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"Martinez, Alexander M."
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The impact after 20 years of an early detection program for severe retinopathy of prematurity in a Latin American city
by
Cantor, Erika
,
Zuluaga-Botero, Claudia
,
Martínez-Blanco, Alexander M
in
Birth Weight
,
Care and treatment
,
Demographic aspects
2023
Purpose:
To evaluate the effects of long-standing early detection program in the incidence and trends of severe retinopathy of prematurity (ROP) in Cali, Colombia.
Methods:
This was a retrospective cohort study of infants included in an ROP prevention, early detection, and prompt treatment program, from January 01, 2002, to December 31, 2021 (20 years). Infants with gestational age (GA) <37 weeks or birth weight (BW) <2000 g and those with known ROP risk factors were screened. The incidence of severe ROP was calculated, and the average annual percent change (AAPC) was estimated through a joinpoint model.
Results:
16,580 infants were screened, with an average GA and BW of 31.4 ± 2.8 weeks and 1526.5 ± 56.7 g, respectively. The incidence of severe ROP was 2.69% (446 cases, 95% confidence interval [95%CI]: 2.45%; 2.95%), with an average annual decrease of − 14% (AAPC, 95%CI: −16.3%; −11.6%) from 13.6% in 2002 to 0.7% in 2021. In infants with GA <32 weeks, the incidence was 5.21%. A significant reduction in the risk of ROP was observed with increasing GA and BW (P < 0.05). Among the cases with severe ROP, 6.5% (29/446) had a GA ≥32 weeks with a maximum of 37 weeks; only 0.4% (2/446) of the detected infants had a BW >2000 g.
Conclusion:
Awareness and screening as part of the early detection program to prevent ROP has shown a significant decline in the incidence of severe ROP over time. Screening infants with GA <32 weeks or BW <2000 g and preterm infants (<37 weeks) with risk factors may be a feasible decision for resource optimization.
Journal Article
Comment on: “Lesion area progression in eyes with neovascular age-related macular degeneration treated using a proactive or a reactive regimen”
by
Niño-Joya, Andrés Felipe
,
Martínez-Blanco, Alexander M.
,
Salamanca, Omar
in
631/443
,
692/308/409
,
Angiogenesis Inhibitors - therapeutic use
2024
Journal Article
Correction to: International prospective observational cohort study of Zika in infants and pregnancy (ZIP study): study protocol
by
Mussi-Pinhata, Marisa M.
,
Arias, Juan F.
,
Ugarte-Gil, César Augusto
in
Correction
,
Gynecology
,
Maternal and Child Health
2019
Following publication of the original article [1], the author mentioned that two additional NIH staff were involved in the development of the protocol who did not receive recognition in the Acknowledgments section in their published article.
Journal Article
International prospective observational cohort study of Zika in infants and pregnancy (ZIP study): study protocol
by
Mussi-Pinhata, Marisa M.
,
Arias, Juan F.
,
Ugarte-Gil, César Augusto
in
Adolescent
,
Adult
,
Antibodies, Viral - blood
2019
Background
Until recently, Zika virus (ZIKV) infections were considered mild and self-limiting. Since 2015, they have been associated with an increase in microcephaly and other birth defects in newborns. While this association has been observed in case reports and epidemiological studies, the nature and extent of the relationship between ZIKV and adverse pregnancy and pediatric health outcomes is not well understood. With the unique opportunity to prospectively explore the full spectrum of issues related to ZIKV exposure during pregnancy, we undertook a multi-country, prospective cohort study to evaluate the association between ZIKV and pregnancy, neonatal, and infant outcomes.
Methods
At research sites in ZIKV endemic regions of Brazil (4 sites), Colombia, Guatemala, Nicaragua, Puerto Rico (2 sites), and Peru, up to 10,000 pregnant women will be recruited and consented in the first and early second trimesters of pregnancy and then followed through delivery up to 6 weeks post-partum; their infants will be followed until at least 1 year of age. Pregnant women with symptomatic ZIKV infection confirmed by presence of ZIKV RNA and/or IgM for ZIKV will also be enrolled, regardless of gestational age. Participants will be tested monthly for ZIKV infection; additional demographic, physical, laboratory and environmental data will be collected to assess the potential interaction of these variables with ZIKV infection. Delivery outcomes and detailed infant assessments, including physical and neurological outcomes, will be obtained.
