scholarly journals PHAGOCYTOSIS OF BACTERIA IN THE ABSENCE OF ANTIBODY AND THE EFFECT OF PHYSICAL SURFACE

1956 ◽  
Vol 104 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Edwin M. Lerner
Keyword(s):  
Filter Paper ◽  
Chemical Effect ◽  
Type I ◽  
Blood Leukocytes ◽  
Experimental Conditions ◽  
Phagocytic Capacity ◽  
E Coli ◽  
Physical Surface ◽  
Type Iv

The present experiments have shown that phagocytosis occurs in the absence of specific antibody and in the absence of a "suitable physical surface", as further that the presence of a rough surface does not increase the in vitro phagocytosis of pneumococci by polymorphonuclear leukocytes. This held true during repetition of Wood's experiments, as well as when more controlled quantitative techniques were employed, when conditions were made optimal for phagocytosis by increasing bacterial concentrations, and when blood leukocytes were substituted for exudate leukocytes. Evidence has been presented previously that the stimulation of phagocytosis of E. coli, B. abortus, and Type IV Pneumococcus, after contact with filter paper or an active compound present in filter paper, is a chemical effect rather than a physical effect. This type of stimulation did not occur with the Type I A5 Pneumococcus. The leukocyte of the circulating blood was found to be definitely superior to the exudate leukocyte in phagocytic capacity, under all the experimental conditions tested.

scholarly journals The biosynthesis of extracellular-matrix components by bovine retinal endothelial cells displaying distinctive morphological phenotypes

1986 ◽  
Vol 235 (2) ◽  
pp. 375-383 ◽  
Author(s):  
A E Canfield ◽  
A M Schor ◽  
S L Schor ◽  
M E Grant
Keyword(s):  
Endothelial Cells ◽  
Type I ◽  
Collagen Gels ◽  
Early Passage ◽  
Experimental Conditions ◽  
Retinal Endothelial Cells ◽  
Type Iv ◽  
Extracellular Matrix Components ◽  
Cells Cultured

Previous studies have indicated that the morphology and behaviour of bovine retinal microvessel endothelial cells are influenced by culture conditions in vitro. Data are presented here concerning the biosynthesis of matrix macromolecules by bovine retinal endothelial cells cultured under conditions in which the cells display either the ‘cobblestone’ or the ‘sprouting’ phenotype. Newly synthesized matrix proteins were identified by their characteristic electrophoretic mobilities, immunoprecipitation with specific antibodies, susceptibilities to enzymic digestions and chromatographic behaviour. Type IV procollagen was the major collagenous species synthesized by early-passage cells forming a ‘cobblestone’ monolayer. In contrast, cells displaying the ‘sprouting’ morphology switched to the predominant synthesis of interstitial fibrillar collagens (types I and III). Fibronectin was synthesized by retinal endothelial cells under all the experimental conditions studied. A non-collagenous glycoprotein of Mr approx. 47,000 was also a major biosynthetic product of these cells. The synthesis of thrombospondin was very much dependent on the nature of the substratum on which the cells were cultured. This glycoprotein was synthesized in large amounts by ‘cobblestone’ endothelial cells cultured on gelatin-coated dishes, whereas its synthesis was markedly decreased by culturing the cells on collagen gels, and the protein appeared to be absent when the cells were plated within collagen gels (‘sprouting’ cells). Late-passage retinal cells synthesized predominantly type I procollagen, variable amounts of type III procollagen and only traces of type IV procollagen, irrespective of whether the cells displayed a ‘cobblestone’ or ‘sprouting’ morphology.

scholarly journals Patterns and Relevance of Langerhans Islet Invasion in Pancreatic Cancer

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 249
Author(s):  
Ruediger Goess ◽  
Ayse Ceren Mutgan ◽  
Umut Çalışan ◽  
Yusuf Ceyhun Erdoğan ◽  
Lei Ren ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Islet Cells ◽  
Human Pancreatic Cancer ◽  
Type I ◽  
Type Iv ◽  
Pancreatic Cancer Cells

