Root cortical burden influences drought tolerance in maize

Background and Aims

Root cortical aerenchyma (RCA) increases water and nutrient acquisition by reducing the metabolic costs of soil exploration. In this study the hypothesis was tested that living cortical area (LCA; transversal root cortical area minus aerenchyma area and intercellular air space) is a better predictor of root respiration, soil exploration and, therefore, drought tolerance than RCA formation or root diameter.

Methods

RCA, LCA, root respiration, root length and biomass loss in response to drought were evaluated in maize (Zea mays) recombinant inbred lines grown with adequate and suboptimal irrigation in soil mesocosms.

Key Results

Root respiration was highly correlated with LCA. LCA was a better predictor of root respiration than either RCA or root diameter. RCA reduced respiration of large-diameter roots. Since RCA and LCA varied in different parts of the root system, the effects of RCA and LCA on root length were complex. Greater crown-root LCA was associated with reduced crown-root length relative to total root length. Reduced LCA was associated with improved drought tolerance.

Conclusions

The results are consistent with the hypothesis that LCA is a driver of root metabolic costs and may therefore have adaptive significance for water acquisition in drying soil.     

Insulin-like peptides and the target of rapamycin pathway coordinately regulate blood digestion and egg maturation in the mosquito Aedes aegypti

Background

Mosquitoes are insects that vector many serious pathogens to humans and other vertebrates. Most mosquitoes must feed on the blood of a vertebrate host to produce eggs. In turn, multiple cycles of blood feeding promote frequent contacts with hosts and make mosquitoes ideal disease vectors. Both hormonal and nutritional factors are involved in regulating egg development in the mosquito, Aedes aegypti. However, the processes that regulate digestion of the blood meal remain unclear.

Methodology/Principal Findings

Here we report that insulin peptide 3 (ILP3) directly stimulated late phase trypsin-like gene expression in blood fed females. In vivo knockdown of the mosquito insulin receptor (MIR) by RNA interference (RNAi) delayed but did not fully inhibit trypsin-like gene expression in the midgut, ecdysteroid (ECD) production by ovaries, and vitellogenin (Vg) expression by the fat body. In contrast, in vivo treatment with double-stranded MIR RNA and rapamycin completely blocked egg production. In vitro experiments showed that amino acids did not simulate late phase trypsin-like gene expression in the midgut or ECD production by the ovaries. However, amino acids did enhance ILP3-mediated stimulation of trypsin-like gene expression and ECD production.

Conclusions/Significance

Overall, our results indicate that ILPs from the brain synchronize blood meal digestion and amino acid availability with ovarian ECD production to maximize Vg expression by the fat body. The activation of digestion by ILPs may also underlie the growth promoting effects of insulin and TOR signaling in other species.     

The Warburg Effect Suppresses Oxidative Stress Induced Apoptosis in a Yeast Model for Cancer

Background

Otto Warburg observed that cancer cells are often characterized by intense glycolysis in the presence of oxygen and a concomitant decrease in mitochondrial respiration. Research has mainly focused on a possible connection between increased glycolysis and tumor development whereas decreased respiration has largely been left unattended. Therefore, a causal relation between decreased respiration and tumorigenesis has not been demonstrated.

Methodology/Principal Findings

For this purpose, colonies of Saccharomyces cerevisiae, which is suitable for manipulation of mitochondrial respiration and shows mitochondria-mediated cell death, were used as a model. Repression of respiration as well as ROS-scavenging via glutathione inhibited apoptosis and conferred a survival advantage during seeding and early development of this fast proliferating solid cell population. In contrast, enhancement of respiration triggered cell death.

Conclusion/Significance

Thus, the Warburg effect might directly contribute to the initiation of cancer formation - not only by enhanced glycolysis - but also via decreased respiration in the presence of oxygen, which suppresses apoptosis.     

Co-Sensitization to Silkworm Moth (Bombyx mori) and 9 Inhalant Allergens among Allergic Patients in Guangzhou,Southern China

Objectives

This study aimed to investigate the profile of sensitization to silkworm moth (Bombyx mori) and other 9 common inhalant allergens among patients with allergic diseases in southern China.

