bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of predictive factors for infection in adults with chronic leg ulcers: A prospective longitudinal study
Authors: Bui Ut T. , Finlayson Kathleen , Edwards Helen
Published: December 2019

Aims and objectives

To validate the ability of factors to predict infection in adults with chronic leg ulcers over a 12‐week period.

Background

Leg ulcers affect ~3% of older adults and are often hard to heal. Infection is a leading contributor for delayed healing, causing delayed wound healing, increased hospitalisation, increased healthcare costs and reduced patient quality of life. The importance of early identification of infection has been highlighted for decades, yet little is known about factors that are associated with increased risk of infection in this specific population.

Design

A longitudinal, prospective observational study in a single centre.

Methods

Between August 2017 and May 2018, a total of 65 adults with chronic leg ulcers were prospectively observed for a 12‐week period. Patients were recruited from an outpatient wound clinic at a tertiary hospital in Australia. Data were collected from recruitment (baseline) and each visit (weekly or fortnightly) up until 12 weeks. Descriptive statistics were calculated for all variables. A Cox proportional hazards regression model was used to identify predictive factors for infection. The TRIPOD guidelines for reporting were followed (See Data S1).

Results

The sample consisted of 65 adults with chronic leg ulcers, and 9.2% of these had their ulcer infected at baseline. Two predictive factors, using walking aids and gout, were found to be significantly related to increased likelihood of developing infection within 12 weeks.

Conclusion

The present study showed that patients who either used walking aids or were diagnosed with gout were at greater risk of infection compared to those without these factors.

Relevance to clinical practice

These findings provide new information for clinicians in early identification of patients at risk of infection, and for patients in enhancing their awareness of their own risk.
The significance of relationships and dynamics in families with a child with end‐stage kidney disease: A qualitative study
Authors: Agerskov Hanne , Thiesson Helle C. , Pedersen Birthe D.
Published: December 2019

Aim and objectives

To explore experiences and the significance of relationships and dynamics among family members living with a child with severe kidney disease.

Background

Chronic kidney disease (CKD) in children is often incurable, leading to irreversible kidney damage. End‐stage kidney failure in a child impacts daily life and routines, requiring significant social adaptation for all family members. However, little is known about how individual family members experience relationships, interactions and dynamics within the family.

Design

A qualitative exploratory study taking a phenomenological–hermeneutic approach.

Method

Data were collected through semi‐structured individual interviews with seven fathers, seven mothers, five children with end‐stage kidney disease and five siblings. The data were analysed using Ricoeur's theory of narrative and interpretation, on three levels: naïve reading; structural analysis; and critical interpretation and discussion. The Consolidated Criteria for Reporting Qualitative Research checklist has been used (see Supporting Information).

Results

All family members experienced relationships within and outside the family as a significant part of everyday life. The well‐being of the sick child had an impact on the dynamics and emotional well‐being of all family members. Siblings were in need of support; however, being fair could be challenging for parents.

Conclusion

CKD in a child has an impact on family dynamics and on the relationships between family members. Family members are vulnerable and in need of practical help and emotional support from close relatives, friends, health professionals and other individuals around them.

Relevance to clinical practice

In clinical practice, the ability to reflect on, or interpret, a range of situations by initiating a dialogue is essential to shape both an individual perspective and the perspective of the entire family unit.
Effects of virtual reality on pain, fear and anxiety during blood draw in children aged 5–12 years old: A randomised controlled study
Authors: Özalp Gerçeker Gülçin , Ayar Dijle , Özdemir Emine Zahide , Bektaş Murat
Published: December 2019

Aim and objectives

Virtual reality (VR) can be used during painful procedures in children. The aim of this study was to evaluate the effects of two different VR methods on procedure‐related pain, fear and anxiety of children aged 5–12 years old during blood draw.

Methods

This randomised controlled study used parallel trial design guided by the CONSORT checklist, see Supporting Information. The sample of children (n = 136) was allocated to the VR‐Rollercoaster (n = 45), VR‐Ocean Rift (n = 45) and control group (n = 46) using blocked randomisation. The primary outcome was pain scores after the blood draw and fear and anxiety scores before and after the blood draw. Before the blood draw, fear and anxiety scores were assessed using self‐report and reports from the parents and the researcher using the Child Fear Scale and Children's Anxiety Meter. After the blood draw, level of pain experienced was assessed using the Wong–Baker Faces Pain Rating Scale and the fear and anxiety levels experienced by the children during the blood draw were re‐evaluated.

Results

Pain scores were found to be lower in the VR‐Rollercoaster group and the VR‐Ocean Rift group. A statistical difference was found between groups according to self‐, parent‐ and researcher‐reported fear and anxiety scores after blood draw. While being in VR‐Rollercoaster and VR‐Ocean Rift group reduced children's fear and anxiety, being in the control group increased fear levels by 20% and anxiety levels by 34.1%.

Conclusions

VR is an effective method in reducing procedure‐related pain, fear and anxiety in children aged 5–12 years old during blood draw.

