Osmolarity effects on bovine articular chondrocytes during three-dimensional culture in alginate beads

OBJECTIVE

With the development of engineered cartilage, the determination of the appropriate culture conditions is vital in order to maximize extracellular matrix synthesis. As osmolarity could affect the fate of chondrocytes, the purpose of this study was to determine the effects of osmolarity on chondrocytes during relatively long-term culture.

DESIGN

Bovine articular chondrocytes were cultured in alginate beads in a biocarbonate free system at 280, 380 and 550 mOsm at pH 7.4 for up to 12 days, respectively. Cell volume, intracellular pH (pH(i)), cell number, glucosaminoglycan (GAG) and collagen retention were measured at day 5 and 12. Cell viability and volume were monitored over the 12 days of culture.

RESULTS

By day 5 and 12, compared to the cell volume at 380 mOsm, around 20% (P<0.01) swelling and 15% (P<0.05) shrinkage were observed when the cells were cultured at 280 and 550 mOsm. The pH(i) over the 12 days of culture varied with osmolarity of the culture medium. In comparison with fresh cells, pH(i) became slightly more acidic by 0.15 pH units at 280 mOsm at day 5. However, by day 12, an alkalization of pH(i), by 0.2 pH units, was noted. A higher proliferation rate was seen at 280 mOsm than at other osmolarities while less GAG was produced.

CONCLUSIONS

Chronic exposure to anisotonic conditions results in cell swelling at 280 mOsm and shrinkage at 550 mOsm. The osmolarity of 280 mOsm appears to encourage proliferation of chondrocytes, but inhibits matrix production.

LXR{beta} is the dominant LXR subtype in skeletal muscle regulating lipogenesis and cholesterol efflux

Liver X receptors (LXRs) are important regulators of cholesterol, lipid, and glucose metabolism and have been extensively studied in liver, macrophages, and adipose tissue. However, their role in skeletal muscle is poorly studied and the functional role of each of the LXRalpha and LXRbeta subtypes in skeletal muscle is at present unknown. To study the importance of each of the receptor subtypes, myotube cultures derived from wild-type (WT) and LXRalpha and LXRbeta knockout (KO) mice were established. The present study showed that treatment with the LXR agonist T0901317 increased lipogenesis and apoA1-dependent cholesterol efflux in LXRalpha KO and WT myotubes but not in LXRbeta KO cells. The functional studies were confirmed by T0901317-induced increase in mRNA levels of LXR target genes involved in lipid and cholesterol metabolism in myotubes established from WT and LXRalpha KO mice, whereas only minor changes were observed for these genes in myotubes from LXRbeta KO mice. Gene expression analysis using microarrays showed that very few genes other than the classical, well-known LXR target genes were regulated by LXR in skeletal muscle. The present study also showed that basal glucose uptake was increased in LXRbeta KO myotubes compared with WT myotubes, suggesting a role for LXRbeta in glucose metabolism in skeletal muscle. In conclusion, LXRbeta seems to be the main LXR subtype regulating lipogenesis and cholesterol efflux in skeletal muscle.

Pharmacological characterization of cis-nitromethylene neonicotinoids in relation to imidacloprid binding sites in the brown planthopper, Nilaparvata lugens