Methods

A total of 175 patients were tested for serum sIgE against silkworm moth in addition to combinations of other allergens: Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis, Blattella germanica, Periplaneta americana, cat dander, dog dander, Aspergillus fumigatus and Artemisia vulgaris by using the ImmunoCAP system. Correlation between sensitization to silkworm moth and to the other allergens was analyzed.

Results

Of the 175 serum samples tested, 86 (49.14%) were positive for silkworm moth sIgE. With high concordance rates, these silkworm moth sensitized patients were concomitantly sensitized to Dermatophagoides pteronyssinus (94.34%), Dermatophagoides farinae (86.57%), Blomia tropicalis (93.33%), Blattella germanica (96.08%), and Periplaneta americana (79.41%). Moreover, there was a correlation in serum sIgE level between silkworm moth and Dermatophagoides pteronyssinus (r = 0.518), Dermatophagoides farinae (r = 0.702), Blomia tropicalis (r = 0.701), Blattella germanica (r = 0.878), and Periplaneta americana (r = 0.531) among patients co-sensitized to silkworm moth and each of these five allergens.

Conclusion

In southern Chinese patients with allergic diseases, we showed a high prevalence of sensitization to silkworm moth, and a co-sensitization between silkworm moth and other five common inhalant allergens. Further serum inhibition studies are warranted to verify whether cross-reactivity exists among these allergens.     

The earliest evidence of holometabolan insect pupation in conifer wood

Background

The pre-Jurassic record of terrestrial wood borings is poorly resolved, despite body fossil evidence of insect diversification among xylophilic clades starting in the late Paleozoic. Detailed analysis of borings in petrified wood provides direct evidence of wood utilization by invertebrate animals, which typically comprises feeding behaviors.

Methodology/Principal Findings

We describe a U-shaped boring in petrified wood from the Late Triassic Chinle Formation of southern Utah that demonstrates a strong linkage between insect ontogeny and conifer wood resources. Xylokrypta durossi new ichnogenus and ichnospecies is a large excavation in wood that is backfilled with partially digested xylem, creating a secluded chamber. The tracemaker exited the chamber by way of a small vertical shaft. This sequence of behaviors is most consistent with the entrance of a larva followed by pupal quiescence and adult emergence — hallmarks of holometabolous insect ontogeny. Among the known body fossil record of Triassic insects, cupedid beetles (Coleoptera: Archostemata) are deemed the most plausible tracemakers of Xylokrypta, based on their body size and modern xylobiotic lifestyle.

Conclusions/Significance

This oldest record of pupation in fossil wood provides an alternative interpretation to borings once regarded as evidence for Triassic bees. Instead Xylokrypta suggests that early archostematan beetles were leaders in exploiting wood substrates well before modern clades of xylophages arose in the late Mesozoic.     

The Relationship between Endogenous Androgens and Body Fat Distribution in Early and Late Postmenopausal Women

Objectives

To investigate the relationship between endogenous androgens and body fat distribution in early and late postmenopausal women.

Materials and Methods

We enrolled postmenopausal women consisting of an early group (≤5 years since menopause, n = 105) and a late group (≥10 years since menopause, n = 107). Each group was subdivided into normal weight (BMI <24 kg/m²) group, overweight and obese (BMI ≥24 kg/m²) group. Fasting total testosterone (T), dehydroepiandrosterone-sulfate (DHEA-S) and sex hormone-binding globulin (SHBG) levels were measured. Body fat distribution was evaluated by dual-energy X-ray absorptiometry (DEXA).

Results

Late postmenopausal women had a higher proportion of body fat than early postmenopausal women. The body fat of the overweight and obese women had a greater tendency to accumulate in the abdomen compared with the normal weight women both in early and late postmenopausal groups. The overweight and obese women had a higher free testosterone (FT) than the normal weight women in early postmenopausal women (P<0.05). In late postmenopausal women, the overweight and obese women had higher DHEA-S levels than normal weight women (P<0.05). No direct relationship was observed between the T levels and body fat distribution both in early and late postmenopausal groups (P>0.05).The FT in early postmenopausal women and the DHEA-S levels in late postmenopausal women correlated positively with the trunk/leg fat ratio (T/L) and the proportion of android fat whereas correlated negatively with the proportion of gynoid fat in the partial correlation and multiple linear regression analyses (all P<0.05).

