CatLet score and Clinical CatLet score as predictors of long-term outcomes for patients with acute myocardial infarction undergoing delayed percutaneous coronary intervention

Background

We have recently developed a Coronary Artery Tree description and Lesion EvaluaTion (CatLet) angiographic scoring system based on the 17 myocardial segment model, law of competitive blood supply, and law of flow conservation. This novel angiographic scoring system can be utilized to account for the variable coronary anatomy, the severity and complexity of coronary artery lesions, and to standardize the collection of angiographic data. Our preliminary study demonstrated that the CatLet score better predicted clinical outcomes than the SYNTAX score for patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). The current study aimed at assessing whether the CatLet score (CS) and the Clinical CatLet score (CCS) predicted clinical outcomes for AMI patients undergoing delayed PCI.

Methods

The CS was calculated in 1018 consecutively prospectively enrolled AMI patients. Primary end point was major adverse cardiac events (MACEs), a composite of myocardial infarction, cardiac death, and ischemia-driven revascularization. CCS was calculated multiplying the CS by the ACEF score constructed using age, creatinine, and LVEF. Tertile partitioning of CS and CCS were as follows: CSlow ≤12, CSmid 13–18, and CStop ≥19; CCSlow ≤13, CCSmid 14–24, and CCStop ≥25, respectively. Cox regression analysis was employed to identify the associations between predictors and clinical outcomes.

Results

Four-year MACE rates were significantly higher with CStop compared with CSlow [4.82 (3.39–6.85), P<0.001], which was also the case for all-cause death, cardiac death, myocardial infarction, and ischemia-driven revascularization; for all these endpoints, there were a significant trend (P<0.001) for higher event rates with the increasing CS tertiles as shown in Figure 1. Stratifying outcomes across CCS tertiles resulted in similar results for the comparisons between CCStop and CCSlow. For MACEs, CCS had a significantly increased C-index [(C-index (95% CI), 0.725 (0.692–0.759) vs. 0.693 (0.659–0.727), P=0.001] compared with CS, which was also the case for all-cause death, cardiac death, and myocardial infarction. However, for ischemia-driven revascularization, CCS had a slightly decreased C-index [0.655 (0.609–0.701) vs. 0.670 (0.625–0.716), P=0.235] compared with CS, without a significant difference. In terms of calibration, CCS was comparable to CS for MACEs, all-cause death, cardiac death, and myocardial infarction. However, calibration for ischemia-driven revascularization worsened for CCS compared with CS (χ2=22.07, P=0.004 vs. χ2=7.79, P=0.454). Both scores remained to be independent predictors of clinical outcomes (in separate models) after adjustment for a broad spectrum of risk factors.

Conclusions

CS and to a greater extent CCS were able to risk-stratify long-term outcomes in AMI patients undergoing delayed PCI.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): 2020YFC2004705 & SYS2019040 Figure 1. Kaplan-Meier curves for endpoints

[Genomic characterization of food-borne Listeria monocytogenes isolates from Nanshan district of Shenzhen during 2009-2019]

Objective: The study aims to investigate the characteristic baseline information about genetic lineages, drug-resistance genes, virulence genes and evolutionary relationships of food-borne Listeria monocytogenes (Lm) isolates from Nanshan district of Shenzhen. Methods: The whole genomes of 46 Lm isolates during 2009-2019 were extracted and sequenced (Illumina PE-150, 100×). The CLC Genomics Workbench 12.0 was used to assemble and align Lm genomes, analyze their housekeeping genes, drug-resistance genes and virulence genes, and construct a k-mer phylogenetic tree. Results: After assembly, all genomes satisfied analytical conditions (contigs N50>20 kb). The medians of GC content, gene count and gene size were 38.3%, 5 960 and 2 952 608 bp, respectively. Based on the Lm genomic reference database, the local k-mer phylogenetic tree had 14 clusters of which the genetic distance was wide. The 46 Lm isolates were classified as Lineage 1 (21), Lineage 2 (23) and Lineage 3 (2). The most common ST type of Lineage 1 was ST87, followed by ST3, ST59, ST224 and ST429, whereas the major ST types of Lineage 2 included ST8 and ST9, the rest being ST121, ST155, ST199, ST204 and ST321. However, Lineage 3 only had ST299. The part of Lm strains carried five drug-resistance genes, such as fosX (17), tetM (6), dfrG (4), catB3 (1) and mefA (1). Furthermore, all strains possessed nine virulence genes, including flaA, iap, actA, hly, mpl, prfA, plcA, plcB and inlB. Nevertheless, six isolates and three of them respectively carried the mutant inlA and inlJ, and other two isolates lacked inlC. Conclusion: The food-borne Lm isolates from Nanshan district of Shenzhen presented genetic and evolutionary diversity. Noted that the drug-resistant strains, which also owned abundant virulence genes with specific functions, could lead to serious infections, particularly those isolates from raw poultry and Flammulina velutipes. It was implied that the local region was at risk due to Listeriosis by food. This study offered reference for prevention, control and treatment of Lm infection to the Greater Bay Area.

