bluuebunny/crossref_metadata_2025 huggingface dataset:
Early history of high‐altitude physiology
Authors: West John B.
Published: March 2015

High‐altitude physiology can be said to have begun in 1644 when Torricelli described the first mercury barometer and wrote the immortal words “We live submerged at the bottom of an ocean of the element air.” Interestingly, the notion of atmospheric pressure had eluded his teacher, the great Galileo. Blaise Pascal was responsible for describing the fall in pressure with increasing altitude, and Otto von Guericke gave a dramatic demonstration of the enormous force that could be developed by atmospheric pressure. Robert Boyle learned of Guericke's experiment and, with Robert Hooke, constructed the first air pump that allowed small animals to be exposed to a low pressure. Hooke also constructed a small low‐pressure chamber and exposed himself to a simulated altitude of about 2400 meters. With the advent of ballooning, humans were rapidly exposed to very low pressures, sometimes with tragic results. For example, the French balloon, Zénith, rose to over 8000 m, and two of the three aeronauts succumbed to the hypoxia. Paul Bert was the first person to clearly state that the deleterious effects of high altitude were caused by the low partial pressure of oxygen (, and later research was accelerated by high‐altitude stations and expeditions to high altitude.
Malignant Seminoma in Two Unilaterally Cryptorchid Stallions
Authors: De Lange V , Chiers K , Lefère L , Cools M , Ververs C , Govaere J
Published: March 2015

Contents

Two unilateral cryptorchid stallions were referred to the clinic because of chronic debilitating condition with emaciation. Rectal examination, and ultrasound and gross examination revealed in both animals an abdominal mass, caudally of the kidney, and multiple nodules spread over the abdomen. Histologic analysis revealed an intra‐abdominal malignant seminoma with intraperitoneal and renal metastasis. Interestingly, a seminoma was also present in the descended testis of the draught horse.
Consumption, Income, and Wealth: Evidence from Age, Cohort, and Period Elasticities
Authors: Lim G. C. , Zeng Q.
Published: March 2015

This paper examines the relationship between non‐durable consumption, income, and wealth (housing and financial) allowing explicitly for generational heterogeneity. A framework is proposed to disentangle cohort, age, and period effects and the empirical analysis is based on the U.S. Consumer Expenditure Survey data. We find that there are significant generational differences and the results highlight the range of elasticities implicit in results presented, thus far, by age groups. Moreover, we find supporting evidence of humped shaped age profiles for the elasticity of consumption with respect to income and the importance of financial wealth for those aged 60+. The framework also allows us to generate cohort profiles which draw attention to the negative role of housing wealth for generation X, and period profiles which reinforce the role of financial wealth for the baby‐boom generation.
Correcting for the Missing Rich: An Application to Wealth Survey Data
Authors: Eckerstorfer Paul , Halak Johannes , Kapeller Jakob , Schütz Bernhard , Springholz Florian , Wildauer Rafael
Published: March 2015

It is a well‐known criticism that if the distribution of wealth is highly concentrated, survey data are hardly reliable when it comes to analyzing the richest parts of society. This paper addresses this criticism by providing a general rationale of the underlying methodological problem as well as by proposing a specific methodological approach tailored to correcting the arising bias. We illustrate the latter approach by using Austrian data from the Household Finance and Consumption Survey. Specifically, we identify suitable parameter combinations by using a series of maximum‐likelihood estimates and appropriate goodness‐of‐fit tests to avoid arbitrariness with respect to the fitting of the Pareto distribution. Our results suggest that the alleged non‐observation bias is considerable, accounting for about one quarter of total net wealth in the case of Austria. The method developed in this paper can easily be applied to other countries where survey data on wealth are available.
A lycopene β‐cyclase/lycopene ε‐cyclase/light‐harvesting complex‐fusion protein from the green alga Ostreococcus lucimarinus can be modified to produce α‐carotene and β‐carotene at different ratios
Authors: Blatt Andreas , Bauch Matthias E. , Pörschke Yvonne , Lohr Martin
Published: March 2015

Biosynthesis of asymmetric carotenoids such as α‐carotene and lutein in plants and green algae involves the two enzymes lycopene β‐cyclase (LCYB) and lycopene ε‐cyclase (LCYE). The two cyclases are closely related and probably resulted from an ancient gene duplication. While in most plants investigated so far the two cyclases are encoded by separate genes, prasinophyte algae of the order Mamiellales contain a single gene encoding a fusion protein comprised of LCYB, LCYE and a C‐terminal light‐harvesting complex (LHC) domain. Here we show that the lycopene cyclase fusion protein from Ostreococcus lucimarinus catalyzed the simultaneous formation of α‐carotene and β‐carotene when heterologously expressed in Escherichia coli. The stoichiometry of the two products in E. coli could be altered by gradual truncation of the C‐terminus, suggesting that the LHC domain may be involved in modulating the relative activities of the two cyclase domains in the algae. Partial deletions of the linker region between the cyclase domains or replacement of one or both cyclase domains with the corresponding cyclases from the green alga Chlamydomonas reinhardtii resulted in pronounced shifts of the α‐carotene‐to‐β‐carotene ratio, indicating that both the relative activities of the cyclase domains and the overall structure of the fusion protein have a strong impact on the product stoichiometry. The possibility to tune the product ratio of the lycopene cyclase fusion protein from Mamiellales renders it useful for the biotechnological production of the asymmetric carotenoids α‐carotene or lutein in bacteria or fungi.
Regulatory–auxiliary subunits of CLC chloride channel–transport proteins
Authors: Barrallo‐Gimeno Alejandro , Gradogna Antonella , Zanardi Ilaria , Pusch Michael , Estévez Raúl
Published: March 2015

