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.

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.

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.

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.

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 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.

Morphological and immune response alterations in the intestinal mucosa of the mouse after short periods on a low-magnesium diet.

The importance of Mg for the immune function is well recognized; however, there is no information available about the effect of Mg intake on the modulation of local immune response in the intestine. Thus, in the present study the hypothesis that short periods of Mg deprivation can affect intestinal mucosa and local immune response was tested. For this purpose, OF1 female mice were fed a semipurified diet (1000 mg Mg/kg diet). For 3 d before immunization and 1 d after, half of the animals were fed a Mg-deficient diet (30 mg Mg/kg diet), three immunizations per os were performed every 3 weeks with Escherichia coli producing the CS31A capsule-like protein (1010 or bacteria per animal). Mice were killed 10 d after the last immunization. The level of specific anti CS31A immunoglobulin (Ig) G and IgA in the serum and secretory IgA in the intestinal secretions and faeces were measured by ELISA. The results indicated that administration of a high dose of immunogen with a low-Mg diet led to lower specific IgA levels in the intestinal mucus and serum. Administration of a low dose of immunogen with a low-Mg diet led to lower IgA and IgG levels in the serum and secretory IgA coproantibodies. To assess alterations of intestinal mucosa caused by a low-Mg diet for a short period, histological and scanning electron microscopy analyses were performed on samples from mice (not submitted to the vaccination protocol) after 3 d on the Mg-deficient diet. These analyses showed several alterations, suggesting perturbations in the growth of the intestinal mucosa. These changes were accompanied by modifications in the expression of several genes involved in cell growth and stress response. From this present work, it may be concluded that short periods of Mg deprivation can affect the intestinal mucosa and local immune response of the intestine.

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.

[Influence of long-term low molecular weight heparin nebulization on selected clinical parameters and course of allergic inflammation in patients with bronchial asthma]. / Wplyw heparyny niskoczasteczkowej w przewleklej nebulizacji na wybrane parametry kliniczne i przebieg zapalenia alergicznego u pacjentów z astma oskrzelowa.

Bronchial asthma is a chronic condition with an inflammatory background--allergic inflammation. In recent years several observations have been published documenting activity of low molecular weight heparin (LMWH) in chronic inflammatory diseases of respiratory tract. This study was set up to evaluate the effect of nebulized LMWH on spirometric parameters and selected markers of allergic inflammation in bronchial asthma. Twenty patients diagnosed with mild or moderate asthma entered the study. At the beginning and at the end of the experiment every patient underwent bronchoscopy with BAL and in 15 of them bronchial biopsy was performed. Blood was drawn for ECP evaluation. LMWH was administered in nebulization in a dose 5000 U Xa/day for two weeks. BALf cellularity was evaluated as well as BALf IL-5 concentration. Further ELAM-1 and VCAM-1 expression in bronchial mucosa was examined in immunohistochemistry. We demonstrated that heparin treatment significantly enhanced FEV1 from 76.02 +/- 21.7% nominate value before to 92.4 +/- 21.8% after treatment (p < 0.005). Cellular profile of BALf changed, showing significant drop in percentages of eosinophils--from 7% to 6% (p < 0.05), macrophages--38 to 32% (p < 0.05) and neutrophils--32 to 28% (p < 0.05). Surprisingly we did not notice any change in ECP concentration in blood serum or IL-5 in BALf. Also adhesion molecules expression in bronchial mucosa remained unchanged. We conclude that chronic LMWH nebulization is a valuable treatment ameliorating asthmatic condition clearly due to anti-inflammatory properties of heparin. Both dose of LMWH used and the time of therapy have to be further investigated in order to develop treatment able to influence more of the elements of allergic inflammation.

[Biological experimental models in orthopedics]. / Biologiczne modele doswiadczalne stosowane w ortopedii.

