Asymptomatic aortic regurgitation: diastolic function and type-B natriuretic peptide as prognostic factors

Introduction

The indication of valve replacement surgery in patients with severe aortic regurgitation (AR) is mainly based on the presence of symptoms or dilatation/dysfunction of the left ventricle (LV). However, diastolic function and natriuretic peptides have not been related to adverse outcomes in these patients. The aim of this study was to evaluate the prognosis impact of different diastolic function parameters as well as type-B natriuretic peptide (BNP).

Methods

Patients with moderate to severe or severe AR evaluated in the Heart Valve Clinic between 2013–2019 were evaluated. Those patients with classical indications for surgical aortic valve replacement (SAVR) at the moment of inclusion were excluded, as well as those patients with atrial fibrillation. Echocardiographic and analytical data were obtained from the medical history. End-point included cardiovascular mortality, SAVR and heart failure.

Results

A total of 126 patients were included. Median age was 65.0±17.7 years. Among them, 75 (59.5%) were men, 78 (62.4%) hypertensive, 44 (35.3%) suffered from dyslipidemia and 11 (9,6%) had ischaemic cardiomyopathy. During a median follow up of 31±17 months, 24.6% of the patients reached the combined end-point (n=5 developed heart failure, n=28 underwent SAVR, and n=4 died).

Among the diastolic parameters [E wave, A wave, E/A, E/e', left atrial volume and diameter, tricuspid regurgitation (TR) degree and pulmonary systolic pressure (PSP)], only TR degree and PSP were associated with a higher incidence of the combined endpoint: TR degree HR=2,08, p=0,039 and PSP HR= 1,1, p=0,007. BNP also showed prognostic impact for the combined endpoint (HR= 1,002, p=0,011).

Conclusions

In patients with asymptomatic significant AR, severity of TR, PSP and BNP levels are associated with worst prognosis. However, classical echocardiographic diastolic parameters do not show prognosis impact, probably due to the limitations of such parameters to identify diastolic dysfunction and high filling pressures in this population. Our findings support the use of PSP and TR over diastolic function parameters to better stratify left valvular patient risk in clinical practice.

Funding Acknowledgement

Type of funding source: None

P1551A genetic risk score predicts recurrent events after myocardial infarction in young adults

Background

To evaluate whether a genetic risk score (GRS) improves the prediction of recurrent events in young non-diabetic patients presenting with an acute myocardial infarction and identifies a more aggressive form of atherosclerosis in this population.

Methods and results

We performed a prospective study including 81 consecutive non-diabetic patients aged below 55 y.o. presenting with an acute myocardial infarction (48±6 y.o., 89% male). A comprehensive study including serum biomarkers, genetic testing and cardiac CT was performed. We studied the association of a GRS composed of 11 genetic variants with a primary composite end-point (all-cause mortality, recurrent acute coronary syndrome, and cardiac re-hospitalisation). After a median follow-up of 4.1 (3.5 - 4.4) years 24 recurrent events were documented. A significantly higher prevalence of 9 out of 11 risk alleles was noted compared with general population. The GRS was significantly associated with recurrent events, especially when baseline LDL-cholesterol levels were elevated. Compared with the low-risk GRS category, the multivariate-adjusted hazard ratio for recurrent events for the intermediate-risk GRS category was 10.2 (95% CI 1.1–100.3, p=0.04) and for the high-risk GRS was 20.7 (2.4–181.0, p=0.006) when LDL-C ≥2.8 mmol/L. Inclusion of the GRS improved the C statistic (ΔC statistic =0.086), the continuous Net Reclassification Index (30%) and the Integrated Discrimination Improvement (0.05) compared with a multivariate clinical risk model. Cardiac CT detected coronary calcified atherosclerosis and numerous plaques but it had a limited value for prediction of recurrences. No association was observed between extracellular matrix metabolism biomarkers and GRS or recurrent events in this population.

