Christos Balaskas

Trichinella spiralis: enteric mucin-related response to experimental infection in conventional and SPF pigs

Experimental Parasitology, 2005

The infectivity of sarcoid clinical material and its bacterial content inoculated in CBA mice

In Vivo

Sarcoidosis is a multisystemic disorder that is currently viewed as the consequence of chronic im... more Sarcoidosis is a multisystemic disorder that is currently viewed as the consequence of chronic immunological response associating genetic susceptibility and specific environmental or transmissible agents. Relevant evidence, although conflicting, justifies a concern about the involvement of specific pathogens to disease causation. In this study we assessed the infectivity of sarcoid clinical material, and of the pathogens found in it, to normal CBA mice used as a model of an immuno-competent host. One hundred and eleven mice were inoculated into their footpads with fresh, filtered, and autoclaved, sputum and bronchoalveolar lavage homogenates, collected from patients with sarcoidosis, and with the mycobacterial and propionibacterial pathogens isolated from this material. The total number of positive reactors of the animals that received raw clinical material and the pathogens it contained was statistically significant compared to those of the control groups. However, the number of af...

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New frontiers in liver surgery. Two-stage liver surgery for the management of advanced metastatic liver disease

Hepato-gastroenterology

To assess the value and the safety of main portal branch transection combined with transarterial ... more To assess the value and the safety of main portal branch transection combined with transarterial targeting locoregional neo and adjuvant immunochemotherapy, 32 patients suffering from advanced metastatic liver disease underwent two-stage hepatectomy. From September 1995 to June 1999, 32 consecutive patients underwent two-stage surgery for advanced metastatic liver disease. Firstly we performed ligation and transection of the main portal branch corresponding to the liver lobe occupied by the tumor and introduction of an arterial jet port catheter towards the hepatic artery. After a locoregional transarterial targeting immunochemotherapy regimen the patient had a 2nd laparotomy for hemihepatectomy. Following surgery, locoregional targeting immunochemotherapy was carried out in all patients via the arterial port of the gastroduodenal artery as an adjuvant treatment. There were no operative deaths. Mean survival was 27 +/- 8 months. Two-stage liver surgery is an appealing alternative th...

Cellular development of the enteric nervous system in the chick embryo

The chemical and structural development of enteric plexuses was studied in the chick from embryon... more The chemical and structural development of enteric plexuses was studied in the chick from embryonic day 4 to hatching. The enteric ganglia consist of neural crest-derived neuronal and glial cells, which can be distinguished morphologically and immunohistochemically in late developmental stages. At what stage different cell lineages originate from uncommitted precursors remains unknown. While the primordial neurons and glial cells could not be distinguished ultrastnicturally from each other until E16, by means of polyclonal antibodies against GFAP and tubulin, distinct populations of neuronal and glial cells were identified from E5 in the duodenal myenteric ganglia. The enteric ganglia display a compact structure with exclusion of blood vessels and collagen, from the earliest stages investigated. A basement membrane, of unknown origin, is recognized ultrastnicturally around ganglia and connecting strands from E12. The distribution of laminin, a basement membrane component, was examin...

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Outbreak of acute tuberculosis in a goat herd: first report of Mycobacterium caprae isolation in Greece

Mycobacterium caprae is a recently defined member of the Mycobacterium tuberculosis complex that ... more Mycobacterium caprae is a recently defined member of the Mycobacterium tuberculosis complex that is responsible for tuberculosis among animals and to a limited extent, humans. Herein we report an outbreak of acute tuberculosis in a dairy goat farm at the North of Greece, which is the first case of M. caprae isolation in the country. The disease was manifested mainly with pneumonia that resulted to the death of the affected animals within 15-60 days after first symptoms appeared. Mortality of goats that developed clinical disease reached 92%. Based on the evidence provided by spoligotyping, the isolate is similar to those commonly found in central Europe. In conclusion it can be stated that caprine tuberculosis caused by M. caprae can be manifested in an acute form, representing like in the case described here a serious economic and health problem.