The CLC family of chloride channels and transporters is composed by nine members, but only three of them, ClC‐Ka/b, ClC‐7 and ClC‐2, have been found so far associated with auxiliary subunits. These CLC regulatory subunits are small proteins that present few common characteristics among them, both structurally and functionally, and their effects on the corresponding CLC protein are different. Barttin, a protein with two transmembrane domains, is essential for the membrane localization of ClC‐K proteins and their activity in the kidney and inner ear. Ostm1 is a protein with a single transmembrane domain and a highly glycosylated N‐terminus. Unlike the other two CLC auxiliary subunits, Ostm1 shows a reciprocal relationship with ClC‐7 for their stability. The subcellular localization of Ostm1 depends on ClC‐7 and not the other way around. ClC‐2 is active on its own, but GlialCAM, a transmembrane cell adhesion molecule with two extracellular immunoglobulin (Ig)‐like domains, regulates its subcellular localization and activity in glial cells. The common theme for these three proteins is their requirement for a proper homeostasis, since their malfunction leads to distinct diseases. We will review here their properties and their role in normal chloride physiology and the pathological consequences of their improper function.
Interaction between visual and motor cortex: a transcranial magnetic stimulation study
Authors: Strigaro Gionata , Ruge Diane , Chen Jui‐Cheng , Marshall Louise , Desikan Mahalekshmi , Cantello Roberto , Rothwell John C.
Published: March 2015

Key points

We studied the interaction between the primary visual cortex and the primary motor cortex using paired transcranial magnetic stimulation (TMS) with an interstimulus interval (ISI) in the range 12–40 ms.

The connection is inhibitory at rest and possibly mediated by inhibitory interneurones in the motor cortex.

The effect with an ISI of 40 ms reverses into facilitation during a visuomotor (but not audiomotor) reaction task. By contrast, there is no change in inhibition with an ISI of 18 ms, suggesting that separate pathways can be probed at different ISIs.

We conclude that a physiologically relevant occipito‐motor connection can be activated by means of TMS. It may contribute to visuomotor integration, as well as being involved in certain types of visual epilepsy.

The major link between the visual and motor systems is via the dorsal stream pathways from visual to parietal and frontal areas of the cortex. Although the pathway appears to be indirect, there is evidence that visual input can reach the motor cortex at relatively short latency. To shed some light on its neural basis, we studied the visuomotor interaction using paired transcranial magnetic stimulation (TMS). Motor‐evoked potentials (MEPs) were recorded from the right first dorsal interosseous in sixteen healthy volunteers. A conditioning stimulus (CS) was applied over the phosphene hotspot of the visual cortex, followed by a test stimulus over the left primary motor cortex (M1) with a random interstimulus interval (ISI)  in range 12–40 ms. The effects of paired stimulation were retested during visual and auditory reaction‐time tasks (RT). Finally, we measured the effects of a CS on short‐interval intracortical inhibition (SICI). At rest, a CS over the occiput significantly (P < 0.001) suppressed test MEPs with an ISI in the range 18–40 ms. In the visual RT, inhibition with an ISI of 40 ms (but not 18 ms) was replaced by a time‐specific facilitation (P < 0.001), whereas, in the auditory RT, the CS no longer had any effect on MEPs. Finally, an occipital CS facilitated SICI with an ISI of 40 ms (P < 0.01). We conclude that it is possible to study separate functional connections from visual to motor cortices using paired‐TMS with an ISI in the range 18–40 ms. The connections are inhibitory at rest and possibly mediated by inhibitory interneurones in the motor cortex. The effect with an ISI of 40 ms reverses into facilitation during a visuomotor RT but not an audiomotor RT. This suggests that it plays a role in visuomotor integration.
Dynamic Modeling of a Six Degree-of-Freedom Flight Simulator Motion Base
Authors: Becerra-Vargas Mauricio , Morgado Belo Eduardo
Published: March 2015

This paper presents a closed-form solution for the direct dynamic model of a flight simulator motion base. The motion base consists of a six degree-of-freedom (6DOF) Stewart platform robotic manipulator driven by electromechanical actuators. The dynamic model is derived using the Newton–Euler method. Our derivation is closed to that of Dasgupta and Mruthyunjaya (1998, “Closed Form Dynamic Equations of the General Stewart Platform Through the Newton–Euler Approach,” Mech. Mach. Theory, 33(7), pp. 993–1012), however, we give some insights into the structure and properties of those equations, i.e., a kinematic model of the universal joint, inclusion of electromechanical actuator dynamics and the full dynamic equations in matrix form in terms of Euler angles and platform position vector. These expressions are interesting for control, simulation, and design of flight simulators motion bases. Development of a inverse dynamic control law by using coefficients matrices of dynamic equation and real aircraft trajectories are implemented and simulation results are also presented.
An Evaluation Approach for the Stall Margin Enhancement With Stall Precursor-Suppressed Casing Treatment
Authors: Sun Dakun , Liu Xiaohua , Sun Xiaofeng
Published: March 2015

