[Translated article] Determining factors on length of stay in primary total knee arthroplasty patients using enhanced recovery protocol after surgery (ERAS) pathway.

INTRODUCTION: There is an increase in degenerative arthropathies because of the increase in the longevity of world's population, making primary knee arthroplasties a procedure to recover quality of life without pain. There are factors associated with the length of hospital stay after this procedure. OBJECTIVE: To determine the risk factors influencing the hospital stay during the postoperative period of patients undergoing primary total knee arthroplasty with an enhanced recovery after surgery protocol (ERAS). METHODS: A retrospective study is carried out on patients undergoing primary total knee arthroplasty at an University Hospital in the period 2017-2020 using the ERAS protocol, during which 957 surgeries were performed. RESULTS: Average age of 71.7±8.2years, 62.4% were women and the 77.3% were classified as ASA II. The significantly associated factors to an increased length of stay are: age (p=.001), ASA scale (p=.04), day of surgery (p<.001), blood transfusion (p<.001), postoperative haemoglobin level at 48-72h (p<.001), the time of first postoperative mobilisation to ambulate and climb stairs (p<.001), the need for analgesic rescues (p=.003), and the presence of postoperative nausea and vomiting (p=.008). CONCLUSIONS: There are statistically significant and clinically relevant factors associated with hospital stay. Determining these factors constitutes an advantage in hospital management, in the development of strategies to improve and optimise the quality of care and available health resources.

Prevalence of DNA-Repair Gene mutations in Mexican men with prostate cancer.

INTRODUCTION AND OBJECTIVE: Mexico reported 26,742 new cases of prostate cancer in 2020. Different risk factors have been identified in the pathogenesis of prostate cancer. Among them, genetic factors and alterations or mutations in specific genes have been described in different ethnic groups worldwide. The aim of our study is to report the prevalence of germline DNA-repair gene mutations in Mexican patients with prostate cancer. MATERIAL AND METHOD: We performed germline genetic testing in 50 patients with localized prostate cancer and 50 patients with metastatic prostate cancer. Demographic, clinical, and histopathological data were collected. RESULTS: Thirty-seven germline mutations were identified in 32 patients. The most commonly affected genes were ATM in 6%, followed by FANCA (5%), and ATR (4%). BRCA2 mutations were identified in 3%. The frequency of mutations was higher in the metastatic group. DISCUSSION AND CONCLUSION: The results of our study show different mutations from those reported in different populations or regions. The use of PARP inhibitors is indicated in patients with germline mutations, specifically BRCA2, showing improvement in overall survival and progression free survival. To our knowledge, this is the first study reporting the prevalence of mutations in DNA-repair genes in Mexican patients with prostate cancer.

Influence of the typology and timing of childhood trauma in psychoticism.

PURPOSE: Child maltreatment (CM) is associated with psychosis; however little is known about the frequency, type, and timing of abuse in the personality pathology domain of psychoticism (PSY) in the DSM-5. The purpose of this study was to analyze childhood trauma typology and frequency according to gender and to identify sensitive periods of susceptibility to CM in women with high PSY. METHODS: The Maltreatment and Abuse Chronology Exposure (MACE) scale was used to evaluate the frequency, severity and timing of each type of maltreatment. The full sample consisted of 83 participants with different psychiatric diagnoses. Psychoticism was assessed with the DSM-5 Personality Inventory (PID-5). To identify the differences in CM exposure between the PSY+ (high psychoticism) and PSY- (low psychoticism) groups, the Mann-Whitney U test, the chi square test and random forest (RF) test were used. RESULTS: Comparing PSY + and PSY-, revealed gender differences in the impact of abuse, with highly frequent and severe types of abuse, in women. In women, PSY + and PSY-, were differentiated especially in non-verbal emotional abuse, peer physical bullying and parental verbal abuse. Several periods with a major peak at age seven followed by peaks at age 17 and 12 years old were identified. CONCLUSION: Increased exposure to CM occurs in women with PSY+. A sensitivity to CM exposure during early childhood and late adolescence could be a risk factor for psychoticism in women.

A new flexible regression model with application to recovery probability Covid-19 patients.