Relevance to clinical practice

Evidence‐based guidelines and protocols should be created for nonpharmacological methods such as VR for procedural pain and anxiety in children.
Effects of chitosan nanoparticle supplementation on growth performance, humoral immunity, gut microbiota and immune responses after lipopolysaccharide challenge in weaned pigs
Authors: Xu Yinglei , Mao Huiling , Yang Caimei , Du Huahua , Wang Haifeng , Tu Jue
Published: December 2019

In this study, we aimed to determine the effects of dietary supplementation with chitosan nanoparticles (CNP) on growth performance, immune status, gut microbiota and immune responses after lipopolysaccharide challenge in weaned pigs. A total of 144 piglets were assigned to four groups receiving different dietary treatments, including basal diets supplemented with 0, 100, 200 and 400 mg/kg CNP fed for 28 days. Each treatment group included six pens (six piglets per pen). The increase in supplemental CNP concentration improved the average daily gain (ADG) and decreased the feed and gain (F/G) and diarrhoea rate (p < .05). However, significant differences in the average daily feed intake (ADFI) among different CNP concentrations were not observed. CNP also increased plasma immunoglobulin (Ig)A and IgG, and C3 and C4 concentrations in piglets in a dose‐dependent manner on day 28, whereas IgM concentration was not affected by CNP. A total of 24 piglets in the control diet and control diet with 400 mg/kg CNP supplementation groups were randomly selected for the experiment of immunological stress. Half of the pigs in each group (n = 6) were injected i.p. with Escherichia coli lipopolysaccharide (LPS) at a concentration of 100 μg/kg. The other pigs in each group were injected with sterile saline solution at the same volume. Plasma concentrations of cortisol, prostaglandin E2 (PEG2), interleukin (IL)‐6, tumour necrosis factor (TNF)‐α and IL‐1β dramatically increased after LPS challenge. However, CNP inhibited the increase in cortisol, PEG2, IL‐6 and IL‐1β levels in plasma, whereas TNF‐α level slightly increased. Moreover, the effects of CNP on the gut microbiota were also evaluated. Our results showed that dietary supplementation with CNP modified the composition of colonic microbiota, where it increased the amounts of some presumably beneficial intestinal bacteria and suppressed the growth of potential bacterial pathogens. These findings suggested CNP supplementation improved the growth performance and immune status, alleviated immunological stress and regulated intestinal ecology in weaned piglets. Based on these beneficial effects, CNP could be applied as a functional feed additives supplemented in piglets diet.
Continued muscle loss increases mortality in cirrhosis: Impact of aetiology of liver disease
Authors: Welch Nicole , Dasarathy Jaividhya , Runkana Ashok , Penumatsa Revathi , Bellar Annette , Reen Jaspreet , Rotroff Daniel , McCullough Arthur J. , Dasarathy Srinivasan
Published: December 2019

Background and Aims

Sarcopenia or skeletal muscle loss adversely affects outcomes in cirrhosis. The impact of aetiology of liver disease on the severity or the rate of muscle loss is not known.

Methods

Consecutive, well‐characterized adult patients with cirrhosis due to viral hepatitis (VH), alcoholic liver disease (ALD) or non‐alcoholic fatty liver disease (NAFLD) and non‐diseased controls with at least two temporally distinct abdominal CT (computed tomography) scans were evaluated. Psoas, paraspinal and abdominal wall muscle areas at the L3 vertebra level were quantified on the CT scans. Standardized rate of change in muscle area was expressed as change in area/100 days. Univariate and multivariable analyses were performed to identify contributors to rate of muscle loss and survival.

Results

Among 83 cirrhotics (NAFLD n = 26, ALD n = 39, VH n = 18), there were 20 (24.1%) deaths over 62.7 ± 41.3 months. The mean percentage change in psoas area was −0.03 ± 0.05/100d in controls and −3.52 ± 0.45/100d in cirrhosis (P < .001). The mean percentage change in psoas area was −1.72 ± 0.27/100d in NAFLD, −5.28 ± 0.86/100d in ALD and −2.29 ± 0.28/100d in VH. Among cirrhotics, patients with ALD had the lowest initial muscle area and most rapid rate of reduction in muscle area. Aetiology of liver disease, model for end‐stage liver disease (MELD) and the rate of loss of muscle area were independent risk factors for survival.

Conclusions

Aetiology of liver disease is an independent risk factor for sarcopenia with the greatest rate of muscle loss noted in ALD. Survival in cirrhosis was dependent on initial muscle mass, rate of muscle loss and MELD score.
Burden of cytomegalovirus DNAemia among pediatric renal transplant patients on antiviral prophylaxis: A hospital‐based analysis
Authors: Mehta Kayur , Al‐Yabes Ohoud , Allen Andrew , Williams Angela , Petrich Astrid , Langlois Valerie , Hébert Diane , Allen Upton
Published: December 2019

Introduction

We examined the burden of CMV DNAemia and time to such events among renal transplant patients receiving CMV prophylaxis. We targeted the first year after transplantation, with the primary focus being on the first 3 months.

Methods

We conducted a retrospective review of renal transplant patients (<18 years) who were transplanted and followed at our center between January 2007, and December 2017. Clinical and laboratory data were obtained from the medical records and laboratory databases.

Results

Among 141 patients, the median age at transplant was 12.7 years (range 0.87‐17.83 years). CMV DNAemia was detected in 33 of 77 patients eligible for prophylaxis (42.9%; 95% CI 31.6‐54.6) during the first post‐transplant year. Proportionately more D+R− patients were present among patients with DNAemia compared with those without DNAemia (15/38, 39.5% vs 16/103, 15.5%, P = .005). Median time to first positivity was 134 days (range 0‐304 days). Eight patients had a positive PCR during the first 3 months (5.7% of all patients). Among those eligible for prophylaxis, 6.5% had DNAemia during the first 3 months while on prophylaxis. Among patients whose first positive PCR was after 3 months post‐transplant, the median time to positivity was 52 days (range 13‐214 days) after the end of prophylaxis.