It is known that a kind of stall precursor-suppressed (SPS) casing treatment can be used to enhance compressor stall margin (SM) without recognizable efficiency loss. The further requirement in this regard is to develop an effective way to determine the variation range of the SM improvement during the design of such SPS casing treatment. In this investigation, based on the extrapolation hypothesis and the existing work, an extended stall inception model for quantitative evaluation of the SM enhancement is presented for both subsonic and transonic compressors with the SPS casing treatment. The capability of the extended model to quantitatively evaluate the SM enhancement with the SPS casing treatment is validated against the experimental data. The quantitative evaluation results show that the SPS casing treatments with different geometric parameters can improve the SM by a diverse percentage. In particular, for the facilities used in the present investigation, the experiments show that the SPS casing treatments can cause relevant increases of the SM. The change trend of the SM enhancement with various design parameters of the SPS casing treatment is in line with the corresponding theoretical results.
Use of Circulating Fluidized Bed Combustors in Compressed Air Energy Storage Systems
Authors: Nakhamkin M. , Patel M. , Louks Bert M.
Published: March 2015

This paper presents the results of a study conducted by Energy Storage and Power Consultants, Inc. (ESPC) in close cooperation with Electric Power Research Institute (EPRI). The objective is to develop and analyze compressed air energy storage (CAES) power plant concepts which utilize coal-fired circulating fluidized bed combustors (CFBC) for heating air during generation periods.
Assessment of Refrigeration-Type Cooling of Inlet Air for Essex Unit No. 9
Authors: Zwillenberg M. L. , Smith D. , Cohn A. , Oliker I. , Major W.
Published: March 2015

The intent of this assessment is to determine the economic and technical feasibility of the reduction of compressor-inlet-air temperature by providing a cooling coil at the entrance to the turbine’s inlet-air section to improve performance and reduce operating costs.

To achieve the desired cooling of the inlet air to the turbine’s compressor, it is proposed to use indirect cooling from a mechanical-vapor compression-type chiller in combination with cool storage.

Two types of cool storage are examined, including chilled-water storage and ice storage.

A sizing methodology for the chiller and storage capacity was formulated by PSE&G to maximize the economic attractiveness which a cooling capability can achieve under the power-pool rules. The study considered an energy/thermal assessment to predict turbine performance and electrical output with and without inlet-air cooling. Total benefits include a capacity benefit, net power-generation increase and turbine fuel-input savings less operating costs. Based on the capital cost of the alternatives, simple paybacks were determined.
A deformable head and neck phantom with in‐vivo dosimetry for adaptive radiotherapy quality assurance
Authors: Graves Yan Jiang , Smith Arthur‐Allen , McIlvena David , Manilay Zherrina , Lai Yuet Kong , Rice Roger , Mell Loren , Jia Xun , Jiang Steve B. , Cerviño Laura
Published: March 2015

Purpose:

Patients’ interfractional anatomic changes can compromise the initial treatment plan quality. To overcome this issue, adaptive radiotherapy (ART) has been introduced. Deformable image registration (DIR) is an important tool for ART and several deformable phantoms have been built to evaluate the algorithms’ accuracy. However, there is a lack of deformable phantoms that can also provide dosimetric information to verify the accuracy of the whole ART process. The goal of this work is to design and construct a deformable head and neck (HN) ART quality assurance (QA) phantom with in vivo dosimetry.

Methods:

An axial slice of a HN patient is taken as a model for the phantom construction. Six anatomic materials are considered, with HU numbers similar to a real patient. A filled balloon inside the phantom tissue is inserted to simulate tumor. Deflation of the balloon simulates tumor shrinkage. Nonradiopaque surface markers, which do not influence DIR algorithms, provide the deformation ground truth. Fixed and movable holders are built in the phantom to hold a diode for dosimetric measurements.

Results:

The measured deformations at the surface marker positions can be compared with deformations calculated by a DIR algorithm to evaluate its accuracy. In this study, the authors selected a Demons algorithm as a DIR algorithm example for demonstration purposes. The average error magnitude is 2.1 mm. The point dose measurements from the in vivo diode dosimeters show a good agreement with the calculated doses from the treatment planning system with a maximum difference of 3.1% of prescription dose, when the treatment plans are delivered to the phantom with original or deformed geometry.

Conclusions:

In this study, the authors have presented the functionality of this deformable HN phantom for testing the accuracy of DIR algorithms and verifying the ART dosimetric accuracy. The authors’ experiments demonstrate the feasibility of this phantom serving as an end‐to‐end ART QA phantom.
The Effects of Sedentary Behavior on Metabolic Syndrome Independent of Physical Activity and Cardiorespiratory Fitness
Authors: Greer Anna E. , Sui Xuemei , Maslow Andréa L. , Greer Beau Kjerulf , Blair Steven N.
Published: March 2015

Background:

To date, no longitudinal studies have examined the influence of sedentary behavior on metabolic syndrome development while accounting for cardiorespiratory fitness.

Purpose and Methods:

This prospective study examined the relationship between sedentary behavior and incident metabolic syndrome while considering the effects of physical activity and cardiorespiratory fitness on the association among 930 men enrolled in the Aerobics Center Longitudinal Study.

Results:

A total of 124 men developed metabolic syndrome during 8974 person-years of exposure. After adjusting for covariates, men with middle and high sedentary behavior had 65% and 76% higher risks of developing metabolic syndrome, respectively, than men with low sedentary behavior (linear trend P = .011). This association remained significant after additional adjustment for activity status and cardiorespiratory fitness. Cardiorespiratory fitness and physical activity were also inversely associated with metabolic syndrome, even after adjustment for sedentary behavior.

