Cytokine-associated neutrophil extracellular traps and antinuclear antibodies in Plasmodium falciparum infected children under six years of age

<p>Abstract</p> <p>Background</p> <p>In <it>Plasmodium falciparum</it>-infected children, the relationships between blood cell histopathology, blood plasma components, development of immunocompetence and disease severity remain poorly understood. Blood from Nigerian children with uncomplicated malaria was analysed to gain insight into these relationships. This investigation presents evidence for circulating neutrophil extracellular traps (NETs) and antinuclear IgG antibodies (ANA). The presence of NETs and ANA to double-stranded DNA along with the cytokine profiles found suggests autoimmune mechanisms that could produce pathogenesis in children, but immunoprotection in adults.</p> <p>Methods</p> <p>Peripheral blood smear slides and blood samples obtained from 21 Nigerian children under six years of age, presenting with uncomplicated malaria before and seven days after initiation of sulphadoxine-pyrimethamine (SP) treatment were analysed. The slides were stained with Giemsa and with DAPI. Levels of the pro-inflammatory cytokines IFN-γ, IL-2, TNF, CRP, and IL-6, select anti-inflammatory cytokines TGF-β and IL-10, and ANA were determined by immunoassay.</p> <p>Results</p> <p>The children exhibited circulating NETs with adherent parasites and erythrocytes, elevated ANA levels, a Th2 dominated cytokine profile, and left-shifted leukocyte differential counts. Nonspecific ANA levels were significant in 86% of the children pretreatment and in 100% of the children seven days after SP treatment, but in only 33% of age-matched control samples collected during the season of low parasite transmission. Levels of ANA specific for dsDNA were significant in 81% of the children both pre-treatment and post treatment.</p> <p>Conclusion</p> <p>The results of this investigation suggest that NET formation and ANA to dsDNA may induce pathology in falciparum-infected children, but activate a protective mechanism against falciparum malaria in adults. The significance of in vivo circulating chromatin in NETs and dsDNA ANA as a causative factor in the hyporesponsiveness of CpG oligonucleotide-based malaria vaccines is discussed.</p

A radiocarpal ligament reconstruction using brachioradialis for secondary ulnar translation of the carpus following radiocarpal dislocation: a cadaver study.

PURPOSE: Radiocarpal dislocation damages the radiocarpal ligaments, typically eliminating the possibility for repair. The goals of this study were to create a model for ulnar translation of the carpus and design a soft-tissue reconstruction using the brachioradialis (BR) to prevent ulnar translation of the carpus. We primarily sought to recreate the stabilizing effect of the radioscaphocapitate ligament. METHODS: Eight cadaveric upper limbs were dissected, leaving only the BR tendon. The wrist was loaded perpendicular to the long axis of the forearm, and load-displacement curves for ulnar translation were generated. The radiocarpal ligaments were sectioned. Substantial ulnar translation was seen only after complete release of the palmar and dorsal radiocarpal ligaments. Reconstruction was performed with the BR tendon, maintaining the insertion on the radial styloid. The proximal tendon stump was brought distally through a drill hole in the center of the capitate, palmar to dorsal, and secured to the dorsal rim of the radius with a suture anchor. The specimens were then retested after this reconstruction. Qualitative evaluation of graphs plotted, mini c-arm fluoroscopy, and visual observation was also performed. RESULTS: Comparison of the intact specimens and the specimens after sectioning of the radiocarpal ligaments revealed a significant difference between mean ulnar translation (11.1 mm vs 18.4 mm; p \u3c 0.05). Comparison of the sectioned specimens before and after BR reconstruction demonstrated a statistically significant difference in mean ulnar translation (18.4 mm vs 10.6 mm; p \u3c 0.05). Comparison of the intact specimens and the specimens after sectioning-reconstruction did not demonstrate a significant difference, indicating that the BR reconstruction re-established the stability seen in the intact specimens with regard to ulnar translation (11.1 mm vs 10.6 mm; p \u3e 0.05). CONCLUSIONS: The model consistently produced significant ulnar translation after division of the radiocarpal ligaments. The BR reconstruction was primarily designed to restore the function of the radioscaphocapitate ligament. This biomechanical study demonstrates the ability of this reconstruction to generate a statistically significant restraint to ulnar translation in a cadaver model of radiocarpal dislocation

A Prospective Pilot Study of Vascular Assessment of the Upper Extremity With Laser Angiography

Our goal was to investigate patients' upper extremity tissue perfusion changes using an indocyanine green laser angiography imaging system for various pathologic states and interventions. This prospective observational study used Spy Elite/LUNA laser angiography to evaluate perfusion in patients with upper extremity vascular compromise. All patients had Spy Elite/LUNA imaging as well as clinical and handheld Doppler examinations preintervention, intraoperatively, if applicable, and at 1 week, 2 weeks, and 2 months postintervention. For each laser angiography scan, we used an unaffected control area with uninjured skin to quantitatively compare with the dysvascular tissues. Twelve patients, 7 men and 5 women, had a total of 16 upper extremities evaluated. The mean age was 53 years, and half of the patients entering the study were smokers. Etiologies of vascular compromise were trauma, primary and secondary vasospastic disease, scleroderma, and intravascular drug injection. Interventions included surgical repair/reconstruction, botulinum toxin injections, and/or systemic medications. Improvement in perfusion following intervention was statistically significant, demonstrated by an increase in Spy Elite/LUNA quantitative score postintervention compared with preintervention scans. Adjusting for other variables, such as smoking and handheld Doppler signal status, demonstrated an independent statistically significant increase in Spy Elite/LUNA scores at all postintervention time points compared with preintervention scores. Laser angiography was able to confirm adequate vascular status, with ultimate tissue survival, in some cases when Doppler signals were not initially present. Laser angiography provided objective data to document improved upper extremity tissue perfusion following various interventions

Association of myosin light chain kinase with lymphocyte membrane-cytoskeleton complex

ABSTRACT A specific antibody against myosin light chain kinase (MLCK) was used to identify the presence of a Ca2+-calmodulin-activated MLCK in mouse T-lymphoma cells. With a double immunofluorescence technique, MLCK was determined to be accumulated directly under Con A-capped structures in a manner similar to that of previously described accumulation of actomyosin. The lymphocyte MLCK was phosphorylated in the uncapped cell and, by immunoprecipitation with a specific MLCK antibody, was shown to possess a Mr of 130,000. The MLCK was also found to constitute a major fraction of the phosphoproteins present in the plasma membrane associated-cytoskeleton. Myosin light chain kinase catalyzed the phosphorylation of both endogenous lymphocyte myosin light chains and those from smooth and skeletal muscle. The enzyme activity was dependent on the presence of Ca2+-calmodulin and was inhibited by the calmodulin-binding drug, trifluoperazine. These data suggest that the membrane-cytoskeleton-associated MLCK activity may be important in regulation of the actinmyosin contraction which is believed to be required for the collection of surface receptors into capped structures. Lymphocyte surface receptors will aggregate into a cap structur