Measurement equivalence of touch‐screen computerized and paper‐based diabetes‐specific quality‐of‐life questionnaires

Current advances in technology have enabled the development of a computer‐based questionnaire that provides advantages over the paper‐based mode of administration, such as automatic data entry, storage and calculations. However, before implementing a computer‐based questionnaire, its equivalence with the original paper‐based questionnaire must first be demonstrated. The purpose of this study was to evaluate the measurement equivalence of the computerized Diabetes‐Specific Quality‐of‐Life questionnaire (cD‐QOL) with its original paper‐based counterpart. A two‐period crossover design was used in this study. The measurement equivalence was evaluated using quadratic weighted kappa coefficients, intraclass correlations and Cronbach's alpha comparisons. The cD‐QOL was equivalent to its original paper‐based counterpart. Participants preferred the cD‐QOL over the paper‐based questionnaire and reported that it was easy to use.     

Red blood cell aging markers during storage in citrate‐phosphate‐dextrose–saline‐adenine‐glucose‐mannitol

BACKGROUND: It has been suggested that red blood cell (RBC) senescence is accelerated under blood bank conditions, although neither protein profile of RBC aging nor the impact of additive solutions on it have been studied in detail. STUDY DESIGN AND METHODS: RBCs and vesicles derived from RBCs in both citrate‐phosphate‐dextrose (CPD)–saline‐adenine‐glucose‐mannitol (SAGM) and citrate‐phosphate‐dextrose‐adenine (CPDA) were evaluated for the expression of cell senescence markers (vesiculation, protein aggregation, degradation, activation, oxidation, and topology) through immunoblotting technique and immunofluorescence or immunoelectron microscopy study. RESULTS: A group of cellular stress proteins exhibited storage time– and storage medium–related changes in their membrane association and exocytosis. The extent, the rate, and the expression of protein oxidation, Fas oligomerization, caspase activation, and protein modifications in Band 3, hemoglobin, and immunoglobulin G were less conspicuous and/or exhibited significant time retardation under storage in CPD‐SAGM, compared to the CPDA storage. There was evidence for the localization of activated caspases near to the membrane of both cells and vesicles. CONCLUSIONS: We provide circumstantial evidence for a lower protein oxidative damage in CPD‐SAGM–stored RBCs compared to the CPDA‐stored cells. The different expression patterns of the senescence markers in the RBCs seem to be accordingly related to the oxidative stress management of the cells. We suggest that the storage of RBCs in CPD‐SAGM might be more alike the in vivo RBC aging process, compared to storage in CPDA, since it is characterized by a slower stimulation of the recognition signaling pathways that are already known to trigger the erythrophagocytosis of senescent RBCs.     

Memantine delayed N‐methyl‐D‐aspartate ‐induced convulsions in neonatal rats

Memantine (1‐amino‐3,5‐dimethyladamantane) is a moderate‐affinity uncompetitive antagonist of N‐methyl‐d‐aspartate (NMDA) receptors. In this study, we have explored the effect of memantine against N‐methyl‐d‐aspartate (NMDA)‐induced seizures in neonatal rats. Here, we evaluated various behavioral seizure abnormalities in neonatal rats (Sprague–Dawley; postnatal day 9) after an intraperitoneal administration of NMDA. Further, we explored whether an acute administration of memantine could protect these neonates against different phases of convulsions induced by NMDA. In a separate study, we have compared the effect of levetiracetam in the same animal model. Exogenous administration of NMDA (30 mg/kg., i.p.) in neonatal rats resulted in arrest of activity, emprosthotonos curvature (trunk is bent forward by the entire muscles), myoclonic jerks, and forelimb/hindlimb clonus. The clonus phase in neonates was followed by loss of righting reflex and continuous seizures (for more than 5 min) suggesting status epilepticus, tonic extension, and death. Pretreatment of memantine hydrochloride (10–30 mg/kg., i.p.) dose‐dependently delayed the onset of different phases of convulsions induced by NMDA. Memantine at the highest dose was found to be ataxic in rat neonates, while lower doses were free of any observed behavioral signs of toxicity. Levetiracetam (25 mg/kg., i.p.) when administered 30 min before the NMDA challenge blocked only the jerk phase and did not affect other phases of NMDA‐induced convulsions. These data indicated that memantine and other safer uncompetitive NMDA receptor antagonists may be protective in the management of neonatal seizures.     

