Comparison of serum amyloid A protein and C-reactive protein levels as inflammatory markers in periodontitis

Carlos Martín Ardila,Isabel Cristina Guzmán 대한치주과학회 2015 Journal of Periodontal & Implant Science Vol.45 No.1

Purpose: The purpose of this study was to compare serum amyloid A (SAA) protein levelswith high-sensitive C-reactive protein (hs-CRP) levels as markers of systemic inflammationin patients with chronic periodontitis. The association of serum titers of antibodies to periodontalmicrobiota and SAA/hs-CRP levels in periodontitis patients was also studied. Methods: A total of 110 individuals were included in this study. Patients were assessed forlevels of hs-CRP and SAA. Nonfasting blood samples were collected from participants atthe time of clinical examination. The diagnosis of adipose tissue disorders was made accordingto previously defined criteria. To determine SAA levels, a sandwich enzyme-linkedimmunosorbent assay was utilized. Paper points were transferred to a sterile tube to obtaina pool of samples for polymerase chain reaction processing and the identification of Porphyromonasgingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia. The serum level of IgG1 and IgG2 antibodies to P. gingivalis, A. actinomycetemcomitans,and T. forsythia was also determined. Results: SAA and hs-CRP levels were higher in periodontitis patients than in controls(P<0.05). In bivariate analysis, high levels of hs-CRP (>3 mg/L) and SAA (>10 mg/L) weresignificantly associated with chronic periodontitis (P=0.004). The Spearman correlationanalysis between acute-phase proteins showed that SAA positively correlated with hs-CRP(r=0.218, P=0.02). In the adjusted model, chronic periodontitis was associated with highlevels of SAA (odds ratio [OR], 5.5; 95% confidence interval [CI], 1.6–18.2; P=0.005) andelevated hs-CRP levels (OR, 6.1, 95% CI, 1.6–23.6; P=0.008). Increased levels of serum IgG2antibodies to P. gingivalis were associated with high levels of SAA (OR, 3.6; 95% CI, 1.4–8.5;P=0.005) and high concentrations of hs-CRP (OR, 4.3; 95% CI, 1.9–9.8; P<0.001). Conclusions: SAA and hs-CRP concentrations in patients with chronic periodontitis arecomparably elevated. High serum titers of antibodies to P. gingivalis and the presence ofperiodontal disease are independently related to high SAA and hs-CRP levels.

Association between immunoglobulin G1 against Tannerella forsythia and reduction in the loss of attachment tissue

Carlos Martín Ardila,Mariana Olarte-Sossa,Isabel Cristina Guzmán 대한치주과학회 2014 Journal of Periodontal & Implant Science Vol.44 No.6

Purpose: To evaluate whether the levels of immunoglobulin G (IgG) antibody to Tanerellaforsythia are associated with periodontal status. Methods: Patients with a diagnosis of chronic periodontitis were considered candidates forthe study; thus 80 chronic periodontitis patients and 28 healthy persons (control group)were invited to participate in this investigation. The presence of T. forsythia was detectedby polymerase chain reaction (PCR) analysis using primers designed to target the respective16S rRNA gene sequences. Peripheral blood was collected from each subject to identify theIgG1 and IgG2 serum antibodies against T. forsythia. All microbiological and immunologicallaboratory processes were completed blindly, without awareness of the clinical status ofthe study patients or of the periodontal sites tested. Results: The bivariate analysis showed that lower mean levels of clinical attachment level(CAL) and probing depth were found in the presence of the IgG1 antibody titers againstwhole-cell T. forsythia; however, only the difference in CAL was statistically significant. Inthe presence of the IgG2 antibody titers against whole-cell T. forsythia, the periodontal parametersevaluated were higher but they did not show statistical differences, except forplaque. The unadjusted linear regression model showed that the IgG1 antibody againstwhole-cell T. forsythia in periodontitis patients was associated with a lower mean CAL(β=–0.654; 95% confidence interval [CI], –1.27 to –0.28; P<0.05). This statistically significantassociation remained after adjusting for possible confounders (β=–0.655; 95% CI,–1.28 to –0.29; P<0.05). On the other hand, smoking was a statistically significant risk factorin the model (β=0.704; 95% CI, 0.24 to 1.38; P<0.05). Conclusions: Significantly lower mean levels of CAL were shown in the presence of theIgG1 antibody titers against whole-cell T. forsythia in periodontitis patients. Thus, the resultsof this study suggest that IgG1 antibody to T. forsythia may have been a protectivefactor from periodontitis in this sample.

