Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers

Background: Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers.

Purpose: We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs.

Results: Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses.

Discussion: A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines.

Conclusion: It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.     

Randomized controlled trial comparing outcomes of video capsule endoscopy with push enteroscopy in obscure gastrointestinal bleeding

BACKGROUND:

Optimal management of obscure gastrointestinal bleeding (OGIB) remains unclear.

OBJECTIVE:

To evaluate diagnostic yields and downstream clinical outcomes comparing video capsule endoscopy (VCE) with push enteroscopy (PE).

METHODS:

Patients with OGIB and negative esophagogastroduodenoscopies and colonoscopies were randomly assigned to VCE or PE and followed for 12 months. End points included diagnostic yield, acute or chronic bleeding, health resource utilization and crossovers.

RESULTS:

Data from 79 patients were analyzed (VCE n=40; PE n=39; 82.3% overt OGIB). VCE had greater diagnostic yield (72.5% versus 48.7%; P<0.05), especially in the distal small bowel (58% versus 13%; P<0.01). More VCE-identified lesions were rated possible or certain causes of bleeding (79.3% versus 35.0%; P<0.05). During follow-up, there were no differences in the rates of ongoing bleeding (acute [40.0% versus 38.5%; P not significant], chronic [32.5% versus 45.6%; P not significant]), nor in health resource utilization. Fewer VCE-first patients crossed over due to ongoing bleeding (22.5% versus 48.7%; P<0.05).

CONCLUSIONS:

A VCE-first approach had a significant diagnostic advantage over PE-first in patients with OGIB, especially with regard to detecting small bowel lesions, affecting clinical certainty and subsequent further small bowel investigations, with no subsequent differences in bleeding or resource utilization outcomes in follow-up. These findings question the clinical relevance of many of the discovered endoscopic lesions or the ability to treat most of these effectively over time. Improved prognostication of both patient characteristics and endoscopic lesion appearance with regard to bleeding behaviour, coupled with the impact of therapeutic deep enteroscopy, is now required using adapted, high-quality study methodologies.     

Neuronal activity of identified posterior hypothalamic neurons projecting to the brainstem peribrachial area of the cat

Following horseradish peroxidase injections in the brainstem peribrachial (PB) area, massive retrograde labeling was found in the posterior hypothalamic region. Single-unit recordings posterior hypothalamic neurons with antidromically identified projections to the PB area revealed that these neurons have higher firing rates in waking than in slow-wave sleep and dissimilar discharge patterns as compared with intralaminar thalamic neurons. The results are discussed in the context of reciprocal hypothalamo-brainstem circuits.     

Diagnostic value of D-dimer in patients with suspected pulmonary embolism: results from a multicentre outcome study

BACKGROUND: D-dimer tests are used in various diagnostic strategies to exclude pulmonary embolism (PE). However, their role as an exclusionary first-line test is still uncertain, mainly because accuracy of the test varies according to the assay and the studied population. METHODS: The aim of this multicentre study was to evaluate the accuracy of D-dimer testing in patients with suspected PE. Diagnosis of PE was based on pre-test clinical probability (PCP) evaluation and both single-detector spiral CT (CT) and lower limbs compression ultrasonography (CUS). Lung scanning and/or pulmonary angiography was mandatory when CT or CUS was inconclusive and when both CT and CUS were normal in a patient with a high PCP. All patients were followed-up for 3 months, looking for VTE recurrence. D-dimers were collected within 24 h of inclusion and stored in each local hematology unit, to be analyzed at the end of all inclusions; physicians in charge of the patient were blinded to D-dimer results. RESULTS: Three hundred and fifty two patients were included in 4 centres. Prevalence of PE was 38.6%. PCP was low in 82 (23.3%), intermediate in 176 (50%) and high in 94 (26.7%) patients. Sensitivity of D-dimer was 96.3% (95% CI: 93-99) and negative predictive value reached 94.4% (95% CI: 90-99). Five patients with a confirmed PE had a D-dimer level below 500 ng/ml (two patients with a high PCP). Among 258 patients with low or intermediate PCP, 80 (31%) had a negative D-dimer test result; three of them had a false negative result and the number needed to test was 3.3. Among 94 patients with a high PCP, 9 had a negative D-dimer test result; two of them had a false negative result and the number needed to test was 13.5. CONCLUSION: These results confirm that rapid assays used in this study can safely exclude PE in first-line testing only in non-high CP patients.     