Comparative evaluation of the performance of the PCR assays commonly used for the determination of sex in avian species

Journal of King Saud University - Science

Laminin immunoreactivity in enteric ganglia of the chick embryo

Cell Tissue Research 289 243 251, Sep 1, 1997

The localization and time of appearance of laminin in the duodenum of the chick embryo were studi... more The localization and time of appearance of laminin in the duodenum of the chick embryo were studied with an anti-laminin polyclonal antibody and immunofluorescence. Laminin immunoreactivity was observed in the basement membranes of the mesothelium, mucosal epithelium, muscle cells and in the adventitia and basal surface of the endothelium in blood vessels. In addition, laminin immunostaining was detected over the contour of myenteric ganglia from embryonic day 7 and inside these ganglia from embryonic day 13. In colocalization experiments, laminin immunoreactivity occurred outside tubulin immunoreactive neuronal cell bodies, thus indicating that it resides in glial cells or in extracellular spaces. In addition connecting strands of the myenteric plexus and intramuscular nerves expressed laminin immunoreactivity. Similar observations were made in the proventriculus, gizzard, ileum and rectum of chick embryos, and in the duodenum and rectum of quail embryos. In the ganglion of Remak, laminin immunofluorescence was detected in the collagenous sheath that surrounds the ganglion and inside the ganglion, where it outlines neuronal cell bodies. Laminin immunoreactivity within the myenteric ganglia during the 3rd week in ovo, appears to be characteristic of the avian species examined, since it was not observed in the rat and mouse intestine at equivalent developmental stages. Immunocytochemical experiments at the electron-microscope level confirmed that structures with laminin or laminin-like immunoreactivity occur both around and inside myenteric ganglia. It is suggested that laminin, or an immunologically similar molecule, may play a role in the development and maturation of avian enteric ganglia.

Reduced Sertoli cell number and altered pituitary responsiveness in male lambs undernourished in utero

Animal Reproduction Science, Aug 31, 2009

The nutritional status of females during pregnancy can have profound effects on the fetus reprodu... more The nutritional status of females during pregnancy can have profound effects on the fetus reproductive system development that could affect the reproductive potential as later as in adulthood (fetal programming). The aim of the present study was to examine the effects of maternal nutrient restriction imposed during different periods of gestation on pituitary responsiveness at different ages postnatal and on Sertoli cell number in male offspring. Pregnant ewes were fed to 100% of Metabolizable Energy and Crude Protein requirements throughout pregnancy (Control) or to 50% from 0 to 30 (R1) or from 31 to 100 days of gestation (R2). Male lambs were selected and fed to appetite throughout the study. At 2, 5.5 and 10 months of age a GnRH challenge was conducted. At slaughter (10 months) testes were removed and examined histologically. Maternal undernutrition did not affect the time of the onset of puberty, defined as the first increase in plasma testosterone concentrations &gt; or =1 ng/ml. The LH and FSH response to GnRH challenge did not differ between groups at 2 and 5.5 months but at 10 months of age a higher (P&lt;0.05) FSH response was found in R2 group. Testes weight did not differ between groups at slaughter. Mean Sertoli cell number was significantly lower in animals of R2 group compared with Control (P&lt;0.01). A smaller seminiferous tubules diameter was detected in R2 group (P&lt;0.05), while the diameter of the lumen was similar in all groups. Collectively, these results provide clear evidence for a direct effect of nutrient restriction during pregnancy on Sertoli cell number in adulthood. The lower number of Sertoli cells is the most candidate factor for the higher pituitary activity through a reduction in the suppressive effect of inhibin.

