Search PubMed⌕ Search

Biomedical subjects

S J O'Brien

Publications and source records attributed to S J O'Brien.

At least 253 records · Page 14Linked to original sources
PubMed1989

Feline lymphomas: immunological and cytochemical characterization.

The immunological and cytochemical phenotypes of five primary feline lymphomas and six feline lymphoma lines are reported. Thymic lymphomas induced by the Rickard strain of FeLV (FeLV-R) are of prothymocyte or (immature) cortical thymocyte origin, as these express terminal deoxynucleotidyl transferase, the guinea pig erythrocyte rosette receptor, Ia antigens, partial cortisone sensitivity, and nonspecific esterase. Lymphomas associated with other strains of FeLV form rosettes with guinea pig erythrocytes, frequently have Ia antigens and cytoplasmic nonspecific esterase, and probably originate from helper T-cells, monocyte/macrophages, or null cells. These data belie previous conclusions that FeLV leukemogenesis is restricted to mature T-cells; rather, the considerable heterogeneity in the surface and cytochemical phenotype of feline lymphomas probably reflects transformation of multipotent lymphoid or monocytoid precursors in the bone marrow by FeLV.

Animals↗
PubMed1989

In vitro maturation and fertilization of domestic cat follicular oocytes.

The time course and conditions necessary for oocyte maturation and subsequent fertilization in vitro were studied in the domestic cat. Darkly pigmented oocytes surrounded by cumulus cells and a tight corona radiata were collected from ovaries removed at ovariohysterectomy. After culture in Eagle's minimum essential medium, oocytes were evaluated for nuclear maturation by analyzing chromosomal spreads. Oocytes achieved metaphase II after intervals of 40-48 hr of in vitro incubation. The incidence of maturation was enhanced (P less than 0.05) when oocytes were recovered from inactive (54%) or follicular (56%) stage donors compared to those recovered from luteal phase (29%) or pregnant (35%) cats. The proportion of oocytes successfully maturing in vitro in medium containing no hormone supplementation (37%) was less (P less than 0.01) than counterparts cultured in follicle-stimulating hormone (FSH) only (48%) or FSH and luteinizing hormone (LH) (54%). The efficiency of maturation was not influenced (P greater than 0.05) by either maintenance/transport temperature (4 degrees C vs. 22 degrees C) or delaying recovery of oocytes from antral follicles (2-8 hr vs. 24-32 hr). Approximately 36% of the in vitro matured oocytes cocultured with spermatozoa demonstrated evidence of fertilization; however, there appeared to be a critical development period for maximizing the incidence of fertilization. These results demonstrate that domestic cat antral oocytes are capable of maturing in vitro, and maturation is influenced by the reproductive status of the donor and the presence of gonadotropins in the culture medium. These oocytes are capable of forming embryos and developing to at least the 16-cell stage in vitro.

Animals↗
PubMed1989

Comparative features of a coronavirus isolated from a cheetah with feline infectious peritonitis.

A coronavirus which was isolated from a cheetah (Acinonyx jubatus) that succumbed to feline infectious peritonitis was characterized in vitro. The virus was determined to be highly cell-associated with Crandell feline kidney (CrFK) cells and was routinely maintained as a persistent infection (CrFK 83-4497). The cheetah coronavirus was compared with other members of the feline coronavirus group including the feline enteric coronavirus (FECV) 79-1683 and the feline infectious peritonitis viruses (FIPV), 79-1146, and UCD-1. The cheetah coronavirus was demonstrated to have a restricted host-cell range with limited cytopathic effect. Indirect immunofluorescence with antisera to FIPV UCD-1 revealed the concentration of viral antigens in the perinuclear region of cells infected with the cheetah coronavirus. Ultrastructural studies of the cheetah coronavirus indicated a limited number of immature viral particles within cytoplasmic vesicles and at the cell surface. This was in contrast to electron microscopy results of FECV 79-1683 and FIPV 79-1146, which had numerous mature virus particles within the cytoplasmic vesicles, as well as at the cell surface. The cheetah coronavirus was tentatively placed in the feline coronavirus family based upon its antigenic reactivity by immunofluorescence; however, the possibility that it represents a unique coronavirus of cheetahs should not be dismissed without further analyses at the host and genomic levels.

