Lactoferrin regulates sebogenesis and inflammation in SZ95 human sebocytes and mouse model of acne.

BACKGROUND: The aim of this study was to explore the anti-inflammatory and anti-lipid effects of lactoferrin on SZ95 human sebaceous gland cells and mouse model of acne. METHODS: SZ95 cells were co-cultured with different concentrations of lactoferrin, and cell viability was determined using the 2,5-diphenyl-2H-tetrazolium bromide method. Oil red O and Nile red staining were performed to determine the lipid content. The mRNA expression of genes related to lipid metabolism (sterol regulatory element-binding protein-1 [SREBP-1], fatty acid synthase [FAS], stearoyl-CoA desaturase-1 [SCD-1], fatty acid desaturase 2 [FADS2]) and inflammation (interleukin-8 [IL-8]) was determined by reverse transcription-polymerase chain reaction. An acne mouse model was established using injection of P. acnes on the backs of mice. The proliferation and apoptosis of sebaceous gland cells were examined by immunohistochemistry against proliferating cell nuclear antigen (PCNA) and TUNEL staining, respectively. Western blotting was used to detect FADS2 and CXCL15 protein expression. RESULTS: Lactoferrin treatment at 10-500 µg/ml significantly decreased the lipid content, as revealed by the oil red O and Nile red staining. It also attenuated the increase of mRNA expression of SREBP-1, FAS, SCD-1, FADS2, and IL-8 in insulin-treated SZ95 cells. Moreover, lactoferrin treatment at the doses of 1-50 mg/mouse significantly reduced the inflammation and lipid production in the mouse model of acne. Also, the number of sebaceous gland cells was significantly reduced, and apoptosis was significantly increased by lactoferrin treatment in the mice. Mechanically, the levels of FADS2 and CXCL15 proteins in tissues were significantly decreased after lactoferrin treatment in the model mice. CONCLUSION: Our results demonstrate the potential of lactoferrin against sebogenesis, sebaceous gland inflammation in acne.

The impact of sedation on quality metrics of colonoscopy: a single-center experience of 48,838 procedures.

PURPOSE: Investigation of the role of sedation during colonoscopy is meaningful as the advantages of colonoscopy performing with sedation are still controversial. METHODS: Medical records of patients who underwent colonoscopy in our institution were retrospectively analyzed. The sedation rate, adenoma detection rate (ADR), polyp detection rate (PDR), cecal intubation rate (CIR), iatrogenic colonic perforation rate (ICP) were calculated. RESULTS: A total of 48,838 colonoscopies (24,498 in males) dated from July 2007 to February 2017 were analyzed. The median age was 50 years (range 16-85 years). An overall sedation rate was 80.38%. The PDR was 26.77%, and was not statistically different between colonoscopy with or without sedation (26.67% vs 27.22, p = 0.474). ADR was 12.9% regardless of applying sedation or not (13.0% vs 12.44%, p = 0.337). The CIR was 87.42% in all examinations with an adjusted CIR of 90.34%, and was higher when performed with sedation than without sedation (88.92% vs 80.64%, p < 0.0001). Five cases (0.01%) of ICP were reported, all of which occurred in patients under sedation. CONCLUSIONS: The use of sedation is associated with increased CIR, but ADR and PDR remain unchanged with or without sedation. However, perforation rate, albeit very low, is significantly higher in sedated patients.

Deca-BDE and alternative halogenated flame retardants in a wastewater treatment plant in Harbin (2009-2016): Occurrence, temporal trends, seasonal variation, and fate.

This study is the first attempt to comprehensively investigate deca-BDE and alternative flame retardants in a wastewater treatment plant in such a long term in China (2009-2016). Influent, effluent and sludge samples were collected. The mean concentration of deca-BDE, Σ19NBFRs and ΣDPs in influent were 311.5, 76.0 and 1.4ng/L, respectively, which were at the low end of the global range. The levels of deca-BDE, Σ19NBFRs and ΣDPs in effluent were range from 9.5-68.6, 4.1-38.5 and BLD-1.6ng/L, respectively. In sludge samples, the mean concentrations were 406.7, 510.5 and 6.9ng/g dw for deca-BDE, Σ19NBFRs and ΣDPs. The concentration of temporal trends in this study may reflected the release of those compounds. Compared to the beginning year of this study, the usage of deca-BDE was decreased but the usage of total NBFRs and DPs presented sustained increase over the sampling period. There were no significant variation of deca-BDE, NBFRs and DPs in the wastewater treatment plant in Harbin was observed in the four seasons except for NBFRs in influents, which the Σ19NBFRs mean concentration in influents in the summer was statistically significantly higher than that in winter indicating that NBFRs was easier impacted by temperature compared to deca-BDE and DPs. In addition, sorption and accumulation to sludge was the major removal mechanism for those compounds, accounting for 73.3% to 89.0%.

