Sucrose isomerase and its mutants from Erwinia rhapontici can synthesise α-arbutin

Sucrose isomerase (SI) from Erwinia rhapontici is an intramolecular isomerase that is normally used to synthesise isomaltulose from sucrose by a mechanism of intramolecular transglycosylation. In this study, it was found that SI could synthesise α-arbutin using hydroquinone and sucrose as substrates, via an intermolecular transglycosylation reaction. Five phenylalanine residues (F185, F186, F205, F297, and F321) in the catalytic pocket of SI were chosen for sitedirected mutagenesis. Mutants F185I, F321I, and F321W, whose hydrolytic activities were enhanced after the mutation, could synthesise α-arbutin through intermolecular transglycosylation with a more than two-fold increase in the molar transfer ratio compared with wild type SI. The F297A mutant showed a strong ability to synthesise a novel α-arbutin derivative and a four-fold increase in its specific activity for intermolecular transglycosylation over the wild type. Our findings may lead to a new way to synthesise novel glucoside products such as α-arbutin derivatives by simply manipulating the Phe residues in the catalytic pocket. From the structure superposition, our strategy of manipulating these Phe residues may be applicable to other similar transglycosylating enzymes.

β-Benzene hexachloride induces apoptosis of rat Sertoli cells through generation of reactive oxygen species and activation of JNKs and FasL

β-benzene hexachloride (β-BHC), the major metabolite of benzene-hexachloride (BHC), is a weak estrogen-like chemical. It is a known persistent organic pollutant and male reproductive toxicant. However, the mechanism by which β-BHC exposure causes male reproductive toxicity remains unknown. In the present study, rat Sertoli cells were used to investigate the molecular mechanism involved in β-BHC-induced toxicity in male reproductive system. The results indicated that β-BHC exposure at over 30 μM showed the induction of apoptotic cell death. β-BHC could induce elevation in reactive oxygen species (ROS) generation, increase in the leakage rate of LDH and MDA level, and decrease in SOD activity. In addition, there was an increase in the cellular levels of phospho-JNKs and FasL in the β-BHC-induced apoptosis; and a significant reduction of procaspase-3 and -8 was observed over 30-μM β-BHC treatment. The translocation of NF-κB enhanced with the increase of concentration of β-BHC. Furthermore, NAC administration, a scavenger of ROS, reversed β-BHC-induced apoptosis effects via inhibition of JNKs activation, FasL expression, and NF-κB translocation. These results lead us to speculate that ROS generation may play a critical role in the initiation of β-BHC-induced apoptosis by activation of the JNKs, translocation of NF-κB, expression of FasL, and further activation of caspase cascade.

MicroRNA-21 expression in neonatal blood associated with antenatal immunoglobulin E production and development of allergic rhinitis

BACKGROUND

The prevalence of allergic diseases has increased in the past decades. It is unknown whether expression of certain microRNAs (miRNAs) in neonatal leucocytes is correlated to IgE production and/or allergic diseases.

OBJECTIVE

This study investigated the association of miRNA expression in neonatal leucocytes with cord blood IgE (CBIgE) elevation and development of allergic disease.

METHODS

We screened for the expression of a panel of 157 miRNAs in mononuclear leucocytes from human umbilical cord blood (CB) samples with elevated CBIgE and tracked the association of down-regulated miRNA expression to the miRNA-targeted gene expression and to children with allergic rhinitis (AR).

RESULTS

Among the initial screen of 10 CB samples with elevated CBIgE, expression of eight of the 157 miRNAs was low. Of these eight down-expressed miRNAs, three remained down-regulation in a validation with other 20 CB samples, and two of the three miRNAs, miR-21 and miR-126, were significantly lower in monocytes from AR children. Further analysis of mRNA expression of the miR-21-targeted genes identified that TGFBR2 expression on monocytes was significantly up-regulated in CB with elevated CBIgE, and in AR patients. Transfection of miR-21 precursor into monocytes from patients with AR increased miR-21 expression and decreased TGFBR2 expression.

CONCLUSION

This study demonstrated the first in the literature that lower miR-21 expression in CB and increased TGFBR2 expression is associated with antenatal IgE production and development of AR.

Gene-gene and gene-environment interactions on IgE production in prenatal stage

BACKGROUND

Prevalence of allergic diseases in children has increased worldwide over the past decades. Allergy sensitization may occur in fetal life. This study investigated whether gene-gene and gene-environment interactions affected cord blood IgE (CBIgE) levels.

METHODS

A total of 575 cord blood DNA samples were subjected to a multiplex microarray for 384 single nucleotide polymorphisms (SNPs) in 159 allergy candidate genes. Genetic association was initially assessed by univariate and multivariate analyses. Multifactor dimensionality reduction (MDR) was used to identify gene-gene and gene-environment interactions. Environmental factors for analysis included maternal atopy, paternal atopy, parental smoking, gender, and prematurity.

RESULTS

Twenty-one SNPs in 14 genes were associated with CBIgE elevation (>or =0.5 KU/l) in univariate analysis. Multivariate analysis identified eleven genes (IL13, IL17A, IL2RA, CCL17, CXCL1, PDGFRA, FGF1, HAVCR1, GNAQ, C11orf72, and ADAM33) which were significantly associated with CBIgE elevation. MDR analyses of gene-gene interactions identified IL13 interacted with IL17A and/or redox genes on CBIgE elevation with the prediction accuracy of 62.52%. Analyses of gene-environment interactions identified that maternal atopy combined with IL13, rs1800925 and CCL22, rs170359 SNPs had the highest prediction accuracy of 67.15%. All the high and low risk classifications on gene-gene and gene-environment interactions by MDR analyses could be validated by Chi-square test.

CONCLUSIONS

Gene-gene (e.g. immune and redox genes) and gene-environment (e.g. maternal atopy and FGF1or redox genes) interactions on IgE production begin in prenatal stage, suggesting that prevention of IgE-mediated diseases may be made possible by control of maternal atopy and redox responses in prenatal stage.

Extracorporeal shockwave for hip necrosis in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) frequently received corticosteroid therapy, resulting in osteonecrosis of the femoral head (ONFH). Prior studies demonstrated the effectiveness of extracorporeal shockwave treatment (ESWT) for ONFH.. This study evaluated the effectiveness of ESWT for ONFH in patients with SLE. We studied 39 patients, including 15 patients with SLE (26 hips) and 24 controls (29 hips). To each affected hip we applied ESWT (6000 impulses at 28 kV in a single session). Patients were ambulated with partial weight bearing for 4-6 weeks. The primary endpoint was the need for hip replacement. The secondary endpoints were improvement in hip pain and function and image changes on X-ray and MRI. Patients received total hip replacement in 12% of patients with SLE and in 14% of controls (P = 0.802). There was no statistically significant difference in pain scores (0.86 vs. 0.89; P = 0.467) and function scores (89% vs. 91%; P = 0.194) between patients with SLE and controls. SLE response to ESWT for ONFH is comparable with ONFH in patients without SLE.

[Effects of p,p'-DDE on expression of inhibin B in sertoli cells of rats]

OBJECTIVE

To study the effects of p,p'-DDE on the expression of inhibin B in sertoli cells of rats.

METHODS

Sertoli cells were separated and cultured from testicular tissue of rats, and ensured the dose of test materials by MTT test, and RT-PCR were measured on the changes of inhibin B expression.

RESULTS

The results indicated that there was high difference in middle and high dose groups in comparison with control group (P < 0.05), and there were statistical significance in comparison with low dose group, and the gray scale of inhibin B decreased with the increase dose of p,p'-DDE.

