bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioinspired Electro‐Organocatalytic Material Efficient for Hydrogen Production
Authors: Moral Octavio González‐del , Call Arnau , Franco Federico , Moya Alicia , Nieto‐Rodríguez Jose Antonio , Frias María , Fierro Jose L. G. , Costas Miquel , Lloret‐Fillol Julio , Alemán José , Mas‐Ballesté Rubén
Published: January 2018

Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devices. Oxidative treatment of such electrodes results in a chemically robust material with high catalytic activity for electrochemical proton reduction, enabling the measurement of quantitative faradaic yields (>95 %) and high current densities. Combination of experiments and DFT calculations reveals that the presence of carboxylic groups triggers such electrocatalytic activity in a bioinspired manner. Analogously to the known Hantzsch esters, the oxidized carbon fiber material is able to transfer hydrides, which can react with protons, generating H2, or with organic substrates resulting in their hydrogenation. A plausible mechanism is proposed based on DFT calculations on model systems.
Stereochemical and Steric Control of Photophysical and Chiroptical Properties in Bichromophoric Systems
Authors: Blázquez‐Moraleja Alberto , Cerdán Luis , García‐Moreno Inmaculada , Avellanal‐Zaballa Edurne , Bañuelos Jorge , Jimeno M. Luisa , López‐Arbeloa Iñigo , Chiara Jose Luis
Published: January 2018

Stereochemical and steric control of the relative spatial arrangement of the chromophoric units in multichromophoric systems offers an interesting strategy for raising unusual and appealing light‐induced emission states. To explore and exploit this strategy, a series of conformationally restricted boron–dipyrromethene (BODIPY) dimers were designed by using tartaric acid as a symmetrical connector between the boron atoms of the dyes. The variety of stereoisomeric forms available for this bis(hydroxy acid) allows the relative spatial orientation of the chromophoric units in the dimer to be modified, which thus opens the door to modulation of the photophysical and chiroptical properties of the new bichromophoric systems. Chromophore alkylation introduces an additional level of control through distance‐dependent steric interactions between the BODIPY units in the dimer, which also modulates their relative spatial disposition and properties.
A Unique (3+2) Annulation Reaction between Meldrum's Acid and Nitrones: Mechanistic Insight by ESI‐IMS‐MS and DFT Studies
Authors: Lespes Nicolas , Pair Etienne , Maganga Clisy , Bretier Marie , Tognetti Vincent , Joubert Laurent , Levacher Vincent , Hubert‐Roux Marie , Afonso Carlos , Loutelier‐Bourhis Corinne , Brière Jean‐François
Published: January 2018

The fragile intermediates of the domino process leading to an isoxazolidin‐5‐one, triggered by unique reactivity between Meldrum's acid and an N‐benzyl nitrone in the presence of a Brønsted base, were determined thanks to the softness and accuracy of electrospray ionization mass spectrometry coupled to ion mobility spectrometry (ESI‐IMS‐MS). The combined DFT study shed light on the overall organocatalytic sequence that starts with a stepwise (3+2) annulation reaction that is followed by a decarboxylative protonation sequence encompassing a stereoselective pathway issue.
Fluorescence detected linear dichroism spectroscopy: A selective and sensitive probe for fluorophores in flow‐oriented systems
Authors: Wemyss Alan M. , Chmel Nikola P. , Lobo Daniela P. , Sutherland John A. , Dafforn Timothy R. , Rodger Alison
Published: January 2018

Fluorescence detection typically enhances sensitivity and selectivity for fluorescent analytes. The potential for combining fluorescence detection with flow orientation of the sample in the normal configuration of linear dichroism experiments is explored in this work by measuring the fluorescence emitted from flow‐orientated DNA‐bound ligands and M13 bacteriophage. Data for ethidium bromide, Hoechst 33258, and 4,6‐diamidino‐2‐phenyindole are presented. The theoretical basis of the technique is also presented for instruments running in both the fixed direct‐current mode, which is the normal operation mode of circular dichroism spectropolarimeters, and also in fixed high‐tension voltage mode. The role of the stray light reaching the detector that results in a spectral shape in fixed direct current mode that resembles the shape of a linear dichroism spectrum, rather than the expected reduced linear dichroism, is also explored.
The influence of microbial communities for triadimefon enantiomerization in soils with different pH values
Authors: Mohamed Ahmed Talab Khaled , Yang Zhong‐Hua , Li Jian‐Hong , Zhao Yue , Alrasheed Mohamed Omer Sara , Xiong Ya‐Bing
Published: January 2018

Enantiomers of chiral molecules can undergo interconversion leading to markedly different toxicities, which can introduce significant uncertainty when evaluating biological and environmental fates. However, enantiomerization (the reversible conversion of one enantiomer into the other) related to soil microorganism is rarely understood. For better understanding, S‐triadimefon and R‐triadimefon enantiopure were incubated in different soils with different pH value. Both high‐performance liquid chromatography and high‐throughput sequencing technology were used to explore target analytes quantitatively and microbial taxa related to the conversion process. Results revealed a significant enantiomerization among the soils. The alkaline soil from Beijing had a faster conversion than neutral soil from Changchun, while acidic soil from Wuhan had no conversion. At the same results, analysis of bacteria community showed higher abundance of Arthrobacter and Halomonas genus in alkaline soil than neutral soil after treatments, but the acidic soil was lower. Moreover, Arthrobacter and Halomonas were responsible for converting S‐triadimefon to R‐triadimefon and R‐triadimefon to S‐triadimefon in alkaline and neutral soil, respectively. Thus, these genera may be one of the reasons to explain the enantiomerization in different soils observed in this study. Thus, research at microbial level is necessary for efficient ecological risk assessment of chiral fungicide.
Mapping Perfluoroalkyl Effects in Togni‐Type Reagents by Thermolysis
Authors: Santschi Nico , Katayev Dmitry , Calvo Roxan , Jelier Benson J.
Published: January 2018

