Fiber-Templated 3D Calcium-Phosphate Scaffolds for Biomedical Applications: The Role of the Thermal Treatment Ambient on Physico-Chemical Properties

A successful bone-graft-controlled healing entails the development of novel products with tunable compositional and architectural features and mechanical performances and is, thereby, able to accommodate fast bone in-growth and remodeling. To this effect, graphene nanoplatelets and Luffa-fibers were chosen as mechanical reinforcement phase and sacrificial template, respectively, and incorporated into a hydroxyapatite and brushite matrix derived by marble conversion with the help of a reproducible technology. The bio-products, framed by a one-stage-addition polymer-free fabrication route, were thoroughly physico-chemically investigated (by XRD, FTIR spectroscopy, SEM, and nano-computed tomography analysis, as well as surface energy measurements and mechanical performance assessments) after sintering in air or nitrogen ambient. The experiments exposed that the coupling of a nitrogen ambient with the graphene admixing triggers, in both compact and porous samples, important structural (i.e., decomposition of β-Ca₃(PO₄)₂ into α-Ca₃(PO₄)₂ and α-Ca₂P₂O₇) and morphological modifications. Certain restrictions and benefits were outlined with respect to the spatial porosity and global mechanical features of the derived bone scaffolds. Specifically, in nitrogen ambient, the graphene amount should be set to a maximum 0.25 wt.% in the case of compact products, while for the porous ones, significantly augmented compressive strengths were revealed at all graphene amounts. The sintering ambient or the graphene addition did not interfere with the Luffa ability to generate 3D-channels-arrays at high temperatures. It can be concluded that both Luffa and graphene agents act as adjuvants under nitrogen ambient, and that their incorporation-ratio can be modulated to favorably fit certain foreseeable biomedical applications.     

Increased gallstone risk in humans conferred by common variant of hepatic ATP-binding cassette transporter for cholesterol

Genomewide scans of inbred strains of mice have linked the genes encoding the hepatocanalicular cholesterol transporter ABCG5/G8 to gallstone formation. Five nonsynonymous coding single-nucleotide polymorphisms (SNPs) in the orthologous human genes are associated with differences in serum cholesterol and plant sterol levels. We now tested these ABCG5/G8 SNPs for linkage and association with gallstone susceptibility in humans. Prospectively, we collected data from 178 white individuals with gallbladder stones or history of cholecystectomy in 84 families and from 70 stone-free controls, as confirmed by abdominal ultrasound. We performed nonparametric linkage (NPL) analysis of affected sib pairs (ASPs) and association tests of cases and controls. In ASPs, gallstones were strongly linked to the D19H variant of the ABCG8 gene (NPL score = 7.1; P = 4.6 x 10(-13)). The risk of gallstones in carriers of the 19H allele was significantly increased in randomly selected cases from the ASP cohort compared to the stone-free controls (OR = 3.018; P = 0.017). Consistent with the mouse model, heterozygosity for the lithogenic ABCG8 allele was associated with gallstones in humans; 21.4% of gallstone patients carried the heterozygous D19H genotype, compared with 8.6% of controls (OR = 2.954; P = 0.026). CONCLUSION: The linkage and association studies identified the cholesterol transporter ABCG5/G8 as a genetic determinant of gallstone formation, or LITH gene, in humans. The function of this transporter and the results of the genetic study taken together indicate that in gallstone-susceptible carriers of the ABCG8 19H allele, cholesterol cholelithiasis is secondary to increased hepatobiliary cholesterol secretion.     

Endogenous Activation of adenosine A1 receptors promotes post-ischemic electrocortical burst suppression

Following transient global cerebral ischemia (GCI), spontaneous electrocortical activity resumes from the isoelectric line through a sequence of “bursts” of activity alternating with periods of electrical “suppression,” commonly referred to as the post-ischemic burst suppression (BS) pattern. Several lines of evidence suggest that BS reflects an impairment of neocortical connectivity. Here we tested in vivo whether synaptic depression by adenosine A₁ receptor (A₁R) activation contributes to BS patterns following GCI. Male Wistar rats were subjected to 1, 5 or 10 min of GCI using a “four-vessel occlusion” model under chloral hydrate anesthesia. Quantification of BS recovery was carried out using BS ratio. During GCI full electrocortical suppression was attained (BS ratio reached 100%). During the following reperfusion the BS ratio returned to 0. The time course of the decay was exponential after 1 and 5-min GCI and bi-exponential after 10-min GCI. The BS recovery was progressively delayed with the duration of ischemia. Administration of the A₁R antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 1.25 mg/kg i.p.) accelerated the post-ischemic BS recovery for all GCI durations. Following the 10-min GCI the effect of DPCPX was only apparent on the initial fast decay of the BS ratio. These data suggest that endogenous adenosine release promotes BS patterns during reperfusion following transient cerebral ischemia. Furthermore, the endogenous A₁R activation may be the primary underlying cause of post-ischemic BS patterns following brief ischemic episodes. It is likely that synaptic depression by post-ischemic A₁R activation functionally disrupts the connectivity within the cortical networks to an extent that promotes BS patterns.     

