Úvod: Kardiovaskulární choroby jsou zodpovědné za významnou morbiditu i mortalitu ve společnosti. Užití umělých cévních materiálů je často nezbytnou součástí v rámci chirurgické léčby, ať již je tato radikální nebo paliativní. V současné době dochází k vývoji řady nových biodegradabilních materiálů určených pro tyto účely. Preklinické testování každého nového materiálu je naprosto nezbytné, je prováděno jak in vitro, tak in vivo. Z tohoto důvodu jsou zvířecí experimentální modely nadále nutnou součástí testování před klinickým užitím. Cílem této práce je prezentovat možnosti užití různých zvířecích modelů na poli kardiovaskulární chirurgie a jejich extrapolace do klinické medicíny. Metody: Autoři prezentují jejich obecné zkušenosti s experimentální chirurgií, na jejich podkladě diskutují optimální výběr zvířecího modelu pro testování nových materiálů pro kardiovaskulární chirurgii a stejně tak optimální lokalitu implantace. Výsledky: Jako optimální experimentální zvířecí modely pro testování hemokompatibility a degradability nových materiálů uvádějí autoři modely potkana, králíka a prasete. Intraperitoneální implantace u potkana je snadná a lehce proveditelná procedura, stejně tak jako arteriální bandáž na aortě králíka či prasete. Rovněž karotické tepny jsou dobře využitelné. Bandáž na prasečí pulmonální tepně je již složitější zákrok s četnějšími komplikacemi. Explantované bandážované cévy po předem definované době jsou vhodné pro další mechanické testování ve smyslu biomechanických analýz, např. inflačně-extenzního testu. Závěr: V posledních fázích preklinického testování nových materiálů se nelze nadále obejít bez in-vivo experimentů. Naší snahou je však striktně dodržovat koncept 3R – Replacement, Reduction a Refinement. V tomto smyslu je třeba využít co nejvíce potenciál každého zvířete tak, abychom mohli redukovat počty zvířat.
Introduction: Cardiovascular diseases are responsible for significant morbidity and mortality in the population. Artificial vascular grafts are often essential for surgical procedures in radical or palliative treatment. Many new biodegradable materials are currently under development. Preclinical testing of each new material is imperative, both in vitro and in vivo, and therefore animal experiments are still a necessary part of the testing process before any clinical use. The aim of this paper is to present the options of using various experimental animal models in the field of cardiovascular surgery including their extrapolation to clinical medicine. Methods: The authors present their general experience in the field of experimental surgery. They discuss the selection process of an optimal experimental animal model to test foreign materials for cardiovascular surgery and of an optimal region for implantation. Results: The authors present rat, rabbit and porcine models as optimal experimental animals for material hemocompatibility and degradability testing. Intraperitoneal implantation in the rat is a simple and feasible procedure, as well as aortic banding in the rabbit or pig. The carotid arteries can also be used, as well. Porcine pulmonary artery banding is slightly more difficult with potential complications. The banded vessels, explanted after a defined time period, are suitable for further mechanical testing using biomechanical analyses, for example, the inflation-extension test. Conclusion: An in vivo experiment cannot be avoided in the last phases of preclinical research of new materials. However, we try to strictly observe the 3R concept – Replacement, Reduction and Refinement; in line with this concept, the potential of each animal should be used as much as possible to reduce the number of animals.