CONCLUSION

The results indicated that p,p'-DDE could inhibit the expression of inhibin B.

p,p'-DDE induces mitochondria-mediated apoptosis of cultured rat Sertoli cells

p,p'-Dichlorodiphenoxydichloroethylene (p,p'-DDE), the major metabolite of dichlorodiphenoxytrichloroethane (DDT), is a known persistent organic pollutant and male reproductive toxicant. However, the mechanism underlying male reproductive toxicity of p,p'-DDE remains limited. In the present study, Sertoli cells were used to investigate the molecular mechanism involved in p,p'-DDE's male reproductive toxicity. Results showed that p,p'-DDE exposure at over 30 microM showed induction of apoptotic cell death. p,p'-DDE could induce mitochondria-mediated apoptotic changes including elevation in reactive oxygen species (ROS) generation, decrease in mitochondrial membrane potential (DeltaPsi(m)), and release of cytochrome c into the cytosol, which could be blocked by antioxidant agent N-acetyl-l-cysteine (NAC). In addition, elevated ratios of Bax/Bcl-w and Bak/Bcl-w and cleavages of procaspase-3 and -9 were induced by p,p'-DDE treatment. All of the results suggested that ROS generation may play a critical role in the initiation of p,p'-DDE-induced apoptosis by mediation of the disruption of DeltaPsi(m), the release of cytochrome c into the cytosol and further the activation of caspase cascade.

Regular Tai Chi Chuan exercise improves T cell helper function of patients with type 2 diabetes mellitus with an increase in T-bet transcription factor and IL-12 production

BACKGROUND

Exercise has been shown to be beneficial in the treatment of type 2 diabetes mellitus (DM); its benefit to immune function, however, remains to be determined.

OBJECTIVE

This study investigated the effect of a 12-week course of Tai Chi Chuan (TCC) exercise on T cell helper (Th) reaction in patients with type 2 DM.

METHODS

A case-control study was performed in 30 pairs of patients with type 2 DM and normal age-matched adults. Fasting blood glucose, HbA1c, mediators (interleukin (IL)-12, IL-4 and transforming growth factor (TGF)beta) and transcription factors (T-bet, GATA-3 and FoxP3) of Th1/Th2/T regulatory (Treg) reaction were measured before and after a 12-week TCC exercise programme.

RESULTS

Fasting glucose and HbA1c levels in the patients with type 2 DM were significantly higher than in age-matched controls before exercise. After TCC exercise, HbA1c levels in patients with type 2 DM significantly decreased (7.59 (0.32)% vs 7.16 (0.22)%; p = 0.047) and blood levels of IL-12 increased significantly (5.96 (1.10) vs 12.96 (3.07); p = 0.035). To study the molecular Th1/Th2/Treg reaction, patients with type 2 DM were found to have lower T-bet but not GATA-3 or FoxP3 expression than normal controls before TCC exercise. After the 12-week TCC exercise T-bet expression significantly increased in patients with type 2 DM.

CONCLUSIONS

A 12-week TCC exercise programme decreases HbA1c levels along with an increase in the Th1 reaction. A combination of TCC with medication may provide an even better improvement in both metabolism and immunity of patients with type 2 DM.

[Mechanisms of mitogen-activated protein kinase pathway in male reproductive toxicity induced organochlorine pesticides]

Mitogen-activated protein kinase pathway may closely associated with cell growth, differentiation and apoptosis, it may play an important role in cell death. With growing evidences from in vitro test, recently it demonstrated that the MAPK play a key role in the reproductive toxicity induced organochlorine pesticides and also showed that the products of Reactive Oxygen Species (ROS) induced organochlorine pesticides in these process. The relationship between MAPK and their activation results in apoptosis induced organochlorine pesticides, for further clarification of the mechanism of male reproductive toxicity induced organochlorine pesticides.

Effects of fluoride on the expression of NCAM, oxidative stress, and apoptosis in primary cultured hippocampal neurons

The mechanisms underlying the neurotoxicity of endemic fluorosis still remain unknown. To investigate the expression level of neural cell adhesion molecules (NCAM), oxidative stress, and apoptosis induced by fluoride, the primary rat hippocampal neurons were incubated with 20, 40, and 80 mg/l sodium fluoride for 24 h in vitro. The results showed that the cell survival rate in the 80 mg/l fluoride-treated group was significantly lower than that of the control group. Forty and 80 mg/l of fluoride induced significantly increased lactate dehydrogenase release, intracellular reactive oxygen species, and the percentage of apoptosis. Compared with control group, the malondialdehyde levels were significantly elevated while glutathione levels and glutathione peroxidase activities were decreased in all fluoride-treated groups, accompanied by the markedly reduced superoxide dismutase activity in 80 mg/l fluoride-treated group. With respect to NCAM mRNA expression levels, a significant dose-dependent decrease was observed in 40 and 80 mg/l fluoride-treated groups against the control group. In addition, as compared to the control group, the protein expression levels of NCAM-180 in 40 and 80 mg/l fluoride-treated groups, NCAM-140 in all fluoride-treated groups, and NCAM-120 in the 80 mg/l fluoride-treated group were significantly decreased. Our study herein suggested that fluoride could cause oxidative stress, apoptosis, and decreased mRNA and protein expression levels of NCAM in rat hippocampal neurons, contributing to the neurotoxicity induced by fluoride.

Interaction of maternal atopy, CTLA-4 gene polymorphism and gender on antenatal immunoglobulin E production

BACKGROUND

Genetic heritability and maternal atopy have been correlated to antenatal IgE production, but very few studies have studied gene-maternal atopy interaction on antenatal IgE production. This study investigated the interaction of CTLA-4 polymorphism with prenatal factors on the elevation of cord blood IgE (CBIgE).

METHODS

Pregnant women were antenatally recruited for collection of prenatal environmental factors by a questionnaire. Umbilical cord blood samples were collected for CBIgE detection by fluorescence-linked enzyme assay and CTLA-4 polymorphism measurement by restriction fragment length polymorphism.

RESULTS

A total of 1104 pregnant women initially participated in this cohort study, and 898 of them completed cord blood collection. 21.4% of the newborns had elevation of CBIgE (>or=0.5 kU/L). The CTLA-4+49A allele (P=0.021), maternal atopy (P<0.001) and gender (P=0.034), but not the CTLA-4+49G allele, -318C allele, -318T allele, parental smoking or paternal atopy, were significantly correlated with the CBIgE elevation in multivariate analysis. A dichotomous analysis of gene-maternal atopy interactions identified maternal atopy and CTLA-4+49A allele had an additive effect on the CBIgE elevation, especially prominent in male newborns; and in the absence of maternal atopy, CTLA-4+49GG genotype had a protective effect on CBIgE elevation in female newborns.

CONCLUSIONS

Maternal but not paternal atopy has significant impacts on CBIgE elevation depending on gender and CTLA-4+49A/G polymorphism of newborns. Control of maternal atopy and modulation of CTLA-4 expression in the prenatal stage may be a target for the early prevention of perinatal allergy sensitization.

Dose-effect relationship between drinking water fluoride levels and damage to liver and kidney functions in children

Although a dose-effect relationship between water fluoride levels and damage to liver and kidney functions in animals has been reported, it was not demonstrated in humans. To evaluate the effects of drinking water fluoride levels on the liver and kidney functions in children with and without dental fluorosis, we identified 210 children who were divided into seven groups with 30 each based on different drinking water fluoride levels in the same residential area. We found that the fluoride levels in serum and urine of these children increased as the levels of drinking water fluoride increased. There were no significant differences in the levels of total protein (TP), albumin (ALB), aspartate transamine (AST), and alanine transamine (ALT) in serum among these groups. However, the activities of serum lactic dehydrogenase (LDH), urine N-acetyl-beta-glucosaminidase (NAG), and urine gamma-glutamyl transpeptidase (gamma-GT) in children with dental fluorosis and having water fluoride of 2.15-2.96 mg/L and in children having water fluoride of 3.15-5.69 mg/L regardless of dental fluorosis were significantly higher than children exposed to water fluoride of 0.61-0.87 mg/L in a dose-response manner. In contrast to children with dental fluorosis and having water fluoride of 2.15-2.96 and 3.10-5.69 mg/L, serum LDH activity of children without dental fluorosis but exposed to the same levels of water fluoride as those with dental fluorosis were also markedly lower, but the activities of NAG and gamma-GT in their urine were not. Therefore, our results suggest that drinking water fluoride levels over 2.0mg/L can cause damage to liver and kidney functions in children and that the dental fluorosis was independent of damage to the liver but not the kidney. Further studies on the mechanisms and significance underlying damage to the liver without dental fluorosis in the exposed children are warranted.

