Silver Nanoparticles Decorated with PEGylated Porphyrins as Potential Theranostic and Sensing Agents

Silver nanoparticles (AgNPs) stand out over other metal nanoparticles thanks to their peculiar bactericidal and spectroscopic properties. Tunability of the AgNPs chemical–physical properties could be provided through their organic covalent coating. On the other hand, PEGylated porphyrin derivatives are versatile heteromacrocycles investigated for uses in the biomedical field as cytotoxic and tracking agents, but also as sensors. In this work, an easy multi-step approach was employed to produce coated silver nanoparticles. Specifically, the AgNPs were functionalized with 5,10,15-[p-(ω-methoxy-polyethyleneoxy)phenyl]-20-(p-hydroxyphenyl)-porphyrin (P(PEG350)₃), using chloropropanethiol as a coupling agent. The P(PEG350)₃ was structurally characterized through MALDI-TOF mass spectrometry, NMR spectroscopy and thermal analyses. The functionalization of AgNPs was monitored step-by-step employing UV-Vis spectroscopy, dynamic light scattering and thermogravimetric techniques. HRTEM and STEM measurements were used to investigate the morphology and the composition of the resulting nanostructured system (AgNP@P(PEG350)₃), observing a long-range alignment of the outer porphyrin layer. The AgNP@P(PEG350)₃ combines the features of the P(PEG350)₃ with those of AgNPs, producing a potential multifunctional theranostic tool. The nanosystem revealed itself suitable as a removable pH sensor in aqueous solutions and potentially feasible for biological environment applications.     

Pelvic emergency management: the first 24 hours

Pelvic ring injuries are a major cause of morbidity and mortality in the polytrauma patient. Mortality rates from pelvic ring injuries have declined, unrelated to injury severity. This is due to an improved understanding of trauma as a disease, initial and subsequent management options. There are a number of guidelines pertaining to these injuries. These have been brought together to provide an overview of the current guidance on the emergent management of these complex injuries. The foundations of treatment for these injuries includes the following: recognition of the high energy involved, rapid assessment, resuscitation and temporary stabilization of bony and soft tissue injuries. It is important to involve a multidisciplinary team prior to definitive management. By following the guidance set out by this article, the orthopaedic trauma team in the receiving hospital can optimize the patient and prepare them for transfer to the regional major trauma centre. This will improve patient morbidity and mortality and ensure standardization of pelvic trauma management in the first 24 hours.     

Infections in hospitalised Russian children with AIDS

OBJECTIVES: (1) To determine the most common infections in hospitalised children with AIDS. (2) To identify the pathogens causing the above infections. (3) To investigate the possibility of nosocomial transmission of potential pathogens in a Russian AIDS hospital. SETTING: Russian AIDS Hospital for Children. SUBJECTS AND METHODS: Swabs/samples of skin, mouth, nose, urine and stool were collected from 95 hospitalised children with AIDS, 12 of their mothers and 11 health care workers in contact with the children. Hospital objects were also sampled. The predominant isolates from the infection sites were speciated. Antibiotic sensitivity profiles, phagotyping and gel electrophoresis of cell lysates were used for the epidemiological marking of Candida albicans, Staphylococcus aureus and Klebsiella pneumoniae. RESULTS: Oral infections were the most prevalent infections in this study group. The most frequently isolated micro-organisms were C. albicans, S. aureus, K. pneumoniae and Escherichia coli. The results of the epidemiological study suggests nosocomial transmission of these strains. CONCLUSIONS: The present chemoprophylaxis programme for opportunistic oral infections requires revision. Systems of microbiological surveillance and cross-infection control monitoring in relation to immunocompromised patients need to be developed to decrease the possibility of nosocomial transmission of potential pathogens between hospitalised children with AIDS, their mothers and health care providers.     

Changes in the international recommendations on neonatal resuscitation, 2010: comments

