3-Dimensional Immunostaining and Automated Deep-Learning Based Analysis of Nerve Degeneration.

Multiple sclerosis (MS) is an autoimmune and neurodegenerative disease driven by inflammation and demyelination in the brain, spinal cord, and optic nerve. Optic neuritis, characterized by inflammation and demyelination of the optic nerve, is a symptom in many patients with MS. The optic nerve is the highway for visual information transmitted from the retina to the brain. It contains axons from the retinal ganglion cells (RGCs) that reside in the retina, myelin forming oligodendrocytes and resident microglia and astrocytes. Inflammation, demyelination, and axonal degeneration are also present in the optic nerve of mice subjected to experimental autoimmune encephalomyelitis (EAE), a preclinical mouse model of MS. Monitoring the optic nerve in EAE is a useful strategy to study the presentation and progression of pathology in the visual system; however, current approaches have relied on sectioning, staining and manual quantification. Further, information regarding the spatial load of lesions and inflammation is dependent on the area of sectioning. To better characterize cellular pathology in the EAE model, we employed a tissue clearing and 3D immunolabelling and imaging protocol to observe patterns of immune cell infiltration and activation throughout the optic nerve. Increased density of TOPRO staining for nuclei captured immune cell infiltration and Iba1 immunostaining was employed to monitor microglia and macrophages. Axonal degeneration was monitored by neurofilament immunolabelling to reveal axonal swellings throughout the optic nerve. In parallel, we developed a convolutional neural network with a UNet architecture (CNN-UNet) called BlebNet for automated identification and quantification of axonal swellings in whole mount optic nerves. Together this constitutes a toolkit for 3-dimensional immunostaining to monitor general optic nerve pathology and fast automated quantification of axonal defects that could also be adapted to monitor axonal degeneration and inflammation in other neurodegenerative disease models.

Understanding Associative Learning Through Higher-Order Conditioning.

Associative learning is often considered to require the physical presence of stimuli in the environment in order for them to be linked. This, however, is not a necessary condition for learning. Indeed, associative relationships can form between events that are never directly paired. That is, associative learning can occur by integrating information across different phases of training. Higher-order conditioning provides evidence for such learning through two deceptively similar designs - sensory preconditioning and second-order conditioning. In this review, we detail the procedures and factors that influence learning in these designs, describe the associative relationships that can be acquired, and argue for the importance of this knowledge in studying brain function.

Dopamine transients do not act as model-free prediction errors during associative learning.

Dopamine neurons are proposed to signal the reward prediction error in model-free reinforcement learning algorithms. This term represents the unpredicted or 'excess' value of the rewarding event, value that is then added to the intrinsic value of any antecedent cues, contexts or events. To support this proposal, proponents cite evidence that artificially-induced dopamine transients cause lasting changes in behavior. Yet these studies do not generally assess learning under conditions where an endogenous prediction error would occur. Here, to address this, we conducted three experiments where we optogenetically activated dopamine neurons while rats were learning associative relationships, both with and without reward. In each experiment, the antecedent cues failed to acquire value and instead entered into associations with the later events, whether valueless cues or valued rewards. These results show that in learning situations appropriate for the appearance of a prediction error, dopamine transients support associative, rather than model-free, learning.

Causal evidence supporting the proposal that dopamine transients function as temporal difference prediction errors.

Reward-evoked dopamine transients are well established as prediction errors. However, the central tenet of temporal difference accounts-that similar transients evoked by reward-predictive cues also function as errors-remains untested. In the present communication we addressed this by showing that optogenetically shunting dopamine activity at the start of a reward-predicting cue prevents second-order conditioning without affecting blocking. These results indicate that cue-evoked transients function as temporal-difference prediction errors rather than reward predictions.

Dupuytren's contracture, alcohol consumption, and chronic liver disease.

