Recently the SNP identified as rs1260326, in the glucokinase regulatory protein (GCKR) was associated with hypertriglyceridemia in adults. Since accumulation of triglycerides in hepatocytes represents the hallmark of the steatosis, we aimed to investigate whether this variant might be associated with fatty liver (hepatic fat content, HFF%). Moreover, since recently rs738409 in the PNPLA3 and rs2854116 in the APOC3 were associated with fatty liver recently, we explored how the GCKR SNP and these two variants jointly influence hepatosteatosis.
Methods and Results
We studied 455 obese children and adolescents (181 Caucasians, 139 African Americans and 135 Hispanics). All underwent an OGTT and fasting lipoprotein subclasses measurement by proton NMR. A subset of 142 children underwent a fast gradient MRI to measure the HFF%.
The rs1260326 was associated with elevated triglycerides (Caucasians p=0.00014; African Americans p=0.00417) large VLDL (Caucasians p=0.001; African Americans p=0.03) and with fatty liver (Caucasians p= 0.034; African Americans p= 0.00002; and Hispanics p= 0.016). The PNPLA3, but not the APOC3 rs2854116 SNP, was associated with fatty liver but not with triglycerides levels. There was a joint effect between the PNPLA3 and GCKR SNPs, explaining 32% of HFF% variance Caucasians (p=0.00161), 39.0% in African Americans (p=0.00000496), and 15% in Hispanics (p=0.00342).
The rs1260326 in GCKR is associated with hepatic fat accumulation along with large VLDL, and triglycerides levels. GCKR and PNPLA3 act together to convey susceptibility to fatty liver in obese youths.
GCKR; PNPLA3; SNPs; obesity; youths
Fanconi anemia (FA) is a rare genetic disorder characterized by bone marrow failure and an increased risk for leukemia and cancer. Fifteen proteins thought to function in the repair of DNA interstrand crosslinks (ICLs) comprise what is known as the FA-BRCA pathway. Activation of this pathway leads to the monoubiquitylation and chromatin localization of FANCD2 and FANCI. It has previously been shown that FANCJ interacts with the mismatch repair (MMR) complex MutLα. Here we show that FANCD2 interacts with the MMR proteins MSH2 and MLH1. FANCD2 monoubiquitylation, foci formation and chromatin loading are greatly diminished in MSH2-deficient cells. Human or mouse cells lacking MSH2 or MLH1 display increased sensitivity and radial formation in response to treatment with DNA crosslinking agents. Studies in human cell lines and Drosophila mutants suggest an epistatic relationship between FANCD2, MSH2 and MLH1 with regard to ICL repair. Surprisingly, the interaction between MSH2 and MLH1 is compromised in multiple FA cell lines, and FA cell lines exhibit deficient MMR. These results suggest a significant role for MMR proteins in the activation of the FA pathway and repair of ICLs. In addition, we provide the first evidence for a defect in MMR in FA cell lines.
Basal cell carcinoma (BCC) incidence is increasing, particularly among adults under age 40. Pigment-related characteristics are associated with BCC in older populations, but epidemiologic studies among younger individuals and analyses of phenotype-genotype interactions are limited. We examined self-reported phenotypes and melanocortin 1 receptor gene (MC1R) variants in relation to early-onset BCC. BCC cases (n=377) and controls with benign skin conditions (n=390) under age 40 were identified through Yale’s Dermatopathology database. Factors most strongly associated with early-onset BCC were skin reaction to first summer sun for one hour [severe sunburn vs. tan odds ratio (OR)=12.27, 95% confidence interval (CI)=4.08–36.94] and skin color (very fair vs. olive OR=11.06, 95% CI=5.90–20.74). Individuals with two or more MC1R non-synonymous variants were 3.59 times (95% CI=2.37–5.43) more likely to have BCC than those without non-synonymous variants. All host characteristics and MC1R were more strongly associated with multiple BCC cases status (37% of cases) than single BCC case status. MC1R, number of moles, skin reaction to first summer sun for one hour, and hair and skin color were independently associated with BCC. BCC risk conferred by MC1R tended to be stronger among those with darker pigment phenotypes, traditionally considered to be at low-risk of skin cancer.