The aim of this study is to propose a generalized odd log-logistic Maxwell mixture model to analyze the effect of gender and age groups on lifetimes and on the recovery probabilities of Chinese individuals with COVID-19. We add new properties of the generalized Maxwell model. The coefficients of the regression and the recovered fraction are estimated by maximum likelihood and Bayesian methods. Further, some simulation studies are done to compare the regressions for different scenarios. Model-checking techniques based on the quantile residuals are addressed. The estimated survival functions for the patients are reported by age range and sex. The simulation study showed that mean squared errors decay toward zero and the average estimates converge to the true parameters when sample size increases. According to the fitted model, there is a significant difference only in the age group on the lifetime of individuals with COVID-19. Women have higher probability of recovering than men and individuals aged ≥60 years have lower recovered probabilities than those who aged <60 years. The findings suggest that the proposed model could be a good alternative to analyze censored lifetime of individuals with COVID-19.

Determining factors on length of stay in primary total knee arthroplasty patients using enhanced recovery protocol after surgery (ERAS) pathway. / Factores determinantes de la duración de la estancia hospitalaria en pacientes operados de artroplastia primaria total de rodilla usando un protocolo de recuperación mejorada (ERAS).

INTRODUCTION: There is an increase in degenerative arthropathies because of the increase in the longevity of world's population, making primary knee arthroplasties a procedure to recover quality of life without pain. There are factors associated with the length of hospital stay after this procedure. OBJECTIVE: To determine the risk factors influencing the hospital stay during the postoperative period of patients undergoing primary total knee arthroplasty with an enhanced recovery after surgery protocol (ERAS). METHODS: A retrospective study is carried out on patients undergoing primary total knee arthroplasty at an University Hospital in the period 2017-2020 using the ERAS protocol, during which 957 surgeries were performed. RESULTS: Average age of 71.7±8.2years, 62.4% were women and the 77.3% were classified as ASAII. The significantly associated factors to an increased length of stay are: age (P=.001), ASA scale (P=.04), day of surgery (P<.001), blood transfusion (P<.001), postoperative hemoglobin level at 48-72h (P<.001), the time of first postoperative mobilization to ambulate and climb stairs (P<.001), the need for analgesic rescues (P=.003), and the presence of postoperative nausea and vomiting (P=.008). CONCLUSIONS: There are statistically significant and clinically relevant factors associated with hospital stay. Determining these factors constitutes an advantage in hospital management, in the development of strategies to improve and optimize the quality of care and available health resources.

What kind of sheets does the fat sleeper fish prefer? Effect of pond bottom color on the growth and health of Dormitator latifrons (Richardson 1844).

A little-studied characteristic of the Mexican native fish Dormitator latifrons is the effect that the color of the bottom or lining of ponds or tubs can have on their growth and blood parameters under controlled conditions. After a quarantine period in prophylactic treatment, an initial assay was performed. The organisms were grouped into four treatments (white, yellow, blue, and black) in triplicate, with 30 individuals with an average weight of 34.7± 2.5 g and average size of 12.5 ± 1.5 cm per tank. The trial lasted 60 days, after which a final biometry to all specimens and blood extractions to six random organisms per tank were performed. The following hematological and blood chemistry parameters were evaluated: erythrocytes, cell counts, and differential counts, as well as glucose, albumin, a/g ratio, and total proteins. Final weight, weight gain, and specific growth rate presented statistical differences between treatments (p<0.05), with dark bottoms (blue and black) above 80% of WG and above 1.0 of SGR. No statistically differences were found in hematological blood chemistry parameters (p>0.05). The growth results suggest that dark pond bottoms promote the adaptation of Dormitator latifrons by allowing it to avoid detection by predators through the adoption of a cryptic coloration. However, the species shows a great capacity for crypsis, being able to change its pigmentation to adapt to different bottom colors.

Posttransplantation diabetes mellitus after liver transplant and the impact of family history of diabetes in a Mexican cohort.

INTRODUCTION AND AIMS: Posttransplantation diabetes mellitus (PTDM) is a serious long-term complication that has a negative impact on graft and patient survival. The purpose of the present study was to describe the incidence of PTDM in a Mexican cohort and evaluate its association with a previous family history of diabetes (FHD). METHODS: A retrospective single-center cohort study was conducted on patients undergoing liver transplantation (LT). The primary outcome was time from LT to PTDM. The diagnosis of PTDM was established using the ADA criteria. A mediation analysis that used adjusted Cox regression models and considered pretransplant prediabetes a mediator was performed, to determine the total effect and direct effect of FHD on PTDM. RESULTS: A total of 152 patients were included, with a median follow-up time of 41 months; 19.2% (n = 29) had pretransplant diabetes. During the follow-up time, 15% of patients developed PTDM (n = 23), with an incidence rate of 4.71 cases/100 person-years. PTDM was significantly higher in patients with FHD, compared with those with no FHD (8.72 cases/100 person-years vs 2.04 cases/100 person-years, respectively; p = 0.001). The adjusted hazard ratio of PTDM for FHD was 4.14 (95% CI 1.60-10.7), p = 0.005) and 3.48 (95% CI 1.35-9.01, p = 0.010), when further controlled for pretransplant prediabetes. CONCLUSION: The occurrence of PTDM was similar to that reported in most international studies. As with type 2 diabetes, family history plays an important role in the development of PTDM, even after accounting for pretransplant prediabetes. Patients with FHD should undergo a stricter metabolic program.

