Secretory function of adipose tissue.

There are two kinds of adipose tissue in mammals: white adipose tissue - WAT and brown adipose tissue - BAT. The main function of WAT is accumulation of triacylglycerols whereas the function of BAT is heat generation. At present, WAT is also considered to be an endocrine gland that produces bioactive adipokines, which take part in glucose and lipid metabolism. Considering its endocrine function, the adipose tissue is not a homogeneous gland but a group of a few glands which act differently. Studies on the secretory function of WAT began in 1994 after discovery of leptin known as the satiation hormone, which regulates body energy homeostasis and maintainence of body mass. Apart from leptin, the following belong to adipokines: adiponectin, resistin, apelin, visfatin and cytokines: TNF and IL 6. Adiponectin is a polypeptide hormone of antidiabetic, anti-inflammatory and anti-atherogenic activity. It plays a key role in carbohydrate and fat metabolism. Resistin exerts a counter effect compared to adiponectin and its physiological role is to maintain fasting glycaemia. Visfatin stimulates insulin secretion and increases insulin sensitivity and glucose uptake by muscle cells and adipocytes. Apelin probably increases the insulin sensitivity of tissues. TNF evokes insulin resistance by blocking insulin receptors and inhibits insulin secretion. Approximately 30% of circulating IL 6 comes from adipose tissue. It causes insulin resistance by decreasing the expression of insulin receptors, decreases adipogenesis and adiponectin and visfatin secretion, and stimulates hepatic gluconeogenesis. In 2004, Bays introduced the notion of adiposopathy, defined as dysfunction of the adipose tissue, whose main feature is insulin and leptin resistance as well as the production of inflammatory cytokines: TNF and IL 6 and monocyte chemoattractant protein. This means that excess of adipose tissue, especially visceral adipose tissue, leads to the development of a chronic subclinical inflammatory condition, which favours the development of insulin resistance and Type 2 diabetes. Obesity is a systemic illness caused by energy transformation homeostasis disorder which results in an increase in the amount of body fat mass. It effects approximately 40% of dogs and 20% of cats. Illnesses which accompany obesity result, to a great extent, from the secretive role of adipose tissue, which is still little known, which should be included when planning treatment of an obese animal.

Side to side coaptation--new technic in peripherial nerve surgery--preliminary report.

This study presents and evaluates side-to-side nerve repair techniques for their ability to induce collateral nerve sprouting. The coaptation of the ventral branches of spinal nerves C5 and C6 to C7 through an incision epineurium was used to repair the nerve. The number of myelinated fiber axons and G-ratio was evaluated. Preliminary results indicate the possibility of using side to side coaptation in brachial plexus nerve surgery.

Experimental osteoporosis in sheep--mechanical and histological approach.

The implementation of new methods of osteoporotic therapy requires tests on animal model. The use of sheep as model has numerous advantages over other animals. The aim of this study was to describe the change in parameters in sheep with osteoporosis induced using steroids and ovariorectomy methods as opposed to the parameters in healthy sheep. The study was performed on female "merinos" breed sheep divided into the three groups: negative control (NC)--healthy animals, positive control (PC)--ovariorectomized animals and steroid control group (SC)--in which methylprednisolone was administered. This paper presents histological and ultrastructural examination with mechanical comparative tests for force/strength values as well as indentation tests of joint cartilage. The obtained results confirm the loss of bone mass associated with mineral composition content in bones, which has an influence on bone strength.

Gait analysis after neurorrhaphy in the brachial plexus.

The gait is a form of human and animal locomotion on land by using limbs. The study assessed functional recovery after end to side and side to side neurorrhaphy the ventral branches of the C5 and C6 spinal nerves to the C7 spinal nerve on the rabbit brachial plexus. Gait statistical analysis showed significant differences between the control group versus the end-to-side and side to side neurorrhaphy groups, in opposite to the comparison between the two experimentals groups. Gait analysis results corresponded with the histomorphometric results. The results indicate the potential use of gait analysis for the assessment of the recovery of nerve function.

