CSF/plasma ratios of amino acids: Reference data and transports in children

Objective: We intended to investigate the effects of age, gender, and medications on amino acid cerebrospinal fluid (CSF)/plasma ratios in children, and to determine whether amino acid transports across the blood–CSF barrier in children differ from those in adults. Patients and methods: Amino acid concentrations measured by ion-exchange high-performance liquid chromatography were used (CSF from 99 children, simultaneously collected plasma from 76 children). Influence of age, gender, and medications on the amino acid CSF concentrations and CSF/plasma ratios were analyzed by linear multiple regression. Interactions of amino acid transports were analyzed by correlation analysis of CSF/plasma ratios. Results: CSF/plasma ratios of serine, valine, histidine, and arginine were higher in younger children. The glutamate CSF/plasma ratio was higher in older children. Serine, alanine, threonine, valine, and histidine CSF/plasma ratios were lower in females. Glutamine, methionine, tyrosine, and phenylalanine CSF/plasma ratios were elevated with valproate therapy. Serine, threonine, valine, leucine, and tyrosine CSF/plasma ratios were lower with clobazam therapy. The asparagine CSF/plasma ratio was elevated with pyridoxal phosphate therapy. Transports of most essential neutral amino acids interacted with each other, as did neutral amino acids with low molecular weights. Cationic amino acids interacted with each other and some essential neutral amino acids. Acidic amino acids had no interactions with other amino acids. Conclusions: Age, gender, and anti-epileptic drugs affect amino acid CSF/plasma ratios in children. Transport interactions between amino acids in children showed no remarkable difference from those of adults and generally followed the substrate specificities of multiple amino acid transport systems.     

Exponential synchronization of delayed memristor-based chaotic neural networks via periodically intermittent control

This paper investigates the exponential synchronization of coupled memristor-based chaotic neural networks with both time-varying delays and general activation functions. And here, we adopt nonsmooth analysis and control theory to handle memristor-based chaotic neural networks with discontinuous right-hand side. In particular, several new criteria ensuring exponential synchronization of two memristor-based chaotic neural networks are obtained via periodically intermittent control. In addition, the new proposed results here are very easy to verify and also complement, extend the earlier publications. Numerical simulations on the chaotic systems are presented to illustrate the effectiveness of the theoretical results.     

Recovering the Lost Art of Naturalistic Family Therapy: Retrospective and Prospective

Naturalistic family therapy is what many of the early therapists did—like sports casters—they observed and reflected back to families continuously what they were saying to one another, in words, looks, body gestures, and even in the indescribable yet in deeper truth quite describable “spirit messages” of emotions. The “cost” or danger of naturalistic family therapy is that it destabilizes people and family groups and disarms long-term defensive processes. The goal of many other types of family therapy is to make most people comfortable, relieved, smiling, grateful, and happily paying clients. If one is a therapist who wants to try to help in severe cases of psychopathology, then the naturalistic family therapy described in this article is a powerful and often very helpful way of doing family therapy that one may want to consider.     

Does the CT improve inter- and intra-observer agreement for the AO,Fernandez and Universal classification systems for distal radius fractures?

Introduction

Distal radius fractures are very common upper limb injuries irrespective of the patient's age. The aim of our study is to evaluate the reliability of the three systems that are often used for their classification (AO – Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation, Fernandez and Universal) and to assess the need for computed tomography (CT) scan to improve inter- and intra-observer agreement.

Materials and methods

Five orthopaedic surgeons and two hand surgeons classified radiographs and CT scans of 26 patients using the Fernandez, AO and Universal systems. All data were recorded using MS Excel and Kappa statistics were performed to determine inter- and intra-observer agreement and to evaluate the role of CT scan.

Results

Fair-to-moderate inter-observer agreement was noted with the use of X-rays for all classification systems. Intra-observer reproducibility did not improve with the addition of CT scans, especially for the senior hand surgeons.

Conclusions

The agreement rates observed in the present study show that currently there is no classification system that is fully reproducible. Adequate experience is required for the assessment and treatment of these injuries. CT scan should be requested only by experienced hand surgeons in order to help guide treatment, as it does not significantly improve inter- and intra-observer agreement for all classification systems.     

