PubMed Health⌕ Search

Biomedical subjects

U Giger

Publications and source records attributed to U Giger.

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

Molecular basis of canine muscle type phosphofructokinase deficiency.

Muscle type phosphofructokinase (M-PFK) deficiency is a rare inherited glycogen storage disease in humans that causes exertional myopathy and hemolysis. The molecular basis of canine M-PFK deficiency, the only naturally occurring animal homologue, was investigated. Lack of M-PFK enzyme activity was caused by a nonsense mutation in the penultimate exon of the M-PFK gene, leading to rapid degradation of a truncated (40 amino acids) and therefore unstable M-PFK protein. A polymerase chain reaction-based test was devised to identify M-PFK-deficient and carrier animals. This represents one of only a few inborn errors of metabolism where the molecular defect has been identified in a large animal model which can now be used to develop and assess novel therapeutic strategies.

Animals↗
PubMed1996

A cDNA encoding canine muscle-type phosphofructokinase.

The canine muscle-type-phosphofructokinase-encoding gene (M-PFK) was sequenced by using a combination of cDNA cloning and RT-PCR amplification. The canine M-PFK sequence shares 88 and 90% identity with rabbit and human M-PFK, respectively. The canine ORF was determined to be 6-bp longer than either human or rabbit M-PFK due to a 6-bp insertion at the end of exon 13.

Amino Acid Sequence↗
PubMed1996

Blood type AB in the feline AB blood group system.

OBJECTIVE: To assess the genetics, frequency, and biochemistry of the AB blood type in cats. ANIMALS: Domestic shorthair and purebred cats in a breeding colony and privately owned catteries and blood samples from a large feline blood typing laboratory. PROCEDURES: Samples from cats with blood type AB were selected from the feline blood typing laboratory at the university. Breeding experiments and family studies were used for the genetic analysis of cats with blood type AB. Simple slide hemagglutination assays were used to type cats. Hemagglutination assays, flow cytometry, and ganglioside analysis by high-performance thin layer chromatography were applied to characterize the AB antigens. RESULTS: Type AB was rare (13/9,239 cats; 0.14% frequency) in cats of the United States and Canada. Type AB occurred only in breeds in which type B was also detected. Cats with type-AB blood express biochemical features of type-A and type-B antigens. Genetic analyses of families with blood type-AB cats are consistent with the hypothesis of 3 alleles: A, B, and AB. The AB allele is recessive to the A allele, but dominant over the B allele. There may be an additional genetic mechanism responsible for the inheritance of blood type AB in cats. CONCLUSION: Blood type AE is an extremely rare and separately inherited type in the feline AB blood group system. CLINICAL RELEVANCE: Kittens with type-AB blood born to queens with type-B blood are at similar risk for neonatal isoerythrolysis as kittens with type-A blood because anti-A alloantiserum from blood type-B queens recognizes AB red blood cells. Furthermore, cats with type-AB blood are best transfused with type-AB or type-A blood.

ABO Blood-Group System↗
PubMed1996

Transfer of colostral antibodies from queens to their kittens.

OBJECTIVE: To examine systemic immunity in kittens, including transfer of maternal immunoglobulins from the queen to kittens, and subsequent decay of passively obtained immunoglobulins. ANIMALS: 6 healthy queens and their 46 kittens. PROCEDURE: Immunoglobulin concentrations were measured in serum, colostrum, and milk of queens and in their kittens' sera. Decay rate constants and half-lives of maternally derived immunoglobulins were determined. To determine intestinal absorption, foreign IgG was given to kittens at 6- to 8-hour intervals after birth, and bovine IgM was given to kittens at birth. RESULTS: Immunoglobulin concentrations of milk and colostrum did not differ significantly after removal of milk fat. Mean IgG concentration was higher in colostrum/ milk, whereas mean IgA and IgM concentrations were lower than those in the queens' serum. No IgG or IgA was detected in any of the precolostral serum samples obtained from kittens. Small amounts of IgM were present in the sera from 5 kittens at birth. Transferred IgG and IgA decreased rapidly with half-lives of 4.4 +/- 3.57 and 1.93 +/- 1.94 days, respectively. Serum IgM concentration increased irregularly during the first week of life, followed by a steady increase. Foreign IgG given up to 12 hours after birth was detected in kittens' serum, whereas IgG given at or after 16 hours was not found in any kitten's serum. CONCLUSIONS: Milk and colostral immunoglobulin concentrations did not differ significantly. The half-lives of maternally derived IgG and IgA in kittens were shorter than those reported in dogs. IgG given at or after 16 hours of life was not absorbed by neonatal kittens. CLINICAL RELEVANCE: Queen's milk obtained anytime during lactation may be used as a replacement for colostrum as a source of antibodies for neonatal kittens. Kittens at risk for neonatal isoerythrolysis must only be removed from the queens during the first day of life.

