Comparison of patterns and rates of cement leakage in percutaneous sacroplasty for sacral insufficiency fractures versus neoplasia

OBJECTIVE

Percutaneous sacroplasty is a minimally invasive procedure which utilises injection of bone cement into the sacrum for stabilisation of osteoporotic sacral insufficiency fractures (SIF) and neoplastic lesions to relieve pain and improve function. While effective, cement leakage is an important complication associated with the procedure. This study aims to compare the incidence and patterns of the cement leakages following sacroplasty for SIF versus neoplasia and discuss the various patterns of cement leakage and their implications.

MATERIALS AND METHODS

This retrospective study analysed 57 patients who underwent percutaneous sacroplasty at a tertiary orthopaedic hospital. Patients were divided into 2 groups of SIF (n=46) and neoplastic lesions (n=11) based on their indication for sacroplasty. Pre- and post-procedural CT fluoroscopy was used to assess for cement leakage. The incidence and patterns of cement leakage were both compared among the two groups. A Fisher's exact test was used for statistical analysis.

RESULTS

Eleven (19%) patients had cement leakage on post-procedural imaging. The most common sites of cement leakage were into the presacral region (6), followed by sacroiliac joints (4), sacral foramina (3) and posterior sacral (1). There was a statistically significant higher incidence of leakage in the neoplastic group in comparison to SIF group (P-value <0.05). The incidence of cement leakage in the neoplastic group was 45% (n = 5/11) versus SIF 13% (n=6/46).

CONCLUSION

There was a statistically significant higher incidence of cement leak in sacroplasties conducted for the treatment of neoplastic lesions compared to those with sacral insufficiency fracture.

Active video games and weight management in overweight children and adolescents-systematic review and meta-analysis

BACKGROUND

The prevalence of childhood obesity has been increasing for several decades. Active video games (AVG) may be an effective intervention to help manage this rising health crisis. The aim of this review is to evaluate whether AVG are effective at reducing weight or improving body composition in overweight youths.

METHOD

Medline, Embase, SportDiscus, ASSIA, CINAHL Plus, CENTRAL, CDSR and PsychINFO databases were searched for studies assessing quantitative or qualitative impact of AVG in overweight adolescents published in English. Three authors screened the results using inclusion/exclusion criteria.

RESULTS

A total of 12 studies met the inclusion criteria; 11 reported a significant decrease in at least one weight outcome. Results from seven randomized controlled trials were pooled by meta-analysis, which compared with controls subjects in AVG groups demonstrated greater body mass index (BMI) Z-score reduction (mean difference: -0.09 (-0.12, -0.05) I2 = 34%, P < 0.0001). The mean weight reduction (-2.66 Kg (-5.67, +0.35) I2 = 0%, P = 0.08) and BMI (-2.29 (-4.81, +0.22) I2 = 49%, P = 0.07) were greater in AVG groups but results did not reach statistical significance.

CONCLUSIONS

BMI Z-score was significantly reduced in the AVG group and the majority of included studies reported significant results in at least one weight outcome, suggesting AVG can be used to reduce weight or improve body composition in overweight youths. Further studies investigating the long-term sustainability of this change in body composition are needed.

Effect of initial GnRH and time of insemination on reproductive performance in cyclic and acyclic beef heifers subjected to a 5-d Co-synch plus progesterone protocol

This study evaluated the effect of initial GnRH and timing of AI in a 5-d Co-synch plus CIDR (device containing 1.38 g of progesterone) protocol on pregnancy per AI (P/AI) and pregnancy loss in beef heifers. A secondary objective was to determine if the effect of initial GnRH on reproductive performance was influenced by cyclicity. Crossbred beef heifers (n = 1068; 301-514 kg of body weight, and 13-15 mo of age) at three locations were assigned to either a 5-d Co-synch plus CIDR protocol with (CIDR5G) or without (CIDR5NG) an initial injection of 100 μg of GnRH at CIDR insertion (Day 0). All heifers received a single dose of 500 μg of cloprostenol at CIDR removal (Day 5) and were divided into two groups to receive GnRH and TAI at either 66 or 72 h (Day 8) after CIDR removal. All heifers were inseminated by one technician with frozen-thawed semen from 1 of 4 sires available commercially. Transrectal ultrasonography was performed on Day 0 to determine cyclicity (presence of CL) and normalcy of the reproductive track, and 27 d after TAI to determine pregnancy status. Non-pregnant heifers (n = 470) were assigned to either a CIDR5G or a CIDR5NG protocol with TAI at 72 h after CIDR removal. Twelve days after second AI, heifers were exposure to bulls for 20 d and pregnancy diagnoses were performed approximately 30 d after second TAI and 60 d after bulls were removed to diagnose bull pregnancies and determine pregnancy loss rate. The percentage of acyclic heifers was 20.3%. Overall P/AI after first TAI was 55.6% (594/1068) and did not differ between CIDR5G and CIDR5NG (56.1 vs. 55.1%), or between TAI66 and TAI72 (55.8 vs. 55.4%). However, cyclic heifers were more likely to become pregnant than acyclic ones (59.3 vs. 41.2%; P < 0.01). Moreover, acyclic heifers subjected to the CIDR5NG had fewer P/AI than those subjected to CIDR5G (P < 0.01). Overall P/AI after resynchronization was 55.1% and did not differ between CIDR5G and CIDR5NG (51.3 vs. 59.0%). Overall pregnancy loss after first and second TAI were 3.0% (18/594) and 3.9% (8/205), respectively. When pregnancy loss data were combined, synchronization protocol (4.1 vs. 2.3% for CIDR5NG and CIDR5G; P = 0.01), cyclicity (5.8 vs. 2.9% for acyclic and cyclic; P = 0.03) and the interaction between synchronization protocol and cyclicity (P = 0.04) were significant. The overall cumulative pregnancy at the end of the breeding season was 94.2% (1006/1068); acyclic heifers were less likely to be pregnant at the end of the breeding season (88.4 vs. 95.8%; P < 0.01). In summary, the initial GnRH administration in a 5-d Co-synch plus CIDR protocol that includes a single PGF treatment is necessary in acyclic beef heifers to optimize P/AI, but not in cyclic heifers. Moreover, omission of initial GnRH was associated to greater pregnancy losses, particularly in acyclic heifers. Timing of AI did not affect P/AI.

