Taxonomic diversity and toxicological assessment of Cyanobacteria in Moroccan inland waters

Research on the ecology, biodiversity and toxicology of cyanobacteria in Moroccan inland waters has been carried out since 1994. The results demonstrate the existence of several taxa of cyanobacteria. Most of them are toxic, bloom‑forming species present in various water bodies of the country. The present study follows upon this earlier work and spans the 2003-2006 period. The major aim was to update and supplement the existing national cyanobacteria inventory and to isolate new toxic strains. During the study period, more than 40 aquatic environments were visited and sampled.Almost 300 taxa of cyanobacteria were recorded. They belonged to 3 orders, 14 families and 46 genera. Among these, about 78 taxa are recorded for the first time in Morocco; 29 strains of cyanobacteria were successfully isolated and cultured in the laboratory. All the collected cyanobacteria, including natural blooms, mats, and cultured strains, were analyzed for toxicity and hepatotoxins (microcystins) were quantified. Using the High-performance liquid chromatography technique coupled to photodiode array (PDA) detector (HPLC-PDA), four samples of Microcystis blooms showed the presence of microcystins (MCs), with a concentration ranging between 1.87 and 64.4 µg•g‑1 MC‑LR eq (microcystin-LR equivalents). A total of five different structural variants of MCs were detected (MC-LR, -RR, -YR, -FR, -WR). Furthermore, 3 of 29 isolates were confirmed as MCs producing strains.The results show that the widening of the survey led to a better knowledge of the diversity of cyanobacteria. The taxonomic inventory was greatly increased and several cyanobacteria strains were characterized for their toxicity. The results should be useful as a database for the identification of various aquatic environments contaminated by cyanobacterial toxins (microcystins), which represent a potent sanitary risk for human and animals.Au Maroc, les recherches sur l’écologie, la biodiversité et la toxicologie des cyanobactéries des eaux continentales ont été entamées à partir de 1994. Les résultats obtenus ont montré l’existence de plusieurs taxons de cyanobactéries, dont certains sont responsables de la formation de blooms toxiques. Faisant suite aux précédents travaux, la présente étude, réalisée lors de la période 2003-2006, où plus de 40 milieux aquatiques ont été prospectés, a pour objectif de compléter et d’actualiser l’inventaire national des cyanobactéries d’eau douce du Maroc et d’isoler de nouvelles souches toxiques.Plus de 300 taxons de cyanobactéries appartenant à 3 ordres, 14 familles et 46 genres ont été inventoriés. À notre connaissance, 78 taxons sont cités pour la première fois au Maroc et 29 souches de cyanobactéries ont pu être isolées et cultivées en laboratoire. Le matériel cyanobactérien planctonique ou benthique collecté sur le terrain (blooms, écumes, films benthiques, etc.) et la biomasse des souches isolées produite en culture au laboratoire, ont été analysés pour l’évaluation de la toxicité et la quantification des cyanotoxines (microcystines).L’utilisation de la technique HPLC-PDA (High-performance liquid chromatography technique coupled to photodiode array (PDA) detector) a permis d’identifier quatre blooms toxiques à Microcystis et la détection de microcystines (MCs) à des concentrations variant entre 1,87 et 64,4 µg•g‑1 eq MC-LR (microcystin-LR equivalents). Cinq variantes structurales de MCs ont pu être détectées (MC-LR, -RR, -YR, -FR, -WR). Parmi les 29 souches isolées et produites au laboratoire, trois seulement ont confirmé la production de microcystines.Les résultats obtenus constituent un apport substantiel à la taxonomie des cyanobactéries et à l’évaluation de la biodiversité des cyanobactéries du Maroc. Ces données peuvent être utilisées comme base pour identifier les milieux aquatiques potentiellement contaminés par les cyanobactéries et capables de générer un haut risque sanitaire pour les hommes et les animaux

Chloroquine Administration in Breastfeeding Mothers Associates with Increased HIV-1 Plasma Viral Loads

