mental retardation, class I obesity, mild dysmorphism and delayed secondary sexual characteristics. The breakpoints of the unbalanced translocation were accurately located at Xq28 and 1q32.1. The large amplification on Chromosome 1 q arm was found to involve 312 genes and the deletion on Chromosome X q arm also involved 141 genes. Overall, genes associated with physiological process (47 genes), cellular process (33), development (23), response to stimulus (1) and reproduction (1) were observed in the amplification on Chromosome 1 q arm. In addition, genes related to physiological process (23 genes), cellular process (13), development (6) and response to stimulus (2) were observed in the large deletion on chromosome X q arm. Late-replication studies revealed the existence of skewed X inactivation in the derivative X chromosome.

CONCLUSIONS

The phenotype of partial monosomy X and partial trisomy 1q is much attenuated in case of unbalanced translocation (X;1) in adulthood probably owing to skewed X inactivation in derivative X chromosome.

Human periodontal ligament cells express osteoblastic phenotypes under intermittent force loading in vitro

Mechanical strain applied to bone leads to bone remodeling. In the oral cavity, it is unclear how such mechanical force applied to move teeth orthodontically induces alveolar bone remodeling. It is known that osteoclasts are the only cells that are responsible for bone resorption, while the formation and activity of osteoclasts are regulated by osteoblasts. So it is believed that osteoblasts play an important role not only in bone formation but in bone remodeling as well. Therefore, the purpose of this study was to examine the effect of mechanical force on human periodontal ligament (PDL) cells and whether they express osteoblastic characters in vitro.

METHODS

Human PDL cells cultured in vitro were loaded with intermittently stretching force for 24 hours. The expression of alkaline phosphatase (ALP), osteocalcin (OCN) and osteoprotegerin (OPG) were detected at mRNA and protein levels at 0, 2nd, 4th, 6th, 12th, 24th hours after intermittent force loading.

RESULTS

Without any stimulation, ALP and OPG mRNA expressions were detected in human PDL cells by in-situ hybridization, but not that of OCN mRNA. ALP mRNA signal was up-regulated and that of OPG was down-regulated by mechanical force within 24 hours. OCN mRNA expression was induced by mechanical force in the late phase of the 24-hours loading cycle. The changes in secreted proteins showed similar results with those seen at the mRNA level.

CONCLUSION

Human PDL cells express osteoblastic phenotypes under intermittent force loading and play a role in alveolar bone remodeling.

Application of an effective method in predicting breakthrough curves of fixed-bed adsorption onto resin adsorbent

Removal of many organic pollutants including phenolic compounds from industrial wastewater can always be achieved by fixed-bed adsorption onto the polymeric resin adsorbent, and the relevant breakthrough curves would provide much valuable information to help to design a fixed-bed adsorption process in field application. In the present study, a model developed based on the constant-pattern wave approach theory and the Freundlich model was adopted to describe the breakthrough curves of phenol and p-nitrophenol adsorption onto a macroreticular resin adsorbent NDA-100 from aqueous solution. Column experiments were performed at different conditions to verify the model and the results proved that the model would describe the breakthrough curves well. Effect of the operation parameters on breakthrough curves was also discussed to get helpful information in choosing the adsorption process.

Characterization of a cellulase-free, neutral xylanase from Thermomyces lanuginosus CBS 288.54 and its biobleaching effect on wheat straw pulp

A xylanase purified from the thermophilic fungus Thermomyces lanuginosus CBS 288.54 was characterized and its potential application in wheat straw pulp biobleaching was evaluated. Xylanase was purified 33.6-fold to homogeneity with a recovery yield of 21.5%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of approx. 26.2 kDa. The purified xylanase had a neutral optimum pH ranging from pH 7.0 to pH 7.5, and it was also stable over pH 6.5-10.0. The optimal temperature of the xylanase was 70-75 degrees C and it was stable up to 65 degrees C. The purified xylanase was found to be not glycosylated. The xylanase was highly specific towards xylan, but did not exhibit other enzyme activity. Apparent Km values of the xylanase for birchwood, beechwood, soluble oat-spelt and insoluble oat-spelt xylans were 4.0, 4.7, 2.0 and 23.4 mg ml-1, respectively. The potential application of the xylanase was further evaluated in biobleaching of wheat straw pulp. The brightness of bleached pulps from the xylanase pretreated wheat straw pulp was 1.8-7.79% ISO higher than that of the control, and showed slightly lower tensile index and breaking length than the control. Although chlorine consumption was reduced by 28.3% during bleaching, the xylanase pretreated pulp (15 U g-1 pulp) still maintained its brightness at the control level. Besides, pretreatment of pulp with the xylanase was also effective at an alkaline pH as high as pH 10.0.

