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Dive into the research topics where Leonidas Leontides is active.

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Featured researches published by Leonidas Leontides.


Journal of The American Animal Hospital Association | 2004

Chronic Canine Ehrlichiosis (Ehrlichia canis): A Retrospective Study of 19 Natural Cases

Mathios E. Mylonakis; Alex F. Koutinas; Edward B. Breitschwerdt; Barbara C. Hegarty; Charalambos Billinis; Leonidas Leontides; Vassilios Kontos

Nineteen dogs from Greece with chronic ehrlichiosis were studied. The dogs exhibited bicytopenia or pancytopenia, bone marrow hypoplasia, seroreactivity to Ehrlichia canis (E. canis) antigens, and had no history of drug or radiation exposure. Anorexia, depression, severe bleeding tendencies, hypoalbuminemia, and increased serum alanine aminotransferase activity were also hallmarks of the disease. All these animals eventually died, irrespective of the treatment applied. Some dogs were also serologically positive for Rickettsia conorii, Leishmania infantum (L. infantum), and Bartonella vinsonii subspp. berkhoffii. Polymerase chain reaction testing of bone marrow samples revealed E. canis, Anaplasma phagocytophilia, Anaplasma platys, and L. infantum in some dogs. Concurrent infections did not appear to substantially influence the clinical course and final outcome of the chronic canine ehrlichiosis.


Veterinary Parasitology | 2002

A cross-sectional study of Leishmania spp. infection in clinically healthy dogs with polymerase chain reaction and serology in Greece.

Leonidas Leontides; Manolis N. Saridomichelakis; Charalambos Billinis; Vasilios Kontos; Alexander F. Koutinas; Apostolos D. Galatos; Mathios E. Mylonakis

A total of 73 clinically healthy hunting dogs, experiencing an outdoor lifestyle and originating from an area where canine leishmaniasis is endemic, were included in the study. Polymerase chain reaction (PCR) and indirect immunofluorescent antibody test (IFAT) for Leishmania spp. were done on bone marrow and serum samples, respectively, obtained from all 73 dogs, just before the beginning of the sandfly season. PCR was found positive in 46/73 (63%) whereas, IFAT only in 9/73 (12.3%) of the dogs. The prevalence and the incidence of Leishmania infection by PCR were 61.9 and 47.1%, respectively. No association was found between the breed, age, sex, length of hair coat of the dog, urban or rural life and the presence of ample vegetation and water collections in the proximity of their living quarters, and the result of PCR. These findings clearly demonstrate that most of the dogs residing areas where leishmaniasis is endemic become infected but usually remain seronegative. Serological screening of the general canine population in these areas may result in an underestimation of the true prevalence of the infection rate.


Veterinary Parasitology | 2001

A randomised, blinded, placebo-controlled clinical trial with allopurinol in canine leishmaniosis.

Alexander F. Koutinas; Manolis N. Saridomichelakis; Mathios E. Mylonakis; Leonidas Leontides; Z. Polizopoulou; Charalambos Billinis; Dimitris Argyriadis; Natasa Diakou; Orestis Papadopoulos