Acinonyx↗
PubMed1989

The use of the contact Nd:YAG laser in arthroscopic surgery: effects on articular cartilage and meniscal tissue.

The contact Nd:YAG laser's small size, tip variety, fiberoptic application, and suitability for use in a saline medium make it a particularly appealing tool for use in arthroscopic procedures. This study was performed to investigate the laser's effects on articular cartilage and meniscal tissue with respect to depth of damage (canine cadaver model) and healing response (rabbit model). Depth of damage in the canine cadaver model was greater in meniscal tissue than in articular cartilage at each wattage level. In the presence of a saline bath, depth damage in both tissues was diminished. Scalpel articular cartilage lesions showed no response over time. Electrocautery lesions uniformly showed significant wide margins of hyaline cartilage necrosis which increased over time. Laser articular cartilage lesions showed vigorous healing responses characterized by fibrocartilage healing by 6 weeks. Scalpel meniscectomies showed characteristic fibrocartilagenous remodeling by 6 weeks, while electrocautery meniscectomies showed wide margins of necrosis with no specimen showing remodeling capability. Laser meniscectomies showed an intermediate response with a small number of menisci remodeling in a normal fashion. This article represents the first comprehensive look at the effects of the Nd:YAG laser on articular cartilage and meniscal tissue in terms of depth of damage and healing response over time, and indicates this laser's biological advantage over scalpel and electrocautery in arthroscopic procedures.

Animals↗
PubMed1989

The human homolog of the Moloney leukemia virus integration 2 locus (MLV12) maps to band p14 of chromosome 5.

The Moloney leukemia virus integration 2 (MLV12) locus represents a common region for proviral integration and a putative oncogene involved in the induction of thymic lymphomas in rodents. The human homolog of the MLV12 locus has been cloned and studies have been initiated to determine its possible role in the induction and progression of human neoplasms. In this study we used a panel of human X rodent somatic cell hybrids and in situ hybridization to metaphase chromosomes to map MLV12 to the short arm of the human chromosome 5, band p14.

Animals↗
PubMed1989

Assignment of the feline alpha-L-iduronidase gene to chromosome D4.

The structural gene encoding feline alpha-L-iduronidase has been assigned to chromosome D4 by electrophoretic analysis of feline-hamster somatic cell hybrids. Previously, the human alpha-L-iduronidase gene had been assigned to the chromosomal region 22pter-q11. alpha-L-Iduronidase is the first human gene on chromosome 22 to be comparatively mapped in cats and the localization of the feline gene should facilitate further genetic analysis of the feline MPS I animal model.

Animals↗
PubMed1989

Molecular analysis of the human serum amyloid A (SAA) gene family.

We have assigned the human serum amyloid A (SAA) gene family to a 90 kb region on the short arm of human chromosome 11 (11p) by hybridization of defined genomic fragments of human SAA genes to DNA from rodent-human somatic cell hybrids and to large DNA fragments separated by transverse alternating field gel electrophoresis. We have also characterized SAA probe hybridization patterns in human DNA cleaved with restriction endonucleases Hind III, Pst I, BglII, TaqI, and XbaI and found invariant patterns except for a two-allele restriction fragment length polymorphism (RFLP) with Hind III. These studies show that the SAA gene family comprises at least three members in the haploid human genome and will be useful in identifying variant patterns and establishing linkage between members of the SAA gene family and other markers on chromosome 11.

Chromosome Mapping↗
PubMed1989

The t(11;14)(p15;q11) in a T-cell acute lymphoblastic leukemia cell line activates multiple transcripts, including Ttg-1, a gene encoding a potential zinc finger protein.