Conclusions

Breakthrough CMV DNAemia was documented among children receiving antiviral prophylaxis. While routine monitoring while on prophylaxis might not be warranted for the majority of patients, studies are needed to determine the optimal indications for CMV PCR testing while on prophylaxis.
Images of Coordination: How Implementing Organizations Perceive Coordination Arrangements
Authors: Molenveld Astrid , Verhoest Koen , Voets Joris , Steen Trui
Published: December 2019

A crucial challenge for the coordination of horizontal policy programs—those designed to tackle crosscutting issues—is how to motivate government organizations to contribute to such programs. Hence, it is crucial to study how practitioners in implementing organizations view and appreciate the coordination of such programs. Assisted by Q‐methodology, this inductive study reveals three significantly different “images”: central frame setting, networking via boundary spanners, and coordination beyond window dressing. Most surprisingly, different images show up among respondents within the same organizations and horizontal programs. The authors find that the images reflect elements of the literature: the resistance to hierarchical central control, the need for local differentiation and increased incentives, and a collaboration‐oriented culture. Most importantly, practitioners of implementing organizations perceive top‐down mechanisms as ineffective to achieve coordination and ask for adaptive arrangements, involvement, and deliberative processes when designing coordination arrangements and during the collaboration.
The Moderating Role of Top‐Down Supports in Horizontal Innovation Diffusion
Authors: Zhang Youlang , Zhu Xufeng
Published: December 2019

How do governments respond to multiple types of external pressures under limited resources? Are the effects of different types of diffusional pressures complementary or substitutive? This article approaches these questions by examining how top‐down supports modify the effects of horizontal pressures on local innovation adoption. Top‐down supports may complement or substitute the effects of horizontal pressures given the former's potential influence on perceived innovation advantage and visibility, organizational autonomy, and environmental uncertainty. The empirical analysis based on China's municipal‐level one‐stop governments (administrative licensing centers, or ALCs) from 1997 to 2012 shows that increases in central and provincial supportive policy signals reduce the effects of neighboring municipality adoption on a municipal government's creation of an ALC. Results affirm that the effects of different types of diffusional pressures can be conditional on one another—that is, increases in top‐down policy supports may substitute the effects of horizontal pressures.
Instrument choice, implementation structures, and the effectiveness of environmental policies: A cross‐national analysis
Authors: Steinebach Yves
Published: December 2019

While both the economics and political science literature have gained considerable knowledge on why some environmental policies work better than others, we still lack a clear and consistent picture on the determinants of environmental policy effectiveness. This is primarily because influences of the policy design and the implementation process have often been studied in isolation from one another. This article intends to close this gap by systematically examining how different instrument types and the implementation structures interact. By analyzing the air pollutant emissions of 14 OECD countries over a period of 25 years (1990 to 2014), it is revealed that only command‐and‐control (C&C) regulations that are put into practice through well‐equipped and ‐designed implementation structures can be associated systematically with reductions in air pollutant emissions. Softer, so‐called new environmental policy instruments (NEPIs), in turn, are found to have no significant influence on the outcome variable and this regardless of how they are executed and enforced. In essence, these findings indicate that (i) market‐ and information‐based policy instruments seem to be not as self‐implementing as often argued in the existing literature and that; (ii) C&C regulations and market‐ and information‐based instruments need quite different prerequisites to function properly.
The Potential Effects of Recall Bias and Selection Bias on the Epidemiological Evidence for the Carcinogenicity of Glyphosate
Authors: Crump Kenny
Published: December 2019

Glyphosate is a widely used herbicide worldwide. The International Agency for Research on Cancer in 2015 declared that glyphosate is probably carcinogenic to humans, noting a positive association for non‐Hodgkin lymphoma (NHL). The principal human data on glyphosate and NHL come from five case–control studies and two cohort studies. The case–control studies are at risk of recall bias resulting from information on exposure to pesticides being collected from cases and controls based on their memories. In addition, two of the case–control studies are additionally at risk of a form of selection bias that can exacerbate the effect of recall bias. Both biases are in the direction of making glyphosate appear carcinogenic. If odds ratios (ORs) are not biased and a pesticide plays no role in causing NHL, the probability that an OR for that pesticide is greater than 1.0 is approximately 0.5. The fractions of ORs for pesticides other than glyphosate that are greater than 1.0 in the case–control studies are 0.90 (n = 92), 0.90 (n = 152), 0.93 (n = 59), 0.76 (n = 140), and 0.53 (n = 54), the first two from studies that are at risk for both types of bias. In the two cohort studies, which are not subject to these biases, the comparable fractions for relative risks for all cancers are 0.51 (n = 70) and 0.48 (n = 158). These results comply closely with what would be expected if evidence for carcinogenicity of glyphosate in these studies results from statistical bias in the case–control studies.
Peptide‐MHC class I and class II tetramers: From flow to mass cytometry
Authors: Christophersen Asbjørn
Published: December 2019