Effects of nonlinear friction compensation in the inertia wheel pendulum

Carlos Aguilar-Avelar,Ricardo Rodríguez-Calderón,Sergio Puga-Guzmán,Javier Moreno-Valenzuela 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.9

This paper discusses for the first time the effects of modeling, identifying and compensating nonlinear friction for the control of the inertia wheel pendulum and proposes a new algorithm for the stabilization of the pendulum at the upward unstable position. First, it is shown that the dynamic model with the proposed asymmetric Coulomb friction component characterizes better the real experimental platform of the system. Then, a feedback linearization based controller with friction compensation was designed, where theoretical results show the stability of the output trajectories. Finally, the new algorithm was experimentally compared with its version without friction compensation, showing that the new scheme yields better performance with less power consumption.

Factors associated with the survival of colorectal cancer in Mexico

( Carlos Quezada-gutiérrez ),( María Teresa Álvarez-bañuelos ),( Jaime Morales-romero ),( Clara Luz Sampieri ),( Raúl Enrique Guzmán-garcía ),( Evangelina Montes-villaseñor ) 대한장연구학회 2020 Intestinal Research Vol.18 No.3

Background/Aims: Colorectal cancer (CRC) is a public health problem. In Mexico, there have been no recent studies conducted on survival in terms of this pathology or on the influence of prognostic factors. The study aims to determine the probability of survival in patients with CRC presence of low levels of schooling and a rural population, adjusted for clinical stage and type of treatment. Methods: A retrospective study was conducted in a cohort of 305 patients with CRC treated at State Cancer Center, located in Veracruz-Mexico; the follow-up period of 60 months (2012-2016). The survival probability was calculated using the Kaplan-Meier estimator and the log-rank test with 95% confidence intervals (CIs). Prognostic factors were determined using hazard ratio (HR) multivariate Cox regression analysis. Results: Overall survival was 40% at 60 months. Subjects in the age group ≥65 years had a low survival rate of 28% (P=0.026) and an advanced clinical stage of 22% (P<0.001). Of the patients with bone metastasis, none survived longer than 5 years (P=0.008). With respect to the unfavorable prognostic factors identified in the multivariate analysis, a decreased level of schooling was associated with an HR of 7.6 (95% CI, 1.1-54.7), advanced clinical stage was associated with an HR of 2.1 (95% CI, 1.2-4.0), and the presence of metastasis had an HR of 1.8 (95% CI, 1.1-2.9). Conclusions: Poor prognostic factors include an advanced clinical stage, the presence of metastasis and a low level of schooling. These findings confirm the importance of screening for early diagnosis, diminishing the barriers to accessing treatment and prospectively monitoring the population. (Intest Res 2020;18:315-324)

Robust GPI Control of a New Parallel Rehabilitation Robot of Lower Extremities

Héctor Azcaray,Andrés Blanco,Carlos García,Manuel Adam,Juan Reyes,Gerardo Guerrero,César Guzmán 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

In this paper, we propose a new robot for lower limbs rehabilitation by using a parallel structure. The goal of this robot is not only to produce smooth and precise motions for ankle, knee, and hip, but also to support trajectory tracking. Its parallel configuration was based on the four-bar mechanism in order to have a more stable and robust structure. For the kinematic analysis, the length of one bar was considered variable. For the dynamic analysis, the Euler-Lagrange method was used to define the equations of motion. For the robot control, the robust generalized proportional integral (GPI) controller was proposed to guarantee safe rehabilitation movements. This parallel robot not only showed good results, but also showed various movement possibilities for lower limbs rehabilitation.