Efficacy and Mechanism of a Chinese Classic Prescription of Yueju in Treating Nonalcoholic Steatohepatitis and Protecting Hepatocytes from Apoptosis

Yueju, a famous classic Chinese prescription, has been extensively used in treating depression syndromes for hundreds of years. Recent studies have reported that Yueju showed good effects in treating metabolic diseases, such as obesity and hyperlipidemia. Nonalcoholic steatohepatitis (NASH), which leads to cirrhosis and severe cardiovascular diseases, is closely linked to obesity and abnormal lipid metabolism. In this study, Yueju could decrease the levels of alanine aminotransferase, aspartate transaminase, triglyceride, cholesterol, and low-density lipoprotein-C but increase the high-density lipoprotein-C in the serum of the NASH rat model induced by high-fat and high-cholesterol diet. Yueju could alleviate hepatosteatosis by increasing the phosphorylation of acetyl-CoA carboxylase and inhibiting the expression of fatty acid synthase and stearoyl-CoA desaturase 1. Yueju downregulated the expression of α-smooth muscle actin and collagen type 1A1, ameliorating the liver fibrilization. Yueju could also protect the hepatocytes from apoptosis by upregulating antiapoptosis protein Bcl-2 and X-linked inhibitor of apoptosis protein and downregulating apoptotic proteins Bax and cleaved poly ADP-ribose polymerase. Thus, Yueju could improve liver function, regulate lipid metabolism, alleviate hepatosteatosis and fibrosis, and protect hepatocytes from apoptosis against NASH. Yueju may be used as an alternative effective medicine for NASH treatment.

[A preliminary study on the registration of MRI and cone beam CT images of temporomandibular joint disc]

Objective: To evaluate the MRI and cone beam CT (CBCT) image registration methods of the temporomandibular joint (TMJ), and to explore the clinical application of the registered images and clinical diagnostic data for examining the relationship between the articular disc and condyle. Methods: Three patients with TMJ disc disposition were recruited at the Department of Oral and Maxillofacial Surgery, School of Stomatology, Wuhan University from January to March 2018. One patient was male, aged 30, and the others were females, aged 21 and 26 respectively. Three-dimensional (3D) images of CBCT and MRI of the TMJ were reconstructed and registered by using Mimics software. The images were then evaluated after the registration. The evaluation indicators selected were the area and volume of the articular disc, the position of the articular disc or the distance between the highest point of the condyle (point C) to the center point of the articular disc (point D), the distance between the last point of the joint disc (point P) to point C, as well as the angle between line CD and FH plane (∠DCF) at either opened- or closed-mouth condition. Results: The registration images of TMJ, at the closed- and opened-mouth positions of the 3 patients, showed the anatomical structures and interrelationships of the articular disc, articular nodules, joint fossa and condyle. Combined with clinical diagnosis, the difference of CD distances at the normal articular disc position was the minimum (1.94 mm), the difference of CD distances was small at the anterior disc displacement with non-reduction and larger with reduction. When the joint disc was in the opened-mouth position, ∠DCF angle was minimal (3.81°). The patients with anterior disc displacement with non-reduction showed the largest ∠DCF angle (48.03°). Conclusions: The position of the articular disc relative to the condyle and articular nodules, either at closed- or opened-mouth conditionds, could be accurately displayed after the image registration and fusion. The registration image not only could fully show the shape and position of the articular disc in different status from a 3D perspective, but also might provide basis for clinical study of TMJ disc displacement.

Photocatalytic membrane combined with biodegradation for toluene oxidation

Photocatalytic membrane coupled to biodegradation offers potential for degrading volatile organic compounds (VOCs) in photocatalytic membrane biofilm reactor. An intimately coupled photocatalysis and biodegradation reactor was operated in continuous operation for 500 days to treat simulated waste gas containing toluene. Toluene removal efficiency obtained 99%, with the elimination capacity of 550 g m^-3·h^-1. Membrane photocatalysis coupled to biodegradation was created to improve toluene removal from 11 to 20%. The dominant genera were Lysinibacillus, Hydrogenophaga, Pseudomonas at 30 d, Rudaea, Dongia, Litorilinea at 230 d xyl, Tod, Tcb, Bed, Tmo, Tbu, Tou, Dmp, Cat were functional genes of toluene metabolism, as shown by16S rDNA and metagenomic sequencing. Photocatalysis destroyed part of the toluene into biodegradable intermediates that were immediately mineralized by microorganisms in biofilm, some toluene was directly degraded by toluene degrading bacterial community into carbon dioxide and water. The novel hybrid photocatalytic membrane biofilm reactor is a cost-effective and robust alternative to VOCs treatment.