The experimental osteoporosis in sheep--clinical approach.

The implementation of new methods of oseoporotic therapy requires tests on an animal model. One of the best is the sheep, whose numerous advantages over other models are described in the literature. The aim of this study was induction of osteoporosis using steroids and ovariorectomy methods in sheep and description of the change in parameters with regard to healthy sheep. The study was performed on female "merino" breed sheep divided into three groups: Negative control (NC) healthy animals, positive control (PC) ovariorectomised animals and steroid group (SC) where methylprednisolone was implemented. Blood tests, diagnostic arthroscopy, quantitative computed tomography and X-Ray micro-tomography of bone were carried out. Blood tests revealed a decreased level of estrogens, progesterone and increased parathormone and cortisol levels in the SC group. A decrease in bone turnover markers and an increase in bone resorption markers in all groups were also noted. Diagnostic arthroscopy revealed osteoarthrosis in PC and SC groups. Radiological density tests showed a slight decrease in PC and NC groups whereas there was more than a triple decrease in SC. Results obtained from microCT showed quickly developing osteoporosis in the SC group, which is reflected in numerous parameters analysed in this study. The best effects for osteoporosis induction were obtained using ovariorectomised sheep with methylprednisolone injections.

The rabbit brachial plexus as an experimental model--anatomy and surgical approach.

The aim of our study was to analyze the anatomy and surgical approach of the rabbit brachial plexus. The research included 18 rabbits. The rabbit seems to be a good experimental model for spinal nerves injury, especially for the C5 and C6 segments. The anatomical structure of the rabbit's brachial plexus is similar to the human brachial plexus. The structure of the rabbit C5 and C6 segments is analogous to the human structure. The spinal nerves of the C5 and C6 segments in the rabbit are wide and long enough for microsurgical procedures.

General intravenous anesthesia for brachial plexus surgery in the rabbit.

The rabbit is a good experimental model for brachial plexus surgery. The risks of death during anesthesia were significantly greater in rabbits than cats or dogs. This article presents the protocol of injectable anesthesia for a short surgical procedure, safe for the rabbit patient and convenient for the surgeon.

Use of spray-dried porcine blood by-products in diets for young chickens.

Spray-dried porcine blood plasma (SDBP) or blood cells (SDBC) at amounts of 20 or 40 g/kg were included to the feed mixtures that were given to young chickens within 1-28 (Exp. 1) or 1-30 (Exp. 2) days post-hatch. In comparison with the group fed mixtures containing plant components, chickens fed mixtures supplemented with 40 g/kg of SDBP significantly (p < 0.01) increased the body weight estimated on 14 day of life (Exp. 1). At the age of 28 or 30 days post-hatch, the body weight was improved significantly (p < 0.01 or 0.05) in both experiments. Significant differences (one-factorial anova) in feed conversion among particular feeding groups were stated in Exp. 1 only; however, calculations using two-factorial anova show insignificant differences depending on the used animal meal. In selected blood parameters (IgG, Ht, Hb), insignificant differences between feeding groups were stated. The use of SDBP in feed mixture significantly increased the Na retention in both experiments, and K accretion in Exp. 1 only. Application of SDBC and 40 g/kg of SDBP significantly or insignificantly improved Fe retention. Insignificant diversification of apparent ileal digestibility of nutrients was stated; the crude fat was significantly better digested in treatments fed mixtures with animal meals but kind of animal meal was without any significant effect. Significant differences in digestibility of amino acids were recorded for Pro, Cys, Val, His, Lys and Arg. In chickens fed mixture with SDBC, higher coefficients of apparent digestibility of Cys, Val and His (Exp. 1) and Cys and His (Exp. 2) than in other feeding groups were obtained. The kind of used blood by-products has not affected the histological structure of intestine wall.

