bluuebunny/crossref_metadata_2025 huggingface dataset:
3D simulation of transport phenomena of onion drying with moving boundary in a vacuum oven
Authors: Demir Hasan , Cihan Ertuğrul , Demir Hande
Published: January 2020

This study aimed to perform numerical simulation of the onion drying process considering its deformed geometry. For this purpose, transport phenomena such as heat and mass transfer in the onion structure and water vapor transfer in its porous structure were simulated in 3D form with Darcy's law during the vacuum drying process for onions. The simulated results were validated by experimental data. Heat and mass transfer rates were determined using kinetic data. Simulation of onion drying revealed that deformed geometry should be included in the model to represent the faster removal of water from the onion due to the increase in mass transfer surface area. The influence of drying temperature (313, 323, 333, and 343 K) on drying time and water concentration of onion was insignificant. The mass transfer Biot number revealed that the water vapor removal from onion was controlled by intraparticle mass transfer resistance.

Practical applications

The main purpose of the vegetable drying industry is to obtain good‐quality dried products accompanied by savings in terms of energy and time. Recently, heat and mass transfer models constructed for drying of vegetables have focused on vegetables such as potato or carrot that provide limited information due to their uniform structure. An onion slice has a porous structure and increasing spaces between its rings; therefore in this study, heat and mass transfer occurring during vacuum drying of an onion was simulated considering the deformed geometry. The analysis of transport phenomenon mechanisms involves valuable information for researchers studying drying of food and large‐scale vacuum dryer designers in which 3D simulation of onion drying revealed that the deformed geometry fitted better to experimental results than undeformed geometry. The results of 3D simulation can be used to predict drying time and energy requirements of the process better than regular numerical modeling and may serve dried onion manufacturers.
Umbilical cord hypercoiling in two rhesus macaques (Macaca mulatta)
Authors: Sarfaty Anna E. , Zeiss Caroline J. , Yekkala Krishna , Wilson Steven R.
Published: December 2019

Obstruction of umbilical blood flow is a common cause of death in fetal nonhuman primates, but cord accidents have not been reported in the macaque. We describe two cases of cord accident in rhesus macaques (Macaca mulatta) resulting in fetal death at approximately 110 and 50 days of gestation, respectively.
Exercise‐based swallowing intervention (McNeill Dysphagia Therapy) with adjunctive NMES to treat dysphagia post‐stroke: A double‐blind placebo‐controlled trial
Authors: Carnaby Giselle D. , LaGorio Lisa , Silliman Scott , Crary Michael
Published: December 2019

Background

Dysphagia following stroke is prevalent; however, dysphagia treatment is often applied haphazardly and outcomes unclear. Neuromuscular electrical stimulation (NMES) has received increased attention as a treatment for post‐stroke dysphagia; but application data remain conflicted.

Objective

This study investigated effectiveness and safety of an exercise‐based swallowing therapy (McNeill Dysphagia Therapy: MDTP) +NMES for dysphagia rehabilitation following stroke.

Methods

Stroke patients (n = 53, x̅ age: 66 [13.2], 47.2% male) with dysphagia admitted to sub‐acute rehabilitation hospital were randomised to MDTP + NMES [NMES], MDTP + sham NMES [MDTP] or usual care [UC] swallowing therapy groups. Patients were treated for 1 hour per day for 3 weeks and monitored to 3 months by a blinded evaluator. Outcomes included clinical swallowing ability, oral intake, weight, patient perception of swallow and occurrence of dysphagia‐related complications.

Results

Post‐treatment dysphagia severity and treatment response were significantly different between groups (P ≤ .0001). MDTP demonstrated greater positive change than either NMES or UC arms, including increase in oral intake (χ2 = 5, P ≤ .022) and improved functional outcome by 3 months post‐stroke (RR = 1.72, 1.04‐2.84). Exploratory Cox regression revealed the MDTP group conferred the greatest benefit in time to “return to pre‐stroke diet” of 4.317 [95% CI: 1.08‐ 17.2, P< .03].

Conclusion

Greater benefit (eg reduction in dysphagia severity, improved oral intake and earlier return to pre‐stroke diet) resulted from a programme of MDTP alone vs NMES or UC.
Effect of dietary supplementation with brewer's yeast hydrolysate on growth performance, faecal microbial counts, diarrhoea score, blood profile, rectal temperature in weanling pigs challenged with lipopolysaccharide
Authors: Hu Jing , Park Jae Won , Kim In Ho
Published: January 2020

The objective of this study was to determine the effects of brewer's yeast hydrolysate (BYH) supplementation on growth performance, blood profile, diarrhoea score, faecal microbial and rectal temperature in lipopolysaccharide (LPS) challenged in weanling pigs. A total of 40 cross‐bred weanling pigs [(Yorkshire × Landrace) × Duroc] with an average body weight of 8.15 ± 0.87 kg were used in a 6 weeks experiment. Pigs were randomly allotted to the following four dietary treatments (five pigs/two replicate/treatment) according to their initial body weight and gender. Treatments were as follows: CON, basal diet + Saline injection; NC, basal diet + LPS challenge; PC1, basal diet + 1.0% BYH + saline injection; and PC2, basal diet + 1.0% BYH + LPS challenge. Our results demonstrated pig fed diets with BYH had higher (p < .05) average daily feed intake (ADFI) during week 2–4 as well as gain:feed (G:F) during the whole experimental period than pigs fed diets without BYH. At the end of experiment, faecal Escherichia coli counts in pigs with an LPS injection tended to increase (p = .08). Meanwhile, the rectal temperature concentration of IgM and lymphocyte percentage in pigs with an LPS injection increase (p = .05) at 6 and 12 hr. In conclusion, the supplementation of 1.0% BYH can improve ADFI and G:F, as well as may reduce the diarrhoea in weanling pigs.
Relationship between tracheobronchoscopic score and bronchoalveolar lavage red blood cell numbers in the diagnosis of exercise‐induced pulmonary hemorrhage in horses
Authors: Lopez Sanchez Carolina M. , Kogan Clark , Gold Jenifer R. , Sellon Debra C. , Bayly Warwick M.
Published: December 2019