Biobleach boosting effect of recombinant xylanase B from the hyperthermophilic Thermotoga maritima on wheat straw pulp

The recombinant xylanase B (XynB) of Thermotoga maritima MSB8 was found to be highly specific towards xylans and exhibit very low activity towards carboxymethylcellulose in previous study. XynB was thermostable at neutral to alkaline pH region at 90 degrees C and retained more than 90% activity after 1 h over the pH range of pH 6.1 to 11.1. The suitability of XynB for use in the biobleaching of wheat straw pulp was investigated. Pretreatment of the pulp with XynB resulted in a substantial improvement in the bleachability of wheat straw pulp. When XynB at 10 U g(-1) was used to treat wheat straw pulp, it reduced pulp kappa number by 1.1 point, enhanced pulp brightness by 5.5% (% ISO) and improved other pulp properties, such as tensile index and breaking length. Biobleaching of wheat straw pulp with XynB saved active chlorine up to 34.5% while still maintaining the brightness at the control level. Besides, pretreatment of pulp with XynB was also effective at an alkaline pH as high as pH 10.1. This is the first report on the potential application of XynB from T. maritima MSB8 in the pulp and paper sector.

Characterization of a xylanase from the newly isolated thermophilic Thermomyces lanuginosus CAU44 and its application in bread making

AIMS

A xylanase from the newly isolated thermophilic fungus, Thermomyces lanuginosus CAU44, was characterized and evaluated for its suitability in bread making.

METHODS AND RESULTS

Xylanase was purified 3.5-fold to homogeneity with a recovery yield of 32.8%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of c. 25.6 kDa. The purified xylanase had an optimum pH of 6.2, and it was stable over pH 5.6-10.3. The optimal temperature of xylanase was 75 degrees C and it was stable up to 65 degrees C at pH 6.2. Study was further carried out to investigate the effect of the purified xylanase on the properties of wheat bread and its staling during storage.

CONCLUSIONS

The purified xylanase from T. lanuginosus CAU44 was stable up to 65 degrees C and had a broad pH range. The presence of thermostable xylanase during bread making led to an improvement of the specific bread volume and better crumb texture. Besides, addition of xylanase provided an anti-staling effect.

SIGNIFICANCE AND IMPACT OF THE STUDY

The xylanase from the newly isolated Thermomyces lanuginosus CAU44 shows great promise as a processing aid in the bread-making industry.

The expression of osteoprotegerin and the receptor activator of nuclear factor kappa B ligand in human periodontal ligament cells cultured with and without 1α,25-dihydroxyvitamin D3

The receptor activator of nuclear factor kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG), are important bone metabolism molecules, which directly control osteoclastogenesis. Periodontal ligament (PDL) cells play a vital role in maintaining the homeostasis of periodontal tissues, releasing cytokines to affect bone metabolism. The purpose of this study was to investigate the expression of OPG and RANKL in cultured human periodontal ligament cells (hPDLCs) derived from permanent teeth and the expression change after stimulation by 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)vitD(3)), a kind of bone resorption promoter. HPDLCs were cultured in the presence or absence of 10(-8)M 1alpha,25(OH)(2)vitD(3) in vitro. The expression of mRNA for OPG and RANKL in hPDLCs during 6 days' culture was examined using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The level of secreted OPG protein in the culture medium during 6 days' culture was detected by enzyme-linked immunoabsorbent assay (ELISA). The result showed that OPG and RANKL were expressed by hPDLCs. OPG expression was down-regulated by 10(-8)M 1alpha,25(OH)(2)vitD(3) in a time-dependent manner, while RANKL mRNA was up-regulated. The ratio of OPG/RANKL was decreased. In conclusion, our findings suggest that hPDLCs may regulate the alveolar bone metabolism through the OPG/RANKL system.