A phase II clinical study evaluating the efficacy and safety of neoadjuvant and adjuvant sunitinib in previously untreated patients with metastatic renal cell carcinoma (mRCC)(NeoSun)

e16087

Background: Sunitinib improves clinical outcomes in patients (pts) with mRCC. The single arm phase II NeoSun trial was designed to investigate its added value to nephrectomy, and to explore translational biological and imaging biomarkers. Methods: Pts with mRCC, scheduled for nephrectomy, no prior systemic therapy were recruited to receive 50mg OD sunitinib for 12 days, then post-surgery on a 4 week-on, 2 week-off, repeating 6 week cycle until disease progression. Diffusion-weighted, BOLD and dynamic contrast enhanced MR imaging (DW-MRI, DCE-MRI) and research blood sample collection were performed at baseline and end of 12 days. CT Imaging was performed at baseline, pre- and post-surgery, and then every 2 cycles. The primary endpoint was objective response rate (RECIST). Secondary endpoints included changes in diffusion DW-MRI, DCE- MRI of the tumour following 12 days suntinib, overall survival (OS), progression-free survival (PFS), response duration, surgical morbidity/mortality, and toxicity. Results: 14 pts received pre-surgery sunitinib, 71% (10/14) took the planned 12 doses. All 14 underwent total nephrectomy, and 13 recommenced sunitinib post-operatively. The mean number of post-surgery cycles was 11 (range 2 – 22). 58.3% (7/12) of pts achieved confirmed response (95% CI: 27.7 - 84.8%).91.7% (11/12) achieved objective clinical benefit (95% CI: 61.5 - 99.8%). Median OS is 33.7m and median PFS is 15.7m. Amongst those achieving PR/CR, median response duration is 8.7m. No unexpected surgical or sunitinib-related toxicities or complications were observed and the mean number of days from surgery to hospital discharge was 5.9 (range 3.0 – 17.0).There was a trend forOS to be better in pts with high baseline plasma VEGF-A (p = 0.06) or VEGF-C (p = 0.02) expression. A larger % tumour volume reduction after 12 days treatment is correlated with a smaller baseline % necrosis (coefficient = -0.51, p = 0.03). Conclusions: Sunitinib is effective and safe when given before and after nephrectomy to previously untreated pts with mRCC. Neoadjuvant studies such as NeoSun can safely explore translational biological and imaging endpoints. Clinical trial information: 2005-004502-82.

A Method to Exploit the Structure of Genetic Ancestry Space to Enhance Case-Control Studies

One goal of human genetics is to understand the genetic basis of disease, a challenge for diseases of complex inheritance because risk alleles are few relative to the vast set of benign variants. Risk variants are often sought by association studies in which allele frequencies in case subjects are contrasted with those from population-based samples used as control subjects. In an ideal world we would know population-level allele frequencies, releasing researchers to focus on case subjects. We argue this ideal is possible, at least theoretically, and we outline a path to achieving it in reality. If such a resource were to exist, it would yield ample savings and would facilitate the effective use of data repositories by removing administrative and technical barriers. We call this concept the Universal Control Repository Network (UNICORN), a means to perform association analyses without necessitating direct access to individual-level control data. Our approach to UNICORN uses existing genetic resources and various statistical tools to analyze these data, including hierarchical clustering with spectral analysis of ancestry; and empirical Bayesian analysis along with Gaussian spatial processes to estimate ancestry-specific allele frequencies. We demonstrate our approach using tens of thousands of control subjects from studies of Crohn disease, showing how it controls false positives, provides power similar to that achieved when all control data are directly accessible, and enhances power when control data are limiting or even imperfectly matched ancestrally. These results highlight how UNICORN can enable reliable, powerful, and convenient genetic association analyses without access to the individual-level data.

12 INITIAL GONADOTROPIN-RELEASING HORMONE TREATMENT INCREASED PREGNANCY PER TIMED INSEMINATION ONLY IN ACYCLIC BEEF HEIFERS SUBJECTED TO A 5-DAY CO-SYNCH PROTOCOL

We have shown that inclusion of initial gonadotropin-releasing hormone (GnRH) in a 5-day Co-synch protocol is unnecessary to achieve acceptable pregnancy rates in dairy heifers (2011 Theriogenology 76, 578). This study determined the efficacy of a modified (without initial GnRH) 5-day Co-synch protocol for timed AI (TAI) and the effect of interval from progesterone device removal to TAI on pregnancy per TAI (P/TAI) in acyclic and cyclic beef heifers. Heifers (n = 1062; 302 to 515 kg of body weight, and 13 to 15 months of age) at 2 locations were assigned to either a 5-day Co-synch protocol with (control) or without (modified) an initial injection of 100 μg of GnRH (Fertagyl; Merck Animal Health, Kenilworth, NJ, USA) at progesterone device (CIDR; Zoetis Animal Health, Florham Park, NJ) insertion (Day 0). All heifers received a single dose of 500 μg of cloprostenol (Estrumate; Merck Animal Health) at CIDR removal (Day 5) and were divided into 2 groups to receive GnRH and simultaneously TAI at either 66 or 72 h (Day 8) after CIDR removal. All heifers were inseminated by one technician with frozen-thawed semen from 1 of 4 commercially available sires. Ovarian ultrasonography was performed on Day 0 to determine cyclicity (presence of corpus luteum) and normalcy of the reproductive track, and on Day 35 (27 days after TAI) to determine pregnancy status. Data were analysed using the PROC GLIMMIX in SAS (SAS Institute Inc., Cary, NC, USA). The CIDR retention rate was 98%; P/TAI in heifers that lost the CIDR was 39%. Pregnancy per TAI [least squares means (n)] did not differ (P > 0.05) among sires [48 (235), 51 (318), 52 (274), and 53% (235)], location [57 (330) v. 53% (732)], timing of TAI [52 (533) v. 50% (529) for 66 and 72 h], or treatment groups [48 (525) v. 53% (537) for control and modified groups]. A total of 226 (21%) heifers were acyclic; P/TAI was lower in acyclic heifers compared with that in those cyclic (P < 0.01; 43 v. 59%). Administration of GnRH at CIDR insertion increased P/TAI in acyclic heifers (P < 0.01; 50 v. 35% for control and modified groups) but did not affect P/TAI in those that were cyclic at initiation of protocol (P > 0.05; 57 v. 62% for control and modified groups). In conclusion, timing of TAI did not affect fertility. However, administration of initial GnRH increased P/TAI by 15 percentiles in acyclic females, but as previously shown in Holstein heifers, initial GnRH was unnecessary to achieve acceptable P/TAI in cyclic beef heifers subjected to a 5-days Co-synch protocol. This study was supported by Alberta Agriculture and Forestry, Intervet Canada Corp., and collaborative beef producers.

