COVID-19 Disease in a Kidney Transplant Recipient With Diffuse Intrarenal Hemorrhage.

Presentation of COVID-19 in renal transplant recipients is similar to that shown in the nonimmunocompromised population; almost all recipients who have this disease present with symptoms of the respiratory system. Acute kidney injury has been found prevalent in transplant recipients with COVID-19. In those with severe COVID-19 disease who transfer to an intensive care unit prevalence of acute kidney injury is more than 50%. The pathophysiological mechanisms of kidney involvement and the type of involvement are unclear. Here, we present a 71-year-old kidney transplant recipient who was admitted to our hospital with pulmonary and renal involvement. A kidney allograft biopsy demonstrated diffuse intrarenal hemorrhage, capillary congestion, and severe acute tubular injury. COVID-19 RNA was detected by real-time polymerase chain reaction from lysed allograft tissues, but no findings of acute or chronic cellular or antibody-mediated rejection were detected. This case indicates that COVID-19 may involve the allograft by causing hemorrhage within the renal parenchymal via direct or indirect pathways.

Systemic treatment with alpha-tocopherol and/or sodium selenite decreases the progression of experimental periodontitis.

OBJECTIVE: To investigate the effects of sodium selenite (Se) and/or α-tocopherol (αT) applications on the alveolar bone loss (ABL), the number of gingival collagen fibers, inducible nitric oxide synthase (iNOS)+ and CD95+ cell numbers, and serum cytokine concentrations in experimental periodontitis in rats. MATERIALS AND METHODS: Forty Sprague Dawley rats were divided into four groups of ten as follows: group A: Se group, group B: αT group, group C: Se and αT combined group, and group D: control group (intraperitoneal (IP) saline injection applied). Using the image analysis method in the connective tissue under the connective epithelium, the numbers of iNOS, CD95 positive cells, and collagen fibers were counted. ELISA kits were used to test the concentrations of serum interleukin (IL)-1ß, IL-6, and IL-4. RESULTS: The combination of Se and αT (group C) suppressed ABL compared with the control group (group D) (P < 0.05). In group A (Se), the number of iNOS+ cells was smaller than in group D (P < 0.05). CONCLUSION: Se has been concluded to inhibit inflammation of the gum due to iNOS. Se and αT can have a remarkable important role in preventing alveolar bone loss, and particularly in combination. CLINICAL RELEVANCE: Se and/or αT application may be useful in preventing the destruction of periodontal tissue and treatment of periodontal disease.

The positive impact of platelet-derived growth factor on the repair of full-thickness defects of articular cartilage.

OBJECTIVES: This study aims to investigate the potential use and histological effects of the local administration of platelet-derived growth factor (PDGF) in the repair of full-thickness osteochondral defects in articular cartilage in an animal model. MATERIALS AND METHODS: Twenty-four adolescent 18-week-old New Zealand White rabbits with an average weight of 2500 g (range, 1600 g to 3200 g) were used in the study. The rabbits were randomly divided into three groups (n=8) as the control group (group A) and two experimental groups (groups B and C). Defects of cylindrical full-thickness (3.5 mm wide, 4 mm deep) were created in the weight-bearing area of the right knee medial femoral condyles. In group A, the defect was left empty. In group B, the defect was filled with a collagen sponge. In group C, the defect was filled with a collagen sponge impregnated with PDGF. All rabbits were followed-up for 12 weeks. Right knee medial femoral condyles were used for macroscopic and histological analyses. RESULTS: At macroscopic level, the repair tissue was similar to normal adjacent cartilage at 12 weeks in group C. The surface of the repair tissue in group C was smoother and more regular compared to groups A and B. The total histological score of defects in group C was statistically significantly superior compared to groups A and B (p<0.05). Matrix staining and immunostaining of collagen type 2 were stronger in group C compared to the other groups, indicating the presence of a tissue similar to a normal cartilage. CONCLUSION: Platelet-derived growth factor can induce repair in full-thickness defects of articular cartilage in an animal model. Thus, this study demonstrates the potential use of PDGF for full-thickness osteochondral defects.