Surgical removal of a choroid plexus oncocytoma in an adult cat.

An 11-year-old male castrated domestic shorthair cat presented with left central vestibular dysfunction. Magnetic resonance imaging of the brain revealed a large, extra-parenchymal, strongly contrast-enhancing mass at the level of the left cerebellopontine angle and compressing the cerebellum and brainstem. The mass was surgically excised via left rostral and sub-tentorial craniectomies and histopathology revealed an epithelial neoplasm composed of anastomosing cords of neoplastic cells that contained large amounts of finely granular hypereosinophilic cytoplasm and round nuclei. The cytoplasmic granules were variably positive with periodic acid-Schiff and modified Gomori trichrome. Immunohistochemical staining with anti-cytokeratin AE1/AE3 was diffusely positive. Electron microscopy revealed neoplastic cells that were full of electron-dense organelles consistent with mitochondria. This is the first case of a choroid plexus oncocytoma in the central nervous system of any domestic animal species and highlights the role of successful surgical intervention in extra-parenchymal neoplasia in the central nervous system.

Heritability and Bayesian genome-wide association study of first service conception and pregnancy in Brangus heifers.

Brangus [3/8 Brahman (Bos indicus) × 5/8 Angus (Bos taurus); n ≈ 800] heifers from 67 sires were used to estimate heritability and conduct a genome-wide association study (GWAS) for 2 binary fertility traits: first service conception (FSC) and heifer pregnancy (HPG). Genotypes were from 53,692 loci on the BovineSNP50 (Infinium Bead Chips, Illumina, San Diego, CA). Yearling heifers were estrous synchronized, bred by AI, and then exposed to natural service breeding. Reproductive ultrasound and DNA-based parentage testing were used to determine if the heifer conceived by AI or natural service, and code for FSC and HPG traits. Success rates for FSC and HPG were 53.3% and 78.0% ± 0.01%, and corresponding heritability estimates were 0.18 ± 0.07 and 0.10 ± 0.06, respectively. The models used in obtaining these heritability estimates and GWAS included fixed effects of year (i.e., 2005 to 2007), birth location, calving season, age of dam, and contemporary group. In GWAS, simultaneous associations of 1 Mb SNP windows with phenotype were undertaken with Bayes C analyses using GenSel software. The 1 Mb windows contained 21.3 ± 1.1 SNP. Analyses fitted a mixture model that treated SNP effects as random, with an assumed fraction pi = 0.9995 having no effect on phenotype. The windows that accounted for 1.0% of genetic variance were considered as QTL associated with FSC or HPG. Eighteen QTL existed on 15 chromosomes for the 2 traits. On average, each QTL accounted for 2.43% ± 0.2% of the genetic variance. Chromosome 8 harbored 2 QTL for FSC and 1 for HPG; however, these regions did not overlap. Chromosomes 3, 15, 16, 19, 24, 26, 27, 29, and X included QTL only for FSC, whereas chromosomes 2, 4, 10, 13, and 20 contained QTL only for HPG. The multitude of QTL detected for FSC and HPG in this GWAS involving Brangus heifers exemplifies the complex regulation of variation in heifer fertility traits of low heritability.

Bayesian genome-wide association analysis of growth and yearling ultrasound measures of carcass traits in Brangus heifers.

Data from developing Brangus heifers (3/8 Brahman-Bos indicus × 5/8 Angus-Bos taurus; n ≈ 802 from 67 sires) registered with International Brangus Breeders Association were analyzed to detect QTL associated with growth traits and ultrasound measures of carcass traits. Genotypes were from BovineSNP50 (Infinium BeadChip, Illumina, San Diego, CA; 53,692 SNP). Phenotypes included BW collected at birth and ∼205 and 365 d of age, and yearling ultrasound assessment of LM area, percent intramuscular fat, and depth of rib fat. Simultaneous association of SNP windows with phenotype were undertaken with Bayes C analyses, using GenSel software. The SNP windows were ≈ 5 SNP in length. Analyses fitted a mixture model that treated SNP effects as random, with an assumed fraction pi = 0.999 having no effect on phenotype. Bootstrap analyses were used to obtain significance values for the SNP windows with the greatest contribution to observed variation. The SNP windows with P < 0.01 were considered as QTL associated with a trait in which case their location was queried from dbSNP and the presence of a previously reported QTL in that location was checked in CattleQTLdb. For 9 traits, QTL were mapped to 139 regions on 25 chromosomes. Forty-one of these QTL were already described in CattleQTLdb, so 98 are new additions. The SNP windows on chromosomes 1, 3, and 6 were associated with multiple traits (i.e., 205- and 365- d BW, and ADG from birth to 205 and 365 d of age). Several chromosomes harbored regions associated with multiple traits; however, the SNP that comprised the window often varied among traits (i.e., chromosomes 1, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15, 16, 20, 21, 22, 24, 28, and 29). Results from whole genome association of SNP with growth and ultrasound carcass traits in developing Brangus heifers confirmed several published QTL and detected several new QTL.

