[The burden of disease attributed to low bone mineral density among population aged ≥40 years old in China, 1990 and 2013]

Objective: To identify cause-specific death and attributed burden of low bone mineral density in China among population aged ≥40 years old , 1990 and 2013. Methods: By using data from Global Burden of Disease(GBD)2013, this study analyzed death caused by low mineral density, and disability-adjusted life years(DALY)among population aged 40 and above in China(not including Taiwan, China). This study also analyzed DALY by composition of injury which due to low bone mineral density. It also analyzed changes in DALY by provinces in China, 1990 and 2013. An average world population age-structure for the period 2000- 2025 was adopted to calculate the age standardized rates. Results: In 2013, there were 38.1 thousands male and 30.7 thousands female who aged 40 and above dead due to low bone mineral density in China. The burden of injury caused by low bone mineral density was more sever in male than female, which accounted for 1.525 million DALY in male and 0.873 million DALY in female. In 1990, low bone mineral density attributed transportation and accidental injury caused 0.794 million and 0.567 million DALY losses, respectively. In 2013, low bone mineral density attributed transportation and accidental injury caused 1.421 million and 0.951 million DALY losses, respectively. Compared to 1990, DALY losses caused by transportation and accidental injury, increased by 79.1% and 67.6%, respectively. In 1990, DALY rate losses due to low bone mineral density attributed transportation and accidental injury were 68.1 per 100 000 and 48.7 per 100 000, respectively. In 2013, DALY rate losses due to low bone mineral density attributed transportation and accidental injury were 102.0 per 100 000 and 68.2 per 100 000, respectively. Compared to 1990, DALY rates which caused by transportation and accidental injury, increased by 49.8% and 40.2%, respectively. According to the ranking of standardized DALY rate in 2013 by provinces, the top 3 provinces, which standardized DALYs attributed to low bone mineral density lost the most, were Zhejiang Province(2.6 per 100 000), Jiangsu Province(2.4 per 100 000), and Fujian Province(2.2 per 100 000). Compared to 1990, the standardized rate of DALY decreased in 27 provinces, while the DALY rate increased in only 6 provinces which included Ningxia Hui Autonomous Region, Qinghai Province, Hebei Province, Guangxi Zhuang Autonomous Region, and Henan Province and Xinjiang Uygur Autonomous Region. Conclusion: This study found that the burden of health losses attributed to it was higher in men than in women. Compared to 1990, DALY rates decreased in most of the provinces, however, the rates of losses of DALY which caused by transportation and accidental injury were still increasing.

[The application of endoscopic strategy and approaches to treat sphenoid sinus inflammatory diseases]

Objective:A retrospective study aimed to investigate the characteristics and prognosis of inflammatory sphenoid sinus diseases and discuss of endoscopic surgical techniques.Method:A total of 105 subjects with isolated inflammatory sphenoid pathologies were treated by endoscopic surgery,which included 41(39.0%) cases of fungal sinusitis,33(31.4%) mucocele,and 31(29.5%) sphenoiditis.They were evaluated by paranasalsinuse CT scan and all patients underwent endoscopic sphenoidsinus surgery under general anesthesia.Twenty cases were selected in Messerklinger,74 cases selected in Wingand,5 cases selected in Draf 3-like,5 cases selected in transphenoidal septum into the contralateral sphenoid sinus,and 1 case selected in trans-medial plate of pterygoid process approach.Result:The postoperative follow up from 6 to 27 months showed that sphenoid ostium were good in 96(91.4%) patients,stenosis in 5(4.8%) patients,and atresia in 4(3.8%)patients who need reoperation.Conclusion:Transnasal endoscopic sphenoidectomy should be the standard option for dealing with isolated inflammatory sphenoid diseases.The five different approaches would be selected according to the extension of the diseases and anatomic structure of the sphenoid sinus.

Variations of rhizosphere bacterial communities in tea (Camellia sinensis L.) continuous cropping soil by high-throughput pyrosequencing approach

AIMS

The goal was to investigate the dynamics of soil bacterial community in the chronosequence tea orchards.

METHOD AND RESULTS

In this study, soils from tea orchards with continuously cropping histories for 1, 10 and 20 years were collected for investigating rhizosphere bacterial communities using 454 pyrosequencing. The results indicated that Gammaproteobacteria, Alphaproteobacteria, Acidobacteria and Actinobacteria were the main phyla in the tea orchard soils and accounted for more than 60% of the bacterial sequences. At the genus level, the relative abundance of beneficial bacteria, such as Pseudomonas, Rhodanobacter, Bradyrhizobium, Mycobacterium and Sphingomonas, significantly decreased in the 20-year tea orchard soils. Similar patterns of bacterial community structure were observed between 1-year and 10-year tea orchards, which significantly differed from those of 20-year tea orchards. Redundancy analysis indicated that soil organic carbon and pH showed high correlations (positive or negative) with the majority of the taxa.

CONCLUSION

Long-term tea cultivation altered the composition and structure of soil bacterial community, which led to the reduction in the beneficial bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results can provide clues on how to regulate the soil microbial community and maintain the health of soils in tea orchard systems.

Protein tyrosine kinase regulates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor trafficking induced by acute hypoxia in cultured brainstem neurons

This study was performed to investigate the modulation effect of protein tyrosine kinase on postsynaptic a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor trafficking induced by acute hypoxia in cultured brainstem neurons. The cultured neurons were exposed to 1% O2 and the expression of AMPA receptor subunit GluR2 on the cell surface was significantly increased, while total GluR2 was not markedly changed. Furthermore, the hypoxia-induced increase in GluR2 expression on the cell surface was partially blocked by the protein tyrosine kinase membrane-permeable inhibitor genistein. In contrast, both the protein tyrosine kinase agonist nerve growth factor and protein tyrosine phosphatase inhibitor vanadate promoted the hypoxia-induced increase of GluR2 expression on cell surface. Moreover, GluR2 could be phosphorylated by tyrosine under normoxia and hypoxia conditions in vitro on brainstem neurons, and tyrosine phosphorylation of GluR2 was significantly stronger under hypoxia conditions. Our results indicate that acute hypoxia induces the AMPA receptor subunit GluR2 to rapidly migrate to the cell membrane to modify the strength of the synapse. This study indicates that tyrosine phosphorylation of the receptor is an important pathway regulating the rapid migration of GluR2 in the postsynaptic domain induced by hypoxia.

[Expenditure in outpatient department and pharmacy on patients with hypertension and the influence from community health management program]

OBJECTIVE

To explore the impact of health management programs on hypertension related to their cost of the hypertensive, so as to provide evidence for related policy-making.

METHODS

Data was from the 2011 China Non-communicable and Chronic Disease Survey Project which was developed in 161 counties (districts) and Xinjiang production and Construction Corps. Information regarding hypertensive patients were collected through a questionnaire. Two-part model was used to analyze the influence from health management scheme.

