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Biomedical subjects

Marta Alonso

Publications and source records attributed to Marta Alonso.

11 recordsLinked to original sources

A Boveri perspective on cancer biomarker testing using artificial intelligence.

Artificial intelligence (AI) can predict genomic alterations from histology, yet its adoption is slowed by a lack of trust. We argue that deliberate morphology (i.e., a cognitive understanding of histological features supported by standardized annotations) creates a bidirectional feedback loop between clinical practice and model outputs.We translate these observations into an actionable hypothesis for clinical and computational teams: that by enhancing explainability, deliberate morphology could facilitate the responsible deployment of AI biomarkers in oncology.

Journal Article↗

Suicidal risk in bipolar I disorder patients and adherence to long-term lithium treatment.

OBJECTIVES: Among the well-established treatments for bipolar disorder (BPD), lithium continues to offer an unusually broad spectrum of benefits that may include reduction of suicidal risk. METHODS: We examined the association of suicidal acts with adherence to long-term lithium maintenance treatment and other potential risk factors in 72 BP I patients followed prospectively for up to 10 years at a Mood Disorders Research Center in Spain. RESULTS: The observed rates of suicide were 0.143, and of attempts, 2.01%/year, with a 5.2-fold (95% CI: 1.5-18.6) greater risk among patients consistently rated poorly versus highly adherent to lithium prophylaxis (11.4/2.2 acts/100 person-years). Treatment non-adherence was associated with substance abuse, being unmarried, being male, and having more hypomanic-manic illness and hospitalizations. Suicidal risk was higher with prior attempts, more depression and hospitalization, familial mood disorders, and being single and younger, as well as treatment non-adherence, but with neither sex nor substance abuse. In multivariate analysis, suicidal risk was associated with previous suicidality > poor treatment adherence > more depressive episodes > younger age. CONCLUSIONS: The findings support growing evidence of lower risk of suicidal acts during closely monitored and highly adherent, long-term treatment with lithium and indicate that treatment adherence is a potentially modifiable factor contributing to antisuicidal benefits.

Adult↗

The ability of Mycobacterium avium subsp. paratuberculosis to enter bovine epithelial cells is influenced by preexposure to a hyperosmolar environment and intracellular passage in bovine mammary epithelial cells.

Mycobacterium avium subsp. paratuberculosis is the cause of Johne's disease in cattle and other ruminants. M. avium subsp. paratuberculosis infection of the bovine host is not well understood; however, it is assumed that crossing the bovine intestinal mucosa is important in order for M. avium subsp. paratuberculosis to establish infection. To examine the ability of M. avium subsp. paratuberculosis to infect bovine epithelial cells in vitro, Madin-Darby bovine kidney (MDBK) epithelial cells were exposed to M. avium subsp. paratuberculosis. It was observed that bacteria can establish infection and replicate within MDBK cells. M. avium subsp. paratuberculosis also has been reported to infect mammary tissue and milk, and we showed that M. avium subsp. paratuberculosis infects bovine mammary epithelial cells (MAC-T cell line). Using polarized MAC-T cell monolayers, it was also determined that M. avium subsp. paratuberculosis crosses apical and basolateral surfaces with approximately the same degree of efficiency. Because M. avium subsp. paratuberculosis can be delivered to the naïve host by milk, it was investigated whether incubation of M. avium subsp. paratuberculosis with milk has an effect on invasion of MDBK cells. M. avium subsp. paratuberculosis exposed to milk entered epithelial cells with greater efficiency than M. avium subsp. paratuberculosis exposed to broth medium or water (P < 0.01). Growth of M. avium subsp. paratuberculosis within MAC-T cells also resulted in augmented ability to subsequently infect bovine MDBK cells (P < 0.001). Microarray analysis of intracellular M. avium subsp. paratuberculosis RNA indicates the increased transcription of genes which might be associated with an invasive phenotype.

Animals↗

Comparative effect of oncolytic adenoviruses with E1A-55 kDa or E1B-55 kDa deletions in malignant gliomas.

Replication-competent oncolytic adenoviruses hold considerable promise for treating malignant gliomas. The toxicity of the clinically tested E1B-55 kDa mutant virus is negligible; however, its full clinical potential is still being evaluated. The purpose of the present study is to compare the antiglioma activity in vitro and in vivo between Delta-24, an E1A mutant adenovirus, and RA55, an E1B-55 kDa mutant adenovirus. We selected human glioma cell lines that were tumorigenic in nude mice and express wild-type p53 (U-87 MG, D54 MG) or mutant p53 (U-251 MG, U-373 MG) protein. Our studies demonstrated that Delta-24 induced a more potent antiglioma effect in vitro than RA55. Moreover, Delta-24 replicated markedly more efficiently than RA55 in both wild-type and mutant p53 scenarios. Importantly, direct intratumoral injection of Delta-24, but not RA55, significantly suppresses tumor growth in intracranial (U-87 MG, U-251 MG) or subcutaneous (D54 MG) animal models. Staining for hexon protein detected replicating adenoviruses in xenografts infected with Delta-24, but not with RA55. Collectively, these data indicate that E1A mutant adenoviruses targeting the Rb pathway are more powerful putative agents for antiglioma therapy than E1B mutant adenoviruses, and suggest that E1A mutant adenoviruses should be tested in the clinical setting for patients with malignant gliomas.

Adenoviridae↗

A novel E1A-E1B mutant adenovirus induces glioma regression in vivo.