Inhibitory Mechanism of Epigallocatechin Gallate on Fibrillation and Aggregation of Amidated Human Islet Amyloid Polypeptide

The abnormal fibrillation of human islet amyloid polypeptide (hIAPP) is associated with development of type II diabetes mellitus (T2DM). (-)-Epigallocatechin gallate (EGCG) can bind amyloid proteins to inhibit the fibrillation of these proteins. However, the mechanic detail of EGCG inhibiting amyloid formation is still unclear at the molecular level. In the present work, we sought to investigate the effect of EGCG on amidated hIAPP (hIAPP-NH₂ ) fibrillation and aggregation by using spectroscopic and microscopic techniques, and also sought to gain insights into the interaction of EGCG and hIAPP_22-27 by using spectroscopic experiments and quantum chemical calculations. ThT fluorescence, real-time NMR, and TEM studies demonstrated that EGCG inhibits the formation of hIAPP-NH₂ fibrils, while promoting the formation of hIAPP-NH₂ amorphous aggregates. Phenylalanine intrinsic fluorescence and NMR studies of the EGCG/hIAPP_22-27 complex revealed three important binding sites including the A ring of EGCG, residue Phe23, and residue Ile26. DFT calculations identified the dominant binding structures of EGCG/Phe23 and EGCG/Ile26 complexes, named structure I and structure II, respectively. Our study demonstrates the inhibitory mechanism of EGCG on fibrillation and aggregation of hIAPP-NH₂ in which EGCG interacts with hIAPP-NH₂ through hydrogen bonding and π-π interactions between the A ring and residue Phe23 as well as hydrophobic interactions between the A ring and residue Ile26, which can thus inhibit the interpeptide interaction between hIAPP-NH₂ monomers and finally inhibit fibrillation of hIAPP-NH₂ . This study agrees with and reinforces previous studies and offers an intuitive explanation at both the atomic and molecular levels. Our findings may provide an invaluable reference for the future development of new drugs in the management of diabetes.

[Treating Type 2 Diabetes Mellitus Patients Complicated with Metabolic Syndrome by Benefiting Qi Dissolving Method]

Objective To observe clinical efficacy of Yiqi Huaju Recipe (YHR) combined routine Western medical treatment on type 2 diabetes mellitus (T2DM) patients complicated metabolic syndrome (MetS). Methods Totally 96 T2DM patients complicated MetS were assigned to the treatment group (YHR +routine Western drugs) and the control group (placebo +routine Western drugs) according to random digit table, 48 cases in each group. The therapeutic course for all was 12 weeks. Body mass index (BMI) , waistline, waist-hip ratio (WHR) , fasting plasma glucose (FPG) , 2 h postprandial plasma glucose (2 h PPG) , glycosylated hemoglobin A1c (HbAlc) , homeostasis model assessment of insulin resistance (HOMA-IR) , blood lipids, blood pressure, disease transformation of MetS, changes of con- stituent numbers were detected before and after treatment. Results BMI, WHR, waistline obviously decreased in the treatment group after treatment, with statistical difference as compared with the control group (P<0.01 , P <0.05). Post-treatment FPG, 2 h PPG, HbAlc, HOMA-IR, systolic blood pressure (SBP), diastolic blood pressure (DBP) , and mean artery pressure (MAP) obviously decreased in the two groups, but more obviously in the treatment group (P <0. 05). Post-treatment total cholesterol (TC) , low density lipoprotein cholesterol (LDL-C) , and triglycerides (TG) all obviously decreased in the two groups , but TG decreased more obviously in the treatment group (P <0. 05). High density lipoprotein cholesterol (HDL-C) obviously increased in the treatment group (P <0. 05). Patient numbers of central obesity, uncontrolled hypertension, and uncontrolled diabetes obviously decreased and constituent numbers were obviously reduced in the treatment group after treatment, with better efficacy than those of the control group (P <0. 01 , P <0. 05). Conclusions YHR plus routine Western drugs could further reduce blood glucose, and had comprehensive interventional effects on multiple cardiovascular risk factors such as central obesity, blood lipids, and blood pressure in T2DM patients complicated with MetS. Its mechanism might be possibly correlated with improving insulin resistance and elevating insulin sensitivity of peripheral tissues.

