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Biomedical subjects

T Waner

Publications and source records attributed to T Waner.

At least 37 records · Page 2Linked to original sources
PubMed1998

Assessment of immunization response to canine distemper virus vaccination in puppies using a clinic-based enzyme-linked immunosorbant assay.

To study the response to vaccination, an enzyme-linked immunosorbant assay (ELISA) immunoblot method was developed and tested to assay canine distemper virus (CDV) IgG antibody in puppies and compared to a standard virus neutralization (VN) test (r2 = 0.748). Ten litters of four puppies each were used in a vaccination study. Seventy-six percent of vaccinated puppies immunized with a modified live vaccine were successfully protected against CDV at 6 weeks of age. One puppy remained seronegative after vaccination at 6 and 9 weeks of age. This is the first report of vaccination responses of puppies to CDV using an in-clinic test kit based on solid-phase immunoassay technology.

Animals↗
PubMed1998

Amplification of ehrlichial DNA from dogs 34 months after infection with Ehrlichia canis.

In order to determine whether dogs in the subclinical phase of canine monocytic ehrlichiosis (CME) are carriers of Ehrlichia canis and to determine the significance of persistent indirect immunofluorescent anti-E. canis antibody titers during this phase, PCR was performed with blood, bone marrow, and splenic aspirates collected 34 months postinoculation from six clinically healthy beagle dogs experimentally infected with E. canis. At least one of the three samples (spleen, bone marrow, and blood) from four of the six dogs was PCR positive. The spleens of all four of these dogs were PCR positive, and the bone marrow and blood of two of the four dogs were PCR positive. Indirect immunofluorescent-antibody titers increased progressively during the first 5 months postinfection, remained high for an additional period of more than 11 months, and declined thereafter, suggesting that the dogs were recovering from the disease. Five of the dogs remained seropositive 34 months postinfection. The data obtained in this study demonstrate for the first time that clinically healthy dogs in the subclinical phase of CME are carriers of the rickettsia. It was shown that dogs can harbor E. canis for years without developing the chronic clinical disease and that dogs can eliminate the parasite and recover from CME without medical treatment. Our findings suggest that the spleen is the organ most likely to harbor E. canis parasites during the subclinical phase and the last organ to accommodate the parasite before elimination. It was concluded that PCR of DNA extracted from splenic aspirates is a reliable method for determining the carrier state of CME.

Animals↗
PubMed1998

Therapeutic effect of doxycycline in experimental subclinical canine monocytic ehrlichiosis: evaluation of a 6-week course.

The efficacy of doxycycline treatment (10 mg/kg of body weight every 24 h for 42 days) in eliminating Ehrlichia canis from four subclinically infected dogs was evaluated. One dog remained PCR positive, suggesting that 6 weeks of doxycycline treatment may not be sufficient to clear E. canis parasites from all subclinically infected dogs. Serology (indirect immunofluorescent antibody assay) was shown to be unreliable in assessing recovery from the carrier state, as anti-E. canis antibodies persisted after elimination of the parasite. Our findings suggest that an increase in the platelet count may be an important indicator for dogs that recover from subclinical ehrlichiosis.

Animals↗
PubMed1997

Canine monocytic ehrlichiosis: a retrospective study of 100 cases, and an epidemiological investigation of prognostic indicators for the disease.

One hundred cases of monocytic ehrlichiosis diagnosed in Israeli dogs were confirmed by the presence of anti-Ehrlichia canis indirect immunofluorescent antibody titres greater than 1:40. The disease occurred in all age groups and there was no sex predilection. German shepherd dogs were significantly over-represented whereas crossbreed dogs were significantly under-represented (P > 0.0005). The most common clinical signs were depression, lethargy, lymphadenomegaly, fever, anorexia, panting, pale mucous membranes and bleeding, of which epistaxis was most common. Thrombocytopenia, anaemia (mainly normocytic normochromic) and lymphopenia were the predominant haematological findings. Forty-nine of the 100 cases were followed up for a year. Thirty-two dogs survived and 17 died. A Cox proportional hazards regression model was used to examine the effect of host, environmental, and haematological prognostic factors on survival. It was concluded that severe anaemia, severe leucopenia, pancytopenia, a tendency to bleed (especially epistaxis) and being a German shepherd dog were important indicators of poor survival in cases of monocytic ehrlichiosis in dogs.

