Protein profiles in rabbit pancreatic juice analyzed by HPLC after stimulation of secretion by secretin and cerulein

This study analyzed the secretory pattern of pancreatic proteins released from the rabbit pancreas after acute stimulation of secretion by the cholecystokinin analog cerulein. To facilitate this, a new analytical approach utilizing high performance liquid chromatography (HPLC) was considered. Secretin (0.1 CU/kg x h) was intravenously infused in anaesthetized rabbits in combination with cerulein (0.05, 0.2 or 0.05 followed by 0.2 ug/kg x h) over 3 hours. Pancreatic juice was collected from the main pancreatic duct. The release of protein, amylase, trypsin and chymotrypsin was measured by conventional photometric methods, and the protein profiles were analyzed by reversed phase HPLC. Separation of pancreatic juice proteins by HPLC (Nucleosil 300-7 RP column; injection of 50 ul aliquots of samples normalized to 10 mg/ml protein concentration) resulted in a resolution of up to 16 peaks. Peaks representing amylase, prolipase, prophospholipase A2, procarboxypeptidases, chymotrypsinogen, trypsinogen, and glycoproteins were identified with some certainty by SDS-gel electrophoresis. Secretin infusion produced a small and short lasting rise in total protein secretion but lead to a persistent increase of fluid flow. The release of enzymes followed a mainly parallel pattern according to the photometric measurements. The resolution of the whole profile of pancreatic juice proteins by HPLC demonstrated only minor variations without a consistent or increasing tendency towards a preferential release of individual enzymes. Since even microheterogenities in the samples became apparent after HPLC, this approach would be sensitive enough to mirror effects like nonparallel release of enzymes.     

Effect of 4-methylpyrazole and pyrazole on the induction of fatty liver by a single dose of ethanol

Pyrazole (272 mg/kg), 4-methylpyrazole (4-MP; 200 mg/kg) or saline was injected intraperitoneally into fasted male and female rats. Ten min later, ethanol (4 or 6 g/kg) or an equicaloric dose of sucrose was given by stomach tube. Hepatic triglyceride (TG) levels were measured at 6, 12 or 16 hr after the gavage. With a 4 g/kg dose of ethanol, pyrazole reduced the accumulation of TG at 6 hr in females, but not at 12 and 16 hr. In males, ethanol gave relatively little TG accumulation at 6 hr and pyrazole did not affect this, but at 16 hr the TG levels in the ethanol-pyrazole group had not risen as much as in the ethanol-saline group. In contrast to pyrazole, 4-MP by itself increased liver TG content, and significantly increased the TG accumulation caused by a 4 g/kg dose of ethanol in both males and females at 16 hr. However, 4-MP caused a significantly smaller TG accumulation in females at 6 hr after the ethanol, but not in males. With a larger dose of ethanol (6 g/kg), both pyrazole and 4-MP decreased the accumulation of TG at 16 hr in males. It is concluded that ethanol per se, ethanol as a metabolic substrate, and pyrazoles as pharmacological agents with complex actions may all contribute to the development of acute fatty liver. Therefore, pyrazole and 4-MP do not appear to be suitable tools for resolving the controversy about the mechanism of production of alcoholic fatty liver.     

Skin permeability

The histochemical and physicochemical aspects of skin permeability and transdermal drug permeation are reviewed under preponderant consideration of the past years' literature supplied by relevant investigations from the author's laboratories. The chemical composition and the physical order of the horny layer lipids as well as the interactions of drugs and vehicle components with these lipids are the basis of understanding drug penetration, its influencing by vehicles and penetration enhancement. By means of measuring drug concentration profiles in human skin the mechanisms of vehicle effects and penetration enhancement are demonstrated. The consequences of increased permeability and xenobiotic enrichment in pathologically altered skin are discussed.     

The challenge of long‐term follow‐up of survivors of childhood acute leukemia after hematopoietic stem cell transplantation in resource‐limited countries: A single‐center report from Brazil

With the number of long‐term HSCT survivors steadily increasing, attention needs to be focused on the late complications and quality of life. We therefore analyzed the outcome of 101 pediatric patients (<18 years old at the time of HSCT) transplanted for acute leukemia between 1981 and 2015 at Complexo Hospital de Clínicas, Federal University of Paraná, Brazil, and who survived at least two years after HSCT. The median follow‐up was 5.9 years (2.0‐29.0); median age at follow‐up was 17.5 years (2.98‐39.0). The 5‐year cumulative incidence of relapse was 27.5% (95% CI 18.6%‐36.4%). Two‐year cumulative incidence of chronic GVHD was 21.8% (95% CI 13.7%‐29.8%). Of the 101 patients, 72 patients (71.3%) presented with late effects. Those surviving longer after HSCT experienced more complications. Patients who received TBI‐based regimen developed more late effects (P = .013) and more endocrinological complications (P = .024). Endocrinological complications were the most common late sequelae found in this study. For childhood survivors, quality of life was not influenced by age (at HSCT or at last visit), time from HSCT, gender, donor, or GVHD. For survivors that no longer were children, only age at last visit impacted financial domain measures, irrespective of gender, donor, or GVHD. The current study confirms the high burden late complications after pediatric HSCT have on the survivors and underlines the importance of extended follow‐up.     

Open porous microscaffolds for cellular and tissue engineering by lipid templating

Porous microspheres fabricated from biodegradable polymers have great potential as microscaffolds in tissue engineering applications, especially for novel strategies such as microtissue fabrication in vitro and microtissue assembly in vivo. Fabrication techniques for microparticulate scaffolds with surface and bulk pore sizes relevant for effective cell intrusion, however, are scarce. This study presents two techniques for the fabrication of open porous microscaffolds from poly(lactide-co-glycolide) in which lipid templating is used for pore formation and combined with either dispersion spraying or a double emulsion technique to determine the size and shape of the particulate structures generated. Both techniques yield microscaffolds with an average size of between 500 and 800 μm, high bulk porosities and open surface pores larger than 50 μm in diameter. Microscaffold morphology was investigated microscopically, particle size distribution was determined and porosity was quantified by intrusion measurements. Particle size and morphology was controlled by the processing parameters and the content and type of lipid porogen. Efficient extraction of the lipid template was shown by thermal analysis. Microscaffold cytocompatibility and in vitro cell culture performance was evaluated with L929 fibroblasts and rat adipose-derived stromal cells (ADSC), respectively. Extracts of different formulations were cytocompatible. Rat ADSC proliferated on the microscaffolds and were differentiated along the adipogenic lineage.     

Adolescent impulsivity phenotypes characterized by distinct brain networks

The impulsive behavior that is often characteristic of adolescence may reflect underlying neurodevelopmental processes. Moreover, impulsivity is a multi-dimensional construct, and it is plausible that distinct brain networks contribute to its different cognitive, clinical and behavioral aspects. As these networks have not yet been described, we identified distinct cortical and subcortical networks underlying successful inhibitions and inhibition failures in a large sample (n = 1,896) of 14-year-old adolescents. Different networks were associated with drug use (n = 1,593) and attention-deficit hyperactivity disorder symptoms (n = 342). Hypofunctioning of a specific orbitofrontal cortical network was associated with likelihood of initiating drug use in early adolescence. Right inferior frontal activity was related to the speed of the inhibition process (n = 826) and use of illegal substances and associated with genetic variation in a norepinephrine transporter gene (n = 819). Our results indicate that both neural endophenotypes and genetic variation give rise to the various manifestations of impulsive behavior.