Lipid disorder and transplant coronary artery disease in long-term survivors of heart transplantation

BACKGROUND: Transplant coronary artery disease is the major cause of late mortality after heart transplantation. The underlying mechanism probably involves various factors including immunologic and nonimmunologic factors. METHODS: The influence of various risk factors concerning both the development and the progression of transplant coronary artery disease was analyzed. Fifty-two heart transplant patients, who survived at least 2 years after transplantation (24 to 60 months), were included. RESULTS: Of these patients 38.5% had angiographic evidence of transplant coronary artery disease. They had significantly higher values of total cholesterol, low-density lipoprotein cholesterol, and log triglycerides than patients without evidence of the disease (p = 0.037, p = 0.002, and p = 0.015, respectively). In addition, preoperative diagnosis of coronary artery disease was a predictor of the development of transplant coronary artery disease, whereas significant differences were not found corresponding to recipient age, donor age, ischemic time, body mass index, lipoprotein (a) value, high-density lipoprotein cholesterol value, time after transplantation, number of postoperative rejection episodes, or prednisone dosage. A 12-month angiographic follow-up indicated disease progression in 25% of the patients. With respect to the majority of factors analyzed within the study, the differences between patients with and those without progression were comparable to the differences between patients in whom transplant coronary artery disease developed and those in whom it did not. However, patients exhibiting disease progression had a higher prednisone intake dosage (p = 0.006) and had significantly higher lipoprotein (a) values (p = 0.0229) than patients without progression. CONCLUSION: This study clearly shows that in heart transplant patients surviving more than 2 years, lipid disorder is one of the main risk factors of both the development and the progression of transplant coronary artery disease.     

Untersuchungen zum Abbau von Maillard-Reaktionsprodukten durch amylolytische Enzyme

The enzymatic degradation of thermal treated α-glucans with amylolytic enzymes depends on the reaction environment (T, pH, moisture), the degree of polymerisation (DP) and the branch of the substrates as well as on the presence of amino compounds. The chemical changes of the α-glucans due to thermolysis at 180 °C are characterized by means of the amount of reducing substances and the amount of maltooligosaccharides (HPLC). In general the enzymatic degradability of the thermal treated α-glucans is decreased with increasing time of thermolysis, temperature and moisture content. The enzyme activity with the thermal treated α-glucans is diminished in the same way. The addition of amino compounds reduces the enzymatic degradability only at the beginning of the reaction. With increasing time of thermolysis the thermolysates without glycine addition are hardly degradated. As reason for these differences in the enzymatic degradation transglycosylation and non-enzymatic browning reactions (caramalisation/ Maillard-reaction) are assumed.     

Fatigue performance of metastable β titanium alloys: Effects of microstructure and surface finish

This investigation examined the role of microstructure and surface finish on the high cycle fatigue (HCF) performance of TIMETAL LCB (Ti-6.8Mo-4.5Fe-1.5Al). The as-received microstructure of LCB consisted of elongated β grains with a semicontinuous grain boundary α layer. In contrast, a fine equiaxed β + spheroidized α LCB microstructure was achieved by hot swaging and solution (recrystallization) anneal. The latter modification of the prior β grain structure, together with the size, morphology, and distribution of the primary α phase, resulted in a significant enhancement in the tensile and HCF properties. Furthermore, prestraining (PS), as would be expected during the fabrication of an automotive coil spring, and prior to aging for 30 min at temperatures between 500 and 550 °C, led to additional increases in tensile strength. In contrast, the HCF performance was always reduced when PS prior to aging was included in the overall processing procedure. Finally, shot-peening and roller-burnishing both resulted in an increased fatigue life in the finite life regimen; however, significant reductions in the 10⁷ cycle fatigue strengths were observed when these procedures were used. These observations have been explained by including the effect of process-induced residual tensile stresses in the fatigue analysis, resulting in subsurface fatigue crack nucleation. This paper was presented at the Beta Titanium Alloys of the 00’s Symposium sponsored by the Titanium Committee of TMS, held during the 2005 TMS Annual Meeting & Exhibition, February 13–16, 2005 in San Francisco, CA.     

Application of a 2D hydrodynamic model to design of reach‐scale spawning gravel replenishment on the Mokelumne River,California

In‐stream chinook salmon (Oncorhynchus tschawytscha) spawning habitat in California's Central Valley has been degraded by minimal gravel recruitment due to river impoundment and historic gravel extraction. In a recent project marking a new direction for spawning habitat rehabilitation, 2450 m³ of gravel and several boulders were used to craft bars and chutes. To improve the design of future projects, a test was carried out in which a commercial modelling package was used to design and evaluate alternative gravel configurations in relation to the actual pre‐ and post‐project configurations. Tested scenarios included alternate bars, central braid, a combination of alternate bars and a braid, and a flat riffle with uniformly spaced boulders. All runs were compared for their spawning habitat value and for susceptibility to erosion. The flat riffle scenario produced the most total, high, and medium quality habitat, but would yield little habitat under flows deviating from the design discharge. Bar and braid scenarios were highly gravel efficient, with nearly 1 m² of habitat per 1 m³ of gravel added, and yielded large contiguous high quality habitat patches that were superior to the actual design. At near bankfull flow, negligible sediment entrainment was predicted for any scenario. Copyright © 2004 John Wiley & Sons, Ltd.