- MeSH
- Acrylates pharmacology adverse effects MeSH
- Gels adverse effects MeSH
- Glycols adverse effects MeSH
- Calcinosis pathology MeSH
- Surgery, Plastic MeSH
- Connective Tissue metabolism MeSH
- Polymers adverse effects MeSH
- Swine MeSH
- Prostheses and Implants MeSH
- Foreign-Body Reaction MeSH
- Muscles pathology MeSH
- Animals MeSH
- Check Tag
- Female MeSH
- Animals MeSH
Cíl: U pacientů se strikturami přední uretry se používají při rekonstrukčních výkonech kožní nebo slizniční štěpy či kožní laloky. Jejich použití je spojeno s přídavným výkonem, odběrem vhodného materiálu, s následnou morbiditou odběrového místa. SIS je acelulární heterologní matrix sloužící jako potenciální tkáňová náhrada pro uretrální rekonstrukce. Naše studie se zabývá úlohou SIS v této indikaci. Materiál a metody: Operovali jsme 7 pacientů s bulbární, 2 s bulbopenilní a 2 se strikturou distální penilní uretry včetně meatu a fossa navicularis. U všech nemocných byla SIS použita formou onlay záplaty. Výsledky: Při průměrné době sledování 17,2 měsíce byly klinické, kosmetické a radiologické výsledky excelentní u 10 nemocných. Pouze u 1 nemocného se objevila krátká recidiva striktury. Nebyly pozorovány žádné komplikace jako píštěle, rané infekce, močové infekce či rejekce. Závěr: Použití SIS se jeví jako slibná metoda u primárních rekonstrukcí uretry u pacientů se strikturami přední uretry.
Aim: Skin and mucosal grafts or skin flaps are used for surgical reconstructions in patients with anterior urethral strictures. Their use is accompanied with increased morbidity from donor site or from flap development. SIS is acellular heterologous matrix available as a potential tissue substitution for urethral reconstructions. Our study addresses the role of SIS in this indication. Materials and methods: We have performed the operation in 7 patients with bulbar, 2 with bulbopenile and 2 with distal penile urethral stricture including meatus and fossa navicularis. SIS was used as an onlay patch in all patients. Results: Clinical, cosmetic and radiologic results were excellent in 10 patients during the mean follow-up 17.2 months. A short relapse of stricture was observed only in 1 patient. No complications, such as fistulas, wound infections, urinary infections or rejection, were seen. Conclusion: The use of SIS appears to be a promising method for primary urethral reconstructions in patients with anterior urethral strictures.
V naší práci hodnotíme zkušenosti s porcinní acelulární kolagenní matrix (SIS) při operační léčbě striktur bulbární a penilní močové trubice. Od ledna do prosince roku 2003 jsme provedli rekonstrukci močové trubice pomocí SIS matrix u 50 mužů ve věku od 45 do 73 let. Medián (rozmezí) sledování byl 31,2 (24 - 36) měsíců. Z 50 případů bylo 40 (80 %) zhodnoceno jako úspěšných a 10 (20 %) jako neúspěšných. Recidiva striktury se vyvinula u 1/10 bulbárních striktur, u 5/31 bulbopenilních striktur a u 4/9 penilních během 6 měsíců po operaci, žádná recidiva nebyla zjištěna později. U všech pacientů s recidivou striktury byla nutná další léčba. Nebyly pozorovány žádné komplikace jako píštěl, infekce v ráně nebo rejekce. Použití prasečí SIS matrix se jeví jako bezpečný a efektivní rekonstrukční materiál pro pacienty s bulbárními a bulbopenilními strikturami uretry, u kterých jsou výsledky srovnatelné s kožními laloky i slizničními štepy.
In our work we evaluate our experience with porcine small intestinal submucosa (SIS) used in the treatment for strictures of the bulbar and penile urethra. From January to December 2003, 50 patients aged 45 - 73 years underwent urethroplasty using porcine SIS collagen based matrix for urethral reconstruction. A mean follow up period was 31.2 months (range 24 - 36 months). The clinical, radiological, and cosmetic findings were excellent in 40 (80 %) of the fifty patients treated. Restricture developed in 1/10 bulbar strictures, 5/31 bulbopenile strictures, and 4/9 penile strictures during 6 months postoperatively with no recurrence observed later on. All patients with recurrences required further therapy. No complications such as fistula, wound infection, UTI, or rejection were observed. Use of inert porcine SIS matrix appears to be beneficial for patients with bulbar and bulbopenile strictures, where mid-term results are comparable to skin flaps and mucosal grafts.
