Density-Dependent Prophylaxis in Freshwater Snails Driven by Oxylipin Chemical Cues.

While animal aggregations can benefit the fitness of group members, the behaviour may also lead to higher risks of parasite infection as group density increases. Some animals are known to moderate their investment in immunity relative to the risk of infection. These animals exhibit density-dependent prophylaxis (DDP) by increasing their immune investment as group density increases. Despite being documented in many taxa, the mechanisms of DDP remain largely unexplored. Snails are known to aggregate and experience large fluctuations in density and serve as required hosts for many parasites. Further, they are known to use chemical cues to aggregate. To test whether freshwater snails exhibit DDP and investigate the role that chemical signaling compounds may play in triggering this phenomenon, we performed four experiments on the freshwater snail Stagnicola elodes, which is a common host for many trematode parasite species. First, we tested if DDP occurred in snails in laboratory-controlled conditions (control vs snail-conditioned water) and whether differences in exposure to chemical cues affected immune function. Second, we used gas chromatography to characterize fatty acids expressed in snail-conditioned water to determine if precursors for particular signaling molecules, such as oxylipins, were being produced by snails. Third, we characterized the oxylipins released by infected and uninfected field-collected snails, to better understand how differences in oxylipin cocktails may play a role in inducing DDP. Finally, we tested the immune response of snails exposed to four oxylipins to test the ability of specific oxylipins to affect DDP. We found that snails exposed to water with higher densities of snails and raised in snail-conditioned water had higher counts of haemocytes. Additionally, lipid analysis demonstrated that fatty acid molecules that are also precursors for oxylipins were present in snail-conditioned water. Trematode-infected snails emitted 50 oxylipins in higher amounts, with 24 of these oxylipins only detected in this group. Finally, oxylipins that were higher in infected snails induced naïve snails to increase their immune responses compared to sham-exposed snails. Our results provide evidence that snails exhibit DDP, and the changes in oxylipins emitted by infected hosts may be one of the molecular mechanisms driving this phenomenon.

Isotopic turnover rates and diet-tissue discrimination depend on feeding habits of freshwater snails.

Estimates of animal diets and trophic structure using stable isotope analysis are strongly affected by diet-tissue discrimination and tissue turnover rates, yet these factors are often unknown for consumers because they must be measured using controlled-feeding studies. Furthermore, these parameters may be influenced by diet quality, growth, and other factors. We measured the effect of dietary protein content on diet-tissue discrimination and tissue turnover in three freshwater snail species. We fed lettuce to individually housed snails (n = 450 per species) for ten weeks, then half were switched to a high-protein diet. Isotopic values of muscle and gonad tissue were assessed at 48 and 80 days post-diet change. Snail discrimination factors varied by diet (low-protein > high-protein) and usually differed among species for both N and C, although species had similar carbon discrimination when fed the low-protein diet. Carbon turnover rates were similar among species for a given tissue type, but nitrogen turnover varied more among species. In addition, diet affected growth of species differently; some species grew larger on high-protein (H. trivolvis) while others grew larger on low-protein diet (Lymnaea spp.). These differences among species in growth influenced turnover rates, which were faster in the species with the highest growth rate following the diet switch from low to high-protein. Thus, growth is one of the main processes that affects tissue turnover, but growth and feeding preference did not affect diet-tissue discrimination, which was greater on low-protein than high-protein diets for all species regardless of growth performance. These results suggest that diet might influence two key parameters of stable isotope analysis differently.

Phenological responses to nitrogen and water addition are linked to plant growth patterns in a desert herbaceous community.

Increases in nitrogen (N) deposition and variation in precipitation have been occurring in temperate deserts; however, little information is available regarding plant phenological responses to environmental cues and their relationships with plant growth pattern in desert ecosystems. In this study, plant phenology and growth of six annuals in response to N and water addition were monitored throughout two consecutive growing seasons in 2011 and 2012 in a temperate desert in northwestern China. The effects of N and water addition on reproductive phenology differed among plant species. N and water addition consistently advanced the flowering onset time and fruiting time of four spring ephemerals; however, their effects on two spring-summer annuals were inconsistent, with advances being noted in one species and delays in another. N and water addition alone increased plant height, relative growth rate, leaf number, flower number, and individual biomass, while their combinative effects on plant growth and reproductive phenology were dependent on species. Multiple regression analysis showed that flowering onset time was negatively correlated with relative growth rate of two species, and negatively correlated with maximum plant height of the other four species. Our study demonstrates that phenological responses to increasing precipitation and N deposition varied in annuals with different life histories, whereby the effects of climate change on plant growth rate were related to reproductive phenology. Desert annuals that were able to accelerate growth rate under increasing soil resource availability tended to advance their flowering onset time to escape drought later in the growing season. This study promotes our understanding of the responses of temperate desert annuals to increasing precipitation and N deposition in this desert.

