X-linked immunodeficiency with hyper-IgM (HIGM1), characterized by failure of immunoglobulin isotype switching, is caused by mutations of the CD40 ligand (CD40L), which is normally expressed on ...activated CD4(+) T cells. As constitutive expression of CD40L induces lymphomas, we corrected the mutation while preserving the natural regulation of CD40L using pre-mRNA trans-splicing. Bone marrow from mice lacking CD40L was modified with a lentivirus trans-splicer encoding the normal CD40L exons 2-5 and was administered to syngenic CD40L-knockout mice. Recipient mice had corrected CD40L mRNA, antigen-specific IgG1 responses to keyhole limpet hemocyanin immunization, regulated CD4(+) T-cell CD40L expression after CD3 stimulation in primary and secondary transplanted mice, attenuation of Pneumocystis carinii pneumonia, and no evidence of lymphoproliferative disease over 1 year. Thus, HIGM1 can be corrected by CD40L trans-splicing, leading to functional correction of the genetic defect without the adverse consequences of unregulated expression of the CD40L gene.
Aneurysm embolization using Guglielmi detachable coils (GDC) is gaining increasing acceptance as a viable alternative to surgery in the treatment of cerebral aneurysms. Although recent reports ...describe a significant rate of symptomatic thromboembolic complications with GDC use, many of the neurologic deficits are transient. We sought to determine the incidence of silent thromboembolic events with the use of diffusion-weighted imaging and to correlate radiologic findings with the results of neurologic examinations.
Diffusion-weighted MR imaging was performed within 48 hours in 14 consecutive elective GDC aneurysm treatments. Embolizations were performed under systemic heparinization; all flush solutions were heparinized, and both guiding catheters and microcatheters were placed for continuous heparinized infusions. Neurologic examination, including the National Institutes of Health Stroke Scale determination, was performed by a stroke neurologist before the coiling procedures were performed, immediately after the procedures were performed, and before discharge. MR imaging examinations were reviewed by a stroke neurologist and an interventional neuroradiologist, with determination and characterization of diffusion-weighted imaging abnormalities.
Small areas of restricted diffusion, presumed to represent procedure-related embolic infarctions, were noted on the images of eight of 14 patients. All except one of the areas were located ipsilateral to the side of the catheterization. Six patients had evidence of multiple infarcts. Most lesions were small (<2 mm); one patient with coil stretch and herniation into the parent vessel had numerous infarcts with a dominant posterior frontal infarct. Pre- and posttreatment National Institutes of Health Stroke Scale scores were unchanged for 13 of 14 patients. Overall, the rate of asymptomatic emboli was 61% (eight of 13 treatments) in uncomplicated treatments. Strokes occurred independently of the number of coils used; the mean number of coils used for patients with strokes was 7.6 (range, two to 13) and for patients without evidence of infarcts was 10.2 (range, one to 30). This was not a significant difference (P > .5).
Silent thromboembolic events related to the use of the GDC system are a common occurrence, despite meticulous technique and systemic anticoagulation. Although clinical sequelae are rare, the high rate of occurrence suggests that alterations in the technique, such as the addition of antiplatelet agents, should be considered.
Embryonic stem cell (ESC)-based therapies open new possibilities as regenerative medicine for the treatment of human disease, but the presence of small numbers of undifferentiated ESCs within the ...transplant could lead to the development of tumors. The safety of ESC transplants would be enhanced if uncontrolled cell growth could be suppressed, using external stimuli. A lentiviral vector carrying the herpes simplex virus thymidine kinase (HSVtk) and green fluorescent protein (GFP) genes was used to genetically modify murine ESCs (HSVtk+GFP+ ESCs). In the presence of ganciclovir (GCV), 100% of HSVtk+GFP+ ESCs were killed in vitro, and 100% of flank tumors derived from HSVtk+GFP+ ESCs were eliminated. When CNS tumors were produced by the HSVtk+GFP+ ESCs, the tumor mass was completely eliminated on GCV treatment for 1 week. After GCV treatment for 3 weeks, histologic analysis showed no residual tumor cells and TaqMan realtime polymerase chain reaction analysis showed no genomic HSVtk copies or HSVtk mRNA. These data demonstrate that it is possible to use ex vivo gene transfer to modify ESCs with conditional genetic elements that can be activated in vivo to control undifferentiated ESC outgrowth and to eliminate transduced ESCs that have escaped growth control after ESC-mediated therapy to the CNS.
