bluuebunny/crossref_metadata_2025 huggingface dataset:
Postoperative Cervical Sagittal Realignment Improves Patient-Reported Outcomes in Chronic Atlantoaxial Anterior Dislocation
Authors: Zhong Junlong , Pan Zhimin , Chen Yiwei , Yao Haoqun , Cheng Zujue , Liu Quanfei , Zeng Zhaoxun , Li Zhiyun , Duan Pingguo , Chen Jiangwei , Li Hu , Huang Sheng , Han Zhimin , Kim Keung Nyun , Ha Yoon , Cao Kai
Published: March 2018

BACKGROUND

Chronic atlantoaxial anterior dislocation (AAD) not only results in myelopathy, but dislocation-related kyphosis also results in cervical malalignment, which permanently affects neck function and patient-reported outcomes (PROs).

OBJECTIVE

To investigate the effect of kyphotic correction on realigning cervical spine and independent cervical alignment parameters, which may be correlated with an improvement of PROs.

METHODS

The study included 21 patients with chronic AAD-related kyphosis who underwent C1-2 reduction and correction surgery. Radiographic parameters were measured to assess cervical realignment preoperatively and postoperatively. Neck disability index (NDI), short form 12 physical component summary (SF-12 PCS), and Japanese Orthopaedic Association (JOA) scores were recorded to reveal changes in PROs. The independent parameters correlated with the improvements of PROs were analyzed.

RESULTS

Of the radiographic parameters, the C1-2 Cobb angle, the C2-7 Cobb angle, thoracic inlet angle, cervical tilt, and T1 slope were significantly changed from −4.0° ± 16.2°, −29.2° ± 11.2°, 73.1° ± 13.3°, 30.4° ± 8.5°, and 29.1° ± 8.8° preoperatively to −13.5° ± 8.1° (P = .005), −18.0° ± 12.0° (P < .001), 67.1° ± 11.6° (P = .042), 23.1° ± 10.3° (P = .007), and 24.0° ± 7.0° (P = .011) at last follow-up, respectively. NDI, JOA, and SF-12 PCS scores were significantly improved postoperatively. The C1-2 Cobb angle was an independent parameter correlated with the improvements in SF-12 PCS, NDI, and JOA scores.

CONCLUSION

Correction and reduction surgery can realign cervical spine in chronic AAD patients. The C1-2 Cobb angle was an independent parameter correlated with the improvements of PROs.
Nonspecific immunomodulators for recurrent respiratory tract infections, wheezing and asthma in children: a systematic review of mechanistic and clinical evidence
Authors: Esposito Susanna , Soto-Martinez Manuel E. , Feleszko Wojciech , Jones Marcus H. , Shen Kun-Ling , Schaad Urs B.
Published: March 2018

Purpose of review

To provide an overview of the mechanistic and clinical evidence for the use of nonspecific immunomodulators in paediatric respiratory tract infection (RTI) and wheezing/asthma prophylaxis.

Recent findings

Nonspecific immunomodulators have a long history of empirical use for the prevention of RTIs in vulnerable populations, such as children. The past decade has seen an increase in both the number and quality of studies providing mechanistic and clinical evidence for the prophylactic potential of nonspecific immunomodulators against both respiratory infections and wheezing/asthma in the paediatric population. Orally administered immunomodulators result in the mounting of innate and adaptive immune responses to infection in the respiratory mucosa and anti-inflammatory effects in proinflammatory environments. Clinical data reflect these mechanistic effects in reductions in the recurrence of respiratory infections and wheezing events in high-risk paediatric populations. A new generation of clinical studies is currently underway with the power to position the nonspecific bacterial lysate immunomodulator OM-85 as a potential antiasthma prophylactic.

An established mechanistic and clinical role for prophylaxis against paediatric respiratory infections by nonspecific immunomodulators exists. Clinical trials underway promise to provide high-quality data to establish whether a similar role exists in wheezing/asthma prevention.
Modified Technique of Separate Vertical Wiring for the Fixation of Patellar Inferior Pole Fracture
Authors: He Shuangjian , Huang Xiaoyi , Yan Bin , Zhu Jian , Bao Nirong , Zhao Jianning
Published: March 2018

To evaluate the biomechanical and clinical results of modified separate vertical wiring technique (SVW) for inferior pole patellar fracture repair we conducted a finite element biomechanical study using 2 fixation methods and evaluated a clinical series of eleven patients. The modified SVW technique was an effective, safe and simple method that can provide stable fixation for early exercise with excellent functional results in fixing inferior pole patella fractures.
Telomerase reverse transcriptase promoter mutations and solar elastosis in cutaneous melanoma
Authors: Lade-Keller Johanne , Yuusufi Sakineh , Riber-Hansen Rikke , Steiniche Torben , Stougaard Magnus
Published: March 2018

