Dahl (S x R) Congenic Strain Analysis Confirms and Defines a Chromosome 5 Female-Specific Blood Pressure Quantitative Trait Locus to <7 Mbp

The detection of multiple sex-specific blood pressure (BP) quantitative trait loci (QTLs) in independent total genome analyses of F2 (Dahl S x R)-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl) challenge, identified only S.R5B congenic rats with lower SBP (−26.5 mmHg, P = 0.002), DBP (−23.7 mmHg, P = 0.004) and MAP (−25.1 mmHg, P = 0.002) compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9–141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.     

Lymphatic Territories (Lymphosomes) in a Canine: An Animal Model for Investigation of Postoperative Lymphatic Alterations

Background

Lymph node dissection is often performed as a part of surgical treatment for breast cancer and malignant melanoma to prevent malignant cells from traveling via the lymphatic system. Currently little is known about postoperative lymphatic drainage pattern alterations. This knowledge may be useful for management of recurrent cancer and prevention of breast cancer related lymphedema. We mapped the complete superficial lymphatic system of a dog and used this canine model to perform preliminary studies of lymphatic architectural changes in postoperative condition.

Methods

Lymphatic territories (lymphosomes) were mapped with 4 female mongrel carcasses using an indocyanine green (ICG) fluorescent lymphography and a radiographic microinjection technique. Two live dogs were then subjected to unilateral lymph node dissection of lymph basins of the forelimb, and ICG lymphography and lymphangiogram were performed 6 months after the surgery to investigate lymphatic changes. Lymphatic patterns in the carcass were then compared with postoperative lymphatic patterns in the live dogs.

Results

Ten lymphosomes were identified, corresponding with ten lymphatic basins. Postoperative fluorescent lymphographic images and lymphangiograms in the live dogs revealed small caliber lymphatic network fulfilling gaps in the surgical area and collateral lymphatic vessels arising from the network connecting to lymph nodes in the contralateral and ipsilateral neck in one dog and the ipsilateral subclavicular vein in another dog.

Conclusion

Our canine lymphosome map allowed us to observe lymphatic collateral formations after lymph node dissection in live dogs. This canine model may help clarify our understanding of postoperative lymphatic changes in humans in future studies.     

小鼠p16~(INK4a)基因位点的结构和功能研究

p1 6INK4a基因的失活与多种肿瘤的发生和发展有联系。通过筛选小鼠基因组文库 ,获得长度为 1 4.5kb的p1 6INK4a基因组DNA片段。对上述 1 4.5kbDNA测序后进行生物信息学分析表明 :该片段包含 3个外显子 ,编码 1个由 1 68个氨基酸残基组成的多肽 ,其相对分子质量的理论计算值为 1 7941 ,有 7个可能的磷酸化位点 ,说明p1 6INK4a蛋白的功能可能受到磷酸化的调控。该DNA片段的非编码区分布着大量短散布元件、长散布元件和简单重复序列 ,这样的结构为转座和同源重组提供了结构基础 ,提示了部分肿瘤细胞中p1 6INK4a基因缺失的可能原因。对第一外显子序列与已发表的相应序列比较发现其DNA序列和所编码的多肽存在多态性     

Survey for Selected Pathogens and Evaluation of Disease Risk Factors for Endangered Hawaiian Monk Seals in the Main Hawaiian Islands

A recently reestablished and increasing population of Hawaiian monk seals in the main Hawaiian Islands (MHI) is encouraging for this endangered species. However, seals in the MHI may be exposed to a broad range of human, pet, livestock, and feral animal pathogens. Our objective was to determine the movement and foraging habitats of Hawaiian monk seals in the MHI relative to the potential exposure of seals to infectious diseases in near-shore marine habitats. We captured 18 monk seals in the MHI between January 27, 2004 and November 29, 2005, tested them for various infectious diseases, and then monitored the foraging movements of 11 of them using satellite-linked radio transmitters for the next 32–167 days. All seals tested negative for canine adenovirus, calicivirus, four morbilliviruses, phocine herpes virus, Leptospira sp., and feline and canine heartworm antigen/antibody. Six of the seals tested positive on complement fixation for Chlamydophila abortus (formerly Chlamydia psittaci). Four seals demonstrated positive titers to Sarcocystis neurona, two to Neospora caninum, and two to Toxoplasma gondii. Fecal cultures showed approximately half (n = 6) positive for E. coli 0157, no Salmonella sp., and only one with Campylobacter sp. Satellite monitored seals spent considerable time foraging, traveling, and resting in neritic waters close to human population centers, agricultural activity, and livestock ranges, and sources of land-based water runoff and sewage dispersal. Consequently, Hawaiian monk seals in the MHI may be at risk of exposure to several infectious disease agents associated with terrestrial animals that can contaminate marine habitats from runoff along drainages and that are known to cause disease in marine mammals. Further, some seals overlapped substantially in their use of coastal habitats and several moved among islands while foraging and were seen on beaches near each other. This suggests that diseased seals could infect healthy conspecifics throughout the MHI.     