We present the thermolysis of cyclic hypervalent iodine(III) perfluoroalkyl transfer reagents carried out in standard GC‐MS instrumentation. Through heating, these structures undergo fragmentation to afford perfluoroalkyl radicals F2n+1Cn. and each reagent can be characterized by means of a threshold temperature, TIP(n). This parameter TIP(n) not only reflects the stability of the F2n+1Cn–I bond, but potentially also carries information regarding fundamental properties of the linear perfluoroalkyl chains.
Transport properties of disordered two‐dimensional complex plasma crystal
Authors: Kostadinova E.G. , Guyton F. , Cameron A. , Busse K. , Liaw C. , Matthews L.S. , Hyde T.W.
Published: January 2018

In this study, we numerically investigate the transport properties of a two‐dimensional (2D) complex plasma crystal using diffusion of coplanar dust lattice waves. In the limit where the Hamiltonian interactions can be decoupled from the non‐Hamiltonian effects, we identify two distinct types of wave transport: Anderson‐type delocalization and long‐distance excitation. We use a recently developed spectral approach to evaluate the contribution of the Anderson problem and compare it to the results of the simulation. The benefit of our approach to transport problems is twofold. First, we employ a highly tuneable macroscopic hexagonal crystal, which exhibits many‐body interactions and allows for the investigation of transport properties at the kinetic level. Second, the analysis of the transport problem in 2D is provided using an innovative spectral approach, which avoids the use of scaling and boundary conditions. The comparison between the analytically predicted and numerically observed wave dynamics allows for the study of important characteristics of this open system. In our simulations, we observe long‐distance lattice excitation, which occurs around lattice defects even when the initial perturbation does not spread from the centre to the exterior of the crystal. In the decoupled Hamiltonian regime, this many‐body effect can be attributed to the dust lattice interaction with the plasma environment.
Automatic fast double KNN classification algorithm based on ACC and hierarchical clustering for big data
Authors: Li Haiyun , Li Haifeng , Wei Kaibin
Published: January 2018

In data mining, k‐nearest neighbors (KNN) classifier is an efficient lazy learning yet simple widely renowned method, which has been widely used in many actual applications, successfully. Because of time and memory restrictions of KNN, when KNN is tested in large‐scale datasets, the classification accuracy is very low. Therefore, we propose an automatic fast double KNN classification algorithm on the basis of automatically determining the cluster centers and hierarchical clustering. We introduce automatically determining the cluster centers into the KNN in training process. Namely, big data samples are divided into several parts depending on our clustering methods. Afterwards, the clusters nearest to testing samples are excavated as the new training samples in the testing process. Each of the new samples is then conducted with hierarchical clustering. In this way, computation and time complexity are greatly reduced. Finally, experiments results conducted on big data show that new KNN classification method can significantly raise the accuracy and efficiency of automatic classification than other state‐of‐the‐art KNN classification algorithms.
Synthesis of boronate‐functionalized organic‐inorganic hybrid monolithic column for the separation of cis‐diol containing compounds at low pH
Authors: Zhao Heqing , Lyu Haixia , Qin Wenfei , Xie Zenghong
Published: January 2018

In this work, an organic‐inorganic hybrid boronate affinity monolithic column was prepared via “one‐pot” process using 4‐vinylphenylboronic acid as organic monomer and divinylbenzene as cross‐linker. The effects of reaction temperature, solvents and composition of organic monomers on the column properties (e.g. morphology, permeability, and mechanical stability) were investigated. A series of test compounds including small neutral molecules, aromatic amines, and cis‐diol compounds were used to evaluate the retention behaviors of the prepared hybrid monolithic column. The results demonstrated that the prepared hybrid monolith exhibited mixed‐interactions including hydrophilicity, cation exchange, and boronate affinity interaction. The run‐to‐run, day‐to‐day and batch‐to‐batch reproducibilities of the prepared hybrid monolith for thiourea's retention time were satisfactory with the relative standard deviations (RSDs) less than 0.09, 1.45 and 4.05% (n = 3), respectively, indicating the effectiveness and practicability of the proposed method.
Effects of copper on expression of methane monooxygenases, trichloroethylene degradation, and community structure in methanotrophic consortia
Authors: Xing Zhilin , Zhao Tiantao , Zhang Lijie , Gao Yanhui , Liu Shuai , Yang Xu
Published: January 2018

Copper plays a key role in regulating the expression of enzymes that promote biodegradation of contaminants in methanotrophic consortia (MC). Here, we utilized MC isolated from landfill cover to investigate cometabolic degradation of trichloroethylene (TCE) at nine different copper (Cu2+) concentrations. The results demonstrated that an increase in Cu2+ concentration from 0 to 15 μM altered the specific first‐order rate constant k1,TCE, the expression levels of methane monooxygenase (pmoA and mmoX) genes, and the specific activity of soluble methane monooxygenase (sMMO). High efficiency TCE degradation (95%) and the expression levels of methane monooxygenase (MMO) were detected at a Cu2+ concentration of 0.03 μM. Notably, sMMO‐specific activity ranged from 74.41 nmol/(mgcell h) in 15 μM Cu2+ to 654.99 nmol/(mgcell h) in 0.03 μM Cu2+, which contrasts with cultures of pure methanotrophs in which sMMO activity is depressed at high Cu2+ concentrations, indicating a special regulatory role for Cu2+ in MC. The results of MiSeq pyrosequencing indicated that higher Cu2+ concentrations stimulated the growth of methanotrophic microorganisms in MC. These findings have important implications for the elucidation of copper‐mediated regulatory mechanisms in MC.
Anxiety symptoms predicted decline in episodic memory in cognitively healthy older adults: A 3‐year prospective study
Authors: Fung Ada Wai Tung , Lee Joyce Sau Wa , Lee Allen Ting Chun , Lam Linda Chiu Wa
Published: January 2018

