Analysis of Drug/Plasma Protein Interactions by Means of Asymmetrical Flow Field-Flow Fractionation

Purpose. The applicability of Asymmetrical Flow Field-Flow Fractionation (Asymmetrical Flow FFF) as an alternative tool to examine the distribution of a lipophilic drug (N-Benzoyl-staurosporine) within human plasma protein fractions was investigated with respect to high separation speed and loss of material on surfaces due to adsorption. Methods. Field-Flow Fractionation is defined as a group of pseudo-chromatographic separation methods, where compounds are separated under the influence of an externally applied force based on differences in their physicochemical properties. This method was used to separate human plasma in its protein fractions. The drug distribution in the fractions was investigated by monitoring the fractionated eluate for drug content by fluorescence spectroscopy. Results. Human plasma was separated into human serum albumin (HSA), high density lipoprotein (HDL), ₂-macroglobulin and low density lipoprotein (LDL) fractions in less than ten minutes. Calibration of the system and identification of the individual fractions was performed using commercially available protein reference standards. The influence of membrane type and carrier solution composition on the absolute recovery of N-Benzoyl-staurosporine and fluorescein-isothio-cyanate-albumin (FITC-albumin) was found to be quite significant. Both factors were optimized during the course of the investigations. N-Benzoyl-staurosporine was found to be enriched in the fraction containing HSA. Conclusions. If experimental conditions are thoroughly selected and controlled to suppress drug and plasma protein adsorption at the separation membrane, Asymmetrical Flow FFF shows high recoveries and fast separation of human plasma proteins, and can be a reliable tool to characterize drug / plasma protein interactions. For analytical purposes it has the potential to rival established technologies like ultracentrifugation in terms of ease-of-use, precision, and separation time.     

Comparison of reg I and reg III levels during acute pancreatitis in the rat

OBJECTIVE: To study alterations of serum levels of the pancreatic reg family of proteins in two models of acute pancreatitis. SUMMARY BACKGROUND DATA: The pancreatic reg family of proteins is expressed in the acinar pancreas. Reg I (pancreatic stone protein, PSP) and reg III (pancreatitis-associated protein, PAP) are induced after the onset of acute pancreatitis, and both have been proposed as potential markers of pancreatitis. METHODS: Pancreatitis was induced in rats by either retrograde infusion of sodium taurocholate or by direct trauma. Serum samples were obtained daily for 4 days after the procedure, and the animals were then killed. Twelve animals underwent sham procedure and six underwent daily analysis without surgery. Levels of reg I/PSP and reg III/PAP were estimated by enzyme-linked immunosorbent assay. RESULTS: Reg III/PAP levels increased significantly the first day after induction of both types of pancreatitis and rapidly returned to baseline in all survivors. Even animals who received retrograde infusion of saline showed a mild increase in reg III/PAP on the first day, whereas control animals that did not undergo surgery showed no variations. Reg I/PSP serum levels remained unchanged throughout all experimental periods. Postinjury reg III/PAP levels significantly correlated with severity of the pancreatic injury and animal survival; reg I/PSP levels did not. CONCLUSION: After induction of pancreatitis, serum levels of reg I and III protein differ significantly. Reg III/PAP levels are a sensitive marker of pancreatic injury and early in the disease may be a useful prognostic indicator for disease severity.     

Consequences of redefining Alzheimer's disease in terms of amyloid burden without regard to cognitive decline

正Alzheimer’s disease(AD)redefined:For the past century,AD has been defined as a disease of progressive cognitive decline paired with a burden of amyloid-β(Aβ)plaques and pathologic tau tangles in the hippocampus and forebrain.However,a recent Framework paper jointly sponsored by the National Institute on Aging and the Alzheimer’s Association(Jack et al.,2018)proposes new classification guidelines for AD,which,if adopted,will have profound     

Differences in Developmental Concerns of Young Children with Autism Spectrum Disorder Across Racial/Ethnic Groups

Purpose: Parents/caregivers of children with autism spectrum disorder (ASD) have varying types of initial concerns regarding their child’s development, which may be culturally bound to parents’ perceptions of their child’s development. This study investigated differences in the types of initial developmental concerns reported by parents or caregivers of different racial/ethnic groups with children in an early intervention program.

Method: This study examined the frequency of endorsement of different types of concerns in African American, Caucasian, and Hispanic families.

Results: No significant differences between racial/ethnic groups were found in the endorsement of concerns related to communication, language/speech, motor, problem behavior, sensory, feeding, prematurity, attention, adaptive functioning, and medical conditions. Racial/ethnic groups differed significantly in their endorsement for social concerns.

Conclusion: Racial/ethnic group differences were confirmed regarding initial developmental concerns related to social behavior, which may be due to cultural beliefs. The implications of these findings on early identification are discussed.