Quantum dots (QDs), also known as nanoscale semiconductor crystals, are nanoparticles with unique optical and electronic properties such as bright and intensive fluorescence. Since most conventional organic label dyes do not offer the near-infrared (>650 nm) emission possibility, QDs, with their tunable optical properties, have gained a lot of interest. They possess characteristics such as good chemical and photo-stability, high quantum yield and size-tunable light emission. Different types of QDs can be excited with the same light wavelength, and their narrow emission bands can be detected simultaneously for multiple assays. There is an increasing interest in the development of nano-theranostics platforms for simultaneous sensing, imaging and therapy. QDs have great potential for such applications, with notable results already published in the fields of sensors, drug delivery and biomedical imaging. This review summarizes the latest developments available in literature regarding the use of QDs for medical applications.

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 ؋ 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. (HEPATOLOGY 2007;46:793-801.)

Main recommendationsESGE recommends the “pull” technique as the standard method for percutaneous endoscopic gastrostomy (PEG) placement.Strong recommendation, low quality evidence.ESGE recommends the direct percutaneous introducer (“push”) technique for PEG placement in cases where the “pull” method is contraindicated, for example in severe esophageal stenosis or in patients with head and neck cancer (HNC) or esophageal cancer.Strong recommendation, low quality evidence.ESGE recommends the intravenous administration of a prophylactic single dose of a beta-lactam antibiotic (or appropriate alternative antibiotic, in the case of allergy) to decrease the risk of post-procedural wound infection.Strong recommendation, moderate quality evidence.ESGE recommends that inadvertent insertion of a nasogastric tube (NGT) into the respiratory tract should be considered a serious but avoidable adverse event (AE).Strong recommendation, low quality evidence.ESGE recommends that each institution should have a dedicated protocol to confirm correct positioning of NGTs placed “blindly” at the patient’s bedside; this should include: radiography, pH testing of the aspirate, and end-tidal carbon dioxide monitoring, but not auscultation alone.Strong recommendation, low quality evidence.ESGE recommends confirmation of correct NGT placement by radiography in high-risk patients (intensive care unit [ICU] patients or those with altered consciousness or absent gag/cough reflex).Strong recommendation, low quality evidence.ESGE recommends that EN may be started within 3 – 4 hours after uncomplicated placement of a PEG or PEG-J.Strong recommendation, high quality evidence.ESGE recommends that daily tube mobilization (pushing inward) along with a loose position of the external PEG bumper (1 – 2 cm from the abdominal wall) could mitigate the risk of development of buried bumper syndrome.Strong recommendation, low quality evidence.

Main recommendationsESGE recommends considering the following indications for enteral tube insertion: (i) clinical conditions that make oral intake impossible (neurological conditions, obstructive causes); (ii) acute and/or chronic diseases that result in a catabolic state where oral intake becomes insufficient; and (iii) chronic small-bowel obstruction requiring a decompression gastrostomy.Strong recommendation, low quality evidence.ESGE recommends the use of temporary feeding tubes placed through a natural orifice (either nostril) in patients expected to require enteral nutrition (EN) for less than 4 weeks. If it is anticipated that EN will be required for more than 4 weeks, percutaneous access should be considered, depending on the clinical setting.Strong recommendation, low quality evidence.ESGE recommends the gastric route as the primary option in patients in need of EN support. Only in patients with altered/unfavorable gastric anatomy (e. g. after previous surgery), impaired gastric emptying, intolerance to gastric feeding, or with a high risk of aspiration, should the jejunal route be chosen.Strong recommendation, moderate quality evidence.ESGE suggests that recent gastrointestinal (GI) bleeding due to peptic ulcer disease with risk of rebleeding should be considered to be a relative contraindication to percutaneous enteral access procedures, as should hemodynamic or respiratory instability.Weak recommendation, low quality evidence.ESGE suggests that the presence of ascites and ventriculoperitoneal shunts should be considered to be additional risk factors for infection and, therefore, further preventive precautions must be taken in these cases.Weak recommendation, low quality evidence.ESGE recommends that percutaneous tube placement (percutaneous endoscopic gastrostomy [PEG], percutaneous endoscopic gastrostomy with jejunal extension [PEG-J], or direct percutaneous endoscopic jejunostomy [D-PEJ]) should be considered to be a procedure with high hemorrhagic risk, and that in order to reduce this risk, specific guidelines for antiplatelet or anticoagulant use should be followed strictly.Strong recommendation, low quality evidence.ESGE recommends refraining from PEG placement in patients with advanced dementia.Strong recommendation, low quality evidence.ESGE recommends refraining from PEG placement in patients with a life expectancy shorter than 30 days.Strong recommendation, low quality evidence*.

BackgroundPathogenic bacteria contribute to various globally important diseases, killing millions of people each year. Various fields of medicine currently benefit from or may potentially benefit from the use of nanotechnology applications, in which there is growing interest. Disease-related biomarkers can be rapidly and directly detected by nanostructures, such as nanowires, nanotubes, nanoparticles, cantilevers, microarrays, and nanoarrays, as part of an accurate process characterized by lower sample consumption and considerably higher sensitivity. There is a need for accurate techniques for pathogenic bacteria identification and detection to allow the prevention and management of pathogenic diseases and to assure food safety.ConclusionThe focus of this review is on the current nanoparticle-based techniques for pathogenic bacterial identification and detection using these applications.