Gene network analyses of first service conception in Brangus heifers: use of genome and trait associations, hypothalamic-transcriptome information, and transcription factors.

Measures of heifer fertility are economically relevant traits for beef production systems and knowledge of candidate genes could be incorporated into future genomic selection strategies. Ten traits related to growth and fertility were measured in 890 Brangus heifers (3/8 Brahman × 5/8 Angus, from 67 sires). These traits were: BW and hip height adjusted to 205 and 365 d of age, postweaning ADG, yearling assessment of carcass traits (i.e., back fat thickness, intramuscular fat, and LM area), as well as heifer pregnancy and first service conception (FSC). These fertility traits were collected from controlled breeding seasons initiated with estrous synchronization and AI targeting heifers to calve by 24 mo of age. The BovineSNP50 BeadChip was used to ascertain 53,692 SNP genotypes for ∼802 heifers. Associations of genotypes and phenotypes were performed and SNP effects were estimated for each trait. Minimally associated SNP (P < 0.05) and their effects across the 10 traits formed the basis for an association weight matrix and its derived gene network related to FSC (57.3% success and heritability = 0.06 ± 0.05). These analyses yielded 1,555 important SNP, which inferred genes linked by 113,873 correlations within a network. Specifically, 1,386 SNP were nodes and the 5,132 strongest correlations (|r| ≥ 0.90) were edges. The network was filtered with genes queried from a transcriptome resource created from deep sequencing of RNA (i.e., RNA-Seq) from the hypothalamus of a prepubertal and a postpubertal Brangus heifer. The remaining hypothalamic-influenced network contained 978 genes connected by 2,560 edges or predicted gene interactions. This hypothalamic gene network was enriched with genes involved in axon guidance, which is a pathway known to influence pulsatile release of LHRH. There were 5 transcription factors with 21 or more connections: ZMAT3, STAT6, RFX4, PLAGL1, and NR6A1 for FSC. The SNP that identified these genes were intragenic and were on chromosomes 1, 5, 9, and 11. Chromosome 5 harbored both STAT6 and RFX4. The large number of interactions and genes observed with network analyses of multiple sources of genomic data (i.e., GWAS and RNA-Seq) support the concept of FSC being a polygenic trait.

Genetic analyses involving microsatellite ETH10 genotypes on bovine chromosome 5 and performance trait measures in Angus- and Brahman-influenced cattle.

ETH10 is a dinucleotide microsatellite within the promoter of signal transducer and activator of transcription 6 (STAT6) gene on bovine chromosome 5. ETH10 is included in the panel of genetic markers used in parentage testing procedures of cattle breed associations. Allelic sizes of ETH10 PCR amplicons range from 199 to 225 bp. Objectives of this study were to use microsatellite data from beef cattle breed associations to investigate genetic distance and population stratification among Angus- and Brahman-influenced cattle and to use ETH10 genotypes and growth and ultrasound carcass data to investigate their statistical relationships. Three series of genotype to phenotype association analyses were conducted with 1) Angus data (n=5,094), 2) Brangus data (3/8 Brahman × 5/8 Angus; n=2,296), and 3) multibreed data (n=4,426) of Angus and Brangus cattle. Thirteen alleles and 38 genotypes were observed, but frequencies varied among breed groups. Tests of genetic identity and distance among 6 breed composition groups increasing in Brahman influence from 0 to 75% revealed that as Brahman-influence increased to ≥50%, genetic distance from Angus ranged from 18.3 to 43.5%. This was accomplished with 10 microsatellite loci. A mixed effects model involving genotype as a fixed effect and sire as a random source of variation suggested that Angus cattle with the 217/219 genotype tended to have 2.1% heavier (P=0.07) 205-d BW than other genotypes. In Brangus cattle, allele combinations were classified as small (≤215 bp) or large (≥217 bp). Brangus cattle with the small/large genotype had 2.0% heavier (P<0.05) birth weight, yet cattle with the large/large genotype had approximately 5.1% greater (P<0.05) percentage of fat within LM and more LM per BW than cattle with small/large or small/small genotypes. Genotype-to-phenotype relationships were not detected in multibreed analyses. The ETH10 locus appears to be associated with growth and carcass traits in Angus and Brangus cattle. Results from this study provide support for STAT6 as one of the candidate genes underlying cattle growth QTL on chromosome 5.