Surgical delivery of drug releasing poly(lactic-co-glycolic acid)/poly(ethylene glycol) paste with in vivo effects against glioblastoma

Introduction

The median survival of patients with glioblastoma multiforme (astrocytoma grade 4) remains less than 18 months despite radical surgery, radiotherapy and systemic chemotherapy. Surgical implantation of chemotherapy eluting wafers into the resection cavity has been shown to improve length of survival but the current licensed therapy has several drawbacks. This paper investigates in vivo efficacy of a novel drug eluting paste in glioblastoma.

Methods

Poly(lactic-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) self-sintering paste was loaded with the chemotherapeutic agent etoposide and delivered surgically into partially resected tumours in a flank murine glioblastoma xenograft model.

Results

Surgical delivery of the paste was successful and practical, with no toxicity or surgical morbidity to the animals. The paste was retained in the tumour cavity, and preliminary results suggest a useful antitumour and antiangiogenic effect, particularly at higher doses. Bioluminescent imaging was not affected significantly by the presence of the paste in the tumour.

Conclusions

Chemotherapy loaded PLGA/PEG paste seems to be a promising technology capable of delivering active drugs into partially resected tumours. The preliminary results of this study suggest efficacy with no toxicity and will lead to larger scale efficacy studies in orthotopic glioblastoma models.     

Shaping Ability of Different Nickel-Titanium Systems in Simulated S-shaped Canals with and without Glide Path

Introduction

The objective of this study was to compare the shaping ability of different rotary and reciprocating nickel-titanium file systems with and without previous glide path preparation in simulated S-shaped canals.

Methods

One hundred twenty S-shaped canals in resin blocks were prepared to an apical size 25 by using Reciproc, WaveOne, HyflexCM, F360, and OneShape systems either with or without previous glide path preparation (Pathfile) (12 canals/group). Material removal was measured at 20 measuring points, beginning 1 mm from the end point of preparation. Incidence of canal aberrations (zip/elbow, ledge formation), preparation time, and instrument failures were also recorded. Statistical analyses were performed by using analysis of variance and Tukey and χ² tests.

Results

For all systems, glide path preparation exerted no significant effect on preparation times (P > .05). Glide path preparation had no influence on the incidence of canal aberrations and instrument fractures (P > .05), with no significant differences between the 5 systems (P > .05). Glide path preparation had no influence on the centering ability of all systems (P > .05). On average, canals prepared with F360, OneShape, and HyflexCM remained better centered compared with those enlarged with WaveOne and Reciproc.

Conclusions

Under the conditions of this study, glide path preparation had no significant impact on canal straightening. Less tapered instruments maintained the original canal curvature better than instruments having greater tapers.     

Focus on Fluorides: Update on the Use of Fluoride for the Prevention of Dental Caries

Improving the efficacy of fluoride therapies reduces dental caries and lowers fluoride exposure.BackgroundFluoride is delivered to the teeth systemically or topically to aid in the prevention of dental caries. Systemic fluoride from ingested sources is in blood serum and can be deposited only in teeth that are forming in children. Topical fluoride is from sources such as community water, processed foods, beverages, toothpastes, mouthrinses, gels, foams, and varnishes. The United States Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA) have proposed changes in their long standing recommendations for the amount of fluoride in community drinking water in response to concerns about an increasing incidence of dental fluorosis in children. Current research is focused on the development of strategies to improve fluoride efficacy. The purpose of this update is to inform the reader about new research and policies related to the use of fluoride for the prevention of dental caries.MethodsReviews of the current research and recent evidence based systematic reviews on the topics of fluoride are presented. Topics discussed include: updates on community water fluoridation research and policies; available fluoride in dentifrices; fluoride varnish compositions, use, and recommendations; and other fluoride containing dental products. This update provides insights into current research and discusses proposed policy changes for the use of fluoride for the prevention of dental caries.ConclusionsThe dental profession is adjusting their recommendations for fluoride use based on current observations of the halo effect and subsequent outcomes. The research community is focused on improving the efficacy of fluoride therapies thus reducing dental caries and lowering the amount of fluoride required for efficacy.