Can We Rely on the Rome IV Questionnaire to Diagnose Children With Functional Gastrointestinal Disorders?

( Desiree F Baaleman ),( Carlos A Velasco-benítez ),( Laura M Méndez-guzmán ),( Marc A Benninga ),( Miguel Saps ) 대한소화기기능성질환·운동학회 2021 Journal of Neurogastroenterology and Motility (JNM Vol.27 No.4

Background/Aims To investigate the intra-rater (test-retest) reliability of the diagnosis of functional gastrointestinal disorders (FGIDs) as measured by the Questionnaire on Pediatric Functional Gastrointestinal Disorders, Rome IV version (QPGS-IV) in children. Methods A prospective cohort study was conducted in a public school in Cali, Colombia. Children and adolescents between 11 and 18 years of age were given the self-report Spanish version of the QPGS-IV at day 0 (baseline) and at day 2 (48 hours later). Results The study protocol was completed by 215 children, of which 97 (45%) were excluded from analysis due to the inability to follow the questionnaire’s instructions. The final analysis included data of 118 children (mean age 15.0 ± SD 1.8 years old, 58.5% boys). The most common diagnoses were functional dyspepsia, functional constipation, and irritable bowel syndrome. We found a moderate intra-rater reliability (κ = 0.61-0.65) for diagnosing an FGID in general, a functional abdominal pain disorder, and the diagnosis of functional dyspepsia. We found a weak intra-rater reliability (κ = 0.46-0.54) for diagnosing a functional defecation disorder, functional constipation, irritable bowel syndrome, and the postprandial distress syndrome subtype of functional dyspepsia. Conclusions Our study shows that a large proportion of children cannot adequately complete the QPGS-IV and that the intra-rater reliability among those who did adequately follow the instructions is moderate. We advise to test the children’s understanding of the instructions prior to completion of questionnaires and recommend to not rely exclusively on a self-reported questionnaire to select, recruit, or evaluate pediatric patients for FGIDs for research purposes. (J Neurogastroenterol Motil 2021;27:626-631)

Nonlinear numerical model of headed shear stud anchors for composite open web steel joists

Sergio J. Yanez,David W. Dinehart,Juan Carlos Pina,Carlos Felipe Guzmán 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.4

Empirical relationships that capture the nonlinear behavior of headed steel shear stud anchors have been derived from standard push out tests, where the specimens are comprised of large wide flanged steel sections attached to flat concrete slabs via the anchors. However, many composite systems used in practice utilize much smaller steel members and/or steel decking as part of the slab system. Composite open web steel joist systems generally include both of these elements and consequently the nonlinear performance ofthe anchor is not accurately represented by existing models. In this paper, a new empirical relation is presented for open web steel joist systems based on experimental results from a modified push out test that more realistically represent a composite open web steel joist system. The methodology for obtaining the proposed nonlinear function where the response of the system is characterized by two parameters( and ) is presented. The two-step process for obtaining the two parameters is described and the empirical relation is calibrated with the experimental data. In comparison with existing expressions, the new proposal herein more accurately predicts the high initialstiffness of the system and overall nonlinear system performance.

Hydrolysis catalyst effect on the textural and structural properties of sol-gel mixed oxides TiO₂-CeO₂

Félix Galindo-Hernández,Gloria del Ángel,Carlos Guzmán,Ricardo Gómez 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

