Single Nucleotide Polymorphisms (SNPs) in Plant Genetics and Breeding

Recent advances in genome technology revealed various single nucleotide polymorphisms (SNPs), the most common form of DNA sequence variation between alleles, in several plant species. The discovery and application of SNPs increased our knowledge about genetic diversity and a better understanding on crop improvement. Natural breeding process which takes an agelong time during collecting, cultivating, and domestication has been accelerated by detecting dozens of SNPs on various species using advanced biotechnological techniques such as next-generation sequencing. This will result in the improvement of economically important traits. Therefore, we would like to focus on the discovery, current technologies, and applications of SNPs in breeding. The chapter covers the following topics: (1) introduction, (2) application of SNPs, (3) techniques to detect SNPs, (4) importance of SNPs for crop improvement, and (5) conclusion

Predictive power of different obesity measures for the presence of diastolic dysfunction

Objective: Body mass index (BMI) and waist circumference (WC) as measures of obesity have some limitations. The aim of this study was to evaluate whether one measure could predict the presence of diastolic dysfunction (DD) more accurately than the other measures. Methods: A total of 91 obese patients without any other risk factors for DD were prospectively enrolled. Echocardiographic examination was performed. DD was defined and categorized according to recent guidelines. The study participants were divided into 2 groups according to the presence of DD. Weight, height, and WC were measured; BMI and waist-to-hip ratio (WHR) were calculated; and a body shape index (ABSI) was calculated as WC/(BMI2/3height1/2). The associations between ABSI, BMI, WHR, and WC and the presence of DD were examined using logistic regression analyses. Analysis of covariance was used to examine the differences. Results: WC and BMI were significantly greater in subjects with DD (p=0.049 and 0.051, respectively). A greater BMI, WC, and WHR increased the risk of the presence of DD (BMI-DD: odds ratio [OR]=1.096, p=0.024; WC-DD: OR=1.059, p=0.007; WHR-DD: OR=2.363, p=0.007). After adjustment for age and sex, only BMI continued to be significantly associated with DD (p=0.031). ABSI was not associated with DD. Conclusion: After adjustment for age and sex, BMI was the only predictor of DD in obesity. Despite its limitations, BMI may still be a potentially more accurate measure of DD compared with other obesity measures. © 2018 Turkish Society of Cardiology

Administration of bone marrow derived mesenchymal stem cells modulate tlr expression during liver regeneration

Liver cell transplantation is a powerful alternative to orthotopic cell transplantation in the treatment of liver failures. Recently, considerable effort is being channeled to understand the nature and kinetics of directing stem cells to effectively accumulate at the regenerating liver site. Mesenchymal stem cells are one of the promising cell sources modulating liver regeneration process. The present was designed to study how mesenchymal stem cells might modulate liver immune behaviors by changing Toll-like receptor (TLR) expression and increase regenerative potential during liver regeneration in rats. Normal and partially hepatectomized rats were treated with mesenchymal stem cells isolated and expanded from rat bone marrows. Accumulation of mesenchymal stem cells was confirmed by Real Time-Polymerase Chain Reaction (RT-PCR), Fluorescence-Activated Cell Sorting (FACS), and Immunofluorescence Staining (IFS). Student's t-test analysis was used to evaluate the significance of differences between sham and partially hepatectomized rat groups. Our results showed that mesenchymal stem cells expressed several TLRs, and their accumulation during regeneration was depended on the timing of injury. Mesenchymal stem cells isolated from bone marrow of normal rats were observed at the injured liver 3 days after the injection. There were no labeled mesenchymal stem cells in the liver sections of the uninjured animals. Mesenchymal stem cell administration significantly altered the expression of TLR2, 3 and 9 while retaining their migration potential to regenerating liver. Our findings implicated that mesenchymal stem cell administration during liver regeneration modulate the immune response through changing the expression of the TLRs in the remaining liver parts into which the cells are recruited or infused. This alteration may contribute to the regeneration process following partial hepatectomy.Karaciğer hücresi nakli, karaciğer yetmezliğinde ortotopik hücre nakline güçlü bir alternatiftir. Son yıllarda, kök hücrelerin doğalarının, kinetiklerinin ve yenilenen karaciğer bölgesinde etkili bir şekilde toplanmalarının sağlanmasının anlaşılması için hatırı sayılır gayretler sarf edilmektedir. Mesenkimal kök hücreler karaciğer yenilenme sürecini modüle eden ümit verici hücre kaynaklarından bir tanesidir. Bu çalışma, mezenkimal kök hücrelerin sıçanlarda toll benzeri reseptör (TLR) ifadesini değiştirmek suretiyle karaciğer immün yanıtını nasıl etkileyebildiklerini ve karaciğer yenilenmesi esnasında yenilenme potansiyelini arttırabildiklerini belirlemek için gerçekleştirilmiştir. Normal ve karaciğerleri kısmen çıkarılmış sıçanlar, sıçan kemik iliğinden elde edilip çoğaltılan mesenkimal kök hücreler ile muamele edilmişlerdir. Mesenkimal kök hücrelerin toplanması Eş Zamanlı Polimeraz Zincir Reaksiyonu (RT-PCR), Floresan Aktivite Hücre Ayırma (FACS), ve Immunfloresan Boyama (IFS) ile doğrulanmıştır. Sham ve karaciğeri kısmen alınmış sıçan grupları arasındaki farklılığın istatistiki analizinde Student's t-testi kullanılmıştır. Elde edilen sonuçlar mezenkimal kök hücrelerinde çeşitli TLR’lerin ifade edildiklerini ve bu hücrelerin yenilenme esnasında toplanmalarının meydana gelen hasarın zamanlamasına bağlı olduğunu göstermiştir. Normal sıçanların kemik iliğinden izole edilen mezenkimal kök hücreler hasarlı karaciğerde enjeksiyon sonrası 3. günde görülmüşlerdir. Hasarsız hayvanların karaciğer kesitlerinde işaretli bir mezenkimal kök hücre görülmemiştir. Mezenkimal kök hücre uygulaması TLR2, 3 ve 9'un ifadesinin anlamlı bir şekilde değiştirirken yenilenen karaciğere göç etme yeteneklerini devam ettirmişlerdir. Sonuçlar, karaciğer yenilenmesi esnasında mezenkimal kök hücre uygulamasının, hücrelerin uygulandığı hasarsız karaciğer parçalarında TLR’lerin ifadelerini değiştirme yoluyla immün yanıtı modüle ettiğini ortaya koymaktadır. TLR ifadesindeki bu değişim kısmı hepatoktemi sonrası yenilenme sürecine katkı sağlayabilir niteliktedir

