Individuals With Prior Chronic Pain and Long-Term Opioid Treatment May Experience Persistence of That Pain Even After Subsequent Complete Cervical Spinal Cord Injury: Suggestions From a Prospective Case-Controlled Study.

Objective: To determine whether chronic pain persists after complete spinal cord injury (SCI). Design: Prospective observational study regarding the outcome of pre-existent chronic pain of inpatients admitted with new clinically diagnosed complete cervical SCI. For patients who acknowledged chronic pain of ≥3 years duration before the SCI, further questions explored whether they still experienced that pain, whether they were experiencing current posttraumatic pain, and whether they had any past exposure to opioids. The included patients were identified during the initial consultation in the trauma center for treatment of the SCI. Setting: Level I trauma center. Participants: From a total of 49 participants with acute cervical SCI with clinically diagnosed complete motor and sensory tetraplegia admitted between 2018 and 2020, 7 were selected on the basis of a history of chronic pain. Intervention: Collected complete history and performed physical examination with serial follow-ups during the acute hospital stay until death or discharge. Main Outcome Measures: The primary outcome was a finding of chronic pain experienced before new clinical diagnosis of complete SCI, compared with whether or not that pain continued after the SCI injury. The secondary outcome was the relation of persistent pain with opioid use; it was formulated after data collection. Results: Among 49 patients with clinically diagnosed complete cervical SCIs, 7 had experienced prior chronic pain. Four participants experienced a continuation of the prior pain after their complete tetraplegia (4/7), whereas 3 participants did not (3/7). All the participants with continued pain had been previously treated with opioids, whereas those whose pain ceased had not received chronic opioid therapy. Conclusions: There may be a unique form of chronic pain that is based in the brain, irrespective of peripheral pain or spinal mechanisms. Otherwise healthy people with longstanding antecedent chronic pain whose pain persists after acute clinically complete SCI with tetraplegia may provide a new model for evaluation of brain-based pain. Opioids may be requisite for this type of pain.

Toll-like receptor 4 orchestrates neutrophil recruitment into airways during the first hours of Bordetella pertussis infection.

Most of the knowledge on the impact of Bordetella pertussis lipo-oligosaccharide (LOS) on the infectious process was obtained when the bacteria was established within the host. The aim of the present work was to determine the role of TLR4 at a very early step of the infectious process. To this end we used a transcriptomic approach on B. pertussis intranasal infection model in C3H/HeN, a TLR4-competent mouse strain, and C3H/HeJ, a TLR4-deficient mouse strain. The expression of approximately 140 genes was significantly changed 2 h post-infection in the C3H/HeN animals compared to the C3H/HeJ animals, which were essentially non-responders at this early time point. Pathways specific for immunity and defense, chemokine- and cytokine-mediated functions and TLR signaling, were activated upon infection in the TLR4 competent mice either at 2 h or 24 h. Furthermore, we observed that TLR4 signaling is absolutely required to promote the rapid recruitment of neutrophils into the airways. Interestingly, the depletion of those neutrophils impacted on B. pertussis lung counts in the first three days, thereby exacerbating the lung infection. In summary, we determined that TLR4 is a central player in initial neutrophil recruitment and orchestration of the very early innate defense against B. pertussis.

Outer membrane vesicles as acellular vaccine against pertussis.

In this study the development and evaluation of outer membrane vesicles (OMVs) obtained from Bordetella pertussis as vaccines against pertussis disease is described. SDS-PAGE, immunoblot techniques and gel electrophoresis associated to tandem mass spectrometry were used to describe the composition of the OMVs obtained from B. pertussis Tohama CIP 8132 strain. These techniques revealed the presence of the main well-known pertussis surface immunogens in the OMVs such as pertactin, adenylate cyclase-haemolysin, pertussis toxin, as well as the lipo-oligosaccharide (LOS). A total of 43 proteins were identified by mass spectrometry. Some of them were predicted to have outer membrane or periplasmic location and the others with cytoplasmic or unknown location. The characterized pertussis OMVs were used in murine B. pertussis intranasal (i.n.) challenge model to examine their protective capacity when delivered by different routes. Killed detoxified whole-cell B. pertussis bacteria were used as reference. For intraperitoneal (i.p.) immunization, aluminum hydroxide was used as adjuvant. Since i.n. treatment with OMVs as well as killed whole-cell bacteria enhanced markers of innate immune response such as TNFalpha, IL-6 and CCL20, i.n. immunizations were performed with no adjuvant added. Immunized BALB/c mice were intranasally challenged with sublethal doses of B. pertussis. Significant differences between immunized animals and the PBS treated group were observed (p<0.001). Adequate elimination rates (p<0.005) were observed in mice immunized either with OMV or whole-cell bacteria. Comparable results were obtained with both types of immunization route. In view to their capacity to induce airways innate and protective immunity in the mouse model, OMVs obtained from B pertussis are candidates to be used to protect against pertussis.

Pulsed-field gel electrophoresis, pertactin, pertussis toxin S1 subunit polymorphisms, and surfaceome analysis of vaccine and clinical Bordetella pertussis strains.

To add new insight to our previous work on the molecular epidemiology of Bordetella pertussis in Argentina, the prn and ptxS1 gene sequences and pulsed-field gel electrophoresis (PFGE) profiles of 57 clinical isolates obtained during two periods, 1969 to 1989 and 1997 to 2006, were analyzed. Non-vaccine-type ptxS1A was detected in isolates obtained since 1969. From 1989 on, a shift of predominance from the vaccine prn1 type to the nonvaccine prn2 type was observed. This was also reflected in a transition of PFGE group IV to group VI. These results show that nonvaccine B. pertussis strains are currently circulating. To analyze whether the observed genomic divergences between vaccine strains and clinical isolates have functional implications, protection assays using the intranasal mouse challenge model were performed. For such experiments, the clinical isolate B. pertussis 106 was selected as representative of circulating bacteria, since it came from the major group of the PFGE dendrogram (PFGE group VI). Groups of mice were immunized either with diphtheria-tetanus-whole-cell pertussis vaccine (ptxS1B prn1) or a vaccine prepared by us containing B. pertussis 106. Immunized mice were then challenged with a B. pertussis vaccine strain (Tohama, harboring ptxS1B and prn1) or the clinical isolate B. pertussis 106 (ptxS1A prn2). An adequate bacterial-elimination rate was observed only when mice were immunized and challenged with the same kind of strain. For further characterization, comparative proteomic profiling of enriched membrane proteins was done using three vaccine strains and the selected B. pertussis 106 clinical isolate. By matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, a total of 54 proteins were identified. This methodology allowed us to detect differing proteins among the four strains studied and, in particular, to distinguish the three vaccine strains from each other, as well as the vaccine strains from the clinical isolate. The differing proteins observed have cellular roles associated with amino acid and carbohydrate transport and metabolism. Some of them have been proposed as novel vaccine candidate proteins for other pathogens. Overall, the global strategy described here is presented as a good tool for the development of next-generation acellular vaccines.