bluuebunny/crossref_metadata_2025 huggingface dataset:
Feeling and thought in collective action on social issues: Toward a systems perspective
Authors: Bou Zeineddine Fouad , Leach Colin Wayne
Published: May 2021

Theories of action have tended to view it—and its basis in thought and feeling—as static, discrete, mechanistic, and decontextualized. Moreover, studies of action have tended to be fragmented in academic silos. The consequences of these problems include a lack of cumulative and contextualized theory‐building, and an inability to recognize emergent, dynamic, and non‐linear causality, especially across levels of analysis. We argue that such problems could be partly alleviated with increased engagement with a meta‐theoretical perspective that has long been advocated for in psychology—the systems approach. In this view, thought, feeling, motivation, action, and context can be viewed as co‐evolving, inextricably linked, systems of systems. We illustrate the need for and benefit of this approach in the domain of collective action on social issues. We conclude that systems perspectives allow more contextualized, generalizable, conceptually rich, and applied directions for research in this domain.
Reconsidering Paul Meehl's disciplinary legacy
Authors: Davidson Ian J.
Published: May 2021

In pursuing paths to methodological reform, many have drawn on the prolific work of American psychologist‐philosopher Paul Meehl. In 1996, the APA awarded both Meehl and controversial German‐British psychologist Hans Eysenck with Clinical Psychologists of the Century Awards. Two years earlier, they had both signed the “Mainstream Science on Intelligence” statement published in reaction to controversy over research on intelligence and race. To better understand Meehl's decision to include his name in that public statement, this article first explores the philosophy and politics of Karl Popper as it relates to the incompatible views of Meehl and Eysenck on the value of psychoanalysis. Despite their stark differences of opinion on psychoanalysis and psychometrics, Meehl and Eysenck shared a vision of scientific psychology with overlapping political values that, consequently, included a commitment to the liberties of race science. This article suggests that interrogating the politics and ethics of research is a crucial aspect of doing human science well, including improving its methodology.
Transmission of malaria from donors to solid organ transplant recipients: A case report and literature review
Authors: Rosso Fernando , Agudelo Rojas Olga Lucia , Suarez Gil Cindy Carolina , Lopez Vargas Jaime Alberto , Gómez‐Mesa Juan Esteban , Carrillo Gomez Diana Cristina , Meza Ramirez Liliana , Caicedo Rusca Luis Armando
Published: May 2021

Malaria is a febrile and potentially fatal infection. It is typically transmitted to humans through the bite of Anopheles mosquitoes and less frequently can be contracted through blood transfusions, sharing contaminated needles and syringes, mother‐to‐child transmission, or after solid organ transplantation. Posttransplant malaria has rarely been reported in the literature, even in endemic areas. We report the cases of three solid organ recipients in which Plasmodium vivax infection was documented during postsurgical evaluation 30 days after transplant surgery. The diagnosis of donor‐derived malaria was confirmed in all patients by demonstrating Plasmodium in a peripheral blood smear and by polymerase chain reaction (PCR). All recipients had symptoms. The liver transplant recipient had myalgia, arthralgia, and thrombocytopenia; the kidney transplant recipient developed acute renal failure; and the heart transplant recipient had fever, cephalalgia, and tonic‐clonic seizures. Pre‐transplant screening of donors and recipients from endemic regions may not be sufficient to safely rule out persistent malaria. In Colombia, according to legislation, no mandatory testing is required for the diagnosis of malaria in organ donors in nonendemic areas. Therefore, donor screening by questionnaire is the only tool for preventing transplant‐borne malaria. The migratory trend from Venezuela to Colombia has increased the number of imported cases of malaria, and the infection may be present in endemic and nonendemic regions. Although donor evaluation is not standardized in current guidelines, we suggest that donors be tested for malaria with a peripheral blood smear, detection of specific IgG antibodies against Plasmodium, and techniques such as PCR, if possible.
A mechanism coordinating root elongation, endodermal differentiation, redox homeostasis and stress response
Authors: Fu Jing , Zhang Xinglin , Liu Jiaming , Gao Xudong , Bai Juan , Hao Yueling , Cui Hongchang
Published: May 2021

Root growth relies on both cell division and cell elongation, which occur in the meristem and elongation zones, respectively. SCARECROW (SCR) and SHORT‐ROOT (SHR) are GRAS family genes essential for root growth and radial patterning in the Arabidopsis root. Previous studies showed that SCR and SHR promote root growth by suppressing cytokinin response in the meristem, but there is evidence that SCR expressed beyond the meristem is also required for root growth. Here we report a previously unknown role for SCR in promoting cell elongation. Consistent with this, we found that the scr mutant accumulated a higher level of reactive oxygen species (ROS) in the elongation zone, which is probably due to decreased expression of peroxidase gene 3, which consumes hydrogen peroxide in a reaction leading to Casparian strip formation. When the oxidative stress response was blocked in the scr mutant by mutation in ABSCISIC ACID 2 (ABA2) or when the redox status was ameliorated by the upbeat 1 (upb1) mutant, the root became significantly longer, with longer cells and a larger and more mitotically active meristem. Remarkably, however, the stem cell and radial patterning defects in the double mutants still persisted. Since ROS and peroxidases are essential for endodermal differentiation, these results suggest that SCR plays a role in coordinating cell elongation, endodermal differentiation, redox homeostasis and oxidative stress response in the root. We also provide evidence that this role of SCR is independent of SHR, even though they function similarly in other aspects of root growth and development.
Bovine ownership and reduced pulmonary tuberculosis risk in Nepal: A case–control study
Authors: Bates Michael N. , Pope Karl , Sijali Tula R. , Albers Autumn E. , Verma Sharat C.
Published: May 2021