Neonicotinoid insecticides, such as imidacloprid, are selective agonists of the insect nicotinic acetylcholine receptors (nAChRs) and extensively used in areas of crop protection and animal health to control a variety of insect pest species. Here we describe that two cis-nitromethylene neonicotinoids (IPPA152002 and IPPA152004), recently synthesized in our laboratory, discriminated between the high and low affinity imidacloprid binding sites in the brown planthopper, Nilaparvata lugens, a major insect pest of rice crops in many parts of Asia. [(3)H]imidacloprid has two binding sites with different affinities (Kd value of 0.0035 +/- 0.0006 nM for the high-affinity site and 1.47 +/- 0.22 nM for the low-affinity site). Although the cis-nitromethylene neonicotinoids showed low displacement ability (Ki values of 0.15 +/- 0.03 microM and 0.42 +/- 0.07 microM for IPPA152002 and IPPA152004, respectively) against [(3)H]imidacloprid binding, low concentrations (0.01 microM) of IPPA152002 completely inhibited [(3)H]imidacloprid binding at its high-affinity site. In Xenopus oocytes co-injected with cRNA encoding Nlalpha1 and rat beta2 subunits, obvious inward currents were detected in response to applications of IPPA152002 and IPPA152004, although the agonist potency is reduced to that of imidacloprid. The previously identified Y151S mutation in Nlalpha1 showed significant effects on the agonist potency of IPPA152002 and IPPA152004, such as a 75.8% and 70.6% reduction in Imax, and a 2.4- and 2.1-fold increase in EC(50). This data clearly shows that the two newly described cis-nitromethylene neonicotinoids act on insect nAChRs and like imidacloprid, discriminated between high and low affinity binding sites in N. lugens native nAChRs. These compounds may be useful tools to further elucidate the pharmacology and nature of neonicotinoid binding sites.

Laparoscopic sacral colpopexy for uterine prolapse with prolene mesh

OBJECTIVE

To analyze the clinical effects of laparoscopic sacral colpopexy using prolene mesh for patients with pelvic organ prolapse.

METHODS

Laparoscopic placement of prolene mesh in the rectovaginal septum and veslcovaginal septum of 42 women with uterine prolapse with bladder and rectum prolapse. One mesh was fixed to the round ligaments and another to the periosteum of the sacral vertebrae. Operation time, blood loss, complication rate and follow-up surgery results were recorded monthly and analyzed according to the POP-Q system. The uterus was preserved in all cases.

RESULTS

The mean operating time was 92 +/- 12 min and the mean blood loss during surgery was 98 +/- 11 ml. Postoperatively, both prolapse and symptoms were highly significantly improved (p < 0.001) according to the pelvic organ prolapse quantification (POP-Q) system.

CONCLUSIONS

Laparoscopic sacral colpopexy for uterine prolapse using prolene mesh is a minimally invasive and effective new technique that offers a chance for patients who desire to preserve their uterus.

FSHB subunit gene is associated with major gene controlling litter size in commercial pig breeds

An insertion fragment in porcine FSHbeta subunit gene was cloned by PCR. Sequencing data show that the insertion is a retroposon of 292 bp sitting in intron I at the site between + 809 and +810 base. Based on these results, a PCR programme was created to genotype animal individuals in different pig breeds at FSW locus and polymorphism of FSHbeta gene was analyzed. With the combination of genotype and litter size of sows, it was demonstrated that FSHbeta locus is closely associated with major gene controlling litter size in commercial pig breeds, such as Yorkshire, Landrace, Durco. Averagely the AA sows give more 1.5 piglets than BB sows do per litter.

In Asian-American Women, Westernization Influences Estrogen Metabolism, but Not Total Endogenous Estrogen Production

Background: Historically, breast cancer incidence rates were 4-7 times higher in the United States than in China and Japan. When Asian women migrate to the U.S., their risk rises over several generations and approaches that in U.S. Whites. Endogenous estrogen has been postulated to explain these international differences. Methods: In a population-based case-control study in Chinese, Japanese, and Filipino women living in San Francisco-Oakland, CA; Los Angeles, CA; or Oahu, HI, we documented a six-fold gradient in breast cancer risk with Westernization. Using 12-h, overnight urines from 263 premenopausal mid-luteal and 168 postmenopausal control subjects, we investigated associations of estrogens and estrogen metabolites (EM) with Westernization, particularly birthplace in the East or West. Fifteen EM were measured concurrently by liquid chromatography-tandem mass spectrometry with high accuracy, precision, and sensitivity. Log-transformed EM measures, adjusted for age and ethnicity, were compared by robust linear regression. Results: Total urinary EM (pmol/mg creatinine) was not associated with birthplace in premenopausal or postmenopausal women. When the three estrogen hydroxylation pathways were expressed as percent of total EM, the relative difference by birthplace, West compared to East, was 15% lower for 2-pathway EM (p=0.009), 7% lower for 4-pathway EM (p=0.37), and 10% higher for 16-pathway EM (p=0.008). Similar results were observed for individual EM in each pathway, premenopausal and postmenopausal women, and the three ethnicities. In both menopausal groups, 2-pathway EM concentration decreased steadily with increasing risk across six categories of Westernization. Conclusions: Our results do not indicate that total estrogen production explains the increased breast cancer risk in Western societies. However, estrogen metabolism patterns, especially reduced 2-hydroxylation, may contribute to the elevated risk; and underlying mechanisms merit further exploration.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3063.