Hyperphosphorylation and accumulation of neurofilament proteins in Alzheimer disease brain and in okadaic acid-treated SY5Y cells

We investigated the role of neurofilament (NF) proteins in Alzheimer disease (AD) neurofibrillary degeneration. The levels and degree of phosphorylation of NF proteins in AD neocortex were determined by Western blots developed with a panel of phosphorylation-dependent NF antibodies. Levels of all three NF subunits and the degree of phosphorylation of NF-H and NF-M were significantly increased in AD as compared to Huntington disease brains used as control tissue. The increase in the levels of NF-H and NF-M was 1.7- and 1.5-fold (P<0.01) as determined by monoclonal antibody SMI33, and was 1.6-fold (P<0.01) in NF-L using antibody NR4. The phosphorylation of NF-H and NF-M in AD was increased respectively at the SMI31 epitope by 1.6- and 1.9-fold (P<0.05) and at the SMI33 epitope by 2.7- and 1.3-fold (P<0.01 and P<0.05). Essentially similar effects were observed in SY5Y human neuroblastoma cells when treated with okadaic acid, an inhibitor of protein phosphatase (PP)-2A and -1. This is the first biochemical evidence which unambiguously demonstrates the hyperphosphorylation and the accumulation of NF subunits in AD brain, and shows that the inhibition of PP-2A/PP-1 activities can lead to the hyperphosphorylation of NF-H and NF-M subunits.

[Alzheimer-like protein phosphatase deficiency leads to abnormal phosphorylation and accumulation of neurofilaments]

OBJECTIVE

To explore the effect of Alzheimer-like protein phosphatase deficiency on neurofilament phosphorylation.

METHODS

Cell culture, light microscopy, immunocytochemistry and biochemistry techniques were used to make a phosphatase deficient cell model, to detect cell morphology, neurofilament phosphorylation and distribution, cell viability and activity.

RESULTS

Non-phosphorylated neurofilament recognized by SMI32 was detected both in cell body and cell processes, it was extremely enriched in cell bodies; Phosphorylated neurofilament bound to SMI34 was mainly determined in cell processes and cell surface. After treatment with okadaic acid (OA), non-phosphorylation-dependent antibodies SMI32 staining was significantly decreased in the cell body, whereas phosphorylated neurofilament reacted with SMI34 was strikingly increased in immunocytochemistry and Western blot, and prominently accumulated to the same cell location. Accompanied with hyper-phosphorylation and accumulation of neurofilament, dose dependent cell toxicity was observed by okadaic acid treatment.

CONCLUSION

Deficiency in protein phosphatase induces in neuroblastoma cell line, neurofilament phosphorylation and accumulation, which is involved in Alzheimer neurofibrillary degeneration.

Inhibition by agmatine on spontaneous activity of rabbit atrioventricular node cells

AIM

To study the effects of agmatine on spontaneous activity of atrioventricular (AV) node and its action mechanisms.

METHODS

Action potentials in AV node cells were recorded using intracellular microelectrode technique.

RESULTS

Agmatine not only reduced the amplitude of action potential (APA), maximal rate of depolarization (Vmax), velocity of diastolic (phase 4) depolarization (VDD), and rate of spontaneous firing (RSF), but also prolonged 90% duration of action potential (APD90) in a concentration-dependent manner. The effects of agmatine (10 mmol/L) could be blocked completely by pretreatment with idazoxan (0.1 mmol/L), an imidazoline receptor (IR) and alpha 2-adrenergic receptor (alpha 2-AR) antagonist. Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 0.5 mmol/L), a nitric oxide (NO) synthase inhibitor, did not affect the effects of agmatine on AV node cells. Elevation of Ca2+ concentration (5 mmol/L) in perfusate antagonized the effects of agmatine (10 mmol/L). Lemakalim (30 mumol/L), an ATP-sensitive potassium channel opener, inhibited the prolonging effects of agmatine on repolarization.