This case–control study sought to confirm and investigate in more depth protective associations previously found of bovine (cattle and water buffalo) ownership with reduced risk of both pulmonary tuberculosis (PTB) and latent tuberculosis infection (LTBI) in humans. The study recruited male and female PTB cases from a diagnostic centre and a frequency‐matched community‐based control group in Kaski District, Nepal. Controls were tested for LTBI status and a separate nested case–control study was conducted based on LTBI status. Data were collected on participant household animal ownership. Using logistic regression, animal ownership was investigated for associations with both PTB and LTBI. Data were obtained from 570 PTB cases and 1,224 controls, the latter group providing 396 LTBI‐positive and 692 LTBI‐negative subjects. Results provided evidence of decreased odds of both PTB and LTBI positivity associated with owning bovines. The evidence was strongest for protection against infection, rather than activation of infection to PTB. Effects were strongest in women, who usually manage the animals in Nepal, and there were exposure‐response relationships with numbers of bovines owned. Results suggest that exposure to bovines is protective against LTBI and PTB. A possible mechanism involves boosting the effect of BCG (Bacillus Calmette‐Guerin) vaccination, particularly in protecting against tuberculous infection. Additional studies with more extensive data collection are needed to confirm the observed associations.
Effect of post-storage filters vs. pre-storage filters for leukoreduction of blood components on clinical outcomes: a systematic review protocol
Authors: Silva Natasha Dejigov Monteiro da , Nukui Youko , Takahashi Juliana , Cruz Diná de Almeida Lopes Monteiro da , Nogueira Lilia de Souza
Published: May 2021

Objective:

This review will synthesize the best available evidence on the effectiveness of leukocyte reduction by comparing post-storage and pre-storage filters. The review will consider the following clinical outcomes: transfusion reactions, bacterial infection, length of stay, and mortality.

Introduction:

Transfusion is a relevant therapy, but it is not risk-free. Leukocyte reduction can be performed either by apheresis or by pre- or post-storage filters in order to reduce the risk of transfusion reactions, transmission of some diseases, alloimmunization, and platelet refractoriness. It can also reduce the length of hospital stay and the use of antibiotics.

Inclusion criteria:

Studies comparing the transfusion of leukocyte reduction through post-storage filters with pre-storage filters in patients of any age who received a transfusion and the clinical outcomes resulting from the transfusion will be considered for inclusion. Studies in Portuguese, English, and Spanish will be considered, with no publication time limit.

Methods:

The research sources will include MEDLINE (PubMed), CINAHL (EBSCO), PsycINFO, Scopus, The Cochrane Library, Web of Science Core Collection, Embase, LILACS, and gray literature sources. The selection of titles and abstracts will be carried out by two independent reviewers, and the critical evaluation of the studies will be based on JBI tools. The data of interest for the review question will be extracted using JBI SUMARI. A narrative synthesis will be performed as will a meta-analysis and risk assessment of publication bias, if possible.

Systematic review registration:

PROSPERO: CRD42020192202.
Use of ECG monitoring for adult patients taking high-risk QT interval–prolonging drugs in clinical practice: a systematic review protocol
Authors: Putnikovic Marijana , Ward Michael , Jordan Zoe
Published: May 2021

Objective:

The objective of this review is to determine the rates of electrocardiogram use in adult patients taking high-risk QT interval–prolonging drugs in clinical settings. This review will determine the extent of ECG monitoring being used to mitigate the risk of drug-induced QT prolongation.

Introduction:

High-risk QT interval–prolonging drugs pose a well-established risk of cardiac arrhythmia, including torsades de pointes, among other serious long QT syndromes, which can be fatal. Detection and mitigation of QT prolongation involves use of electrocardiogram monitoring. This systematic review will present evidence for uptake of electrocardiogram monitoring in clinical practice to support the quality use of high-risk QT interval–prolonging drugs.

Inclusion criteria:

Quantitative studies, published from 2004 that determine the rate of electrocardiogram monitoring before and during use of high-risk QT interval–prolonging drugs in adults 18 years or older, either in community or hospital settings, will be eligible for inclusion.

Methods:

CINAHL, Cochrane Library, Embase, and PubMed will be searched to identify published studies. EThOS, OpenGrey, and ProQuest Dissertations and Theses will be searched to identify unpublished studies. Conference abstracts will be excluded. There will be no restriction on country or language. Two reviewers will independently screen and select studies, assess methodological quality, and extract data. The JBI approach to systematic reviews of prevalence and incidence will be followed. Meta-analysis will be performed, if possible, and the Grading of Recommendations Assessment Development and Evaluation (GRADE) Summary of Findings presented.
Observational study methods used to assess pharmacotherapy effects of type 2 diabetes on fracture risk: a scoping review protocol
Authors: Hayes Kaleen N. , Hundal Anisha K. , Cadarette Suzanne M.
Published: May 2021

Objective:

The objective of this review is to summarize observational research methods employed to study fracture risk and the use of type 2 diabetes mellitus medications. The methods summary will be used as a case study to illustrate current practices in the study of medication effects on fracture risk.