Investigating the recheck rules for urine analysis in children

The aim of this study was to establish recheck rules of urinalysis in children by investigating the concordance rate of the results obtained using the LabUMat urine dry chemistry analyzer (referred to as dry chemistry) and the UriSed tangible composition analyzer with that of the microscopic examination. First, 1040 urine samples from children (mean age 6.5 years) were analyzed using LabUMat and UriSed analyzers, and subsequently subjected to microscopic examination. The missed detection rate was evaluated and recheck rules were established to avoid missed diagnoses of abnormal renal function. Finally, clinical validations of the recheck rules were performed on 200 additional specimens. Among the samples used to investigate the recheck rules, the samples with positive microscopic examination results accounted for 58.65% of the total, while the samples with negative results accounted for 41.35%. Of the positive samples, a major portion (>50%) were RBC positive. The samples that were WBC positive and CAST positive accounted for 23.08 and 7.69%, respectively. The concordance rate was 87.5% and the missed detection rate was 2.9%. For the validation of the recheck rules in 200 urine samples, the concordance rate was 87.5% and the missed detection rate was 2.4%. When the detection of occult blood, WBC, and protein by dry chemistry, and the detection of RBC, WBC, and CAST by the UriSed analyzer are inconsistent, or the differences between them greater than 2 levels, recheck by microscopic examination is suggested.

Influence of trehalose on human islet amyloid polypeptide fibrillation and aggregation

A lower dose of trehalose inhibits or delays, while higher dose of trehalose promotes the hIAPP fibrillation and aggregation.

Influence of Aluminium and EGCG on Fibrillation and Aggregation of Human Islet Amyloid Polypeptide

The abnormal fibrillation of human islet amyloid polypeptide (hIAPP) has been implicated in the development of type II diabetes. Aluminum is known to trigger the structural transformation of many amyloid proteins and induce the formation of toxic aggregate species. The (-)-epigallocatechin gallate (EGCG) is considered capable of binding both metal ions and amyloid proteins with inhibitory effect on the fibrillation of amyloid proteins. However, the effect of Al(III)/EGCG complex on hIAPP fibrillation is unclear. In the present work, we sought to view insight into the structures and properties of Al(III) and EGCG complex by using spectroscopic experiments and quantum chemical calculations and also investigated the influence of Al(III) and EGCG on hIAPP fibrillation and aggregation as well as their combined interference on this process. Our studies demonstrated that Al(III) could promote fibrillation and aggregation of hIAPP, while EGCG could inhibit the fibrillation of hIAPP and lead to the formation of hIAPP amorphous aggregates instead of the ordered fibrils. Furthermore, we proved that the Al(III)/EGCG complex in molar ratio of 1 : 1 as Al(EGCG)(H₂O)₂ could inhibit the hIAPP fibrillation more effectively than EGCG alone. The results provide the invaluable reference for the new drug development to treat type II diabetes.

Yiqi Huaju formula, a Chinese herbal medicine, reduces arterial pressure in salt‑sensitive hypertension by inhibiting renin‑angiotensin system activation

Hypertension is a chronic disease with a high prevalence, and is associated with a high risk of vascular disease and premature death. Traditional Chinese medicine has been administered to treat hypertension for many years. In the present study, the effects of Yiqi Huaju formula (YQ; a compound used in traditional Chinese herbal medicine) were observed in salt‑sensitive hypertension, which was induced by a high‑salt and high‑fat (HSF) diet and the potential mechanism was investigated. YQ was prepared from five plant extracts and was dissolved in normal sodium chloride prior to use. Male Sprague‑Dawley rats were randomly divided into three groups, and fed either a normal diet (control), an HSF diet or an HSF diet with YQ. At week eight, blood pressure was measured and 24‑h urine samples were collected from all of the rats. The rats were subsequently sacrificed, and their blood was collected for biochemical analyses and kidney tissue samples were dissected for the immunohistochemical assay. YQ was observed to decrease the high arterial pressure and serum total cholesterol level, which had been induced by the HSF diet. It also enhanced the excretion of urinary angiotensinogen, Na+, and decreased the loss of urinary aldosterone, K+ and microalbuminuria. In addition, YQ inhibited the high mRNA expression level of renal renin, angiotensin II (Ang II), and Ang II receptor, type 1 (AT1R), and inhibited the protein expression of renal AT1R and Ang II receptor type 2, which had been induced by the HSF diet. These results indicate that YQ may reduce the arterial pressure in salt‑sensitive hypertension via the inhibition of renin‑angiotensin system activation.

Marrow adiposity recovery after early zoledronic acid treatment of glucocorticoid-induced bone loss in rabbits assessed by magnetic resonance spectroscopy

BACKGROUND

Although there is an inverse relationship between bone mass and marrow adiposity, the reversal function of zoledronic acid (ZOL) on increased marrow fat has not been studied. The aim of our study is to use the 3T magnetic resonance spectroscopy (MRS) to characterize the dynamical change process of the marrow fat responding to early ZOL treatment in the rabbit model with glucocorticoid-induced bone loss.

