Adv Exp Med Biol
-
The occurrence of toxic cyanobacterial blooms in Florida waters have become more prominent following increased growth, declining groundwater supplies, and identification of impaired surface waters as future drinking water sources. Cyanobacterial toxins have been identified in source waters used for drinking water supply and in post-treated drinking water during algal bloom events. Algal toxin concentrations in post-treated drinking water have exceeded existing and proposed World Health Organization guidelines for the oral consumption of microcystin and cylindrospermopsin. ⋯ Epidemiological studies may also be required in Florida to assess potential human health risks due to algal toxin consumption at the tap and for those exposed to cyanotoxic blooms during recreational use of lakes, springs and rivers. Without adequate water treatment and coordinated state-wide monitoring efforts, it is anticipated that the likelihood for human exposure to cyanobacteria and their toxins will increase as Florida becomes more dependent upon surface waters to supply a growing population and an expanding urban environment. Coordination and communication between surface water managers and public health officials at the local level will be critical to the overall protection of the environment and public health during toxic cyanobacterial bloom events.
-
A number of countries have developed regulations or guidelines for cyanotoxins and cyanobacteria in drinking water, and in some cases in water used for recreational activity and agriculture. The main focus internationally has been upon microcystin toxins, produced predominantly by Microcystis aeruginosa. This is because microcystins are widely regarded as the most significant potential source of human injury from cyanobacteria on a world-wide scale. ⋯ The major limitations that need to be overcome include: the capacity to deal with multiple toxin congeners, the absence of robust analytical methods for compliance monitoring, and the absence of certified toxin standards to support analyses. However, the current WHO provisional guideline for microcystin-LR, or the other national guideline variants that are based upon it, (e.g., Canadian, Australian) may be appropriate to adopt as a health advisory in the short-term, while regulations are developed. The bathing and recreationa water guidelines developed in other countries could also be translated fo use as recreational water guidelines situation in the US.
-
Oxy- (HbO2) and deoxy- (HHb) haemoglobin signals measured by near infrared (NIR) spectroscopy over the human frontal lobes frequently contain respiratory and low frequency oscillations (LFOs). It has been suggested previously that venous oxygen saturation (SvO2) can be calculated from these respiratory oscillations. In this paper, we investigated the use of a Fourier transform based algorithm to calculate an oxygen saturation measure known as S(osc)O2 which may be a close estimate of the underlying SvO2. ⋯ The calculated S(osc)O2 values were compared with other cerebral oxygenation measures including an intraparenchymal catheter based brain tissue oxygen tension (PbrO2) and the NIR based tissue oxygenation index (TOI). It was found that the S(osc)O2 calculated using the combined respiratory and LFO frequency range and the SRS method resulted in the highest detection rates of hyperoxic changes. This measure of S(osc)O2 may provide a viable, continuous, non invasive, bedside measure of cerebral venous oxygen saturation.
-
We now have more than 30 years of solid, scientific research about Lyme disease, a relatively common, vector-borne illness in parts of the United States and of Europe. Although there is still widespread misunderstanding of and misinformation about the disease among the lay public, its clinical manifestations as well as how to diagnose and to treat it are now well understood. In the vast majority of cases simple treatment with a relatively short course of orally administered antimicrobials results in long-term cure with no adverse sequelae.
-
Pharyngeal muscle tone decreases in sleep and this predisposes some individuals to obstructive sleep apnea. This review summarizes the control of the genioglossus muscle by sleep-state dependent neuromodulators at the hypoglossal motor nucleus, the source of motor output to the genioglossus muscle of the tongue. Knowledge of such mechanisms is relevant to identifying and developing new strategies to augment pharyngeal muscle activity in sleep, potentially as treatments for obstructive sleep apnea.