Research progress of phytosterolemia and its laboratory diagnosis / 中华检验医学杂志

Phytosterolemia is a rare, severe autosomal recessive sterol storage disorder caused by homozygous or compound heterozygous mutations in one of the ABCG5 and/or ABCG8 adenosine triphosphate binding cassette (ABC) genes. The most prominent features of phytosterolemia are the significantly increased serum content of plant sterols. Present review focused on the laboratory diagnosis of phytosterolemia, briefly described the metabolism of phytosterols, and introduced the latest research progress on phytosterolemia diagnosis, its relationship with ASCVD and laboratory diagnostic methods (including the detection of serum concentrations of phytosterols, ABCG5/G8 gene mutation). We hope this article could improve readers′ awareness and attention on this disease.

Attention to plant sterols: a novel risk factor for residual risk assessment of atherosclerotic cardiovascular disease / 中华检验医学杂志

Plant sterols are a class of compounds naturally produced by plants and structurally similar to cholesterol. For human, plant sterols can only be obtained from food and cannot be utilized directly. With the development of gas chromatography technology and in-depth research on the molecular mechanisms of rare diseases, plant sterols have been found to play important roles in atherosclerotic cardiovascular disease (ASCVD)and become a residual risk factor after statin therapy. As a novel metabolic marker, plant sterols can reflect steady state the imbalance of the cholesterol and the increase of the cholesterol absorption within the human body, and is expected to become a new risk factor for ASCVD residual risk assessment.

Features of radionuclide myocardial perfusion imaging in patients with homozygous familial hypercholesterolemia / 中华核医学与分子影像杂志

Objective To evaluate the features of myocardial perfusion imaging (MPI) in patients with homozygous familial hypercholesterolemia (HoFH) and its influence factors.Methods Forty-two consecutive HoFH patients (21 males,21 females;average age:(14.8±8.4) years) were retrospectively enrolled in this study from June 2010 to November 2016.Diagnosis was proved by clinical and chromosome tests,and all patients underwent ATP stress and rest 99Tcm-methoxyisobutylisonitrile (MIBI) SPECT MPI with a two-day protocol.Summed stress score (SSS) and summed rest score (SRS) were acquired,and summed difference score (SDS;SSS-SRS) was calculated.Relations between SSS,SRS,SDS and age,lipid profile were analyzed.Two-sample t test,x2 test,multiple linear regression analysis and multivariate logistic regression were used to analyze the data.Results There were 24 patients with positive MPI results (SSS≥1),and females (76.2％,16/21) showed more positive MPI results than males (38.1％,8/21;x2=6.22,P＜0.05).Eighteen patients had negative MPI results.There were 6,8,10 patients with MPI positive results in ＜ 10 years group (n =14),10-18 years group (n =14) and ≥ 19 years group,respectively (x2=2.33,P＞0.05).Positive electrocardiograph (ECG) in ATP stress test was observed in 9 females (42.9％,9/21) and 3 males (14.3％,3/21;x2 =4.20,P＜0.05).Sixty-three (8.8％,63/714) abnormal myocardial perfusion segments (SSS≥ 1) were found,which was mainly (60.3％,38/63) distributed in myocardial regions supplied by left anterior descending branch (LAD).SSS was positively correlated with age and high density lipoprotein cholesterol (HDLC).SRS,SDS were positively correlated with HDLC and age respectively.Multivariate logistic regression analysis indicated that the female was the only independent risk factor to predict positive MPI (odds ratio=5.2,95％ CI:1.363-19.774).Conclusions In HoFH patients,abnormal myocardial perfusion had a rising trend with age increasing.Female patients are more likely to have abnormal MPI.Abnormal myocardial perfusion segments are mainly located in myocardial regions supplied by LAD.Age and gender are influence factors of abnormal MPI in HoFH patients.