METHODS

Fifteen 20-week-old female New Zealand White rabbits were randomized to control group, methylprednisolone (MPS) group, and MPS+ZOL group equally. Bone mineral density (BMD) and marrow fat fraction (FF) at L3-L4 vertebrae and left proximal femur were measured by Dual-energy X-ray absorptiometry and MRS at week 0, 4, 8, and 12. The animals were euthanized at the end of our experiment and their left femurs were dissected out for the histopathological examination.

RESULTS

The MPS group demonstrated a remarkable increase in FF but a reduction in BMD compared with the controls at week 4 and 8, respectively (P<0.05 for all). Early treatment of ZOL can inhibit bone degeneration, although the bone mass would not recover to its original level. FF in MPS group exhibited a dramatic increase over time, with an increased FF variation (+31.6%, P=0.009) at week 4 from baseline and it was maintained until week 12 (+75.2%, P<0.001). In MPS+ZOL group, the FF returned to baseline value after the ZOL treatment. Comparing with the controls, larger marrow adipocyte density, the mean of the adipocyte diameter, and the percentage area of the adipocyte were observed in the MPS group (P<0.05 for all), whereas there were no significant differences in quantitative parameters of marrow adipocytes between the ZOL-treated group and the normal rabbits.

CONCLUSION

An increase of the marrow adiposity is synchronized with the deterioration of the MPS-induced bone mass. A single dose of early ZOL can reverse the marrow adiposity to its original level completely.

Exogenous abscisic acid increases antioxidant enzymes and related gene expression in pepper (Capsicum annuum) leaves subjected to chilling stress

To elucidate how physiological and biochemical mechanisms of chilling stress are regulated by abscisic acid (ABA) pretreatment, pepper variety (cv. 'P70') seedlings were pretreated with 0.57 mM ABA for 72 h and then subjected to chilling stress at 10°/6°C (day/night). Chilling stress caused severe necrotic lesions on the leaves and increased malondialdehyde and H(2)O(2) levels. Activities of monodehydroascorbate reductase (DHAR), dehydroascorbate reductase, glutathione reductase, guaiacol peroxidase, ascorbate peroxidase, ascorbate, and glutathione increased due to chilling stress during the 72 h, while superoxide dismutase and catalase activities decreased during 24 h, suggesting that chilling stress activates the AsA-GSH cycle under catalase deactivation in pepper leaves. ABA pretreatment induced significant increases in the above-mentioned enzyme activities and progressive decreases in ascorbate and glutathione levels. On the other hand, ABA-pretreated seedlings under chilling stress increased superoxide dismutase and guaiacol peroxidase activities and lowered concentrations of other antioxidants compared with untreated chilling-stressed plants. These seedlings showed concomitant decreases in foliage damage symptoms, and levels of malondialdehyde and H(2)O(2). Induction of Mn-SOD and POD was observed in chilling-stressed plants treated with ABA. The expression of DHAR1 and DHAR2 was altered by chilling stress, but it was higher in the presence than in the absence of ABA at 24 h. Overall, the results indicate that exogenous application of ABA increases tolerance of plants to chilling-induced oxidative damage, mainly by enhancing superoxide dismutase and guaiacol peroxidase activities and related gene expression.

Left ventricular posterior wall thickness is an independent risk factor for paroxysmal atrial fibrillation

BACKGROUND

Atrial fibrillation is the most common significant cardiac arrhythmia in clinical practice, but its risk factors remain to be clarified. We have hypothesized that left ventricular posterior wall thickness is an independent risk factor for paroxysmal atrial fibrillation (PAF).

METHODS

A total of 166 consecutive patients with paroxysmal atrial fibrillation were included in this study. Another 166 healthy check-up people, strictly age and sex-matched, were enrolled as controls in the same period. Univariable analysis and multivariable conditional logistic stepwise regression analysis were conducted. Receiver operating characteristic (ROC) curve analysis was performed on those significant indices obtained from the multivariable logistic regression analysis.

RESULTS

The multivariable stepwise analysis identified left ventricular posterior wall thickness, left atrial diameter tricuspid insufficiency and residence (countryside) as independent predictors for paroxysmal atrial fibrillation. Receiver operating characteristic curve analysis demonstrated the cutoff values of those risk factors aforementioned.

CONCLUSIONS

In this strictly age and sex-matched population-based sample, left ventricular posterior wall thickness, left atrial diameter, tricuspid insufficiency and residence were predictive risks for paroxysmal atrial fibrillation. This study offers novel information therapeutically beyond that provided by traditional clinical atrial fibrillation risk factors.