Cox regression analysis between GRS terciles and LDL-C Univariate analysis Multivariate analysis* HR (95% CI) p-value HR (95% CI) p-value* Low GRS 1 1 Intermediate GRS 2.0 (0.7–5.8) 0.21 LDL-C≤110 mg/dL (≤2.8 mmol/L) 1.0 (0.3–4.0) >110 mg/dL (>2.8 mmol/L) 10.2 (1.1–100.3) 0.04 High GRS 3.0 (1.0–9.2) 0.05 LDL-C≤110 mg/dL (≤2.8 mmol/L) 0.3 (0.1–1.9) >110 mg/dL (>2.8 mmol/L) 20.7 (2.4–181.0) 0.006 *Multivariate model adjusted for GRACE risk score and LDL-C and interaction. There was a strong interaction between GRS terciles and LDL-C (p<0.01).

Recurrent events based on genetic risk

Conclusions

A multilocus genetic risk score identified non-diabetic young patients at increased risk for recurrent events after a myocardial infarction. The significance of LDL-cholesterol in relation to genetic predisposition for recurrences merits further evaluation.

Acknowledgement/Funding

Instituto de Salud Carlos III (PI12/0564, PI14/01152 and PI15/00667), the CIBERCV and the Spanish Society of Cardiology (2015/CC)

P3370Prevalence of right ventricular dysfunction according to different parameters: basal and one year after transcatheter aortic valve implantation

Background

Right ventricle (RV) is not often specifically studied in patients with severe aortic stenosis (AS). It's difficult to find the correct tool to assess RV function with echocardiographic parameters, and the percentage of patients with dysfunction may vary depending on the parameter that we use.

The aim of the study was to evaluate the prevalence of RV dysfunction basal and one year after transcatheter aortic valve implantation (TAVI), according to different parameters.

Methods

Consecutive patients with severe AS undergoing TAVI from January 2016 to July 2017 were included. RV anatomical and functional parameters were analyzed according to ESC and ASE guidelines. RV dysfunction was assessed using tricuspid annular plane systolic excursion (TAPSE) <17 mm, fractional area change <35%, systolic movement of the RV lateral wall by tissue Doppler imaging (RV-S'TDI) <9.5 cm/s, global longitudinal (RV-GLS) and free wall strain (RV-FWS) using as cutting point [20]. Pre procedure echo, immediate post procedure and 1 year echo were analyzed. Statistical analysis was performed using SSPS version 22.

Results

The final study population consisted of 78 patients (115 patients were included, 37 were excluded due to suboptimal acoustic window for RV anatomical and functional evaluation), mean age 83.73±6.31 year-old, 38.2% females. We analyzed the percentages of RV dysfunction according to the different parameters evaluated before and in the control one year after. They are shown in Figure 1.

Prevalence of RV dysfunction

Conclusions

The presence of RV dysfunction in patients with severe AS is higher than expected Our data suggest that RV function improve one year after TAVI, in terms of a reduction in the number of patients with dysfunction. The assessment of RV function is difficult, and there is no agreement on what tools are more accurate and useful. RV strain seems to be the most sensible parameter to assess RV function in patients with AS undergoing TAVI. Impact of these measurements in patients management needs further evaluation.

Differential phenotype of immune cells in blood and milk following pegylated granulocyte colony-stimulating factor therapy during a chronic Staphylococcus aureus infection in lactating Holsteins

Neutrophils are principal host innate immune cell responders to mastitis infections. Thus, therapies have been developed that target neutrophil expansion. This includes the neutrophil-stimulating cytokine granulocyte colony-stimulating factor (gCSF). Pegylated gCSF (PEG-gCSF; Imrestor, Elanco Animal Health, Greenfield, IN) has been shown to reduce the natural incidence of mastitis in periparturient cows in commercial settings and reduce severity of disease against experimental mastitis challenge. Pegylated gCSF stimulates neutrophil expansion but also induces changes in monocyte and lymphocyte circulating numbers, surface protein expression changes, or both. We hypothesized that PEG-gCSF modulates surface expression of monocytes and neutrophils and facilitates their migration to the mammary gland. We challenged 8 mid-lactation Holsteins with approximately 150 cfu of Staphylococcus aureus (Newbould 305) in a single quarter via intramammary infusion. All animals developed chronic infections as assessed by bacteria counts and somatic cell counts (SCC). Ten to 16 wk postchallenge, 4 of the animals were treated with 2 subcutaneous injections of PEG-gCSF 7 d apart. Complete blood counts, SCC, bacterial counts, milk yield, feed intake, neutrophils extracellular trap analysis, and flow cytometric analyses of milk and blood samples were performed at indicated time points for 14 d after the first PEG-gCSF injection. The PEG-gCSF-treated cows had significantly increased numbers of blood neutrophils and lymphocytes compared with control cows. Flow cytometric analyses revealed increased surface expression of myeloperoxidase (MPO) on neutrophils and macrophages in milk but not in blood of treated cows. Neutrophils isolated from blood of PEG-gCSF-treated cows had decreased surface expression of CD62L (L-selectin) in blood, consistent with cell activation. Surprisingly, CD62L cell surface expression was increased on neutrophils and macrophages sourced from milk from treated animals compared with cells isolated from controls. The PEG-gCSF-treated cows did not clear the S. aureus infection, nor did they significantly differ in SCC from controls. These findings provide evidence that PEG-gCSF therapy modifies cell surface expression of neutrophils and monocytes. However, although surface MPO⁺ cells accumulate in the mammary gland, the lack of bacterial control from these milk-derived cells suggests an incomplete role for PEG-gCSF treatment against chronic S. aureus infection and possibly chronic mammary infections in general.

