Stereoselective assembly of C-oligosaccharides via modular difunctionalization of glycals

C-oligosaccharides are found in natural products and drug molecules. Despite the considerable progress made during the last decades, modular and stereoselective synthesis of C-oligosaccharides continues to be challenging and underdeveloped compared to the synthesis technology of O-oligosaccharides. Herein, we design a distinct strategy for the stereoselective and efficient synthesis of C-oligosaccharides via palladium-catalyzed nondirected C1-H glycosylation/C2-alkenylation, cyanation, and alkynylation of 2-iodoglycals with glycosyl chloride donors while realizing the difunctionalization of 2-iodoglycals. The catalysis approach tolerates various functional groups, including derivatives of marketed drugs and natural products. Notably, the obtained C-oligosaccharides can be further transformed into various C-glycosides while fully conserving the stereochemistry. The results of density functional theory (DFT) calculations support oxidative addition mechanism of alkenyl-norbornyl-palladacycle (ANP) intermediate with α-mannofuranose chloride and the high stereoselectivity of glycosylation is due to steric hindrance.

Visible-Light-Mediated Synthesis of C-Alkyl Glycosides via Glycosyl Radical Addition and Aryl Migration

A visible-light-induced glycoarylation of activated olefins has been accomplished. Glycosyl radicals are generated via radical transfer strategies between (TMS)3SiOH and glycosyl bromides. Subsequent radical translocation and rapid 1,4-aryl migration form β-sugar amide derivatives, and eight types of sugars are compatible with this reaction. Further, the cascade reaction produced a quaternary carbon center with good functional group adaptability and high regioselectivity in mild conditions.

Photoredox-Catalyzed N-Directed Regioselective Difluoroalkylation of Unactivated C(sp3)-H Bonds

We report a redox-neutral, visible-light-mediated difluoroalkylation of unactivated C(sp³)-H bonds in amides via nitrogen-centered radicals triggered intramolecular hydrogen atom transfer. Notably, all types (tertiary, secondary, and primary) of γ-C(sp³)-H bonds displayed excellent reactivity. This methodology presents a facile route for the regioselective introduction of α,α-difluoroketone fragments into organic molecules. Moreover, the resulting gem-difluoroketones can be readily converted to structurally diverse difluoro-containing molecules, offering broad potential applications in medicinal chemistry and chemical biology.

Aryl-to-vinyl 1,4-Nickel Migration/Reductive Cross-Coupling Reaction Applied to the Stereoselective Synthesis of Multisubstituted Olefins

The aryl-to-vinyl nickel 1,4-migration (1,4-Ni migration) reaction has been reported for the first time. The generated alkenyl Ni species undergo a reductive coupling reaction with unactivated brominated alkanes affording a series of trisubstituted olefins. This tandem reaction exhibits mild conditions, a broad substrate scope, high regioselectivity, and excellent Z/E stereoselectivity. A series of controlled experiments have shown that the critical 1,4-Ni migration process is reversible. In addition, the alkenyl nickel intermediates obtained after migration are highly Z/E stereoselective and do not undergo Z/E isomerization. The obtained trace isomerization products are caused by the instability of the product.

Enantioselective Synthesis of Both Axially and Planar Chiral Ferrocenes via Axial-to-Planar Diastereoinduction

Ferrocenes with planar chirality have emerged as an important class of scaffolds for ligands in asymmetric catalysis; however, ferrocene molecules with polychiral structures have not been well explored. Herein, both axially and planar chiral ferrocenes were synthesized via palladium/chiral norbornene cooperative catalysis and axial-to-planar diastereoinduction. In this work, chiral norbornene was used to stereoselectively control the aromatic axial chirality, and further selectivity induced C(sp²)-H activation for ferrocene planar chirality. Based on density functional theory calculations, the catalytic model of chiral norbornene with the substrate and the axial-to-planar diastereoinduction process were confirmed.