Background

Exercise‐induced pulmonary hemorrhage (EIPH) is diagnosed and its severity assessed by post‐exercise tracheobronchoscopy, and enumeration of bronchoalveolar lavage fluid red blood cells (BALFRBC). Minimal information is available regarding the relationship of tracheobronchoscopy score to BALFRBC number.

Objective

Evaluate the relationship between BALFRBC number and tracheobronchoscopy scores and determine their diagnostic sensitivities.

Animals

Nine sedentary horses, 21 fit Thoroughbreds, 129 Barrel Racers.

Methods

Normal BALFRBC number and the effect of bronchoalveolar lavage (BAL) on it were evaluated by performing 2 BALs 24 hours apart in sedentary horses. Tracheobronchoscopy followed by BAL was performed 247 times on 150 horses after treadmill, racetrack, or barrel racing exercise. Lastly, a BALFRBC diagnostic threshold number that optimized the geometric mean of the sensitivity and precision (F1‐score) was determined using Bayesian analysis.

Results

No increase in BALFRBC occurred after the second BAL (mean ± SD, 304 ± 173/μL). Tracheobronchoscopy scores ranged from 0 (n = 112) to 4 (n = 4) and BALFRBC ranged from 102 to 4605268/μL. Spearman correlation between tracheobronchoscopy score and BALFRBC was weak (P < .001; rs = 0.42) with large ranges of BALFRBC associated with each tracheobronchoscopy score. The highest F1‐score occurred for a BALFRBC threshold number = 992/μL. Seventy‐five tracheobronchoscopy scores equaled 0 although BALFRBC number was ≥992/μL. Sensitivity of tracheobronchoscopy for diagnosing EIPH was poor (0.59; 95% confidence intervals [CI], 0.49‐0.68), compared to BALFRBC number ≥992/μL (0.93; 95% CI, 0.88‐0.96).

Conclusions and Clinical Importance

False negatives are common with tracheobronchoscopy. Follow‐up determination of BALFRBC may be indicated for tracheobronchoscopy scores = 0 before EIPH can be ruled out.
Tenuazonic acid from Stemphylium loti inhibits the plant plasma membrane H+‐ATPase by a mechanism involving the C‐terminal regulatory domain
Authors: Bjørk Peter K. , Rasmussen Silas A. , Gjetting Sisse K. , Havshøi Nanna W. , Petersen Thomas Isbrandt , Ipsen Johan Ø. , Larsen Thomas O. , Fuglsang Anja T.
Published: December 2019

Pathogenic fungi often target the plant plasma membrane (PM) H+‐ATPase during infection. To identify pathogenic compounds targeting plant H+‐ATPases, we screened extracts from 10 Stemphylium species for their effect on H+‐ATPase activity.

We identified Stemphylium loti extracts as potential H+‐ATPase inhibitors, and through chemical separation and analysis, tenuazonic acid (TeA) as a potent H+‐ATPase inhibitor. By assaying ATP hydrolysis and H+ pumping, we confirmed TeA as a H+‐ATPase inhibitor both in vitro and in vivo. To visualize in planta inhibition of the H+‐ATPase, we treated pH‐sensing Arabidopsis thaliana seedlings with TeA and quantified apoplastic alkalization.

TeA affected both ATPase hydrolysis and H+ pumping, supporting a direct effect on the H+‐ATPase. We demonstrated apoplastic alkalization of A. thaliana seedlings after short‐term TeA treatment, indicating that TeA effectively inhibits plant PM H+‐ATPase in planta. TeA‐induced inhibition was highly dependent on the regulatory C‐terminal domain of the plant H+‐ATPase.

Stemphylium loti is a phytopathogenic fungus. Inhibiting the plant PM H+‐ATPase results in membrane potential depolarization and eventually necrosis. The corresponding fungal H+‐ATPase, PMA1, is less affected by TeA when comparing native preparations. Fungi are thus able to target an essential plant enzyme without causing self‐toxicity.
Association of anthropometry and weight change with risk of dementia and its major subtypes: A meta‐analysis consisting 2.8 million adults with 57 294 cases of dementia
Authors: Lee Crystal ManYing , Woodward Mark , Batty G. David , Beiser Alexa S. , Bell Steven , Berr Claudine , Bjertness Espen , Chalmers John , Clarke Robert , Dartigues Jean‐Francois , Davis‐Plourde Kendra , Debette Stéphanie , Di Angelantonio Emanuele , Feart Catherine , Frikke‐Schmidt Ruth , Gregson John , Haan Mary N. , Hassing Linda B. , Hayden Kathleen M. , Hoevenaar‐Blom Marieke P. , Kaprio Jaakko , Kivimaki Mika , Lappas Georgios , Larson Eric B. , LeBlanc Erin S. , Lee Anne , Lui Li‐Yung , Moll van Charante Eric P. , Ninomiya Toshiharu , Nordestgaard Liv Tybjærg , Ohara Tomoyuki , Ohkuma Toshiaki , Palviainen Teemu , Peres Karine , Peters Ruth , Qizilbash Nawab , Richard Edo , Rosengren Annika , Seshadri Sudha , Shipley Martin , Singh‐Manoux Archana , Strand Bjorn Heine , van Gool Willem A. , Vuoksimaa Eero , Yaffe Kristine , Huxley Rachel R.
Published: January 2020