Objective

Prospective studies on late‐life anxiety disorders suggested that history of anxiety symptoms may be predictive of cognitive decline in old age. However, the relationship between anxiety and cognitive decline is still inconclusive due to heterogeneity in sample and methodology. This study was to explore how baseline anxiety symptoms associated with the change of memory in older people without cognitive impairment over a 3‐year period.

Methods

This was a 3‐year prospective study on 91 cognitively normal older adults with anxiety symptoms. They were matched with 91 controls based on age, gender, and education. Anxiety symptoms were assessed with Revised Clinical Interview Schedule (CIS‐R). Physical health was assessed with Chronic Illness Rating Scale (CIRS). Cognitive performance was measured using Cantonese version of the mini‐mental state examination (CMMSE); 10‐minute delay recall; Category verbal fluency test (CVFT); Trail making tests (TMT); and digit and visual span tests. Outcomes were determined as the change of cognitive performance over a 3‐year period.

Results

As expected, anxiety group had higher score in CIRS score (t = 4.45, P < .001) and CIS‐R score (t = 9.24, P < .001) than control group. Linear regression showed that baseline anxiety symptoms were associated with change in delayed recall (B = 0.77, P = 0.027, 95% CI = 0.09–1.46), after adjusting for cognitive performance, physical, and mental health statuses.

Conclusions

Anxious healthy older adults showed specific decline in episodic memory over a 3‐year interval. Our result suggested that anxiety symptoms are predictive of episodic memory decline in cognitively healthy older adults and may be an early sign of neurodegenerative disorders.
Development of full‐field optical spatial coherence tomography system for automated identification of malaria using the multilevel ensemble classifier
Authors: Singla Neeru , Srivastava Vishal , Mehta Dalip Singh
Published: January 2018

Malaria is a life‐threatening infectious blood disease affecting humans and other animals caused by parasitic protozoans belonging to the Plasmodium type especially in developing countries. The gold standard method for the detection of malaria is through the microscopic method of chemically treated blood smears. We developed an automated optical spatial coherence tomographic system using a machine learning approach for a fast identification of malaria cells. In this study, 28 samples (15 healthy, 13 malaria infected stages of red blood cells) were imaged by the developed system and 13 features were extracted. We designed a multilevel ensemble‐based classifier for the quantitative prediction of different stages of the malaria cells. The proposed classifier was used by repeating k‐fold cross validation dataset and achieve a high‐average accuracy of 97.9% for identifying malaria infected late trophozoite stage of cells. Overall, our proposed system and multilevel ensemble model has a substantial quantifiable potential to detect the different stages of malaria infection without staining or expert.
Cu (I) Catalyzed One Pot SN‐Click Reactions of Halogenated Coumarins and 1‐aza‐coumarins
Authors: Revankar Hrishikesh M. , Kulkarni Manohar V.
Published: January 2018

A one pot three component, copper catalyzed azide‐alkyne cycloaddition reaction has been employed for the synthesis of bis‐coumarinyl triazoles (A–D) using 4‐chloro, 4‐bromomethyl, 3‐bromoacetyl and 4‐bromomethyl‐1‐aza‐coumarins (I–IV), sodium azide, and coumarin propargyl ethers (V–IX) in moderate yields.
Heterogeneity Among Alveolar Macrophages in Humoral and Cell-Mediated Immune Responses: Separation of Functional Subpopulations by Density Gradient Centrifugation on Percoll
Authors: Murphy Mary Ann , Herscowitz Herbert B
Published: January 2018

Rabbit alveolar macrophages (AM) were separated into four subpopulations by centrifugation on discontinuous density gradients of Percoll. The subpopulations were compared to unseparated AM populations for their ability to provide accessory function to adherent cell-depleted splenocytes for antigen-stimulated lymphoproliferation and for the production of lymphokine. They were also tested for their ability to modulate in vitro plaque-forming (PFC) responses. AM subpopulations that provided accessory function for the production of migration inhibitory factor (MIF)-containing culture supernantants were recovered from the least dense fractions of the Percoll gradients. These cells were cytochemically characterized as mature cells. AM that suppressed the in vitro PFC response and augmented the antigen-stimulated lymphoproliferative response to the greatest degree were recovered from the most dense fractions of the Percoll gradients and were characterized as immature cells. These results suggest that there are distinct subpopulatins of AM, the function of which may represent different stages of maturation (or differentiation).
Cellular Interactions and Exaggerated Arachidonic Acid Metabolism in Rabbit Renal Injury
Authors: Jonas Phyllis E , Leahy Kathleen M , DeSchryver-Kecskemeti Katherine , Needleman Philip
Published: January 2018

