This thesis describes a series of investigations into the problems that hamper the progress of myocardial preservation for transplantation in man. Six positive aspects of cardiac preservation have emerged from this study: - (1) A clear fluid hyperosmolar solution was formulated that adequately preserved viability of pig and baboon hearts. (2) A pneumatically powered portable preservation unit was designed which successfully preserved pig and baboon hearts when assessed by either functional testing or orthotopic transplantation. (3) A method of in vitro testing of hearts was developed that correlated with results from orthotopic transplantation. (4) A technique of cardiac autotransplantation in baboons was perfected. (5) The high release of lysosomal acid phosphatase during the period of hypothermic preservation was shown to be non-pathological and was reversible after a period of warm blood perfusion. (6) Successful preservation of human hearts for periods longer than 4 hours, not previously achieved, was obtained. The preservation solution and the portable preservation unit that emerged from this experimental study were thoroughly investigated before clinical application. During the development of this perfusate the author had numerous consultations and discussions with colleagues and senior members of neighbouring departments.

Liver transplantation is an accepted form of treatment in advanced liver disease. The procedure qualifies as one of the most severe surgical insults that can be inflicted upon a patient. Despite an ever increasing number of clinical and experimental transplants, a vast number of unanswered questions remains about the effects of storage and transplantation per se, on the functions of this complex organ. The administration of drugs and blood, with the effects of the donor state and preservation damage obscure changes in parameters that are inherently due only to the process of transplantation, Changes in calcium and other electrolyte homeostasis, liver function assessment, acid base metabolism and coagulation defects that are seen after liver grafting, are of particular interest to transplant physicians. Current clinically employed indices of liver function, such as enzyme levels, are notoriously lacking in specificity and sensitivity, The aim of the study was to investigate in the experimental situation, the effects of standardised preservation and transplantation, without the added effects of blood transfusion or immunosuppressive drug administration, upon calcium and other electrolyte homeostasis, liver function and coagulation changes. Furthermore, reliable indicators of liver function and/or damage were looked for. It was not an investigation into preservation methods to determine superiority of one or another of these methods, but an evaluation of changes occurring utilising established and clinically proven methods of preservation. Since researchers in the J.S. Marais laboratory, as well as their international counterparts, have experienced problems in successful storage of the pig liver for periods longer than 9 hours, a storage duration of six hours was chosen for maximum reproducibility. A brief overview of liver transplantation history has been given, available literature perused and used in assessment and discussion of data obtained. Five groups of six animals were used for orthotopic liver transplantation. Two groups were autografted with a non-flushed and Ringers lactate flushed liver respectively. Two groups were allografted with livers stored in Collins and University of Wisconsin solutions respectively. A fifth group was transplanted with a liver stored for six hours by surface cooling alone, without any flushing at all. The latter method has not been described in experimental or clinical liver transplantation before. No immunosuppression was used in any animal, to eliminate the effects of hepatotoxic drugs. No blood was transfused at any point during or after the transplant. An animal survival rate in excess of 90%, for seven days or longer, was aimed for and obtained. Blood sampling was done at short intervals in the immediate postoperative period up to six hours and daily for a week. All currently used clinical parameters were determined, as well as indicators which are known, but novel in transplantation. Changes in total and ionised calcium values occurred in all groups and no explanatory mechanism could be identified. There was no correlation in changes between total and ionised calcium, nor any correlation with calcium content of preservation fluids. A reciprocal change in magnesium was identified. Acid base metabolism was markedly changed during and after the transplant. An increase in serum bicarbonate indicated survival, and a persisting metabolic alkalosis was seen in all survivors. Sodium and potassium values did not show marked changes, except for a temporary hyperkalaemia immediately following reperfusion. Serum values of liver transaminases were not found to be of value to discriminate between groups. Protein metabolism was not affected by transplantation. Glucose metabolism was markedly affected by transplantation and even more so by poor function. Early return of normal glucose metabolism indicated survival. Lactic acid metabolism was conspicuously altered during transplantation and could also be regarded as an indicator of hepatocyte function. Coagulation in this series of experiments was affected negligibly and not thought to be influenced by transplantation of a normal liver under ideal circumstances. Thus, changes in values within groups and variance between groups, if any, were described and possible mechanisms causing variation discussed. New indicators of good liver function post-transplant were identified. The conclusion was reached that the process of transplantation per se does cause major changes in electrolyte and acid-base metabolism, but that coagulation was not affected by the process of successful preservation and transplantation.

Please read the abstract in the front section of this document / Dissertation (MSc (Food Science))--University of Pretoria, 2007. / Food Science / unrestricted

No description available.