The aims of this study were to assess the prognostic potential of solar elastosis grading and telomerase reverse transcriptase (TERT) promoter mutations (TERTpmut) in melanoma and to evaluate whether an association between solar elastosis and TERTpmut exists. Solar elastosis in the dermis was evaluated in hematoxylin and eosin-stained whole slides from 486 malignant melanomas. Pyrosequencing was used to detect TERTpmut in 189 samples. There was no association between solar elastosis and TERTpmut (P=0.3). Severe elastosis was associated with older age (P<0.0001), ulceration (P=0.03), and location in the head/neck region (P<0.0001). The absence of elastosis was associated with younger age (P<0.0001), benign nevus remnants (P=0.001), and a positive BRAF V600E expression (P<0.0001). Severe elastosis predicted a worse relapse-free survival (hazard ratio: 2.18; 95% confidence interval: 1.30–3.64; P=0.003). However, it was not independent of age. TERTpmut was not associated with any adverse prognostic or clinicopathological outcome, nor any mitogen-activated protein kinase-related protein expressions. However, at a cutoff corresponding to the sensitivity of Sanger sequencing, TERTpmut predicted melanoma-specific death independently of age, and was associated with Breslow thickness, ulceration, tumor stage at diagnosis, BRAF V600E oncoprotein, and absence of p16 expression. In conclusion, TERTpmut were not related to severe elastosis and may thus be triggered by both chronic and acute intermittent sun exposure, the latter not visible on ordinary hematoxylin and eosin-stained slides. Neither TERTpmut nor severe elastosis predicted an adverse outcome in melanoma. An absence of elastosis was seen in younger melanoma patients and may be used to select those melanomas originating in a nevus, which often harbors a BRAF mutation.
Perinatal exposure to venlafaxine leads to lower anxiety and depression-like behavior in the adult rat offspring
Authors: Bogi Eszter , Belovicová Kristina , Ujhazy Eduard , Mach Mojmír , Koprdova Romana , Zilava Ludmila , Garafová Alexandra , Jezova Daniela , Dubovicky Michal
Published: March 2018

Depression during pregnancy and in the post-partum period is a growing health issue. Venlafaxine, a representative of serotonin and noradrenaline reuptake inhibitors, is used to treat a wide spectrum of mood disorders. However, the limited number of prenatal and perinatal studies raises the question about the long-term consequences of venlafaxine therapy. The aim of this study was to investigate the effect of venlafaxine exposure during pregnancy and lactation on anxiety-like and depression-like behaviors, as well as adrenocortical hormone concentrations in the adult rat offspring. For this purpose, rat dams were treated orally with venlafaxine from day 15 of gestation to postnatal day 20 at doses of 7.5, 37.5, and 75 mg/kg. Administration of venlafaxine during gestation and lactation affected anxiety-like and depression-like behaviors in adult rat offspring of both sexes. The animals exposed through their mothers to venlafaxine, particularly at the lowest and middle doses, were less anxious and less depressive in several relevant behavioral tests, which can be considered a deviation from the normal state. At clinically relevant doses, venlafaxine did not alter circulating level of corticosterone and aldosterone in the adult offspring. In general, the consequences of venlafaxine were dose dependent and more apparent in females. Together, these results suggest that prenatal and early postnatal exposure to venlafaxine may interfere with functional development of the brain, though not necessarily in a negative way.
Decline of Seroprevalence and Incidence of Congenital Toxoplasmosis Despite Changing Prevention Policy—Three Decades of Cord-blood Screening in North-western Switzerland
Authors: Rudin Christoph , Hirsch Hans H. , Spaelti Rahel , Schaedelin Sabine , Klimkait Thomas
Published: March 2018

Background:

Due to the lack of prospective data, there is an ongoing debate about the need for screening and prevention programs for congenital toxoplasmosis in Europe. Accordingly, individual countries have chosen different public health strategies.

Methods:

A cord-blood screening program for congenital toxoplasmosis was established in 1982 in obstetric units of hospitals in North-Western Switzerland. Samples were tested for specific immunoglobulin G (IgG) and IgM, and after 1992 also for IgA antibodies. Suspicious test results triggered additional investigations to identify children with congenital toxoplasmosis.

Results:

From 1982 to 2015, 119,166 cord-blood samples have been collected and analyzed for the presence of Toxoplasma-specific antibodies. Although maternal age rose from 28.2 to 32.2 years during this period, a decrease of seroprevalence from 53% to 20% was observed. The incidence of congenital toxoplasmosis decreased by 85% (from 0.08% to 0.012%) and remained low despite abandoning prevalent nonsystematic screening during pregnancy in Switzerland.

Conclusions:

Our data document a steady decline of both Toxoplasma gondii seroprevalence and congenital toxoplasmosis incidence in Switzerland even after abolition of the nonsystematic prenatal screening a decade ago. The data support abandoning toxoplasmosis screening programs in low-incidence, high-income countries such as Switzerland.
Detection of Porcine Bocavirus From a Child With Acute Respiratory Tract Infection
Authors: Safamanesh Saghar , Azimian Amir , Shakeri Abdolreza , Ghazvini Kiarash , Jamehdar Saeid Amel , Khosrojerdi Mahsa , Youssefi Masoud
Published: March 2018

Porcine bocavirus is a recently discovered virus classified within the Bocavirus genus. We present a case of upper respiratory tract infection associated with porcine bocavirus in a 3-year-old child who was in close contact with hogs in northeastern Iran. To the best of our knowledge, this is the first report on the human porcine bocavirus infection.
In Vitro Study on the Effect of Maraviroc or Dolutegravir on Bilirubin to Albumin Binding
Authors: Schreiner Cynthia N. , Ahlfors Charles E. , Wong Ronald J. , Stevenson David K. , Clarke Diana F. , Mirochnick Mark
Published: March 2018