Uncertainty exists regarding the relation of body size and weight change with dementia risk. As populations continue to age and the global obesity epidemic shows no sign of waning, reliable quantification of such associations is important. We examined the relationship of body mass index, waist circumference, and annual percent weight change with risk of dementia and its subtypes by pooling data from 19 prospective cohort studies and four clinical trials using meta‐analysis. Compared with body mass index–defined lower‐normal weight (18.5‐22.4 kg/m2), the risk of all‐cause dementia was higher among underweight individuals but lower among those with upper‐normal (22.5‐24.9 kg/m2) levels. Obesity was associated with higher risk in vascular dementia. Similarly, relative to the lowest fifth of waist circumference, those in the highest fifth had nonsignificant higher vascular dementia risk. Weight loss was associated with higher all‐cause dementia risk relative to weight maintenance. Weight gain was weakly associated with higher vascular dementia risk. The relationship between body size, weight change, and dementia is complex and exhibits non‐linear associations depending on dementia subtype under scrutiny. Weight loss was associated with an elevated risk most likely due to reverse causality and/or pathophysiological changes in the brain, although the latter remains speculative.
Refinement and preliminary evaluation of two tablet‐based tests of real‐world visual function
Authors: Jones Pete R , Tigchelaar Iris , Demaria Giorgia , Wilson Iain , Bi Wei , Taylor Deanna J , Crabb David P
Published: December 2019

Purpose

To describe, refine, evaluate, and provide normative control data for two freely available tablet‐based tests of real‐world visual function, using a cohort of young, normally‐sighted adults.

Methods

Fifty young (18–40 years), normally‐sighted adults completed tablet‐based assessments of (1) face discrimination and (2) visual search. Each test was performed twice, to assess test‐retest repeatability. Post‐hoc analyses were performed to determine the number of trials required to obtain stable estimates of performance. Distributions were fitted to the normative data to determine the 99% population‐boundary for normally sighted observers. Participants were also asked to rate their comprehension of each test.

Results

Both tests provided stable estimates in around 20 trials (~1–4 min), with only a further reduction of 14%–17% in the 95% Coefficient of Repeatability (CoR95) when an additional 40 trials were included. When using only ~20 trials: median durations for the first run of each test were 191 s (Faces) and 51 s (Search); test‐retest CoR95 were 0.27 d (Faces) and 0.84 s (Search); and normative 99% population‐limits were 3.50 d (Faces) and 3.1 s (Search). No participants exhibited any difficulties completing either test (100% completion rate), and ratings of task‐understanding were high (Faces: 9.6 out of 10; Search: 9.7 out of 10).

Conclusions

This preliminary assessment indicated that both tablet‐based tests are able to provide simple, quick, and easy‐to‐administer measures of real‐world visual function in normally‐sighted young adults. Further work is required to assess their accuracy and utility in older people and individuals with visual impairment. Potential applications are discussed, including their use in clinic waiting rooms, and as an objective complement to Patient Reported Outcome Measures (PROMs).
A seaweed's response to a warming world
Authors: Baral Anirban
Published: December 2019

For plants, climate change comes with more challenging facets than just increasing temperature. While terrestrial forests are suffering from erratic rainfall, drought and wildfires, marine vegetation is under a different kind of threat. Rapidly melting polar ice caps are causing a surge of freshwater in the seas, lowering the salinity near coastlines. For marine plants adapted to grow in seawater, hyposalinity can be a serious detriment to growth. To assess the possible impact of climate change on marine flora, Li et al. (2019) explored the physiological and transcriptomic response of the kelp Saccharina latissima to increased temperature and hyposaline conditions.
Radical hope in revolting times: Proposing a culturally relevant psychological framework
Authors: Mosley Della V. , Neville Helen A. , Chavez‐Dueñas Nayeli Y. , Adames Hector Y. , Lewis Jioni A. , French Bryana H.
Published: December 2019

Growing research supports the link between individual expressions of hope and psychological well‐being. In this paper, we draw on psychological theories of hope, racial and ethnic studies, and the literature on radical healing to propose a framework of radical hope. Although the proposed multidimensional framework integrates cultural practices of People of Color in the United States, it is flexible enough to be adapted to other contexts. The paper begins by providing a brief review of the literature that conceptualizes the concept of hope in the field of psychology as a prelude to comparing the concept to the interdisciplinary notion of radical hope. Based on this body of work, we then introduce a culturally relevant psychological framework of radical hope, which includes the components of collective memory as well as faith and agency. Both components require an orientation to one of four directions including individual orientation, collective orientation, past orientation, and future orientation. The framework also consists of pathways individuals can follow to experience radical hope including (a) understanding the history of oppression along with the actions of resistance taken to transform these conditions, (b) embracing ancestral pride, (c) envisioning equitable possibilities, and (d) creating meaning and purpose in life by adopting an orientation to social justice. We conclude with a proposed research agenda for radical hope.
Detection of HLA‐C*12:109, an HLA‐C*12 variant, in a Taiwanese hematopoietic stem cell donor
Authors: Yang Kuo‐Liang , Lin Py‐Yu
Published: December 2019

