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Biomedical subjects

Enrique Medina-Acosta

Publications and source records attributed to Enrique Medina-Acosta.

10 recordsLinked to original sources

A pan-cancer multi-omic SuperLearner for regulated cell death survival topologies.

INTRODUCTION: Regulated cell death (RCD) pathways influence tumor progression and immune modulation. We previously constructed a signature database mapping 25 RCD forms across seven multi-omic layers and 33 tumor types (CancerRCDShiny). Despite their ability to identify risk populations, translating these signatures into personalized clinical workflows requires a shift from cohort stratification to individualized risk mapping by modeling patient risk (survival topologies) to capture the non-linear dynamics of RCD signatures. METHODS: We engineered a pan-cancer multi-omic SuperLearner pipeline across 33 cancer types. Phase I performed zero-leakage harmonization and groupwise imputation to prevent cross-cohort amalgamation. Phase II deployed Elastic Net-regularized Cox regression as a CANARY diagnostic to map proportional hazards failures. Strata with a 35% missingness barrier entered Phase III, deploying a Quadripartite ensemble: Random Survival Forests, XGBoost, Survival-Boruta, and Multi-Task Logistic Regression, fused within an Elastic Net Multi-View Meta-Learner (MVL), with post-hoc TreeSHAP and LIME interpretability. RESULTS: The CANARY diagnostic demonstrated the structural invalidity of pan-cancer geometric proportional hazards. Across 96 admissible strata, Phase III executed algorithmic displacement: continuous multi-omic topologies suppressed static genomic mutations and copy number variations (85.7% vs. 0.0% apex retention). The MVL stabilized predictions against extreme variance; LIME surrogate validations (R 2&#x202f;<&#x202f;0.10) confirmed the systematic failure of linear interpretative proxies. N-dimensional TreeSHAP interaction mapping exposed synergistic and antagonistic rescue trajectories defining individualized Survival Topologies, which were invisible to additive models. The architecture was deployed as CancerRCDPredictor, a digital molecular tumor board with integrated LLM capabilities. The MVL SuperLearner achieved a median C-index of 0.749 (IQR: 0.722-0.836) across 96 modelable strata, with 95% bootstrap confidence intervals confirming precision (median width: 0.052) and permutation significance in 93.8% of strata (p&#x202f;<&#x202f;0.001). External CPTAC validation across ten cancer types demonstrated significant cross-cohort generalizability in clear cell renal carcinoma (KIRC; C-index 0.675, p&#x202f;=&#x202f;0.017) and modest performance across the remaining adequately powered cancers (median 0.582), underscoring the need for larger multi-institutional validation cohorts. CONCLUSION: This pan-cancer multi-omic SuperLearner bypasses linear topological failures, advancing beyond generalized stratification to establish a deterministically mapped architecture for predicting RCD-related survival topologies. Through the CancerRCDPredictor interface, multi-omic insights translate into individualized survival topology exploration, providing a foundation for future precision oncology validation.

SuperLearner↗

[Prevention of vertical HIV transmission in Campos dos Goytacazes, Rio de Janeiro, Brazil].

Prevention of mother-to-child HIV transmission is an emerging public health challenge. In Brazil, preventive prophylaxis with AZT during pregnancy, at delivery, and for newborns was introduced in 1996, with a marked reduction in transmission (less than 5.0% nationwide). Since 1999 the Municipal STD/AIDS Program in Campos dos Goytacazes, Rio de Janeiro State (population = 416,441) has acted in the prevention of vertical transmission. In 2001/2003, there was a moderately increased implementation (from 28.0% to 36.0%) of HIV screening services during pregnancy, and more pregnant women were knowledgeable about vertical HIV transmission. Remaining challenges are to expand HIV screening to pregnant women at large and to effectively introduce rapid diagnostic tests for HIV in the delivery room. Such actions are expected to change the current situation, in which only 6.8% of infected children under observation had access to prophylaxis for vertical HIV transmission.

Adult↗

Suitability of a recombinant Staphylococcus aureus enterotoxin C bovine variant for immunodiagnostics and therapeutic vaccine development.

Recombinant bovine variant of staphylococcal enterotoxin C (SECbovine), produced as a NH2-terminal histidine hexamer fusion protein (His6-tagged SECbovine), expressed at high levels (25%) in Escherichia coli and affinity purified to homogeneity (99.9%), was tested for its diagnostic and therapeutic potentials. His6-tagged SECbovine is antigenically authentic to native SECbovine across host species, as confirmed by antibody-based capture detection assays using human, mouse, rabbit and chicken hyperimmune sera. His6-tagged SECbovine showed significant T-cell stimulation activity in vitro. His6-tagged SECbovine was immunogenic for IgG in mice (intragastric and intravenous routes) and rabbits (intramuscular and subcutaneous routes), dispensing immunoadjuvant coadministration. The formation of neutralizing antibodies reduced the severity of intoxication symptoms in immunized rabbits. Purified anti-recombinant SECbovine rabbit polyclonal IgG neutralized the pyrexic and diarrhoeagenic effects of native SEC/SED and recombinant SEC, tested by the kitten and rabbit bioassays, respectively.