The re-parameterized inverse Gaussian regression to model length of stay of COVID-19 patients in the public health care system of Piracicaba, Brazil.

Among the models applied to analyze survival data, a standout is the inverse Gaussian distribution, which belongs to the class of models to analyze positive asymmetric data. However, the variance of this distribution depends on two parameters, which prevents establishing a functional relation with a linear predictor when the assumption of constant variance does not hold. In this context, the aim of this paper is to re-parameterize the inverse Gaussian distribution to enable establishing an association between a linear predictor and the variance. We propose deviance residuals to verify the model assumptions. Some simulations indicate that the distribution of these residuals approaches the standard normal distribution and the mean squared errors of the estimators are small for large samples. Further, we fit the new model to hospitalization times of COVID-19 patients in Piracicaba (Brazil) which indicates that men spend more time hospitalized than women, and this pattern is more pronounced for individuals older than 60 years. The re-parameterized inverse Gaussian model proved to be a good alternative to analyze censored data with non-constant variance.

A random effect regression based on the odd log-logistic generalized inverse Gaussian distribution.

In recent decades, the use of regression models with random effects has made great progress. Among these models' attractions is the flexibility to analyze correlated data. In various situations, the distribution of the response variable presents asymmetry or bimodality. In these cases, it is possible to use the normal regression with random effect at the intercept. In light of these contexts, i.e. the desire to analyze correlated data in the presence of bimodality or asymmetry, in this paper we propose a regression model with random effect at the intercept based onthe generalized inverse Gaussian distribution model with correlated data. The maximum likelihood is adopted to estimate the parameters and various simulations are performed for correlated data. A type of residuals for the new regression is proposed whose empirical distribution is close to normal. The versatility of the new regression is demonstrated by estimating the average price per hectare of bare land in 10 municipalities in the state of São Paulo (Brazil). In this context, various databases are constantly emerging, requiring flexible modeling. Thus, it is likely to be of interest to data analysts, and can make a good contribution to the statistical literature.

[Translated article] Results of a preoperative screening and decolonization programme for Staphylococcus aureus in primary hip and knee arthroplasty.

INTRODUCTION: Detection and decolonization of Staphylococcus aureus prior to surgery is postulated as an option to reduce the risk of infection in arthroplasties. The aim of this study was to evaluate the effectiveness of a screening programme for S. aureus in total knee arthroplasty (TKA) and total hip arthroplasty (THA), the incidence of infection with respect to a historical cohort, and its economic viability. MATERIAL AND METHODS: Pre-post intervention study in patients undergoing primary knee and hip prostheses in 2021, a protocol was carried out to detect nasal colonization by S. aureus and eradication if appropriate, with intranasal mupirocin, post-treatment culture with results three weeks between post-treatment culture and surgery. Efficacy measures are evaluated, costs are analyzed and the incidence of infection is compared with respect to a historical series of patients operated on between January and December 2019, performing a descriptive and comparative statistical analysis. RESULTS: The groups were statistically comparable. Culture was performed in 89%, with 19 (13%) positive patients. Treatment was confirmed in 18, control culture in 14, all decolonized; none suffered infection. One culture-negative patient suffered from Staphylococcus epidermidis infection. In historical cohort: three suffered deep infection by S. epidermidis, Enterobacter cloacae, Staphylococcus aureus. The cost of the programme is €1661.85. CONCLUSION: The screening programme detected 89% of the patients. The prevalence of infection in the intervention group was lower than in the cohort, with S. epidermidis being the main micro-organism, different from S. aureus described in the literature and in the cohort. We believe that this programme is economically viable, as its costs are low and affordable.

Results of a preoperative screening and decolonization program for Staphylococcus aureus in primary hip and knee arthroplasty. / Resultados de un programa de descolonización de Staphylococcus aureus en cirugía protésica primaria de cadera y rodilla.