Single nucleotide polymorphisms in the growth hormone-insulin-like growth factor axis in straightbred and crossbred Angus, Brahman, and Romosinuano heifers: population genetic analyses and association of genotypes with reproductive phenotypes.

The growth endocrine axis influences reproduction. The objectives of this study were to evaluate population genetic characteristics of SNP genotypes within genes of the GH-IGF axis in straightbred and crossbred Angus, Brahman, and Romosinuano heifers (n = 650) and to test the association of these genotypes with measures of reproduction. These objectives were achieved using 73 SNP within 7 genes on chromosome 5 and the pregnancy-associated plasma protein A2 (PAPP-A2) and GH-receptor genes, which map to chromosomes 16 and 20, respectively. The SNP were elucidated by resequencing conserved regions of each gene by using DNA from familial-unrelated cattle of a multibreed discovery population. A multiplex SNP assay yielded 59 biallelic SNP useful for evaluating genetic identity and distance. Specifically, the divergence of straightbred Brahman cattle was approximately 15.5% from 5 Bos taurus-influenced breed groups. In the straightbred groups used as a validation population, only 3 SNP had minor allele frequencies >10%. These SNP were in the genes PAPP-A2 (ss115492449-A/C and ss115492450-G/T within intron 10) and signal transducers and activators of transcription 2 (STAT2; ss252841035-A/G within the 5' untranslated region), and they met the conditions of Hardy-Weinberg equilibrium (P > 0.31). The other 56 SNP were useful for assigning each animal into ancestral clusters (n = 3 proportions) to account for population stratification in genotype to phenotype association analyses. The 2 SNP in the PAPP-A2 gene influenced (P < 0.05) traits indicative of first-calf heifer rebreeding (i.e., calving interval, days to calving, and pregnancy rate). A STAT2 SNP genotype (i.e., GG) × primary ancestral cluster interaction (P < 0.05) suggested heifers primarily of B. taurus ancestry had a reduction of approximately 16.4 ± 0.1% in calving interval and days to calving relative to heifers clustering primarily as Bos indicus ancestry. Even though additional research is needed to delineate the allelic variation attributed to genes of the GH-IGF axis, results of this study provide support for STAT2 and PAPP-A2 as potential candidate genes associated with first-calf heifer rebreeding traits.

Growth characteristics, reproductive performance, and evaluation of their associative relationships in Brangus cattle managed in a Chihuahuan Desert production system1.

Balancing growth and reproductive performance in beef cattle managed in desert environments is challenging. Our objectives were to 1) evaluate trends in growth and reproductive traits, and 2) assess associative relationships between growth characteristics and reproductive performance in a Brangus herd managed in a Chihuahuan Desert production system from 1972 to 2006. Data were from bull (n = 597) and heifer calves (n = 585; 1988 to 2006) and cows (n = 525; repeated records of cows, n = 2,611; 1972 to 2006). Variables describing the growth curve of each cow were estimated using a nonlinear logistic function (each cow needed 6 yr of data). Mixed-effect models and logistic regression were used to analyze trends across years in growth and reproductive traits (both continuous and categorical). For continuous traits of calves, a slight cubic response (P < 0.01) described the dynamics of birth weight, 205-d BW, and 365-d BW across years. For categorical traits of females, positive linear trends (P < 0.05) across years were observed in percent pregnant as yearlings, calved at 2 yr of age, and first-calf heifer rebreeding (slopes ranged from 0.007 to 0.014%/yr). Autumn cow BW increased gradually until 1997 (509 kg +/- 8.8) and then decreased gradually by 0.6 kg/yr, whereas pregnancy percentage decreased gradually until 1995 (78.4% +/- 1.0) and then increased slightly by 0.2%/yr. A quadratic effect best described the dynamics of these 2 variables across years (P < 0.01) as well as estimates describing the growth curve of each cow. Specifically, asymptotic BW and age increased (P < 0.05) from 1972 to 1983 and 1990, respectively. Asymptotic age then decreased by 27% from 1983 to 1996 (P < 0.05). The maturing rate index was negatively correlated with age at first calving and calving interval (r = -0.42 and -0.18, P < 0.01), which suggested that early-maturing cows had enhanced fertility in this environment and production system. In summary, minimal changes were observed in measures of growth in bulls and heifers in a Brangus herd managed in the Chihuahuan Desert. Opposing relationships were observed among measures of cow size and fertility; as growth curves shifted toward earlier maturity, measures of reproductive performance suggested that fertility improved.