The association between central adiposity and autonomic dysfunction in obesity

Objective: To determine the relationship between central adiposity parameters and autonomic nervous system (ANS) dysfunction. Subjects and Methods: The study included 114 obese individuals without any cardiovascular risk factors. Weight (in kg), height (in m), and waist circumference (WC; in cm) were measured and body mass index was calculated. Echocardiographic examination was performed to measure left ventricular mass and epicardial fat thickness (EFT). All the participants underwent an exercise test and electrophysiological evaluation using electromyography. Heart rate recovery (HRR) at 1-5 min, R-R interval variation at rest and during hyperventilation, and sympathetic skin response were measured. Pearson's correlation analysis was used. Multiple linear regression analysis was used to identify the factors associated with autonomic dysfunction. Results: The HRR at 1-5 min was negatively correlated with WC and age (WC-HRR1: r = -0.32; WC-HRR2: r = -0.31; WC-HRR3: r = -0.26; WC-HRR4: r = -0.23; WC-HRR5: r = -0.21; age-HRR2: r = -0.32; age-HRR3: r = -0.28; age-HRR4: r = -0.41; age-HRR5: r = -0.42). Age was the only independent predictor of reduced HRR at 1-5 min. In addition, WC predicted a reduced HRR at 3 min. There were no significant associations between central obesity and electrophysiological parameters. EFT was not associated with ANS dysfunction. Conclusion: In this study, central adiposity and aging were associated with ANS dysfunction in obese individuals. The WC could be a marker of ANS dysfunction in obese individuals without any cardiovascular risk factors. The HRR assessment at a later decay phase could be more valuable for evaluating ANS function than during early recovery. © 2016 S. Karger AG, Basel

Cephalometric Mandibular Dimensions in Growing Turkish Children: Trends of Change, Sex-Specific Differences, and Comparisons with Published Norms

Objective: The aims of this study were to investigate cephalometric mandibular dimensions in growing Anatolian Turkish children and to identify the periods of rapid growth for boys and girls. Furthermore, the secondary aim was to compare obtained values with published standards in the literature.Methods: A total of 528 pretreatment lateral cephalometric radiographs, grouped according to age and sex, were analyzed. Effective mandibular length, ramus height, and corpus lengths were comparatively evaluated within age groups for boys and girls and between sexes for the same age group. Data acquired from this study were compared with American, Canadian, Chinese, and European norms. Growth curves for mandible were constructed for each sex group.Results: Effective mandibular length was almost always significantly longer in boys, except for 9- and 12-year-age groups. Effective mandibular length in girls increased significantly between ages 8 and 10, 10 and 12, and 11 and 13 years, while in boys between ages 8 and 10, 9 and 11, and 13 and 15 years. Turkish girls had significantly shorter effective mandibular lengths than American girls at age 14. No significant difference was found between Turkish and Chinese girls and boys. Turkish girls and boys had significantly shorter corpus lengths from their Norwegian counterparts at age 12.Conclusion: Except for 9- and 12-year-age groups, effective mandibular length was almost always significantly longer in boys compared to the girls. It is suggested to use norm values from more recently conducted studies and which are representative of the studied population. Growth curves can be used to predict the approximate mandibular dimensions at a particular age

The initial part of polymorphic ventricular tachycardia as a clue for the sustainability of tachycardia and ablation success: A varying degree of purkinje–Myocardial complicity?

