An effective analytical method for the quantification of N-nitrosodimethylamine (NDMA) using a liquid chromatography coupled with tandem mass spectrometry was developed and applied to a process optimization study of the production of metformin film coated tablets in order to identify the key factors behind the NDMA formation in metformin products. The method uses a linear gradient elution with mobile phases 0.1 % formic acid in water for chromatography and methanol for chromatography and a column Acquity UPLC HSS T3 1.8 μm. The use of the tandem mass spectrometry in a positive ion mode with an atmospheric pressure chemical ionization allows for the use of an isotopically labelled internal standard and an external calibration standard. The method was validated according to the guidelines of International Council for Harmonization in terms of limit of detection and quantification, linearity, precision, accuracy and method selectivity. To further justify the effectiveness of the method, a comparison between two laboratories was performed using a linear regression testing. Both methods give comparable results. 469 samples of both metformin active pharmaceutical ingredient and film coated tablets were analysed and the key factors behind NDMA formation were identified. Hypotheses explaining the mechanism were formulated and confronted with measurements and scientific literature. Protective measures to prevent NDMA contamination in metformin products were drawn.
BACKGROUND: The aim of our study was to assess the impact of different thawing protocols on morphological changes arising in cryopreserved human saphenous vein grafts. METHODS: The study was performed in 12 saphenous vein grafts harvested in brain death donors. Storage in the vapor phase of liquid nitrogen for 3 or 5 years followed. Two thawing protocols were tested: slow thawing in a refrigerator at temperature +4°C for 2 hr and rapid thawing-in a water bath at +37°C. Grafts were processed for scanning electron microscopy. Comparisons of continuous parameters under study between experimental groups were performed using the t-test (age, cold ischemia time, exposure to cryoprotectant, time of storage, total thawing time, mean thawing rate, morphology scoring of thawed HSVG) and the median test (HSVG length). Categorical parameters (sex and blood group) were formally tested using the chi-square test. RESULTS: All samples were evaluated according to morphological changes and scored in terms of morphologically intact endothelium, confluent endothelium with structural inhomogeneity, disruption of the intercellular contacts, separation of the endothelial cells, complete loss of the endothelium, and damage of the subendothelial layers. There is no statistically significant difference between the sample sets at the significance level of 0.05. There was no association with donors' age, sex, and time of storage. CONCLUSIONS: Human cryopreserved saphenous vein grafts in our experimental work showed no difference in terms of structural deterioration of the endothelial surface and basal membrane depending on different thawing protocols used.
- MeSH
- Time Factors MeSH
- Adult MeSH
- Endothelial Cells drug effects transplantation ultrastructure MeSH
- Cryopreservation * MeSH
- Cryoprotective Agents pharmacology MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Tissue and Organ Harvesting MeSH
- Tissue Survival MeSH
- Saphenous Vein drug effects transplantation ultrastructure MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
1. vydání 59 stran : barevné ilustrace ; 21 cm
Publikace obsahuje vzpomínky herců loutkového divadla, kteří vystupují v nemocnicích. Určeno široké veřejnosti.; Vzpomínková knížka herců, kteří jezdí do nemocnic, hospiců a LDN rozdávat radost dětem i seniorům.Tato knížka je plná příběhů, které členové souboru Loutky v nemocnici posbírali cestou za dětmi i dříve narozenými. Vznikla u příležitosti 15 let činnosti spolku, který přináší do nemocnic a léčeben loutkové divadlo - takovou zvláštní medicínu. Loutka v rukou loutkoherce má tu moc vtáhnout nás do říše fantazie, má sílu vrátit nás do dětství. Nutí nás začít si zase hrát, uvěřit v příběh, který se před námi odvíjí, ať se zdá být momentální situace jakkoli těžká.