Urosepsis. Clinical aspects--therapy--results.

Nine cases of urosepsis registered between 1986 and 1990 are analyzed. Authors intended to find out practical conclusions which can improve the prognosis of urosepsis. Risk factors are considered advanced age, preoperative disorders (diabetes, malnutrition), preexistent end organ failure (kidney, liver, lung) and urinary infection. Early diagnosis, emergency restoration of urinary flow, suppression of primary focus of infection, intravenous antibiotherapy and energetic intensive care measures are necessary for the outcome of patients.     

Drug related deaths between 2008 and 2011. A retrospective study in 32 Romanian counties

The purpose of this study is to determine the pattern of drug related deaths in Romania between 2008 and 2011 by analyzing the medical-legal cases, from a significant proportion of Romanian Counties (out of 41 plus the capital), in which the direct causal link between drug overdose and death was drug related. Material and methods. 446 forensic toxicology cases were analyzed in a four year period, obtained from more than two thirds of the counties in Romania. Results. 54.26% yielded a positive toxicological analysis, most often with benzodiazepines, opiates, barbiturates and cannabinoids. Males around 31 years old represented the most affected group. Illegal drug related deaths were more frequent in males and non-illegal drug related deaths were proportionally more frequent in females. Discussions and conclusions. The pattern of consumption is similar to the one obtained by similar studies in neighboring countries. The city capital has a very distinct pattern of consumption compared to other cities/counties.     

Endogenous activation of adenosine A(1) receptors accelerates ischemic suppression of spontaneous electrocortical activity

Cerebral ischemia induces a rapid suppression of spontaneous brain rhythms prior to major alterations in ionic homeostasis. It was found in vitro during ischemia that the rapidly formed adenosine, resulting from the intracellular breakdown of ATP, may inhibit synaptic transmission via the A(1) receptor subtype. The link between endogenous A(1) receptor activation during ischemia and the suppression of spontaneous electrocortical activity has not yet been established in the intact brain. The aim of this study was to investigate in vivo the effects of A(1) receptor antagonism by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) on the time to electrocortical suppression during global cerebral ischemia. Adult male Wistar rats under chloral hydrate anesthesia were subjected to 1-min transient "four-vessel occlusion" ischemic episodes, separated by 20-min reperfusion. The rats were injected intraperitoneally with either 1.25 mg/kg DPCPX dissolved in 2 ml/kg dimethyl sulfoxide (DMSO) or the same volume of DMSO alone, 15 min before the third ischemic episode. Time to electrocortical suppression was estimated based on the decay of the root mean square of two-channel electrocorticographic recordings. During the first two ischemic episodes, electrocortical suppression appeared after approximately 12 s in both groups. After DMSO administration, ischemic suppression remained unchanged. After DPCPX administration, the time to electrocortical suppression was increased by approximately 10 s, and bursts of activity were recorded during the entire ischemia. These effects disappeared within 15 h after DPCPX administration. Our data provide evidence that during cerebral ischemia endogenous activation of A(1) receptors accelerates the electrical "shut-down" of the whole brain.     

The place of general practitioners in cancer care in Champagne-Ardenne

IntroductionIn France, general practitioners (GPs) are playing a key role in cancer care since the HPST law and the second national cancer plan.MethodA postal questionnaire survey was conducted in Champagne-Ardenne Area to evaluate GPs’ satisfaction and needs in cancer management. A questionnaire was sent by mail in March and April 2011 to 1231 GPs. Statistical analysis of the results was done using Sphinx software (France).ResultsParticipation rate was 33% (n = 405/1231). Most of the participants were male (n = 296; 73%), and the mean age was 51.8 years (s.d.: 9 years). Participants described as acceptable their communication with oncologists (n = 343; 85%), the delay of receiving the multidisciplinary team meeting report (n = 353; 88%) and the patient personalised care plan (n = 319; 81%). However, 69% (n = 269) stated that the communication between GPs and oncologists should improve and 64% (n = 243) were not satisfied with their level of oncology knowledge.ConclusionThis study identified important key points that need to be improved in order to strengthen the place of GPs in cancer management.     

