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E J Smith

Publications and source records attributed to E J Smith.

At least 19 recordsLinked to original sources
PubMed2001

Frequency and distribution in three ethnic populations of single nucleotide polymorphisms in the MICA gene.

The Homo sapiens major histocompatibility complex (MHC) class 1 chain related gene A (MICA) was scanned for novel single nucleotide polymorphisms (SNPs) using a panel of DNA samples from African-, Japanese- and Mexican-Americans. Overlapping primer-pairs were used to amplify products in the size range of 300 to 400 bp that were sequenced and scanned for SNPs using Phred, Phrap, Polyphred and Consed sequence analysis programs. A total of 16 SNPs were detected, six of which represent new variant nucleotides in the Homo sapiens MICA gene. Three of the variants also represent amino acid changes in the MICA protein. Differences among the three ethnic panels in the frequency of the variant nucleotides observed were inconsistent, but significant for seven of the SNPs detected. Though a small sample size, this study represents the first multi-population based analysis of the frequency and distribution of SNPs in the MICA gene, a locus that may be essential in the antigenic recognition by gammadelta T cells.

Alleles↗
PubMed2000

IRF3 and IRF7 phosphorylation in virus-infected cells does not require double-stranded RNA-dependent protein kinase R or Ikappa B kinase but is blocked by Vaccinia virus E3L protein.

Induction of interferon-alpha (IFNalpha) gene expression in virus-infected cells requires phosphorylation-induced activation of the transcription factors IRF3 and IRF7. However, the kinase(s) that targets these proteins has not been identified. Using a combined pharmacological and genetic approach, we found that none of the kinases tested was responsible for IRF phosphorylation in cells infected with Newcastle disease virus (NDV). Although the broad-spectrum kinase inhibitor staurosporine potently blocked IRF3 and -7 phosphorylation, inhibitors for protein kinase C, protein kinase A, MEK, SAPK, IKK, and protein kinase R (PKR) were without effect. Both IkappaB kinase and PKR have been implicated in IFN induction, but cells genetically deficient in IkappaB kinase, PKR, or the PKR-related genes PERK, IRE1, or GCN2 retained the ability to phosphorylate IRF7 and induce IFNalpha. Interestingly, PKR mutant cells were defective for response to double-stranded (ds) RNA but not to virus infection, suggesting that dsRNA is not the only activating viral component. Consistent with this notion, protein synthesis was required for IRF7 phosphorylation in virus-infected cells, and the kinetics of phosphorylation and viral protein production were similar. Despite evidence for a lack of involvement of dsRNA and PKR, vaccinia virus E3L protein, a dsRNA-binding protein capable of inhibiting PKR, was an effective IRF3 and -7 phosphorylation inhibitor. These results suggest that a novel cellular protein that is activated by viral products in addition to dsRNA and is sensitive to E3L inhibition is responsible for IRF activation and reveal a novel mechanism for the anti-IFN effect of E3L distinct from its inhibition of PKR.

Animals↗
PubMed2000

Cementless acetabular replacement in the young. A 5- to 10-year prospective study.

This article presents a prospective clinical and radiologic review of 55 total hip replacements in 50 patients in which the cementless Harris-Galante porous-coated acetabular component was used. All patients were 50 years of age or younger. The cups were inserted by 15 different surgeons. The minimum followup was 5 years, with a mean of 7 years. No acetabular component has been revised for loosening, and none have migrated. Three (5.5%) cups have progressive bone-component radiolucent lines, two (3.6%) of which are complete. Six (10.9%) acetabular liners have been replaced for excessive polyethylene wear, and an additional four (7.3%) show sufficient wear to produce obvious radiographic eccentricity of the femoral head. All of the revised liners had 32-mm femoral heads and an initial polyethylene thickness of less than 6 mm. Although the results reflect excellent fixation of this component in the medium term, the incidence of exchange of the polyethylene liner for excessive wear is unacceptably high. The reduction in polyethylene thickness associated with the use of a metal-backed component and a 32-mm articulation was one of the factors contributing to the accelerated wear patterns seen in this series.

Acetabulum↗
PubMed1999

A mechanism for Rb/p130-mediated transcription repression involving recruitment of the CtBP corepressor.