[Study on the correlation between PPG and HVPG in patients with portal hypertension]

Objective: To explore the correlation between portal vein pressure gradient (PPG) and hepatic vein pressure gradient (HVPG) in patients with portal hypertension (PHT). Methods: 752 cases with portal hypertension (PHT) who underwent transjugular intrahepatic portosystemic shunt (TIPS) and met the enrollment criteria between January 2016 to December 2019 were analyzed for hepatic vein, inferior vena cava and portal vein pressure. Paired t-test was used for analysis. Pearson correlation test was used to estimate correlation coefficient and coefficient of determination. P<0.05 were considered statistically significant. Results: Wedged hepatic vein pressure (WHVP), portal vein pressure (PVP), correlation coefficient, and coefficient of determination were 27.98±8.95 mmHg, 33.85±7.33 mmHg, 0.329 (P<0.001), and 0.108, respectively. HVPG, PPG,correlation coefficient, and coefficient of determination were 16.84±7.97 mmHg, 25.11±6.95 mmHg (P<0.001), 0.145, and 0.021 (P<0.001), respectively. The difference between HVPG and PPG was greater than 5 mmHg in 524 cases, accounting for 69.7%. The difference between HVPG and PPG was within 5 mmHg or basically equal in 228 cases, accounting for 30.3%. The correlation coefficient between free hepatic venous pressure (FHVP) and inferior vena cava pressure (IVCP) was 0.568 (P<0.001), and the coefficient of determination was 0.323. According to the presence or absence of hepatic venous collaterals after balloon occluded hepatic angiography, they were divided into two groups: 157 (20.9%) cases in the group with hepatic venous collaterals, and 595 (79.1%) cases in the group without hepatic venous collaterals. The parameters of the two groups were compared: WHVP (15.73±3.63) mmHg vs. (31.22±6.90) mmHg, P<0.001; PVP (31.69±8.70) mmHg vs. (34.42±6.81) mmHg, P<0.001; HVPG (7.18±4.40) mmHg vs. (19.40±6.62) mmHg, P<0.001; PPG (24.24±8.11) mmHg vs. (25.34±6.60) mmHg, P<0.001; free hepatic venous pressure (FHVP) (8.58±3.37) mmHg vs. (11.82±5.07) mmHg , P<0.001; inferior vena cava pressure (IVCP) (7.45±3.29) mmHg vs. (9.09±4.14) mmHg, P<0.001. Conclusion: The overall correlation is poor between HVPG and PPG. HVPG of most patients is not an accurate representation of PPG, and the former is lower than the latter. Hepatic venous collateral formation is one of the important reasons for the serious underestimation of HVPG values.

Visible-Light-Induced Copper-Catalyzed Asymmetric C(sp3)-C(sp3)-H Glycosylation: Access to C-Glycopeptides

Herein, a practical and highly efficient method for visible-light-induced copper-catalyzed N-aminoquinoline-directed asymmetric C(sp³)-C(sp³)-H glycosylation was reported. At the same time, C(sp³)-C(sp³)-H glycosylation of nondeoxysugars with amino acids to construct C-glycopeptides was achieved. This approach promoted the synthesis of various C-glycopeptides and provided a new model for the synthesis of C-glycoamino acids.

[The role of TNF-α/TNFR1 inhibiting autophagy of M1-type Kupffer cells in liver injury in trichloroethylene-sensitized mice]

Objective: To detect the expression levels of M1-type polarization and autophagy-related indicators in the liver of trichloroethylene (TCE) -sensitized mice, and to explore the role of liver tumor necrosis factor-α (TNF-α) and tumor necrosis factor receptor 1 (TNFR1) in regulating M1-type Kupffer cells autophagy in liver injury in TCE-sensitized mice. Methods: In November 2019, according to simple random grouping, 45 SPF grade BALB/c female mice (6-8 weeks old) were divided into 4 groups: blank control group (n=5) , solvent control group (n=5) , TCE treatment group (n=18) , TCE+R7050 (inhibitor) treatment group (n=17) . Transdermally sensitized mice, 24 h after the last challenge, the mice were divided into TCE sensitized group and TCE non-sensitized group according to the skin reaction score. The livers of mice were harvested, and the pathological changes of the livers were observed under light and electron microscopes. Western blotting was used to detect the expressions of TNF-α, TNFR1 and autophagy-related indexes. The expression of inducible nitric oxide synthase (iNOS) , a marker of M1-type Kupffer cells, was detected by immunohistochemistry, and the occurrence of autophagy in M1-type Kupffer cells was detected by immunofluorescence double-labeling method. Results: The sensitization rate of TCE treatment group was 38.9% (7/18) , and TCE+R7050 treatment group was 35.3% (6/17) , with no significant difference between the two groups (P=1.000) . Compared with the blank control group, mice in the TCE sensitized group had abnormal liver ocytes, obvious liver injury, reduced mitochondria and broken endoplasmic reticulum. Western blotting results showed that the expressions of TNF-α and TNFR1 protein in the liver of the mice in the TCE sensitized group increased, the expression of iNOS protein in M1-type Kupffer cells increased, and the expressions of autophagic microtubule-associated protein 1 light-chain 3 (LC3B) and Beclin1 protein were decreased (P<0.05) . The results of immunohistochemistry showed that iNOS was not significantly expressed in the blank control group and solvent control group, and a small amount of expression was found in the TCE non-sensitized group, the positive staining area was obvious in TCE sensitized group, and the expression of iNOS was significantly increased (P<0.05) . Immunofluorescence results showed that the iNOS protein levels in the blank control group, solvent control group and TCE non-sensitized group were lower, and only partially colocalized with P62; the colocalization of iNOS with P62 in the TCE sensitized group was significantly increased. Conclusion: TNF-α/TNFR1 signaling pathway may promote liver injury in TCE-sensitized mice by inhibiting autophagy of M1-type Kupffer cells.