Introduction:

Observational studies examining drug effects on fracture risk fill knowledge gaps left by clinical trials but require specific design considerations. In recent years, several pharmacoepidemiologic studies have examined fracture risk as a possible adverse effect of type 2 diabetes mellitus medications using varying methodologies; these studies can illustrate design considerations for studies of fracture risk.

Inclusion criteria:

This scoping review will consider peer-reviewed observational studies that examine the effects of type 2 diabetes mellitus medications on fracture risk. Primary literature comprising empirical pharmacoepidemiologic studies, such as cohort, case-control, case-crossover, self-controlled, case series, and case-cohort designs, that evaluate fracture risk associated with at least one type 2 diabetes mellitus medication will be eligible. Studies without use of an administrative database and those with an experimental, cross-sectional, or time-series design will be excluded.

Methods:

This scoping review will follow JBI methodology for scoping reviews. MEDLINE (Ovid), Embase (Ovid), and CINAHL Plus with Full Text (EBSCO) will be searched from January 1, 2000 (to capture recent methodologies) to the present to identify eligible articles. After de-duplication, titles and abstracts will be screened independently by two reviewers, then full texts will be reviewed. Data on study methods will be extracted from eligible texts using a piloted form developed by the authors, and study methods will be aggregated in tabular format.
Magnetic Nanoparticle Hyperthermia for Cancer Treatment: a Review On Nanoparticle Types and Thermal Analyses
Authors: Tofani Kassianne J , Tiari Saeed
Published: May 2021

Magnetic nanoparticle hyperthermia (MNH) is a localized cancer treatment which uses an alternating magnetic field to excite magnetic nanoparticles (MNPs) injected into a tumor, causing them to generate heat. Once the temperature of the tumor tissue reaches about 43°C, the cancerous cells die. Different types of MNPs have been studied, including iron oxides with various coatings, Cu-Ni alloys and complex manganese/zinc particles. This paper reviews different types of MNPs and assesses them by magnetization, SAR, and Curie Temperature. We reviewed the achievements and limitations of the works in this field. A major issue with MNH is maintaining effective hyperthermia while preserving healthy tissue. Numerical modeling can predict temperature distribution and safely simulate hyperthermia. The most used bioheat transfer equation is Pennes' equation which includes a term for blood perfusion, an important factor for temperature distribution. While some models safely neglect it, most include blood perfusion term. Some recent models have also included large blood vessels, others used their own heat transfer models. This article reviews the different models and classifies them based on how they address blood flow. A need for studies with realistic tumor shapes was identified. The irregular shape of most tumors could result in less uniform temperature distribution than in the commonly used circular or spherical models. This article aims to identify potential future work to create more realistic tumor models.
Prediction of Surface Oil Rates for Volatile Oil and Gas Condensate Reservoirs Using Artificial Intelligence Techniques
Authors: Al Dhaif Redha , Ibrahim Ahmed Farid , Elkatatny Salaheldin
Published: May 2021

Allocated well production rates are crucial to evaluate the well performance. Test separators and flowmeters were replaced with choke formulas due to economic and technical issues special for high gas–oil ratio (GOR) reservoirs. This study implements Adaptive network-based fuzzy logic (ANFIS), and functional networks (FN) techniques to predict the oil rate through wellhead chokes. A set of data containing 1200 wells were obtained from actual oil fields in the Middle East. The data set included GOR, upstream and downstream pressure, choke size, and actual oil and gas rates based on the well test. GOR varied from 1000 to 9265 scf/stb, while oil rates ranged between 1156 and 7982 stb/d. Around 650 wells were flowing under critical flow conditions, while the rest were subcritical. Seventy percent of the data were used to train the artificial intelligence (AI) models, while thirty percent of the data were used to test and validate these models. The developed AI models were then compared against the previous formulas. For subcritical flow conditions, rate prediction was correlated to both upstream and downstream pressures, while at critical flow conditions, changes in the downstream pressure did not affect the prediction of the production rates. For each AI method, two models were developed for subcritical flow and critical flow conditions. The average absolute percent error (AAPE) in the case of subcritical flow for ANFIS and FN were 0.88, and 1.01%, respectively. While in the case of critical flow, the AAPE values were 1.07, and 1.3% for ANFIS and FN models, respectively. All developed AI models outperform the published formulas, where the AAPE values for published formulas were higher than 34%. The results from this study will greatly assist petroleum engineers to predict the oil and gas rates based on available data from wellhead chokes in real-time with no need for additional operational costs or field intervention.
A Numerical Study Into the Use of Auxectic Structures for Structural Damping in Composite Sandwich Core Panels for Wind Turbine Blades
Authors: Khalid Seher Ahsan , Khan Abdul Munem , Shah Owaisur Rahman
Published: May 2021