This prospective study was undertaken to assess the prevalence of Dupuytren's contracture (DC) and its relationship with possible causes, especially alcohol consumption and chronic liver disease. Four hundred thirty-two consecutively hospitalized patients were examined for evidence of DC. They were divided into five groups based on the following clinical, biologic, and histologic criteria: alcoholic cirrhosis (89 patients), noncirrhotic alcoholic liver disease (55 patients), chronic alcoholism without liver disease (46 patients), nonalcoholic chronic liver disease (68 patients), and a control group (174 patients). The prevalence of DC in these five groups of patients was 32.5%, 22%, 28%, 6%, and 12%, respectively; the prevalence of DC was higher in patients with cirrhotic or noncirrhotic alcoholic liver disease (25.5%) than it was in patients with nonalcoholic liver disease (6%), but it was not significantly different in alcoholic patients with or without liver disease. The relationship between DC and age, sex, manual labor, previous hand injuries, diabetes mellitus, alcohol consumption, and cigarette smoking was assessed by univariate and logistic regression methods. Nine variables were significantly different in patients with or without DC: age, sex, manual labor, previous hand injuries, diabetes mellitus, daily alcohol consumption, duration of alcohol consumption, total alcohol consumption, and duration of cigarette smoking. In our patients, variables that could explain DC were, in decreasing order, age, total alcohol consumption, sex (male), and previous hand injuries. In alcoholic patients, these variables were age and previous hand injuries; in nonalcoholic patients, these variables were age and cigarette smoking. These results emphasize the high prevalence of DC in alcoholic patients and the absence of a correlation between DC and chronic liver disease. Age and alcohol consumption are the best explanatory variables of DC in hospitalized patients.

Pharmacokinetics of ornidazole in patients with acute viral hepatitis, alcoholic cirrhosis, and extrahepatic cholestasis.

Pharmacokinetics of ornidazole, a nitroimidazole derivative, was investigated after intravenous injection in 3 groups of 10 patients with different hepatic diseases: hepatitis, noncholestatic cirrhosis and extrahepatic cholestasis. Plasma concentrations of ornidazole and its two major hydroxylated metabolites, M1 [alpha-(chloromethyl)-2-hydroxymethyl-5-nitroimidazole-1-ethanol] and M4 [3-(2-methyl-5-nitroimidazole 1-yl)-1,2-propane diol] were measured by HPLC assay. As a consequence of a decreased clearance (26% to 48%), the half-life and MRT are increased in all patients by 19% to 38% when compared with healthy volunteers. No clear difference could be established between the different groups. The volume of distribution remains the same in all patients and controls except those suffering from cancer. As previously shown in patients with severe liver cirrhosis, both metabolites accumulate in plasma as a result of decreased elimination; formation is no longer the rate-limiting step of their kinetics. This metabolite accumulation is in part due to decreased biliary excretion and to hepatocellular failure.

Bile levels of carcino-embryonic antigen in patients with hepatopancreatobiliary disease.

OBJECTIVE: To evaluate the value of biliary carcino-embryonic antigen (CEA) in the differential diagnosis of malignant and benign hepatopancreatobiliary disease. PATIENTS: One hundred patients were prospectively studied. Benign diseases were present in 39% of the patients while 61% had malignant diseases. METHODS: Samples of serum were taken from all patients just before endoscopic retrograde cholangiopancreatography (ERCP) and samples of biliary CEA were obtained during ERCP. RESULTS: The sensitivity of serum CEA and carbohydrate antigen 19-9 (CA 19-9) in detecting malignancy were 50% and 92%, respectively, while the respective specificities were 95% and 72%. The mean biliary CEA level of the benign group was significantly different from that of the malignant group (35.7 +/- 8.7 ng/ml vs 268 +/- 85.5 ng/ml), but there was considerable overlap between the two groups. With a cut-off level of 20 ng/ml, the sensitivity and specificity were 84% and 64% respectively. The mean bilirubinaemia value was significantly higher in malignant disease than in benign disease (57.4 +/- 13.9 mumol/l vs 235 +/- 19.8 mumol/l). Multidimensional analysis indicated that only bilirubinaemia (P < 109-3)) was independently predictive of malignant disease. CONCLUSION: Biliary CEA assessment seems useless in distinguished between benign and malignant causes of cholestasis.

Relations between effectiveness of a diagnostic test, prevalence of the disease, and percentages of uninterpretable results. An example in the diagnosis of jaundice.

