Microsporidia cause opportunistic infections in AIDS patients and commonly infect laboratory animals, as well. Euthymie C57B1/6 mice experimentally infected with intraperitoneal injections of lxlO6 Encephalitozoon cuniculi Levaditi, Nicolau et Schoen, 1923, Encephalitozoon hellem Didier et al., 1991, or Nosema comeum Shadduck et al., 1990 displayed no clinical signs of disease. Athymic mice, however, developed ascites and died 8-16 days after inoculation with N. comeum, 21-25 days after inoculation with E. cuniculi, and 34-37 days after inoculation with E. hellem. All athymic mice displayed hepatomegaly, dilated intestine and accumulation of ascites fluid. Granulomatous lesions were primarily located in the liver, lung, pancreas, spleen, and on serosal surfaces of abdominal organs.
Acute lung injury in the preterm newborns can originate from prematurity of the lung and insufficient synthesis of pulmonary surfactant. This situation is known as respiratory distress syndrome (RDS). In the term neonates, the respiratory insufficiency is related to a secondary inactivation of the pulmonary surfactant, for instance, by action of endotoxins in bacterial pneumonia or by effects of aspirated meconium. The use of experimental models of the mentioned situations provides new information on the pathophy siology of these disorders and offers unique possibility to test novel therapeutic approaches in the conditions which are very similar to the clinical syndromes. Herewith we review the advantages and limitations of the use of experimental models of RDS and meconium aspiration syndrome (MAS) and their value for clinics., D. Mokra, A. Calkovska., and Obsahuje bibliografii
The first experimental model of atherosclerosis (in rabbits) is more than hundred years old. Several animal species have bee n used to produce hyperlipoproteine mia and possible atherosclerosis. The gene manipulation produced the most used models recently. This review acknowledges the extensive study of atherosclerotic changes in experimental models of hyperlipoprotein emia and at herosclerosis to come to light thus far and the purpose here is not only to summariz e the published data but also to try to add some details of our experience in using these models. In addition to rabbit (the old but also improved model by reno-vascular hy pertension) dog, birds, pig, hamster, mice, rat and non-human primate’s animal models are described. The gene manipulation produced the most used models two decades ago. Germline genetically engineered (without apoE or LDL receptor genes) animals have beco me the most used models producing atherosclerotic changes in the aorta. Recent new models also producing atherosclerotic changes but without germline genetic manipulation are also described., R. Poledne, L. Jurčíková-Novotná., and Obsahuje bibliografii
Sudden cardiac death defined as natural death from cardiac causes occurring within one hour of the onset of acute symptoms is one of the most significant non-injury causes of death in the adult population of industrialised countries. The understanding of the mechanisms leading to sudden cardiac death is so far limited. Recently, a number of experimental animal models with high incidence of sudden cardiac death were developed and are intensively studied to get new insights into the sudden cardiac death mechanisms. In this review the animal models of sudden cardiac death are summarized and their principal properties shortly described., M. Štengl., and Obsahuje bibliografii a bibliografické odkazy
The development of the swimbladder nematode Anguillicola crassus Kuwahara, Niimi et Itagaki, 1974 in the definitive host (eels) was studied under experimental conditions. Small eels, Anguilla anguilla (L.) with body length 8-16 cm were infected by feeding them intermediate host copepods (Cyclops strenuus Fischer) harbouring third-stage larvae of this parasite. These experiments showed that, at 20-22° C, the development from the third-to the fourth-stage larvae lasted approximately three weeks, but some retarding third-stage larvae occurred in the wall of the host’s swimbladder or hyperparasitizing in the cuticle of adult nematodes as late as three months p.i. Young adults developed in the lumen of the swimbladder within approximately one month and noneinbryonated eggs first appeared in females 6-7 weeks p.i. The prepatent period was about three months and the patent period could be estimated to last no more than a month. Females degenerated soon after oviposition. The experiments confirmed that the size of mature A. crassus depends on the body size of its definitive host (eel).
The swimbladder parasite Anguillicola crassus Kuwahara, Niimi et Itagaki, 1974 (Nematoda: Dracunculoidea) is a well-known pathogenic parasite of the Japanese and European eels. Numerous studies on the life cycle of the parasite have revealed the involvement of a copepod or an ostracod intermediate host and a fish paratenic host, in which the third-stage larvae (Lj) infective to the eel develop. The present study comprised infection experiments with the larvae of A. crassus. These experiments can be divided into three groups: (1) experimental reproduction of the parasite's life cycle via copepod intermediate hosts and fish paratenic hosts, (2) infection of another potential paratenic host with third-stage larvae of A. crassus collected from a paratenic host; (3) study of the ability of larvae damaged by paratenic hosts to infect the final host, the eel. Infection experiments have revealed that larvae which are still viable but have become encapsulated as a result of the host reaction mounted against them by cyprinid paratenic hosts (bleak, Alhumus alhumus) have lost their ability to infect the final host, the eel. At the same time, experimental infection of the eel with larvae derived from other paratenic fish hosts (river goby, Neogobius fluviati-lis: ruffe, Gymnocephalus cemua) showing no or only weak host reaction proved to be successful.