The ever-increasing demand for energy necessitates the use of renewable energy sources such as wind energy. Wind turbines are widely used to convert wind energy into electrical and mechanical energy, with designs constantly being improved to increase efficiency and power. The turbine blades are considered as long cantilever structures, which are susceptible to vibrations that reduce the performance of the turbine. Honeycomb and closed cell foam sandwich structures have been previously used for turbine blade planking. In this research work, the use of an auxetic core instead of a honeycomb core is proposed for use in wind turbine blades to reduce structural vibrations. Different auxetic topologies are investigated and compared with the half-power method, and their vibration and damping behavior is analyzed in comparison with the conventional honeycomb core. It has been shown through finite element analysis simulations that both the damping ratios are higher and the vibration amplitudes are lower for the auxetic as compared with conventional closed celled structures like honeycombs.
Numerical Simulation on Proppant Transport in Fracture Junctions Affected by the Fracture Scale
Authors: Liu Chunting , Li Mingzhong , Guo Tiankui , Zhang Guodong
Published: May 2021

The proppant distribution significantly affects the conductivity of fracture networks. However, the law of proppant transport in fracture networks is still unclear, and the influence of fracture scale on the proppant distribution has not been determined. Thus, in the present study, the influence of fracture scale was investigated, and the influences of approaching angle and width ratio on fluid split ratio were analyzed. An Eulerian–Eulerian model was utilized to simulate suspended proppant and bed load proppant migration in fracture junctions. Then, a sensitivity analysis was carried out to evaluate the parameters that may affect the proppant distribution pattern, such as injection velocity, fluid viscosity, and proppant density. The results show that the approaching angle and width ratio significantly influence the fluid split ratio in a small-scale fracture. Moreover, the effect of the approaching angle decreases with an increase in the fracture scale. The split ratio of suspended proppant increases with increasing sand ratio, fluid split ratio, and width ratio. The split ratio of bed load proppant increases with increasing injection rate, fluid viscosity, width ratio, fluid split ratio, and decreasing proppant diameter. In small-scale fracture junctions, the approaching angle affects the split ratio of suspended proppant or bed load proppant by influencing the fluid split ratio; however, the effect is inconspicuous in large-scale fractures. The increase in fluid split ratio with the fracture scale leads to an increase in the split ratio of suspended proppant or bed load proppant.
Flow Characterization of Bluff Bodies: A Two-Dimensional Transformation From Square to Triangular Cylinder
Authors: Borah Rajashree , Jain Siddhant , Joshi Dyuman V. , Saha Ujjwal K.
Published: May 2021

In the present study, two-dimensional unsteady, incompressible flow around a square body that is being transformed into a vertex oriented towards the flow configuration of a triangular body is numerically investigated at Re =100 using ANSYS FLUENT 19.0 software. The purpose is to explore the effect of this transformation on the wake characteristics of a square body with l/d = 1 to a triangular body with l/d = 0; where l is the length of lateral and front surface, and d is the body height. The effect on the flow behavior caused by the leading-edge transformation from the prospect of wake width, recirculation length and stagnation pressure difference is discussed. It is seen that as the l/d ratio decreases, the vortex strength increases which is attributed to the higher stagnation pressure difference value resulting in more intense rolling of the shedding vortex and a smaller wake width. For lower l/d, the fluid traverses a longer distance along the lateral surfaces resulting in greater loss of momentum and hence the lower vortex formation length. The mean drag coefficient is found to be minimum for l/d = 0.75 with stagnation pressure difference and recirculation length being the more dominating factor on this variation. The flow in all the cases separates at the rear surface and the general trend of decrease in drag coefficient with decrease in wake width is not followed. However, such modification leads to better aerodynamic outcome by weakening the periodic drag and lift forces.
Fluid Dynamics Behind a Circular Cylinder Embedded With an Active Flapping Jet Actuator
Authors: Gao Donglai , Chang Xu , Chen Guanbin , Chen Wenli
Published: May 2021

The effects of an active flapping jet actuator on the wake flow dynamics behind a circular cylinder in wind tunnel tests were investigated. An active flapping jet actuator was embedded in the cylinder in advance to invoke a spontaneous flapping jet into the cylinder's wake. The experiment, which was performed in a wind tunnel with a Reynolds number of Re = 1.99 × 104, was based on the oncoming wind speed, cylinder diameter, and kinematic viscosity of the air at the laboratory's temperature. The flow-field structures behind the cylinder model with different dimensionless jet momentum coefficients, Cu, were obtained using the high-speed particle image velocimetry technique. The proper orthogonal decomposition (POD) method was used to represent the variation of the POD mode energy, mode coefficients, and the reconstructed spreading vorticity. The dynamic temporal evolution and time-averaged results in the near wake region of the cylinder with and without active flapping-jet control were calculated and analyzed to illustrate the rich phenomena produced by, and the control effect of, the flapping jet. For Cu values up to 0.0554, the periodic vortex shedding was pushed to farther wakes. Meanwhile, the time-averaged wake changed considerably, and the distributions of the turbulent kinetic energy and Reynolds shear stress decreased significantly. A data-driven dynamic mode decomposition method was used to extract the coherent structure of the wake of the cylinder embedded with the flapping jet actuator. The Strouhal number of the main mode of the Cu = 0.0865 case was different from the natural case.
Wetting and Capillarity Effects on Bubble Formation From Orifice Plates Submerged in Pools of Water
Authors: Manoharan Sanjivan , Manglik Raj M. , Jog Milind A.
Published: May 2021