Nucleotide replacement in codon 194 of HLA‐C*12:03:01:01 results in a novel allele, HLA‐C*12:109.
Printing Medical Scans
Authors: Sethi Chitra , Borge Richard
Published: January 2020

Revolutionizing healthcare by combining powerful digital workflows with 3D printing technologies.
Guideline on Probabilistic Fracture Mechanics Analysis for Japanese Reactor Pressure Vessels
Authors: Katsuyama Jinya , Osakabe Kazuya , Uno Shumpei , Li Yinsheng , Yoshimura Shinobu
Published: January 2020

In Japan, to prevent nil-ductile fracture of reactor pressure vessels (RPVs) due to neutron irradiation embrittlement, deterministic fracture mechanics evaluation in accordance with the codes provided by the Japan Electric Association is performed for assessing the structural integrity of RPVs under pressurized thermal shock (PTS) events considering neutron irradiation embrittlement. In recent years, a structural integrity assessment methodology based on probabilistic fracture mechanics (PFM) has been introduced into the regulations in the United States and a few European countries. PFM is a rational methodology for evaluating the failure frequency of important pressure boundary components by considering the probabilistic distributions of various influence factors related to aged degradation due to the long-term operation. In Japan Atomic Energy Agency (JAEA), a PFM analysis code called PASCAL has been developed to evaluate the failure frequency of RPVs considering neutron irradiation embrittlement and PTS events. In addition, we have developed a guideline for structural integrity assessment of RPVs based on PFM to improve the applicability of PFM in Japan and enable persons who have knowledge on fracture mechanics to perform PFM analyses and evaluate through-wall cracking frequency (TWCF) of RPVs easily. The guideline consists of a main body, explanation, and several supplements. The technical basis for PFM analysis is provided, and the latest knowledge is included in the guideline. In this paper, an overview of the guideline and some typical analysis results obtained based on the guideline and the Japanese database related to PTS evaluation are presented.
Clear speech improves listeners' recall
Authors: Keerstock Sandie , Smiljanic Rajka
Published: December 2019

The present study examined the effect of intelligibility-enhancing clear speech on listeners' recall. Native (n = 57) and non-native (n = 31) English listeners heard meaningful sentences produced in clear and conversational speech, and then completed a cued-recall task. Results showed that listeners recalled more words from clearly produced sentences. Sentence-level analysis revealed that listening to clear speech increased the odds of recalling whole sentences and decreased the odds of erroneous and omitted responses. This study showed that the clear speech benefit extends beyond word- and sentence-level recognition memory to include deeper linguistic encoding at the level of syntactic and semantic information.
Effects of Visually Augmented Gait Training on Foot-Ground Clearance: An Intervention to Reduce Tripping-Related Falls
Authors: Straaten Rob van der , Tirosh Oren , Sparrow William A. (Tony) , Begg Rezaul
Published: January 2020

Minimum toe clearance (MTC ∼10–30 mm) is a hazardous mid-swing gait event, characterized by high-foot velocity (∼4.60 m·s−1) and single-foot support. This experiment tested treadmill-based gait training effects on MTC. Participants were 10 young (4 males and 6 females) and 10 older (6 males and 4 females) healthy ambulant individuals. The mean age, stature, and body mass for the younger group was 23 (2) years, 1.72 (0.10) m, and 67.5 (8.3) kg, and for older adults was 77 (9) years, 1.64 (0.10) m, and 71.1 (12.2) kg. Ten minutes of preferred speed treadmill walking (baseline) was followed by 20 minutes with MTC information (feedback) and 10 minutes without feedback (retention). There were no aging effects on MTC in baseline or feedback. The MTC in baseline for older adults was 14.2 (3.5) mm and feedback 27.5 (8.7) mm, and for the younger group, baseline was 12.7 (2.6) mm and feedback 28.8 (5.1) mm, respectively. Retention MTC was significantly higher for both groups, indicating a positive effect of augmented information: younger 40.8 (7.3) mm and older 27.7 (13.6) mm. Retention joint angles relative to baseline indicated that the young modulated joint angles control MTC differently using increased ankle dorsiflexion at toe off and modulating knee and hip angles later in swing closer to MTC.
Once More, With Feeling: Sport, National Anthems, and the Collective Power of Affect
Authors: McDonald Mary G.
Published: January 2020

In this paper I apply insights from Sport Studies, Indigenous Studies, Music Studies, and Feminist Cultural Studies to illuminate and theorize the cultural, material, and political affective salience of national anthems staged prior to sporting events. To do so I analyze two different cases: The Aboriginal musical trio Asani’s 2014 multi-lingual performance of “O Canada” prior to an Oilers hockey game which closed Truth and Reconciliation Commission (TRC) events in Edmonton, Alberta; and the projection of hatred onto former NFL quarterback Colin Kaepernick’s kneeling protest of racism during the playing of the U.S. national anthem in 2016. Analysis suggests that these emotive, often visceral musical performances and responses are not contained within individual subjects but instead reflect contextually specific repetitive (dis)articulations across time, space, and a variety of bodies. Placed within broader colonial contexts, Asani’s version of the Canadian anthem is exemplary of the embodied sensory, but politically limited settler-oriented communitas of Canadian TRC inclusionary music as previously explicated by Robinson. Kaepernick’s anti-racist kneeling activism provides an additional case to theorize the relationship of national anthems in regards to movements for and against an imagined white nation as well as State-sanctioned colonization and hatreds.
Evidence for dispersing 1D Majorana channels in an iron-based superconductor
Authors: Wang Zhenyu , Rodriguez Jorge Olivares , Jiao Lin , Howard Sean , Graham Martin , Gu G. D. , Hughes Taylor L. , Morr Dirk K. , Madhavan Vidya
Published: January 2020

