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J Catalfamo

Publications and source records attributed to J Catalfamo.

9 recordsLinked to original sources
PubMed1999

Two distinct mutations cause severe hemophilia B in two unrelated canine pedigrees.

The molecular defects causing severe factor IX deficiency were identified in two distinct canine breed-variants. Both defects were associated with an absence of plasma factor IX coagulant activity and antigen. A large deletion mutation was found in 1 breed variant, spanning the entire 5' region of the factor IX gene extending to exon 6. An approximately 5 kb insertion disrupted exon 8 of the second breed-variant. This insertion was associated with alternative splicing between a donor site 5' and acceptor site 3' to the normal exon 8 splice junction, with introduction of a new stop codon. The resultant transcript lacked most of the factor IX catalytic domain and 3' untranslated region. Molecular analyses of canine hemophilia B define an experimental model for study of inhibitor formation and gene therapy strategies, and provide insight into spontaneous mutation mechanisms in the factor IX gene and on the X chromosome of mammalian species.

Animals↗
PubMed1996

Severe, recessive von Willebrand's disease in German Wirehaired Pointers.

OBJECTIVE: To characterize the biochemical and genetic basis of a clinically severe form of von Willebrand's disease (vWD) in German Wirehaired Pointers. DESIGN: Case series. SAMPLE POPULATION: Plasma samples from 335 German Wirehaired Pointers (8 clinically affected). PROCEDURE: Plasma samples were evaluated, using an ELISA, to determine von Willebrand factor (vWF) antigen concentration. Additional studies performed on samples from clinically affected dogs included coagulation screening tests, factor VIII coagulant activity assays, and immunoelectrophoresis to determine vWF multimeric composition. RESULTS: Mucosal bleeding and bleeding at sites of cutaneous injury were observed in affected dogs by 6 months old. Plasma vWF antigen concentration was markedly reduced, and there was a lack of high molecular weight vWF multimers; findings compatible with type-II vWD. Inheritance and expression pattern of vWD in this breed was most compatible with that of an autosomal recessive trait. CLINICAL IMPLICATIONS: Von Willebrand's disease should be included in the differential diagnoses of bleeding diatheses in German Wirehaired Pointers, with definitive diagnosis confirmed on the basis of canine-specific vWF assays.

Animals↗
PubMed1996

Plasma von Willebrand factor antigen concentration as a predictor of von Willebrand's disease status in German Wirehaired Pointers.

OBJECTIVE: To evaluate the use of plasma von Willebrand's factor (vWF) concentration as a screening test for inherited von Willebrand's disease (vWD) in German Wirehaired Pointers (GWHP). DESIGN: Prospective study. SAMPLE POPULATION: Plasma samples from 467 GWHP. PROCEDURE: Plasma vWF concentrations were measured as vWF antigen (vWF:Ag), using ELISA, and test values were used to estimate prevalence of vWD in GWHP and predict parental vWD status. Test results of progeny from matings of carrier and noncarrier parents were then compared with the predicted outcome of such matings. RESULTS: 376 (81%) GWHP were classified as vWD noncarriers, 58 (12%) as carriers, and 5 (1%) as affected with vWD. An additional 28 (6%) GWHP could not be classified on the basis of plasma vWF:Ag concentration. The observed outcome of tests of 213 pups was not significantly different from that predicted on the basis of parental vWF:Ag concentration. The predictive value of a positive test result (vWF: Ag% < 50) for identifying vWD carriers was 0.89. CLINICAL IMPLICATIONS: Plasma vWF:Ag concentration was an effective predictor of genetic status for the vWD trait, and for the outcome of matings between carriers and noncarriers of vWD in this study of GWHP.

Animals↗
PubMed1996

Isolation and characterization of canine factor IX.

Canine plasma factor IX was purified to homogeneity by a combination of barium citrate precipitation and three-step column chromatographies of DEAE sepharose, heparin agarose and a monoclonal antifactor IX antibody-linked agarose. Canine factor IX has an apparent molecular size of 61 kDa, which is slightly smaller than that of human factor IX, as determined by denatured polyacrylamide gel electrophoresis. Its amino acid composition, amino-terminal and carboxyterminal amino acid sequences agreed well with those predicted from the reported cDNA. Unlike purified human factor IX, canine factor IX preparation often showed a discrete smaller molecular species (approximately 50 kDa) which was generated by a specific proteolytic cleavage between Arg310 and Val311. When purified canine factor IX was utilized as a standard for enzyme linked immunosorbent assay, the concentration of canine factor IX in the pooled normal dog plasma was determined to be 5.3 micrograms/ml with 11.2% carbohydrate content (or 4.7 micrograms/ml for its polypeptide chain moiety). Concentration of plasma factor IX antigen was measured in six severely affected, unrelated hemophilia B dogs. Four had factor IX antigen of less than 1% of the normal, and two had undetectable levels. The latter two had gross molecular abnormalities in their factor IX genes. Three obligate carrier females had variable but proportionately reduced factor IX antigen and factor IX coagulant activity levels. These results provide a quantitative method for measuring canine factor IX antigen which is a prerequisite for studying hemostasis and development of gene transfer approaches in the canine model of hemophilia B.