Conclusions:

The findings highlight the importance of reducing sedentary behavior, increasing physical activity, and improving cardiorespiratory fitness for preventing metabolic syndrome.
Scapular Kinematics During Late Cocking of a Simulated Throwing Activity in Baseball Players With Shoulder Injury: A Cross-Sectional Study Using a 3D-to-2D Registration Technique
Authors: Saka Masayuki , Yamauchi Hiroki , Yoshioka Toru , Hamada Hidetoshi , Gamada Kazuyoshi
Published: March 2015

Context:

Abnormal scapular kinematics during throwing motion in baseball players with shoulder disorders has not yet been clarified, although altered scapular position has been suggested to be associated with shoulder disorder.

Objective:

To determine if the shoulders of baseball players with throwing disorders demonstrate abnormal scapular kinematics during the simulated arm-cocking phase of throwing activity.

Design:

Cross sectional study.

Setting:

Laboratory.

Participants:

Eleven baseball players (age 21.1 ± 1.2 y) with a unilateral shoulder disorder volunteered to participate, including 9 players at the college level and 2 at the adult level. The mean playing experience was 12.1 ± 2.7 y.

Main Outcome Measures:

Scapular upward/downward rotation, anteroposterior tilting, and external/internal rotation during simulated arm-cocking motion were analyzed using a 3-to-2-dimensional registration technique.

Results:

Scapular external rotation in the throwing shoulder was significantly smaller by 2.0–6.0° than that of the contralateral shoulder. There were no detectable differences in scapular upward/downward rotation or anteroposterior tilting between the throwing and contralateral shoulders.

Conclusions:

Compared with that in the contralateral shoulder, scapular external rotation was smaller in the throwing shoulder, which would increase glenohumeral horizontal abduction during the arm-cocking phase and be related to the throwing-shoulder disorder.
The Effects of a Multimodal Rehabilitation Program on Symptoms and Ground-Reaction Forces in Runners With Patellofemoral Pain Syndrome
Authors: Esculier Jean-Francois , Bouyer Laurent J. , Roy Jean-Sébastien
Published: March 2015

Context:

Patellofemoral pain (PFP) is one of the most frequent running-related injuries. However, few interventions taking into consideration the specificity of running have been shown to be effective in runners with PFP.

Objective:

To evaluate the effects of a multimodal rehabilitation program including lower-limb-strengthening/motor-control exercises, advice on running biomechanics, and symptoms management on symptoms, strength, and ground-reaction forces in runners with PFP.

Design:

Pre- to post- quasi-experimental.

Setting:

Gait-analysis laboratory and private physical therapy clinic.

Participants:

21 runners with PFP (34.1 ± 6.0 y old, symptoms duration 38.1 ± 45.5 mo).

Intervention:

An 8-wk multimodal rehabilitation program including lower-limb- and core-strengthening and motor-control exercises, as well as advice on running gait and symptoms management.

Main Outcome Measures:

The Activities of Daily Living Scale of the Knee Outcome Survey (KOS-ADLS) questionnaire and visual analog scales for usual pain (VAS-U), worst pain (VAS-W), and pain during running (VAS-R) were used to assess changes in symptoms and function. Vertical ground-reaction forces (VGRF) during running and lower-limb isometric strength were also measured.

Results:

Statistically and clinically significant improvements (P < .001) were reported on KOS-ADLS (+17.8 pts), VAS-U (−19.2 pts), VAS-W (−28.7 pts), and VAS-R (−32.2 pts) after the intervention. No significant changes in isometric strength were observed. The instantaneous vertical loading rate was decreased after the intervention (P = .002), and this reduction was correlated with changes in KOS-ADLS scores (P = .028).

Conclusion:

This multimodal intervention was successful in reducing pain and improving function of runners with PFP. However, no significant changes in lower-limb strength were observed. It appears that changes in VGRF combined with appropriate training advice could explain the clinical outcomes.
The B cell follicle shields HIV
Authors: Sun Jie
Published: March 2015

B cell follicles protect HIV from being eliminated by CD8
+
cytotoxic T lymphocytes.
Some things get better with age
Authors: Gerber David E.
Published: March 2015

Animal studies identify age-related factors that inhibit tumor progression.
iHeart nano: A sweet cure
Authors: Price Elvin
Published: March 2015

Sugar-based nanoparticles prevent foam cell formation and limit atherogenesis.
Taking TREM to the brain
Authors: Serezani Henrique
Published: March 2015

TREM2 deficiency protects mice from Alzheimer’s disease.
Lactate trumps blood pressure for trauma triage
Authors: White Nathan J.
Published: March 2015

Measurement of blood lactate concentrations by paramedics improves the identification of trauma victims who require resuscitation.
Inhibition of Protein Synthesis and Malaria Parasite Development by Drug Targeting of Methionyl-tRNA Synthetases
Authors: Hussain Tahir , Yogavel Manickam , Sharma Amit
Published: March 2015