An experimental study of bubble growth from submerged orifice plates in pools of water is carried out to scale and correlate the effects of surface wettability and orifice diameter D0 on ebullience. Measurements of bubble growth on surfaces with nine different contact angles (38 deg ≤ θ ≤ 128 deg) and varying air flow rates (1–300 ml/min) were made using high speed videography and image processing. In the static or constant-volume regime, below a critical contact angle θc, the bubble base remains attached to the orifice, and the equivalent departure diameter Db is independent of θ. On the other hand, above the critical contact angle, the bubble base spreads on the surface resulting in larger Db. For θ > θc, Db is strongly dependent on θ and increases with it. Using minimum energy method, it is shown that the wettability effects can be scaled and correlated by a modified capillary length, defined as a function of the Laplace length and contact angle. The proposed correlation provides predictions of Db that agree with experimental data of this study as well as those available in the literature to within ±15%. Moreover, for a hydrophobic surface when D0 > twice the modified capillary length, the bubble grows inside the orifice; for a hydrophilic surface, this scales with twice the capillary length, and effect of θ is not seen.
Resistance Factor-Mediated Spectinomycin Resistance
Authors: Smith David H. , Janjigian J. A. , Prescott Naomi , Anderson Porter W.
Published: May 2021

Of 100 natural isolates of drug-resistant enteric bacteria, 51 were resistant to spectinomycin (Spc) and 46 contained transferable R factors mediating Spc resistance. All Spc
R
R factors mediated streptomycin and bluensomycin resistance and were fi
+
type. Extracts of R-Spc
R
strains adenylated Spc, dihydrospectinomycin, actinamine, streptomycin, and bluensomycin in vitro in the presence of adenosine triphosphate and Mg
++
. Results of genetic and biochemical studies support the hypothesis that these reactions are mediated by a single enzyme.
In Vivo Susceptibility of
Cryptococcus neoformans
to Hamycin, Amphotericin B, and 5-Fluorocytosine
Authors: Shadomy Smith , Shadomy H. Jean , Utz J. P.
Published: May 2021

Previous investigations have shown that hamycin is 5 to 10 times more active in vitro than amphotericin B against
Cryptococcus neoformans
, whereas 5-fluorocytosine is approximately 15 times less active. Present studies are concerned with a comparison of these drugs in vivo. Three strains of
C. neoformans
which varied in both their virulence for mice and their susceptibilities to the antifungal agents were studied. Acute experimental infections were established in mice by using inocula containing approximately 4 × 10
6
cells. The mice were treated by gastric intubation for 28 days; daily dosages of the three drugs ranged from 12.5 to 250 mg/kg. The polyenes were suspended in 5% dimethyl sulfoxide, whereas 5-fluorocytosine was suspended in saline. Amphotericin B was the most effective drug, with almost complete absence of toxic deaths in control mice and increased survival in mice infected with two of the three strains and treated with 25 mg/kg per day or more. 5-Fluorocytosine was nontoxic but provided protection against only one strain. Hamycin was both the least effective and the most toxic compound, providing only slight protection at doses of 12.5 or 25 mg/kg per day and causing toxic deaths in over 50% of uninfected mice at doses above 25 mg/kg per day.
Isolation and Characterization of
Neisseria meningitidis
Groups A, C, X, and Y Polysaccharide Antigens
Authors: Robinson John A. , Apicella Michael A.
Published: May 2021

To prepare
Neisseria meningitidis
groups A, C, X, and Y polysaccharide antigens, culture supernatant fluids were subjected to serial processes of salt precipitation, alkaline hydrolysis, ethyl alcohol precipitation, and Sephadex G-200 chromatography. This method resulted in the isolation of large quantities of group antigens. All are acidic polysaccharides, the group C antigen being a polymer of
n
-acetyl neuraminic acid. Thiobarbituric acid assay failed to reveal sialic acids in the other group antigens. Protein was undetectable by absorption at 280 nm or by Folin analysis. These antigens are of similar molecular size, the majority of which are excluded by Sephadex G-200. They migrate in the upper one-third of sucrose density gradients and are retained by 5% acrylamide gel. All are highly group-specific and react only with homologous hyperimmune antisera in hemagglutination, complement fixation, and immunodiffusion systems. As little as 0.03 μmoles of
n
-acetyl neuraminic acid in group C antigen inhibits the hemagglutination of group C-sensitized red cells. All antigens are immunogenic in rabbits. These techniques afford a simplified method for the production of relatively large yields of highly specific group antigens which participate in multiple immunologic systems.
Osmotically Sensitive
Brucella
in Infected Normal and Immune Macrophages
Authors: McGhee Jerry R. , Freeman Bob A.
Published: May 2021

When
Brucella suis
is grown in tissue cultures of normal guinea pig macrophages, the
Brucella
multiplies significantly without the induction of osmotically sensitive forms. In immune macrophages in the presence of normal guinea pig serum, there is a reduction in the number of intracellular
Brucella
and no multiplication is seen over a 72-hr period. After 6 hr of exposure to immune macrophages, however, approximately 50% of the surviving intracellular
Brucella
are osmotically sensitive, i.e., they will survive and grow only on medium containing 0.2
m
sucrose.
Brucella
grown in immune macrophages, in the presence of rabbit antiserum against whole guinea pig serum, show the presence of osmotically sensitive forms, although at a reduced level compared to the number seen with immune macrophages in normal guinea pig serum.
Synthesis of Enterotoxin by L-Forms of
Staphylococcus aureus
Authors: Czop Joyce K. , Bergdoll Merlin S.
Published: May 2021