Analysis of compound heterozygous mutation of low-density lipoprotein receptor gene in two patients with familial hypercholesterolemia / 中华检验医学杂志

Objective To determine LDLR gene mutation in 2 clinically diagnosed FH patients from Hubei province and provide basis for gene diagnosis of FH.Methods Clinical data of 2 FH patients and their parents were collected.The promoter region and exon 1 to exon 18 region of LDLR gene were amplified through PCR and the amplified products were analyzed by forward and reverse DNA sequencing.The mutations were identified after comparison with LDLR gene sequence in GenBank.The pathogenic gene mutations were confirmed according to both genotype and phenotype of FH probands.Results The levels of plasma TC of two probands were 12.79 and 11.98 mmol/L.respectively.No gene mutations were detected in region 3 500 to 3 531 of ApoB100. The mutations of LDLR gene were compound heterozygous mutations. The novel mutation 665G > T detected in the exon 4 of No. 1 proband's LDLR gene was heterozygous missense mutation. The novel mutation 1 358 +32C > T was detected in the exon 9 of No. 1 proband's LDLR gene.The mutations 665G > T ( paternal origin) and 1 358 + 32C > T ( maternal origin) were inherited from the parents. A novel mutation 1 257 C > A was detected in the exon 9 of No. 2 proband's LDLR gene, resulting the presence of a premature termination codon, which was different from 1 257 C > G reported in Belgium.Another heterozygous missense mutation 1 879 G > A was detected in exon 13. They were derived from paternal origin and maternal origin, respectively. Conclusions There are three novel gene mutations:665G >T, 1 358 +32C > T, 1 257C > A found in two probands with compound heterozygous mutations in LDLR respectively. They maybe play a potential role in FH pathogensis.

SSCP screening of mutation in exon 13 of low density lipoprotein receptor gene in Chinese familial hypercholesterolemia patients / 中华检验医学杂志

Objective To investigate the application of polymerase chain reaction and single strand conformation polymorphism analysis(PCR-SSCP)to the screening of gene mutation of exon 13 of the LDLR gene in familial hypercholesterolemia(FH).Methods Peripheral blood DNA of 16 clinically diagnosed FH patients was extracted and the exon 13 coding region of the LDLR gene was amplified by PCR.PCR products were separated by optimized SSCP electrophoresis and visualized by silver staining.DNA fragments with abnormal mobility were sequenced to determine the nature and position of mutations.Results The SSCP electrophoresis conditions were optimized as 8%polyaerylamide(degree of cross linking 49:1)gel without glycerin at a electrophoresis temperature of 10℃ or 8%polyacrylamide gel with 5%glycerin at room temperature,gel thickness of＜0.4 mm,and a voltage of 5 V/cm.DNA fragments were well resolved with the conditions and sequencing of the abnormal bands resuhed in detections of missense mutations of A606T,D601N,Y601D and G636V together with a synonymous mutation of 1959C→T in 4 patients and a sole synonymous mutation of 1959C→T in other 4 patients.Conclusion PCR-SSCP is an effective method for the screening of exon13 mutations of LDLR gene in FH patients.

Effect of emblic leafflower fruit on total antioxidation and levels of malondialdehyde as well as endothelin in plasma in rabbits with atherosclerosis / 中国组织工程研究