RESULTS

This study included 11 294 participants who were 35 years old or beyond, with 4 904 (43.42%) males and 6 390 (56.58%) females. The median cost from the outpatient was 100 (30-200) Yuan, and the cost of patients under management program were significantly lower than those without (P<0.05). Median pharmacy cost appeared as 30 (15-100) Yuan but there was no significant difference noticed between the cost from the managed or unmanaged patients (P>0.05). Regarding the calculation on the outpatient cost, results showed that the patients under the management program were more likely to practice 'outpatient-medical-behavior' (OR =2.50, 95% CI:2.26-2.76) with nearly three quarters of the cost from the unmanaged patients. Hypertensive patients from the urban areas were more likely to adopt 'medical behavior'(OR=1.31, 95% CI:1.18-1.45) which was 1.69 times of the costs from the rural patients. RESULTS of the pharmacy cost showed that the urban hypertension patients were more likely to purchase medicine (OR=1.10, 95% CI:1.01-1.20) and was 1.19 times the costs of the rural patients.

CONCLUSION

Health management program on hypertension showed preliminary but promising results in reducing the out-patient cost in the treatment of hypertension,thus should be promoted and implemented.

[Disease burden of leukemia in the Chinese population, in 1990 and 2013]

OBJECTIVE

To analyze the disease burden of leukemia in the Chinese population, in 1990 and 2013.

METHODS

Data related to province-specific disease burden in China was used to analyze and compare related parameters as incidence, mortality, the disability-adjusted life years (DALY), years of life lost due to premature mortality (YLL) and years lived with disability (YLD) on leukemia in China in 1990 and 2013. Standardized mortality rates of leukemia in each province in 2013 and the changes since 1990, were described.

RESULTS

In 2013, the standardized incidence and mortality rates of leukemia in China were 6.70/100 000 and 4.05/100 000, with reduction of 8.84% and 36.22% when compared with those in 1990, respectively. The standardized DALY rate and YLL rate appeared as 174.58/100 000 and 170.42/100 000 in 2013, with 44.68% and 45.32% reduction, respectively, when compared with the figures in 1990. The standardized YLD rate of leukemia in 2013 was 4.16/100 000, with an 6.94% increase, comparing with that in 1990. Age-specific data showed that the proportion of people who died from leukemia among those who died from all the cancers was more than 10% in people under 35 years old. DALY rate of leukemia was highest among children aged 5 years old and under, which appeared as 317.61/100 000. Compared with those in 1990, the standardized mortality of leukemia appeared decreasing in all the provinces in 2013. The top three provinces with the highest standardized mortality of leukemia in 2013 were Xinjiang (4.72/100 000), Ningxia (4.56/100 000) and Fujian (4.50/100 000).

CONCLUSIONS

Although the standardized incidence rate, mortality rate, DALY rate and YLL rate due to leukemia decreased, YLD rate due to leukemia increased. Proportions of children and adolescents who died from leukemia remained high. Although the standardized mortalities of leukemia decreased in all the provinces, the differences among them still remained.

[Health Station, a product of combining the ideas of public health with the modern Chinese national conditions]

The Health Station was a local health organization founded by the pioneers of the public health in modern China under the national conditions of "poverty, ignorance, illness and selfishness" , being the result of combining the ideas of public health with the Chinese national conditions of modern times. Though this organization appeared in backward modern China, it was advanced all over the world. John Grant was the planner of the Peiping First Health Station, whereas Li Ting'an, its builder.

Chemical speciation of cadmium: An approach to evaluate plant-available cadmium in Ecuadorian soils under cacao production

Elevated concentration of cadmium (Cd) in cacao beans has raised serious concerns about the chocolate consumption on human health. Accumulation of Cd in cacao bean in southern Ecuador has been related to soil contamination. In this study, soil fractionation approach was used to identify available Cd pools in the soils and to correlate these Cd pools with bean Cd concentration and soil test indexes. The distribution of soil Cd fractions decreased in the order: oxidizable > acid-soluble > residual > reducible >> water-soluble (+exchangeable). Oxidizable and acid-soluble fractions accounted for 59 and 68% of the total recoverable Cd for the 0-5 and 5-15 cm soil depth, respectively. Acid-soluble fraction was closely related to bean-Cd, with correlation coefficients (r) of 0.70 and 0.81 (P < 0.01) for the 0-5 and 5-15 cm soil depth, respectively. Acid-soluble Cd was significantly correlated with 0.01 M HCl- (r = 0.99, P < 0.01) or Mehlich 3- extractable Cd (r = 0.97, P < 0.01). These results indicate that acid-soluble Cd fraction is an important part of available Cd pool. Since approximately 60% of Cd in the cacao-growing soils is related to the acid-soluble fraction and bound to organic matter, remediation of the contaminated soils should consider to the dynamics of soil pH and organic matter content.

[Burden of chronic obstructive pulmonary disease attributable to ambient ozone pollution in 1990 and 2013 in China]

OBJECTIVE

To investigate the burden of chronic obstructive pulmonary disease (COPD) in China attributable to ambient ozone pollution in 1990 and 2013.

METHODS

Based on the results of the China Global Burden of Disease Study (GBD) 2013, the population attributable fractions was used to analyze the deaths and disability-adjusted life years (DALY) of COPD attributable to ambient ozone pollution in all provinces (not including Taiwan, China) in 1990 and 2013, and to compare changes of the attributable disease burden in 1990 and 2013.

RESULTS

In 2013, 7.4% (95% uncertainty interval (95% UI): 6.1%-8.6%) of COPD were attributable to ambient ozone pollution, with the highest rate in Hebei province (15.0%, 95%UI: 12.0%-18.7%) and the lowest in Heilongjiang province (2.8%,95%UI: 0.9%-5.3%). In 2013, 67 485 COPD deaths in China were due to ambient ozone pollution, with the highest number in Sichuan province (11 929) and in China lowest in Macao (11). A total of 1.168 million DALYs caused by COPD were due to ambient ozone pollution, with the highest in Sichuan province (0.189 million) and lowest in Macao (257.4). In 2013, the DALY per 100 000 population caused by COPD due to ambient ozone pollution after age standardization was lowest in Heilongjiang province (21.9), Shanghai (26.7), Beijing (38.4), Tianjin (39.3), and Jilin province (39.7) and highest in Sichuan province (206.4), Qinghai province (202.5), Guizhou province (175.3), and Gansu province (171.4). DALYs caused by COPD attributable to ambient ozone pollution increased with age (0.144 million person years for ages 15-49 years, 0.43 million person years for age 50-69 years and 0.594 million person years for age 70 years and above), which were higher in men than in women (0.708 million person years for men and 0.459 million person years for women in 2013). Deaths of COPD attributable to ambient ozone pollution were 49 514 and 67 485 in 1990 and 2013, respectively. DALYs caused by COPD attributable to ozone pollution totaled 0.894 million and 1.168 million person years in 1990 and 2013, respectively. Ambient ozone pollution-related deaths and DALYs increased 36.3% and 30.6%, respectively.

CONCLUSION

Compared with 1990, the disease burden of COPD in 2013 attributed to ambient ozone pollution in China increased substantially. Ambient ozone pollution caused great losses among Chinese residents. More attention should be directed toward western provinces with a particularly high disease burden due to ambient ozone pollution.