One-Pot Stereoselective Synthesis of 2,3-Diglycosylindoles and Tryptophan-C-glycosides via Palladium-Catalyzed C-H Glycosylation of Indole and Tryptophan

We described a novel palladium-catalyzed C-H glycosylation of indole or tryptophan for a one-pot stereoselective synthesis of 2,3-diglycosylindoles and tryptophan-C-glycosides. In this strategy, the use of air and base-free and ligand-free conditions provided a highly efficient route to construct C-glycosides. The method can be applied to a wide range of cost-effective and convenient glycosyl chloride donors. Mechanistic studies indicated that the indole 2,3-diglycosylation sequence was C3 and then C2.

Palladium-Catalyzed Rearrangement Reaction to Access 1-Phenanthrol Derivatives

This manuscript describes an unusual Pd-catalyzed rearrangement reaction. It provides efficient access to 1-phenanthrol derivatives using allyloxy-tethered aryl iodides. This rearrangement process involves the cleavage of C-I bond, C-O bond...

Palladium-Catalyzed C-H Amination/[2 + 3] or [2 + 4] Cyclization via C(sp3 or sp2)-H Activation

This report describes a palladium-catalyzed Catellani reaction consisting of amination/[2 + 3] or [2 + 4] cyclization via a carboxylate ligand-exchange strategy. This method effectively activates ortho-substituents that avoid a second C-H palladation. The scope of substrates was broad, o-methyl-substituted iodoarenes were applied to the reaction smoothly, and o-phenyl-substituted iodoarenes can also be obtained by this method. In terms of mechanism, density functional theory calculations proved the sequence of the key five-membered aryl-norbornene-palladacycle intermediate formation and C(sp³ or sp²)-H activation.

Palladium-catalyzed C-H glycosylation and retro Diels-Alder tandem reaction via structurally modified norbornadienes (smNBDs)

This report describes palladium-catalyzed C–H glycosylation and retro Diels–Alder tandem reaction via structurally modified norbornadienes (smNBDs). smNBDs were proposed to regulate the reactivity of the aryl-norbornadiene-palladacycle (ANP), including its high chemoselectivity and regioselectivity, which were the key to constructing C2 and C3 unsubstituted C4-glycosidic indoles. The scope of this substrate is extensive; the halogenated six-membered and five-membered glycosides were applied to the reaction smoothly, and N-alkyl (primary, secondary and tertiary) C4-glycosidic indoles can also be obtained by this method. In terms of mechanism, the key ANP intermediates characterized by X-ray single-crystal diffraction and further controlled experiments proved that the migration-insertion of smNBDs with phenylpalladium intermediate endows them with high chemo- and regioselectivity. Finally, density functional theory (DFT) calculation further verified the rationality of the mechanism.

This report describes palladium-catalyzed C–H glycosylation and retro Diels–Alder tandem reaction via structurally modified norbornadienes (smNBDs).

Highly regioselective and stereoselective synthesis of C-Aryl glycosides via nickel-catalyzed ortho-C-H glycosylation of 8-aminoquinoline benzamides

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C-H activation could be the rate-determining step.