[Study on reproductive and developmental toxicity of the pregnant mice and their foetus co-administered by p, p'-DDE and beta-BHC]

OBJECTIVE

To explore effects of p, p'-DDE and beta-BHC on reproduction and development in mice.

METHODS

The pregnant Kunming SPF mice of 12 to 14 days were co-administered by oral gavage for 3 days at different concentrations of 0, 1, 5 and 10 mg/kg bw of p, p'-DDE and beta-BHC. The concentrations of estradiol (E2) and progesterone (P) in sera of the dosed mice were determined by the Serozyme kits (Bio-Ekon biotechnology Co., Beijing, China), following the procedures described by the manufacturer. RT-PCR was employed to detect abundant expression of alpha-estrogen receptor (alpha-ER) gonadtropin releasing hormone (GnRH) and beta-endorphin (beta-EP) mRNA in placentae.

RESULTS

(1) Reproductive effects: with increase of the administered p,p'-DDE and P-BHC,the organ coefficient of uterus and its intraluminal fluid increased, the unterine nidation quantity decreased, the anogenital distance (AGD) and ratio of female to male raised, the concentration of estradiol and progesterone in sera of the dosed mice went up, and the abundant expression of alpha-ER and GnRH mRNA rised while beta-EP dropped in placentae in a dose-dependant manner. Significant difference of these indexes were found between the treat groups and control (P < 0.05). (2) Developmental effects: with increase of the administered p,p'-DDE and beta-BHC, the gained weights of pregnant mice reduced, organ coefficient of liver increased,the quantity of live foetus decreased, the times of adverse pregnancy outcome went up, and the percent of female foetus increased. They all presented a dose-effect relation and significance of difference (P < 0.05).

CONCLUSION

p, p'-DDE and beta-BHC disrupt reproductive function, thereby result in dysreproduction and maldevelopment, and unbalance of ratio of female to male.

[Effects of selenium on expression of TERT, c-Myc and p53 induced by cadmium in rat liver]

OBJECTIVE

To study the effects of sodium selenite on expression of telomerase reverse transcriptase mRNA, c-Myc and p53 induced by cadmium chloride in rat liver.

METHODS

Male SD rats were divided randomly into 6 groups, each group had 5 animals. The groups comprised the control group, Se group (5 micromol/kg sodium selenite), 5 micromol/kg cadmium chloride group, 10 micromol/kg cadmium chloride group, Se (5 micromol/kg sodium selenite) + 5 micromol/kg cadmium chloride group, Se (5 micromol/kg sodium selenite) + 10 micromol/kg cadmium chloride group. After 48 hours of the first injection, the expression of TERT mRNA was measured with RT-PCR and c-Myc, and p53 proteins were measured by immunohistochemistry method.

RESULTS

Compared with control group, the expression of TERT was increased in 5 micromol/kg Cd group and 10 micromol/kg Cd group, c-Myc protein was increased in 10 micromol/kg Cd group, and the expression of p53 protein was increased in 5 micromol/kg group and 10 micromol/kg Cd group. TERT expression in Se + 10 micromol/kg Cd group was lower than that of 10 micromol/kg Cd group significantly. c-Myc protein was decreased in Se + 10 micromol/kg Cd group compared with 10 micromol/kg Cd group. p53 protein of Se + 5 micromol/kg Cd group and Se + 10 micromol/kg Cd group were decreased significantly compared with 5 micromol/kg Cd group and 10 micromol/kg Cd group respectively.

CONCLUSION

The cadmium at the doses of between 5 and 10 micromol/kg can activate TERT and up-regulate c-Myc and p53 proteins. The selenium at the dose of 5 micromol/kg has the antagonistic effect on expression of TERT, c-Myc and p53 induced by cadmium in rat liver.

Effects on protein and mRNA expression levels of p53 induced by fluoride in human embryonic hepatocytes

We investigated the effects of protein and mRNA expression levels on p53 induced by fluoride in human embryo hepatocyte L-02 cells. The protein and mRNA levels of p53 in L-02 cells were measured after in vitro cultured L-02 was exposed to sodium fluoride at different doses (40, 80, and 160 microg/ml) for 24 h. The results showed that the cell survival rate of L-02 cells in the high dose fluoride group was significantly lower than that of the control group. The protein expression levels of p53 in the middle and high dose fluoride group were significantly higher than in the control group and elevated with increasing fluoride concentration. The mRNA expression levels of p53 in the fluoride groups were markedly higher than in the control group. The mRNA expression level of p53 in the high dose fluoride group was however lower compared to the middle dose fluoride group, but similar to the low dose fluoride group. These finding suggest that fluoride can decrease the L-02 cells survival rate and induce protein and mRNA expressions of p53; however, there is no consistency between the protein expression level of p53 and the mRNA expression level.

Increased plasma concentration of nitric oxide in type 2 diabetes but not in nondiabetic individuals with insulin resistance

OBJECTIVE

Insulin resistance (IR) is a key element in the pathogenesis of type 2 diabetes. The results of recent experiments on insulin-mediated vasodilatation have suggested that vascular insensitivity is a component of IR. However, it is still controversial that patients with type 2 diabetes have a decreased ability of insulin to increase endothelial nitric oxide (NO) release.

METHOD

Plasma concentration of NO was examined in 26 patients with type 2 diabetes and 78 nondiabetic volunteers during an insulin suppression test. The test measured the efficacy of insulin in promoting disposal of the infused glucose load, in which the steady state plasma glucose (SSPG) during the 150-180 min of the test was used as an index of IR. Plasma NO levels were assayed by measurement of the stable end products of their metabolism. Comparison of plasma NO levels between groups were performed by Mann-Whitney test and relationships between SSPG and different variables were analyzed by partial correlations.

RESULTS

Our results showed that the plasma NO levels were significantly higher in the diabetic group. When the nondiabetic subjects were analyzed according to their SSPG levels, there was no difference of plasma NO levels between those with SSPG>160 mg/dl and those with SSPG<160 mg/dl. There were also no difference of NO levels between those with a family history of type 2 diabetes and those without. In the nondiabetic group, SSPG correlated with BMI, fasting insulin, triglyceride and HDL-cholesterol, but neither with plasma NO levels nor fasting plasma glucose.

CONCLUSION

Our data suggests that the impairment of NO activity in patients with type 2 diabetes is due to an impaired effect rather than its production. This altered NO signaling pathway is not an early event in insulin resistant individuals. Any such changes will not be apparent until type 2 diabetes with overt hyperglycemia develops.

[Effects of p,p'-DDE on intracellular MAPK pathway of rat Sertoli cells in vitro]

OBJECTIVE

To study effects of p,p'-DDE on intracellular p-ERK of rat Sertoli cells in vitro.

METHODS

We cultured Sertoli cells separated from testicular tissue of rats and examined the changes of intracellular p-ERK, using immunohistochemical SABC method.

RESULTS

It was showed that intracellular p-ERK increased with the dose of p,p'-DDE and had a dose-dependent trend.

CONCLUSION

The results suggested that p,p'-DDE could result in the phosphorylation of ERK and induce the activation of the downstream road and the transcription and expression of genes.