Pavlovian trace conditioning critically depends on the medial prefrontal cortex (mPFC) and hippocampus (HPC), whereas delay conditioning does not depend on these brain structures. Given that the cholinergic basal forebrain system modulates activity in both the mPFC and HPC, it was reasoned that the level of acetylcholine (ACh) release in these regions would show distinct profiles during testing in trace and delay conditioning paradigms. To test this assumption, microdialysis probes were implanted unilaterally into the mPFC and HPC of rats that were pre-trained in appetitive trace and delay conditioning paradigms using different conditional stimuli in the two tasks. On the day of microdialysis testing, dialysate samples were collected during a quiet baseline interval before trials were initiated, and again during performance in separate blocks of trace and delay conditioning trials in each animal. ACh levels were quantified using high performance liquid chromatography and electrochemical detection techniques. Consistent with our hypothesis, results showed that ACh release in the mPFC was greater during trace conditioning than during delay conditioning. The level of ACh released during trace conditioning in the HPC was also greater than the levels observed during delay conditioning. While ACh efflux in both the mPFC and HPC selectively increased during trace conditioning, ACh levels in the mPFC during trace conditioning testing showed the greatest increases observed. These results demonstrate a dissociation in cholinergic activation of the mPFC and HPC during performance in trace but not delay appetitive conditioning, where this cholinergic activity may contribute to attentional mechanisms, adaptive response timing, or memory consolidation necessary for successful trace conditioning.
microdialysis; attention; cholinergic system; nucleus basalismagnocellularis; medial septal area
Babesiosis is an emerging zoonosis with important public health implications, as the incidence of the disease has risen dramatically over the past decade. Because the current gold standard for detection of Babesia is microscopic examination of blood smears, accurate identification requires trained personnel. Species in the genus cannot be distinguished microscopically, and Babesia can also be confused with the early trophozoite stage (ring forms) of Plasmodium parasites. To allow more accurate diagnosis in a format that is accessible to a wider variety of laboratories, we developed a real-time PCR assay targeting the 18S rRNA gene of Babesia microti, the dominant babesiosis pathogen in the United States. The real-time PCR is performed on DNA extracted from whole-blood specimens and detects Babesia microti with a limit of detection of ∼100 gene copies in 5 μl of blood. The real-time PCR assay was shown to be 100% specific when tested against a panel of 24 organisms consisting of Babesia microti, other Babesia species, Plasmodium species, tick-borne and other pathogenic bacteria, and other blood-borne parasites. The results using clinical specimens show that the assay can detect infections of lower parasitemia than can be detected by microscopic examination. This method is therefore a rapid, sensitive, and accurate method for detection of Babesia microti in patient specimens.
Carriers of a premutation (CGG repeat length 55–200) in the fragile X mental retardation (FMR1) gene are at risk for primary ovarian insufficiency (FXPOI). The anti-Müllerian hormone (AMH) level acts as a useful marker of ovarian follicle reserve and, thus, may serve to predict when this ovarian reserve becomes too low to sustain ovarian function. We investigated the intra-individual variation of AMH levels over time for premutation carriers compared with non-carriers.
We determined AMH levels in blood samples from 240 women ascertained through fragile X families, of which 127 were premutation carriers and 113 were non-carriers. Linear mixed models were used to assess the effect of age and premutation status on AMH levels and to determine a modeled AMH value. The stability over time of the deviation of observed AMH levels from modeled levels, referred to as standardized AMH values, was assessed through correlation coefficients of 41 longitudinal samples.
At all ages, premutation carriers exhibited lower AMH levels. For all women, AMH was found to decrease by 10% per year. The added effect of having a premutation decreased AMH levels by 54%. The deviation of an individual's AMH level from the modeled value showed a reasonable intra-individual correlation. The Pearson correlation coefficient of two samples taken at different ages was 0.36 (P = 0.05) for non-carriers and 0.69 (P = 0.01) for carriers.
We developed a unique standardized AMH value, taking FMR1 premutation status and the subject's age into account, which appears to be stable over time and may serve as a predictor for FXPOI after further longitudinal assessment.
anti-Müllerian hormone (AMH); premutation carriers; FMR1 gene; fragile X-associated primary ovarian insufficiency (FXPOI); ovarian reserve
Granulocyte colony-stimulating factor (G-CSF) in combination with plerixafor produces significant mobilization of CD34+ cells in rhesus macaques. We sought to evaluate whether these CD34+ cells can stably reconstitute blood cells with lentiviral gene marking.
We performed hematopoietic stem cell (HSC) transplantation using G-CSF and plerixafor-mobilized rhesus CD34+ cells transduced with a lentiviral vector, and these data were compared to those of G-CSF and stem cell factor (SCF) mobilization.