Aminoacyl-tRNA synthetases (aaRSs) are housekeeping enzymes that couple cognate tRNAs with amino acids to transmit genomic information for protein translation. The
Plasmodium falciparum
nuclear genome encodes two
P. falciparum
methionyl-tRNA synthetases (PfMRS), termed PfMRS
cyt
and PfMRS
api
. Phylogenetic analyses revealed that the two proteins are of primitive origin and are related to heterokonts (PfMRS
cyt
) or proteobacteria/primitive bacteria (PfMRS
api
). We show that PfMRS
cyt
localizes in parasite cytoplasm, while PfMRS
api
localizes to apicoplasts in asexual stages of malaria parasites. Two known bacterial MRS inhibitors, REP3123 and REP8839, hampered
Plasmodium
growth very effectively in the early and late stages of parasite development. Small-molecule drug-like libraries were screened against modeled PfMRS structures, and several “hit” compounds showed significant effects on parasite growth. We then tested the effects of the hit compounds on protein translation by labeling nascent proteins with
35
S-labeled cysteine and methionine. Three of the tested compounds reduced protein synthesis and also blocked parasite growth progression from the ring stage to the trophozoite stage. Drug docking studies suggested distinct modes of binding for the three compounds, compared with the enzyme product methionyl adenylate. Therefore, this study provides new targets (PfMRSs) and hit compounds that can be explored for development as antimalarial drugs.
Moraxella catarrhalis AcrAB-OprM Efflux Pump Contributes to Antimicrobial Resistance and Is Enhanced during Cold Shock Response
Authors: Spaniol Violeta , Bernhard Sara , Aebi Christoph
Published: March 2015

Moraxella catarrhalis
is a common pathogen of the human respiratory tract. Multidrug efflux pumps play a major role in antibiotic resistance and virulence in many Gram-negative organisms. In the present study, the role of the AcrAB-OprM efflux pump in antibiotic resistance was investigated by constructing mutants that lack the
acrA
,
acrB
, and
oprM
genes in
M. catarrhalis
strain O35E. We observed a moderate (1.5-fold) decrease in the MICs of amoxicillin and cefotaxime and a marked (4.7-fold) decrease in the MICs of clarithromycin for
acrA
,
acrB
, and
oprM
mutants in comparison with the wild-type O35E strain. Exposure of the
M. catarrhalis
strains O35E and 300 to amoxicillin triggered an increased transcription of all AcrAB-OprM pump genes, and exposure of strains O35E, 300, and 415 to clarithromycin enhanced the expression of
acrA
and
oprM
mRNA. Inactivation of the AcrAB-OprM efflux pump genes demonstrated a decreased ability to invade epithelial cells compared to the parental strain, suggesting that
acrA
,
acrB
, and
oprM
are required for efficient invasion of human pharyngeal epithelial cells. Cold shock increases the expression of AcrAB-OprM efflux pump genes in all three
M. catarrhalis
strains tested. Increased expression of AcrAB-OprM pump genes after cold shock leads to a lower accumulation of Hoechst 33342 (H33342), a substrate of AcrAB-OprM efflux pumps, indicating that cold shock results in increased efflux activity. In conclusion, the AcrAB-OprM efflux pump appears to play a role in the antibiotic resistance and virulence of
M. catarrhalis
and is involved in the cold shock response.
Epoxy-α-Lapachone Has
In Vitro
and
In Vivo
Anti-Leishmania (Leishmania) amazonensis Effects and Inhibits Serine Proteinase Activity in This Parasite
Authors: Souza-Silva Franklin , Bourguignon Saulo Cabral , Pereira Bernardo Acácio Santini , Côrtes Luzia Monteiro de Castro , de Oliveira Luiz Filipe Gonçalves , Henriques-Pons Andrea , Finkelstein Lea Cysne , Ferreira Vitor Francisco , Carneiro Paula Fernandes , de Pinho Rosa Teixeira , Caffarena Ernesto Raul , Alves Carlos Roberto
Published: March 2015

Leishmania
(
Leishmania
)
amazonensis
is a protozoan that causes infections with a broad spectrum of clinical manifestations. The currently available chemotherapeutic treatments present many problems, such as several adverse side effects and the development of resistant strains. Natural compounds have been investigated as potential antileishmanial agents, and the effects of epoxy-α-lapachone on
L
. (
L
.)
amazonensis
were analyzed in the present study. This compound was able to cause measurable effects on promastigote and amastigote forms of the parasite, affecting plasma membrane organization and leading to death after 3 h of exposure. This compound also had an effect in experimentally infected BALB/c mice, causing reductions in paw lesions 6 weeks after treatment with 0.44 mM epoxy-α-lapachone (mean lesion area, 24.9 ± 2.0 mm
2
), compared to untreated animals (mean lesion area, 30.8 ± 2.6 mm
2
) or animals treated with Glucantime (mean lesion area, 28.3 ± 1.5 mm
2
). In addition, the effects of this compound on the serine proteinase activities of the parasite were evaluated. Serine proteinase-enriched fractions were extracted from both promastigotes and amastigotes and were shown to act on specific serine proteinase substrates and to be sensitive to classic serine proteinase inhibitors (phenylmethylsulfonyl fluoride, aprotinin, and antipain). These fractions were also affected by epoxy-α-lapachone. Furthermore,
in silico
simulations indicated that epoxy-α-lapachone can bind to oligopeptidase B (OPB) of
L
. (
L
.)
amazonensis
, a serine proteinase, in a manner similar to that of antipain, interacting with an S1 binding site. This evidence suggests that OPB may be a potential target for epoxy-α-lapachone and, as such, may be related to the compound's effects on the parasite.
Impact of Extended-Spectrum β-Lactamase Production on Treatment Outcomes of Acute Pyelonephritis Caused by Escherichia coli in Patients without Health Care-Associated Risk Factors
Authors: Park Sun Hee , Choi Su-Mi , Lee Dong-Gun , Cho Sung-Yeon , Lee Hyo-Jin , Choi Jae-ki , Choi Jung-Hyun , Yoo Jin-Hong
Published: March 2015

