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Psychoneuroimmunology, Stress and Disease
Published in Herman Friedman, Thomas W. Klein, Andrea L. Friedman, Psychoneuroimmunology, Stress, and Infection, 2020
Michael Schlesinger, Yair Yodfat
How people react to stress is a very complicated issue. Some stressors have an adverse effect on the individual while other stressors can even be health- or growth-promoting. Most retrospectively designed human studies in the area of psychoneuroimmunology link disease with “bad” stressors such as depression, loneliness, and hopelessness. Unresolved conceptual issues related to stress include the following problems: can stressors be chronic, unchanging conditions rather than events? Must all stressors be perceived as undesirable or distressing? Are certain physiologic processes specific to the stress process?7 Life event instruments are complicated by considerable methodological problems and in many retrospective studies, there are serious reporting biases. There are many confounding variables like age, sex, socioeconomic status and concomitant illnesses. In most studies, a very small (less than 5% of the variance) linear correlation could be demonstrated between life event scores and subsequent illness.8,9
Polypharmacy
Published in Medha N. Munshi, Lewis A. Lipsitz, Geriatric Diabetes, 2007
Sudeep S. Gill, Lorraine L. Lipscombe, Paula A. Rochon
Drug absorption is largely unaffected by normal aging, despite well-documented changes in gastric motility and blood flow to the gut. In particular, the overall extent of drug absorption is generally unaffected by age, although the rate of absorption and time-to-peak serum concentrations may be delayed with advancing age. Factors other than aging have a greater influence on the absorption of a drug. Such factors include the concomitant use of certain drugs and the patient’s comorbid illness profile. For example, the absorption of antibiotics such as fluoroquinolones and tetracycline is decreased when they are taken together with calcium or iron supplements. As another example, the use of acid-lowering medications such as histamine-2 receptor blockers and proton pump inhibitors has been linked to an increased risk of developing vitamin B12 deficiency (13). Drug absorption (and elimination) may be affected in some cases by drug interactions mediated by P-glycoprotein, a multidrug efflux pump located on the luminal surface of the epithelial cells of the small intestine as well as several other locations (including the liver, kidneys, and blood-brain barrier) (14). Delayed gastric emptying (gastroparesis) due to autonomic neuropathy is common in diabetics and may be an important cause of alterations in drug absorption and blood glucose control (15).
Psychiatric Research
Published in M. Venkataswamy Reddy, Statistical Methods in Psychiatry Research and SPSS, 2019
A variable that is observed in a statistical experiment but that is not specially measured is called a concomitant variable. It is sometimes necessary to correct for concomitant variable in order to prevent distortion of the results of experiment or survey.
The positive and negative cardiovascular effects of cannabis
Published in Expert Review of Cardiovascular Therapy, 2020
Mitchell Adamson, Bennett Di Giovanni, Diego H. Delgado
Ultimately, advances in cannabis research would greatly help guide decisions regarding the use of cannabinoids in a clinical setting. Countries that have federally legalized recreational and medicinal cannabis (Canada, Uruguay) have a unique and feasible opportunity to study the cardiovascular implications of cannabis in an unbiased and comprehensive manner, eventually implementing findings into clinical practice. These countries may provide a framework for developing treatment guidelines and economic evaluations on the production and distribution of cannabis for medical and non-medical use. In order to address current limitations on cannabis research, future studies should focus on the differential therapeutic and pharmacological profiles of each individual cannabinoid – i.e., THC versus CBD – rather than grouping them under the umbrella term of cannabis. It is also necessary to analyze how dosage, frequency, and length of use, method of consumption, and exposure to secondhand cannabis smoke contribute to health outcomes. This is especially important, as fewer individuals are users of inhaled combustible cannabis smoke, compared to vaporizers and ingestible; given almost all risk studies are based on combustible cannabis smoke, risks profiles pertaining to cannabis must be updated. Furthermore, studies must explicitly control for confounding variables which may modify outcomes, such as concomitant drug/tobacco use, lifestyle, and eating habits. These are all necessary variables which must be considered in order to efficiently characterize the relationship that cannabis has with cardiovascular health.