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
60 l. : il. ; 31 cm
The subject of the project is to create the experimental model of I/R of a muscular free flap of domestic swine by elucidating a set of changes which influence the tissue functionally and morphologically by the complex of pathophysiologic processes, which affect the vitality of the transferred tissue adversely. This model would be possible to use for further studying of I/R and examining possibilities of its influencing. The experiment will be carried out by bilateral lift of MLD flap. Thus its nutrition will be retained only on vascular pedicle of thoracodorsal bundle. The left MLD will be a check muscular tissue, the right MLD will be temporarily clipped. Blood sampling will be carried out from the artery and the vein of the vascular pedicle and their ?AV difference? will be detected (the changes ongoing during I/R only in a certain muscular flap). Furthermore, bioptic samples will be used for creating muscular homogenates, in which the enzyme activity of oxidative stress will be determined.
Vytvoření experimentálního modelu I/R svalového volného laloku prasete domácího ozřejměním souboru změn ovlivňující tkáň funkčně i morfologicky komplexem patofyziologických procesů, které nepříznivě ovlivňují vitalitu přenášené tkáně. Tento model bude tedy poté možno dále užívat k dalšímu studiu I/R a zkoumat možnosti jeho ovlivnění. Experiment bude proveden oboustranným zvednutím m. latissimus dorsi (MLD) prasete domácího, takže jeho výživa bude zachována pouze na cévní stopce thorakodorzálního svazku.Levý MLD bude kontrolní svalová tkáň, cévní stopka pravého MLD bude dočasně zasvorkována (na 60 min.) - model I/R. Odběr vzorků krve bude prováděn z artérie a žíly cévní stopky laloku a bude zjišťována jejich ?AV diference?. Tímto postupem obsáhneme změny I/R pouze daného svalového laloku. Budou též odebírány bioptické vzorky ze svalové tkáně MLD k tvorbě svalových homogenátů v nichž bude stanovována aktivita enzymů oxidativního stresu.
- MeSH
- Surgical Flaps MeSH
- Animal Experimentation MeSH
- Ischemia MeSH
- Microsurgery MeSH
- Models, Animal MeSH
- Surgery, Plastic MeSH
- Swine MeSH
- Reperfusion Injury MeSH
- Conspectus
- Ortopedie. Chirurgie. Oftalmologie
- NML Fields
- chirurgie
- NML Publication type
- závěrečné zprávy o řešení grantu IGA MZ ČR
The monophyodont molar teeth, prismatic enamel and the complexity of enamel microarchitecture are regarded as essential dental apomorphies of mammals. As prominent background factors of feeding efficiency and individual longevity these characters are crucial components of mammalian adaptive dynamics. Little is known, however, to which degree these adaptations are influenced by the crystallographic properties of elementary hydroxyapatite crystallites, the only inorganic component of enamel. In a miniature pig where individual molars differ significantly in duration of their development and in enamel resistance to attrition stress, we found highly significant differences between the molars in the size of crystallites, amount of microstrain, crystallinity and in enamel stiffness and elasticity, all clearly scaled with the duration of tooth calcification. The same pattern was found also in red deer bearing different molar type. The results suggest that the prolongation of tooth development is associated with an increase of crystallinity, i.e. the atomic order of enamel hydroxyapatite, an obvious component of micromechanical property of mature enamel. This relation could contribute to prolongation of dental development, characteristic of mammals in general. The aspects of enamel crystallinity, omitted in previous studies on mammalian and vertebrate dental evolution, are to be taken in account in these topics.
- MeSH
- Apatites chemistry MeSH
- Adaptation, Physiological * MeSH
- Crystallography MeSH
- Swine, Miniature MeSH
- Molar growth & development MeSH
- Swine MeSH
- Tooth Eruption physiology MeSH
- Dental Enamel chemistry MeSH
- Animals MeSH
- Check Tag
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
CONCLUSIONS: From the clinical point of view, the healing process following radiofrequency-induced thermotherapy (RFITT) is faster and less painful for the patient. This corresponds with the histopathological findings, as in a case of diode laser treatment, the damage to the tissue was greater, and the regenerative and reparative processes were less prominent. OBJECTIVE: Comparison of histopathologic changes and the healing process in the turbinate tissue regarding the kind of treatment and intensity of energy used for surgery. MATERIALS AND METHODS: Pigs were chosen as laboratory animals for this study. The animals were divided into two groups. Two different techniques were used: treatment with diode laser fiber applied submucosally in contact mode and RFITT. The first tissue samples were taken on the third postoperative day; further sampling was done on the eight postoperative day. RESULTS: Histological features of the specimens taken from turbinates 8 days after the surgery included necrosis and ulceration, fibrin deposition in the mucosa, necrotizing sialometaplasia, as well as proliferation of the granulation tissue. Generally, the changes found in the turbinates treated by diode laser were more severe, with more intensive tissue damage and less prominent regenerative and reparative changes.