The efficacy of homemade tolcapone in the treatment of patients with Parkinsons disease.

The aim of the study was to investigate the efficacy of homemade tolcapone in treatment of patients with Parkinson's disease (PD). Eighty patients with PD were subjected to randomized, double-blind, placebo-controlled and parallel-group study. PD patients were randomly divided into the tolcapone treatment group (41 cases) and placebo group (39 cases). Each patient received 1 pill of tolcapone or placebo, 3 times per day for 26 weeks. Efficacy was evaluated using the internationally used unified Parkinson's disease rating scale (UPDRS) scoring system for PD symptoms. After the treatment for 26 weeks, the cognitive function, tremor, muscle stiffness, voluntary movement and autonomic nerve symptoms were compared between the two groups using UPDRS scores. Compared with the placebo group, cognitive function, muscle stiffness and voluntary movement reduction were significantly improved in patients of the tolcapone group (P<0.05). However, no significant differences in UPDRS scores of autonomic nerve symptoms and tremor were found between two groups after treatment (P>0.05). Tolcapone, a catechol-O-methyl transferase (COMT) inhibitor, can improve the motor function of patients with PD, especially exercise and muscle stiffness. Tolcapone can also improve the cognitive function of patients.

Low cholesterol level associated with severity and outcome of spontaneous intracerebral hemorrhage: Results from Taiwan Stroke Registry.

The relationship between cholesterol level and hemorrhagic stroke is inconclusive. We hypothesized that low cholesterol levels may have association with intracerebral hemorrhage (ICH) severity at admission and 3-month outcomes. This study used data obtained from a multi-center stroke registry program in Taiwan. We categorized acute spontaneous ICH patients, based on their baseline levels of total cholesterol (TC) measured at admission, into 3 groups with <160, 160-200 and >200 mg/dL of TC. We evaluated risk of having initial stroke severity, with National Institutes of Health Stroke Scale (NIHSS) >15 and unfavorable outcomes (modified Rankin Scale [mRS] score >2, 3-month mortality) after ICH by the TC group. A total of 2444 ICH patients (mean age 62.5±14.2 years; 64.2% men) were included in this study and 854 (34.9%) of them had baseline TC <160 mg/dL. Patients with TC <160 mg/dL presented more often severe neurological deficit (NIHSS >15), with an adjusted odds ratio [aOR] of 1.80; 95% confidence interval [CI], 1.41-2.30), and 3-month mRS >2 (aOR, 1.41; 95% CI, 1.11-1.78) using patients with TC >200 mg/dL as reference. Those with TC >160 mg/dL and body mass index (BMI) <22 kg/m2 had higher risk of 3-month mortality (aOR 3.94, 95% CI 1.76-8.80). Prior use of lipid-lowering drugs (2.8% of the ICH population) was not associated with initial severity and 3-month outcomes. A total cholesterol level lower than 160 mg/dL was common in patients with acute ICH and was associated with greater neurological severity on presentation and poor 3-month outcomes, especially with lower BMI.

Profile Changes in the Soil Microbial Community When Desert Becomes Oasis.

The conversion of virgin desert into oasis farmland creates two contrasting types of land-cover. During oasis formation with irrigation and fertilizer application, however, the changes in the soil microbial population, which play critical roles in the ecosystem, remain poorly understood. We applied high-throughput pyrosequencing to investigate bacterial and archaeal communities throughout the profile (0-3 m) in an experimental field, where irrigation and fertilization began in 1990 and cropped with winter wheat since then. To assess the effects of cultivation, the following treatments were compared with the virgin desert: CK (no fertilizer), PK, NK, NP, NPK, NPKR, and NPKM (R: straw residue; M: manure fertilizer). Irrigation had a greater impact on the overall microbial community than fertilizer application. The greatest impact occurred in topsoil (0-0.2 m), e.g., Cyanobacteria (25% total abundance) were most abundant in desert soil, while Actinobacteria (26%) were most abundant in oasis soil. The proportions of extremophilic and photosynthetic groups (e.g., Deinococcus-Thermus and Cyanobacteria) decreased, while the proportions of R-strategy (e.g., Gammaproteobacteria including Xanthomonadales), nitrifying (e.g., Nitrospirae), and anaerobic bacteria (e.g., Anaerolineae) increased throughout the oasis profile. Archaea occurred only in oasis soil. The impact of fertilizer application was mainly reflected in the non-dominant communities or finer taxonomic divisions. Oasis formation led to a dramatic shift in microbial community and enhanced soil enzyme activities. The rapidly increased soil moisture and decreased salt caused by irrigation were responsible for this shift. Furthermore, difference in fertilization and crop growth altered the organic carbon contents in the soil, which resulted in differences of microbial communities within oasis.

