Short-Term Effect of Spinal Manipulation on the Magnitude of Exophoria in Adults Who Are Asymptomatic: A Randomized Controlled Trial.

OBJECTIVE: This study aimed to assess the immediate and short-term effects of cervical spinal manipulation (SM), compared with a placebo, on the magnitude of near and distance exophoria in adults with asymptomatic exophoria. METHODS: In this single-blind, randomized controlled trial, individuals with a clinical diagnosis of horizontal exophoria confirmed with the prism alternating cover test (PACT) were allocated to a single intervention session using a high-velocity, low-amplitude cervical SM technique or a sham intervention (manual contact under the head). Outcomes were the magnitude of horizontal heterophoria, as a measure of binocular vision efficiency at near (40 cm) or distance (4 m) fixation, using the PACT. Evaluations were made at baseline, immediately after intervention, and at a 1-week follow-up. RESULTS: From May to September 2021, 44 volunteers (23 women), with a mean age of 35 (SD = 9.5) years, were recruited and equally distributed into the study groups. All participants completed follow-up assessments, and no adverse events were reported. There was a significant time × group interaction for exophoria at near vision, but not at distance fixation. The SM group showed a significant decrease of near exophoria compared with the control group at the 1-week follow-up (mean difference = -1.09 prism diopters; 95% CI = -0.20 to -1.98 prism diopters). CONCLUSION: The use of cervical SM therapy resulted in a significant reduction of the magnitude of horizontal exophoria at near vision (medium effect size), compared with the placebo, in young adults who are asymptomatic. However, these effects were not observed at distance fixation and should be considered cautiously due to the pre-post design with a single intervention session and the short-term follow-up. IMPACT: The findings suggest short-term benefits of SM therapy can manage undiagnosed ocular convergence disorders, although changes were not clinically relevant.

The Role of Diisocyanate Structure to Modify Properties of Segmented Polyurethanes.

Segmented thermoplastic polyurethanes (PU) were synthetized using a polycarbonatediol macrodiol as a flexible or soft segment with a molar mass of 2000 g/mol, and different diisocyanate molecules and 1,4-butanediol as a rigid or hard segment. The diisocyanate molecules employed are 3,3'-Dimethyl-4,4'-biphenyl diisocyanate (TODI), 4,4'-diphenylmethane diisocyanate (MDI), 4,4'-Methylenebis(phenyl isocyanate) 1-isocyanato-4-[(4-phenylisocyanate)methyl]benzene and 1-isocyanate-4-[(2-phenylisocyanate) methyl]benzene (ratio 1:1) (MDIi), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI). The polyurethanes obtained reveal a wide variation of microphase separation degree that is correlated with mechanical properties. Different techniques, such as DSC, DMA, and FTIR, have been used to determine flexible-rigid segment phase behavior. Mechanical properties, such as tensile properties, Shore D hardness, and "compression set", have been determined. This work reveals that the structure of the hard segment is crucial to determine the degree of phase miscibility which affects the resulting mechanical properties, such as tensile properties, hardness, and "compression set".

Tunable Structure and Properties of Segmented Thermoplastic Polyurethanes as a Function of Flexible Segment.

Segmented thermoplastic polyurethanes (PUs) were synthetized using macrodiols with different functional groups (carbonate, ester, and /or ether) as a segment with a molar mass of 1000 and 2000 g/mol, and 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol as a rigid segment. The polyurethanes obtained reveal a wide variation of microphase separation degree that is correlated with mechanical properties and retention of tensile properties under degradation by heat, oil, weather, and water. Different techniques such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FTIR), and synchrotron small-angle X-ray scattering (SAXS) were used to determine rigid-flexible segments' phase behaviour. Retention of tensile properties determines the stability of the samples under different external factors. This work reveals that pure polycarbonate-based macrodiols induce the highest degree of phase miscibility, better tensile properties, hardness shore A, and retention of tensile properties under external agents.

Influence of polysulphone-derived dialysis membranes on the interaction of circulating mononuclear cells with the endothelium.