G-CSF and plerixafor mobilization resulted in CD34+ cell yields that were 2-fold higher than yields with G-CSF and SCF. CD123 (IL-3 receptor) expression was greater in G-CSF and plerixafor-mobilized CD34+ cells when compared to G-CSF alone. Animals transplanted with G-CSF and plerixafor-mobilized cells showed engraftment of all lineages, similar to animals who received G-CSF and SCF-mobilized grafts. Lymphocyte engraftment was accelerated in animals receiving the G-CSF and plerixafor-mobilized CD34+ cells. One animal in the G-CSF and plerixafor group developed cold agglutinin associated skin rash during the first 3 months of rapid lymphocyte recovery. One year after transplantation, all animals had 2–10% transgene expression in all blood cell lineages.
G-CSF and plerixafor-mobilized CD34+ cells accelerate lymphocyte engraftment and contain HSC capable of reconstituting multi-lineage blood cells. These findings indicate important differences to consider in plerixafor based HSC mobilization protocols in rhesus macaques.
hematopoietic stem cell transplantation; hematopoietic stem cell mobilization; lentivirus vector
Background: Polychlorinated biphenyls (PCBs) manufactured in Anniston, Alabama, from 1929 to 1971 caused significant environmental contamination. The Anniston population remains one of the most highly exposed in the world.
Objectives: Reports of increased diabetes in PCB-exposed populations led us to examine possible associations in Anniston residents.
Methods: Volunteers (n = 774) from a cross-sectional study of randomly selected households and adults who completed the Anniston Community Health Survey also underwent measurements of height, weight, fasting glucose, lipid, and PCB congener levels and verification of medications. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationships between PCBs and diabetes, adjusting for diabetes risk factors. Participants with prediabetes were excluded from the logistic regression analyses.
Results: Participants were 47% African American, 70% female, with a mean age of 54.8 years. The prevalence of diabetes was 27% in the study population, corresponding to an estimated prevalence of 16% for Anniston overall; the PCB body burden of 35 major congeners ranged from 0.11 to 170.42 ppb, wet weight. The adjusted OR comparing the prevalence of diabetes in the fifth versus first quintile of serum PCB was 2.78 (95% CI: 1.00, 7.73), with similar associations estimated for second through fourth quintiles. In participants < 55 years of age, the adjusted OR for diabetes for the highest versus lowest quintile was 4.78 (95% CI: 1.11, 20.6), whereas in those ≥ 55 years of age, we observed no significant associations with PCBs. Elevated diabetes prevalence was observed with a 1 SD increase in log PCB levels in women (OR = 1.52; 95% CI: 1.01, 2.28); a decreased prevalence was observed in men (OR = 0.68; 95% CI: 0.33, 1.41).
Conclusions: We observed significant associations between elevated PCB levels and diabetes mostly due to associations in women and in individuals < 55 years of age.
diabetes; epidemiology; polychlorinated biphenyls (PCBs); POPs
Despite educational and public health campaigns to convey the risks of indoor tanning, many individuals around the world continue to engage in this behavior. Few descriptive studies of indoor tanning have collected information pertaining to the lifetime history of indoor tanning, thereby limiting our ability to understand indoor tanning patterns and potentially target interventions for individuals who not only initiate, but continue to persistently engage in indoor tanning.
In-person interviews elicited detailed retrospective information on lifetime history of indoor tanning among white individuals (n = 401) under age 40 seen by a dermatologist for a minor benign skin condition. These individuals were controls in a case-control study of early-onset basal cell carcinoma. Outcomes of interest included ever indoor tanning in both males and females, as well as persistent indoor tanning in females - defined as females over age 31 who tanned indoors at least once in the last three or all four of four specified age periods (ages 11-15, 16-20, 21-30 and 31 or older). Multivariate logistic regression was used to identify sociodemographic and lifestyle correlates of ever and persistent indoor tanning in females.
Approximately three-quarters (73.3%) of females and 38.3% of males ever tanned indoors, with a median age of initiation of 17.0 and 21.5, respectively. Among indoor tanners, 39.3% of females and 21.7% of males reported being burned while indoor tanning. Female ever indoor tanners were younger, had darker color eyes, and sunbathed more frequently than females who never tanned indoors. Using unique lifetime exposure data, 24.7% of female indoor tanners 31 and older persistently tanned indoors starting as teenagers. Female persistent indoor tanners drank significantly more alcohol, were less educated, had skin that tanned with prolonged sun exposure, and sunbathed outdoors more frequently than non-persistent tanners.
Indoor tanning was strikingly common in this population, especially among females. Persistent indoor tanners had other high-risk behaviors (alcohol, sunbathing), suggesting that multi-faceted behavioral interventions aimed at health promotion/disease prevention may be needed in this population.