Modular Synthesis of Aryl Thio/Selenoglycosides via the Catellani Strategy

We described a novel palladium-catalyzed domino procedure for the preparation of (hetero)aryl thio/selenoglycosides. Readily available (hetero)aryl iodides and easily accessible 1-thiosugars/1-selenosugars are utilized as the substrates. Meanwhile, 10 types of sugars are quite compatible with this reaction with good regio- and stereoselectivity, high efficiency, and broad applicability (up to 89%, 53 examples). This method enables the straightforward formation of the C(sp²)-S/Se bond of (hetero)aryl thio/selenoglycosides.

Palladium-Catalyzed Chemoselective Oxidative Addition of Allyloxy-Tethered Aryl Iodides: Synthesis of Medium-Sized Rings and Mechanistic Studies

This Letter describes a Pd-catalyzed Tsuji-Trost-type/Heck reaction with allyloxy-tethered aryl iodides and aziridines. The strategy provides efficient access to benzannulated medium-sized rings via intermolecular cyclization. The substrate aryl iodide has two oxidative addition sites, that is, the aromatic C-I bond and the allyl-oxygen bond. The chemoselective oxidative addition of allyl-oxygen bonds is favored, followed by the activation of aromatic C-I bonds. Aziridine plays a key role. Mechanistic studies shed light on the reaction pathway.

Alkylation-Terminated Catellani Reactions by Cyclobutanol C-C Cleavage

This report describes the first application of a cyclobutanol ring-opening procedure in the Catellani termination reaction, which includes two β-carbon elimination processes. This tandem reaction features mild conditions, high yields, good functional group tolerance, and a broad substrate scope. Meanwhile, four types of electrophiles (N-benzoyloxyamines, alkyl iodides, aryl bromides, and benzyl chlorides) are quite compatible with this termination reaction for the construction of various types of polysubstituted aromatic hydrocarbons.

Three-component ruthenium-catalyzed remote C-H functionalization of 8-aminoquinoline amides

Multicomponent reactions can efficiently construct complex molecular structures from simple precursors. Herein, a novel ruthenium-catalyzed three-component highly selective remote C-H functionalization of 8-aminoquinoline amides has been described. The reaction tolerates a wide range of functional groups, producing arylation/difluoroalkylation products of olefins with potential biological activity and pharmaceutical value. Radical scavenging and radical clock experiments show that a free radical process is involved and a H/D exchange experiment suggests that the reaction might involve ortho-C-H activation of the aromatic ring. A possible mechanism is proposed.

Palladium-Catalyzed ortho-C-H Glycosylation/ipso-Alkenylation of Aryl Iodides

This report describes the first example of palladium-catalyzed ortho-C-H glycosylation/ipso-alkenylation of aryl iodides, and the easily accessible glycosyl chlorides are used as a glycosylation reagent. The reaction is compatible with the functional groups of the substrates, and a series of C-aryl glycosides have been synthesized in good to excellent yield and with excellent diastereoselectivity. It is found that a cheap 5-norbornene-2-carbonitrile as a transient mediator can effectively promote this reaction. In addition, ipso-arylation and cyanation were also realized by the strategy.

Visible-Light-Induced Pd-Catalyzed Radical Strategy for Constructing C-Vinyl Glycosides

A novel visible-light-induced palladium-catalyzed Heck reaction for bromine sugars and aryl olefins with high regio- and stereochemistry selectivity for the preparation of C-glycosyl styrene is described. This reaction takes place in one step at room temperature by using a simple and readily available starting material. This protocol can be scaled up to a wide range of glycosyl bromide donors and aryl olefin substrates. Mechanistic studies indicate that a radical addition pathway is involved.

Copper-Catalyzed Three-Component Redox-Neutral Ring Opening of Benzothiazoles to 1-Amino-N-(2-(phenylthio)phenyl)methanimine

Copper-catalyzed three-component redox-neutral ring opening of benzothiazoles with aryl iodides and O-benzoyl hydroxylamines for the synthesis of 1-amino-N-(2-(phenylthio)phenyl)methanimine has been developed. This one-pot reaction undergoes C-S and N-O bond cleavage and new C-S and C-N bond construction. Several control experiments excluded a free radical procedure and also demonstrated the secondary amine as a possible intermediate, which was vital to the catalytic reaction. Meanwhile, the deuteration experiment got rid of the C-H activation dehydroisomerization of the benzothiazole mechanism.

A carboxylate-assisted amination/unactivated C(sp2)–H arylation reaction via a palladium/norbornene cooperative catalysis

A carboxylate-assisted palladium-catalysed Catellani reaction, which is compatible with ortho-amination and unactivated C(sp²)–H arylation, synthesized a series of 1-amino substituted dihydrophenanthridines, phenanthridines and 6H-benzo[c]chromenes.

