Volume regulation by Amphiuma red blood cells. The membrane potential and its implications regarding the nature of the ion-flux pathways

After osmotic perturbation, the red blood cells of Amphiuma exhibited a volume-regulatory response that returned cell volume back to or toward control values. After osmotic swelling, cell-volume regulation (regulatory volume decrease; RVD) resulted from net cellular loss of K, Cl, and osmotically obliged H2O. In contrast, the volume-regulatory response to osmotic shrinkage (regulatory volume increase; RVI) was characterized by net cellular uptake of Na, Cl, and H2O. The net K and Na fluxes characteristic of RVD and RVI are increased by 1-2 orders of magnitude above those observed in studies of volume-static control cells. The cell membrane potential of volume-regulating and volume-static cells was measured by impalement with glass microelectrodes. The information gained from the electrical and ion-flux studies led to the conclusion that the ion fluxes responsible for cell-volume regulation proceed via electrically silent pathways. Furthermore, it was observed that Na fluxes during RVI were profoundly sensitive to medium [HCO3] and that during RVI the medium becomes more acid, whereas alkaline shifts in the suspension medium accompany RVD. The experimental observations are explained by a model featuring obligatorily coupled alkali metal-H and Cl-HCO3 exchangers. The anion- and cation-exchange pathways are separate and distinct yet functionally coupled via the net flux of H. As a result of the operation of such pathways, net alkali metal, Cl, and H2O fluxes proceed in the same direction, whereas H and HCO3 fluxes are cyclic. Data also are presented that suggest that the ion-flux pathways responsible for cell-volume regulation are not activated by changes in cell volume per se but by some event associated with osmotic perturbation, such as changes in intracellular pH

Cluster of legionnaires’ disease in an Italian prison

Background: Legionella pneumophila (Lp) is the most common etiologic agent causing Legionnaires’ Disease (LD). Water systems offer the best growth conditions for Lp and support its spread by producing aerosols. From 2015 to 2017, the Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis of Palermo monitored the presence of Lp in nine prisons in Western Sicily. During this investigation, we compared Lp isolates from environmental samples in a prison located in Palermo with isolates from two prisoners in the same prison. Methods: We collected 93 water samples from nine Sicilian prisons and the bronchoalveolar lavages (BALs) of two prisoners considered cases of LD. These samples were processed following the procedures described in the Italian Guidelines for the Prevention and Control of Legionellosis of 2015. Then, genotyping was performed on 19 Lp colonies (17 from water samples and 2 from clinical samples) using the Sequence-Based Typing (SBT) method, according to European Study Group for Legionella Infections (ESGLI) protocols. Results: Lp serogroup (sg) 6 was the most prevalent serogroup isolated from the prisons analyzed (40%), followed by Lp sg 1 (16%). Most of all, in four penitentiary institutions, we detected a high concentration of Lp >104 Colony Forming Unit/Liter (CFU/L). The environmental molecular investigation found the following Sequence Types (STs) in Lp sg 6: ST 93, ST 292, ST 461, ST 728, ST 1317 and ST 1362, while most of the isolates in sg 1 belonged to ST 1. We also found a new ST that has since been assigned the number 2451 in the ESGLI-SBT database. From the several Lp sg 1 colonies isolated from the two BALs, we identified ST 2451. Conclusions: In this article, we described the results obtained from environmental and epidemiological investigations of Lp isolated from prisons in Western Sicily. Furthermore, we reported the first cluster of Legionnaires’ in an Italian prison and the molecular typing of Lp sg 1 from one prison’s water system and two BALs, identified the source of the contamination, and discovered a new ST

Socio-Demographic Characteristics and Sexual Behavioral Factors of Patients with Sexually Transmitted Infections Attending a Hospital in Southern Italy

