Long term in-vivo studies of a photo-oxidized bovine osteochondral transplant in sheep

BACKGROUND: Articular cartilage has limited capacity to repair. Defects greater than 3 mm heal with formation of inferior fibrous cartilage. Therefore, many attempts have been made to find the ideal graft for larger cartilage lesions. Different grafts, such as untreated or cryopreserved osteochondral transplants, have been used with variable success. METHODS: Photo-oxidized osteochondral grafts were implanted in both femoral condyles of one ovine knee. Untreated xenogeneic and autogeneic grafts served as controls. Three groups of 8 sheep each were formed and they were sacrificed 6, 12 or 18 months after surgery. RESULTS: The macroscopic evaluation of the condyle and graft showed a well-maintained cartilage surface in most grafts at all time points. However, the host cartilage matrix deteriorated considerably in all xenogeneic, most autogeneic and fewer of the photo-oxidized grafts at 12 and 18 months, respectively. The blue colour of the photo-oxidized grafts resulting from the process of photo-oxidation was visible in all grafts at 6 months, had diminished at 12 months and had completely disappeared at 18 months after surgery. Histologically a loss of matrix staining was almost never noticed in untreated xenografts, transiently at 6 months in photo-oxidized grafts and increased at 12 and 18 months. Fusion between graft and host cartilage could be seen in photo-oxidized grafts at 12 and 18 months, but was never seen in autografts and xenografts. CONCLUSIONS: The photo-oxidation of osteochondral grafts and its use as transplant appears to have a beneficial effect on cartilage and bone remodelling. Osteochondral grafts pre-treated with photo-oxidation may be considered for articular cartilage replacement and therefore may delay artificial joint replacements in human patients

LGBTQ parenting post heterosexual relationship dissolution

The chapter examines parenting among sexual and gender minorities post heterosexual relationship dissolution (PHRD). Reviewing the literature around intersecting identities of LGBTQ parents, we consider how religion, race, and socioeconomic status are associated with routes into and out of heterosexual relationships and variation in the lived experience of sexual and gender identity minorities, in particular how LGBTQ parents PHRD feel about being out. Further consideration is given to examining how family relationships change and develop as parental sexual and/or gender identity changes. We also explore the impact of PHRD identity and parenthood on new partnerships and stepfamily experiences. The chapter addresses the reciprocal relationship between research on LGBTQ parenting and policy and legal influences that impact upon the experience of LGBTQ parenting PHRD when custody and access are disputed. Finally, the chapter includes future research directions and implications for practice in an area that has been revitalized in recent years

Fuel stagnation temperature effects on mixing with supersonic combustion flows

An experimental study of the effect of fuel stagnation temperature on mixing in a supersonic hydrogen-air flame is described, The combustor consisted of a constant-area rectangular duct with a centrally located fuel-injection strut that spanned the width. A high-enthalpy stream of air was supplied by a free-piston shock tunnel, and heated hydrogen fuel, supplied by a gun-tunnel, was injected into the freestream as a coflowing planar jet. The freestream total enthalpies were 5.6, 6.5, and 9 MJ/kg, and fuel stagnation temperatures were 300, 450, and 700 K, Raising the fuel stagnation temperature increased the fuel velocity to be near that of the airstream and resulted in a decrease in the mixing rate, Even as the fuel and air velocities became equal, significant mixing still occurred because of a large difference in density, Increasing the freestream enthalpy reduced the difference between the initial air temperature and the adiabatic flame temperature, which in turn reduced the heat addition, and subsequently, the amount of pressure rise in the duct

Considering planned change anew: stretching large group interventions strategically, emotionally and meaningfully

Large Group Interventions, methods for involving “the whole system” in a change process, are important contemporary planned organizational change approaches. They are well known to practitioners but unfamiliar to many organizational researchers, despite the fact that these interventions address crucial issues about which many organizational researchers are concerned. On the other hand, these interventions do not appear to be informed by contemporary developments in organizational theorizing. This disconnect on both sides is problematic. We describe such interventions and their importance; illustrate them with extended descriptions of particular Future Search and Whole‐Scale™ change interventions; summarize research on strategy, emotion, and sensemaking that may inform them; and suggest questions about the interventions that may stimulate research and reflection on practice. We also discuss conditions that may foster effective engagement between Large Group Interventions practitioners and organizational researchers. Our approach represents a way to conduct a review that combines scholarly literature and skilled practice and to initiate a dialog between them

Aderências peritoneais em eqüinos: tratamento profilático com carboximetilcelulose Peritoneal adhesions in horses: prophylactic treatment with carboxymethylcelullose

