Factors Affecting the Accuracy of Pedicle Screw Placement in Robot-Assisted Surgery: A Multicenter Study.

STUDY DESIGN: Retrospective multicenter. OBJECTIVE: The aim was to investigate the factors involved in, and their relative contributions to, the overall accuracy of robot-assisted pedicle screw placement. SUMMARY OF BACKGROUND DATA: Robot-assisted surgery has reportedly resulted in greater accuracy for placement of pedicle screws than conventional methods. There are many potential factors affecting the accuracy of pedicle screws placed with a robot. No study has investigated these factors in a robust way. MATERIALS AND METHODS: Radiographic and clinical data of three centers were pooled. Preoperative and postoperative computerized tomographies were obtained by all three centers to assess the accuracy of the placed screws. The primary outcome measured was accuracy of pedicle screws placed with the robot. The authors performed a multivariate regression analysis to determine the significant patient-related and screw-related variables and their relative contribution to the overall accuracy. In addition, an ordinal regression analysis was conducted to investigate the effects of different variables on accuracy of robot-placed screws graded by Gertzbein-Robbins grading system (GRS). RESULTS: The total contribution of all studied variables to overall accuracy variation as measured by offsets between the placed and planned screws was only 18%. Obesity, long constructs, female gender, surgeon, and vertebral levels were among the factors that had small contributions to the different screw offsets. For GRS grades, significant variables were gender (Log odds: 0.62, 95% CI: 0.38-0.85), age (Log odds: 0.02, 95% CI: 0.01-0.03), length of constructs (Log odds: 0.07, 95% CI: 0.02-0.11), screw diameter (Log odds: 0.55, 95% CI: 0.39-0.71), and length of the screws (Log odds: 0.03, 95% CI: 0.01-0.05). However, these variables too, regardless of their significant association with the accuracy of placed screws, had little contribution to overall variability of accuracy itself (only about 7%). CONCLUSION: The accuracy of screws placed with robotic assistance, as graded by GRS or measured offsets between planned and placed screw trajectories, is minimally affected by different patient-related or screw-related variables due to the robustness of the robotic navigation system used in this study. LEVEL OF EVIDENCE: Level III.

Family supportive supervisor behaviors and organizational culture: Effects on work engagement and performance.

Informed by social information processing (SIP) theory, in this study, we assessed the associations among family supportive supervisor behaviors (FSSBs) as perceived by subordinates, subordinate work engagement, and supervisor-rated work performance. Moreover, we explored the role of family supportive organizational culture as a contextual variable influencing our proposed associations. Our findings using matched supervisor-subordinate data collected from a financial credit company in Mexico (654 subordinates; 134 supervisors) showed that FSSBs influenced work performance through subordinate work engagement. Moreover, the positive association between subordinates' perceptions of FSSBs and work engagement was moderated by family supportive organizational culture. Our results contribute to emerging theories on flexible work arrangements, particularly on family supportive work policies. Moreover, our findings carry practical implications for improving employee work engagement and work performance. (PsycINFO Database Record

Seroepidemiology of Toxoplasma in a coastal region of Haiti: multiplex bead assay detection of immunoglobulin G antibodies that recognize the SAG2A antigen.

Toxoplasma gondii is a globally distributed parasitic protozoan that infects most warm-blooded animals. We incorporated a bead coupled with recombinant SAG2A protein into our Neglected Tropical Disease (NTD) multiplex bead assay (MBA) panel and used it to determine Toxoplasma infection rates in two studies in Haiti. In a longitudinal cohort study of children aged 0-11 years, the infection rate varied with age reaching a maximum of 0·131 infections/year in children aged 3 years [95% confidence interval (CI) 0·065-0·204]. The median time to seroconversion was estimated to be 9·7 years (95% CI 7·6-∞). In a cross-sectional, community-wide survey of residents of all ages, we determined an overall seroprevalence of 28·2%. The seroprevalence age curve from the cross-sectional study also suggested that the force of infection varied with age and peaked at 0·057 infections/year (95% CI 0·033-0·080) at age 2·6 years. Integration of the Toxoplasma MBA into NTD surveys may allow for better estimates of the potential burden of congenital toxoplasmosis in underserved regions.

