Effect of estrogen deficiency on the fixation of titanium implants in chronic kidney disease mice

We established a chronic kidney disease (CKD) mouse model with estrogen deficiency and inserted titanium implants into the femur of such mice to investigate the fixation of the implants. Both the histomorphometry and implant resistance indicated that estrogen deficiency impaired the fixation of titanium implants inserted into such mice.

INTRODUCTION

CKD has been regarded as a worldwide public health problem. Estrogen is a critical factor for both renal protection and bone remodeling. A previous study demonstrated that CKD impairs the early healing of titanium implants. However, the combined effect of estrogen deficiency and CKD on the fixation of titanium implants is largely unknown.

METHODS

Forty 9-week-old female C57BL mice were randomly divided into sham, ovariectomy (OVX), CKD, and CKD + OVX groups. Uremia and estrogen deficiency were induced by 5/6 nephrectomy and OVX, respectively. Experimental titanium implants were inserted into the distal end of the femur. Bone-implant contact (BIC) ratio and bone volume (BV/TV) around the implants were histomorphometrically analyzed. The fixation strength of the implant was measured by a biomechanical push-in resistance test.

RESULTS

Serum measurement confirmed a significant increase in serum blood urea nitrogen (BUN) in the CKD group, which was further increased by OVX. Estrogen deficiency led to significant decreases in the BIC ratio, BV/TV, and the push-in resistance in CKD animals. There was a significant interaction between the effects of OVX and CKD, with OVX exacerbating the effects of CKD on BIC ratio and push-in resistance.

CONCLUSIONS

The results indicated that estrogen deficiency exerts a synergistic effect with CKD and further impairs the fixation of titanium implants in CKD mice.

Characterization and polymorphic analysis of 4.5 kb genomic full-length HLA-C in the Chinese Han population

This study used long-range polymerase chain reaction to sequence 4.5 or 4.3 kb of genomic DNA covering human leukocyte antigen C (HLA-C) and its flanks in 45 Chinese Han subjects to better characterize variation in the gene in a single population. Sequences of 35 HLA-C alleles were obtained from the population, including major alleles of 13 lineages of HLA-C. Four novel alleles, C*03:04:01:02, C*04:01:01:03, C*08:22, and C*17:01:01:02, were identified, and complete full-length sequences of 18 HLA-C alleles were obtained for the first time. All sequences herein reported also represent extensions through the promoter region and the 3'-untranslated region. Fourteen 5'-nucleotide sequences and 14 3'-nucleotide sequences were detected outside the coding region. In total, 316 single-nucleotide polymorphisms unequally distributed in HLA-C subregions were observed. In addition to exons 2 and 3, nucleotide variability was found to be particularly high in exon 5, which encodes the transmembrane region. The differentiation of the C*07 and C*17 lineages in this region accounts for the high variability. The congruence of phylogeny across most regions of the gene suggests that gene conversion or recombination has not markedly influenced divergence between lineages in the evolution of HLA-C.

The purification of human urinary kallikrein with ion-exchange radial flow membrane chromatography

A method was developed for the purification of kallikrein from human urine. The procedure consisted of three steps: ultradialysis, diethyl-(2-hydroxypropyl) aminoethyl (QAE) ion exchange radial flow membrane chromatography and affinity chromatography on aprotinin agarose. It is simple and suitable for large-scale purification. The purified product was checked by SDS-PAGE and matrix-assisted laser desorption:ionization mass spectrometery (MALDI). A single band with apparent molecular weight (MW) 42,000 in SDS-PAGE and a single monomer peak with MW33,000 in MALDI were observed, respectively. The biological activity tested by ELISA showed positive immunological identity of the purified product compared with human urinary kallikrein standard.

Indazolo[3,2-b]quinazolinones Attack Hepatocellular Carcinoma Hep3B Cells by Inducing Mitochondrial-Dependent Apoptosis and Inhibition of Nrf2/ARE Signaling Pathway

BACKGROUND AND OBJECTIVE

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Genotoxic stress resistance in patients often contributes to poor clinical outcomes, and is intensively associated to the upregulation of Nrf2/ARE signaling pathway. In this study, we examined the connection between the anticancer activity of two novel indazolo[3,2-b]quinazolinone (IQ) derivatives, IQ-7 and IQ-12, and their effect on the Nrf2/ARE signaling pathway.