INTRODUCTION: Detection and decolonization of Staphylococcus aureus prior to surgery is postulated as an option to reduce the risk of infection in arthroplasties. The aim of this study was to evaluate the effectiveness of a screening program for S. aureus in total knee arthroplasty (TKA) and total hip arthroplasty (THA), the incidence of infection with respect to a historical cohort, and its economic viability. MATERIAL AND METHODS: Pre-post intervention study in patients undergoing primary knee and hip prostheses in 2021, a protocol was carried out to detect nasal colonization by S. aureus and eradication if appropriate, with intranasal mupirocin, post-treatment culture with results three weeks between post-treatment culture and surgery. Efficacy measures are evaluated, costs are analyzed and the incidence of infection is compared with respect to a historical series of patients operated on between January and December 2019, performing a descriptive and comparative statistical analysis. RESULTS: The groups were statistically comparable. Culture was performed in 89%, with 19 (13%) positive patients. Treatment was confirmed in 18, control culture in 14, all decolonized; none suffered infection. One culture-negative patient suffered from Staphylococcus epidermidis infection. In historical cohort: 3 suffered deep infection by S. epidermidis, Enterobacter cloacae, S. aureus. The cost of the program is €1661.85. CONCLUSION: The screening program detected 89% of the patients. The prevalence of infection in the intervention group was lower than in the cohort, with S. epidermidis being the main microorganism, different from S. aureus described in the literature and in the cohort. We believe that this program is economically viable, as its costs are low and affordable.

Contribution of halloysite as nanotubular clay mineral on mechanism and adsorption rate of Cd(II) onto nanocomposites alginate-halloysite.

In this work nanocomposites based on alginate (Alg) and halloysite as a nanotubular clay (Hy) were developed. Characterization techniques reveal that Hy/Alg nanocomposites are cation exchangers with predominantly negative charge density and good thermal stability. The adsorption equilibrium of Cd(II) in aqueous solution onto Hy/Alg nanocomposites revealed that by increasing the mass of halloysite in the nanocomposite, the adsorption capacity diminished significantly due to the halloysite-alginate interactions. Maximum adsorption capacities of 8, 65, 88, and 132 mg/g of Cd(II) were obtained for samples Hy, Hy/Alg 50%, Hy/Alg 95%, and Alg, respectively. In addition, the adsorption equilibrium of Cd(II) on the Hy/Alg bionanocomposites was affected by the pH and temperature of the solution, demonstrating the presence of electrostatic interactions during adsorption and that this is an exothermic process. The controlling mechanism of adsorption was cation exchange influenced by electrostatic forces. The Cd(II) adsorption rate studies were interpreted by the diffusion-permeation model and reveal that the presence of Hy in the structure of the nanocomposites enhances the permeation coefficient, that is, the adsorption rate was increased. The values of the permeation coefficient varied from 1.95 × 10-7 to 8.50 × 10-7 cm2/s for Hy/Alg 50% and from 1.70 × 10-7 to 3.55 × 10-7 cm2/s for Hy/Alg 95%.

Capacitors Based on Polypyrrole Nanowire Electrodeposits.

The electrochemical polymerization of polypyrrole nanowires is carried out using potentiodynamic and galvanostatic methods in order to enhance the performance of the modified electrodes as capacitor devices. The electrochemical, spectroscopic, and morphological properties are determined through cyclic voltammetry, Raman spectroscopy and scanning electron microscopy, respectively, corroborating the presence of PPy-nw in dimensions of 30 nm in diameter. Characterization as a capacitor revealed that the nanowire structure enhances key parameters such as specific capacitance with 60 times greater value than bulk polymer modification, in addition to a significant increase in stability. In this way, it is verified that electrodes modified with polypyrrole nanowires obtained in situ by electrochemical methods constitute an excellent candidate for the development of capacitors.

A new regression model for rates and proportions data with applications.

We propose a new continuous distribution in the interval ( 0 , 1 ) based on the generalized odd log-logistic-G family, whose density function can be symmetrical, asymmetric, unimodal and bimodal. The new model is implemented using the gamlss packages in R. We propose an extended regression based on this distribution which includes as sub-models some important regressions. We employ a frequentist and Bayesian analysis to estimate the parameters and adopt the non-parametric and parametric bootstrap methods to obtain better efficiency of the estimators. Some simulations are conducted to verify the empirical distribution of the maximum likelihood estimators. We compare the empirical distribution of the quantile residuals with the standard normal distribution. The extended regression can give more realistic fits than other regressions in the analysis of proportional data.

The semiparametric regression model for bimodal data with different penalized smoothers applied to climatology, ethanol and air quality data.