Gill area and dimensions of gilthead sea bream Sparus aurata L

Journal of Fish Biology, 2006

ABSTRACT Detailed measurements of gill area and constituent variables (total filament length, lam... more ABSTRACT Detailed measurements of gill area and constituent variables (total filament length, lamellar frequency and bilateral area) were performed on both hemibranchs of all eight arches in six specimens of gilthead sea bream Sparus aurata (mean ±s.e. 49·9 ± 0·2 g). Shrinkage was also quantified and results were corrected accordingly. Filament number decreased from the first to the fourth gill arch, and average bilateral area of secondary lamellae was higher in the second and third arches. Total and mean filament length, total number of secondary lamellae and total gill area (ATG) were lower in posterior than in anterior hemibranchs of the second, third and fourth gill arches; while the opposite was observed for the first arch. Lamellar frequency was increased in posterior hemibranchs of all arches compared to that in anterior hemibranchs, especially at the fourth arch. Comparison of the actually measured ATG and constituent variables with estimates revealed that the third gill arch is the most representative for appropriate measurements and that any of its components (even one hemibranch) approximates the best ATG (within the range of 0·2–4·3%, P &gt; 0·05) and related dimensions. Consequently, necessary measurements were restricted to the posterior hemibranch of the third gill arch, and ATG and dimensions (y) were estimated in 21 specimens (23·5–217·6 g) and correlated to body mass (M) according to the allometric equation y = aMb. As fish increased in size, ATG (b= 0·664), total (b= 0·425) and mean (b= 0·323) filament length, total number of filaments (b= 0·103) and secondary lamellae (b= 0·377), as well as average lamellar bilateral area (b= 0·288), increased, while the opposite was observed for lamellar frequency (b=−0·049) and mass-specific area (b=−0·336). Data obtained are discussed in relation to S. aurata activity and living ethology.

Reduced Sertoli cell number and altered pituitary responsiveness in male lambs undernourished in utero

Animal Reproduction Science, 2009

The nutritional status of females during pregnancy can have profound effects on the fetus reprodu... more The nutritional status of females during pregnancy can have profound effects on the fetus reproductive system development that could affect the reproductive potential as later as in adulthood (fetal programming). The aim of the present study was to examine the effects of maternal nutrient restriction imposed during different periods of gestation on pituitary responsiveness at different ages postnatal and on Sertoli cell number in male offspring. Pregnant ewes were fed to 100% of Metabolizable Energy and Crude Protein requirements throughout pregnancy (Control) or to 50% from 0 to 30 (R1) or from 31 to 100 days of gestation (R2). Male lambs were selected and fed to appetite throughout the study. At 2, 5.5 and 10 months of age a GnRH challenge was conducted. At slaughter (10 months) testes were removed and examined histologically. Maternal undernutrition did not affect the time of the onset of puberty, defined as the first increase in plasma testosterone concentrations &gt; or =1 ng/ml. The LH and FSH response to GnRH challenge did not differ between groups at 2 and 5.5 months but at 10 months of age a higher (P&lt;0.05) FSH response was found in R2 group. Testes weight did not differ between groups at slaughter. Mean Sertoli cell number was significantly lower in animals of R2 group compared with Control (P&lt;0.01). A smaller seminiferous tubules diameter was detected in R2 group (P&lt;0.05), while the diameter of the lumen was similar in all groups. Collectively, these results provide clear evidence for a direct effect of nutrient restriction during pregnancy on Sertoli cell number in adulthood. The lower number of Sertoli cells is the most candidate factor for the higher pituitary activity through a reduction in the suppressive effect of inhibin.

Dietary probiotic inclusion level modulates intestinal mucin composition and mucosal morphology in broilers