Extended-spectrum β-lactamase-producing
Escherichia coli
(ESBL-EC) is increasingly identified as a cause of acute pyelonephritis (APN) among patients without recent health care contact, i.e., community-associated APN. This case-control study compared 75 cases of community-associated ESBL-EC APN (CA-ESBL) to 225 controls of community-associated non-ESBL-EC APN (CA-non-ESBL) to identify the risk factors for ESBL-EC acquisition and investigate the impact of ESBL on the treatment outcomes of community-associated APN (CA-APN) caused by
E. coli
at a Korean hospital during 2007 to 2013. The baseline characteristics were similar between the cases and controls; the risk factors for ESBL-EC were age (>55 years), antibiotic use within the previous year, and diabetes with recurrent APN. The severity of illness did not differ between CA-ESBL and CA-non-ESBL (Acute Physiology and Chronic Health Evaluation [APACHE] II scores [mean ± standard deviation], 7.7 ± 5.9 versus 6.4 ± 5.3;
P
= 0.071). The proportions of clinical (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.57 to 5.38;
P
= 0.323) and microbiological (OR, 1.16; 95% CI, 0.51 to 2.65;
P
= 0.730) cures were similar, although the CA-ESBL APN patients were less likely to receive appropriate antibiotics within 48 h. A multivariable Cox proportional hazards analysis of the prognostic factors for CA-APN caused by
E. coli
showed that ESBL production was not a significant factor for clinical (hazard ratio [HR], 0.39; 95% CI, 0.12 to 1.30;
P
= 0.126) or microbiological (HR, 0.49; 95% CI, 0.21 to 1.12;
P
= 0.091) failure. The estimates did not change after incorporating weights calculated using propensity scores for acquiring ESBL-EC. Therefore, ESBL production did not negatively affect treatment outcomes among patients with community-associated
E. coli
APN.
Bacterial Secretions of Nonpathogenic Escherichia coli Elicit Inflammatory Pathways: a Closer Investigation of Interkingdom Signaling
Authors: Zargar Amin , Quan David N. , Carter Karen K. , Guo Min , Sintim Herman O. , Payne Gregory F. , Bentley William E.
Published: March 2015

There have been many studies on the relationship between nonpathogenic bacteria and human epithelial cells; however, the bidirectional effects of the secretomes (secreted substances in which there is no direct bacterium-cell contact) have yet to be fully investigated. In this study, we use a transwell model to explore the transcriptomic effects of bacterial secretions from two different nonpathogenic
Escherichia coli
strains on the human colonic cell line HCT-8 using next-generation transcriptome sequencing (RNA-Seq).
E. coli
BL21 and W3110, while genetically very similar (99.1% homology), exhibit key phenotypic differences, including differences in their production of macromolecular structures (e.g., flagella and lipopolysaccharide) and in their secretion of metabolic byproducts (e.g., acetate) and signaling molecules (e.g., quorum-sensing autoinducer 2 [AI-2]). After analysis of differential epithelial responses to the respective secretomes, this study shows for the first time that a nonpathogenic bacterial secretome activates the NF-κB-mediated cytokine-cytokine receptor pathways while also upregulating negative-feedback components, including the NOD-like signaling pathway. Because of AI-2's relevance as a bacterium-bacterium signaling molecule and the differences in its secretion rates between these strains, we investigated its role in HCT-8 cells. We found that the expression of the inflammatory cytokine interleukin 8 (IL-8) responded to AI-2 with a pattern of rapid upregulation before subsequent downregulation after 24 h. Collectively, these data demonstrate that secreted products from nonpathogenic bacteria stimulate the transcription of immune-related biological pathways, followed by the upregulation of negative-feedback elements that may serve to temper the inflammatory response.

IMPORTANCE
The symbiotic relationship between the microbiome and the host is important in the maintenance of human health. There is a growing need to further understand the nature of these relationships to aid in the development of homeostatic probiotics and also in the design of novel antimicrobial therapeutics. To our knowledge, this is the first global-transcriptome study of bacteria cocultured with human epithelial cells in a model to determine the transcriptional effects of epithelial cells in which epithelial and bacterial cells are allowed to “communicate” with each other only through diffusible small molecules and proteins. By beginning to demarcate the direct and indirect effects of bacteria on the gastrointestinal (GI) tract, two-way interkingdom communication can potentially be mediated between host and microbe.
Regulation of Plasmodium yoelii Oocyst Development by Strain- and Stage-Specific Small-Subunit rRNA
Authors: Qi Yanwei , Zhu Feng , Eastman Richard T. , Fu Young , Zilversmit Martine , Pattaradilokrat Sittiporn , Hong Lingxian , Liu Shengfa , McCutchan Thomas F. , Pan Weiqing , Xu Wenyue , Li Jian , Huang Fusheng , Su Xin-zhuan
Published: March 2015

One unique feature of malaria parasites is the differential transcription of structurally distinct rRNA (rRNA) genes at different developmental stages: the A-type genes are transcribed mainly in asexual stages, whereas the S-type genes are expressed mostly in sexual or mosquito stages. Conclusive functional evidence of different rRNAs in regulating stage-specific parasite development, however, is still absent. Here we performed genetic crosses of
Plasmodium yoelii
parasites with one parent having an oocyst development defect (ODD) phenotype and another producing normal oocysts to identify the gene(s) contributing to the ODD. The parent with ODD—characterized as having small oocysts and lacking infective sporozoites—was obtained after introduction of a plasmid with a green fluorescent protein gene into the parasite genome and subsequent passages in mice. Quantitative trait locus analysis of genome-wide microsatellite genotypes of 48 progeny from the crosses linked an ~200-kb segment on chromosome 6 containing one of the S-type genes (D-type small subunit rRNA gene [
D-ssu
]) to the ODD. Fine mapping of the plasmid integration site, gene expression pattern, and gene knockout experiments demonstrated that disruption of the
D-ssu
gene caused the ODD phenotype. Interestingly, introduction of the
D-ssu
gene into the same parasite strain (self), but not into a different subspecies, significantly affected or completely ablated oocyst development, suggesting a stage- and subspecies (strain)-specific regulation of oocyst development by
D-ssu
. This study demonstrates that
P. yoelii
D-ssu
is essential for normal oocyst and sporozoite development and that variation in the
D-ssu
sequence can have dramatic effects on parasite development.