The relations between effectiveness, the percentages of uninterpretable results of a test, and the prevalence of the disease are studied in the example of the diagnosis of jaundice. Ten hepatologists and ten hepatobiliary surgeons were interviewed, and nineteen articles were reviewed. Accuracies of ultrasonography, endoscopic retrograde cholangiography, and transhepatic cholangiography, as well as of three strategies combining these tests, were ranked by hepatologists in an order that differed from chance, and by surgeons in an order that did not differ from chance. Analyses of published data, taking into account the percentages of uninterpretable results, showed that for a high prevalence of extrahepatic cholestasis, as in jaundiced patients seen by surgeons, there is no significant difference between the respective effectiveness of each test or strategy. We concluded that effectiveness must take into account the percentages of uninterpretable results and must be expressed as a function of prevalence.

Diagnostic ERCP in the era of laparoscopic surgery.

BACKGROUND/AIMS: The purpose of this paper is to reassess the place and risks of ERCP in a diagnostic view. METHODS: Analysis of 196 non-operative ERCP performed in 196 patients aged 57 +/- 20 yrs. ERCP was performed for: unexplained cholestasis = 98; non tumoral pancreatic diseases = 43; suspected neoplasm of the pancreatic/biliary tract = 13; cholangitis = 12; unexplained abdominal pain = 30. Precut papillotomy was performed in 40 cases (20.4%). 10.7% were cirrhotics; 3.1% were gastrectomized. 164/196 received peri-operative broad-spectrum antibiotics. RESULTS: 108 had normal ERCP (group I); 74 had abnormal ERCP (group II); 12 had undetermined diagnosis after ERCP (group III). Strictly ERCP-induced mortality was nil; 2 patients died a few days after ERCP from: hemorrhage after transhepatic drainage (1); continuing severe cholangitis after failed CBD cannulation (1). Morbidity was: acute pancreatitis = 6 (3%) and fever = 4 (2%). No complication followed precut papillotomy. The 6 pancreatitis recovered within 48 h to 5 days. Fevers alleviated with antibiotics within 12 to 48 h. Pancreatitis occurred in 5/6 after normal ERCP; fevers followed pathologic ERCP in 3/4 (NS). The high rate of precuts in this series did not increase morbidity. CONCLUSION: ERCP-related morbidity was 5.1 % and ERCP accurately diagnosed or unequivocally eliminated biliary-pancreatic disease in 92.9%. These results suggest that ERCP remains a useful and safe diagnostic tool.

Ultrasonography, angiography, computed tomography and magnetic resonance in nodular regenerative hyperplasia of the liver: report of a pseudo-tumoral case.

Ultrasonographic, computed tomographic, and angiographic abnormalities of nodular regenerative hyperplasia have been described in very few cases. We report here the case of a 50-year-old man with round, well-limited hypoechogenic lesions involving the two lobes of the liver, and hypervascular, poorly delineated angiographic lesions. Computed tomography and magnetic resonance of the liver were normal. Histological examination of large liver specimens provided by intraoperative biopsy allowed the diagnosis of nodular regenerative hyperplasia. Such a pseudo-tumoral ultrasonographic and angiographic pattern must be recognized in order to avoid diagnostic and therapeutic mistakes, especially since percutaneous liver biopsy usually fails to diagnose this disease.

[Mediastinal pseudotumors in cirrhosis. Diagnostic value of nuclear magnetic resonance in 3 cases]. / Pseudo-tumeurs médiastinales au cours de la cirrhose. Intérêt diagnostique de la résonance magnétique nucléaire dans 3 cas.

We report 3 cases of mediastinal pseudotumours in cirrhotic patients. In the 3 cases, plain chest X-ray showed regular homogeneous radiolucency superposed on cardiac shadow. Computerized tomography bolus injection, performed in 2 cases, was poorly contributive in one case. On the other hand, magnetic resonance imaging ensured the diagnosis in all 3 patients showing significant dilatation of the azygos vein and prominent esophageal varices connected with spontaneous abdominal portacaval shunts. These vascular mediastinal structures were well documented by frontal and sagittal spin echoes. Knowledge of such neovascular mediastinal pseudotumours may prevent the use of invasive investigations such as direct puncture or thoracotomy.