Magnetic resonance imaging characteristics of necrotizing meningoencephalitis in Pug dogs.

BACKGROUND: The magnetic resonance imaging (MRI) characteristics of necrotizing meningoencephalitis (NME) are not well documented. OBJECTIVES: To describe common MRI features of NME, to compare the MRI features to histopathologic findings, and to determine whether or not MRI lesions are predictive of survival time. ANIMALS: Eighteen Pugs with NME. METHODS: Retrospective MRI case study of Pugs identified by a search of medical records at 6 veterinary institutions. Eighteen dogs met inclusion criteria of histopathologically confirmed NME and antemortem MRI exam. MRI lesions were characterized and compared with histopathology with the kappa statistic. Survival times were compared with MRI findings by use of Mann-Whitney U-tests and Spearman's rho. RESULTS: Twelve of 18 lesions were indistinctly marginated with mild parenchymal contrast enhancement. Prosencephalic (17/18) lesion distribution included the parietal (16/18), temporal (16/18), and occipital (16/18) lobes. There were cerebellar (4/18) and brainstem (3/18) lesions. Asymmetric lesions were present in both gray and white matter in all dogs. Falx cerebri shift was common (11/18), and 6 dogs had brain herniation. Leptomeningeal enhancement was present in 9/18 dogs. A moderate positive association was found between parenchymal contrast enhancement and both necrosis (kappa= 0.45; P= .045) and monocytic inflammation (kappa= 0.48; P= .025). Higher MRI lesion burden was correlated with longer time from disease onset to MRI (P= .045). MRI lesion burden did not correlate to survival time. CONCLUSIONS AND CLINICAL IMPORTANCE: Asymmetric prosencephalic grey and white matter lesions with variable contrast enhancement were consistent MRI changes in Pugs with confirmed NME. While not pathognomonic for NME, these MRI characteristics should increase confidence in a presumptive diagnosis of NME in young Pugs with acute signs of neurologic disease.

Dynamics of GHRH in third-ventricle cerebrospinal fluid of cattle: relationship with serum concentrations of GH and responses to appetite-regulating peptides.

Objectives were to (1) characterize the relationship of third-ventricle (IIIV) cerebrospinal fluid (CSF) concentrations of growth hormone-releasing hormone (GHRH) with concentrations of GH in the peripheral circulation; and (2) assess the influence of acute administration of appetite-regulating peptides leptin (anti-orexigenic) and neuropeptide Y (NPY; orexigenic) on the release of GHRH. Six mature beef cows fitted with IIIV and jugular vein cannulae were treated intracerebroventricularly with saline, and leptin (600 microg) and NPY (500 microg) in saline, in a replicated 3x3 Latin square design. Third-ventricle CSF and blood were collected 10 min before and continued 220 min after treatments. Mean concentrations of GHRH and frequency of pulses after treatments were 2.2+/-0.13 ng/mL and 1.2+/-0.15 pulses/220 min, respectively. These measures were not influenced by treatments. Concentrations of GHRH in CSF were weakly correlated (r=0.15; P<0.03) with serum concentrations of GH; however, 58% of the GH pulses were preceded by a pulse of GHRH and 90% of the GHRH pulses occurred within 20 min preceding a pulse of GH. Leptin tended (P<0.10) to suppress GH area under the curve (AUC) compared to saline. Concomitantly, NPY tended (P<0.10) to increase GH AUC, which appeared to be a consequence of increased (P<0.05) pulse amplitude. Infusion of NPY also increased (P<0.05) AUC of GHRH relative to saline. No differences were detected among treatments in serum concentrations of insulin-like growth factor-I or its AUC. Sampling CSF from the IIIV appears to be a viable procedure for assessing hypothalamic release of GHRH coincident with anterior pituitary gland secretion of GH in cattle. These data also demonstrate the differential responsiveness of the GH axis to appetite-regulating peptides.