We performed an in vitro evaluation of the effect of maraviroc or dolutegravir on bilirubin to albumin binding. At typical treatment and low albumin concentrations, maraviroc had no impact, while dolutegravir affected bilirubin to albumin binding to an equivalent extent as sulfisoxazole. However in vivo, neither is likely to significantly impact bilirubin to albumin binding because of their low concentrations relative to albumin.
Understanding the carbon dioxide gaps
Authors: Scheeren Thomas W.L. , Wicke Jannis N. , Teboul Jean-Louis
Published: March 2018

Purpose of review

The current review attempts to demonstrate the value of several forms of carbon dioxide (CO2) gaps in resuscitation of the critically ill patient as monitor for the adequacy of the circulation, as target for fluid resuscitation and also as predictor for outcome.

Recent findings

Fluid resuscitation is one of the key treatments in many intensive care patients. It remains a challenge in daily practice as both a shortage and an overload in intravascular volume are potentially harmful. Many different approaches have been developed for use as target of fluid resuscitation. CO2 gaps can be used as surrogate for the adequacy of cardiac output (CO) and as marker for tissue perfusion and are therefore a potential target for resuscitation. CO2 gaps are easily measured via point-of-care analysers. We shed light on its potential use as nowadays it is not widely used in clinical practice despite its potential. Many studies were conducted on partial CO2 pressure differences or CO2 content (cCO2) differences either alone, or in combination with other markers for outcome or resuscitation adequacy. Furthermore, some studies deal with CO2 gap to O2 gap ratios as target for goal-directed fluid therapy or as marker for outcome.

CO2 gap is a sensitive marker of tissue hypoperfusion, with added value over traditional markers of tissue hypoxia in situations in which an oxygen diffusion barrier exists such as in tissue oedema and impaired microcirculation. Venous-to-arterial cCO2 or partial pressure gaps can be used to evaluate whether attempts to increase CO should be made. Considering the potential of the several forms of CO2 measurements and its ease of use via point-of-care analysers, it is recommendable to implement CO2 gaps in standard clinical practice.
Helicobacter pylori-induced autoimmune thyroiditis: is the pathogenic link concluded or still a hypothesis?
Authors: Thiyagarajan Santhanamari , Saini Anil M.R. , Alruwaili Jamal
Published: March 2018

Infection caused by Helicobacter pylori is considered as a serious health issue as it can cause severe damage of gastric mucosa, impair the digestive mechanism and even lead to neoplastic disease. Research studies have projected its survival in many parts of the body beyond the gastric system. The ability of these bacteria to withstand the gastric juice and change the surrounding conditions makes its survival in the stomach successful. As an outcome of H. pylori infection, there occurs the release of inflammatory mediators and immune modulators, which could cause further complications. Recent investigations on H. pylori have demonstrated the association of its infection with many systemic diseases including lung cancer, urticaria, type-1 diabetes, autoimmune diseases and so on. Autoimmune thyroiditis (AIT) is an organ-specific autoimmune disease, which occurs as a result of production of autoantibodies to thyroid gland leading to thyroid dysfunction. Antibodies of similar kind produced against H. pylori have been demonstrated for their occurrence in patients suffering with AIT in many studies. On the other hand, some of the studies have experimentally proved the lack of link between H. pylori infection and AIT. As the findings attributing H. pylori infection with the AIT are increasingly reported in recent years, this article reviews the concepts and controversies over their association.
Report of plasmid-mediated colistin resistance in Klebsiella oxytoca from Iran
Authors: Ghasemian Abdolmajid , Mobarez Ashraf Mohabati , Peerayeh Shahin Najar , Abadi Amin Talebi Bezmin , Khodaparast Sepideh , Nojoomi Farshad
Published: March 2018

Background:

Colistin resistance occurs via either the chromosomal mutations or transfer of plasmid-mediated mobilized colistin resistance (mcr-1) and mcr-2 genes. The objective of this study was characterization of plasmid-mediated colistin-resistant Klebsiella oxytoca clinical isolates.

Methods:

A total of five colistin-resistant K. oxytoca isolates were obtained from patients with antibiotic-associated haemorrhagic colitis. The resistance pattern and phenotypic tests, and the virulence genes were investigated by the phenotypic method and the PCR.

Results:

Four mcr-1 and one mcr-2-positive K. oxytoca isolates were detected. The ceftazidime and cefotaxime minimum inhibitory concentrations was more than 128 μg/ml and imipenem minimum inhibitory concentrations were 4 μg/ml for four isolates and 1 μg/ml for one isolate. The extended-spectrum beta-lactamases including bla
CTX-M1, bla
SHV and bla
TEM1 and Citrobacter-like (CIT) (encoding AmpC) genes were detected among all the isolates, and bla
IMP (100%, n = 5) and bla
OXA-48 (80%, n = 4) carbapenemase genes were also detected, but none amplified bla
KPC-2, bla
VIM or bla
NDM1 and the fosA3 (fosfomycin-resistant) genes. The virulence encoding genes including npsB (100%, n = 5), fimA (4/5, 80%), matB (100%, n = 5), mrkA (80%, n = 4) and pilQ (100%, n = 5) were detected among them. There was no significant difference regarding the presence of any of adhesion genes between colistin-resistant and susceptible isolates (P > 0.05). In this study, carbapenem and colistin-resistant K. oxytoca with a high rate of adhesions and toxin-encoding genes were detected from hospitalized patients with antibiotic-associated hemorrhagic colitis (AAHC)