- MeSH
- History, 21st Century MeSH
- Child, Hospitalized MeSH
- Inpatients MeSH
- Play and Playthings MeSH
- Hospitals MeSH
- Organizations, Nonprofit MeSH
- Psychodrama MeSH
- Psychosocial Support Systems MeSH
- Check Tag
- History, 21st Century MeSH
- Publication type
- Personal Narrative MeSH
- Popular Work MeSH
- Geographicals
- Czech Republic MeSH
- Conspectus
- Druhy sociální pomoci a služeb
- NML Fields
- sociologie
- psychoterapie
OBJECTIVES AND DESIGN: At the present time there are two waiting list for patients with vascular prosthetic infection indicated for arterial transplantation in the Czech Republic. The inclusion of each patient for cold-stored or cryopreserved arterial transplantation is the preference of indicating surgeon. In this experimental work we studied the immunogenicity of rat aortal allografts treated by our new clinical cryopreservation/slow thawing protocol. MATERIAL AND METHODS: Brown-Norway (BN) (N = 6, 203-217 g) or Lewis (LEW) (N = 6, 248-254 g) abdominal aortal grafts treated in accordance with our new clinical cryopreservation/slow thawing protocol were orthotopically transplanted to Lewis recipients (N = 12, 191-245 g). Aortal wall histology and infiltration by recipient immune cells, as well as donor specific anti MHC class I and II antibodies in recipient serum were studied in both isografts and allografts on day 30 postransplant. Core data of cryopreserved allografts were compared to our previous data of cold-stored aortal allografts treated in accordance with our clinical cold-storage protocol. RESULTS: Cryopreserved allografts showed regular morphology of aortal wall with clear differentiation of all three basic anatomical layers on day 30 postransplant. Intimal layer showed no hyperplasia, luminal surface was covered by endothelial cells. No statistical difference was observed in tunica media thickness between isografts and allografts. The medial layer showed no necrosis, shrinkage or immunoglobuline G deposition in any experimental group. The adventitial infiltration by immune cells was significantly higher (P<0.05) in allografts. Cryopreserved allografts showed significant lower activation of both cell- and antibody mediated immunity compared to historical data of cold-stored allografts. CONCLUSION: Aortal wall histology of rat allografts treated by our new standardized clinical cryopreservation/slow thawing protocol was comparable to that of the cryopreserved isografts on day 30 posttranspant. The immunogenicity of cryopreserved aortal allografts was significantly lower compared to that of cold-stored aortal allografts.
- MeSH
- Allografts physiology MeSH
- Aorta transplantation MeSH
- Arteries transplantation MeSH
- Transplantation, Homologous methods MeSH
- Cryopreservation methods standards MeSH
- Rats MeSH
- Models, Animal MeSH
- Rats, Inbred BN MeSH
- Rats, Inbred Lew MeSH
- Graft Rejection immunology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Základní informace: Popisujeme soubor čtyř pacientů s kritickou ischemií končetiny a absencí autologních náhrad (konduitů), kteří byli ošetřeni vytvořením kompozitního (s anastomózou „end-to-end“) alogenního bypassu z čerstvého nebo kryoprezervovaného štěpu z vena saphena (saféna). Použití této techniky může být nezbytné při vytváření femoropedálního bypassu, kdy jde o extrémní situaci charakterizovanou příliš krátkými či nedostatečně kvalitními žilními štěpy. Podobně dlouhá rekonstrukce vyžaduje dvě dárcovské safény. Kasuistiky: U čtyř pacientů bylo indikováno vytvoření „I-kompozitního“ femoropedálního bypassu s využitím čerstvého žilního alograftu. Jeden kompozitní štěp se uzavřel s odstupem čtyř měsíců od operace, jeden za 21 měsíců od operace a další dva zůstaly průchodné po dobu sledování s mediánem 23 měsíců. U žádného z pacientů nebylo po dobu sledování nutno provést amputaci. Závěr: Střednědobého udržení průchodnosti rekonstrukce lze uspokojivě dosáhnout za předpokladu kompatibility v systému ABO, krátké chladné ischemie štěpu, adekvátní imunosupresivní terapie a dodržení správného protokolu pro sledování nemocných po transplantaci cévního alograftu. Cévní chirurgové by měli mít na paměti možnost uplatnění této techniky zejména u diabetiků s kritickou ischemií končetiny a okluzí bércových tepen.