A coleção de fungos do Instituto de Medicina Tropical de São Paulo/USP compreende 1047 isolados de fungos, algas e actinomicetos de interesse médico e veterinário, que até o início deste estudo eram mantidos sob repiques sucessivos a cada três meses. Criada em 1925 pelo Prof. Dr. Floriano Paulo de Almeida e, a partir de 1953, mantida pelo Prof. Dr. Carlos da Silva Lacaz, a coleção necessitava de adequação de seu espaço físico e atualização nos métodos de preservação dos isolados. A reforma física foi realizada de acordo com as normas de biossegurança recomendadas pelo manual de procedimentos para manipulação de patógenos. Diversos estudos têm demonstrado que repiques sucessivos propiciam alterações nas características morfológicas, antigênicas, genéticas e de virulência de isolados fúngicos. Deste modo, foram aplicadas metodologias de preservação de longo prazo, como: liofilização, água destilada esterilizada, congelamento a -80ºC e em nitrogênio líquido (-196ºC). Foram selecionados 386 isolados, entre fungos dimórficos (213), filamentosos (hialinos e melanizados - 106) e leveduras (67), relacionados às infecções fúngicas mais prevalentes em nosso meio. Foram utilizados dois métodos de preservação para cada grupo de fungos: as leveduras foram submetidas à liofilização e congelamento em freezer -80ºC; e os fungos dimórficos e filamentosos preservados em água destilada esterilizada e no vapor de nitrogênio líquido. Esses isolados foram inicialmente avaliados quanto à caracterização morfológica e, após aplicação dos métodos de preservação, avaliou-se a viabilidade dos mesmos dentro de um período de dois anos, bem como a morfologia. As leveduras apresentaram 100% de viabilidade pelos dois métodos de preservação, mantendo suas características fenotípicas. Do mesmo modo, os dois métodos aplicados aos fungos filamentosos resultaram em elevados índices de viabilidade, com manutenção das características morfológicas. Em relação aos fungos dimórficos, a manutenção em nitrogênio líquido resultou em índices variáveis de viabilidade, dependendo do gênero avaliado. Do total de isolados do estudo, 75 foram submetidos também à identificação molecular por sequenciamento automatizado, após amplificação da região ITS do DNA ribossomal por PCR. A técnica molecular demonstrou, para alguns desses isolados, discordância na identificação das espécies quando comparada aos métodos fenotípicos. Os resultados deste estudo demonstraram que os repiques sucessivos não são recomendados para a preservação de fungos em coleções, por alterarem as características fenotípicas, bem como a capacidade de produzir esporos. As novas metodologias de preservação adotadas mantiveram a morfologia típica dos gêneros e espécies, permitindo ainda a viabilidade da maioria dos isolados estudados. A identificação molecular demonstrou ser importante ferramenta para autenticação dos isolados / The fungal culture collection from the Instituto de Medicina Tropical de São Paulo/USP comprises 1047 isolates of fungi, algae and actinomycetes with medical and veterinary relevance, which up to now have been preserved by subculturing every three months. Created in 1925 by Prof. Floriano Paulo de Almeida and maintained by Prof. Carlos da Silva Lacaz and his assistants since 1953, this fungal collection needed to be realocated to another area in 2007, as well as updated and revised as to its preservation methods. This new area was reformed according to safety procedures recommended in guidelines for pathogenic microorganisms manipulation. Several studies demonstrated that storage of fungi by subculturing may induce antigenic changes, phenotypic and genetic alterations, in addition to attenuation of virulence. The present study was aimed at utilizing more adequate methods of long-term preservation, such as lyophilization, sterile distilled water, and cryopreservation (freezing at -80°C and storage in liquid nitrogen [-196°C]). Three hundred eight six isolates consisting of dimorphic (213) and filamentous fungi (hyaline and melanized - 106), and yeasts (67) associated with the most prevalent fungal diseases in our setting were randomly selected. Two methods were applied for storage of each fungal group: yeasts were submitted to lyophilization and freezing at -80ºC; dimorphic and filamentous fungi were preserved in sterile distilled water and liquid nitrogen. All isolates were initially evaluated for their morphological features, submitted to the different methods of storage, and during a period of up to two years, reassessed for viability and morphological features. Yeasts showed 100% viability by the two applied preservation methods, maintaining their phenotypic characteristics. Similarly, the two methods applied to filamentous fungi resulted in high rates of viability, with maintenance of morphology. Regarding the dimorphic fungi, the preservation in liquid nitrogen resulted in variable rates of recovery, depending on the genus assessed. From all studied isolates, 75 were also submitted to molecular identification by sequencing after PCR amplification of the ITS region of the ribossomal DNA. This molecular technique showed, for some isolates, a lack of agreement in species identification when compared with the phenotypic methods. The new long-term storage methods used in the study preserved the typical genus and species morphology of the studied isolates, while resulting in high viability rates. The molecular identification proved to be an important tool for the authentication of isolates