Transport limitation of chlorine disinfection of Pseudomonas aeruginosa entrapped in alginate beads

An artificial biofilm system consisting of Pseudomonas aeruginosa entrapped in alginate and agarose beads was used to demonstrate transport limitation of the rate of disinfection of entrapped bacteria by chlorine. Alginate gel beads with or without entrapped bacteria consumed chlorine. The specific rate of chlorine consumption increased with increasing cell loading in the gel beads and decreased with increasing bead radius. The value of an observable modulus comparing the rates of reaction and diffusion ranged from less than 0.1 to 8 depending on the bead radius and cell density. The observable modulus was largest for large (3-mm-diameter) beads with high cell loading (1.8 x 10(9) cfu/cm(3)) and smallest for small beads (0.5 mm diameter) with no cells added. A chlorine microelectrode was used to measure chlorine concentration profiles in agarose beads (3.0 mm diameter). Chlorine fully penetrated cell-free agarose beads rapidly; the concentration of chlorine at the bead center reached 50% of the bulk concentration within approximately 10 min after immersion in chlorine solution. When alginate and bacteria were incorporated into an agarose bead, pronounced chlorine concentration gradients persisted within the gel bead. Chlorine did gradually penetrate the bead, but at a greatly retarded rate; the time to reach 50% of the bulk concentration at the bead center was approximately 46 h. The overall rate of disinfection of entrapped bacteria was strongly dependent on cell density and bead radius. Small beads with low initial cell loading (0.5 mm diameter, 1.1 x 10(7) cfu/cm(3)) experienced rapid killing; viable cells could not be detected (<1.6 x 10(5) cfu/cm(3)) after 15 min of treatment in 2.5 mg/L chlorine. In contrast, the number of viable cells in larger beads with a higher initial cell density (3.0 mm diameter, 2.2 x 10(9) cfu/cm(3)) decreased only about 20% after 6 h of treatment in the same solution. Spatially nonuniform killing of bacteria within the beads was demonstrated by measuring the transient release of viable cells during dissolution of the beads. Bacteria were killed preferentially near the bead surface. Experimental results were consistent with transport limitation of the penetration of chlorine into the artificial biofilm arising from a reaction-diffusion interaction. The methods reported here provide tools for diagnosing the mechanism of biofilm resistance to reactive antimicrobial agents in such applications as the treatment of drinking and cooling waters.

Distribution of ABO blood group allele and identification of three novel alleles in the Chinese Han population

BACKGROUND

The ABO blood group system is clinically important in blood transfusion. The molecular characterization of ABO blood group has clinical and anthropological importance. Here, we determined the ABO alleles distribution and identified three novel alleles in the Chinese Han population.

STUDY DESIGN AND METHODS

Four hundred and seventeen Chinese Han individuals were determined by standard serologic techniques for the ABO blood group phenotypes. The ABO genotypes and alleles were analysed by polymerase chain reaction sequence-based typing (PCR-SBT) for sequencing exon 6 to 7 of the ABO gene. The polymorphisms of intron 5 and 6 of the ABO gene were also analysed by PCR-SBT. The two haplotypes including new alleles were separated by a Dynabeads M-270 Streptavidin protocol.

RESULTS

All ABO genotypes of the samples were consistent with the phenotypes. Fourteen alleles were identified based on the nucleotide sequences of exon 6 and 7, with five common alleles (A101, A102, B101, O01 and O02), six known rare alleles (A205, B110, O04, O05, O07 and O50) and three novel alleles (B112, CisAB06 and 061). The three new alleles appeared with the frequencies of 0.12%, 0.12% and 0.36%, respectively.