Since previous publication in 2005, the most significant changes that have been addressed in the 2010 International Liaison Committee on Resuscitation (ILCOR) recommendations are as follows: (i) use of 2 vital characteristics (heart rate and breathing) to initially evaluate progression to the following step in resuscitation; (ii) oximetry monitoring for the evaluation of oxygenation (assessment of color is unreliable); (iii) for babies born at term it is better to start resuscitation with air rather than 100% oxygen; (iv) administration of supplementary oxygen should be regulated by blending oxygen and air; (v) controversy about endotraqueal suctioning of depressed infants born through meconium-stained amniotic fluid; (vi) chest compression-ventilation ratio should remain at 3/1 for neonates unless the arrest is known to be of cardiac etiology, in which case a higher ratio should be considered; (vii) use of therapeutic hypothermia for infants born at term or near term evolving to moderate or severe hypoxic-ischemic encephalopathy, with protocol and follow-up coordinated through a regional perinatal system (post-resuscitation management); (viii) cord clamping delay for at least 1 minute in babies who do not require resuscitation (there is insufficient evidence to recommend a time for clamping in those who require resuscitation) and, (ix) it is appropriate to consider discontinuing resuscitation if there has been no detectable heart rate for 10 minutes, although many factors contribute to the decision to continue beyond 10 minutes. Under certain circumstances, non-initiation of resuscitation could be proposed taking into consideration general recommendations, own results and parents' opinion.     

Production of chitosan from endolichenic fungi isolated from mangrove environment and its antagonistic activity

Objective

To screen the chitosan producing ability of endolichenic fungi and its antibacterial activity.

Methods

Lichen collected from mangroves was screened for endophytes and the chitosan producing ability of endolichenic fungi by submerged fermentation was also determined. Antibacterial activity was carried out against different pathogens.

Results

Totally 4 different groups of fungi were isolated from the lichen Roccella montagnei. Among the four genera, Aspergillus niger (A. niger) is potential to produce chitosan (1.3 g/L) on the twelfth day of incubation. Glucose plays an important role in the productivity of chitosan and the yield was maximum at 10% (1.93 g/L). Antibacterial activity revealed that Vibrio cholerae was sensitive to chitosan followed by Escherichia coli.

Conclusions

In conclusion, our findings suggest that A. niger is a potential candidate to produce more chitosan than the other strains and glucose plays an important role in the production of chitosan which proves to have a good antibacterial activity.     

Oxidative and nitrosative stress in acute pancreatitis. Modulation by pentoxifylline and oxypurinol

Reactive oxygen species are considered mediators of the inflammatory response and tissue damage in acute pancreatitis. We previously found that the combined treatment with oxypurinol - as inhibitor of xanthine oxidase- and pentoxifylline - as inhibitor of TNF-α production-restrained local and systemic inflammatory response and decreased mortality in experimental acute pancreatitis. Our aims were (1) to determine the time-course of glutathione depletion and oxidation in necrotizing pancreatitis in rats and its modulation by oxypurinol and pentoxifylline; (2) to determine whether TNF-α is responsible for glutathione depletion in acute pancreatitis; and (3) to elucidate the role of oxidative stress in the inflammatory cascade in pancreatic AR42J acinar cells. We report here that oxidative stress and nitrosative stress occur in pancreas and lung in acute pancreatitis and the co-treatment with oxypurinol and pentoxifylline prevents oxidative stress in both tissues. Oxypurinol was effective in preventing glutathione oxidation, whereas pentoxifylline abrogated glutathione depletion. This latter effect was independent of TNF-α since glutathione depletion occurred in mice deficient in TNF-α or its receptors after induction of pancreatitis. The beneficial effects of oxypurinol in the inflammatory response may also be ascribed to a partial inhibition of MEK1/2 activity. Pentoxifylline markedly reduced the expression of Icam1 and iNos induced by TNF-α in vitro in AR42J cells. Oxidative stress significantly contributes to the TNF-α-induced up-regulation of Icam and iNos in AR42J cells. These results provide new insights into the mechanism of action of oxypurinol and pentoxifylline as anti-inflammatory agents in acute pancreatitis.     

Potential role of a hybrid intraoperative probe based on OCT and positron detection for ovarian cancer detection and characterization

Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in the late stages due to the lack of reliable symptoms and efficacious screening techniques. A novel hybrid intraoperative probe has been developed and evaluated for its potential role in detecting and characterizing ovarian tissue. The hybrid intraoperative dual-modality device consists of multiple scintillating fibers and an optical coherence tomography imaging probe for simultaneously mapping the local activities of (18)F-FDG uptake and imaging of local morphological changes of the ovary. Ten patients were recruited to the study and a total of 18 normal, abnormal and malignant ovaries were evaluated ex vivo using this device. Positron count rates of 7.5/8.8-fold higher were found between malignant and abnormal/normal ovaries. OCT imaging of malignant and abnormal ovaries revealed many detailed morphologic features that could be potentially valuable for evaluating local regions with high metabolic activities and detecting early malignant changes in the ovary. These initial results have demonstrated that our novel hybrid imager has great potential for ovarian cancer detection and characterization during minimally invasive endoscopic procedures.