To develop better vaccines and more targeted treatments for cancer and autoimmune disorders, the disease‐specific T cells and their cognate antigens need to be better characterized. For more than two decades, peptide‐major histocompatibility complex (pMHC) tetramers and flow cytometry have been the gold standard for detection of CD8+ and CD4+ T cells specific to antigens in the context of MHC class I and class II, respectively. Nonetheless, more recent studies combining such reagents with mass cytometry, that is, cytometry by time of flight (CyTOF), have offered far more comprehensive profiling of antigen‐specific T‐cell responses. In addition, mass cytometry has enabled ex vivo screening of CD8+ T‐cell reactivities against hundreds of MHC class I restricted candidate epitopes. MHC class II molecules, on the other hand, have been challenging to combine with mass cytometry as they are more complex and bind with lower affinities to cognate T‐cell receptors than MHC class I molecules. In this review, I discuss how techniques originally developed to improve the staining capacity of pMHC tetramers in flow cytometry led to the successful combination of such reagents with mass cytometry. Especially, I will highlight very recent advances facilitating the combination with pMHC class II tetramers. Together, these mass cytometry‐based studies can help develop more targeted treatments for cancer and autoimmune disorders.
Role of the Nonrotating Decay Heat Removal Blower Pressure Loss in ALLEGRO Reactor
Authors: Mayer G. , Guba A.
Published: December 2019

ALLEGRO is a helium-cooled fast reactor, which is being developed by the Czech Republic, France, Hungary, Slovakia, and Poland. It will be the demonstrator of the GFR-2400-MWth Generation IV gas-cooled fast reactors. In ALLEGRO, a three-loop safety system is designed to remove decay heat during accident conditions. The nonrotating blower blades may represent a huge pressure loss in the decay heat removal loop (DHR), which hinders natural circulation. The lower the pressure loss coefficient of the DHR blower blades is, the better cooling is available during natural circulation. On the other hand, a large core bypass develops if a DHR valve is opened inadvertently during normal operation. In this case, the higher DHR blower pressure loss is better from core cooling point of view. Consequently, the low pressure loss of the DHR blower is advantageous for core cooling in station blackout (SBO) event but disadvantageous for inadvertent DHR valve opening event. Both the above-mentioned cases may lead to insufficient core cooling in accident conditions, which threatens the integrity of the reactor core. In this study, we present CATHARE thermohydraulic calculations to assess the sensitivity of the DHR blower pressure loss coefficient for the above-mentioned two cases.
Local Strain Distribution and Increased Intracellular Ca2+ Signaling in Bovine Articular Cartilage Exposed to Compressive Strain
Authors: Huang Wenjing , Nagasaka Minami , Furukawa Katsuko S. , Ushida Takashi
Published: December 2019

Articular cartilage is exposed to compressive strain of approximately 10% under physiological loads in vivo, and intracellular Ca2+ signaling is one of the earliest responses in chondrocytes under this physical stimulation. However, it remains unknown whether compressive strain itself evokes intracellular Ca2+ signaling in chondrocytes located within each layer (from surface to deep) in an equal manner with physiological levels of strain. The purpose of this study, therefore, was to determine the distribution of local strain and increased intracellular Ca2+ signaling in layer-dependent cell populations in response to 10% compressive strain loading. For this purpose, the time course of strain was measured in each layer to calculate layer-specific deformation properties. In addition, layer-specific changes in chondrocyte intracellular Ca2+ signals were recorded over time using a fluorescent Ca2+ indicator, Fluo-3, to establish ratios of cells with increased Ca2+ signaling at each depth of cartilage under static conditions or exposed to compression. The results showed that the surface layer was compressed with a larger strain compared with other layers. Few cells with Ca2+ signaling were observed under static conditions. Percentages of responsive cells within compressed cartilage were higher than those within cartilage under static conditions. However, increased intracellular Ca2+ signals were observed in a prominent number of chondrocytes within the deep layer, but not the surface layer, of compressed cartilage. Our results suggest that at a physiological compression level, Ca2+ is upregulated, but the stimulation of Ca2+ signaling in articular cartilage is not simply defined by local deformation.
On the Influence of Gas Content on the Rotordynamic Force Coefficients of a Three-Wave (Air in Oil) Annular Seal for Multiple Phase Pumps
Authors: San Andrés Luis , Lu Xueliang , Wu Tingcheng
Published: December 2019

Subsea multiphase pumps must operate reliably with a process fluid transitioning from a pure liquid, to a mixture of gas and liquid, and to eventually just gas; and pressure seals controlling secondary leakage paths are important for both pump efficiency and dynamic stability considerations, in particular, for flows with a sizable gas volume fraction (GVF). Early work advances a three-wave shape seal that generates significant direct stiffness and hence aids to increase the natural frequency of a vertical pump. This paper details dynamic load tests and produces rotordynamic force coefficients for the wavy-seal operating with a gas in liquid mixture made of air in light ISO VG 10 oil. For operation with pure liquid, GVF = 0, a stiffness (K), damping (C), and added mass (M) model fully characterizes the test article. For operation with a mixture, the seal dynamic stiffness coefficients vary greatly with excitation frequency; the direct dynamic stiffness hardens while the cross coupled stiffness decreases as the whirl frequency approaches shaft speed and then increases for super synchronous frequency. For operation with GVF from 0.1 to 0.8, the seal produces a large positive centering dynamic stiffness. Notably, the seal direct damping coefficient does not depend on frequency though reduces continuously as the inlet GVF increases from 0 to 1 (all gas). The current research adds relevant test data and unique dynamic force coefficients to the design selection of seals in multiphase pumps.
Sound localization by the internally coupled ears of lizards: From biophysics to biorobotics
Authors: Christensen-Dalsgaard Jakob , Manley Geoffrey A.
Published: December 2019

