The genus Massalongia (lichenised ascomycetae) in the Southern Hemisphere

The species of Massalongia recorded and described from the Southern Hemisphere are revised and it is shown that only one is present; M. patagonica which is widespread, with populations in Australia and New Zealand that differ from the South American populations, but at present best regarded as part of the variation of that species. Records from this hemisphere of all other species placed in the genus are incorrect. The type species, M. carnosa, is restricted to the Northern Hemisphere. Two species, M. antarctica and M. novozelandica cannot be identified precisely due to lack of sufficient type material and with the types as the only collections known of these, but none belongs in Massalongia according to available data. Massalongia griseolobata (from Gough Isl.) is shown here to belong in the Pannariaceae and is part of the parmelielloid clade. M. intricata (from South Georgia) and M. olechiana (from South Shetland) have both recently been correctly transferred to the genus Steinera in the Arctomiaceae

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Mechanisms in the Pathophysiology of Diving: Bubble Formation and Cardiovascular Effects of Simulated Diving, Exercise-Induced Muscle Injury and Hyperbaric Oxygen Preconditioning

Currently, there are millions of recreational divers and underwater workers worldwide. Although humans cannot live naturally underwater, certain physiological mechanisms can adapt the human body so that it may explore the underwater environment. During diving, increased pressure surrounding the body leads to high levels of different breathing gasses, for example nitrogen (N2) and oxygen (O2). During a dive, N2 accumulates in the tissues. On ascent to the surface, the ambient pressure decreases (decompression) and bubbles may form due to excess N2. The general opinion is that these gas bubbles are the cause of the clinical manifestations termed decompression sickness (DCS), which is a major health risk to divers. However, even when dives are performed in compliance with today’s procedures, which are commonly accepted as safe, bubble formation and DCS still occur. Despite many years of study, there is still limited knowledge of the mechanisms by which bubbles form and how they are involved in DCS development. Previous studies have shown that physical exercise and exposure to increased levels of O2 in the breathing gas may have a significant impact, in both reducing and increasing bubble formation and DCS risk. It is believed that exercise-induced muscle injury may enhance bubble formation and that high levels of O2 during diving may enhance DCS risk. In contrast, exposure to high O2 levels prior to diving may reduce DCS risk. However, little is known about the mechanisms behind these observations. In the present study, we investigated whether physical exercise may lead to enhanced vascular bubble formation (paper I), how diving-induced bubbles may initiate DCS (paper II and III), and how exposures to high levels of O2 in the breathing gas may increase or reduce injury from diving (paper II and III). To simulate diving, rats were exposed to a high ambient pressure in a hyperbaric chamber, then a rapid pressure reduction to induce bubble formation. Immediately after the dive, the rats were anesthetized and the amount of vascular bubbles was evaluated by ultrasonic imaging. Blood and tissues were collected and analyzed. The first findings were that eccentric exercise-induced skeletal muscle injury made prior to diving did not seem to affect vascular bubble formation (paper I). Thus, our results do not endorse a link between exercise-induced muscle injury and vascular bubble formation. Analysis of the effects of diving on the early genetic responses in vascular tissue after diving, using full genome gene expression profiling (paper II), found that high levels of O2 in the breathing gas are likely to be an important contributor in DCS etiology. In addition, it was noted that enhanced coagulation and inflammation may be involved in DCS development. Finally, we found that high bubble loads after diving led to elevated cardiac stressmarker levels (paper III). Further, it seemed that that preconditioning with hyperbaric O2 prior to diving prevented cardiac injury induced by vascular gas bubbles, which was indicated by an attenuated rise in stress-marker levels. Thus, the factors that were identified as being important in DCS development included exposure to high levels of O2 prior to and during the dive, as well as high bubble loads occurring post-dive. The main implications of the present study are that eccentric exercise causing muscle injury prior to diving does not seem to increase vascular bubble formation after diving and that exposure to high levels of O2 during diving seem to be involved in the adverse effects of diving. However, the adverse effects may be prevented by prophylactic exposure to high O2 levels prior to the dive. Understanding how physical exercise and exposure to high levels of O2 affect the risk of bubble formation and DCS is important, as it will facilitate preventive measures to help increase the safety of divers. Furthermore, it is our hope that this study may yield new and broader insight into the mechanisms of bubble formation and the pathogenesis of DCS after diving

The genus Massalongia (lichenised ascomycetae) in the Southern Hemisphere

The species of Massalongia recorded and described from the Southern Hemisphere are revised and it is shown that only one is present; M. patagonica which is widespread, with populations in Australia and New Zealand that differ from the South American populations, but at present best regarded as part of the variation of that species. Records from this hemisphere of all other species placed in the genus are incorrect. The type species, M. carnosa, is restricted to the Northern Hemisphere. Two species, M. antarctica and M. novozelandica cannot be identified precisely due to lack of sufficient type material and with the types as the only collections known of these, but none belongs in Massalongia according to available data. Massalongia griseolobata (from Gough Isl.) is shown here to belong in the Pannariaceae and is part of the parmelielloid clade. M. intricata (from South Georgia) and M. olechiana (from South Shetland) have both recently been correctly transferred to the genus Steinera in the Arctomiaceae

Effects of hyperbaric oxygen preconditioning on cardiac stress markers after simulated diving.