Background: We report a series of four patients with critical limb ischaemia and lack of autologous conduits, treated with composite (end-to-end anastomosis) allogenic fresh/or cryopreserved saphenous vein bypass grafting. This technique may be necessary in case of femoro-pedal artery bypass grafting, which is an extreme situation if there is shortage in length or inadequate quality of the venous allograft. Such a long reconstruction requires two donor saphenous veins. Case report: Four patients were indicated for “I-composite” fresh venous allograft for femoro-pedal bypass grafting. One composite graft occluded 4 months postoperatively, one 21 months postoperatively, two other remained patent with median follow-up 23 months. No amputation was required in any of the patients during the follow-up. Conclusion: Midterm patency of the reconstruction may be satisfactory provided that the ABO compatibility, short cold ischaemia time of the graft, adequate immunosuppressive therapy and proper follow-up protocol of the patient after vascular allograft transplantation are observed. Surgeons should keep in mind possibility of this technique mainly in diabetic patients with critical limb ischaemia and occluded crural vessels.
- MeSH
- Allografts surgery MeSH
- Leg surgery blood supply MeSH
- Blood Vessel Prosthesis Implantation methods MeSH
- Cryopreservation MeSH
- Humans MeSH
- Foot surgery blood supply MeSH
- Peripheral Arterial Disease * surgery classification MeSH
- Aged MeSH
- Saphenous Vein transplantation MeSH
- Treatment Outcome MeSH
- Tissue and Organ Procurement MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Aged MeSH
- Publication type
- Case Reports MeSH
OBJECTIVES AND DESIGN: The aim of our study was to simulate in rats all aspects and techniques used in our new clinical program of cryopreserved alloarterial transplantation and investigate the influence of two immunosuppressive protocols with tacrolimus on acute rejection of these allografts. MATERIALS AND METHODS: Cryopreserved abdominal aortic grafts were transplanted between Brown-Norway and Lewis rats. Tacrolimus (0.2 mg/kg daily) was administered from day 1 to day 30 (TAC1) or from day 7 to day 30 (TAC7), respectively. No immunosuppressed isogeneic (ISO) and allogeneic (ALO) rats combination served as control. Aortal wall infiltration by immunocompetent cells (MHC II+ cells of recipient origin) was studied on day 30 after transplantation. Flow cytometry was used for the analysis of day 30 sera for the presence of donor specific anti-MHC class I and II antibodies. RESULTS: The aortal allografts in both immunosuppressed groups showed regular morphology of aortal wall with no depositions of immunoglobulin G on day 30. The adventitial infiltration of non-immunosuppressed aortal allografts by MHC class II positive cells of recipient origin was significantly higher (ALO 20.7±6.7 cells, P<0.001) compared to both immunosuppressed groups (TAC1 5.9±5.5 cells, TAC7 6.1±5.1 cells). Day 30 sera from the allogeneic non-immunosuppressed animals decreased significantly the binding of fluorescence-labelled MHC class I (46.9±19.4%) and class II (65.8±11.9%) antibody to donors spleen cells compared with day 30 sera from both immunosuppressed groups (TAC1, anti-MHC class I 102.4±4.2%, p < 0.001, anti-MHC class II 102.6±6.0%), (TAC7, anti-MHC class I 79.9±3.3%, p < 0.001, anti-MHC class II 80.9±2.7%). CONCLUSION: Both immunosuppressed protocols with tacrolimus (administration from day 1 or from day 7 following transplantation) were able to suppress acute cell- and antibody-mediated rejection of cryopreserved abdominal aortic allografts processed in accordance with our new standardized clinical protocol.
