Epidural anesthesia improves pancreatic perfusion and decreases the severity of acute pancreatitis

AIM: To study the safety of epidural anesthesia(EA),its effect on pancreatic perfusion and the outcome of patients with acute pancreatitis(AP).METHODS: From 2005 to August 2010,patients with predicted severe AP [Ranson score ≥ 2,C-reactive protein 100 or necrosis on computed tomography(CT)] were prospectively randomized to either a group receiving EA or a control group treated by patientcontrolled intravenous analgesia. Pain management was evaluated in the two groups every eight hours using the visual analog pain scale(VAS). Parameters for clinical severity such as length of hospital stay,use of antibiotics,admission to the intensive care unit,radiological/clinical complications and the need for surgical necrosectomy including biochemical data were recorded. A CT scan using a perfusion protocol was performed on admission and at 72 h to evaluate pancreatic blood flow. A significant variation in blood flow was defined as a 20% difference in pancreatic perfusion between admission and 72 h and was measured in the head,body and tail of the pancreas.RESULTS: We enrolled 35 patients. Thirteen were randomized to the EA group and 22 to the control group. There were no differences in demographic characteristics between the two groups. The Balthazar radiological severity score on admission was higher in the EA group than in the control group(mean score 4.15 ± 2.54 vs 3.38 ± 1.75,respectively,P = 0.347) and the median Ranson scores were 3.4 and 2.7 respectively(P = NS). The median duration of EA was 5.7 d,and no complications of the epidural procedure were reported. An improvement in perfusion of the pancreas was observed in 13/30(43%) of measurements in the EA group vs 2/27(7%) in the control group(P = 0.0025). Necrosectomy was performed in 1/13 patients in the EA group vs 4/22 patients in the control group(P = 0.63). The VAS improved during the first ten days in the EA group compared to the control group(0.2 vs 2.33,P = 0.034 at 10 d). Length of stay and mortality were not statistically different between the 2 groups(26 d vs 30 d,P = 0.65,and 0% for both respectively).CONCLUSION: Our study demonstrates that EA increases arterial perfusion of the pancreas and improves the clinical outcome of patients with AP.     

SARS-CoV-2 Reinfection in a Healthcare Worker Despite the Presence of Detectable Neutralizing Antibodies

So far, only a few reports about reinfections with SARS-CoV-2 have been published, and they often lack detailed immunological and virological data. We report about a SARS-CoV-2 reinfection with a genetically distinct SARS-CoV-2 variant in an immunocompetent female healthcare worker that has led to a mild disease course. No obvious viral escape mutations were observed in the second virus variant. The infectious virus was shed from the patient during the second infection episode despite the presence of neutralizing antibodies in her blood. Our data indicate that a moderate immune response after the first infection, but not a viral escape, did allow for reinfection and live virus shedding.     

Aspects of Informed Consent in Medical Practice in the Eastern Mediterranean Region During the 17th and 18th Centuries

Informed consent is a question of central importance in contemporary medical ethics, and clinical practice is inconceivable without considering the issues it raises. Although it is often vigorously argued that consent, informed or otherwise, is a recent phenomenon and that no sources testify to its existence before the 20th century, it is difficult to accept that a process for regulating the common and fundamental parameters in the relationship between doctor and patient and the planning of treatment had not concerned previous eras. A review of the Registers of the Islamic Court of Candia (Heraklion) in Crete, a series of records that touches on, among other things, matters of medical interest, reveals that the concept of informed consent was not only known during a period that stretched from the mid-17th to the early 19th century, but it was concerned with the same principles that prevail or have been a point of contention today. An extension of this study into other periods may thus provide contemporary researchers with material and information valuable in the discussion of today's bioethical issues.     

Role of mitochondrial dysfunction in calcium signalling alterations in dorsal root ganglion neurons of mice with experimentally-induced diabetes