Effects of phenobarbital on metabolism and toxicity of diclofenac sodium in rat hepatocytes in vitro

Diclofenac sodium (DF-Na) was a nonsteroidal anti-inflammatory drug used in various aspects of inflammatory disease. The purpose of this study was to examine the effects of phenobarbital (PB) on metabolism and toxicity of DF-Na in vitro and explore the potential mechanism of DF-Na induced hepatotoxicity. Rat hepatocytes were isolated by a modification of the two-step in situ collagenase perfusion technique and the harvested rat hepatocytes were cultured with sandwich method. Control or PB (2 mM) pre-treated hepatocytes were incubated with DF-Na (0.1, 0.05 or 0.01 mM) in vitro and cytosolic enzyme leakage levels, cytochrome P450 (CYP) 3A activity, and metabolite content of DF-Na in cell culture medium were measured. The results showed that without any treatment hepatocyte CYP 3A activity gradually decreased with culture time. On day four, CYP 3A activity was 53% of the initial value. The decline of CYP 3A was partially reversed by CYP inducer PB, and the maximum induction of CYP 3A was 2.2-fold over control after continuous exposure of hepatocytes to 2 mM PB for 48 h. Lactic dehydrogenase (LDH), aspartate transaminase (AST), and alanine transamine (ALT) activity and the contents of the DF-Na metabolites 4'-hydroxydiclofenac (4'-OH-DF) and 5-hydroxydiclofenac (5-OH-DF) in media appeared to increase with increasing DF-Na concentrations, though there were no significant differences between DF-Na exposed and control hepatocytes. However, if the hepatocytes first were pre-treated with 2 mM PB for 2 days and then exposed to DF-Na, the concentrations of DF-Na metabolites and the activity of LDH in the media were significantly higher than that of control group. These findings suggest that the hepatotoxicity and metabolism of DF-Na in rat hepatocytes are increased when hepatic CYP 3A activity is increased.

[Effects on DNA damage and apoptosis and p53 protein expression induced by fluoride in human embryo hepatocytes]

OBJECTIVE

To study the effects of DNA damage and apoptosis and p53 expression, and to explore the relationship between apoptosis and p53 expression in human embryo hepatocytes induced by fluoride.

METHODS

The rate of DNA damage, apoptosis and the level of p53 expression were investigated after the cells were incubated with sodium fluoride for about 24 hours. The concentrations of sodium fluoride of the control, A, B and C group were 0 microg/ml, 40 microg/ ml, 80 microg/ml and 160 microg/ml individually.

RESULTS

The rate of DNA damage of every group treated with sodium fluoride were significantly higher than the control group (P < 0.05). The percentage of apoptosis of B and C groups increased apparently (P < 0.05). The level of p53 expression of B and C groups were significantly higher than the control group (P < 0.01).

CONCLUSION

Fluoride can increase the rate of DNA damage, and induce apoptosis and expression of p53 in human embryo hepatocytes. Furthermore, both apoptosis and the level of p53 expression, there exists a rise tendency with the increase concentration of fluoride.

Polymorphism of the immune-braking gene CTLA-4 (+49) involved in gender discrepancy of serum total IgE levels and allergic diseases

BACKGROUND

A variety of genes are related to allergic disorders in different ethnic populations. The genetic basis for the gender discrepancy of allergic diseases remains to be determined.

OBJECTIVE

This study was conducted to investigate whether IL-4 promoter (-590 C/T) and cytotoxic T lymphocyte antigen 4 (CTLA-4) (+49 A/G) polymorphisms were correlated with a gender discrepancy of total IgE levels and allergic diseases in a Chinese population.

METHODS

A total of 1333 participants aged 19-49 years were enrolled in this study. Allergic diseases were recognized by the presence of asthma, rhinitis or atopic dermatitis in conjunction with detectable specific IgE in the blood. Polymorphisms of IL-4 promoter (-590) and CTLA-4 (+49) were determined by restriction fragment length polymorphism.

RESULTS

Males or females with allergic diseases had higher total IgE levels than those without (P=0.000). Females with the A/A genotype in the CTLA-4 (+49) position had significantly higher total IgE levels than those with A/G, and those with the G/G genotype had the lowest IgE levels (154.9 vs. 107.1 vs. 79.8 KU/L; mean log values: 1.79 vs. 1.65 vs. 1.54, P< 0.001). However, males with different genotypes in the CTLA-4 (+49) position exhibited no difference in the total IgE levels. Females with allergic rhinitis had a significantly higher frequency of the A/A genotype in the CTLA-4 (+49) polymorphism than those without atopic diseases (P=0.016). In contrast, males with and without allergic disorders exhibited no significant difference in the CTLA-4 (+49) polymorphisms (P>0.05). The IL-4 promoter (-590) polymorphisms, however, had no correlation with the total IgE levels or allergic diseases in either females or males.

CONCLUSION

In females only, the CTLA-4 (+49), but not the IL-4 promoter (-590), polymorphism was significantly associated with elevation of total IgE levels and allergic rhinitis. Here, we have, for the first time, demonstrated a gender-linked genetic relationship with allergic disease.

[Studies on purification of polyprenol from Ginkgo biloba L. leaves]

OBJECTIVE

To research the methods of purifying polyprenol from leaves of Ginkgo biloba L..

METHODS

The purity of polyprenol was determined by HPLC to select the optimal purifying conditions.

RESULTS

The optimal conditions were degreased by 160 times of petroleum ether-ethyl acetate (9:1) firstly, then through a silica gel column (100-140 mesh) and eluted with petroleum etherethyl acetate (19:1).

CONCLUSION

The methods are feasible to purify polyprenol from leaves of Ginkgo biloba L. and could increase the purity of polyprenol obviously.

[Study on the production condition of extraction in combination hydrolysis in situ for isolating diosgenin]

OBJECTIVE

To study the production technology of extraction in combination hydrolysis in situ for isolating diosgenin from Dioscorea nipponica by orthogonal design.

METHOD

The optimum production conditions were investigated with the recovery of diosgenin as an index by extraction in combination hydrolysis in situ, and were compared with the traditional method.

RESULT

Extraction in combination hydrolysis in situ conducted in 1.5 mol x L(-1) sulfuric acid of water containing 75% isopropanol at 100 degrees C for 4.5 h could get higher recovery of diosgenin than traditional methods.

CONCLUSION

This production technology can get higher recovery of diosgenin, and it is simple, time and money saving.

[Isolation and HPLC analysis of ginkgolic acid]

OBJECTIVE

To isolate ginkgolic acids (GA) from exopleura of Ginkgo biloba and to analyse GA.

METHODS

GA were ultrasonic-extracted from exopleura of Ginkgo biloba with petroleum ether, and purified by silica gel column chromatography. The content of GA in sample was determined by HPLC with methanol-3% acetic acid (90:10) as mobile phase at a flow rate of 1 ml/min. UV detection wavelength was set at 310 nm. A HiQ sil C18 column was used at 40 degrees C in analysis.

RESULTS

A good linearity was obtained in the range of 1.144-5.720 micrograms (r = 0.9978) for GA. The average recovery of GA was 97.50% with RSD of 1.70%.

CONCLUSION

The method may be employed to prepare GA from exopleura of Ginkgo biloba. The analysis method for GA is accurate and reliable, and can be used for determination of GA in sample.

[Studies on supercritical CO2 fluid extraction for ginkgolic acids in the epicarp of Ginkgo biloba]

The technology of supercritical CO2 fluid extraction for ginkgolic acids in the epicarp of Ginkgo biloba L. was studied. The effect of pressure, temperature and extraction time on the yield of the ginkgolic acids was explored. The optimum conditions for supercritical CO2 fluid extraction was 30 MPa, 45 degrees C, extraction time 6 h and the flow rate of CO2 2L/min. The ginkgolic acids were determined by HPLC. Supercritical CO2 fluid extraction exceled the traditional solvent extraction in high yield, high purification and easy operation.

[Research progress on oxidative stress and apoptosis]

Many research findings revealed that oxidative stress may induce apoptosis. At present, the explanations for this phenomenon are: 1) ROS activated nuclear factor-KB and induction of the expression of nuclear factor-KB; 2) mitochondria-mediated cell apoptosis; 3) ROS mediated DNA damage and P53 activation; 4) ROS activated SAPK pathway to apoptosis. In this paper, the progress on oxidative stress and apoptosis was reviewed.

