Insulin, insulin-like peptides, and EGF have all been implicated as regulators of placental growth and function. In this report, the ontogeny of receptors for insulin, ILAs (J.C.E.M. 47: 1240, 1978), and EGF was studied utilizing fractions prepared by differential centrifugation of early gesta

Differentiation between rejection and infection of lung allografts remains difficult. The effects of these two pathologic entities on the cytolytic activity of bronchoalveolar lavage (BAL) and peripheral blood lymphocytes (PBL) were investigated. Left lung allotransplantation was performed on sixteen mongrel dogs of which twelve were available for complete studies. All animals received cyclosporine A, azathioprine and prednisone for 2 weeks. Four grafts developed left lower lobe Gram negative pneumonia. The eight remaining recipients progressed gradually to severe rejection following acute reduction of immunosuppression. Cytolytic activity of blood and left lung BAL lymphocytes was quantitated by the natural killer (NK) and lectin dependent cell mediated cytotoxicity (LDCMC) assays. Two additional groups serving as controls were either given a ten day course of immunosuppressants or had right lower lobe pneumonia induced by transbronchial inoculation of gram negative bacteria. Immunosuppressed control animals showed significant depression of PBL and BAL lymphocyte LDCMC and NK activity. Similarly, BAL lymphocytes expressed very low LDCMC in normal allografts (2.8 $ pm$.8%). Once rejection developed and progressed, LDCMC became significantly higher (15.6 $ pm$ 2.2% and 52.7 $ pm$ 2.8% in moderate and severe rejection respectively). There was no detectable NK activity in rejecting lung allografts. BAL lymphocytes from infected allografts, on the other hand, showed an elevation of both NK and LDCMC activity (9.1 $ pm$ 1.1% and 14.6 $ pm$ 1.0% respectively). Similarly, bacterial pneumonia in control animals manifested an increase in NK and LDCMC activity in lung and blood. Peripheral blood lymphocytes of lung allograft recipients, however, had increased NK and LDCMC activity in both rejection and infection. LDCMC/NK activity ratio (LM/NK index) of lung lymphocytes was significantly higher in rejecting allografts (11.2 $ pm$ 1.0 and 12.4 $ pm$ 1.6 for moderate and sev

The adaptability of the respiratory muscles to training and/or emphysema was investigated. The diaphragmatic (DIA) length-tension curve of the emphysematous animals shifted significantly towards the left; maximal tetanic tensions were generated at shorter absolute DIA lengths. This decrease in DIA length occurred in proportion to the hyperinflation and mainly occurred due to a loss in the number of sarcomeres. In states of acute DIA shortening, were no adaptations in length occurred, we noted marked alterations in the twitch characteristics and in the shape of the force-frequency curve; at acutely shorter DIA lengths, a disproportionately greater excitability was required in order to reach a given submaximal tension. In the chronically shortened DIA, however, the re-establishment of a new shorter length allowed for the twitch characteristics, the force frequency curve and the maximal tetanic tension to remain unchanged. Therefore, the dropping out of sarcomeres in the chronic condition appears to maintain normal DIA function. Training produced no effects on the contractile or structure properties of the DIA. / The acutely shortened DIA fatigued at a faster rate when initial tensions were comparable as to the optimal length. In emphysematous animals, however, the DIA showed a significantly greater resistance to fatigue. The mechanisms responsible for the enhanced DIA endurance were biochemical increases in the oxidative capacity with a concomitant decrease in the glycolytic capacity. Histochemically, the DIA from sedentary emphysematous animals revealed a selective fast fiber atrophy which was prevented by endurance training. The intercostal muscles revealed histochemical and biochemical evidence of adaptations consistent with a greater resistance to fatigue.

Medium chain fatty acid oxidation was investigated in riboflavin deficient and 2-octynoic acid treated rats. Urinary metabolites of deuterium labelled fatty acid substrates were determined using gas chromatography-mass spectrometry. Control and experimental animals both produced labelled dicarboxylic acids. The ratio of chain length of dicarboxylates (C$ sb{ rm n+2}$/C$ sb{ rm c}$) was lowest in riboflavin deficient rats. As mitochondrial $ beta$-oxidation is inhibited, Peroxisomal $ beta$-oxidation appears to increase in response to inhibited mitochondrial oxidation in riboflavin deficiency. Administration of L-carnitine with the labelled substrates to half the rats showed that there were no differences in organic acid excretion between carnitine supplemented and unsupplemented rats. A new method to quantitate individual acylcarnitines in urine using fast atom bombardment-mass spectrometry and deuterium labelled acylcarnitines as internal standards demonstrated that administration of L-carnitine did enhance excretion of free carnitine and short chain acylcarnitines along with some dicarboxylcarnitines in all groups.

No description available.

No description available.