Genome-wide association analysis identifies 13 new risk loci for schizophrenia

Schizophrenia is a heritable disorder with substantial public health impact. We conducted a multi-stage genome-wide association study (GWAS) for schizophrenia beginning with a Swedish national sample (5,001 cases, 6,243 controls) followed by meta-analysis with prior schizophrenia GWAS (8,832 cases, 12,067 controls) and finally by replication of SNPs in 168 genomic regions in independent samples (7,413 cases, 19,762 controls, and 581 trios). In total, 22 regions met genome-wide significance (14 novel and one previously implicated in bipolar disorder). The results strongly implicate calcium signaling in the etiology of schizophrenia, and include genome-wide significant results for CACNA1C and CACNB2 whose protein products interact. We estimate that ∼8,300 independent and predominantly common SNPs contribute to risk for schizophrenia and that these collectively account for most of its heritability. Common genetic variation plays an important role in the etiology of schizophrenia, and larger studies will allow more detailed understanding of this devastating disorder.

Interaction between ERAP1 and HLA-B27 in ankylosing spondylitis implicates peptide handling in the mechanism for HLA-B27 in disease susceptibility

Ankylosing spondylitis is a common form of inflammatory arthritis predominantly affecting the spine and pelvis that occurs in approximately 5 out of 1,000 adults of European descent. Here we report the identification of three variants in the RUNX3, LTBR-TNFRSF1A and IL12B regions convincingly associated with ankylosing spondylitis (P < 5 × 10(-8) in the combined discovery and replication datasets) and a further four loci at PTGER4, TBKBP1, ANTXR2 and CARD9 that show strong association across all our datasets (P < 5 × 10(-6) overall, with support in each of the three datasets studied). We also show that polymorphisms of ERAP1, which encodes an endoplasmic reticulum aminopeptidase involved in peptide trimming before HLA class I presentation, only affect ankylosing spondylitis risk in HLA-B27-positive individuals. These findings provide strong evidence that HLA-B27 operates in ankylosing spondylitis through a mechanism involving aberrant processing of antigenic peptides.

Integrating common and rare genetic variation in diverse human populations

Despite great progress in identifying genetic variants that influence human disease, most inherited risk remains unexplained. A more complete understanding requires genome-wide studies that fully examine less common alleles in populations with a wide range of ancestry. To inform the design and interpretation of such studies, we genotyped 1.6 million common single nucleotide polymorphisms (SNPs) in 1,184 reference individuals from 11 global populations, and sequenced ten 100-kilobase regions in 692 of these individuals. This integrated data set of common and rare alleles, called 'HapMap 3', includes both SNPs and copy number polymorphisms (CNPs). We characterized population-specific differences among low-frequency variants, measured the improvement in imputation accuracy afforded by the larger reference panel, especially in imputing SNPs with a minor allele frequency of <or=5%, and demonstrated the feasibility of imputing newly discovered CNPs and SNPs. This expanded public resource of genome variants in global populations supports deeper interrogation of genomic variation and its role in human disease, and serves as a step towards a high-resolution map of the landscape of human genetic variation.

Human aging-associated DNA hypermethylation occurs preferentially at bivalent chromatin domains

There is a growing realization that some aging-associated phenotypes/diseases have an epigenetic basis. Here, we report the first genome-scale study of epigenomic dynamics during normal human aging. We identify aging-associated differentially methylated regions (aDMRs) in whole blood in a discovery cohort, and then replicate these aDMRs in sorted CD4(+) T-cells and CD14(+) monocytes in an independent cohort, suggesting that aDMRs occur in precursor haematopoietic cells. Further replication of the aDMRs in buccal cells, representing a tissue that originates from a different germ layer compared with blood, demonstrates that the aDMR signature is a multitissue phenomenon. Moreover, we demonstrate that aging-associated DNA hypermethylation occurs predominantly at bivalent chromatin domain promoters. This same category of promoters, associated with key developmental genes, is frequently hypermethylated in cancers and in vitro cell culture, pointing to a novel mechanistic link between aberrant hypermethylation in cancer, aging, and cell culture.

Targeted inhibition of the serotonin 5HT2A receptor improves coronary patency in an in vivo model of recurrent thrombosis

BACKGROUND

Release of serotonin and activation of serotonin 5HT2A receptors on platelet surfaces is a potent augmentative stimulus for platelet aggregation. However, earlier-generation serotonin receptor antagonists were not successfully exploited as antiplatelet agents, possibly owing to their lack of specificity for the 5HT2A receptor subtype.

OBJECTIVE

To assess whether targeted inhibition of the serotonin 5HT2A receptor attenuates recurrent thrombosis and improves coronary patency in an in vivo canine model mimicking unstable angina.

METHODS

In protocol 1, anesthetized dogs were pretreated with a novel, selective inverse agonist of the 5HT2A receptor (APD791) or saline. Recurrent coronary thrombosis was then initiated by coronary artery injury+stenosis, and coronary patency was monitored for 3 h. Protocol 2 was similar, except that: (i) treatment with APD791 or saline was begun 1 h after the onset of recurrent thrombosis; (ii) template bleeding time was measured; and (iii) blood samples were obtained for in vitro flow cytometric assessment of platelet responsiveness to serotonin.

RESULTS

APD791 attenuated recurrent thrombosis, irrespective of the time of treatment: in both protocols, flow-time area (index of coronary patency; normalized to baseline coronary flow) averaged 58-59% (P<0.01) following administration of APD791 vs. 21-28% in saline controls. Moreover, the in vivo antithrombotic effect of APD791 was not accompanied by increased bleeding, but was associated with significant and selective inhibition of serotonin-mediated platelet activation.

CONCLUSION

5HT2A receptor inhibition with APD791, even when initiated after the onset of recurrent thrombosis, improves coronary patency in the in vivo canine model.

Genome-wide association study of ankylosing spondylitis identifies non-MHC susceptibility loci

To identify susceptibility loci for ankylosing spondylitis, we undertook a genome-wide association study in 2,053 unrelated ankylosing spondylitis cases among people of European descent and 5,140 ethnically matched controls, with replication in an independent cohort of 898 ankylosing spondylitis cases and 1,518 controls. Cases were genotyped with Illumina HumHap370 genotyping chips. In addition to strong association with the major histocompatibility complex (MHC; P < 10(-800)), we found association with SNPs in two gene deserts at 2p15 (rs10865331; combined P = 1.9 x 10(-19)) and 21q22 (rs2242944; P = 8.3 x 10(-20)), as well as in the genes ANTXR2 (rs4333130; P = 9.3 x 10(-8)) and IL1R2 (rs2310173; P = 4.8 x 10(-7)). We also replicated previously reported associations at IL23R (rs11209026; P = 9.1 x 10(-14)) and ERAP1 (rs27434; P = 5.3 x 10(-12)). This study reports four genetic loci associated with ankylosing spondylitis risk and identifies a major role for the interleukin (IL)-23 and IL-1 cytokine pathways in disease susceptibility.

