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Biomedical subjects

T Waner

Publications and source records attributed to T Waner.

At least 19 recordsLinked to original sources
PubMed2006

Seroprevalence of Anaplasma phagocytophilum among healthy dogs and horses in Israel.

The presence of reacting antibodies to Anaplasma phagocytophilum has previously been demonstrated in Israel, both in humans and the golden jackal (Canis aureus syriacus). This study was undertaken to determine the seroprevalence of A. phagocytophilum antibodies in two additional potential hosts, domestic dogs and horses in order to investigate the possibility of exposure to the organism in Israel. Of 195 dogs tested, 9% were seroreactive with A. phagocytophilum antigen and 30% were seroreactive to Ehrlichia canis. Twenty-nine percent of the dogs seropositive for E. canis were also reactive to A. phagocytophilum. Two dogs had immunofluorescence antibody (IFA) antibody titres for A. phagocytophilum greater than E. canis. The equine serological survey (n = 300) revealed no seroreactive horses. The results presented in this study suggest that dogs in Israel could have been accidentally exposed to A. phagocytophilum, for example by ticks carried on migrating birds, however, the possibility of cross-reaction with E. canis should also be considered. In spite of the high prevalence of ticks on horses in Israel during the summer months, no evidence for exposure to A. phagocytophilum was apparent.

Anaplasma phagocytophilum↗
PubMed2005

Novel cationic amphiphilic derivatives from vernonia oil: synthesis and self-aggregation into bilayer vesicles, nanoparticles, and DNA complexants.

Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesized from vernonia oil, a natural epoxydized triglyceride. The presence of a 12,13-epoxy group on the C18 unsaturated fatty acid, vernolic acid, which is the main constituent of vernonia oil, permitted the synthesis of novel amphiphilic derivatives with a hydrogen-bonding hydroxyl and a cationic headgroup moiety on adjacent carbon atoms. The amphiphiles were prepared in a two-stage synthesis that comprised opening of the epoxy groups with a haloacetic acid, followed by quaternization of the halo group with a tertiary amine containing a C12 aliphatic chain. Intact vernonia oil as the starting material gave a triple-headed cationic amphiphile, containing three vernolic acid derived moieties connected through a glycerol backbone. A single-headed amphiphile with two alkyl chains and a single quaternary ammonium headgroup was synthesized from the methyl ester of vernolic acid as the starting material. The triple-headed derivative could form nonencapsulating structures. Cholesterol was required in the formulation (1:1) to make spherical vesicles that could encapsulate a water-soluble marker. The single-headed derivative, however, formed spherical encapsulating vesicles without cholesterol. TEM, NMR, and FT-IR were used to characterize the vesicles, and molecular structure vs morphology relationships were postulated on the basis of these data. The triple-headed amphiphile also formed a DNA complex that was highly resistant to hydrolysis by DNase. This amphiphile-DNA complex was used as vector for gene transfer in cell culture demonstrating efficient DNA transfection.

Animals↗
PubMed2003

Evaluation of a dot ELISA kit for measuring immunoglobulin M antibodies to canine parvovirus and distemper virus.

A dot ELISA for the detection of immunoglobulin M (IgM) antibodies to canine distemper virus (CDC) and canine parvovirus (CPV) was assessed. The titres of IgM antibodies to CDV and CPV in 100 dogs were measured by the Immunocomb ELISA kit and compared with the results derived from the immunofluorescence assay (IFA). There was a strong correlation between the results of the dot ELISA technique and the IFA (P < 0.001). The dot ELISA kit was also used to assess the changes in the levels of immunoglobulin G (IgG) and IgM antibodies to CPV and CDV in 10 puppies vaccinated with a polyvalent vaccine. High levels of IgM antibodies to CPV were first detected seven days after they were vaccinated, and after nine days all the pups had high titres of IgG antibodies to CPV. High levels of IgM antibodies to CDV were detected after nine days and the highest average titres were recorded after 12 days. IgG antibodies to CDV were present from nine days after vaccination.

