Surgical treatment of a persistent right aortic arch with concurrent patent ductus arteriosus in a 4-month-old German shepherd dog.

A 4-month-old intact female German shepherd dog was presented with a history of postprandial regurgitation, a palpably distended cervical oesophagus after eating, and poor weight gain despite a ravenous appetite. Computed tomography angiography, esophagoscopy and echocardiography identified a persistent right aortic arch with a concurrent patent ductus arteriosus (PDA) causing extraluminal oesophageal compression leading to marked segmental megaoesophagus. A heart murmur was not detectable. A left lateral thoracotomy was performed to ligate and transect the PDA without complication. The dog was discharged with mild aspiration pneumonia which resolved with antimicrobial therapy. Twelve months post-surgery the owners reported no regurgitation.

Evaluation of Polymeric Matrix Loaded with Melatonin for Wound Dressing.

The development of scaffolds mimicking the extracellular matrix containing bioactive substances has great potential in tissue engineering and wound healing applications. This study investigates melatonin-a methoxyindole present in almost all biological systems. Melatonin is a bioregulator in terms of its potential clinical importance for future therapies of cutaneous diseases. Mammalian skin is not only a prominent melatonin target, but also produces and rapidly metabolizes the multifunctional methoxyindole to biologically active metabolites. In our methodology, chitosan/collagen (CTS/Coll)-contained biomaterials are blended with melatonin at different doses to fabricate biomimetic hybrid scaffolds. We use rat tail tendon- and Salmo salar fish skin-derived collagens to assess biophysical and cellular properties by (i) Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), (ii) thermogravimetric analysis (TG), (iii) scanning electron microscope (SEM), and (iv) proliferation ratio of cutaneous cells in vitro. Our results indicate that melatonin itself does not negatively affect biophysical properties of melatonin-immobilized hybrid scaffolds, but it induces a pronounced elevation of cell viability within human epidermal keratinocytes (NHEK), dermal fibroblasts (NHDF), and reference melanoma cells. These results demonstrate that this indoleamine accelerates re-epithelialization. This delivery is a promising technique for additional explorations in future dermatotherapy and protective skin medicine.

Effect of Electron-Beam Radiation and Other Sterilization Techniques on Structural, Mechanical and Microbiological Properties of Thermoplastic Starch Blend.

This work investigates the potential application of various sterilization methods for microorganism inactivation on the thermoplastic starch blend surface. The influence of the e-beam and UV radiation, ethanol, isopropanol and microwave autoclave on structural and packaging properties were studied. All the applied methods were successful in the inactivation of yeast and molds, however only the e-beam radiation was able to remove the bacterial microflora. The FTIR analysis revealed no significant changes in the polymer structure, nevertheless, a deterioration of the mechanical properties of the blend was observed. The least invasive method was the UV radiation which did not affect the mechanical parameters and additionally improved the barrier properties of the tested material. Moreover, it was proved that during the e-beam radiation the chain scission and cross-linking occurred. The non-irradiated and irradiated samples were subjected to the enzymatic degradation studies performed in the presence of amylase. The results indicated that irradiation accelerated the decomposition of material, which was confirmed by the measurements of weight loss, and mass of glucose and starch released to the solution in the course of biodegradation, as well as the FTIR and thermal analysis.

Computed tomography characteristics of equine paranasal sinus cysts.

BACKGROUND: Computed tomography (CT) is commonly used to investigate equine paranasal sinus disease, however, only limited information is available in the literature about the detailed CT appearance of equine paranasal sinus cysts. OBJECTIVES: To investigate if paranasal sinus cysts have specific characteristics in CT images that allow differentiation from other sinus diseases. STUDY DESIGN: Retrospective observational study. METHODS: Evaluation and comparison of CT studies of eight horses with surgically and/or histopathologically confirmed paranasal sinus cysts and 10 horses with other confirmed paranasal sinus diseases. RESULTS: A discrete hyperattenuating wall-like structure was detected in the periphery of the sinus lesion in precontrast acquisition in 7/8 horses with paranasal sinus cysts. A similar wall-like structure was detected in 3/10 horses with other sinus diseases, however, in contrast to horses with paranasal sinus cysts, two of these also had hyperattenuating regions within the contents of the sinus lesion. Bone destruction and formation affecting cancellous and cortical bone and dental disease were frequent in horses with paranasal sinus cysts. No significant difference in attenuation values was found when the fluid/soft tissue attenuation contents of lesions in horses with paranasal sinus cysts (mean 28.9 ± SD 9.2 HU) were compared with other sinus diseases when ethmoid haematomas were excluded (30.4 ± 12.9 HU, P = .8). MAIN LIMITATIONS: Low number of cases. CONCLUSIONS: Detection of a hyperattenuating cystic wall is a helpful feature for identifying paranasal sinus cysts in CT images of horses. In contrast, measurement of attenuation values of the soft tissue/fluid contents of the sinus lesions was not helpful in identifying paranasal sinus cysts.