Rapid colorimetric determination of dopamine based on the inhibition of the peroxidase mimicking activity of platinum loaded CoSn(OH)6 nanocubes

Platinum nanoparticles were loaded on CoSn(OH)6 nanocubes via a co-precipitation method. The material (NCs) is shown to be a viable peroxidase mimic that catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (H₂O₂) to generate oxidized TMB (oxTMB) with absorption at 652 nm. The formation of the blue color can be observed in <30 s. Thus, a visual and colorimetric assay was worked out for H₂O₂. It has a detection limit as low as 4.4 μM and works in the 5 to 200 μM concentration range. The method was also used to detect dopamine (DA) which is found to inhibit the enzyme mimicking activity of the NCs. Hence, less blue color is formed in its presence. The respective DA assay has a linear response in the 5.0 to 60 μM concentration range and a 0.76 μM detection limit. Graphical abstractSchematic diagram of a visual colorimetric method for determination of H₂O₂ and dopamine (DA) with the aid of color change of 3,3',5,5'-tetramethylbenzidine (oxTMB), based on the peroxidase-like activity of Pt/CoSn(OH)₆ nanocubes.

Effects of isomaltooligosaccharide and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status. Multiparous gestating sows (n = 130) with similar body conditions were randomly allocated to five groups (n = 26) receiving a basal diet (CON group) or a basal diet supplemented with 0.5% IMO (IMO group); 0.5% IMO and 0.02% Bacillus subtilis (IMO + S group); 0.5% IMO and 0.02% Bacillus licheniformis (IMO + L group); or 0.5% IMO, 0.02% Bacillus subtilis, and 0.02% Bacillus licheniformis (IMO + S+L group). There were no significant differences in the litter sizes among all dietary groups. The average piglet birth weight was improved in all treatment groups, and the placental efficiency was greater in the IMO + S and IMO + S+L groups than in the CON group (P < 0.05). The IMO + S+L group had increased the low-density lipoprotein cholesterol and reduced the total cholesterol in umbilical venous serum (P <  0.05). Additionally, the malondialdehyde concentrations were greater in umbilical venous serum of piglets in all treatment groups relative to that in the CON piglets (P <  0.05). The placental total antioxidant capacity was increased in the IMO+L and IMO+S+L groups (P <  0.05). Furthermore, the growth hormone concentration in umbilical venous serum was greater (P <  0.05) in all treatment groups. Overall, IMO and Bacillus supplementation during late gestation resulted in a changed metabolism of sows, improved the placental antioxidant capacity, and increased the growth hormone concentrations in umbilical venous serum, which ultimately improved the piglet birth weight and placental efficiency.

[Binding characteristics of chemosynthetic Ac-SDKP analogue FAM-Aca-SDKP to hepatic stellate cell-T6 cells]

OBJECTIVE

To investigate the binding of the chemosynthetic analogue of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) FAM-Aca-SDKP to hepatic stellate cell-T6 (HSC-T6) cells and basic physical characteristics.

METHODS

The Ac-SDKP analogue short-peptide FAM-Aca-SDKP carrying green fluorescence was synthesized chemically. Quantitative real-time PCR was used to evaluate its effect on the secretion of HSC collagen and verify the consistency in the biological effect between FAM-Aca-SDKP and Ac-SDKP. A fluorescence microscope was used to observe the binding between FAM-Aca-SDKP and HSC-T6, and flow cytometry was used to evaluate the time-concentration effect of the binding between FAM-Aca-SDKP and HSC-T6. The t-test or rank sum test was used for the statistical analysis of different types of data.

RESULTS

After HSC-T6 was incubated with Ac-SDKP or FAM-Aca-SDKP for 24 hours, the expression of type I collagen in HSC-T6 was increased, when the action time was 0.5 hour, Ac-SDKP and FAM-Aca-SDKP caused a 30%-50% reduction in the expression of type I collagen. After HSC-T6 was incubated with FAM-Aca-SDKP, strong green fluorescence was observed on cell surface under a fluorescence microscope, and after Ac-SDKP was added, Ac-SDKP significantly reduced the fluorescence intensity on cell surface due to competitive inhibition. Flow cytometry showed that when the concentration of FAM-Aca-SDKP was 0-50μmol/L, the rate of fluorescence-positive cells rapidly increased from 0 to 12%; when the concentration was 50-100μmol/L, the rate of fluorescence-positive cells only increased from 12% to 14%; co-incubation with Ac-SDKP significantly reduced the rate of fluorescence-positive cells. The number of positive cells reached the peak at the 45-minute point of the incubation and then decreased gradually.