Identification of Quantitative Trait Loci (QTL) for Canine Hip Dysplasia and Canine Elbow Dysplasia in Bernese Mountain Dogs

A genome-wide association study for canine hip dysplasia (CHD) and canine elbow dysplasia (CED) using the Illumina canine high density bead chip had been performed for 174 Bernese mountain dogs. General and mixed linear model analysis identified two different regions with single nucleotide polymorphisms (SNPs) on dog chromosome (CFA) 14 significantly associated with CHD and a further significantly CHD-associated region on CFA37. For CED, four SNPs on CFA11 and 27 were significantly associated. The identified SNPs of four associated regions included nearby candidate genes. These possible positional candidates were the genes PON2 on CFA14 and FN1 on CFA37 for CHD and the genes LMNB1 on CFA11 and WNT10B on CFA27 for CED.     

Comparison of Cryopreservation Protocols (Single and Two-steps) and Thawing (Fast and Slow) for Canine Sperm

In addition to the existence of several cryopreservation protocols, no systematic research has been carried out in order to confirm the suitable protocol for canine sperm. This study aims to assess the effect of adding 5% glycerol during cryopreservation at 37°C (one-step) and 5°C (two-steps), in addition of testing two thawing protocols (37°C for 30 seconds, and 70°C for 8 seconds). We used 12 sperm samples divided into four experimental groups: Single-Step - Slow Thawing Group; Two-Step - Slow Thawing Group; Single-Step - Fast Thawing Group; and Two-Step - Fast Thawing Group. Frozen-thawed samples were submitted to automated analysis of sperm motility, evaluation of plasmatic membrane integrity, acrosomal integrity, mitochondrial activity, sperm morphology, sperm susceptibility to oxidative stress, and sperm binding assay to perivitellinic membrane of chicken egg yolk. Considering the comparison between freezing protocols, no statistical differences were verified for any of the response variables. When comparison between thawing protocols was performed, slow thawing protocol presented higher sperm count bound to perivitelline membrane of chicken egg yolk, compared to fast thawing protocol. Regardless of the freezing process, the slow thawing protocol can be recommended for the large scale cryopreservation of canine semen, since it shows a consistent better functional result.     

一个新的小鼠被毛突变位点（Uncv）的高分辨遗传图谱和物理图谱的构建

迄今为止 ,人们已经发现了 10 0多个影响小鼠和人的毛发发育的基因 ,在以前的研究中 ,Uncv被证实是一个新的影响小鼠被毛的位点 ,具体表现为纯合突变体为无毛 ,杂合突变体表现为稀毛。除此之外 ,纯合的突变体还表现为生长和发育的迟缓。克隆这一突变基因将有助于更好地了解人类毛发发育异常相关的疾病。尽管这一位点已经被定位在小鼠 11号染色体上 ,但是没有该区域的精细遗传图谱和物理图谱直接克隆该基因有一定的难度。利用了两组杂交方式 ,[BALB/c(Uncv/Uncv)×C3H ( / ) ]×BALB/c (Uncv/Uncv)和 [BALB/c (Uncv/Uncv)×C5 7BL/6 ( / ) ]×BALB/c(Uncv/Uncv) ,共 2 0 74个F2代个体 ,通过对 11号染色体上的 16个微卫星标记的基因分型连锁分析 ,最终把该基因定位于11号染色体上位于D11Mit337和D11Mit338之间的约 1.4cM之间的区域。随后 ,利用BAC文库杂交和BAC末端序列PCR锚定的方法 ,构建了由 35个BAC构成的高分辨的BAC重叠群 ,这一高分辨的遗传图谱和物理图谱的构建 ,为进一步克隆这一突变基因打下了基础。     

Genetic Variation in the Familial Mediterranean Fever Gene (MEFV) and Risk for Crohn's Disease and Ulcerative Colitis

Background and Aims

The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1β processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn''s disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene.

Methodology and Results

MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5′ haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele.

Conclusion

The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.     