Conclusions

Serum T levels do not correlate directly with body fat distribution, the FT in early postmenopausal women and DHEA-S levels in late postmenopausal women correlate positively with abdominal fat accumulation.     

Roots affect the response of heterotrophic soil respiration to temperature in tussock grass microcosms

Aims and Background

While the temperature response of soil respiration (R_S) has been well studied, the partitioning of heterotrophic respiration (R_H) by soil microbes from autotrophic respiration (R_A) by roots, known to have distinct temperature sensitivities, has been problematic. Further complexity stems from the presence of roots affecting R_H, the rhizosphere priming effect. In this study the short-term temperature responses of R_A and R_H in relation to rhizosphere priming are investigated.

Methods

Temperature responses of R_A, R_H and rhizosphere priming were assessed in microcosms of Poa cita using a natural abundance δ¹³C discrimination approach.

Results

The temperature response of R_S was found to be regulated primarily by R_A, which accounted for 70 % of total soil respiration. Heterotrophic respiration was less sensitive to temperature in the presence of plant roots, resulting in negative priming effects with increasing temperature.

Conclusions

The results emphasize the importance of roots in regulating the temperature response of R_S, and a framework is presented for further investigation into temperature effects on heterotrophic respiration and rhizosphere priming, which could be applied to other soil and vegetation types to improve models of soil carbon turnover.     

The effect of physical activity on serum IL-6 and vaspin levels in late elementary school children

[Purpose]

This study investigates the effects of physical activity on serum IL-6 and vaspin in late elementary school children.

[Methods]

Those who (n = 220) completed the 7-day physical activity monitoring underwent a second round of measurements including body fat, serum glucose and insulin, and serum IL-6 and vaspin. One way ANOVAs followed by LSD post hoc tests were used to test for significant differences in dependent variables across incremental physical activity levels at p=0.05. Multivariate stepwise linear regression analyses were used to determine significant predictors for serum IL-6 and vaspin levels at p=0.05.

[Results]

The results showed significant inverse linear trends for body fat parameters across incremental physical activity levels (from low to high); the lower the body fat, the higher the physical activity levels. On the other hand, there were no significant linear trends for insulin resistance markers or dietary intake across incremental physical activity levels. Multiple stepwise linear regression analyses were used to determine significant predictors for individual variations in serum IL-6 and vaspin in the study population. We found that body mass index (p=0.002) and low- and moderate-intensity physical activities (p=0.002 and p=0.0045, respectively) were significant determinants of serum IL-6. In addition, low- and moderate-intensity physical activities (p=0.01 & p=0.022, respectively) were significant determinants of serum vaspin levels in this study population.

[Conclusion]

In summary, the findings of the current study suggest that promotion of physical activity along with a healthy diet should be key components of lifestyle interventions to improve serum cytokine profiles associated with insulin resistance syndrome in late elementary school children.     

Cholecystolithiasis Is Associated with Clonorchis sinensis Infection

Background

The objective of this study was to analyze gallbladder stones for direct evidence of a relationship between Clonorchis sinensis infection and gallbladder stones formation.

Methodology

We investigated one hundred eighty-three gallbladder stones for the presence of Clonorchis sinensis eggs using microscopy, and analyzed their composition using Fourier transform infrared spectroscopy. We confirmed the presence of Clonorchis sinensis eggs in the gallbladder stones using real-time fluorescent PCR and scanning electron microscopy.

Principal Findings

Clonorchis sinensis eggs were detected in 122 of 183 gallbladder stones based on morphologic characteristics and results from real-time fluorescent PCR. The proportion of pigment stones, cholesterol stones and mixed gallstones in the egg-positive stones was 79.5% (97/122), 3.3% (4/122) and 17.2% (21/122), respectively, while 29.5% (18/61), 31.1% (19/61) and 39.3% (24/61) in the egg-negative stones. The proportion of pigment stone in the Clonorchis sinensis egg-positive stones was higher than in egg-negative stones (P<0.0001). In the 30 egg-positive stones examined by scanning electron microscopy, dozens or even hundreds of Clonorchis sinensis eggs were visible (×400) showing a distinct morphology. Many eggs were wrapped with surrounding particles, and in some, muskmelon wrinkles was seen on the surface of the eggs. Also visible were pieces of texture shed from some of the eggs. Some eggs were depressed or without operculum while most eggs were adhered to or wrapped with amorphous particles or mucoid matter (×3000).