Non-motor symptoms burden, mood, and gait problems are the most significant factors contributing to a poor quality of life in non-demented Parkinson's disease patients: Results from the COPPADIS Study Cohort

OBJECTIVE

To identify factors related to a poor health-related and global quality of life (QoL) in a cohort of non-demented Parkinson's disease (PD) patients and compare to a control group.

METHODS

The data correspond to the baseline evaluation of the COPPADIS-2015 Study, an observational, 5-year follow-up, multicenter, evaluation study. Three instruments were used to assess QoL: (1) the 39-item Parkinson's disease Questionnaire (PDQ-39), (2) a subjective rating of global QoL (PQ-10), and (3) the EUROHIS-QOL 8-item index (EUROHIS-QOL8). Multiple linear regression methods were used to evaluate the direct impact of different variables on these QoL measures.

RESULTS

QoL was worse in PD patients (n = 692; 62.6 ± 8.9 years old, 60.3% males) than controls (n = 206; 61 ± 8.3 years old, 49.5% males): PDQ-39, 17.1 ± 13.5 vs 4.4 ± 6.3 (p < 0.0001); PQ-10, 7.3 ± 1.6 vs 8.1 ± 1.2 (p < 0.0001); EUROHIS-QOL8, 3.8 ± 0.6 vs 4.2 ± 0.5 (p < 0.0001). A high correlation was observed between PDQ-39 and Non-Motor Symptoms Scale (NMSS) (r = 0.72; p < 0.0001), and PDQ-39 and Beck Depression Inventory-II (BDI-II) (r = 0.65; p < 0.0001). For health-related QoL (PDQ-39), non-motor symptoms burden (NMSS), mood (BDI-II), and gait problems (Freezing Of Gait Questionnaire [FOGQ]) provided the highest contribution to the model (β = 0.32, 0.28, and 0.27, respectively; p < 0.0001); whereas mood and gait problems contributed the most to global QoL (PQ-10, β = -0.46 and -0.21, respectively; EUROHIS-QOL8, β = -0.44 and -0.23, respectively).

CONCLUSIONS

QoL is worse in PD patients than in controls. Mood, non-motor symptoms burden, and gait problems seem to be the most relevant factors affecting health-related and global perceived QoL in non-demented PD patients.

Effect of perfluorodecanoic acid on pig oocyte viability, intracellular calcium levels and gap junction intercellular communication during oocyte maturation in vitro

Perfluorodecanoic acid (PFDA) is a synthetic perfluorinated compound, which has been reported to exert adverse effects on somatic cells. However, its effects on germ cells have not been studied to date. The aim of the present study was to analyze the effects of PFDA on the viability, intracellular calcium levels and gap junction intercellular communication (GJIC) during porcine oocyte maturation in vitro. PFDA negatively impacted oocyte viability (medium lethal concentration, LC₅₀ = 7.8 μM) and maturation (medium inhibition of maturation, IM₅₀ = 3.8 μM). Oocytes exposed to 3.8 μM PFDA showed higher levels of intracellular calcium relative to control oocytes. In addition, GJIC among the cumulus cells and the oocyte was disrupted. The effects of PFDA on oocyte calcium homeostasis and intercellular communication seem to be responsible for the inhibition of oocyte maturation and oocyte death. In addition, since the deleterious effects of PFDA on oocyte viability, maturation and GJIC are significantly stronger than the previously reported effects of another widely used perfluorinated compound (Perfluorooctane sulfonate) in the same model, the use of PFDA in consumer products is questioned.