Use of Intravenous Thrombolytic Therapy in Acute Ischemic Stroke Patients: Evaluation of Clinical Outcomes.

The use of intravenous thrombolytic therapy (ITT) in acute ischemic stroke (AIS) patients is still debated in China. We present the analysis of clinico-demographic retrospective data of 646 AIS patients that were treated by alteplase ITT at our hospital. The data collected included age, gender, education, income, drug use before disease onset, and awareness of stroke/ITT. The risk factors studied were hypertension, diabetes, hyperlipidemia, atrial fibrillation, coronary heart disease, cerebral infarction, transient ischemic attack, valvular heart disease, thyroid disease, migraine, asymptomatic carotid stenosis, family history of stroke, hyperhomocysteinemia, smoking, drinking, and gingivitis. Pre-ITT patient data included blood pressure and time from onset to hospital. Post-ITT patient data included National Institutes of Health Stroke Scale (NIHSS) scores, clinical outcome, revascularization, hemorrhage, healing rate, and 90-day mortality. Hospital management information included monthly ITT cases, discharges, bed turnaround times, length of hospital stay, bed utilization, drug ratio, massive cerebral infarction decompressive craniectomy, and social impact. Prognosis evaluation was based on post-ITT NIHSS and modified Rankin Scale (mRS) scores. We found that ITT success rate was 75.85 %, with a bleeding rate of 1.55 % and a 90-day mortality rate of 2.01 %. Overall, the data suggest that the ITT therapy was highly successful in AIS patients treated at our hospital.

Safety and Effectiveness of Intravenous Thrombolysis with Recombinant Tissue Plasminogen Activator in 80 Years and Older Acute Ischemic Stroke Patients.

This study aims to explore the safety and efficacy of intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator (rt-PA) in elderly (≥80 years old) acute ischemic stroke (AIS) patients. The clinical data of patients who were treated in Tianjin Huanhu Hospital from June 2012 to November 2013 were retrospectively analyzed; among them, 404 patients had received IVT with rt-PA and 200 patients had not received IVT. Among ≥80-year-old patients, 204 had received IVT and 200 had not. And the 404 patients who had received IVT were divided into two subgroups: elderly (≥80 years of age; n = 204) and controls (<80 years old; n = 200). The incidence of intracranial hemorrhage (ICH) and symptomatic intracranial hemorrhage, case fatality rate, and other prognostic indicators were compared. Among all ≥80-year-old patients, the IVT subgroup had significantly superior good outcome rates than the non-IVT subgroup at 24-h and 3-month along with significantly lower case fatality rate. But for the patients those who had received IVT, the incidence of ICH and the 7-day case fatality rate were not significantly increased in both the elderly and control subgroups. The 24-h and 3-month good outcome rates were not significantly different between these two subgroups as well. IVT with rt-PA is a safe and effective treatment for ≥80-year-old AIS patients.

Automated segmentation and quantification of white matter hyperintensities in acute ischemic stroke patients with cerebral infarction.

White matter hyperintensities (WMHs) of presumed vascular origin are common in ageing population, especially in patients with acute cerebral infarction and the volume has been reported to be associated with mental impairment and the risk of hemorrhage from antithrombotic agents. WMHs delineation can be computerized to minimize human bias. However, the presence of cerebral infarcts greatly degrades the accuracy of WMHs detection and thus limits the application of computerized delineation to patients with acute cerebral infarction. We propose a computer-assisted segmentation method to depict WMHs in the presence of cerebral infarcts in combined T1-weighted, fluid attenuation inversion recovery, and diffusion-weighted magnetic resonance imaging (MRI). The proposed method detects WMHs by empirical threshold and atlas information, with subtraction of white matter voxels affected by acute infarction. The method was derived using MRI from 25 hemispheres with WMHs only and 13 hemispheres with both WMHs and cerebral infarcts. Similarity index (SI) and correlation were utilized to assess the agreement between the new automated method and a gold standard visually guided semi-automated method done by an expert rater. The proposed WMHs segmentation approach produced average SI, sensitivity and specificity of 83.142±11.742, 84.154±16.086 and 99.988±0.029% with WMHs only and of 68.826±14.036, 74.381±18.473 and 99.956±0.054% with both WMHs and cerebral infarcts in the derivation cohort. The performance of the proposed method with an external validation cohort was also highly consistent with that of the experienced rater.