Animals↗
PubMed2002

Development of hypertrophic osteodystrophy and antibody response in a litter of vaccinated Weimaraner puppies.

Two different vaccination protocols were compared with regard to the development of hypertrophic osteodystrophy (HOD) (also termed metaphyseal osteopathy) and effectiveness of immunisation in a litter of 10 Weimaraner puppies. Five puppies (group 1) were vaccinated with a modified live canine parvovirus vaccine (CPV) and then two weeks later with a trivalent vaccine containing modified live canine distemper virus and adenovirus type 2 combined with a Leptospira bacterin (DHL). The CPV and DHL vaccine protocols were administered a further two times, at two-week intervals. Group 2 was vaccinated with three consecutive multivalent vaccines containing modified live canine distemper virus, canine parvovirus, parainfluenza and adenovirus type 2 combined with a Leptospira bacterin, at four-week intervals. All puppies were first vaccinated at the age of eight weeks. Three dogs in group 1 developed HOD, while all five dogs in group 2 developed HOD during the study period. Dogs in group 2 had more episodes of HOD than those in group 1. Dogs in group 1 developed higher antibody titres to canine distemper virus and parvovirus compared with those in group 2. Only two out of the 10 dogs developed protective antibody titres to parvovirus. The results of this study suggest that the two different vaccination protocols affected the pattern of appearance of HOD and immunisation in this litter of Weimaraner puppies. The results obtained and the previously reported data suggest that a larger controlled study is needed to further elucidate the effect of different vaccination protocols on HOD and immunisation in Weimaraner puppies.

Adenoviridae↗
PubMed2001

Presence of immune-complexes, and absence of antinuclear antibodies, in sera of dogs naturally and experimentally infected with Ehrlichia canis.

Antinuclear antibodies (ANA), immunoglobulin G (IgG) concentrations and circulating immune-complexes (CIC) were measured, over a period of 3 years, in 6 dogs experimentally infected with Ehrlichia canis, and in 10 dogs naturally infected with the rickettsia. No ANA were detected in any of the samples tested. The IgG concentrations were shown to be higher in the infected dogs when compared to the control dogs. CIC were detected in 2 of 10 naturally and 2 of 6 experimentally infected dogs, during both the acute and the subclinical phases of the disease. The results of this study suggest that ANA do not play a role in the pathogenesis of CME. It is however suggested that some manifestations in canine ehrlichiosis are immune-complex mediated.

Animals↗
PubMed2001

Dynamics of IgG1 and IgG2 subclass response in dogs naturally and experimentally infected with Ehrlichia canis.

Immunoglobulin (Ig) G subclasses were measured in dogs naturally and experimentally infected with Ehrlichia canis using enzyme-linked immunosorbant assay (ELISA). In this study, a higher IgG2 subclass response was noticed to natural and experimental E. canis infection in dogs. Anti-E. canis-IgG2 optic density (OD) values were found to be significantly higher than anti-E. canis-IgG1 during the different phases of the disease, and no differences in the IgG subclass responses to E. canis infection were found between symptomatic and asymptomatic dogs. Doxycycline treatment, which eliminated the rickettsia in three of four persistently infected dogs, had no noticeable influence on the E. canis-IgG subclass OD values during the treatment period. In order to facilitate the study, an ELISA for the detection of anti-E. canis IgG was developed and was shown to be sensitive and specific for E. canis-IgG, and in a significant correlation with the indirect immunofluorescence antibody test.

Animals↗
PubMed2001

Significance of serological testing for ehrlichial diseases in dogs with special emphasis on the diagnosis of canine monocytic ehrlichiosis caused by Ehrlichia canis.

Dogs are susceptible to a number of ehrlichial diseases. Among them, canine monocytic ehrlichiosis is an important and potentially fatal disease of dogs caused by the rickettsia Ehrlichia canis. Diagnosis of the disease relies heavily on the detection of antibodies and is usually carried out using the indirect immunofluoresence antibody (IFA) test. The IFA test may be confounded by cross-reactivities between a number of the canine ehrlichial pathogens. This article presents a review of the ehrlichial diseases affecting dogs with reference to their immune responses, host specificities, cross-reactivites and diagnosis. Diagnostic means such as Western immunblot, dot-blot and PCR are discussed. The use of the IFA test as a diagnostic means for E. canis is presented along with its potential pitfalls. The review emphasizes that the disease process, cross-reactivites with other ehrlichial species, multiple tick-borne infections and persistent IFA antibody titers post-treatment, should all be considered when interpreting E. canis serological results.