Animals↗
PubMed1997

Characterization of the subclinical phase of canine ehrlichiosis in experimentally infected beagle dogs.

Beagle dogs were examined during the subclinical phase of canine ehrlichiosis under controlled conditions. Emphasis was placed on gathering data before artificial inoculation with Ehrlichia canis, and comparing these data with those of the subclinical phase of the disease. In this study all dogs were clinically healthy throughout the 6 month examination period. All subclinically infected dogs had IFA antibody titers to E. canis at a dilution varying from 1:2560 to 1:20480. The most prominent haematological finding was mild thrombocytopenia with a concomitant increase in platelet size, seen in eight of the nine dogs examined. Leukocyte counts were statistically significantly reduced in 78% of the dogs, compared with their preinfection values, with 71% of dogs having significantly reduced absolute neutrophil counts. None of the dogs were either leukopenic nor neutropenic. Six of the nine dogs had increased serum gamma-globulin concentrations. No dogs were overtly anemic, although declines in packed cell volume, haemoglobin concentration and total erythrocyte count were detected in an inconsistent manner among the dogs. It was concluded that, the most reliable parameters for judging possible subclinical ehrlichial infection in beagle dogs was mild thrombocytopenia, together with a persistently high antibody titer to E. canis. Hypergammaglobulinemia would increase the suspicion further. Based on the results presented, routine testing of dogs in E. canis endemic areas is recommended in order to identify and treat dogs in the subclinical phase of the disease.

Animals↗
PubMed1996

Serum protein alterations in canine ehrlichiosis.

Serum protein electrophoresis was performed in 42 dogs with naturally occurring Ehrlichia canis infection and in 15 clinically healthy dogs (control dogs). The infected dogs were found to have a significant hypoalbuminaemia, hyperglobulinaemia and hypergammaglobulinaemia compared to the control dogs (P < 0.001). A polyclonal gammopathy was found in all but one of the infected dogs which presented a monoclonal gammopathy. alpha-1 globulin was lower while alpha-2 and beta-2 globulin concentrations were significantly higher in the infected dogs (P < 0.0001, P < 0.05 and P < 0.005, respectively). The infected dogs were divided into two subgroups according to haematological parameters, defined as pancytopenic (n = 13) and non-pancytopenic (n = 29). When compared, the pancytopenic group revealed significantly lower concentrations of total protein, total globulin and gammaglobulin (P < 0.01, P < 0.05 and P < 0.005 respectively). The lower concentrations of the gammaglobulins coupled with the pancytopenia suggest that the immune state of the pancytopenic E. canis infected dogs is more compromised, and therefore secondary infections should be expected more frequently in these dogs.

Animals↗
PubMed1996

Platelet dysfunction associated with experimental acute canine ehrlichiosis.

To determine whether platelet dysfunction occurs in canine ehrlichiosis, platelet aggregation studies in response to collagen/epinephrine, thrombin and adenosine diphosphate (ADP) were carried out by the indirect method, using sera from six dogs experimentally infected with Ehrlichia canis. Samples of serum taken before infection and four and 20 days after infection were tested by incubation with platelet-rich plasma from a seronegative healthy dog. Platelet aggregation was significantly inhibited in five of six infected dogs in response to at least one of the agonists used. A significant increase in preaggregation lag time was recorded in response to collagen/epinephrine in sera taken 20 days after infection from three of five dogs (P < 0.05). When compared with the preinfection values, a significant increase of 45 per cent in the mean preaggregation lag time was detected (P < 0.05). Maximal relative aggregation responses to ADP decreased significantly in one serum sample taken four days and one taken 20 days after infection (P < 0.01) and there was a significantly lower relative slope for one serum sample 20 days after infection (P < 0.05). Maximal relative aggregation responses to thrombin were significantly decreased together with their relative slopes in serum samples from two of four dogs four days after infection (P < 0.05). The results suggest that platelet dysfunction may occur in the acute stage of canine ehrlichiosis, and may be a contributing factor to the tendency to bleed commonly observed in this disease. Antiplatelet antibodies directed against platelet glycoproteins may play a role in the inhibition of platelet aggregation.

