Increased GH responsiveness to dopamine receptor stimulation in alcohol addicts during the late withdrawal syndrome

In humans the release of growth hormone (GH) elicited by dopamine (DA) and DA agonists may represent a reliable model to assess change in sensitivity of DA receptors. We now report that in chronic alcoholics, 4–7 days after the suspension of alcohol consumption, the increase of GH response to DA infusion was higher than that seen in non alcoholic volunteers. The specificity of this GH response to DA administration was demonstrated by the use of domperidone, a novel peripheral antagonist of DA receptors. These results suggest the development of hyper-responsiveness of DA receptors involved in the control of GH secretion in chronic alcoholics during the later phases of the “withdrawal syndrome”.     

Chymotrypsin-like enzymes are involved in sperm penetration through the vitelline coat of Ciona intestinalis egg

In Ciona intestinalis, sperm penetration through the egg vitelline coat is an essential event of fertilization. We investigated whether trypsin- and chymotrypsin-like enzymes are involved in this event. Inhibitors and peptide substrates for chymotrypsin-like enzymes blocked the overall process of fertilization in a concentration-dependent manner. The inhibitory activity was specifically exerted on the step of sperm penetration. Chymotrypsin-like protease activity was identified in spermatozoa with the fluorogenic synthetic substrate Suc-Ala-Ala-Phe-AMC, which was the most effective substrate in blocking sperm penetration. These data indicate that a chymotrypsin-like protease activity is a sperm lysin of Ciona intestinalis.     

Destruction of gram-negative food-borne pathogens by high pH involves disruption of the cytoplasmic membrane.

High pH has been shown to rapidly destroy gram-negative food-borne pathogens; however, the mechanism of destruction has not yet been elucidated. Escherichia coli O157:H7, Salmonella enteritidis ATCC 13706, and Listeria monocytogenes F5069 were suspended in NaHCO3-NaOH buffer solutions at pH 9, 10, 11, or 12 to give a final cell concentration of approximately 5.2 x 10(8) CFU/ml and then held at 37 or 45 degrees C. At 0, 5, 10, and 15 min the suspensions were sterilely filtered and each filtrate was analyzed for material with A260. Viability of the cell suspensions was evaluated by enumeration on nonselective and selective agars. Cell morphology was evaluated by scanning electron microscopy and transmission electron microscopy. A260 increased dramatically with pH and temperature for both E. coli and S. enteritidis; however, with L. monocytogenes material with A260 was not detected at any of the pHs tested. At pH 12, numbers of E. coli and S. enteritidis decreased at least 8 logs within 15 s, whereas L. monocytogenes decreased by only 1 log in 10 min. There was a very strong correlation between the initial rate of release of material with A260 and death rate of the gram-negative pathogens (r = 0.997). At pH 12, gram-negative test cells appeared collapsed and showed evidence of lysis while gram-positive L. monocytogenes did not, when observed by scanning and transmission electron microscopy. It was concluded that destruction of gram-negative food-borne pathogens by high pH involves disruption of the cytoplasmic membrane.     

A comparison of diversity estimators applied to a database of host–parasite associations

Understanding the drivers of biodiversity is important for forecasting changes in the distribution of life on earth. However, most studies of biodiversity are limited by uneven sampling effort, with some regions or taxa better sampled than others. Numerous methods have been developed to account for differences in sampling effort, but most methods were developed for systematic surveys in which all study units are sampled using the same design and assemblages are sampled randomly. Databases compiled from multiple sources, such as from the literature, often violate these assumptions because they are composed of studies that vary widely in their goals and methods. Here, we compared the performance of several popular methods for estimating parasite diversity based on a large and widely used parasite database, the Global Mammal Parasite Database (GMPD). We created artificial datasets of host–parasite interactions based on the structure of the GMPD, then used these datasets to evaluate which methods best control for differential sampling effort. We evaluated the precision and bias of seven methods, including species accumulation and nonparametric diversity estimators, compared to analyzing the raw data without controlling for sampling variation. We find that nonparametric estimators, and particularly the Chao2 and second-order jackknife estimators, perform better than other methods. However, these estimators still perform poorly relative to systematic sampling, and effect sizes should be interpreted with caution because they tend to be lower than actual effect sizes. Overall, these estimators are more effective in comparative studies than for producing true estimates of diversity. We make recommendations for future sampling strategies and statistical methods that would improve estimates of global parasite diversity.     

