Differential effect of interleukin 1 on naive and memory CD4+ T cells.

Freshly derived murine CD4+ T cells are divided into naive and memory cells based on the expression of CD45 isoforms. Cross-linking the T cell receptor CD3 complex either by plastic-bound anti-CD3 antibodies or the antibody presented on non-lymphoid Fc gamma receptor type II-positive Chinese hamster ovary cells in absence of competent antigen-presenting cells fails to activate naive cells to either secrete cytokines or to proliferate. In contrast, memory cells secrete their characteristic cytokines [interleukin (IL) 2, IL4, and interferon-gamma] and show significant proliferation to this stimulus. IL 1 however, is required for their optimal clonal expansion. Differential expression of IL 1 receptor mRNA in memory cells also correlate with their responsiveness to IL 1. Thus, these data reveal a basic difference in the requirements for activation of naive and memory CD4+ T cells.     

Can the Reaction Mechanism of Radical Solution Polymerization Explain the Microgel Final Particle Volume in Precipitation Polymerization of N‐Isopropylacrylamide?

Precise particle size customization is a key requirement for the applications of stimuli‐sensitive poly(N‐isopropylacrylamide) microgels. No empirically supported mechanism has been presented to explain the microgel particle size dependence on polymerization conditions. In this work, nonstirred precipitation polymerization is employed to address this question. It is argued that the reaction proceeds by radical solution polymerization mechanism rather than as emulsion polymerization. The number of particles in the batch, and the microgel particle volume, is shown to correlate with the charge density of the particles determined by the kinetic chain length. Cross‐linking efficiency is recognized to be an important factor in the particle nucleation. Properties of radical solution polymerization, such as differences in the rate of decomposition of thermally decomposing initiator and redox initiator, are used to tune the particle number density in the batch. Contemporary synthesis approaches, including temperature‐programmed synthesis, are discussed in the context of these results.

     

Uptake of heavy metal ions from aqueous media by hydrogels and their conversion to nanoparticles for generation of a catalyst system: two-fold application study

Poly(methacrylic acid) (P(MAA)), poly(acrylamide) (P(AAm)) and poly(3-acrylamidopropyltrimethyl ammonium chloride) (P(APTMACl)) were synthesized as anionic, neutral and cationic hydrogels, respectively. The synthesized hydrogels have the ability to be used as absorbents for the removal of selected heavy metal ions such as Cu²⁺, Co²⁺, Ni²⁺ and Zn²⁺ from aqueous media. Absorption studies revealed that the absorption of metal ions by the hydrogels followed the order Cu²⁺ > Ni²⁺ > Co²⁺ > Zn²⁺. For the mechanism of absorption, both Freundlich and Langmuir absorption isotherms were applied. Metal ion entrapped hydrogels were treated using an in situ chemical reduction method in order to convert the metal ions into metal nanoparticles for the synthesis of hybrid hydrogels. The synthesis and morphology were confirmed using FT-IR and SEM, while the absorbed metal amounts were measured using TGA and AAS. The hybrid hydrogels were further used as catalysts for the reduction of macro (methylene blue, methyl orange and congo red) and micro (4-nitrophenol and nitrobenzene) pollutants from the aqueous environment. The catalytic performance and re-usability of the hybrid hydrogels were successfully investigated.

Poly(methacrylic acid) (P(MAA)), poly(acrylamide) (P(AAm)) and poly(3-acrylamidopropyltrimethyl ammonium chloride) (P(APTMACl)) were synthesized as anionic, neutral and cationic hydrogels respectively.     

Ethyl glucuronide and ethyl sulfate: a review of their roles in forensic toxicology analysis of alcohol postmortem

Forensic Toxicology - This review presents the current methods used for determining ethyl glucuronide (EtG) and ethyl sulfate (EtS) concentrations in postmortem specimens, including sample...     

Menace of childhood non-accidental traumatic brain injuries: A single unit report

Background:

Childhood traumatic brain injury (TBI) has high rate of mortality and morbidity worldwide. There are dearths of reports from developing countries with large paediatric population on trauma; neurosurgery trauma of nonaccidental origin is not an exemption. This study analysed menace of non-accidental TBI in the paediatric population from our center.

Materials and Methods:

This is a single unit, retrospective study of the epidemiology of non-accidental TBI in children starting from September, 2008 to March, 2014. The management outcomes of the epidemiology of the non-accidental TBI were analysed.

Results:

Total of 109 children age range from 0 (intra-natal) to 16 years with a mean of 5.8 ± 4.6 years (median, 5 years) were enrolled into the study. 34 (31.2%) were domestic violence, 26 (23.9%) street assaults, 16 (14.7%) were due to animal assaults and mishaps, 17 (15.6%) fall from heights. Seven (6.4%) cases of collapsed buildings were also seen during the period. Four (3.7%) industrial accidents and two (1.8%) were self-inflicted injuries. There were also three (2.8%) cases of iatrogenic TBI out of which two infants (1.8%) sustained TBI from cesarean section procedure while one patient (0.9%) under general anaesthesia felt from the operation bed resulting to severe TBI.

Conclusion:

Child abuse, unprotected child labour, parental/care-givers negligence are the main cause of nonaccidental TBI. Human right activists and government agents should be incorporated in curtailing the menace.     

Effects of pre-emptive analgesia on efficacy of buccal infiltration during pulpotomy of mandibular primary molars: a double-blinded randomized controlled trial

Objective: To assess the effect of preoperative administration of ibuprofen and acetaminophen on the efficacy of buccal infiltration for pulp therapy in mandibular primary molars.

