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Biomedical subjects

J E Collins

Publications and source records attributed to J E Collins.

At least 55 records · Page 3Linked to original sources
PubMed1996

Fetal microscopic lesions in porcine reproductive and respiratory syndrome virus-induced abortion.

Microscopic lesions in four cases of abortion caused by porcine reproductive and respiratory syndrome virus (PRRSV) were characterized by arteritis, myocarditis, and encephalitis. Fetal PRRSV infection was confirmed by virus isolation or immunohistochemistry and serology. Although fetal microscopic lesions in PRRSV abortions are rarely reported, diagnosticians should consider PRRSV when these lesions occur.

Abortion, Veterinary↗
PubMed1996

Chronological immunohistochemical detection and localization of porcine reproductive and respiratory syndrome virus in gnotobiotic pigs.

An immunogold-silver immunohistochemical technique was used to determine the chronological distribution and localization of porcine reproductive and respiratory syndrome virus (PRRSV) in experimentally infected gnotobiotic pigs. Thirty-two pigs were randomly allocated to infected (n = 24) or control (n = 8) groups. Pigs in infected groups were inoculated at 3 days of age by nasal instillation of PRRSV isolate ATCC VR-2332 (total dose = 10(2.64) TCID50), and control pigs were exposed in the same manner to uninfected cell culture supernatant. Three infected and one control pigs were euthanatized at 12 hours and at 1, 2, 3, 5, 7, 14, and 21 days postexposure (DPE). Bronchiolar epithelial cells, arteriolar endothelial cells, monocytes, and interstitial, alveolar, and intravascular macrophages stained for PRRSV antigen at 12 hours postexposure. Staining for PRRSV antigen in endothelial cells, monocytes, and alveolar, interstitial, and intravascular macrophages was most intense and widespread in lung sections from 14 and 21 DPE. In the heart, macrophages in the interstitial and subendocardial spaces and endothelial cells in a few arterioles stained for PRRSV antigen at 14 and 21 DPE. Tonsillar macrophages and mucosal epithelium stained for PRRSV antigen at 12 hours postexposure and sporadically with less intensity in subsequent sampling periods. In the nasal turbinate, PRRSV antigen was identified in macrophages within the mucosal epithelium at 12 hours postexposure and again at 14 and 21 DPE. There was focal staining for PRRSV antigen in the choroid plexus in one pig at 14 DPE. Based on the results of this experiment, the pathogenesis of PRRSV infection in gnotobiotic pigs can be described as initial virus entry through nasal epithelial, tonsillar, and pulmonary macrophages, with viremia occurring by 12 hours postexposure followed by the development of pneumonia, myocarditis, encephalitis, rhinitis, vasculitis, and lymphoid necrosis. Although PRRSV can infect macrophages in heart, tonsil, turbinate, and choroid plexus, pulmonary macrophages are predominantly and consistently infected and are the predominantly cells for virus replication in gnotobiotic pigs.

Animals↗
PubMed1995

A high-density YAC contig map of human chromosome 22.

We have constructed a high-resolution clone map of human chromosome 22 which integrates the available physical and genetic information, establishing a single consensus. The map consists of all classes of DNA landmarks ordered on 705 yeast artificial chromosomes (YACs) at an average landmark density of more than one per 70 kilobases. This map represents the practical limits of currently available YAC resources and provides the basis for determination of the entire gene content and genomic DNA sequence of human chromosome 22.

Chromosome Mapping↗
PubMed1995

Two newly established cell lines derived from the same colonic adenocarcinoma exhibit differences in EGF-receptor ligand and adhesion molecule expression.

Two morphologically distinct cell lines, GP2d and GP5d, derived from the same adenocarcinoma of the colon, have been established and characterised. Both clones have the same genetic changes, consistent with the usual pattern of tumour progression in colon cancer. The cells also have an inverted duplication of bands 10q11 to 10q21, but Southern blot analysis failed to identify any translocations involving the ret protooncogene, which maps to this region. GP2d grew by spreading from the edges of microcolonies to form a confluent layer of cells. GP5d grew in discrete islands of cells forming multi-layered colonies. These differing patterns of growth correlated with variation in expression or cellular distribution of alpha 2-integrin, desmoplakin and e-cadherin. Only GP2d responded to exogenously added epidermal growth factor (EGF), transforming growth factor-alpha (TGF alpha) or insulin with an increase in cell numbers, even though both cell lines possessed similar numbers of EGF receptors. Analysis of EGF receptor ligand expression showed that GP5d cells expressed relatively more TGF alpha mRNA than did GP2d; in contrast, amphiregulin mRNA, which was abundant in GP2d, was virtually undetectable in GP5d. Even though GP5d failed to exhibit a growth response to EGF, it underwent a marked epithelial-mesenchymal transition when treated with EGF, indicating separation of growth and morphological responses to EGF.