A total of 45 non-uremic dogs, with clinical signs indicating leishmaniosis, entered the study. Diagnosis was confirmed by indirect immunofluorescence assay (IFA) on serum and polymerase chain reaction (PCR) on bone marrow samples. The dogs were randomly allocated into Group A (n=37) that received allopurinol (10mg/kg B.W., per os, twice daily) for 4 consecutive months, and Group B (n=8) that were placebo-treated. Clinical signs were scored just before and at monthly intervals throughout the study period, in a blinded and independent fashion. Complete blood count, serum biochemistry profile, urinalysis, lymph node and bone marrow parasitology, IFA and enzyme-linked immunosorbent assay (ELISA) serology and bone marrow PCR were carried out at the beginning and at the end of the trial. A total of three Group A and one Group B dogs died of end stage kidney disease that developed during the trial. In Group A animals that endured the trial there was a significant improvement in the general body condition, conjunctivitis, peripheral lymphadenopathy, splenomegaly, masticatory muscle atrophy, ulcerative stomatitis, epistaxis, exfoliative dermatitis, cutaneous ulcerations, blepharitis and nasodigital hyperkeratosis. The same observation was made for anemia, lymphopenia, hyperproteinemia, hyperglobulinemia, hyperphosphatemia, increased alkaline phosphatase activity and the low albumin/globulin ratio. By contrast, no improvement of any kind was seen in Group B dogs. Lymph node and bone marrow parasite numbers were significantly decreased in Group A animals. In Group B, that occurred only in the lymph nodes. Apart from remission of clinical signs and restoration to normal of clinicopathological abnormalities, allopurinol did not eliminate Leishmania organisms, as the PCR result on bone marrow was still positive in all the dogs that finished the trial.


Veterinary Microbiology | 2003

Evaluation of cytology in the diagnosis of acute canine monocytic ehrlichiosis (Ehrlichia canis): a comparison between five methods

Mathios E. Mylonakis; A. F. Koutinas; Charalambos Billinis; Leonidas Leontides; Vassilios I. Kontos; Orestis Papadopoulos; Tim S. Rallis; Anna Fytianou

The purpose of this study was the comparison of the diagnostic sensitivity between buffy coat (BC), peripheral blood (PB), lymph node (LN), bone marrow (BM) and short-term culture (P-D) cytology that has been based on the detection of Ehrlichia canis morulae, in the acute phase of canine monocytic ehrlichiosis (CME). Their cellular localization, total numbers and microscopic differentials were also investigated. The highest sensitivities were achieved after evaluating 1000 oil immersion fields (OIFs) in BC (66%) and an equal number in LN (60.9%) smears, separately or together (74%). The morulae were more often detected into lymphocytes than monocytes. The highest total number of morulae (n=143) were found in P-D smears. Finally, to avoid false positive diagnoses, platelets, lymphocytic azurophilic granules, lymphoglandular bodies and phagocytosed nuclear material should not be confused with the morulae.


Veterinary Parasitology | 2000

Efficacy of moxidectin against sarcoptic mange and effects on milk yield of ewes and growth of lambs.

G.C. Fthenakis; E. Papadopoulos; C. Himonas; Leonidas Leontides; S. K. Kritas; J. Papatsas

Forty-eight dairy ewes and 45 lambs naturally infested with sarcoptic mange, were divided into three equal groups and treated with moxidectin 1% inj. sol. at a dose rate of 0.2 mg moxidectin kg(-1) bodyweight once or twice ten days apart. During the study, the skin lesions were scored and the number of mites recovered in facial skin scrapings from the animals were recorded. Moxidectin was found to be effective against ovine sarcoptic mange, when given twice; the percentage reduction of mites was 100% (p < 0.0001) and the skin lesions disappeared completely (p = 0.0001). In sheep treated once only, the percentage reduction of mites varied from 75% to 92%. Treated ewes produced up to 22.4% more milk than the infested ones (p = 0.0001). Treated lambs had up to 15% greater final weight and up to 23.7% more growth than infested controls (p = 0.0001). It is concluded that two injections of moxidectin 1% inj. sol. at a dose rate of 0.2 mg kg(-1) bodyweight, given ten days apart, were effective against ovine sarcoptic mange. Furthermore, it is considered that sarcoptic mange adversely affects the production of the infested animals.


