Progenitor cells in auricular cartilage demonstrate promising cartilage regenerative potential in 3D hydrogel culture

The reconstruction of auricular deformities is a very challenging surgical procedure that could benefit from a tissue engineering approach. Nevertheless, a major obstacle is presented by the acquisition of sufficient amounts of autologous cells to create a cartilage construct the size of the human ear. Extensively expanded chondrocytes are unable to retain their phenotype, while bone marrow-derived mesenchymal stromal cells (MSC) show endochondral terminal differentiation by formation of a calcified matrix. The identification of tissue-specific progenitor cells in auricular cartilage, which can be expanded to high numbers without loss of cartilage phenotype, has great prospects for cartilage regeneration of larger constructs. This study investigates the largely unexplored potential of auricular progenitor cells for cartilage tissue engineering in 3D hydrogels

The role of vitamin A during bio-mineral tissue development in pigs

PhD ThesisSkeletal health is a critical determinant of animal health and welfare. Kyphosis is one such idiopathic skeletal disease that compromises the welfare of commercial pigs. Vitamin A regulates the expression of genes that define bone growth and development, and has been suggested to associate with kyphosis. This thesis aimed to establish the molecular basis of kyphosis, clarify vitamin A’s role on the expression of genes that regulate skeletal development, and to ascertain vitamin A’s role on gene expression in kyphotic pigs. The TGF-β signalling pathway was associated with kyphotic bone and cartilage tissues. This was due to bone and cartilage tissues showing associations with small-leucine rich proteoglycans, ASPN and DCN respectively, which regulate TGF- β signalling. Potential effects as a result of differential gene expression include reduced endochondral bone growth and deterioration of articular cartilage. The dose of vitamin A was observed to be a critical factor in the regulation of expression of skeletal genes within bone tissue. Genes related to the family of Rho-GTPases, which control cytoskeletal dynamics, were observed to be differentially regulated within the trabecular bone in response to vitamin A. In addition, vitamin A dose was observed to initially antagonise serum 25(OH) D, and upon full saturation of the liver with vitamin A, serum 25(OH) D was restored through, as of yet, unknown mechanisms. The gene GIT2, which associates with Rho-GTPases, was observed to be differentially downregulated within kyphotic trabecular bone, and showed a dose-response relationship with vitamin A supplementation. Furthermore, kyphotic pigs were indicated to have reduced vitamin D status. This research has outlined the molecular basis of kyphosis in pigs, and has indicated vitamin A and vitamin D drive the disease. The research also outlines the role of how excessive vitamin A controls the expression of genes that regulate bio-mineralisation in trabecular bone. The thesis has also offered novel insights into vitamin A’s potential role in regulating gene expression during kyphotic development

Viral infections in 47 CVID patients in allergy and immunology department of Rasool E Akram hospital in Tehran

Background: CVID is a heterogeneous primary immune deficiency with infectious, autoimmune and autoinflamatory features. It is most common symptomatic PID in Iran, with prevalence of 1 in 25000 to 50000 people. CVID has been divided into some phenotypes to produce more homogenized subpopulations. CVID is not a pure Ab deficiency .and because of both abnormalities in Tcell and innate immunity in combination with B cell dysfunction these patients are predisposed to viral and opportunistic infections. Method: prevalence of viral infections is reported in 47 CVID patients registered in Rasool E Akram hospital in Tehran. Patients have been diagnosed as CVID with the PAGID-ESID diagnostic criteria in our department or referred from other clinics for follow up and treatment. Diagnosis of viral germs has been made by clinical signs, pathological significances and in some cases by PCR. Cases: 9 patients (19%) had problems with viral infections. Infections occurred befor diagnosis of CVID in some cases or after that. Four patients (8.5 %) had problems with wart. Sever mucocutaneus HSV infection has occurred in 3 (6 %), recurrent zona in one (2 %) and CMV infection as colitis or pneumonitis in 3(6 %) patients. Sever progressive lethal CNS infection with JC virus occurred in one patient. Conclusion: evidences show that CVID is not a pure B cell defect, and we should be aware of opportunistic and viral infections that in some cases may be fatal