Animals↗

Coproantibodies to the enteropathogenic Escherichia coli vaccine candidates BfpA and EspB in breastfed and artificially fed children.

A diagnostic test was developed to discriminate active from past enteropathogenic Escherichia coli (EPEC) infection, which uses the affinity-purified recombinant proteins BfpA (bundle-forming pilus (BFP) structural repeating subunit A) and EspB (pore-forming secreted protein B) as reliable markers of virulence to detect antigen-specific coproantibodies by immunoblot analysis, and verification of active typical EPEC infection by gene-specific (bfpA and espB) PCR amplification using DNA extracted directly from specimens and/or culture-enriched preparations. To begin addressing the potential protective role of anti-EPEC antibodies at early age, the prevalence of IgA coproantibodies to these antigens was determined in either breastfed or artificially fed children <2 years of age hospitalized for watery diarrhea.

Antibodies, Bacterial↗

Prevention of lethal murine candidiasis using HP (2-20), an antimicrobial peptide derived from the N-terminus of Helicobacter pylori ribosomal protein L1.

Peptide HP (2-20), A(2)KKVFKRLEKLFSKIQNDK(20), is a cationic antimicrobial peptide derived from the N-terminus of Helicobacter pylori ribosomal protein 1, HpRpL1. Native peptide HP (2-20) and its synthetic derivatives have been shown in vitro to exhibit potent killing activity against Gram-positive, Gram-negative and yeast cells, thus, making them promising candidates for treatment of polymicrobial infections. However, the therapeutic potential of peptide HP (2-20) or its synthetic derivatives in any animal model of either bacterial or fungal diseases has not yet been investigated. In this study, we demonstrate that synthetic peptide amide HP (2-20), administered in six doses (300microg each; one intraperitoneal dose at the time of the infection, followed by five intravenous doses at 12h intervals) to CBA/J male mice experimentally infected with a lethal inoculum ( [Formula: see text] CFU) of Candida albicans, delayed the onset of disease, suppressed disease progression, and greatly increased survival rate and time (16.6% by day 14), as compared with the untreated infected control mice (100% mortality by day 5). Further, using isotonic buffer systems differing in ionic strength, peptide HP (2-20) was shown in vitro to exhibit an ionic strength-dependent hemolytic activity, previously not detected. Repeated intravenous administration of uninfected control CBA/J male mice with peptide HP (2-20), however, caused neither morbidity nor mortality. These findings strongly evidence the therapeutic efficacy and safety values of peptide HP (2-20) as a lead drug for the treatment of acquired candidiasis.

Animals↗

Treatment efficacy of the lead RNAIII-inhibiting peptide YSPWTNF-NH2 in acquired Staphylococcus aureus sepsis: a histopathological assessment.

The quorum-sensing interfering RNAIII-inhibiting peptide (RIP) YSPXTNF and its synthetic analogues YSPWTNF and YSPITNF have been shown to prevent and suppress diseases caused by Staphylococcus aureus at different body sites in different animal models. This study was designed to investigate histopathologically the therapeutic efficacy of lead peptide RIP YSPWTNF-NH(2) in the subcutaneous air sac murine model of acquired S. aureus sepsis. Two experimental protocols were evaluated: an infection/therapy protocol, for which twenty BALB/c mice per group were infected with a subcutaneous inoculum of S. aureus strain ATCC 25923 ( [Formula: see text] colony forming units) that were either pretreated or not with 150microg of peptide RIP, and a safety protocol, for which three uninfected mice per group received treatment with either 150microg of peptide RIP or saline. Therapeutic efficacy was assessed by clinical examination for a period of 20 days and histopathology at 12, 24, 36, 48, 96 and 168h after inoculation. Treatment safety was assessed histopathologically at 24, 48 and 264h after inoculation. Subcutaneous administration of uninfected control mice with a single dose of peptide RIP YSPWTNF caused no significant histopathology in most organs examined, except for slight to moderate lung and liver congestions. In contrast to the situation with the untreated infected control group mice that presented with histopathological alterations consistent with the diagnosis of rapidly progressive and highly erosive disease (100% mortality by day 3), treatment of infected animals with peptide RIP YSPWTNF had a profound therapeutic effect on survival rate (67% by day 20) and on disease progression. The histopathological examination confirmed the clinical findings showing that extensive tissue damage at the site of the infection and in organs were greatly suppressed in the peptide RIP-treated animals.