Conclusion:

A high rate of carbapenem resistance and emergence of colistin resistance which have been located on mobile genetic elements is a concern. Detection, surveillance and control of multidrug-resistant Enterobacteriacea spread are essential to eradicate due infections.
Polarization Variability in Age-related Macular Degeneration
Authors: VanNasdale Dean A. , Elsner Ann E. , Malinovsky Victor E. , Peabody Todd D. , Kohne Kimberly D. , Haggerty Bryan P. , Clark Christopher A.
Published: March 2018

SIGNIFICANCE

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss. Complementary imaging techniques can be used to better characterize and quantify pathological changes associated with AMD. By assessing specific light-tissue interactions, polarization-sensitive imaging can be used to detect tissue disruption early in the disease process.

PURPOSE

The aim of this study was to compare variability in central macular polarization properties in patients with nonexudative AMD and age-matched control subjects.

METHODS

A scanning laser polarimeter (GDx, LDT/CZM) was used to acquire 15 × 15-degree macular images in 10 subjects diagnosed with nonexudative AMD and 10 age-matched control subjects. The coefficient of variation (COV, SD/mean) was used to quantify variability in pixel intensity in the central 3.3° of the macula for custom images emphasizing multiply scattered light (the depolarized light image) and polarization-retaining light (the maximum of the parallel detector image). The intensity COV was compared across subject categories using paired t tests for each image type.

RESULTS

The COV in the central macula was significantly higher in the AMD subject group (average, 0.221; 95% confidence interval [CI], 0.157 to 0.265) when compared with matched control subjects (average 0.120; 95% CI, 0.107 to 0.133) in the depolarized light image (P = .01). The COV in the maximum of the parallel detector image was not statistically different between the two subject groups (AMD average, 0.162 [95% CI, 0.138 to 0.185]; control average, 0.137 [95% CI, 0.115 to 0.158]; P = .21).

CONCLUSIONS

Variability in multiply scattered light is higher than that of light that is more polarization preserving in patients with nonexudative AMD. Multiple scattering may act as an early indicator representing disruption to the macula in early AMD.
Visual Acuity and Over-refraction in Myopic Children Fitted with Soft Multifocal Contact Lenses
Authors: Schulle Krystal L. , Berntsen David A. , Sinnott Loraine T. , Bickle Katherine M. , Gostovic Anita T. , Pierce Gilbert E. , Jones-Jordan Lisa A. , Mutti Donald O. , Walline Jeffrey J.
Published: March 2018

SIGNIFICANCE

Practitioners fitting contact lenses for myopia control frequently question whether a myopic child can achieve good vision with a high-add multifocal. We demonstrate that visual acuity is not different than spectacles with a commercially available, center-distance soft multifocal contact lens (MFCL) (Biofinity Multifocal “D”; +2.50 D add).

PURPOSE

To determine the spherical over-refraction (SOR) necessary to obtain best-corrected visual acuity (BCVA) when fitting myopic children with a center-distance soft MFCL.

METHODS

Children (n = 294) aged 7 to 11 years with myopia (spherical component) of −0.75 to −5.00 diopters (D) (inclusive) and 1.00 D cylinder or less (corneal plane) were fitted bilaterally with +2.50 D add Biofinity “D” MFCLs. The initial MFCL power was the spherical equivalent of a standardized subjective refraction, rounded to the nearest 0.25 D step (corneal plane). An SOR was performed monocularly (each eye) to achieve BCVA. Binocular, high-contrast logMAR acuity was measured with manifest spectacle correction and MFCLs with over-refraction. Photopic pupil size was measured with a pupilometer.

RESULTS

The mean (±SD) age was 10.3 ± 1.2 years, and the mean (±SD) SOR needed to achieve BCVA was OD: −0.61 ± 0.24 D/OS: −0.58 ± 0.27 D. There was no difference in binocular high-contrast visual acuity (logMAR) between spectacles (−0.01 ± 0.06) and best-corrected MFCLs (-0.01 ± 0.07) (P = .59). The mean (±SD) photopic pupil size (5.4 ± 0.7 mm) was not correlated with best MFCL correction or the over-refraction magnitude (both P ≥ .09).

CONCLUSIONS

Children achieved BCVA with +2.50 D add MFCLs that was not different than with spectacles. Children typically required an over-refraction of −0.50 to −0.75 D to achieve BCVA. With a careful over-refraction, these +2.50 D add MFCLs provide good distance acuity, making them viable candidates for myopia control.
Submental Intubation: an Underutilized Technique for Airway Management in Patients With Panfacial Trauma
Authors: Kaiser Adam , Semanoff Adam , Christensen Louis , Sadoff Rory , DiGiacomo Jody C.
Published: March 2018

Purpose:

To evaluate submental intubation compared with secure airways of patients who have sustained significant maxillofacial trauma.

Patients and Methods:

Patient series of 3 patients who underwent submental intubation prior to open reduction internal fixation of fractures associated with the mid and lower face. All of these patients were initially orally intubated, and then converted to submental intubation prior to the reparative procedure. Detailed description of the procedure is discussed in each patient.