Bacillus licheniformistrehalose-6-phosphate hydrolase structures suggest keys to substrate specificity

Trehalose-6-phosphate hydrolase (TreA) belongs to glycoside hydrolase family 13 (GH13) and catalyzes the hydrolysis of trehalose 6-phosphate (T6P) to yield glucose and glucose 6-phosphate. The products of this reaction can be further metabolized by the energy-generating glycolytic pathway. Here, crystal structures ofBacillus licheniformisTreA (BlTreA) and its R201Q mutant complexed withp-nitrophenyl-α-D-glucopyranoside (R201Q–pPNG) are presented at 2.0 and 2.05 Å resolution, respectively. The overall structure ofBlTreA is similar to those of other GH13 family enzymes. However, detailed structural comparisons revealed that the catalytic site ofBlTreA contains a long loop that adopts a different conformation from those of other GH13 family members. Unlike the homologous regions ofBacillus cereusoligo-1,6-glucosidase (BcOgl) andErwinia rhaponticiisomaltulose synthase (NX-5), the surface potential of theBlTreA active site exhibits a largely positive charge contributed by the four basic residues His281, His282, Lys284 and Lys292. Mutation of these residues resulted in significant decreases in the enzymatic activity ofBlTreA. Strikingly, the281HHLK284motif and Lys292 play critical roles in substrate discrimination byBlTreA.

Effects of CD3McAb and rhIL-2 activated bone marrow on the killing and purging of leukemia cells

We investigated the roles of CD3McAb and rhIL-2 activated bone marrow in the killing and purging of leukemia cells. Cytotoxicity of activated bone marrow was detected with MTT assay. CFU-GM level in activated bone marrow and the destruction of leukemia cells were measured using the semi-solid cell culture. Immune activation markers in activated bone marrow were detected by indirect immunofluorescence assay. Bone marrow activated by CD3McAb and rhIL-2 displayed significantly upregulated the killing and purging abilities on the leukemia cell line K562 and HL-60. Such effects were superior to that of bone marrow activated by rhIL-2 or CD3McAb alone (P < 0.05, P < 0.01). Activation by rhIL-2 and (or) CD3McAb exerted no obvious influence on CFU-GM level in bone marrow. Compared with bone marrow activated by rhIL-2 or CD3McAb alone, the synergistic effect of both CD3McAb+ and hIL-2 caused significant increase of CD3(+), CD8(+), CD19(+), CD25(+), CD38(+), and CD56(+) levels. Our study indicates that CD3McAb enhanced the killing and purging effects of rhIL-2 activated bone marrow on leukemia cells.

Higher mortality in patients with right hemispheric intracerebral haemorrhage: INTERACT1 and 2

BACKGROUND AND PURPOSE

Controversy exists over the prognostic significance of the affected hemisphere in stroke. We aimed to determine the relationship between laterality of acute intracerebral haemorrhage (ICH) and poor clinical outcomes.

METHODS

A subsidiary analysis of the INTERACT Pilot and INTERACT2 studies--randomised controlled trials of patients with spontaneous acute ICH with elevated systolic blood pressure (BP), randomly assigned to intensive (target systolic BP <140 mm Hg) or guideline-based (<180 mm Hg) BP management. Outcomes were the combined and separate end points of death and major disability (modified Rankin scale (mRS) scores of 3-6, 6 and 3-5, respectively) at 90 days.

RESULTS

A total of 2708 patients had supratentorial/hemispheric ICH and information on mRS at 90 days. Patients with right hemispheric ICH (1327, 49%) had a higher risk of death at 90 days compared to those with left hemispheric ICH after adjustment for potential confounding variables (OR, 1.77 (95% CI 1.33 to 2.37)). There were no differences between patients with right and left hemispheric ICH regarding the combined end point of death or major disability or major disability in the multivariable-adjusted models (1.07 (0.89 to 1.29) and 0.85 (0.72 to 1.01), respectively).

CONCLUSIONS

Right hemispheric lesion was associated with increased risk of death in patients with acute ICH. The laterality of the ICH does not appear to affect the level of disability in survivors.

TRIAL REGISTRATION NUMBER

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00226096 and NCT00716079.

Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador

Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg(-1)) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0-5, 5-15, 15-30, and 30-50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg(-1), respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg(-1). Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg(-1)), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans>shell>>leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg(-1), and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0-5 and 5-15 cm depths (r=0.80 and 0.82 for M3, and r=0.78 and 0.82 for HCl; P<0.01). These results indicate that accumulation of Cd in surface layers results in excessive Cd in cacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils.

Gas Chromatography-Mass Spectrometric Analysis of Nematicidal Essential Oil ofValeriana amurensis P Smirn ex Kom (Valerianaceae) Roots and its Activity against Heterodera avenae

Purpose: To investigate the chemical composition and nematicidal activity of the essential oil of Valeriana amurensis roots against cereal cyst nematodes (Heterodera avenae).Methods: The essential oil of V. amurensis roots was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromaotography-mass spectrometry (GC-MS). The nematicidal activity of the essential oil and its major constituents was determined against second stage juveniles of H. avenae.Results: A total of 33 components of the essential oil were identified. The major constituents were bornyl acetate (12.5 %), patchoulol (11.6 %), caryophyllene (8.2 %), 3-methylvaleric acid (7.3 %) and isovaleric acid (6.5 %). The essential oil exhibited nematicidal activity against H. avenae with a medium lethal concentration (LC50) value of 311.6 μg/mL. The major constituents, isovaleric acid and 3- methylvaleric acid, exhibited nematicidal activity against H. avenae with LC50 of 218.2 and 683.8 μg/mL, respectively.Conclusion: The study indicates that the essential oil of V. amurensis roots and its two major constituents, isovaleric acid and 3-methylvaleric acid, have a potential to be developed to natural nematicides for the control of cereal cyst nematodes.Keywords: Valeriana amurensis, Heterodera avenae, Nematicidal activity, Isovaleric acid, 3- Methylvaleric acid, Essential oil, Cereal cyst nematodes

Selected representative microsatellite loci for genetic monitoring and population structure analysis of miniature swine

To optimize the combination of microsatellite loci for genetic control of outbred swine stocks, 32 of 100 loci distributed among almost all chromosomes (except 12) were screened out by 1.5% agarose, 8% polyacrylamide gel and capillary electrophoresis scanning among 3 miniature swine outbred stocks, namely Bama (BM), Guizhou (GZ) and Tibeta (TB). The mean total and effective allele numbers among these stocks were 12.1 and 5.9, respectively. The mean heterozygosity for these breeds was 0.5428, 0.6978 and 0.7646, and polymorphism information content was 0.5469, 0.7296 and 0.7663, respectively. Accordingly, hereditary variation from low to high was BM < GZ < TB. This showed that the genetic relationship between BM and GZ pigs was closer, and both were distant from TB. Additionally, the effectiveness of the 32-locus combination for evaluation of genetic quality was demonstrated in Changchun-junmo-1 (CJ-1), a standard outbred Chinese pig stock, in which the mean total and effective allele numbers and mean heterozygosity were 6.1613, 3.8483 and 0.6903, respectively. Since our results were consistent with the breeding pedigrees, the 32 loci could be used for both genetic monitoring within the individual outbred miniature swine stocks and population structure analysis between them.