CONCLUSIONS

FAM-Aca-SDKP can bind to the surface of HSC-T6 cells, and this process has ligand-receptor binding characteristics such as competitive inhibition, saturability, and time-concentration effect.

Antiestrogenic activity and related disinfection by-product formation induced by bromide during chlorine disinfection of sewage secondary effluent

Chlorine disinfection, widely used in wastewater reclamation, can form toxic and harmful disinfection by-products (DBPs), some of which are associated with endocrine disruption. In this study, the presence of bromide was found to promote an increase in antiestrogenic activity using a yeast two-hybrid assay in the sewage secondary effluent during chlorine disinfection. Among the dissolved organic matters in the secondary effluent, hydrophobic acids and hydrophilic substance fractions were determined as potential precursors associated with increase in antiestrogenic activity in the secondary effluent induced by bromide. Further antiestrogenic activity evaluation and mass spectrum characterization following the semipreparative liquid chromatography fractionation of a natural organic matter precursor, tyrosine, after chlorination under the presence of bromide revealed, for the first time, that 2-(bromo-4-hydroxyphenyl) acetonitrile (Br-HPAN) and 2-(dibromo-4-hydroxyphenyl) acetonitrile (DBr-HPAN) exhibited antiestrogenic activity. Br-HPAN and DBr-HPAN were the DBPs involved in the increase in antiestrogenic activity in the tyrosine solution. Bromide was shown to induce the formation of Br-HPAN and DBr-HPAN in the secondary effluent during chlorine disinfection.

Prevalence of chronic kidney disease and prediabetes and associated risk factors: a community-based screening in Zhuhai, Southern China

BACKGROUND

The prevalence of chronic kidney disease (CKD) and prediabetes has increased in China, and at different rates in different locations. Therefore a community-based screening research was conducted in order to determine the prevalence of CKD and prediabetes, and to analyze associated risk factors of CKD and prediabetes in a city of Southern China.

METHODS

A total of 7801 community residents aged 18 year and older from 6 communities were screened by a stratified random cluster sampling method. An estimated glomerular filtration rate (eGFR), albuminuria, fasting plasma glucose (FPG), and homeostatic model assessment of insulin resistance (HOMA-IR) were measured. Age-standardized prevalence was calculated by the direct method with the use of data on the population distribution in China in 2006. Multivariate logistic analysis was used to analyze the risk factors of CKD and prediabetes, and association of insulin resistance (IR) with CKD and prediabetes was analyzed.

RESULTS

The age-standardized prevalence of CKD was 12.5%, eGFR < 60 ml×min(-1)×1.73 m(-2) was 2.7% and ACR (albumin to creatinine ratio) > 30 mg/g was 10.3%. The age-standardized prevalence of prediabetes was 12.1%. Logistic regression suggests that IR was a common independent risk factor of CKD and prediabetes. Further analysis show that HOMA-IR was increased with the aggravation of kidney injury and FPG.

CONCLUSION

CKD and prediabetes have become a major public health problem in Zhuhai, Southern China; insulin resistance may be an important risk factor.

[Clinical significance of skin prick test for inhalant allergens in 3085 children with allergic diseases]

OBJECTIVE

To investigate the main inhalant allergens and their distribution patterns in children with allergic diseases from Xi'an and the surrounding area and to provide evidence for the prevention and treatment of allergic diseases in children.

METHODS

Skin prick test was performed using liquid with 13 standardized allergens (ALK-ABELL, Denmark) on 3085 children from Xi'an and the surrounding area who were treated for allergic diseases between July 2006 and July 2011, to detect inhalant allergens.

RESULTS

Of the 3085 patients, 1368 (44.34%) had positive SPT results, with the most prevalent inhalant allergen being Dermatophagoides pteronyssinus (804 cases, 26.06%), followed by Dermatophagoides farinae (793 cases, 25.71%), Blomia tropicalis (440 cases, 14.26%), mugwort (282 cases, 9.14%), and cat hair (204 cases, 6.61%). The positive rates were 28.66% in the <4 years group, 41.85% in the 4-6 years group, and 58.61% in the 7-15 years group (P<0.01). Males had a significantly higher SPT positive rate than females (47.78% vs 38.50%；P<0.05). The SPT positive rate was highest in children with allergic rhinitis (72.41%), followed by bronchial asthma (62-25%), allergic dermatosis (45.83%), and allergic purpura (36.28%).