Veterinary Parasitology | 2001

Factors affecting the frequency of ear canal and face infestation by Otodectes cynotis in the cat

S.T Sotiraki; A. F. Koutinas; Leonidas Leontides; Katerina K. Adamama-Moraitou; C. Himonas

Otodectes cynotis is responsible for at least 50% of canker cases diagnosed in cats world-wide. The role of Demodex cati in the pathogenesis of otitis and acne is still obscure. The aims of this study were to estimate the prevalence of O. cynoyis and D. cati infestations in clinically normal cats in northern Greece, to determine the factors that are associated with the probability and severity of infestation in the cat, and to examine the importance of these mites in the pathogenesis of feline acne. Samples from 161 cats were examined by flushing the ear canals and by taking skin scrapings of the chin and lip area. The results were combined with various factors (sex, age, living style, hair coat type and presence of pruritus, of ear discharge, of acne-like lesions) in order to carry out a risk analysis. Two separate logistic regression analyses were performed. One, on the infestation/non-infestation potential with O. cynotis and the other, on the degree of such infestation as mild-to-moderate (< or =5 mites/field) or severe (>5 mites/field). D. cati was not detected in any of the 161 cats. The prevalence of O. cynotis was estimated at 25.5% (95% confidence interval (CI) 19-32). The rate of mite infestation was higher with the presence of ear discharge (odds ratio 9, 95% CI 3.3-24.5), periaural pruritus (odds ratio 3.6, 95% CI 1.8-8) and acne-like lesions (odds ratio 3.3, 95% CI 1.2-9). Cats with mild-to-moderate degree of infestation had 18 times higher chance of exhibiting an ear discharge than those with a severe infestation. The log-odds of mild-to-moderate parasitism were linearly related to the age.


Epidemiology and Infection | 2003

Factors associated with the serological prevalence of Salmonella enterica in Greek finishing swineherds

Leonidas Leontides; E. Grafanakis; C. Genigeorgis

Blood samples were taken from 50 finishing pigs at 90-105 kg in each of 59 randomly selected farrow-to-finish herds. The sera were tested for antibodies to Salmonella enterica by the Danish mix-ELISA. Samples with an optical density of > 10% were considered to be positive. Associations between the odds of seropositivity of pigs and possible risk factors were evaluated in multivariable logistic regression models. The results of the analysis indicated that pigs fed non-pelleted dry or wet ration had 11 (P = 0.0004) or 9 (P = 0.02) times, respectively, lower odds of seropositivity than those fed pelleted ration. The risk of seropositivity was 4 (P = 0.0006) times higher in pigs fed a combination of chlortetracycline, procaine penicillin and sulphamethazine during fattening than in those fed an approved growth promotor or a probiotic.


Journal of Veterinary Internal Medicine | 2008

Factors associated with the occurrence of epistaxis in natural canine leishmaniasis (Leishmania infantum)

Theodoros Petanides; A. F. Koutinas; Mathios E. Mylonakis; M. J. Day; Manolis N. Saridomichelakis; Leonidas Leontides; R. Mischke; Pedro Paulo Vissotto de Paiva Diniz; Edward B. Breitschwerdt; M. Kritsepi; V.A. Garipidou; Christos K. Koutinas; S. Lekkas

BACKGROUND Canine leishmaniasis (CanL) is a common cause of epistaxis in dogs residing in endemic areas. The pathogenesis of CanL-associated epistaxis has not been fully explored because of the limited number of cases reported so far. HYPOTHESIS Epistaxis in CanL could be attributed to more than 1 pathomechanism such as hemostatic dysfunction, biochemical abnormalities, chronic rhinitis, and coinfections occurring in various combinations. ANIMALS Fifty-one dogs with natural CanL. METHODS The allocation of 51 dogs in this cross-sectional study was based on the presence (n = 24) or absence (n = 27) of epistaxis. The potential associations among epistaxis and concurrent infections (Ehrlichia canis, Bartonella spp., and Aspergillus spp.), biochemical and hemostatic abnormalities, and nasal histopathology were investigated. RESULTS Hypergammaglobulinemia (P= .044), increased serum viscosity (P= .038), decreased platelet aggregation response to collagen (P= .042), and nasal mucosa ulceration (P= .039) were more common in the dogs with epistaxis than in those without epistaxis. The other significant differences between the 2 groups involved total serum protein (P= .029) and gamma-globulin (P= .013) concentrations, which were higher, and the percentage platelet aggregation to collagen, which was lower (P= .012) in the epistaxis dogs. CLINICAL IMPORTANCE CanL-associated epistaxis appears to be the result of multiple and variable pathogenetic factors such as thrombocytopathy, hyperglobulinemia-induced serum hyperviscosity, and nasal mucosa ulceration.