Adenocarcinoma↗
PubMed1995

Neospora caninum pneumonia in an adult dog.

Neospora caninum was identified in a lung aspirate specimen from an adult dog with severe pneumonia. Neosporosis was tentatively diagnosed by cytologic examination of a Wright-Giemsa-stained smear of the aspirate specimen, using light microscopy. The infection was confirmed by immunohistochemical examination of a section of lung tissue obtained at necropsy. Neosporosis is usually a fatal ascending neurologic disease of dogs less than 1 year of age. Neospora caninum infections are uncommon in adult dogs and do not have a consistent clinical course. The disease in the dog of this report was unique because the dog had clinical respiratory tract disease and because preliminary diagnosis was made by cytologic examination.

Animals↗
PubMed1995

Epithelial differentiation in the mouse preimplantation embryo: making adhesive cell contacts for the first time.

The preimplantation embryo generates two distinct tissues, the trophectoderm, which is a transporting polarized epithelium, and the inner cell mass. Epithelial differentiation and tissue segregation, here examined in relation to the maturation of membrane adhesion and cell junction systems, are coordinated events regulated by a combination of the zygotic gene expression programme, kinase-mediated protein activation and cell-cell interactions.

Animals↗
PubMed1995

Organization of the human immunoglobulin lambda light-chain locus on chromosome 22q11.2.

The maps of the human immunoglobulin heavy-chain and kappa light-chain loci have recently been completed. We have now completed a map of the human lambda locus (IGL) located on chromosome 22q11.2. We mapped 52 V lambda genes from 10 V lambda families and 7 J lambda and C lambda genes on a 1140 kb contig constructed from eight YACs and 129 cosmid clones. The V lambda genes are arranged within 800 kb. Genes of the different V lambda families are organized in three clusters, V lambda II and III families (cluster A); V lambda I, V, VII and IX families (cluster B); V lambda IV, VI, VIII and X families (cluster C), in contrast to the dispersed organization of the different VH and V kappa families within the human VH and V kappa loci. We note that the most frequently used V lambda families (V lambda II and III) are proximal to the J lambda and C lambda genes. The VpreB gene, encoding part of the surrogate light chain, the GGT2 gene and the BCRL4 pseudogene were also mapped within the lambda locus.

Base Sequence↗
PubMed1995

Pathogenesis of porcine reproductive and respiratory syndrome virus infection in gnotobiotic pigs.

The pathogenesis of porcine reproductive and respiratory syndrome virus (PRRSV) was determined in gnotobiotic pigs by studying the sequential development of microscopic lesions and sites of virus distribution and replication. Thirty-two pigs (three pigs/infected group and one pig/control group) were inoculated by nasal instillation of either PRRSV isolate ATCC VR-2332 (total dose 10(2.6) TCID50) or uninfected cell culture supernatant. Infected and control pigs were euthanized at 12 hours, and 1, 2, 3, 5, 7, 14, and 21 days postexposure (PE). Gnotobiotic pigs experimentally infected with PRRSV were viremic by 12 hours PE and subsequently developed pneumonia, lymphadenopathy, vasculitis, myocarditis and encephalitis. Lung lesions developed by day 3 PE, persisted through day 21 PE and were characterized by alveolar septa thickened by macrophages, alveolar proteinaceous and karyorrhectic debris, alveolar syncytial cells, and multifocal type II pneumocyte hypertrophy. Lymph node lesions varied in distribution and severity and were characterized by germinal center hypertrophy and hyperplasia, lymphocyte necrosis, multiple cystic spaces, and polykaryocytes within the cystic spaces. Heart lesions were a late feature of infection and all infected pigs had heart lesions on day 21 PE characterized by subendocardial, myocardial, and perivascular foci of lymphocytes. Vasculitis also varied in distribution and severity and affected all sizes of vessels. Results of this experiment indicate that PRRSV is a multisystem disease characterized initially by viremia with subsequent virus distribution and replication in multiple organs causing interstitial pneumonia, vasculitis, lymphadenopathy, myocarditis, and encephalitis.