Conclusion

Clonorchis sinensis eggs were detected in the gallbladder stones which suggests an association between Clonorchis sinensis infection and gallbladder stones formation, especially pigment stones.     

The relationship of creatine kinase variability with body composition and muscle damage markers following eccentric muscle contractions

[Purpose]

The purpose of the study was to investigate the relationship between CK variability and body composition and muscle damage markers following eccentric exercise.

[Methods]

Total 119 healthy male subjects were recruited to perform 50 eccentric contractions consisted of 2 sets of 25 contractions. Then, blood creatine kinase (CK) activity was analyzed to divide into three groups based on their CK activity levels. Maximum isometric strength (MIS), muscle soreness (SOR) and body composition data were obtained before and after exercise.

[Results]

The results showed that high CK responders had a significant decrease in MIS (p<0.001) and greater SOR (p<0.01) following eccentric exercise compared to low CK responders. Percent body fat was also higher in high responders compared to low responders (p=0.014). Peak CK activity was significantly correlated with MIS and SOR but no correlation with % body fat, muscle mass, and body mass index.

[Conclusion]

CK variability following eccentric exercise is closely related to MIS and SOR and % body fat may be a potent factor for CK variability.     

Effects of precipitation increase on soil respiration: a three-year field experiment in subtropical forests in china

Background

The aim of this study was to determine response patterns and mechanisms of soil respiration to precipitation increases in subtropical regions.

Methodology/Principal Findings

Field plots in three typical forests [i.e. pine forest (PF), broadleaf forest (BF), and pine and broadleaf mixed forest (MF)] in subtropical China were exposed under either Double Precipitation (DP) treatment or Ambient Precipitation (AP). Soil respiration, soil temperature, soil moisture, soil microbial biomass and fine root biomass were measured over three years. We tested whether precipitation treatments influenced the relationship of soil respiration rate (R) with soil temperature (T) and soil moisture (M) using R = (a+cM)exp(bT), where a is a parameter related to basal soil respiration; b and c are parameters related to the soil temperature and moisture sensitivities of soil respiration, respectively. We found that the DP treatment only slightly increased mean annual soil respiration in the PF (15.4%) and did not significantly change soil respiration in the MF and the BF. In the BF, the increase in soil respiration was related to the enhancements of both soil fine root biomass and microbial biomass. The DP treatment did not change model parameters, but increased soil moisture, resulting in a slight increase in soil respiration. In the MF and the BF, the DP treatment decreased soil temperature sensitivity b but increased basal soil respiration a, resulting in no significant change in soil respiration.

Conclusion/Significance

Our results indicate that precipitation increasing in subtropical regions in China may have limited effects on soil respiration.     

A biomimetic membrane device that modulates the excessive inflammatory response to sepsis

Objective

Septic shock has a clinical mortality rate approaching fifty percent. The major clinical manifestations of sepsis are due to the dysregulation of the host''s response to infection rather than the direct consequences of the invading pathogen. Central to this initial immunologic response is the activation of leukocytes and microvascular endothelium resulting in cardiovascular instability, lung injury and renal dysfunction. Due to the primary role of leukocyte activation in the sepsis syndrome, a synthetic biomimetic membrane, called a selective cytopheretic device (SCD), was developed to bind activated leukocytes. The incorporation of the SCD along an extracorporeal blood circuit coupled with regional anticoagulation with citrate to lower blood ionized calcium was devised to modulate leukocyte activation in sepsis.

Design

Laboratory investigation.

Setting

University of Michigan Medical School.

Subjects

Pigs weighing 30-35 kg.

Interventions

To assess the effect of the SCD in septic shock, pigs were administered 30×10¹⁰ bacteria/kg body weight of Escherichia coli into the peritoneal cavity and within 1 hr were immediately placed in an extracorporeal circuit containing SCD.

Measurements and Main Results

In this animal model, the SCD with citrate compared to control groups without the SCD or with heparin anticoagulation ameliorated the cardiovascular instability and lung sequestration of activated leukocytes, reduced renal dysfunction and improved survival time compared to various control groups. This effect was associated with minimal elevations of systemic circulating neutrophil activation.

