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.

[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.

[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.

[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.

[High prevalence of infection by hepatitis B virus and HIV in incarcerated French drug addicts]. / Forte prévalence de l'infection par le virus de l'hépatite B et le virus HIV chez les toxicomanes français incarcérés.

This clinical and biological study was undertaken to assess the prevalence of infection by HIV, HBV and HDV in male drug abusers entering a prison. One hundred and thirteen drug users accepted to be tested: 14 (12 p. 100) were homosexual; 12 (11 p. 100) consumed more than 80 g per day of alcohol. The mean duration of drug addiction was 5 +/- 2.9 years; 50 (44 p. 100) declared having used a personal syringe while 63 (56 p. 100) usually shared their syringe. Serum activity of transaminases higher than twice the normal value was noted in 36 cases (32 p. 100). One hundred and two (90 p. 100) drug abusers had a HBV marker, 17 (15 p. 100) were HBs Ag carriers, 9 had anti-HBc antibody alone. The prevalence of antibodies to the HDV was 23 p. 100 and was higher among the HBs Ag carriers (65 p. 100). There were no cases of AIDS. Clinical examination showed lymphadenopathy in 49 cases (43 p. 100), a weight loss of more than 10 p. 100 in 47 cases (42 p. 100), and in 69 cases (61 p. 100), HIV positive serology, confirmed by Western blot. The duration of drug addiction was longer in the 102 drug users with HBV markers. Long duration of drug abuse and the use of a shared syringe increased the risk of HIV infection. No relation was noted between the presence of HBV markers and HIV positive serology. In this population the prevalence of HIV, HDV markers and HIV infection was high, but no relation with the duration of previous incarceration or homosexuality was found.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prognosis of acute viral hepatitis in patients with alcoholic cirrhosis]. / Pronostic des hépatites virales aiguës survenant chez des malades atteints de cirrhose alcoolique.

We report 20 cases of alcoholic cirrhosis with superimposed episodes of acute viral hepatitis. Four had acute type B hepatitis and 16, presumed non A non B hepatitis. Before hepatitis, 17 patients had stopped drinking and only four had a complicated cirrhosis. Eighteen patients had received a blood transfusion within the 6 months before the occurrence of hepatitis (mean: 52 days). All patients developed jaundice, 7 encephalopathy, and 5 ascites. The ASAT/ALAT ratio was greater than 1 in 18 patients. Two patients died of hepatic failure. Follow-up was known in 17 of the 18 surviving patients: in all patients jaundice disappeared and transaminases returned to values less than 3 times the upper limits of normal. In our experience, the prognosis is good when viral hepatitis occurs in patients with non complicated alcoholic cirrhosis.

[Lithiasis of the common bile duct in the aged subject treated with endoscopy (227 patients)]. / Lithiase de la voie biliaire principale du sujet âgé traitée par voie endoscopique (277 malades).

One hundred and sixteen patients aged from 65 to 80 years (first group including 39 previously cholecystectomized patients) and 161 patients aged over 80 years (second group, including 31 previously cholecystectomized patients) underwent endoscopic papillotomy for choledocholithiasis. We compared clinical, biochemical and morphological features of choledocolithiasis with early results of endoscopic papillotomy. Clinical symptoms were not different between the old and very old patients, cholecystectomized or not. Charcot's triade was observed in one third of patients. Biochemical data just before endoscopic retrograde cholangiography were not different according to groups: 21 p. 100 of the 277 patients had a biological cholestasis without elevation of bilirubin and 10 p. 100 of the patients had no abnormality of the liver function. Diagnosis of choledocholithiasis was accurately suspected in 90 p. 100 of patients. Complete removal of gallstones after endoscopic papillotomy was obtained in 95 p. 100 of patients in the first group and 93 p. 100 of patients in the second group. Morbidity and mortality rates related to endoscopic papillotomy were not different between the 2 groups (6.9 and 0.8 p. 100 in the first group and 8.7 and 3.1 p. 100 in the second group, the first group and 8.7 and 3.1 p. 100 in the second group, respectively). These results suggest that clinical and biochemical features of choledocholithiasis, and early results of endoscopic treatment do not present any particularities in the elderly.

[Imaging of nodular regenerative hyperplasia of the liver. Study of 9 cases]. / Imagerie de l'hyperplasie nodulaire régénérative du foie. Etude de 9 cas.

Radiologic patterns of the liver in nodular regenerative hyperplasia are poorly known. The authors describe the features of the liver observed during ultrasonography, angiography, computed tomography and magnetic resonance imaging in 9 patients with nodular regenerative hyperplasia. Generally the liver appeared normal, occasionally with signs of portal hypertension. However, a pseudotumoral pattern was observed in 2 patients: they had well limited hypoechoic lesions on ultrasonography, and in one patient angiography showed hypervascularity.