Experimental evaluation of safety and efficacy of plasma-treated poly-ε-caprolactone membrane as a substitute for human amniotic membrane in treating corneal epithelial defects in rabbit eyes

Purpose:To evaluate biocompatibility and safety of plasma-treated poly-ε-caprolactone (pPCL) membrane compared to the human amniotic membrane in the healing of corneal epithelial defects in an experimental model.Methods:This is a prospective, randomized animal study including 12 rabbits. Circular epithelial injury measuring 6 mm in diameter was induced over the central cornea of one eye in twelve rabbits. The rabbits were randomized into two groups; in group A, the defect was covered with human amniotic membrane, while in group B, an artificial membrane made of bio-polymer plasma-treated poly-ε-caprolactone was grafted. Six rabbits were euthanized after 1 month and the other six after 3 months and the corneal epithelium was evaluated histopathologically and with immunohistochemistry.Results:Light microscopy of the corneal tissue performed after 1 month and 3 months demonstrated similar findings with no significant complications in either group. Immunohistochemistry with anti-CK-3 antibody showed characteristic corneal phenotype in the healed epithelium. In eyes grafted with pPCL membrane, epithelial healing as estimated by a decrease in size of the defect was significantly better than the group treated with the human amniotic membrane at all time periods monitored (P < 0.05), except day 1 (P = 0.83). The percentage reduction in the size of the epithelial defect was also significantly more in the pPCL membrane group as compared to the human amniotic membrane at all time periods (P < 0.05 at all observations) post-implantation except day 1 (P = 0.73).Conclusion:Plasma-treated poly-ε-caprolactone membrane is safe, biocompatible, and effective in the healing of corneal epithelial defects in rabbits.     

Oral micronized progesterone for prevention of preterm birth

Objective

To evaluate oral micronized progesterone (OMP) to prevent preterm birth (PTB).

Methods

A randomized, double-blind, placebo-controlled trial of 150 women with at least one PTB who received 100 mg of OMP or placebo twice a day from recruitment (18-24 weeks) until 36 weeks or delivery.

Results

PTB occurred in 29 (39.2%) women in the OMP group (n = 74) compared with 44 (59.5%) in the control group (n = 74, P = 0.002). Mean gestational age at delivery was higher in the OMP group (36.1 vs 34.0 weeks, P < 0.001). Fewer preterm births occurred between 28 and 31 weeks plus 6 days in the OMP group (RR 0.20; 95% CI, 0.05-0.73, P < 0.001). Neonatal age at delivery (34 vs 32 weeks, P < 0.001), birth weight (2400 vs 1890 g, P < 0.001), NICU stay (> 24 h, P < 0.001), and Apgar scores (P < 0.001) were more favorable in the OMP group, and fewer neonatal deaths occurred (3 vs 7, P = 0.190).

Conclusion

OMP reduced the risk of PTB between 28 and 31 weeks plus 6 days, NICU admissions, and neonatal morbidity and mortality in high risk patients.     

Addition of L-glutamine to total parenteral nutrition and its effects on portal insulin and glucagon and the development of hepatic steatosis in rats

Infusion of total parenteral nutrition (TPN) with excess carbohydrate calories leads to hepatic steatosis in rats and is associated with an elevated portal insulin/glucagon molar ratio. Previously we have shown that adding glucagon to TPN prevents and reverses hepatic steatosis in rats, possibly by increasing hepatic lipid export. It has been reported that steatosis is eliminated in rats by the addition of L-glutamine to TPN. In this study, we examined the effect of glutamine on portal insulin and glucagon levels and the development of hepatic steatosis. Adult rats (n = 19) received internal jugular catheters: Group 1 (n = 6), saline (3 cc/hr) and chow ad libitum; Group 2 (n = 7), 25% dextrose base TPN; Group 3 (n = 6), 25% dextrose base TPN with 2% glutamine. The infusion rate of TPN was 1.2 cc/100 g body wt/hr. Daily nitrogen balance was determined and at 7 days, portal venous blood was drawn for insulin and glucagon radioimmunoassay, livers were removed for histology and lipid content determination, and the small intestines were removed for mucosal protein and DNA content determination. Panlobular vacuolization of the hepatocytes was noted on histology in Group 2 (TPN) while Group 1 (chow) and Group 3 (TPN + glutamine) showed normal liver morphology. Hepatic lipid content was significantly elevated in Group 2 (P less than 0.05). The portal insulin/glucagon molar ratio was increased because of excessive portal venous insulin in Group 2 (TPN). In contrast, portal glucagon was significantly elevated while the insulin/glucagon ratio and hepatic lipid content did not increase above control levels in the glutamine-supplemented Group 3 rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aortic debranching for descending thoracic aortic aneurysm repair by stent grafts

Endovascular repair of a descending thoracic aortic aneurysm may result in covering the ostia of the left carotid or left subclavian artery for proper proximal landing zones, and the celiac artery or superior mesenteric artery ostia in the abdomen for distal landing zones. To prevent possible complications of occluding the ostia of these vessels, the authors performed an innominate to left common carotid and left subclavian artery bypass as the first procedure in one patient. In the second patient they performed an aortoceliac and aortomesenteric bypass before stent graft placement. The stent graft repair of the descending thoracic aortic aneurysm was performed subsequently in both patients. This aortic debranching provides subsequent proper placement of thoracic stent grafts.