Adenosine Diphosphate↗
PubMed1996

Survey of Ehrlichia canis antibodies among dogs in Israel.

A seroepidemiological survey was made of the prevalence of antibodies reactive with Ehrlichia canis in stray and pet dogs from five geographical regions of Israel. Serum samples from 410 dogs were assayed by an indirect fluorescent antibody test and serum reactive at a 1:20 dilution or greater was considered positive. The overall seroprevalence was 30 per cent with 23.9 per cent in pet dogs and 37.5 per cent in stray dogs. The seroprevalence in apparently healthy pets (17.6 per cent) was lower but did not differ significantly from the seroprevalence in sick animals (26.6 per cent). The seroprevalence was highest in the north of Israel and lowest in the central hilly area, and followed the same trend in both the populations sampled. Young dogs (under one year old) had a lower seroprevalence (14.9 per cent) than adult (one to eight years) (36.4 per cent) or older dogs (over eight years) (34.2 per cent). The results demonstrate that dogs in Israel are extensively exposed to E canis and indicate that ehrlichiosis is endemic in this area of the Middle East.

Animals↗
PubMed1996

Kinetics of serum antiplatelet antibodies in experimental acute canine ehrlichiosis.

The pattern of appearance of serum antiplatelet antibodies during the acute phase of experimental canine ehrlichiosis (Ehrlichia canis) was investigated in six beagles and correlated with the development of thrombocytopenia. The earliest detection of serum antiplatelet antibodies was made on Day 7 post-inoculation in one dog, on Day 13 in three out of six dogs, and on Day 17 post-inoculation in the remaining two dogs. Thrombocytopenia developed in all infected dogs. The results of this study suggest that antiplatelet antibodies play a role in the destruction of platelets in the acute phase of the disease. It is proposed that E. canis infection in dogs alters the immune system resulting in the overproduction of natural antiplatelet antibodies.

Acute Disease↗
PubMed1996

The first isolation, in vitro propagation, and genetic characterization of Ehrlichia canis in Israel.

Ehrlichia canis, the etiologic agent of canine ehrlichiosis, was isolated in Israel from a naturally infected dog with acute signs of the disease. The organism designated E. canis 611, was passaged experimentally to a beagle, from which it was propagated in primary canine monocytes. The organism was then grown in vitro in a continuous canine cell line, DH82. Nine beagles subsequently injected with whole E. canis-infected blood all developed typical symptoms of ehrlichiosis. An indirect immunofluorescence antibody test to E. canis was developed and compared with a commercial kit, revealing a good correlation between the two assays. Transmission electron microscopy of DH82 cells infected with the Israeli strain of E. canis (611), revealed organisms similar to those described in the literature: two different forms of morulae appeared, one tightly, the other loosely, packed. The 16S rRNA gene sequence obtained from the Israeli Ehrlichia isolate was compared with other isolates, E. canis Oklahoma and E. canis Florida. The Israeli strain 16S rRNA had three nucleotide differences from the Oklahoma isolate, and four nucleotide differences from the Florida isolate, in addition to one nucleotide gap in each. The Israeli isolate was found to be 0.54% different from the Oklahoma strain, and 0.61% different from the Florida strain. There are the same magnitudes of differences displayed by the other most closely related group in the phylogenetic tree, namely Ehrlichia equi, Ehrlichia phagocytophilia and the human granulocytic ehrlichia.