Animals↗

Antibody responsiveness to the enteropathogenic Escherichia coli bundle-forming pilus subunit A in lactating mothers and asymptomatic children.

UNLABELLED: The objective of this study was to examine the antibody responsiveness to the bundle-forming pilus subunit A of enteropathogenic Escherichia coli in human colostrum (n = 36) and serum (n = 90) of paediatric ambulatory patients, 3-24 months of age. Affinity purified recombinant bundle-forming pilus subunit A was used in immunoblot analysis to detect antigen-specific serum immunoglobulins G and A, and colostrum immunoglobulin A. Circulating immunoglobulin G antibody activity to the bundle-forming pilus subunit A was readily detected in all children. The frequency of immunoglobulin A antibody activity to the bundle-forming pilus subunit A in serum was 83.3%. Immunoglobulin A antibody activity to the bundle-forming pilus subunit A was detected in 75% of colostrum samples. The high frequency of immunoglobulin A antibody activity to the bundle-forming pilus subunit A observed in serum reveals a predominance of typical enteropathogenic Escherichia coli priming/infection in the study population. CONCLUSION: these findings demonstrate that the bundle-forming pilus subunit A is immunogenic, for both immunoglobulins G and A, in both pregnant/lactating women and asymptomatic children.

Adolescent↗

Phytosecretion of enteropathogenic Escherichia coli pilin subunit A in transgenic tobacco and its suitability for early life vaccinology.

A plant expression cassette system was engineered to efficiently target proteins to the default secretory pathway, allowing the expression of DNA inserts in three frames as fusion proteins containing a synthetic tobacco calreticulin cleavable signal peptide sequence, with the advantage of producing the recombinant proteins by phytosecretion. As one approach to develop a vaccine to enteropathogenic Escherichia coli (EPEC) infection, the oral immunogenicity of phytosecreted BfpA, the structural subunit A of the bundle-forming pilus, expressed at high levels (7.7% of soluble protein) in transgenic tobacco tissues, was demonstrated in BALB/c mice by the induction and detection of fecal anti-BfpA antibodies.

Administration, Oral↗

Expression and purification of the recombinant enteropathogenic Escherichia coli vaccine candidates BfpA and EspB.

BfpA, the structural repeating protein subunit A of the bundle-forming pilus and EspB, a type-III-secreted pore-forming protein of enteropathogenic Escherichia coli (EPEC), both virulence factors central for EPEC pathogenesis, were overexpressed in E. coli DH5alpha and M15 laboratory strains, respectively, using the pQE-30 cloning expression system, as chimeric fusions to a NH(2)-terminal histidine hexapeptide (His(6)-tag) sequence. After isopropyl beta-d-thiogalactoside induction, the expression levels achieved were 11 and 40% of total soluble protein for BfpA and EspB, respectively. The His(6)-tagged recombinant proteins were purified (up to 98% homogeneity) by Ni-agarose affinity chromatography and produced yields varying from 0.65 to 3.1 mg of recombinant protein per gram of wet weight cells. The immunogenicity and antigenicity of the final products were tested in rabbits and using fecal specimens obtained from children suffering from acute watery diarrhea, respectively. The recombinant products correspond to antigenically authentic protein standards, useful in future epidemiological and neonatal vaccinology studies.

Animals↗

Prevalent transfer of human colostral IgA antibody activity for the enteropathogenic Escherichia coli bundle-forming pilus structural repeating subunit A in neonates.

The frequency of IgA antibody activity to the structural protein subunit BfpA of the enteropathogenic Escherichia coli bundle-forming pilus was determined in 40 mother-infant pairs by immunoblot analysis using affinity purified recombinant BfpA to monitor for IgA in maternal colostrum and in feces of the neonates. Fecal samples were collected from exclusively breastfed term infants < 24-h after the first breastmilk feeding and colostral samples from their mothers. Infants were monitored prospectively with monthly visits to ascertain dietary practices and diarrheal illnesses. The percentage of colostral anti-BfpA IgA positive patients that were also coproantibody positive was 67.5%. The median duration of lactation was 108 days and the incidence of infantile diarrheal disease was 7.5%. Thus, colostral anti-BfpA IgA antibody activity survives passage through the gut of breastfed neonates, persisting in their feces. It is suggested that oral passive immunotherapy may be used to prevent and/or treat typical EPEC infection during infancy.

Adolescent↗