Indoor tanning; Correlates; Epidemiology; Skin cancer prevention
Basal cell carcinomas (BCCs) are the most common cancers in the United States. The histologic appearance distinguishes several subtypes, each of which can have a different biologic behavior. In this study, global miRNA expression was quantified by high-throughput sequencing in nodular BCCs, a subtype that is slow growing, and infiltrative BCCs, aggressive tumors that extend through the dermis and invade structures such as cutaneous nerves. Principal components analysis correctly classified seven of eight infiltrative tumors on the basis of miRNA expression. The remaining tumor, on pathology review, contained a mixture of nodular and infiltrative elements. Nodular tumors did not cluster tightly, likely reflecting broader histopathologic diversity in this class, but trended toward forming a group separate from infiltrative BCCs. Quantitative polymerase chain reaction assays were developed for six of the miRNAs that showed significant differences between the BCC subtypes, and five of these six were validated in a replication set of four infiltrative and three nodular tumors. The expression level of miR-183, a miRNA that inhibits invasion and metastasis in several types of malignancies, was consistently lower in infiltrative than nodular tumors and could be one element underlying the difference in invasiveness. These results represent the first miRNA profiling study in BCCs and demonstrate that miRNA gene expression may be involved in tumor pathogenesis and particularly in determining the aggressiveness of these malignancies.
miR-150; miR-183; histopathology; skin cancer; expression profiling
The genetic factors associated with susceptibility to nonalcoholic fatty liver disease (NAFLD) in pediatric obesity remain largely unknown. Recently, a nonsynonymous single-nucleotide polymorphism (rs738409), in the patatin-like phospholipase 3 gene (PNPLA3) has been associated with hepatic steatosis in adults. In a multiethnic group of 85 obese youths, we genotyped the PNLPA3 single-nucleotide polymorphism, measured hepatic fat content by magnetic resonance imaging and insulin sensitivity by the insulin clamp. Because PNPLA3 might affect adipogenesis/lipogenesis, we explored the putative association with the distribution of adipose cell size and the expression of some adipogenic/lipogenic genes in a subset of subjects who underwent a subcutaneous fat biopsy. Steatosis was present in 41% of Caucasians, 23% of African Americans, and 66% of Hispanics. The frequency of PNPLA3(rs738409) G allele was 0.324 in Caucasians, 0.183 in African Americans, and 0.483 in Hispanics. The prevalence of the G allele was higher in subjects showing hepatic steatosis. Surprisingly, subjects carrying the G allele showed comparable hepatic glucose production rates, peripheral glucose disposal rate, and glycerol turnover as the CC homozygotes. Carriers of the G allele showed smaller adipocytes than those with CC genotype (P = 0.005). Although the expression of PNPLA3, PNPLA2, PPARγ2(peroxisome proliferator-activated receptor gamma 2), SREBP1c(sterol regulatory element binding protein 1c), and ACACA(acetyl coenzyme A carboxylase) was not different between genotypes, carriers of the G allele showed lower leptin (LEP)(P = 0.03) and sirtuin 1 (SIRT1) expression (P = 0.04).
A common variant of the PNPLA3 gene confers susceptibility to hepatic steatosis in obese youths without increasing the level of hepatic and peripheral insulin resistance. The rs738409 PNPLA3 G allele is associated with morphological changes in adipocyte cell size.
In previous analyses, we identified a region of chromosome 19 as harboring a susceptibility locus for chronic otitis media with effusion and/or recurrent otitis media (COME/ROM). Our aim was to further localize the linkage signal and ultimately identify the causative variant or variants. We followed up our previous linkage scan with dense SNP genotyping across in a 5 Mb region. A total of 607 individuals from 139 families, including 159 affected sib pairs and 62 second-degree affected relative pairs, were genotyped at 1,091 SNPs. We carried out a nonparametric linkage analysis, modeling marker-to-marker linkage disequilibrium.
The maximum log of the odds (LOD) score increased to 3.75 (P = 1.6 × 10-5) at position 63.4 Mb, with a LOD-1 support interval between 61.6 Mb and 63.8 Mb, providing significant evidence of linkage between this region and COME/ROM. The support interval contains over 90 known genes, including several genes involved in the inflammasome protein complex, a key regulator of the innate immune response to harmful exogenous or endogenous stimuli. Parametric linkage analysis suggests that for a sib of an affected individual, the recurrence risk of COME/ROM due to this linkage region is twice the recurrence risk in the population. We examined potential associations between the SNPs genotyped in this region and COME/ROM, however none provided evidence for association.
This study has refined the 19q region of linkage with COME/ROM, and association results suggest that the linkage signal may be due to rare variants.