Protective effects of PF‐4708671 against N‐methyl‐d‐aspartic acid‐induced retinal damage in rats

We previously demonstrated that rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), protects against N‐methyl‐d ‐aspartic acid (NMDA)‐induced retinal damage in rats. Rapamycin inhibits mTOR activity, thereby preventing the phosphorylation of ribosomal protein S6, which is a downstream target of S6 kinase. Therefore, we aimed to determine whether PF‐4708671, an inhibitor of S6 kinase, protects against NMDA‐induced retinal injury. Intravitreal injection of NMDA (200 nmol/eye) caused cell loss in the ganglion cell layer and neuroinflammatory responses, such as an increase in the number of CD45‐positive leukocytes and Iba1‐positive microglia. Surprisingly, simultaneous injection of PF‐4708671 (50 nmol/eye) with NMDA significantly attenuated these responses without affecting phosphorylated S6 levels. These results suggest that PF‐4708671 and rapamycin likely protect against NMDA‐induced retinal damage via distinct pathways. The neuroprotective effect of PF‐4708671 is unlikely to be associated with inhibition of the S6 kinase, even though PF‐4708671 is reported to be a S6 kinase inhibitor.     

MRI tumor characterization using Gd‐GlyMe‐DOTA‐perfluorooctyl‐mannose‐conjugate (Gadofluorine M™), a protein‐avid contrast agent

The rationale and objectives were to define the MRI tumor‐characterizing potential of a new protein‐avid contrast agent, Gd‐GlyMe‐DOTA‐perfluorooctyl‐mannose‐conjugate (Gadofluorine M?; Schering AG, Berlin, Germany) in a chemically induced tumor model of varying malignancy. Because of the tendency for this agent to form large micelles in water and to bind strongly to hydrophobic sites on proteins, it was hypothesized that patterns of dynamic tumor enhancement could be used to differentiate benign from malignant lesions, to grade the severity of malignancies and to define areas of tumor necrosis. Gadofluorine M, 0.05 mmol Gd kg^?1, was administered intravenously to 28 anesthetized rats that had developed over 10 months mammary tumors of varying degrees of malignancy as a consequence of intraperitoneal administration of N‐ethyl‐N‐nitrosourea (ENU), 45–250 mg kg^?1. These tumors ranged histologically from benign fibroadenomas to highly undifferentiated adenocarcinomas. Dynamic enhancement data were analyzed kinetically using a two‐compartment tumor model to generate estimates of fractional plasma volume (fPV), apparent fractional extracellular volume (fEV*) and an endothelial transfer coefficient (K^PS) for this contrast agent. Tumors were examined microscopically for tumor type, degree of malignancy (Scarff–Bloom–Richardson score) and location of necrosis. Eighteen tumor‐bearing rats were successfully imaged. MRI data showed an immediate strong and gradually increasing tumor enhancement. K^PS and fEV*, but not fPV obtained from tumors correlated significantly (p < 0.05) with the SBR tumor grade, r = 0.65 and 0.56, respectively. Estimates for K^PS and fEV* but not fPV were significantly lower in a group consisting of benign and low‐grade malignant tumors compared with the group of less‐differentiated high‐grade tumors (1.61 ± 0.64 vs 3.37 ± 1.49, p < 0.01; 0.45 ± 0.17 vs 0.78 ± 0.24, p < 0.01; and 0.076 ± 0.048 vs 0.121 ± 0.088, p = 0.24, respectively). It is concluded that the protein‐avid MRI contrast agent Gadofluorine M enhances tumors of varying malignancy depending on the tumor grade, higher contrast agent accumulation for more malignant lesions. The results show potential utility for differentiating benign and low‐grade malignant lesions from high‐grade cancers. Copyright © 2006 John Wiley & Sons, Ltd.     

Injectable freeze‐dried chitosan‐platelet‐rich‐plasma implants improve marrow‐stimulated cartilage repair in a chronic‐defect rabbit model

Bone‐marrow stimulation (BMS) improves knee‐joint function but elicits incomplete repair. Liquid chitosan (CS)–glycerol phosphate/blood clots have been shown to improve BMS‐based cartilage repair. Platelet‐rich‐plasma (PRP)—a rich source of growth factors and cytokines—improves recruitment and chondrogenic potential of subchondral mesenchymal stem cells. We hypothesised that repair response in a rabbit chronic‐defect model will improve when freeze‐dried CS/PRP is used to augment BMS. Bilateral trochlear defects created in New Zealand white rabbits were allowed to progress to a chronic stage over 4 weeks. Chronic defects were debrided and treated by BMS in second surgery, then augmented with PRP (BMS + PRP) or freeze‐dried CS/PRP implants (BMS + CS/PRP). The quality of 8‐week repair tissue was assessed by macroscopic, histological, and micro computed tomography (Micro‐CT) analysis. ICRS macroscopic scores indicated fibrocartilaginous or fibrous repair in control defects that were improved in the BMS + CS/PRP group. An overall improvement in repair in BMS + CS/PRP group was further confirmed by higher O'Driscoll scores, %Saf‐O and %Coll‐II values. Micro‐CT analysis of subchondral bone indicated ongoing remodelling with repair still underway. Quality and quantity of cartilage repair was improved when freeze‐dried CS/PRP implants were used to augment BMS in a chronic defect model.     