METHODS

We initially measured the cytotoxicity of IQ-7 and IQ-12 in Hep3B (human hepatoma cell) and HL-7702 (normal human liver cell) cell lines, then further detected their effects on Nrf2/ARE signaling pathway and apoptosis.

RESULTS

IQ-7 and IQ-12 downregulated the expression levels of Nrf2 and its downstream target genes, such as NQO1, HO-1 and Gclc. In Hep3B cells treated with IQ-7 or IQ-12, the mitochondrial membrane potential decreased dramatically while the expression level of the pro-apoptotic protein VDAC1 and anti-apoptotic protein Bcl-2 significantly increased and decreased, respectively. In addition, IQ-7 (but not IQ-12) also induced the activity of Caspase-3. Interestingly, IQ-7 appeared to selectively inhibit Hep3B cells while having rare adverse effect on HL-7702 cells.

CONCLUSION

The two compounds were shown to induce apoptosis and inhibit the Nrf2/ARE signaling pathway in Hep3B cells, and IQ-7 was suggested a degree of specificity against cancer cells. The design of these compounds may therefore represent a new strategy for designing quinazoline derivatives that could selectively target carcinoma cells.

Synthesis and characteristics of the human serum albumin-triazine chiral stationary phase

Human serum albumin (HSA) was successfully bonded to silica with s-triazine as activator. The coupling reaction by this method was rapid and effective. The triazine-activated silica is relatively stable and can be installed for at least 1 month without obvious loss of reactivity when stored below 30 degrees C, pH below 7. It was observed that the amount of bound HSA reached 120 mg/g silica calculated from the UV absorbance difference of the HSA solution. d, l-tryptophan was selected as the probe solute to characterize the properties of HSA bonded s-triazine chiral stationary phase, and separation factor of 9.4 was obtained for d,l-tryptophan. Furthermore, the amount of effective HSA on silica was measured by high-performance frontal analysis, and only 16.8 mg/g silica was responsible for the resolution of d,l-tryptophan. These results indicate that the amount of both the bound and effective HSA on silica with triazine as activator was much higher than those by the Schiff base coupling method. Different kinds of enantiomers were resolved successfully on the aminopropylsilica-bonded HSA s-triazine chiral stationary phase.

Determination of the hydrophobicity of local anesthetic agents

Hydrophobicity, a term used to describe a fundamental physicochemical property of local anesthetics, was in the past obtained by octanol/buffer partitioning. It has been suggested that the octanol method, despite its obvious advantages, also has some drawbacks. HPLC has become an attractive alternative for the measurement of hydrophobicity and has been applied to local anesthetics recently. However, the methods in current use for measuring the hydrophobicity of local anesthetics suffer from a number of limitations and remain obscure. This study introduces a new HPLC method for measuring the hydrophobicity of eight local anesthetics in current clinical use. Using a C(18) derivatized polystyrene-divinylbenzene stationary phase HPLC column, the log k'(w) values of local anesthetics were determined by measuring the capacity factor k'(i) in the process of chromatographic separation using a hydrophobic stationary phase and a hydrophilic mobile phase. A rapid reversed-phase HPLC method was developed to directly measure log k'(w) of eight local anesthetics. A high correlation between log k'(w) and hydrophobicity (log P(oct)) from the traditional shake-flask method was obtained for the local anesthetics, demonstrating the reliability of the method. The results reveal an improved method for measuring the hydrophobicity of the local anesthetic agents in the unionized form. This simple, sensitive and reproducible approach may serve as a valuable tool for describing the physicochemical properties of novel local anesthetics.

Separation of 4-dimethylamino-6-(4-methoxy-1-naphthyl)-1,3,5-triazine-2-hydrazine derivatives of carbonyl compounds by reversed-phase capillary electrochromatography

4-Dimethylamino-6-(4-methoxy-1-naphthyl)-1,3,5-triazine-2-hydrazine (DMNTH) is a novel derivatizing reagent specially designed for the determination of carbonyl compounds. In this work, we describe the separation of DMNTH-derivatized carbonyl compounds by reversed-phase capillary electrochromatography (CEC). After systematic investigations of the effects of experimental conditions viz. pH and concentration of buffer, type of stationary phase, injection volume of sample, organic modifier, and temperature, optimal conditions were found. The sample compounds, which were separated with gradient high performance liquid chromatography (HPLC), were separated by CEC under isocratic elution due to the high efficiency. Comparisons of separations by CEC and micellar electrokinetic chromatography (MEKC) were made.