[Molecular basis of a new O61 allele in ABO blood group]

Objective of this study was to explore the molecular basis of a new O61 allele in ABO blood group. The ABO group antigens on red cells of the blood samples were identified by monoclonal antibodies and the ABO antibody in serum was detected by the standard A, B, O red cells. The coding region sequences of exon 5 to exon 7 in ABO gene were amplified by polymerase chain reaction (PCR) and the amplification products were purified with double enzyme digestion and directly sequenced for exon 6 and 7. The diploid of the individual with B phenotype was separated into its haploid components with a haplotype specific extraction method. The exons 6 to 7 of the two single ABO haplotypes were then amplified and sequenced separately. The results indicated that 3 samples had mutation at 743 site in total 417 individuals, in which 2 individuals were with O phenotype and 1 individual was with B phenotype. The DNA sequencing of exon 6 and 7 in 2 samples with O phenotype showed 261G deletion and 743G/C heterozygotes. The DNA sequencing of exon 6 and 7 in the sample with B phenotype showed 261G/deletion and 297A/G, 526C/G, 743G/C, 657C/T, 703G/A, 796C/A, 803G/C, 930G/A heterozygotes. After separating of the 2 single strands in the B sample with haplotype specific extraction, an O and B101 allele were identified after sequencing. The novel allele was submitted to the Blood Group Antigen Gene Mutation database and is named as O61. It is concluded that 743G>C is a novel mutation in exon 7 of ABO and a novel O61 allele with 743G>C has been identified.

[Cloning and expression of MHC class I chain-related gene A in E. coli]

In order to construct prokaryotic expression system of MHC classI chain-related gene A (mica) and purify MICA protein, RNAs were extracted from the peripheral blood samples and mica cDNA fragments were obtained by RT-PCR method. The cDNA for mica was ligated with cloning vector by TOPO method. The recombinant cloning vector and prokaryotic expression vector pET-28a were digested by two restriction enzymes and ligated to construct pET-28a-MICA recombinant expression vector, then the pET-28a-MICA vector was transformed and expressed in E. coli BL21 DE3. The recombinant protein was purified by Ni-NTA Spin method. The results showed that the recombinant MICA protein expressed with soluble form in host with pET-28a-MICA vector after IPTG induction. The recombinant target protein was obtained by Ni-NTA spin purification. In conclusion, this study has constructed prokaryotic expression system of mica gene and has purified MICA protein which would help to explore the interaction between MICA and transplantation immunology.

[Pollen Typhae total flavones inhibit expression of interleukin-6 in C2C12 skeletal muscle cells cultured with palmitate]

OBJECTIVE

To observe the effects of Pollen Typhae total flavones (PTF) on expression of interleukin-6 (IL-6) mRNA and protein secretion in C2C12 cell strain of skeletal muscle cells cultured with palmitate, and to explore the mechanism of PTF in relieving insulin resistance (IR).

METHODS

The IR of C2C12 cells was induced by co-culturing with palmitate. The C2C12 cells were divided into normal control group, untreated group, PDTC (a nuclear factor-kappaB inhibitor) treated group, rosiglitazone (ROS)-treated group, ROS+ PDTC-treated group, PTF-treated group and PTF+PDTC-treated group. Sixteen hours after culture, the transportation rate of glucose was observed by (3)H-deoxyglucose uptake method; IL-6 mRNA expression in C2C12 cells was assayed by real time polymerase chain reaction (Real-time PCR), and level of IL-6 protein secretion in culture supernatant was detected by enzyme linked immunosorbent assay.

RESULTS

Compared with the normal control group, the transportation rate of glucose of cells in untreated group was decreased 30.43% after 16-hour palmitate culture, and was increased 32.39% in the PTF-treated group. Compared with the untreated group, the levels of IL-6 mRNA expression in cells and IL-6 protein secretion in supernatant were significantly decreased in the PTF-treated group (P<0.05). The levels of IL-6 mRNA expression in cells and IL-6 protein secretion in supernatant were increased in PTF+PDTC-treated group as compared with PFT-treated group (P<0.05).

CONCLUSION

PTF can inhibit the IL-6 mRNA expression and IL-6 protein secretion via nuclear factor-kappaB pathway in C2C12 skeletal muscle cells, which may be one of its mechanisms in relieving inflammation conditions and insulin resistance in C2C12 skeletal muscle cells.

[Effects of berberine on cell proliferation, peroxisome proliferation activated receptor gamma, CAAT/enhancer binding protein mRNA and protein expression in 3T3-L1 pre-adipocytes]

OBJECTIVE

To study the effect and mechanism of berberine (BER) on the proliferation and differentiation of adipocytes.

METHODS

The proliferation of 3T3-L1 pre-adipocytes was detected by XTT method. Lipid droplets accumulated in the cytoplasm of adipocytes in the differentiating process were observed by oil red O staining and quantified by colorimetry. The expressions of peroxisome proliferation activated receptor gamma (PPARgamma), CAAT/enhancer binding protein alpha (C/EBPalpha) mRNA and protein were detected by Real-time PCR and Western blotting respectively.