Cell cultures from explants of the rabbit hydronephrotic kidney (HNK) cortex consisted of fibroblasts and an esterase-positive cell that phagocytizes zymosan. Cortical cell cultures from the contralateral kidney (CLK) contained only the fibroblast. The HNK cultures exhibited an endotoxin-induced prostaglandin (PG) E2 (three - fourfold) release indicative of the presence of macrophages, whereas no response was observed in the CLK cultures. At bradykinin concentrations as low as 10–9M there was a 20-fold stimulation of PGE2 from the HNK cultures and a sevenfold stimulation in the CLK cultures. The heterogeneous population of cells in the HNK cultures was separated using a mild trypsin treatment which permits passage of only the fibroblasts. The HNK-passaged cultures contained no phagocytic cells and did not release PGE2 in response to endotoxin. The passaged HNK cultures released less PGE2 in response to bradykinin as compared to primary cultures and had a decreased cyclooxygenase activity as determined by exogenous arachidonic acid conversion to PGE2. Conditioned media from adherent rabbit peripheral blood mononuclear cells stimulated basal PGE2 production (two - threefold) from both the HNK and CLK cultures. These findings demonstrated the similarity of the PGE2 production by cultured HNK cortical cells as compared to the ex vivo perfused HNK.
Purification of Human Blood Basophils by Single Step Isopycnic Banding on Percoll
Authors: Leonard Edward J , Roberts Robert L , Skeel Alison
Published: January 2018

Human venous blood, anticoagulated with EDTA, was layered onto a discontinuous Percoll gradient, made from solutions of density 1.088, 1.079, and 1.070 gm/ml. After centrifugation at 700g for 15 min at 22°C, the majority of the blood basophils was found in a narrow band at the density 1.070–1.079 interface (Percoll band 2). For 15 normal donors, mean total basophil number recovered from all locations in the gradient was 3.8 ± 1.2 (SD) × 104 basophils per ml of blood applied. Thus, 95% of the values ranged from 1.5 to 6 × 104, which compares favorably with the reported range of 1 to 8 × 104 basophils per ml for normal subjects. In the basophil-rich Percoll band 2, 2.8 ± 0.8 × 104 basophils were recovered per ml of blood applied. The mean percentage of basophils in Percoll band 2 was 19%, with a range of 5 to 53%. Monocytes and neutrophils were present in very small numbers; the majority of accompanying cells were small lymphocytes.
Abortive Ectromelia Virus Infection in Peritoneal Macrophages Activated by Corynebacterium parvum
Authors: Cohen Donald A , Morris Randal E , Bubel H Curt
Published: January 2018

We have previously demonstrated that peritoneal macrophages (Mϕs) from C3H mice were resistant to in vitro infection by ectromelia virus, following activation by intraperitoneal injection of the immunomodulator Corynebacterium parvum. In contrast, resident and mineral oil-elicited Mϕs were fully susceptible to virus infection. This report analyzes the infectious cycle of ectromelia virus in C parvum-activated and mineral oil-elicited Mϕs and demonstrates that an abortive infection occurred in the activated Mϕs that blocked the infectious cycle prior to the release of DNA from the infecting virions. The kinetics of adsorption of radiolabeled virus were similar in both susceptible and resistant Mϕ cultures; however, viral-induced incorporation of uridine and thymidine occurred only in the mineral oil-elicited and not the C parvum-activated Mϕs. In addition, the late protein hemagglutinin was only detected in infected cultures of susceptible mineral oil-elicited Mϕs. An electron micrographic analysis of the infectious cycle indicated that the adsorption of virus to the plasma membrane, uptake into lysosomes, and the primary undercoating and release of viral cores into the Mϕ cytoplasm were identical in both Mϕ types. In contrast, secondary uncoating (release of genomic DNA from the viral cores into the cytoplasm) was never detected in infected C parvum Mϕs. These data are consistent with our previous findings and with the hypothesis that activation of Mϕs by C parvum induces an interferon-mediated resistance to ectromelia virus infection.
Macrophage Effector Function in Pulmonary Oxygen Toxicity: Hyperoxia Damages and Stimulates Alveolar Macrophages to Make and Release Chemotaxins for Polymorphonuclear Leukocytes
Authors: Harada Ruth N , Vatter Albert E , Repine John E
Published: January 2018

Macrophages synthesize many secretory products in vitro but the stimuli for their production and their pathophysiologic significance in vivo are largely unknown. In the present investigation, we found that hyperoxia damaged rabbit alveolar macrophages (AM) in vitro as manifested by decreased cell numbers, increased lactate dehydrogenase (LDH) release, and the development of ultrastructural abnormalities that resembled those seen in AM in situ or lavaged from lungs of rabbits exposed to hyperoxia in vivo. Hyperoxia also stimulated cultured rabbit AM to release chemotaxins for polymorphonuclear leukocytes (PMN) that were similar in molecular weight to chemotaxins obtained from lung lavages of rabbits exposed to hyperoxia in vivo. Our results suggest that alveolar macrophage secretory products may play a physiologically relevant role in recruitment of PMN to the lungs in pulmonary oxygen toxicity.
Macrophages in Resistance to Rickettsial Infections: Protection Against Lethal Rickettsia tsutsugamushi Infections by Treatment of Mice With Macrophage-Activating Agents
Authors: Nacy Carol A , Meltzer Monte S
Published: January 2018