Retraction: Origin of colossal permittivity in (In1/2Nb1/2)TiO2via broadband dielectric spectroscopy.

Retraction of 'Origin of colossal permittivity in (In1/2Nb1/2)TiO2via broadband dielectric spectroscopy' by Xiao-gang Zhao et al., Phys. Chem. Chem. Phys., 2015, 17, 23132-23139.

Lubiprostone Is Effective in the Treatment of Chronic Idiopathic Constipation and Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: To evaluate the efficacy and safety of lubiprostone in the treatment of chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C). PATIENTS AND METHODS: We performed a literature search of the MEDLINE, Cochrane, Google Scholar, and ClinicalTrials.gov databases (from January 1, 2005, through January 31, 2015). Relevant studies meeting the inclusion criteria were manually searched by 2 independent reviewers. Efficacy outcomes evaluated at 1 week, 1 month, and 3 months of intervention were weekly frequency of spontaneous bowel movements, severity of constipation, consistency of stools, degree of abdominal pain/discomfort, degree of straining, and abdominal bloating. RESULTS: Of 246 studies identified, data from 9 trials comprising 1468 patients (63.6%) in the lubiprostone group and 841 (36.4%) in the placebo group were analyzed. We found that lubiprostone treatment significantly improved the severity of constipation, stool consistency, abdominal pain, degree of straining, and abdominal bloating at 1 week (P≤.03) and 1 month (P≤.004), except for abdominal pain at 1 month, which was similar to that when treated with placebo (P=.21). At 3 months, except for abdominal bloating (P=.03), there was no difference between lubiprostone and placebo groups in all other outcomes (P≥.05). Adverse effects such as nausea, vomiting, and diarrhea were common (incidence rate, 2.4%-75%); however, the incidence of serious adverse effects was low (<5%) and was mostly unrelated to lubiprostone treatment. CONCLUSION: Lubiprostone is a safe and efficacious drug for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation, with limited adverse effects in 3 months of follow-up.

Correction: Origin of colossal permittivity in (In1/2Nb1/2)TiO2via broadband dielectric spectroscopy.

Correction for 'Origin of colossal permittivity in (In1/2Nb1/2)TiO2via broadband dielectric spectroscopy' by Xiao-gang Zhao et al., Phys. Chem. Chem. Phys., 2015, 17, 23132-23139.

Origin of colossal permittivity in (In1/2Nb1/2)TiO2via broadband dielectric spectroscopy.

(In1/2Nb1/2)TiO2 (IN-T) ceramics were prepared via a solid-state reaction route. X-ray diffraction (XRD) and Raman spectroscopy were used for the structural and compositional characterization of the synthesized compounds. The results indicated that the sintered ceramics have a single phase of rutile TiO2. Dielectric spectroscopy (frequency range from 20 Hz to 1 MHz and temperature range from 10 K to 270 K) was performed on these ceramics. The IN-T ceramics showed extremely high permittivities of up to ∼10(3), which can be referred to as colossal permittivity, with relatively low dielectric losses of ∼0.05. Most importantly, detailed impedance data analyses of IN-T demonstrated that electron-pinned defect-dipoles, interfacial polarization and polaron hopping polarization contribute to the colossal permittivity at high temperatures (270 K); however, only the complexes (pinned electron) and polaron hopping polarization are active at low temperatures (below 180 K), which is consistent with UDR analysis.

Overexpression of Csk-binding protein decreases growth, invasion, and migration of esophageal carcinoma cells by controlling Src activation.

AIM: To investigate the mechanisms by which Csk-binding protein (CBP) inhibits tumor progression in esophageal carcinoma. METHODS: A CBP overexpressing esophageal carcinoma cell line (TE-1) was established. The growth, invasion, and migration of CBP-TE-1 cells, as well as the expression of Src were then determined and compared with those in normal TE-1 cells. RESULTS: The expression of Src was decreased by the overexpression of CBP in TE-1 cells. The growth, invasion, and migration of TE-1 cells were decreased by the overexpression of CBP. CONCLUSION: This study indicates that CBP may decrease the metastasis of esophageal carcinoma by inhibiting the activation of Src. CBP may be a potential tumor suppressor and targeting the CBP gene may be an alternative strategy for the development of therapies for esophageal carcinoma.