Sol-gel TiO2-CeO2 semiconductors were synthesized at pH 3 and 9 using titanium alkoxide as the initial reactant; and either nitric acid or ammonium hydroxide as hydrolysis agents. The gels annealed at 473, 673 and 873 K were characterized by nitrogen adsorption,X-ray diffraction and Raman spectroscopy. The surface fractal dimension, crystallite size, titanium deficiency and electron density were calculated by the Frenkel-Halsey-Hill method, Rietveld refinement, and Fourier electron density map, respectively. Mesoporous materials showing high specific surface areas (250-99m2/g for pH 3 and 267-88 m2/g for pH 9) were obtained in both preparations. Anatase and anatase-cerianite crystalline phases were observed by X-ray diffraction in the samples prepared at pH 3 and pH 9 respectively. Nanocrystalline structures (from 7.1 to 43.6 nm) and an important titanium deficiency, depending on the synthesis conditions are reported. The Fourier electron density maps showed that for the semiconductors prepared at pH 3 the electron density was contracted in comparison with the samples synthesized at pH 9 where enlarged electron density maps were observed. A good agreement between the electron density maps and the surface fractal dimensions was obtained. Sol-gel TiO2-CeO2 semiconductors were synthesized at pH 3 and 9 using titanium alkoxide as the initial reactant; and either nitric acid or ammonium hydroxide as hydrolysis agents. The gels annealed at 473, 673 and 873 K were characterized by nitrogen adsorption,X-ray diffraction and Raman spectroscopy. The surface fractal dimension, crystallite size, titanium deficiency and electron density were calculated by the Frenkel-Halsey-Hill method, Rietveld refinement, and Fourier electron density map, respectively. Mesoporous materials showing high specific surface areas (250-99m2/g for pH 3 and 267-88 m2/g for pH 9) were obtained in both preparations. Anatase and anatase-cerianite crystalline phases were observed by X-ray diffraction in the samples prepared at pH 3 and pH 9 respectively. Nanocrystalline structures (from 7.1 to 43.6 nm) and an important titanium deficiency, depending on the synthesis conditions are reported. The Fourier electron density maps showed that for the semiconductors prepared at pH 3 the electron density was contracted in comparison with the samples synthesized at pH 9 where enlarged electron density maps were observed. A good agreement between the electron density maps and the surface fractal dimensions was obtained.

Alcohol dehydrogenase 1 participates in the Crabtree effect and connects fermentative and oxidative metabolism in the Zygomycete Mucor circinelloides

Rosa Angélica Rangel-Porras,Sharel P. Díaz-Pérez,Juan Manuel Mendoza-Hernández,Pamela Romo-Rodríguez,Viridiana Alejandre-Castañeda,Marco I Valle-Maldonado,Juan Carlos Torres-Guzmán,Gloria Angélica Gon 한국미생물학회 2019 The journal of microbiology Vol.57 No.7

Mucor circinelloides is a dimorphic Zygomycete fungus that produces ethanol under aerobic conditions in the presence of glucose, which indicates that it is a Crabtree-positive fungus. To determine the physiological role of the alcohol dehydrogenase (ADH) activity elicited under these conditions, we obtained and characterized an allyl alcohol-resistant mutant that was defective in ADH activity, and examined the effect of adh mutation on physiological parameters related to carbon and energy metabolism. Compared to the Adh+ strain R7B, the ADH-defective (Adh-) strain M5 was unable to grow under anaerobic conditions, exhibited a considerable reduction in ethanol production in aerobic cultures when incubated with glucose, had markedly reduced growth capacity in the presence of oxygen when ethanol was the sole carbon source, and exhibited very low levels of NAD+-dependent alcohol dehydrogenase activity in the cytosolic fraction. Further characterization of the M5 strain showed that it contains a 10-bp deletion that interrupts the coding region of the adh1 gene. Complementation with the wild-type allele adh1+ by transformation of M5 remedied all the defects caused by the adh1 mutation. These findings indicate that in M. circinelloides, the product of the adh1 gene mediates the Crabtree effect, and can act as either a fermentative or an oxidative enzyme, depending on the nutritional conditions, thereby participating in the association between fermentative and oxidative metabolism. It was found that the spores of M. circinelloides possess low mRNA levels of the ethanol assimilation genes (adl2 and acs2), which could explain their inability to grow in the alcohol.