CONCLUSIONS

In children from Xi'an and the surrounding area, the main inhalant allergens for allergic diseases include Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis, mugwort and cat hair. The SPT positive rate increases with age. Male children have a higher SPT positive rate than female children. The SPT positive rate is highest in children with allergic rhinitis.

Removal of genotoxicity in chlorinated secondary effluent of a domestic wastewater treatment plant during dechlorination

PURPOSE

Dechlorination with tetravalent sulfur is widely used in wastewater treatment processes after chlorination. Dechlorination can remove certain genotoxic disinfection by-products (DBPs). However, the reactions occurring during dechlorination of chlorinated secondary effluent and their genotoxic chemicals are still very complex, and the related genotoxicity changes remain unknown. Therefore, the effects of dechlorination on genotoxicity in secondary effluent and its fractions and typical genotoxic chemical after chlorination were evaluated.

METHODS

The dissolved organic matter in the secondary effluent sample was separated into four fractions with XAD-8 resin. Genotoxicity of secondary effluent and its fractions was evaluated by SOS/umu test, an ISO standard method. The concentration of typical genotoxic chemical named ofloxacin was determined by liquid chromatography with a mass spectrometer and a fluorescence detector.

RESULTS

Dechlorination with the addition of Na(2)SO(3) notably decreased the genotoxicity in the chlorinated secondary effluent, especially in the presence of high ammonia nitrogen concentration in the sample before chlorination. The Na(2)SO(3) addition significantly decreased the genotoxicity of the secondary effluent and its genotoxic ofloxacin prior to chlorination. The genotoxicity in the fractions containing hydrophobic acids (HOA) increased after chlorination, while addition of Na(2)SO(3) decreased the genotoxicity induced by chlorination. Tryptophan found in HOA exhibited genotoxicity after chlorination, while dechlorination decreased the genotoxicity in chlorinated tryptophan induced by DBPs.

CONCLUSIONS

Dechlorination was found to decrease the genotoxicity of chlorinated secondary effluent. The decrease was associated with the reduction of genotoxicity in genotoxic chemicals in secondary effluent prior to chlorination and DBPs.

Acetato-chlorido[2,2'-(ethane-1,2-di-yl)di-1H-benzimidazole]-copper(II) monohydrate

In the title complex, [Cu(CH₃COO)Cl(C₁₆H₁₄N₄)]·H₂O, the Cu^II ion is five-coordinated by two N atoms from a 2,2′-(ethane-1,2-di­yl)di-1H-benzimidazole ligand, two O atoms from a chelating acetate ligand and one terminal monodentate Cl atom in a distorted square-pyramidal geometry. In the crystal, adjacent mol­ecules are linked through O—H⋯Cl, N—H⋯Cl, N—H⋯O and O—H⋯O hydrogen bonds into a three-dimensional network.

catena-Poly[[(acetato-κO,O')(methanol-κO)cadmium(II)]-μ-[1,2-bis-(1H-benzimid-azol-2-yl)ethane]-κN:N-[(acetato-κO,O')(methanol-κO)cadmium(II)]-di-μ-chlorido]

In the title complex, [Cd₂(CH₃COO)₂Cl₂(C₁₆H₁₄N₄)(CH₃OH)₂]_n, the Cd^II atom is six-coordinated by one N atom from a centrosymmetric bridging 1,2-bis­(2,2′-1H-benzimidazol-2-yl)ethane (bbe) ligand, two O atoms from a chelating acetate ligand, one O atom from a methanol mol­ecule and two bridging Cl atoms in a distorted octa­hedral geometry. The Cd^II atoms are connected alternately by the Cl atoms and bbe ligands, leading to a chain along [001]. These chains are further linked by O—H⋯O hydrogen bonds. Intra­chain N—H⋯O hydrogen bonds are observed.

Progress in treatment of liver fibrosis by stem cells

Latest studies from home and abroad indicate that stem cells exist in different adult tissues and various stages of individual development. There are stem cells not only derived from liver, but also from other tissues, such as bone marrow and pancreas in liver, which can differentiate into mature hepatocyte-like cells finally. Therefore, stem cell replacement therapy offers a new way for the clinical treatment of hepatic fibrosis in patients with end-stage liver diseases. This paper summarizes the progress in treating liver fibrosis by stem cells in recent years.