Intra-abdominal infections are a common entity faced by general surgeons, which, when complicated by pneumonia lead to increased mortality. The susceptibility to a second infection is correlated with impaired polymorphonuclear neutrophil (PMN) migration to the remote site, perhaps due to inadequate PMN number. We tested the second front hypothesis that the elevated mortality arising from a second infection is due to insufficient circulating PMN, the majority being sequestered at the first site of infection. Further, augmentation of systemic PMN number by granulocyte colony stimulating factor (G-CSF) will decrease mortality. / We established a murine model for peritonitis and pneumonia. PMN counts in the blood, lung tissue, peritoneal cavity and bronchoalveolar system were measured. The results indicated significant PMN recruitment to the primary site of infection, whether lung or abdomen. Almost no PMN were found in the lung if it was the second site of infection. This was consistent with the second front hypothesis.

Cystic fibrosis (CF) patients have airway neutrophilic inflammation associated with high levels of interleukin-8 (IL-8) and often develop airway hyperresponsiveness (AHR). Aerosolized uridine triphosphate (UTP) has been used to improve mucosal clearance by inducing Cl- secretion. However, nucleotides such as UTP and ATP (adenine triphosphate) also evoke the release of intracellular Ca2+ ([Ca2+]i), which are enhanced by pro-inflammatory mediators, such as IL-1beta. Since most of the CF airway epithelium is lost during infection and inflammation, the underlying airway smooth muscle cells (ASMC) are exposed to IL-8 and extracellular nucleotides. Thus, we were particularly interested in evaluating the effects of IL-8, extracellular ATP and UTP on contractile responses of ASMC. For this study, cultured ASM from normal and CF lung specimens were used. We have found that human ASM cells (HASMC) express mRNA and protein for IL-8 receptors (CXCR1 and CXCR2) and IL-8 causes an increase in [Ca2+]; as well as cellular contraction and migration. Furthermore, changes in the [Ca2+] i were abrogated on blocking IL-8 receptors with specific neutralizing antibodies, and were also decreased following inhibition of phospholipase C (PLC), indicating that changes in [Ca2+]i were likely mediated by inositol trisphosphate. The effects of IL-8 on HASMC prompted us to investigate whether IL-8 induced ASMC contraction in CF was different from normal. IL-8 caused larger ASM contractions and greater phosphorylation of myosin light chain (MLC20) compared to normal cells. CF cells expressed more MLC20 compared to normal cells. However, the expression of CXCR1, CXCR2, IL-8 induced changes in [Ca2+]i and ASMC migration in CF cells were similar to normal cells. We also found that normal HASMC express receptors (subtypes of P2Y) for ATP and UTP, which stimulated the release of intracellular Ca2+. Brief exposure of normal HASMC with UTP enhanced Ca2+ transients in response t

Early growth response protein-1 (EGR-1) is a transcription factor induced by stress or injury, mitogens, and differentiation factors. It has been shown to be regulated by various cytokines, growth factors and by ischemic/hypoxic stress as well as shear stress and mechanical injury. These regulators have been linked to both the development as well the degeneration of the musculoskeletal system, namely articlar cartilage, intervertebral discs (IVDs) and bone. Furthermore, Egr-1 has been shown to regulate the expression of collagens and enzymes affecting the extracellular matrix. Polymorphisms of DNA binding sites for EGR-1 have shown to be associated with both disc degeneration and osteoporosis. The aim of this study was to determine the affects of EGR-1 deficiency on articular cartilage, IVD and bone phenotype. / Wild-type (+/+) C57Bl/6 or Egr-1-deficient (−/−) mice were sacrificed at the same age interval (8- to 9-months). Standard histological preparation and staining with Safranin-O/Fast Green were done. Also immuncohistochemistry was performed using anti-bodies to type X collagen, cleavage products of both type II collagen and aggrecan. Imaging of mice was with plain radiographs, bone mineral density measurements and microCT analysis. / Results revealed that these mice have differences including abnormal bone structure and density, structural and possibly compositional differences in articular cartilage and structural and biochemical changes in IVDs. This points to the importance of Egr-1 in the maintenance of normal bone, IVD and articular cartilage and makes it a possible target for initiating pathological conditions of these tissues. / La protéine de croissance EGR-1 (Early Growth Response protein-1, en anglais) est un facteur de transcription qui est induit par la tension ou la blessure, les facteurs mitogènes, et les facteurs de différenciation. EGR-1 est ainsi régulé par divers cytokines, facteurs de croissance, par les conditions ischémique, ainsi que la tension et les blessures mécaniques. Ces régulateurs ont été reliés au développement ainsi que la dégradation du système squeletto-musculaire, particulièrement le cartilage articulaire, les disques intervertébraux (DIV) et l'os. De plus, il a été démontré que EGR-1 peut réguler l'expression des collagènes et d'enzymes contribuant à la matrice extracellulaire. Le polymorphisme de séquences d'ADN pour les des sites d'attachements d'EGR-1 a démontré être associé avec la dégradation de disques intervertébraux et l'ostéoporose. L'objectif de cette étude était de déterminer l'effet d'une expression réduite d'EGR-1 sur les phénotypes du cartilage articulaire, les DIV, et l'os. / Les souris C57Bl/6 de phénotype sauvage (+/+) ou ceux avec une expression réduite d'EGR-1 (−/−) ont été sacrifiées au même intervalle d'âge (8 à 9 mois). La préparation histologique standard et la coloration avec Safranin-O/Fast Green a été fait. Aussi l'immunohistochimie a été exécuté avec des anticorps pour le collagène de type X, et les produits de clivage du collagène de type II ainsi que les aggrécanes. L'imagerie de souris a été faite avec les radiographies simples, les mesures de densité minéraux de l'os, et avec l'analyse de micro-tomodensitomètre. / Les résultats ont révélé que ces souris ont des différences incluant la structure et densité d'os anormaux, les différences structurelles et possiblement compositionnelles dans le cartilage articulaire, et les changements structurels et biochimiques dans les DIV. Ceci indique à l'importance d'EGR-1 dans l'entretien d'os normal, des DIV et le cartilage articulaire, et le rend une cible possible pour initier les conditions pathologiques de ces tissus.