Conclusions

These preclinical studies along with two favorable exploratory clinical trials form the basis of an FDA-approved investigational device exemption for a pivotal multicenter, randomized control trial currently underway.     

Detailed analysis of variants in FTO in association with body composition in a cohort of 70-year-olds suggests a weakened effect among elderly

Background

The rs9939609 single-nucleotide polymorphism (SNP) in the fat mass and obesity (FTO) gene has previously been associated with higher BMI levels in children and young adults. In contrast, this association was not found in elderly men. BMI is a measure of overweight in relation to the individuals'' height, but offers no insight into the regional body fat composition or distribution.

Objective

To examine whether the FTO gene is associated with overweight and body composition-related phenotypes rather than BMI, we measured waist circumference, total fat mass, trunk fat mass, leg fat mass, visceral and subcutaneous adipose tissue, and daily energy intake in 985 humans (493 women) at the age of 70 years. In total, 733 SNPs located in the FTO gene were genotyped in order to examine whether rs9939609 alone or the other SNPs, or their combinations, are linked to obesity-related measures in elderly humans.

Design

Cross-sectional analysis of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort.

Results

Neither a single SNP, such as rs9939609, nor a SNP combination was significantly linked to overweight, body composition-related measures, or daily energy intake in elderly humans. Of note, these observations hold both among men and women.

Conclusions

Due to the diversity of measurements included in the study, our findings strengthen the view that the effect of FTO on body composition appears to be less profound in later life compared to younger ages and that this is seemingly independent of gender.     

Testing the ontogenetic base for the transient model of inflorescence development

Backgrounds and Aims

Current research in plant science has concentrated on revealing ontogenetic processes of key attributes in plant evolution. One recently discussed model is the ‘transient model’ successful in explaining some types of inflorescence architectures based on two main principles: the decline of the so called ‘vegetativeness’ (veg) factor and the transient nature of apical meristems in developing inflorescences. This study examines whether both principles find a concrete ontogenetic correlate in inflorescence development.

Methods

To test the ontogenetic base of veg decline and the transient character of apical meristems the ontogeny of meristematic size in developing inflorescences was investigated under scanning electron microscopy. Early and late inflorescence meristems were measured and compared during inflorescence development in 13 eudicot species from 11 families.

Key Results

The initial size of the inflorescence meristem in closed inflorescences correlates with the number of nodes in the mature inflorescence. Conjunct compound inflorescences (panicles) show a constant decrease of meristematic size from early to late inflorescence meristems, while disjunct compound inflorescences present an enlargement by merging from early inflorescence meristems to late inflorescence meristems, implying a qualitative change of the apical meristems during ontogeny.

Conclusions

Partial confirmation was found for the transient model for inflorescence architecture in the ontogeny: the initial size of the apical meristem in closed inflorescences is consistent with the postulated veg decline mechanism regulating the size of the inflorescence. However, the observed biphasic kinetics of the development of the apical meristem in compound racemes offers the primary explanation for their disjunct morphology, contrary to the putative exclusive transient mechanism in lateral axes as expected by the model.     

Effect of a 12-week walking exercise program on body composition and immune cell count in patients with breast cancer who are undergoing chemotherapy

Purpose

The purpose of this study was to examine the effect of a 12-week walking exercise program on body composition and immune cell count in patients with breast cancer who are undergoing chemotherapy.

Methods

Twenty patients (age, 47.8 ± 3.12) participated in the study. Body composition (weight, body mass index, muscle weight, body fat mass, and percent body fat) and the cell counts for immune cells (white blood corpuscles, lymphocytes, helper T cells, cytotoxic T cells, natural killer cells, and natural killer T cells) were measured before and after the 12-week walking exercise program. SPSS 17.0 statistical software was used. The two-way repeated ANOVA with post hoc was used to determine the difference between time and interaction.

Results

There were significant reductions in the weight (p < .05), BMI (p < .01), and percent body fat (p < .05) after the 12-week walking exercise program. However, the immune cell counts did not change significantly.

Conclusion

These results indicated that the 12-week walking exercise program had an effect on the balances among weight, BMI and percent body fat in patients with breast cancer.     