Temporal and spatial expression of bone morphogenetic proteins in extracorporeal shock wave-promoted healing of segmental defect

Extracorporeal shock wave (ESW) is a noninvasive acoustic wave, which has recently been demonstrated to promote bone repair. The actual healing mechanism triggered by ESW has not yet been identified. Bone morphogenetic proteins (BMP) have been implicated as playing an important role in bone development and fracture healing. In this study, we aimed to examine the involvement of BMP-2, BMP-3, BMP-4, and BMP-7 expression in ESW promotion of fracture healing. Rats with a 5-mm segmental femoral defect were given ESW treatment using 500 impulses at 0.16 mJ/mm(2). Femurs and calluses were subjected to immunohistochemistry and RT-PCR assay 1, 2, 4, and 8 weeks after treatment. Histological observation demonstrated that fractured femurs received ESW treatment underwent intensive mesenchymal cell aggregation, hypertrophic chondrogenesis, and endochondral/intramembrane ossification, resulting in the healing of segmental defect. Aggregated mesenchymal cells at the defect, chondrocytes at the hypertrophic cartilage, and osteoblasts adjunct to newly formed woven bone showed intensive proliferating cell nuclear antigen expression. ESW treatment significantly promoted BMP-2, BMP-3, BMP-4, and BMP-7 mRNA expression of callus as determined by RT-PCR, and BMP immunoreactivity appeared throughout the bone regeneration period. Mesenchymal cells and immature chondrocytes showed intensive BMP-2, BMP-3, and BMP-4 immunoreactivity. BMP-7 expression was evident on osteoblasts located at endochondral ossification junction. Our findings suggest that BMP play an important role in signaling ESW-activated cell proliferation and bone regeneration of segmental defect.

Different proinflammatory reactions in fatal and non-fatal enterovirus 71 infections: implications for early recognition and therapy

AIM

The mechanism of pulmonary oedema, a life-threatening manifestation of enterovirus 71 (EV71) encephalitis, is unclear. Our aim was to assess the relationship of proinflammatory cytokines to EV71-related pulmonary oedema.

METHODS

Proinflammatory responses in 33 EV71 patients with various complications and 21 normal healthy children were measured using an enzyme-linked immunosorbent assay.

RESULTS

EV71 patients with both encephalitis and pulmonary oedema were found to have much higher levels of blood interleukin-6 (IL-6) (947 +/- 1239 vs 4.9 +/- 3.1 pg/ml, p = 0.0003), tumour necrosis factor-alpha (TNF-alpha) (22.4 +/- 29.5 vs 5.3 +/- 1.0 pg/ml, p = 0.0035), interleukin Ibeta (IL-1beta) (48.4 +/- 85.2 vs 4.9 +/- 10.1 pg/ml, p = 0.01), white blood cell count (28.3 +/- 7.6 vs 15.5 +/- 6.8 10(9)/L, p > or = 0.0001) and blood glucose (501 +/- 186 vs 165 +/- 117 mg/dL, p = 0.0009) than patients with EV71 encephalitis alone. In fact, the cytokine levels in patients with encephalitis only or in those without complications were not significantly different from the levels found in normal children. The sensitivity, specificity, positive and negative predictive values of IL-6 > 70 pg/ml for EV71 encephalitis with pulmonary oedema were all 100%.

CONCLUSION

Patients with EV71-related encephalitis combined with pulmonary oedema were found to have significantly elevated levels of proinflammatory cytokines and the best predictor for this complicated condition was found to be the level of serum IL-6.

[Study on hydrolysis conditions of Dioscorea nipponica with uniform design method]

OBJECTIVE

To optimize hydrolysis conditions of Dioscorea nipponica so as to provide parameters for extracting diosgenin in industry.

METHODS

The optimum hydrolysis conditions were investigated using diosgenin as an index with uniform design and high performance liquid chromatography method.

RESULTS

The optimum conditions were as follows: the hydrochloric acid concentration was 2.5 mol/L, solid-liquid rate was 1:5, the reaction temperature was 140 degrees C, the reaction time was 4.0 h, the mix round speed was 120 r/min.

CONCLUSION

The content of diosgenin under the optimum hydrolysis conditions is raised, and the hydrochloric acid concentration should be strictly controlled because of its large influences on the results.

[Effects of selenium and fluoride on apoptosis and lipid peroxidation in human hepatocytes]

OBJECTIVE

To study the influence of selenium and fluoride on apoptosis and lipid peroxidation in human hepatocytes in vitro.

METHODS

The apoptosis, cell cycle, GSH content and lipid peroxides (LPO) level in human hepatocytes, LPO level and LDH, AST and ALT activity in cell culture supernatants were investigated after hepatocytes were incubated with selenium and/or fluoride for around 12 hours periods in vitro.

RESULTS

The percentage of hepatocyte apoptosis bodies (15.557 +/- 2.056)%, the number of cells in S phase (4.823 +/- 0.454)% and LPO level in liver tissue and supernatant [(2.884 +/- 0.589) and (3.547 +/- 0.561) nmol/L MDA/mg.prot, respectively], AST and LDH activity in supernatants (91.1 +/- 36.4 and 140.4 +/- 7.6 U/L, respectively) in the fluoride treated group was higher than the control group [(10.313 +/- 1.023)%, (3.253 +/- 0.743)%, (1.473 +/- 0.401) nmol/L MDA/mg.prot, (1.694 +/- 0.443) nmol/L MDA/mg.prot, (54.5 +/- 3.2) U/L and (126.4 +/- 2.6) U/L, respectively], The GSH content in live tissue [(4.225 +/- 0.781) microgram/mg.prot] is lower than control group [(7.595 +/- 1.042) microgram/mg.prot]. Selenium treatment reduced these kinds of toxicity of fluoride through raising GSH content, reducing LPO level, LDH and AST activity and percentage of apoptosis bodies.

CONCLUSIONS

Selenium can antagonist apoptosis and lipid peroxidation of hepatocytes induced by fluoride.

[Studies on DNA damage and apoptosis in rat brain induced by fluoride]

OBJECTIVE

To explore the DNA damage effects and apoptosis in brain cells of rats induced by sodium fluoride.

METHODS

SD rats were divided into two groups, i.e. control group and fluoride treated group, which were injected intraperitoneally with distilled water and sodium fluoride (20 mg.kg(-1).d(-1)) respectively. On the hand, 5 mmol/L NaF were used in in vitro study. Single Cell Gel Electrophosis (SCGE or Comet Assay) was utilized to measured DNA damage and apoptosis was detected by the TUNEL method and Flow Cytometry (FCM).

RESULTS

The DNA damage in pallium neurons in rats of the fluoride group was much more serious compared with those of the control group, with the Ridit value being 0.351 and 0.639 respectively (P < 0.01) in vivo, and 0.384 4 and 0.650 1 respectively (P < 0.01) in vitro. TUNEL positive cells were found in pallium, hippocampus and cerebellar granule cells in rats of fluoride group, whereas those in the control group were rare. It was demonstrated by FCM results that the percentages of apoptotic cells both in pallium and hippocampus were significantly higher (P < 0.01) in rats of fluoride group (27.12 +/- 3.08, 34.97 +/- 5.46) than those in control group (4.63 +/- 0.98, 5.35 +/- 0.79), (P < 0.01).

CONCLUSION

Sodium fluoride could induce DNA damage and apoptosis in rats brain.

Extracorporeal shock wave promotes growth and differentiation of bone-marrow stromal cells towards osteoprogenitors associated with induction of TGF-beta1

Extracorporeal shock-wave (ESW) treatment has been shown to be effective in promoting the healing of fractures. We aimed to determine whether ESW could enhance the growth of bone-marrow osteoprogenitor cells. We applied ESW to the left femur of rats 10 mm above the knee at 0.16 mJ/mm2 in a range of between 250 and 2000 impulses. Bone-marrow cells were harvested after ESW for one day and subjected to assessment of colony-forming unit (CFU) granulocytes, monocytes, erythocytes, megakaryocytes (CFU-Mix), CFU-stromal cells (CFU-S) and CFU-osteoprogenitors (CFU-O). We found that the mean value for the CFU-O colonies after treatment with 500 impulses of ESW was 168.2 CFU-O/well (SEM 11.3) compared with 88.2 CFU-O/well (SEM 7.2) in the control group. By contrast, ESW treatment did not affect haematopoiesis as shown by the CFU-Mix (p = 0.557). Treatment with 250 and 500 impulses promoted CFU-O, but not CFU-Mix formations whereas treatment with more than 750 impulses had an inhibiting effect. Treatment with 500 impulses also enhanced the activity of bone alkaline phosphatase in the subculture of CFU-O (p<0.01), indicating a selective promotion of growth of osteoprogenitor cells. Similarly, formation of bone nodules in the long-term culture of bone-marrow osteoprogenitor cells was also significantly enhanced by ESW treatment with 500 impulses. The mean production of TGF-beta1 was 610 pg/ml (SEM 84.6) in culture supernatants from ESW-treated rats compared with 283 pg/ml (SEM 36.8) in the control group. Our findings suggest that optimal treatment with ESW could enhance rat bone-marrow stromal growth and differentiation towards osteoprogenitors presumably by induction of TGF-beta1.