Animals↗
PubMed1995

Inheritance of cystinuria and renal defect in Newfoundlands.

OBJECTIVE: To describe clinical features, characterize metabolic renal abnormalities, and evaluate mode of inheritance of cystinuria in Newfoundlands. DESIGN: Prospective study. ANIMALS: Two families of Newfoundlands including 11 dogs with dysuria, stranguria, or obstruction attributable to cystine calculi. PROCEDURE: Urinalysis and nitroprusside spot tests were performed to evaluate cystinuria in the affected dogs. All calculi were analyzed by crystallography. Amino acid concentrations in urine and plasma of affected dogs were compared with those in clinically normal related dogs. Renal fractional excretion and reabsorption of amino acids were determined in 5 affected Newfoundlands. RESULTS: Nine dogs had pure cystine calculi in the bladder, and 4 of these had renal cystine calculi. Affected dogs persistently excreted excessive amounts of cystine (> 500 nmol/mg of creatinine; reference = 54 +/- 38 nmol/mg of creatinine) and had typical cystine crystals in acidic urine. Urinary excretion of ornithine, lysine, and arginine was also high. Dogs with cystinuria had complete lack of reabsorption and active secretion of cystine, and reabsorption of lysine, ornithine, and arginine was moderately impaired. Although clinical signs of urinary obstruction were observed only in males, cystinuric male and female offspring were produced from noncystinuric parents, consistent with an autosomal recessive mode of inheritance. Obligate heterozygotes did not have clinical signs, and had normal urinary cystine content and renal amino acid reabsorption. CLINICAL IMPLICATIONS: Because detection of carriers by routine urinalysis is currently not possible, Newfoundlands with cystinuria and their parents and offspring should be excluded from breeding.

Animals↗
PubMed1995

An acute hemolytic transfusion reaction caused by dog erythrocyte antigen 1.1 incompatibility in a previously sensitized dog.

An acute hemolytic transfusion reaction resulting from dog erythrocyte antigen (DEA) 1.1 incompatibility developed in a dog previously sensitized to DEA 1.1 by a transfusion 3 years earlier. The dog developed fever, pigmenturia, and lethargy, and its PCV did not rise as expected. The donor blood was type DEA 1.1 positive, whereas the recipient's blood was type DEA 1.1, DEA 1.2, and DEA 7 negative. A major crossmatch was later found to be strongly incompatible. Studies of the recipient's plasma revealed a specific anti-DEA 1.1 alloantibody of the IgG class with high hemolysin and agglutinin activity. Such acute hemolytic transfusion reactions can be avoided by crossmatching previously transfused dogs and by using dogs that are type DEA 1.1 negative (and preferably also type DEA 1.2 and DEA 7 negative) as blood donors.

Acute Disease↗
PubMed1995

Naturally occurring human anti-band 3 autoantibodies accelerate clearance of erythrocytes in guinea pigs.

A variety of naturally occurring autoantibodies (NOAs) have been found in sera of animals and humans. Although their specific homeostatic role in the clearance of altered or senescent cells has been proposed and in vitro studies support such functions, in vivo evidence has been lacking. We studied the effect of affinity-purified human anti-band 3 NOA on the survival of untreated and diamide-treated erythrocytes in normal and complement C3-deficient guinea pigs. In vitro exposure to diamide, an oxidative agent, severely reduced the erythrocyte deformability and increased the amount of high-molecular-weight forms of band 3 protein and band 3-hemoglobin adducts in erythrocyte membranes, thereby markedly shortening the survival of these cells in vivo. Human anti-band 3 NOA bound in a dose-dependent manner to erythrocytes, and binding increased with exposure to diamide. In normal guinea pigs anti-band 3 NOA significantly accelerated the clearance of erythrocytes that were mildly damaged by iodine surface labeling and of those that were further oxidized by diamide. However, the anti-band 3 effect was transient and small. In contrast, anti-band 3 NOA did not significantly alter erythrocyte survival in functionally C3-deficient guinea pigs, thereby supporting the C3b requirement for anti-band 3 NOA activity. On the other hand, a pretreatment of animals with purified human band 3 protein slowed down the clearance of erythrocytes incubated with IgG depleted of anti-band 3 NOA. These results provide the first in vivo evidence of a role for anti-band 3 NOA in the clearance of erythrocytes.