Linkage; fine mapping; otolaryngology
Rapid, accurate diagnosis of community-acquired pneumonia (CAP) due to Mycoplasma pneumoniae is compromised by low sensitivity of culture and serology. PCR has emerged as a sensitive method to detect M. pneumoniae DNA in clinical specimens. However, conventional real-time PCR is not cost-effective for routine out-patient or implementation. Here, we evaluate a novel microfluidic real-time PCR platform (Advanced Liquid Logic, Inc.) that is rapid, portable, and fully automated. We enrolled patients with CAP and extracted DNA from nasopharyngeal wash (NPW) specimens using a biotinylated capture probe and streptavidin-coupled magnetic beads. Each extract was tested for M. pneumoniae-specific DNA by real-time PCR on both conventional and microfluidic platforms using Taqman probe and primers. Three of 59 (5.0%) NPWs were positive, and agreement between the methods was 98%. The microfluidic platform was equally sensitive but three times faster and offers an inexpensive and convenient diagnostic test for microbial DNA.
Mycoplasma pneumoniae; real-time PCR; DNA-based diagnostics; community-acquired pneumonia; diagnostic microbiology
A novel method to quantify dyssynchrony using phase analysis of single-photon emission computed tomography (SPECT) myocardial perfusion imaging has been developed. We sought to determine the prevalence of SPECT-derived mechanical dyssynchrony, and we report clinical variables which predict mechanical dyssynchrony in patients with left ventricular dysfunction.
We used a count-based Fourier analysis method to convert the regional myocardial counts from discrete frames per cardiac cycle into a continuous thickening function which allows resolution of the phase of the onset of myocardial contraction. The standard deviation of left ventricular phases (Phase SD) describes the regional phase dispersion as a measure of dyssynchrony. Significant dyssynchrony was defined as Phase SD ≥ 43°. 260 patients with left ventricular ejection fraction ≤35% were examined.
The prevalence of mechanical dyssynchrony in the entire cohort of patients studied was 52%. Univariate predictors of Phase SD were age (P = .03), black race (P = .0005), QRS duration, EF, EDV, summed stress score (SSS), and summed rest score (SRS) (all P = <.0001). Black race, male gender, QRS EF, and SRS were independent predictors of SPECT-based mechanical dyssynchrony.
Significant SPECT-based mechanical dyssynchrony is relatively common among patients with left ventricular dysfunction. In a population of patients with predominantly ischemic heart disease referred for SPECT, a reduced EF, increasing QRS duration, severity and extent of myocardial scar on SPECT imaging are independent predictors of mechanical dyssynchrony and may serve to identify patients for dyssynchrony screening.
Myocardial perfusion imaging: SPECT; coronary artery disease; gated SPECT; heart failure; diagnostic and prognostic applications
Abnormalities of amount and function of presynaptic terminals may have an important role in the mechanism of illness in schizophrenia. The SNARE proteins (SNAP-25, syntaxin, and VAMP) are enriched in presynaptic terminals, where they interact to form a functional complex to facilitate vesicle fusion. SNARE protein amounts are altered in the cortical regions in schizophrenia, but studies of protein–protein interactions are limited. We extended these investigations to the striatal regions (such as the nucleus accumbens, ventromedial caudate (VMC), and dorsal caudate) relevant to disease symptoms. In addition to measuring SNARE protein levels, we studied SNARE protein–protein interactions using a novel ELISA method. The possible effect of antipsychotic treatment was investigated in parallel in the striatum of rodents that were administered haloperidol and clozapine. In schizophrenia samples, compared with controls, SNAP-25 was 32% lower (P=0.015) and syntaxin was 26% lower (P=0.006) in the VMC. In contrast, in the same region, SNARE protein–protein interactions were higher in schizophrenia (P=0.008). Confocal microscopy of schizophrenia and control VMC showed qualitatively similar SNARE protein immunostaining. Haloperidol treatment of rats increased levels of SNAP-25 (mean 24%, P=0.003), syntaxin (mean 18%, P=0.010), and VAMP (mean 16%, P=0.001), whereas clozapine increased only the VAMP level (mean 13%, P=0.004). Neither drug altered SNARE protein–protein interactions. These results indicate abnormalities of amount and interactions of proteins directly related to presynaptic function in the VMC in schizophrenia. SNARE proteins and their interactions may be a novel target for the development of therapeutics.