Previous work has demonstrated the critical role for transcription repression in quiescent cells through the action of E2F-Rb or E2F-p130 complexes. Recent studies have shown that at least one mechanism for this repression involves the recruitment of histone deacetylase. Nevertheless, these studies also suggest that other events likely contribute to E2F/Rb-mediated repression. Using a yeast two-hybrid screen to identify proteins that specifically interact with the Rb-related p130 protein, we demonstrate that p130, as well as Rb, interacts with a protein known as CtIP. This interaction depends on the p130 pocket domain, which is important for repression activity, as well as an LXCXE sequence within CtIP, a motif previously shown to mediate interactions of viral proteins with Rb. CtIP interacts with CtBP, a protein named for its ability to interact with the C-terminal sequences of adenovirus E1A. Recent work has demonstrated that the Drosophila homologue of CtBP is a transcriptional corepressor for Hairy, Knirps, and Snail. We now show that both CtIP and CtBP can efficiently repress transcription when recruited to a promoter by the Gal4 DNA binding domain, thereby identifying them as corepressor proteins. Moreover, the full repression activity of CtIP requires a PLDLS domain that is also necessary for the interaction with CtBP. We propose that E2F-mediated repression involves at least two events, either the recruitment of a histone deacetylase or the recruitment of the CtIP/CtBP corepressor complex.

Alcohol Oxidoreductases↗
PubMed1999

Turkey sperm mobility influences paternity in the context of competitive fertilization.

We have devised a novel means of investigating competitive fertilization in turkeys, using microsatellite genotyping to identify male parentage. Our results demonstrate that sperm mobility is a mechanism responsible in part for paternity efficiency in turkeys. Sperm mobility is composed of several parameters in which sperm motility is a component. Differences between ejaculates in the number of sperm penetrating into a dense, insert, nontoxic solution were measured and used to classify males into high, average, or low sperm mobility phenotypes. Microsatellite genotyping was used to determine parentage of poults after equal numbers of sperm from 10 males (either high or average phenotype, n = 5, mixed with low phenotype, n = 5) were inseminated simultaneously. In a separate study, the numbers of sperm hydrolyzing the perivitelline layer of eggs were compared between hens inseminated with sperm from high-, average-, or low-phenotype males. Overall, heterospermic inseminations resulted in consistently fewer offspring produced by low-mobility phenotype males. This correlated with physiological data in which semen from the low-mobility males had reduced numbers of sperm at the fertilization site as determined by sperm hole counts in the perivitelline layer of eggs. This is the first illustration of a measurable sperm trait predictive of paternity success in a competitive fertilization trial in turkeys, a species that is predominately reproduced by artificial insemination of multiple-sire pools.

Animals↗
PubMed1998

Mapping chicken genes using preferential amplification of specific alleles.

To map the chicken genome, an international reference population was developed at our laboratory (East Lansing, MI) using an F2 backcross between inbred jungle fowl (JF) and inbred white leghorns (WL). To augment the number of type I genes on the East Lansing (E) map, segregation of the JF-specific allele was followed using preferential amplification of specific alleles (PASA) in polymerase chain reactions (PCR). Among 15 functional genes that were added to the E map, agrin and mannose-6-phosphate receptor genes were found to occur in conserved syntenic groups. Using this PCR-based approach, six conserved groups spanning more than 243 centimorgans (cM) in the chicken were syntenic with human and mouse.

Alleles↗
PubMed1998

The CAR1 gene encoding a cellular receptor specific for subgroup B and D avian leukosis viruses maps to the chicken tvb locus.

Host susceptibility to subgroup B, D, and E avian leukosis viruses (ALV) is determined by specific alleles of the chicken tvb locus. Recently, a chicken gene that encodes a cellular receptor, designated CAR1, specific for subgroups B and D ALV was cloned, and it was proposed that this gene was the s3 allele of tvb (J. Brojatsch, J. Naughton, M. M. Rolls, K. Zingler, and J. A. T. Young, Cell 87:845-855, 1996). We now report that in a backcross derived from an F1 (Jungle Fowl x White Leghorn [WL]) male mated with inbred WL females, the cloned ALV receptor gene cosegregated with two markers linked to tvb. The two markers used were a tvb(s1)-specific antigen recognized by the chicken R2 alloantiserum and restriction fragment length polymorphisms associated with the expressed sequence tag com152e. With all three markers, no crossovers were observed among 52 backcross progeny tested and LOD linkage scores of 15.7 were obtained. These data demonstrate that CAR1 is the subgroup B and D ALV susceptibility gene located at tvb(s3).