Profound Sinus Node Dysfunction in Anti‐N‐Methyl‐D‐Aspartate Receptor Limbic Encephalitis

A form of limbic encephalitis associated with antibodies against the N‐methyl‐D‐aspartate receptor (NMDAR) was discovered in 2007. It is often a multistage illness that progresses from psychosis, memory deficits, seizures into a state of unresponsiveness with catatonic features, abnormal movements, autonomic, and respiratory instability. We present two cases of anti‐NMDAR encephalitis to highlight the cardiac complications and their management.     

Endothelium‐dependent and endothelium‐independent effects of 1‐nitro‐2‐propylbenzene on rat aorta

A group of nitro compounds contains a benzene ring in a short aliphatic chain with the NO₂ group, property that supposedly favors its vasodilator profile. In this study, we evaluated in isolated rat aorta the effects of 1‐nitro‐2‐propylbenzene (NPB), a nitro compound containing the NO₂ in the aromatic ring. In aorta precontracted with KCl, NPB (1‐3000 μm ) induced full endothelium‐independent relaxation. In endothelium‐intact preparations, phenylephrine‐induced contractions were fully relaxed by NPB, effect unaltered by N(ω)‐nitro‐L‐arginine methyl ester (L‐NAME) or 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one (ODQ). In the concentration range of 30–300 μm , NPB slightly but significantly potentiated the phenylephrine‐induced contraction. Such potentiation was unaltered by the thromboxane‐prostanoid receptor antagonist seratrodast, but was abolished by endothelium removal or by preincubation of endothelium‐intact preparations with L‐NAME, ODQ or by ruthenium red and HC‐030031, blockers of subtype 1 of ankyrin transient receptor potential (TRPA₁) channels. Verapamil exacerbated the potentiating effect of NPB. The potentiating effect was undetectable in preparations precontracted by 9,11‐dideoxy‐11α,9α‐epoxymethanoprostaglandin F2α (U‐46619). Relaxation was reduced by ruthenium red while it was enhanced by HC‐030031. In conclusion, NPB has vasodilator properties but with a mechanism of action distinct from its analogues. Contrary to other nitro compounds, its relaxing effects did not involve recruitment of the guanylyl cyclase pathway. NPB has also endothelium‐dependent potentiating properties on phenylephrine‐induced contractions, a phenomenon that putatively required a role of endothelial TRPA₁ channels. The present findings reinforce the notion that the functional group NO₂ in the aliphatic chain of these nitro compounds determines favorably their vasodilator properties.     

D‐ and L‐[123I]‐2‐I‐phenylalanine show a long tumour retention compared with D‐ and L‐[123I]‐2‐I‐tyrosine in R1M rhabdomyosarcoma tumour‐bearing Wag/Rij rats

The aim of this study was the comparison of the tumour uptake and the long‐term retention of [¹²³I]‐2‐I‐L ‐phenylalanine and [¹²³I]‐2‐I‐D ‐phenylalanine with those of [¹²³I]‐2‐I‐L ‐tyrosine and [¹²³I]‐2‐I‐D ‐tyrosine in R1M rhabdomyosarcoma tumour‐bearing rats. The biodistribution of the radioactivity as a function of time in R1M tumour‐bearing rats was measured by planar gamma camera imaging (dynamic and static). If dissection was applied, the activity in the tumours and tissues of interest was measured by gamma counting. [¹²³I]‐2‐iodo‐L ‐phenylalanine, [¹²³I]‐2‐iodo‐D ‐phenylalaine, [¹²³I]‐2‐I‐L ‐tyrosine showed a considerable tumour uptake reaching a maximum between 10 and 30 min. At 30 min p.i. the differential uptake ratio values of this uptake were, respectively, 2.1, 2.3, 2.5 and 1.7. The activity in the tumour was shown to be related to a tumour cell uptake and not to an increased blood pool activity. All the tracers showed a clearance from the blood to the bladder without renal retention. At longer times both L ‐ and D ‐ [¹²³I]‐2‐I‐tyrosine were cleared for a large part from the tumours and the body. [¹²³I]‐2‐I‐L ‐Phe and [¹²³I]‐2‐I‐D ‐Phe showed a considerable and equal retention in the tumours: as compared with 0.5 h, 91% at 24 h and 80% at 48 h. This was related to the longer retention of activity in the blood pool noticed for these compounds (81% at 24 h and 65% at 48 h). The tumour‐to‐background ratio increased with 25% at those longer times. At short times all the tracers were taken up to a considerable extent in the tumours. In the R1M‐bearing Wag/Rij rat model only [¹²³I]‐2‐I‐L ‐phenylalanine and [¹²³I]‐2‐I‐D ‐phenylalanine showed an especially high retention at long times without any significant difference between the enantiomers. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and characterization of poly(glycerol‐co‐sebacate‐co‐ε‐caprolactone) elastomers