Physical shock wave mediates membrane hyperpolarization and Ras activation for osteogenesis in human bone marrow stromal cells

Physical shock wave (SW) has shown effectiveness on promotion of bone growth. We have recently demonstrated that SW could promote bone marrow stromal cell differentiation toward osteoprogenitor associated with induction of TGF-beta1. We have further demonstrated that SW-induced membrane hyperpolarization and Ras activation acted an early signal for the osteogenesis in human bone marrow stromal cells. An optimal dose of SW treatment at 0.16 mJ/mm(2) for 500 impulses induced a rapid membrane hyperpolarization in 5 min, activation of Ras in 30 min, and cell proliferation in 2 days. The SW-promoted cell growth was related to osteogenesis as demonstrated by increase of bone alkaline phosphatase activity in 6 days and osteocalcin mRNA expression in 12 days. In support that SW-induced Ras activation mediated osteogenesis of human bone marrow stromal cells, we further demonstrated that transfection of bone marrow stromal cells with a dominant negative Ras mutant (Asn-17 ras(H)) abrogated the SW enhancement of osteogenic transcription factor (CBFA1) activation, osteocalcin mRNA expression, and bone nodule formations. These results suggest that physical SW promotes bone marrow stromal cell differentiation toward osteogenic lineage via membrane hyperpolarization, followed by Ras activation and specific osteogenic transcription factor CBFA1 expression. A link between physical SW and biomembrane perturbation-mediated Ras activation may highlight how noninvasive physical agents could be used to promote fracture healing and to rescue patients with osteoporosis and osteopenic disorders in the future.

A single dose of nebulized budesonide decreases exhaled nitric oxide in children with acute asthma

This study was conducted to investigate whether a single dose of nebulized budesonide effectively decreased airway inflammation as demonstrated by exhaled nitric oxide (eNO) levels. A single dose of nebulized budesonide, but not nebulized terbutaline, rapidly decreased eNO levels in 6 hours. The decrease in eNO levels induced by nebulized budesonide was correlated to an increase in peak expiratory flow rate.

Granulocyte function disorders: aspects of development, genetics and management

The field of phagocytic disorders has attained major biologic and clinical significance in the past 40 years. The development of exciting new techniques in molecular biology and the cellular physiology of signal transduction have made it possible to identify the genetic defects involved in many of these disorders. Moreover through immunopharmacologic intervention, bone marrow or peripheral or cord blood stem cell transplantation along with the prospect of gene therapy, we have begun attempts to at least partially correct genetic defects in cell development and activation pathways in the entire spectrum of phagocyte disorders. Carrier detection and prenatal diagnosis employing with chain reaction techniques or direct nucleotide sequencing in fetal blood have made these diseases potentially preventable or treatable in utero or shortly after birth.

Evaluation of different nebulized bronchodilators on clinical efficacy and hypokalemia in asthmatic children

Acute asthma attack continues to be a major cause for children admitted to the emergency room. Nebulized beta 2-adrenergic agonists are still the first-line drugs for a rapid bronchodilation effect and an easily administered drug during acute asthma attack. The bronchodilator-induced hypokalemia is thought significant in adult group, but is often ignored in children group. In this study, we conducted a randomized study to compare the laboratory and clinical effects between nebulized salbutamol and terbutaline. We found that both salbutamol and terbutaline nebulization induced a significant hypokalemia (p < 0.05). Terbutaline nebulization also significantly improved the peak expiratory flow rate (PEFR) and respiratory rate (RR), but not venous partial pressure of oxygen (PvO2), venous carbon dioxide tension (PvCO2) and O2 saturation in venous blood (SvO2). In contrast, salbutamol improved not only PEFR and RR, but also PvO2, PvCO2, and SvO2 30 minutes of administration. In conclusion, the nebulized salbutamol, although induced a hypokalemic effect which is similar to terbutaline group, has a better effect on improving O2 saturation than nebulized terbutaline with the same dose 30 minutes after administered for children with acute asthma attack.

Effect of shock wave therapy on acute fractures of the tibia: a study in a dog model

The effect of shock wave therapy on acute fractures of the tibia was studied in eight adult dogs. A fracture with a 3-mm gap was created in both tibias and the fractures were fixed internally with a small metallic plate and screws. Each of the right limbs received 2,000 impulses of shock waves at 14 kV whereas the left limbs were used as controls. The evaluations included the callus formations based on serial radiographic examinations at 1, 4, 8, and 12 weeks and histologic examinations at 12 weeks for tissue distribution including bone tissues. Based on radiographic findings, there was no statistically significant difference in the amount of callus formation between the treated and the control groups at 8 weeks or less. However, the radiographic findings at 12 weeks statistically showed more callus formations in the treated group. In histologic examinations, there was significantly more cortical bone formation in the treated group at 12 weeks and the bone tissues were thicker, denser, and heavier. Shock wave therapy enhanced callus formation and induced cortical bone formation in acute fractures in dogs at 12 weeks. The effect of shock wave therapy seemed to be time-dependent at 3 months.

Treatment of nonunions of long bone fractures with shock waves

A prospective clinical study investigated the effectiveness of shock waves in the treatment of 72 patients with 72 nonunions of long bone fractures (41 femurs, 19 tibias, seven humeri, one radius, three ulnas and one metatarsal). The doses of shock waves were 6,000 impulses at 28 kV for the femur and tibia, 3,000 impulses at 28 kV for the humerus, 2,000 impulses at 24 kV for the radius and ulna, and 1,000 impulses at 20 kV for the metatarsal. The results of treatment were assessed clinically, and fracture healing was assessed with plain radiographs and tomography. The rate of bony union was 40% at 3 months, 60.9% at 6 months, and 80% at 12 months followup. Shock wave treatment was most successful in hypertrophic nonunions and nonunions with a defect and was least effective in atrophic nonunions. There were no systemic complications or device-related problems. Local complications included petechiae and hematoma formation that resolved spontaneously. In the authors' experience, the results of shock wave treatment were similar to the results of surgical treatment for chronic nonunions with no surgical risks. Shock wave treatment is a safe and effective alternative method in the treatment of chronic nonunions of long bones.

Chronic granulomatous disease: a case report

Chronic granulomatous disease is one form of the phagocyte function disorder. Unlike most patients with chronic granulomatous disease who develop signs and symptoms of chronic and recurrent pyogenic infections during the first 2 years of life, patients with mild forms of the disease may not present until the teenage years or even adulthood. Thus, the diagnosis in these mild-form patients is often delayed. This paper describes a patient with the mild form of chronic granulomatous disease. A 7-year-old boy was admitted to our ward with intermittent high fever and a left neck mass present for about 1 week. He had a history of persistent infection in the bilateral lower face lasting for about 1 year during his fourth year of life. Family history was unremarkable except that the patient's elder sister had a history of persistent oral mucosal wound infection for about 1 year during the fifth year of life. On physical examination, there were scars over the patient's bilateral lower face. Bacterial culture of pus drained from the neck mass revealed Burkholderia cepacia, a rare species in patients without immunodeficiency. A series of antibiotics, including oxacillin, clindamycin, and piperacillin, was given, and two incision operations for drainage and debridement were performed. The neck mass resolved completely about 1.5 months later. This history indicated that the patient might have chronic granulomatous disease. A definite absence of superoxide activity in the patient's granulocytes detected by chemiluminescence and nitroblue tetrazolium dye test confirmed this diagnosis.