The role of mitochondrial dysfunction in alterations of calcium signalling in primary sensory neurons has been studied in mice with streptozotocin-induced and genetically predisposed diabetes mellitus before and after additional treatment with insulin infusions. Cytosolic calcium transients triggered by membrane depolarization were measured using a membrane-permeable form of fluorescent indicator indo-1, and their changes after application of mitochondrial uncoupler carbonyl cyanide m-chlorphenylhydrazone were compared in cells of control and diabetic animals. Considerable prolongation of residual elevation of cytosolic calcium after termination of membrane depolarization was observed in diabetic mice, which was expressed mainly in small-sized (nociceptive) neurons. This correlated with the level of hyperglycemia, which was maximal in cells from streptozotocin-treated mice. Insulin partly reversed these changes. Carbonyl cyanide m-chlorophenylhydrazone application to neurons of control mice enlarged the peak of calcium transients and decreased residual calcium elevations, indicating that mitochondria in physiological conditions participate in shaping of these transients by diminishing their peak due to rapid uptake of calcium ions and by prolonging them due to subsequent slow calcium release back into the cytosol. Depression of the calcium accumulating function of mitochondria by carbonyl cyanide m-chlorophenylhydrazone eliminated these changes. The prolonged residual elevation of cytosolic calcium characteristic for neurons of diabetic animals was also eliminated by carbonyl cyanide m-chlorophenylhydrazone, confirming the suggestion that such elevation is determined mainly by mitochondrial dysfunction, the latter being dependent on the level of hyperglycemia. Predominant expression of such changes in small-sized neurons can be explained by the absence in them of effective calcium-buffering by the endoplasmic reticulum. Possible role of the described calcium signalling changes in the origin of neuropathic syndromes is discussed.     

In situ monitoring of tendon structural changes by elastic scattering spectroscopy: correlation with changes in collagen fibril diameter and crimp

The aim of this study was to monitor structural changes in loaded rabbit digital flexor tendons in situ and ex situ via elastic scattering spectroscopy (ESS). The optical setup consisted of a xenon white light source (lambda = 320-860 nm), connected to a fiber optic probe (with a source-detector separation of approximately 350 microm) and a spectrometer, controlled by a personal computer (PC). Cadaveric rabbit tendons were studied in situ under 3 tensional regimens: unloaded (no extrinsic tension applied), stretched, and 1-kg loaded and compared with excised tendons (i.e., no tension). Four times more light was detected in in situ unloaded tendons perpendicular to the tendon long axis than parallel to it. Backscatter anisotropy was expressed as the anisotropy factor (AF600nm: ratio of greatest to least backscatter intensity, measured with orthogonal probe positions). Differences in backscatter anisotropy between tendons from different digits were not significant. AF600nm had the smallest value (2.72 +/- 0.38) for the least aligned tendon preparations (excised tendons), and increased to 7.17 +/- 0.54 (1-kg loaded) as in situ loads were applied. Electron microscopy revealed that the distribution of collagen fibril diameters changed as loads were applied, with the diameter of larger fibrils decreasing approximately 33% for 1-kg loaded compared with excised tendons. Polarized light microscopy showed a characteristic crimp pattern in excised tendons, but this was hardly detectable in unloaded tendons and not detectable in tendons fixed in situ under a 1-kg load. We propose that the increase in optical anisotropy is a function of collagen fibril straightening and reducing fibril diameter as the tendon undergoes progressive loading. These findings are important for monitoring structure in vivo and in bioreactors for tissue engineers.     

Comparative Performance Analysis of State-of-the-Art Classification Algorithms Applied to Lung Tissue Categorization

In this paper, we compare five common classifier families in their ability to categorize six lung tissue patterns in high-resolution computed tomography (HRCT) images of patients affected with interstitial lung diseases (ILD) and with healthy tissue. The evaluated classifiers are naive Bayes, k-nearest neighbor, J48 decision trees, multilayer perceptron, and support vector machines (SVM). The dataset used contains 843 regions of interest (ROI) of healthy and five pathologic lung tissue patterns identified by two radiologists at the University Hospitals of Geneva. Correlation of the feature space composed of 39 texture attributes is studied. A grid search for optimal parameters is carried out for each classifier family. Two complementary metrics are used to characterize the performances of classification. These are based on McNemar’s statistical tests and global accuracy. SVM reached best values for each metric and allowed a mean correct prediction rate of 88.3% with high class-specific precision on testing sets of 423 ROIs.     

Contrast enhanced ultrasonography versus MR angiography in aortocaval fistula: case report

Aortocaval fistula (ACF) is a rare, life threatening complication of abdominal aortic aneurysms. Time to diagnosis is crucial as preoperative diagnosis and early surgical intervention significantly improve the outcome. The clinical spectrum being varied, the challenge of prompt and reliable diagnosis rests on emergency radiology. While the gold standard for detecting ACF today is CT angiography (CTA), frequently complicating renal insufficiency discourages the use of iodinated contrast making MR angiography (MRA) a useful alternative. Contrast enhanced ultrasound (CEUS) provides a promising new diagnostic option allowing rapid, non invasive and bedside diagnosis, especially in hemodynamically unstable patients. We present a case of prompt diagnosis of ACF by CEUS in comparison to modern MRA, thus establishing the new potential role of CEUS.