Background: Pancreatic cancer‐associated diabetes mellitus (PC‐DM) is present in most patients with pancreatic cancer, but its pathogenesis remains poorly understood. Therefore, we aimed to characterize tumor infiltration in Langerhans islets in pancreatic cancer and determine its clinical relevance. Methods: Langerhans islet invasion was systematically analyzed in 68 patientswith pancreatic ductal adenocarcinoma (PDAC) using histopathological examination and 3D in vitro migration assays were performed to assess chemoattraction of pancreatic cancer cells to isletcells. Results: Langerhans islet invasion was present in all patients. We found four different patterns of islet invasion: (Type I) peri‐insular invasion with tumor cells directly touching the boundary, but not penetrating the islet; (Type II) endo‐insular invasion with tumor cells inside the round islet; (Type III) distorted islet structure with complete loss of the round islet morphology; and (Type IV)adjacent cancer and islet cells with solitary islet cells encountered adjacent to cancer cells. Pancreatic cancer cells did not exhibit any chemoattraction to islet cells in 3D assays in vitro. Further, there was no clinical correlation of islet invasion using the novel Islet Invasion Severity Score (IISS), which includes all invasion patterns with the occurrence of diabetes mellitus. However, Type IV islet invasion was related to worsened overall survival in our cohort. Conclusions: We systematically analyzed, for the first time, islet invasion in human pancreatic cancer. Four different main patterns of islet invasion were identified. Diabetes mellitus was not related to islet invasion. However, moreresearch on this prevailing feature of pancreatic cancer is needed to better understand underlying principles.

scholarly journals Shift in collagen type as an early response to induction of the metanephric mesenchyme.

1981 ◽  
Vol 89 (2) ◽  
pp. 276-283 ◽  
Author(s):  
P Ekblom ◽  
E Lehtonen ◽  
L Saxén ◽  
R Timpl
Keyword(s):  
Basal Lamina ◽  
Type Iv Collagen ◽  
Early Response ◽  
Type I ◽  
Metanephric Mesenchyme ◽  
Type Iv ◽  
Interstitial Collagens ◽  
Membrane Components

Conversion of the nephrogenic mesenchyme into epithelial tubules requires an inductive stimulus from the ureter bud. Here we show with immunofluorescence techniques that the undifferentiated mesenchyme before induction expresses uniformly type I and type III collagens. Induction both in vivo and in vitro leads to a loss of these proteins and to the appearance of basement membrane components including type IV collagen. This change correlates both spatially and temporally with the determination of the mesenchyme and precedes and morphological events. During morphogenesis, type IV collagen concentrates at the borders of the developing tubular structures where, by electron microscopy, a thin, often discontinuous basal lamina was seen to cover the first pretubular cell aggregates. Subsequently, the differentiating tubules were surrounded by a well-developed basal lamina. No loss of the interstitial collagens was seen in the metanephric mesenchyme when brought into contact with noninducing tissues or when cultured alone. Similar observations were made with nonnephrogenic mesenchyme (salivary, lung) when exposed to various heterotypic tissues known to induce tubules in the nephrogenic mesenchyme. The sequential shift in the composition of the extracellular matrix from an interstitial, mesenchymal type to a differentiated, epithelial type is so far the first detectable response of the nephrogenic mesenchyme to the tubule-inducing signal.

scholarly journals Amino acid depletion and appearance during porcine preimplantation embryo development in vitro

Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 655-668 ◽  
Author(s):  
Paul J Booth ◽  
Peter G Humpherson ◽  
Terry J Watson ◽  
Henry J Leese
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Embryo Development ◽  
Preimplantation Embryos ◽  
Type I ◽  
Preimplantation Embryo Development ◽  
Type Iv ◽  
Stage Of Development ◽  
Amino Acid Depletion