IMPORTANCE
Malaria parasites are the only known organisms that express structurally distinct rRNA genes at different developmental stages. The differential expression of these genes suggests that they play unique roles during the complex life cycle of the parasites. Conclusive functional proof of different rRNAs in regulating parasite development, however, is still absent or controversial. Here we functionally demonstrate for the first time that a stage-specifically expressed D-type small-subunit rRNA gene (
D-ssu
) is essential for oocyst development of the malaria parasite
Plasmodium yoelii
in the mosquito. This study also shows that variations in
D-ssu
sequence and/or the timing of transcription may have profound effects on parasite oocyst development. The results show that in addition to protein translation, rRNAs of malaria parasites also regulate parasite development and differentiation in a strain-specific manner, which can be explored for controlling parasite transmission.
New Method for the Orthogonal Labeling and Purification of Toxoplasma gondii Proteins While Inside the Host Cell
Authors: Wier Gregory M. , McGreevy Erica M. , Brown Mark J. , Boyle Jon P.
Published: March 2015

Toxoplasma gondii
is an obligate intracellular protozoan parasite that is capable of causing severe disease in immunocompromised humans. How T. gondii is able to modulate the host cell to support itself is still poorly understood. Knowledge pertaining to the host-parasite interaction could be bolstered by developing a system to specifically label parasite proteins while the parasite grows inside the host cell. For this purpose, we have created a strain of T. gondii that expresses a mutant Escherichia coli methionyl-tRNA synthetase (MetRS
NLL
) that allows methionine tRNA to be loaded with the azide-containing methionine analog azidonorleucine (Anl). Anl-containing proteins are susceptible to a copper-catalyzed “click” reaction to attach affinity tags for purification or fluorescent tags for visualization. The MetRS
NLL
-Anl system labels nascent T. gondii proteins in an orthogonal fashion, labeling proteins only in MetRS
NLL
-expressing parasites. This system should be useful for nonradioactive pulse-chase studies and purification of nascently translated proteins. Although this approach allows labeling of a diverse array of parasite proteins, secreted parasite proteins appear to be only minimally labeled in MetRS
NLL
-expressing T. gondii. The minimal labeling of secreted proteins is likely a consequence of the selective charging of the initiator tRNA (and not the elongator methionine tRNA) by the heterologously expressed bacterial MetRS.

IMPORTANCE
Studying how T. gondii modifies the host cell to permit its survival is complicated by the complex protein environment of the host cell. The approach presented in this article provides the first method for specific labeling of T. gondii proteins while the parasite grows inside the host cell. We show that this approach is useful for pulse-chase labeling of parasite proteins during
in vitro
growth. It should also be applicable during
in vivo
infections and in other apicomplexan parasites, including Plasmodium spp.
Cervical cancer screening and HPV vaccine acceptability among rural and urban women in Kilimanjaro Region, Tanzania
Authors: Cunningham Melissa S , Skrastins Emily , Fitzpatrick Ryan , Jindal Priya , Oneko Olola , Yeates Karen , Booth Christopher M , Carpenter Jennifer , Aronson Kristan J
Published: March 2015

Objective

To determine cervical cancer screening coverage and the knowledge, attitudes and barriers toward screening tests among women in rural and urban areas of Tanzania, as well as explore how they view the acceptability of the HPV vaccine and potential barriers to vaccination.

Setting

A cross-sectional study using interview-administered questionnaires was conducted using multistage random sampling within urban and rural areas in Kilimanjaro Region, Tanzania.

Participants

Women aged 18–55 were asked to participate in the survey. The overall response rate was 97.5%, with a final sample of 303 rural and 272 urban dwelling women.

Primary and secondary outcome measures

Descriptive and simple test statistics were used to compare across rural and urban strata. Multivariate logistic regression models were used to estimate ORs and 95% CIs.

Results

Most women (82%) reported they had heard of cervical cancer, while self-reported cervical cancer screening among women was very low (6%). In urban areas, factors associated with screening were: older age (OR=4.14, 95% CI 1.86 to 9.24 for ages 40–49, and OR=8.38, 95% CI 2.10 to 33.4 for >50 years), having health insurance (OR=4.15, 95% CI 1.52 to 11.4), and having knowledge about cervical cancer (OR=5.81, 95% CI 1.58 to 21.4). In contrast, among women residing in rural areas, only condom use (OR=6.44, 95% CI 1.12 to 37.1) was associated with screening. Women from both rural and urban areas had low vaccine-related knowledge; however, most indicated they would be highly accepting if it were readily available (93%).

