Relation between insulin resistance and plasma concentrations of lipid hydroperoxides, carotenoids, and tocopherols

BACKGROUND: It is not known whether total circulating lipid hydroperoxides are increased in insulin-resistant individuals and whether this correlates with depletion of liposoluble antioxidant vitamins that are consumed during lipid peroxidation. OBJECTIVE: The goal of this study was to define the relation between resistance to insulin-mediated glucose disposal and plasma concentrations of lipid hydroperoxides and liposoluble antioxidant vitamins in healthy volunteers. DESIGN: Insulin-mediated glucose disposal was determined in 36 healthy, nondiabetic volunteers by measuring their steady-state plasma insulin (SSPI) and glucose (SSPG) concentrations in response to a 180-min constant infusion of octreotide, insulin, and glucose. In addition, fasting plasma concentrations of lipid hydroperoxides and liposoluble antioxidant vitamins were determined by using the FOX 2 assay and liquid chromatography. RESULTS: Statistically significant direct relations were observed between SSPG and mean arterial blood pressure (r = 0.44, P: = 0.008) and plasma lipid hydroperoxide concentrations (r = 0.42, P: = 0.01), whereas significant inverse correlations were found between SSPG and alpha-carotene (r = -0.58, P: = 0.0002), beta-carotene (r = -0.49, P: = 0.004), lutein (r = -0.35, P: = 0.04), alpha-tocopherol (r = -0. 36, P: = 0.04), and delta-tocopherol (r = -0.45, P: = 0.007). CONCLUSIONS: Variations in insulin-mediated glucose disposal in healthy individuals are significantly related to plasma concentrations of lipid hydroperoxides and liposoluble antioxidant vitamins. These findings suggest that total plasma lipid peroxidation is increased in insulin-resistant individuals at an early, preclinical stage, ie, well before the development of glucose intolerance and type 2 diabetes.     

Choledocholithiasis in African American and Hispanic Patients: A Comparison Between Painless Presentation and Classical Biliary Pain with Regards to Clinical Manifestations and Outcomes

Choledocholithiasis (CDL) usually presents with biliary pain. Painless CDL is also known to occur, especially in the elderly. The purpose of this study is to determine whether the mode of presentation (painful vs. painless) influences the clinical course and outcomes of CDL in African American and Hispanic patients. Ten years of admission and discharge records (January 1998–December 2007) were reviewed retrospectively, yielding 527 community hospital patients, aged 23–97 years, with the final diagnosis of CDL. Patients with painless presentation had higher odds of having comorbidities compared to patients presenting with pain. However, patients who presented with biliary pain were predominantly younger (mean age 34 years), and 59 % were Hispanic females (p = 0.001). In our study painless CDL was associated with higher morbidity and mortality.     

Indoleamine 2,3-dioxygenase is expressed in the endometrium of cycling mice throughout the oestrous cycle

Indoleamine 2,3-dioxygenase (IDO), an enzyme responsible for tryptophan catabolism, is thought to be required to prevent the rejection of the allogenic fetus by maternal T cells and to protect against intra- and extra-cellular pathogens. Consequently, we studied the expression of IDO in the endometrium of female Balb/c mice during the oestrous cycle. At each phase, the endometrium was peeled away and the relative expression of IDO mRNA was detected by semi-quantitative RT-PCR. The presence of IDO protein was confirmed in each phase by Western blotting and immunohistochemistry. Our results showed that IDO is expressed in the endometrium of cycling mice during all the phases of oestrous cycle. The expression of IDO was highest at the oestrus and lowest at the dioestrus. By means of Western blotting and immunohistochemistry, we obtained evidence that IDO protein is synthesised in the endometrium of cycling mice throughout the oestrous cycle. In accordance with RT-PCR results, IDO protein was predominant at the oestrus phase. IDO protein was mainly localised in the glandular and luminal epithelial cells. Our results support the concept of IDO providing a mechanism of innate immunity to protect from ascending infections of the female reproductive tract. In addition, considering the fact that mating only occurs during the oestrus phase, the high expression of IDO in this phase is likely to be a mechanism that induces immunological tolerance of the fetus.     

Asymmetric septal hypertrophy in patients on long-term hemodialysis.

Echocardiographic studies were performed in 23 hypertensive patients who were receiving therapy with long-term hemodialysis. Five patients (22 percent) had normal thickness of the left ventricular wall. Eleven (48 percent) had symmetric left ventricular hypertrophy, and seven (30 percent) showed asymmetric septal hypertrophy, with a ratio of septal to posterior wall thickness of 1.3 or greater. The latter group differed from patients with hypertrophic cardiomyopathy in that patients on long-term hemodialysis had a dilated left ventricular dimension, a relatively normal diastolic slope of the mitral valve, absence of systolic motion of the mitral valve, and a septal to posterior wall ratio of less than 1.5. A high incidence of asymmetric septal hypertrophy in this and other studies indicates that this condition is not specific for hypertrophic cardiomyopathy. We suggest that in addition to asymmetric septal hypertrophy, the diagnosis of hypertrophic cardiomyopathy should be made in the light of the clinical picture, as well as other echocardiographic features.