Peritoneal macrophages of BALB/c and C3H/HeN mice activated in vivo by intraperitoneal inoculation of viable Mycobacterium bovis strain BCG or the nonliving macrophage-activating agent Propionibacterium acnes (Corynebacterium parvum), were resistant to infection with Rickettsia tsutsugamushi, and they killed bacteria that did gain entry into the intracellular environment of these cells. This macrophage resistance to infection and intracellular destruction of rickettsiae was dependent upon development of an immune response to the activating agents, since macrophages elicited by sterile inflammatory agents failed to display either microbicidal activity unless cells were exposed to factors present in lymphokine-rich culture fluids from antigen or mitogen stimulated spleen cells (LK) in vitro. C3H/HeN mice that had been treated with activating agents, but not sterile inflammatory irritants, also survived intraperitoneal inoculation of up to 104 R. tsutsugamushi. This nonspecific protection required the chronic presence of activated macrophages: acute immune response induced by intraperitoneal injection of PPD into mice inoculated intradermally with BCG, or intraperitoneal inoculation of conconavalin A, were not sufficient to induce survival of rickettsial disease, although macrophages from these animals were activated to kill rickettsiae at the time of challenge. The critical nature of activated macrophages in nonspecific protection against rickettsial infection was demonstrated with the macrophage-defective C3H/HeJ mice. These mice are equally as susceptible as C3H/HeN mice to intraperitoneal inoculation of R. tsutsugamushi, but do not develop activated macrophages in response to BCG infection, and are not protected against lethal rickettsial challenge following BCG treatment.
Demonstration of M Cells in the Specialized Follicle-Associated Epithelium Overlying Isolated Lymphoid Follicles in the Gut
Authors: Rosner Arthur J , Keren David F
Published: January 2018

Within the epithelium that overlies the dome regions of Peyer's patches, exist specialized surface epithelial cells (M) which function to take up macromolecules from the gut lumen. These cells may be of great importance in processing antigenic material in the gut. The predominant lymphoid structures of the small intestine are isolated lymphoid follicles, by virtue of their frequency. These follicles are difficult to study because they are not grossly visible. In the present study, three guinea pigs drank India ink mixed into their water for 1, 3, and 5 months. Two hours prior to sacrifice, animals were given an intraintestinal injection of ferritin or India ink. Using a hand lens, the Peyer's patches and isolated folicles were clearly identified among the villi of the intestine. Light microscopy revealed ink in the surface epithelium covering the isolated follicles and within the substance of the follicles. Transmission electron microscopy demonstrated M cells over isolated follicles and Peyer's patches. These cells had lighter staining cytoplasm, while the mitochrondria stained darker with prominent cristae, and the microvilli were shorter. Therefore, M cells do exist within isolated follicles and structurally appear the same as those found in Peyer's patches. This implicates the isolated follicles in the overall antigen processing role of gut-associated lymphoid tissues. The present method facilitates identification of isolated lymphoid follicles which will allow functional studies to be performed on these structures.
Characteristics of Bovine Alveolar Macrophage Elastase
Authors: Valentine Rudolph , Fisher Gerald L
Published: January 2018

Lavage of isolated bovine lung lobes was used to retrieve pulmonary alveolar macrophages (PAM). Nominal yields of 72 million viable PAM were routinely obtained using 500 ml of calcium- and magnesium-free phosphate-buffered saline. Bovine PAM readily attached to glass coverslips and within 24 hours, provided cell monolayers consisting exclusively of macrophages. Bovine PAM synthesized and secreted a calcium-dependent elastase in serum-free media. Optimal proteolytic activity using a radiolabeled elastin substrate was observed at pH 7.6. The elastase was insensitive to synthetic peptide chloromethyl ketone elastase inhibitors and to the serine protease inhibitor, phenylmethylsulfonyl fluoride. Enzyme activity, however, was effectively inhibited by the metal chelator, ethylenediaminetetraacetic acid, or suppressed by inhibition of protein synthesis with cycloheximide.
In Vitro Cytostatic Properties of Unactivated Rat Kupffer Cells
Authors: Keller Françoise , Wild Marie-Thérèse , Kirn A
Published: January 2018

Kupffer cells from the liver of normal rats were checked for their natural cytostatic capabilities using an in vitro target cell growth inhibition assay. A strong cytostatic effect was observed on an human tumor cell line and was shown to be exerted on various transformed or normal target cells with only small differences in their susceptibility. The inhibition of target cell proliferation was shown to depend on the effector/target cell ratio. Different experimental data suggest that an intimate membranal contact between Kupffer cells and target cells is required.
The Macrophage-Phagocyte System in Rabbits With Experimentally Induced Serum Sickness: Functional Studies
Authors: Ito S , Cunningham R K , Brentjens J R , Andres G A
Published: January 2018