No association found between the promoter variants of TNF-alpha and diabetic retinopathy in Chinese patients with type 2 diabetes

PURPOSE

Necrosis tumor factor (TNF) is known to be associated with diabetic retinopathy (DR). The objective of this study was to examine the genetic variations of TNF-alpha and assess their possible relationship to DR in type 2 diabetic patients in the Chinese population.

MATERIALS AND METHODS

We conducted a case-control association study between the promoter variants of TNF-alpha and diabetic retinopathy in Chinese patients with type 2 diabetes. We selected three variants in the promoter region of TNF-alpha, namely rs1800629, rs1041981, and rs2857713.

RESULTS

No individual SNP nor any haplotype was found to be associated with DR in our study.

CONCLUSION

This is the first study to report TNF-alpha polymorphisms in patients with DR in the Chinese population. The results suggest that the variants among the promoter of TNF-alpha are unlikely to play a major role in the susceptibility to DR in Chinese patients with type 2 diabetes.

Coupling of a P2Z-like purinoceptor to a fatty acid-activated K(+) channel in toad gastric smooth muscle cells

1. Extracellular application of ATP generates two whole-cell currents in toad gastric smooth muscle cells: an immediate inward non-selective cation current (due to the activation of a P2X or P2Z-like receptor) and a slowly developing outward K(+) current. The inward non-selective cation current depends on the continuous presence of ATP while the outward K(+) current can last for minutes after ATP application ceases. 2. In cell-attached patches, application of ATP to the extra-patch membrane can activate K(+) channels in the patch indicating that a diffusible cellular messenger may be involved. The characteristics of these K(+) channels are similar to those of a previously described fatty acid-activated K(+) channel that is also a stretch-activated channel. 3. This whole-cell K(+) current can be induced by ATP in the absence of extracellular Ca(2+) (with EGTA present to chelate trace amounts). However, the current generated in the presence of extracellular Ca(2+) is considerably larger. 4. The pharmacological profiles for the activation of the non-selective cation current and the K(+) current are similar, suggesting that the same P2Z-like receptor could be mediating both responses. This type of plasma membrane receptor/channel-channel coupling by a process that does not appear to involve Ca(2+) flow through the receptor/channel or a subsequent membrane potential change may be representative of a new class of signalling mechanisms.

Characterization of HLA-B*5516, -B*1313, -B*9512, and -DRB1*1457 alleles identified in a southwest Chinese population

The human leukocyte antigen (HLA)-B*5516 allele differs from the B*5502 by a single 97 T --> C substitution (His to Tyr at position 33) in exon 2. The B*1313 allele results from 419 T --> A and 420 A --> C substitutions, encoding a Leu to Tyr substitution at 140 in exon 2 of the B*1301 allele. The B*9512 allele differs from B*1502 by a single 360 G --> C substitution (Gln to His at 120) in exon 3. The DRB1*1457 allele appears to be a hybrid molecule generated by recombination between the DRB1*13 and DRB1*14 alleles. The serological equivalents of these new alleles are HLA-B22, -B13, -B15, and DR13, respectively. Family studies detected two rare haplotypes: A*11, B*9512, DRB1*14 and A*24, B*52, Cw*07, DRB1*1457, DRB3*020201, DQB1*050301. The gene frequencies of these alleles in the Chinese population are less than 0.0001.

Human papillomavirus type 16 infection may be involved in esophageal squamous cell carcinoma carcinogenesis in Chinese Kazakh patients

The aim of this study was to investigate human papillomavirus type 16 (HPV16) prevalence in esophageal squamous cell carcinoma (ESCC) in Xinjiang Kazakh patients and its role in ESCC carcinogenesis. One hundred and fifty cases of ESCC and 150 cases of corresponding normal esophageal mucosa (CNGM) samples were collected from north Xinjiang where the Kazakh ethnic group has lived since ancient times. HPV16 infection in ESCC and CNGM was detected by genotype-specific polymerase chain reaction. HPV16 DNA was detected in 55 of 150 ESCC samples (36.7%) and 24 of 150 corresponding normal esophageal mucosa samples (16%) with significant differences (P < 0.001, odds ratio = 3.039, 95% confidence interval: 1.756-5.260). No statistically significant correlations were found between HPV16 infection and the age or gender of patients, tumor site, tumor cell differentiation, or lymph node metastasis (P > 0.05). HPV16 infection is common in cases of ESCC in the Kazakh ethnic group in Xinjiang and may be involved in ESCC carcinogenesis.