Spanish translation and linguistic validation of the quality of life in neurological disorders (Neuro-QoL) measurement system.

INTRODUCTION: The quality of life in neurological disorders (Neuro-QoL) measurement system is a 470-item compilation of health-related quality of life domains for adults and children with neurological disorders. It was developed and cognitively debriefed in English and Spanish, with general population and clinical samples in the USA. This paper describes the Spanish translation and linguistic validation process. METHODS: The translation methodology combined forward and back-translations, multiple reviews, and cognitive debriefing with 30 adult and 30 pediatric Spanish-speaking respondents in the USA. The adult Fatigue bank was later also tested in Spain and Argentina. A universal approach to translation was adopted to produce a Spanish version that can be used in various countries. Translators from several countries were involved in the process. RESULTS: Cognitive debriefing results indicated that most of the 470 Spanish items were well understood. Translations were revised as needed where difficulty was reported or where participants' comments revealed misunderstanding of an item's intended meaning. Additional testing of the universal Spanish adult Fatigue item bank in Spain and Argentina confirmed good understanding of the items and that no country-specific word changes were necessary. CONCLUSION: All the adult and pediatric Neuro-QoL measures have been linguistically validated with Spanish speakers in the USA. Instruments are available for use at www.assessmentcenter.net.

Cómo los empleados mantienen su engagement en el trabajo / How do engaged employees stay engaged?

El presente trabajo apunta a descubrir qué pueden hacer los empleados para estar más engaged con su trabajo. Después de definir qué se entiende por un engagement perdurable, hacemos una revisión de la bibliografía existente sobre el engagement entendido como un estado mental del individuo. Además, analizamos las diferentes investigaciones que se han dedicado a estudiar la relación que hay entre engagement, por un lado, y (a) desempeño laboral, (b) conducta proactiva y (c) personalización del trabajo, por el otro. Finalmente, revisamos la evidencia que sustenta las relaciones recíprocas entre el engagement, los recursos personales y laborales. Concluimos que los empleados engaged se encargan de mantener su propio compromiso en el trabajo, modificando proactivamente su ambiente laboral. Como resultado, los empleados engaged no sólo hacen un uso total de los recursos laborales disponibles, sino que también son capaces de crear sus propios recursos para mantenerse comprometidos.

The present literature review focuses on what employees can do to stay engaged. After defining enduring work engagement, we review the literature on state work engagement. In addition, we discuss research on the relationship between engagement on the one hand, and (a) job performance, (b) proactive behavior, and (c) job crafting on the other. Finally, we review the evidence for reciprocal relationships between work engagement and job and personal resources. We conclude that engaged employees take care of their own work engagement by proactively shaping their work environment. As a result, engaged employees do not only make full use of the available job resources, but they also create their own resources to stay engaged.

Effect of coupling medium temperature on rate of intramuscular temperature rise using continuous ultrasound.

OBJECTIVE: We determined the effects of coupling medium temperature on the rate of intramuscular temperature rise (RTR) during continuous ultrasound. DESIGN AND SETTING: Ultrasound was applied in a continuous mode at a frequency of 1 MHz and intensity of 1.5 W/cm(2). Each subject received 3 treatments, using water-based coupling gel at temperatures of 18 degrees C, 25 degrees C, and 39 degrees C. All treatments were performed in an athletic training room under controlled environmental conditions. SUBJECTS: Eighteen healthy male subjects (mean age = 23.6 +/- 3.5 years; height = 177.8 +/- 6.9 cm; weight = 76.6 +/- 8.2 kg; calf size = 37.6 +/- 2.4 cm) participated in this study. MEASUREMENTS: A thermistor was inserted into the left medial triceps surae at a depth of 5 cm, and baseline tissue temperatures were recorded before treatment. Intramuscular temperature was recorded every 30 seconds until the temperature rose 4 degrees C above baseline or until discomfort was felt. RTR was calculated by dividing the absolute temperature change by treatment time. RESULTS: A 1-way, repeated-measures analysis of variance revealed a significant difference in RTR among gel temperatures, RTR was significantly faster using the 25 degrees C gel compared with the 18 degrees C and 39 degrees C gels. There was no difference between the 18 degrees C and 39 degrees C gel treatments. CONCLUSIONS: These results suggest that the use of a cooled or heated gel may be counterproductive when maximal thermal effects are desired within a given time frame.