Common variants in the region around Osterix are associated with bone mineral density and growth in childhood

Peak bone mass achieved in adolescence is a determinant of bone mass in later life. In order to identify genetic variants affecting bone mineral density (BMD), we performed a genome-wide association study of BMD and related traits in 1518 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). We compared results with a scan of 134 adults with high or low hip BMD. We identified associations with BMD in an area of chromosome 12 containing the Osterix (SP7) locus, a transcription factor responsible for regulating osteoblast differentiation (ALSPAC: P = 5.8 x 10(-4); Australia: P = 3.7 x 10(-4)). This region has previously shown evidence of association with adult hip and lumbar spine BMD in an Icelandic population, as well as nominal association in a UK population. A meta-analysis of these existing studies revealed strong association between SNPs in the Osterix region and adult lumbar spine BMD (P = 9.9 x 10(-11)). In light of these findings, we genotyped a further 3692 individuals from ALSPAC who had whole body BMD and confirmed the association in children as well (P = 5.4 x 10(-5)). Moreover, all SNPs were related to height in ALSPAC children, but not weight or body mass index, and when height was included as a covariate in the regression equation, the association with total body BMD was attenuated. We conclude that genetic variants in the region of Osterix are associated with BMD in children and adults probably through primary effects on growth.

Haplotype-based search for SNPs associated with differential type 1 diabetes risk among chromosomes carrying a specific HLA DRB1-DQA1-DQB1 haplotype

AIM

The aim of this study was to test chromosomes carrying the same DRB1-DQA1-DQB1 haplotype for single nucleotide polymorphisms (SNPs) in the major histocompatibility complex (MHC) that might mark subgroups of the haplotype with different risks for type 1 diabetes (T1D).

METHODS

Chromosomes from T1D children, their parents and non-diabetic siblings in families of the Type 1 Diabetes Genetics Consortium (T1DGC) were analysed by two haplotype-based methods: (i) logistic regression analysis restricted to phased chromosomes carrying the same DRB1-DQA1-DQB1 haplotype but differentiated by the two alleles at MHC SNPs, which were individually tested for association with T1D and (ii) homozygous parent transmission disequilibrium test (TDT) for biased transmission of a SNP allele to diabetic children from parents who are heterozygous at the SNP but homozygous for the specific DRB1-DQA1-DQB1 haplotype being evaluated.

RESULTS

A number of SNPs gave nominally significant (p < 0.05) evidence of marking two subsets of the 301-501-201 haplotype that might differ with respect to their diabetogenic potency. However, none of the SNPs achieved experiment-wide significance and hence may be false-positive associations.

CONCLUSIONS

We discuss limitations and possible deficiencies of our study suggesting further work that might yield more robust SNP associations marking two subgroups of a DRB1-DQA1-DQB1 haplotype with different T1D risks.

A genome-wide survey of the prevalence and evolutionary forces acting on human nonsense SNPs

Nonsense SNPs introduce premature termination codons into genes and can result in the absence of a gene product or in a truncated and potentially harmful protein, so they are often considered disadvantageous and are associated with disease susceptibility. As such, we might expect the disrupted allele to be rare and, in healthy people, observed only in a heterozygous state. However, some, like those in the CASP12 and ACTN3 genes, are known to be present at high frequencies and to occur often in a homozygous state and seem to have been advantageous in recent human evolution. To evaluate the selective forces acting on nonsense SNPs as a class, we have carried out a large-scale experimental survey of nonsense SNPs in the human genome by genotyping 805 of them (plus control synonymous SNPs) in 1,151 individuals from 56 worldwide populations. We identified 169 genes containing nonsense SNPs that were variable in our samples, of which 99 were found with both copies inactivated in at least one individual. We found that the sampled humans differ on average by 24 genes (out of about 20,000) because of these nonsense SNPs alone. As might be expected, nonsense SNPs as a class were found to be slightly disadvantageous over evolutionary timescales, but a few nevertheless showed signs of being possibly advantageous, as indicated by unusually high levels of population differentiation, long haplotypes, and/or high frequencies of derived alleles. This study underlines the extent of variation in gene content within humans and emphasizes the importance of understanding this type of variation.

Genetic association analyses of non-synonymous single nucleotide polymorphisms in diabetic nephropathy

AIMS/HYPOTHESIS

Diabetic nephropathy, characterised by persistent proteinuria, hypertension and progressive kidney failure, affects a subset of susceptible individuals with diabetes. It is also a leading cause of end-stage renal disease (ESRD). Non-synonymous (ns) single nucleotide polymorphisms (SNPs) have been reported to contribute to genetic susceptibility in both monogenic disorders and common complex diseases. The objective of this study was to investigate whether nsSNPs are involved in susceptibility to diabetic nephropathy using a case-control design.

METHODS

White type 1 diabetic patients with (cases) and without (controls) nephropathy from eight centres in the UK and Ireland were genotyped for a selected subset of nsSNPs using Illumina's GoldenGate BeadArray assay. A chi (2) test for trend, stratified by centre, was used to assess differences in genotype distribution between cases and controls. Genomic control was used to adjust for possible inflation of test statistics, and the False Discovery Rate method was used to account for multiple testing.

RESULTS

We assessed 1,111 nsSNPs for association with diabetic nephropathy in 1,711 individuals with type 1 diabetes (894 cases, 817 controls). A number of SNPs demonstrated a significant difference in genotype distribution between groups before but not after correction for multiple testing. Furthermore, neither subgroup analysis (diabetic nephropathy with ESRD or diabetic nephropathy without ESRD) nor stratification by duration of diabetes revealed any significant differences between groups.

CONCLUSIONS/INTERPRETATION

The nsSNPs investigated in this study do not appear to contribute significantly to the development of diabetic nephropathy in patients with type 1 diabetes.

Population-specific risk of type 2 diabetes conferred by HNF4A P2 promoter variants: a lesson for replication studies

OBJECTIVE

Single nucleotide polymorphisms (SNPs) in the P2 promoter region of HNF4A were originally shown to be associated with predisposition for type 2 diabetes in Finnish, Ashkenazi, and, more recently, Scandinavian populations, but they generated conflicting results in additional populations. We aimed to investigate whether data from a large-scale mapping approach would replicate this association in novel Ashkenazi samples and in U.K. populations and whether these data would allow us to refine the association signal.