The effect of pegylated granulocyte colony-stimulating factor treatment prior to experimental mastitis in lactating Holsteins

Neutrophils are the first-acting and most prominent cellular defense against mastitis-causing pathogens. This makes neutrophil activation and expansion obvious candidates for targeted therapeutics. The granulocyte colony-stimulating factor (G-CSF) cytokine stimulates the bone marrow to produce granulocytes and stem cells and release them into the bloodstream, which results in neutrophilia as well as increasing the presence of other progenitor cells in the bloodstream. A pegylated form of G-CSF (PEG-gCSF) has been shown to significantly decrease naturally occurring mastitis rates in cows postpartum. The use of PEG-gCSF had not been evaluated in response to an experimental mastitis challenge. In an effort to examine the effect and mechanism of PEG-gCSF treatment, we challenged 11 mid-lactation Holsteins with ∼400 cfu Escherichia coli P4 by intramammary infusion. Five cows received 2 PEG-gCSF injections, one at 14 d and the other at 7 d before disease challenge, and 6 cows remained untreated. To evaluate the response of cows to the PEG-gCSF treatment, we measured complete blood counts, somatic cell counts, bacterial counts, milk yield, and feed intake data. The PEG-gCSF-treated cows had significantly increased circulating levels of neutrophils and lymphocytes after each PEG-gCSF injection, as well as following mastitis challenge. The PEG-gCSF-treated cows had significantly lower bacterial counts and lower milk BSA levels at the peak of infection. In addition, control cows had significant decreases in milk yield postinfection and significantly reduced feed intake postinfection compared with PEG-gCSF-treated cows. Collectively, PEG-gCSF treatment resulted in reduced disease severity when administered before a bacterial challenge. Mechanistically, we show that G-CSF treatment increases cell surface expression of an E-selectin ligand before infection on neutrophils and monocytes found in the blood. These cells quickly disappear from the blood shortly after infection, suggesting a mechanism for the reduced mastitis severity by priming immune cells for quick targeting to the site of infection.

Gene methylation biomarkers in sputum as a classifier for lung cancer risk

CT screening for lung cancer reduces mortality, but will cost Medicare ∼2 billion dollars due in part to high false positive rates. Molecular biomarkers could augment current risk stratification used to select smokers for screening. Gene methylation in sputum reflects lung field cancerization that remains in lung cancer patients post-resection. This population was used in conjunction with cancer-free smokers to evaluate classification accuracy of a validated eight-gene methylation panel in sputum for cancer risk. Sputum from resected lung cancer patients (n=487) and smokers from Lovelace (n=1380) and PLuSS (n=718) cohorts was studied for methylation of an 8-gene panel. Area under a receiver operating characteristic curve was calculated to assess the prediction performance in logistic regressions with different sets of variables. The prevalence for methylation of all genes was significantly increased in the ECOG-ACRIN patients compared to cancer-free smokers as evident by elevated odds ratios that ranged from 1.6 to 8.9. The gene methylation panel showed lung cancer prediction accuracy of 82–86% and with addition of clinical variables improved to 87–90%. With sensitivity at 95%, specificity increased from 25% to 54% comparing clinical variables alone to their inclusion with methylation. The addition of methylation biomarkers to clinical variables would reduce false positive screens by ruling out one-third of smokers eligible for CT screening and could increase cancer detection rates through expanding risk assessment criteria.