As they are generally small and only hear low frequencies, lizards have few cues for localizing sound. However, their ears show extreme directionality (up to 30 dB direction-dependent difference in eardrum vibrations) created by strong acoustical coupling of the eardrums, with almost perfect internal transmission from the contralateral ear over a broad frequency range. The activity of auditory nerve fibers reflects the eardrum directionality, so all auditory neurons are directional by default. This suggests that the ensuing neural processing of sound direction is simple in lizards. Even the simplest configuration of electrical analog models—two tympanic impedances connected via a central capacitor—produces directional patterns that are qualitatively similar to the experimental data on lizard ears. Several models, both analytical and (very recently) finite-element models, have been published. Robotic implementations using simplified models of the ear and of binaural comparison show that robust phonotaxic behavior can be generated with little additional processing and be performed by simple (and thus small and cheap) units. The authors review lizard directional processing and attempts at modeling and robotics with a twofold aim: to clarify the authors' understanding of central processing of sound localization in lizards, and to lead to technological developments of bioinspired robotics.
Localization of arylsulfatase in Pseudomonas C12B
Authors: Fitzgerald J W , George J R
Published: December 2019

Arylsulfatase was released almost completely from intact cells of Pseudomonas C12B after osmotic shock or after treatment with lysozyme. These results suggest that the enzyme is cell wall associated in this soil isolate.
Comparison of denitrification by Pseudomonas stutzeri, Pseudomonas aeruginosa, and Paracoccus denitrificans
Authors: Carlson C A , Ingraham J L
Published: December 2019

A comparison was made of denitrification by Pseudomonas stutzeri, Pseudomonas aeruginosa, and Paracoccus denitrificans. Although all three organisms reduced nitrate to dinitrogen gas, they did so at different rates and accumulated different kinds and amounts of intermediates. Their rates of anaerobic growth on nitrate varied about 1.5-fold; concomitant gas production varied more than 8-fold. Cell yields from nitrate varied threefold. Rates of gas production by resting cells incubated with nitrate, nitrite, or nitrous oxide varied 2-, 6-, and 15-fold, respectively, among the three species. The composition of the gas produced also varied markedly: Pseudomonas stutzeri produced only dinitrogen; Pseudomonas aeruginosa and Paracoccus denitrificans produced nitrous oxide as well; and under certain conditions Pseudomonas aeruginosa produced even more nitrous oxide than dinitrogen. Pseudomonas stutzeri and Paracoccus denitrificans rapidly reduced nitrate, nitrite, and nitrous oxide and were able to grow anaerobically when any of these nitrogen oxides were present in the medium. Pseudomonas aeruginosa reduced these oxides slowly and was unable to grow anaerobically at the expense of nitrous oxide. Furthermore, nitric and nitrous oxide reduction by Pseudomonas aeruginosa were exceptionally sensitive to inhibition by nitrite. Thus, although it has been well studied physiologically and genetically, Pseudomonas aeruginosa may not be the best species for studying the later steps of the denitrification pathway.
Quantitative Influences of Butyrate or Propionate on Thermophilic Production of Methane from Biomass
Authors: Henson J. Michael , Bordeaux F. M. , Rivard Christopher J. , Smith P. H.
Published: December 2019

Sodium butyrate and sodium propionate were continuously infused into separate 4-liter thermophilic digesters. These digesters were operated at 55°C, had a retention time of 20 days, and had a pH of 7.8. Infusion rates were started at 10 mM day
−1
and were increased incrementally when new stable external organic acid pool sizes and new stable gas production rates were observed. Stable conditions were obtained in both digesters at an infusion rate of 15 mM day
−1
, with methanogenesis elevated over that of control digesters. Calculations based on expected CH
4
at this infusion rate and measured CH
4
production in the treated and control digesters, however, showed an approximately 25% inhibition of methanogenesis in both digesters. A digester infused with sodium chloride showed little or no inhibition at this infusion rate, but was totally inhibited when its infusion rate was increased to 20 mM day
−1
, and cumulative added NaCl reached 0.38 M. The butyrate and propionate-amended digesters tolerated addition rates of 20 mM day
−1
, but both failed when they were increased to 25 mM day
−1
. These results indicate that the thermophilic digesters could function stably at higher external pool sizes of butyrate or propionate than routinely observed.
Rates of Digestion of Bacteria by Marine Phagotrophic Protozoa: Temperature Dependence
Authors: Sherr Barry F. , Sherr Evelyn B. , Rassoulzadegan Fereidoun
Published: December 2019

The effect of temperature on length of time for digestion of bacteria was evaluated, by using fluorescently labeled bacteria (FLB), for phagotrophic flagellates and ciliates isolated from coastal northwest Mediterranean waters. Accumulation of FLB in protozoan food vacuoles was followed until a plateau of FLB per cell occurred; then after a 1:10 dilution of FLB with unlabeled bacteria, disappearance of FLB in food vacuoles was monitored. For both 3- to 5-μm flagellates and 10- to 40-μm ciliates, the absolute linear slopes of FLB uptake and disappearance were nearly identical in individual experiments over a temperature range of 12 to 22°C. We inferred from these results that the leveling off of the uptake curves resulted when equilibrium between ingestion and digestion of bacteria was attained. The time to leveling off then represented the average time needed for complete digestion of the bacteria ingested at the start of the experiment, and the inverse of this time represented a bacterial digestion rate. The digestion rate increased exponentially from 12 to 22°C for both a mixed flagellate assemblage and the oligotrichous ciliate
Strombidium sulcatum,
with a
Q
10
of 2.8 for the flagellates and 2.0 for the ciliate. Although bacterial ingestion rates varied greatly, depending on protozoan cell size, total bacterial abundance, and temperature, digestion times appeared to be significantly influenced only by protozoan cell size (or type of protozoan) and by temperature.
Cyanase-mediated utilization of cyanate in Pseudomonas fluorescens NCIB 11764
Authors: Kunz D A , Nagappan O
Published: December 2019

