Increased intrarenal renin-angiotensin system activity contributes to diabetic nephropathy. ANG II generation in mesangial cells (MC) is increased by high-glucose (HG) exposure. This study assessed the mechanisms involved in the glucose-induced ANG II generation in rat MC. Under basal conditions, MC mainly secreted prorenin. HG decreased prorenin secretion and induced a striking 30-fold increase in intracellular renin activity. After 72 h of HG exposure, only the mRNA levels for angiotensinogen and angiotensin-converting enzyme (ACE) were significantly elevated. However, after shorter periods of 24 h of HG stimulation the mRNA levels of the enzymes prorenin and cathepsin B, besides that for ACE, were significantly increased. The results suggest that the HG-induced increase in ANG II generation in MC results from an increase in intracellular renin activity mediated by at least three factors: a time-dependent stimulation of (pro)renin gene transcription, a reduction in prorenin enzyme secretion, and an increased rate of conversion of prorenin to active renin, probably mediated by cathepsin B. The increase in angiotensinogen mRNA in parallel to increased renin activity indicates that HG also increased the availability of the renin substrate. The consistent upregulation of ACE mRNA suggests that, besides renin, ACE is directly involved in the increased mesangial ANG II generation induced by HG.

We demonstrated the preliminary results of transplantation of EVCAU for corneal surface reconstruction in cases with total LSCD. Future studies are needed to further assess the long-term efficacy of this procedure.

High glucose (HG) increases angiotensin II (AngII) generation in mesangial cells (MC). Chymase, an alternative AngII-generating enzyme, is upregulated in the glomeruli of diabetic kidneys. In this study, we examined AngII synthesis by human MC via angiotensin-converting enzyme (ACE)-dependent and chymase-dependent pathways under normal glucose (NG, 5 mM) and HG (30 mM) conditions. NG cells expressed ACE and chymase mRNA. Under NG conditions the chymase inhibitor chymostatin reduced AngII levels in cell lysates and in the culture medium, and the ACE inhibitor captopril had no effect. HG induced a 3-fold increase in chymase mRNA and protein but not in ACE mRNA; however, HG induced a 10-fold increase in intracellular ACE activity. The increase in AngII generation induced by HG was found in the cell lysate but not in the culture medium. The rise in intracellular AngII was not prevented by captopril or by chymostatin. Moreover, captopril inhibited extracellular ACE activity but failed to block intracellular ACE activity; these results suggested that captopril was unable to reach intra-cellular ACE. Losartan did not change the intracellular AngII content in either NG or HG conditions, and this lack of change suggested that the increase in AngII was due to intracellular generation. Together these results suggest that chymase may be active in human MC and that both ACE and chymase are involved in increased AngII generation during the HG stimulus by different mechanisms, including an upregulation of chymase mRNA and a rise in intracellular ACE activity, favoring the generation and accumulation of intracellular AngII.

0.05) regarding the clinical evaluation on 1st, 7th and 30th PO days. On transmission electron microscopy, the basement membrane in lyophilized and control groups was more continuous and homogeneous than in the glycerol group. CONCLUSIONS: The freeze-drying method seems to be a good option to preserve human amniotic membrane to be used in ocular surface reconstruction. This preservative method reduces the preservation costs and may enhance the use of AM, facilitating its storage and transport.]]>