Expression divergence of FRUITFULL homeologs enhanced pod shatter resistance in Brassica napus

To improve pod shatter resistance in the important oilseed crop Brassica napus, the phenotypic diversity of B. napus was tested using 80 B. napus varieties for pod shatter resistance by a random impact test. Among these varieties, R1-1 was identified as resistant, while R2, 8908B was susceptible to shatter. To understand the molecular basis for this phenotypic difference based on the candidate gene approach, B. napus FRUITFULL (FUL) homologs were identified and characterized. Two FUL loci in the A and C genomes of B. napus were identified. In the susceptible variety, both BnaA.FUL and BnaC.FUL were expressed in the same tissues. However, the expression level of BnaC.FUL differed in varieties with different pod shatter resistance. In the most resistant variety, R1-1, only BnaA.FUL was expressed, while BnaC.FUL was silenced. Therefore, the functional divergence and differing expression of BnaX.FUL homeologs may significantly affect phenotypic variation, which is an important consequence of allopolyploid evolution. This expression level divergence may be useful for selecting pod shatter resistant lines through marker-assisted selection in B. napus-breeding programs.

Wogonin attenuates endotoxin-induced prostaglandin E2 and nitric oxide production via Src-ERK1/2-NFκB pathway in BV-2 microglial cells

Microglia are the major component of intrinsic brain immune system in neuroinflammation. Although wogonin expresses anti-inflammatory function in microglia, little is known about the molecular mechanisms of the protective effect of wogonin against microglia activation. The aim of this study was to evaluate how wogonin exerts its anti-inflammatory function in BV2 microglial cells after LPS/INFγ administration. Wogonin not only inhibited LPS/ INFγ-induced PGE2 and NO production without affecting cell viability but also exhibited parallel inhibition on LPS/INFγ-induced expression of iNOS and COX-2 in the same concentration range. While LPS/INFγ-induced expression of P-p65 and P-IκB was inhibited by wogonin-only weak inhibition on P-p38 and P-JNK were observed, whereas it significantly attenuated the P-ERK1/2 and its upstream activators P-MEK1/2 and P-Src in a parallel concentration-dependent manner. These results indicated that the blockade of PGE2 and NO production by wogonin in LPS/INFγ-stimulated BV2 cells is attributed mainly to interference in the Src-MEK1/2-ERK1/2-NFκB-signaling pathway.

Impact of different vehicles for laser-assisted drug permeation via skin: full-surface versus fractional ablation

PURPOSE

This study aimed to assess impact of different vehicles for laser-assisted skin drug delivery. We also tried to uncover the mechanisms by which different vehicles affect laser-aided skin permeation.

METHODS

Full-surface ablative (conventional) and fractional lasers were used to irradiate nude mouse skin. Imiquimod and 5-aminolevulinic acid (ALA) were used as lipophilic and hydrophilic permeants. Vehicles employed included water with 40% polyethylene glycol 400 (PEG 400), propylene glycol (PG), and ethanol. Lipid nanoparticles were also utilized as carriers.

RESULTS

In vitro permeation profiles showed improvement in imiquimod flux with conventional laser (2.5 J/cm2) producing a 12-, 9-, and 5-fold increase when loading imiquimod in 40% PEG400, PG, and ethanol, respectively, as compared with intact skin. Nanoparticulate delivery by laser produced a 6-fold enhancement in permeation. Fractional laser produced less enhancement of imiquimod delivery than conventional laser. Laser exposure increased follicular imiquimod accumulation from 0.80 to 5.81 μg/cm2. ALA permeation from aqueous buffer, PEG 400, and PG with conventional laser treatment was 641-, 445-, and 104-fold superior to passive control. In vivo skin deposition of topically applied ALA examined by confocal microscopy indicated the same trend as the in vitro experiment, with aqueous buffer showing the greatest proporphyllin IX signaling. Diffusion of cosolvent molecules into ablated skin and drug partitioning from vehicle to skin are two predominant factors controlling laser-assisted delivery. In contrast to conventional laser, lateral drug diffusion was anticipated for fractional laser.

CONCLUSIONS

Our results suggest that different drug delivery vehicles substantially influence drug penetration enhanced by lasers.

Interactions that influence the binding of synthetic heparan sulfate based disaccharides to fibroblast growth factor-2

Heparan sulfate (HS) is a linear sulfated polysaccharide that mediates protein activities at the cell-extracellular interface. Its interactions with proteins depend on the complex patterns of sulfonations and sugar residues. Previously, we synthesized all 48 potential disaccharides found in HS and used them for affinity screening and X-ray structural analysis with fibroblast growth factor-1 (FGF1). Herein, we evaluated the affinities of the same sugars against FGF2 and determined the crystal structures of FGF2 in complex with three disaccharides carrying N-sulfonated glucosamine and 2-O-sulfonated iduronic acid as basic backbones. The crystal structures show that water molecules mediate different interactions between the 3-O-sulfonate group and Lys125. Moreover, the 6-O-sulfonate group forms intermolecular interactions with another FGF2 unit apart from the main binding site. These findings suggest that the water-mediated interactions and the intermolecular interactions influence the binding affinity of different disaccharides with FGF2, correlating with their respective dissociation constants in solution.

Preparation and malachite green adsorption behavior of polyurethane/chitosan composite foam

A series of Polyurethane/Chitosan composite foam with different chitosan content of 5–25 wt% was prepared, and their adsorption performance of malachite green (MG) in aqueous solutions was investigated by pH values, contact time, temperatures and chitosan content. It was observed that Polyurethane/Chitosan composite foam exhibited well-developed open cell structures. Malachite green adsorption capacities of the composite foam increased with the increment of chitosan content in composite foam. Polyurethane/Chitosan composite foam with 20% chitosan content exhibited a maximum removal capacity of 16.67 mg/g and 95.60% MG removal efficiency. In addition, MG adsorption capacities of composite foam increased with pH value increase, 30℃ was the optimum temperature, which affects the adsorption process, and the adsorption maximum was attained within 12 hours. The result of SEM showed the prepared composite foam possess well-developed open cell structures. The MG adsorption kinetics and equilibrium isotherm of the composite foam were well described with the pseudo-second order kinetic model and Langmuir isotherm model, respectively. This work provided an attractive adsorbent for removing of the hazardous materials from water.

Structural dynamics of the two-component response regulator RstA in recognition of promoter DNA element

The RstA/RstB system is a bacterial two-component regulatory system consisting of the membrane sensor, RstB and its cognate response regulator (RR) RstA. The RstA of Klebsiella pneumoniae (kpRstA) consists of an N-terminal receiver domain (RD, residues 1-119) and a C-terminal DNA-binding domain (DBD, residues 130-236). Phosphorylation of kpRstA induces dimerization, which allows two kpRstA DBDs to bind to a tandem repeat, called the RstA box, and regulate the expression of downstream genes. Here we report the solution and crystal structures of the free kpRstA RD, DBD and DBD/RstA box DNA complex. The structure of the kpRstA DBD/RstA box complex suggests that the two protomers interact with the RstA box in an asymmetric fashion. Equilibrium binding studies further reveal that the two protomers within the kpRstA dimer bind to the RstA box in a sequential manner. Taken together, our results suggest a binding model where dimerization of the kpRstA RDs provides the platform to allow the first kpRstA DBD protomer to anchor protein-DNA interaction, whereas the second protomer plays a key role in ensuring correct recognition of the RstA box.

