Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise

OBJECTIVE: The purpose of this study was to compare the cardiovascular responses of patients with chronic fatigue syndrome (CFS) to healthy control subjects when performing stressful cognitive tasks before and after strenuous exercise. METHOD: Beat-by-beat blood pressure and electrocardiogram were recorded on 19 women with CFS and 20 healthy nonexercising (ie, sedentary) women while they performed cognitive tests before, immediately after, and 24 hours after incremental exercise to exhaustion. RESULTS: Diminished heart rate (p <.01) and systolic (p <.01) and diastolic (p <.01) blood pressure responses to stressful cognitive testing were seen in patients with CFS when compared with healthy, sedentary controls. This diminished stress response was seen consistently in patients with CFS across three separate cognitive testing sessions. Also, significant negative correlations between self-ratings of CFS symptom severity and cardiovascular responses were seen (r = -0.62, p <.01). CONCLUSIONS: Women with CFS have a diminished cardiovascular response to cognitive stress; however, exercise did not magnify this effect. Also, the data showed that the patients with the lowest cardiovascular reactivity had the highest ratings of CFS symptom severity, which suggests that the individual response of the patient with CFS to stress plays a role in the common complaint of symptoms worsening after stress.     

Development of an implantable artificial lung: challenges and progress

Unlike dialysis, which functions as a bridge to renal transplantation, or a ventricular assist device, which serves as a bridge to cardiac transplantation, no suitable bridge to lung transplantation exists. Our goal is to design and build an ambulatory artificial lung that can be perfused entirely by the right ventricle and completely support the metabolic O2 and CO2 requirements of an adult. Such a device could realize a substantial clinical impact as a bridge to lung transplantation, as a support device immediately post-lung transplant, and as a rescue and/or supplement to mechanical ventilation during the treatment of severe respiratory failure. Research on the artificial lung has focused on the design, mode of attachment to the pulmonary circulation, and intracorporeal versus paracorporeal placement of the device.     

Proliferative responses by immune murine popliteal lymph node cells to high-molecular-weight basic allergen of ryegrass pollen and its cyanogen bromide fragments

High-molecular-weight basic allergen (HMBA) of ryegrass pollen and its fragmented form obtained by cleavage with cyanogen bromide (CNBr) (HMBA-frag) were evaluated for their immunogenicity in terms of their capacity to stimulate the in vitro proliferative responses of the in vivo antigen-primed popliteal lymph node (PLN) cells. For this purpose, mice (C3H/HeJ) were immunized in the hind foot pads with solutions containing 1-5 micrograms of HMBA or HMBA-frag emulsified in Freund's complete adjuvant (FCA). Eleven days later, single-cell suspensions of the PLN were cultured in vitro for 4 days in the presence of either HMBA or HMBA-frag at concentrations ranging from 0.625 to 20 micrograms/ml. 3H-thymidine was added to the cultures 6 h prior to harvesting the cells. The degree of proliferation was assessed from the extent of intracellular incorporation of the 3H-thymidine by the PLN cells. Comparable degrees of lymphocyte proliferation were consistently obtained on stimulation with either HMBA or HMBA-frag of PLN cells from mice immunized with the allergen HMBA. A similar finding was made using PLN cells from mice immunized with the HMBA-frag. This study demonstrated that the CNBr-derived fragments of HMBA retained the immunogenicity of the parent molecule HMBA in terms of being able to (i) induce the in vivo priming of PLN cells and (ii) elicit the in vitro proliferative response of the antigen-primed PLN cells.     

Anti-progesterones and the law

Antiprogesterone drugs such a RU 486 can be used as an occasional contraceptive when administered in the luteal phase, as a last-chance contraceptive when administered before completion of implantation, as an abortifacient when administered after completion of implantation, or as a cervical primer for diagnostic purposes or to ease the expulsion of a dead fetus. A critical legal question raised by these agents is: when does contraception end and abortion begin? Completion of implantation represents the beginning of legal pregnancy in many jurisdictions. The legal event necessary to establish criminal liability for abortion is evidence that a health worker believed that implantation had occurred. If it is known to be biologically unlikely that implantation has occurred, it will be more credible that a health worker's intent is contraceptive-based. The prosecuting attorney still bears the burden of establishing a high level of evidence of what a defendant actually knew. An aid to use of RU 486 taken as a last chance contraceptive would be a presumption of contraceptive intention when it is used with the longest possible interval between a woman's last menstrual period and completion of implantation. A presumption of contraceptive intent up to 35 days after the last menstrual period is consistent with both traditional law and modern public policy.     