Results:

All the patients received appropriate reduction of facial fractures following submental intubation with no intraoperative complications. Two of the 3 patients were extubated immediately postoperatively and 1 was extubated on the second postoperative day. None of the patients had any complications associated with submental intubation.

Conclusions:

Submental intubation is a safe and expedient technique to divert the airway in patients who require operative repair of panfacial injuries. This procedure is preferable over tracheostomy in selected patients of maxillofacial trauma without indication for prolonged ventilation support.
Porcine Bone Incorporated With 4-Hexylresorcinol Increases New Bone Formation by Suppression of the Nuclear Factor Kappa B Signaling Pathway
Authors: Song Ji-Young , Kim Seong-Gon , Park Na-rae , Choi Je-Yong
Published: March 2018

Objective:

The objectives of this study were to evaluate the suppression of the nuclear factor kappa B (NF-kB) pathway by 4-hexylresorcinol (4HR), which was activated by tumor necrosis factor-α (TNF-α) in osteoblasts, and new bone formation by 4HR-incorporated porcine bone in an animal model.

Study Design:

For the confirmation of successful incorporation of 4HR into porcine bone, scanning electron microscopy (SEM) and Fourier transform-infrared (FT-IR) analysis were performed. High performance liquid chromatography was performed for the analysis of the 4HR release profile from porcine bone. MC 3T3-E1 cells were used for the analysis of the NF-kB signaling pathway activation by western blotting and real-time reverse transcriptase polymerase chain reaction. New bone formation and the analysis of marker protein expression were studied in a rat calvarial critical-sized defect model.

Results:

Both SEM and FT-IR analysis demonstrated successful incorporation of 4HR into porcine bone. Approximately 30% of 4HR was steadily released from porcine bone for 18 days. 4HR suppressed the NF-kB signaling pathway, which was activated by TNF-α application in MC 3T3-E1 cells. Histological analysis revealed that porcine bone particles with incorporated 4HR showed significantly greater new bone formation than those without 4HR at 4 and 8 weeks after operation (P < 0.05). The expression intensities of alkaline phosphatase, osteoprotegerin, and osteocalcin were also higher in the 4HR-incorporated group.

Conclusion:

The application of 4HR suppressed the NF-kB signaling pathway in osteoblasts and 4HR-containing porcine bone particles promoted new bone formation in a rat calvarial defect model.
Comparison of the WarmCloud and Bair Hugger Warming Devices for the Prevention of Intraoperative Hypothermia in Patients Undergoing Orthotopic Liver Transplantation: A Randomized Clinical Trial
Authors: Pearce Brett , Mattheyse Linda , Ellard Louise , Desmond Fiona , Pillai Param , Weinberg Laurence
Published: March 2018

Background

The avoidance of hypothermia is vital during prolonged and open surgery to improve patient outcomes. Hypothermia is particularly common during orthotopic liver transplantation (OLT) and associated with undesirable physiological effects that can adversely impact on perioperative morbidity. The KanMed WarmCloud (Bromma, Sweden) is a revolutionary, closed-loop, warm-air heating mattress developed to maintain normothermia and prevent pressure sores during major surgery. The clinical effectiveness of the WarmCloud device during OLT is unknown. Therefore, we conducted a randomized controlled trial to determine whether the WarmCloud device reduces hypothermia and prevents pressure injuries compared with the Bair Hugger underbody warming device.

Methods

Patients were randomly allocated to receive either the WarmCloud or Bair Hugger warming device. Both groups also received other routine standardized multimodal thermoregulatory strategies. Temperatures were recorded by nasopharyngeal temperature probe at set time points during surgery. The primary endpoint was nasopharyngeal temperature recorded 5 minutes before reperfusion. Secondary endpoints included changes in temperature over the predefined intraoperative time points, number of patients whose nadir temperature was below 35.5°C and the development of pressure injuries during surgery.

Results

Twenty-six patients were recruited with 13 patients randomized to each group. One patient from the WarmCloud group was excluded because of a protocol violation. Baseline characteristics were similar. The mean (standard deviation) temperature before reperfusion was 36.0°C (0.7) in the WarmCloud group versus 36.3°C (0.6) in the Bairhugger group (P = 0.25). There were no statistical differences between the groups for any of the secondary endpoints.

Conclusions

When combined with standardized multimodal thermoregulatory strategies, the WarmCloud device does not reduce hypothermia compared with the Bair Hugger device in patients undergoing OLT.
An upper bound on the particle-laden dependency of shear stresses at solid–fluid interfaces
Authors: Zohdi T. I.
Published: March 2018

In modern advanced manufacturing processes, such as three-dimensional printing of electronics, fine-scale particles are added to a base fluid yielding a modified fluid. For example, in three-dimensional printing, particle-functionalized inks are created by adding particles to freely flowing solvents forming a mixture, which is then deposited onto a surface, which upon curing yields desirable solid properties, such as thermal conductivity, electrical permittivity and magnetic permeability. However, wear at solid–fluid interfaces within the machinery walls that deliver such particle-laden fluids is typically attributed to the fluid-induced shear stresses, which increase with the volume fraction of added particles. The objective of this work is to develop a rigorous
strict upper bound
for the tolerable volume fraction of particles that can be added, while remaining below a given stress threshold at a fluid–solid interface. To illustrate the bound’s utility, the expression is applied to a series of classical flow regimes.
Manipulating nanoparticle transport within blood flow through external forces: an exemplar of mechanics in nanomedicine
Authors: Ye Huilin , Shen Zhiqiang , Yu Le , Wei Mei , Li Ying
Published: March 2018