Animals↗
PubMed1996

Detection of ehrlichial antigen in plasma of beagle dogs with experimental acute Ehrlichia canis infection.

Six beagles were experimentally infected with Ehrlichia canis. All dogs developed typical clinical signs of ehrlichiosis and sero-converted. Ehrlichial antigenemia in the plasma of the infected dogs was detected using a sandwich enzyme-linked immunosorbent assay (ELISA). Ehrlichial antigen was present starting 15-20 days post-infection, after the development of clinical signs and antibody titre to Ehrlichia canis. The appearance of ehrlichial antigen in the plasma for a relatively short and variable period after the clinical and haematological signs, limits its potential as an early diagnostic prognosticator of canine ehrlichiosis.

Animals↗
PubMed1996

Assessment of maternal antibody decay and response to canine parvovirus vaccination using a clinic-based enzyme-linked immunosorbent assay.

Interference caused by maternal antibodies is considered a major cause of canine parvovirus (CPV) vaccination failure. In this study, an immunoblot clinic-based enzyme-linked immunosorbent assay (ELISA) method was used to detect CPV antibodies in sera of pregnant bitches and their offspring to study the response of pups to vaccination. With a easily accessible procedure for CPV antibody determination, the veterinarian should be able to gauge the response of pups after vaccination. The validity of the technique was tested in parallel against the standard hemagglutination inhibition (HI) test. Results of the ELISA were correlated with those of the standard HI method for quantification of CPV antibodies. With the ELISA, successfully immunized pups were identified, allowing for a more reliable and cost-effective program of vaccination. This simple clinic-based test could be used for the assessment of vaccination status of pups during the critical phase of 6 to about 16 weeks of age. This study is the first in which vaccination response to CPV in pups was followed, using a clinic-based ELISA for CPV antibody monitoring.

Animals↗
PubMed1996

Harmonization of animal clinical pathology testing in toxicity and safety studies. The Joint Scientific Committee for International Harmonization of Clinical Pathology Testing.

Ten scientific organizations formed a joint international committee to provide expert recommendations for clinical pathology testing of laboratory animal species used in regulated toxicity and safety studies. For repeated-dose studies in rodent species, clinical pathology testing is necessary at study termination. Interim study testing may not be necessary in long-duration studies provided that it has been done in short-duration studies using dose levels not substantially lower than those used in the long-duration studies. For repeated-dose studies in nonrodent species, clinical pathology testing is recommended at study termination and at least once at an earlier interval. For studies of 2 to 6 weeks in duration in nonrodent species, testing is also recommended within 7 days of initiation of dosing, unless it compromises the health of the animals. If a study contains recovery groups, clinical pathology testing at study termination is recommended. The core hematology tests recommended are total leukocyte (white blood cell) count, absolute differential leukocyte count, erythrocyte (red blood cell) count, evaluation of red blood cell morphology, platelet (thrombocyte) count, hemoglobin concentration, hematocrit (or packed cell volume), mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. In the absence of automated reticulocyte counting capabilities, blood smears from each animal should be prepared for reticulocyte counts. Bone marrow cytology slides should be prepared from each animal at termination. Prothrombin time and activated partial thromboplastin time (or appropriate alternatives) and platelet count are the minimum recommended laboratory tests of hemostasis. The core clinical chemistry tests recommended are glucose, urea nitrogen, creatinine, total protein, albumin, calculated globulin, calcium, sodium, potassium, total cholesterol, and appropriate hepatocellular and hepatobiliary tests. For hepatocellular evaluation, measurement of a minimum of two scientifically appropriate blood tests is recommended, e.g., alanine aminotransferase, aspartate aminotransferase, sorbitol dehydrogenase, glutamate dehydrogenase, or total bile acids. For hepatobiliary evaluation, measurement of a minimum of two scientifically appropriate blood tests is recommended, e.g., alkaline phosphatase, gamma glutamyltransferase, 5' -nucleotidase, total bilirubin, or total bile acids. Urinalysis should be conducted at least once during a study. For routine urinalysis, an overnight collection (approximately 16 hr) is recommended. It is recommended that the core tests should include an assessment of urine appearance (color and turbidity), volume, specific gravity or osmolality, pH, and either the quantitative or semiquantitative determination of total protein and glucose. For carcinogenicity studies, only blood smears should be made from unscheduled sacrifices (decedents) and at study termination to aid in the identification and differentiation of hematopoietic neoplasia.