Is cathelicidin a novel marker of diabetic microangiopathy in patients with type 1 diabetes?

AIM: The aim was to evaluate the relationship between higher serum cathelicidin levels with the occurrence of chronic microangiopathic complications in patients with diabetes mellitus type 1 (DM1). METHODS: The study group consisted of 62 patients with DM1 (35 men), aged 30 (24-38) years and with duration of DM1 12 (9-17) years. Patients were divided into two groups depending on the level of cathelicidin, with cut-off point 24.5ng/ml (median value for the whole group) and according to the presence or absence of any microangiopathy. RESULTS: The group with higher serum level of cathelicidin (n=31) in comparison with patients with lower levels (n=31) had higher serum level of total cholesterol [5.0(4.5-5.6) vs 4.5(3.9-5.0) mmol/l; p=0.04], HDL cholesterol [1.9(1.5-2.1) vs 1.4(1.3-1.8) mmol/l; p=0.009], LDL cholesterol [2.6(2.2-3.1) vs 2.3(1.9-2.8) mmol/l; p=0.03] and higher TSH value [1.8(1.5-2.6) vs 1.4(0.9-2.1) mIU/L; p=0.01]. Moreover, higher serum levels of cathelicidin were in women than men (58% vs 29%, p=0.02) and in patients with vs without microangiopathy (45% vs 19%, p=0.03). In the multiple regression model higher serum level of cathelicidin was related to the presence of microangiopathy, independently from sex, waist to hip ratio, serum total cholesterol level and TSH. CONCLUSIONS: Patients with type 1 diabetes and presence of microangiopathy characterize higher level of serum cathelicidin. This observation may have important clinical implication and needs further investigations.

Colchicine against ischemia-reperfusion injury in experimental lung transplantation.

BACKGROUND: To asses the influence of colchicine, a potent antinflammatory agent and neutrophile migration inhibitor, on Ischemia-Reperfusion Injury (IRI) in rat lung isogeneic transplantation. MATERIAL/METHODS: Isogeneic, orthotropic single left lung transplantations were performed among male Wistar rats after total ischemic graft storage time of 12 or 18 hours in temperature of 4 degrees C. Recipients received either no specific treatment (control) or Colchicine 1.2 mg/kg/d ip. Twenty-four hours after transplantation, the native contralateral lung was occluded to assess graft gas exchange function (PaO(2)). The lung graft was excised and assessed for Wet/Dry ratio (W/D) as a measure of edema, Myeloperoxidase activity (MPO) as a measure of neutrophile migration and histology. RESULTS: PaO(2) differences were not significant among all groups. Comparing colchicine to control group, the W/D ratio 3.93+/-0.66 vs. 1.86+/-0.32, p=0.002 and MPO 8.1+/-3.34 vs. 5.87+/-1.76, p=0.046 were significantly higher for 18 hours colchicine group. Comparing 18 to 12 hours time groups, the W/D ratio 5.70+/-1.53 vs. 1.86+/-0.32, p=0.007 for control groups and 5.40+/-1.49 vs. 3.93+/-0.66, p=0.049 for colchicine groups were significantly higher for both 12 h groups. Histology favored colchicine treated animals. CONCLUSIONS: Colchicine in tested dose does not decrease edema after lung transplantation and does not improve lung function. 18 vs. 12 hours total ischemic graft storage time causes less lung edema.

Protective effect of green tea on erythrocyte membrane of different age rats intoxicated with ethanol.

It is known that aging is characterized by changes in cell metabolism resulting in modification of the structure and function of cell membrane components which is mainly the consequence of reactive oxygen species action. These disturbances are also enhanced by different xenobiotics, e.g. ethanol. Therefore, the aim of this paper is to examine green tea influence on total antioxidant status (TAS) and on composition and electric charge of erythrocyte membrane phospholipids in ethanol intoxicated rats of various ages. Antioxidant abilities of erythrocytes were estimated by measuring TAS. Qualitative and quantitative composition of phospholipids in the membrane was determined by HPLC, while the extent of erythrocytes lipid peroxidation was estimated by HPLC measurement of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) levels. Electrophoresis was used to determine the surface charge density of the rat erythrocyte membrane. It was shown that the process of aging was accompanied by a decrease in TAS and in the total amount of phospholipids as well as by enhancement of lipid peroxidation and increase in surface charge density of erythrocyte membrane. Ethanol administration caused, in term, decrease in TAS and increase in the level of all phospholipids and lipid peroxidation products. Ethanol as well significantly enhanced changes in surface charge density of erythrocyte membrane. The ingestion of green tea partially prevented decrease in erythrocyte antioxidant abilities observed during aging and ethanol intoxication. Moreover, long-term drinking of green tea protects the structure of the erythrocytes membrane disturbed during aging process and/or chronic ethanol intoxication.