Animals↗
PubMed2001

Cultivation of Ehrlichia canis in a continuous BALB/C mouse macrophage cell culture line.

This report describes the successful adaptation of the Israeli isolate of Ehrlichia canis on a continuous mouse macrophage cell line (J774.A1). Successful infection of the J774.AI cells was first judged by the direct immunofluorescence antibody test using an anti-E. canis-IgG:FITC conjugate. A particular property of infected J774.A1 cells was the ability to reestablish after harvesting of the monolayer by scaping. Infected cells were used as antigen for immunofluorescence antibody tests (IFA), and the results compared well with those of DH82 cells. It was concluded that the J774.A1 continuous cell line could serve as an alternate propagation cell line for E. canis organisms.

Animals↗
PubMed2000

Detection of platelet-bound antibodies in beagle dogs after artificial infection with Ehrlichia canis.

Six dogs were infected with Ehrlichia canis by intravenous injection of heavily infected DH82 cells. All dogs developed typical signs of canine monocytic ehrlichiosis. Using flow cytometric technology, platelet-bound IgG (PBIgG) were detected in 5 of the 6 dogs after experimental infection with E. canis over a period of 3-10 days post infection (PI). The first detection of PBIgG was made as early as day 3 PI in 2 out of 6 dogs, and on day 5 PI in 1 dog. On day 7 PI, PBIgG was detected in 2 dogs, and on day 10 PI in 3 out of 6 dogs. This is the first report documenting the presence of PBIgG following E. canis infection in dogs. This finding further supports the theory that the thrombocytopenia seen in canine monocytic ehrlichiosis has an immunological component and that exposure to an infectious agent, in this case the rickettsia E. canis, can trigger autoimmune mechanisms. Due to the heterogeneous appearance of PBIgG among the infected dogs it was concluded that other non-immunological mechanisms are probably also involved in the pathogenesis of the thrombocytopenia seen in canine monocytic ehrlichiosis.

Animals↗
PubMed2000

Gluconeogenesis in non-obese diabetic (NOD) mice: in vivo effects of vandadate treatment on hepatic glucose-6-phoshatase and phosphoenolpyruvate carboxykinase.

The contribution of gluconeogenesis to hyperglycemia in non-obese diabetic (NOD) mice has been investigated using oral vanadate administration. Vanadate compounds have been shown to mimic many actions of insulin; however, the exact mechanism is poorly understood. The aims of the present study were (1) to elucidate vanadate's action in vivo, and to assess the possibility that its glucose-reducing effect is dependent on the presence of a minimal concentration of insulin; and (2) to evaluate the effects of vanadate administration on the key hepatic gluconeogenesis enzymes, glucose-6-phosphatase (G-6-Pase) and phosphoenolpyruvate carboxykinase (PEPCK), as well as glucose-6-phosphate dehydrogenase (G-6-PDH). Vanadate caused a significant reduction in blood glucose but failed to normalize it, despite effective serum vanadate concentrations (26.2 +/- 1.6 micromol/L). Two weeks after initiation of treatment, blood glucose levels were 26.0 +/- 1.8, 21.7 +/- 3.0, 16.0 +/- 1.6, and 14.3 +/- 2.3 mmol/L in the control (C), insulin (I), vanadate (V), and combined vanadate and insulin (V + I) groups, respectively (P < .001). G-6-Pase activity was significantly reduced by vanadate (622 +/- 134 v365 +/- 83 nmol/min/mg protein in C vV, P < .05). PEPCK activity was also significantly reduced (844 +/- 370, 623 +/- 36, 337 +/- 43, and 317 +/- 75 nmol/min/mg in the C, I, V, and V + I groups, respectively, P < .001). No significant differences in the hepatic glycogen stores and G-6-PDH activity were noted between treatment groups. Our study suggests that the inhibition of hepatic G-6-Pase and PEPCK activity by vanadate plays an important role in reducing blood glucose levels in NOD mice.