Opioid-induced constipation (OIC), a prevalent and distressing side effect of opioid therapy, does not reliably respond to treatment with conventional laxatives. OIC can be a treatment-limiting ...adverse event. Recent advances in medications with peripherally acting μ-opioid receptor antagonists, such as methylnaltrexone, naloxegol, and alvimopan, hold promise for treating OIC and thus extending the benefits of opioid analgesia to more chronic pain patients. Peripherally acting μ-opioid receptor antagonists have been clinically tested to improve bowel symptoms without compromise to pain relief, although there are associated side effects, including abdominal pain. Other treatment options include fixed-dose combination products of oxycodone analgesic together with naloxone.
PROBLEM: In vivo and in vitro studies have indicated that estradiol can affect cytokine production in different cell types. This study examines whether estradiol affects inflammatory cytokine ...production by murine splenic macrophages.
METHODS: Mouse splenic macrophages were first treated with 17β‐estradiol, followed by lipopolysaccharide (LPS) stimulation. The production of cytokines by macrophages with or without estradiol treatment was determined at both the protein and mRNA levels. The nuclear factor‐kB (NFkB) activity of activated mouse splenic macrophages was also evaluated by electrophoretic mobility shift assay.
RESULT: Our results show that 17β‐estradiol decreases LPS‐induced IL‐1α, IL‐6, and TNF‐α production but not IL‐10, IL‐12, and macrophage inflammatory protein (MIP) production by splenic macrophages. Furthermore, inhibition of cytokine production by 17β‐estradiol was associated with a decreased LPS‐induced NFkB‐binding activity.
CONCLUSION: Because cytokines are important mediators of immune function, the alteration of cytokine production by 17β‐estradiol may thus have a profound effect on the outcome of immune response during inflammation.
Neurological manifestations are increasingly reported in a subset of COVID-19 patients. Previous infections related to coronaviruses, namely Severe Acute Respiratory Syndrome (SARS) and Middle ...Eastern Respiratory Syndrome (MERS) also appeared to have neurological effects on some patients. The viruses associated with COVID-19 like that of SARS enters the body via the ACE-2 receptors in the central nervous system, which causes the body to balance an immune response against potential damage to nonrenewable cells. A few rare cases of neurological sequelae of SARS and MERS have been reported. A growing body of evidence is accumulating that COVID-19, particularly in severe cases, may have neurological consequences although respiratory symptoms nearly always develop prior to neurological ones. Patients with preexisting neurological conditions may be at elevated risk for COVID-19-associated neurological symptoms. Neurological reports in COVID-19 patients have described encephalopathy, Guillain-Barré syndrome, myopathy, neuromuscular disorders, encephalitis, cephalgia, delirium, critical illness polyneuropathy, and others. Treating neurological symptoms can pose clinical challenges as drugs that suppress immune response may be contraindicated in COVID-19 patients. It is possible that in some COVID-19 patients, neurological symptoms are being overlooked or misinterpreted. To date, neurological manifestations of COVID-19 have been described largely within the disease trajectory and the long-term effects of such manifestations remain unknown.