Discussion
With the emergence of ZIKV in the Americas and its association with adverse pregnancy outcomes in this region, a much better understanding of the spectrum of clinical outcomes associated with exposure to ZIKV during pregnancy is needed. This cohort study will provide information about maternal, fetal, and infant outcomes related to ZIKV infection, including congenital ZIKV syndrome, and manifestations that are not detectable at birth but may appear during the first year of life. In addition, the flexibility of the study design has provided an opportunity to modify study parameters in real time to provide rigorous research data to answer the most critical questions about the impact of congenital ZIKV exposure.
Trial registration
NCT02856984
. Registered August 5, 2016. Retrospectively registered.
Journal Article
Quantitative Assessment of Human Motor Performance During Post-Earthquake Evacuation Using Virtual Reality
The 2020 earthquake in Puerto Rico exposed the need for effective evacuation strategies. This study used immersive virtual reality (VR) to safely examine how earthquake-related stress influences gait. A high-fidelity model of the Polytechnic University of Puerto Rico’s cafeteria was created using Revit and Unity, including dynamic elements like falling objects and earthquake sounds. Thirty healthy adults completed three walking trials: (1) normal walking without VR, (2) VR evacuation without an earthquake, and (3) VR evacuation following an earthquake simulation. Gait was recorded using the BTS GAITLAB, while anxiety was assessed via questionnaires and heart rate monitors. Although the VR earthquake simulation did not significantly increase group-level anxiety or heart rate, it revealed clear sex-specific gait adaptations. Males adopted a stabilization strategy with reduced joint variability, while females showed greater joint motion and reported higher simulator sickness. This research provides a foundation for developing VR-based evacuation systems that are both biomechanically valid and psychologically responsive.
Dissertation
The impact after 20 years of an early detection program for severe retinopathy of prematurity in a Latin American city
by
Cantor, Erika
,
Martínez-Blanco, Alexander M
,
Bonilla, Francisco
in
Demographic aspects
,
Diagnosis
,
Medical screening
2023
To evaluate the effects of long-standing early detection program in the incidence and trends of severe retinopathy of prematurity (ROP) in Cali, Colombia. This was a retrospective cohort study of infants included in an ROP prevention, early detection, and prompt treatment program, from January 01, 2002, to December 31, 2021 (20 years). Infants with gestational age (GA) <37 weeks or birth weight (BW) <2000 g and those with known ROP risk factors were screened. The incidence of severe ROP was calculated, and the average annual percent change (AAPC) was estimated through a joinpoint model. 16,580 infants were screened, with an average GA and BW of 31.4 ± 2.8 weeks and 1526.5 ± 56.7 g, respectively. The incidence of severe ROP was 2.69% (446 cases, 95% confidence interval [95%CI]: 2.45%; 2.95%), with an average annual decrease of - 14% (AAPC, 95%CI: -16.3%; -11.6%) from 13.6% in 2002 to 0.7% in 2021. In infants with GA <32 weeks, the incidence was 5.21%. A significant reduction in the risk of ROP was observed with increasing GA and BW (P 2000 g. Awareness and screening as part of the early detection program to prevent ROP has shown a significant decline in the incidence of severe ROP over time. Screening infants with GA <32 weeks or BW <2000 g and preterm infants (<37 weeks) with risk factors may be a feasible decision for resource optimization.
