Biomechanical Analysis of Cervical Motion With a Pediatric Immobilization and Extrication Device.

OBJECTIVE: To determine the motions produced during pediatric extrication when using a system of motion estriction and extrication. METHODS: Simulation-based biomechanical analysis study conducted with inertial sensors to measure motion produced in the cervical spine of a pediatric simulator during extrication from a vehicle. RESULTS: The mean of the movements was 3.5° (SD ±1.35°). The mean time was 4 minutes 1 second (SD, ±45.09 seconds). The mean rotation toward the right was 3.34° (SD ±3.52°) and toward the left 2.62° (SD ±2.26°). The mean for lateralization was 6.24° (SD ±3.20°) toward the right and 2.50° (DE ±2.76°) toward the left. The mean for flexion was 2.36° (SD ±2.10°) and for extension 4.21° (SD ±2.15°). CONCLUSIONS: The device analyzed allows for the extrication of the pediatric patient with high levels of motion restriction of the spinal column with the Pediatric Immobilization and Extrication System.

Effective definition of low humoral response to Clostridioides difficile infection.

BACKGROUND: Determination of the humoral response to Clostridioides difficile (CD) toxins could be of great value in the management of patients with CD infection (CDI). METHODS: A prospective study was conducted on the clinical characteristics and humoral response in patients with CDI. Determination of ELISA IgG CD anti-toxin B (tgcBiomics, Germany) was performed. The following dilutions were planned for each patient, 1:100, 1: 200, 1: 400, 1: 800: 1: 1600. A significant concentration of antibody was considered to be present in each dilution if an optical density 0.2 units higher than the negative control of the technique was evident. RESULTS: Eighty-five patients were included during the study period, November 2018-February 2020. The median age was 73 years (interquartile range: 62.5-85 years), with female predominance (45 patients, 52.9%). Thirty-nine patients (45.9%) had a severe infection. Seven patients (8.2%) had suffered an episode of CDI in the previous three months. Seventeen patients (20%) had one or more recurrent episodes during the three-month follow-up: No patient died during admission or required surgery for severe-complicated infection. The incidence of recurrence in patients with no antibody detected at 1:400 dilution was 25.4% (16 patients) while it was 4.3% (one patient) in patients with antibody present at that dilution (p = 0.03). Liver cirrhosis was associated with higher humoral response against CD. CONCLUSIONS: Antibodies IgG CD anti-toxin B detection at a dilution of 1:400, using a B ELISA technique, effectively identified patients at increased risk of recurrence. This information could help assist in the management of patients.

In Vitro Propagation, Genetic Assessment, and Medium-Term Conservation of the Coastal Endangered Species Tetraclinis articulata (Vahl) Masters (Cupressaceae) from Adult Trees.

Tetraclinis articulata (Vahl) Masters is an endangered tree growing in coastal and arid environments that is widely exploited by the timber and resin industry, among other applications. In this context, the use of in vitro techniques is highly encouraged for its propagation. We present a protocol for micropropagation using twigs from adult trees as a source of explants. The Schenk and Hildebrandt basal medium (SH) supplemented with 30 g L-1 sucrose, 6.5 g L-1 plant agar, 4.0 mg L-1 6-benzyladenine (BA), and 0.05 mg L-1 1-naphthaleneacetic acid (NAA) provided the optimum multiplication rate (90.48 ± 9.52 explants with basal shoots and 2.58 ± 0.29 basal shoots per explant). Application of activated charcoal (AC) or ½ Knop solution in a liquid overlay produced significantly longer shoots. Supplementation of solid media with indole-3-butyric acid (IBA) or NAA gave low rooting percentages (<17%). Addition of 0.9 g L-1 AC improved rooting (40%) but rooting performance was optimal (66.7%) after a pulse treatment consisting of 4 h immersion in liquid SH medium without growth regulators, followed by 8 weeks of cultivation. Rooted microplants were successfully acclimatized (93.33%) in a peat moss and vermiculite mixture (1:1 v/v ratio). The genetic stability of the in vitro regenerated plantlets was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Explant survival and growth remained higher than 90% after 28 weeks of cold storage at both 4 °C and 10 °C. The protocol presented here allows for largescale T. articulata production and could be applied for both ex situ conservation strategies and industrial purposes.