A possible propagating Majorana

Majorana states in solid-state systems may one day form a basis for topological quantum computing. Most of the candidates identified so far have been Majorana bound states, but theorists have predicted that propagating Majorana states may exist as well. Wang
et al.
looked for such a state on the surface of the material FeSe
0.45
Te
0.55
(see the Perspective by Tewari and Stanescu). Using scanning tunneling spectroscopy, the researchers measured a flat, bias-independent density of states along a particular type of domain wall, which was consistent with a theoretical prediction for a propagating Majorana state in this material. Although topologically trivial origins of this finding are difficult to completely rule out, the work is likely to stimulate interest in iron-based superconductors as hosts of Majorana states.

Science
, this issue p.
104
; see also p.
23
On-chip integrated laser-driven particle accelerator
Authors: Sapra Neil V. , Yang Ki Youl , Vercruysse Dries , Leedle Kenneth J. , Black Dylan S. , England R. Joel , Su Logan , Trivedi Rahul , Miao Yu , Solgaard Olav , Byer Robert L. , Vučković Jelena
Published: January 2020

Miniaturizing particle accelerators

Particle accelerators are usually associated with large national facilities. Because photons are able to impart momentum to electrons, there are also efforts to develop laser-based particle accelerators. Sapra
et al.
developed an integrated particle accelerator using photonic inverse design methods to optimize the interaction between the light and the electrons. They show that an additional kick of around 0.9 kilo–electron volts (keV) can be given to a bunch of 80-keV electrons along just 30 micrometers of a specially designed channel. Such miniaturized dielectric laser accelerators could open up particle physics to a number of scientific disciplines.

Science
, this issue p.
79
Gene expression regulated by RNA stability
Authors: Shoshani Ofer , Cleveland Don W.
Published: January 2020

The factor responsible for autoregulation of tubulin RNA stability is identified
Role of Glycolipids and Phosphatidylglycerol in the Serological Activity of
Mycoplasma pneumoniae
Authors: Razin S. , Prescott B. , Caldes G. , James W. D. , Chanock R. M.
Published: January 2020

Mycoplasma pneumoniae
lipids were fractionated by combined silicic acid and diethylaminoethyl-cellulose chromatography. The lipid fractions were tested for complement-fixing activity and for blocking of metabolism-inhibiting antibodies in human and rabbit antisera to
M. pneumoniae
. Thin-layer chromatography and carbohydrate analysis of hydrolysates of the lipid fractions indicated that glycolipids were responsible for the specific serological activities of the lipid extracts of the organism. Phosphatidylglycerol, which accompanied the glycolipids, was serologically inactive when isolated free from glycolipids. Phosphatidylglycerol considerably enhanced the serological activity of the glycolipids, serving as an auxiliary lipid. Because of this auxiliary effect, minute quantities of contaminating glycolipids sufficed to render serological activity to “purified” phosphatidylgylcerol preparations, providing an explanation to the previous identification of the active lipid as a phospholipid.
Cellular Immunity to
Listeria monocytogenes
Induced by Sensitization and Challenge with Bovine Gamma Globulin
Authors: Dodd R. Y.
Published: January 2020

Resistance to
Listeria monocytogenes
was demonstrated in guinea pigs undergoing systemic delayed-type hypersensitivity reactions to bovine gamma globulin.
Phagocytosis by macrophages of mycoplasma pneumoniae after opsonization by complement
Authors: Bredt W
Published: January 2020

Mycoplasma pneumoniae cells are not phagocytized by peritoneal macrophages without opsonization. They are taken up after treatment with complement or antibody.
Effect of glucocorticosteroids on the phagocytosis and intracellular killing by peritoneal macrophages
Authors: Zwet T L , Thompson J , Furth R
Published: January 2020

The effect of hydrocortisone on the phagocytosis and intracellular killing by mouse peritoneal macrophages in vitro was studied by a method making it possible to measure these processes separately. The results showed that in vivo treatment with 15 mg of hydrocortisone acetate did not significantly decrease the phagocytosis of several bacterial species such as Staphylococcus albus, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The killing indexes of normal macrophages for the various microorganisms were found to be significantly different. This may indicate that the bactericidal mechanisms are not uniform for these bacteria. The effect of hydrocortisone on the intracellular killing was also variable. For Staphylococcus albus a normal killing index was found. For the other species of bacterial and for Candida albicans some decrease was found, but this was only significant for Salmonella typhimurium. It is concluded that a decrease host resistance due to glucocorticosterioid treatment is not caused by a direct effect of these drugs on the phagocytosis and intracellular killing by mononuclear phagocytes.
Purification and serological characterization of a type-specific antigen of Streptococcus equisimilis
Authors: Woods R D , Ross R F
Published: January 2020

A microtiter complement fixation (CF) procedure was developed for use in detection of antibodies in sera of swine and rabbits vaccinated with Streptococcus equisimilis. Crude ultrasonic as well as acid-extracted preparations contained CF antigen, but the ultrasonic procedure resulted in a higher yield of active antigen. Evidence of serotype specificity with varying degrees of cross reactivity was detected with the CF procedure when representative strains of four different serotypes of S. equisimilis were compared by using their respective unadsorbed antisera. Fractionation of crude sonic extract or acid extract by centrifugation, precipitation with ammonium sulfate, and chromatography on carboxymethyl cellulose yielded a purified, type-specific antigen that reacted only with the homologous antiserum in the CF test and formed a single band by immunodiffusion. Complement-fixing antibodies in immune swine sera were predominately immunoglobulin G.
Effect of pretreatment with Mycobacterium bovis (strain BCG) and immune syphilitic serum on rabbit resistance to Treponema pallidum
Authors: Graves S R , Johnson R C
Published: January 2020