CONCLUSION

The detailed frequencies distribution of ABO alleles was studied in the Chinese Han population. We identified 14 alleles, including 3 novel alleles.

Lattice parameter, lattice disorder and resistivity of carbohydrate doped MgB2 and their correlation with the transition temperature

The change in the lattice parameters or the lattice disorder is claimed as a cause of the slight reduction in the transition temperature by carbon doping in MgB2. In this work, an extensive investigation on the effects of carbohydrate doping has been carried out. It is found that not only the a-axis but also the c-axis lattice parameter increases with the sintering temperature. A linear relation between the unit cell volume and the critical temperature is observed. Compared with the well known correlation between the lattice strain and the critical temperature, the X-ray peak broadening itself shows a closer correlation with the transition temperature. The residual resistivity and the critical temperature are linearly correlated with each other as well and its implication is further discussed.

Normal aging in the basal ganglia evaluated by eigenvalues of diffusion tensor imaging

BACKGROUND AND PURPOSE

The age effect on the diffusion pattern in the basal ganglia differs from that in the white matter. The main purpose of our study was to provide further insight into the change of water diffusion in the basal ganglia during human brain aging by using the eigenvalues of DTI.

MATERIALS AND METHODS

We examined 71 healthy subjects (mean age, 41.8 +/- 14.5 years; age range, 20-79 years). The values of MD, FA, and the eigenvalues lambda(1) and lambda(23) (lambda(23) = [lambda(2) + lambda(3)]/2) were determined in regions of the head of the caudate nucleus, putamen, globus pallidus, and in some regions of white matter. The age-dependence of these measurements was tested for statistical significance by using the Pearson correlation analysis.

RESULTS

A significant reduction of MD with aging was found in the head of caudate nucleus (r = -0.319, P = .007) and putamen (r = -0.410, P < .001), and an increase in FA with aging was found in the putamen (r = 0.535, P < .001). Eigenvalue lambda(23) showed a significant age-related decrease in the putamen (r = -0.451, P < .001) and the head of the caudate nucleus (r = -0.312, P = .008), but no significant changes of lambda(23) were found in the globus pallidus. The results for eigenvalue lambda(1) in the head of caudate nucleus (r = -0.299, P = .011) were close to statistical significance.

CONCLUSIONS

The eigenvalues provide more insights into the different diffusion patterns in the basal ganglia during human brain aging.

Patterns and correlates of stress among rural Chinese males: a four-region study

OBJECTIVES

Prior research has revealed a high prevalence of stress among general urban populations in China. However, little is known about stress in rural Chinese counterparts. This research estimates the prevalence of severe stress among rural Chinese males and identifies sociodemographic and psychological correlates.

STUDY DESIGN

The study design was a cross-sectional survey with multistage sampling.

METHODS

Subjects were male residents aged > or =15 years from four geographic regions of China (N=4414), namely Jinbei, Jinnan, Guidongbei and Subei. Information was collected on perceived stress and potential sociodemographic and behavioural correlates as well as on perceived health status. Data were assessed by means of chi(2) tests and unconditional logistic regression analysis.

RESULTS

The mean score for the rural male resident sample on the Chinese Perceived Stress Scale (CPSS) was 24.8 (standard deviation=7.7), and 44% of subjects reported severe stress. With Subei residents as the referent, respondents from Guidongbei region [adjusted odds ratio (OR)=0.66; 95% confidence interval (CI)=0.52-0.84] had a lower likelihood of reporting severe stress and those from Jinbei region (OR=3.54; 95% CI=2.85-4.39) and Jinnan region (OR=2.73; 95% CI=2.21-2.39) had higher likelihoods. Respondents aged 35-44 years (OR=0.69; 95% CI=0.55-0.85) and > or =45 years (OR=0.67; 95% CI=0.54-0.83) had a lower likelihood of reporting severe stress than those aged <25 years, and respondents in non-farming jobs (OR=1.33; 95% CI=1.09-1.62) had an excess likelihood relative to those in farming. An excess likelihood of reporting severe stress was manifest among the divorced and widowed relative to the unmarried, and a lower likelihood was observed among respondents with a higher education relative to the least educated. Hedonism seeking was positively associated with severe stress among rural Chinese males (OR=2.43; 95% CI=2.09-2.84) and social participation was negatively associated (OR=0.62, 95% CI=0.54-0.73).