Surface Roughness Analysis and Prediction with an Artificial Neural Network Model for Dry Milling of Co–Cr Biomedical Alloys

The aim of this paper is to conduct an experimental study in order to obtain a roughness (Ra) prediction model for dry end-milling (with an AlTiCrSiN PVD-coated tool) of the Co–28Cr–6Mo and Co–20Cr–15W–10Ni biomedical alloys, a model that can contribute to more quickly obtaining the desired surface quality and shortening the manufacturing process time. An experimental plan based on the central composite design method was adopted to determine the influence of the axial depth of cut, feed per tooth and cutting speed process parameters (input variables) on the Ra surface roughness (response variable) which was recorded after machining for both alloys. To develop the prediction models, statistical techniques were used first and three prediction equations were obtained for each alloy, the best results being achieved using response surface methodology. However, for obtaining a higher accuracy of prediction, ANN models were developed with the help of an application made in LabView for roughness (Ra) prediction. The primary results of this research consist of the Co–28Cr–6Mo and Co–20Cr–15W–10Ni prediction models and the developed application. The modeling results show that the ANN model can predict the surface roughness with high accuracy for the considered Co–Cr alloys.     

Lead poisoning from Ayurvedic treatment: a further case

Purpose:We report a case of a 30 years old Indian sailor with microcytic anemia (Hb 9.9), persistent abdominal pain, emesis, dark stool, hyperchromic urine, latent jaundice and asthenia. Lead intoxication was confirmed (blood lead value of 102 µg/dL). The patient assumed Ayurvedic medicines in the previous months. Ayurveda is an ancient form of Indian traditional popular medicine aiming to re-establish health and body function through herbal preparations, heavy metals are often added. Our purpose was to treat the patient and to establish the source of poisoning.Methods:After testing blood and urine lead concentration of other 3 crew members and analyzing over than 150 products used on the ship professional exposure was excluded. We analyzed the two Ayurvedic drugs assumed by the patient with an Inductively Coupled Plasma Mass Spectrometry. The patient underwent three chelation cycles with Calcium Disodium Ethylenediaminetetraacetic acid (EDTA) while monitoring blood and urinary lead levels.Results:The final blood lead level at discharge, after three chelation cycles, was 36.27 µg/dL. One of the two drugs contained extremely high concentrations of lead and mercury. The three different mixtures of this preparation showed lead concentrations of 12,638.54 mg/kg (Sample 2A), 23,043.02 mg/kg (Sample 2B), 21,352.97 mg/kg (Sample 2C); these levels are much higher than the highest values reported in literature for the indian soil (32 mg/kg).Conclusions:This case and similar cases raise the safety alert on complementary and alternative medicines; Ayurvedic medicine users should be carefully informed about potential risks and signs of poisoning.     

MRI contrast using solid‐state,B1‐distorting,microelectromechanical systems (MEMS) microresonant devices (MRDs)

Presently, signal generation in MRI depends on the concentration and relaxivity of protons or other MR‐active nuclei, and contrast depends on local differences in signal. In this proof‐of‐principle study, we explore the use of nonchemical, solid‐state devices for generating detectable signal and/or contrast in vitro and in vivo. We introduce the concept of microresonant devices (MRDs), which are micron‐sized resonators fabricated using microelectromechanical systems (MEMS) technology. Fifteen‐micrometer (15‐μm)‐thick, coil MRDs were designed to resonate at the 3T Larmor frequency of protons (127.7 MHz) and were fabricated using tantalum (Ta) oxide thin‐film capacitors and copper‐plated spiral inductors. The performance of MRDs having final diameters of 300, 500, and 1000 μm were characterized in saline using a radio frequency (RF) scanning microscope and a clinical 3T MR scanner. The measured B₁ fields of 300 μm to 1000 μm MRDs ranged from 3.25 μT to 3.98 μT, and their quality factors (Q) ranged from 3.9 to 7.2. When implanted subcutaneously in the flank of a mouse, only MRDs tuned to the resonant frequency of protons generated a measurable in vivo B₁ field. This study lays the foundation for a new class of solid‐state contrast agents for MRI. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.