Stimulation of the rabbit reticuloendothelial system with viable Mycobacterium bovis (strain BCG), and other agents, had no effect on the development of syphilitic lesions after intradermal or intravenous inoculation with graded doses of Treponema pallidum (virulent Nichol's strain; mean infective doses less than 10). The simultaneous administration of immune syphilitic rabbit serum retarded the development of lesions, but this appeared to be due solely to the immune serum, suggesting no synergism between the activated reticuloendothelial system and the anti-T. pallidum antibodies. The administration of two doses of BCG enhanced syphilitic lesion development in the rabbit.
Antigenic independence of some microbial urate oxidases
Authors: Fitzpatrick D A , McGeeney K F
Published: January 2020

Antisera were prepared to urate oxidase derived from three microbial species, a yeast (Candida utilis), a mold (Aspergillus flavus), and a bacterium (Bacillus fastidious). The antisera inhibited enyme activity to a limited extent. Cross-reaction studies with preparations of the enzyme from these and other species indicated that the microbial enzyme exhibits a high degree of antigenic independence. This appeared to be particularly true of the bacteria studied.
Effect of dextranase on the extracellular polysaccharide synthesis of Streptococcus mutans; chemical and scanning electron microscopy studies
Authors: Hamada S , Mizuno J , Murayama Y , Ooshima Y , Masuda N
Published: January 2020

A dextranase preparation (AD17) partially purified from a culture liquor of Spicaria violacea strain IFO 6120 significantly inhibited the formation of artifcial dental plaque on a steel wire or on an extracted tooth surface. Changes in the surface morphology of Streptococcus mutans cells due to AD17 action were studied using scanning electron microscopy. S. mutans cells grown in 5% sucrose-containing broth were coated with sticky amorphous capsule-like material, whereas cells grown in sucrose in the presence of AD17 or in glucose instead of sucrose did not synthesize such capsular material. AK17 degraded commercially available dextrans of molecular weight 7 X 1(04) and 2 X 10(6) to liberate glucose and various oligosaccharides, including isomaltose. On the other hand, AD17 hydrolyzed the extracellular polysaccharides (mainly glucan in nature) of some strains of S. mutans to a limited degree. Only 15 to 36% of the total polysaccharides were hydrolyzed by AD1M with little release of isomaltose. Prolonged incubation of the polysaccharides from S. mutans with AD17 did not release additional reducing sugars, which indicates that AD17 did not contain alpha-1,3-glucanase activity. These results suggest that glucosidic linkages which are susceptible to AD17 may play an important role in the adherence of S. mutans cells to smooth surfaces.
Comparative toxic effect of the surface lipid of Corynebacterium ovis on peritoneal macrophages
Authors: Hard G C
Published: January 2020

The postphagocytic effect on mouse, rabbit, and guinea pig peritoneal macrophages of a petrol-ether lipid extract from Corynebacterium ovis (C. pseudotuberculosis) representing the surface coat of the organism external to the cell wall was investigated by examing three parameters of cytotoxicity, viability assayed by dye exclusion, glycolytic activity, and ultrastructural morphology. The viability test demonstrated a lethal effect on normal and immune mouse macrophages but not on those of the rabbit or guinea pig. Measurement of glycolsis indicated a significant degree of cytotoxicity in normal mouse macrophages ingesting lipid, a nonsignificant depression of activity in cells from immune mice, and no alteration in the activities of rabbit and guinea pig macrophages. Electron microscopy demonstrated that C. ovis surface lipid caused acute lethal injury in normal and immune mouse macrophages. The early stages of degeneration were typified by dilatation of the cisternae of rough endoplasmic reticulum, Golgi lamellae, and nuclear envelope, proceeding to focal disruption of various cell membranes, particularly those of the lipidcontaining phagolysosomes and nucleus. In contrast, over the 3-h period of study, no cytotoxic change was evident in rabbit or guinea pig macrophages. The results add further support to previous observations that the surface lipid of C. ovis plays a major role in the pathogenesis of the organism in mice, but they do not explain the guinea pig's marked susceptibility to infection.
Evaluation ofprimary blood monocyte and bone marrow cell culture for the isolation of Rickettsia rickettsii
Authors: Buhles W C , Huxsoll D L , Ruch G , Kenyon R H , Elisberg B L
Published: January 2020

Rickettsia rickettsii was isolated from experimentally infected guinea pigs by culture of blood monocytes and bone marrow cells, and from experimentally infected rhesus monkeys by blood monocyte culture. Rickettsiae were identified in monocyte-macrophage monolayers stained by Giménez or flourescent antibody techniques. A total of 78 culture attempts were made from 20 guinea pigs and 16 monkeys. The success of isolation of R. rickettsii in culture was positively correlated with the numbers of rickettsiae present in the blood and bone marrow. in cultures derived from infected guinea pigs, rickettsiae were usually observed after 5 to 7 days of culture, and in monkeys monocyte cultures they were usually observed within 3 to 5 days. Positive cultures were derived from guinea pigs and monkeys as early as the first day of fever and 1 to 3 days before the appearance of other clinical signs. Monocyte cultures became negative with the resolution of rickettsemia and concomitantly with the appearance of serum antibody. Monocyte culture isolation of R. rickettsii may be as sensitive for the detection of rickettsiae in blood and marrow as the intraperitoneal inoculation of guinea pigs or the plaque assay technique. Because of the simplicity of the method and because rickettsiae were often identified within 3 to 5 days after initiation, the monocyte culture technique may be useful in the early diagnois of human rickettsial disease.
Comparison of subcutaneous and intraperitoneal staphylococcal infections in normal and complement-deficient mice
Authors: Easmon C S , Glynn A A
Published: January 2020