A large number of nanoparticles (NPs) have been raised for diverse biomedical applications and some of them have shown great potential in treatment and imaging of diseases. Design of NPs is essential for delivery efficacy due to a number of biophysical barriers, which prevents the circulation of NPs in vascular flow and their accumulation at tumour sites. The physiochemical properties of NPs, so-called ‘4S’ parameters, such as size, shape, stiffness and surface functionalization, play crucial roles in their life journey to be delivered to tumour sites. NPs can be modified in various ways to extend their blood circulation time and avoid their clearance by phagocytosis, and efficiently diffuse into tumour cells. However, it is difficult to overcome these barriers simultaneously by a simple combination of ‘4S’ parameters for NPs. At this moment, external triggerings are necessary to guide the movement of NPs, which include light, ultrasound, magnetic field, electrical field and chemical interaction. The delivery system can be constructed to be sensitive to these external stimuli which can reduce the non-specific toxicity and improve the efficacy of the drug-delivery system. From a mechanics point of view, we discuss how different forces play their roles in the margination of NPs in blood flow and tumour microvasculature.
Common and unique strategies of male killing evolved in two distinctDrosophilasymbionts
Authors: Harumoto Toshiyuki , Fukatsu Takema , Lemaitre Bruno
Published: March 2018

Male killing is a selfish reproductive manipulation caused by symbiotic bacteria, where male offspring of infected hosts are selectively killed. The underlying mechanisms and the process of their evolution are of great interest not only in terms of fundamental biology, but also their potential applications. The two bacterialDrosophilasymbionts,WolbachiaandSpiroplasma, have independently evolved male-killing ability. This raises the question whether the underlying mechanisms share some similarities or are specific to each bacterial species. Here, we analyse pathogenic phenotypes ofD. bifasciatainfected with its natural male-killingWolbachiastrain and compare them with those ofD. melanogasterinfected with male-killingSpiroplasma. We show that male progeny infected with theWolbachiastrain die during embryogenesis with abnormal apoptosis. Interestingly, male-killingWolbachiainfection induces DNA damage and segregation defects in the dosage-compensated chromosome in male embryos, which are reminiscent of the phenotypes caused by male-killingSpiroplasmainD. melanogaster. By contrast, host neural development seems to proceed normally unlike male-killingSpiroplasmainfection. Our results demonstrate that the dosage-compensated chromosome is a common target of two distinct male killers, yetSpiroplasmauniquely evolved the ability to damage neural tissue of male embryos.
Mobile marine predators: an understudied source of nutrients to coral reefs in an unfished atoll
Authors: Williams Jessica J. , Papastamatiou Yannis P. , Caselle Jennifer E. , Bradley Darcy , Jacoby David M. P.
Published: March 2018

Animal movements can facilitate important ecological processes, and wide-ranging marine predators, such as sharks, potentially contribute significantly towards nutrient transfer between habitats. We applied network theory to 4 years of acoustic telemetry data for grey reef sharks (
Carcharhinus amblyrhynchos
) at Palmyra, an unfished atoll, to assess their potential role in nutrient dynamics throughout this remote ecosystem. We evaluated the dynamics of habitat connectivity and used network metrics to quantify shark-mediated nutrient distribution. Predator movements were consistent within year, but differed between years and by sex. Females used higher numbers of routes throughout the system, distributing nutrients over a larger proportion of the atoll. Extrapolations of tagged sharks to the population level suggest that prey consumption and subsequent egestion leads to the heterogeneous deposition of 94.5 kg d
−1
of nitrogen around the atoll, with approximately 86% of this probably derived from pelagic resources. These results suggest that sharks may contribute substantially to nutrient transfer from offshore waters to near-shore reefs, subsidies that are important for coral reef health.
The ecology of insect–yeast relationships and its relevance to human industry
Authors: Madden Anne A. , Epps Mary Jane , Fukami Tadashi , Irwin Rebecca E. , Sheppard John , Sorger D. Magdalena , Dunn Robert R.
Published: March 2018

Many species of yeast are integral to human society. They produce many of our foods, beverages and industrial chemicals, challenge us as pathogens, and provide models for the study of our own biology. However, few species are regularly studied and much of their ecology remains unclear, hindering the development of knowledge that is needed to improve the relationships between humans and yeasts. There is increasing evidence that insects are an essential component of ascomycetous yeast ecology. We propose a ‘dispersal–encounter hypothesis' whereby yeasts are dispersed by insects between ephemeral, spatially disparate sugar resources, and insects, in turn, obtain the benefits of an honest signal from yeasts for the sugar resources. We review the relationship between yeasts and insects through three main examples: social wasps, social bees and beetles, with some additional examples from fruit flies. Ultimately, we suggest that over the next decades, consideration of these ecological and evolutionary relationships between insects and yeasts will allow prediction of where new yeast diversity is most likely to be discovered, particularly yeasts with traits of interest to human industry.
Trait evolution, resource specialization and vulnerability to plant extinctions among Antillean hummingbirds
Authors: Dalsgaard Bo , Kennedy Jonathan D. , Simmons Benno I. , Baquero Andrea C. , Martín González Ana M. , Timmermann Allan , Maruyama Pietro K. , McGuire Jimmy A. , Ollerton Jeff , Sutherland William J. , Rahbek Carsten
Published: March 2018