A coleção de fungos do Instituto de Medicina Tropical de São Paulo/USP compreende 1047 isolados de fungos, algas e actinomicetos de interesse médico e veterinário, que até o início deste estudo eram mantidos sob repiques sucessivos a cada três meses. Criada em 1925 pelo Prof. Dr. Floriano Paulo de Almeida e, a partir de 1953, mantida pelo Prof. Dr. Carlos da Silva Lacaz, a coleção necessitava de adequação de seu espaço físico e atualização nos métodos de preservação dos isolados. A reforma física foi realizada de acordo com as normas de biossegurança recomendadas pelo manual de procedimentos para manipulação de patógenos. Diversos estudos têm demonstrado que repiques sucessivos propiciam alterações nas características morfológicas, antigênicas, genéticas e de virulência de isolados fúngicos. Deste modo, foram aplicadas metodologias de preservação de longo prazo, como: liofilização, água destilada esterilizada, congelamento a -80ºC e em nitrogênio líquido (-196ºC). Foram selecionados 386 isolados, entre fungos dimórficos (213), filamentosos (hialinos e melanizados - 106) e leveduras (67), relacionados às infecções fúngicas mais prevalentes em nosso meio. Foram utilizados dois métodos de preservação para cada grupo de fungos: as leveduras foram submetidas à liofilização e congelamento em freezer -80ºC; e os fungos dimórficos e filamentosos preservados em água destilada esterilizada e no vapor de nitrogênio líquido. Esses isolados foram inicialmente avaliados quanto à caracterização morfológica e, após aplicação dos métodos de preservação, avaliou-se a viabilidade dos mesmos dentro de um período de dois anos, bem como a morfologia. As leveduras apresentaram 100% de viabilidade pelos dois métodos de preservação, mantendo suas características fenotípicas. Do mesmo modo, os dois métodos aplicados aos fungos filamentosos resultaram em elevados índices de viabilidade, com manutenção das características morfológicas. Em relação aos fungos dimórficos, a manutenção em nitrogênio líquido resultou em índices variáveis de viabilidade, dependendo do gênero avaliado. Do total de isolados do estudo, 75 foram submetidos também à identificação molecular por sequenciamento automatizado, após amplificação da região ITS do DNA ribossomal por PCR. A técnica molecular demonstrou, para alguns desses isolados, discordância na identificação das espécies quando comparada aos métodos fenotípicos. Os resultados deste estudo demonstraram que os repiques sucessivos não são recomendados para a preservação de fungos em coleções, por alterarem as características fenotípicas, bem como a capacidade de produzir esporos. As novas metodologias de preservação adotadas mantiveram a morfologia típica dos gêneros e espécies, permitindo ainda a viabilidade da maioria dos isolados estudados. A identificação molecular demonstrou ser importante ferramenta para autenticação dos isolados / The fungal culture collection from the Instituto de Medicina Tropical de São Paulo/USP comprises 1047 isolates of fungi, algae and actinomycetes with medical and veterinary relevance, which up to now have been preserved by subculturing every three months. Created in 1925 by Prof. Floriano Paulo de Almeida and maintained by Prof. Carlos da Silva Lacaz and his assistants since 1953, this fungal collection needed to be realocated to another area in 2007, as well as updated and revised as to its preservation methods. This new area was reformed according to safety procedures recommended in guidelines for pathogenic microorganisms manipulation. Several studies demonstrated that storage of fungi by subculturing may induce antigenic changes, phenotypic and genetic alterations, in addition to attenuation of virulence. The present study was aimed at utilizing more adequate methods of long-term preservation, such as lyophilization, sterile distilled water, and cryopreservation (freezing at -80°C and storage in liquid nitrogen [-196°C]). Three hundred eight six isolates consisting of dimorphic (213) and filamentous fungi (hyaline and melanized - 106), and yeasts (67) associated with the most prevalent fungal diseases in our setting were randomly selected. Two methods were applied for storage of each fungal group: yeasts were submitted to lyophilization and freezing at -80ºC; dimorphic and filamentous fungi were preserved in sterile distilled water and liquid nitrogen. All isolates were initially evaluated for their