Semiparametric regressions can be used to model data when covariables and the response variable have a nonlinear relationship. In this work, we propose three flexible regression models for bimodal data called the additive, additive partial and semiparametric regressions, basing on the odd log-logistic generalized inverse Gaussian distribution under three types of penalized smoothers, where the main idea is not to confront the three forms of smoothings but to show the versatility of the distribution with three types of penalized smoothers. We present several Monte Carlo simulations carried out for different configurations of the parameters and some sample sizes to verify the precision of the penalized maximum-likelihood estimators. The usefulness of the proposed regressions is proved empirically through three applications to climatology, ethanol and air quality data.

Joint regression modeling of location and scale parameters of the skew t distribution with application in soil chemistry data.

In regression model applications, the errors may frequently present a symmetric shape. In such cases, the normal and Student t distributions are commonly used. In this paper, we shall be concerned only to model heavy-tailed, skewed errors and absence of variance homogeneity with two regression structures based on the skew t distribution. We consider a classic analysis for the parameters of the proposed model. We perform a diagnostic analysis based on global influence and quantile residuals. For different parameter settings and sample sizes, various simulation results are obtained and compared to evaluate the performance of the skew t regression. Further, we illustrate the usefulness of the new regression by means of a real data set (amount of potassium in different soil areas) from a study carried out at the Department of Soil Science of the Luiz de Queiroz School of Agriculture, University of São Paulo.

A new heteroscedastic regression to analyze mass loss of wood in civil construction in Brazil.

A heteroscedastic regression based on the odd log-logistic Marshall-Olkin normal (OLLMON) distribution is defined by extending previous models. Some structural properties of this distribution are presented. The estimation of the parameters is addressed by maximum likelihood. For different parameter settings, sample sizes and some scenarios, various simulations investigate the performance of the heteroscedastic OLLMON regression. We use residual analysis to detect influential observations and to check the model assumptions. The new regression explains the mass loss of different wood species in civil construction in Brazil.

Fatty liver index as a predictor for type 2 diabetes in subjects with normoglycemia in a nationwide cohort study.

Our aim was to evaluate whether fatty liver index (FLI) is associated with the risk of type 2 diabetes (T2DM) development within the Spanish adult population and according to their prediabetes status; additionally, to examine its incremental predictive value regarding traditional risk factors. A total of 2260 subjects (Prediabetes: 641 subjects, normoglycemia: 1619 subjects) from the Di@bet.es cohort study were studied. Socio-demographic, anthropometric, clinical data and survey on habits were recorded. An oral glucose tolerance test was performed and fasting determinations of glucose, lipids and insulin were made. FLI was calculated and classified into three categories: Low (< 30), intermediate (30-60) and high (> 60). In total, 143 people developed diabetes at follow-up. The presence of a high FLI category was in all cases a significant independent risk factor for the development of diabetes. The inclusion of FLI categories in prediction models based on different conventional T2DM risk factors significantly increase the prediction power of the models when all the population was considered. According to our results, FLI might be considered an early indicator of T2DM development even under normoglycemic condition. The data also suggest that FLI could provide additional information for the prediction of T2DM in models based on conventional risk factors.

Socio-academic Factors Influencing Knowledge About Organ Donation among Medical Students in Paraguay, 2018.

Organ donation currently is an extremely important issue in public health. Proper information about the details of this topic is extremely important, but is not yet widespread among the public. This study was carried out with the aim to determine the level of knowledge about organ donation among medical students in Paraguay and associated socio-academic factors influencing their level of knowledge. This was an analytical cross-sectional study, based on a multicenter survey among university medical students. About 68.7% (235) of the respondents were preclinical students doing basic sciences. Two aspects were evaluated, the knowledge regarding the donation of the organs and the socio-academic factors, then both the aspects were evaluated through bivariate and multivariate analyses. There were 342 respondents with a median age of 22 years (interquartile range: 20-23 years) of which 263 (77%) were women. One hundred and eighty-eight (55%) reported not knowing the law that protects and regulates the activities of organ and tissue donation in Paraguay. In the multivariate analysis, the highest frequency of a good level of knowledge of organ donation occurred in those who were older [RPA: 1.07, 95% confidence interval (CI): 1.02-1.12, P = 0.007] and in two of the universities evaluated (both with values P <0.012). On the contrary, those who were preclinical students, in general, had a lower level of knowledge of organ donation (RPa: 0.61, 95% CI: 0.46-0.79; value P <0.001). Our findings denote relatively a poor knowledge of organ donation in some socio-academic subsets. Therefore, it is important to develop strategies to increase the knowledge about the subject, by creating opportunities by way of discussions and debates among the students at all academic levels and also by conducting academic conferences on the subject.