Pseudomonas fluorescens NCIB 11764 was capable of utilizing cyanate (OCN-) as a sole nitrogen source for growth. Crude cell extracts from cells grown on cyanate, but not on ammonium sulfate, were induced for an enzyme catalyzing cyanate conversion to ammonia. Enzymatic activity was shown to be bicarbonate dependent and specific for cyanate as a substrate, suggesting that cyanate utilization in this organism is facilitated by an enzyme resembling cyanase (cyanate amidohydrolase; EC 3.5.5.3), as described previously in Escherichia coli and Flavobacterium sp.
A Monoclonal Antibody Specific to Surface Antigen on
Candida krusei
Authors: Robert Raymond , Faure Odile , Carloti Arnaud , Lebeau Bernadette , Bernard Christian , Marot-Leblond Agnès , Grillot Renée , Senet Jean-Marcel
Published: December 2019

A monoclonal antibody (MAb; MAb 6B3) which reacts specifically with a cell wall antigen found in all strains or isolates of
Candida krusei
was developed. MAb 6B3 was extensively tested by immunofluorescence assay for cross-reaction with many
Candida
,
Cryptococcus
,
Saccharomyces
,
Trichosporon
, and
Rhodotorula
species and was found to react only with the species
C. krusei
. The specific epitope is expressed on the surface of fungal cells and appears to reside on a protein moiety. Taking into account the increasing importance of fluconazole-resistant strains in nosocomial fungal infections, the very high degree of specificity of this MAb for
C. krusei
could be useful for the routine detection of
C. krusei
in culture or in tissue samples.
Assessment of a New Immunoassay for Serological Confirmation and Discrimination of Human T-Cell Lymphotropic Virus Infections
Authors: Zrein Maan , Louwagie Joost , Boeykens Hilde , Govers Loeki , Hendrickx Greet , Bosman Fons , Sablon Erwin , Demarquilly Catherine , Boniface Michel , Saman Eric
Published: December 2019

The present study evaluated a new confirmatory assay for antibodies to human T-cell lymphotropic virus type 1 and 2 (HTLV-1 and HTLV-2) proteins performed with serum samples from various commercial sources. The new test is a line immunoassay (LIA) with a nylon membrane sensitized with the most relevant antigens of HTLVs: the envelope gp46 and gp21 as well as thegagp24 and p19 antigens, represented by either recombinant proteins or synthetic peptides. A total of 176 serum or plasma samples were tested, of which 66 were HTLV-1 positive, 72 were HTLV-2 positive, and 38 were HTLV negative; of the 38 HTLV-negative samples 23 were indeterminate by Western blotting (WB). Serially diluted samples (n= 33) from HTLV-1- and HTLV-2-infected patients were also analyzed to determine the sensitivity of the new assay. The new confirmatory assay (INNO-LIA HTLV) performed markedly better than WB assays for those samples reactive by screening. Accurate confirmation of the presence of HTLV-1 and HTLV-2 antibodies and accurate discrimination of HTLV-1 and HTLV-2 antibodies were obtained for all the HTLV-seropositive samples. Due to its enhanced specificity and sensitivity, the new assay not only improves the ability to confirm and discriminate HTLV infections but also eliminates the vast majority of WB-indeterminate and false-positive specimens.
Apoptosis in Cord Blood T Lymphocytes from Infants of Human Immunodeficiency Virus-Infected Mothers
Authors: Economides Athena , Schmid Ingrid , Anisman-Posner Deborah J. , Plaeger Susan , Bryson Yvonne J. , Uittenbogaart Christel H.
Published: December 2019

Apoptosis continues to be controversial in human immunodeficiency virus (HIV)-induced pathogenesis. To investigate whether apoptosis occurs with HIV exposure with or without subsequent infection, levels of apoptosis were measured in cord blood lymphocytes (CBL) from seven newborns delivered to HIV-infected mothers and seven normal, unexposed newborns. Live cells were costained with antibodies to cell surface markers and the DNA dye 7-amino actinomycin D to immunophenotype apoptotic CBL subsets. Apoptosis was measured in fresh and cultured CBL in the presence and absence of CD3 T-cell receptor stimulation. Compared to the CD4+CBL from HIV-unexposed newborns, CD4+CBL from six HIV-exposed, noninfected newborns demonstrated significantly greater apoptosis after overnight culture even in the absence of CD3 stimulation. Compared to HIV-unexposed controls, CD8+CBL from the six HIV-exposed newborns also demonstrated increased levels of apoptosis after overnight culture without stimulation. The one HIV-infected newborn in this study showed the highest levels of CD4+and CD8+apoptotic CBL. The data suggest that levels of apoptosis are increased in infants in association with HIV infection. Furthermore, CD4+and CD8+cord blood lymphocytes from HIV-exposed infants behaved differently than T lymphocytes from either normal, unexposed infants or an HIV-infected infant. These results suggest that exposure to HIV or HIV-induced factors increases the levels of apoptosis in CBL.
Specific Antibodies in Sera and Gastric Aspirates of Symptomatic and Asymptomatic
Helicobacter pylori
-Infected Subjects
Authors: Mattsson A. , Tinnert A. , Hamlet A. , Lönroth H. , Bölin I. , Svennerholm A.-M.
Published: December 2019

