Renal clear cell carcinoma: diffusion tensor imaging diagnostic accuracy and correlations with clinical and histopathological factors.

AIM: To investigate whether diffusion tensor imaging (DTI) can be used to assess renal clinical histopathology, including the nuclear grade (NG), cell density (CD), and the presence of ki-67. MATERIALS AND METHODS: Thirty patients were enrolled in the study and were confirmed at surgical histopathology to have clear cell renal cell carcinoma (CCRCC). For DTI, a coronal echo-planar imaging sequence was performed (1400 ms repetition time, 76 ms echo time, diffusion direction=6, number of excitations=4; b=0 and 800 s/mm2, 6 mm section thickness with no intersection gap). CD and the presence of ki-67 were compared between the different NGs. Correlations between apparent diffusion coefficients (ADCs), E1, fractional anisotropy (FA), CD, and ki-67 were evaluated. RESULTS: ADC, E1, and FA values are important tools used to identify NG. The cut-off values were 1.003×10-3 mm2/s, 1.277×10-3 mm2/s, and 0.218 mm2/s, respectively. The difference between high- and low-grade CD was significant (t=-4.50, p<0.05). Similarly, a significant difference between high and low grade was also found in ki-67 (t=-4.03, p<0.05). ADC, E1, and FA values were decreased with increased CD; a significant negative correlation was found (r=-0.796, -0.865, and -0.996, respectively). Significant negative correlations between ADC, E1, and FA values, and ki-67 were found (r=-0.739, -0.826, and -0.876, respectively). CONCLUSIONS: DTI can be used to non-invasively assess CCRCC.

Effect of miR-132 on lung injury in sepsis rats via regulating Sirt1 expression.

OBJECTIVE: The aim of this study was to explore the effects of the expressions of micro ribonucleic acid (miR)-132 and sirtuin1 (Sirt1) on lung injury in sepsis rats, and to elucidate the regulatory relation between miR-132 and Sirt1. MATERIALS AND METHODS: The model of sepsis-induced lung injury was successfully established in rats via injection of lipopolysaccharide (LPS) into the caudal vein (model group). Before modeling, the rats were infused with miR-132 antagomir via the trachea (miR-132 antagomir group) or intraperitoneally injected with the Sirt1 activator (SRT1720) (SRT1720 group). Meanwhile, the rats injected with an equal volume of normal saline via the caudal vein were enrolled in the control group. The expressions of the inflammatory factors interleukin-6 (IL-6), IL-1ß, and tumor necrosis factor-α (TNF-α) were determined using enzyme-linked immunosorbent assay (ELISA). Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and Western blotting were applied to detect gene and protein expressions in lung tissues, respectively. Targeted relationship between miR-132 and Sirt1 was explored using Luciferase reporter assay. In addition, tissue sections of the right lung were stained with hematoxylin-eosin (HE) to observe the degree of lung injury. RESULTS: The model of sepsis-induced lung injury was successfully established in rats by LPS. The results showed that the expressions of IL-6, IL-1ß, TNF-α and miR-132 rose significantly in lung tissues (p<0.01), whereas the expression of Sirt1 significantly declined (p<0.01). Lung injury was alleviated by miR-132 antagomir and SRT1720. Both miR-132 antagomir and SRT1720 significantly reduced the expressions of miR-132, IL-6, IL-1ß and TNF-α (p<0.01). However, the expression of Sirt1 was remarkably upregulated in rats with lung injury (p<0.01). Luciferase reporter gene assay indicated that miR-132 regulated Sirt1 in a targeted manner. CONCLUSIONS: MiR-132 may cause lung injury in sepsis rats by regulating the expression of Sirt1.

Genetic dissection of ethanol tolerance in the budding yeast Saccharomyces cerevisiae.