Protective Effects of N-Acetylcysteine and Vitamin E Derivative U83836E on Proteins Modifications Induced by Methanol Intoxication.

Methanol is oxidized into the formaldehyde and formate and these processes are accompanied by free radicals' generation. Formaldehyde and free radicals induce chemical modifications of proteins, leading to changes in their structure and function. The aim of this paper has been to evaluate the effect of N-acetylcysteine and vitamin E derivative U83836E on free radicals' generation and protein modifications induced during acute methanol intoxication. U83836E is an analog of alpha-tocopherol and similarly protects cells against oxidative damage. Moreover, this compound has hydrophilic properties and can be dissolved in an aqueous phase of blood and interstitial fluid, and next, membranes readily take it up. This compound belonging to the benzopyran family contains the reactive trolox ring and possesses antioxidant properties. The ESR determination indicates the increase in free radicals' signal 6 and 12 h after intoxication. Methanol ingestion causes a significant decrease in GSH level (by about 35%) and a significant increase in the lipid peroxidation product malondialdehyde (by about 25%). During methanol metabolism the aromatic amino acids of proteins are modified-the amount of carbonyl groups is increased (by about 42%) and fluorescence intensity of tryptophan is statistically decreased (by about 30%). The increase (by about 200%) in bityrosine fluorescence is also observed. Moreover, a significant decrease in free sulphydryl (by about 40%) and amino groups (by about 30%) in liver proteins is observed during intoxication. This is accompanied by the loss of lysosomal protease-cathepsin B activity (by about 25%). N-acetylcysteine (in dose 150 mg/kg body weight) and U83836E (in dose 10 mg/kg body weight) prevent free radicals' generation to a similar degree. U83836E protects membrane phospholipids against peroxidation a little stronger than N-acetylcysteine (concentration of MDA is decreased by 9 to 20% in the U83836 group and by 7 to 14% in the N-acetylcysteine group compared to methanol group). However after treating methanol-intoxicated rats with N-acetylcysteine, the changes in protein modification parameters are significantly smaller than in the group receiving methanol alone and they are a little smaller than after U83836E application. These findings suggest that N-acetylcysteine and to a smaller degree U83836E protect protein from modification in methanol intoxication, which can prevent liver pathologies.

Proteasome inhibitor prevents experimental arterial thrombosis in renovascular hypertensive rats.

Recent studies indicate that highly selective proteasome inhibitors can be useful in prevention of some cardiovascular events. Here we demonstrate that proteasome inhibitor, Z-Ile-Glu (Ot-Bu) Ala-Leucinal (PSI), is active in the prevention of platelet-dependent arterial thrombosis induced in renovascular hypertensive rats (two-kidney, one clip Goldblatt model, and 2K1C, n=5). The administration of PSI intravenously at a single dose of 0.3 mg/kg before induction of arterial thrombosis markedly increased carotid final flow rate, as compared to control (vehicle) group (10.36 +/- 1.8 ml/min and 1.2 +/- 1.2 ml/min, respectively), significantly decreased the wet (1.23 +/- 0.23 mg and 4.1 +/- 0.94 mg, respectively), and dry (0.46 +/- 0.145 mg and 1.46 +/- 0.39, respectively) thrombus weight, and completely prevented arterial occlusion. Moreover, platelets from PSI - treated thrombotic 2K1C rats, showed in response to collagen a significant inhibition of aggregation in the whole blood (10.26 +/- 0.6 ohms vs. 15.51 +/- 0.91 ohms in the control group). In contrast, collagen-induced platelet aggregation was not inhibited in vitro, after pre-treatment of the blood with PSI at the concentration of 10 microM that effectively inhibited the 20S proteasome activity in platelets, indicating that ex vivo anti-aggregatory effect of PSI proceeds through an indirect mechanism not associated with suppression of 20S proteasome activity in platelets. In conclusion, our in vivo findings demonstrate that proteasome inhibitor, Z-Ile-Glu(Ot-Bu)Ala-Leucinal, prevents the development of arterial thrombosis in renovascular hypertensive rats and effectively suppresses platelet aggregation by an indirect mechanism. Thus the data provide a new insight into the potential role for the proteasome-dependent pathway in cardiovascular events.