The objective of this study was to measure the phagocytic functions of the spleen and the liver and, if possible, to correlate them with the morphology and the immunohistology of these organs in rabbits with serum sickness. Serum sickness was induced by repeated intravenous injections of bovine serum albumin (BSA). Rabbits with acute serum sickness (stage A of serum sickness), with chronic serum sickness (stage C), rabbits in a stage of immunization between stage A and stage C (stage B), and rabbits that did not respond to the antigenic challenge [nonresponders (NR)], as well as nonimmunized (NI) rabbits were used. The function of the spleen and of the liver was measured by the clearances of 51Cr-labeled heat damaged (HE), periodate-treated (PE), or immunoglobulin G (IgG)-coated (IgGE) autologous erythrocytes. In NR rabbits the functions of the spleen and liver were normal. In rabbits in stage A of serum sickness the clearance of HE, the only one measured in this stage, was decreased. In rabbits in stage B the clearances of HE and IgGE were determined; both clearances were decreased. In rabbits in stage C, the clearances of HE and IgGE were decreased, while the time of clearance of 50% (T 1/2) of PE was not significantly prolonged. In addition, in rabbits in stages A, B, and C the ratio of whole spleen vs liver radioactivity was increased. In rabbits in stage B the clearance of HE returned to normal 3 days after discontinuation of BSA injections. While all animals with detectable morphologic and immunohistologic changes of the spleen and the liver had prolonged clearances of treated erythrocytes, some animals with similarly prolonged clearances lacked evidence of pathology of these organs. The results obtained indicate that: (1) In NI and in NR rabbits, treated erythrocytes are rapidly removed by the macrophage-phagocyte system (MPS) and preferentially by the liver. (2) In rabbits in stages A, B, and C of serum sickness the clearances of treated erythrocytes are significantly prolonged. Moreover, treated erythrocytes appear to be preferentially removed by the spleen, indicating that the ability of the spleen to clear treated erythrocytes is less impaired than that of the liver. (3) In stages A, B, and C of serum sickness the nonimmunologic clearance of autologous erythrocytes is as altered as the clearance that occurs via Fc receptors. (4) In rabbits in stage B of serum sickness recovery of MPS function occurs after the interruption of BSA injections, suggesting reversible damage. (5) Impaired clearance of treated erythrocytes in rabbits without immunohistologic changes in any of the organs studied might indicate that functional tests are more sensitive than histology and immunohistology in detecting early abnormalities of the MPS in immune complex disease. In addition, this observation emphasizes that factors other than the MPS function are important for accumulation of immune complexes in tissues.
Interferon Fever: Absence of Human Leukocytic Pyrogen Response to Recombinant α-Interferon
Authors: Ackerman Samuel K , Hochstein H Donald , Zoon Kathryn , Browne Walter , Rivera Evelyn , Elisberg Bennett
Published: January 2018

A sensitive in vitro assay for generation of human leukocytic pyrogen has been used to study the pathogenesis of fever accompanying administration of human α-interferon. Unlike other potent pyrogens, two recombinant interferon preparations tested over a wide concentration range did not stimulate release of leukocytic pyrogen. This result suggests that interferon may cause fever by a novel mechanism not dependent on leukocytic pyrogen.
Specificity of the T Cells That Mediate and Suppress Adoptive Immunotherapy of Established Tumors
Authors: Dye Earl S , North Robert J
Published: January 2018

This study was designed to investigate the specificity of the T cells that express and suppress antitumor immunity in a model of adoptive immunization against established tumors. Results obtained with the P815 mastocytoma, L5178Y lymphoma, and P388 lymphoma showed, in agreement with previous findings from this laboratory, that an intravenous infusion of splenic T cells from immunized mice can cause the regression of a tumor growing in T-cell-deficient mice. So far as specificity of adoptive immunity is concerned, reciprocal passive transfer experiments with these three tumors revealed that T cells from donor mice immunized against the P815 tumor are not capable of causing regression of the P388 tumor or L5178Y tumor, even if both the P815 and L5178Y tumors are growing in the same host. Similarly splenic T cells from mice immunized against the P388 tumor or L5178Y tumor had no effect on growth of the P815 tumor. Suppression of adoptive immunity was also specific, in that passively transferred suppressor T cells from mice bearing a progressive P815 tumor were capable of suppressing adoptive T-cell-mediated regression of the P815 tumor, but not the P388 tumor growing in T-cell-deficient recipients. Reciprocally, P388 suppressor spleen cells from mice bearing a progressive P388 tumor prevented adoptive T-cell-mediated regression of the P388 tumor, but not the P815 tumor. The results indicate, therefore, that the T cells from immunized mice that mediate adoptive antitumor immunity and the T cells from tumor-bearing mice that suppress the expression of this immunity are specific for the tumor that evokes their generation.
Recombinant Inbred Mouse Strains Derived From A/J and C57BL/6J: A Tool for the Study of Genetic Mechanisms in Host Resistance to Infection and Malignancy
Authors: Nesbitt Muriel N , Skamene Emil
Published: January 2018

A number of recombinant inbred mouse strains (currently 48) have been developed from the strains A/J and C57BL/6J. These strains are likely to become an excellent probe in the study of genetic mechanisms underlying host resistance to infections and tumors.
Redistribution of Ecto-5′-Nucleotidase During Phagocytosis by Guinea Pig Polymorphonuclear Leukocytes
Authors: Cramer Elisabeth , Werb Zena , Bainton Dorothy F
Published: January 2018

We demonstrate that 5′-nucleotidase (5′NT), an ectoenzyme of guinea pig polymorphonuclear leukocytes, is largely excluded from phagosomal membrane, rather than internalized randomly during phagocytosis of heat-killed bacteria, latex microbeads, or zymosan particles. Cells were fixed in 0.25% glutaraldehyde (pH 6.3) at 4°C for 10 min and incubated in a cytochemical medium for the demonstration of 5′NT. In the nonphagocytosing cells, 5′NT was evenly distributed on the external side of the plasma membrane. In cells phagocytosing bacteria, 5′NT appeared to be cleared from the nascent phagosomal membrane; after 5 min of phagocytosis, most of the phagocytic vacuoles containing bacteria, latex, or zymosan particles were devoid of reaction product. When phagosomes containing latex particles were isolated and biochemically assayed, they contained less than 3% of the total cellular 5′NT activity even after 60 min of phagocytosis, and at that time the total cellular 5′NT activity had not declined. When the diazonium salt of sulfanilic acid (DASA), a nonpermeable ectoenzyme inhibitor, was used to determine the distribution of extracellular and intracellular 5′NT activity, no increase in DASA- insensitive intracellular 5′NT was found after phagocytosis of latex or opsonized zymosan. Cytochemical and biochemical evidence led us to conclude that 5′NT is excluded from phagosomal membrane, and that the exclusion is due to redistribution rather than to inactivation by granule enzymes.
Functions of Neutrophils in Endemic Chediak-Higashi Syndrome
Authors: Goihman-Yahr Mauricio , Merino Fernando , Duque Pedro Ramírez , Apitz Rafael , Martín Blanca San , de Gómez Maria Helena , de Román Ana , Pereira José
Published: January 2018