Similar Organization of the Lipopolysaccharide-Binding Protein (LBP) and Phospholipid Transfer Protein (PLTP) Genes Suggests a Common Gene Family of Lipid-Binding Proteins

The transfer of lipids in aqueous environments such as serum has been attributed to a recently characterized class of proteins. Abnormal regulation of serum lipids by these proteins is thought to be a key event in the pathophysiology of cardiovascular diseases. Lipopolysaccharide (endotoxin) binding protein (LBP) was identified by virtue of its ability to bind bacterial lipid A. We have analyzed the exon–intron organization of the LBP gene and the nucleotide sequence of its approximately 20 kb spanning 5′- and 3′-untranslated regions. When comparing the genomic organization of LBP with that of two other genes coding for lipid transfer proteins, significant homologies were found. The LBP gene includes 15 exons, and the 2-kb promoter contains recognition elements of acute phase-typical reactants and a repetitive 12-mer motif with an as yet unknown protein-binding property. Detailed sequence comparison revealed a closer relatedness of LBP with PLTP than with CETP as demonstrated by an almost identical intron positioning. This high degree of similarity supports functional studies by others suggesting that like LBP, PLTP may also be able to bind and transport bacterial lipopolysaccharide.     

The Structure of a Type 3 Secretion System (T3SS) Ruler Protein Suggests a Molecular Mechanism for Needle Length Sensing

The type 3 secretion system (T3SS) and the bacterial flagellum are related pathogenicity-associated appendages found at the surface of many disease-causing bacteria. These appendages consist of long tubular structures that protrude away from the bacterial surface to interact with the host cell and/or promote motility. A proposed “ruler” protein tightly regulates the length of both the T3SS and the flagellum, but the molecular basis for this length control has remained poorly characterized and controversial. Using the Pseudomonas aeruginosa T3SS as a model system, we report the first structure of a T3SS ruler protein, revealing a “ball-and-chain” architecture, with a globular C-terminal domain (the ball) preceded by a long intrinsically disordered N-terminal polypeptide chain. The dimensions and stability of the globular domain do not support its potential passage through the inner lumen of the T3SS needle. We further demonstrate that a conserved motif at the N terminus of the ruler protein interacts with the T3SS autoprotease in the cytosolic side. Collectively, these data suggest a potential mechanism for needle length sensing by ruler proteins, whereby upon T3SS needle assembly, the ruler protein''s N-terminal end is anchored on the cytosolic side, with the globular domain located on the extracellular end of the growing needle. Sequence analysis of T3SS and flagellar ruler proteins shows that this mechanism is probably conserved across systems.     

Morbid Obesity as a Risk Factor for Hospitalization and Death Due to 2009 Pandemic Influenza A(H1N1) Disease

Background

Severe illness due to 2009 pandemic A(H1N1) infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1), independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP) to increase the risk of influenza-related complications.

Methodology/Principal Findings

We used a case-cohort design to compare cases of hospitalizations and deaths from 2009 pandemic A(H1N1) influenza occurring between April–July, 2009, with a cohort of the U.S. population estimated from the 2003–2006 National Health and Nutrition Examination Survey (NHANES); pregnant women and children <2 years old were excluded. For hospitalizations, we defined categories of relative weight by body mass index (BMI, kg/m²); for deaths, obesity or morbid obesity was recorded on medical charts, and death certificates. Odds ratio (OR) of being in each BMI category was determined; normal weight was the reference category. Overall, 361 hospitalizations and 233 deaths included information to determine BMI category and presence of ACIP-recognized medical conditions. Among ≥20 year olds, hospitalization was associated with being morbidly obese (BMI≥40) for individuals with ACIP-recognized chronic conditions (OR = 4.9, 95% CI 2.4–9.9) and without ACIP-recognized chronic conditions (OR = 4.7, 95%CI 1.3–17.2). Among 2–19 year olds, hospitalization was associated with being underweight (BMI≤5^th percentile) among those with (OR = 12.5, 95%CI 3.4–45.5) and without (OR = 5.5, 95%CI 1.3–22.5) ACIP-recognized chronic conditions. Death was not associated with BMI category among individuals 2–19 years old. Among individuals aged ≥20 years without ACIP-recognized chronic medical conditions death was associated with obesity (OR = 3.1, 95%CI: 1.5–6.6) and morbid obesity (OR = 7.6, 95%CI 2.1–27.9).

Conclusions/Significance

Our findings support observations that morbid obesity may be associated with hospitalization and possibly death due to 2009 pandemic H1N1 infection. These complications could be prevented by early antiviral therapy and vaccination.     

The Risk of Disease to Great Apes: Simulating Disease Spread in Orang-Utan (Pongo pygmaeus wurmbii) and Chimpanzee (Pan troglodytes schweinfurthii) Association Networks

