Cross-Linking in Collagen by Nonenzymatic Glycation Increases the Matrix Stiffness in Rabbit Achilles Tendon

Nonenzymatic glycation of connective tissue matrix proteins is a major contributor to the pathology of diabetes and aging. Previously the author and colleagues have shown that nonenzymatic glycation significantly enhances the matrix stability in the Achilles tendon (Reddy et al., 2002, Arch. Biochem. Biophys., 399, 174–180). The present study was designed to gain further insight into glycation-induced collagen cross-linking and its relationship to matrix stiffness in the rabbit Achilles tendon. The glycation process was initiated by incubating the Achilles tendons (n = 6) in phosphate-buffered saline containing ribose, whereas control tendons (n = 6) were incubated in phosphate-buffered saline without ribose. Eight weeks following glycation, the biomechanical attributes as well as the degree of collagen cross-linking were determined to examine the potential associations between matrix stiffness and molecular properties of collagen. Compared to nonglycated tendons, the glycated tendons showed increased maximum load, stress, strain, Young's modulus of elasticity, and toughness indicating that glycation increases the matrix stiffness in the tendons. Glycation of tendons resulted in a considerable decrease in soluble collagen content and a significant increase in insoluble collagen and pentosidine. Analysis of potential associations between the matrix stiffness and degree of collagen cross-linking showed that both insoluble collagen and pentosidine exhibited a significant positive correlation with the maximum load, stress, and strain, Young's modulus of elasticity, and toughness (r values ranging from .61 to .94) in the Achilles tendons. However, the soluble collagen content present in neutral salt buffer, acetate buffer, and acetate buffer containing pepsin showed an inverse relation with the various biomechanical attributes tested (r values ranging from .22 to .84) in the Achilles tendons. The results of the study demonstrate that glycation-induced collagen cross-linking is directly associated with the increased matrix stiffness and other mechanical attributes of the tendon

A comparative study on placebo and trenaxamic acid for the prophylaxis is of post-partum hemorrhage: a randomised double-blind control study

Background: Obstetric haemorrhage accounts for 20-25% of maternal mortality and morbidity. Anti-fibrinolytics are being widely used in field of surgery. It is also used to reduce heavy menstrual blood loss. The aim of this study was to analyse the effectiveness of TXA in reducing blood loss during normal vaginal delivery.Methods: The randomized double-blind control study was done in the Labour ward. It was conducted on 100 women undergoing Normal vaginal delivery. They were allocated to either Study or Control group by randomization. TXA was given during the Third stage of delivery in study group in addition to the routine care whereas the control group had routine care alone. Blood loss was measured in both groups by bag method.Results: The significant of reduction in blood loss calculated from placental delivery to 2hrs. 141.9 ml in study group versus 270.4 ml in control group. Among primi patients, the control group average blood loss was 325ml, the study group avg blood loss was 169ml. Among G2 patients, the control group average blood loss was 248.5ml. The study group average blood loss was 128.25ml. Among G3 patients, the control group average blood loss was 203ml, the study group average blood loss was 115ml.Conclusions: TXA significantly reduced the amount of blood loss during normal vaginal delivery. Thus, TXA can be used safely and effectively in subjects undergoing normal vaginal delivery

The Development of Long-Term Adverse Health Effects in Oil Spill Cleanup Workers of the Deepwater Horizon Offshore Drilling Rig Disaster

BackgroundThe purpose of this study was to assess the long-term adverse health effects of the 2010 Deepwater Horizon Gulf oil spill exposure in workers who participated in its cleanup work.MethodsMedical charts of both the oil spill exposed and unexposed subjects were reviewed. The changes in the white blood cells, platelets, hemoglobin, hematocrit, blood urea nitrogen, creatinine, alkaline phosphatase (ALP), aspartate amino transferase (AST), alanine amino transferase (ALT) levels, as well as their pulmonary and cardiac functions were evaluated.ResultsMedical records from 88 subjects (oil spill cleanup workers, n = 44 and unexposed, n = 44) were reviewed during initial and 7 years follow up visits after the disaster occurred. Compared with the unexposed subjects, oil spill exposed subjects had significantly reduced platelet counts (×103/µL) at their initial (254.1 ± 46.7 versus 289.7 ± 63.7, P = 0.000) and follow-up (242.9 ± 55.6 versus 278.4 ± 67.6, P = 0.000) visits compared with the unexposed subjects (254.6 ± 51.9 versus 289.7 ± 63.7, P = 0.008). The hemoglobin and hematocrit levels were increased significantly both at their initial and follow-up visits in the oil spill exposed subjects compared to the unexposed subjects. Similarly, the oil spill exposed subjects had significantly increased ALP, AST, and ALT levels at their initial and follow-up visits compared with those of the unexposed subjects. Illness symptoms that were reported during their initial visit still persisted at their 7-year follow-up visit. Notably, at their 7-year follow-up visit, most of the oil spill exposed subjects had also developed chronic rhinosinusitis and reactive airway dysfunction syndrome as new symptoms that were not reported during their initial visit. Additionally, more abnormalities in pulmonary and cardiac functions were also seen in the oil spill exposed subjects.ConclusionThis long-term follow-up study demonstrates that those people involved in the oil spill cleanup operations experiences persistent alterations or worsening of their hematological, hepatic, pulmonary, and cardiac functions. In addition, these subjects experienced prolonged or worsening illness symptoms even 7 years after their exposure to the oil spill