Endemic Chediak-Higashi Syndrome occurs in a restricted geographic area (Pregonero, State of Táchira, Venezuela). Neutrophils from these patients were unable to digest Candida albicans in vitro, but showed normal or increased metabolic activities. This finding supports the view that the endemic syndrome is bona fide Chediak-Higashi Sydrome.
Identification of the Bone Marrow-Derived Ia Positive Cells in the Rat Thymus: A Morphological and Cytochemical Study
Authors: Duijvestijn A M , Barclay A N
Published: January 2018

Ia+ cells of bone marrow origin were studied in the thymus of normal and bone marrow-reconstituted radiation chimeras of rats and characterized on morphology and acid phosphatase (APh)- and la-staining pattern in-vivo and in- vitro, In-vivo, the majority of the bone marrow-derived la+ ceils were present in the medulla. They were large, had cell processes extending between surrounding thymocytes, and frequently weak APh activity. In-vitro, the la staining was demonstrated on the cell surface in variable intensity, la + cells showed a frayed outline with cell processes between adherent thymocytes and had weak cytoplasmic APh activity, frequently in a central spot. They had an elongated, usually invaginated, nucleus and a rather pale cytoplasm, in which Birbeck granules sometimes were observed. The characteristics of the bone marrow- derived la + cells demonstrate these cells are an equivalent of the interdigitating cells present in thymus medulla. They distinguish themselves from a population of la-, strongly APh+ macrophages predominantly localized in the cortex, and from the la +, APh - thymic reticular epithelial cells.
Fc- and Complement Receptor-Dependent Degradation of Soluble Immune Complexes and Stable Immunoglobulin Aggregates by Guinea Pig Monocytes, Peritoneal Macrophages, and Kupffer Cells
Authors: Daha Mohamed R , van Es Leendert A
Published: January 2018

The degradation of soluble immune complexes (ICx) and stable soluble immunoglobulin aggregates was studied in vitro. To obtain insight into the capacity of phagocytes from different organs to degrade soluble ICx we studied monocytes, peritoneal macrophages, and Kupffer cells. Peritoneal macrophages and Kupffer cells degrade similar amounts of aggregated guinea pig lgG2 (AlgG) and ICx per cell. Monocytes were at least ten times less effective than peritoneal macrophages and Kupffer cells.

The presence of normal guinea pig serum as a source of complement enhanced the degradation of ICx and AlgG by peritoneal macrophages and monocytes. There was, however, a diminished degradation of ICx and AlgG by freshly isolated Kupffer cells in the presence of complement. After culturing of the Kupffer cells for 40 hours, there was an increase in the density of C3b receptors and a concomitant reversal of inhibition of AlgG degradation in the presence of complement. It can be concluded from the present experiments that the capacities of peritoneal macrophages and Kupffer cells to degrade soluble ICx and AlgG are comparable and that monocytes are much less active than peritoneal macrophages and Kupffer cells.
The Macrophage Content of Tumors Is Unrelated to Levels of NK Cell-Mediated Resistance
Authors: Polentarutti Nadia , Acero Raffaella , Bottazzi Barbara , Taraboletti Giulia , Mantovani Alberto
Published: January 2018

Three malignant tumors (3LL carcinoma, mFS6 sarcoma, and B16 F1 melanoma) were transplanted in mice with congenital (beige) or acquired (antiasialo GM1-treated) defects of natural killer cell (NK) activity. The macrophage content of the neoplastic tissues was not influenced by host NK activity levels. These data suggest that NK cell-mediated resistance does not play an appreciable role in the regulation of the levels of tumor-associated macrophages in established malignancy.
Release of Interleukin-1 (IL-1) and IL-1-Like Factors From Rabbit Macrophages With Silica
Authors: Kampschmidt Ralph F , Worthington Martin L , Mesecher Maria I
Published: January 2018

Oil-elicited rabbit macrophages stimulated by endotoxin were found to release increased amounts of interleukin 1 (IL-1) when incubated with silica. The assays used to determine the amount of IL-1 released were uptake of thymidine by mouse thymocytes, fever in rabbits, and neutrophilia in rats. All three assays showed that endotoxin-stimulated macrophages released five to 10 times more IL-1 when incubated with silica. Most of the IL-1 had a molecular weight (MW) of about 14,000 with a smaller amount at a MW of approximately 35,000. All of the neutrophilia-producing activity had an isoelectric point (pl) near 7. Thymocyte proliferation was promoted about equally by activities near pH 5 and 7. Fever was found not only at these two isoelectric points but also at a pl above 8 which had neither of the other two activities.
Rapid Killing of Actinomycin D-Treated Tumor Cells by Mononuclear Phagocytes: Characterization of Effector Cells in Mice
Authors: Colotta Francesco , Polentarutti Nadia , Bersani Laura , Poll Guido , Mantovani Alberto
Published: January 2018