SNAREs; schizophrenia; striatum; postmortem; protein interactions; SNAP-25; Schizophrenia/Antipsychotics; Plasticity; Neurochemistry; Neuropharmacology; SNARE proteins
This paper details the development of a digital microfluidic platform for multiplexed real-time polymerase chain reactions. Liquid samples in discrete droplet format are programmably manipulated upon an electrode array by the use of electrowetting. Rapid PCR thermocycling is performed in a closed-loop flow-through format where for each cycle the reaction droplets are cyclically transported between different temperature zones within an oil-filled cartridge. The cartridge is fabricated using low-cost printed-circuit-board technology and is intended to be a single-use disposable device. The PCR system exhibited remarkable amplification efficiency of 94.7%. To test its potential application in infectious diseases, this novel PCR system reliably detected diagnostic DNA levels of methicillin-resistant Staphylococcus aureus (MRSA), Mycoplasma pneumoniae, and Candida albicans. Amplification of genomic DNA samples was consistently repeatable across multiple PCR loops both within and between cartridges. In addition, simultaneous real-time PCR amplification of both multiple different samples and multiple different targets on a single cartridge was demonstrated. A novel method of PCR speed optimization using variable cycle times has also been proposed and proven feasible. The versatile system includes magnetic bead handling capability, which was applied to the analysis of simulated clinical samples that were prepared from whole blood using a magnetic bead capture protocol. Other salient features of this versatile digital microfluidic PCR system are also discussed, including the configurability and scalability of microfluidic operations, instrument portability and substrate-level integration with other pre- and post-PCR processes.
digital microfluidics; real-time PCR; electrowetting; droplets; Candida albicans; Mycoplasma pneumoniae; Staphylococcus aureus; molecular diagnostics
Here we report the sequence of 569,202 base pairs of Saccharomyces cerevisiae chromosome V. Analysis of the sequence revealed a centromere, two telomeres and 271 open reading frames (ORFs) plus 13 tRNAs and four small nuclear RNAs. There are two Ty1 transposable elements, each of which contains an ORF (included in the count of 271). Of the ORFs, 78 (29%) are new, 81 (30%) have potential homologues in the public databases, and 112 (41%) are previously characterized yeast genes.
CRT has been shown to be beneficial in the majority of patients with NYHA class III–IV symptoms, prolonged QRS duration, and an EF ≤35%. The use of imaging modalities to quantify dyssynchrony may help identify patients who may benefit from CRT, but do not meet current selection criteria. We hypothesize that patients with mild-to-moderate LV dysfunction have significant degrees of mechanical dyssynchrony.
We compared phase analysis measures of mechanical dyssynchrony from gated SPECT imaging in patients with mild-to-moderate LV dysfunction (EF 35–50%, n = 93), with patients with severe LV dysfunction (EF ≤ 35%, n = 167), and with normal controls (EF ≥ 55%, n = 75). Furthermore, we evaluated the relationships between QRS duration and dyssynchrony and determined the prevalence of dyssynchrony in patients with mild-moderate LV dysfunction.
Patients with mild-moderate LV dysfunction have more dyssynchrony than normal controls (phase SD 37.7° vs 8.8°, P < .001 and bandwidth 113.5° vs 28.7°, P < .001), but less dyssynchrony than patients with severe LV dysfunction (phase SD 37.7° vs 52.0°, P < .001 and bandwidth 113.5° vs 158.2°, P < .001). In the cohort of patients with LV EF 35–50%, there were only weak correlations between QRS duration and dyssynchrony (phase SD, r = 0.28 and bandwidth, r = 0.20). There were 73 patients with LVEF 35–50% and QRS duration <120 milliseconds of which 21 (28.8%) had mechanical dyssynchrony. Overall, 37% of patients with mild-to-moderate LV dysfunction had significant degrees of mechanical dyssynchrony.
This is the largest reported study evaluating mechanical dyssynchrony in patients with mild-moderate LV dysfunction using phase analysis of gated SPECT imaging. In this study, approximately one-third of patients with mild-to-moderate LV dysfunction had significant LV mechanical dyssynchrony. With further study, phase analysis of gated SPECT imaging may help improve patient selection for CRT.
Mechanical dyssynchrony; cardiac resynchronization therapy; heart failure; SPECT imaging
This study was designed to examine the possibility of self-protective changes in athletic identity (AI) being initiated after the occurrence of a severe injury.
People (72 men and 36 women) undergoing anterior cruciate ligament (ACL) surgery and rehabilitation were asked to complete a measure of AI prior to surgery and measures of AI and rehabilitation progress at approximately 6, 12, and 24 months after surgery.
A repeated-measures ANCOVA controlling for age and gender indicated that AI decreased significantly across the 24-month period following surgery, with the most substantial decline occurring between 6 and 12 months postsurgery. Significantly greater decreases in AI were observed among participants whose rehabilitation progress was slowest from 6 to 12 months postsurgery.