After prolonged treatment with methicillin and penicillin, L-forms were prepared from 12 of 22 strains of
Staphylococcus aureus
. These L-forms were obtained from five of nine strains which produced enterotoxin A, from three of six strains that produced enterotoxin B, and from three of six strains that produced enterotoxin C. An L-form was also prepared from
S. aureus
strain AH, which produces both enterotoxins A and C. The synthesis of enterotoxin A by parent strains was least affected by the conditions required for L-form growth. Detectable amounts of enterotoxin A were produced by all of the revertants tested and by five of the six L-forms which were derived from type A-producing cells. Detectable amounts of enterotoxin B were produced by four of the five revertants but by none of the L-forms derived from type B-producing cells. Revertants and L-forms from cells which produced enterotoxin C did not produce enough enterotoxin C to be detectable on microslides.
Extent of Specific to Nonspecific Resistance in Mice: Parenteral Versus Aerosol Challenge
Authors: Hackett Roberta J. , Marcus Stanley
Published: May 2021

Quantitative data were gathered concerning the extent of resistance induced in mice immunized by specific and nonspecific means and subsequently challenged both parenterally and by aerosol. Animals were immunized specifically by subcutaneous or intraperitoneal injection of Formalin-killed
Klebsiella pneumoniae
type I, which was also employed as a challenge organism. The intraperitoneal
ld
50
was 30 bacilli. Nonspecific resistance was induced by injection of a Boivin preparation of
Salmonella typhimurium
endotoxin. Nonspecific resistance was highest 24 hr after injection of 10 μg of endotoxin. At this time, more than half of the mice survived challenge with 10
2
but not with 10
3
ld
50
. Specifically immunized mice were resistant to as much as 10
5
ld
50
, depending upon the route of immunization. Potency ratios for parenteral challenge were: nonspecific to normal, 100; specific to normal, 10
4
to 10
5
; specific to nonspecific, 10
2
to 10
3
. Employing aerosol challenge, specific immunization protected in the
ld
100
range; nonspecifically immunized animals showed significant prolongation of survival time, but the 30-day mortality was similar to the control group.
Genetic Transfer of
Shigella flexneri
Antigens to
Escherichia coli
K-12
Authors: Formal S. B. , Gemski P. , Baron L. S. , Labrec E. H.
Published: May 2021

The genes controlling synthesis of
Shigella flexneri
group- and type-specific antigens were transferred to
Escherichia coli
K-12 recipients by conjugation with an
S. flexneri
Hfr. After mating
E. coli
with an Hfr strain of
S. flexneri
2a and selecting for
his
+
recombinants, a high proportion of the
E. coli
hybrids agglutinated in
S. flexneri
grouping serum. None of these hybrids expressed
S. flexneri
type-specific antigen II. When an
E. coli his
+
hybrid possessing the
S. flexneri
group antigen was remated with the same Hfr with selection for
pro
+
hybrids, a high proportion now expressed the type-specific antigen as well as the previously inherited group antigen. If such crosses were performed in reverse order (i.e.,
pro
+
followed by
his
+
selection), a different pattern of serological behavior was observed. None of the
pro
+
hybrids showed the type-specific antigen. Subsequent mating for
his
+
resulted in hybrids with both the group- and type-specific antigens. These results show that genes controlling the synthesis of
S. flexneri
group antigen (linked to the
his
locus) and type-specific antigen (linked to the
pro
locus) are widely separated on the chromosome. Expression of the type-specific antigen II depends on the presence of the group antigen.
Interaction of Gram-Negative Bacteria with the Lysosomal Fraction of Polymorphonuclear Leukocytes I. Role of Cell Wall Composition of
Salmonella typhimurium
Authors: Friedberg D. , Shilo M.
Published: May 2021

Wild-type
Salmonella typhimurium
and cell wall mutants with sequential deficiencies in their cell wall polysaccharide were examined for sensitivity to the bactericidal action of the lysosomal fraction of polymorphonuclear leukocytes. The complete lipopolysaccharide basal core was essential for resistance to the bactericidal action. O-specific side chains of the wild type did not enhance the resistance. Absence of
N
-acetyl glucosamine considerably enhanced sensitivity, whereas absence of other core sugars did not; additional increase in sensitivity was obtained when the heptose phosphate was absent. Under conditions where appropriate supplementation of the medium permitted complete cell wall synthesis, the uridine diphosphate-
gal-4
-epimeraseless mutant regained resistance that was essentially equal to that of the wild type. Cells coated with specific antiserum and nongrowing cells were more resistant than normal growing cells.
Interaction of Gram-Negative Bacteria with the Lysosomal Fraction of Polymorphonuclear Leukocytes II. Changes in the Cell Envelope of
Escherichia coli
Authors: Friedberg D. , Friedberg I. , Shilo M.
Published: May 2021