Užití mezenchymálních kmenových buněk (MSC) je jedním z experimentálních terapeutických přístupů k léčbě poranění míchy. MSC lze získat z kostní dřeně, tukové tkáně i z jiných periferních tkání dospělých jedinců. Výhodou je, v porovnání s jinými kmenovými buňkami, jejich dobrá dostupnost, snadná expanze a možnost autologního použití. MSC byly v posledních 15 letech studovány v experimentálním míšním poranění zejména u hlodavců se slibnými výsledky. Existuje několik mechanizmů, jakými působí MSC na míšní lézi. Především to je remyelinizace demyelinizovaných vláken, podpora pučení axonů (sprouting), angiogeneze, imunosupresivní efekt či sekrece neurotrofních faktorů, které mohou vést k funkčnímu zlepšení. Tyto slibné výsledky urychlily zahájení klinických studií u pacientů s poraněním míchy. Klinické studie fáze I/II ukázaly, že se jedná o bezpečnou metodu, avšak funkční průkaz vyžaduje další klinické studie. Ukazuje se, že MSC bude třeba kombinovat s jinými metodami, jako je přemostění léze, enzymatické štěpení jizvy a blokátory inhibičních faktorů. Tato práce přináší přehledný souhrn o aplikaci MSC u míšního poranění v experimentu i klinice., The use of mesenchymal stem cells (MSC) represents an experimental therapeutic modality in the treatment of spinal cord injury. MSC can be harvested from the bone marrow, fat tissue and other peripheral tissues from adult individuals. Compared to other types of stem cells, MSC are easy to access and expand and they can be used in autologous settings. Over the last 15 years, MSC have been widely studied in experimental spinal cord injury, especially in rodents, with promising results. MSC support remyelination of demyelinated axons, axonal sprouting, angiogenesis, have immunosuppressive effect and secrete neurotrophic factors that may led to functional improvement. These promising results led to launching of clinical studies in patients with spinal cord injury. Phase I/II clinical studies showed that the use of MSC represent a safe method. However, functional effect needs to be proved in further clinical studies. Data suggest that MSC will need to be combined with other methods, such as lesion bridging, scar tissue breakdown and blocking of inhibitory molecules. This paper provides an overview of the use of MSC in experimental and clinical SCI., and A. Hejčl, P. Jendelová, M. Sameš, E. Syková
Poranění míchy není v současném stavu poznání v klinické praxi stále léčitelné. Standardní péče se tak soustředí na včasnou dekompresi míchy, stabilizaci poraněné páteře a prevenci sekundárního míšního poranění. Na druhou stranu se v experimentální oblasti rozvíjí velké množství nových terapeutických postupů. Některé z nich prokázaly částečný funkční a morfologický efekt u laboratorních zvířat. V posledních 20 letech pak byly tyto experimentální postupy aplikovány i v klinických studiích, zatím však bez jednoznačných výsledků. V této práci poskytujeme souhrn současného stavu klinické a především experimentální terapie míšního poranění., Spinal cord injuries still remain incurable in current clinical practice. Standard therapy focuses on early decompression and stabilization of the injured spine together with prevention of a secondary injury. On the other hand, several experimental therapies are being developed in laboratories. Some of these showed partial functional and morphological effect in laboratory animals. Over the last 20 years, some of the experimental therapies have been applied in clinical studies but did not provide unambiguous results. In the present paper, we provide an overview of current clinical and experimental therapies of spinal cord injuries. Key words: spinal cord injury – stem cells – biomaterials – regeneration – experimental treatment The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers., and A. Hejčl, P. Jendelová, M. Sameš, E. Syková
The effect of host variables such as size and density, on the transmission of cercariae of Diplostomum spathaceum (Rudolphi, 1819) into a second intermediate fish host, rainbow trout, Oncorhynchus mykiss (Walbaum), was studied quantitatively in laboratory experiments under varying exposure conditions. Differences in the number of established metacercariae were noted in differently sized fish exposed singly to the same number of cercariae and in water volumes related to the body surface area of the host. When exposed (1) singly in an equal water volume or, (2) simultaneously in the same tank, no differences in recovery of metacercariae per fish were found between “small” and “large" hosts. The latter observation is valid for three water volumes tested using the same number of cercariae per host. No significant difference in metacercarial infection was revealed in similar sized fish exposed at different host densities. It appears that transmission is more influenced by cercarial density (number of cercariae per water volume) and fish size than by fish density. These experimental findings support the view that cercarial infection offish occurs by chance, presumably mainly in the gill region. Accordingly, in the field, individual fish size and cercarial density rather than fish population density, prevail in parasite transmission from snail to fish. This is of interest in coastal areas heated by cooling water, where fish growth and fish population density are enhanced.