Animals↗
PubMed2000

Comparison of a clinic-based ELISA test kit with the immunofluorescence test for the assay of Ehrlichia canis antibodies in dogs.

The "gold standard" for the detection of antibodies to Ehrlichia canis, the cause of canine monocytic ehrlichiosis (CME), is the indirect immunofluorescence antibody (IFA) test. The IFA test however is generally available only in selected laboratories and requires extensive equipment and trained personnel. A double-blind study was conducted to compare the ability of an in-clinic standardized enzyme-linked immunosorbent assay (ELISA) test kit to measure E. canis IgG antibodies in dogs compared with the standard IFA technique. A good correlation was found between the 2 techniques (r2 = 0.8793; P < 0.0001). Evidence for the sensitivity of the ELISA technique for the early detection of E. canis IgG antibodies was demonstrated by comparing the appearance of E. canis antibody titers by the IFA and ELISA techniques after artificial infection of 2 sets of dogs. In both experimental infections, both tests were equally sensitive for the early detection of IgG antibodies against E. canis, and the results correlated well with the appearance of fever and clinical signs. Proposed application of the in-clinic ELISA test is to aid in the diagnosis of CME.

Animals↗
PubMed2000

Attempt to prevent the development of diabetes in non-obese diabetic mice by oral vanadate administration.

BACKGROUND: Despite current treatment protocols, the long-term complications of insulin-dependent diabetes mellitus have prompted the investigation of strategies for the prevention of IDDM. OBJECTIVES: To investigate the effect of oral vanadate in reducing diabetes type I in non-obese diabetic mice. METHODS: Sodium metavanadate, 3.92 mmol/L, was added to the drinking water of 8-week-old female NOD mice. Blood glucose levels, water consumption and body weight were measured, and the end point of the study was judged by the appearance of hyperglycemia in the mice. RESULTS: Treatment with vanadate did not significantly reduce the incidence of type I diabetes as compared to the control group. However, oral vanadate therapy significantly reduced the blood glucose levels after the fourth week of treatment compared to the control group (3.83 +/- 0.67 vs. 4.44 +/- 0.83 mmol/L, P < 0.03). There was a consistent and significant increase in body weight of the vanadate-treated pre-diabetic NOD mice compared to the controls. Diabetic mice treated with vanadate had significantly lower levels of serum insulin as compared to control diabetic mice (104 +/- 27 vs. 151 +/- 36 mumol/L, P < 0.03). Histologically, no significant differences were found in inflammatory response of the islets of Langerhans between the control and treated groups. CONCLUSIONS: This study suggests that the post-receptor insulin-like effect induced by vanadate is not sufficient to prevent the development of diabetes and insulitis in pre-diabetic NOD mice.

Administration, Oral↗
PubMed1999

Antibodies reactive with Ehrlichia canis, Ehrlichia phagocytophila genogroup antigens and the spotted fever group rickettsial antigens, in free-ranging jackals (Canis aureus syriacus) from Israel.

A seroepidemiological survey was conducted to investigate the prevalence of antibodies reactive with the Ehrlichia canis and Ehrlichia phagocytophila genogroup antigens, and the spotted fever group (SFG) rickettsiae antigens in jackals in Israel (Canis aureus syriacus), to assess the possible role of the jackal in the epidemiology of these diseases. Fifty-three serum samples from jackals were assayed by the indirect immunofluorescence antibody test. Antibodies to E. canis were detected in 35.8% serum samples while 26.4% of the samples tested were positive to Ehrlichia chaffeensis. Twenty-six percent of the jackals tested were seropositive to E. phagocytophila, of which 5.7% were seropositive to E. phagocytophila alone without any seroreactivity to either E. canis or E. chaffeensis. Fifty-five percent of the jackals were seropositive to the SFG-rickettsiae antigens. The results suggest a high exposure rate of jackals in Israel to E. canis. Positive reactivity to E. chaffeensis was considered to be due to antigenic cross-reactions with E. canis. The study demonstrated for the first time the presence of E. phagocytophila antibodies in free-range jackals. The high incidence of antibodies to the SFG-rickettsiae and their relatively high antibody titers was suggestive of either recent or persistent infection. The possibility that jackals may play a role in the transmission of E. canis, E. phagocytophila and the SFG-rickettsiae for human and canine infections is discussed.