Exercise training in childhood-onset systemic lupus erythematosus: a controlled randomized trial

Introduction

Exercise training has emerged as a promising therapeutic strategy to counteract physical dysfunction in adult systemic lupus erythematosus. However, no longitudinal studies have evaluated the effects of an exercise training program in childhood-onset systemic lupus erythematosus (C-SLE) patients. The objective was to evaluate the safety and the efficacy of a supervised aerobic training program in improving the cardiorespiratory capacity in C-SLE patients.

Methods

Nineteen physically inactive C-SLE patients were randomly assigned into two groups: trained (TR, n = 10, supervised moderate-intensity aerobic exercise program) and non-trained (NT, n = 9). Gender-, body mass index (BMI)- and age-matched healthy children were recruited as controls (C, n = 10) for baseline (PRE) measurements only. C-SLE patients were assessed at PRE and after 12 weeks of training (POST). Main measurements included exercise tolerance and cardiorespiratory measurements in response to a maximal exercise (that is, peak VO₂, chronotropic reserve (CR), and the heart rate recovery (ΔHRR) (that is, the difference between HR at peak exercise and at both the first (ΔHRR1) and second (ΔHRR2) minutes of recovery after exercise).

Results

The C-SLE NT patients did not present changes in any of the cardiorespiratory parameters at POST (P > 0.05). In contrast, the exercise training program was effective in promoting significant increases in time-to-exhaustion (P = 0.01; ES = 1.07), peak speed (P = 0.01; ES = 1.08), peak VO₂ (P = 0.04; ES = 0.86), CR (P = 0.06; ES = 0.83), and in ΔHRR1 and ΔHRR2 (P = 0.003; ES = 1.29 and P = 0.0008; ES = 1.36, respectively) in the C-SLE TR when compared with the NT group. Moreover, cardiorespiratory parameters were comparable between C-SLE TR patients and C subjects after the exercise training intervention, as evidenced by the ANOVA analysis (P > 0.05, TR vs. C). SLEDAI-2K scores remained stable throughout the study.

Conclusion

A 3-month aerobic exercise training was safe and capable of ameliorating the cardiorespiratory capacity and the autonomic function in C-SLE patients.

Trial registration

NCT01515163.     

Automated Entire Thrombus Density Measurements for Robust and Comprehensive Thrombus Characterization in Patients with Acute Ischemic Stroke

Background and Purpose

In acute ischemic stroke (AIS) management, CT-based thrombus density has been associated with treatment success. However, currently used thrombus measurements are prone to inter-observer variability and oversimplify the heterogeneous thrombus composition. Our aim was first to introduce an automated method to assess the entire thrombus density and then to compare the measured entire thrombus density with respect to current standard manual measurements.

Materials and Method

In 135 AIS patients, the density distribution of the entire thrombus was determined. Density distributions were described using medians, interquartile ranges (IQR), kurtosis, and skewedness. Differences between the median of entire thrombus measurements and commonly applied manual measurements using 3 regions of interest were determined using linear regression.

Results

Density distributions varied considerably with medians ranging from 20.0 to 62.8 HU and IQRs ranging from 9.3 to 55.8 HU. The average median of the thrombus density distributions (43.5 ± 10.2 HU) was lower than the manual assessment (49.6 ± 8.0 HU) (p<0.05). The difference between manual measurements and median density of entire thrombus decreased with increasing density (r = 0.64; p<0.05), revealing relatively higher manual measurements for low density thrombi such that manual density measurement tend overestimates the real thrombus density.

Conclusions

Automatic measurements of the full thrombus expose a wide variety of thrombi density distribution, which is not grasped with currently used manual measurement. Furthermore, discrimination of low and high density thrombi is improved with the automated method.     

Inter-simple sequence repeat markers and flow cytometry for the characterization of closely related Citrus limon germplasms

The genetic relationship among commercial cultivars of Citrus limon (lemon) was analysed by inter-simple sequence repeats (ISSR) and flow cytometry techniques. Two cultivars with a close germplasm were distinguished by screening 10 SSR primers and by measuring DNA content of prestained nuclei.     

Synthesis of diastereomerically enriched 2-bromoesters and their reaction with nucleophiles

2-Bromoesters enriched in the (S,R)-diastereoisomer can be easily prepared by coupling of racemic 2-bromoacids with (R)-pantolactone. Displacement of the bromine atom with nucleophiles, under suitable reaction conditions, occurs without epimerization of starting compounds, giving (R,R)-2-substituted carboxylic acid derivatives.