Identification of a missense variant in LNPEP that confers psoriasis risk.

Psoriasis is a chronic inflammatory disease with a complex genetic architecture. To further advance gene discovery, we extended our genome-wide association study data set of 1,139 cases and 2,234 controls and replicated two independent cohorts of 7,200 cases and 10,491 controls. We identified the missense variant rs2303138 (p.Ala763Thr) within the LNPEP gene associated with psoriasis (Pcombined=1.83 × 10(-13), odds ratio=1.16) and validated four previously reported genes: IL28RA, NFKBIA, TRAF3IP2, and CARD14 (9.74 × 10(-11)P9.37 × 10(-5)), which confirmed the involvement of the nuclear factor-κB signaling pathway in psoriasis pathogenesis. LNPEP, also named insulin-responsive aminopeptidase, was identified as an angiotensin IV receptor. Protein function prediction suggested that this missense variant of LNPEP was most likely deleterious. Expression analysis showed that LNPEP was significantly downregulated in psoriatic lesions compared with the control skin (P=1.44 × 10(-6)) and uninvolved patient skin (P=2.95 × 10(-4)). Pathway analysis indicated that LNPEP was involved in the renin-angiotensin system, which also has a key role in cardiovascular disease and diabetes. These results provided genetic evidence that psoriasis might share common mechanisms with hypertension and diabetes, which was consistent with clinical observations. Our study identified a genetic susceptibility factor and provided genetic evidence of insight into psoriasis pathogenesis with the involvement of the renin-angiotensin system pathway.

Determination of organophosphorus pesticide residues in vegetables by an enzyme inhibition method using α-naphthyl acetate esterase extracted from wheat flour.

The widespread use of organophosphorus pesticides (OPs) poses a great threat to human health and has made the detection of OP residues in food an important task, especially in view of the fact that easy and rapid detection methods are needed. Because OPs have inhibitory effects on the activity of α-naphthyl acetate esterase (ANAE) in plants, in this work we evaluated the possibility of detecting OPs in vegetables with ANAE extracted from commercial flour. The limits of detection (LODs) obtained for methamidophos, dichlorvos, phoxim, dimethoate, and malathion in lettuce samples with crude ANAE were 0.17, 0.11, 0.11, 0.96, and 1.70 mg/kg, respectively. Based on the maximum residue limits (MRLs) for OPs in food stipulated by Chinese laws which are 0.05, 0.20, 0.05, 1.00, and 8.00 mg/kg for methamidophos, dichlorvos, phoxim, dimethoate, and malathion, respectively, the esterase inhibition method with crude ANAE had sufficient sensitivity to detect the residues of dichlorvos, dimethoate, and malathion in lettuce, but it could not be used to guarantee the safety of the same samples if methamidophos or phoxim residue was present. The sensitivity of the method was improved by the use of esterase purified by ammonium sulfate salting-out. The LODs obtained for methamidophos and phoxim with purified esterase were lower than the MRLs for these OPs in food. This is a very promising method for the detection of OP residues in vegetables using crude or purified esterase because of its cheapness, sensitivity, and convenience.

[Expression of Csk-binding protein in esophageal carcinoma and its possible implications].

OBJECTIVE: To investigate the expression of Csk-binding protein (CBP) in esophageal carcinoma and its association with the tumorigenesis and progression of esophageal cancer. METHODS: RT-PCR and Western blotting were employed to determine the expressions of CBP at the mRNA and protein levels in 50 pairs of fresh esophageal carcinoma tissue and the adjacent normal tissues. RESULTS: CBP mRNA and protein expressions in normal tissues were 1.43- and 1.28-fold higher than those in the cancer tissues, respectively (P<0.05). The expressions of CBP mRNA and protein were positively correlated (P=0.015). The decreased expressions of CBP were significantly correlated to lymph node metastasis of esophageal cancer (P<0.05). CONCLUSION: The expression of CBP gene is decreased in esophageal carcinoma, which might contribute to the tumorigenesis and progression of this malignancy.

Cholecystokinin facilitates neuronal excitability in the entorhinal cortex via activation of TRPC-like channels.