Chemical composition and biological value of spray dried porcine blood by-products and bone protein hydrolysate for young chickens.

The chemical composition of spray dried porcine blood by-products is characterised by wide variation in crude protein contents. In spray dried porcine blood plasma (SDBP) it varied between 670-780 g/kg, in spray dried blood cells (SDBC) between 830-930 g/kg, and in bone protein hydrolysate (BPH) in a range of 740-780 g/kg. Compared with fish meal, these feeds are poor in Met and Lys. Moreover, in BPH deep deficits of Met, Cys, Thr and other amino acids were found. The experiment comprised 7 dietary treatments: SDBP, SDBC, and BPH, each at an inclusion rate of 20 or 40 g/kg diet, plus a control. The addition of 20 or 40 g/kg of the analysed meals into feeds for very young chickens (1-28 d post hatch) significantly decreased the body weight (BW) of birds. Only the treatments with 40 g/kg of SDBP and SDBC showed no significant difference in BW as compared with the control. There were no significant differences between treatments and type of meal for feed intake, haematocrit and haemoglobin concentrations in blood. Addition of bone protein and blood cell meals to feed decreased the IgG concentration in blood and caused shortening of the femur and tibia bones. However, changes in the mineral composition of bones were not significantly affected by the type of meal used. The blood by-products, which are rich in microelements, improved retention of Ca and Cu only. In comparison to control chickens, significantly better accretion of these minerals was found in treatments containing 20 g/kg of SDBP or 40 g/kg of SDBC. Great variability in apparent ileal amino acid digestibility in chickens was determined. In this respect, some significant differences related to the type of meal fed were confirmed for Asp, Pro, Val, Tyr and His. In general, the apparent ileal digestibility of amino acids was about 2-3 percentage units better in chickens fed on diets containing the animal by products than in control birds.

Experimental allogenic transplantation of cornea endothelial cells in cats.

BACKGROUND: The aim of the present study was assessing the possibility of experimental allogenic transplantation of cat cornea endothelial cells, multiplied in vitro, into the anterior chamber of the eyeball in recipient cats. The reason for undertaking the research is the need to develop a method that would help in the cornea treatment in animals with corneal opacification following cataract surgery, as well as lens dislocation, injuries and endothelium degeneration. METHODS: Cats aged 10-12 months were used in the experiment. Cornea fragments consisting of the posterior limiting membrane and posterior epithelium were placed in Iscove's medium with addition of 10% foetal calf serum. Multiplied in vitro cells were injected into the anterior chamber of recipient cats. The cornea was subject to histological, histometric and SEM examination on the 3rd, 7th, 20th and 30th day after the surgery. RESULTS: Micromorphological examination of the cornea showed full restitution of its endothelium 30 days after transplantation. Complete regeneration of structures indispensable for normal functioning of the posterior epithelium occurred as a result of implantation. CONCLUSIONS: In this study the results show that implantation of the cells of posterior corneal epithelium of donor cats, multiplied into vitro and injected into the anterior chamber of recipient cats. The cornea regained its full function, the layer of the posterior epithelium was regenerated and the stroma stabilized, presenting the image of full and proper corneal translucency.

Effect of sweet chestnut tannin (SCT) on the performance, microbial status of intestine and histological characteristics of intestine wall in chickens.

