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Indian Journal of Pediatrics Oct 2023Enlargement of breasts among boys is termed gynecomastia. This could be due to an alteration in the androgen-estrogen ratio along with the effects of other hormones... (Review)
Review
Enlargement of breasts among boys is termed gynecomastia. This could be due to an alteration in the androgen-estrogen ratio along with the effects of other hormones including growth hormone, insulin like growth factor 1, prolactin, and other factors affecting aromatase enzyme. The common causes of gynecomastia are pubertal gynecomastia, obesity, drugs and hypogonadism. Several other diseases including liver or renal failure, thyrotoxicosis, Klinefelter syndrome, tumors and environmental pollutants can cause gynecomastia. History and clinical examination will help formulate targeted investigations and management. The factors to be evaluated in these include examination of breasts and testes, in addition to other parts of systemic examination. Treatment of underlying disorders can improve gynecomastia, such as use of testosterone in hypogonadism. Some boys may not need any intervention as gynecomastia may resolve on its own. Medical management is useful in simple gynecomastia. Tamoxifen has been tried successfully in adolescents with gynecomastia. Other drugs including clomiphene, danazol, letrozole and anastrozole have not been consistently useful in this age group. In severe chronic gynecomastia, surgery is the treatment of choice.
Topics: Adolescent; Male; Humans; Gynecomastia; Hypertrophy; Tamoxifen; Growth Hormone; Hypogonadism
PubMed: 37592101
DOI: 10.1007/s12098-023-04810-7 -
Nature Reviews. Immunology Feb 2024Cells can die as a consequence of being phagocytosed by other cells - a form of cell death that has been called phagotrophy, cell cannibalism, programmed cell removal... (Review)
Review
Cells can die as a consequence of being phagocytosed by other cells - a form of cell death that has been called phagotrophy, cell cannibalism, programmed cell removal and primary phagocytosis. However, these are all different manifestations of cell death by phagocytosis (termed 'phagoptosis' for short). The engulfed cells die as a result of cytotoxic oxidants, peptides and degradative enzymes within acidic phagolysosomes. Cell death by phagocytosis was discovered by Metchnikov in the 1880s, but was neglected until recently. It is now known to contribute to developmental cell death in nematodes, Drosophila and mammals, and is central to innate and adaptive immunity against pathogens. Cell death by phagocytosis mediates physiological turnover of erythrocytes and other leucocytes, making it the most abundant form of cell death in the mammalian body. Immunity against cancer is also partly mediated by macrophage phagocytosis of cancer cells, but cancer cells can also phagocytose host cells and other cancer cells in order to survive. Recent evidence indicates neurodegeneration and other neuropathologies can be mediated by microglial phagocytosis of stressed neurons. Thus, despite cell death by phagocytosis being poorly recognized, it is one of the oldest, commonest and most important forms of cell death.
Topics: Animals; Humans; Cell Death; Phagocytosis; Microglia; Macrophages; Neurons; Mammals
PubMed: 37604896
DOI: 10.1038/s41577-023-00921-6 -
Current Biology : CB Dec 2023Dyneins are a family of motor proteins that carry out motility and force generation functions towards the minus end of microtubule filaments. Cytoplasmic dynein...
Dyneins are a family of motor proteins that carry out motility and force generation functions towards the minus end of microtubule filaments. Cytoplasmic dynein (dynein-1) is responsible for transporting intracellular cargos in the retrograde direction in the cytoplasm, anchoring several organelles to the microtubule network, driving nuclear migration in developing neurons, and orienting the mitotic spindle in dividing cells. All other dyneins are localized to cilia. Similar to dynein-1, dynein-2 walks along microtubules and drives intraflagellar transport in the retrograde direction. Other ciliary dyneins are positioned between adjacent microtubule doublets of the axoneme and power ciliary beating by sliding microtubules relative to each other. In this primer, we first highlight the structure, mechanism, and regulation of dynein-1, which is the best-characterized member of the dynein motor family, and then describe the unique features and cellular roles of other dyneins. We also discuss accessory proteins that regulate the activation and motility of dynein motors in different cellular contexts.
Topics: Dyneins; Microtubules; Axoneme; Kinesins; Spindle Apparatus
PubMed: 38113834
DOI: 10.1016/j.cub.2023.10.064