90 research outputs found
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No Entiendo: The Effects of Bilingualism on Hispanic Earnings
This paper examines whether the ability to communicate in English and Spanish is rewarded in labor markets. Using data from the 2000 U.S. Census we find that among Hispanics, earnings are higher as the ability to speak English increases. We also find that bilingualism, is associated with higher wages reversing the negative effect found in earlier studies. The reversal could be explained by increasing immigration, and from economic integration with Latin America. Our results also show that bilingualism is negatively correlated with wages among different occupational categories and sectors, but particularly among managers and those employed in the public sector
Anatomical Variants of Anterior Cerebral Arterial Circle: A Study by Multidetector Computerized 3D Tomographic Angiography
SUMMARY: One of the most common causes of stroke is rupture of aneurysms whose approach requires knowledge of anatomical variants. The aim of this study was to determine the prevalence of anatomical variants of the anterior cerebral artery (ACA) and the anterior communicating artery (AComA) by 3D computed tomography angiography (3D CTA) in Mexican individuals. A retrospective, observational, cross-sectional descriptive study of 283 patients, independent of sex or age, in which morphometric measurements of cerebral vessels were evaluated using contrasted 3D CTA from a period of two years was performed. We found at least one "atypical" variant in a third of the study population (33.93 %). The most common "atypical" variant was the absence of the AComA (14.1 %). A significant association between the hypoplastic variant of the right A1 segment and hypoplasia of the left A1 and the right A2 was found, while hypoplasia of the left A1 was associated with hypoplasia of the right A2. There is a difference in the prevalence of anatomical variants of the ACA-AComA complex in Mexican population in relation to other populations. The typical variant is the most prevalent form in the study population. However, the presence of atypical variants represents an important number that should be taken into account in clinical and surgical procedures.
KEY WORDS: Anterior cerebral artery; Anatomical variant; Anterior communicating artery; Cerebral arterial circle; Subarachnoid hemorrhage; Cerebral endovascular surgery
Neurovascular Structures at Risk During Anterolateral and Medial Arthroscopic Approaches of the Hip
To describe the safety areas for placement of 5 anterolateral portals (anterior, anterior lateral, posterior lateral, proximal anterior medial and distal anterior medial portals) and 3 recently described medial portals (anterior medial, posterior medial and distal posterior medial portals) to provide topographical description of the safety of each. A descriptive, observational and crosssectional study in which femoral triangle dissection was performed in 12 hips. 5 lateral portals and the 3 medial portals were placed. Clinically relevant neurovascular structures associated with each portal, were identified measured and documented. The lateral portal with the highest risk of injury to a nearby neurovascular structure was the anterior portal, the most adjacent to the femoral cutaneous nerve, 1.42 cm (±0.85) lateral to the portal. In the medial portals, the anterior medial portal has the narrowest margin in relation to the femoral artery, 2.14 cm (±0.35) lateral to the portal and medial to the obturator nerve by 0.87 cm (±0.62). The lateral portals have a higher safety margin; the portal with the most proximity to a neurovascular structure is the anterior portal, associated laterally with the femoral cutaneous nerve, presenting a higher risk of injury. Medial portals have a higher risk of injuring the femoral neurovascular bundle as well as the obturator nerve
Prevalencia y características morfométricas del foramen mastoideo y vena emisaria mastoidea en población mexicana
Las descripciones anatómicas del foramen mastoideo (FM) y la vena emisaria mastoidea (VEM) son escasas en la
literatura. Dicho conocimiento es fundamental para realizar un abordaje quirúrgico de la fosa craneal posterior o región mastoidea. El objetivo del estudio fue determinar la prevalencia, variantes y características morfométricas del FM y VEM en población mexicana. Se
evaluaron 176 hemicráneos por dos observadores independientes cegados el uno del otro, se determinaron la prevalencia, número y características morfométricas. La prevalencia del FM entre los dos lados fue de 75% con una mayor frecuencia de forámenes del lado izquierdo comparado con el lado derecho; respecto al número de forámenes se encontraron 108 hemicráneos con un foramen único, 22 con doble foramen y 2 con triple foramen. La prevalencia del FM y VEM fue de 75%, siendo la variante única la más frecuente
Morphological Analysis of Major Segments of Coronary Artery Occlusion: Importance in Myocardial Revascularization Surgery
Revascularization surgery should ensure morphological similarity between the coronary artery and the graft. This is an important factor for its duration and permeability. The aim of this study was to analyze the morphological characteristics and morphometrics of the coronary artery segments with greater occlusion. This was an observational, cross-sectional descriptive study that