Confocal laser scanning microscopy for detection of Schistosoma mansoni eggs in the gut of mice

Background

The gold standard for diagnosing Schistosoma mansoni infections is the detection of eggs from stool or biopsy specimens. The viability of collected eggs can be tested by the miracidium hatching procedure. Direct detection methods are often limited in patients with light or early infections, whereas serological tests and PCR methods fail to differentiate between an inactive and persistent infection and between schistosomal species. Recently, confocal laser scanning microscopy (CLSM) has been introduced as a diagnostic tool in several fields of medicine. In this study we evaluated CLSM for the detection of viable eggs of S. mansoni directly within the gut of infected mice.

Methodology/Principal Findings

The confocal laser scanning microscope used in this study is based on the Heidelberg Retina Tomograph II scanning laser system in combination with the Rostock Cornea Module (image modality 1) or a rigid endoscope (image modality 2). Colon sections of five infected mice were examined with image modalities 1 and 2 for schistosomal eggs. Afterwards a biopsy specimen was taken from each colon section and examined by bright-field microscopy. Visualised eggs were counted and classified in terms of viability status.

Conclusions/Significance

We were able to show that CLSM visualises eggs directly within the gut and permits discrimination of schistosomal species and determination of egg viability. Thus, CLSM may be a suitable non-invasive tool for the diagnosis of schistosomiasis in humans.     

Detection of Schistosoma mansoni eggs in feces through their interaction with paramagnetic beads in a magnetic field

Background

Diagnosis of intestinal schistosomiasis in low endemic areas is a problem because often control measures have reduced egg burdens in feces to below the detection limits of classical coproparasitological methods. Evaluation of molecular methods is hindered by the absence of an established standard with maximum sensitivity and specificity. One strategy to optimize method performance, where eggs are rare events, is to examine large amounts of feces. A novel diagnostic method for isolation of Schistosoma mansoni eggs in feces, and an initial evaluation of its performance is reported here.

Methodology/Principal Findings

Known amounts of S. mansoni eggs were seeded into 30 g of normal human feces and subjected to a sequence of spontaneous sedimentation, sieving, Ritchie method, incubation and isolation through interaction with paramagnetic beads. Preliminary tests demonstrated the efficacy of lectins as ligands, but they also indicated that the paramagnetic beads alone were sufficient to isolate the eggs under a magnetic field through an unknown mechanism. Eggs were identified by microscopic inspection, with a sensitivity of 100% at 1.3 eggs per gram of feces (epg). Sensitivity gradually decreased to 25% at a concentration of 0.1 epg. In a preliminary application of the new method to the investigation of a recently established focus in southern Brazil, approximately 3 times more eggs were detected than with the thick-smear Kato-Katz method.

Conclusions/Significance

The novel S. mansoni detection method may significantly improve diagnosis of infections with low burdens in areas of recent introduction of the parasite, areas under successful control of transmission, or in infected travelers. It may also improve the evaluation of new treatments and vaccines.     

Eosinophil Granule Proteins ECP and EPX as Markers for a Potential Early-Stage Inflammatory Lesion in Female Genital Schistosomiasis (FGS)

Background

Genital granulomas induced by Schistosoma haematobium eggs can manifest as different lesion types visible by colposcopy; rubbery papules (RP), homogenous sandy patches (HSP) and grainy sandy patches (GSP). Pronounced tissue eosinophilia is a candidate marker for active S. haematobium pathology, as viable schistosome egg granulomas often are eosinophil rich. Here it was investigated whether eosinophil granule proteins ECP (eosinophil cationic protein) and EPX (eosinophil protein-X) in urine and genital lavage can be used as markers for active FGS lesions.

Methods

Uro-genital samples from 118 Malagasy women were analysed for ECP and EPX by standard sandwich avidin/biotin amplified ELISA.

Principal findings

The women with RP lesions had significantly higher levels of ECP and EPX in both lavage and urine. Furthermore, women with RP lesions were significantly younger than those with GSP. This could indicate that RP lesions might be more recently established and thus represent an earlier inflammatory lesion stage.

Conclusion

ECP in genital lavage might be a future tool aiding the identification of FGS pathology at a stage where reversibility remains a possibility following praziquantel treatment.