Proteinuria independently predicts unfavorable outcome of ischemic stroke patients receiving intravenous thrombolysis.

BACKGROUND AND PURPOSE: Patients with low estimated glomerular filtration rate (eGFR) and proteinuria may be at increased risk for stroke. This study investigated whether low eGFR and proteinuria are outcome predictors in stroke patients treated with intravenous thrombolysis. METHODS: We studied 432 consecutive stroke patients who received thrombolysis from January 2006 to December 2012, in Taiwan. Unfavorable outcome was defined as modified Rankin scale ≥2 at 3 months after stroke. Proteinuria was classified as negative or trace, mild, and moderate to severe. Using logistic regression analysis, we identified independent factors for unfavorable outcome after thrombolysis. RESULTS: Of all patients, 32.7% had proteinuria. Patients with proteinuria were older, had higher frequencies of diabetes mellitus, hyperlipidemia, atrial fibrillation, lower eGFR, and greater severity of stroke upon admission than those without proteinuria. Proteinuria, not low eGFR, was an independent predictor for unfavorable outcome for stroke (OR = 2.00 for mild proteinuria, p = 0.035; OR = 2.54 for moderate to severe proteinuria, p = 0.035). However, no clear relationship was found between proteinuria and symptomatic hemorrhage after thrombolysis. CONCLUSIONS: Proteinuria is an independent predictor of unfavorable outcome for acute ischemic stroke in patients treated with intravenous thrombolysis, indicating the crucial role of chronic kidney disease on the effectiveness of thrombolysis.

Eosinophilic meningitis caused by Angiostrongylus cantonensis in an adolescent with mental retardation and pica disorder.

Eosinophilic meningitis or encephalitis is a rare disorder and is most commonly caused by Angiostrongylus cantonensis. Humans are accidentally infected when they ingest raw snails or vegetables contaminated with the parasite larvae. Because of the improvement in sanitary food handling practices, the occurrence of A. cantonensis eosinophilic meningitis has been decreasing in Taiwan in recent decades. The common symptoms and signs of eosinophilic meningitis are severe headache, neck stiffness, paresthesia, vomiting, nausea, and fever. Acute urinary retention is a rare presentation. We report a case of A. cantonensis eosinophilic meningitis in an intellectually disabled patient who presented with acute urinary retention without any other meningeal signs. The patient received supportive treatment with corticosteroid therapy and was discharged and received urinary rehabilitation at home.

[Eighteen cases of 2009 influenza A H1N1 associated with respiratory failure in adults].

OBJECTIVE: To investigate the clinical feature, treatment and outcome of respiratory failure in patients with 2009 influenza A H1N1 infection in critically ill adults. METHODS: A prospective observational study of 18 patients with respiratory failure suffering from 2009 influenza A H1N1 infection admitted between November 22, 2009 and January 16, 2010. Their clinical data were analyzed. RESULTS: Respiratory failure occurred in 18 patients with confirmed (n=9) or probable (n=9) 2009 influenza A H1N1. Among the 18 patients 8 patients were male, 10 patients were female (7 were pregnant or postpartum). Eight patients had pre-existing medical conditions. Twelve patients were between 20 and 40 years of age, the mean age was 37.1 years. Three were obese with body mass index over 30 kg/m (2). The 28-day mortality was 33.3% (6/18) with 1 additional late death. The median duration from the onset of the illness to hospital admission was 4.1 days (1-5 days) and from the onset to first dose of oseltamivir was 5.5 days (2-12 days), from onset to mechanical ventilation initiation was 6.8 days (4-12 days). Seventeen patients had primary viral pneumonia and 1 patient had an asthma exacerbation and 3 patients experienced multiple organ dysfunction syndrome (MODS). Twelve patients received corticosteroids, 10 patients required vasopressors. All patients were mechanically ventilated, 1 patient underwent extracorporeal membrane oxygenation (ECMO). Patients who died had higher acute physiology and chronic health evaluation II score compared to survivors (29.2 + or - 7.3 vs. 18.6 + or - 6.4, P=0.02). All deceased patients received high-level ventilation settings [peak inspiratory pressure > or = 35 cm H(2)O (1 cm H(2)O=0.098 kPa) and positive end-expiratory pressure > or = 18 cm H(2)O] within the first 7 days of ventilation, and the hypoxemia [oxygenation index < or = 60 mm Hg (1 mm Hg=0.133 kPa)] lasted 24 hours. In contrast only 1 among survivors did (9.1% vs. 100.0%, P<0.01). Compared with survivors, acute kidney injury and barotrauma occurred more frequently in non-survivors (42.9% vs. 27.3%, 28.6% vs. 9.1%, both P<0.05). Whereas all deceased patients received vasopressors, only 4 survivors required vasopressor support (100.0% vs. 36.4%, P<0.05). CONCLUSION: Severe acute respiratory distress syndrome is the most common manifestation in critically ill patients with 2009 influenza A H1N1 infection in adult. Failure to obtain satisfactory oxygenation with high-level ventilation settings within the first 7-days, onset of acute kidney injury and barotrauma, and continuous need for vasopressors portend a poor prognosis.