Ambiguous and forbidden parameter combinations for aqueous plutonium.

The concepts of forbidden and ambiguous oxidation-state distributions for plutonium are easier to understand when presented graphically. This note describes two diagrams that illustrate the phenomena.

Promoter region of the bovine growth hormone receptor gene: single nucleotide polymorphism discovery in cattle and association with performance in Brangus bulls.

Expression of the GH receptor (GHR) gene and its binding with GH is essential for growth and fat metabolism. A GT microsatellite exists in the promoter of bovine GHR segregating short (11 bp) and long (16 to 20 bp) allele sequences. To detect SNP and complete an association study of genotype to phenotype, we resequenced a 1,195-bp fragment of DNA including the GT microsatellite and exon 1A. Resequencing was completed in 48 familialy unrelated Holstein, Jersey, Brown Swiss, Simmental, Angus, Brahman, and Brangus cattle. Nine SNP were identified. Phylogeny analyses revealed minor distance (i.e., <5%) in DNA sequence among the 5 Bos taurus breeds; however, sequence from Brahman cattle averaged 27.4 +/- 0.07% divergence from the Bos taurus breeds, whereas divergence of Brangus was intermediate. An association study of genotype to phenotype was completed with data from growing Brangus bulls (n = 553 from 96 sires) and data from 4 of the SNP flanking the GT microsatellite. These SNP were found to be in Hardy-Weinberg equilibrium and in phase based on linkage disequilibrium analyses (r(2) = 0.84 and D'= 0.92). An A/G tag SNP was identified (ss86273136) and was located in exon 1A, which began 88 bp downstream from the GT microsatellite. Minor allele frequency of the tag SNP was greater than 10%, and Mendelian segregation was verified in 3 generation pedigrees. The A allele was derived from Brahman, and the G allele was derived from Angus. This tag SNP genotype was a significant effect in analyses of rib fat data collected with ultrasound when bulls were ~365 d of age. Specifically, bulls of the GG genotype had 6.1% more (P = 0.0204) rib fat than bulls of the AA and AG genotypes, respectively. Tag SNP (ss86273136), located in the promoter of GHR, appears to be associated with a measure of corporal fat in Bos taurus x Bos indicus composite cattle.

Associations of DNA polymorphisms in growth hormone and its transcriptional regulators with growth and carcass traits in two populations of Brangus bulls.

Sequence polymorphisms in the growth hormone (GH) gene and its transcriptional regulators, Pit-1 and Prop-1, were evaluated for associations with growth and carcass traits in two populations of Brangus bulls Chihuahuan Desert Rangeland Research Center (CDRRC, N = 248 from 14 sires) and a cooperating breeding program (COOP, N = 186 from 34 sires). Polymorphisms were SNP mutations in intron 4 (C/T) and exon V (C/G) in GH, A/G in exon VI in Pit-1, and A/G in exon III in Prop-1. In the COOP population, bulls of Pit-1 GG genotype had a significantly greater percentage of intramuscular fat than bulls of the AA or AG genotype, and bulls of the Prop-1 AA genotype had significantly greater scrotal circumference than bulls of AG or GG genotypes at ~365 days of age. Also, heterozygous genotypes for the two GH polymorphisms appeared advantageous for traits of muscularity and adiposity in the COOP population. The heterozygous genotype of GH intron 4 SNP was associated with advantages in weight gain, scrotal circumference, and fat thickness in the CDRRC population. The two GH polymorphisms accounted for >/=27.7% of the variation in these traits in the CDRRC population; however, R(2) was <5% in the COOP population. Based on haplotype analyses the two GH SNPs appeared to be in phase; the haplotype analyses also paralleled with the genotype analyses. Polymorphisms in GH and its transcriptional regulators appear to be predictors of growth and carcass traits in Brangus bulls, particularly those with heterozygous GH genotypes.