In this study, poly(glycerol‐co‐sebacate‐co‐ε‐caprolactone) (PGSCL) elastomers were synthesized for the first time from the respective monomers. The structural analysis of PGSCL elastomers by nuclear magnetic resonance (¹H‐NMR) and Fourier transform infrared spectroscopy (FTIR) revealed that the elastomers have a high number of hydrogen bonds and crosslinks. X‐ray diffraction (XRD) and thermal analysis indicated an amorphous state. Differential scanning calorimetry (DSC) analysis showed that the elastomers has a glass transition temperature (T_g) of –36.96°C. The Young's modulus and compression strength values were calculated as 46.08 MPa and 3.192 MPa, respectively. Calculations based on acid number and end groups analysis revealed a number average molecular weight of 148.15 kDa. Even though the foaming studies conducted by using supercritical CO₂ resulted in a porous structure; the obtained morphology tended to disappear after 48 h, leaving small cracks on the surface. This phenomenon was interpreted as an indication of self‐healing due to the high number of hydrogen bonds. The PGSCL elastomers synthesized in this study are flexible, robust to compression forces and have self‐healing capacity. Thanks to good biocompatibility and poor cell‐adhesion properties, the elastomers may find diverse applications where a postoperative adhesion barrier is required. Copyright © 2013 John Wiley & Sons, Ltd.     

Mn‐citrate and Mn‐HIDA: intermediate‐affinity chelates for manganese‐enhanced MRI

In this study we investigated two manganese chelates in order to improve the image enhancement of manganese‐enhanced MRI and decrease the toxicity of free manganese ions. Since both MnCl₂ and a low‐affinity chelate were associated with a slow continuous decrease of cardiac functions, we investigated intermediate‐affinity chelates: manganese N‐(2‐hydroxyethyl)iminodiacetic acid (Mn‐HIDA) and Mn‐citrate. The T₁ relaxivity values for Mn‐citrate (4.4 m m ^?1 s^?1) and Mn‐HIDA (3.3 m m ^?1 s^?1) in artificial cerebrospinal fluid (CSF) were almost constant in a concentration range from 0.5 to 5 m m at 37 °C and 4.7 T. In human plasma, the relaxivity values increased when the concentrations of these Mn chelates were decreased, suggesting the presence of free Mn²⁺ bound with serum albumin. Mn‐HIDA and Mn‐citrate demonstrated a tendency for better contractility when employed with an isolated perfused frog heart, compared with MnCl₂. Only minimal changes were demonstrated after a venous infusion of 100 m m Mn‐citrate or Mn‐HIDA (8.3 µmol kg^?1 min^?1) in rats and a constant heart rate, arterial pressure and sympathetic nerve activity were maintained, even after breaking the blood–brain barrier (BBB). Mn‐citrate and Mn‐HIDA could not cross the intact BBB and appeared in the CSF, and then diffused into the brain parenchyma through the ependymal layer. The responses in the supraoptic nucleus induced by the hypertonic stimulation were detectable. Therefore, Mn‐citrate and Mn‐HIDA appear to be better choices for maintaining the vital conditions of experimental animals, and they may improve the reproducibility of manganese‐enhanced MRI of the small nuclei in the hypothalamus and thalamus. Copyright © 2012 John Wiley & Sons, Ltd.     

A hydrolytically‐tunable photocrosslinked PLA‐PEG‐PLA/PCL‐PEG‐PCL dual‐component hydrogel that enhances matrix deposition of encapsulated chondrocytes

In this study, a series of photocrosslinked hydrogels were designed composed of both poly(lactide)‐poly(ethylene glycol)‐poly(lactide) (PEL) and poly(ε‐caprolactone)‐poly(ethylene glycol)‐poly(ε‐caprolactone) (PEC) macromers. The PEL/PEC hydrogels at ratios of 100:0, 75:25, 50;50, 25:75 and 0:100 were studied for their degradation characteristics and their ability to support chondrogenesis of encapsulated chondrocytes. Difference in hydrolytic susceptibility between copolymers led to different degradation patterns where higher PEC content correlated with slower degradation. Increased chondrogenic gene expression was observed in chondrocyte‐laden hydrogels within a 4‐week culture period. Biochemical and histological evaluations revealed significant accumulation of extracellular matrix proteins such as glycosaminoglycans and collagen in the 50/50 hydrogel owing to appropriate tuning of hydrogel degradation. These results demonstrate that the dual‐component photocrosslinked hydrogel system is suitable for use as scaffold to support chondrogenesis and, moreover, the tunability of these systems opens up possibilities for use in different cell culturing applications. Copyright © 2014 John Wiley & Sons, Ltd.