Preimplantation embryos can consume and produce amino acids in a manner dependent upon the stage of development that may be predictive of subsequent viability. In order to examine these relationships in the pig, patterns of net depletion and appearance of amino acids byin vitroproduced porcine preimplantation embryos were examined. Cumulus oocyte complexes derived from slaughterhouse pre-pubertal pig ovaries were matured for 40 h in defined TCM-199 medium (containing PVA) before being fertilised (Day 0) with frozen-thawed semen in Tris–based medium. After 6 h, presumptive zygotes were denuded and cultured in groups of 20, in NCSU-23 medium modified to contain 0.1 mM glutamine plus a mixture of 19 amino acids (aa) at low concentrations (0.02–0.11 mM) (NCSU-23aa). Groups of 2–20 embryos were removed (dependent on stage) on Day 0 (1 cell), Day 1 (two- and four-cells), Day 4 (compact morulae) and Day 6 (blastocysts) and placed in 4 μl NCSU-23aafor 24 h. After incubation, the embryos were removed and the spent media was analysed by HPLC. The net rate of amino acid depletion or appearance varied according to amino acid (P< 0.001) and, apart from serine and histidine, stage of development (P< 0.014). Glycine, isoleucine, valine, phenylalanine, tryptophan, methionine, asparagine, lysine, glutamate and aspartate consistently appeared, whereas threonine, glutamine and arginine were consistently depleted. Five types of stage-dependent trends could be observed: Type I: amino acids having high rates of net appearance on Day 0 that reached a nadir on Day 1 or 4 but subsequently increased by Day 6 (glycine, glutamate); Type II: those that exhibited lower rates of net appearance on Days 0 and 6 compared with the intermediate Days 1 and 4 (isoleucine, valine, phenylalanine, methionine, arginine); Type III: amino acids which showed a continuous fall in net appearance (asparagine, aspartate); Type IV: those that exhibited a steady fall in net depletion from Day 0 to Day 6 (glutamine, threonine); Type V: those following no discernable trend. Analysis of further embryo types indicated that presumptive polyspermic embryos on Day 0 had increased (P< 0.05) net rates of leucine, isoleucine, valine and glutamate appearance, and reduced (P< 0.05) net rates of threonine and glutamine depletion compared with normally inseminated oocytes. These data suggest that the net rates of depletion and uptake of amino acids by pig embryos vary between a) amino acids, b) the day of embryo development and, c) the type of embryos present at a given stage of development. The results also suggested that the net depletion and appearance rates of amino acids by early pig embryos might be more similar to those of the human than those of the mouse and cow.

scholarly journals Hypersensitivity Reactions to Monoclonal Antibodies in Children

Medicina ◽  
2020 ◽  
Vol 56 (5) ◽  
pp. 232
Author(s):  
Francesca Mori ◽  
Francesca Saretta ◽  
Annamaria Bianchi ◽  
Giuseppe Crisafulli ◽  
Silvia Caimmi ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Therapeutic Option ◽  
Provocation Test ◽  
Type I ◽  
Hypersensitivity Reactions ◽  
Biologic Drugs ◽  
Type Iv ◽  
Drug Provocation Test

Biologic drugs are widely used in pediatric medicine. Monoclonal antibodies (mAbs) in particular are a therapeutic option for rheumatic, autoinflammatory and oncologic diseases. Adverse drug reactions and hypersensitivity reactions (HSR) to mAbs may occur in children. Clinical presentation of HSRs to mAbs can be classified according to phenotypes in infusion-related reactions, cytokine release syndrome, both alpha type reactions and type I (IgE/non-IgE), type III, and type IV reactions, all beta-type reactions. The aim of this review is to focus on HSRs associated with the most frequent mAbs in childhood, with particular attention to beta-type reactions. When a reaction to mAbs is suspected a diagnostic work-up including in-vivo and in-vitro testing should be performed. A drug provocation test is recommended only when no alternative drugs are available. In selected patients with immediate IgE-mediated drug allergy a desensitization protocol is indicated. Despite the heavy use of mAbs in childhood, studies evaluating the reliability of diagnostic test are lacking. Although desensitization may be effective in reducing the risk of reactions in children, standardized pediatric protocols are still not available.

