Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Cardio-oncology, the myth of Sisyphus, and cardiovascular disease in breast cancer survivors

The number of breast cancer (BC) survivors has been increasing lately, due to the improvement in early detection strategies and oncological treatments. However, BC survivors are 3 times as likely to develop heart failure (HF) within 5 years of cancer diagnosis, and 7/100 of them will develop HF in a median follow-up of 8.5 years. Furthermore, HF in BC survivors has a worse prognosis compared to other causes of HF. Anthracyclines and trastuzumab have been proven to improve survival. However, they are also considered as the main causative factors of HF in BC survivors. Old patients, those with a pre-existing cardiovascular (CV) risk factors/disease, prior exposure to chemotherapy and radiotherapy are at increased risk. Serial evaluation of troponins and cardiac imaging parameters using echocardiography and cardiovascular magnetic resonance can significantly contribute to the early diagnosis of cardiac involvement before overt HF will develop. Assessment and immediate treatment of traditional CV risk factors is the first step for cardiotoxicity prevention. In BC survivors with known heart disease, the clinical stabilization is strongly recommended for cardiotoxicity prevention. Finally, in high-risk CV patients, primary prevention including cardioprotectants and/or CV drugs should be applied. According to recent studies, the early start of ACE inhibitors and β-blockers and the modification of anti-cancer treatment can prevent the decline in left ventricular ejection fraction. However, further multicenter studies are needed to establish both prevention and treatment protocols to successfully overcome HF development in BC survivors. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

A carcinoid tumor of the middle ear masquerading as a glomus tympanicum presenting with temporal lobe hemorrhage in a 70-year-old woman: Case report and review of the literature

Paragangliomas in the central nervous system account for 0.6% of all head and neck neoplasms, with glomus tympanicum being the most common middle ear tumor. Carcinoid tumors are neuroendocrine tumors, representing less than 1% of neuroendocrine neoplasms in the middle ear. Misdiagnoses have been reported in the literature regarding glomus and carcinoid tumors, however, none have been in the central nervous system or middle ear. A 70-year-old female with a history of left temporal lobe tumor underwent unsuccessful resection due to intraoperative bleeding at an outside institution. However, biopsy prior to aborting the case led to the diagnosis of paraganglioma. Eight years postoperatively, the patient presented at our institution with acute confusion, aphasia, and altered mental status. Imaging revealed a 4cm left temporal intraparenchymal hematoma at the known tumor site with concern for intracranial tumor extension. Surgical resection was performed and previous symptoms resolved. Final pathology revealed a Grade II atypical carcinoid tumor with an unusually high Ki-67 of 50%. Carcinoid tumors of the middle ear constitute a differential diagnosis for patients presenting with temporal lobe hemorrhage. A combination of immunohistochemical staining with electron microscopy can assist in differentiating the tumor types. This atypical presentation for a carcinoid tumor in the middle ear suggests the need to consider carcinoid as the diagnosis in patients with a middle ear tumor invading into the temporal lobe and causing hemorrhage. These tumors may demonstrate an unusually high Ki-67 rate, in which case they should be treated aggressively