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1.
Bone ; 178: 116930, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37844715

RESUMEN

PURPOSE: To investigate the skeletal phenotype of adolescent girls with premature ovarian insufficiency (POI). METHODS: Data are presented from two adolescent girls who participated in a clinical research protocol to evaluate axial bone mineral density (BMD) (via dual-energy x-ray absorptiometry, DXA) and appendicular bone density, microarchitecture, and strength (via high-resolution peripheral quantitative computed tomography, HRpQCT). Anthropometric data were also obtained, and pubertal staging was performed by a clinician. RESULTS: Both cases presented with an undetectable estradiol concentration and an elevated follicle stimulating hormone (FSH), meeting the criteria for POI. Each also received alkylating agents as part of their chemotherapy and radiotherapy, but in different locations as one presented with stage IV neuroblastoma and the other, metastatic medulloblastoma. Both had a low BMD of the axial and appendicular skeleton, as well as microarchitectural changes of the latter. The low BMD Z-score (<-2.0) seen when interpreting their DXA measurements for chronological age improved when adjusted for short stature, but it was not normalized. Lastly, most variables obtained by HRpQCT were abnormal for each participant, indicating that appendicular bone structure and strength were compromised. CONCLUSIONS: Chemotherapy and radiation affect growth, puberty, and bone accrual deleteriously. However, as these cases show, POI in an adolescent is not always classic primary ovarian insufficiency. Adolescents with brain cancer can present with signs of estrogen deficiency but may not be able to secrete FSH to the extent of elevation typically seen in long-term cancer survivors. Estrogen deficiency is almost universally present in either clinical setting and prompt recognition facilitates early provision of hormone replacement therapy that may then allow for a resumption of bone accrual as an adolescent approaches her peak bone mass.


Asunto(s)
Supervivientes de Cáncer , Hipogonadismo , Neoplasias , Insuficiencia Ovárica Primaria , Humanos , Adolescente , Femenino , Densidad Ósea , Insuficiencia Ovárica Primaria/complicaciones , Insuficiencia Ovárica Primaria/diagnóstico , Absorciometría de Fotón , Hormona Folículo Estimulante , Estrógenos
2.
Ann Fam Med ; 21(4): 344-346, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37487718

RESUMEN

The human papillomavirus (HPV) vaccine is the most expensive of all routinely recommended pediatric vaccines. Adequate cost reimbursement by 3rd-party payers is a critical enabling factor for clinicians to continue offering vaccines. This study found that net returns from HPV vaccine cost reimbursements are lowest for family physicians ($0.34/dose) and highest for pediatricians ($5.08/dose). Furthermore, a $1 increment in return was associated with an increase in HPV vaccine doses administered (highest for family physicians; 0.08% per dollar). Reimbursement for HPV vaccine costs by private payers is adequate; however, return margins are small for non-pediatric specialties.


Asunto(s)
Medicina , Vacunas contra Papillomavirus , Humanos , Niño , Sector Privado , Médicos de Familia , Vacunación
3.
Artículo en Inglés | MEDLINE | ID: mdl-31316462

RESUMEN

Thyroid hormone (T3) plays several key roles in development of the nervous system in vertebrates, controlling diverse processes such as neurogenesis, cell migration, apoptosis, differentiation, and maturation. In anuran amphibians, the hormone exerts its actions on the tadpole brain during metamorphosis, a developmental period dependent on T3. Thyroid hormone regulates gene transcription by binding to two nuclear receptors, TRα and TRß. Our previous findings using pharmacological and other approaches supported that TRα plays a pivotal role in mediating T3 actions on neural cell proliferation in Xenopus tadpole brain. Here we used Xenopus tropicalis (X. tropicalis) tadpoles with an inactivating mutation in the gene that encodes TRα to investigate roles for TRα in mitosis and gene regulation in tadpole brain. Gross morphological analysis showed that mutant tadpoles had proportionally smaller brains, corrected for body size, compared with wildtype, both during prometamorphosis and at the completion of metamorphosis. This was reflected in a large reduction in phosphorylated histone 3 (pH3; a mitosis marker) immunoreactive (ir) nuclei in prometamorphic tadpole brain, when T3-dependent cell proliferation is maximal. Treatment of wild type premetamorphic tadpoles with T3 for 48 h induced gross morphological changes in the brain, and strongly increased pH3-ir, but had no effect in mutant tadpoles. Thyroid hormone induction of the direct TR target genes thrb, klf9, and thibz was dysregulated in mutant tadpoles. Analysis of gene expression by RNA sequencing in the brain of premetamorphic tadpoles treated with or without T3 for 16 h showed that the TRα accounts for 95% of the gene regulation responses to T3.

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