Sexually transmitted infections (STIs) are a serious global health problem. In Italy, data describing the vulnerability to STIs of specific sexual minorities and the influence of sociodemographic and behavioral determinants are limited, as most infections are not subject to mandatory notification. This retrospective study describes the sociodemographic profile and main sexual behaviors of patients attending a hospital in Palermo (Sicily, Italy) from January 2018 to March 2019 as predictors of STI risk. Patients were divided in subgroups: men-who-have-sex-with-men (MSM), men-who-have-sex-with-women (MSW), bisexual men and females. Data were obtained through an anonymous questionnaire. Patients were tested for chlamydia, syphilis, Mycoplasma genitalium infection, genital herpes and HPV infection. A total of 294 subjects with STIs (male/female ratio about 2:1) were screened. Of the total sample, 79.6% of patients were Italian. MSM accounted for 34.3%, MSW for 29.6%, bisexual men for 5.8% and females for 30.3%. A total of 44.5% of patients had a high education level, 42.5% reported irregular use of condoms, 20.7% reported having had 5-10 partners in the six months prior to the visit and 32.9% were HIV-positive. HPV infection and syphilis were the most prevalent STIs. Conclusions: The most common profile of patients attending our clinic was that of an adult, Italian man with a high level of education, poor use of condoms and a high number of partners. MSM had the highest sex-behavior-related risk for STIs. In addition, our results suggest that all STD teams need to implement counselling topics and recommendations to share with patients, as well as tips on how to approach sexual health education/counselling, thereby promoting patient-centered approaches and educational programs

VIRULENCE FACTORS AND ANTIMICROBIAL RESISTANCE OF ESCHERICHIA COLI ST131 IN COMMUNITY-ONSET HEALTHCARE-ASSOCIATED INFECTIONS IN SICILY, ITALY

Escherichia coli ST131 is an emerging resistant agent recently called \u201csuperbug\u201d in England. This strain is responsible of community-acquired urinary tract infections and nowadays showing increasing resistance to antibiotics like fluoroquinolones and cephalosporins. Survey of virulent bacterial clone is relevant to control its spreading in community. We aim to assess the circulation of resistant clones Escherichia coli ST131 outside of the hospital to prompt control of outbreak in our geographical area. We selected 105 E. coli resistant isolates from community-acquired urinary infections and performed a multiplex PCR to evaluate if they belonged to the ST131 type. We investigated their set of virulence factors; in particular, kpsMII, papA, sfaS, focG, iutA, papC, hlyD and afa genes, and finally, we evaluated beta lactamases genes and quinolone resistance determinants. E. coli ST 131 clone was present in 66.6% of our isolates and showed positivity to a wide range of resistance genes, in particular blaCTX-M-15 among beta lactamases and plasmid-related quinolone resistance genes (qnrA, qnrS and aac (6\u2019)-Ib-cr). Moreover, 81% of the strains showed positivity to at least one of the virulence factor genes. Our results suggested a high presence of E. coli ST131 in community. We suggest antibiotic stewardship for outpatient clinicians and facilities to contain the spread of \u201csuperbug\u201d agents

Molecular Analyses of Circadian Gene Variants Reveal Sex-Dependent Links Between Depression and Clocks

An extensive literature links circadian irregularities and/or sleep abnormalities to mood disorders. Despite the strong genetic component underlying many mood disorders, however, previous genetic associations between circadian clock gene variants and major depressive disorder (MDD) have been weak. We applied a combined molecular/functional and genetic association approach to circadian gene polymorphisms in sex-stratified populations of control subjects and case subjects suffering from MDD. This approach identified significant sex-dependent associations of common variants of the circadian clock genes hClock, hPer3 and hNpas2 with major depression and demonstrated functional effects of these polymorphisms on the expression or activity of the hCLOCK and hPER3 proteins, respectively. In addition, hCLOCK expression is affected by glucocorticoids, consistent with the sex-dependency of the genetic associations and the modulation of glucocorticoid-mediated stress response, providing a mechanism by which the circadian clock controls outputs that may affect psychiatric disorders. We conclude that genetic polymorphisms in circadian genes (especially hClock and hPer3, where functional assays could be tested) influence risk of developing depression in a sex- and stress-dependent manner. These studies support a genetic connection between circadian disruption and mood disorders, and confirm a key connection between circadian gene variation and major depression

Predictors and outcomes of neurological deterioration in intracerebral hemorrhage: results from the TICH-2 randomised controlled trial