Research in Veterinary Science | 2010

Factors affecting the occurrence, duration of hospitalization and final outcome in canine parvovirus infection

Iris Kalli; Leonidas Leontides; Mathios E. Mylonakis; Katerina K. Adamama-Moraitou; Timoleon S. Rallis; Alexander F. Koutinas

The objectives of this matched case-control study in a veterinary teaching hospital were to investigate the influence of signalment and historical data on the odds of occurrence of canine parvovirus (CPV) enteritis and the potential usefulness of the clinical signs and clinicopathologic abnormalities recorded on admission as prognostic indicators of mean duration of hospitalization (DOH) and outcome of the disease. Ninety-four puppies with natural CPV enteritis and 188 age-matched controls were studied. The odds to develop CPV enteritis were higher in purebreds compared to mixed-breed puppies. Vomiting and depression at the time of admission were associated with a prolongation of DOH by 2 and 1.75 days, respectively. The lymphopenic and hypoalbuminemic dogs were hospitalized for 1.9 and 2.5 more days, respectively, compared to those without these abnormalities. The odds of non-survival were higher in those puppies with evidence of systemic inflammatory response syndrome (SIRS) at the time of admission.


Journal of Veterinary Internal Medicine | 2011

Serum acute phase proteins as clinical phase indicators and outcome predictors in naturally occurring canine monocytic ehrlichiosis.

Mathios E. Mylonakis; José J. Cerón; Leonidas Leontides; Victoria I. Siarkou; S. Martínez; Asta Tvarijonaviciute; A. F. Koutinas; Shimon Harrus

BACKGROUND Canine monocytic ehrlichiosis (CME), caused by Ehrlichia canis, is an important tick-borne disease of global importance. Currently, limited information is available on the diagnostic and prognostic value of acute phase proteins (APPs) in dogs naturally infected with E. canis. HYPOTHESIS APPs may be useful indicators of the clinical phase of CME and predictive of the clinical outcome (death or survival). ANIMALS Fifty-six dogs naturally infected with E. canis and 7 clinically healthy control dogs. METHODS C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), and albumin concentrations determined on admission were retrospectively compared among 27 dogs with nonmyelosuppressive CME, 29 dogs with myelosuppressive CME and 7 healthy dogs. Diagnosis of CME was based on clinical and clinicopathological findings, seropositivity to E. canis, polymerase chain reaction amplification of E. canis-specific 16S rDNA, microscopic observation of Ehrlichia sp. morulae in blood monocytes or some combination of these. RESULTS Mean concentrations of CRP, SAA, and Hp were significantly higher in the myelosuppressed dogs compared with the other groups, but no significant differences were found in the concentration of albumin. Survival analysis of the affected animals indicated that APP concentrations were not associated with clinical outcome; the latter was strongly associated with pancytopenia (odds ratio for death 22.7) and neutropenia (odds ratio for death 7.7). CONCLUSIONS AND CLINICAL IMPORTANCE CRP, SAA, and Hp serum concentrations on admission are useful indicators of the clinical phase of CME, but are not useful predictors of clinical outcome.

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Mathios E. Mylonakis

Aristotle University of Thessaloniki

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Alexander F. Koutinas

Aristotle University of Thessaloniki

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A. F. Koutinas

Aristotle University of Thessaloniki

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Rania Farmaki

Aristotle University of Thessaloniki

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Victoria I. Siarkou

Aristotle University of Thessaloniki

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