PURPOSE: Cardiovascular morbidity in hemodialysis (HD) patients may be influenced by the activation of circulating mononuclear cells (MCs) with subsequently increased endothelium interaction. The use of more biocompatible membranes would reduce this monocyte activation. We compare monocyte activation after using two different high-flux polymers, polysulphone and polyethersulphone. METHODS: The first part of the study was done with 10 patients who successively received dialysis for 2 weeks with polysulphone and polyethersulphone. The second part with 30 patients dialyzed for 3 months with polysulphone or polyethersulphone. Blood samples were taken before (pre-HD) and after (post-HD) the first HD session with each membrane to evaluate the effect of a single HD session. To assess acute and chronic effects of membranes, blood samples were taken pre-HD, after 2 weeks (first part of study) and after 3 months (second part of study). MCs were isolated from blood and then incubated with cultured human endothelial cells to evaluate MC adhesion, MC-dependent endothelial toxicity, and endothelial protein expressions of nitric oxide synthase and endothelin-converting enzyme-1 (ECE-1). RESULTS: One single HD session did not induce any changes. Dialysis for 2 weeks (first part of study) with polyethersulphone reduced MC adhesion to endothelium, cellular toxicity, and ECE-1 protein expression compared to polysulphone or basal conditions. Dialysis for 3 months (second part of study) increased MC adhesion to endothelium, whereas cellular toxicity was decreased with both dialyzers compared to the basal situation. CONCLUSIONS: Although polyethersulphone HD decreased the interaction of MC with the endothelium in short-term experiments, both membranes were comparable in the long-term.

Eficacia de la técnica de thrust en rotación del atlas con contacto indexial en pacientes con cefalea tensional: estudio piloto / Effectiveness of thrust technique in rotation of the atlas with indexial contact in patients with tension-type headache: pilot study

Introducción: La cefalea tensional (CT) es uno de los dolores de cabeza más comunes en la población. Su prevalencia es alta y puede influir en la calidad de vida, el entorno laboral y social, induciendo a la ingesta de fármacos y favoreciedo la cefalea crónica. Objetivos: Evaluar la eficacia de la técnica de thrust en rotación del atlas, con contacto indexial, (TTRA) en pacientes con CT. Material y Métodos: Se realizó un estudio piloto aleatorizado. La muestra estuvo formada por veintinueve pacientes (n=29), los cuales fueron aleatoriamente distribuidos en dos grupos; experimental (GE, n=12) y control (GC, n=17). Ambos grupos fueron evaluados con mediciones goniométricas antes y después de la intervención. Se inhibieron los puntos de Jones de los músculos esternocleiodomastoideo, angular de la escápula, oblícuo inferior y recto lateral de la cabeza del lado de la disfunción del atlas. Al GE se le aplicó además la TTRA y al GC un placebo no activo. Se analizaron los cambios en la movilidad cervical mediante un goniómetro universal Cervical Range of Movement (CROM). Resultados: Encontramos un aumento significativo en la flexión suboccipital en el GE comparado con el GC (p=0.002). Las demás variables de movilidad cervical no presentaron significacióne. Conclusiones: La TTRA aumenta significativamente la flexión suboccipital (AU)

Introduction: Tension-type headache (TTH) is one of the most common headaches among the population. Its prevalence is high and can influence the quality of life and the social and work environment, leading to the intake of drugs and this way, favouring chronic headaches. Objectives: Evaluate the effectiveness of the thrust technique in rotation of the atlas, with indexial contact (TTRA), in patients with TTH. Material and methods: A randomized pilot study was carried out. The sample consisted of twenty-nine patients (n=29), whom were randomly distributed into two groups; experimental group (EG, n=12) and control group (CG, n=17). Both groups were evaluated using goniometric measurements before and after the intervention. Jones' points from the sternocleidomastoid, levator scapulae, obliquus capitis inferior and rectus capitis lateralis muscles, on the side of the atlas dysfunction, were inhibited. The TTRA was applied to the EG and non-active placebo to the CG. Changes in cervical mobility were analysed through a universal goniometer, Cervical Range of Movement (CROM). Results: We found a significant increase in the suboccipital flexion, in the EG compared to the CG (p=0.002). The other variables of cervical mobility were not significant. Conclusions: TTRA significantly increases the suboccipital flexion (AU)

Variations of nNOS and its mRNA in the neurons of the hypothalamic supraoptic nucleus in response to stress by immobilization

Using rats subjected to immobilization stress, the aim of the present study was to investigate the expression of neuronal nitric oxide synthase and of its mRNA in the magnocellular neurons of the supraoptic nucleus of the hypothalamus, which does not have parvocellular neurons or direct neurohaemal connections with the anterior lobe of the hypophysis. nNOS expression was studied with immunohistochemistry using sheep antinNOS serum, and the intraneural detection of nNOS mRNA was accomplished using a nonisotopic in situ hybridization technique, employing a specific biotinylated probe. The acute stress elicited by restraint induced an increase in the overall size of the supraoptic nucleus, together with an increase in the number of magnocellular neurons expressing nNOS immunoreaction. The optical densitometry values of the nNOS immunoreaction, the nuclear areas of the immunoreactive neurons, and the density of neurons showing nNOS mRNA hybrids were higher in the supraoptic nucleus of the stress-treated animals than in the controls, suggesting that nitric oxide of nNOS origin plays an active role in the magnocellular neurons of the hypophyseal-hypothalamic system and the involvement of this system in the stress axis (AU)

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