Di(2-ethylhexyl) phthalate (DEHP) and thyroid: biological mechanisms of interference and possible clinical implications

Head and neck squamous cell carcinoma (HNSCC) is a unique malignancy associated with two distinct risk factors: exposure to typical carcinogens and infection of human papillomavirus (HPV). HPV encodes the potent oncoproteins E6 and E7, which bypass many important oncogenic processes and result in cancer development. In contrast, HPV-negative HNSCC is developed through multiple mutations in diverse oncogenic driver genes. While the risk factors associated with HPV-positive and HPV-negative HNSCCs are discrete, HNSCC patients still show highly complex molecular signatures, immune infiltrations, and treatment responses even within the same anatomical subtypes. Here, we summarize the current understanding of biological mechanisms, treatment approaches, and clinical outcomes in comparison between HPV-positive and -negative HNSCCs.

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Within-Person Variation in Serum Thyrotropin Concentrations: Main Sources, Potential Underlying Biological Mechanisms, and Clinical Implications

Frontiers in Endocrinology ◽

10.3389/fendo.2021.619568 ◽

2021 ◽

Vol 12 ◽

Author(s):

Evie van der Spoel ◽

Ferdinand Roelfsema ◽

Diana van Heemst

Keyword(s):

Circadian Rhythm ◽

Clinical Practice ◽

Clinical Research ◽

Thyroid Stimulating Hormone ◽

Thyroid Peroxidase ◽

Clinical Implications ◽

Biological Mechanisms ◽

Serum Tsh ◽

Tsh Levels ◽

Over Time

BackgroundIndividuals exhibit fluctuations in the concentration of serum thyroid-stimulating hormone (TSH) over time. The scale of these variations ranges from minutes to hours, and from months to years. The main factors contributing to the observed within-person fluctuations in serum TSH comprise pulsatile secretion, circadian rhythm, seasonality, and ageing. In clinical practice and clinical research however, such within-person biological variation in serum TSH concentrations is often not considered. The aim of this review is to present an overview of the main sources of within-person variation in TSH levels, as well as the potential underlying biological mechanisms, and the clinical implications.SummaryIn euthyroid individuals, the circadian rhythm, with a nocturnal surge around 02:00–04:00 h and a nadir during daytime has the greatest impact on variations in serum TSH concentrations. Another source of within-person variation in TSH levels is seasonality, with generally higher levels during the cold winter months. Since TSH is secreted in a pulsatile manner, TSH levels also fluctuate over minutes. Furthermore, elevated TSH levels have been observed with ageing. Other factors that affect TSH levels include thyroid peroxidase (TPO)-antibody positivity, BMI, obesity, smoking, critical illness, and many xenobiotics, including environmental pollutants and drugs. Potential underlying biological mechanisms of within-person variation in TSH levels can be safely concluded from the ability of TSH to respond quickly to changes in cues from the internal or external environment in order to maintain homeostasis. Such cues include the biological clock, environmental temperature, and length of day. The observed increase in TSH level with ageing can be explained at a population level and at an organism level. In clinical practice, the season for thyroid testing can influence a patient’s test result and it occurs frequently that subclinical hypothyroid patients normalize to euthyroid levels over time without intervention.ConclusionsSerum TSH concentrations vary over time within an individual, which is caused by multiple different internal and external factors. It is important to take the within-person variations in serum TSH concentrations into account when testing a patient in clinical practice, but also in performing clinical research.

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Sex differences in ADHD

10.1093/med/9780198739258.003.0016 ◽

2018 ◽

Cited By ~ 1

Author(s):

Corina U. Greven ◽

Jennifer S. Richards ◽

Jan K. Buitelaar

Keyword(s):

Sex Differences ◽

Sex Chromosome ◽

Neurocognitive Functioning ◽

Future Research ◽

Clinical Implications ◽

Biological Mechanisms ◽

Brain Structure And Function ◽

Endocrine Factors ◽

And Function ◽

Pituitary Adrenal Axis

This chapter reviews sex differences in ADHD, focusing on differences in prevalence, comorbidity, and impairment, and discusses potential mechanisms underlying these differences. ADHD is more common in males than females (sex ratio ~3:1). Males with ADHD show greater comorbidity with comorbid externalizing (conduct) problems, while females with ADHD show internalizing problems. Females with ADHD may experience greater subjective impairment than males with ADHD. Referral and diagnostic issues, relating to sex-specific display of ADHD symptoms (more overt and disruptive in males, more subtle in females), underdiagnosis, or misdiagnosis in girls, as well as biases due to informant source, likely contribute to sex differences in ADHD. Potential biological mechanisms include endocrine factors (testosterone, glucocorticoids, and hypothalamic–pituitary–adrenal axis activation differences), aetiological sex differences (sex-chromosome genes), sex differences in neurocognitive functioning, and differences in brain structure and function. The chapter provides an outlook for future research and clinical implications.

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The level of manganese superoxide dismutase content is an independent prognostic factor for glioblastoma. Biological mechanisms and clinical implications

British Journal of Cancer ◽

10.1054/bjoc.2000.1594 ◽

2001 ◽

Vol 84 (4) ◽

pp. 529-534 ◽

Cited By ~ 29

Author(s):

F Ria ◽

M Landriscina ◽

F Remiddi ◽

R Rosselli ◽

M Iacoangeli ◽

...

Keyword(s):

Superoxide Dismutase ◽

Prognostic Factor ◽

Manganese Superoxide Dismutase ◽

Independent Prognostic Factor ◽

Clinical Implications ◽

Biological Mechanisms ◽

Manganese Superoxide

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Adolescent suicide and testosterone

International Journal of Adolescent Medicine and Health ◽

10.1515/ijamh-2015-0058 ◽

2015 ◽

Vol 29 (4) ◽

Cited By ~ 5

Author(s):

Timothy R. Rice ◽

Leo Sher

Keyword(s):

Emotion Regulation ◽

Adolescent Suicide ◽

Relevant Literature ◽

Neural System ◽

Regulation System ◽

Clinical Implications ◽

Biological Mechanisms ◽

Specific Effects ◽

Completed Suicide ◽

Male Sex

Abstract Completed suicide is much more common in men than in women. Its incidence rises precipitously in adolescence. One biological hypothesis that accounts for the increased frequency of completed suicide in men is that the male sex hormone testosterone partially mediates the observed increase in suicide frequency among men. It is the aim of this communication to review the relevant literature and to describe putative biological mechanisms for this association. Specifically, we propose that the impairment wrought by of high levels of testosterone in the adolescent upon the emotion regulation system contribute to an account for these findings. Herein, we describe this neural system and the specific effects of testosterone upon the system. We conclude with a discussion of clinical implications and applications with an aim of stimulating further research.

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