Rutin decreases lipopolysaccharide-induced acute lung injury via inhibition of oxidative stress and the MAPK-NF-κB pathway

Acute lung injury (ALI) is a serious disease with unacceptably high mortality and morbidity rates. Up to now, no effective therapeutic strategy for ALI has been established. Rutin, quercetin-3-rhamnosyl glucoside, expresses a wide range of biological activities and pharmacological effects, such as anti-inflammatory, antihypertensive, anticarcinogenic, vasoprotective, and cardioprotective activities. Pretreatment with rutin inhibited not only histopathological changes in lung tissues but also infiltration of polymorphonuclear granulocytes into bronchoalveolar lavage fluid in lipopolysaccharide (LPS)-induced ALI. In addition, LPS-induced inflammatory responses, including increased secretion of proinflammatory cytokines and lipid peroxidation, were inhibited by rutin in a concentration-dependent manner. Furthermore, rutin suppressed phosphorylation of NF-κB and MAPK and degradation of IκB, an NF-κB inhibitor. Decreased activities of antioxidative enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase-1 caused by LPS were reversed by rutin. At the same time, we found that ALI amelioration by chelation of extracellular metal ions with rutin is more efficacious than with deferoxamine. These results indicate that the protective mechanism of rutin is through inhibition of MAPK-NF-κB activation and upregulation of antioxidative enzymes.

Cytotoxicity and genotoxicity of chlorhexidine on macrophages in vitro

Chlorhexidine (CHX) is the most widely used antiseptic for wound, skin disinfection, and dental hygiene. The aim of this study is to investigate the possible correlation between CHX-induced cytogenotoxicity and alterations in normal cell cycle on RAW264.7 macrophages. The cytotoxicity, mechanism of cell death, mitotic activity, and reactive oxygen species (ROS) generation were determined by tetrazolium bromide reduction assay, flow cytometry, cytokinesis-block proliferation index, and superoxide dismutase-inhibitable reduction of ferricytochrome c, respectively. The genotoxicity was measured using comet assay and cytokinesis-block micronucleus assay. The cytotoxicity of CHX in RAW264.7 cells presented a dose- and time-dependent manner (p < 0.05). The mode of cell death shifted from apoptosis to necrosis when the dosage of CHX increased. The genotoxicity of CHX in RAW264.7 cells had shown DNA damage in a dose-dependent manner (p < 0.05). Prolongation of cell cycle and the increase of ROS generation also expressed in a dose-dependent manner (p < 0.05). Taken together, the data suggested that CHX-induced cytotoxicity and genotoxicity on macrophages may be via ROS generation.

Bisgma stimulates prostaglandin E2 production in macrophages via cyclooxygenase-2, cytosolic phospholipase A2, and mitogen-activated protein kinases family

BACKGROUND

Bisphenol A-glycidyl-methacrylate (BisGMA) employs as a monomer in dental resins. The leakage of BisGMA from composite resins into the peripheral environment can result in inflammation via macrophage activation. Prostaglandin E2 (PGE2) is a key regulator of immunopathology in inflammatory reactions. Little is known about the mechanisms of BisGMA-induced PGE2 expression in macrophage. The aim of this study was to evaluate the signal transduction pathways of BisGMA-induced PGE2 production in murine RAW264.7 macrophages.

METHODOLOGY/PRINCIPAL FINDINGS

Herein, we demonstrate that BisGMA can exhibit cytotoxicity to RAW264.7 macrophages in a dose- and time-dependent manner (p<0.05). In addition, PGE2 production, COX-2 expression, and cPLA2 phosphorylation were induced by BisGMA on RAW264.7 macrophages in a dose- and time-dependent manner (p<0.05). Moreover, BisGMA could induce the phosphorylation of ERK1/2 pathway (MEK1/2, ERK1/2, and Elk), p38 pathway (MEK3/6, p38, and MAPKAPK2), and JNK pathway (MEK4, JNK, and c-Jun) in a dose- and time-dependent manner (p<0.05). Pretreatment with AACOCF3, U0126, SB203580, and SP600125 significantly diminished the phosphorylation of cPLA2, ERK1/2, p38, and JNK stimulated by BisGMA, respectively (p<0.05). BisGMA-induced cytotoxicity, cPLA2 phosphorylation, PGE2 generation, and caspases activation were reduced by AACOCF3, U0126, SB203580, and SP600125, respectively (p<0.05).

CONCLUSIONS

These results suggest that BisGMA induced-PGE2 production may be via COX-2 expression, cPLA2 phosphorylation, and the phosphorylation of MAPK family. Cytotoxicity mediated by BisGMA may be due to caspases activation through the phosphorylation of cPLA2 and MAPKs family.

On the structural basis and design guidelines for type II topoisomerase-targeting anticancer drugs

Type II topoisomerases (Top2s) alter DNA topology via the formation of an enzyme-DNA adduct termed cleavage complex, which harbors a transient double-strand break in one DNA to allow the passage of another. Agents targeting human Top2s are clinically active anticancer drugs whose trapping of Top2-mediated DNA breakage effectively induces genome fragmentation and cell death. To understand the structural basis of this drug action, we previously determined the structure of human Top2 β-isoform forming a cleavage complex with the drug etoposide and DNA, and described the insertion of drug into DNA cleavage site and drug-induced decoupling of catalytic groups. By developing a post-crystallization drug replacement procedure that simplifies structural characterization of drug-stabilized cleavage complexes, we have extended the analysis toward other structurally distinct drugs, m-AMSA and mitoxantrone. Besides the expected drug intercalation, a switch in ribose puckering in the 3'-nucleotide of the cleavage site was robustly observed in the new structures, representing a new mechanism for trapping the Top2 cleavage complex. Analysis of drug-binding modes and the conformational landscapes of the drug-binding pockets provide rationalization of the drugs' structural-activity relationships and explain why Top2 mutants exhibit differential effects toward each drug. Drug design guidelines were proposed to facilitate the development of isoform-specific Top2-targeting anticancer agents.

Development and characterization of novel expressed sequence tag-derived simple sequence repeat markers in Hevea brasiliensis (rubber tree)

Cultivated clones of Hevea brasiliensis have a narrow genetic base. In order to broaden the genetic base, it is first necessary to investigate the genetic diversity of wild populations. Expressed sequence tag-simple sequence repeat (EST-SSR) markers were developed to investigate the genetic diversity of Hevea populations. Four hundred and thirty microsatellites were identified and 148 primers were designed to amplify the loci. Twenty-nine primer pairs were synthesized and evaluated for their ability to detect genetic polymorphisms among 40 wild accessions of H. brasiliensis. Twenty-one of the 29 loci were polymorphic. The number of alleles per locus in the 40 accessions ranged from 2 to 7. H(O) and H(E) at each locus ranged from 0.0000 to 0.9000 and from 0.0000 to 0.8704, respectively. All 21 loci could amplify in H. brasiliensis, H. pauciflora, H. nitida, H. spruceana, and H. camargoana. The EST-SSR primers developed herein can be used in genetic diversity and structure studies in H. brasiliensis.