Humoral/Cellular Immune Discordance in Stem Cell Donors: Impact on Cytomegalovirus-Specific Immune Reconstitution after Related Hematopoietic Transplantation.

Cytomegalovirus (CMV) reactivation is an important cause of complications after hematopoietic stem cell transplantation (HSCT). Discrepancies between serologic and cellular CMV-specific immune response have been reported. This study evaluated the impact of lack of CMV-specific CD8+ T cell response in seropositive donors (ie, discordant donors) on the reconstitution of CMV-specific cell-mediated immunity (CMI) after related HSCT in seropositive recipients. CMV-CMI was assessed in donors and recipients using the QuantiFERON-CMV assay (QF). CMV-CMI was prospectively assessed for 1 year in 81 CMV-seropositive HSCT recipients with a haploidentical or matched related donor. A Cox proportional hazard regression analysis was performed. Of the 67 CMV-seropositive donors, 54 (80.6%) were D+QFpos. The remaining 13 CMV-seropositive donors (19.4%) had a QFneg result and thus were classified as discordant donors (D+QFneg). We found that patients with D+QFneg had a significantly higher risk of impaired CMV-CMI reconstitution compared with patients with D+QFpos (log-rank test, P = .001) or D- donors (log-rank test, P = .023). In addition, the D+QFneg group had a higher incidence of single-episode reactivation compared with D+QFpos or D- donors (69.2% versus 44.4% and 28.6%, respectively) but a lower incidence of CMV recurrence compared with the D- group (7.7% versus 57.1%; P = .003). After adjusting for other relevant variables, immune discordance in donors was independently associated with impaired CMV-CMI reconstitution compared with D+QFpos donors (adjusted hazard ratio [HR], 0.18; 95% confidence interval [CI], .06 to .52; P = .001) and D- donors (adjusted HR, .17; 95% CI, .05 to .59; P = .005). Discordant donors were associated with undetectable CMV-CMI during the 12-month follow-up period using the QF assay. The inability of these patients to become QFpos persisted even after CMV reactivation. This might be related to the low frequency of CMV recurrence in this group. CMV-CMI assessment, in conjunction with CMV serostatus, can be of utility to better classify stem cell donors as well as the risk of impaired CMV-CMI reconstitution after HSCT.

Cryopreservation of Tetraclinis articulata (vahl.) Masters.

Tetraclinis articulata shoot tips excised from in vitro grown shoots were cryopreserved using a modified PVS2-based vitrification protocol. Preliminary experiments with non-cryostored shoot tips showed that the high concentrations of sucrose in loading (LS), vitrification (PVS2) and unloading (US) solutions employed in the protocol were very toxic for the explants. Replacement of sucrose by sorbitol in equal molar concentration in all these solutions enhanced survival of shoot tips after all treatments. However, cold-hardening of donor shoots before shoot tip excision was strictly required to obtain post-rewarming survival. Therefore, the protocol was outlined as follows: pre-conditioning of explants at 4 degree C for 3 weeks in the dark; excision of 1 mm long shoot tips; loading for 20 min in modified LS at room temperature; dehydration in modified PVS2 at 0 degree C for 60 min; immersion in liquid nitrogen (LN); rewarming at 40 degree C for 2 min and subsequent transfer of shoot tips in modified US for 20 min.

Effects of extended exposure to cadmium and subsequent recovery period on growth, antioxidant status and polyamine pattern in in vitro cultured carnation.

The effect of different doses of Cd (0.05, 0.1 and 0.2 mM) and subsequent period in a Cd-free medium on growth, the antioxidant status and the polyamine (PA) pattern was studied using in vitro cultured nodal segments of carnation. The Cd within the tissues increased in parallel with its concentration in the culture medium, inhibited growth, altered the concentration of some minerals and decreased the levels of pigments and the total antioxidants. However, the concentration of ascorbate (Asc) + dehydroascorbate (DHA) and the Asc redox status remained unaffected, and malondialdehyde (MDA) increased only with 0.2 mM Cd. Cd also affected PA metabolism, decreasing the total PA concentration and disturbing the relative predominance of each PA fraction. Cd exposure increased the total putrescine (Put)/(spermidine (Spd) + spermine (Spm)) ratio, and an opposite pattern was recorded during the phase in Cd-free medium. Regarding individual amines, Cd induced significant changes mainly in the free Put levels. Our results suggest that Cd produces oxidative stress and that PA (especially free Put and the total Put/(Spd+Spm) ratio), are good indicators of the stress caused by Cd.

