Peripapillary intrachoroidal cavitation at the crossroads of peripapillary myopic changes.

AIM: To analyze the prevalence of peripapillary intra-choroidal cavitation (PICC) in eyes with gamma peripapillary atrophy (γPPA), in eyes with peripapillary staphyloma (PPS) and in those combining γPPA and PPS and to analyze border tissue discontinuity in PICC. METHODS: This prospective cross-sectional non interventional study included highly myopic eyes. Non-highly myopic eyes were used as control. Radial and linear scans centered on the optic nerve head were performed using spectral-domain optical coherence tomography. Variables were analyzed along the twelve hourly optical coherence tomography sections in both eyes of each subject. RESULTS: A total of 667 eyes of 334 subjects were included: 229 (34.3%) highly myopic eyes and 438 (65.7%) non highly myopic eyes. The mean age of the highly myopic group was 48.99±17.81y. PICC was found in a total of 40 eyes and in 13.2% (29/220) of highly myopic eyes. PICC was found in 10.4% (40/386) of eyes with γPPA, in 20.5% (40/195) of eyes with PPS and in 22.7% (40/176) of those combining γPPA and PPS. All the eyes with PICC showed the co-existence of γPPA and PPS whereas none of the eyes presenting only one of these entities exhibited PICC. A border tissue discontinuity in the γPPA area was found in all eyes with PICC. CONCLUSION: We confirm the presence of a border tissue discontinuity in the γPPA area of all eyes with PICC. These findings suggest the involvement of mechanical factors in the pathogenesis of PICC which may contribute to PICC-related visual field defects.

Acrylamide does not induce tumorigenesis or major defects in mice in vivo.

Chronic administration of acrylamide has been shown to induce thyroid tumors in rat. In vitro acrylamide also causes DNA damage, as demonstrated by the comet assay, in various types of cells including human thyroid cells and lymphocytes, as well as rat thyroid cell lines. In this work, mice were administered acrylamide in their drinking water in doses comparable with those used in rats, i.e., around 3-4 mg/kg per day for mice treated 2, 6, and 8 months. Some of the mice were also treated with thyroxine (T(4)) to depress the activity of the thyroid. Others were treated with methimazole that inhibits thyroid hormone synthesis and consequently secretion and thus induces TSH secretion and thyroid activation. These moderate treatments were shown to have their known effect on the thyroid (e.g. thyroid hormone and thyrotropin serum levels, thyroid gland morphology...). Besides, T(4) induced an important polydipsia and degenerative hypertrophy of adrenal medulla. Acrylamide exerted various discrete effects and at high doses caused peripheral neuropathy, as demonstrated by hind-leg paralysis. However, it did not induce thyroid tumorigenesis. These results show that the thyroid tumorigenic effects of acrylamide are not observed in another rodent species, the mouse, and suggest the necessity of an epidemiological study in human to conclude on a public health policy.

Computed tomography and magnetic resonance imaging in the assessment of acute pancreatitis.

BACKGROUND & AIMS: This study aimed to compare the accuracy of magnetic resonance imaging (MRI) with computed tomography (CT) in assessing acute pancreatitis (AP) and to explore the correlation between MRI findings and clinical outcome. METHODS: Patients with AP were investigated by contrast-enhanced CT and MRI on admission and 7 and 30 days thereafter. MRI was performed with intravenous secretin and contrast medium. Balthazar's grading system was used to measure CT and MRI severity indices (CTSI and MRSI, respectively). RESULTS: Thirty-nine patients (median age, 47 years; range, 15-86) were studied. AP was of biliary etiology in 19 patients (49%). On admission, AP was assessed clinically as severe in 7 patients (18%). A strong correlation was demonstrated between CTSI and MRSI on admission and 7 days later. MRSI on admission correlated with the following: the Ranson score, C-reactive protein levels 48 hours after admission, duration of hospitalization, and clinical outcome regarding morbidity, including local and systemic complications. Considering the Ranson score as the gold standard, MRI detected severe AP with 83% (58-96, 95% CI) sensitivity, 91% (68-98) specificity vs. 78% (52-93) and 86% (63-96) for CT. Magnetic resonance cholangiopancreatography after i.v. secretin injection showed pancreatic duct leakage in 3 patients (8%). CONCLUSIONS: MRI is a reliable method of staging AP severity, has predictive value for the prognosis of the disease, and has fewer contraindications than CT. It can also detect pancreatic duct disruption, which may occur early in the course of AP.