RESEARCH DESIGN AND METHODS

Using a dense linkage disequilibrium map of 20q, we selected SNPs from a 10-Mb interval centered on HNF4A. In a staged approach, we first typed 4,608 SNPs in case-control populations from four U.K. populations and an Ashkenazi population (n = 2,516). In phase 2, a subset of 763 SNPs was genotyped in 2,513 additional samples from the same populations.

RESULTS

Combined analysis of both phases demonstrated association between HNF4A P2 SNPs (rs1884613 and rs2144908) and type 2 diabetes in the Ashkenazim (n = 991; P < 1.6 x 10(-6)). Importantly, these associations are significant in a subset of Ashkenazi samples (n = 531) not previously tested for association with P2 SNPs (odds ratio [OR] approximately 1.7; P < 0.002), thus providing replication within the Ashkenazim. In the U.K. populations, this association was not significant (n = 4,022; P > 0.5), and the estimate for the OR was much smaller (OR 1.04; [95%CI 0.91-1.19]).

CONCLUSIONS

These data indicate that the risk conferred by HNF4A P2 is significantly different between U.K. and Ashkenazi populations (P < 0.00007), suggesting that the underlying causal variant remains unidentified. Interactions with other genetic or environmental factors may also contribute to this difference in risk between populations.

Bone mineral density, osteoporosis, and osteoporotic fractures: a genome-wide association study

BACKGROUND

Osteoporosis is diagnosed by the measurement of bone mineral density, which is a highly heritable and multifactorial trait. We aimed to identify genetic loci that are associated with bone mineral density.

METHODS

In this genome-wide association study, we identified the most promising of 314 075 single nucleotide polymorphisms (SNPs) in 2094 women in a UK study. We then tested these SNPs for replication in 6463 people from three other cohorts in western Europe. We also investigated allelic expression in lymphoblast cell lines. We tested the association between the replicated SNPs and osteoporotic fractures with data from two studies.

FINDINGS

We identified genome-wide evidence for an association between bone mineral density and two SNPs (p<5x10(-8)). The SNPs were rs4355801, on chromosome 8, near to the TNFRSF11B (osteoprotegerin) gene, and rs3736228, on chromosome 11 in the LRP5 (lipoprotein-receptor-related protein) gene. A non-synonymous SNP in the LRP5 gene was associated with decreased bone mineral density (rs3736228, p=6.3x10(-12) for lumbar spine and p=1.9x10(-4) for femoral neck) and an increased risk of both osteoporotic fractures (odds ratio [OR] 1.3, 95% CI 1.09-1.52, p=0.002) and osteoporosis (OR 1.3, 1.08-1.63, p=0.008). Three SNPs near the TNFRSF11B gene were associated with decreased bone mineral density (top SNP, rs4355801: p=7.6x10(-10) for lumbar spine and p=3.3x10(-8) for femoral neck) and increased risk of osteoporosis (OR 1.2, 95% CI 1.01-1.42, p=0.038). For carriers of the risk allele at rs4355801, expression of TNFRSF11B in lymphoblast cell lines was halved (p=3.0x10(-6)). 1883 (22%) of 8557 people were at least heterozygous for these risk alleles, and these alleles had a cumulative association with bone mineral density (trend p=2.3x10(-17)). The presence of both risk alleles increased the risk of osteoporotic fractures (OR 1.3, 1.08-1.63, p=0.006) and this effect was independent of bone mineral density.

INTERPRETATION

Two gene variants of key biological proteins increase the risk of osteoporosis and osteoporotic fracture. The combined effect of these risk alleles on fractures is similar to that of most well-replicated environmental risk factors, and they are present in more than one in five white people, suggesting a potential role in screening.

A second generation human haplotype map of over 3.1 million SNPs

We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between 0.9 and 0.96 depending on population. We demonstrate that the current generation of commercial genome-wide genotyping products captures common Phase II SNPs with an average maximum r2 of up to 0.8 in African and up to 0.95 in non-African populations, and that potential gains in power in association studies can be obtained through imputation. These data also reveal novel aspects of the structure of linkage disequilibrium. We show that 10-30% of pairs of individuals within a population share at least one region of extended genetic identity arising from recent ancestry and that up to 1% of all common variants are untaggable, primarily because they lie within recombination hotspots. We show that recombination rates vary systematically around genes and between genes of different function. Finally, we demonstrate increased differentiation at non-synonymous, compared to synonymous, SNPs, resulting from systematic differences in the strength or efficacy of natural selection between populations.

Airway remodeling in the smoke exposed guinea pig model

Although small airway remodeling (SAR) leading to airflow obstruction is a common consequence of human cigarette smoking, the airways have been largely ignored in animal models of chronic obstructive pulmonary disease (COPD). We examined lung structure in a guinea pig model of chronic cigarette smoke exposure to ascertain whether smoke induced SAR, and to evaluate how these anatomic lesions correlate with physiologic changes. We used tissue from guinea pigs exposed to cigarette smoke or air for 6 mo. Pulmonary function tests were performed, and histologic sections were prepared. Airspace size (Lm) and changes in the structure of the small airways were evaluated by morphometric analysis. Chronic smoke exposure was associated with increased airway wall thickness and increased amounts of thick collagen fibers in the walls of the small airways, as well as with increased Lm. The increase in thick collagen fibers related negatively to peak expiratory volume (PEF) and the ratio of forced expiratory volume in 1 s to forced ventilatory capacity (FEV(0.1)/FVC), and positively to airway resistance. Physiologic lung volumes were predicted by airspace size, but residual volume (RV) and total lung capacity (TLC) also were related to airway wall thickness. Amounts of smooth muscle were not changed and did not predict any physiologic abnormalities. We conclude that cigarette smoke exposure results in SAR in the guinea pig, alterations that are reflected in increased airways resistance with diminished airflow and air trapping, mimicking human disease. This model should prove useful in further investigations into the mechanisms of airway remodeling.

The brain-derived neurotrophic factor rs6265 (Val66Met) polymorphism and depression in Mexican-Americans

The hypothesis that brain-derived neurotrophic factor (BDNF) is involved in the pathogenesis of major depression is supported by several research findings; however, genetic studies assessing the relationship between BDNF and psychiatric disorders have produced conflicting results. We examined the effect of a BDNF polymorphism on depression susceptibility in Mexican-Americans. The single nucleotide polymorphism (Val66Met), which has been shown to have functional and behavioral effects, was genotyped in 284 depressed participants and 331 controls, showing association with depression (P=0.005). Individuals homozygous for the major allele (GG) had an increased chance of being depressed (OR=1.7 95% CI 1.17-2.47). Our findings support the association of BDNF single nucleotide polymorphism rs6265 and depression, suggesting that this polymorphism may increase susceptibility to major depression in Mexican-Americans.