Abstract 3261: Gene methylation biomarkers in sputum as a classifier for lung cancer risk

Lung cancer is the leading cause of cancer death primarily because it is often diagnosed at an advanced stage. Results from the National Lung Screening Trial (NLST) showed that CT screening can reduce lung cancer mortality by 20%, but the high number of false positives and need for additional testing suggest that better risk classification of smokers prior to screening could save more lives with less cost and improved efficiency. Furthermore, eligibility criteria for NLST were restricted to smokers ages of 55-74 with &gt;30 pack-years of smoking and &lt; 15y since smoking cessation, which captures only ~40% of incident lung cancer cases. Molecular biomarkers could augment current risk stratification used to select smokers for screening. We have shown that gene specific promoter hypermethylation detected in sputum provides an assessment of field cancerization within the lungs of smokers that in turn predicts lung cancer. The current study addressed whether our validated 8-gene methylation panel could be extended to improve the existing risk prediction model used to recommend people for a CT screen by evaluating methylation in 487 resected Stage I lung cancer patients from the ECOG-ACRIN5597 trial (field of injury remains), 1378 current and former smokers from the Lovelace Smokers cohort (LSC) and 718 current and former smokers from the PLuSS cohort. Our initial analysis was restricted to individuals from each cohort who met NLST criteria for CT screening (n=371 ECOG-ACRIN, n=466 LSC and n=597 PLuSS). The methylation prevalence of all 8 genes was significantly increased in resected lung cancer patients compared to cancer-free smokers (odds ratios 1.6 to 8.9). The area under the receiver operator characteristic curve (AUC) was used to evaluate classification accuracy of different logistic regression models. Classification accuracy for clinical risk factors alone was 74-76%, methylation alone, 82-86%; and clinical risk factors plus methylation, 87-90% (p&lt;10-9 - 10-16). Setting the sensitivity at 95% improved specificity from 25% to 54% with both methylation and clinical factors in the model. Assessment of the performance of the gene methylation panel in all of the cancer patients and smokers did not reduce classification accuracy or increase specificity. Implementation of gene methylation biomarkers for screening could be a paradigm shift for lung cancer management by providing a much improved risk assessment model that will allow for expanding the number of smokers considered for screening, decreasing by one-third the actual number referred, and reducing mortality through increasing the CT positive predictive value. (Supported largely by R01 CA095568 and in part P30 CA118100)

Citation Format: Maria A. Picchi, Shuguang Leng, Guodong Wu, Donna M. Klinge, Cynthia L. Thomas, Elia Casas, Christine A. Stidley, Sandra J. Lee, Seena Aisner, Jill M. Siegfried, Suresh Ramalingam, Fadlo R. Khuri, Daniel D. Karp, Steven A. Belinsky. Gene methylation biomarkers in sputum as a classifier for lung cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3261. doi:10.1158/1538-7445.AM2017-3261

Effect of perfluorooctane sulfonate on viability, maturation and gap junctional intercellular communication of porcine oocytes in vitro

Perfluorooctane sulfonate (PFOS) is a broadly used man-made surfactant whose long half-life has led to bioaccumulation. This perfluorinated compound is ubiquitous in human body fluids. PFOS concentrations as high as 26μM in plasma have been reported in occupationally exposed populations, and high levels of PFOS in human follicular fluid have been associated with subfertility. However, the effect of PFOS on the maturation of oocytes in mammals has not been reported to date. The aim of this study was to determine the effects of PFOS during oocyte maturation. Results indicate that PFOS inhibits oocyte viability (Lethal Concentration50=32μM) and maturation (inhibition of maturation50=22μM) at physiologically relevant concentrations. In order to evaluate the mechanisms of oocyte maturation inhibition by PFOS, gap junctional intercellular communication (GJIC) between oocytes and granulosa cells was assessed. GJIC between granulosa cells and the oocyte was significantly affected during the first 8h of maturation. However, the inhibitory effect of PFOS on GJIC was not due to an alteration on the expression of connexin genes Cx43, Cx45 and Cx60. These findings suggest that occupationally exposed populations could be at risk, and that PFOS might affect oocyte maturation by interfering the GJIC in the cumulus-oocyte complexes during the first hours of maturation.