Interchromosomal translocations within lymphoid neoplasms frequently involve the antigen receptor genes. We cloned the breakpoints of the t(11;14)(p15;q11) in a CD3-negative T-cell acute lymphoblastic leukemia cell line (RPMI 8402) in order to identify new genes potentially involved in T-cell neoplasia. An extensive comparison of both breakpoints and their germ line counterparts indicated that an inadvertant recombinase-mediated break at chromosome segment 11p15 recombined with the delta T-cell receptor at 14q11. The derivative 11 breakpoint resembles a coding joint in which 11p15 rather than a variable region was introduced 5' to a D delta 1 D delta 2 J delta 1 intermediate rearrangement. Conversely, the derivative 14 breakpoint corresponds to a signal joint between the 5' heptamer-spacer-nonamer recombinational signal of D delta 1 and an isolated heptamer at 11p15. Multiple, apparently distinct transcripts were found flanking both breakpoints of 8402. RNAs of 3.5, 4.4, 1.4, and 8.0 kilobases originating from either side of the derivative 14 breakpoint were highly expressed in 8402 compared with other cells. This suggests that this translocation deregulated multiple genes and provides the opportunity to assess any multifactorial contribution they may have to malignancy. We cloned and sequenced several cDNAs representing the 1.4-kilobase transcript (termed Ttg-1 [T-cell translocation gene 1]) from an 8402 library. The predicted protein of 156 amino acids contained two internal repeats which could potentially form zinc fingers.

Amino Acid Sequence↗
PubMed1989

The human endonexin II (ENX2) gene is located at 4q28----q32.

A relatively recently identified family of structurally similar Ca2(+)-dependent phospholipid binding proteins is called the annexin gene family. At least seven genes are known, although their exact functions are unclear. The endonexin II gene (ENX2), one member of the gene family, is assigned to 4q28----q32 using both Southern transfer analysis of human x rodent somatic cell hybrid DNAs and in situ chromosome hybridization. One of the lipocortin II genes, another annexin, had previously been assigned to the long arm of chromosome 4.

Animals↗
PubMed1989

The human chromogranin A gene: chromosome assignment and RFLP analysis.

Chromogranin A/secretory protein I (CgA) is a glycoprotein that is stored and released along with peptide hormones and neurotransmitters from several tissues, although its exact function is not known. A cDNA (gene symbol CHGA) clone was used as a probe in Southern blot analyses of human-rodent somatic cell hybrid DNAs. Discordancy analysis allowed confirmation of the assignment of the gene to chromosome 14. These results were extended using in situ chromosome hybridization, and a signal was found at 14q32. BglII digestion of genomic DNA from 28 unrelated Caucasian individuals probed with CHGA detected a two-allele RFLP with allelic frequencies of .34 and .66.

Blotting, Southern↗
PubMed1989

Approaches to senior care #7. Shoulder pain in the geriatric patient. Part II. Treatment options.

Shoulder pain is one of the most common musculoskeletal complaints in the elderly. The rewards of accurate diagnosis and early treatment often elude the orthopaedist without a systematic approach to this region. A thorough understanding of shoulder anatomy, pain referral patterns, and the pathophysiology of the aging process must be combined with an awareness of the latest treatment modalities and surgical techniques.

Acromioclavicular Joint↗
PubMed1989

Approaches to senior care #6. Shoulder pain in the geriatric patient. Part I. Evaluation and pathophysiology.

Shoulder pain is one of the most common musculoskeletal complaints in the elderly. The rewards of accurate diagnosis and early treatment often elude the orthopaedist without a systematic approach to this region. A thorough understanding of shoulder anatomy, pain referral patterns, and the pathophysiology of the aging process must be combined with an awareness of the latest treatment modalities and surgical techniques.

Aged↗
PubMed1988

The kappa-deleting element. Germline and rearranged, duplicated and dispersed forms.