Preconditioning ischemia attenuates molecular indices of platelet activation-aggregation

BACKGROUND

Previous studies have shown that ischemic preconditioning (PC) not only limits infarct size, but also improves arterial patency in models of recurrent thrombosis. We hypothesize that this enhanced patency is presumably because of a PC-induced attenuation of platelet-mediated thrombosis. However, there is, at present, no direct evidence that PC acts on the platelets per se and favorably down-regulates platelet reactivity.

OBJECTIVES

Our goal was to test the concept that PC ischemia attenuates molecular indices of platelet activation-aggregation.

METHODS

Anesthetized dogs were randomly assigned to receive 10 min of PC ischemia followed by 10 min of reperfusion or a time-matched control period. Spontaneous recurrent coronary thrombosis was then initiated in all dogs by injury + stenosis of the left anterior descending coronary artery. Coronary flow was monitored for 3 h poststenosis, and molecular indices of platelet activation-aggregation were quantified by whole blood flow cytometry.

RESULTS

Coronary patency was, as expected, better-maintained following injury + stenosis in the PC group vs. controls (53% +/- 5%* vs. 23% +/- 5% of baseline flow, respectively; *P < 0.05). Moreover, PC was accompanied by: (i) a significant down-regulation of platelet-fibrinogen binding and formation of neutrophil-platelet aggregates (112% +/- 14%* vs. 177% +/- 21% and 107% +/- 8%* vs. 155% +/- 19% of baseline values in PC vs. control groups); and (ii) a trend towards a reduction in platelet P-selectin expression (148% +/- 12% vs. 190% +/- 21% of baseline; *P < 0.05 and P = 0.09 vs. control).

CONCLUSION

These data provide novel, direct evidence in support of the concept that ischemic PC attenuates molecular indices of platelet activation-aggregation.

Phosphodiesterase genes are associated with susceptibility to major depression and antidepressant treatment response

Cyclic nucleotide phosphodiesterases (PDEs) constitute a family of enzymes that degrade cAMP and cGMP. Intracellular cyclic nucleotide levels increase in response to extracellular stimulation by hormones, neurotransmitters, or growth factors and are down-regulated through hydrolysis catalyzed by PDEs, which are therefore candidate therapeutic targets. cAMP is a second messenger implicated in learning, memory, and mood, and cGMP modulates nervous system processes that are controlled by the nitric oxide (NO)/cGMP pathway. To investigate an association between genes encoding PDEs and susceptibility to major depressive disorder (MDD), we genotyped SNPs in 21 genes of this superfamily in 284 depressed Mexican Americans who participated in a prospective, double-blind, pharmacogenetic study of antidepressant response, and 331 matched controls. Polymorphisms in PDE9A and PDE11A were found to be associated with the diagnosis of MDD. Our data are also suggestive of the association between SNPs in other PDE genes and MDD. Remission on antidepressants was significantly associated with polymorphisms in PDE1A and PDE11A. Thus, we found significant associations with both the diagnosis of MDD and remission in response to antidepressants with SNPs in the PDE11A gene. We show here that PDE11A haplotype GAACC is significantly associated with MDD. We conclude that PDE11A has a role in the pathophysiology of MDD. This study identifies a potential CNS role for the PDE11 family. The hypothesis that drugs affecting PDE function, particularly cGMP-related PDEs, represent a treatment strategy for major depression should therefore be tested.

A high-resolution HLA and SNP haplotype map for disease association studies in the extended human MHC

The proteins encoded by the classical HLA class I and class II genes in the major histocompatibility complex (MHC) are highly polymorphic and are essential in self versus non-self immune recognition. HLA variation is a crucial determinant of transplant rejection and susceptibility to a large number of infectious and autoimmune diseases. Yet identification of causal variants is problematic owing to linkage disequilibrium that extends across multiple HLA and non-HLA genes in the MHC. We therefore set out to characterize the linkage disequilibrium patterns between the highly polymorphic HLA genes and background variation by typing the classical HLA genes and >7,500 common SNPs and deletion-insertion polymorphisms across four population samples. The analysis provides informative tag SNPs that capture much of the common variation in the MHC region and that could be used in disease association studies, and it provides new insight into the evolutionary dynamics and ancestral origins of the HLA loci and their haplotypes.

Variation within the gene encoding the upstream stimulatory factor 1 does not influence susceptibility to type 2 diabetes in samples from populations with replicated evidence of linkage to chromosome 1q

The gene encoding the transcription factor upstream stimulatory factor (USF)1 influences susceptibility to familial combined hyperlipidemia (FCHL) and triglyceride levels. Phenotypic overlap between FCHL and type 2 diabetes makes USF1 a compelling positional candidate for the widely replicated type 2 diabetes linkage signal on chromosome 1q. We typed 22 variants in the F11R/USF1 region (1 per 3 kb), including those previously implicated in FCHL-susceptibility (or proxies thereof) in 3,726 samples preferentially enriched for 1q linkage. We also examined glucose- and lipid-related continuous traits in an overlapping set of 1,215 subjects of European descent. There was no convincing evidence for association with type 2 diabetes in any of seven case-control comparisons, individually or combined. Family-based association analyses in 832 Pima subjects were similarly negative. At rs3737787 (the variant most strongly associated with FCHL), the combined odds ratio, per copy of the rarer A-allele, was 1.10 (95% CI 0.97-1.24, P = 0.13). In 124 Utah subjects, rs3737787 was significantly associated (P = 0.002) with triglyceride levels, but direction of this association was opposite to previous reports, and there was no corroboration in three other samples. These data exclude USF1 as a major contributor to type 2 diabetes susceptibility and the basis for the chromosome 1q linkage. They reveal only limited evidence for replication of USF1 effects on continuous metabolic traits.

