Pericytes are distinctive regulators of angiogenesis and are adumbrated to provide vessel stability and control of endothelial proliferation. The present article spotlights the persona of pericytes in physiological angiogenesis, recruitment of pericytes and different mechanisms of pericyte depletion. Developing retina appears particularly dependent on pericytes, and pericyte loss is considered as hallmark of early diabetic retinopathies. Several factors are contemplated to be engaged in pericyte conscription including angiopoietin-1 and its receptor tyrosine kinase Tie-2, vascular endothelial growth factor-A and its receptor flk-1 and the platelet-derived growth factor PDGF-B/PDGF-beta system. At present, the mechanisms by which diabetes persuade apoptosis in the retinal microvasculature remain indecisive, albeit oxidative stress, formation of advanced glycation end products , upregulation of protein kinase C, increased polyol pathway flux and focal leukostasis may be important. In this context, accelerated microvascular cell death may become a constructive surrogate end-point in pharmacological studies of experimental diabetic.

Successful wound healing depends upon angiogenesis, and impaired angiogenesis is a hallmark of the chronic wounds encountered with diabetes and venous or arterial insufficiency. To intervene and improve wound closure, it is essential to investigate the effects of different natural remedies in wound healing. The chicken dorsum skin excisional wound assay was used to investigate the influence of different concentrations of aged garlic solution (AGS) on wound healing. Gross, histopathology, scanning electron microscopy (SEM) and computer-based three-dimensional (3D) image-probing techniques were utilized to determine the effects of AGS on wound closure, re-epithelialization, dermal matrix regeneration, and angiogenesis. Ninety chicks, aged 1 week and divided in 6 groups, were topically exposed to different concentrations of AGS for 6 days: control (group A), 1% (group B), 5% (group C), 10% (group D), 15% (group E), and skin lotion (group F). Different patterns, ranging from incomplete to almost complete wound closure, were observed among different groups with highly significant results (P < 0.001) in group E. Histological investigations revealed a positive augment in the re-epithelialization of all AGS exposed wounds. An increase in the number of new loosely packed collagen and maturation of collagen bundles was observed in all treated wounds at days 4 and 6 post-wounding, respectively. Similar results were achieved through SEM of treated wounds. Histological investigations revealed the profuse dose-dependent neovascularization among AGS-treated wounds. Abbott curve, angular spectrum, and different parameters of 3D surface roughness of wounds were also measured for the precise quantification of angiogenesis. A very highly significant (P < 0.001) increase in angiogenesis was observed among all treated groups. No significant change was observed among control and skin lotion-treated groups. These observations substantiate the beneficial use of AGS in the treatment of wounds. Additional studies are needed to study the specific wound-healing mechanisms of chemical, or group of chemicals, present in AGS.

A 25-yr-old male freshwater crocodile (Crocodylus johnstoni) was diagnosed with pulmonary mycobacteriosis caused by Mycobacterium szulgai. Necropsy revealed fibrinous exudate in the right pleural cavity and white miliary nodules in the right lung lobe. Histopathologic examination revealed well-demarcated granulomas consisting of multinucleated giant cells and epithelioid cells surrounded by fibrous connective tissue. Atypically, lymphocytes had accumulated in the outer region of fibrous connective tissue. Mycobacterial infection was confirmed by nested polymerase chain reaction targeting the hsp65 gene and by Fite's method for detection of acid-fast bacilli within formalin-fixed, paraffin-embedded lung tissue. Sequence analysis of the DNA amplicon revealed that the species of mycobacterium shared 98% homology with the gene encoding the hsp65 gene of M. szulgai. This is the first report of M. szulgai as the causative agent of mycobacteriosis in a reptile.

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Decisive indulgence of angiogenesis requires a more holistic assessment and several in vivo assays have been developed that permit a more realistic appraisal of the angiogenic response. One of the most popular assays to study angiogenic activity is the chick chorioallantoic membrane (CAM). Although CAM assay is a vital technique used to study normal and putative angiogenesis, a serious drawback in its utilization is the lack of quantitative assessment of vascularization. In this study, we proposed a new 3-D model of the developing CAM for precise quantification of normal vasculature of CAM from Day 4 to Day 13 of incubation. Image probing technique was used to quantify different 3-D parameters of vascular microarchitecture. A significant increase (P < 0.05) in surface roughness (Sa) was observed at Day 5 of incubation, while highly significant increase (P < 0.01) in Sa values was observed at Day 6 of incubation. Maximum increase (P < 0.001) in Sa values was observed from Day 7 to Day 9 of incubation and slight decrease in Sa values was observed in successive days. Similar results were observed for root mean square values (Sq), absolute heights of the surface (Sz), and amount of lowest valleys (Sy) on CAM. A significant increase (P < 0.05) in developed surface area (Sdr) from Day 5 of incubation, reaching to its maximum (P < 0.01) at Day 9 also was noted. Similarly, significant increase (P < 0.05) in fluid core retention (Sci) illustrates presence of copious fluid in blood vessels. Image probing technique offers a useful modality for visualizing 3-D microvascular architecture of CAM to exaggerate the fine details and reveal the hidden information that can be helpful for precise quantification of angiogenesis. This approach can be used to evaluate the angiogenic and antiangiogenic potential of different biological substances and also can be a valuable independent prognostic indicator in a wide variety of human cancers.