Fructose-induced steatosis in mice: role of plasminogen activator inhibitor-1, microsomal triglyceride transfer protein and NKT cells

Plasminogen activator inhibitor-1 (PAI-1) is an acute-phase protein known to be involved in alcoholic liver disease and hepatic fibrosis. In the present study, the hypothesis that PAI-1 is causally involved in the onset of fructose-induced hepatic steatosis was tested in a mouse model. Wild-type C57BL/6J and PAI-1?/? mice were fed with 30% fructose solution or water for 8 weeks. Markers of hepatic steatosis, expression of PAI-1, apolipoprotein B (ApoB), cluster of differentiation 1d (CD1d), markers of natural killer T (NKT) cells, protein levels of phospho-c-Met and tumor necrosis factor-α (TNF-α) were determined. Activity of the microsomal triglyceride transfer protein (MTTP) was measured in liver tissue. In comparison with water controls, chronic intake of 30% fructose solution caused a significant increase in hepatic triglycerides, PAI-1 expression and plasma alanine aminotransferase levels in wild-type mice. This effect of fructose feeding was markedly attenuated in PAI-1?/? mice. Despite no differences in portal endotoxin levels and hepatic TNF-α protein levels between fructose-fed groups, the protective effect of the loss of PAI-1 against the onset of fructose-induced steatosis was associated with a significant increase in phospho-c-Met, phospho Akt, expression of ApoB and activity of MTTP in livers of PAI-1?/? mice in comparison with fructose-fed wild types. Moreover, in PAI-1?/? mice, expressions of CD1d and markers of CD1d-reactive NKT cells were markedly higher than in wild-type mice; however, expression of markers of activation of CD1d-reactive NKT cells (eg, interleukin-15 and interferon-γ) were only found to be increased in livers of fructose-fed PAI-1?/? mice. Taken together, these data suggest that PAI-1 has a causal role in mediating the early phase of fructose-induced liver damage in mice through signaling cascades downstream of Kupffer cells and TNF-α.     

Characterization of Corynebacterium diphtheriae isolates from infected skin lesions in the Northern Territory of Australia

Corynebacterium diphtheriae is commonly isolated from cutaneous skin lesions in the Northern Territory of Australia. We prospectively assessed 32 recent isolates from infected skin lesions, in addition to reviewing 192 isolates collected over 5 years for toxin status. No isolates carried the toxin gene. Toxigenic C. diphtheriae is now a rare occurrence in the Northern Territory.     

Extensive clinical experience: relative prevalence of different androgen excess disorders in 950 women referred because of clinical hyperandrogenism

CONTEXT: We undertook this study to estimate the prevalence of the various androgen excess disorders using the new criteria suggested for the diagnosis of polycystic ovary syndrome (PCOS). SETTING: The study was performed at two endocrine departments at the University of Palermo (Palermo, Italy). PATIENTS: The records of all patients referred between 1980 and 2004 for evaluation of clinical hyperandrogenism were reevaluated. All past diagnoses were reviewed using the actual diagnostic criteria. To be included in this study, the records of the patients had to present the following available data: clinical evaluation of hyperandrogenism, body weight and height, testosterone (T), free T, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone, progesterone, and pelvic sonography. A total of 1226 consecutive patients were seen during the study period, but only the scores of 950 patients satisfied all criteria and were reassessed for the diagnosis. RESULTS: The prevalence of androgen excess disorders was: PCOS, 72.1% (classic anovulatory patients, 56.6%; mild ovulatory patients, 15.5%), idiopathic hyperandrogenism, 15.8%; idiopathic hirsutism, 7.6%; 21-hydroxylase-deficient nonclassic adrenal hyperplasia, 4.3%; and androgen-secreting tumors, 0.2%. Compared with other androgen excess disorders, patients with PCOS had increased body weight whereas nonclassic adrenal hyperplasia patients were younger and more hirsute and had higher serum levels of T, free T, and 17-hydroxyprogesterone. CONCLUSIONS: Classic PCOS is the most common androgen excess disorder. However, mild androgen excess disorders (ovulatory PCOS and idiopathic hyperandrogenism) are also common and, in an endocrine setting, include about 30% of patients with clinical hyperandrogenism.     

Primary diphtheria immunisation of adolescents and adults with low-dose vaccine,a survey of historic evidence from the literature

The Public Health Agency of Sweden carried out a literature review on diphtheria vaccinations for seronegative people above 6 years of age with an uncertain vaccine history. The aim was to harmonise national Swedish recommendations with the current World Health Organization recommendations. There was no firm conclusion about dosage. Some low-dose vaccines used in the past had suboptimal potency, while others evoked adequate levels of antitoxin after three primary doses. We concluded that low-dose diphtheria vaccines that have been approved by a national medical products agency can be used for primary vaccination against diphtheria for individuals above 6 years of age.     

White matter microstructure in habit and reward circuits in anorexia nervosa: Insights from a neurite orientation dispersion and density imaging study

Background

Behavioral features of anorexia nervosa (AN) suggest abnormalities in reward and habit. Neuroimaging evidence suggests morphometric and functional perturbations within these circuits, although fewer studies have assessed white matter characteristics in AN, and no studies to date have assessed white matter microstructure in AN.

Methods

In this brain imaging study, 29 female adolescents with partially or fully weight-restored AN and 27 healthy controls, all between 10 and 19 years, underwent whole-brain multi-shell diffusion tensor imaging. Utilizing neurite orientation dispersion and density imaging methods, we investigated group differences in white matter neurite density, orientation dispersion, and myelin density in tracts between prominent nodes of the reward circuit (ventral tegmental area (VTA) to nucleus accumbens (NAcc)) and the habit circuit (sensory motor area [SMA] to putamen).

Results

Findings revealed reduced neurite (F = 5.20, p = 0.027) and myelin density (F = 5.39, p = 0.025) in the left VTA-NAcc tract, and reduced orientation dispersion in the left (F = 7.00, p = 0.011) and right (F = 6.77, p = 0.012) VTA-NAcc tract. There were no significant group differences in the SMA-putamen tract. Significant relationships, after corrections, were not evident between tract microstructure and reward responsiveness, compulsive behaviors, illness duration, or BMI.

Conclusions

Adolescents with AN exhibit less dense, undermyelinated, and less dispersed white matter tracts connecting prominent reward system nodes, which could potentially signify underutilization of this part of the reward circuit. These results provide a detailed examination of white matter microstructure in tracts underlying instrumental behavioral phenotypes contributing to illness in AN.