CONCLUSION

The inhibitory effects of agmatine on spontaneous activity of AV node cells in rabbits were likely mediated by IR and/or alpha 2-AR, and were related to the reduction in calcium influx and potassium efflux.

Electrophysiological effects of agmatine on human atrial fibers

The objective of the present study was to study the electrophysiological effects of agmatine on human atrial fibers obtained at cardiac surgery using standard microelectrode techniques. Agmatine (1 to approximately 10 mM) decreased the action potential amplitude (APA), maximum upstroke velocity of phase 0 depolarization (Vmax), velocity of diastolic (phase 4) depolarization (VDD), rate of pacemaker firing (RPF), and action potential duration at 50 and 90% of repolarization (APD(50-90)) in a concentration-dependent manner. Pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 0.5 mM), a NOS inhibitor, did not affect the electrophysiological effects of agmatine (5 mM) on human atrial fibers. The effects of agmatine (5 mM) could be blocked completely by pretreatment with idazoxan (0.1 mM), an alpha-2 adrenergic receptor (alpha2-AR) and imidazoline receptor (IR) antagonist. All these results indicate that the effects of agmatine on human atrial fibers are likely due to a decrease of intracellular calcium mediated by IR and/or alpha2-AR.

Effects of agmatine on afterdepolarizations induced by isoproterenol in guinea pig papillary muscles

AIM

To study the effects of agmatine (Agm) on early afterdepolarizations (EAD) and delayed afterdepolarizations (DAD) induced by isoproterenol (Iso) in guinea pig papillary muscles.

METHODS

EAD and DAD were recorded using intracellular glass microelectrode technique.

RESULTS

(1) EAD and DAD induced by Iso 20 nmol.L-1 were markedly inhibited by pretreatment with Agm 1.0-2.0 mmol.L-1 in a concentration-dependent manner. (2) NG-nitro-L-arginine methyl ester (L-NAME, 0.5 mmol.L-1), a NOS inhibitor, did not affect the inhibitory effects of Agm (1.0 mmol.L-1) on EAD and DAD induced by Iso. (3) The inhibitory effects of Agm (1.0 mmol.L-1) on EAD and DAD induced by Iso (20 nmol.L-1) were eliminated by pretreatment with idazoxan (Ida, 0.1 mmol.L-1), an alpha-2 adrenergic receptor (alpha 2-AR) and imidazoline receptor (IR) antagonist.

CONCLUSION

The inhibitory effects of Agm on EAD and DAD induced by Iso in papillary muscles is related to the reduction in calcium influx and mediated by alpha 2-AR and/or IR.

Electrophysiologic effects of agmatine on pacemaker cells in sinoatrial node of rabbits

AIM

To study the electrophysiologic effects of agmatine (Agm) on pacemaker cells in sinoatrial (SA) node.

METHODS

Parameters of action potential (AP) in SA node were recorded using intracellular microelectrode technique.

RESULTS

Agm not only slowed down the amplitude of action potential (APA), maximal rate of depolarization (Vmax), velocity of diastolic (phase 4) depolarization (VDD), and rate of pacemaker firing (RPF), but also prolonged 90% duration of action potential (APD90) in a concentration-dependent manner. The effects of Agm (10 mmol.L-1) could be blocked completely by pretreatment with idazoxan (0.15 mmol.L-1), an alpha 2-adrenergic receptor (alpha 2-AR) and imidazoline receptor (IR) antagonist. Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 1 mmol.L-1), an NOS inhibitor, did not affect the electrophysiologic effects of Agm on pacemaker cells in SA node. Elevation of Ca2+ concentration (5 mmol.L-1) in perfusate antagonized the effects of Agm (10 mmol.L-1). Lemakalim (Lem, 30 mumol.L-1), an opener of ATP-sensitive potassium channels, partially inhibited the prolonging effect of Agm on repolarization.

CONCLUSION

The electrophysiologic effects of Agm on pacemaker cells in SA node were likely attributed to the reduction in calcium influx and potassium efflux and mediated by alpha 2-AR and IR.