Cholecystokinin (CCK) is one of the most abundant neuropeptides in the brain, where it interacts with two G protein-coupled receptors (CCK-1 and CCK-2). Activation of both CCK receptors increases the activity of PLC, resulting in increases in intracellular calcium ion (Ca(2+)) release and activation of PKC. Whereas high density of CCK receptors has been detected in the superficial layers of the entorhinal cortex (EC), the functions of CCK in this brain region have not been determined. Here, we studied the effects of CCK on neuronal excitability of layer III pyramidal neurons in the EC. Our results showed that CCK remarkably increased the firing frequency of action potentials (APs). The effects of CCK on neuronal excitability were mediated via activation of CCK-2 receptors and required the functions of G proteins and PLC. However, CCK-mediated facilitation of neuronal excitability was independent of inositol trisphosphate receptors and PKC. CCK facilitated neuronal excitability by activating a cationic channel to generate membrane depolarization. The effects of CCK were suppressed by the generic, nonselective cationic channel blockers, 2-aminoethyldiphenyl borate and flufenamic acid, but potentiated by gadolinium ion and lanthanum ion at 100 µM. Depletion of extracellular Ca(2+) also counteracted CCK-induced increases in AC firing frequency. Moreover, CCK-induced enhancement of neuronal excitability was inhibited significantly by intracellular application of the antibody to transient receptor potential channel 5 (TRPC5), suggesting the involvement of TRPC5 channels. Our results provide a cellular and molecular mechanism to help explain the functions of CCK in vivo.

Glutathione S-transferase gene polymorphisms and risk of gastric cancer in a Chinese population.

AIM: The potential role of GSTM1, GSTT1 and GSTP1 polymorphisms in risk of gastric cancer in Chinese was studied. METHODS: We collected 194 gastric cancers by pathologic examination and 412 controls from southern China during January 2007 to January 2011. Genotyping was based upon duplex polymerase-chain-reaction with the PCR-CTPP method. RESULTS: Individuals carrying null GSTM1 and GSTT1 had 1.49 and 1.96 fold risk sof gastric cancer when compared with respective non-null genotypes. We also found a non-significant 37% excess risk of gastric cancer among carriers of GSTP1 1b/1b genotype when compared with 1a/1a genotype (OR=1.37, 95% CI=0.81-2.25). The combination of null/null GSTM1 and GSTT1 genotypes showed higher increased risk of gastric cancer (OR=3.17, 95% CI=1.68-4.21). Moreover, cancers in ever smokers and ever drinkers were observed to be strongly associated with null GSTM1 and GSTT1, and a significant cancer risk was observed in positive H.pylori infection individuals with null GSTT1. CONCLUSION: Our study provided evidence that genetic deletion of GSTM1 and GSTT1 may contribute to increased susceptibility to gastric cancer in our Chinese population, while the GSTP1a/b polymorphism may not.

Association analyses identify six new psoriasis susceptibility loci in the Chinese population.

We extended our previous genome-wide association study for psoriasis with a multistage replication study including 8,312 individuals with psoriasis (cases) and 12,919 controls from China as well as 3,293 cases and 4,188 controls from Germany and the United States and 254 nuclear families from the United States. We identified six new susceptibility loci associated with psoriasis in the Chinese study containing the candidate genes ERAP1, PTTG1, CSMD1, GJB2, SERPINB8 and ZNF816A (combined P < 5 × 10⁻8) and replicated one locus, 5q33.1 (TNIP1-ANXA6), previously reported (combined P = 3.8 × 10⁻²¹) in the European studies. Two of these loci showed evidence for association in the German study at ZNF816A and GJB2 with P = 3.6 × 10⁻³ and P = 7.9 × 10⁻³, respectively. ERAP1 and ZNF816A were associated with type 1 (early onset) psoriasis in the Chinese Han population (test for heterogeneity P = 6.5 × 10⁻³ and P = 1.5 × 10⁻³, respectively). Comparisons with the results of previous GWAS of psoriasis highlight the heterogeneity of disease susceptibility between the Chinese and European populations. Our study identifies new genetic susceptibility factors and suggests new biological pathways in psoriasis.

Psoriasis genome-wide association study identifies susceptibility variants within LCE gene cluster at 1q21.