Interaction of lysosomal fraction with
Escherichia coli
caused damage to the cell envelope of these intact cells and to the cytoplasmic membrane of
E. coli
spheroplasts. The damage to the cytoplasmic membrane was manifested in the release of 260-nm absorbing material and β-galactosidase from the spheroplasts, and by increased permeability of cryptic cells to
O
-nitrophenyl-β-
d
-galactopyranoside; damage to the cell wall was measured by release of alkaline phosphatase. Microscope observation showed morphological changes in the cell envelope.
Competence for Deoxyribonucleic Acid Uptake and Deoxyribonuclease Action External to Cells in the Genetic Transformation of
Diplococcus pneumoniae
Authors: Lacks S. , Greenberg B.
Published: May 2021

A mutant of
Diplococcus pneumoniae
that apparently does not require activator can become competent for uptake of deoxyribonucleic acid (DNA) when grown in dilute cultures or in the presence of trypsin. Development of competence in both mutant and wild strains is temperature dependent, being 10-fold greater at 30 C than at 37 C. Induction of competence on a shift from 37 to 30 C requires protein synthesis and the presence of Mg
2+
and Ca
2+
; uptake of DNA does not require protein synthesis. Competence decays exponentially at higher temperatures. As well as taking up DNA, competent cells release oligonucleotide fragments of donor DNA in the medium external to the cells. Normal strains release fragments comparable in amount to the DNA taken up; but, in a mutant selected for inability to degrade DNA in agar, the amount of fragments formed external to the cells is only 40% of DNA uptake. Requirements for external deoxyribonuclease action are identical to those for DNA uptake: prior development of competence and the presence during treatment with DNA of Mg
2+
ions and a source of energy.
Biotransformation of Doxorubicin Promotes Resilience in Simplified Intestinal Microbial Communities
Authors: Blaustein Ryan A. , Seed Patrick C. , Hartmann Erica M.
Published: May 2021

While chemotherapy is an essential intervention for treating many forms of cancer, gastrointestinal side effects may precede infections and risks for additional health complications. We developed an
in vitro
model to characterize key changes in bacterial community dynamics under chemotherapeutic stress and the role of bacterial interactions in drug detoxification to promote microbiota resilience.
Rare case of diabetic neuropathic cachexia along with diabetic amyotrophy
Authors: Khan Zahid Ullah , Ghuman Nasrullah , Mak KaHinKaren
Published: May 2021

A 65-year-old patient with background of alcohol excess and previous gunshot wounds was admitted with significant weight loss, leg cramps, dizziness and lethargy for the last 3 months. He was diagnosed with type 2 diabetes mellitus in July 2020 and was started on Metformin and Gliclazide by his in July; he was later commenced on alogliptin and empaglaflozin by diabetes specialist nurse in early August. He also had generalised muscle wasting, dorsal guttering in both hands and was cachectic when he presented to hospital. His haemoglobin A1c (HbA1c) was 124 mmol/mol in July 2020 and was 63 mmol/mol in September 2020. The patient had negative autoimmune and TB screen. CT abdomen/pelvis and CT lumbosacral spine that showed mild diverticular disease and bilateral L5 spondylolysis with L5-S1 spondylotic changes. Electrophysiological studies confirmed sensory motor peripheral neuropathy. Patient was diagnosed with diabetic neuropathic cachexia secondary to poorly controlled diabetes and was commenced on 30 units two times per day of NovoMix 30 insulin; this was adjusted to 24 units two times per day in endocrine clinic 3 months later, after gaining 10 kg in weight. Good glycaemic control is key to the management of such cases and, therefore, we recommend early referral to diabetes specialist input for consideration of insulin therapy.
NAI: never actually injured
Authors: Kilgarriff David , Brannick Sinead , Daly Edwina , Ring Conor
Published: May 2021

A female infant presented at 31 days of life following a head injury with concerning features for non-accidental injury. Examination revealed a noticeable depression in the left temporoparietal region with a concave depression of the left parietal bone on CT imaging. After careful consideration of the history and examination findings, along with standard investigations for non-accidental injury, the infant was diagnosed with faulty fetal packing (also known as congenital vault depression). The defect had almost completely resolved by follow-up at 5 months. This case represented a diagnostic conundrum not previously reported in the literature.
Nosocomial transmission of necrotising fasciitis organisms from prepartum patient to healthcare worker
Authors: Zhang Jacques X , McSweeney Connor T , Bush Kevin L
Published: May 2021

Necrotising fasciitis is an aggressive skin and soft tissue infection requiring urgent surgical treatment, resuscitative efforts and intensive care management. We herein present a case of necrotising fasciitis with nosocomial transmission of causative organisms from patient to healthcare worker. Bacterial transmission from human to human despite personal protective equipment is quite rare, and with limited reports in the literature. The patient was also prepartum, representing to our knowledge, one of only a handful of cases of prepartum necrotising fasciitis. Recommendations to avoid healthcare worker transmission include wearing Association of the Advancement of Medical Instrumentation level 4 gowns during debridement, as well as eye protection and changing scrubs and showering between cases.
Scrub typhus and lateral rectus palsy: an uncommon presentation of a common illness
Authors: Chauhan Ajay , Jandial Aditya , Mishra Kundan , Sandal Rajeev
Published: May 2021