Uncovering genetic control of variation in ethanol tolerance in natural populations of yeast Saccharomyces cerevisiae is essential for understanding the evolution of fermentation, the dominant lifestyle of the species, and for improving efficiency of selection for strains with high ethanol tolerance, a character of great economic value for the brewing and biofuel industries. To date, as many as 251 genes have been predicted to be involved in influencing this character. Candidacy of these genes was determined from a tested phenotypic effect following gene knockout, from an induced change in gene function under an ethanol stress condition, or by mutagenesis. This article represents the first genomics approach for dissecting genetic variation in ethanol tolerance between two yeast strains with a highly divergent trait phenotype. We developed a simple but reliable experimental protocol for scoring the phenotype and a set of STR/SNP markers evenly covering the whole genome. We created a mapping population comprising 319 segregants from crossing the parental strains. On the basis of the data sets, we find that the tolerance trait has a high heritability and that additive genetic variance dominates genetic variation of the trait. Segregation at five QTL detected has explained approximately 50% of phenotypic variation; in particular, the major QTL mapped on yeast chromosome 9 has accounted for a quarter of the phenotypic variation. We integrated the QTL analysis with the predicted candidacy of ethanol resistance genes and found that only a few of these candidates fall in the QTL regions.

Constructing genetic linkage maps under a tetrasomic model.

An international consortium has launched the whole-genome sequencing of potato, the fourth most important food crop in the world. Construction of genetic linkage maps is an inevitable step for taking advantage of the genome projects for the development of novel cultivars in the autotetraploid crop species. However, linkage analysis in autopolyploids, the kernel of linkage map construction, is theoretically challenging and methodologically unavailable in the current literature. We present here a theoretical analysis and a statistical method for tetrasomic linkage analysis with dominant and/or codominant molecular markers. The analysis reveals some essential properties of the tetrasomic model. The method accounts properly for double reduction and incomplete information of marker phenotype in regard to the corresponding phenotype in estimating the coefficients of double reduction and recombination frequency and in testing their significance by using the marker phenotype data. Computer simulation was developed to validate the analysis and the method and a case study with 201 AFLP and SSR markers scored on 228 full-sib individuals of autotetraploid potato is used to illustrate the utility of the method in map construction in autotetraploid species.

Modeling population genetic data in autotetraploid species.

Allozyme and PCR-based molecular markers have been widely used to investigate genetic diversity and population genetic structure in autotetraploid species. However, an empirical but inaccurate approach was often used to infer marker genotype from the pattern and intensity of gel bands. Obviously, this introduces serious errors in prediction of the marker genotypes and severely biases the data analysis. This article developed a theoretical model to characterize genetic segregation of alleles at genetic marker loci in autotetraploid populations and a novel likelihood-based method to estimate the model parameters. The model properly accounts for segregation complexities due to multiple alleles and double reduction at autotetrasomic loci in natural populations, and the method takes appropriate account of incomplete marker phenotype information with respect to genotype due to multiple-dosage allele segregation at marker loci in tetraploids. The theoretical analyses were validated by making use of a computer simulation study and their utility is demonstrated by analyzing microsatellite marker data collected from two populations of sycamore maple (Acer pseudoplatanus L.), an economically important autotetraploid tree species. Numerical analyses based on simulation data indicate that the model parameters can be adequately estimated and double reduction is detected with good power using reasonable sample size.

Predictive factors for open conversion of laparoscopic adrenalectomy: a 13-year review of 456 cases.

BACKGROUND AND PURPOSE: Laparoscopic adrenalectomy has largely replaced open adrenalectomy for the treatment of adrenal tumor. However, certain cases still require conversion to open procedures. Identifying the risk of conversion remains difficult. This study identified risk factors that may predict conversion from a laparoscopic to an open procedure. PATIENTS AND METHODS: From January 1993 to September 2006, a total of 456 laparoscopic adrenalectomies were performed at two urologic centers. A retrospective analysis of parameters, including tumor size, patient age, American Society of Anesthesiology classification, body mass index (BMI), sex, laparoscopic approach, previous abdominal surgery, laterality, type of tumor, laparoscopist experience, and surgeon, was performed. Multivariate logistic regression was used to identify those variables predicting conversion. RESULTS: A total of 25 (5.5%) laparoscopic adrenalectomies required conversion. Significant predictors of conversion according to univariate analysis were tumor size > or =5 cm, BMI > or =24 kg/m(2), and pheochromocytoma. Multivariate analysis showed that the significant independent predictive factors for conversion were tumor size > or =5 cm (8.884 greater odds ratio [OR] of conversion; 95% confidence interval 3.543, 22.277; P < 0.001), BMI > or = 24 kg/m(2) (OR 3.632; 95% confidence interval 1.367, 9.648; P = 0.010), and pheochromocytoma (OR 3.068; 95% confidence interval 1.175, 8.007; P = 0.022). CONCLUSIONS: Knowledge of tumor size, BMI, and tumor type can help in counseling patients undergoing laparoscopic adrenalectomy with regard to the probability of conversion. The size of the tumor was found to be the most important predictor.

