Search

In this chapter, geographical distribution of nontuberculous mycobacteria both in clinical and environmental isolates are investigated by analyzing the data performed using geographical information system. The distribution of each reported clinical species is analyzed and compared to environmental samples reported within same period of time.

In this chapter, chest X-ray and computed tomography findings are used to differentiate between nontuberculous mycobacteria (NTM) and tuberculosis infection. Common and recognized patterns of NTM infection include cavitary diseases, bronchiectasis, and pulmonary infections in AIDS patients. Less commonly, the nodular pattern, a mass mimicking malignancy and of hypersensitivity pneumonitis can be seen. Any diagnosis requires a combination of laboratory, clinical and radiological findings.

This chapter provides a comprehensive overview and detailed information concerning tissue engineering for researchers and clinicians. Basically, tissue engineering can be best defined as the interactive effect of cells, scaffold, and growth factors (GFs) for improving or replacing biological functions. Cell in tissue engineering refers to the stem cell or cells that are in different stages of differentiation. These cells seed in tissue culture or are directly injected into the desired organ. Scaffold is a three-dimensional (3D) structure that is made from biodegradable and biocompatible polymers, either natural, synthetic, or a mixture of both. The nanostructural components of the scaffold act as an extracellular matrix (ECM) and increase cellular attachment to induce shear stress and promote cell maturation. For enhanced cellular functions compared to traditional scaffolds, nanostructural scaffolds deliver signaling molecules such as mitogens, GFs, and morphogens that support cell adhesion, proliferation, differentiation, and control the generation of tissue. Nanostructural scaffolds attach to GFs with simple adsorption, electrostatic, or covalent binding. Nanofibrous and nanocomposite scaffolds are used for the regeneration of various tissues. Electrospinning nanofibrous scaffolds are very similar in physical structure to natural nanofibers in ECM. These fibers fabricate a tunable pore structure and the formation of sponge-like scaffolding. Nanocomposite scaffolds are mechanical strength and electrical conductivity and are incorporated into 3D architectures. Drug-delivery systems in nanoscale include nanoparticles, nanogels, nanocapsules, and dendrimers. Nanocomposite hydrogels combine both nanofillers and hydrogel matrices to improve the mechanical and biological properties for drug delivery and tissue engineering scaffold materials. This system increases solubility and controls release and cellular uptake of signaling molecules. Controlled release of biomolecules in scaffolds dramatically enhance the maturity of tissue. Controlled release can be applied to deliver other biological molecules (plasmid DNA and siRNA) to cells to regulate cell function. Two strategies for the presentation of signaling molecules from nanostructural scaffolds are chemical immobilization and physical encapsulation.