Animal Welfare↗
PubMed1995

Investigation of potential oncogenetic effects of beta-cyclodextrin in the rat and mouse.

The results of oncogenicity studies of beta-cyclodextrin in inbred Fischer 344 rats and CD-1 outbred mice are presented. Chronic feeding of beta-cyclodextrin to Fischer 344 rats and CD-1 mice did not cause any treatment related carcinogenic effects. The only toxic effect was seen in mice as macroscopic distension of the large intestine with soft or fluid contents, histologically associated with the mucosa covered by mucous secretion containing exfoliated cells, and mucosal flattening and intestinal gland atrophy. Despite these observations, no differences between control and treated groups were observed concerning mortality, clinical observations or body weight and food consumption.

Animals↗
PubMed1995

Demonstration of serum antiplatelet antibodies in experimental acute canine ehrlichiosis.

This report presents evidence for the presence of antiplatelet antibodies in sera of dogs experimentally infected with Ehrlichia canis, during the acute phase of the disease. Six healthy adult male beagle dogs were inoculated intravenously with blood from a longstanding infected dog with the Israel strain 611 of E. canis. Thrombocytopenia and concurrent increase in mean platelet volume were the most consistent haematological signs of the disease. The dogs developed an antibody titre to E. canis from Day 15 postinoculation. All dogs were antiplatelet antibody negative before inoculation. Twenty-four days postinoculation with E. canis, when the platelet count was at its lowest, antibodies to platelets were demonstrated, in the sera of five of the six dogs.

Acute Disease↗
PubMed1995

Effect of cadmium on bone repair in young rats.

The effect of cadmium (Cd) in drinking water on repair of bone at a site of hole injury to the tibia of young rats was followed using quantitative methods. The rats (3-4 wk old) were given 20 ppm and 200 ppm Cd for 5 wk and compared to a control group. A slight reduction (about 10%) in body weight and water and food consumption was observed in cadmium-exposed rats as compared to control rats. Clinical chemistry tests in the blood and histology of kidney, liver, and bone did not indicate changes related to Cd toxicity. A significant reduction (43%) in alkaline phosphatase (ALP) and tartarate-resistant acid phosphatase (TRAP) (46%) enzymatic activity was observed at 4 and 7 d postinjury respectively, in the site of injury in the rats receiving 200 ppm Cd in drinking water as compared to control rats. Calcium accumulation in the newly formed repair tissue at the site of injury was also significantly reduced (53%) at 13 d postinjury in the Cd-treated (200 ppm) rats as compared to control rats. It is concluded that Cd probably exhibits an effect on the bone repair process as reflected by reduction in ALP activity (osteoblastic cells) and mineralization at the site of injury in the tibia of young rats.

Animals↗
PubMed1995

Intracranial gangliocytoma in a dog.

The clinical, pathologic, immunohistochemical, and electron microscopic characteristics of a pure intracranial gangliocytoma in a 6-year-old spayed female dog are presented. The tumor is very rare in humans, and has not been previously reported in the dog. The most remarkable feature of this tumor was that it was composed of a single neuronal cell type without the presence of glial elements, as demonstrated by the negative immunohistochemical reaction to glial fibrillary acidic protein.

Animals↗