Dry eye is a multifactorial disease comprising a wide spectrum of ocular surface alterations and symptoms of discomfort. In most patients with aqueous-deficient dry eye, pharmaceutical tear substitutes are used to control symptoms and prevent ocular surface damage. However, in severe dry eye conditions caused by cicatricial disorders, such as Stevens-Johnson syndrome and ocular cicatricial mucous membrane pemphigoid, noninvasive treatments are insufficient, and patients are at risk of developing complications that can lead to blindness. The use of salivary glands as a source of lubrication to treat severe cases of dry eye has been proposed by different authors. The first reports proposed parotid or submandibular gland duct transplantation into the conjunctival fornix. However, complications limited the functional outcomes. Minor salivary gland autotransplantation together with labial mucosa has been used as a complex graft to the conjunctival fornix in severe dry eye with a good outcome. Our group demonstrated significant improvements in best-corrected visual acuity, Schirmer I test score, corneal transparency, and neovascularization after using this technique. A symptoms questionnaire applied to these patients revealed improvements in foreign body sensation, photophobia, and pain. Similar to tears, saliva has a complex final composition comprising electrolytes, immunoglobulins, proteins, enzymes, and mucins. We demonstrated the viability of minor salivary glands transplanted into the fornix of patients with dry eye by performing immunohistochemistry on graft biopsies with antibodies against lactoferrin, lysozyme, MUC1, and MUC16. The findings revealed the presence of functional salivary gland units, indicating local production of proteins, enzymes, and mucins.

To evaluate the impact of instillation angle and nozzle tip geometry on crosscontamination risk of multidose ocular solution bottles. Methods: Pseudomonas aeruginosa solution was passed exclusively on the outside of the nozzle to simulate contamination on the exterior of topical agents. Three drops were administered from angles of 90°and 45°from bottles with either a round or sharp tip geometry, and the cultures were examined for growth. Two-hundred sixteen cultures from nine lubricant eyedrop brands currently existing in the Brazilian market were assessed for bacterial growth. Results: After seven days, bacterial contamination was detected in 53.7% of cultures when drops were administered at 90°and in 70.4% of cultures at 45°. Eyedrops collected from a rounded nozzle tip and an instillation angle of 90°transmitted bacteria in 69.4% of cases, whereas those administered from a sharp tip transmitted bacteria in only 22.2% of cases (P = 0.001). At an instillation angle of 45°, contamination was identified in 83.3% of bottles with a rounded tip geometry and in only eight of 18 bottles (44.4%) from those with a sharp nozzle geometry (P = 0.005). Conclusions: Adjusting the instillation angle of eyedrop solutions to 90°, as well as using a nozzle geometry that prevents flow of the solution to the side of the bottle, significantly reduced contamination rates. Translational Relevance: Standardizing drop bottles and adjusting delivery angle shows promise in reducing contamination rates and may critically impact the quality of care for patients requiring topical therapeutic agents.

The AM storage temperature of -80°C was found optimal for maintaining the concentrations of most of the tested cytokines, and enriched TC199 medium was the optimal long-term storage medium for maintaining the concentration of 3 of the cytokines, and with less decrease. When possible, AM should be used within 1 to 7 days after harvesting.

Chymase is an alternative pathway for angiotensin-converting enzyme in angiotensin II (Ang II) formation, and its expression is increased in human diabetic kidneys and in human mesangial cells (MCs) stimulated with high glucose. In addition, chymase activates transforming growth factor (TGF-β1) via an Ang II-independent pathway. The aim of this study was to evaluate the role of chymase on TGF-β1 activation in diabetic rats and in rat MCs (RMCs) stimulated with high glucose (HG). Diabetes was induced in male Wistar rats by streptozotocin (60 mg/kg, intravenous). After 30 (D30) or 60 (D60) days, chymase activity and the expression of profibrotic markers were evaluated. RMCs were stimulated with HG in the presence or absence of 50 μmol/L chymostatin, a chymase inhibitor, or 100 nmol/L of losartan, an Ang II antagonist. Chymase activity and expression increased in D60 kidneys, with increased expression of fibronectin, type I and III collagen, TGF-β1 and Smad 3 and with no change in Smad 7 expression. RMCs exposed to HG presented increases in chymase activity and expression, together with upregulation in fibrosis markers and in the TGF-β1 signaling pathway. All these effects were reversed by chymostatin and by losartan, but type 1 angiotensin II receptor blockade did not interfere with the Smad 3 and 7 pathway. Similar to HG-stimulated RMCs, control RMCs treated with chymase responded with increased expression of TGF-β1, Smad 3 and fibrosis markers. These effects were reversed by chymostatin but not by losartan. The results indicate an important role for chymase in inducing fibrosis through TGF-β1 activation, parallel with Ang II effects.