Animals↗
PubMed1998

Entrainment of the circadian system of mammals by nonphotic cues.

Although light is the principal zeitgeber to the mammalian circadian system, other cues can be shown to have a potent resetting effect on the clock of both adult and perinatal mammals. Nonphotic entrainment may have both biological and therapeutic significance. This review focuses on the effect of behavioral arousal as a nonphotic cue and the neurochemical circuitry that mediates arousal-induced entrainment in the adult rodent. In addition, it considers the role of nonphotic entrainment of the developing circadian system in perinatal life prior to the establishment of retinal input to the clock.

Animals↗
PubMed1998

Distinct mechanisms control the accumulation of the Rb-related p107 and p130 proteins during cell growth.

A variety of studies have demonstrated the critical role of the Rb/E2F pathway in the control of cell growth and have highlighted a complexity in the accumulation of both the E2F family proteins and the Rb family of proteins. Whereas the Rb protein is found in both growing and quiescent cells, the accumulation of p130 and p107 is tightly regulated with respect to the growth state of the cell. The p130 protein is found in quiescent cells but not in growing cells, whereas the inverse is true for the p107 protein. Control of p130 accumulation is posttranscriptional, because p130 RNA is relatively constant in growing and quiescent cells. The disappearance of the p130 protein after stimulation of cell growth coincides with cyclin-dependent kinase-mediated phosphorylation and is blocked by inhibitors of the 26S proteasome. In contrast, the cell growth-dependent regulation of p107 expression reflects the transcriptional regulation of the p107 gene. Similar to several other growth-regulated genes, the control of p107 expression is largely the result of E2F-dependent repression in quiescent cells. These experiments thus demonstrate a control of Rb family member expression mediated through distinct mechanisms of both transcriptional and posttranslational control and also suggest an intimate relationship in which p130 controls the expression of p107.

Adenoviridae↗
PubMed1997

The chicken genome contains two functional nonallelic beta1,4-galactosyltransferase genes. Chromosomal assignment to syntenic regions tracks fate of the two gene lineages in the human genome.

Two distinct but related groups of cDNA clones, CKbeta4GT-I and CKbeta4GT-II, have been isolated by screening a chicken hepatoma cDNA library with a bovine beta1,4-galactosyltransferase (beta4GT) cDNA clone. CKbeta4GT-I is predicted to encode a type II transmembrane glycoprotein of 41 kDa with one consensus site for N-linked glycosylation. CKbeta4GT-II is predicted to encode a type II transmembrane glycoprotein of 43 kDa with five potential N-linked glycosylation sites. At the amino acid level, the coding regions of CKbeta4GT-I and CKbeta4GT-II are 52% identical to each other and 62 and 49% identical, respectively, to bovine beta4GT. Despite this divergence in amino acid sequence, high levels of expression of each cDNA in Trichoplusia ni insect cells demonstrate that both CKbeta4GT-I and CKbeta4GT-II encode an alpha-lactalbumin-responsive, UDP-galactose:N-acetylglucosamine beta4-galactosyltransferase. An analysis of CKbeta4GT-I and CKbeta4GT-II genomic clones established that the intron positions within the coding region are conserved when compared with each other, and these positions are identical to the mouse and human beta4GT genes. Thus CKbeta4GT-I and CKbeta4GT-II are the result of the duplication of an ancestral gene and subsequent divergence. CKbeta4GT-I maps to chicken chromosome Z in a region of conserved synteny with the centromeric region of mouse chromosome 4 and human chromosome 9p, where beta4-galactosyltransferase (EC 2.4.1.38) had previously been mapped. Consequently, during the evolution of mammals, it is the CKbeta4GT-I gene lineage that has been recruited for the biosynthesis of lactose. CKbeta4GT-II maps to a region of chicken chromosome 8 that exhibits conserved synteny with human chromosome 1p. An inspection of the current human gene map of expressed sequence tags reveals that there is a gene noted to be highly similar to beta4GT located in this syntenic region on human chromosome 1p. Because both the CKbeta4GT-I and CKbeta4GT-II gene lineages are detectable in mammals, duplication of the ancestral beta4-galactosyltransferase gene occurred over 250 million years ago in an ancestral species common to both mammals and birds.

Alleles↗
PubMed1997

Inadequate polyethylene thickness and osteolysis in cementless hip arthroplasty.