consisted of two phases. A macroscopic phase in which 11 cadaveric hearts were extracted and coronary dominance and length of the anterior interventricular artery (AIA), the right coronary artery (RCA) and the circumflex artery (CXA) were determined. In the microscopic phase a total of 77 segments of these arteries were obtained and the luminal diameter, wall thickness, and amount of elastic fibers and the presence and size of the atheroma were determined. Right coronary dominance was the most frequent. Total vessel length was 15.65±1.17 cm for the AIA, 12.67±2.02 cm for the RCA and 8.79±2.5 cm for the CXA. Diameters ranged from 2.3 mm in the proximal segments and between 1.1 mm to 1.8 mm in the distal segments. Wall thickness in the proximal segments was between 354 µm and 396 µm and in the distal segments it ranged from 120 µm to 305 µm. The amount of elastic fibers showed that they were muscular arteries. Atheromas were present in 35% in the CXA, and in 32.5% in the AIA and the RCA. The largest ones were found in the proximal segments. This study examined the morphology and morphometry of the segments of the coronary arteries that are more frequently occluded. It provides information on the most significant parameters to be considered for election of the vascular graft in myocardial revascularization surgery
Pelvimetry by Reformatted Computed Tomography in 290 Female Pelvis: Morphometric Variations Regarding Age
The Mexican government passed a new reform of article 11 of the General Law in 2014 regarding Women's Access
to a Life Free of Violence, which states that a cesarean section may not be performed if a vaginal birth is viable. Cesarean sections are
excessively indicated in Northen Mexico, using the diagnosis of cephalopelvic disproportion due to a narrow pelvis. Currently, there is
no standardized morphometry of the female pelvis in a Mexican population to establish adequate diagnostic parameter. Our study
measures the pelvic diameters of the birth canal using abdominopelvic computed tomography (CT). Two hundred and ninety CT from
Mexican women between the ages of 18 and 50 were collected and 3D reformatted in order to morphologically measure the pelvic
diameters of clinical relevance. Measurements were conducted by two diagnostic imaging specialists. The mean and standard deviation
of the measured diameters were: anatomical conjugate diameter (ACD) 11.65±0.99 cm, the obstetric conjugate diameter (OCD) 11.73±0.98
cm, diagonal conjugate diameter (DCD) 12.49±0.98 cm and Interspinous distance (ISD) 10.41±0.78 cm. Significant differences were
found in all four mean diameters in between the 20–29 age groups versus the >40, as well as between the 30–39 groups versus the >40.
Our study shows that as Mexican women get older, the mean pelvic diameters become narrower
Safe Areas for the Placement of Standard Shoulder Arthroscopy Portals: An Anatomical Study
The abundant vascular structures that surround the shoulder joint are complex and variable, complicating arthroscopy approaches. The aim of this study is to determine safe and risky areas around standard posterior and standard anterior portals, and accounting for the distribution of neurovascular structures of small and medium diameters that can lead to intra-articular bleeding during surgery. The standard posterior portal, and standard anterior portal were placed as described in the literature, and punch dissection was performed 2.5 cm around the trocar in situ. The arrangement of each identified structure was photographically documented and digitalized for each anatomic plane; the distance to the trocar and the diameter of each structure were measured. Based on each digitalized anatomic plane, safe and risky tissue areas were determined, and a clock face coordinate system was used to represent these areas. The safe area
around the standard posterior portal was located between 11 and 1 o´clock for the left shoulder and 11 and 2 o´clock for the right shoulder. For the standard anterior portal, the safe area was located between 2 and 3 o´clock for the left shoulder and between 9 and 12 o´clock for the right shoulder. However, we did document a risk of injuring the cephalic vein 5 times, the axillary artery 3 times and the deltoid branch of the thoracoacromial artery once. This study reports quantitatively the total number of small diameter structures present in the two shoulder arthroscopic portals evaluated. The safe areas proposed in this study must be evaluated to propose new access points for performing arthroscopic procedures on the shoulder
Morphometric characteristics of lumbar vertebral pedicles in Mexican population. Implications for transpedicular lumbar fusion surgery
Introduction. Spinal fusion surgery using transpedicular fixation is the most common technique for surgical
treatment of spinal pathologies of any etiology. The morphometric characteristics of the vertebral pedicle
determine the size and shape of pedicle implants. The objective of this study is to determine the morphometric
characteristics of the lumbar vertebral pedicle in Mexican population by direct measurement of bone parts.
Materials and Methods. We analyzed 65 L1–L5 cadaver lumbar spines from a collection of bone specimens
from the Department of Human Anatomy. Pedicle width, height, and length were determined bilaterally in each
sample studied. We obtained measures of central tendency, and parametric correlation tests were performed
with a 95% confidence interval to determine if significant differences exist between the lumbar vertebral levels.
Results. Pedicle width increased from L1 to L5. We obtained a minimum mean value of 7.40 ± 1.84 mm at
L1 and a maximum mean value of 14.74 ± 3.77 mm at L5. Pedicle height decreased from L1 to L4 with a
subsequent increase at L5. We obtained a maximum mean value of 18.32 ± 4.15 mm at L5 and minimum mean
value of 14.09 mm ± 2.75 at L4. Significant differences were observed (P < 0.05) when groups were compared.
Conclusions. This study accurately describes the morphometric characteristics of the lumbar vertebral pedicle.
These data will be useful for correct selection and positioning of transpedicular screws
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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THE MEXICAN CHAMBER OF DEPUTIES AND THE MEXICAN POLITICAL SYSTEM
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