In this study we have determined systemic and local antibody responses against different
Helicobacter pylori
antigens in
H. pylori
-infected and noninfected subjects. In addition, we studied whether differences in antibody responses between patients with duodenal ulcers and asymptomatic
H. pylori
carriers might explain the different outcomes of infection. Sera and in most instances gastric aspirates were collected from 19 duodenal ulcer patients, 15 asymptomatic
H. pylori
carriers, and 20 noninfected subjects and assayed for specific antibodies against different
H. pylori
antigens, i.e., whole membrane proteins (MP), lipopolysaccharides, flagellin, urease, the neuraminyllactose binding hemagglutinin HpaA, and a 26-kDa protein, by enzyme-linked immunosorbent assay. The
H. pylori
-infected subjects had significantly higher antibody titers against MP, flagellin, and urease in both sera and gastric aspirates compared with the noninfected subjects. Furthermore, the antibody titers against HpaA were significantly elevated in sera but not in gastric aspirates from the infected subjects. However, no differences in antibody titers against any of the tested antigens could be detected between the duodenal ulcer patients and the asymptomatic
H. pylori
carriers, either in sera or in gastric aspirates.
Use of Lytic Bacteriophage for Control of Experimental
Escherichia coli
Septicemia and Meningitis in Chickens and Calves
Authors: Barrow Paul , Lovell Margaret , Berchieri Angelo
Published: December 2019

A lytic bacteriophage, which was previously isolated from sewage and which attaches to the K1 capsular antigen, has been used to prevent septicemia and a meningitis-like infection in chickens caused by a K1
+
bacteremic strain of
Escherichia coli
. Protection was obtained even when administration of the phage was delayed until signs of disease appeared. The phage was able to multiply in the blood. In newly borne colostrum-deprived calves given the
E. coli
orally, intramuscular inoculation of phage delayed appearance of the bacterium in the blood and lengthened life span. With some provisos there is considerable potential for this approach to bacterial-disease therapy.
Detection of Antibodies to
Candida albicans
Germ Tubes during Experimental Infections by Different
Candida
Species
Authors: Bikandi Joseba , San Millán Rosario , Regúlez Pilar , Moragues María D. , Quindós Guillermo , Pontón José
Published: December 2019

Identification and characterization of
Candida albicans
germ tube-specific antigens may be of relevance for the serodiagnosis of invasive candidiasis since they could be the basis for the development of new diagnostic tests. In this study, we have identified two antigens of 180 and >200 kDa in the cell wall of
C. albicans
germ tubes which are responsible for the induction of antibodies to
C. albicans
germ tubes. Antigens of similar molecular masses have been demonstrated in the cell walls of the
Candida
species
C. stellatoidea
,
C. parapsilosis
,
C. guilliermondii
,
C. tropicalis
, and
C. krusei
, but not
C. glabrata
. The kinetics of the antibody responses to
C. albicans
germ tubes were studied in rabbits infected with different
Candida
species. Although these antibodies were detected in rabbits infected with all
Candida
species except
C. glabrata
, the kinetics of the antibody responses to
C. albicans
germ tubes induced by the
Candida
species studied were different. Both the highest titer and the earliest response of antibodies to
C. albicans
germ tubes were observed in rabbits infected with either of the two serotypes of
C. albicans
used. However, the time needed to elicit the antibodies to
C. albicans
germ tubes can be reduced as the result of an anamnestic antibody response. The results presented in this study show that a test designed to detect antibodies against
C. albicans
germ tube antigens may be suitable for the diagnosis of infections caused by most of the medically important
Candida
species.
Physiologic-Chemoattractant-Induced Migration of Polymorphonuclear Leukocytes in Milk
Authors: Manlongat Natasha , Yang T. J. , Hinckley L. S. , Bendel Robert B. , Krider H. M.
Published: December 2019

The somatic cell count (SCC; leukocytes and epithelial cells) in milk is used as an indicator of udder health status. A SCC above the regulatory standard is generally considered as an indication of mastitis. Therefore, milk with a SCC equal to or greater than the regulatory limit cannot be sold to the public because it is unsuitable for human consumption. This study was performed to determine whether SCC levels above the regulatory limit observed in goats during late lactation are a physiologic or a pathological response of the goat mammary gland. Differential counts of cells in nonmastitic goat milk samples during late lactation revealed that approximately 80% of the cells were polymorphonuclear leukocytes (PMNs). In addition, microchemotaxis assay results indicated that normal nonmastitic late-lactation-stage goat milk is significantly higher (P< 0.001) in PMN chemotactic activity than early-lactation-stage goat milk, with a mean chemotactic activity of 14.9 and 42.7/mg of protein for early and late lactation stages, respectively. Physicochemical analyses also suggest that the PMN infiltration observed in normal late-lactation-stage goat milk is due to a PMN chemotactic factor(s) that is different from the PMN chemotactic factor(s) present in mastitic milk. Interestingly, the PMN chemotactic factor in late-lactation-stage goat milk is highly acid resistant (pH 2), suggesting that the factor is able to survive the highly acidic gastric environment and may therefore be important in the augmentation of the immune systems of sucklings. These results indicate that the chemotactic factor(s) present in the milk of normal late-lactation-stage goats is nonpathological and may play a physiologic regulatory role in mammary gland involution. Hence, the regulatory standard for goat milk needs to be redefined in order to reflect this.
Identification of Potential Diagnostic and Vaccine Candidates of
Helicobacter pylori
by Two-Dimensional Gel Electrophoresis, Sequence Analysis, and Serum Profiling
Authors: McAtee C. Patrick , Lim Moon Young , Fung Kevin , Velligan Mark , Fry Kirk , Chow Theresa , Berg Douglas E.
Published: December 2019