[A cross-sectional survey of receiving no methadone maintenance treatment in HIV infected injecting drug users in Dehong Dai and Jingpo autonomous prefecture, Yunnan province].

Objective: To understand the current status of receiving no methadone maintenance treatment (MMT) and influencing factors in HIV infected injecting drug users (IDUs) in Dehong Dai and Jingpo autonomous prefectures, Yunnan province. Methods: Data of survival of IDUs with AIDS in Dehong were collected from " Chinese National Comprehensive HIV/AIDS and Care Information System" in December, 2014. Results: There were 987 IDUs who should receive MMT, the majority of them were males (94.6%, 934/987), aged 35-44 years (53.0%, 523/987) and farmers (77.2%, 762/987). Among the 987 IDUs, 60.2% (592/987) received no MMT. Multivariate logistic regression analysis showed that being female (OR=2.66, 95%CI: 1.21-5.87), in Jingpo ethnic group (OR=3.05, 95% CI: 1.97-4.71) were the major risk factors for receiving no MMT; not being farmers (OR=0.46, 95%CI: 0.31-0.70), in Dai ethnic group (OR=0.53, 95%CI: 0.36-0.79), diagnosed HIV infection history ≥10 years (OR=0.60, 95%CI: 0.45-0.81) were the major protective factors for receiving no MMT. The reasons for receiving no MMT included long distance journey (289, 48.8%), fear of exposure (124, 20.9%), poor daily medication compliance (59, 10.0%), fear of side effects (47, 7.9%), others (73, 12.3%). Conclusions: The proportion of receiving no MMT in IDUs with AIDS in Dehong was high. Being female and farmer, in Jingpo ethnic group, low educational level, short diagnosed HIV infection history were influencing factors for receiving no MMT. The effective intervention measures should be taken to further improve MMT coverage according to the different characteristics of the patients.

High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma.

AIMS: To investigate the frequency and clinical significance of RET rearrangement in Chinese patients with papillary thyroid carcinoma (PTC) and discuss the role of RET rearrangement in therapeutic decision-making after the performance of level VI lymph node dissection and the 2002 AJCC staging system. METHODS: RET/PTC-1 and RET/PTC-3 were detected in 126 PTCs using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing. RESULTS: RET rearrangement was detected in 18 cases of PTC. The patient group aged < 20 years had the highest frequency (3/6) of RET rearrangement among the age groups (< 20 years, 20-40 years and > or = 40 years; P=0.03). RET/PTC-1 positive patients were more likely to suffer from Hashimoto's thyroiditis simultaneously (P=0.02) while RET/PTC-3 positive patients had a higher frequency of extrathyroidal extension (P<0.01) and advanced T classification (P<0.01). RET rearrangement (OR=8.70, 95% CI 1.69-44.81), male (OR=3.88, 95% CI 1.41-10.69), age (OR=0.96, 95% CI 0.93-0.99), multifocality (OR=3.54, 95% CI 1.33-9.41) and advanced T classification (OR=7.32, 95% CI 2.91-18.40) were all identified as risk factors of level II-V lymph node involvement in the multivariate analysis. CONCLUSIONS: The frequency of RET rearrangement in Chinese patients is low and age related. RET/PTC-1 and RET/PTC-3 are associated with different clinical pathological characteristics but not with lymph node involvement. The RET/PTC positive patients should receive more attention to lateral neck in the management of PTC.