A matched series Porous Coated Anatomic (PCA), Howmedica, Rutherford, NJ) cementless hip arthroplasties comparing a 26-mm with a 32-mm head were reviewed. The 26-mm head was used in 63 hips of 56 patients (group 1), and the 32-mm head was inserted into 97 hips of 90 patients (group 2). The two groups were matched for age, sex, and primary diagnosis. The postoperative follow-up period ranged from 3 to 6.9 years (mean, 4.2 years) in group 1, compared with 3 to 7.9 years (mean, 4.5 years) for group 2. The mean clinical scores for pain, movement, and function were similar for the two groups. Erosive osteolytic lesions were encountered in 25.7% of the group 2 hips but in none of the group 1 cases. These lesions were not seen before 3 years after surgery and were present in Gruen zone 7 of all involved hips, although in two patients they were also noted in zone 1. Osteolysis was encountered only with the 32-mm head where the outer diameter of the metal backed cup was 52 mm or less. Therefore, inadequate polyethylene thickness, rather than head size, is implicated as the cause of plastic-particle mediated osteolysis.

Adult↗
PubMed1997

Massive early subsidence following femoral impaction grafting.

The incidence of massive early subsidence (subsidence greater than 10 mm) following impaction grafting of the femur in revision surgery is reported. The first 79 consecutive revision total hip arthroplasties using morselized allograft, polymethyl methacrylate cement, and a double-tapered, polished, collarless stem were reviewed. Nine (11%) of the 79 revision femoral prostheses showed massive subsidence, with another nine hips subsiding to a lesser degree. Further elucidation of the critical factors contributing to the initial stability of the biologic composite is required.

Adult↗
PubMed1997

Ethical evaluation of hypnosis research: a survey of investigators and their institutional review boards.

We surveyed hypnosis researchers and Institutional Review Boards (IRBs) with regard to the ethical evaluation of research protocols. Researchers and IRB administrators were independently surveyed within the same institutions. Both objective and free response items were used to address substantive issues such as deception and at-risk populations, as well as practical matters such as paperwork. Parallel questions allowed a point-counterpoint between researchers and IRBs. Overall, the results suggest that IRBs do not treat hypnosis research differently than other types of research. We end with recommendations for facilitating interactions between hypnosis researchers and their IRBs.

Adult↗
PubMed1997

Comparative mapping of the chicken genome using the East Lansing reference population.

The annotation of known genes on linkage maps provides an informative framework for synteny mapping. In comparative gene mapping, conserved synteny is broadly defined as groups of two or more linked markers that are also linked in two or more species. Although many anonymous markers have been placed on the chicken genome map, locating known genes will augment the number of conserved syntenic groups and consolidate linkage groups. In this report, 21 additional genes have been assigned to linkage groups or chromosomes; five syntenic groups were identified. Ultimately, conserved syntenic groups may help to pinpoint important quantitative trait loci.

Animals↗
PubMed1997

Role of contact and genetic transmission of endogenous virus-21 in the susceptibility of chickens to avian leukosis virus infection and tumors.

The role of contact and genetic transmission of endogenous virus-21 (EV21) on response of chickens to avian leukosis virus (ALV) infection and tumors was studied. F1 progeny of a cross between RPRL late-feathering (LF) line EV21+ males and RPRL early feathering (EF) line 15B1 females harboring or lacking EV21 were used. The EF chicks lacking EV21 were inoculated with a field strain of subgroup A ALV at hatch and contact exposed to LF, EV21+ hatchmates for various time intervals. In a second experiment, EV21 contact-exposed and unexposed EF chicks as well as LF, EV21+ hatchmates were inoculated with ALV at various ages. Chickens were tested for ALV-induced viremia and antibody and were observed for tumors until 24 wk of age. Antibody to EV21 in EF chickens contact-exposed to LF, EV21+ hatchmates varied from 10 to 65%, and was detected by 10 wk of age. By 24 wk of age, ALV-induced viremia and tumors in EF chickens varied from 5 to 30%, and from 15 to 32%, respectively, regardless of exposure to EV21. The incidence of ALV-induced tumors was significantly higher in LF chickens genetically infected with EV21 than in EV21 contact-exposed or unexposed EF chickens, but only in chickens inoculated with ALV at hatch. The data suggest that contact infection with EV21 has no influence on ALV infection and tumors. The data also suggest that genetic transmission of EV21 may increase susceptibility of chickens to ALV infection and tumors following infection with ALV at hatch, but not at 4 wk of age or older.

Animals↗