by K. Fegeros and Christos Balaskas

Poultry Science, 2012

The aim of this study was to investigate the effect of dietary probiotic inclusion level on mucin... more The aim of this study was to investigate the effect of dietary probiotic inclusion level on mucin composition (monosaccharide ratio), mucosal morphometry, mucus layer staining intensity, and mucus layer thickness along the broiler intestinal tract. One-day-old male Cobb broilers were administered maize-soybean meal basal (BD) diets for 42 d and depending on the feed additive used, broilers were allocated into the following 5 experimental treatments: control C (BD, no additive), treatment P1 (10(8) colony forming units of probiotic/kg of BD), treatment P2 (10(9) cfu of probiotic/kg of BD), treatment P3 (10(10) cfu of probiotic/kg of BD), and treatment A (2.5 mg avilamycin/kg of BD). Intestinal samples from duodenum, ileum, and cecum of 14- and 42-d-old broilers were collected and analyzed. Mannose (Man) decreased linearly with increasing probiotic level in duodenum (P=0.015) and ileum (P=0.042) of 14-d-old broilers. N-Acetyl-glucosamine and galactose decreased linearly (P=0.012 and P=0.001, respectively), while fucose increased linearly (P&lt;0.001) with increasing probiotic feed inclusion level in 42-d-old broiler cecum, with treatment A not differing from treatment C (P≥0.05). Cecal villus height and crypt depth increased linearly (P=0.016 and P=0.003, respectively) with probiotic inclusion level, with treatment A having higher (P≤0.05) values only from treatment C. Mucus layer thickness increased linearly with probiotic inclusion level in duodenum at 14 d and 42 d (P=0.007 and P=0.030, respectively). Finally, mucus layer staining intensity was influenced (P&lt;0.001) by villus fragment (i.e., tip, midsection, and base) but not from the treatment, age, and intestinal segment examined. As a conclusion, this study provides evidence that probiotic inclusion level affects intestinal mucin monosaccharide composition, mucus layer thickness, and intestinal morphology in broilers.

The Infectivity of Sarcoid Clinical Material and its Bacterial Content Inoculated in CBA Mice

In Vivo, 2006

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Outbreak of acute tuberculosis in a goat herd: first report of Mycobacterium caprae isolation in Greece

Mycobacterium caprae is a recently defined member of the Mycobacterium tuberculosis complex that ... more

Lygidakis NJ, Vlachos L, Raptis S, et al. New frontiers in liver surgery: two-stage liver surgery for the management of advanced metastatic liver disease

Hepato-gastroenterology

ABSTRACT

Mycobacterial infections of fowl

The significance of mycobacterial infections of birds may have been decreased considerably by the... more The significance of mycobacterial infections of birds may have been decreased considerably by the broad application of modern farming practices, but their study continues to be important with reference to fowl, animal and public health protection. Mycobacterial infections of birds are mainly caused by members of the Mycobacterium avium complex (MAC). This is divided into 28 serotypes that are grouped into species: serotypes 1 to 6, 8 to 11 and serotype 21 consist the M. avium subsp. avium (MA), serotypes 4 and 8 are also referred to as M. avium subsp. hominisuis, whereas serotypes 7, 12 to 20 and 22 to 28 consist the Mycobacterium intracellulare. Serotypes 1 to 3 of MA are the only ones that cause systemic tuberculosis in chickens. M. intracellulare and the rest of the serotypes that consist MA usually cause only focal tuberculous lesions. Recently, another member of the Mycobacterium species, namely Mycobacterium genavense, has been added to those that can infect fowl. Cases of fow...

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The infectivity of sarcoid clinical material and its bacterial content inoculated in CBA mice

In vivo (Athens, Greece)

Sarcoidosis is a multisystemic disorder that is currently viewed as the consequence of chronic im... more Sarcoidosis is a multisystemic disorder that is currently viewed as the consequence of chronic immunological response associating genetic susceptibility and specific environmental or transmissible agents. Relevant evidence, although conflicting, justifies a concern about the involvement of specific pathogens to disease causation. In this study we assessed the infectivity of sarcoid clinical material, and of the pathogens found in it, to normal CBA mice used as a model of an immuno-competent host. One hundred and eleven mice were inoculated into their footpads with fresh, filtered, and autoclaved, sputum and bronchoalveolar lavage homogenates, collected from patients with sarcoidosis, and with the mycobacterial and propionibacterial pathogens isolated from this material. The total number of positive reactors of the animals that received raw clinical material and the pathogens it contained was statistically significant compared to those of the control groups. However, the number of af...