Experimental research in orthopedics is conducted on different experimental models. Animal models have to be characterized by high similarity and consistence of the animal bone tissue with human metabolism and must undergo similar biomechanical changes. This paper presents the advantages and disadvantages of the most commonly used animal models, with particular attention given to sheep.

The influence of dehydroepiandrosterone on histology of selected organs in rabbits on an atherogenic diet.

The influence of dehydroepiandrosterone (DHEA) in fodder on the histology of selected organs in rabbits with induced hypercholesterolemia and in healthy rabbits was studied. Rabbits were randomly assigned into four groups: (1) control; (2) atherogenic diet; (3) atherogenic diet with addition of DHEA; (4) normal diet with addition of DHEA. After 12 weeks, the rabbits were bled. Tissue samples were collected, fixed in a 0.4% solution of buffered formalin, dehydrated and embedded in paraffin. Fragments of 5-7 microns were stained with hematoxylin and eosin as well as according to the van Gieson method. Histological analysis showed features of steatosis and intense degenerative changes in analyzed organs of animals from group 2, i.e. liver, kidneys, adrenal glands, lungs and bone. The degenerative changes in the group which in addition to a fat-rich diet received DHEA, were similar to group 2, but much less intense. Histological pictures of organs of the rabbits which received DHEA and normal diet did not differ significantly from the control group. In animals with experimental hyperlipidemia, DHEA acts protectively, decreasing degenerative changes in internal organs caused by an atherogenic diet. DHEA does not change the histological picture of organs in healthy animals.

[Influence of heparin on macrophages activity and expression of endothelin in experimentally provoked rat bronchitis]. / Wplyw heparyny na aktywnosc makrofagów i ekspresje endoteliny w zapaleniu oskrzeli wywolanym u szczurów dwutlenkiem siarki.

The rats exposition for 15 weeks to SO2 inhalation resulted in chronic bronchitis. The BALF evaluation revealed an increase in inflammatory cells number: neutrophils, macrophages, lymphocytes. Electron microscope examination demonstrated that macrophages were activated in comparison to healthy rats. Immunoreactive endothelin was found in bronchial specimens mainly in alveolar macrophages (we used a computer-assisted system of image analysis). The expression of endothelin was significantly increased in rats irritated with SO2. Low molecular weight heparin-nadroparine has been administered parenterally in 3 doses to 3 groups of rats. In animals subjected to SO2 irritation and simultaneous heparin treatment we observed significant decrease in number and activation of macrophages and endothelin expression as well. The results of this experiment suggest antiinflammatory properties of heparin.

Accelerated thymus involution in magnesium-deficient rats is related to enhanced apoptosis and sensitivity to oxidative stress.

Experimental Mg deficiency leads to alterations in the immune response. Reduction of thymus weight and histological changes were previously observed in Mg-deficient rats after several weeks on a deficient diet, suggesting that functions of this immune organ may be affected by Mg deficiency. More recently, changes in the immune system during early Mg deficiency were shown. Thus, in the present study we examined modifications in the thymus during the early stages of Mg deficiency in weanling rats. From our results, it appears that Mg deficiency accelerates thymus involution. The assessment of apoptosis (enumeration of apoptotic cells on the basis of morphological criteria and intranucleosomal degradation of genomic DNA) showed greater values in thymuses from Mg-deficient rats as compared with controls. This was observed very early, since a significant difference was shown on the second day of deficiency, before reduced weight of thymus, which was recorded in the later period. These results indicate the relationship of accelerated thymus involution with an active process of cell death. Mg deficiency led to histological changes in the thymus. In the early stage of deficiency (second day) the presence of inflammatory cells was shown, suggesting that the inflammatory process was already occurring in the tissue studied. Later (eighth day) an increased proportion of epithelial reticular cells in the cortex was shown, indicating a remodelling process occurring in this period. Enhanced susceptibility to peroxidation also occurred very early during Mg deficiency. It may be hypothesized that disturbances in Mg status of short duration could have cellular effects with various deleterious consequences.

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.