As aderências peritoneais formam-se freqüentemente nos eqüinos submetidos a laparotomia. As aderências podem ser assintomáticas ou podem causar complicações como cólica e osbstrução intestinal, às vezes com estrangulamento vascular. Com o objetivo de avaliar a eficiência do uso intraperitoneal de carboximetilcelulose (CMC) na prevenção de aderências peritoneais em eqüinos, fez-se o seguinte experimento: dezoito eqüinos clinicamente normais, sem raça definida (SRD), foram anestesiados e submetidos a laparotomia na linha mediana ventral, quando se produziu lesões no jejuno distal para induzir a formação de aderências peritoneais. Em quatro animais (bloco I) foram criadas seis lesões: um segmento com aproximadamente 45cm de comprimento foi submetido à isquemia, através da ligadura da circulação mural e dos vasos mesentéricos por duas horas; em cinco pequenas áreas, com cerca de três por cinco centímetros, foi feita abrasão da serosa pela fricção 100 vezes de uma gaze seca e um ponto simples seromuscular de categute cromado foi aplicado no seu centro. Nos outros 14 animais (bloco II). o modelo adotado foi semelhante com pequenas modificações: ao invés de um segmento de isquemia foram criados quatro segmentos com 25cm de comprimento; a abrasão das cinco pequenas áreas foi feita com uma pinça Rochester aberta e não com uma gaze seca; a sutura seromuscular com categute aplicada no centro das áreas de abrasão foi uma linha contínua simples, com aproximadamente 2,5cm de comprimento e não um ponto simples. Os animais foram aleatoriamente divididos em dois grupos. Em dois animais do bloco I e sete animais do bloco II (grupo tratamento), antes da síntese da parede abdominal, foi instilada, na cavidade peritoneal, uma solução decmC a 7% na dose de 7 ml/kg. Nos outros nove animais (grupo controle) a parede foi suturada da mesma forma, mas nenhum medicamento foi aplicado na cavidade peritoneal. Os eqüinos foram examinados diariamente. Quatorze dias após a cirurgia, todos os animais sofreram eutanásia e foram submetidos à necropsia. Seis, dentre os nove animais do grupo controle e quatro, dentre os nove animais do grupo tratamento, desenvolveram aderências perítoneais. Não houve diferença significativa entre o número de animais com aderências nem entre o número ou o grau das aderências formadas nos dois grupos. Os animais do grupo tratamento não apresentaram qualquer sinal de toxicidade ou hipersensibilidade àcmC. Concluiu-se que a carboximetilcelulose não foi eficiente na prevenção de aderências peritoneais no intestino delgado de eqüinos induzidas por abrasão da serosa e isquemia. Concluiu-se também que esta droga não causou efeitos colaterais e não prejudicou a cicatrização do peritônio.<br>Peritoneal adhesions form very often in horses submitted to laparotomy. Adhesions may be assymptomatic or they could cause complications such as colic and intestinal obstruction, sometimes with vascular strangulation. To evaluate intra-peritoneal use of carboxymethylcellulose (CMC) in prevention of peritoneal adhesions in horses, the following experiment was conducted: eighteen clinically normal mixed breed horses were anesthetized and submitted to ventral midline laparotomy. Lesions in the distal jejunum were produced to induce peritoneal adhesion formation. In four horses (block I) six lesions were created: one segment 45cm in length was submitted to ischemia by ocluding mural circulation and mesenteric vessels for two hours; in five small areas with approximately three x five centimeters serosal abrasion was produced by rubbing a dry gauze sponge 100 times with a single chromic catgut suture placed in the center through the seromuscular layer. For the other fourteen animals (block II) the model adopted was similar with small chances: instead of one ischemic segment, four segments 25cm in length were created: abrasïon of the five areas was produced with the jaw of an open Rochester forceps; the suture made in the center of the abrasion areas was a line of a simple continuous pattern with 2.5cm in length approximately. Horses were randomly placed into two groups. In nine animals (treatment group), a volume of 7 ml/kg of 1%cmC was instilled in the peritoneal cavity before abdominal wall synthesis. In the other nine animals (control group) the wall was sutured in the same way, but no drug was instilled in the peritoneal cavity. Horses were monitored daily. All animals were submitted to euthanasiu and necropsy fourteen days after surgery. Six of the nine animals in the control group and four of nine animals of treatment group developed peritaneal adhesions. There were no significant differences between the numher of animals with adhesians in the two groups nor between the number and the grade of adhesions developed in the groups. Animals in the treatment group did not show any sign of toxicity or hypersensivity forcmC. Based on these results it may be concluded that carboxymethylcellulose was not efficient in preventing peritoneal adhesions in equine small intestine induced by serosal abrasion and ischemia. Also it may be concluded that this drug did not cause any collateral effects neither impaired peritoneal healing