Malignant gliomas are the most frequently occurring primary brain tumors and are resistant to conventional therapy. Conditionally replicating adenoviruses are a novel strategy in glioma treatment. Clinical trials using E1B mutant adenoviruses have been reported recently and E1A mutant replication-competent adenoviruses are in advanced preclinical testing. Here we constructed a novel replication-selective adenovirus (CB1) incorporating a double deletion of a 24 bp Rb-binding region in the E1a gene, and a 903 bp deleted region in the E1b gene that abrogates the expression of a p53-binding E1B-55 kDa protein. CB1 exerted a potent anticancer effect in vitro in U-251 MG, U-373 MG, and D-54 MG human glioma cell lines, as assessed by qualitative and quantitative viability assays. Replication analyses demonstrated that CB1 replicates in vitro in human glioma cells. Importantly, CB1 acquired a highly attenuated replicative phenotype in both serum-starved and proliferating normal human astrocytes. In vivo experiments using intracranially implanted D-54 MG glioma xenografts in nude mice showed that a single dose of CB1 (1.5 x 10(8) PFU/tumor) significantly improved survival. Immunohistochemical analyses of expressed adenoviral proteins confirmed adenoviral replication within the tumors. The CB1 oncolytic adenovirus induces a potent antiglioma effect and could ultimately demonstrate clinical relevance and therapeutic utility.

Adenovirus E1A Proteins↗

Fine-tuned aminal cleavage: a concise route to differentially protected enantiopure syn-alpha,beta-diamino Esters.

A survey of routes for aminal cleavage of N-sulfinylimidazolidines has been carried out, and selective conditions to cleave the aminal moiety while preserving the sulfinamide group unaltered have been found. Thus, the treatment of enantiopure N-sulfinylimidazolidines with aqueous H(3)PO(4) in THF affords enantiopure N-sulfinyldiamino esters in excellent yields, while the presence of MeOH as cosolvent allows for the simultaneous removal of the sulfinamide group and aminal cleavage. The behavior of these substrates in a variety of chemical transformations has been explored.

Amines↗

The NV gene of snakehead rhabdovirus (SHRV) is not required for pathogenesis, and a heterologous glycoprotein can be incorporated into the SHRV envelope.

Snakehead rhabdovirus (SHRV) affects warm-water fish in Southeast Asia and belongs to the genus Novirhabdovirus by virtue of its "nonvirion" (NV) gene. To examine the function of the NV gene, we used a recently developed reverse genetic system to produce a viable recombinant SHRV carrying an NV gene deletion. The recombinant virus was produced at the same rate and same final concentrations as the wild-type virus in cultured fish cells in spite of the NV gene deletion. The role of the NV protein in fish pathogenesis was also investigated. Zebra fish (Danio rerio) were infected with the NV deletion mutant or with a recombinant virus containing a copy of the SHRV genome, and similar mortality rates as well as final mortalities were recorded, suggesting no apparent role for the NV protein in fish pathogenesis. Interestingly, the unsuccessful rescue of fully viable recombinants with genomes containing deletions in the G/NV gene junction suggested a role for the gene junction in virus transcription and replication. Finally, we demonstrated that the SHRV glycoprotein can be replaced by the glycoprotein of infectious hematopoietic necrosis virus (IHNV) or by a hybrid protein composed of SHRV and IHNV sequences.

Animals↗

Highly diastereoselective[3+2] cycloadditions between nonracemic p-tolysulfinimines and iminoesters: an efficient entry to enantiopure imidazolidines and vicinal diaminoalcohols.

A new procedure for the asymmetric synthesis of imidazolidines and vicinal diamines is reported. The 1,3-dipolar cycloaddition between nonracemic p-tolylsulfinimines and azomethine ylides generated in situ from alpha-iminoesters and LDA produces N-sulfinylimidazolidines with a high degree of stereocontrol. In contrast, the presence of Lewis acids promotes formation of the cycloadducts through a highly diastereoselective process with opposite stereochemistry. Subsequent transformations of the imidazolidines including oxidative, reductive, and hydrolytic processes that provide easy access to vicinal diaminoalcohols have been explored. Among these, reductive cleavage of the aminal with LiAlH4 is an extremely efficient and general reaction for the synthesis of enantiopure N-sulfinyl-N'-benzyldiaminoalcohols

Journal Article↗

A fish specific expression vector containing the interferon regulatory factor 1A (IRF1A) promoter for genetic immunization of fish.

DNA plasmid vectors were constructed with inducible rainbow trout promoters to take the place of the cytomegalovirus immediate early promoter in DNA vaccines for fish. DNA fragments containing the promoter regions upstream of the rainbow trout Mx1 and interferon regulatory factor 1A (IRF1A) genes were obtained and their nucleotide sequences were determined. Vectors containing the G gene of IHNV linked to the trout promoters were found to be very effective as vaccines in rainbow trout. In addition, we demonstrated that the IRF1A promoter is transcriptionally active in mouse cells NIH-3T3 suggesting that this fish promoter might be used for mammalian DNA vaccine development as well.

3T3 Cells↗

Suppressive subtraction libraries to identify interferon-inducible genes in fish.

Previous attempts to identify genes in fish that respond to virus infection or interferon induction have not been particularly productive. Since these genes are very important in developing strategies to control disease outbreaks in aquaculture, we began a study of interferon-inducible genes in fish using suppressive subtraction hybridization to construct cDNA libraries enriched for interferon-inducible genes. Subtraction hybridization libraries were constructed with cDNA obtained from the kidney, spleen, and liver of Chinook salmon (Oncorhynchus tshawytscha) and staghorn sculpin (Hemilepidotus spinosus) before and after injection with poly IC, a potent interferon inducer. The "identified" genes in both cDNA libraries corresponded to previously identified genes of the fish complement system, the interferon-inducible proteins observed in mammalian cells, and the Vig-1 gene, identified in fish cells after infection with fish rhabdoviruses.

Journal Article↗