Quantum Criticality of the Ising-like Screw Chain Antiferromagnet SrCo_{2}V_{2}O_{8} in a Transverse Magnetic Field

The quantum criticality of an Ising-like screw chain antiferromagnet SrCo_{2}V_{2}O_{8}, with a transverse magnetic field applied along the crystalline a axis, is investigated by ultralow temperature NMR measurements. The Néel temperature is rapidly and continuously suppressed by the field, giving rise to a quantum critical point (QCP) at H_{C_{1}}≈7.03  T. Surprisingly, a second QCP at H_{C_{2}}≈7.7  T featured with gapless excitations is resolved from both the double-peak structure of the field-dependent spin-lattice relaxation rate 1/^{51}T_{1} at low temperatures and the weakly temperature-dependent 1/^{51}T_{1} at this field. Our data, combined with numerical calculations, suggest that the induced effective staggered transverse field significantly lowers the critical fields, and leads to an exposed QCP at H_{C_{2}}, which belongs to the one-dimensional transverse-field Ising universality.

Psychometric assessment and application of the Chinese version of the Compliance with Annual Diabetic Eye Exams Survey in people with diabetic retinopathy

AIM

To translate the Compliance with Annual Diabetic Eye Exams Survey (CADEES) into Chinese, allowing assessment of its reliability and validity, and to identify variables that predict attendance at annual eye examinations.

METHODS

People with vision-threatening diabetic retinopathy were recruited from the Shanghai Diabetic Eye Study. The study involved three phases: (1) translation and cross-cultural adaptation, (2) a pilot study (n = 496) to evaluate the psychometric properties of the Chinese-CADEES, and (3) a primary cross-sectional survey (n = 3818) to assess self-reported attendance at annual eye examinations. Factors related to non-attendance were identified using univariate analysis, and then a multiple logistic regression model. Finally, a component model and individual item models were built to predict attendance.

RESULTS

The Chinese-CADEES had satisfactory reliability and validity. The issue of low attendance at annual eye examinations was serious. In addition to 13 health belief items, living in semi-urban suburban areas, shorter duration of diabetes, poor glucose control, lower education level, better presenting visual acuity and milder diabetic retinopathy diagnosis were significantly related to non-attendance. The multivariate predictive model was able to predict, with 64.7% accuracy, whether or not participants were going to attend annual eye examinations and explained ~ 11.3% of the variance in attendance.

CONCLUSIONS

The Chinese-CADEES showed good reliability and validity for predicting attendance at annual eye examinations in people with diabetic retinopathy. Clinicians and researchers can improve attendance by addressing modifiable characteristics and increasing education on diabetic retinopathy and the importance of eye health in people with diabetes.

MiR-10b regulates the proliferation and apoptosis of pediatric acute myeloid leukemia through targeting HOXD10

OBJECTIVE

To investigate the role of miR-10b in the proliferation and apoptosis of acute myeloid leukemia (AML), and to explore the underlying mechanism.

PATIENTS AND METHODS

The expression level of miR-10b in clinical AML cases and cell lines was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The interaction between miR-10b and homeobox D10 (HOXD10) was confirmed by qRT-PCR, Western blotting and Luciferase assay. The effect of miR-10b on biological functions of AML cell line (HL60) was analyzed in vitro. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and colony formation assay were used to detect the proliferation and colony formation ability of AML cells, respectively. Meanwhile, flow cytometry and TUNEL staining were applied to measure cell cycle and apoptosis of AML cells, respectively.