Evidence for a distinct nigropallidal dopaminergic projection in the squirrel monkey

Injections of the retrograde fluorescent tracer fast blue in the striatum (STR) and nuclear yellow in the internal segment of the globus pallidus (GPi) in the squirrel monkey (Saimiri sciureus) revealed a nigropallidal projection whose cellular origin was largely distinct from that of the nigrostriatal pathway. Neurons containing the tracer injected in GPi were scattered throughout the substantia nigra-ventral tegmental area complex where they formed approximately 20-25% of the total number of retrogradely labeled cells. Only about 5-10% of all positive neurons were double-labeled after STR-GPi injections. In experiments combining the use of the fluorescent tracer propidium iodide with immunofluorescence, the majority of neurons projecting to GPi displayed tyrosine hydroxylase immunoreactivity. Hence, in addition to their important role at striatal level, midbrain dopaminergic neurons may influence directly the output neurons of the basal ganglia at pallidal level in primates.     

Inhibition of apoptosis by hyperbaric oxygen in a rat focal cerebral ischemic model.

The hypothesis was tested that hyperbaric oxygen therapy (HBO) reduced brain infarction by preventing apoptotic death in ischemic cortex in a rat model of focal cerebral ischemia. Male Sprague-Dawley rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and subsequently were exposed to HBO (2.5 atmospheres absolute) for 2 h, at 6 h after reperfusion. Rats were killed and brain samples were collected at 24, 48, 72 h, and 7 days after reperfusion. Neurologic deficits, infarction area, and apoptotic changes were evaluated by clinical scores, 2,3,7-triphenyltetrazolium chloride staining, caspase-3 expression, DNA fragmentation assay, and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate-biotin nick end labeling (TUNEL)-hematoxylin and eosin (H&E) costaining. In MCAO/R without HBO treatment animals, DNA fragmentation was observed in injured cortex at 24, 48, and 72 h but not in samples at 7 days after reperfusion. Double labeling of brain slides with NeuN and caspase-3 demonstrated neurons in the injured cortex labeled with caspase-3. TUNEL+H&E costaining revealed morphologic apoptotic changes at 24, 48, and 72 h after reperfusion. Hyperbaric oxygen therapy abolished DNA fragmentation and reduced the number of TUNEL-positive cells. Hyperbaric oxygen therapy reduced infarct area and improved neurologic scores at 7 days after reperfusion. One of the molecular mechanisms of HBO-induced brain protection is to prevent apoptosis, and this effect of HBO might preserve more brain tissues and promote neurologic functional recovery.     

Cutaneous necrotizing vasculitis after low dose methotrexate therapy for rheumatoid arthritis: A possible manifestation of methotrexate hypersensitivity

Summary Large haemorrhagic and necrotic cutaneous lesions developed after two low dose (5mg) methotrexate injections in a patient suffering from long standing rheumatoid arthritis. Differential clinical diagnosis included factitia dermatitis, infectious processes, pyoderma gangrenosum, rheumatoid neutrophilic dermatitis, necrotizing arteritis and vasculitis. Histological and direct immunofluo-rescent examinations of skin biopsies supported the diagnosis of leucocytoclastic vasculitis. We discuss the respective roles of methotrexate and rheumatoid arthritis in the outbreak of leucocytoclastic vasculitis. Hypersensitivity is strongly suspected.     

A randomized, controlled trial of vicarious experience through peer support for male first-time cardiac surgery patients: impact on anxiety, self-efficacy expectation, and self-reported activity

OBJECTIVES: The purpose of this study was to determine whether vicarious experience, in which former patients exemplify the active lives they are leading, reduces anxiety and increases self-efficacy expectation and self-reported activity in patients after cardiac surgery. DESIGN: A randomized, controlled trial was used to evaluate an intervention that linked volunteers who had recovered from cardiac surgery in dyadic support with patients about to undergo similar surgery. The linking was achieved by means of visits during the hospitalization and recovery period. SUBJECTS: Fifty-six first-time male patients undergoing coronary artery bypass graft (CABG) surgery, with a mean age of 56.5 years, were randomly assigned to an experimental (n = 27) or control group (n = 29). Outcome Measures: Anxiety was measured at 48 hours and 24 hours before surgery, and again at 5 days and 4 weeks after surgery. Self-efficacy expectation and self-reported activity were both evaluated at 5 days and 4 weeks after surgery. RESULTS: Only the experimental group showed a significant decrease in anxiety during hospitalization. At all measurement times after the first intervention, the experimental group reported significantly lower levels of anxiety compared with the control group. The experimental group reported significantly higher levels of self-efficacy expectation and self-reported activity for general activities, walking, and climbing stairs evaluated at 5 days, and for general activities at 4 weeks after surgery. CONCLUSIONS: Vicarious experience provided through dyadic support is effective in helping patients undergoing cardiac surgery cope with surgical anxiety and in improving self-efficacy expectations and self-reported activity after surgery. Dyadic support is a valuable tool for recovery from cardiac surgery that needs to be maintained and explored through nursing practice and research.