Pretreatment with Actinomycin D (Act D, 1 μg/ml for 3 hr) rendered WEHI 164 tumor cells susceptible to killing by mouse resident or peptone-induced peritoneal exudate cells (PEC) in a 6-hr 51Cr release assay. Cytotoxicity was attributed to cells of the monocyte macrophage lineage on the basis of tissue distribution, separation by adherence on plastic and carbonyl iron, membrane antigens, and expression in mice with defective T cell- or NK cell-mediated immunity. Macrophages from four strains of mice (C3H/HeJ, A/J, P/J, C57BI/10 ScCR) previously shown to have defective “classical” nonspecific tumoricidal activity were examined for killing of Act-D-treated WEHI 164 cells. C3H/HeJ peritoneal macrophages had little or no DDCC, whereas cells from A/J, P/J, and C57BI/10 ScCR mice had normal levels of this reactivity. Tumor cells exposed to ActD were heterogenous in their susceptibility to killing by PEC, with five lines showing significant, though variable, lysis, whereas 12 tumor lines, normal fibroblasts, and lymphoblasts were not appreciably killed under the same conditions. Macrophage-mediated DDCC was also detectable in a colony assay. DDCC could explain how macrophages contribute to the antitumor activity of selected chemotherapeutic agents in murine tumor models.
A Monoclonal Antibody Against Migration Inhibitory Factor (MIF) Obtained by Immunization With MIF From the Human Lymphoblast Cell Line Mo
Authors: Kawaguchi Tsutomu , Mednis Alma , Golde David W , David John R , Remold Heinz R
Published: January 2018

A monoclonal antibody-secreting hybrid cell line, E7, was constructed from myeloma cells and spleen cells from BALB/c mice immunized with partially purified human MIF from culture fluid of the human T-lymphoblast cell line Mo. The hybrid cell line E7 was selected by screening hybridoma cultures for their capacity to adsorb added MIF activity when assayed together with rabbit antimouse IgG-coupled to protein A-Sepharose. The monoclonal antibody produced by the cloned hybridoma E7 also directly neutralized MIF activity from Mo cells and two species of MIF from the culture fluid of human peripheral blood lymphocytes, but did not neutralize IFN-gamma from Mo cells and from human peripheral blood lymphocytes. This antibody reacted also with a component in phytohemagglutinin preparations with an apparent molecular weight of 60,000; however, it did not react with the active tetramer of phytohemagglutinin.
Comparison of Cell-Mediated and Humoral Immunity in the Dog Lung After Localized Lung Immunization
Authors: Galvin Jennifer B , Bice David E , Muggenburg Bruce A
Published: January 2018

This study evaluated cell-mediated immunity (CMI) and antibody production serially in control and immunized lung lobes of beagle dogs. A fiberoptic bronchoscope was used to immunize selected airways in the left cardiac lung lobe with 1010 sheep red blood cells (SRBC); the right cardiac lobe received saline as control. The immune responses produced by this localized lung immunization were evaluated in cells and fluids obtained from blood and serial bronchial washings of the immunized and control lung lobes from 5 to 21 days after immunization. The antigen-specific production of procoagulant activity (LPCA) and inhibition of migration of alveolar macrophages by SRBC antigen were used to measure CMI in lavage cells from immunized and control lung lobes. The level of specific IgM and IgG antibody in lavage fluid from the control and immunized lung lobes was evaluated with the enzyme-linked immunosorbent assay (ELISA). The results of this study showed a significantly greater percentage of neutrophils and lymphocytes in the lavage fluid from the immunized lung lobes than from the control lung lobes. The increased number of lymphocytes in the immunized lung lobes showed a positive correlation with increased antibody concentrations. In contrast to the antibody response, CMI as measured by LPCA and MIF assays was positive, with nearly equal responses in control and immunized lung lobes. Even though there were only a few lymphocytes in the control lung lobes, there were apparently enough specific immune lymphocytes present that produced mediators after antigen stimulation to result in positive CMI responses.
The In Vitro Mitogenic Response to Intact Bacteria by Murine B Cells Does Not Predict In Vivo Susceptibility to Salmonella typhimurium
Authors: Elkins Karen , Metcalf Eleanor S
Published: January 2018

We are interested in developing in vitro culture systems that will permit immune responses to intact Salmonella typhimurium, since these systems would have certain advantages over in vivo infection models for the characterization of the host's responding cell types. In this report, the in vitro proliferative response of nonimmune murine spleen cells to four different killed preparations of S. typhimurium, strain TML (TML), are examined. These studies show that UV-killed TML, heat-killed TML, glutaraldehyde-killed TML, and acetone-killed and dried TML, all elicit a nonspecific mitogenic spleen cell response in vitro, as does a live, avirulent, temperature-sensitive mutant of TML, TS27. This response reaches a maximum on day 2 after initiation of culture, which is similar to the time course of a conventional lipopolysaccharide (LPS) response. Unlike the LPS response, little 3H-thymidine incorporation is observed in low-density cultures (2 × 105 cells/well), which suggests a critical role for accessory cells. The responding cell types include, but are not necessarily limited to, the B-cell population. The response cannot be readily inhibited by polymyxin B, which binds specifically to the lipid A portion of LPS. Thus, the bacterial components required for mitogenicity are not yet definitively identified. A survey of the mitogenic responses of lymphocytes from various inbred mouse strains, including the C3H/HeJ LPS hyporesponsive strain, indicates that all B cells tested are capable of proliferating vigorously in response to intact TML, regardless of the in vivo susceptibility to virulent infection. These results also emphasize the importance of assessing the nonspecific components of the immune response when studying the specific immune response to intact S. typhimurium.