Estimates of epistatic and pleiotropic effects of () and () genetic markers on beef heifer performance traits enhanced by selection

Genetic marker effects and type of inheritance are estimated with poor precision when minor marker allele frequencies are low. A stable composite population (MARC II) was subjected to marker assisted selection for 2 yr to equalize and genetic marker frequencies to evaluate the epistatic and pleiotropic effects of these markers on BW, reproduction, and first calf performance traits in replacement beef females ( = 171) managed under 2 postweaning development protocols. Traits evaluated on the heifers were birth BW, weaning BW, 11-mo BW, 12-mo BW, 13-mo BW, first breeding season pregnancy evaluation BW, first calving season BW, 11-mo puberty, 12-mo puberty, 13-mo puberty, first breeding season pregnancy, and first calf weaning rate. Additionally, heifer's first calf performance traits of ordinal calving date, first calf birth BW, and first calf weaning BW (with and without age adjustment) were analyzed. Selection to increase minor allele frequencies and balanced sampling across genotype classes enhanced the ability to detect all genetic effects except dominance × dominance epistasis. The × genotype effect was significant ( < 0.05) for 11-mo BW and 12-mo BW and tended to be significant ( = 0.08) for 13-mo BW. Consistently, for all 3 traits, the most significant effect among epistatic × genotype effects was the additive effect, with the G allele decreasing BW. There were no associations between × genotype and fertility related traits ( ≥ 0.46) in this study. Additionally, there were no × genotype associations with first progeny performance traits ( ≥ 0.14). The large effect of the additive × additive interaction on first calf weaning BW was imprecisely estimated, which may warrant further investigation.

Seasonal variation in vitamin D status of beef cattle reared in the central United States

The objective was to retrospectively measure seasonal sunlight-associated variation in serum concentrations of 25-hydroxyvitamin D (25OHD) in beef cattle. The concentration of 25OHD was measured in crossbred animals born from March to May in 2011 and 2012. Vitamin D status 2 to 3 mo after birth (period 1) was only available for 2012 calves and was measured in June 2012. Period 1 animals had serum 25OHD concentrations of 26.3 ± 1.5 ng/mL. The 25OHD concentrations for late summer (period 2) were 46.6 ± 1.4 and 51.0 ± 1.5 ng/mL for 2011 and 2012, respectively. Serum concentration of 25OHD in early fall (period 3) were 63.8 ± 1.4 and 55.2 ± 1.5 ng/mL for calves in 2011 and 2012, respectively. Values observed for both late summer and early fall indicated vitamin D sufficiency (P < 0.001) compared with period 1. With diminishing exposure to ultraviolet B and consuming ∼800 IU or 1800 IU (2011 and 2012, respectively) of supplemental vitamin D, the calves' midwinter (period 4) 25OHD concentrations fell to 15.2 ± 1.6 and 16.7 ± 1.5 ng/mL for 2011 and 2012, respectively, after 4 to 5 mo on a finishing diet (P < 0.0001). This is considered vitamin D insufficiency in most species. Results indicate that calves are marginally sufficient to insufficient for vitamin D based on serum 25OHD concentrations soon after birth and during winter. Some individual animals would be classified vitamin D deficient. In the absence of sufficient UVB exposure, the dietary vitamin D requirements for rapidly growing beef cattle may need to be increased.

Genome data from a sixteenth century pig illuminate modern breed relationships

Ancient DNA (aDNA) provides direct evidence of historical events that have modeled the genome of modern individuals. In livestock, resolving the differences between the effects of initial domestication and of subsequent modern breeding is not straight forward without aDNA data. Here, we have obtained shotgun genome sequence data from a sixteenth century pig from Northeastern Spain (Montsoriu castle), the ancient pig was obtained from an extremely well-preserved and diverse assemblage. In addition, we provide the sequence of three new modern genomes from an Iberian pig, Spanish wild boar and a Guatemalan Creole pig. Comparison with both mitochondrial and autosomal genome data shows that the ancient pig is closely related to extant Iberian pigs and to European wild boar. Although the ancient sample was clearly domestic, admixture with wild boar also occurred, according to the D-statistics. The close relationship between Iberian, European wild boar and the ancient pig confirms that Asian introgression in modern Iberian pigs has not existed or has been negligible. In contrast, the Guatemalan Creole pig clusters apart from the Iberian pig genome, likely due to introgression from international breeds.