Factors governing selective formation of specific disulfides in synthetic variants of alpha-conotoxin.

alpha-Conotoxin GI is a snail toxin protein consisting of 13 amino acids cross-linked by 2 intramolecular disulfide bridges. This toxin is an antagonist of acetylcholine receptors. The native sequence has been synthesized, along with nine additional variants in which non-cysteine residues are replaced by alanine or the cysteine positions are altered. Each reduced peptide has been oxidized by reaction with oxygen or glutathione both in a folding buffer and in 6 M guanidine hydrochloride. Purified products of oxidation have been characterized with respect to molecular weights and the positions of disulfides. The four cysteines in conotoxin can form two intramolecular disulfides in three different combinations. Relative yields of each of the three isomers have been determined, thereby permitting evaluation of the roles of non-cysteine residues and cysteine placements in the folding of conotoxin. Cysteine positions dominate factors directing formation of the nativelike isomer in a manner that may be predicted from equilibrium constants for loop formation in model peptides containing two cysteines. Alanine substitutions at several positions which are conserved in naturally occurring conotoxins affect the discrimination between the two most favored disulfide arrangements. Substitutions at three nonconserved positions have no structural effect on isomer yields. It therefore is possible to vary these latter three positions in a manner which might help to generate a functional binding surface which is complementary to receptors in the specific prey of a particular species of snail, without affecting the toxin's folding.

Dependence of formation of small disulfide loops in two-cysteine peptides on the number and types of intervening amino acids.

Microscopic disulfide-exchange rate constants have been measured for the formation and opening of small disulfide loops in reactions between glutathione and peptides containing 2 cysteines. Twelve cysteine-Xm-cysteine peptides have been studied, where X is an amino acid and m is the number of amino acids between the cysteines. Homopolymers of alanine for m equaling 0-5 are evaluated, as well as X1 and X2 series employing glycine, valine, or proline. Equilibrium constants Kc for loop closing are only slightly dependent on the nature of X. Loops with even values of m generally are favored relative to loops with odd values. Kc increases in the rank order X1, X3, X0, X5, X4, and X2. Formation of a disulfide between sequentially adjacent cysteines therefore is not especially difficult. The dependence of Kc on the odd-even nature of m is compared with similar patterns observed both in statistics of disulfide formation in naturally occurring proteins and in theoretical studies of peptide cyclization. The relative equilibrium populations of intramolecular disulfides in peptides containing cysteine-cysteine-cysteine and cysteine-serine-cysteine-serine-cysteine clusters are consistent with predictions based on the values of Kc in the two-cysteine peptides.

Theoretical basis for genetic linkage analysis in autotetraploid species.

Linkage analysis in autotetraploid species has been an historical challenge in quantitative genetics theory and is a stumbling block that urgently needs to be removed in the rapidly emerging genome research on this species, such as cultivated potato. This article presents theory of a full model of tetrasomic linkage and develops a statistical framework for the linkage analysis. The model considers both double reduction and recombination, the most essential features of tetrasomic inheritance with linked loci, whereas the statistical method takes appropriate account of the major complexities in analyzing both dominant and codominant molecular marker data during map reconstruction in tetraploid species. These complexities include the problems arising from multiple dosage of allelic inheritance, the null allele, allelic segregation distortion, mixed bivalent and quadrivalent pairing in meiosis, and incomplete information of marker phenotype data. The theoretical analysis established the relationship between the coefficients of double reduction at linked loci, which is essential in the present tetrasomic linkage analysis and in assessing the impact of double reduction on the evolution of tetraploid populations. The statistical method, based on the combination of theoretical analysis and a computer-based algorithm, provided analytical tools for predicting the maximum-likelihood estimates of the model parameters. A simulation study showed the feasibility of a practical implementation of the method, detailed the procedure of the analysis, validated the power and reliability in the parameter estimation, and compared the present method with those proposed in the current literature.

Induced recovery of defective membrane expression of a CC chemokine receptor 5 mutant by phytohemagglutinin.

CC chemokine receptor 5 (CCR5) is a member of the G-protein-coupled receptor superfamily. It plays an important role in macrophage tropic human immunodeficiency virus-1 entry and in some inflammatory reactions. CCR5-893(-) is a single-nucleotide deletion that results in complete truncation of the C tail of the gene product. We detected CCR5-893(-) in a sample of patients infected with non-tuberculosis mycobacteria and found that it was maintained heterozygously with a frequency of 2%. There is no association between this mutation and any immunodeficiency. Membrane expression of CCR5-893(-) was substantially reduced compared to the wild type, but this defective surface presentation recovered greatly recovered in the presence of 2 mg l(-1) phytohemagglutinin (PHA). However, PHA inducement did not affect the total intracellular expression of CCR5-893(-) or wild-type CCR5. Thus we suggest there exist some PHA-induced factor(s) that could mediate the presentation of truncated CCR5.