Brief and extended abstinence from chronic oral methylphenidate treatment produces reversible behavioral and physiological effects

Methylphenidate (MP) is a commonly prescribed psychostimulant to individuals with Attention Deficit Hyperactivity Disorder, and is often used illicitly among healthy individuals with intermittent breaks to coincide with breaks from school. This study examined how intermittent abstinence periods impact the physiological and behavioral effects of chronic oral MP self-administration in rats, and whether these effects persist following prolonged abstinence from the drug. Rats were treated orally with water, low-dose (LD), or high-dose (HD) MP, beginning at PND 28. This daily access continued for three consecutive weeks followed by a 1-week abstinence; after three repeats of this cycle, there was a 5-week abstinence period. Throughout the study, we examined body weight, food intake, locomotor activity, and anxiety- and depressive-like behaviors. During the treatment phase, HD MP decreased body weight, food intake, and depressive- and anxiety-like behaviors, while it increased locomotor activity. During intermittent abstinence, the effects of MP on locomotor activity were eliminated. During prolonged abstinence, most of the effects of HD MP were ameliorated to control levels, with the exception of weight loss and anxiolytic effects. These findings suggest that intermittent exposure to chronic MP causes physiological and behavioral effects that are mostly reversible following prolonged abstinence.     

Long-term changes in hepatobiliary physiology after Roux-en-Y hepaticojejunostomy

Hepaticojejunostomy (HJ) is a common operation used to by-pass extrahepatic biliary obstructions and to establish biliary-enteric continuity after resections for benign and malignant diseases. Little is known about the effect of this procedure on hepatobiliary physiology. The aim of the present study was to investigate in a swine model the changes in biliary dynamics, bile composition, and hepatic histology induced by Roux-Y HJ. Twenty-four swine (57 (47 to 76) kg) underwent cholecystectomy, with HJ (Group I; n = 12) or without any biliodigestive anastomosis (Group II, n = 12), and were followed up for 6 or 12 mo by repeated weight scaling, blood, serum, and bile analysis, (99m)Technetium (Tc), diethyliminodiacetic acid (HIDA) dynamic biligraphy, and histological analysis. During follow-up, HJ was associated with less weight gain, colonization of the bile duct with aerobic bacteria Escherichia coli dominating (in 75% of the animals), a shortened hilum-intestine transit time but reduced liver clearance in dynamic biligraphy, and fibrous periportal changes in liver histology (in 50% of the animals). We conclude that during 1 y follow-up HJ with no anastomotic stricture formation is associated with improved extrahepatic bile drainage, but with ascending contamination of bile ducts with bacteria, which might be involved with the fibrous periportal changes in the liver resulting in diminished excretion of Tc-HIDA from the hepatocytes into the bile. The clinical significance of these changes, and the reduced weight gain observed is a topic of further investigations.     

Comparison of spectral domain optical coherence tomography parameters between disc suspects and “pre-perimetric” glaucomatous discs classified on disc photos

Purpose:The aim of this study was to compare SD-OCT parameters between disc suspects and “pre-perimetric” glaucomatous discs classified on disc photos.Methods:Disc photos of suspicious discs with normal Humphrey visual fields (HVF) were graded as normal or pre-perimetric glaucomatous based on the consensus of three masked glaucoma specialists. RNFL and GCL-IPL maps of SD-OCT (Cirrus OCT) of these eyes were studied. Quantitative RNFL parameters were compared. Both groups were also compared with respect to parameters being classified as abnormal (at the 1% level), and the pattern of GCL-IPL and NFL maps were assessed qualitatively and classified as normal or pre-perimetric glaucomatous by a masked glaucoma specialist.Results:The average and inferior RNFL thicknesses were decreased in pre-perimetric glaucomatous eyes compared to normal eyes (p 0.01) The average, minimal, inferotemporal and inferior sector GCL-IPL thicknesses were decreased in pre-perimetric glaucomatous eyes (all P < 0.002) The highest AUC was for the inferior RNFL thickness (0.771) followed by average RNFL thickness (0.757) The sensitivity and specificity for any one abnormal RNFL parameter was 71.9% and 59.7%, for GCL-IPL parameters was 70% and 69.1% The positive (PLR) and negative likelihood ratios (NLR) were 1.78 and 0.47 for RNFL and 2.26 and 0.43 for GCL-IPL parameters. For the qualitative assessment of RNFL and GCL-IPL maps, the sensitivity, specificity, PLR and NLR were 75%, 77.2%, 3.29, and 0.32, respectively.Conclusion:Pre-perimetric disc suspects had greater OCT changes compared to normal disc suspects. Qualitative assessment of RNFL and GCL-IPL maps had the highest discriminatory ability.     