Journal Article
The impact after 20 years of an early detection program for severe retinopathy of prematurity in a Latin American city
by
Cantor, Erika
,
Martínez-Blanco, Alexander M
,
Bonilla, Francisco
in
Demographic aspects
,
Diagnosis
,
Medical screening
2023
To evaluate the effects of long-standing early detection program in the incidence and trends of severe retinopathy of prematurity (ROP) in Cali, Colombia. This was a retrospective cohort study of infants included in an ROP prevention, early detection, and prompt treatment program, from January 01, 2002, to December 31, 2021 (20 years). Infants with gestational age (GA) <37 weeks or birth weight (BW) <2000 g and those with known ROP risk factors were screened. The incidence of severe ROP was calculated, and the average annual percent change (AAPC) was estimated through a joinpoint model. 16,580 infants were screened, with an average GA and BW of 31.4 ± 2.8 weeks and 1526.5 ± 56.7 g, respectively. The incidence of severe ROP was 2.69% (446 cases, 95% confidence interval [95%CI]: 2.45%; 2.95%), with an average annual decrease of - 14% (AAPC, 95%CI: -16.3%; -11.6%) from 13.6% in 2002 to 0.7% in 2021. In infants with GA <32 weeks, the incidence was 5.21%. A significant reduction in the risk of ROP was observed with increasing GA and BW (P 2000 g. Awareness and screening as part of the early detection program to prevent ROP has shown a significant decline in the incidence of severe ROP over time. Screening infants with GA <32 weeks or BW <2000 g and preterm infants (<37 weeks) with risk factors may be a feasible decision for resource optimization.
Journal Article
A population of dust-enshrouded objects orbiting the Galactic black hole
by
Morris, Mark R.
,
Ghez, Andrea M.
,
Chu, Devin S.
in
639/33/34/4118
,
639/33/34/863
,
Astrophysics
2020
The central 0.1 parsecs of the Milky Way host a supermassive black hole identified with the position of the radio and infrared source Sagittarius A* (refs.
1
,
2
), a cluster of young, massive stars (the S stars
3
) and various gaseous features
4
,
5
. Recently, two unusual objects have been found to be closely orbiting Sagittarius A*: the so-called G sources, G1 and G2. These objects are unresolved (having a size of the order of 100 astronomical units, except at periapse, where the tidal interaction with the black hole stretches them along the orbit) and they show both thermal dust emission and line emission from ionized gas
6
–
10
. G1 and G2 have generated attention because they appear to be tidally interacting with the supermassive Galactic black hole, possibly enhancing its accretion activity. No broad consensus has yet been reached concerning their nature: the G objects show the characteristics of gas and dust clouds but display the dynamical properties of stellar-mass objects. Here we report observations of four additional G objects, all lying within 0.04 parsecs of the black hole and forming a class that is probably unique to this environment. The widely varying orbits derived for the six G objects demonstrate that they were commonly but separately formed.
The Galactic Centre is orbited by two objects that look like gas and dust clouds but behave more like stars, and now four additional similar objects are reported.
Journal Article
B cell activation and plasma cell differentiation are inhibited by de novo DNA methylation
2018
B cells provide humoral immunity by differentiating into antibody-secreting plasma cells, a process that requires cellular division and is linked to DNA hypomethylation. Conversely, little is known about how de novo deposition of DNA methylation affects B cell fate and function. Here we show that genetic deletion of the de novo DNA methyltransferases
Dnmt3a
and
Dnmt3b
(Dnmt3-deficient) in mouse B cells results in normal B cell development and maturation, but increased cell activation and expansion of the germinal center B cell and plasma cell populations upon immunization. Gene expression is mostly unaltered in naive and germinal center B cells, but dysregulated in Dnmt3-deficient plasma cells. Differences in gene expression are proximal to Dnmt3-dependent DNA methylation and chromatin changes, both of which coincide with E2A and PU.1-IRF composite-binding motifs. Thus, de novo DNA methylation limits B cell activation, represses the plasma cell chromatin state, and regulates plasma cell differentiation.
DNA methylation is known to contribute to B cell differentiation, but de novo methylation has not been studied in this context. Here the authors use a conditional Dnmt3a/b knockout mouse to map the function of de novo DNA methylation in B cell differentiation and the development of humoral immunity.
Journal Article