Animals↗
PubMed1995

Detection of platelet-bound and serum platelet-bindable antibodies for diagnosis of idiopathic thrombocytopenic purpura in dogs.

The sensitivity and specificity of 2 antibody tests for diagnosis of idiopathic thrombocytopenic purpura (ITP) in dogs were investigated prospectively. An ELISA to detect antibodies bound to the surface of platelets from affected dogs (direct test) was performed in 34 dogs with a clinical diagnosis of ITP and in 21 dogs with thrombocytopenia attributable to other causes. An ELISA to detect platelet-bindable antibodies in serum from affected dogs (indirect test) was performed in 32 dogs with ITP and in 15 dogs with other causes of thrombocytopenia. The direct test was positive in 32 of 34 dogs with ITP (sensitivity, 94%) and negative in 13 of 21 dogs with other causes of thrombocytopenia (specificity, 62%). Positive direct test results were obtained in 2 dogs with systemic lupus erythematosus, and in 1 dog each with concurrent Ehrlichia canis and Babesia canis infections, dirofilariasis, myelodysplasia, disseminated intravascular coagulation (of unknown cause), and thrombocytopenia subsequent to administration of trimethoprim/sulfadiazine, as well as in 1 dog with thrombocytopenia 14 days after a whole blood transfusion. The indirect test had positive results in 11 of 32 dogs with ITP (sensitivity, 34%) and negative results in 12 of 15 dogs with other causes of thrombocytopenia (specificity, 80%). Positive indirect test results were obtained in 1 dog each with systemic lupus erythematosus, concurrent E canis and B canis infections, and thrombocytopenia subsequent to administration of trimethoprim/sulfadiazine. Detection of platelet-bound antibodies was more sensitive than detection of serum-platelet bindable antibodies in confirming a diagnosis of ITP in dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Feline transfusion medicine. Blood types and their clinical importance.

Anemia is the most common indications for a blood transfusion in cats and fresh whole blood is typically administered. Recent experimental studies and clinical reports have elucidated the importance of feline blood types in transfusion medicine. The AB blood group system, the only recognized feline blood group system, consists of three blood types: type A is most common, type B is frequently found in certain breeds, and type AB occurs rarely. The blood type frequently varies geographically among domestic shorthair cats and between breeds. Because of the presence of naturally occurring alloantibodies, only AB-matched transfusions are effective and safe. Blood typing is now readily available and incompatibilities are easily recognized with blood crossmatching tests. Owing to the general presence of strong anti-A alloantibodies in type B cats, type A blood given to a type B cat results in life-threatening acute hemolytic transfusion reactions. Immediate withdrawal of a transfusion and supportive care may save a patient. Other transfusion reactions, unrelated to AB mismatch, cause only mild and transient signs. Peculiarities of feline blood banking also are reviewed.

Animals↗
PubMed1995

Inherited platelet delta-storage pool disease in dogs causing severe bleeding: an animal model for a specific ADP deficiency.

The nature of a disorder producing moderate to severe bleeding after minor trauma, venipuncture, and surgery was studied in 3 families of American cocker spaniel dogs. In the 5 affected dogs tested, platelet counts and measurements of plasma coagulant function and von Willebrand factor were normal. However, bleeding times were prolonged in 4 of the 5 affected dogs tested, and platelet aggregation in response to ADP and collagen was consistently abnormal in 3, suggesting that the bleeding disorder was due to abnormal platelet function. Measurements of 14C-serotonin uptake and retention by the affected platelets were normal. However, their ADP content was decreased, while their ATP content was normal, resulting in a mean ATP/ADP ratio of 8.32, compared to a mean ratio of 1.9 in normal canine platelets. Electron microscopy revealed that the number and appearance of the dense granules in the affected platelets were indistinguishable from those of normal controls. These studies suggest that this bleeding disorder results from a deficient delta-granule storage pool of ADP; given the normal serotonin uptake and retention by affected platelets and the apparently normal number of dense granules, the ADP deficiency may be the consequence of a selective defect in delta-granule ADP transport. Additional studies of this unique platelet disorder will provide an opportunity to understand the mechanism of adenine nucleotide storage in platelet delta-granules.