Research progress in directional differentiation from bone marrow stem cells into hepatocyte-like cells

Recent researches indicate that bone marrow stem cells not only can differentiate into bone, cartilage, fat, muscle cells and various blood cells, but also can differentiate into cells of trans-germinal layer, such as ectoderm original neuronal cells, endoderm original hepatocytes, insular cells, under suitable microenvironment. It is called "plasticity" or "trans-differentiation". This paper reviews the research advances that bone marrow stem cell differentiation into hepatocyte-like cells and their clinical application in liver disease treatment.

[Therapeutic effect of infrared radiation on skin scald in rats]

OBJECTIVE

To investigate the therapeutic effect of infrared radiation (IR) on the skin scald in rats.

METHODS

Thirty-nine male Wistar rats were used in the study, and they were randomly divided into normal control (C, n = 13), scald (S, n = 13, no treatment after scalding) and treatment (T, n = 13, with IR radiation treatment for 5 days since 2nd post scalding day (PSD) groups. The rats in S and T groups were subjected to deep partial thickness scalding on the back. The cutaneous tissue samples from rat wound in each group were harvested on the 3rd and 7th PSD for pathomorphological examination. DNA synthesis in wound tissue was analyzed by 3H-TdR incorporation method, and the vascular permeability in cutaneous tissue, degree of tissue edema and MDA content were determined by corresponding methods.

RESULTS

Epidermal exfoliation, cutaneous ulcer, follicular atrophy and damage, and massive formation of collagen were identified in the skin wound of rats in S group on the 7th PSD compared with C group. The skin in T group was smooth with slight atrophy and a few collagen fibers in follicles. The 3H-TdR incorporation amount in the rats in T group (1856.33 +/- 343.81 cpm/mg) on the 7th PSD was significantly higher than that in S group (1353.95 +/- 274.48 cpm/mg) (P < 0.01). The tissue permeability, edema degree and MDA content in the cutaneous tissue in S group were obviously higher than those in group C, while these indices were markedly lower in T group when compared with those in S group (P < 0.01-0.001).

CONCLUSION

Treatment with IR seemed to be beneficial to the promotion of skin tissue metabolism and tissue repair.

Effects of monocyte macrophages stimulation on hepatic lipoprotein receptors

The first series of in vivo experiments were designed to investigate the effects of monocytic macrophages (MM phi) stimulation by zymosan in cholesterol-fed rats. We found that the MM phi stimulation significantly decreased plasma very-low-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol but not high-density lipoprotein-cholesterol. The hepatic and aortic cholesterol levels were also significantly decreased; meanwhile, the biliary total bile acid and fecal sterol excretion were significantly enhanced. These results were beneficial to the prevention and regression of atherosclerosis. The second series of in vitro experiments led to the discovery that zymosan did not have effect on HDL and LDL binding, uptake and degradation of hepatic parenchymal and nonparenchymal cells isolated from normal rats, but did have significant effects on those isolated from cholesterol-fed rats. The experiments of Kupffer cells modulating hepatocytes also demonstrated that hepatocyte HDL receptor activity was significantly enhanced by conditioned medium from acetylated LDL plus zymosan added to Kupffer cells. Bmax of 125I-labeled HDL specific binding was increased from 237.8 to 295.2 ng/mg cell protein. The Ka value was not affected, indicating that there might be an increment in receptor number, but not receptor affinity. Cholesterol-loaded zymosan-stimulated Kupffer cells might secrete a soluble mediator affecting hepatocyte HDL receptor activity. Zymosan and other MM phi-stimulating reagents are promising in the exploration of a new approach for prevention and treatment of hypercholesterolemia and atherosclerosis.

[Use of technique of culturing cells in diffusion chamber in host-mediate for testing chromosomal effects of gossypol acetate on human lymphocytes]

Human peripheral blood lymphocytes were cultured in diffusion chamber in mice after short-term administration of gossypol acetate. The induced chromosomal aberrations of human target cells indiffusion chamber were used as indices of DNA damage. The results showed that the mean frequency of chromosomal aberration of the human lymphocytes in Gossypol-treated mice was slightly higher than that in the control group, but the difference between them was not statistically significant (p 0.05).