1. In experiments carried out with 950 one-day-old male chickens, the effect of tannin supplementation (0, 250, 500 and 1000 mg/kg) on performance, microbial status of chickens small intestine and colon of 28- and 41-d-old chickens, as well as histological changes of jejunum walls at 41 d and carcase quality were determined. 2. Application of 250 or 500 mg of sweet chestnut tannin per kg of feed had an insignificant effect on body weight and feed conversion of 41-d-old chickens (30 and 26%) in comparison to control birds. The highest tannin supplement (1000 mg/kg) reduced final body weight. 3. No effects of tannin supplementation on feed conversion and carcase quality were found. 4. Addition of tannin increased dry matter content of the litter by 88 (Group II) and 77% (Group III) when compared to control. 5. Higher doses of tannins significantly reduced the number of E. coli and coliform bacteria in small intestine of 28-d-old chickens; in other microorganisms great variability of microbial populations in small intestine and colon were observed. 6. The histologies of jejunal walls in chickens of control, II (250 mg/kg) and III (500 mg/kg) groups were similar. The structure was characteristic of correctly developed and functioning tissues and the villi were formed correctly. Tannin applied at the highest dose (1000 mg) slowed down the proliferation rate in the mother-cell zone. Single cells and enterocyte complexes showed the features characteristic of degradation processes. These unfavourable symptoms indicated some disturbances in intestinal wall morphology and function.

Lactoferrin accelerates reconstitution of the humoral and cellular immune response during chemotherapy-induced immunosuppression and bone marrow transplant in mice.

Experimental evidence from previous studies supports the conclusion that orally administered lactoferrin (LF) restores the immune response in mice treated with a sublethal dose of cyclophosphamide (CP). The aim of this study was to elucidate potential benefit of LF in mice undergoing chemotherapy with busulfan (BU) and CP, followed by intravenous (i.v.) injection of bone marrow cells. CBA mice were treated orally with busulfan (4 mg/kg) for 4 consecutive days, followed by two daily doses of CP delivered intraperitoneally (i.p.) at a dose of 100 mg/kg and reconstituted next day with i.v. injection of 10(7) syngeneic bone marrow cells. One group of these mice was given LF in drinking water (0.5% solution). After treatment, mice were immunized with ovalbumin (OVA) to subsequently measure delayed type hypersensitivity responsiveness and with sheep red blood cells to determine humoral immunity by evaluation of splenic antibody-forming cells. As expected, both humoral and cellular immune responses of mice that were treated with these chemotherapeutic agents was markedly impaired. Here we report that this impairment was remarkably attenuated by oral administration of LF. Humoral immunity fell to levels that were 66-88% lower than that of untreated animals. Humoral immunity of LF-treated animals was equivalent to that of untreated mice within 1 month. Cellular immune responses were inhibited by chemotherapy treatment to a lesser degree, reaching levels that were approximately 50% lower than those of untreated animals. Again, LF mitigated this decrease, resulting in responses that were only slightly lower than those observed in untreated animals. Furthermore, when mice were given a lethal dose of BU (4 x 25 mg daily doses, i.p.) followed by a bone marrow transplant, LF caused enhanced lympho-, erythro-, and myelopoiesis in the bone marrow and appearance of transforming splenic lymphoblasts, similar to effects caused by administration of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). In summary, our study suggests that LF may be a useful agent to accelerate restoration of immune responsiveness induced by chemotherapy in bone marrow transplant recipients.

Specific pollen allergen activates eosinophils of the patient with chronic allergic contact urticaria.

The aim of the study was to evaluate the activation of eosinophils in an unique case of a young man with atopy manifested as chronic pollen contact urticaria. In order to reveal the role of eosinophils in that case, the study was performed by means of monoclonal antibodies EG2 and chemiluminescence. In addition, comparative electron microscopic study of peripheral blood and skin infiltrating eosinophils were performed for which the name ultrastructural morphometric analysis of intracytoplasmic eosinophil granules has been proposed. The results indicated, that 40% of peripheral blood eosinophils were activated spontaneously and they were more active than those in skin infiltrates. Specific pollen allergen caused activation of 100% of peripheral blood eosinophils. The study suggests presence of a systemic pattern of eosinophil activation in atopy.

Effect of heparin on the course of sulphur dioxide induced bronchitis in rats.