Neurological deterioration is common after intracerebral hemorrhage (ICH). We aimed to identify the predictors and effects of neurological deterioration and whether tranexamic acid reduced the risk of neurological deterioration. Data from the Tranexamic acid in IntraCerebral Hemorrhage-2 (TICH-2) randomized controlled trial were analyzed. Neurological deterioration was defined as an increase in National Institutes of Health Stroke Scale (NIHSS) of ≥ 4 or a decline in Glasgow Coma Scale of ≥ 2. Neurological deterioration was considered to be early if it started ≤ 48 h and late if commenced between 48 h and 7 days after onset. Logistic regression was used to identify predictors and effects of neurological deterioration and the effect of tranexamic acid on neurological deterioration. Of 2325 patients, 735 (31.7%) had neurological deterioration: 590 (80.3%) occurred early and 145 (19.7%) late. Predictors of early neurological deterioration included recruitment from the UK, previous ICH, higher admission systolic blood pressure, higher NIHSS, shorter onset-to-CT time, larger baseline hematoma, intraventricular hemorrhage, subarachnoid extension and antiplatelet therapy. Older age, male sex, higher NIHSS, previous ICH and larger baseline hematoma predicted late neurological deterioration. Neurological deterioration was independently associated with a modified Rankin Scale of > 3 (aOR 4.98, 3.70–6.70; p [less than] 0.001). Tranexamic acid reduced the risk of early (aOR 0.79, 0.63–0.99; p = 0.041) but not late neurological deterioration (aOR 0.76, 0.52–1.11; p = 0.15). Larger hematoma size, intraventricular and subarachnoid extension increased the risk of neurological deterioration. Neurological deterioration increased the risk of death and dependency at day 90. Tranexamic acid reduced the risk of early neurological deterioration and warrants further investigation in ICH

Development, intercomparison, and evaluation of an improved mechanism for the oxidation of dimethyl sulfide in the UKCA model

Dimethyl sulfide (DMS) is an important trace gas emitted from the ocean. The oxidation of DMS has long been recognised as being important for global climate through the role DMS plays in setting the sulfate aerosol background in the troposphere. However, the mechanisms in which DMS is oxidised are very complex and have proved elusive to accurately determine in spite of decades of research. As a result the representation of DMS oxidation in global chemistry–climate models is often greatly simplified. Recent field observations and laboratory and ab initio studies have prompted renewed efforts in understanding the DMS oxidation mechanism, with implications for constraining the uncertainty in the oxidation mechanism of DMS as incorporated in global chemistry–climate models. Here we build on recent evidence and develop a new DMS mechanism for inclusion in the UK Chemistry Aerosol (UKCA) chemistry–climate model. We compare our new mechanism (CS2-HPMTF) to a number of existing mechanisms used in UKCA (including the highly simplified three-reactions–two-species mechanism used in CMIP6 studies with the model) and to a range of recently developed mechanisms reported in the literature through a series of global and box model experiments. Global model runs with the new mechanism enable us to simulate the global distribution of hydroperoxylmethyl thioformate (HPMTF), which we calculate to have a burden of 2.6–26 Gg S (in good agreement with the literature range of 0.7–18 Gg S). We show that the sinks of HPMTF dominate uncertainty in the budget, not the rate of the isomerisation reaction forming it and that, based on the observed DMS / HPMTF ratio from the global surveys during the NASA Atmospheric Tomography mission (ATom), rapid cloud uptake of HPMTF worsens the model–observation comparison. Our box model experiments highlight that there is significant variance in simulated secondary oxidation products from DMS across mechanisms used in the literature, with significant divergence in the sensitivity of the rates of formation of these products to temperature exhibited; especially for methane sulfonic acid (MSA). Our global model studies show that our updated DMS scheme performs better than the current scheme used in UKCA when compared against a suite of surface and aircraft observations. However, sensitivity studies underscore the need for further laboratory and observational constraints. In particular our results suggest that as a priority long-term DMS observations be made to better constrain the highly uncertain inputs into the system and that laboratory studies be performed that address (1) the uptake of HPMTF onto aerosol surfaces and the products of this reaction and (2) the kinetics and products of the following reactions: CH3SO3 decomposition, CH3S + O2, CH3SOO decomposition, and CH3SO + O3.</p

In vitro anthelmintic effect of Melia azedarach L. and Trichilia claussenii C. against sheep gastrointestinal nematodes.