A novel approach to brachytherapy in hepatocellular carcinoma using a phosphorous32 (32P) brachytherapy delivery device--a first-in-man study

PURPOSE: While potentially very useful, percutaneously delivered brachytherapy of inoperable intra-abdominal solid tumors faces significant technical challenges. This first-in-man study is designed to determine the safety profile and therapeutic efficacy of a novel phosphorous (32P) brachytherapy device (BrachySil) in patients with unresectable hepatocellular carcinoma. METHODS AND MATERIALS: Patients received single percutaneous and transperitoneal implantations of BrachySil under local anesthesia directly into liver tumors under ultrasound or computed tomographic guidance, at an activity level of 4 MBq/cc of tumor. Toxicity was assessed by the nature, incidence, and severity of adverse events (Common Toxicity Criteria scores) and by hematology and clinical chemistry parameters. Target tumor response was assessed with computed tomographic scans at 12 and 24 weeks postimplantation using World Health Organization criteria. RESULTS: Implantations were successfully carried out in 8 patients (13-74 MBq, mean 40 MBq per tumor) awake and under local anesthesia. Six of the 8 patients reported 19 adverse events, but no serious events were attributable to the study device. Changes in hematology and clinical chemistry were similarly minimal and reflected progressive underlying hepatic disease. All targeted tumors were responding at 12 weeks, with complete response (100% regression) in three lesions. At the end of the study, there were two complete responses, two partial responses, three stable diseases, and one progressive disease. CONCLUSION: Percutaneous implantation of this novel 32P brachytherapy device into hepatocellular carcinoma is safe and well tolerated. A significant degree of antitumor efficacy was demonstrated at this low dose that warrants further investigation.     

A non-invasive isotope dilution technique for quantifying hepatic blood flow using radiolabelled red blood cells

Clinically significant changes in hepatic haemodynamics accompany the development of portal hypertension, hepatocellular carcinoma, liver metastases and liver cirrhoses, and after major liver resection. Hepatic blood flow parameters, such as hepatic arterial flow (HAF), hepatic portal flow (HPF), total hepatic blood flow (THBF) and hepatic perfusion index (HPI), are useful adjuncts to the diagnosis of liver pathology, the evaluation of disease progress and prognostication. Here, we describe a non-invasive method that combines the measurement of these parameters in a single study in real time. Red blood cells from eight pigs were labelled with 99Tc(m) using an in-vitro method and re-injected into the pigs. Data acquisition over the heart, lungs, liver and kidneys was started immediately and a blood sample was obtained 15 min post-injection. Hepatic arterial flow was determined from the ratio of the maximum gradients between the integrated time-activity curve of the left ventricle and the first-pass time-activity curve of the liver before the peak of the kidneys time-activity curve. The hepatic perfusion index was determined by comparing the slope of the liver time-activity curve before and after the kidney peak. Hepatic portal flow was determined from the hepatic arterial flow and the hepatic perfusion index, and total hepatic blood flow was determined as the sum of arterial and portal flow. The results were compared against those obtained from a clearance method using 99Tc(m)-DISIDA. The average hepatic perfusion index was 0.38, and the average hepatic arterial flow and hepatic portal flow were 168.3 +/- 52.9 and 274.6 +/- 60.1 ml x min(-1) respectively. The average total hepatic blood flow was 442.8 +/- 53.5 ml x min(-1), while the total hepatic flow determined by 99Tc(m)-DISIDA clearance was 419.7 +/- 62.6 ml x min(-1). No significant difference in total hepatic blood flow was found between the two methods. The results of this study show that it is possible to obtain all hepatic haemodynamics data in a single study using a non-invasive method.     

A Novel Biodegradable Biliary Stent in the Normal Duct Hepaticojejunal Anastomosis: an 18-month Follow-up in a Large Animal Model

Creating a well-functioning hepaticojejunostomy (HJ) anastomosis with nondilated bile ducts remains a challenge. Our aim was to study the use in a large animal model of a novel, braided polylactide barium sulfate biodegradable biliary stent (BDBS) without external connection and with no need for later removal. Fifty swine were randomly operated on for Roux-Y HJ with or without BDBS in the anastomosis, and followed up (dynamic biligraphy, x-ray, serum determinations, anastomosis inner diameter, and histology) for 1.5, 3, 6, 12, and 18 months. During the follow-up, one nonstented animal died because of anastomotic leakage. In x-ray BDBS was seen in place until 1.5 months in all of the stented animals. In the nonstented animals HJ anastomosis inner diameter was decreased at 18 months [6.3 (5.0–7.0) mm vs 7.4 (7.0–9.0) mm, p = 0.05] and liver clearance reduced at 12 and 18 months compared to stented animals. Serum liver values and liver and bile duct histology did not differ between the groups. We conclude that this novel BDBS is easy to insert into the HJ anastomosis with nondilated ducts. It is nontoxic, dissolves safely, and may be associated with a larger and better draining anastomosis at 18-month follow-up. These results encourage us to proceed to clinical studies.