[Fenofibrate-induced acute hepatitis with pseudo-cholangitis]. / Hépatite aiguë pseudo-angiocholitique au fénofibrate.

We report the case of acute hepatitis probably due to fenofibrate. Clinical features included abdominal pain and fever. Serum aminotransferases and alkaline phosphatase activities were moderately increased. Rechallenge induced a relapse of the symptoms and liver test abnormalities. High levels of eosinophils were present in the blood and in the liver suggesting an immunoallergic mechanism. Fenofibrate withdrawal was rapidly followed by favorable outcome.

[Stenosis of the left hepatic duct with intrahepatic lithiasis: treatment by the percutaneous transhepatic approach]. / Sténose du canal hépatique gauche avec lithiase intrahépatique: traitement par voie percutanée transhépatique.

The authors report the case of a 78-year-old woman suffering from cholangitis secondary to intrahepatic biliary stricture and intrahepatic lithiasis. Successful management consisted of successive percutaneous transhepatic internal-external biliary drainage, balloon dilatation of the stricture and gallstone mobilisation and removal through the stricture. No complications were noted.

[Ascitic pH and infection in alcoholic cirrhosis]. / pH et infection de l'ascite dans la cirrhose alcoolique.

The pH values of 108 samples of ascitic fluid in 94 alcoholic cirrhotic patients were analyzed in order to assess their diagnostic and prognostic value. The mean pH value of ascitic fluid was significantly lower (p less than 0.001) in patients with spontaneous bacterial peritonitis (7.23 +/- 0.22) or with suspected diagnosis of spontaneous bacterial peritonitis (7.29 +/- 0.15) than in patients with sterile ascites (7.45 +/- 0.06). However, there was an important overlap between these groups. In patients with and without spontaneous bacterial peritonitis, measurement of the difference between blood and ascitic pH was more discriminative than the ascitic pH alone: a difference of 0.10 or more was detected in all patients with spontaneous bacterial peritonitis, in 2 of 5 patients with suspected diagnosis of spontaneous bacterial peritonitis and in 3 of 97 patients with sterile ascites. When the ascitic pH value was lower than 7.15, death occurred rapidly. Ascitic pH rapidly increased when treatment of spontaneous bacterial peritonitis was clinically effective. These results suggest that measurement of pH in ascitic fluid is contributive to the diagnosis and prognosis of spontaneous bacterial peritonitis in alcoholic cirrhosis.

[Psoas abscess exteriorized in the groin revealed late after acute pancreatitis]. / Abcès du psoas extériorisé au creux inguinal se révélant tardivement après une pancréatite aiguë.

Two cases of psoas abscess complicating acute necrotizing pancreatitis are reported. These cases were particular because the abscesses exteriorized in the groin and symptoms were misleading. The abscesses were detected late, three and five months after the beginning of the pancreatitis respectively. The difficulties in diagnosis and the long delay to diagnosis are emphasized as possible sources of superinfection.

[Relation between serum markers of hepatitis B virus and alpha fetoprotein in hepatocellular carcinoma in France]. / Relations entre marqueurs sériques du virus de l'hépatite B et alphafoetoprotéine dans les carcinomes hépatocellulaires en France.

Prevalences of serum markers of hepatitis B virus and alphafetoprotein levels were investigated in 96 patients with hepatocellular carcinoma. Serum HBs Ag was present in 17 patients (17.5 p. 100), anti-HBc antibody alone in 10 patients (10.5 p. 100), and anti-HBs antibody with or without associated anti-HBc antibody in 32 patients (33.5 p. 100). Serum alphafetoprotein levels were increased (greater than 20 ng/ml) in 71 patients (74 p. 100). Serum alphafetoprotein levels were significantly higher in patients with than in patients without serum HBs Ag. Serum alphafetoprotein levels above 1,000 ng/ml were more frequently found in patients with serum HBs Ag or anti-HBc antibody than in other patients. These results suggest the presence of a link between HBs Ag and alphafetoprotein in hepatocellular carcinoma.

[Value of molluscum pendulum in the diagnosis of colorectal neoplastic lesions]. / Valeur du "molluscum pendulum" pour le diagnostic des lésions néoplasiques colorectales.