From a comparison of the effects produced by injecting different strains of Staphylococcus aureus either subcutaneously or intraperitoneally into normal, complement-deficient, or complement-depleted mice, it was possible to assess the pathogenic significance of various staphylococcal virulence factors and the defensive role of complement components in the two sites of infection. In skin lesions the inflammation-suppressing factor found in the cell walls of strain PS80 played a major role. In contrast, in intraperitoneal infection the antiphagocytic capsule of the Smith diffuse and M strains was more important. All strains used produced alpha-hemolysin, which is the ultimate lethal agent in intraperitoneal infection but is only one factor in the production of dermonecrosis. The severity of the skin lesions was inversely related to the amount of early fluid exudate rather than to the rate of bacterial growth, whereas in the peritoneum increased bacterial growth was associated with increased mortality. Both C3 and C5 were needed in the production of fluid exudate in response to staphylococcal skin infection. C3 appeared to be more important in the increased exudate formed in immune mice. In the peritoneum the opsonic and chemotactic actions for complement were important as shown by the results in cobra venom-treated normal mice and in C5-deficient B10D2 old-line mice.
Influenza infection in ferrets: role of serum antibody in protection and recovery
Authors: Small P A , Waldman R H , Bruno J C , Gifford G E
Published: January 2020

The passive administration of ferret antiserum to Ao (H0N1) influenza virus failed to protect the recipient ferrets from subsequent infection with homologous virus. This susceptibility to infection was observed even when the passively acquired serum hemagglutination inhibition (HI) titer was similar to peak convalescent titers. It is therefore concluded that serum antibody alone is probably not a major factor in the prevention of influenza infection. This does not rule out a possible role for serum antibody in prevention of illness. Subsequent to infection, ferrets that had received passive antisera failed to develop high levels of serum HI antibody. In fact, many had no detectable serum antibody (less than 1:8). These animals shed virus for periods of time quite similar to those of infected control animals, which did develope serum antibody. From these data it was concluded that detectable serum HI antibody does not play a significant role in the recovery of ferrets from influenza infection. Interferon was present in high concentrations in the secretions a few days prior to cessation of virus shedding, but it is not clear whether this was the cause of the recovery or merely a concomitant event. Twenty-one days after initial infection two-thirds of the ferrets that had received passive antibody and all control animals were immune to reinfection with the homologous influenza virus. Since the former group had little or no detectable serum HI antibody but most members were immune, there must be some other host mechanism to account for the immunity.
Adherence of bacterial to vaginal epithelial cells
Authors: Mårdh P A , Westtöm L
Published: January 2020

Vaginal epithelial cells from healthy women were washed and incubated in tissue culture medium with freshly isolated bacteria of the indigenous vaginal flora and with bacteria of species that have been discussed in conjunction with genital infections. After incubation and washing, the number of bacteria that adhered per cell was determined. The influence on the attachment rate of such factors as variations in the washing procedure, bacterial density, and incubation time was assessed. Lactobacillus acidophilus and other bacterial species that occur in the lower genital tract of healthy women, e.g., some strictly anaerobic species, adhered by significantly lower numbers per cell than Neisseria gonorrhoeae, group B streptococci, and Corynebacterium vaginale. Significantly more freshly isolated gonococci adhered per cell than gonococci that had been passaged on artificial medium. The adherence of gonococci increased with increasing acidity of the test medium.
Chemically induced temperature-sensitive mutants of dengue virus type 2: comparison of temperature sensitivity in vitro with infectivity suckling mice, hamsters, and rhesus monkeys
Authors: Tarr G C , Lubiniecki A S
Published: January 2020

A series of temperature-sensitive (ts) mutants of dengue virus type 2 (DEN-2, TH-36 isolate) were induced by treatment with 5-azacytidine. These mutants and parental viruses were compared for the ts trait and/or attenuation in four systems: primary hamster kidney cells, suckling mice, golden Syrian hamsters, and rhesus monkeys. Seven clones judged to possess the ts trait in virto demonstrated a variety of patterns in vivo. On initial isolation, five of seven ts mutants exhibited reduced mouse lethality. The remaining two mutants possessed parental levels of mouse lethality. In hamsters, neither ts mutant nor parental viruses replicated very well, and then only when inoculated intracerebrally. Studies in rhesus monkeys indicated that all seven ts clones and parental viruses were capable of inducing abtibody responses; however, ts-1 and ts-2 failed to produce detectable viremia. After challenge with parental virus, all vaccinated monkeys demonstrated rapid secondary-type antibody response. Reversion from ts to ts(+) was confirmed to ts-1 in mice and ts-3 in monkeys, and was strongly suspected in several other instances.
Genetic control of natural immunity to ecotropic mouse leukemia viruses: production of endogenous immunogen
Authors: Nowinski R C , Kaehler S L , Baron J
Published: January 2020