Chloroquine (CQ) and Hydroxychloroquine (HCQ) have been proposed to be effective at treating COVID-19 patients. We, and others, have previously reported on the capacity of CQ to reduce HIV-1 replication in vitro. We tested CQ administration in post-partum mothers on influencing HIV-1 viral loads in human milk as a means of lowering mother to child transmission. A Phase I/II, randomized, placebo-controlled study to evaluate chloroquine administration to reduce HIV-1 RNA levels in human milk: the CHARGE study. Thirty HIV-1 positive pregnant Rwandese women (CQ n = 20; placebo n = 10) were enrolled in a 16-week study, with the treatment group receiving a 200 mg oral dose of CQ daily. Base-line plasma viral load (pVL) measurements and CD4 counts were determined prior to delivery, and pVL, breast milk VL (bmVL) and CQ levels measured during treatment. For women receiving treatment, CQ concentration was higher in breast milk compared to plasma (over 2.5-fold), with a positive correlation between the levels in the two compartments (P \u3c 0.003). A link between high CQ concentrations in plasma and high CD4 counts (P \u3c 0.001) was observed. Surprisingly, we found a significant increase in pVL after CQ treatment in over half of the mothers (n=11; P \u3c 0.001) and with no alteration to bmVL measurements. No specific amino acid alterations in the gp120 envelope sequences could be associated with CQ administration. CQ usage is associated with a significant increase to pVL in early breastfeeding mothers from Rwanda which cautions against the use of CQ in such individuals. Our results highlight a discrepancy between CQ effects on modulating HIV-1 replication in vitro versus in vivo and indicate caution when prescribing CQ to postpartum HIV-1 untreated mothers. This discrepancy should be taken into consideration when testing CQ or HCQ treatment in COVID-19 clinical trials, especially relating to the post-partum setting

Lower leukotriene C4 levels in bronchoalveolar lavage fluid of asthmatic subjects after 2.5 years of inhaled corticosteroid therapy

Long-term treatment with inhaled corticosteroids has been shown to result in improvement of symptoms and lung function in subjects with asthma. Arachidonic acid (AA) metabolites are thought to play a role in the pathophysiology of asthma. It was assessed whether differences could be found in bronchoalveolar lavage (BAL) AA metabolite levels between subjects with asthma who were treated for 2.5 years with inhaled bronchodilators alone or in combination with inhaled corticosteroids. Prostaglandin (PG)D2, PGF2α, 6-keto-PGF1α, thromboxane B2, leukotriene (LT)C4 and LTB4 levels and cell numbers were assessed in BAL fluid from 22 non-smoking asthmatic subjects. They were participating in a randomized, double-blind multicentre drug trial over a period of 2.5 years. Results of the group treated with inhaled corticosteroids (CS+: beclomethasone 200 μg four times daily) were compared with the other group (CS−) which was treated with either ipratropium bromide (40 μg four times daily) or placebo. BAL LTC4 levels of asthmatic subjects were significantly lower after 2.5 years inhaled corticosteroid therapy (CS+, 9(1–17) pg/ml vs. CS−, 16(6-53) pg/ml; p = 0.01). The same trend was observed for the PGD2 levels. The results suggest that inhaled corticosteroids may exert their beneficial effect on lung function via a mechanism in which inhibition of LTC4 synthesis in the airways is involved

X-ray Absorption Near-Edge Structure (XANES) at the O K-Edge of Bulk Co₃O₄: Experimental and Theoretical Studies

We combine theoretical and experimental X-ray absorption near-edge spectroscopy (XANES) to probe the local environment around cationic sites of bulk spinel cobalt tetraoxide (Co3O4). Specifically, we analyse the oxygen K-edge spectrum. We find an excellent agreement between our calculated spectra based on the density functional theory and the projector augmented wave method, previous calculations as well as with the experiment. The oxygen K-edge spectrum shows a strong pre-edge peak which can be ascribed to dipole transitions from O 1s to O 2p states hybridized with the unoccu- pied 3d states of cobalt atoms. Also, since Co3O4 contains two types of Co atoms, i.e., Co3+ and Co2+, we find that contribution of Co2+ ions to the pre-edge peak is solely due to single spin-polarized t2g orbitals (dxz, dyz, and dxy) while that of Co3+ ions is due to spin-up and spin-down polarized eg orbitals (dx2−y2 and dz2 ). Furthermore, we deduce the magnetic moments on the Co3+ and Co2+ to be zero and 3.00 μB respectively. This is consistent with an earlier experimental study which found that the magnetic structure of Co3O4 consists of antiferromagnetically ordered Co2+ spins, each of which is surrounded by four nearest neighbours of oppositely directed spins

Do patients’ information needs decrease over the course of radiotherapy?