Polymorphisms in calpastatin and mu-calpain genes are associated with beef iron content

The objective of this study was to assess the association of markers in the calpastatin and mu-calpain loci with iron in beef cattle muscle. The population consisted of 259 cross-bred steers from Beefmaster, Brangus, Bonsmara, Romosinuano, Hereford and Angus sires. Total iron and heme iron concentrations were measured. Markers in the calpastatin (referred to as CAST) and mu-calpain (referred to as CAPN4751) genes were used to assess their association with iron levels. The mean and standard error for iron and heme iron content in the population was 35.6 ± 1.3 μg and 27.1 ± 1.4 μg respectively. Significant associations (P < 0.01) of markers were observed for both iron and heme iron content. For CAST, animals with the CC genotype had higher levels of iron and heme iron in longissimus dorsi muscle. For CAPN4751, individuals with the TT genotype had higher concentrations of iron and heme iron than did animals with the CC and CT genotypes. Genotypes known to be associated with tougher meat were associated with higher levels of iron concentration.

Long-term benefits of nevirapine-containing regimens: multicenter study with 506 patients, followed-up a median of 9 years

OBJECTIVE

To evaluate long-term outcomes in patients maintaining a nevirapine (NVP)-based regimen.

METHODS

Retrospective, multicenter, cohort study including patients currently receiving an NVP regimen that had been started at least 5 years previously. Demographic, clinical, and analytical variables were recorded.

RESULTS

Median follow-up was 8.9 (5.7-11.3) years. Baseline characteristics: 74% men, 47 years old, 36% drug users, 40% AIDS, 40% HCV+, 51.4% detectable HIV-1 viral load, CD4 count 395 (4-1,421)/μL, 19% CD4 < 200/μL, 27% ALT grade 1-2, 36% AST grade 1-2. Thirty percent ART-naive, 83%received NVP associated with 2 nucleoside analogues during the study period, and 17% a protease inhibitor. A significant improvement was observed in general health status markers, including hemoglobin, platelets, and albumin, regardless of HCV coinfection. CD4 cell gain was +218 and +322/μL after 6 and 9 years, respectively (+321 and +391 in naive patients). Triglycerides significantly decreased in pretreated patients, whereas the percentage of patients with HDLc < 1.03 mmol/L and LDL-c > 3.37 mmol/L significantly decreased in a subsample with available values. A significant decrease in transaminases, alkaline phosphatase, and Fib4 score was observed, mainly in HCV+ and ARV-naive patients.

CONCLUSIONS

In patients who tolerate NVP therapy, (even those with HCV coinfection), long term benefits may be significant in terms of a progressive improvement in general health status markers and CD4 response, a favorable lipid profile, and good liver tolerability.

Selection for genetic markers in beef cattle reveals complex associations of thyroglobulin and casein1-s1 with carcass and meat traits

Genetic markers in casein (CSN1S1) and thyroglobulin (TG) genes have previously been associated with fat distribution in cattle. Determining the nature of these genetic associations (additive, recessive, or dominant) has been difficult, because both markers have small minor allele frequencies in most beef cattle populations. This results in few animals homozygous for the minor alleles. selection to increase the frequencies of the minor alleles for 2 SNP markers in these genes was undertaken in a composite population. The objective was to obtain better estimates of genetic effects associated with these markers and determine if there were epistatic interactions. Selection increased the frequencies of minor alleles for both SNP from <0.30 to 0.45. Bulls (n = 24) heterozygous for both SNP were used in 3 yr to produce 204 steer progeny harvested at an average age of 474 d. The combined effect of the 9 CSN1S1 × TG genotypes was associated with carcass-adjusted fat thickness (P < 0.06) and meat tenderness predicted at the abattoir by visible and near-infrared reflectance spectroscopy (P < 0.04). Genotype did not affect BW from birth through harvest, ribeye area, marbling score, slice shear force, or image-based yield grade (P > 0.10). Additive, dominance, and epistatic SNP association effects were estimated from genotypic effects for adjusted fat thickness and predicted meat tenderness. Adjusted fat thickness showed a dominance association with TG SNP (P < 0.06) and an epistatic additive CSN1S1 × additive TG association (P < 0.03). For predicted meat tenderness, heterozygous TG meat was more tender than meat from either homozygote (P < 0.002). Dominance and epistatic associations can result in different SNP allele substitution effects in populations where SNP have the same linkage disequilibrium with causal mutations but have different frequencies. Although the complex associations estimated in this study would contribute little to within-population selection response, they could be important for marker-assisted management or reciprocal selection schemes.