CONCLUSIONS

This study found a high stress level among rural Chinese males. To ameliorate this problem, we recommend policy and prevention initiatives at national and local levels.

[Extracorporeal membrane oxygenation for severe acute respiratory and heart failure in a child with severe pneumonia]

OBJECTIVE

To report clinical application of Extracorporeal membrane oxygenation for severe acute respiratory and heart failure in a child with severe pneumonia.

METHOD

A seven-year old male patient with severe pneumonia complicated with heart and lung function failure was admitted to PICU in 28th of December, 2008.Veno-artery access was set up via euthyphoria cannulation in operative incision. Blood was drained from the right atrium through a cannula introduced via femoral veins, and returned via femoral artery. The inter-surface of the ECMO equipment system was completely coated with heparin-coating technique. Anticoagulation was maintained with heparin to keep the activated clotting time (ACT) between 150 and 200 seconds and heparin usage dose was 10 U/(kg.h), mean blood flow was 1/2-2/3 of 80-120 ml/(kg.min) during ECMO assistant period. During ECMO, ventilator settings were gradually reduced to allow lung rest, i.e. peak inspiratory pressure less than 25 cm H2O (1 cm H2O=0.098 kPa), end expiratory pressure 8-10 cm H2O, rate 10-15 breaths per minute and FiO2 30%-40%.

RESULTS

In management of ECMO, the incipient blood flow was set at 0.8 L/min, the radio of oxygen and blood flow was 1:1, FiO2 60%. After ten minutes of ECMO working, the blood oxygen saturation of radial artery increased from 40 mm Hg (1 mm Hg=0.133 kPa) to 177 mm Hg, Lac decreased from 3.5 mmol/L to 2.8 mmol/L. Four hours later, blood gas analysis of radial artery showed PaO2 202 mm Hg, PCO2 44 mm Hg, Lac 1.5 mmol/L, blood flow was set at 0.6 L/min, FiO2 60%, PaO2 kept above 150 mm Hg. 96 hours after ECMO supporting, the blood flow was set at 0.4 L/min [20 ml/(kg.min)], the results of blood gas analysis of radial artery was PaO2 190 mm Hg, PaCO2 36 mm Hg, SaO2 100%, Lac 0.9 mmol/L, then the child weaned off successfully from ECMO. Two days later, the child was successfully extubated. After two weeks treatment, the patient was discharged. The main complication associated with extracorporeal membrane oxygenation were bleeding.

CONCLUSION

ECMO is an effective mechanical assistant therapy method for severe pulmonary and cardiac failure in a child.

Risk factors for gestational diabetes mellitus in Chinese women: a prospective study of 16,286 pregnant women in China

AIMS

To determine the incidence of gestational diabetes mellitus (GDM) in China and to further identify population specific risk factors for GDM.

METHODS

Following a universal GDM screening recommendation, 16,286 pregnant women who underwent a 50-g glucose challenge test from 18 cities in China were followed up through pregnancy. GDM was confirmed by oral glucose tolerance test according to American Diabetes Association criteria.

RESULTS

The incidence of GDM was 4.3%. Previously reported risk factors for GDM, including advanced maternal age, pre-pregnancy obesity and family history of diabetes, were strongly associated with an elevated GDM risk. Moreover, after the adjustment for the above-mentioned risk factors, a history of recurrent vulvovaginal candidiasis, residency in south China and a history of spontaneous abortion were significantly associated with an increased GDM risk; adjusted odds ratio (OR) [95% confidence interval (95% CI)] were 1.97 (1.39, 2.80), 1.84 (1.59-2.13), and 1.46 (1.12, 1.91), respectively.

CONCLUSIONS

In this large study of GDM in Chinese women, advanced maternal age, pre-pregnancy overweight or obesity and family history of diabetes were confirmed to be risk factors. In addition, a history of recurrent vulvovaginal candidiasis or spontaneous abortion and residency in south China appeared to be novel risk factors in this population.