BACKGROUND: Emblic leafflower fruit contains rich vitamin C, organic acid and mineral substance. It is indicated in modern research that emblic leaafflower fruit acts on preventing from cancer and anti-aging too. In recent years, more and more concerns have been paid to the researches on functional factor of emblic leafflower fruit and the development of the relevant functional food. It has been verified that emblic leafflower fruit acts on reducing lipid and anti-oxidation in vitro, but there are still lacks of enough basic researches to support it.OBJECTIVE: To probe into mechanism of emblid leafflower fruit on anti-oxidation and protection of vascular endothelial function in rabbits with hyperlipemia.DESIGN: Randomized controlled experimental study based on the experimental animals.SETTING: Atherosclerosis(As) experimental room in a university hospital.MATERIALS: Totally 24 normal NewZealand male rabbits, mass weighted (2.2±0.5) kg.METHODS: The experiment was performed in As Experimental Room of Beijing Anzhen Hospital from September 2001 to May 2002. Totally 24 New Zealand male rabbits were randomized into the control, the power of emblid leafflower fruit group(powder group)(4 g/kg day) and hypercholesterolemia model group (model group), 8 rabbits in each group. In both power and model groups, the rabbits were fed with hypercholesterol food. Oxidase method was applied to assay the content of serum lipid, chemical method to assay the plasma total anti-oxidation and the content of malondialdehyde (MDA), radio-immune method to assay the content of plasma endothelin-1 (ET-1), digoxin labeled probe and tissue hybridism in situ to assay the expression of endothelin mRNA of aortic tunica intima, and image analyzer to assay the area of aortic intimal atherosclerosis plaque and the ratio between the area of tunica intima and the area of tunica media.MAIN OUTCOME MEASURES: The primary outcomes included blood lipid level, serum MDA concentration and the comparison of artery plaque areas. The secondary outcomes included the changes in plasma ET-1.RESULTS: By the comparison between the powder group and model group in triglyceride(TG) and low density lipoprotein cholesterol(LDL-C) were significantly reduced [(11.70 ± 1.73), (14.32 ±2.22) mmol/L, P<0.05; (0.740 ± 0.107), (1.450 ± 0.220) mmol/L, P <0.01 successively]and thehigh density lipoprotein cholesterol(HDL-C) was increased MDA was significantly decreased [ (3.88 ± 0.51 ), (6. 29 ± 1.43 ) mmol / L,P < 0.01 ] and the total anti-oxidation significantly increased [ (10. 771der photo-microscope that the plaque area and the ratio between intima area and media area were remarkably decreased [(39.46±6.53), (50.69± 12.36)mmol/L, P < 0.05; (0. 62 ±0. 32), (1.38 ±0.38) mmol/L, Pgranules of aortic intima ET-1 gene were rem~kably decreased compared with the model group.CONCLUSION: Emblic leafflower fruit prevents from the formation of experimental atheromatous plaque in rabbits probably by regulating rabbit lipid metabolism, improving anti-oxidation to reduce lipid peroxidation and protecting endothelial function to inhibit the expression of artery intima ET-1 gene.

Analysis of low-density lipoprotein receptor gene mutations in a Chinese patient with clinically homozygous familial hypercholesterolemia / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To screen the point mutation of the low-density lipoprotein receptor (LDL-R) gene in Chinese familial hypercholesterolemia (FH) patients, characterize the relationship between the genotype and the phenotype and discuss the molecular pathological mechanism of FH.</p><p><b>METHODS</b>A patient with clinical phenotype of homozygous FH and her parents were investigated for mutations in the promoter and all eighteen exons of the LDL-R gene. Screening was carried out using Touch-down PCR and direct DNA sequencing; multiple alignment analysis by DNASIS 2.5 was used to find base alteration, and the LDL-R gene mutation database was searched to identify the alteration. In addition, the apolipoprotein B gene (apo B) was screened for known mutations (R3500Q) that cause familial defective apo B100 (FDB) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).</p><p><b>RESULTS</b>Two new heterozygous mutations in exons 4 and 9 of the LDL-R gene were identified in the proband (C122Y and T383I) as well as her parents. Both of the mutations have not been published in the LDL-R gene mutation database. No mutation of apo B100 (R3500Q) was observed.</p><p><b>CONCLUSION</b>Two new mutations (C112Y and T383I) were found in the LDL-R gene, which may result in FH and may be particularly pathogenetic genotypes in Chinese people.</p>

Detection of High Methylation of p15(INK4B) and p16(INK4A) Genes in Multiple Myeloma / 中国实验血液学杂志

To study the action, characteristics and expression of high methylation of p15(INK4B) and p16(INK4A) genes in multiple myeloma (MM), the sensitive methylation specific PCR method was employed to detect the hypermethylation of p15(INK4B) and p16(INK4A) in 24 patients with MM. Results showed that the methylation incidence of p15(INK4B) and p16(INK4A) genes were 70.8% (17/24) and 58.3% (14/24) in the MM patients, with the products of 148 bp and 150 bp fragments, respectively. The methylation of p15(INK4B) and p16(INK4A) genes were simultaneously happened in MM patients of plasmocytoma type with two cases at II phase and two cases at III phase. The simultaneous non-methylation of p15(INK4B) and p16(INK4A) genes were founded in five cases of MM patients, all of the tumor cells were of small plasmocyte type with mature differention. Conclusion suggested that there were high incidence of methylation of p15(INK4B) and p16(INK4A) genes in patients with MM. Hypermethylation can be detected in the early stage of disease, which was associated with its progress. It indicated a bad prognosis when methylation happended simultaneously in the two genes. Methylation of p15(INK4B) and p16(INK4A) genes may be related to the pathogeny of MM.