We report the first large genome-wide association study (GWAS) in a Chinese population to identify susceptibility variants for psoriasis using a two-stage case-control design. In the first stage, we carried out a genome-wide association analysis in 1,139 cases and 1,132 controls of Chinese Han ancestry using Illumina Human 610-Quad BeadChips. In the second stage, we took top SNPs forward for replication in two independent samples of 5,182 cases and 6,516 controls of Chinese Han ancestry, and 539 cases and 824 controls of Chinese Uygur ancestry. In addition to the strong replication for two known susceptibility loci MHC (rs1265181, P = 1.93 x 10(-208), OR = 22.62) and IL12B (rs3213094, P(combined) = 2.58 x 10(-26), OR = 0.78), we identified a new susceptibility locus within the LCE gene cluster on 1q21 (rs4085613, P(combined) = 6.69 x 10(-30), OR = 0.76).

Association of HLA-DQA1 and DQB1 alleles with keloids in Chinese Hans.

BACKGROUND: Some studies have suggested that human HLA status might potentiate development of keloids phenotype, and exists ethnic differences. No report has been published about HLA-DQA1 and DQB1 alleles associated with keloids in Chinese Hans. OBJECTIVES: To investigate whether HLA-DQA1 and DQB1 alleles are associated with genetic susceptibility to keloids in Chinese Hans. METHODS: Polymerase chain reaction-sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA-DQA1 and DQB1 alleles among 192 patients with keloids and 273 healthy controls in Chinese Hans. RESULTS: (1) The frequencies of HLA-DQA1*0104, DQB1*0501 and DQB1*0503 (OR = 2.13, P(c) = 0.0063; OR = 14.42, P(c) < 10(-7) and OR = 6.09, P(c) < 10(-7), respectively) were significantly higher, while the frequencies of DQA1*0501, DQB1*0201 and DQB1*0402 (OR = 0.46, P(c) = 0.0099; OR = 0.24, P(c) < 10(-4) and OR = 0.10, P(c)=0.0054, respectively) were lower in patients than in controls. (2) In this study significant susceptibility haplotypes to keloids were DQA1*0104-DQB1*0501 and DQA1*0104-DQB1*0503. (3) HLA-DQB1*0501 and DQB1*0503 were positively associated with all subgroups of keloid patients. However, the DQA1*0104 (OR = 2.51, P(c) = 0.0009; OR = 2.22, P(c) = 0.0090 and OR = 2.20, P(c) = 0.0117, respectively) was only prevalent in keloid patients with single site, moderate severity and negative family history. (4) HLA-DQB1*0201 (OR = 0.27, P(c) = 0.0018 and OR = 0.27, P(c) = 0.0012, respectively) and DQB1*0402 (OR = 0.07, P(c) = 0.0270 and OR = 0.07, P(c) = 0.0306, respectively) were negatively associated with moderate severity and negative family history in keloids, moreover, HLA-DQB1*0201 (OR = 0.23, P(c) = 0.0003) and DQA1*0501 (OR = 0.43, P(c) = 0.0234) were less prevalent in patients with single site. CONCLUSION: This study demonstrated the positive association of HLA-DQA1 and DQB1 alleles and haplotypes with keloids.

[Enantioselective interaction between plants and chiral compounds].

There exists a close relationship between plants and chiral compounds. On one hand, plants can secrete and synthesize some chiral compounds such as glucosides, enzymes, terpenoids, organic acids and phytohormones that play important roles in plant physiological and biochemical processes, and on the other hand, artificial synthetic chiral compounds, especially pesticides, had enantioselective interactions with plants. The pesticides can enantioselectively inhibit the growth of plants, or can be enantioselectively absorbed and metabolized by plants. Therefore, in the exploitation, production and application of chiral compounds, it's needed to consider the enantioselective interaction between plants and chiral compounds. In the meanwhile, choosing appropriate plants to ameliorate the environment polluted by chiral compounds is of practical significance. In this review, the enantioselective interaction between plants and chiral compounds was summarized, and the amelioration of chiral compounds-polluted environment by plants was prospected.

[Characterization of napropamide enantiomers by CD and determination of the enantiomeric ratios in water].

The enantiomers of napropamide were separated by normal phase HPLC (HPLC: high performance liquid Chromatography) with Chiralpak OJ-H column and charactered by circular dichroism. On this basis, a method for the chiral separation and micro-determination of napropamide in water was established. The linearity of calibration curve for racemic mixture was 10-100 ng x mL(-1) and the correlation coefficient was 0. 99. When 10 microL was injected, the detection limit of racemic mixture was 8 ng mL(-1), and the detection limits of both enantiomers were 4 ng x mL(-1).