Spatial-temporal analysis of drink-driving patterns in Hong Kong

Normally, bars and restaurants are the preferred locations for drinking. Therefore, there is concern that the roads in bar and restaurant areas could have a higher probability of drink-drivers and alcohol-related road crashes. Many studies have been conducted to model the association between drinking locations and the prevalence of drink-driving, so that cost-effective enforcement strategies can be developed to combat drink-driving. In this study, a cluster analysis approach was applied to model the spatial-temporal variation of drink-driving distribution in Hong Kong. Six spatial-temporal clusters of drink-driving distribution emerged from the data: (i) bar and restaurant area, weekend-overnight; (ii) bar and restaurant area, other timespan; (iii) urban area, weekend-overnight; (iv) urban area, other timespans; (v) rural area, weekend-overnight; and (vi) rural area, other timespans. Next, separate zero-inflated regression models were established to identify the factors contributing to the prevalence of drink-driving for each of the six recognized clusters. The results indicated that drivers in rural areas tend to consume more alcohol than those in urban areas, regardless of the time period. In addition, both seasonal variation and vehicle class were found to determine the breath alcohol concentration (BrAC) levels among drivers.

Indium chloride-induced micronuclei via reactive oxygen species in Chinese hamster lung fibroblast V79 cells

We study the cytotoxicity of indium chloride (InCl₃) in Chinese hamster lung fibroblasts, the V79 cells, using MTT assay. The results showed that InCl₃ did not induce significant cytotoxicity at various concentrations tested. In addition, the frequency of micronuclei (MN) was assayed to evaluate the genotoxic effects of InCl₃ in V79 cells. InCl₃ at concentrations ranged 0.1-1 μM significantly increased MN frequency in a concentration-dependent manner. Both catalase and superoxide dismutase at concentrations of 75 and 150 μg/mL significantly inhibited InCl₃-induced MN. Similarly, Germanium oxide (GeO₂) and dimercaprol expressed antigenotoxic effects. From these findings, it is concluded that InCl₃ is a potent genotoxic chemical, which may be mediated partly by inducing oxidative stress. The significance of this study shows that the workers in the semiconductor factories should be cautious in exposing to the hazardous genotoxic InCl₃.

Anaemia and type 2 diabetes: implications from a retrospectively studied primary care case series

OBJECTIVES. To identify the prevalence of anaemia in Chinese type 2 diabetic patients managed in a primary care setting and to explore its associations with cardiovascular complications and kidney disease. DESIGN. Retrospective case series study. SETTING. General Out-patient Clinic of Hospital Authority, Hong Kong. PATIENTS. Chinese type 2 diabetic patients who had annual assessments between 1 January 2010 and 31 December 2011 were recruited. Their complete blood picture, serum creatinine, estimated glomerular filtration rate (calculated by Modification of Diet in Renal Disease method), haemoglobin A1c, and urine albumin-creatinine ratio were retrieved. Anaemia was defined as a haemoglobin level of <130 g/L in men and <120 g/L in women (World Health Organization criteria). Student's t test and analysis of variance were used to analyse continuous variables and the Chi squared test for categorical data. Pearson's correlation coefficient and multivariate logistic regression were used to examine associations between haemoglobin level and different variables including age, gender, serum creatinine level, estimated glomerular filtration rate, and urine albumin-creatinine ratio. All statistical tests were two-sided, and a P value of <0.05 was considered significant. RESULTS. Among 6325 Chinese type 2 diabetic patients fulfilling the inclusion criteria, 1441 were found to have anaemia with a period prevalence of 22.8%. The prevalence of anaemia increased significantly with deterioration of renal function. Compared with diabetic patients with normal haemoglobin levels, anaemic diabetic patients had a higher co-morbidity rate for stroke, ischaemic heart disease, hypertension, and chronic kidney disease (P<0.001). Independent predictors for haemoglobin level among diabetic patients were age, gender, serum creatinine level, estimated glomerular filtration rate, haemoglobin A1c, and urine albumin-creatinine ratio (P<0.001). Multivariate analysis showed that male gender, old age, increased serum creatinine level, decreased estimated glomerular filtration rate, elevated urine albumin-creatinine ratio, and co-morbidity with stroke or ischaemic heart disease were associated with greater odds for the presence of anaemia. CONCLUSION. Anaemia is common among Chinese type 2 diabetic patients, particularly those with impaired renal function or established cardiovascular disease. Early detection of anaemia and prompt referral to specialist care for optimal treatment, if associated with severe renal impairment or high-risk proteinuria at the primary care settings, is recommended.

Molecular analysis and frequency of Staphylococcus aureus virulence genes isolated from bloodstream infections in a teaching hospital in Tianjin, China

Staphylococcus aureus is an important cause of bloodstream infections worldwide. We examined the prevalence of genes that encode erythromycin ribosome methylase and bacterial toxins in S. aureus collected from bloodstream infections. Sixty different S. aureus isolates were obtained from blood cultures of patients who were admitted to a Teaching Hospital in Tianjin from January 2006 to August 2011. The susceptibility of the isolates to 16 antibiotics was tested. Methicillin-resistant S. aureus (MRSA) was identified using the disk diffusion method with cefoxitin. PCR was used to detect genes that encode the staphylococcal enterotoxins, Panton-Valentine leukocidin, toxic shock syndrome toxin 1 and erythromycin ribosome methylase. Molecular analysis of the MRSA strains was done using pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome mec (SCCmec) typing. The positivity rates of mecA, ermA, ermB, and ermC in the isolates were 13/60, 10/60, 18/60, and 18/60, respectively. Among the 60 isolates, 30 harbored enterotoxin genes, with sea as the most frequent toxin gene (33%), followed by sec (15%), sed (12%), and seb (5%). The see and tst genes were not found in any of the isolates. The pvl gene was detected in four strains. Eleven MRSA isolates were of the SCCmec type III; two MRSA isolates could not be determined through SCCmec typing. PFGE analysis of the 13 MRSA isolates produced 8 distinct pulsotypes. Virulence genes and erythromycin ribosome methylase genes were highly prevalent in these isolates. The PFGE results demonstrated that the MRSA spread through cloning, mainly involving SCCmec type III.

Ginkgo biloba leaves extract (EGb 761) attenuates lipopolysaccharide-induced acute lung injury via inhibition of oxidative stress and NF-κB-dependent matrix metalloproteinase-9 pathway

Acute lung injury (ALI) presents high mortality and morbidity clinically and by far no effective preventive strategy has been established. Extract of Ginkgo biloba leaves, EGb 761, is a complex mixture that possesses several clinical beneficial effects such as anti-oxidation, anti-inflammation, anti-tumor, and cardioprotective property. With EGb 761 pretreatment, both lipopolysaccharide (LPS)-induced protein leakage and neutrophil infiltration, and LPS-induced inflammatory responses including increased myeloperoxidase (MPO) activity, lipid peroxidation, and metalloproteinase (MMP)-9 activity, were inhibited; LPS-suppressed activation of antioxidative enzymes (AOE) were reversed; and not only the phosphorylation of NF-κB but also the degradation of its inhibitor, IκB, were suppressed. These results suggested that the protection mechanism of EGb 761 is by inhibition of NFκB activation, possibly via the up-regulation of antioxidative enzymes. More studies are needed to further evaluate whether EGb 761 is a suitable candidate as an effective dietary strategy to reduce the incidence of endotoxin-induced ALI.