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Comparative evaluation of positive tests to Mycobacterium avium subsp. paratuberculosis in clinically healthy sheep and goats in South-West Greece using molecular techniques, serology, and culture

The Veterinary Journal, 2007

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Japanese quail acute exposure to methamidophos: Experimental design, lethal, sub-lethal effects and cholinesterase biochemical and histochemical expression

Science of The Total Environment, 2013

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Dietary probiotic inclusion level modulates intestinal mucin composition and mucosal morphology in broilers

Poultry Science, 2012

The aim of this study was to investigate the effect of dietary probiotic inclusion level on mucin... more The aim of this study was to investigate the effect of dietary probiotic inclusion level on mucin composition (monosaccharide ratio), mucosal morphometry, mucus layer staining intensity, and mucus layer thickness along the broiler intestinal tract. One-day-old male Cobb broilers were administered maize-soybean meal basal (BD) diets for 42 d and depending on the feed additive used, broilers were allocated into the following 5 experimental treatments: control C (BD, no additive), treatment P1 (10(8) colony forming units of probiotic/kg of BD), treatment P2 (10(9) cfu of probiotic/kg of BD), treatment P3 (10(10) cfu of probiotic/kg of BD), and treatment A (2.5 mg avilamycin/kg of BD). Intestinal samples from duodenum, ileum, and cecum of 14- and 42-d-old broilers were collected and analyzed. Mannose (Man) decreased linearly with increasing probiotic level in duodenum (P=0.015) and ileum (P=0.042) of 14-d-old broilers. N-Acetyl-glucosamine and galactose decreased linearly (P=0.012 and P=0.001, respectively), while fucose increased linearly (P&lt;0.001) with increasing probiotic feed inclusion level in 42-d-old broiler cecum, with treatment A not differing from treatment C (P≥0.05). Cecal villus height and crypt depth increased linearly (P=0.016 and P=0.003, respectively) with probiotic inclusion level, with treatment A having higher (P≤0.05) values only from treatment C. Mucus layer thickness increased linearly with probiotic inclusion level in duodenum at 14 d and 42 d (P=0.007 and P=0.030, respectively). Finally, mucus layer staining intensity was influenced (P&lt;0.001) by villus fragment (i.e., tip, midsection, and base) but not from the treatment, age, and intestinal segment examined. As a conclusion, this study provides evidence that probiotic inclusion level affects intestinal mucin monosaccharide composition, mucus layer thickness, and intestinal morphology in broilers.

Gill area and dimensions of gilthead sea bream Sparus aurata L

by Christos Balaskas and Sofronios Papoutsoglou

Journal of Fish Biology, 2006

ABSTRACT Detailed measurements of gill area and constituent variables (total filament length, lam... more ABSTRACT Detailed measurements of gill area and constituent variables (total filament length, lamellar frequency and bilateral area) were performed on both hemibranchs of all eight arches in six specimens of gilthead sea bream Sparus aurata (mean ±s.e. 49·9 ± 0·2 g). Shrinkage was also quantified and results were corrected accordingly. Filament number decreased from the first to the fourth gill arch, and average bilateral area of secondary lamellae was higher in the second and third arches. Total and mean filament length, total number of secondary lamellae and total gill area (ATG) were lower in posterior than in anterior hemibranchs of the second, third and fourth gill arches; while the opposite was observed for the first arch. Lamellar frequency was increased in posterior hemibranchs of all arches compared to that in anterior hemibranchs, especially at the fourth arch. Comparison of the actually measured ATG and constituent variables with estimates revealed that the third gill arch is the most representative for appropriate measurements and that any of its components (even one hemibranch) approximates the best ATG (within the range of 0·2–4·3%, P &gt; 0·05) and related dimensions. Consequently, necessary measurements were restricted to the posterior hemibranch of the third gill arch, and ATG and dimensions (y) were estimated in 21 specimens (23·5–217·6 g) and correlated to body mass (M) according to the allometric equation y = aMb. As fish increased in size, ATG (b= 0·664), total (b= 0·425) and mean (b= 0·323) filament length, total number of filaments (b= 0·103) and secondary lamellae (b= 0·377), as well as average lamellar bilateral area (b= 0·288), increased, while the opposite was observed for lamellar frequency (b=−0·049) and mass-specific area (b=−0·336). Data obtained are discussed in relation to S. aurata activity and living ethology.

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