Species traits are thought to predict feeding specialization and the vulnerability of a species to extinctions of interaction partners, but the context in which a species evolved and currently inhabits may also matter. Notably, the predictive power of traits may require that traits evolved to fit interaction partners. Furthermore, local abiotic and biotic conditions may be important. On islands, for instance, specialized and vulnerable species are predicted to be found mainly in mountains, whereas species in lowlands should be generalized and less vulnerable. We evaluated these predictions for hummingbirds and their nectar-food plants on Antillean islands. Our results suggest that the rates of hummingbird trait divergence were higher among ancestral mainland forms before the colonization of the Antilles. In correspondence with the limited trait evolution that occurred within the Antilles, local abiotic and biotic conditions—not species traits—correlate with hummingbird resource specialization and the vulnerability of hummingbirds to extinctions of their floral resources. Specifically, hummingbirds were more specialized and vulnerable in conditions with high topographical complexity, high rainfall, low temperatures and high floral resource richness, which characterize the Antillean Mountains. These findings show that resource specialization and species vulnerability to extinctions of interaction partners are highly context-dependent.
Nursing protects honeybee larvae from secondary metabolites of pollen
Authors: Lucchetti Matteo A. , Kilchenmann Verena , Glauser Gaetan , Praz Christophe , Kast Christina
Published: March 2018

The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen ofEchium vulgareon honeybee adults and larvae. Echimidine, a PA present inE. vulgarepollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen.
Higher-order thalamocortical inputs gate synaptic long-term potentiation via disinhibition
Authors: Williams Leena E. , Holtmaat Anthony
Published: March 2018

Sensory experience and perceptual learning changes the receptive field properties of cortical pyramidal neurons, largely mediated by long-term potentiation (LTP) of synapses. The circuit mechanisms underlying cortical LTP remain unclear. In the mouse somatosensory cortex (S1), LTP can be elicited in layer (L) 2/3 pyramidal neurons by rhythmic whisker stimulation. We combined electrophysiology, optogenetics, and chemogenetics in thalamocortical slices to dissect the synaptic circuitry underlying this LTP. We found that projections from higher-order, posteriormedial thalamic complex (POm) to S1 are key to eliciting NMDAR-dependent LTP of intracortical synapses. Paired activation of intracortical and higher-order thalamocortical pathways increased vasoactive intestinal peptide (VIP) interneuron and decreased somatostatin (SST) interneuron activity, which was critical for inducing LTP. Our results reveal a novel circuit motif in which higher-order thalamic feedback gates plasticity of intracortical synapses in S1 via disinhibition. This motif may allow contextual feedback to shape synaptic circuits that process first-order sensory information.
Deep genome annotation of the opportunistic human pathogenStreptococcus pneumoniaeD39
Authors: Slager Jelle , Aprianto Rieza , Veening Jan-Willem
Published: March 2018

A precise understanding of the genomic organization into transcriptional units and their regulation is essential for our comprehension of opportunistic human pathogens and how they cause disease. Using single-molecule real-time (PacBio) sequencing we unambiguously determined the genome sequence ofStreptococcus pneumoniaestrain D39 and revealed several inversions previously undetected by short-read sequencing. Significantly, a chromosomal inversion results in antigenic variation of PhtD, an important surface-exposed virulence factor. We generated a new genome annotation using automated tools, followed by manual curation, reflecting the current knowledge in the field. By combining sequence-driven terminator prediction, deep paired-end transcriptome sequencing and enrichment of primary transcripts by Cappable-Seq, we mapped 1,015 transcriptional start sites and 748 termination sites. Using this new genomic map, we identified several new small RNAs (sRNAs), riboswitches (including twelve previously misidentified as sRNAs), and antisense RNAs. In total, we annotated 92 new protein-encoding genes, 39 sRNAs and 165 pseudogenes, bringing theS. pneumoniaeD39 repertoire to 2,151 genetic elements. We report operon structures and observed that 9% of operons lack a 5’-UTR. The genome data is accessible in an online resource called PneumoBrowse (https://veeninglab.com/pneumobrowse) providing one of the most complete inventories of a bacterial genome to date. PneumoBrowse will accelerate pneumococcal research and the development of new prevention and treatment strategies.
Auxin is not asymmetrically distributed in initiating Arabidopsis leaves
Authors: Bhatia Neha , Heisler Marcus G.
Published: March 2018

It has been proposed that asymmetric auxin levels within initiating leaves help establish leaf polarity, based in part on observations of the DII auxin sensor. Here we show that the mDII control sensor also exhibits an asymmetry and that according to the ratio-metric auxin sensor R2D2, no obvious asymmetry in auxin exists. Together with other recent findings, our results argue against the importance of auxin asymmetry in establishing leaf polarity.
Seasonal variation of fermentation rate inSaccharomyces spp. (Ascomycota)?
Authors: Tiefenbrunner Dagmar , Gangl Helmut , Lopandic Ksenija , Tiefenbrunner Wolfgang
Published: March 2018

Yeast species of the genusSaccharomycesshow some reaction to visible light – although they lack photo pigments and the typical clock genes of fungi – that can be explained by damage of the cytochrome electron transport chain of the mitochondria. Evidence for a circadian clock, entrainable by cyclic environmental stimuli, exists for periodic changing temperature and light as zeitgeber. Whether seasonality follows from the existence of a circadian clock – which is a necessary requirement for annual rhythms – remains unknown.