A high-resolution linkage-disequilibrium map of the human major histocompatibility complex and first generation of tag single-nucleotide polymorphisms

Autoimmune, inflammatory, and infectious diseases present a major burden to human health and are frequently associated with loci in the human major histocompatibility complex (MHC). Here, we report a high-resolution (1.9 kb) linkage-disequilibrium (LD) map of a 4.46-Mb fragment containing the MHC in U.S. pedigrees with northern and western European ancestry collected by the Centre d'Etude du Polymorphisme Humain (CEPH) and the first generation of haplotype tag single-nucleotide polymorphisms (tagSNPs) that provide up to a fivefold increase in genotyping efficiency for all future MHC-linked disease-association studies. The data confirm previously identified recombination hotspots in the class II region and allow the prediction of numerous novel hotspots in the class I and class III regions. The region of longest LD maps outside the classic MHC to the extended class I region spanning the MHC-linked olfactory-receptor gene cluster. The extended haplotype homozygosity analysis for recent positive selection shows that all 14 outlying haplotype variants map to a single extended haplotype, which most commonly bears HLA-DRB1*1501. The SNP data, haplotype blocks, and tagSNPs analysis reported here have been entered into a multidimensional Web-based database (GLOVAR), where they can be accessed and viewed in the context of relevant genome annotation. This LD map allowed us to give coordinates for the extremely variable LD structure underlying the MHC.

The impact of SNP density on fine-scale patterns of linkage disequilibrium

Linkage disequilibrium (LD) is a measure of the degree of association between alleles in a population. The detection of disease-causing variants by association with neighbouring single nucleotide polymorphisms (SNPs) depends on the existence of strong LD between them. Previous studies have indicated that the extent of LD is highly variable in different chromosome regions and different populations, demonstrating the importance of genome-wide accurate measurement of LD at high resolution throughout the human genome. A uniform feature of these studies has been the inability to detect LD in regions of low marker density. To investigate the dependence of LD patterns on marker selection we performed a high-resolution study in African-American, Asian and UK Caucasian populations. We selected over 5000 SNPs with an average spacing of approximately 1 SNP per 2 kb after validating ca 12 000 SNPs derived from a dense SNP collection (1 SNP per 0.3 kb on average). Applications of different statistical methods of LD assessment highlight similar areas of high and low LD. However, at high resolution, features such as overall sequence coverage in LD blocks and block boundaries vary substantially with respect to marker density. Model-based linkage disequilibrium unit (LDU) maps appear robust to marker density and consistently influenced by marker allele frequency. The results suggest that very dense marker sets will be required to yield stable views of fine-scale LD in the human genome.

Identification of foodborne bacteria by infrared spectroscopy using cellular fatty acid methyl esters

Identification of bacterial species by profiling fatty acid methyl esters (FAMEs) has commonly been carried out by using a 20-min capillary gas chromatographic procedure followed by library matching of FAME profiles using commercial MIDI databases and proprietary pattern recognition software. Fast GC (5 min) FAME procedures and mass spectrometric methodologies that require no lipid separation have also been reported. In this study, bacterial identification based on the rapid (2 min) infrared measurement of FAME mixtures was demonstrated. The microorganisms investigated included Gram positive bacteria Staphylococcus aureus, Listeria monocytogenes, Bacillus anthracis, and Bacillus cereus, and Gram negative bacteria from the family Enterobacteriacae: Yersinia enterocolitica, Salmonella typhimurium, Shigella sonnei, and Escherichia coli (four strains of E. coli), and non-Enterobacteriacae: Vibrio cholerae, Vibrio vulnificus, and Vibrio parahemolyticus. Foodborne bacterial mixtures of FAMEs were measured by using an attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectroscopic procedure and discriminated by multivariate analysis. Results showed that the Enterobacteriacae could be discriminated from the vibrios. The identification was at the level of species (for the Bacillus and Vibrio genera) or strains (for the E. coli species). A series of bacterial FAME test samples were prepared and analyzed for accuracy of identification, and all were correctly identified. Our results suggest that this infrared strategy could be used to identify foodborne pathogens.

Acute toxicity of carbonyl iron and sodium iron EDTA compared with ferrous sulfate in young rats

According to the American Association of Poison Control Centers, exposures to excessive doses of iron supplements still occur in children less than 6 years of age. Since 1998, there has been one death among U.S. children in this age group. Exposures, including adverse events, to iron supplements and iron-containing vitamins for the years 1999 and 2000 were 23,215 and 24,249, respectively. To reduce the potential seriousness of such exposures, carbonyl iron (Fe(0)) has been suggested as a possible replacement for ferrous sulfate (FeSO(4)). Carbonyl Fe is a unique form of elemental iron because of its small particle size. It is highly bioavailable when used to correct iron deficiency anemia. There is also current interest in using sodium iron(III) ethylenediaminetetraacetate (NaFeEDTA) for food fortification. In this study both NaFeEDTA and carbonyl Fe were compared with FeSO(4), the most common form of iron for dietary supplements, to obtain information relevant to the acute toxicological profile in young rats. With FeSO(4) and NaFeEDTA, total liver nonheme iron increased with increasing dose, but the response was approximately 50% lower with NaFeEDTA compared with FeSO(4). Serum iron peaked at approximately 0.5 to 1 h for both FeSO(4) and carbonyl Fe, while NaFeEDTA was elevated up to 4 h. FeSO(4) had an LD(50) of 1.1 g Fe/kg and was approximately 45 times more toxic than carbonyl Fe, which had an LD(50) greater then 50 g Fe/kg. NaFeEDTA had an LD(50) of 1.3 g Fe/kg and, when compared with FeSO(4), had approximately the same level of toxicity.

The DNA sequence and comparative analysis of human chromosome 20

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

No loss in the in vivo efficacy of ischemic preconditioning in middle-aged and old rabbits

OBJECTIVES

We tested the hypothesis that cardioprotection with ischemic preconditioning (PC) is lost in the aging, or senescent, heart.

BACKGROUND

Although infarct size reduction with PC has been documented in virtually all models, a purported exception to this paradigm is the aging heart, the population in which cardioprotection is most relevant. However, no previous studies have assessed the concept of an age-associated loss in the efficacy of PC in an in vivo model of acute myocardial infarction in which definitive hallmarks of cardiovascular aging were demonstrated and a reduction of infarct size, the "gold standard" of PC, served as the primary end point.

METHODS

Using the in vivo rabbit model, three cohorts of animals were studied: adult (4 to 6 months old), middle-aged ( approximately 2 years old) and old ( approximately 4 years old) rabbits. Within each cohort we assessed: 1) infarct size (measured by tetrazolium staining and expressed as percent myocardium at risk) in control and PC groups; and 2) morphologic and functional hallmarks of cardiovascular aging (progressive myocyte hypertrophy, increased myocardial fibrosis and attenuated responsiveness to beta-adrenergic stimulation).

RESULTS

In adult animals, infarct size was significantly smaller in the PC group than in the control group (29 +/- 4% vs. 57 +/- 2%; p < 0.01). Although middle-aged and old rabbits exhibited all three archetypal indexes of cardiovascular aging, a comparable (approximately 50%) reduction in infarct size with PC was evident in both cohorts.