Human light chain genes are used in a kappa before lambda order. Accompanying this hierarchy is the rearrangement of a kappa-deleting element (Kde) which eliminates the kappa locus before lambda gene rearrangement. In approximately 60% of rearrangements the Kde recombines at a conserved heptamer within the J kappa-C kappa intron. We demonstrated that aberrant V/J rearrangements possessing apparent "N" nucleotides existed 5' to the J kappa-Kde rearrangements. This suggests that the Kde may selectively eliminate nonfunctional V/J alleles. A kappa-producing cell that displayed the unusual finding of lambda gene rearrangement demonstrated a rearranged Kde. This rearrangement was a V kappa/Kde recombination and the heptamer-11 bp spacer-nonamer flanking the V kappa is the target site of the Kde 40% of the time. The mouse possesses a counterpart to the Kde (recombining sequence [RS]) and the highly conserved regions surround the heptamer-spacer-nonamer signals. No complete protein product was predicted from the germline Kde near its break-point and no consistent fusion product was predicted from either the V/Kde or V/J-Kde rearrangements. A distal portion of the Kde is duplicated and is present at 2q11 as well as 2p11. The evolutionary conservation of the kappa-elimination event, the duplication and maintenance of the Kde indicates that it has a function. A portion of the Kde may still prove to encode a trans-acting factor that directly affects lambda rearrangement. A certain role for the Kde is its site-specific rearrangement, which destroys ineffective kappa genes and sets the stage for lambda gene utilization.

Alleles↗
PubMed1988

Molecular characterization and genetic mapping of class I and class II MHC genes of the domestic cat.

The major histocompatibility complex (MHC) of the domestic cat has been poorly characterized to date, primarily because of numerous difficulties in the preparation of allotypic sera. We present here a comparative analysis of class I and class II genes in domestic cat populations using molecular probes of the MHC from man and mouse. The cat possesses a minimum of 20 class I loci and 5 class II genes per haploid genome. Class I genes of the domestic cat expressed limited restriction fragment length polymorphism. The average percent difference of the size of DNA fragments between individual cats was 9.0%, a value five times lower than the value for mice, but comparable to the human DNA polymorphism level. Class I and class II genes were both genetically mapped to feline chromosome B2 using a panel of rodent x cat somatic cell hybrids. Since feline chromosome B2 is syntenically homologous to human chromosome 6 and mouse chromosome 17, these results affirm the linkage conservation of the MHC-containing linkage group in the three mammalian orders.

Animals↗
PubMed1988

Biological and pathological consequences of feline infectious peritonitis virus infection in the cheetah.

An epizootic of feline infectious peritonitis in a captive cheetah population during 1982-1983 served to focus attention on the susceptibility of the cheetah (Acinoyx jubatus) to infectious disease. Subsequent observations based upon seroepidemiological surveys and electron microscopy of fecal material verified that cheetahs were indeed capable of being infected by coronaviruses, which were antigenically related to coronaviruses affecting domestic cats, i.e. feline infectious peritonitis virus/feline enteric coronavirus. Coincident with the apparent increased susceptibility of the cheetah to infectious diseases, were observations that the cheetah was genetically unusual insofar as large amounts of enzyme-encoding loci were monomorphic, and that unrelated cheetahs were capable of accepting allogenic skin grafts. These data provided the basis for a hypothesis that the cheetah, through intensive inbreeding, had become more susceptible to viral infections as a result of genetic homogeneity.

Acinonyx↗
PubMed1988

Chromosomal localization of the human interleukin 1 alpha (IL-1 alpha) gene.

The human interleukin 1 alpha gene was assigned to chromosome 2 using Southern transfer analysis of human-rodent somatic cell hybrid DNAs. The gene was regionally localized to 2q12-21 using in situ hybridization to metaphase chromosomes. These results indicate that the IL-1 alpha gene maps to the same general region on the long arm of chromosome 2 as the IL-1 beta gene, which has been previously assigned.

Animals↗