Adenine Nucleotides↗
PubMed1994

Factor XI deficiency in Kerry Blue Terriers.

A 9-year-old female Kerry Blue Terrier with postoperative hemorrhage and prolonged activated partial thromboplastin and activated clotting times was determined to have factor XI deficiency. Transfusions of fresh-frozen plasma given on 4 consecutive days transiently returned the values for activated clotting time and plasma factor XI activity to within reference range limits and controlled the hemorrhage. Analysis of data from 10 other factor XI-deficient Kerry Blue Terriers with a tendency for mild posttraumatic or postoperative bleeding was suggestive of an autosomal mode of inheritance, with a mild tendency for posttraumatic or postoperative bleeding in homozygous and heterozygous dogs. Factor XI deficiency is the only contact phase protein defect that causes a bleeding disorder in animals, which can be explained by the fact that thrombin is more efficient than factor XIIa in activating factor XI. Factor XIa plays a key role in sustaining coagulation.

Animals↗
PubMed1994

Canine mitochondrial myopathy associated with reduced mitochondrial mRNA and altered cytochrome c oxidase activities in fibroblasts and skeletal muscle.

Skeletal muscle and fibroblast biopsies obtained from a normal dog and an old English sheep dog with exertional myopathy and lactic acidosis were examined for mitochondrial enzyme activities and mitochondrially coded mRNAs. The fibroblast cultures of the affected dog showed reduced cytochrome c oxidase (COX) I+II mRNA content (25% of control) and COX enzyme activities (23% of control). The skeletal muscle of the affected dog was similarly affected and showed not only decreased COX I+II mRNA content, but also decreased ATPase6 mRNA level. Apart from COX enzyme activity (62% of control), the oligomycin sensitive ATPase and NADH-Ferricyanide reductase activities were also reduced in the skeletal muscle of the affected dog (12-20% of control). These results suggest that a mitochondrial dysfunction may be the causative factor of the exertional metabolic myopathy with lactic acidosis in this affected old English sheep dog. These animals may serve as an excellent model for mitochondrial myopathies.

Adenosine Triphosphatases↗
PubMed1993

Use of a bovine hemoglobin preparation in the treatment of cyclic ovarian hemorrhage in a miniature horse.

Anemia that was secondary to ovarian hemorrhage in a 4-year-old miniature horse mare was treated prior to laparotomy with polymerized ultrapurified bovine hemoglobin (PUBH). Two previous whole-blood transfusions had resulted in acute transfusion reaction, and a suitable blood donor could not be found among 9 horses, necessitating use of the blood substitute. Subsequent blood typing revealed the mare to be Aa-negative, with allo-antibodies against Aa in serum. Serious adverse reactions were not observed after infusion of PUBH, and the mare recovered. Although the safety and efficacy of using PUBH in horses has not been established, PUBH may prove to be an excellent alternative to whole-blood transfusions, when indicated.

Anemia↗
PubMed1993

Idiopathic immune-mediated hemolytic anemia in dogs: 42 cases (1986-1990)

Forty-two cases of Coombs' positive or agglutinating immune-mediated hemolytic anemia (IMHA) in dogs were reviewed. Dogs ranged in age from 1 to 13 years, with a mean age of 6.4 +/- 3.4 years. The majority of dogs (74%) tested positive for IgG antibodies without complement. Spherocytosis was seen in 67% of the dogs, but hemoglobinemia and hemoglobinuria were found in only 10%. Marked bilirubinuria was found in all the dogs. A significant seasonal incidence was observed, with 40% of all cases diagnosed during the months of May and June. Severe anemia, with PCV < or = 20% was observed in 37 dogs (88%). Sixteen dogs (38%) had moderate to severe reticulocytosis and 12 dogs (29%) had mild reticulocytosis. Thus, the absence of reticulocytosis should not be used to rule out a diagnosis of IMHA. Concomitant mild to severe thrombocytopenia was observed in 28 dogs (67%). A mortality of 29% was observed during hospitalization. Risk of death was significantly increased in dogs without marked reticulocytosis, those with lower PCV, and dogs with serum bilirubin concentrations > or = 10 mg/dl. In severe cases of IMHA, rapid and aggressive supportive therapy is required.

Agglutination Tests↗