- MeSH
- Wound Healing physiology MeSH
- Hyperthermia, Induced methods MeSH
- Laser Therapy MeSH
- Turbinates physiology surgery pathology MeSH
- Nasal Mucosa physiology surgery pathology MeSH
- Swine MeSH
- Radiofrequency Therapy MeSH
- Radio Waves MeSH
- Regeneration MeSH
- Plastic Surgery Procedures methods MeSH
- Animals MeSH
- Check Tag
- Female MeSH
- Animals MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
Bisphenol A (BPA), a chemical component of plastics, is a widely distributed environmental pollutant and contaminant of water, air, and food that negatively impacts human health. Concerns regarding BPA have led to the use of BPA-free alternatives, one of which is bisphenol S (BPS). However, the effects of BPS are not well characterized, and its specific effects on reproduction and fertility remain unknown. It is therefore necessary to evaluate any effects of BPS on mammalian oocytes. The present study is the first to demonstrate the markedly negative effects of BPS on pig oocyte maturation in vitro, even at doses lower than those humans are exposed to in the environment. Our results demonstrate (1) an effect of BPS on the course of the meiotic cell cycle; (2) the failure of tubulin fibre formation, which controls proper chromosome movement; (3) changes in the supply of maternal mRNA; (4) changes in the protein amounts and distribution of oestrogen receptors α and β and of aromatase; and (5) disrupted cumulus cell expansion. Thus, these results confirm that BPS is an example of regrettable substitution because this substance exerts similar or even worse negative effects than those of the material it replaced.
- MeSH
- Aromatase genetics MeSH
- Cell Differentiation drug effects genetics MeSH
- Phenols pharmacology MeSH
- Meiosis drug effects MeSH
- RNA, Messenger genetics MeSH
- Oocytes cytology drug effects metabolism MeSH
- Swine MeSH
- Receptors, Estrogen genetics MeSH
- Sulfones pharmacology MeSH
- Gene Expression Regulation, Developmental drug effects MeSH
- Animals MeSH
- Check Tag
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: In clinical medicine, little is known about the use of allografts for portal vein (PV) reconstruction after pancreaticoduodenectomy (PD). Portal and caval systems are physiologically different, therefore the properties of allografts from caval and portal systems were studied here in a pig model. MATERIALS AND METHODS: PD with PV reconstruction with allogeneic venous graft from PV or inferior vena cava (IVC) was performed in 26 pigs. Biochemical analysis and ultrasonography measurements were performed during a 4-week monitoring period. Computer simulations were used to evaluate haemodynamics in reconstructed PV and explanted allografts were histologically examined. RESULTS: The native PV and IVC grafts varied in histological structure but were able to adapt morphologically after transplantation. Computer simulation suggested PV grafts to be more susceptible to thrombosis development. Thrombosis of reconstructed PV occurred in four out of five cases in PV group. CONCLUSION: This study supports the use of allografts from caval system for PV reconstruction in clinical medicine when needed.
- MeSH
- Allografts MeSH
- Anastomosis, Surgical methods MeSH
- Hemodynamics MeSH
- Organ Sparing Treatments MeSH
- Cadaver MeSH
- Tissue and Organ Harvesting MeSH
- Pancreaticoduodenectomy * MeSH
- Computer Simulation * MeSH
- Postoperative Complications etiology MeSH
- Swine MeSH
- Pylorus MeSH
- Regional Blood Flow MeSH
- Ultrasonography MeSH
- Organ Size MeSH
- Vena Cava, Inferior anatomy & histology diagnostic imaging physiology transplantation MeSH
- Portal Vein anatomy & histology diagnostic imaging physiology surgery MeSH
- Plastic Surgery Procedures methods MeSH
- Venous Thrombosis etiology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