The control of parasitic diseases in small ruminants is mainly done with the use of synthetic anthelmintics. However, incorrect and indiscriminate use of these products has caused the emergence of parasite resistance. Plants with anthelmintic activity are used in folk veterinary medicine, but it is necessary to investigate and scientifically validate low-cost phytotherapeutic alternatives for future use to control gastrointestinal nematodes in small ruminants by family farmers. Thus, the aim of this study was to evaluate the in vitro anthelmintic effect of plant extracts from Melia azedarach and Trichilia claussenii by the egg hatch test (EHT) and larval development test (LDT) against sheep gastrointestinal nematodes. The hexane extract of M. azedarach fruits was extracted through cold percolation and the methanol extract of T. claussenii leaves was obtained by extraction at room temperature in solvents in order of increasing polarity. The efficacy results were analyzed using the Probit program of SAS. The M. azedarach extract showed a LC50 of 572.2 lg/mL and LC99 of 1137.8 lg/mL in the EHT, and LC50 of 0.7 lg/mL and LC99 of 60.8 lg/mL in the LDT. In turn, the T. claussenii extract presented a LC50 of 263.8 lg/mL and LC99 of 522.5 lg/mL in the EHT and LC50 of 1.1 lg/mL and LC99 of 26.4 lg/mL in the LDT. Comparing the extracts of the species from the Meliaceae family, T. claussenii showed greater anti-parasite potential in vitro than M. azedarach. However, studies on the isolated compounds, toxicity and administration forms to animals are also needed to validate low-cost alternative herbal remedies for use to control gastrointestinal nematodes by family farmers

Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

Background High blood pressure is common in acute stroke and is a predictor of poor outcome; however, large trials of lowering blood pressure have given variable results, and the management of high blood pressure in ultra-acute stroke remains unclear. We investigated whether transdermal glyceryl trinitrate (GTN; also known as nitroglycerin), a nitric oxide donor, might improve outcome when administered very early after stroke onset. Methods We did a multicentre, paramedic-delivered, ambulance-based, prospective, randomised, sham-controlled, blinded-endpoint, phase 3 trial in adults with presumed stroke within 4 h of onset, face-arm-speech-time score of 2 or 3, and systolic blood pressure 120 mm Hg or higher. Participants were randomly assigned (1:1) to receive transdermal GTN (5 mg once daily for 4 days; the GTN group) or a similar sham dressing (the sham group) in UKbased ambulances by paramedics, with treatment continued in hospital. Paramedics were unmasked to treatment, whereas participants were masked. The primary outcome was the 7-level modified Rankin Scale (mRS; a measure of functional outcome) at 90 days, assessed by central telephone follow-up with masking to treatment. Analysis was hierarchical, first in participants with a confirmed stroke or transient ischaemic attack (cohort 1), and then in all participants who were randomly assigned (intention to treat, cohort 2) according to the statistical analysis plan. This trial is registered with ISRCTN, number ISRCTN26986053. Findings Between Oct 22, 2015, and May 23, 2018, 516 paramedics from eight UK ambulance services recruited 1149 participants (n=568 in the GTN group, n=581 in the sham group). The median time to randomisation was 71 min (IQR 45–116). 597 (52%) patients had ischaemic stroke, 145 (13%) had intracerebral haemorrhage, 109 (9%) had transient ischaemic attack, and 297 (26%) had a non-stroke mimic at the final diagnosis of the index event. In the GTN group, participants’ systolic blood pressure was lowered by 5·8 mm Hg compared with the sham group (p<0·0001), and diastolic blood pressure was lowered by 2·6 mm Hg (p=0·0026) at hospital admission. We found no difference in mRS between the groups in participants with a final diagnosis of stroke or transient ischaemic stroke (cohort 1): 3 (IQR 2–5; n=420) in the GTN group versus 3 (2–5; n=408) in the sham group, adjusted common odds ratio for poor outcome 1·25 (95% CI 0·97–1·60; p=0·083); we also found no difference in mRS between all patients (cohort 2: 3 [2–5]; n=544, in the GTN group vs 3 [2–5]; n=558, in the sham group; 1·04 [0·84–1·29]; p=0·69). We found no difference in secondary outcomes, death (treatment-related deaths: 36 in the GTN group vs 23 in the sham group [p=0·091]), or serious adverse events (188 in the GTN group vs 170 in the sham group [p=0·16]) between treatment groups. Interpretation Prehospital treatment with transdermal GTN does not seem to improve functional outcome in patients with presumed stroke. It is feasible for UK paramedics to obtain consent and treat patients with stroke in the ultraacute prehospital setting