RESULTS

Intervention with BER in concentration below 10 micromol/L for 24 h showed insignificant effect on the proliferation of adipocytes, as compared with that in the control group (P > 0.05); but that in concentrations 20, 40 and 80 micromol/L revealed significant suppressive effect; that in different concentrations acting for 48 h and 72 h could affect the proliferation and the effect displayed a dose-dependent manner, i. e. the higher the concentration of BER, the more apparent the suppression, showing significant difference as compared with those in the control group (P <0.05 or P <0.01). The pre-adipocyte treated with 10 micromol/L BER showed that the lipid droplets in the cytoplasm significantly lessened, so did the expression of differentiation related factor PPAR gamma mRNA as well as the expressions of C/EBPalpha mRNA and protein, as compared with those in the blank control group and the group intervened with rosiglitazone, the difference was significant (P < 0.05 or P < 0.01).

CONCLUSIONS

BER can suppress the proliferation and differentiation of 3T3-L1 pre-adipocytes, reduce the accumulation of lipid drops in the adipocyte differentiating process, which may be associated with its effects in decreasing the expressions of adipocyte differentiation related gene PPARgamma, C/EBPalpha mRNA and protein. The study provides a basis for applying BER on the prevention and treatment of such metabolic related diseases as obesity.

[Effects of Pollen Typhae total flavone on glucose and lipid metabolism in 3T3-L1 adipocytes]

OBJECTIVE

To observe the effects of Pollen Typhae total flavone (PTF) on glucose and lipid metabolism in 3T3-L1 adipocytes.

METHODS

The content of glucose which disappeared from the culture medium after incubation with drugs for 24 hours was determined as glucose consumption of the cells. The activity of cells was detected by XTT method. The transport of glucose was observed by (3)H-glucose uptake method. The efflux of free fatty acid (FFA) from adipocytes was observed by the concentration of FFA in the culture medium.

RESULTS

The glucose concentration in culture medium was significantly decreased with a concentration-dependent effect, when PTF concentrations were from 0.025 g/L to 0.4 g/L. The toxic effect on cells appeared while PTF concentration was 0.4 g/L, and the MTT value decreased. PTF also significantly increased glucose transportation in the 3T3-L1 adipocytes as rosiglitazone (ROS) did. At the same time, FFA concentration in culture medium was significantly decreased as compared to the normal control group, while ROS-treated group did not show any difference.

CONCLUSION

PTF can increase insulin sensitivity by increasing glucose transportation and consumption in the 3T3-L1 adipocytes as well as decreasing the FFA efflux from the cells.

Carrot Antifreeze Protein Does Not Exhibit the Polygalacturonase-inhibiting Activity of PGIP Family

The carrot (Daucus carota) antifreeze protein (DcAFP) has a strong antifreeze activity and identified as belonging to the plant polygalacturonase-inhibiting protein (PGIP) family based on its sequence similarities, including the presence of a leucine-rich repeat (LRR) motif. In this study, yeast two-hybrid technology was used to analyze whether the carrot AFP could act as a PGIP. The complete DcAFP and polygalacturonase (PGase; obtained from fungus Alternaria alternata by RT-PCR) coding sequences were cloned into the bait and capture vectors, respectively, and yeast two-hybrid assays were performed. The results revealed that there was no evidence of an interaction between DcAFP and PGase, which suggests that DcAFP probably lacks PGIP activity. An analysis of the electrostatic potential of DcAFP and other PGIPs revealed that a large number of nonconservative residues within the beta-helix of the DcAFP LRR motif had been substituted to basic amino acids, thus changing the surface from negative to positive. This will electrostatically prevent DcAFP from binding with the positively charged surface of PGase. This is the first report that showed the correlation between nonconservative amino acids within the LRR motif of the DcAFP and its loss of polygalacturonase inhibiting activity.

Effects of Pinus massoniana bark extract on cell proliferation and apoptosis of human hepatoma BEL-7402 cells

AIM: To study the effects of Pinus massoniana bark extract (PMBE) on cell proliferation and apoptosis of human hepatoma BEL-7402 cells and to elucidate its molecular mechanism.

METHODS: BEL-7402 cells were incubated with various concentrations (20-200 µg/mL) of PMBE for different periods of time. After 48 h, cell proliferation was determined by 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was evaluated by morphological observation, agarose gel electrophoresis, and flow cytometry analysis. Possible molecular mechanisms were primarily explored through immunohistochemical staining.

RESULTS: PMBE (20-200 µg/mL) significantly suppressed BEL-7402 cell proliferation in a time- and dose-dependent manner. After treatment of BEL-7402 cells with 160 µg/mL PMBE for 24, 48, or 72 h, a typical apoptotic “DNA ladder” was observed using agarose gel electrophoresis. Nuclear condensation and boundary aggregation or split, apoptotic bodies were seen by fluorescence and electron microscopy. Sub-G₁ curves were displayed by flow cytometry analysis. PMBE decreased the expression levels of Bcl-2 protein in a time-dependent manner after treatment of cells with 160 µg/mL PMBE.