Animals↗
PubMed1998

Kinetics of serologic cross-reactions between Ehrlichia canis and the Ehrlichia phagocytophila genogroups in experimental E. canis infection in dogs.

The serological cross-reactions between the Ehrlichia canis and Ehrlichia phagocytophila genogroups, and the kinetics of development of antibodies in dogs to the E. phagocytophila group after artificial infection with the Israeli strain of E. canis was investigated. Results of this study indicate that the development of antibodies to the E. phagocytophila genogroup in dogs after infection with E. canis is a time dependent event probably conditional on the continued propagation of the rickettsia in the host. After spontaneous clinical recovery, and at the beginning of the subclinical phase, no antibodies to E. phagocytophila were yet detectable. The first evidence of IgG antibodies to E. phagocytophila were found in two of the six dogs, 55 days after artificial infection with E. canis, while another two dogs became seropositive to E. phagocytophila 22 days later. All surviving dogs were seropositive to E. phagocytophila by 150 days PI. It is suggested that the appearance of E. phagocytophila antibodies following treatment of acute E. canis infection may be used to judge treatment failure and/or persistence of infection.

Animals↗
PubMed1998

Acute blindness associated with monoclonal gammopathy induced by Ehrlichia canis infection.

Ehrlichia canis infection was diagnosed in a Labrador retriever presented with a primary complaint of acute blindness. Ocular signs on admission included bilateral hyphema, retinal haemorrhage and retinal detachment. Serum protein electrophoresis results revealed monoclonal gammopathy. This report discusses and suggests the pathogenesis of ocular bleeding in canine monocytic ehrlichiosis. Blood hyperviscosity, elevation in oncotic pressure, vasculitis, thrombocytopenia and platelet dysfunction are all proposed to be important factors in the pathogenesis of acute blindness in canine monocytic ehrlichiosis.

Acute Disease↗
PubMed1998

Investigation of splenic functions in canine monocytic ehrlichiosis.

In order to determine the role of the spleen in the pathogenesis of canine monocytic ehrlichiosis (CME), the effect of splenectomy on the course of the acute phase of experimental was investigated. Intact and splenectomized dogs, sero-negative for Ehrlichia canis antibodies, were infected with the Israeli strain of E. canis. Serology, clinical signs and haematological parameters were recorded prior to infection, and over a period of 60 days post infection, and were compared between the intact and the splenectomized dogs. All dogs seroconverted for IFA E. canis antibodies by days 10 to 17 post infection. There did not appear to be any difference in the day of appearance or in the titer of anti-E. canis IgG antibodies, between the splenectomized and intact groups throughout the course of the study. During the acute stage, food consumption (percentage change) was significantly lower in the intact group compared to the splenectomized group (-66.3% and -25.3%, respectively, p < 0.0001). During this period, significant higher body temperatures were measured in the intact group (average of 39.76 degrees C vs. 38.96 degrees C, p < 0.0001). The haematocrit, red blood cell counts, haemoglobin concentrations and platelet counts were significantly lower (p < 0.05) in the intact group when compared to the splenectomized group during the whole course of the study. The clinical and the haematological findings in our study suggest that the disease process was milder in the splenectomized dogs compared to the intact dogs. The results of this study suggest that the spleen plays an important role in the pathogenesis of CME. Splenic inflammatory mediators and/or other splenic substances, are proposed to play a key role in the pathogenesis of the disease. Our results further substantiate the involvement of immune mechanisms in the pathogenesis of CME.

Acute Disease↗