Animals↗
PubMed1993

Buccal mucosa bleeding time is prolonged in canine models of primary hemostatic disorders.

Bleeding times are reported in many studies using canine models, with a variety of techniques employed to adapt these tests for dogs. We evaluated a canine model of template bleeding time, the buccal mucosa bleeding time (BMBT), by examining the test's sensitivity and specificity for defects of primary hemostasis. We examined thirty-five dogs having defined defects of either primary hemostasis (Types I, II, III von Willebrand's disease, thrombasthenia, thrombopathia) or secondary hemostasis (hemophilia A and B, Factor VII deficiency). Comparisons of BMBT and cuticle bleeding time were made in a subset of these dogs. All dogs having primary hemostatic disorders had long BMBT, and all factor deficient dogs had BMBT within normal range. The BMBT in canine models appears to be a specific and sensitive test of primary hemostasis; suitable for evaluating factors affecting template bleeding time and potential efficacy and thrombogenicity of treatment regimens.

Animals↗
PubMed1992

Collagen-induced rat platelet reactivity is enhanced in whole blood in both the presence and absence of dense granule secretion.

Collagen induced aggregation, ATP secretion and thromboxane (TxB2) generation of storage pool deficient platelets were compared to normal platelets of closely related rat strains. Platelet function was monitored in citrated-platelet-rich-plasma (PRP) and citrated whole blood. Wistar (W) and fawn-hooded (FH) rat strains and their F2 hybrids were utilized. The W strain, which is ancestral to the FH strain, is not storage pool deficient while the FH strain is. This was manifested by the total lack of collagen induced ATP secretion from platelets of the FH strain while the platelets of the W strain secreted normally. Utilizing platelets from the F2 generation of WxFH matings, the absence of dense granule secretion (ATP) from the FH platelets, as well as other platelet defects of FH rats, were shown to be associated with homozygosity for the red-eyed dilution gene [r]. The non-secreting FH platelets were utilized to determine the effects of secreted dense granule constituents upon collagen induced aggregation and TxB2 generation. The non-secreting storage pool deficient platelets did aggregate and did generate TxB2 upon stimulation with collagen; however, the storage pool deficient FH platelets demonstrated less TxB2 generation and did not aggregate as effectively as the normally secreting platelets of the W strain. When evaluating collagen induced platelet function in whole blood as compared to PRP, the storage pool deficient platelets remained less reactive than normally secreting platelets, but both platelet types demonstrated enhanced aggregation and increased TxB2 generation in whole blood.

Adenosine Triphosphate↗
PubMed1976

Cell isoperoxidases in sweet potato plants in relation to mechanical injury and ethylene.

Leaves and storage roots of sweet potato plants (Ipomea batatas) showed the same qualitative isoperoxidase patterns and a similar distribution of distinctive isoperoxidases between the cell protoplast and cell wall free, ionically bound, and covalently bound fractions. No changes in the qualitative isoenzyme spectrum were found in relation to age, mechanical injury, or ethylene action. Thus, as in tobacco plants, the cell isoperoxidases in sweet potato did not reflect the possible differential mRNA synthesis in relation to organ, age, or injury. Transcription does not seem to be a limiting factor in injury- and ethylene-dependent peroxidase enhancement during the first 24 hr.The contribution of the wall ionically bound and protoplast fractions was highest in young and old leaves, respectively. In the protoplast and wall ionically and covalently bound fractions, 14, 6, and 5 isoenzyme bands were found; in addition, 4 bands, not detected in the protoplast, were also revealed in the covalently bound fraction. The distinctive "juvenile" and, developing with age, "mature" isoforms were mainly found in the ionically bound and protoplast fractions, respectively.The injury-enhanced and/or ethylene-enhanced peroxidase development was most pronounced in young leaves. Ethylene suppressed some injury-enhanced, had no effect on some other injury-enhanced, and greatly promoted some of the injury-unaffected or enhanced isoperoxidases. After ethylene removal, an increase in the "mature" isoforms was found in the protoplast of intact leaves.Electron microscopy of leaves revealed peroxidase in membrane-bound vesicles located mainly in the vacuole; a thin layer of reaction products was also found on the wall's outer surface. No Golgi apparatus were seen in the cells of control or ethylene-treated intact leaves. In ethylene-treated intact or injured leaves accumulations of reaction products between the plasmalemma and wall were also found. Numerous Golgi apparatus with dark stained vesicles were seen in injured, and especially in injured and ethylene-treated leaves; the vacuolar bodies seemed to occur in very great number.

Journal Article↗