RESULTS

miR-10b was significantly up-regulated in AML cases and cell lines. The potential target genes of miR-10b were analyzed by three public databases. Results showed that HOXD10 was a direct target of miR-10b. QRT-PCR, Western blotting and luciferase assay confirmed the regulatory effect of miR-10b on HOXD10. Overexpression of miR-10b accelerated the proliferation and colony formation ability of AML cells. Meanwhile, miR-10b overexpression decreased the percentage of AML cells in the G0/G1 phase when compared with S phase, and suppressed the apoptosis of AML cells. However, the addition of HOXD10 could reverse the effects of miR-10b.

CONCLUSIONS

MiR-10b could regulate the proliferation, colony formation, cell cycle and apoptosis of AML cells through targeting HOXD10, indicating that miR-10b might be a potential therapeutic target for the treatment of AML.

High pressure homogenization inactivation of Escherichia coli and Staphylococcus aureus in phosphate buffered saline, milk and apple juice

High pressure homogenization (HPH) offers new opportunities for food pasteurization/sterilization. Escherichia coli and Staphylococcus aureus suspended in phosphate buffered saline (PBS) buffer, milk and apple juice at initial concentration of ~10⁶ log₁₀ CFU per ml were subjected to HPH treatments up to 200 MPa with inlet temperatures at 4-40°C. After HPH at 200 MPa with the inlet temperature at 40°C, the count of E. coli suspended in PBS, milk and apple juice reduced by 3·42, 3·67 and 3·19 log₁₀ CFU per ml respectively while the count of S. aureus decreased by 2·21, 1·02 and 2·33 log₁₀ CFU per ml respectively suggesting that S. aureus was more resistant. The inactivation data were well fitted by the polynomial equation. Milk could provide a protective effect for S. aureus against HPH. After HPH at 200 MPa with the inlet temperature at 20°C, the cell structure of E. coli was destroyed, while no obvious damages were found for S. aureus.

Atmospheric organic nitrogen deposition: analysis of nationwide data and a case study in Northeast China

The origin of atmospheric dissolved organic nitrogen (DON) deposition is not very clear at present. Across China, the DON deposition was substantially larger than that of world and Europe, and we found significant positive correlation between contribution of DON and the deposition flux with pristine site data lying in outlier, possibly reflecting the acute air quality problems in China. For a case study in Northeast China, we revealed the deposited DON was mainly derived from intensive agricultural activities rather than the natural sources by analyzing the compiled dataset across China and correlating DON flux with NH4(+)-N and NO3(-)-N. Crop pollens and combustion of fossil fuels for heating probably contributed to summer and autumn DON flux respectively. Overall, in Northeast China, DON deposition could exert important roles in agro-ecosystem nutrient management and carbon sequestration of natural ecosystems; nationally, it was suggested to found rational network for monitoring DON deposition.

Characterization of a novel variant allele, HLA-C*04:03:02, identified in a Chinese Han individual

HLA-C*04:03:02 differs from the closest allele C*04:03:01 at 218T>C in exon 2 and is synonymous.

Hippophae rhamnoides reverses decreased CYP2D6 expression in rats with BCG-induced liver injury

In this study, we investigated the effect of Hippophae rhamnoides L. (HRP) on the activity of CYP2D6 via the CAMP/PKA/NF-κB pathway in rats with Bacille Calmette-Guerin (BCG)-induced immunological liver injury. BCG (125 mg/kg) was injected to establish the rat model of liver injury. HRP was administered intragastrically for one week as the intervention drug. Proteomics techniques were used to analyze protein expression levels, obtaining a comprehensive understanding of the liver injury process. ELISA or western blotting was used to detect specific protein levels. Dextromethorphan was detected using high-performance liquid chromatography to reflect the metabolic activity of CYP2D6. BCG downregulated the expression of CYP2D6, cAMP, PKA, IκB, and P-CREB and upregulated that of NF-κB, IL-1β, TNF-α, and CREB in the liver; HRP administration reversed these effects. Therefore, HRP may restore the metabolic function of the liver by reversing the downregulation of CYP2D6 through inhibition of NF-κB signal transduction and regulation of the cAMP/PKA/CREB/CYP2D6 pathway. These findings highlight the role of HRP as an alternative clinical drug for treating hepatitis B and other immune-related liver diseases.

A novel HLA allele, HLA-B*37:06:02, identified in a Chinese family

The novel allele HLA-B*37:06:02 differs from HLA-B*37:06:01 by a silent nucleotide substitution at codon 47P.