Self-extraction with and without a cervical collar: a biomechanical simulation study. / Comparación biomecánica de la autoextracción con y sin collarín cervical: estudio de simulación.

OBJECTIVES: To compare self-extraction with and without a cervical collar in subjects at low risk of cervical spine injuries. MATERIAL AND METHODS: Simulation study analyzing biomechanical data from inertial sensors to detect misalignment of the cervical spine during self-extraction with and without a cervical collar. RESULTS: Misalignment was a mean (SD) 3.12 (34.62) degrees greater during self-extraction with a Stiffneck collar in place (95% CI, -15.33 to 21.57 degrees; P=.7234) than during extraction without a collar. Misalignment was also greater, by 5.95 (31.76) degrees, with an X-collar in place (95% CI, -10.98 to 22.87; P=.4654) than without a collar. The between-collar comparison of differences showed that misalignment was 2.83 (12.10) degrees greater with the X-collar (95% CI, -3.62 to 9.27 degrees; P=.3650). CONCLUSION: Misalignment of the cervical spinal column is similar during self-extraction with or without a cervical collar in place.

OBJETIVO: Comparar la autoextracción (AE) frente a la AE con collarines en sujetos con bajo riesgo de lesión cervical. METODO: Estudio de simulación mediante análisis biomecánico con sensores inerciales, determinando la desalineación de la columna cervical durante la AE con y sin collarines cervicales. RESULTADOS: El desequilibrio fue 3,12 (DE 34,62) grados mayor con el collarín STIFNECK (SN) (IC al 95% de ­15,33 a 21,57; p =0,7234) que con AE y también 5,95 (DE 31,76) grados mayor con collarín X-COLLAR (XC) (IC al 95% de ­10,98 a 22,87; p = 0,4654) que con AE. Cuando comparamos la AE con los diferentes tipos de collarines, observamos que con el collarín XC se produjeron 2,83 (DE 12,10) grados de desalineación más que con el collarín SN (IC al 95% de ­3,62 a 9,27; p = 0,3650). CONCLUSIONES: La desalineación de la columna cervical mediante la AE es similar a la provocada cuando se aplican collarines cervicales.

[Biomechanical analysis of cervical spine movement on removal of motorcycle helmets]. / Análisis biomecánico del movimiento cervical en la extracción del casco en motoristas.

OBJECTIVES: To measure cervical spine movement during removal of a motorcycle helmet by health care professionals. MATERIAL AND METHODS: Observational study using biomechanical inertial sensors to detect movement in the spinal column during removal of helmets. RESULTS: Thirty-four emergency medicine specialists and nurses participated. The mean (SD) rotation was 1.14° (0.82°) to the left and 3.30° (1.69°) to the right (P<.001). Mean flexion was 9.82° (7.46°) and mean extension was 6.23° (6.86°) (P<.001). Mean lateral displacement was 5.73° (2.97°) to the left and 5.62° (8.22°) to the right (P=.678). The removal maneuvers took a mean of 70 seconds (4 seconds). CONCLUSION: Helmet removal was completed in an average of 70 seconds with flexion and rotation mainly toward the side where the professional supporting the head was positioned.

OBJETIVO: Determinar el movimiento cervical durante la extracción de un casco realizada por profesionales sanitarios. METODO: Estudio observacional mediante análisis biomecánico con sensores inerciales de los movimientos producidos en la columna durante la extracción de un casco. RESULTADOS: La muestra final la componen 34 profesionales de servicios de urgencias y emergencias. La rotación fue de 1,14 (DE 0,82)° hacia el lado izquierdo y de 3,30 (1,69)° hacia el lado derecho (p < 0,001). La flexoextensión fue de 9,82 (7,46)° para la flexión y de 6,23 (6,86)° para la extensión (p < 0,001). La lateralización fue de 5,73 (2,97)° para el lado izquierdo y de 5,62 (8,22)° para el lado derecho (p = 0,678). El tiempo medio de realización de la extracción fue 70 (4) seg. CONCLUSIONES: La extracción del casco se realizó en 70 segundos con flexión y rotación hacia el lado donde se encuentra colocado el profesional que sujeta la cabeza.