Mice of the AKR and C57L strains naturally produced low titers of antibody against ecotropic murine leukemia viruses (MuLV). The F1 hybrid of these strains produced anti-MuLV antibody in higher titer than mice of either of the parental strains. Progeny of the genetic backcross C57L X (AKR X C57L)F1 segregated for the production of infectious ecotropic MuLV (according to the Akv-1 and Akv-2 loci) and for the production of antibody against MuLV. All mice that contained infectious MuLV produced anti-MuLV antibodies. Thus, the persistent production of high-titered MuLV in these mice did not result in immunological tolerance towards viral antigens. In contrast, mice that did not contain infectious MuLV could be separated into antibody-producing and -nonproducing classes. The absence of detectable antibody to MuLV in an individual mouse was invariably associated with a virus-free phenotype. Antibody against MuLV reacted primarily with p15 and gp70 proteins of the viral envelope. It was concluded that overt production of endogenous ecotropic MuLV served as a major immunogenic stimulus for the production of anti-MuLV antibody in these mice.
Evidence for an extrinsic immunogen in effective ribosomal vaccines from Salmonella typhimurium
Authors: Hoops P , Prather N E , Berry J , Ravel J M
Published: January 2020

Previous work has indicated that ribosomes isolated from Salmonella typhimurium were highly immunogenic and afforded excellent protection against homologous challenge. Effective protection was obtained also when ribonucleic acid ( RNA) extracted from these ribosomes was used as a vaccine. In this investigation ribosomes prepared by another method and washed repeatedly in 1 M NH1Cl lost much of their prophylactic potency and yielded poorly protective RNA. The high-salt wash of the ribosomes was immunogenic. The RNA and the protein isolated from the salt wash of the ribosomes were effective vaccines. No intrinsic component of the ribosomes was removed by the NH4Cl wash, since the ability of both "crude" and "clean" ribosomes to function equally well in an in vitro protein synthesizing system was demonstrated. The presence of a component with toxic properties similar to those of endotoxin was found in active vaccines but not in weak ones. This was shown by the ability of effective vaccines to kill lead acetate-sensitized mice and to induce tolerance to endotoxin.
Vaccinia virus meningitis in mice after intracerebral inoculation
Authors: Ginsberg A H , Johnson K P
Published: January 2020

The pathogenesis of experimental vaccinia virus infection in weanling mice after intracerebral inoculation was followed with virological, histological, and immunohistological methods. High-dose inoculation, virus spread from brain to thoracic and abdominal viscera probably by an undetected early viremia. Virus did rise to detectable levels in blood by day 5 and was found to be associated with the mononuclear cell fraction. By day 12, 30% of the animals had died and no further deaths occurred. Rise of neutralizing antibody correlated with disappearance of cell-free virus in blood, brain, and viscera. Virus was present in the brains of animals for 20 days after inoculation. This animal model may be useful to study mechanisms of persistent central nervous system virus disease relevant to man.
Comparison of central nervous system disease produced by wild-type and temperature-sensitive mutants of vesicular stomatitis virus
Authors: Rabinowitz S G , Dal Canto M C , Johnson T C
Published: January 2020

The pathogenicity of infection produced following intracerebral (i.c.) inoculation of wild-type vesicular stomatitis virus (VSV) or temperature-sensitive (ts) mutants of VSV was compared. ts mutants used were ts 31 (VSV complementation group II) and ts 41 (VSV complementation group IV). The i.c. injection of wild-type VSV in weanling Swiss mice produced a rapidly fatal encephalitis with death of mice in 2 to 3 days. Histopathologically, such mice exhibited minimal changes of encephalitis on light microscopy. In contrast to the highly virulent, rapidly fatal central nervous system (CNS) infection seen after i.c. inoculation of wild-type VSV, infection with ts 31 VSV produced a more slowly progressive CNS infection characterized by hind limb paralysis and death 6 to 9 days after infection. Histopathologically, CNS infection with ts 31 is associated with previously unreported extensive spongiform changes in the gray matter of the spinal cord. The inoculation of ts 41 i.c., on the other hand, did not result in either clinical illness or histopathological changes in the spinal cords or brains of infected mice. The absence of clinical and histopathological lesions following i.c. infection of ts 41 VSV suggests that the capacity to alter the pathogenesis of VSV CNS infection may be a function of only certain ts mutants of VSV.
Importance of Actinomyces and certain gram-negative anaerobic organisms in the transformation of lymphocytes from patients with periodontal disease
Authors: Baker J J , Chan S P , Socransky S S , Oppenheim J J , Mergenhagen S E
Published: January 2020

Dental plaque deposits are known to be potent stimulants of lymphocyte transformation in patients with periodontal disease but not in normal subjects. Since plaque deposits consist mainly of whole bacteria, the cell walls of the most commonly found organisms in plaque were tested for their capacity to induce lymphocyte transformation. There was a direct correlation between the severity of peridontal disease and the amount of transformation induced by the cell walls of oral bacteria and by solubilized dental plaque. Cord blood leukocytes and lymphocytes from clinically normal people did not respond, which indicates that these stimulants are antigens rather than mitogens. Of the eleven bacteria tested, four members of the family Actinomycetaceae (Actinomyces viscosus, A. israelii, A. naeslundii, and Arachnia propionica), the related Propionibacterium acnes, and an anaerobic gram-negative anaerobic rod (27N). The high prevalence of the former organisms in the mature dental plaque that forms around the gingival crevice area and the potent efficacy with which they stimulate lymphocytes indicates that Actinomyces and certain gram-negative anaerobes may be important etiological agents in chronic periodontal inflammation in man.