Altered cellular but not humoral reactions in children with complicated enterovirus 71 infections in Taiwan

Enterovirus 71 (EV 71) infections have high neurovirulence and fatality. Immune responses were assessed in 78 patients with EV 71 infection. EV 71 meningoencephalitis occurred more frequently in younger children and in boys. C-reactive protein levels were not elevated, although total leukocyte counts were increased in these patients. The CD40-ligand expression on T cells significantly decreased in children with meningoencephalitis (P=.041). Polymorphism of the cytotoxic T lymphocyte antigen-4 (CTLA-4) at position 49 of exon 1 showed a higher frequency of G/G genotype in patients with EV 71 meningoencephalitis than in those without meningoencephalitis (18/31 vs. 14/47; P=.045) and in control subjects (18/31 vs. 25/93l; P=.007). Specific EV 71 neutralizing antibody titers were detectable but did not differ in children with and without meningoencephalitis in the acute and convalescent stages. Results from this study suggest that younger children with a certain CTLA-4 polymorphism and altered cellular but not humoral response may be linked to EV 71 meningoencephalitis.

Antibody-dependent enhancement of heterotypic dengue infections involved in suppression of IFNgamma production

Antibody-dependent enhancement has been implicated in some outbreaks of epidemic dengue hemorrhagic fever, however, the mechanism of antibody-dependent enhancement is not well known. This study was conducted to investigate the cross-protection and cross-enhancement of dengue-2 virus infections by dengue-1 immune sera. It was found that dengue-1 immune sera at 1:5 dilution (n = 12) could neutralize dengue-2 infections in BHK-21 cells, as assessed by a standard plaque-reduction neutralization assay. Two-thirds of the dengue-1 immune sera at 1:25 dilution demonstrated neutralizing effects for dengue-2 infections, whereas, non-immune sera revealed no neutralization for dengue-2 infections in BHK-21 cells. Human mononuclear leukocytes in response to dengue-2 infections elicited a T cell helper 1 (Th1) response revealing induction of IFNgamma but not IL-4 production. Dengue-1 immune sera did not neutralize dengue-2 infections in mononuclear leukocytes. Subneutralizing titers of dengue-1 immune sera at 1:250, but not at 1:10 dilution, enhanced dengue-2 infections in mononuclear leukocytes (1.2 +/- 0.7 x 10(4) vs. 2.8 +/- 0.3 x 10(2) PFU/ml). The enhancement of dengue-2 infections in mononuclear leukocytes by dengue-1 immune sera at 1:250 was associated with an increase in the lymphocyte proliferation index, and a decrease in IFNgamma production (56 +/- 24 vs. 12 +/- 3 pg/ml). The addition of IFNgamma (0.1 microg/ml) suppressed significantly the antibody-dependent enhancement induced by dengue-1 immune sera, whereas the presence of anti-IFNgamma F(ab)2 antibody augmented the antibody-dependent enhancement effect. Results from this study suggest that suppression of Th1 response may be involved in the antibody-dependent enhancement of heterotypic dengue infections. Better regulation of Th1/Th2 reactions may be useful for prevention of heterotypic immune enhancement of dengue infections.

A model of the real-time correlation of viral titers with immune reactions in antibody-dependent enhancement of dengue-2 infections

We simultaneously assessed dengue-2 virus (DEN-2) titers by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immune reactions including interleukin-4 (IL-4), interferon-gamma (IFN-gamma) and prostaglandin E(2) (PGE(2)) production by human mononuclear cells (MNLs) in a model of antibody-dependent enhancement (ADE). We found that DEN-1 immune sera at 1:100 and 1:250, but not those at 1:10 or control sera, enhanced DEN-2 infections in human MNLs as assessed by the fluorogenic RT-PCR technique. The enhanced profiles of DEN-2 infections determined by the RT-PCR in 6 h were reproducible by the standard plaque-forming unit (PFU) measurement established after 7 days. The ADE-enhanced DEN-2 titers determined by the RT-PCR were 5.5-33-fold higher than those detected by PFU assay, suggesting that total virions during infections were much higher than the viable ones detected by PFU assay. MNLs in response to DEN-2 infections had higher IFN-gamma and PGE(2) production. However, the enhancement of DEN-2 infections by DEN-1 immune sera in MNLs was not associated with further enhancement of IFN-gamma production. In contrast, the presence of subneutralizing DEN-1 immune sera that enhanced DEN-2 infections also enhanced PGE(2) but not IL-4 production. The results of this study suggest that ADE of DEN-2 infections associated with induction of immunosuppressive mediators such as PGE(2) and IL-4 can be simultaneously assessed in a real-time fashion.

A model to study antioxidant regulation of endotoxemia-modulated neonatal granulopoiesis and granulocyte apoptosis

Neonates with septicemia tend to develop granulocytopenia, which may, in part, be due to septic mediators such as oxygen free radicals and tumor necrosis factor alpha (TNF-alpha). Granulocytopenia may be caused by a decrease in granulocyte growth and/or an increase in granulocyte destruction. In the present study, we investigated antioxidant regulation of endotoxin-modulated neonatal granulopoiesis and granulocyte apoptosis. Using human umbilical cord blood (HUCB), we found that simulating endotoxemia in vitro elicited significant superoxide production within a few minutes. Endotoxin exposure suppressed colony-forming unit-granulocyte and monocyte formation in a dose-dependent fashion. Addition of antioxidants such as N-acetyl-cysteine could reverse the endotoxin suppression of colony-forming unit-granulocyte and monocyte formation (13 +/- 5 versus 75 +/- 5 colony-forming units/mL). Spontaneous in vitro granulocyte apoptosis in 6 h, as reflected by phosphatidylserine expression on the cell surface, was higher in granulocytes from HUCB than in those from adult blood (10.8 +/- 1.0% versus 5.6 +/- 1.2%). The addition of endotoxin or IL-8 to the cells in the in vitro model did not promote granulocyte apoptosis, but TNF-alpha, a major mediator of the effects of endotoxin, significantly induced granulocyte apoptosis in HUCB (control versus TNF-alpha: 8.9 +/- 1.2% versus 35.9 +/- 2.9%). Addition of the antioxidant N-acetyl-cysteine effectively blocked TNF-alpha-induced granulocyte apoptosis as demonstrated by DNA fragmentation. Results from these studies indicate that oxygen radicals are directly involved in endotoxin suppression of granulopoiesis, and indirectly promote granulocyte apoptosis, presumably through TNF-alpha-mediated action. Thus, under certain conditions, modulation of oxygen radical production in the blood may benefit neonates with granulocytopenia.

Childhood asthma: aspects of global environment, genetics and management

The prevalence of asthma in children dramatically increased over the past two decades. In Taiwan, the prevalence of childhood asthma has risen to around 10% in the 1990s, in contrast to a prevalence of about 1% in the 1970s. Currently, Australia and New Zealand have the highest prevalence in the world (> 15%). African and Asian countries have a low prevalence of about 5 to 10%. In general, countries in coastal, temperate and subtropical zones have the highest mite-sensitive asthma prevalence. Countries in the subarctic or in semiarid areas have a lower prevalence. Indoor allergens such as house dust mites, cockroaches and fungi usually cause perennial asthma; outdoor allergens such as grass and tree pollens as well as outdoor fungi induce seasonal asthma. A gene on chromosome 11q13 is significantly linked to maternal inheritance of asthma, and possibly involves polymorphisms in the beta subunit of the high affinity IgE receptor. Cytokine genes in chromosome 5q31-33 are known to regulate IgE production resulting in various severities of allergic diseases. Recent studies suggest that pollutants such as diesel exhaust, O3, NO2, and SO2, together with allergens and susceptible genes are likely to promote IgE production and allergic reactions. As a result, asthma is apparently not a single gene disorder, but a disease determined by the interaction between gene and environment. In practice, immunopharmacological interventions to block IgE-mediated early bronchospasm and late inflammatory reactions are the major regimens for asthma treatments. This makes possible a step-wise self-management based on portable monitoring of airway resistance using the peak expiratory flow rate (PEFR). Early avoidance of allergen exposure in utero as well as early anti-inflammatory therapy in infancy have decreased the prevalence of allergic diseases. A combination of both strategies may bring much more benefit in the prevention of childhood asthma. As progress in therapeutic gene vaccines as well as genetic immunoregulation continues, we expect early environmental avoidance and genetic vaccines may prevent childhood asthma in the near future.