Risk assessment of excess drug and sunscreen absorption via skin with ablative fractional laser resurfacing : optimization of the applied dose for postoperative care

The ablative fractional laser is a new modality used for surgical resurfacing. It is expected that laser treatment can generally deliver drugs into and across the skin, which is toxicologically relevant. The aim of this study was to establish skin absorption characteristics of antibiotics, sunscreens, and macromolecules via laser-treated skin and during postoperative periods. Nude mice were employed as the animal model. The skin received a single irradiation of a fractional CO2 laser, using fluences of 4-10 mJ with spot densities of 100-400 spots/cm(2). In vitro skin permeation using Franz cells was performed. Levels of skin water loss and erythema were evaluated, and histological examinations with staining by hematoxylin and eosin, cyclooxygenase-2, and claudin-1 were carried out. Significant signs of erythema, edema, and scaling of the skin treated with the fractional laser were evident. Inflammatory infiltration and a reduction in tight junctions were also observed. Laser treatment at 6 mJ increased tetracycline and tretinoin fluxes by 70- and 9-fold, respectively. A higher fluence resulted in a greater tetracycline flux, but lower skin deposition. On the other hand, tretinoin skin deposition increased following an increase in the laser fluence. The fractional laser exhibited a negligible effect on modulating oxybenzone absorption. Dextrans with molecular weights of 4 and 10 kDa showed increased fluxes from 0.05 to 11.05 and 38.54 μg/cm(2)/h, respectively. The optimized drug dose for skin treated with the fractional laser was 1/70-1/60 of the regular dose. The skin histology and drug absorption had recovered to a normal status within 2-3 days. Our findings provide the first report on risk assessment of excessive skin absorption after fractional laser resurfacing.

Skin permeation of small-molecule drugs, macromolecules, and nanoparticles mediated by a fractional carbon dioxide laser: the role of hair follicles

PURPOSE

To evaluate skin permeation enhancement mediated by fractional laser for different permeants, including hydroquinone, imiquimod, fluorescein isothiocyanate-labeled dextran (FD), and quantum dots.

METHODS

Skin received a single irradiation of a fractional CO(2) laser, using fluence of 2 or 4 mJ with densities of 100 ∼ 400 spots/cm(2). In vitro and in vivo skin penetration experiments were performed. Fluorescence and confocal microscopies for imaging delivery pathways were used.

RESULTS

The laser enhanced flux of small-molecule drugs 2 ∼ 5-fold compared to intact skin. A laser fluence of 4 mJ with a 400-spot/cm(2) density promoted FD flux at 20 and 40 kDa from 0 (passive transport) to 0.72 and 0.43 nmol/cm(2)/h, respectively. Microscopic images demonstrated a significant increase in fluorescence accumulation and penetration depth of macromolecules and nanoparticles after laser exposure. Predominant routes for laser-assisted delivery may be intercellular and follicular transport. CO(2) laser irradiation produced 13-fold enhancement in follicular deposition of imiquimod. Laser-mediated follicular transport could deliver permeants to deeper strata. Skin barrier function as determined by transepidermal water loss completely recovered by 12 h after irradiation, much faster than conventional laser treatment (4 days).

CONCLUSIONS

Fractional laser could selectively enhance permeant targeting to follicles such as imiquimod and FD but not hydroquinone, indicating the importance of selecting feasible drugs for laser-assisted follicle delivery.

Electronic structure inheritance and pressure-induced polyamorphism in lanthanide-based metallic glasses

We report that a series of lanthanide-based bulk metallic glasses show a pressure-induced polyamorphic phase transition observed by in situ angle-dispersive x-ray diffraction under high pressures. The transition started from a low-density state at lower pressures, and went through continuous densification ending with a high-density state at higher pressures. We demonstrate that, under high pressure, this new type of polyamorphism in densely packed metallic glasses is inherited from its lanthanide-solvent constituent and related to the electronic structure of 4f electrons. The found electronic structure inheritance could provide the guidance for designing new metallic glasses with unique functional physical properties.

Effect of RECK gene polymorphisms on hepatocellular carcinoma susceptibility and clinicopathologic features

BACKGROUND

The reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) down-regulation has been confirmed in numerous human cancers and is clinically associated with metastasis. This study investigates the potential associations of RECK single-nucleotide polymorphisms (SNPs) with hepatocellular carcinoma (HCC) susceptibility and its clinicopathologic characteristics.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 135 HCC cancer patients and 501 cancer-free controls were analyzed for four RECK SNPs (rs10814325, rs16932912, rs11788747, and rs10972727) using real-time PCR and PCR-RFLP genotyping analysis. After adjusting for other co-variants, the individuals carrying RECK promoter rs10814325 inheriting at least one C allele had a 1.85-fold [95% confidence interval (CI), 1.03-3.36] risk of developing HCC compared to TT wild type carriers. The HCC patients, who carried rs11788747 with at least one G allele, had a higher distant metastasis risk than wild type probands.

CONCLUSIONS

RECK gene polymorphisms might be a risk factor increasing HCC susceptibility and distant metastasis in Taiwan.

Functional analysis and consequences of Mdm2 E3 ligase inhibition in human tumor cells

Mdm2 is the major negative regulator of p53 tumor-suppressor activity. This oncoprotein is overexpressed in many human tumors that retain the wild-type p53 allele. As such, targeted inhibition of Mdm2 is being considered as a therapeutic anticancer strategy. The N-terminal hydrophobic pocket of Mdm2 binds to p53 and thereby inhibits the transcription of p53 target genes. Additionally, the C-terminus of Mdm2 contains a RING domain with intrinsic ubiquitin E3 ligase activity. By recruiting E2 ubiquitin-conjugating enzyme(s), Mdm2 acts as a molecular scaffold to facilitate p53 ubiquitination and proteasome-dependent degradation. Mdmx (Mdm4), an Mdm2 homolog, also has a RING domain and hetero-oligomerizes with Mdm2 to stimulate its E3 ligase activity. Recent studies have shown that C-terminal residues adjacent to the RING domain of both Mdm2 and Mdmx contribute to Mdm2 E3 ligase activity. However, the molecular mechanisms mediating this process remain unclear, and the biological consequences of inhibiting Mdm2/Mdmx co-operation or blocking Mdm2 ligase function are relatively unexplored. This study presents biochemical and cell biological data that further elucidate the mechanisms by which Mdm2 and Mdmx co-operate to regulate p53 level and activity. We use chemical and genetic approaches to demonstrate that functional inhibition of Mdm2 ubiquitin ligase activity is insufficient for p53 activation. This unexpected result suggests that concomitant treatment with Mdm2/Mdmx antagonists may be needed to achieve therapeutic benefit.

A novel role for vitamin D: modulation of expression and function of the local renin-angiotensin system in mouse pancreatic islets

AIMS/HYPOTHESIS

The aim of this study was to demonstrate that hormonal vitamin D (calcitriol) modulates the local pancreatic islet renin-angiotensin system (RAS) whilst improving islet beta cell secretory function.

METHODS

Isolated islets cultured ex vivo under high- or low-glucose conditions and treated with or without calcitriol were examined for changes in RAS component activity and glucose-stimulated insulin secretion (GSIS). Isolated islets from vitamin D receptor knockout (VDR-KO) mice were compared with islets from wild-type (WT) mice for major RAS component expression and RAS protein production.