Green tea protects against ethanol-induced lipid peroxidation in rat organs.

Ethanol metabolism is accompanied by generation of free radicals, which stimulates lipid peroxidation. Natural antioxidants are particularly useful in such a situation. The current study was designed to investigate the efficacy of green tea, as a source of water-soluble antioxidants (catechins), on lipid peroxidation in liver, brain, and blood induced by chronic (4 weeks) ethanol intoxication in rats. Feeding of ethanol led to a significant increase in lipid peroxidation, as measured by increased concentrations of lipid hydroperoxides, 4-hydroxynonenal, and malondialdehyde. Feeding of ethanol also changed the glutathione-dependent lipid hydroperoxide decomposition system, resulting in a decrease in both reduced glutathione concentration and activity of glutathione peroxidase. Observed changes were statistically significant in all examined tissues. Enhancement in lipid peroxidation was associated with disruption of hepatocyte cell membranes, as observed through electron microscopic evaluation. Green tea protects phospholipids from enhanced peroxidation and prevents changes in biochemical parameters and morphologic changes observed after ethanol consumption. These results support the suggestion that green tea protects membranes from peroxidation of lipids associated with ethanol consumption.

Human platelet 20S proteasome: inhibition of its chymotrypsin-like activity and identification of the proteasome activator PA28. A preliminary report.

Earlier studies have demonstrated that human platelets contain the 20S proteasome, and its protein activator. However, understanding the potential role of the proteasome in human platelets requires a detailed knowledge about its chymotryptic-like activity, a crucial one for protein degradation in all eukaryotic cells. In this communication we have shown that human platelet 20S proteasome exhibited chymotryptic-like activity towards succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin as substrate at a broad pH range, with optimum between pH 7.5-8.0 and 5.0-5.5. These two activities were markedly inhibited by a 10 micromol/l concentration of two structurally unrelated proteasome inhibitors: lactacystin/beta-lactone or benzyloxycarbonyl-Ile-Glu(O-tert.-butyl)-Ala-leucinal, but not by ebelactone B, an inhibitor of lysosomal cathepsin A/deamidase. The chymotryptic-like activity of the 20S proteasome against succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin was also significantly inhibited in platelets, after exposure of platelet-rich plasma to 10 micromol/l lactacystin and benzyloxycarbonyl-Ile-Glu(O-tert.-butyl)-Ala-leucinal for up to 60 min. This indicates that these inhibitors can enter platelets and selectively inhibit 20S proteasome activity. We also demonstrated for the first time by Western blot analysis that human platelets contain a proteasome activator, PA28, which is known to play a key role in antigen processing by significant stimulation of the proteasomal chymotryptic-like activity. Since the platelet 20S proteasome was also present in a latent form, this suggests that its activity may be regulated in vivo in human platelets. All these results can therefore be beneficial in future studies on the role of the 20S proteasome in platelet biology.

SeqA-mediated stimulation of a promoter activity by facilitating functions of a transcription activator.

It was demonstrated recently that the SeqA protein, a main negative regulator of Escherichia coli chromosome replication initiation, is also a specific transcription factor. SeqA specifically activates the bacteriophage lambda pR promoter while revealing no significant effect on the activity of another lambda promoter, pL. Here, we demonstrate that lysogenization by bacteriophage lambda is impaired in E. coli seqA mutants. Genetic analysis demonstrated that CII-mediated activation of the phage pI and paQ promoters, which are required for efficient lysogenization, is less efficient in the absence of seqA function. This was confirmed in in vitro transcription assays. Interestingly, SeqA stimulated CII-dependent transcription from pI and paQ when it was added to the reaction mixture before CII, although having little effect if added after a preincubation of CII with the DNA template. This SeqA-mediated stimulation was absolutely dependent on DNA methylation, as no effects of this protein were observed when using unmethylated DNA templates. Also, no effects of SeqA on transcription from pI and paQ were observed in the absence of CII. Binding of SeqA to templates containing the tested promoters occurs at GATC sequences located downstream of promoters, as revealed by electron microscopic studies. In contrast to pI and paQ, the activity of the third CII-dependent promoter, pE, devoid of neighbouring downstream GATC sequences, was not affected by SeqA both in vivo and in vitro. We conclude that SeqA stimulates transcription from pI and paQ promoters in co-operation with CII by facilitating functions of this transcription activator, most probably by allowing more efficient binding of CII to the promoter region.