[Effects of p53 inhibitor-alpha on the proliferation and apoptosis in large intestinal epithelial cells damaged by hyperthermic chemotherapy].

OBJECTIVE: To investigate the effects of p-fifty three inhibitor-alpha (PFT-alpha), a p53 inhibitor, on the proliferation and apoptosis of colon epithelial cells damaged by hyperthermic chemotherapy. METHODS: Normal epithelial cells were obtained from the mucosa at least 10 cm away from the cancer tissue in a specimen of large intestine cancer resected during operation and cultured. PFT-alpha at different concentrations was added into the culture fluid to observe its effects on the proliferation of the epithelial cells. Epithelial cell in logarithmic growth phase were inoculated in 6-well plate and divided into 3 groups: normal control (CON) group; hyperthermic chemotherapy (HTC) group, undergoing treatment of cisplatin and bath in water at 43 degrees C; and PFT-alpha + HTC group, undergoing treatment of PFT-alpha at different concentrations, cisplatin, and warm water bath. The cell apoptosis was observed by annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining and flow cytometry (FCT). The cell cycle was observed by PI staining and FCT. Western blotting was used to detect the protein expression of cyclinB1 and Cdc2, and RT-PCR was used to detect the mRNA expression of cyclinB1. RESULTS: PFT-alpha at the concentration > 60 micromol/L significantly inhibited the proliferation of the large intestine epithelial cells. The natural apoptosis rate of the large intestine epithelial cells (CON group) was 2.9% +/- 0.4%, the apoptosis rate was 27.0% +/- 2.1% in the HTC group, and the apoptosis rates of the PFT-alpha + HTC group were 14.8% +/- 1.5%, 9.7% +/- 1.2%, 6.1% +/- 1.3%, and 3.8% +/- 0.3%, on a downward trend, corresponding to the increase of PFT-alpha concentration from 0, 20, 30, to 40 micromol/L (all P < 0.05). The G(0)/G(1) phase rate of epithelial cells was higher and the S phase rate was lower significantly in the PFT-alpha + HTC group. The G(2)/M phase rate was higher since the PFT-alpha concentration reached 10 micromol/L and then increased along with the increase of the PFT-alpha concentration; the S phase rates of the PFT-alpha + HTC group with different PFT-alpha concentrations were all significantly higher than that of the HTC group (all P < 0.01), however, were still lower than that of the CON group (all P < 0.01). The protein expressions of cyclinB1 and Cdc2 in the PFT-alpha + HTC group were both significantly higher than those in the CON and HTC groups (all P < 0.01), without a significant difference between the latter 2 groups. The mRNA expression of cyclinB1 in the PFT-alpha + HTC group increased along with the increase of the PFT-alpha concentration, and there wee significant differences in the mRNA expression of cyclinB1 between the CON and PFT groups and PFT-alpha + HTC group with the PFT-alpha concentration > or = 10 micromol/L (P < 0.05 or P < 0.01). CONCLUSION: PFT-alpha dose-dependently protects the hyperthermic chemotherapy-induced damage to the large intestine epithelial cells via upregulation of protein and mRNA expression of cyclinB1, increasing the phosphorylation level of Cdc2, decreasing the cyclinB1/Cdc2 activity, and increasing the G(2)/M phase rate of the cells.

Effects of cyclodextrins on hydrolysis of malathion.

Cyclodextrins (CDs), with hydrophobic interior cavity and hydrophilic external surface, are capable of accelerating or inhibiting chemical degradation of organophosphorus pesticides through forming inclusion complexes between CDs and pesticides. This work evaluated the effects of CDs on hydrolysis of malathion in an attempt to assess their potential application in environmental approach. beta-CD and its two derivatives, randomly methylated beta-CD (RAMEB) and hydroxypropyl beta-CD (HP-beta-CD), were tested. It was found that RAMEB could inhibit the hydrolysis of malathion, and this was the function of pH and temperature, the inhibitory effects increase with increasing concentration of RAMEB and elevating temperature between 15 and 35 degrees C. On the other hand, beta-CD and HP-beta-CD have little or no stabilizing effects on malathion at all pH and temperature studied, except that the large concentration of beta-CD and HP-beta-CD can mildly reduce hydrolysis of malathion. Both 2 mol/L and 5 mol/L urea increase the inhibitory effects of RAMEB on hydrolysis of malathion at 25 degrees C, pH 9.0.