Preservation of female fertility is an important issue today. There are a few effective clinical options for preserving female fertility. Conventional IVF followed by embryo cryopreservation is the only established procedure but is not applicable to all women. Oocyte cryopreservation avoids the ethical and moral concerns related to cryopreservation of embryos but conventional slow freezing methods are associated with low survival rate of oocytes. The main objective of this translational research thesis was to develop an efficient and safe methodology for oocyte cryopreservation that is clinically applicable for female fertility preservation. Specific research objectives were to investigate cryobiology of oocytes in terms of: 1) cryoprotectant (CPA) toxicity effect on oocyte ultra-structures and embryonic developmental potential; 2) Vitrification versus conventional slow freezing of oocytes and their effects of oocyte structures and embryonic developmental potential; 3) Vitrification of embryos using the McGill Cryoleaf and its effect of embryonic development and DNA fragmentation; 4) Clinical efficacy of oocyte vitrification in prospective clinical trials; 5) Effects of oocyte vitrification in terms of the clinical obstetrical and perinatal outcomes; 6) Clinical applications of vitrification of oocytes for preservation of female fertility. The CPA mixture of ethylene glycol (EG) and 1,2-propanediol (PROH) was found to be the most suitable combination for oocyte vitrification, resulting in high embryo development and the least DNA fragmentation. Vitrification of oocyte using the CPA mixture of EG and PROH in combination with the McGill Cryoleaf system is superior to the conventional slow-cooling method, resulting in better preservation of egg ultra-structures and functions. The reduced embryonic development potential of cryopreserved oocyte is related to increased DNA fragmentation and activation of caspase enzymes. Vitrification of human oocytes using the McG / Préservation de la fécondité est un sujet important à ce jour. Il y a peu de traitements effectifs pour préserver la fécondité des femmes. La fécondation in vitro (FIV) conventionnelle suivie par la cryoconservation des embryons est la seule procédure bien établie. Cependant, celle-ci n'est pas possible pour certaines femmes. La cryopréservation des ovocytes évite les problèmes éthiques et moraux reliés à la cryoconservation des embryons. Cependant, les méthodes de congélation lente sont associées à des taux de survie des ovocytes faible. Les objectifs principaux de cette thèse de recherche translationnelle était de développer une méthode efficace et sécuritaire pour la cryopréservation des ovocytes qui est cliniquement applicable pour la préservation de la fécondité des femmes. Les objectifs spécifiques de cette recherche étaient d'étudier la cryobiologie des ovocytes à propos de : 1) l'effet toxique du cryoprotectant sur l'ultra-structures des ovocytes et le potentiel de développement des embryons; 2) la vitrification versus la congélation lente des ovocytes et leur effets sur la structure des ovocytes et le potentiel de développement embryonnaire; 3) la vitrification des embryons en utilisant le McGill Cryoleaf et son effet sur le développement embryonnaire et la fragmentation de l'ADN; 4) l'efficacité clinique de vitrification des ovocytes dans des études prospectives cliniques; 5) les effets de long terme de vitrification des ovocytes au niveau des résultats obstétriques et périnatals; 6) l'application clinique de vitrification des ovocytes pour la préservation de la fécondité des femmes. Le mélange de CPA de l'éthylène glycol (EG) et de 1-2 propanediol (PROH) a été trouvé d'être la combinaison la plus convenable pour la vitrification des ovocytes en donnant des résultats de développement embryonnaire supérieur et à un taux de fragmentation de l'ADN diminué. La vitrification des ovocytes en utilisant l