Animals↗
PubMed1995

Regulation of desmocollin transcription in mouse preimplantation embryos.

The molecular mechanisms regulating the biogenesis of the first desmosomes to form during mouse embryogenesis have been studied. A sensitive modification of a reverse transcriptase-cDNA amplification procedure has been used to detect transcripts of the desmosomal adhesive cadherin, desmocollin. Sequencing of cDNA amplification products confirmed that two splice variants, a and b, of the DSC2 gene are transcribed coordinately. Transcripts were identified in unfertilized eggs and cumulus cells and in cleavage stages up to the early 8-cell stage, were never detected in compact 8-cell embryos, but were evident again either from the 16-cell morula or very early blastocyst (approx 32-cells) stages onwards. These two phases of transcript detection indicate DSC2 is encoded by maternal and embryonic genomes. Previously, we have shown that desmocollin protein synthesis is undetectable in eggs and cleavage stages but initiates at the early blastocyst stage when desmocollin localises at, and appears to regulate assembly of, nascent desmosomes that form in the trophectoderm but not in the inner cell mass (Fleming, T. P., Garrod, D. R. and Elsmore, A. J. (1991), Development 112, 527-539). Maternal DSC2 mRNA is therefore not translated and presumably is inherited by blastomeres before complete degradation. Our results suggest, however, that initiation of embryonic DSC2 transcription regulates desmocollin protein expression and thereby desmosome formation. Moreover, data from blastocyst single cell analyses suggest that embryonic DSC2 transcription is specific to the trophectoderm lineage. Inhibition of E-cadherin-mediated cell-cell adhesion did not influence the timing of DSC2 embryonic transcription and protein expression. However, isolation and culture of inner cell masses induced an increase in the amount of DSC2 mRNA and protein detected. Taken together, these results suggest that the presence of a contact-free cell surface activates DSC2 transcription in the mouse early embryo.

Animals↗
PubMed1995

Serologic studies of experimentally induced Salmonella choleraesuis var kunzendorf infection in pigs.

Two indirect ELISA containing outer membrane protein (OMP) and lipopolysaccharide (LPS) antigens from a field isolate of Salmonella choleraesuis var kunzendorf were developed and evaluated in experimentally infected and uninfected control pigs. Experimentally induced infection with S choleraesuis was successfully established in 10 pigs by oral inoculation with 10(8) organisms, and 3 pigs died of clinical salmonellosis at postinoculation (PI) weeks 1, 2, and 4. Swab specimens from tonsils, nostrils, and rectum of pigs were obtained for culture, and sera were evaluated at weekly intervals for 9 weeks after inoculation. The ELISA containing OMP and LPS antigens with either anti-swine IgG or protein albumin-to-globulin ratio (antiglobulin) conjugates were standardized for serologic evaluation. All 4 ELISA (2 OMP and 2 LPS) detected seroconversion by PI week 3 and had sensitivities and specificities of 97.8 and 88.8, 100 and 100, 95.6 and 88.8, and 93.3 and 72.5%, at their ideal cutoff points (negative mean optical density +2 SD). There was excellent agreement between all 4 ELISA systems as determined by kappa values. Cultures of fecal, tonsil, and nasal swab specimens were positive for S choleraesuis until the fourth week of infection. Fecal swab specimens from 1 pig were positive for S choleraesuis until PI week 7. Persistent infection after antemortem culture results were negative was detected by all 4 ELISA, which indicated consistently high titers until the end of PI week 9.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Lipopolysaccharide and cytokine augmentation of human monocyte IgA receptor expression and function.