The aim of this study was to investigate the effect of heparin on the rat bronchial mucosa changes induced by sulphur dioxide (SO2) inhalation. Sixty five rats were used in this experiment. Five of them constituted a control group, while 60 were exposed to SO2. Forty of the latter subgroup were additionally treated with low molecular weight heparin (LMWH), either during or after terminating exposure to SO2. In all animals exposed to SO2 inflammatory cells were found in broncho-alveolar lavage fluid (BALf) in numbers significantly higher from those observed in healthy controls. The rats exposed to SO2 and treated with LMWH showed intermediate cell pattern in the bronchi between healthy and SO2- exposed animals. When comparing histological picture of the bronchi, we noted extensive changes in irritated rats. These changes were either less expressed or totally absent in animals treated with heparin. The activity of enzymes: acid phosphatase (ACP), alkaline phosphatase (AP) and lactate dehydrogenase (LDH) rose in BALf, although the rise was not parallel and did not correlate with the magnitude of cellular influx or histological changes. Heparin did not influence this changes.

Natural history of experimental intestinal atresia: morphologic and ultrastructural study.

PURPOSE: The aim of this study was to evaluate a natural history of congenital intestinal atresia (IA) in the chick embryo and to assess the type and nature of changes in the intestine at various developmental stages. METHODS: Chick embryos underwent operative induction of IA on the 12th day of incubation. The procedure consisted of electrocoagulation of the mesenteric vessels supplying a 7- to 8-mm intestinal segment. The embryos were subjected to macroscopic examination, histologic and ultrastructural studies of the preatretic and postatretic bowel using the light microscope, scanning, and transmission electron microscopes. All investigations were performed in an experimental group (operated embryos), in a control group, and in a sham-operated group on the 15th, 17th, 19th, and 21st day of incubation. RESULTS: The original technique of an iatrogenic "vascular event" proved to be effective because IA developed in 96% of embryos surviving the procedure. The affected portion of the bowel underwent progressive necrosis, and signs of bowel obstruction could be observed 48 hours after operation. Cord atresia (type II) developed in 81% of embryos. Histologic investigations showed progressive thinning of mucosa, flattening of mucosal folds, and epithelial detachment within the intestine proximal to atresia. There was only mild hypertrophy of the muscular layers. All these pathomorphologic changes were of rapidly progressive nature until the 17th day of incubation. Later, the rate of distension of preatretic bowel and histologic changes were less. Ultrastructural investigation of the proximal bowel showed progressive flattening of the enterocytes associated with their apical bulging, widening of the intercellular spaces, and microvilli atrophy. Surprisingly, at days 19 and 21 of incubation, signs of induction of adaptive mechanisms with partial restoration of near-normal microvilli pattern were observed. CONCLUSIONS: Study of natural history of experimental IA indicates that histologic and ultrastructural lesions of the bowel are of dynamic nature and are not only the effect of pathologic intraluminal pressure.

Early morphological and immunological alterations in the spleen during magnesium deficiency in the rat.

Dietary magnesium deficiency in rodents, and especially in rats, causes inflammation and leads to alterations in the immune response. One of the characteristics of magnesium deficiency in the rat is a marked enlargement of the spleen. Considering the importance of the spleen for the immune response, in this study we have evaluated histological, cytological and immunological changes in this organ of rats in early stages of this deficiency. For this purpose, male weaning Wistar rats were pair-fed with either control or magnesium-deficient diet, for 2, 4 or 8 days. Results indicate that after 8 days on the deficient diet rats presented clinical signs of inflammation, splenomegalia and leukocytosis. As shown by histometrical analysis, both the red and white spleen pulps of deficient rats displayed an increased incidence of polymorphonuclear leukocytes and macrophages in all studied stages of deficiency. Concomitantly, the relative number of lymphocytes decreased. This observation was confirmed by the analysis of the cell suspension obtained from the spleen. The greater number of adherent cells in the cell suspension from deficient rats provides an additional confirmation of the increased number of macrophages in the spleen of these rats. Analysis of lymphocyte populations demonstrated a reduced proportion of CD5+ and CD8+ cells after 8 days of deficiency. The reduction in the number of CD8+ cells in deficient rats could be related to the observed decrease in IFN-gamma concentration in the spleen homogenate. In short, this study shows that magnesium deficiency causes early cytological and immunological modifications in the spleen which appeared before macroscopical changes in this organ and before clinical symptoms of inflammation. These changes could be related to the altered immune response of deficient animals.