Common variable immunodeficiency with mosaic trisomy 8: report of one case

This case study reported a 17-year-old female of common variable immunodeficiency (CVID) associated with bronchiectasis, pernicious anemia and mosaic trisomy 8. Clinically this patient presented with recurrent sinopulmonary infections, intractable diarrhea, macrocytic anemia, and primary amenorrhea. Immunological tests showed pan-hypogammaglobulinemia and a decrease of peripheral blood B cells (4%) and CD4+ cells (25%). Lymphoproliferative responses to mitogen (PHA) and specific antigen (BCG) were profoundly impaired in the patient in comparison to those in control. Production of interleukin 4 (IL-4) and gamma interferon (IFN-gamma) in the in vitro lymphoproliferation was also profoundly depressed. Pernicious anemia demonstrated by larger MCV (112.9 fl) and hyper-segmental granulocytes on peripheral blood smear responded to parental administration of vitamin B12. Interestingly, she had a mosaic trisomy 8 in peripheral blood mononuclear cells but normal 46XX karyotype in the bone marrow cells. To our knowledge, this is the first case of CVID associated with mosaic trisomy 8 reported in the literature. As the case exemplifies, CVID should be considered when the physicians evaluate the patient presenting with recurrent sinopulmonary infections, diarrhea, malnutrition, and pernicious anemia. It requires further study to explore whether the genes in the chromosome 8 are linked to CVID.

Pentoxifylline synergizes with all-trans retinoic acid to induce differentiation of HL-60 myelocytic cells, but suppresses tRA-augmented clonal growth of normal CFU-GM

All-trans retinoic acid (tRA) has been shown to promote terminal differentiation of promyelocytic leukemia cells, but frequently induce hyperleukocytosis and pulmonary leakage syndrome. Employing pentoxifylline (PTX), a phosphodiesterase inhibitor which could raise intracellular cAMP and modulate leukocyte activation, we sought to investigate if PTX could enhance tRA-induced promyelocytic leukemic cell differentiation but suppress tRA-augmented growth and activation of human granulocytes. tRA could significantly suppress clonal growth of U937 and HL-60 leukemic cells but enhanced the CFU-GM formation of normal bone marrow cells (22 +/- 6 vs. 90 +/- 16 CFU/well). PTX significantly augmented tRA suppression of clonal growth of U937 and HL-60 leukemic cells but suppressed tRA-augmented CFU-GM formation of normal bone marrow cells (90 +/- 16 vs. 25 +/- 9 CFU/well). In addition, PTX enhanced tRA-induced growth inhibition and differentiation of promyelocytic HL-60 leukemic cells, but suppressed respiratory burst activation by the immature granulocytic HL-60 cells and suppressed CD11b adhesion molecule expression by mature granulocytes. PTX similar to dibutyric cAMP promoted HL-60 myelocytic leukemic cell differentiation and growth inhibition, whereas PTX, in contrast to dibutyric cAMP which could augment phorbol myristate acetate (PMA)-elicited respiratory burst activity by immature granulocytes, suppressed the PMA-elicited respiratory burst activity by immature and mature granulocytes. PTX did not raise the intracellular cAMP level of HL-60 cells, but partly suppressed the dibutyric cAMP-elicited elevation of intracellular cAMP level. Results from these studies suggest that PTX might act through different signaling pathways to enhance tRA-induced myelocytic leukemic cell differentiation but prevent from hyperreactive normal granulopoiesis and granulocyte activation.

Potential dengue virus-triggered apoptotic pathway in human neuroblastoma cells: arachidonic acid, superoxide anion, and NF-kappaB are sequentially involved

Direct in vivo evidence for the susceptibility of human neuronal cells to dengue virus has not been reported. In this study, we demonstrated that type 2 dengue (DEN-2) virus infection induced extensive apoptosis in the human neuroblastoma cell line SK-N-SH. Phospholipase A(2) (PLA(2)) was activated by DEN-2 infection, which led to the generation of arachidonic acid (AA). Inhibition of PLA(2) activity by the PLA(2) inhibitors, AACOCF(3) and ONO-RS-082, diminished DEN-2 virus-induced apoptosis. In contrast, the cyclooxygenase inhibitors aspirin and indomethacin, thought to increase AA accumulation by blocking AA catabolism, enhanced apoptosis. Exogenous AA induced apoptosis in a dose-dependent manner. Superoxide anion, which is thought to be generated through the AA-activated NADPH oxidase, was increased after infection. Pretreatment with superoxide dismutase (SOD) protected cells against DEN-2 virus-induced apoptosis. Furthermore, generation of superoxide anion was blocked by AACOCF(3). In addition, the transcription factors, NF-kappaB and c-Jun, were found to be activated after DEN-2 virus infection. However, pretreatment of cells with oligodeoxynucleotides containing NF-kappaB, but not c-Jun, binding sites (transcription factor decoy) strongly prevented dengue virus-induced apoptosis. The finding that AACOCF(3) and SOD significantly block activation of NF-kappaB suggests that this activation is derived from the AA-superoxide anion pathway. Our results indicate that DEN-2 virus infection of human neuroblastoma cells triggers an apoptotic pathway through PLA(2) activation to superoxide anion generation and subsequently to NF-kappaB activation. This apoptotic effect can be either directly derived from the action of AA and superoxide anion on mitochondria or indirectly derived from the products of apoptosis-related genes activated by NF-kappaB.

Atopic cataracts in a child with atopic dermatitis: a case report and review of the literature

Cataracts induced by atopic dermatitis rarely occur in adolescent and young adult patients suffering from this problem. Lenticular opacity is an important ocular complication in atopic dermatitis. Although the cause of atopic dermatitis and its ocular complications are unknown, cataracts have been observed to develop and progress during periods of exacerbation of the dermatitis. We report the case of a 16-year-old boy with atopic dermatitis who abruptly developed cataracts in both eyes while suffering from severe skin itching which began 2 months before the initial examination. His peroxidation test result was very high, and we postulate the retinal peroxidation might play a key role in cataractogenesis. Lens aspiration and intraocular artificial lens implantation were performed smoothly with restoration of visual acuity in both eyes.

Profiles of inflammatory cytokines in bronchoalveolar lavage fluid from premature infants with respiratory distress disease

In view of cytokine's effects in promoting or inhibiting inflammation, the objective of this study was to explore the characteristics of the proinflammatory cytokine, interleukin-8 (IL-8), and the inhibitory cytokine, interleukin-10 (IL-10), in the bronchoalveolar lavage (BAL) fluid of premature infants suffering from respiratory distress disease. Eighteen premature neonates with respiratory distress disease with gestational age (GA) ranging from 24 to 37 weeks were recruited for study. BAL fluids were collected following endotracheal intubation during an episode of hypoxemia or dyspnea. A series of BAL samples were obtained on day 1, 2, 4 and 7 after intubation for measuring IL-8 and IL-10 levels. The results indicate that premature infants with GA ranging from 24 to 32 weeks had a higher level of IL-8 (p = 0.029), but not level of IL-10 (p = 0.109), in the BAL obtained during the first intubation compared to premature infants with GA ranging from 33 to 37 weeks. The administration of exogenous surfactant did not influence the profiles of IL-8 and IL-10, as compared to those in-patients without treatment. Levels of IL-8 were correlated with IL-10 levels (r = 0.613, p = 0.007) in BAL fluid samples obtained on the day of intubation. The level of IL-8, but not IL-10, was significantly correlated with the duration of intubation. IL-8 and IL-10 levels in BAL fluid samples collected on the day of intubation were correlated with the development of chronic lung disease (CLD). The results suggest that extreme prematurity tends to have increased IL-8 and IL-10 levels in BAL fluid compared to premature infants with older GA, and that these increased levels are associated with the development of CLD.