Receptors for IgA (Fc alpha R) are found on phagocytic cells in the peripheral blood and tissues associated with mucosal areas where IgA Abs constitute a major line of defense. Because Fc alpha R are capable of triggering protective functions of monocytes and neutrophils, such as phagocytosis and the oxidative burst, they may be important in amplifying the antimicrobial effects of IgA. Various cytokines play a role in regulating function and FcR expression of monocytes, macrophages, and neutrophils. The present studies examine the modulation of monocyte Fc alpha R by LPS and cytokines. LPS strongly up-regulated monocyte Fc alpha R expression. TNF and IL-1, produced in response to LPS, promoted Fc alpha R increase, as did GM-CSF; whereas IFN-gamma down-regulated Fc alpha R. Increased receptor expression was accompanied by augmented IgA-mediated phagocytosis. An increase in Fc alpha R-specific mRNA was detected in monocytes treated with TNF, IL-1, GM-CSF, and LPS; whereas message was reduced in cells treated with IFN-gamma. Monocyte-derived macrophages and cells of the Monomac 6 monocyte-like line expressed greater numbers of Fc alpha R than monocytes but were less responsive to LPS and TNF. Cell lines THP-1 and U937, which expressed similar or lower levels of Fc alpha R than monocytes, displayed an increase in Fc alpha R in response to LPS and, to various degrees, to TNF, IL-1, and GM-CSF. These results indicate that Fc alpha R on monocytes are modulated by endotoxin and an array of cytokines distinct from those that regulate expression of FcR for IgG.

Cell Line↗
PubMed1994

Interaction between Streptococcus suis serotype 2 and porcine reproductive and respiratory syndrome virus in specific pathogen-free piglets.

Secondary specific pathogen-free (sSPF) piglets were inoculated intranasally with Streptococcus suis serotype 2 alone, porcine reproductive and respiratory syndrome virus (PRRSV) alone, or with PRRSV followed by S suis. Uninfected piglets were used as controls. Pigs inoculated with PRRSV (ATCC VR-2332) followed by challenge with a virulent strain (87555) of S suis serotype 2 developed clinical signs, suppurative meningitis and large numbers of S suis in their tissues, including the brain and meninges. Pigs inoculated with PRRSV alone, S suis (87555) alone, or with PRRSV and the DH5 strain of S suis serotype 2 (lacking a protein associated with virulence) and the uninfected piglets did not develop clinical signs or lesions or have large numbers of bacteria in their tissues. The results suggest that PRRSV predisposes sSPF pigs to infection and disease caused by virulent S suis serotype 2. Co-infection of piglets with PRRSV and a virulent strain of S suis may provide a useful model for the study of S suis septicaemia and meningitis.

Animals↗
PubMed1994

Genetic mapping of 14 short tandem repeat polymorphisms on human chromosome 22.

We have constructed a linkage map of 14 short tandem repeat polymorphisms (11 with heterozygosity > 70%) on the long arm of human chromosome 22 using 23 non-CEPH pedigrees. Twelve of the markers could be positioned uniquely with a likelihood of at least 1,000:1, and distributed at an average distance of 6.62 cM (range 1.5-16.1 cM). The sex-combined map covers a total of 79.6 cM, the female map 93.2 cM and the male map 64.6 cM. Based on comparisons between physical maps and other genetic maps, we estimate that our map covers 70%-80% of the chromosome. The map integrates markers from previous genetic maps and uniquely positions one marker (D22S307). Data from physical mapping on the location of four genetic markers correlates well with our linkage map, and provides information on an additional marker (D22S315). This map will facilitate high resolution mapping of additional polymorphic loci and disease genes on chromosome 22, and act as a reference for building and verifying physical maps.

Chromosome Mapping↗
PubMed1994

Characterization of a new member of the human beta-adaptin gene family from chromosome 22q12, a candidate meningioma gene.

A 140 kb homozygous deletion from 22q12 in one meningioma directed us towards the cloning and characterization of a new member of the human beta-adaptin gene family (named BAM22). Adaptins are essential for the formation of clathrin coated vesicles in the course of intracellular transport of receptor-ligand complexes. The BAM22 gene is totally inactivated in the tumor with homozygous deletion. Northern blot analysis of 70 sporadic meningiomas showed specific loss of expression in 8 tumors, suggesting inactivation of BAM22. Based on this, we propose BAM22 as a second chromosome 22 locus important in meningioma development, after the neurofibromatosis type 2 gene.

Adaptor Protein Complex 1↗