- MeSH
- Aorta physiology transplantation MeSH
- Blood Vessel Prosthesis * MeSH
- Transplantation, Homologous MeSH
- Immunosuppressive Agents administration & dosage MeSH
- Immunosuppression Therapy MeSH
- Cryopreservation * MeSH
- Rats MeSH
- Rats, Inbred BN MeSH
- Rats, Inbred Lew MeSH
- Graft Survival MeSH
- Flow Cytometry MeSH
- Graft Rejection immunology MeSH
- Drug Administration Schedule MeSH
- Tacrolimus administration & dosage MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
Úvod: Pedální bypass je jednou z léčebných možností záchrany končetiny u kritické končetinové ischemie. Metoda: Retrospektivní analýza dat 20 pacientů, u kterých byl proveden pedální bypass na II. chirurgické klinice VFN a 1. LF UK buď jako jednoduchý (14 pacientů), nebo větvený konduit (6 pacientů) a kteří měli alespoň jedno sledování po dimisi. U větveného bypassu bylo hlavní raménko napojeno na pedální tepnu lepší kvality a odbočka na tepnu na opačné straně nohy. Ve skupině s větveným bypassem bylo hlavní tělo zhotoveno jako reverzní bypass z v. saphena magna u všech pacientů. U jednoduchého bypassu bylo 9 pacientů s reverzním bypassem z v. saphena magna, 3 pacienti s allograftem a po 1 pacientovi s PTFE graftem a in situ bypassem z v. saphena magna. Výsledky: Rozdíl v délce trvání operace nebyl významný. V pooperačním období bylo nutno reoperovat jednoho pacienta s jednoduchým bypassem pro krvácení z rány a perioperační mortalita byla zaznamenána u jednoho pacienta z téže skupiny. Ve sledovaném období jsme neprokázali významný rozdíl v primární nebo sekundární průchodnosti, v počtu amputací či celkovém přežití. Závěr: Na našem souboru pacientů jsme neprokázali významný rozdíl ani v průchodnosti, ani v zachování končetiny či peroperačních komplikacích. Domníváme se proto, že zvýšení rizika selhání rekonstrukce vytvořením další anastomózy není dostatečně vyváženo předpokládaným zlepšením hemodynamiky přidáním odbočky na druhou pedální tepnu. Rozšíření použití větveného bypassu tak bude zřejmě muset předcházet zlepšení techniky zejména použití primárně větveného žilního štěpu.
Introduction: Pedal bypass is a therapeutic option for limb salvage in critical limb ischemia. Method: Retrospective analysis of 20 patients who underwent either simple (14 patients) or branched (6 patients) pedal bypass in a single center and had at least one postoperative follow-up. In patients with branched pedal bypass, the main trunk was connected to the pedal artery of better quality and the side branch to an artery on the opposite side of the foot. The main trunk was constructed as a reverse saphenous bypass in all patients with branched bypass. From patients with simple bypass, nine had reverse saphenous graft, three had an allograft, one patient had in situ saphenous graft, and one PTFE prosthesis. Results: The difference in the operation time was not significant. One patient with simple bypass required reoperation for wound bleeding and there was one case of perioperative mortality in the same group. The difference between the groups in the primary or secondary patency rates, limb salvage and overall survival was not significant. Conclusions: We did not find any significant difference in patency rates, limb salvage, or perioperative complications between patients with simple and branched pedal bypass in our cohort. We believe that the anticipated benefits of constructing an additional branch are masked by the disadvantageous presence of an additional anastomosis. Adoption of a branched pedal bypass may therefore require further improvements perhaps the utilization of a branched saphenous graft.
