pH-controlled delivery of luminescent europium coated nanoparticles into platelets

Water soluble, luminescent gold nanoparticles are delivered into human platelets via a rapid, pH-controlled mechanism using a pH low insertion peptide, pHLIP. The approach introduces cocoating of gold nanoparticles with a europium luminescent complex, EuL and the pHLIP peptide to give pHLIP•EuL•Au. The 13-nm diameter gold nanoparticles act as a scaffold for the attachment of both the luminescent probe and the peptide to target delivery. Their size allows delivery of approximately 640 lanthanide probes per nanoparticle to be internalized in human platelets, which are not susceptible to transfection or microinjection. The internalization of pHLIP•EuL•Au in platelets, which takes just minutes, was studied with a variety of imaging modalities including luminescence, confocal reflection, and transmission electron microscopy. The results show that pHLIP•EuL•Au only enters the platelets in low pH conditions, pH 6.5, mediated by the pHLIP translocation across the membrane, and not at pH 7.4. Luminescence microscopy images of the treated platelets show clearly the red luminescence signal from the europium probe and confocal reflection microscopy confirms the presence of the gold particles. Furthermore, transmission electron microscopy gives a detailed insight of the internalization and spatial localization of the gold nanoparticles in the platelets. Thus, we demonstrate the potential of the design to translocate multimodal nanoparticle probes into cells in a pH dependent manner.     

Understanding children's dental anxiety and psychological approaches to its reduction

International Journal of Paediatric Dentistry 2012; 22: 397-405 Background. Dental anxiety is a common problem, which can affect people of all ages, but appears to develop mostly in childhood and adolescence. Childhood dental anxiety is not only distressing for the child and their family but is also associated with poor oral health outcomes and an increased reliance on costly specialist dental services. Aim. This article will consider the prevalence, development, and implications of children's dental anxiety. It will also discuss the opportunities for and challenges of psychological approaches such as cognitive behavioural therapy aimed at the reduction of dental anxiety in children.     

Salivary bacteria and oral health status in medicated and non-medicated children and adolescents with attention deficit hyperactivity disorder (ADHD)

Objectives

Attention deficit hyperactivity disorder (ADHD) is a childhood neurological disorder. Studies have shown that children with ADHD are more prone to caries than those without. The study investigated children diagnosed with ADHD, both with and without pharmacological intervention, and the following: DMFT\dmft, plaque index (PI), mutans streptococci (MS) levels, lactobacilli (LB) levels, salivary flow, salivary buffer capacity, oral hygiene, and diet.

Study design

DMFT/dmft index, PI, MS and LB levels, salivary flow, and salivary buffer capacity were examined in three groups of children: ADHD1—diagnosed with ADHD with no pharmacological intervention (N?=?31), ADHD2—treated with medications for ADHD (N?=?30), and a healthy control group (N?=?30). Diet and oral health habits were assessed through questionnaires completed by parents.

Results

There were no differences in the DMFT/dmft index, MS and LB counts, salivary buffer capacity, and parent reported diet and oral health behavior between the three groups. Children with ADHD demonstrated a higher plaque index.

Conclusions

Although children with ADHD did not report different diet and oral health behavior from children without ADHD, this group had significantly higher levels of plaque than the control group, which combined with hyposalivation may be a risk factor for caries at an older age.

Clinical relevance

Medicated and non-medicated ADHD children were similar to control children in their caries rate, MS and LB counts, salivary buffer capacity, and diet and oral health behavior. They differed in the amount of plaque found on their teeth. As a group, ADHD children demonstrated hyposalivation compared with the control.     

Prognostic value of C-reactive protein in parapneumonic effusions

Background and objective: Parapneumonic effusions (PPE) that require drainage are referred to as complicated parapneumonic effusions (CPPE). Following resolution of these effusions, residual pleural thickening (RPT) may persist. We hypothesize that the concentrations of CRP in pleural fluid (CRP_pf) and serum (CRP_ser) can be used to identify CPPE and to predict RPT. Methods: All patients with non‐purulent PPE, who were admitted to two tertiary hospitals during a 30‐month period, were enrolled in the study. Baseline CRP_pf and CRP_ser levels were compared between patients with complicated or uncomplicated PPE, as well as between patients with or without RPT of >10 mm, 6 months after discharge from hospital. Cut‐off values for identification of CPPE and prediction of RPT were determined by receiver operating characteristic curve analysis. Logistic regression analysis was performed to assess the association between CRP levels and RPT. Results: Fifty‐four patients were included in the study. Patients with CPPE (n = 23) had significantly higher levels of both CRP_pf and CRP_ser than those with uncomplicated PPE. For identification of CPPE, a CRP_pf level >78.5 mg/L and a CRP_ser level >83 mg/L gave 84% and 47% sensitivity, with 65% and 87% specificity, respectively. Classical criteria (pleural fluid pH <7.20, LDH >1000 IU/L, glucose <600 mg/L) were superior for this purpose. A combination of classical biomarkers with CRP levels using an ‘AND’ or ‘OR’ rule improved the positive and negative predictive values, respectively. CRP_ser was an independent predictor for development of RPT (adjusted OR 1.18). A CRP_ser level >150 mg/L had 91% specificity and 61% sensitivity for prediction of RPT. Conclusions: This study demonstrated the value of CRP_ser for prediction of RPT in patients with PPE. Moreover, when used in combination with classical biomarkers, CRP levels may be a useful adjunct for decision‐making in relation to treatment of patients with non‐purulent PPE.