CONCLUSION: PMBE suppresses proliferation of BEL-7402 cells in a time- and dose-dependent manner and induces cell apoptosis by possibly downregulating the expression of the bcl-2 gene.

Expression, purification, and antifreeze activity of carrot antifreeze protein and its mutants

Antifreeze proteins (AFPs) enable organisms to survive under freezing or sub-freezing conditions. AFPs have a great potential in the low temperature storage of cells, tissues, organs, and foods. This process will require a large number of recombinant AFPs. In the present study, the recombinant carrot AFP was highly expressed in Escherichia coli strain BL21 (DE3). The activity of the purified and refolded recombinant proteins was analyzed by measurement of thermal hysteresis (TH) activity and detection of in vitro antifreeze activity by measuring enhanced cold resistance of bacteria. Two carrot AFP mutants generated by site-directed mutagenesis were also expressed and purified under these conditions for use in parallel experiments. Recombinant DcAFP displayed a TH activity equivalent to that of native DcAFP, while mutants DcAFP-N130Q and rDcAFP-N130V showed 32 and 43% decreases in TH activity, respectively. Both the recombinant DcAFP and its mutants were able to enhance the cold resistance of bacteria, to degrees consistent with their respective TH activities.

[Diagnosis of thalassemia by using genechips]

OBJECTIVE

The new technology of genechip is exerting a significant impact on the identification of thalassemia, and allows to rapidly and efficiently detect a number of molecular disorders. The aim of the present study was to explore the application value of the diagnostic genechip in determining thalassemia.

METHODS

The subjects group consisted of 62 children with alpha thalassemia and 93 children with beta thalassemia (60 with thalassemia trait, 33 with thalassemia major) from Guangdong province were tested from July 2002 to July 2003; 115 were males and 40 were females, the age ranged from 1 day to 11 years. These children had mild, moderate or severe anemia. Laboratory examinations showed microcytosis and hypochromocytosis. DNA was extracted from ACD coagulated blood with Invisorb DNA extraction kit. After preparation, the alpha and beta globin gene organization and structure of sample was analyzed by genechip technology.

RESULTS

(1) Heterozygotes, homozygotes and compound heterozygotes of the three commonest deletional alpha thalassemia (--(SEA), -alpha(3.7), -alpha(4.2)) and two non-deletional alpha thalassemia (HbCS, HbQS) were successfully detected. (2) Eight different mutations were identified in 126 chromosomes among 60 cases with beta thalassemia traits and 33 cases with beta thalassemia major, namely CD41-42, IVS-II-654, TATAbox-28, CD17, CD71-72 (+A), betaE(26) CD27-28 (+C) and CD71-72 (+T), with the frequencies of 33.5%, 23.9%, 15.0%, 15.0%, 4.8%, 2.4%, 2.4% and 1.5% respectively. (3) Eight cases (13.3%) in 60 thalassemia traits, two cases (6%) 33 cases with thalassemia major were detected to be combined with alpha thalassemia mutation.

CONCLUSION

(1) The usage of genechip in identifying thalassemia mutations has the advantages of simplicity, economy and shorter time. This technique does not use radioisotope and could also detect alpha and beta thalassemia mutations simultaneously. (2) The occurrence of alpha and beta thalassemia dual heterozygotes is frequent in Guangdong province and the genechip technology is important in genetic counseling and prenatal diagnosis of thalassemia in this area.

Significance of conservative asparagine residues in the thermal hysteresis activity of carrot antifreeze protein

The approximately 24-amino-acid leucine-rich tandem repeat motif (PXXXXXLXXLXXLXLSXNXLXGXI) of carrot antifreeze protein comprises most of the processed protein and should contribute at least partly to the ice-binding site. Structural predictions using publicly available online sources indicated that the theoretical three-dimensional model of this plant protein includes a 10-loop beta-helix containing the approximately 24-amino-acid tandem repeat. This theoretical model indicated that conservative asparagine residues create putative ice-binding sites with surface complementarity to the 1010 prism plane of ice. We used site-specific mutagenesis to test the importance of these residues, and observed a distinct loss of thermal hysteresis activity when conservative asparagines were replaced with valine or glutamine, whereas a large increase in thermal hysteresis was observed when phenylalanine or threonine residues were replaced with asparagine, putatively resulting in the formation of an ice-binding site. These results confirmed that the ice-binding site of carrot antifreeze protein consists of conservative asparagine residues in each beta-loop. We also found that its thermal hysteresis activity is directly correlated with the length of its asparagine-rich binding site, and hence with the size of its ice-binding face.