Due to an accidental observation, we were able to show that fermentation taking place in complete darkness and at constant temperature is influenced in some yeast strains by the history of the inoculum culture. Using yeast cultures growing on agar plates and exposed to diffuse daylight for three weeks either in March or in May as inoculum, leads to significantly different fermentation rates in the inoculated grape juice in both months: rates are higher in March when day length is shorter than in May. In must inoculated with cultures that grew in darkness or daylight, respectively, higher fermentation rates occur by the former. Other yeast strains react to artificial white light in the same way.

We used strains ofS. cerevisiae, S. eubayanus, S. kudriavzevii, S. uvarumand furthermore hybrid strains of two or even three of these species. The most pronounced reaction to daylight was shown by theS. eubayanusxS. uvarumxS. cerevisiaehybrid, followed byS. cerevisiaexS. kudriavzeviihybrids,S. eubayanusandS. cerevisiae. S. uvarumwas sensitive to artificial white light.

These observations can hardly be explained by some kind of photo damage because they base on an effect that persists through many cell division cycles after yeasts were exposed to light. If it really represents seasonality epigenetic memory is likely involved, since fermentation lasts for many days and yeast generations. If the existence of a circadian clock and seasonal behaviour inSaccharomycesis confirmed these yeasts could become an important tool in basic research concerning epigenetic memory.
Muscarinic receptors regulate auditory and prefrontal cortical communication during auditory processing
Authors: James Nicholas M. , Gritton Howard J. , Kopell Nancy , Sen Kamal , Han Xue
Published: March 2018

Much of our understanding about how acetylcholine modulates prefrontal cortical (PFC) networks comes from behavioral experiments that examine cortical dynamics during highly attentive states. However, much less is known about how PFC is recruited during passive sensory processing and how acetylcholine may regulate connectivity between cortical areas outside of task performance. To investigate the involvement of PFC and cholinergic neuromodulation in passive auditory processing, we performed simultaneous recordings in the auditory cortex (AC) and PFC in awake head fixed mice presented with a white noise auditory stimulus in the presence or absence of local cholinergic antagonists in AC. We found that a subset of PFC neurons were strongly driven by auditory stimuli even when the stimulus had no associative meaning, suggesting PFC monitors stimuli under passive conditions. We also found that cholinergic signaling in AC shapes the strength of auditory driven response in PFC, by modulating the intra-cortical sensory response through muscarinic interactions in AC. Taken together, these findings provide novel evidence that cholinergic mechanisms have a continuous role in cortical gating through muscarinic receptors during passive processing and expand traditional views of prefrontal cortical function and the contributions of cholinergic modulation in sensory gating.

Highlights

Prefrontal cortex actively monitors non-associative stimuli under passive conditions

Acetylcholine facilitates cortical signaling even outside of attentional contexts

Local scopolamine infusion reduced intracortical signaling and impaired cortical gating

mAChR have an ongoing role in sound processing
The draft genome of the invasive walking stick,Medauroidea extradendata, reveals extensive lineage-specific gene family expansions of cell wall degrading enzymes in Phasmatodea
Authors: Brand Philipp , Lin Wei , Johnson Brian R.
Published: March 2018

Plant cell wall components are the most abundant macromolecules on Earth. The study of the breakdown of these molecules is thus a central question in biology. Surprisingly, plant cell wall breakdown by herbivores is relatively poorly understood, as nearly all early work focused on the mechanisms used by symbiotic microbes to breakdown plant cell walls in insects such as termites. Recently, however, it has been shown that many organisms make endogenous cellulases. Insects, and other arthropods, in particular have been shown to express a variety of plant cell wall degrading enzymes in many gene families with the ability to break down all the major components of the plant cell wall. Here we report the genome of a walking stick,Medauroidea extradentata, an obligate herbivore that makes uses of endogenously produced plant cell wall degrading enzymes. We present a draft of the 3.3Gbp genome along with an official gene set that contains a diversity of plant cell wall degrading enzymes. We show that at least one of the major families of plant cell wall degrading enzymes, the pectinases, have undergone a striking lineage-specific gene family expansion in the Phasmatodea. This genome will be a useful resource for comparative evolutionary studies with herbivores in many other clades and will help elucidate the mechanisms by which metazoans breakdown plant cell wall components.

Data availability

TheMedauroidea extradentatagenome assembly, Med v1.0, is available for download via NCBI (Bioproject: PRJNA369247). The genome, annotation files, and official gene set Mext_OGS_v1.0 are also available at the i5k NAL workspace (https://i5k.nal.usda.gov/medauroidea-extradentata) and at github (https://github.com/pbrec/medauroidea_genome_resources). The genomic raw reads are available via NCBI SRA: SRR6383867 and the raw transcriptomic reads are available at NCBI SRA: SRR6383868, SRR6383869.