Scrub typhus is a zoonosis, which usually manifests as an acute febrile illness. It is caused by a rickettsia,Orientia tsutsugamushi, which is endemic in the Asian region. It can present with varied clinical manifestations, ranging from acute febrile illness to life-threatening multiorgan dysfunction syndrome. Central nervous system involvement in the form of altered sensorium and/or meningitis is frequently observed in scrub typhus. However, isolated cranial nerve involvement is uncommon and so far only a few such cases have been reported in the literature. We present a rare case of scrub typhus with fever and diplopia at presentation, which completely improved with doxycycline-based treatment.
Combined heart–liver transplantation in a case of haemochromatosis
Authors: Shubin Andrew D , De Gregorio Lucia , Hwang Christine , MacConmara Malcolm
Published: May 2021

Hereditary haemochromatosis results in multiorgan dysfunction secondary to iron overload. Haemojuvelin (HJV)-associated haemochromatosis, is a rapidly progressing form of haemochromatosis caused by mutation in the HJV that frequently results in heart and liver failure. Herein, we describe the successful treatment of a 39-year-old woman with decompensated heart failure and liver cirrhosis requiring extracorporeal membrane oxygenation who was successfully treated with combined heart–liver transplantation. Following her life-saving multiorgan transplantation, she was also noted to have rapid correction of her serum ferritin to normal levels. She remains healthy with excellent allograft function and normal iron and ferratin levels 4 years after the procedure. To our knowledge, this case is the first demonstration that combined heart–liver transplantation is a feasible option for patients with heart and liver failure secondary to HJV-associated haemochromatosis and indeed offers a long-standing corrective solution to treat this condition and restore physiologically normal iron metabolism.
Secondary immune thrombocytopenia supposedly attributable to COVID-19 vaccination
Authors: Fueyo-Rodriguez Omar , Valente-Acosta Benjamin , Jimenez-Soto Rodolfo , Neme-Yunes Yvette , Inclán-Alarcón Sergio Ignacio , Trejo-Gonzalez Roxana , García-Salcido Miguel Ángel
Published: May 2021

Immune thrombocytopenia (ITP) has been widely reported as a complication of SARS-CoV-2 infection, but to our knowledge, there have been no reports on the association of the COVID-19 vaccine with thrombocytopenia. Here, we report a case of secondary ITP in a patient who was recently immunised with the messenger RNA COVID-19 vaccine BNT162b2 (Pfizer–BioNTech).
COVID-19 in a premature infant
Authors: NG David CE , Chin Ling , Choo Pauline Poh Ling , Paramasivam Umathevi
Published: May 2021

We report a case of COVID-19 in a 29-week preterm infant. This child is the youngest reported case of SARS-CoV-2 infection in Malaysia, and to the best of our knowledge, one of the youngest documented cases of established vertical transmission of SARS-CoV-2 reported in literature. Our report highlights the clinical course, timelines of viral shedding by real-time reverse transcription-PCR and antibody seroconversion in a premature infant infected with SARS-CoV-2. In addition, we discuss the challenges faced in managing a preterm infant infected with SARS-CoV-2 and the knowledge gaps that need to be explored.
Persons with type 1 diabetes have low blood oxygen levels in the supine and standing body positions
Authors: Laursen Jens Christian , Clemmensen Kim Katrine Bjerring , Hansen Christian Stevns , Diaz Lars Jorge , Bordino Marco , Groop Per-Henrik , Frimodt-Moller Marie , Bernardi Luciano , Rossing Peter
Published: May 2021

Introduction

Blood oxygen saturation is low compared with healthy controls (CONs) in the supine body position in individuals with type 1 diabetes (T1D) and has been associated with complications. Since most of daily life occurs in the upright position, it is of interest if this also applies in the standing body position. In addition, tissue oxygenation in other anatomical sites could show different patterns in T1D. Therefore, we investigated blood, arm and forehead oxygen levels in the supine and standing body positions in individuals with T1D (n=129) and CONs (n=55).

Research design and methods

Blood oxygen saturation was measured with pulse oximetry. Arm and forehead mixed tissue oxygen levels were measured with near-infrared spectroscopy sensors applied on the skin.

Results

Data are presented as least squares means±SEM and differences (95% CIs). Overall blood oxygen saturation was lower in T1D (CON: 97.6%±0.2%; T1D: 97.0%±0.1%; difference: −0.5% (95% CI −0.9% to −0.0%); p=0.034). In all participants, blood oxygen saturation increased after standing up (supine: 97.1%±0.1%; standing: 97.6%±0.2%; difference: +0.6% (95% CI 0.4% to 0.8%); p<0.001). However, the increase was smaller in T1D compared with CON (CON supine: 97.3%±0.2%; CON standing: 98.0%±0.2%; T1D supine: 96.9%±0.2%; T1D standing: 97.2%±0.1%; difference between groups in the change: −0.4% (95% CI −0.6% to −0.2%); p<0.001). Arm oxygen saturation decreased in both groups after standing and more in those with T1D. Forehead oxygen saturation decreased in both groups after standing and there were no differences between the changes when comparing the groups.

Conclusion

Compared with CON, individuals with T1D exhibit possible detrimental patterns of tissue oxygen adaptation to standing, with preserved adaptation of forehead oxygenation. Further studies are needed to explore the consequences of these differences.