The findings suggest that some participants reduced their identification with the athlete role in response to the threat to a positive self-image posed by their ACL injuries and the difficulties they encountered in postoperative rehabilitation.
knee surgery; self-identity; injury; sport
There are currently limited data on the relationships between resting perfusion abnormalities, LVEF, New York Heart Association (NYHA) functional class, and exercise capacity as defined by peak VO2 and six-minute walk test in patients with heart failure and reduced left ventricular ejection fraction. Furthermore, the association between resting perfusion abnormalities and left ventricular dyssynchrony is currently unknown. This manuscript addresses The Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION) gated SPECT imaging (gSPECT) substudy baseline results.
HF-ACTION was a multi-center, randomized controlled trial of aerobic exercise training vs. usual care in 2331 stable patients with LVEF ≤35% and NYHA class II–IV heart failure symptoms treated with optimal medical therapy. Subjects enrolled in the HF-ACTION sub-study underwent resting Tc 99m tetrofosmin gSPECT at baseline (n=240). Images were evaluated for extent and severity of perfusion abnormalities using a 17-segment and a 5-degree gradation severity score (SRS). LV function and dyssynchrony were assessed using validated available commercial software.
The average age of patients enrolled was 59, 69% were male, 63% were white, and 33% were African-American. Of the 240 participants, 129 (54%) were ischemic and 111 (46%) were non-ischemic in etiology. The median LVEF by gated SPECT for the entire cohort was 26%. Among the nuclear variables, there was a modest correlation between LVEF and SRS (r= − 0.31, p < 0.0001) and there were stronger correlations between phase SD and SRS (r= 0.66, p< 0.0001) as well as phase SD and LVEF (r= −0.50, p< 0.0001). Patients with NYHA class III symptoms had more severe and significant degrees of dyssynchrony, median phase SD 54°, than those with NYHA class II symptoms, median phase SD 39° (p value=0.001). Patients with an ischemic etiology had a higher SRS (p< 0.0001) and significantly more dyssynchrony (p< 0.0001) than those who were nonischemic. However, there was no difference in LVEF or objective measures of exercise capacity between these groups. With respect to peak VO2, there was a weak correlation with LVEF (r = 0.18, p= 0.006) and no correlation with SRS (r = −0.04, p= 0.59) or with dyssynchrony (r= −0.13, p= 0.09). A weak, but statistically significant correlation between SRS and 6-minute walk was observed (r= −0.15, p = 0.047).
Gated SPECT imaging can provide important information in patients with heart failure due to severe LV dysfunction including quantitative measures of global systolic function, perfusion and dyssynchrony. These measurements are modestly but significantly related to symptom severity and objective measures of exercise capacity.
Fracture healing can be enhanced by load bearing, but the specific components of the mechanical environment which can augment or accelerate the process remain unknown. The ability of low-magnitude, high-frequency mechanical signals, anabolic in bone tissue, are evaluated here for their ability to influence fracture healing. The potential for short duration (17 min), extremely low-magnitude (25 μm), high-frequency (30 Hz) interfragmentary displacements to enhance fracture healing was evaluated in a mid-diaphyseal, 3-mm osteotomy of the sheep tibia. In a pilot study of proof of concept and clinical relevance, healing in osteotomies stabilized with rigid external fixation (Control: n = 4), were compared to the healing status of osteotomies with the same stiffness of fixation, but supplemented with daily mechanical loading (Experimental: n = 4). These 25-μm displacements, induced by a ferroactive shape-memory alloy (“smart” material) incorporated into the body of the external fixator, were less than 1% of the 3-mm fracture gap, and less than 6% of the 0.45-mm displacement measured at the site during ambulation (p <0.001). At 10-weeks post-op, the callus in the Experimental group was 3.6-fold stiffer (p <0.03), 2.5-fold stronger (p =0.05), and 29% larger (p <0.01) than Controls. Bone mineral content was 52% greater in the Experimental group (p <0.02), with a 2.6-fold increase in bone mineral content (BMC) in the region of the periosteum (p <0.001). These data reinforce the critical role of mechanical factors in the enhancement of fracture healing, and emphasize that the signals need not be large to be influential and potentially clinically advantageous to the restoration of function.