Loci on Bos taurus chromosome 2 and Bos taurus chromosome 26 are linked with bovine respiratory disease and associated with persistent infection of bovine viral diarrhea virus

The objective of this study was to identify loci linked with bovine respiratory disease (BRD) and subsequently to determine if these same loci were associated with bovine viral diarrhea virus persistent infection (BVD-PI) in affected calves or their dams. A genome-wide linkage study using 312 microsatellites was conducted to identify loci linked with BRD in a Brahman × Hereford sire half-sib family. Disease incidence was recorded from birth to slaughter by daily monitoring. Linkage was suggestive for a QTL on BTA2 (F = 7.31, P = 0.007) and BTA26 (F = 10.46, P = 0.001). Six and 7 markers were added and genotyped between 110 and 126 cM on BTA2 and between 42 and 72 cM on BTA26, respectively, in the intervals where linkage was found. These markers were used to reevaluate the Brahman × Hereford family and to evaluate 3 additional crossbred half-sib families. Linkage was found with BRD on BTA2 (F = 4.94, P < 0.01), with a peak at 110 cM, and on BTA26 (F = 4.03, P < 0.05), with peaks at 42 and 52 cM. The same markers were then tested for an association with BVD-PI in 1) BVD-PI calves compared with age-matched unaffected calves from the same herd or 2) dams with BVD-PI compared with age-matched unaffected calves. Sixty commercial beef cow-calf herds were tested for BVD-PI, and 79 calves from 8 ranches had BVD-PI. Four of 6 markers were associated (P = 4.8 × 10(-9) to P = 0.01) with BVD-PI on BTA2, and 4 of 7 markers were associated (P = 0.008 to P = 0.04) with BVD-PI on BTA26 when BVD-PI calves were compared with unaffected calves. The comparison of BVD-PI dams with unaffected calves detected associations with BVD-PI for all markers tested on BTA2 (P = 3 × 10(-9) to P = 0.005) and for 3 of 7 markers on BTA26 (P = 1.4 × 10(-6) to P = 0.006).

Birth and weaning traits in crossbred cattle from Hereford, Angus, Brahman, Boran, Tuli, and Belgian Blue sires

The objective of this study was to characterize breeds representing diverse biological types for birth and weaning traits in crossbred cattle. Gestation length, calving difficulty, percentage of unassisted calving, percentage of perinatal survival, percentage of survival from birth to weaning, birth weight, BW at 200 d, and ADG were measured in 2,500 calves born and 2,395 calves weaned. Calves were obtained by mating Hereford, Angus, and MARC III (one-fourth Hereford, one-fourth Angus, one-fourth Pinzgauer, and one-fourth Red Poll) mature cows to Hereford or Angus (British breed), Brahman, Tuli, Boran, and Belgian Blue sires. Calves were born during the spring seasons of 1992, 1993, and 1994. Sire breed was significant for all traits (P < 0.002). Offspring from British breeds and the Belgian Blue breed had the shortest gestation length (285 d) when compared with progeny from other sire breeds (average of 291 d). Calving difficulty was greater in offspring from Brahman sires (1.24), whereas the offspring of Tuli sires had the least amount of calving difficulty (1.00). Offspring from all sire breeds had similar perinatal survival and survival from birth to weaning (average of 97.2 and 96.2%, respectively), with the exception of offspring from Brahman sires, which had less (92.8 and 90.4%, respectively). Progeny of Brahman sires were heaviest at birth (45.7 kg), followed by offspring from British breed, Boran, and Belgian Blue sires (average of 42.4 kg). The lightest offspring at birth were from Tuli sires (38.6 kg). Progeny derived from Brahman sires were the heaviest at 200 d (246 kg), and they grew faster (1.00 kg/d) than offspring from any other group. The progeny of British breeds and the Belgian Blue breed had an intermediate BW at 200 d (238 kg) and an intermediate ADG (average of 0.98 kg/d). The progeny of Boran and Tuli sires were the lightest at 200 d (227 kg) and had the least ADG (0.93 kg/d). Male calves had a longer gestation length, had a greater incidence of calving difficulty, had greater mortality to weaning, were heavier, and grew faster than female calves. Sire breed effects can be optimized by selection and use of appropriate crossbreeding systems.