Materials and methods: A randomized controlled trial with an ID no. NCT03423329 in Clinical-Trials.gov was conducted in the outpatient clinic of Paediatric Dentistry Department at Ain Shams University. The study was designed with two test arms where either ibuprofen or acetaminophen was administered to children whereas in the control arm a multivitamin placebo was used. Children's self-reported pain responses were recorded using Wong–Baker FACES pain scale. For statistical analysis, Chi-square test or Fisher’s exact test was used to compare between the three groups whereas Friedman’s test was used to study changes within each group.

Results: In a sample of 60 children, a significant decrease in the mean pain rating scores was detected in all groups where success rates ranged from 40% with ibuprofen to 55% and 65% with acetaminophen and placebo, respectively. However, there was no statistically significant difference between the three groups regarding severity of pain during access cavity preparation.

Conclusions: Both analgesics have no clinical advantage over the placebo in increasing the efficacy of buccal infiltration during pulp therapy in mandibular primary molars.     

The Influence of MMA Esterification on Interfacial Adhesion and Mechanical Properties of Hybrid Kenaf Bast/Glass Fiber Reinforced Unsaturated Polyester Composites

The demand for natural fiber hybrid composites for various applications has increased, which is leading to more research being conducted on natural fiber hybrid composites due to their promising mechanical properties. However, the incompatibility of natural fiber with polymer matrix limits the performance of the natural fiber hybrid composite. In this research work, the mechanical properties and fiber-to-matrix interfacial adhesion were investigated. The efficiency of methyl methacrylate (MMA)-esterification treatments on composites’ final product performance was determined. The composite was prepared using the hand lay-up method with varying kenaf bast fiber (KBF) contents of 10, 15, 20, 25, 30, 35 (weight%) and hybridized with glass fiber (GF) at 5 and 10 (weight%). Unsaturated polyester (UPE) resin and methyl ethyl ketone peroxide (MEKP) were used as binders and catalysts, respectively. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used to examine the effects of MMA-esterification treatment on tensile strength and morphology (tensile fracture and characterization of MMA-esterification treatment) of the composite fabricated. The tensile strength of MMA-treated reinforced UPE and hybrid composites are higher than that of untreated composites. As for MMA treatment, 90 min of treatment showed the highest weight percent gain (WPG) and tensile strength of KBF-reinforced UPE composites. It can be concluded that the esterification of MMA on the KBF can lead to better mechanical properties and adhesion between the KFB and the UPE matrix. This research provides a clear reference for developing hybrid natural fibers, thus contributing to the current field of knowledge related to GF composites, specifically in transportation diligences due to their properties of being lightweight, superior, and involving low production cost.     

Transient insulin increase in reactive hypoglycemia in obese and non-obese subjects

(1). Insulin levels at the moment of glucose-induced reactive hypoglycemia have been compared with zero-hour insulin levels in 108 subjects in whom the blood glucose had decreased to 50 mg percent or less (50 to 31 mg) at the third, fourth, or fifth hour in the course of an oral glucose tolerance test (1.75 g/kg of body weight). (2). Of the 47 obese subjects, insulin levels at the time of the reactive hypoglycemia were inappropriately high, ie exceeded the fasting insulin level by 20 uU/ml or more in 38 percent and by 40 microunits/ml or higher in 26 percent of the tests. (3). In 61 non-obese subjects, employing the same criteria, inappropriately high insulinemia at the time of reactive hypoglycemia was recorded with about the same frequency. (4). In each instance of reactive hypoglycemia of 50 mg percent or less with concomitant insulin levels above the starting value to the degree stipulated, the so-termed inappropriate hyperinsulinemia was transient. In other words, judging by levels preceding and/or following the reactive hypoglycemia, insulin titers were decreasing and hence, the inappropriately high insulin level at the moment of hypoglycemia represented a lag phenomenon. (5). The above data suggest that insulin levels elevated above the starting value may play a role in reactive hypoglycemia. In subjects with insulin levels at the time of reactive hypoglycemia equal to or below the starting value, the low blood glucose level cannot be attributed to insulin. In such instances, delay or lag in hepatic glucose output and/or counter-regulatory responses probably play the dominant or sole role in the reactive hypoglycemia.     

Association of Intraprocedural Blood Pressure and End Tidal Carbon Dioxide with Outcome After Acute Stroke Intervention

Background

General anesthesia (GA) for acute stroke interventions may be associated with inferior functional outcomes. Our goal was to identify physiologic parameters that mediate this association.

Methods

Consecutive patients treated at our institution between August 2007 and December 2010 were identified from a prospective database. Clinical data were then extracted by retrospective chart review. Variables significantly associated with outcome in univariate analysis were also examined in multivariate analysis, controlling for well-established prespecified predictors of functional outcome.

Results

Of the 106 patients identified, 20 were excluded (17 due to the absence of 90-day mRS and 3 due to insufficient anesthetic records). Blood pressure (BP) decreased significantly after induction of GA, but there was no association between BP and outcome. End tidal carbon dioxide values (ETCO2) at 60 and 90 min, however, were significantly associated with outcomes in both univariate and multivariate analyses. Mean ETCO2 in patients with favorable outcomes (modified Rankin Scale (mRS) 0–3) was higher than in those with unfavorable outcomes (mRS 4–6): 35.2 mmHg versus 32.2 (p = 0.03) at 60 min and 34.9 versus 31.9 (p = 0.04) at 90 min. The adjusted odds ratios for poor outcomes for each 1 mmHg decrease in ETCO2 were the same: 0.76 (95 % CI 0.65–0.92; p = 0.004) at 60 min and 0.76 (95 % CI 0.61–0.93; p = 0.01) at 90 min.

Conclusions

While BP decreased significantly in patients undergoing GA for acute stroke intervention, it did not correlate with patient outcome. Decreases in ETCO2 at 30 and 60 min, however, were associated with 90-day mRS.