Associations of DNA polymorphisms in growth hormone and its transcriptional regulators with growth and carcass traits in two populations of Brangus bulls

Sequence polymorphisms in the growth hormone (GH) gene and its transcriptional regulators, Pit-1 and Prop-1, were evaluated for associations with growth and carcass traits in two populations of Brangus bulls Chihuahuan Desert Rangeland Research Center (CDRRC, N = 248 from 14 sires) and a cooperating breeding program (COOP, N = 186 from 34 sires). Polymorphisms were SNP mutations in intron 4 (C/T) and exon V (C/G) in GH, A/G in exon VI in Pit-1, and A/G in exon III in Prop-1. In the COOP population, bulls of Pit-1 GG genotype had a significantly greater percentage of intramuscular fat than bulls of the AA or AG genotype, and bulls of the Prop-1 AA genotype had significantly greater scrotal circumference than bulls of AG or GG genotypes at ~365 days of age. Also, heterozygous genotypes for the two GH polymorphisms appeared advantageous for traits of muscularity and adiposity in the COOP population. The heterozygous genotype of GH intron 4 SNP was associated with advantages in weight gain, scrotal circumference, and fat thickness in the CDRRC population. The two GH polymorphisms accounted for ³27.7% of the variation in these traits in the CDRRC population; however, R2 was <5% in the COOP population. Based on haplotype analyses the two GH SNPs appeared to be in phase; the haplotype analyses also paralleled with the genotype analyses. Polymorphisms in GH and its transcriptional regulators appear to be predictors of growth and carcass traits in Brangus bulls, particularly those with heterozygous GH genotypes

Evaluation of DNA polymorphisms involving growth hormone relative to growth and carcass characteristics in Brahman steers.

Associations of DNA polymorphisms in growth hormone (GH) relative to growth and carcass characteristics in growing Brahman steers (N = 324 from 68 sires) were evaluated. Polymorphisms were an Msp-I RFLP and a leucine/valine SNP in the GH gene as well as a Hinf-I RFLP and a histidine/arginine SNP in transcriptional regulators of the GH gene, Pit-1 and Prop-1. Genotypic frequencies of the GH SNP, Pit-1 RFLP, and Prop-1 SNP were greater than 88% for one of the bi-allelic homozygous genotypes. Genotypic frequencies for the GH Msp-I RFLP genotypes were more evenly distributed with frequencies of 0.43, 0.42, and 0.15 for the genotypes of +/+, +/-, and -/-, respectively. Mixed model analyses of growth and carcass traits with genotype and contemporary group serving as fixed effects and sire fitted as a random effect suggested that sire was a significant source of variation (P < 0.05) in average daily gain, carcass yield, and marbling score. However, measures of growth and carcass traits were similar across GH Msp-I genotypes as steers were slaughtered when fat thickness was estimated to be approximately 1.0 cm. These polymorphisms within the GH gene and/or its transcriptional regulators do not appear to be informative predictors of growth and carcass characteristics in Brahman steers. This is partly due to the high level of homozygosity of genotypes. These findings do not eliminate the potential importance of these polymorphisms as predictors of growth and carcass traits in Bos taurus or Bos taurus x Bos indicus composite cattle.

Evaluation of DNA polymorphisms involving growth hormone relative to growth and carcass characteristics in Brahman steers

Associations of DNA polymorphisms in growth hormone (GH) relative to growth and carcass characteristics in growing Brahman steers (N = 324 from 68 sires) were evaluated. Polymorphisms were an Msp-I RFLP and a leucine/valine SNP in the GH gene as well as a Hinf-I RFLP and a histidine/arginine SNP in transcriptional regulators of the GH gene, Pit-1 and Prop-1. Genotypic frequencies of the GH SNP, Pit-1 RFLP, and Prop-1 SNP were greater than 88% for one of the bi-allelic homozygous genotypes. Genotypic frequencies for the GH Msp-I RFLP genotypes were more evenly distributed with frequencies of 0.43, 0.42, and 0.15 for the genotypes of +/+, +/-, and -/-, respectively. Mixed model analyses of growth and carcass traits with genotype and contemporary group serving as fixed effects and sire fitted as a random effect suggested that sire was a significant source of variation (P < 0.05) in average daily gain, carcass yield, and marbling score. However, measures of growth and carcass traits were similar across GH Msp-I genotypes as steers were slaughtered when fat thickness was estimated to be ~1.0 cm. These polymorphisms within the GH gene and/or its transcriptional regulators do not appear to be informative predictors of growth and carcass characteristics in Brahman steers. This is partly due to the high level of homozygosity of genotypes. These findings do not eliminate the potential importance of these polymorphisms as predictors of growth and carcass traits in Bos taurus or Bos taurus x Bos indicus composite cattle.