PURPOSE: We aimed to investigate if cancer patients’ information needs decrease during radiotherapy and if so, which patient, consultation and radiation oncologist characteristics are associated with a decrease in information needs over time. METHODS: In this longitudinal study, patients (n = 104) completed a baseline questionnaire a week before the initial radiotherapy consultation, immediately following this initial consultation, and 1 week prior to the first follow-up visit, which took place on average 3–5 weeks after the initial visit. Besides information needs, measured by the Information Preference for Radiotherapy Patients scale, the questionnaire assessed patient, consultation and radiation oncologist characteristics. RESULTS: Information needs decreased over time, but remained at a high level. Being religious, being male, having low health literacy and higher perceived involvement during the consultation were all statistically significantly associated to a decrease in information needs on specific domains (e.g. procedures or side effects). CONCLUSIONS: Cancer patients’ information needs decline between the initial consultation and the first follow-up visit, but remain high. It is therefore advised to investigate the patients’ information needs at every radiotherapy visit and not rely on giving information just once. Furthermore, radiation oncologists should check if the information given at first consultation is understood and remembered. By those means, tailored information giving becomes possible

Bacterial flagellar motors and osmoelectric molecular rotation by an axially transmembrane well and turnstile mechanism

AbstractBacterial ion-driven flagellar motors are the smallest known rotatory mechanical devices, natural or artificial, their overall diameter being only about 25 nm or one millionth of an inch. They are unique in the fields of biology and engineering. This paper develops a possible osmoelectric or local electrokinetic mechanism of molecular rotatory motion in bilayer membranes, which may help to explain how bacterial flagellar motors work, and may incidentally encourage new developments in the bioenergetics and biomechanics of enzyme, osmoenzyme and porter action

Disturbance and resource availability act differently on the same suite of plant traits: revisiting assembly hypotheses.

Understanding the mechanisms of trait selection at the scale of plant communities is a crucial step toward predicting community assembly. Although it is commonly assumed that disturbance and resource availability constrain separate suites of traits, representing the regenerative and established phases, respectively, a quantification and test of this accepted hypothesis is still lacking due to limitations of traditional statistical techniques. In this paper we quantify, using structural equation modeling (SEM), the relative contributions of disturbance and resource availability to the selection of suites of traits at the community scale. Our model specifies and reflects previously obtained ecological insights, taking disturbance and nutrient availability as central drivers affecting leaf, allometric, seed, and phenology traits in 156 (semi-) natural plant communities throughout The Netherlands. The common hypothesis positing that disturbance and resource availability each affect a set of mutually independent traits was not consistent with the data. Instead, our final model shows that most traits are strongly affected by both drivers. In addition, trait-trait constraints are more important in community assembly than environmental drivers in half of the cases. Both aspects of trait selection are crucial for correctly predicting ecosystem processes and community assembly, and they provide new insights into hitherto underappreciated ecological interactions. © 2012 by the Ecological Society of America

The RESPITE trial: remifentanil intravenously administered patient-controlled analgesia (PCA) versus pethidine intramuscular injection for pain relief in labour: study protocol for a randomised controlled trial

Background The commonest opioid used for pain relief in labour is pethidine (meperidine); however, its effectiveness has long been challenged and the drug has known side effects including maternal sedation, nausea and potential transfer across the placenta to the foetus. Over a third of women receiving pethidine require an epidural due to inadequate pain relief. Epidural analgesia increases the risk of an instrumental vaginal delivery and its associated effects. Therefore, there is a clear need for a safe, effective, alternative analgesic to pethidine. Evidence suggests that remifentanil patient-controlled analgesia (PCA) reduces epidural conversion rates compared to pethidine; however, no trial has yet investigated this as a primary endpoint. We are, therefore, comparing pethidine intramuscular injection to remifentanil PCA in a randomised controlled trial. Methods/design Women in established labour, requesting systemic opioid pain relief, will be randomised to either intravenously administered remifentanil PCA (intervention) or pethidine intramuscular injection (control) in an unblinded, 1:1 individual randomised trial. Following informed consent, 400 women in established labour, who request systemic opioid pain relief, from NHS Trusts across England will undergo a minimised randomisation by a computer or automated telephone system to either pethidine or remifentanil. In order to balance the groups this minimisation is based on four parameters; parity (nulliparous versus multiparous), maternal age (<20, 20 < 30, 30 < 40, 40+ years), ethnicity (South Asian (Pakistani/Indian/Bangladeshi) versus Other) and induced versus spontaneous labour. The effectiveness of pain relief provided by each technique will be recorded every 30 min after time zero, until epidural placement, delivery or transfer to theatre, quantified by Visual Analogue Scale. Incidence of maternal side effects including sedation, delivery mode, foetal distress requiring delivery, neonatal status at delivery and rate of initiation of breastfeeding within the first hour of birth will also be recorded. Maternal satisfaction with her childbirth experience will be determined by a postpartum questionnaire prior to discharge from the delivery ward. Discussion The RESPITE trial’s primary outcome is the proportion of women who have an epidural placed for pain relief in labour in each arm. Trial Registration Current Controlled Trials registration number: ISRCTN29654603. Registered on 23 July 2013