The influence of long-term administration of Tolpa Peat Preparation on immune reactivity in mice. I. Morphological changes in the thymus.

In experiment I BALB/c 200 mice were given in drinking water the TPP (Tolpa Peat Preparation) in daily doses of 1, 10 and 50 mg/kg over the period of 3, 5, 7, 9 and 12 weeks. In experiment II before the administration of TPP (as in experiment I) mice were immunized with a single dose i.p. administration of 0.2 cm3 of a 10% suspension of sheep erythrocytes (SRBC), i.e. 4 x 10(8) cells. Histopathological and ultrastructural studies have shown that TPP in all three doses causes morphological changes characteristic of thymus activity stimulation. However, the doses of 10 and 50 mg/kg administered longer than 7 weeks caused retrograde changes that did not occur after administration of 1 mg/kg of TPP. Morphological changes in the thymus of immunized and non-immunized mice simultaneously receiving TPP were similar.

[Experimental model of chronic bronchitis]. / Doswiadczalny model przewleklego zapalenia oskrzeli.

In 20 rats bronchitis was evoked by permanent 12-week long inhalation of SO2. For this purpose a special chamber with gas supply was prepared. In all rats exposed to SO2 changes in cellularity of BALF were found (a statistically significant increase of the percent of macrophages and neutrophils). Histologic examination revealed bronchial changes especially in epithelium. The method applied, based on an original technology is cheap and effective and can be recommended in developing experimental bronchitis.

[The influence of heparin on the course of bronchitis experimentally provoked by sulfur dioxide in rats in evaluation of lung histology and cytology of bronchial alveolar lavage fluid]. / Wplyw heparyny na przebieg zapalenia oskrzeli wywolanego dwutlenkiem siarki u szczurów w ocenie histologicznej pluc i cytologicznej plynu z plukania oskrzeli.

UNLABELLED: The aim of our study was to evaluate the influence of heparin on inflammed bronchial mucosa in rats. Sixty five animals were used in the study; 5 of them constituted the control group, whereas 60 were submitted to long term SO2 irritation in specially constructed chamber, what resulted in chronic bronchitis. Low molecular weight heparin preparation--Frexiparine has been administered in inhalation or parenterally to 40 rats, simultaneously or immediately after SO2 exposition. In all animals exposed to SO2 the BALF evaluation revealed predomination of inflammatory cells. The results obtained in healthy rats were different and BALF cellular sediment contained 92% of epithelial cells. However in animals submitted to SO2 irritation and simultaneous heparin treatment we observed significant increase of the number of inflammatory cells in BALF in comparison to healthy rats but it was not as high when compared to animals irritated only with SO2. In all animals exposed only to SO2 we were able to find disseminate inflammatory changes and/or planoepithelial metaplasia in bronchial specimens. However we did not observe any sings of inflammation in specimens obtained from 50% of heparin treated rats, whereas in the other 50% they were described as mild or moderate. CONCLUSIONS: 1. Low molecular weight heparin decreased signs of experimentally provoked bronchial inflammation in rats. 2. Simultaneous heparin and SO2 administration was extremely efficient. This finding suggests prophylactic properties of heparin. 3. The heparin activity does not depend on inhalatory or parenteral way of administration.

Ultrastructural studies on the morula in cattle.

Embryos at morula stage were ultrastructurally examined. Blastomeres of normal embryos are characterized by the presence of ribosomes, short single and branched cisterns of endoplasmic reticulum, small spherical mitochondria and vacuolar-granular structures. An enhanced autophagy and the presence of numerous and large lipid droplets are signs of the beginning degeneration.