The cardiac Purkinje system is capable of very rapid burst activity suggestive of its potential role in being a driver of polymorphic ventricular tachycardia (VT) (PMVT) or ventricular fibrillation (VF). It plays a pivotal role, however, not only in the triggering of but also the perpetuation of ventricular arrhythmias. A varying degree of Purkinje–myocardial complicity has been blamed in determining not only the sustained or non-sustained nature of PMVT but also the pleomorphism of the non-sustained runs. The initial part of PMVT before cascading to the whole ventricle to establish disorganized VF can give important clues for ablation of PMVT and VF. We present a case of an electrical storm after acute myocardial infarction that was successfully ablated after identifying Purkinje potentials that triggered polymorphic, monomorphic, and pleiomorphic VTs and VF

Mechanisms of T-Cell Exhaustion in Pancreatic Cancer.

T-cell exhaustion is a phenomenon that represents the dysfunctional state of T cells in chronic infections and cancer and is closely associated with poor prognosis in many cancers. The endogenous T-cell immunity and genetically edited cell therapies (CAR-T) failed to prevent tumor immune evasion. The effector T-cell activity is perturbed by an imbalance between inhibitory and stimulatory signals causing a reprogramming in metabolism and the high levels of multiple inhibitory receptors like programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), and Lymphocyte-activation gene 3 (Lag-3). Despite the efforts to neutralize inhibitory receptors by a single agent or combinatorial immune checkpoint inhibitors to boost effector function, PDAC remains unresponsive to these therapies, suggesting that multiple molecular mechanisms play a role in stimulating the exhaustion state of tumor-infiltrating T cells. Recent studies utilizing transcriptomics, mass cytometry, and epigenomics revealed a critical role of Thymocyte selection-associated high mobility group box protein (TOX) genes and TOX-associated pathways, driving T-cell exhaustion in chronic infection and cancer. Here, we will review recently defined molecular, genetic, and cellular factors that drive T-cell exhaustion in PDAC. We will also discuss the effects of available immune checkpoint inhibitors and the latest clinical trials targeting various molecular factors mediating T-cell exhaustion in PDAC

The width of life is more important than the length of life

A 58-year-old man with previous inferior myocardial infarction (MI) was referred for cardiac resynchronization therapy pacemaker (CRT-P) for decreased left ventricular ejection fraction (LVEF; 45%) and left bundle branch block (LBBB) (Figure 1). He had New York Heart Association Class I functional classification but palpitation for 3 months. General physical and cardiac examinations were normal. On the admission day, the electrocardiogram showed a narrow QRS rhythm with and without tachycardia (Figures 2 and 3). Would you recommend or consider a CRT-P device or a CRT defibrillator or only an implantable cardioverter defibrillator (ICD) based on these clinical and electrocardiographic findings, or ablation or medical therapy only

Transhepatic left ventricular only pacing after left bundle branch area pacing attempt with high pacing threshold

A 50-year-old male with a permanent dual chamber pacemaker (DDD) 23 years ago was referred for a rapid increase in right ventricular (RV) pacing impedance. His left ventricular (LV) ejection fraction was 45%. Since the patient was pacemaker-dependent, the insertion of a new RV lead was planned. However, the venography and imaging studies revealed both left and right subclavian veins to be occluded/non-accessible. We failed also to cross the lesion by percutaneous approach. Then, we planned the extraction procedure as a first stage with the thought that it can provide a new venous route via extraction sheath; however, the patient did not accept the procedure as its high risk. Therefore, the surgical epicardial LV lead was implanted and connected to the left subpectoral pocket by using the previous functional right atrial (RA) lead for DDD pacing. Unfortunately, 1 month later, the patent presented with a left-sided pocket infection, and we had to remove all endocardial RA and RV leads using the lead extraction system. We could not again pass the calcified superior vena cava despite the successful lead extraction. Due to an active pocket infection, the surgically placed pacemaker was removed from the skin leaving the epicardial LV lead in place to remove or drain the infected fluid. A leadless pacemaker was an option, but due to financial constraints could not be done for this patient. The femoral venous access could not be taken due to the non-availability of 69 cm RV lead. The hepatic vein was the only available access to implant a DDD pacemaker