Assessing the Impact of Salt Reduction Initiatives on the Chronic Disease Burden of Singapore

Globally, many countries are facing an increasing burden of chronic disease due to ageing populations, of which cardiovascular disease forms a large proportion. Excess dietary sodium contributes to cardiovascular disease risk and requires intervention at a population level. This study aimed to quantify the impact of several salt reduction initiatives on population health over a 30-year horizon using GeoDEMOS, a population model from Singapore. Four interventions were modelled in four demographic groups in 2020 for a total of 16 intervention scenarios. The effect of 0.5, 2.0, and 4.0 g/day reductions in daily salt consumption, along with adherence to the World Health Organization guidelines of a maximum of 5.0 g of salt each day, was modelled in the entire population, including the overweight and obese, the elderly, and diabetics. In each scenario, the number of averted incident cases of acute myocardial infarction and stroke, along with the disability-adjusted life years up to 2050, was monitored. We found 4.0 g/day reductions in salt consumption were the most effective when implemented across the entire population, resulting in 24,000 averted incident cases of cardiovascular disease and 215,000 disability-adjusted life years over 30 years. This is a large figure when compared with the 29,200 projected annual incident cases of cardiovascular disease in 2050. When targeted at specific high-risk demographic groups, the largest effects were observed in the overweight and obese, with the same intervention yielding 10,500 averted incident cases of cardiovascular disease and 91,500 disability-adjusted life years. Quantifying the benefits of salt reduction initiatives revealed a significant impact when administered across the entire population or the overweight and obese. Health promotion efforts directed toward sustainably reducing salt consumption will help to lower the chronic disease burden on the healthcare system in years to come.     

The effect of respiratory activity,non-invasive respiratory support and facemasks on aerosol generation and its relevance to COVID-19

Respirable aerosols (< 5 µm in diameter) present a high risk of SARS-CoV-2 transmission. Guidelines recommend using aerosol precautions during aerosol-generating procedures, and droplet (> 5 µm) precautions at other times. However, emerging evidence indicates respiratory activities may be a more important source of aerosols than clinical procedures such as tracheal intubation. We aimed to measure the size, total number and volume of all human aerosols exhaled during respiratory activities and therapies. We used a novel chamber with an optical particle counter sampling at 100 l.min^-1 to count and size-fractionate close to all exhaled particles (0.5–25 µm). We compared emissions from ten healthy subjects during six respiratory activities (quiet breathing; talking; shouting; forced expiratory manoeuvres; exercise; and coughing) with three respiratory therapies (high-flow nasal oxygen and single or dual circuit non-invasive positive pressure ventilation). Activities were repeated while wearing facemasks. When compared with quiet breathing, exertional respiratory activities increased particle counts 34.6-fold during talking and 370.8-fold during coughing (p < 0.001). High-flow nasal oxygen 60 at l.min^-1 increased particle counts 2.3-fold (p = 0.031) during quiet breathing. Single and dual circuit non-invasive respiratory therapy at 25/10 cm.H₂O with quiet breathing increased counts by 2.6-fold and 7.8-fold, respectively (both p < 0.001). During exertional activities, respiratory therapies and facemasks reduced emissions compared with activities alone. Respiratory activities (including exertional breathing and coughing) which mimic respiratory patterns during illness generate substantially more aerosols than non-invasive respiratory therapies, which conversely can reduce total emissions. We argue the risk of aerosol exposure is underappreciated and warrants widespread, targeted interventions.     

Findings From a Community Survey of Individuals Who Engage in Pup Play

Archives of Sexual Behavior - This study presents findings from a community survey on pup play. Pup play is a kink activity and a form of role play that is growing in popularity internationally,...