There is great interest in characterizing the proteins of the gastric pathogen
Helicobacter pylori
, especially those to which humans respond immunologically, because of the potential importance of such proteins in diagnosis and vaccine development. Two-dimensional gel electrophoresis was used to separate and identify potential antigens of
H. pylori
ATCC 43504. Over 30 proteins were reactive in Western blots with pooled sera from 14 infected patients. These proteins were analyzed by N-terminal sequence analysis. Fourteen proteins were determined to be distinct from any proteins previously described from
H. pylori
; the others were previously isolated and characterized proteins. Analysis of eight distinct
H. pylori
strains showed that most of these antigens were produced by all of the strains. We propose that collection of new antigens such as those recognized here will be useful in serologic tests for detecting and monitoring
H. pylori
infection and may also serve as potential targets for antimicrobial agent or vaccine development.
Assignment of Immunoglobulin G1 and G2 Concentrations to Pneumococcal Capsular Polysaccharides 3, 6B, 14, 19F, and 23F in Pneumococcal Reference Serum 89-SF
Authors: Soininen Anu , Seppälä Ilkka , Wuorimaa Tomi , Käyhty Helena
Published: December 2019

We describe standardization of an enzyme-linked immunosorbent assay (ELISA) for measuring immunoglobulin G1 (IgG1) and IgG2 concentrations of antibodies to pneumococcal capsular polysaccharide (Pnc PS). The ELISA uses a human pneumococcal reference serum pool, lot 89-SF, as a reference. IgG1 and IgG2 concentrations were assigned to antibodies to Pnc PS serotypes 3, 6B, 14, 19F, and 23F in 89-SF by ELISA using affinity-purified monoisotypic IgG1 and IgG2 preparations. The sum of IgG1 and IgG2 concentrations in 89-SF agrees well with the previously assigned IgG concentrations. The IgG1 and IgG2 values in 89-SF were used to measure antibodies to Pnc PS 6B, 14, and 23F in adult pre- and postimmunization sera and the sum of IgG1 and IgG2 concentrations correlated well with the IgG values. Furthermore, the IgG2/IgG1 ratio did not affect the detection of IgG1, the isotype usually represented by a lower concentration.
Development of a Colony Lift Immunoassay To Facilitate Rapid Detection and Quantification of
Escherichia coli
O157:H7 from Agar Plates and Filter Monitor Membranes
Authors: Ingram David T. , Lamichhane Chinta M. , Rollins David M. , Carr Lewis E. , Mallinson Edward T. , Joseph Sam W.
Published: December 2019

E. coli
O157:H7 is a food-borne adulterant that can cause hemorrhagic ulcerative colitis and hemolytic uremic syndrome. Faced with an increasing risk of foods contaminated with
E. coli
O157:H7, food safety officials are seeking improved methods to detect and isolate
E. coli
O157:H7 in hazard analysis and critical control point systems in meat- and poultry-processing plants. A colony lift immunoassay was developed to facilitate the positive identification and quantification of
E. coli
O157:H7 by incorporating a simple colony lift enzyme-linked immunosorbent assay with filter monitors and traditional culture methods. Polyvinylidene difluoride (PVDF) membranes (Millipore, Bedford, Mass.) were prewet with methanol and were used to make replicates of every bacterial colony on agar plates or filter monitor membranes that were then reincubated for 15 to 18 h at 36 ± 1°C, during which the colonies not only remained viable but were reestablished. The membranes were dried, blocked with blocking buffer (Kirkegaard and Perry Laboratories [KPL], Gaithersburg, Md.), and exposed for 7 min to an affinity-purified horseradish peroxidase-labeled goat anti-
E. coli
O157 antibody (KPL). The membranes were washed, exposed to a 3,3′,5,5′-tetramethylbenzidine membrane substrate (TMB; KPL) or aminoethyl carbazole (AEC; Sigma Chemical Co., St. Louis, Mo.), rinsed in deionized water, and air dried. Colonies of
E. coli
O157:H7 were identified by either a blue (via TMB) or a red (via AEC) color reaction. The colored spots on the PVDF lift membrane were then matched to their respective parent colonies on the agar plates or filter monitor membranes. The colony lift immunoassay was tested with a wide range of genera in the family
Enterobacteriaceae
as well as different serotypes within the
E. coli
genus. The colony lift immunoassay provided a simple, rapid, and accurate method for confirming the presence of
E. coli
O157:H7 colonies isolated on filter monitors or spread plates by traditional culture methods. An advantage of using the colony lift immunoassay is the ability to test every colony serologically on an agar plate or filter monitor membrane simultaneously for the presence of the
E. coli
O157 antigen. This colony lift immunoassay has recently been successfully incorporated into a rapid-detection, isolation, and quantification system for
E. coli
O157:H7, developed in our laboratories for retail meat sampling.