CONCLUSIONS

These data provide the first in vivo evidence that infarct size reduction with PC is not precluded by increased cardiovascular age, per se.

Effect of increasing iron supplementation on blood lipids in rats

The effects of increasing levels of Fe on serum fatty acids, cholesterol, triacylglycerol, liver and heart were examined in male Sprague-Dawley rats fed either Fe-deficient or carbonyl Fe-supplemented diets with 35 (control), 350, 3500 and 20 000 microg Fe/g for 12 weeks. As intake of Fe increased, serum total cholesterol increased from 2.0 mmol/l in controls to 5.2 mmol/l at the highest level of Fe. Also, the total serum phospholipid fatty acids increased from 609 mg/dl in controls to 1292 mg/l at the highest level of Fe. Except for the highest dose of Fe, the ratio of saturated to unsaturated phospholipid fatty acids increased from 1.2 to 1.7. The serum total free fatty acid levels remained constant among all groups with a range from 162 to 228 mg/l, while a ratio of 0.6 to 0.8 for saturated to unsaturated fatty acids was maintained. A dose-related increase in liver non-haem Fe from 18 to 3500 microg/g correlated with increases in lipid peroxidation (r 0.87), measured by the lipid-conjugated diene assay. Oxidative changes in the liver may have resulted in alterations in sterol synthesis, leading to increased serum cholesterol levels with increases in serum phospholipids and changes in the ratios of their saturated to unsaturated fatty acids. Animals with heart damage showed myocardial degeneration and cardiomyopathy with haemosiderin in interstitial macrophages or myocardial fibres and, when these were coupled with the findings of increased non-haem Fe in the heart and lipid peroxidation in the liver, suggested that oxidative stress is involved in the pathogenesis of the lesions.

Iron and folate in fortified cereals

BACKGROUND

Fortification of cereal-grain products was introduced in 1941 when iron and three vitamins were added to flour and bread. Ready-to-eat cereals were fortified at about the same time. These fortifications have contributed to increased dietary iron intake and reductions in iron deficiency anemia in the US. In 1996, FDA finalized rules for fortification of specific enriched cereal-grain products with folic acid. This measure was instituted to increase the folate intakes of women of child-bearing age and thereby reduce the risk of having a pregnancy affected with a neural tube birth defect. However, with recent increases in fortification, public health officials in the US are concemed that excess intake of specific nutrients such as iron and folic acid may result in toxic manifestations.

OBJECTIVE

Our objective was to measure iron and total folate content in breakfast cereals and compare assay to label values for % Daily Value. We also determined by weight the amount of a ready-to-eat breakfast cereal adults would eat and compared this to the labeled serving size, for which the reference amount for this cereal per eating occasion was 1 cup or 30 g.

DESIGN

Twenty-nine breakfast cereals were analyzed for iron content using the bathophenanthroline reaction. Twenty-eight cereals were analyzed for total folate, utilizing a microbiological assay with tri-enzyme digestion. Serving size quantities were estimated in seventy-two adults who regularly ate breakfast cereal and were asked to fill a 16 or 22 cm round bowl with the amount of cereal that they would consume for breakfast.

RESULTS

When the labeled value was compared to the assayed value for iron content 21 of the 29 breakfast cereals were 120% or more of the label value and 8 cereals were 150% or more of the label value. Overall, analyzed values for iron ranged from 80% to 190% of label values. Analyzed values for folate ranged from 98% to 320% of label values. For 14 of 28 cereals, analyzed values exceeded label declarations by more than 150%. Bran-containing cereals contained the highest amounts of folate relative to their label declarations. The median analyzed serving size for the breakfast cereal was 47 g for females, 61 g for males with a combined median of 56 g as compared to the label value of 30 g.

CONCLUSIONS

Analyzed values of iron and folic acid in breakfast cereals were considerably higher than labeled values. For adults, the amount of cereal actually consumed was approximately 200% of the labeled serving size. When the quantity of cereal consumed is more than the labeled serving size and when the levels of iron and folate are higher than declared, the intake of both will be significantly greater than the labeled values. It will be important to continue monitoring serum ferritin and folate levels in NHANES IV, since daily consumption of breakfast cereals may contribute to excessive intakes of iron and folate.

Histologic signatures of thermal injury: applications in transmyocardial laser revascularization and radiofrequency ablation

BACKGROUND AND OBJECTIVE

Cardiac treatments such as transmyocardial laser revascularization and radiofrequency ablation cause thermal injury. We sought to provide quantitative histologic methods of assessing such injury by using the inherent birefringence of cardiac muscle and collagen; specifically, to exploit the connection between thermal injury and the loss of birefringence.

STUDY DESIGN/MATERIALS AND METHODS

We quantified tissue birefringence changes in vitro for temperatures up to 130 degrees C. This information was used to assess thermal injury associated with myocardial channels made in vitro. We then measured in vivo cardiac injury 30 minutes and 3 days after radiofrequency exposure.

RESULTS

Birefringence decreased above 60 degrees C for muscle and above 70 degrees C for collagen. Temperatures above 80 degrees C were associated with collagen fiber straightening and above 95 degrees C with little muscle birefringence. Injury adjacent to laser channels was greatest parallel to cell orientation. In vivo, muscle with reduced birefringence was surrounded by cells exhibiting focal birefringence increases (contraction bands). Early injury assessment marked by birefringence changes corresponded to lesion size at 3 days.

CONCLUSION

Polarized light revealed histologic temperature signatures corresponding to irreversible muscle injury and collagen denaturation.

The physical maps for sequencing human chromosomes 1, 6, 9, 10, 13, 20 and X

We constructed maps for eight chromosomes (1, 6, 9, 10, 13, 20, X and (previously) 22), representing one-third of the genome, by building landmark maps, isolating bacterial clones and assembling contigs. By this approach, we could establish the long-range organization of the maps early in the project, and all contig extension, gap closure and problem-solving was simplified by containment within local regions. The maps currently represent more than 94% of the euchromatic (gene-containing) regions of these chromosomes in 176 contigs, and contain 96% of the chromosome-specific markers in the human gene map. By measuring the remaining gaps, we can assess chromosome length and coverage in sequenced clones.

Dissociation between improvement in angina pectoris and myocardial perfusion after transmyocardial revascularization with an excimer laser

Xenon chloride excimer laser transmyocardial revascularization significantly reduced angina in all patients and increased regional myocardial perfusion in most patients; however, there was no correlation between symptomatic improvement and flow improvement. Patients' symptomatic improvement preceded improved perfusion by several months.