fracture healing; mechanical; callus; loading; endochondral bone repair
Estrogens play an important role in prostatic development, health, and disease. While estrogen signaling is essential for normal postnatal prostate development, little is known about its prenatal role in control animals. We tested the hypothesis that estrogen signaling is needed for normal male prostatic bud patterning. Budding patterns were examined by scanning electron microscopy of urogenital sinus epithelium from wild-type mice, mice lacking estrogen receptor (ER)α, ERβ, or both, and wild-type mice exposed to the antiestrogen ICI 182,780. Budding phenotypes did not detectably differ among any of these groups, strongly suggesting that estrogen signaling is not needed to establish the prototypical prostatic budding pattern seen in control males. This finding contributes to our understanding of the effects of low level estrogen exposure on early prostate development. In utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can greatly alter the pattern in which prostatic buds form and reduce their number. For several reasons, including a prior observation that inhibitory effects of TCDD on prostatic budding in rats depend heavily on the sex of adjacent fetuses, we tested the hypothesis that estrogen signaling is needed for TCDD to disrupt prostatic budding. However, budding did not detectably differ among wild-type mice, or mice lacking ERα, ERβ, or both, that were exposed prenatally to TCDD (5 μg/kg on embryonic day 13.5). Nor did ICI 182,780 detectably affect the response to TCDD. These results strongly suggest that estrogen signaling is not needed for TCDD to inhibit prostatic epithelial budding.
Prostatic budding patterns; Estrogen signaling; 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD); ICI 182,780; Estrogen receptor knockout mice; Prostate development
MEN1, the gene responsible for the cancer predisposition syndrome multiple endocrine neoplasia type I, has been implicated in DNA repair, cell cycle control, and transcriptional regulation. It is unclear to what degree these processes are integrated into a single encompassing function in normal cellular physiology and how deficiency of the MEN1-encoded protein, “menin”, contributes to cancer pathogenesis. In this study, we found that loss of Men1 in mouse embryonic fibroblasts caused abrogation of the G1/S and intra-S checkpoints following ionizing radiation. The cyclin-dependent kinase inhibitor, p21, failed to be upregulated in the mutant although upstream checkpoint signaling remained intact. Menin localized to the p21 promoter in a DNA damage-dependent manner. The MLL histone methyltransferase, a positive transcriptional regulator, bound to the same region in the presence of menin but not in Men1−/− cells. Finally, p53 retained damage-responsive binding to the p21 promoter in the Men1 mutant. These data indicate that menin participates in the checkpoint response in a transcriptional capacity, upregulating the DNA damage-responsive target p21.
Human immunodeficiency virus type 1 (HIV-1) vectors transduce rhesus blood cells poorly due to a species-specific block by TRIM5α and APOBEC3G, which target HIV-1 capsid and viral infectivity factor (Vif), respectively. We sought to develop a lentiviral vector capable of transducing both human and rhesus blood cells by combining components of both HIV-1 and simian immunodeficiency virus (SIV), including SIV capsid (sCA) and SIV Vif. A chimeric HIV-1 vector including sCA (χHIV) was superior to the conventional SIV in transducing a human blood cell line and superior to the conventional HIV-1 vector in transducing a rhesus blood cell line. Among human CD34+ hematopoietic stem cells (HSCs), the χHIV and HIV-1 vectors showed similar transduction efficiencies; in rhesus CD34+ HSCs, the χHIV vector yielded superior transduction rates. In in vivo competitive repopulation experiments with two rhesus macaques, the χHIV vector demonstrated superior marking levels over the conventional HIV-1 vector in all blood lineages (first rhesus, 15 to 30% versus 1 to 5%; second rhesus, 7 to 15% versus 0.5 to 2%, respectively) 3 to 7 months postinfusion. In summary, we have developed an HIV-1-based lentiviral vector system that should allow comprehensive preclinical testing of HIV-1-based therapeutic vectors in the rhesus macaque model with eventual clinical application.
Much of the UK government's 1999 report on teenage pregnancy was by necessity based on rather old or non‐longitudinal research.
To examine the associations between risk factors identified in the report and pregnancy at or before age 16 years among young women and partners of young men using the more recent data.
Socioeconomic disadvantage, being born to a teenage mother, expectation of being a teenage parent, low educational expectations and various other behaviours are potential risk factors for teenage pregnancy, as suggested by unadjusted analyses. Those who cited school as providing information on sex had a reduced risk of pregnancy at or before age 16 years, as did girls reporting easy communication with parent or guardian at baseline. Various measures of low sexual health knowledge were not associated, in either adjusted or unadjusted analyses, with increased risk of pregnancy at or before age 16 years among boys or girls.
A focus on many of the risk factors identified in the 1999 report is supported herein. It is suggested that knowledge may not be an important determinant, but that relationships with parents and school, as well as expectations for the future, may have important influences on teenage pregnancy. The analysis also provides new insights into risk factors for pregnancies among the partners of young men.