A routine search for skin tags was made before performing colonoscopy in 220 patients, whose mean age was 61.8 years. Sixty-one p. 100 of patients were male. The reasons for colonoscopy were digestive symptoms (95 cases), past history of malignant disease of the colon (MDC) or rectum (67 cases) or other symptoms (58 cases). Eighty-five patients had one or more skin tags, while 78 patients had one or more MDC. MDC in patients with skin tags was more frequent than in patients without skin tags (43.5 p. 100 vs. 30.4 p. 100 respectively, p less than 0.05). However this relationship was age-dependent. No significant relationship was found between the discovery of skin tags and the number of MDC, the carcinomatous nature of the lesion or not, or its degree of dysplasia. In 153 patients without personal history of MDC there was no significant relationship between the existence of skin tags and the discovery of colorectal lesions at colonoscopy. In this series of 220 patients, the sensitivity and specificity of skin tags associated with MDC on colonoscopy was poor (0.47 and 0.66 respectively).

[Pancreas divisum: clinical and therapeutic study in man. Apropos of 87 cases]. / Le pancréas divisum: étude clinique et thérapeutique chez l'homme. A propos de 87 cas.

In order to evaluate the responsibility of pancreas divisum in the occurrence of pancreatitis, we studied retrospectively 1,808 endoscopic retrograde pancreatograms. Eighty-seven pancreas divisum (4.8 p. 100) were found in 50 males and 37 females, mean age 53.3 +/- 16.8 yrs. Acute pancreatitis was significantly more frequent (p less than 0.001) in this group (19.6 p. 100) than in the patients with fused pancreas (4.3 p. 100). The difference was also significant (p less than 0.01) for idiopathic recurrent acute pancreatitis. Histologic lesions in the dorsal pancreas were in favor of a retentional mechanism of pancreatitis. Sphincterotomy of the accessory papilla, proposed to improve the drainage of the dorsal pancreas, was performed in 11 patients (10 endoscopic, 1 surgical). This treatment, repeated in case of secondary stenosis of the accessory papilla, was successful in 5 out of 8 patients with acute pancreatitis followed up from 12 to 30 months. After reviewing the literature, secondary stenosis of accessory papilla was found significantly less frequently (p less than 0.05) after surgical sphincterotomy or sphincteroplasty (4 out of 46, 8.6 p. 100) than after endoscopic sphincterotomy (6 out of 22, 27.2 p. 100). Treatment, preferentially surgical, should be proposed only to patients with idiopathic recurrent pancreatitis before constitution of chronic non reversible pancreatitis.

[Hepatocellular carcinoma in France. Clinical, biological and virological aspects in 197 patients]. / Carcinomes hépato-cellulaires en France. Aspects cliniques, biologiques et virologiques chez 197 malades.

The authors report the clinical and biological features in 197 patients with hepatocellular carcinoma seen in two French hospitals. Mean age was 63 +/- 12 years. Eighty-nine per cent were men. Cirrhosis was present in 88 p. 100. Alcoholic liver disease was associated with hepatocellular carcinoma in 71.5 p. 100. At the time of diagnosis, ascites was present in 62 p. 100 of the patients, jaundice in 49 p. 100, encephalopathy in 20 p. 100 and gastrointestinal bleeding in 12.5 p. 100. Twenty patients (10 p. 100) did not have any of these complications. An increase in serum gammaglutamyl transpeptidase and ASAT was the most frequent biological abnormality observed in 96 and 94 p. 100 of patients respectively. Hypercalcemia and a high hematocrit were present in 5 and 6 p. 100 of patients respectively. Serum HBs Ag (RIA) was present in 17.5 p. 100 of patients, anti-HBc in 50 p. 100 and anti-HBs in 33.5 p. 100; 38.5 p. 100 of patients had no serum HBV marker. Serum alphafetoprotein levels were higher than 20 ng/ml, 250 ng/ml and 1,000 ng/ml in 76.5 p. 100, 43.5 p. 100 and 33 p. 100 of patients respectively. There were no relationships between the presence of serum markers of HBV or high alphafetoprotein levels and clinical and biological data. These results confirm that the clinical, biological and virological aspects of hepatocellular carcinoma in France are similar to those reported in other western countries.