Hyperbaric oxygen preconditioning (HBO-PC) can protect the heart from injury during subsequent ischemia. The presence of high loads of venous gas emboli (VGE) induced by a rapid ambient pressure reduction on ascent from diving may cause ischemia and acute heart failure. The aim of this study was to investigate the effect of diving-induced VGE formation on cardiac stress marker levels and the cardioprotective effect of HBO-PC. To induce high loads of VGE, 63 female Sprague-Dawley rats were subjected to a rapid ambient pressure reduction from a simulated saturation dive (50 min at 709 kPa) in a pressure chamber. VGE loads were measured for 60 min in anesthetized animals by the use of ultrasonography. The animals were divided into five groups. Three groups were exposed to either diving or to HBO-PC (100% oxygen, 38 min at 303 kPa) with a 45 or 180 min interval between HBO-PC and diving. Two additional groups were used as baseline controls for the measurements; one group was exposed to equal handling except for HBO-PC and diving, and the other group was completely unexposed. Diving caused high loads of VGE, as well as elevated levels of the cardiac stress markers, cardiac troponin T (cTnT), natriuretic peptide precursor B (Nppb), and αB-crystallin, in blood and cardiac tissue. There were strong positive correlations between VGE loads and stress marker levels after diving, and HBO-PC appeared to have a cardioprotective effect, as indicated by the lower levels of stress marker expression after diving-induced VGE formation. KEYWORDS: Cardioprotection, decompression illness, diving, gas embolism, hyperbaric oxygen preconditionin

Eccentric exercise 48 h prior to simulated diving has no effect on vascular bubble formation in rats

PURPOSE: Decompression sickness (DCS) caused by vascular bubble formation is a major risk when diving. Prior studies have shown that physical exercise has a significant impact in both reducing and increasing bubble formation. There is limited knowledge about the mechanisms, but there are indications that exercise-induced muscle injury prior to diving may cause increased bubble formation. The purpose of this study was to investigate the role of exercise-induced muscle injury as a possible mechanism of bubble formation during diving. METHODS: Muscle injury was induced by exposing female Sprague-Dawley rats (n = 30) to a single bout of eccentric exercise, 100 min intermittent, downhill (-16°) treadmill running. Forty-eight hours later, the animals were exposed to a 50-min simulated saturation dive (709 kPa) in a pressure chamber, when the degree of muscle injury and inflammation would be the most pronounced. Bubble formation after the dive was observed by ultrasonic imaging for 4 h. RESULTS: No difference in bubble loads was found between the groups at any time despite evident muscle injury. Maximum bubble loads (bubbles cm-2 heart cycle-1) were not different, exercise: 1.6 ± 3.5 SD vs control: 2.2 ± 4.1 SD, P = 0.90, n = 15 in each group. CONCLUSIONS: Eccentric exercise performed 48 h prior to diving causes skeletal muscle injury but does not increase the amount of vascular bubbles in rats. The prevailing recommendation is that physical activity prior to diving is a risk factor of DCS. However, present and previous studies implicate that pre-dive physical activity does not increase the DCS risk

Fluoroscopy-free resuscitative endovascular balloon occlusion of the aorta (REBOA) for controlling life threatening postpartum hemorrhage

Background Severe postpartum hemorrhage occurs in 1/1000 women giving birth. This condition is often dramatic and may be life threatening. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) has in recent years been introduced as a novel treatment for hemorrhagic shock. We present a series of fluoroscopy-free REBOA for controlling life threatening postpartum hemorrhage. Methods In 2008 an ‘aortic occlusion kit’ was assembled and used in three Norwegian university hospitals. The on-call interventional radiologist (IR) was to be contacted with a response time < 30 minutes in case of life threatening PPH. Demographics and characteristics were noted from the medical records. Results This retrospective study includes 36 patients treated with fluoroscopy-free REBOA for controlling severe postpartum hemorrhage in the years 2008–2015. The REBOA success rate was 100% and no patients died from REBOA related complications. Uterine artery embolization was performed in 17 (47%) patients and a hysterectomy in 16 (44%) patients. A short (11cm) introducer length was strongly associated with iliac artery thrombus formation (ρ = 0.50, P = 0.002). In addition, there was a strong negative correlation between uterine artery embolization and hysterectomy (ρ = -0.50, P = 0.002). Conclusions Our Norwegian experience indicates the clinical safety and feasibility of REBOA in life threatening PPH. Also, REBOA can be used in an emergency situation without the use of fluoroscopy with a high degree of technical success. It is important that safety implementation of REBOA is established, especially through limited aortic balloon occlusion time and a thorough balloon deflation regime

Acute and potentially persistent effects of scuba diving on the blood transcriptome of experienced divers

During scuba diving, the circulatory system is stressed by an elevated partial pressure of oxygen while the diver is submerged and by decompression-induced gas bubbles on ascent to the surface. This diving-induced stress may trigger decompression illness, but the majority of dives are asymptomatic. In this study we have mapped divers' blood transcriptomes with the aim of identifying genes, biological pathways, and cell types perturbed by the physiological stress in asymptomatic scuba diving. Ten experienced divers abstained from diving for >2 wk before performing a 3-day series of daily dives to 18 m depth for 47 min while breathing compressed air. Blood for microarray analysis was collected before and immediately after the first and last dives, and 10 matched nondivers provided controls for predive stationary transcriptomes. MetaCore GeneGo analysis of the predive samples identified stationary upregulation of genes associated with apoptosis, inflammation, and innate immune responses in the divers, most significantly involving genes in the TNFR1 pathway of caspase-dependent apoptosis, HSP60/HSP70 signaling via TLR4, and NF-κB-mediated transcription. Diving caused pronounced shifts in transcription patterns characteristic of specific leukocytes, with downregulation of genes expressed by CD8+ T lymphocytes and NK cells and upregulation of genes expressed by neutrophils, monocytes, and macrophages. Antioxidant genes were upregulated. Similar transient responses were observed after the first and last dive. The results indicate that sublethal oxidative stress elicits the myeloid innate immune system in scuba diving and that extensive diving may cause persistent change in pathways controlling apoptosis, inflammation, and innate immune responses