Isolation and purification of a squamous cell carcinoma of the head and neck-associated antigen identified by autologous antibody.

We have previously shown that detection of autologous antibody activity to squamous cell carcinoma of the head and neck may be augmented by dissociation of immune complexes. Western blot analysis with autologous antibody has identified a 60 kDa squamous cell carcinoma of the head and neck-associated antigen in spent media and immune complex-dissociated serum ultrafiltrate not recognized by normal human sera. Antigen-containing fractions of spent media were eluted from anion exchange columns immediately after serum albumin indicating that the antigen has an acidic pI < 4. Preparative purification of the squamous cell carcinoma antigen was accomplished by anion exchange of concentrated spent media (protein concentration 300 mg/ml) followed by lectin affinity chromatography with a Triticum vulgaris column. A single 60 kDa band was detected by silver stain and Western blot in antigen-containing fractions eluted following lectin affinity chromatography and SDS-PAGE. Final concentration of the antigen was determined to be 1 microgram/ml of protein with relative activity increased 1600 x over unfractionated spent media. We conclude that a squamous cell carcinoma of the head and neck-associated antigen, detected by autologous antibody, is an acidic 60 kDa glycoprotein.

Serial studies of autologous antibody reactivity to squamous cell carcinoma of the head and neck.

In previous studies we evaluated the incidence and specificity of autologous antibody reactivity against squamous cell carcinoma of the head and neck (SCCHN). We were able to demonstrate that autologous antibody reactivity is present in native sera but was usually of too low a titer to allow further analysis. Dissociation of immune complexes by acidification and ultrafiltration of serum augmented autologous antibody reactivity in nine out of nine autologous systems tested. Native antibody and antibody derived from immune complexes produced by the host and reactive with autologous tumor cells may be directed against physiologically relevant antigens. Therefore, correlations of antibody titers with clinical course may provide insight into the nature of the host response to cancer. In the present analysis, serological studies of six patients with SCCHN were performed with serum samples obtained over many months. Results of serial serological assays were correlated to tumor progression and clinical course. Fluctuations in autologous antibody reactivity were noted over time. In four cases, rises in autologous antibody titers preceded the clinical diagnosis of recurrence by several months. Drops in autologous antibody reactivity were noted in two cases following surgery or radiation therapy. In two cases of long-term survivors, no correlation between antibody reactivity and clinical course was noted. Specificity analysis of the six autologous systems demonstrated reactivity against autologous and allogeneic SCCHN as well as melanoma cell lines. These sera did not react with glioma, neuroblastoma, renal cell, breast, bladder and colon carcinoma cell lines nor with fetal calf serum, pooled lymphocytes, red blood cells and platelets. Autologous serial serological studies may provide a means by which to evaluate the host/tumor relationship in patients with SCCHN.

MMPI supplemental scale performance of Mexican Americans and level of acculturation.

Mexican American and Anglo American's performance on the Wiggins Content Scales, Harris-Lingoes subscales, and Serkownek subscales was assessed in a college student population. Level of acculturation (Mexican vs. Anglo orientation), age, and social class were statistically controlled. The results showed statistically significant differences between means of Anglo and Mexican Americans on most of the supplemental scales assessed. These differences were more numerous before scale validity criteria were applied. The number of statistically significant differences were further reduced when level of acculturation and age were statistically controlled. The results showed that level of acculturation is a highly important variable which moderates interpretation of the MMPI scale elevations we measured. Acculturation far outweighed the influence of the well established MMPI moderator variables of age and social class.