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Cluster Headaches
Published in Alexander R. Toftness, Incredible Consequences of Brain Injury, 2023
We don't yet know exactly what triggers the pain, but one current avenue of research is on a particular kind of vasodilator called calcitonin gene-related peptide, which can be found in the hypothalamus (Carmine Belin et al., 2020). A vasodilator is a chemical that widens blood vessels. It may be this widening, along with neuroinflammation causing additional swelling, that causes the pain behind the person's eye. Infusing calcitonin gene-related peptides into a person who is currently experiencing an active cluster can trigger a headache but infusing them during their remission period does not trigger such an attack (Vollesen et al., 2018). It has also been shown that there are places in a person's genetic code that make them vulnerable to cluster headaches, and those genes seem to be associated with neuroinflammation (O'Connor et al., 2021). Indeed, cluster headaches run in families, where relatives are more likely to experience attacks (Waung et al., 2020).
Emergence of Therapeutic Strategies
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
We commenced with reconsideration of the recent studies of refractory cardiac failure (Solomon et al., 2018, 2020; Braunwald, 2015a; and others); these studies led to “spectacular improvement” in the management of cardiac failure in patients who required admission to hospital. While a focus was on the new drugs which had been introduced (Solomon et al., 2018, 2020; Braunwald, 2015b), patients improved in hospital when on the placebo control, earlier than expected, and dramatically. Improvement in cardiac failure status was sustained after hospital discharge. Something connected with hospitalization was responsible, but this could not be identified. Patients were treated with general measures – oxygen, diuretics, vasodilator therapy of different types. Similar benefits were seen in patients with “systolic” or “diastolic” heart failure, or when classified as HFrEF or HFpEF.
Effects of Hypoxia/Blood Flow Restriction on Cellular Adaptations to Training
Published in Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse, The Routledge Handbook on Biochemistry of Exercise, 2020
Scott J. Dankel, Jeremy P. Loenneke
One other utility of blood flow restriction in the absence of exercise involves its use to enhance acute exercise performance in what is known as ischemic pre-conditioning. This differs from traditional blood flow restriction applied at rest or during exercise, in that the pressure applied is intended to completely cut off arterial blood flow to the muscle. Ischemic pre-conditioning consists of occluding blood flow for 5-minute periods interspersed by 3-minute unoccluded or unrestricted blood flow. The repeated cessation and subsequent reperfusion of blood flow is done prior to exercise and is thought to enhance performance, but the mechanisms by which it does so are unknown. The most commonly speculated mechanism is through an increase in nitric oxide–induced vasodilation allowing for greater blood flow. This could improve performance by enabling a greater delivery of oxygen and a greater clearance of metabolic by-products, under the assumption that this magnitude of vasodilation would exceed that which would occur via exercise itself. Another hypothesized mechanism is via a greater activation of ATP-sensitive potassium channels, reducing energy depletion. Despite some studies showing beneficial effects of ischemic pre-conditioning, the results are far from conclusive, with numerous studies showing no additional benefit over exercise performed without ischemic preconditioning (17).
Cardiovascular responses to hot skin at rest and during exercise
Published in Temperature, 2023
Ting-Heng Chou, Edward F. Coyle
One may notice that there is an inconsistency regarding the control of cutaneous vasoconstrictor and vasodilator pathways by exercise. The onset of exercise only increases vasoconstrictor activity, whereas the delayed initiation of active cutaneous vasodilation and the lower upper limit of skin blood flow are only controlled by inhibition of the vasodilation system. The explanation is that the classical “exercise reflexes” affect the vasoconstrictor system as in other vascular beds at the onset of exercise [5], whereas changes in plasma osmolality affect the vasodilator system and delay the initiation of cutaneous vasodilation. The lower upper limit of skin blood flow during exercise is achieved by limiting the active vasodilator system, but the specific mechanism is unknown. In addition, the effect of vasoconstrictor activity on cutaneous blood flow may be too small once the active cutaneous vasodilation is triggered to lower skin blood flow. Therefore, no effect is seen with vasoconstrictor blockage on skin blood flow during exercise except at the onset of exercise.
Review of the international hypnosis literature
Published in American Journal of Clinical Hypnosis, 2022
Shelagh Freedman, Ian Wickramasekera
Preeclampsia is a serious condition, marked by high blood pressure, which can occur during pregnancy. Since perceived stress is a cause of preeclampsia, this study tested the effects of hypnosis on perceived stressed in pregnant women (32–28 weeks gestation) hospitalized with preeclampsia. The forty women who received interventions using hypnosis and were compared to 40 women who received routine pregnancy care only. The intervention consisted of three 30-minute sessions of stress reduction techniques during hypnosis over three consecutive nights, and self-hypnosis training. The pregnant women in the intervention group were taught progressive muscle relaxation, and the hypnosis involved the “acceptance or lack of aversion and attachment to life issues and release from entering the vicious cycle of problems.” Suggestions for vasodilation and lower blood pressure were also given. The women in the intervention group repeated the exercise with audio CD at night before bed. While no differences were found between the groups’ pre-intervention, using hypnosis was found to enhance the reduction of perceived stress. The authors conclude that hypnosis is a simple, low-cost, effective method for delivering intervention that can lower perceived stress in women with preeclampsia. Address for reprints: Dr. Mahin Tafazoli, Department of Midwifery, Evidence-Based Care Research Center, School of Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran. E-Mail: [email protected]
The effects of bisphenols on the cardiovascular system
Published in Critical Reviews in Toxicology, 2022
Patrícia Dias, Václav Tvrdý, Eduard Jirkovský, Marija Sollner Dolenc, Lucija Peterlin Mašič, Přemysl Mladěnka
Summing up the available information, the majority of BPA or the NextGen BPA analogues can exert potentially harmful vascular effects via the modulation of numerous ion channels that play a role in vessels and heart contractility, as well as through endocrine-disrupting activities, metabolic changes with a risk of atherosclerosis development and progression and oxidative stress. Prospective human studies are essentially missing. Moreover, in some respects, there is an apparent difference between in vitro/ex vivo studies reporting of vasodilation, while in vivo and observational studies have suggested an increase in arterial blood pressure. Also, studies with an isolated heart have shown that bisphenols can decrease cardiac contractility. This would again suggest a decrease in arterial blood pressure, which however, as mentioned, has not been observed in in vivo or observational studies. On the other hand, it must be underlined that some studies have used very high, hence unachievable concentrations, as well as specific genetic animal models.