- Keywords
- pedální bypass,
- MeSH
- Lower Extremity diagnostic imaging blood supply physiopathology MeSH
- Ischemia diagnosis surgery MeSH
- Humans MeSH
- Peripheral Arterial Disease * diagnostic imaging surgery MeSH
- Postoperative Care MeSH
- Retrospective Studies MeSH
- Vascular Grafting MeSH
- Vascular Surgical Procedures methods MeSH
- Limb Salvage * methods MeSH
- Check Tag
- Humans MeSH
Úvod: Chondrosarkom je maligní kostní tumor představující 20 % všech kostních malignit. Prezentujeme případ 35letého muže s recidivou chondrosarkomu dolní končetiny, který opouzdřil arteria tibialis anterior a arteria fibularis. Pacient podstoupil primární resekci chondrosarkomu pravé dolní končetiny před třemi lety, s pravidelnými CT a MR kontrolami postižené dolní končetiny. Pacient udával recidivu tuhé hmatné rezistence v pravém lýtku tři roky od primooperace s intermitentními bolestivými atakami a občasným otokem pravého lýtka. CT vyšetření prokázalo v místě původní resekce nový tumor vycházející z holenní kosti. Kasuistika: Poté, co CT angiografie upřesnila anatomickou lokalizaci tumoru a jeho vztah k přilehlým strukturám, byla u pacienta provedena chirurgická resekce tumoru s okrajovým lemem nepostižených měkkých tkání a opouzdřených bércových tepen. Zvláštní pozornost byla věnována zachování nervus tibialis. Resekované bércové tepny byly nahrazeny větvenou krurální cévní rekonstrukcí (bypass a. poplitea – a. fibularis, a. tibialis anterior). Vzhledem k nízkému věku pacienta byla k cévní rekonstrukci použita vena saphena magna jako nevhodnější štěp. Po odstranění nádoru došlo k okamžitému ústupu bolestí i přechodných otoků končetiny. Na základě předoperačních vyšetření nádoru a jeho vztahu k okolním strukturám pacient podstoupil kompletní resekci tumoru s rekonstrukcí bércových tepen, po které byla zachována plná funkčnost končetiny. Dle posledního vyšetření pomocí dopplerovské ultrasonografie zůstává větvená krurální cévní rekonstrukce průchodná bez známek stenózy. Závěr: Široká resekce je jedinou adekvátní chirurgickou metodou volby s nutností pečlivé předoperační rozvahy.
Background: Chondrosarcoma is a malignant bone tumor accounting for 20% of all bone malignancies. We are presenting a case of a lower extremity recurrence of chondrosarcoma that encapsulated the anterior tibial artery and the fibular artery in a 35-year-old Caucasian male patient. The patient underwent a primary resection of a chondrosarcoma of the right lower extremity 3 years ago. The patient underwent regular MRI and CT check-ups of the affected lower extremity. The patient reported a hard palpable mass with intermittent pain attacks and occasional limb swelling on his right calf 3 years from the initial surgery. A CT scan revealed a new tumor arising from the tibial bone in the place of the original tumor resection. Case presentation: After a CT angiography revealed the tumor’s anatomical localization to the surrounding structures, we performed a surgical resection of the entire tumor with a safe margin of soft tissue and encapsulated crural arteries. Extra attention was paid to the preservation of the tibial nerve. The resected crural arteries were replaced with a branched crural reconstruction (popliteal-fibular, anterior tibial bypass). Due to the young age of the patient, the great saphenous vein was the first choice as a graft for the vascular reconstruction. After the tumor resection, the patient was instantly relieved from intermittent pain attack and limb swellings. Based on the preoperative evaluation of the tumor and its surrounding structures, the patient underwent a complete tumor resection with crural arteries reconstruction after which the patient retained full limb functionality. The branched crural arteries reconstruction that replaced the resected crural arteries remains patent up-to-date with no signs of stenosis, when checked by Doppler ultrasonography. Conclusion: Wide resection is the only adequate surgical treatment of choice and has to be planned carefully.
- MeSH
- Anastomosis, Surgical MeSH
- Chondrosarcoma * diagnosis surgery MeSH
- Lower Extremity * surgery blood supply MeSH
- Adult MeSH
- Humans MeSH
- Tibia pathology MeSH
- Vascular Grafting MeSH
- Vascular Surgical Procedures methods MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Case Reports MeSH