Virus-mediated transfer of genes coding for intracellular toxins holds promise for cancer therapy, but the inherent toxicity of such vectors make them a risk to normal tissues and a challenge to ...produce due to the intrinsic dilemma that expression of toxin molecules kills producer cells. We employed pre-mRNA segmental trans-splicing (STS), in which two engineered DNA fragments coding for 5' "donor" and 3' "acceptor" segments of a toxin gene, respectively, are expressed by viral vectors. When co-delivered to target cells, the two vectors generate two toxin pre-mRNA fragments which are spliced by the target cell machinery to produce functional mRNA and toxin. To test this approach, we used an enzymatic fragment of Shigatoxin1A1 (STX1A1) known to provoke apoptotic cell death. Two adenovirus vectors, Shigatoxin1A1 donor (AdStx1A1Do) and Shigatoxin1A1 acceptor (AdStx1A1Ac), respectively, were used to deliver the Stx1A1 gene fragments. HeLa, HEp2, and A549 cells transfected with AdStx1A1Do and AdStx1A1Ac had a dose-dependent reduction in viability and inhibition of protein synthesis. Intratumoral injection of AdStx1A1Do and AdStx1A1Ac into preexisting HeLa, Hep2, and A549 tumors in immunodeficient mice revealed significant inhibition of tumor growth. There was no evidence of liver damage, suggesting that there was no leakage of vector or toxin from the site of injection following intratumoral injection of AdStx1A1Do and AdStx1A1Ac. These results suggest that the obstacles preventing gene transfer of intracellular toxins for local cancer therapy could be overcome by pre-mRNA segmental trans-splicing.
Joint cartilage injury remains a major problem in orthopaedics with more than 500,000 cartilage repair procedures performed yearly in the United States at a cost of hundreds of millions of dollars. ...No consistently reliable means to regenerate joint cartilage currently exists. The technologies of gene therapy and tissue engineering were combined using a retroviral vector to stably introduce the human bone morphogenic protein-7 complementary deoxyribonucleic acid into periosteal-derived rabbit mesenchymal stem cells. Bone morphogenic protein-7 secreting gene modified cells subsequently were expanded in monolayer culture, seeded onto polyglycolic acid grafts, implanted into a rabbit knee osteochondral defect model, and evaluated for bone and cartilage repair after 4, 8, and 12 weeks. The grafts containing bone morphogenic protein-7 gene modified cells consistently showed complete or near complete bone and articular cartilage regeneration at 8 and 12 weeks whereas the grafts from the control groups had poor repair as judged by macroscopic, histologic, and immunohistologic criteria. This is the first report of articular cartilage regeneration using a combined gene therapy and tissue engineering approach.
Concern about the appropriate role of nonsteroidal anti-inflammatory drugs (NSAIDs) in COVID-19 speculate that NSAIDs, in particular ibuprofen, may upregulate the entry point for the virus, the ...angiotensin-converting enzyme (ACE) 2 receptors and increase susceptibility to the virus or worsen symptoms in existing disease. Adverse outcomes with COVID-19 have been linked to cytokine storm but the most effective way to address exaggerated inflammatory response is complex and unclear. The Expert Working Group on the Commission of Human Medicines in the UK and other organizations have stated that there is insufficient evidence to establish a link between ibuprofen and susceptibility to or exacerbation of COVID-19. NSAID use must also be categorized by whether the drugs are relatively low-dose over-the-counter oral products taken occasionally versus higher-dose or parenteral NSAIDs. Even if evidence emerged arguing for or against NSAIDs in this setting, it is unclear if this evidence would apply to all NSAIDs at all doses in all dosing regimens. Paracetamol (acetaminophen) has been proposed as an alternative to NSAIDs but there are issues with liver toxicity at high doses. There are clearly COVID-19 cases where NSAIDs should not be used, but there is no strong evidence that NSAIDs must be avoided in all patients with COVID-19; clinicians must weigh these choices on an individual basis.
In the light of the COVID-19 pandemic, anti-vaccine sentiments have been on the rise, with a recent seminal study on the development of anti-vaccine views in social media even making its way into
...Nature Communications
. Yet, with the current scientific consensus being in overwhelming agreement over the safety and efficacy of vaccines, many scientists lose their grasp on the fears, concerns, and arguments that the opposition may hold. This paper discusses and evaluates vaccine-hesitant individuals on a socioeconomic, historical, and philosophical landscape. It also provides an analysis of common argumentative patterns and the psychological impact that these arguments may have on undecided individuals. The discussion also explores why anti-vaccine sentiments are on the rise, and how members of the scientific and medical community require a more structured approach to communicating key arguments. This is particularly important if vaccination rates and herd immunity are to be sustained. No longer is it sufficient to win arguments based on a factual and scientific basis, but rather scientists and medical practitioners have to focus on conveying confidence and reassurance on both an informative and emotional level to those with doubts and fears.
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