All great ape species are endangered, and infectious diseases are thought to pose a particular threat to their survival. As great ape species vary substantially in social organisation and gregariousness, there are likely to be differences in susceptibility to disease types and spread. Understanding the relation between social variables and disease is therefore crucial for implementing effective conservation measures. Here, we simulate the transmission of a range of diseases in a population of orang-utans in Sabangau Forest (Central Kalimantan) and a community of chimpanzees in Budongo Forest (Uganda), by systematically varying transmission likelihood and probability of subsequent recovery. Both species have fission-fusion social systems, but differ considerably in their level of gregariousness. We used long-term behavioural data to create networks of association patterns on which the spread of different diseases was simulated. We found that chimpanzees were generally far more susceptible to the spread of diseases than orang-utans. When simulating different diseases that varied widely in their probability of transmission and recovery, it was found that the chimpanzee community was widely and strongly affected, while in orang-utans even highly infectious diseases had limited spread. Furthermore, when comparing the observed association network with a mean-field network (equal contact probability between group members), we found no major difference in simulated disease spread, suggesting that patterns of social bonding in orang-utans are not an important determinant of susceptibility to disease. In chimpanzees, the predicted size of the epidemic was smaller on the actual association network than on the mean-field network, indicating that patterns of social bonding have important effects on susceptibility to disease. We conclude that social networks are a potentially powerful tool to model the risk of disease transmission in great apes, and that chimpanzees are particularly threatened by infectious disease outbreaks as a result of their social structure.     

Vitamin D Receptor (VDR) Gene Polymorphisms and Risk of Coronary Artery Disease (CAD): Systematic Review and Meta-analysis

Biochemical Genetics - Several studies have noted that vitamin D receptor (VDR) gene polymorphisms are involved in the susceptibility to Coronary artery disease (CAD). Nonetheless, the results have...     

Albuminuria as a Risk Factor for Anemia in Chronic Kidney Disease: Result from the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD)

Background

Anemia is a common complication among patients with chronic kidney disease (CKD), and it is associated with unfavorable clinical outcomes in patients with CKD independent of the estimated glomerular filtration rate (eGFR). We assessed the association of the urinary albumin-to-creatinine ratio (ACR) and eGFR with anemia in CKD patients.

Methods

We conducted a cross-sectional study using baseline data from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD). Multiple regression analysis was performed to identify the independent association of albuminuria with anemia. Furthermore, odds ratios for anemia were calculated by cross-categorization of ACR and eGFR.

Results

Among 1,456 patients, the mean age was 53.5 ± 12.4 years, and the mean eGFR and ACR were 51.9 ± 30.5 mL/min per 1.73 m² and 853.2 ± 1,330.3 mg/g, respectively. Anemia was present in 644 patients (40.5%). Multivariate analysis showed that the odds ratio of anemia increased according to ACR levels, after adjusting for age, sex, eGFR, body mass index, pulse pressure, cause of CKD, use of erythropoiesis stimulating agents, serum calcium and ferritin (ACR < 30 mg/g as a reference group; 30–299 mg/g, adjusted odds ratio (OR) = 1.43, 95% confidence interval (CI) = 0.88–2.33; ≥300 mg/g, adjusted OR = 1.86, 95% CI = 1.12–3.10). In addition, graded associations were observed in cross-categorized groups of a higher ACR and eGFR compared to the reference group with an ACR <30 mg/g and eGFR ≥60 mL/min per 1.73 m².

Conclusion

The present study demonstrated that albuminuria was a significant risk factor for anemia in CKD patients independent of the eGFR.     

Genome-Wide Association and Trans-ethnic Meta-Analysis for Advanced Diabetic Kidney Disease: Family Investigation of Nephropathy and Diabetes (FIND)

Diabetic kidney disease (DKD) is the most common etiology of chronic kidney disease (CKD) in the industrialized world and accounts for much of the excess mortality in patients with diabetes mellitus. Approximately 45% of U.S. patients with incident end-stage kidney disease (ESKD) have DKD. Independent of glycemic control, DKD aggregates in families and has higher incidence rates in African, Mexican, and American Indian ancestral groups relative to European populations. The Family Investigation of Nephropathy and Diabetes (FIND) performed a genome-wide association study (GWAS) contrasting 6,197 unrelated individuals with advanced DKD with healthy and diabetic individuals lacking nephropathy of European American, African American, Mexican American, or American Indian ancestry. A large-scale replication and trans-ethnic meta-analysis included 7,539 additional European American, African American and American Indian DKD cases and non-nephropathy controls. Within ethnic group meta-analysis of discovery GWAS and replication set results identified genome-wide significant evidence for association between DKD and rs12523822 on chromosome 6q25.2 in American Indians (P = 5.74x10^-9). The strongest signal of association in the trans-ethnic meta-analysis was with a SNP in strong linkage disequilibrium with rs12523822 (rs955333; P = 1.31x10^-8), with directionally consistent results across ethnic groups. These 6q25.2 SNPs are located between the SCAF8 and CNKSR3 genes, a region with DKD relevant changes in gene expression and an eQTL with IPCEF1, a gene co-translated with CNKSR3. Several other SNPs demonstrated suggestive evidence of association with DKD, within and across populations. These data identify a novel DKD susceptibility locus with consistent directions of effect across diverse ancestral groups and provide insight into the genetic architecture of DKD.