Conclusions

The current proportion of women screened for cervical cancer is very low in Kilimanjaro Region, and our study has identified several modifiable factors that could be addressed to increase screening rates. Although best implemented concurrently, the availability of prophylactic vaccination for girls may provide an effective means of prevention if they are unable to access screening in the future.
VAlidation of an 8-item-questionnaire predictive for a positive caLprotectin tEst and Real-life implemenTation in primary care to reduce diagnostic delay in inflammatory bowel disease (ALERT): protocol for a prospective diagnostic study
Authors: Hasler Susann , Zahnd Nadine , Müller Salomé , Vavricka Stephan , Rogler Gerhard , Tandjung Ryan , Rosemann Thomas
Published: March 2015

Introduction

Diagnosis of inflammatory bowel disease (IBD) in primary healthcare is challenging and often associated with a considerable diagnostic delay. This delay is associated with worse disease progression and outcomes. Although testing for faecal calprotectin is a useful screening tool to identify patients who need endoscopy for IBD, the widespread use may not be appropriate due to the low prevalence of patients with IBD among all patients attending a general practitioner (GP) with gastrointestinal symptoms. To increase the appropriate application of the faecal calprotectin test, an 8-item questionnaire, the CalproQuest, has been developed to increase pretest probability for a positive test result.

Methods and analysis

This is a prospective diagnostic trial. The study consists of two independent and consecutive parts A and B, conducted by gastroenterologists (A) and GPs (B), respectively. Patients included in part A are referred to the gastroenterologist for any endoscopic evaluation. Patients included in part B present at their GP because of ongoing unspecific gastrointestinal symptoms (abdominal pain, bloating, stool irregularities, diarrhoea) for at least 2 weeks. CalproQuest consists of four main and four secondary questions specific for IBD; it is considered positive if ≥2 main criteria are answered positively or one main criterion and two secondary criteria are answered positively. In part A, the sensitivity and specificity of CalproQuest for stool calprotectin levels ≥50 μg/g faeces and for positive IBD diagnosis will be investigated. In part B, the feasibility of CalproQuest in daily primary healthcare practice will be assessed.

Ethics and dissemination

The study protocol was approved by the Ethics Committee of the Kanton Zurich (reference KEK-ZH-number 2013-0516). The results will be published in a peer-reviewed journal and shared with the worldwide medical community.

Trial registration number

ISRCTN66310845.
Crystal engineering and characterization of a structure-H ionic clathrate hydrate
Authors: Shin Kyuchul , Moudrakovski Igor L. , Udachin Konstantin A. , Ratcliffe Christopher I. , Ripmeester John A.
Published: March 2015

Ionic hydrates are known to form numerous clathrate structures in which either the cations or anions sit in cages and the counterions are incorporated into the water framework. Due to the inclusion of the ionic species, such ionic clathrate hydrates not only show many peculiar features such as metal ion encagement and superoxide ion generation, but also exhibit notable physicochemical properties such as outstanding ionic conductivity and thermal stability. Thus, the ionic clathrate hydrates are considered for their potential applicability in various fields, including those that involve solid electrolytes, gas sensors, and energy storage. In this study, we report the design, synthesis, and characterization of the first ionic clathrate hydrate of the hexagonal structure-H (Str.H) crystal type. Diethyl-dimethyl-ammonium hydroxide hydrate was synthesized with CH4and Xe as help gases, and the crystal structure was identified by powder X-ray diffraction analysis. Further confirmation of the formation of Str.H was obtained from Raman spectroscopy and13C,129Xe, and2H solid-state NMR spectroscopy. From13C NMR and ab initio calculations, it was shown that the quaternary ion occupies the large cage of Str.H with a conformation different from that in solution, due to constraints imposed by the dimensions of the cage. The H deficiency introduced by substitution of OH–for a water molecule appears, from129Xe NMR, to be disordered over the framework, and, from2H NMR, to substantially increase the rate of reorientational mobility of the D atoms in the framework, over that observed for a Str.I hydrate and for ice. The Str.H hydrates are commonly more stable than other structures, thus the present findings on the ionic Str.H clathrate hydrate may offer a new approach for improving the stability of ionic clathrate hydrates for their practical application.
Vitamins and their derivatives in the prevention and treatment of metabolic syndrome diseases (diabetes),
Authors: Dakshinamurti Krishnamurti
Published: March 2015

A cluster of inter-related conditions such as central obesity, dyslipidemia, impaired glucose metabolism, and hypertension is referred to as Metabolic Syndrome, which is a risk factor for the development of type-2 diabetes. The micro- and macro-vascular complications of diabetes contribute to its morbidity and mortality. In addition to its calcitropic effect, vitamin D is a regulator of gene expression as well as cell proliferation and differentiation. Various cross-sectional and longitudinal cohort studies have indicated a beneficial effect from vitamin D supplementation on the development of type-2 diabetes. Binding of retinol-bound retinol-binding protein to a membrane-binding protein suppresses insulin signaling. All-trans retinoic acid, a derivative of vitamin A, reverses these effects, resulting in increased insulin sensitivity, suppression of the phosphoenolpyruvate carboxy kinase (PEPCK) gene, and the induction of the glucokinase gene. Glucokinase and PEPCK are also regulated in opposite directions by the vitamin biotin, acting at the transcriptional level. Biotin also regulates the synthesis of insulin by the islet of Langerhans cells of the pancreas. The increase in advanced glycation end products (AGEs) is implicated in the initiation and progression of diabetes-associated microvascular diseases. Benfotiamine, a derivative of thiamine, and pyridoxamine, a vitamer of vitamin B6, both have anti-AGE properties, making them valuable therapeutic adjuvants in the treatment of diabetic complications. Thus, various vitamins and their derivatives have profound therapeutic potential in the prevention and treatment of type-2 diabetes.