morphological features, submitted to the different methods of storage, and during a period of up to two years, reassessed for viability and morphological features. Yeasts showed 100% viability by the two applied preservation methods, maintaining their phenotypic characteristics. Similarly, the two methods applied to filamentous fungi resulted in high rates of viability, with maintenance of morphology. Regarding the dimorphic fungi, the preservation in liquid nitrogen resulted in variable rates of recovery, depending on the genus assessed. From all studied isolates, 75 were also submitted to molecular identification by sequencing after PCR amplification of the ITS region of the ribossomal DNA. This molecular technique showed, for some isolates, a lack of agreement in species identification when compared with the phenotypic methods. The new long-term storage methods used in the study preserved the typical genus and species morphology of the studied isolates, while resulting in high viability rates. The molecular identification proved to be an important tool for the authentication of isolates

Bakgrund: Hypotermi definieras som en kärntemperatur under 36 grader och är en vanlig komplikation i samband med anestesi. Hypotermi vid kirurgi är förknippat med ökad mortalitet och kan leda till komplikationer som innebär lidande, förlänger tid för återhämtning och orsakar ökade vårdrelaterade kostnader. Komplikationer på grund av hypotermi är exempelvis försämrad sårläkning, ökad risk för blödning och ökad incidens av infektioner. För många patienter innebär det ett lidande att frysa eftersom att vara kall är förknippat med känslor av utsatthet, sårbarhet och att få sämre vård. Olika metoder och hjälpmedel för att förhindra att hypotermi uppstår under anestesi finns att tillgå. I Sverige saknas specifika riktlinjer på nationell nivå. Forskning har visat att följsamheten till lokala riktlinjer är låg. Patienten behöver hjälp med att bibehålla adekvat kroppstemperatur och här har anestesisjuksköterskan en viktig uppgift. Syfte: Syftet var att sammanställa tillgängliga interventioner för att förhindra oavsiktlig intraoperativ hypotermi.  Metod: En strukturerad litteraturöversikt med narrativ analys genomfördes. Informationssökning gjordes i databaserna PubMed och CINAHL.  Resultat: Tre grupper av värmebevarande metoder identifierades: aktiv, passiv och invasiv uppvärmning. Den mest förekommande metoden var aktiv värmning med forced-air warming, som också verkade vara den mest effektiva metoden för att bibehålla normal kroppstemperatur och förhindra hypotermi. Skillnaderna i effektivitet mellan metoderna varierade. Ingen aktiv eller passiv metod förhindrade hypotermi helt. Slutsats: Trots att effektiva metoder för att förhindra oavsiktlig intraoperativ hypotermi finns och används är incidensen av hypotermi hög. Ytterligare forskning behövs för att undersöka orsaker till den höga incidensen. / Bakgrund: Hypotermi definieras som en kärntemperatur under 36 grader och är en vanlig komplikation i samband med anestesi. Hypotermi under operation är förknippad med ökad dödlighet och kan leda till komplikationer som skapar lidande, förlänger återhämtningstiden och orsakar ökade vårdrelaterade kostnader. Komplikationer på grund av hypotermi är till exempel försämrad sårläkning, ökad blödningsrisk och ökad förekomst av infektioner. För många patienter innebär frysning lidande eftersom förkylning är förknippad med känslor av exponering, sårbarhet och att få sämre vård. Olika metoder och hjälpmedel finns tillgängliga för att förhindra hypotermi uppstår under anestesi. I Sverige finns inga särskilda riktlinjer på nationell nivå. Forskning har visat att efterlevnaden av lokala riktlinjer är låg. Patienten behöver hjälp med att upprätthålla en tillräcklig kroppstemperatur, och här har anestesisjuksköterskan ett viktigt ansvar. Syfte: Målet var att sammanställa tillgängliga interventioner för att förhindra oavsiktlig intraoperativ hypotermi. Metod: En strukturerad litteraturstudie med narrativ analys genomfördes. En informationssökning gjordes i databaserna PubMed och CINAHL. Resultat: Tre grupper av värmebevarande metoder identifierades: aktiv, passiv och invasiv uppvärmning. Den vanligaste metoden var aktiv uppvärmning med påtvingad luftuppvärmning, vilket också visade sig vara den mest effektiva metoden för att upprätthålla normal kroppstemperatur och förhindra hypotermi. Skillnaderna i effektivitet mellan metoderna varierade dock. Ingen aktiv eller passiv metod förhindrade helt hypotermi. Slutsats: Även om effektiva metoder för att förhindra oavsiktlig intraoperativ hypotermi finns och används, är förekomsten av hypotermi hög. Ytterligare forskning behövs för att undersöka orsakerna till den höga förekomsten. Sökord: Anestesi, kroppstemperatur, värmebevarande metoder, förebyggande och kontroll av hypotermi, oavsiktlig hypotermi, intraoperativ vård, kvantitativ, litteraturöversikt, perioperativ vård, kirurgi.