Isolation, characterization, and recombinant expression of multiple serpins from the cat flea, Ctenocephalides felis.

Several clones encoding serine protease inhibitors were isolated from larval and adult flea cDNA expression libraries by immunoscreening and PCR amplification. Each cDNA contained an open reading frame encoding a protein of approximately 45 kDa, which had significant sequence similarity with the serpin family of serine protease inhibitors. The thirteen cDNA clones isolated to date encode serpin proteins, which share a primary structure that includes a nearly identical constant region of about 360 amino acids, followed by a C-terminal variable region of about 40-60 amino acids. The variable C-terminal sequences encode most of the reactive site loop (RSL) and are generated by mutually exclusive alternative exon splicing, which may confer unique protease selectivity to each serpin. Utilization of an alternative exon splicing mechanism has been verified by sequence analysis of a flea serpin genomic clone and adjacent genomic sequences. RNA expression patterns of the cloned genes have been examined by Northern blot analysis using variable region-specific probes. Several putative serpins have been overexpressed using the cDNA clones in Escherichia coli and baculovirus expression systems. Two purified baculovirus-expressed recombinant proteins have N-terminal amino acid sequences identical to the respective purified native mature flea serpins indicating that appropriate N-terminal processing occurred in the virus-infected insect cells.

Toxic epidermal necrolysis: does immunoglobulin make a difference?

Experimental evidence implicates Fas ligand-mediated keratinocyte apoptosis as an underlying mechanism of toxic epidermal necrolysis syndrome (TEN). In vitro studies indicate a potential role for immunoglobulin (Ig) therapy in blocking Fas ligand signaling, thus reducing the severity of TEN. Anecdotal reports have described successful treatment of TEN patients with Ig; however, no study to date has analyzed outcome data in a large series of patients treated with Ig using institutional controls. The SCORTEN severity-of-illness score ranks severity and predicts prognosis in TEN patients using age, heart rate, TBSA slough, history of malignancy, and admission blood urea nitrogen, serum bicarbonate, and glucose levels. A retrospective chart review was performed that included all patients treated for TEN at our burn center since 1997. Ig therapy was instituted for all patients with biopsy-proven TEN beginning in January 2000. Twenty-one TEN patients were treated before Ig (no-Ig group), and 24 patients have been treated with Ig. SCORTEN data were collected, as well as length of stay (LOS) and status upon discharge. Each patient was given a SCORTEN of 0 to 6, with 1 point each for age greater than 40, TBSA slough greater than 10%, history of malignancy, admission BUN greater than 28 mg/dl, HCO3 less than 20 mg/dl, and glucose greater then 252 mg/dl. Outcome was compared between patients treated with Ig and without Ig. Overall mortality for patients treated before Ig was 28.6% (6/21), and with Ig, mortality was 41.7%% (10/24). There was no significant difference in age or TBSA slough. The average SCORTEN between the groups was equivalent (2.2 in no-Ig group vs 2.7 in Ig group, P = 0.3), and no group of patients with any SCORTEN score showed a significant benefit from Ig therapy. Overall LOS as well as LOS for survivors was longer in the Ig group. This series represents the largest single-institution analysis of TEN patient outcome after institution of Ig therapy. Our data do not show a significant improvement in mortality for TEN patients treated with Ig at any level of severity and may indicate a potential detriment in using Ig. Ig should not be given to TEN patients outside of a clinical trial. A multicenter, prospective, double-blinded randomized trial is necessary and urgently indicated to determine whether Ig therapy is beneficial or harmful in the care of TEN patients.

Work and disproportionation for aqueous plutonium.

The relation of two plutonium work integrals has recently been illustrated. One of the integrals applies to the work of disproportionation of tetravalent plutonium in 1 M acid and the other to the work of oxidation of plutonium from the trivalent to a higher oxidation state. This paper generalizes the disproportionation work integral so that it can be applied to tetravalent plutonium at any acid concentration. An equation is provided that can be used to verify work estimations obtained by integration. It applies to oxidation and disproportionation processes and it is easy to use.

Plutonium disproportionation: the ambiguity phenomenon.

Plutonium oxidation-state studies may yield ambiguous results if the parameters are not carefully chosen. The effect can be related to environmental plutonium as illustrated by an example.