RESULTS

Isolated islets incubated ex vivo under high-glucose conditions showed increased expression and production of major RAS components; this was prevented and reversed by calcitriol in parallel with increases in GSIS. VDR-KO mice displayed increased RAS component mRNA expression and protein production as compared with WT mice, despite comparable glucose homeostasis.

CONCLUSIONS

Young mice with vitamin D receptor ablation showed abnormal increases in islet RAS components at mRNA and protein levels, despite unaltered glucose homeostasis. Calcitriol prevents and can correct induction of RAS component production under high-glucose conditions in parallel with the well-known effect of calcitriol on increasing islet beta cell secretory responses to glucose.

Relationship of interleukin-8 gene polymorphisms with hepatocellular carcinoma susceptibility and pathological development

BACKGROUND AND OBJECTIVES

Hepatocellular carcinoma (HCC) is one of the most frequent malignant neoplasms worldwide, and the second leading cause of death from cancer in Taiwan. Interleukin-8 (IL-8) is an angiogenic chemokine with important roles in the development and progression of many human malignancies including HCC. This study investigates the effects of single-nucleotide polymorphisms (SNPs) in the IL-8 gene on the susceptibility and clinicopathological characteristics of HCC.

METHODS

One hundred thirty-one HCC patients and 340 control subjects were analyzed for four IL-8 SNPs (-251 T/A, +781 C/T, +1633 C/T, and +2767 A/T) using PCR-RFLP genotyping analysis.

RESULTS

After adjusting for other confounders, results show that individuals with the IL-8 +781 T/T polymorphic genotype had a significantly lower risk of developing HCC than those with the wild-type (C/C) genotype (AOR = 0.346; 95% CI: 0.132-0.909). Multiple regression analysis showed that the presence of T/A or A/A at IL-8 -251 may indicate higher potential risk of hepatitis B infection (AOR = 2.847; 95% CI: 1.083-8.656). Additionally, these four IL-8 SNPs did not associate with liver-related clinicopathological markers in serum.

CONCLUSIONS

Genetic polymorphism at IL-8 +781 is an important factor in determining susceptibility to HCC in the Taiwanese population.

Evaluation of differential representative values between Chinese hamster cells and human lymphocytes in mitomycin C-induced cytogenetic assays and caspase-3 activity

Chinese hamster ovary (CHO) cells, its lung fibroblasts (V79), and human lymphocytes are routinely used in in vitro cytogenetic assays, which include micronuclei (MN), sister chromatid exchange (SCE), and chromosome aberration (CA) assays. Mitomycin C (MMC), a DNA cross-link alkylating agent, is both an anticancer medicine and a carcinogen. To study the differential representative values of cell types in MMC-treated cytogenetic assays and its upstream factor, cysteine aspartic acid-specific protease (caspase)-3. Among the chosen cell types, lymphocytes expressed the highest sensitivity in all three MMC-induced assays, whereas CHO and V79 showed varied sensitivity in different assays. In MN assay, the sensitivity of CHO is higher than or equal to V79; in SCE assay, the sensitivity of CHO is the same as V79; and in CA assay, the sensitivity of CHO is higher than V79. In-depth analysis of CA revealed that in chromatid breaks and dicentrics formation, lymphocyte was the most sensitive of all and CHO was more sensitive than V79; and in acentrics and interchanges formation, lymphocyte was much more sensitive than the others. Furthermore, we found caspase-3 activity plays an important role in MMC-induced cytogenetic assays, with MMC-induced caspase-3 activity resulting in more sensitivity in lymphocytes than in CHO and V79. Based on these findings, lymphocyte will make a suitable predictive or representative control reference in cytogenetic assays and caspase-3 activity with its high specificity, positive predictive value, and sensitivity.

Effects of E-cadherin (CDH1) gene promoter polymorphisms on the risk and clinicopathological development of hepatocellular carcinoma

BACKGROUND AND OBJECTIVES

Hepatocellular carcinoma (HCC) is one of the most frequent malignant neoplasms worldwide, and is the second leading cause of cancer death in Taiwan. E-cadherin is an epithelial cell adhesion molecule, and decreased E-cadherin expression in HCC is associated with a poor prognosis. This study investigates the effects of single nucleotide polymorphisms (SNPs) in the E-cadherin/CDH1 gene promoter on the risk and clinicopathological characteristics of HCC METHODS: 131 HCC patients and 347 controls were recruited for this study. Genetic polymorphisms of CDH1-160 and -347 were analyzed by PCR-RFLP genotyping analysis.

RESULTS

After adjusting for other confounders, results show that individuals with the CDH1-347G/GA or GA/GA polymorphic genotypes had a significantly higher risk of developing HCC than those with the wild-type (G/G) genotype (adjusted odds ratio = 2.477; 95%CI: 1.421-4.319). Furthermore, patients with HCC with at least one mutant A allele of CDH1-160 had a 4.031-fold risk of progressing to stage III or IV.

CONCLUSIONS

This study shows that SNPs in CDH1-347 gene are associated with an increased risk of HCC, and at least one mutant A allele of CDH1-160 gene is associated with the development of stage III or IV of HCC in Taiwanese.

Predicting microstructures in polymer blends under two-step quench in two-dimensional space

The formation of nanostructures during two-step quench in binary polymer systems having various types of liquid miscibility gaps are investigated systematically via computer simulations using the phase field method. Coupled liquid spinodal decomposition and fluid flow processes are considered by solving simultaneously the Cahn-Hilliard and Navier-Stokes equations. Various interesting phenomena and morphological patterns are predicted. It is found that the primary microstructures developed at the first quench and isothermal holding temperature greatly affect the secondary microstructures developed during the second quench and isothermal holding. Depending on the morphology and scale of the primary microstructure, either multicore and multishell or unicore and unishell structures are predicted. The breakup of annuluses in a core-shell structure in two dimensions is analyzed. The effects of viscosity on the formation of core-shell structure and on the growth and coarsening behaviors of bimodal droplets produced by the two-step quench in systems are also investigated.

Association of androgen receptor CAG repeat polymorphism with VO₂max response to hypoxic training in North China Han men

The purposes of this study were to investigate the distribution characteristics of CAG repeat polymorphism in exon 1 of androgen receptor gene and the association of CAG polymorphism with VO₂max response to hypoxic training in North China Han men. Sixty-five healthy young men completed a 30-day HiHiLo training (living high, exercise high and training low) in a simulated normobaric hypoxic environment. All subjects slept in 14.3-14.8% O₂ concentration, and participated in hypoxic training three times a week in 15.4% O₂ concentration. VO₂max (peak oxygen consumption) and body weight were measured before and after hypoxic training. A total of 15 repeat alleles were observed by CAG genotype analyze, in which (CAG)22 was most common. When using 21 and 22 alleles, respectively, as cut-off points, we found that the baseline body weight of two shorter genotype groups was significantly lower than that of longer ones, and that the ΔVO₂max and ΔrVO₂max (Δrelative value of VO₂max) of two shorter genotype groups were significantly higher than those of longer ones after hypoxic training. These findings indicated that AR CAG repeat polymorphism was associated with the exercise performance after simulated normobaric hypoxic HiHiLo training in North China Han men, and that the shorter genotypes had a better individual response to hypoxic training.