[Clinical effects of low-stretch ventilation on acute respiratory distress syndrome].

OBJECTIVE: To investigate the effectiveness of low-stretch as compared with low-tidal-volume strategy in the treatment of acute respiratory distress syndrome (ARDS). METHODS: Eighty-five cases of ARDS patients were randomly divided into low-stretch group (42 cases) and low-tidal-volume group (43 cases). The former group of patient received pressure assist control mode with not higher than 35 cm H(2)O (1 cm H(2)O=0.098 kPa) of peak pressure or pressure support mode ventilation with not higher than 30 cm H(2)O of Pplateau, while in low-tidal-volume group tidal volume of no more than 6 ml/kg of predicted body weight was given. The mortality rate within 28 days, the incidence of hypercapnia, the duration of using sedatives and neuromuscular blockade agents, the time of ventilation and the length of intensive care unit (ICU) stay were compared between two groups. According to the monitored expiratory tidal volume (V(T)e), the low-stretch group was divided into low-tidal-volume subgroup (V(T)e < or =6 ml/kg, 11 cases) and non-low-tidal-volume subgroup (V(T)e >6 ml/kg, 31 cases). The mortality within 28 days and the incidence of hypercapnia were compared between two subgroups. RESULTS: There was no significant difference in the 28-day mortality rate between two groups (34.0% vs. 37.0%, P>0.05), but patients of low-stretch group had lower incidence of hypercapnia than low-tidal-volume group (10.6% vs. 40.7%, P<0.05), and also the duration of using sedatives [(4.5+/-1.2) days vs. (8.7+/-2.3) days] and neuromuscular blockade agents [(8.4+/-2.1) days vs. (10.7+/-1.2) days], and the length of ventilation and ICU stay [(10.2+/-2.2) days vs. (13.7+/-3.1) days, all P<0.05] were less. Low tidal volume occurred in 26.2% of low-stretch group, and the low-tidal-volume subgroup had higher 28-day mortality rate (40.8%) and incidence of hypercapnia (65.7%) than non-low-tidal-volume subgroup (13.2% and 8.6%, both P<0.05). CONCLUSION: Compared with low-tidal-volume strategy, low-stretch strategy can reduce the incidence of hypercapnia, the length of ventilation and ICU stay for ARDS patients, but have similar mortality rate. When low-stretch strategy is exercised, an inappropriate low tidal volume may be associated with poor outcome of ARDS.

[Construction of middle fragment deletion mutant with improved gene splicing by overlap extension].

OBJECTIVE: To construct a phosphatidylinositol 4-kinase beta (PI4K-beta) mutant with the 325th to 373rd amino acid codons deleted, and try to develop a simple method for constructing middle fragment deletion mutant. METHODS: In line with the mechanism of gene splicing by overlap extension(SOE), an additional PCR was used to get the PI4K-beta mutant in which the 325th to 373rd amino acid codons were deleted. Then the mutated gene was cloned into pCMV-Tag4A mammalian expression vector. RESULTS: A mutant with the 325th to 373rd amino acid codons deleted was constructed successfully. CONCLUSION: The improved SOE is a very effective and reliable method to construct middle fragment deletion mutant. It is worthy to be popularized.