Monomeric and dimeric GDF-5 show equal type I receptor binding and oligomerization capability and have the same biological activity

2006 ◽  
Vol 387 (4) ◽  
pp. 451-460 ◽  
Author(s):  
Christina Sieber ◽  
Frank Plöger ◽  
Raphaela Schwappacher ◽  
Rolf Bechtold ◽  
Michael Hanke ◽  
...  
Keyword(s):  
Biological Activity ◽  
Biochemical Analysis ◽  
Gene Activation ◽  
Disulfide Bridge ◽  
Living Cells ◽  
Type I ◽  
E Coli ◽  
Interchain Disulfide Bond ◽  
Dimeric Form

Abstract Growth and differentiation factor 5 (GDF-5) is a homodimeric protein stabilized by a single disulfide bridge between cysteine 465 in the respective monomers, as well as by three intramolecular cysteine bridges within each subunit. A mature recombinant human GDF-5 variant with cysteine 465 replaced by alanine (rhGDF-5 C465A) was expressed in E. coli, purified to homogeneity, and chemically renatured. Biochemical analysis showed that this procedure eliminated the sole interchain disulfide bond. Surprisingly, the monomeric variant of rhGDF-5 is as potent in vitro as the dimeric form. This could be confirmed by alkaline phosphatase assays and Smad reporter gene activation. Furthermore, dimeric and monomeric rhGDF-5 show comparable binding to their specific type I receptor, BRIb. Studies on living cells showed that both the dimeric and monomeric rhGDF-5 induce homomeric BRIb and heteromeric BRIb/BRII oligomers. Our results suggest that rhGDF-5 C465A has the same biological activity as rhGDF-5 with respect to binding to, oligomerization of and signaling through the BMP receptor type Ib.

scholarly journals In vitro glycoxidation alters the interactions between collagens and human polymorphonuclear leucocytes

2000 ◽  
Vol 350 (3) ◽  
pp. 777-783 ◽  
Author(s):  
Jean-Claude MONBOISSE ◽  
Laure RITTIE ◽  
Hasnae LAMFARRAJ ◽  
Roselyne GARNOTEL ◽  
Philippe GILLERY
Keyword(s):  
Diabetes Mellitus ◽  
Type I Collagen ◽  
Inhibitory Effect ◽  
Type I ◽  
Polymorphonuclear Leucocytes ◽  
Type Iv ◽  
And Migration ◽  
Significant Stimulatory Effect

Glycation and glycoxidation processes, which are increased in diabetes mellitus, are generally considered causative mechanisms of long-term complications. With reference to our previous studies, type-I and -IV collagens could induce differentially the adhesion and stimulation of polymorphonuclear leucocytes (PMNs). As PMNs play a role in sustained diabetic oxidative stress, the present study was designed to determine whether in vitro glycoxidation of these macromolecules could alter PMN adhesion, activation and migration. The adhesion of PMNs to in vitro-glycoxidized collagens was significantly increased when compared with control collagens: +37% (P < 0.05) and +99% (P < 0.01) for collagens I and IV, respectively. Glycoxidized type-I collagen increased the chemotactic properties of PMNs without significant stimulatory effect on respiratory burst, whereas pre-incubation of PMNs with glycoxidized type-I collagen induced a priming on subsequent stimulation by N-formyl-methionyl-leucyl-phenylalanine. Glycoxidation of type-IV collagen suppressed its inhibitory effect on further PMN stimulation or migration. Collectively, these results indicate that glycoxidation of two major extracellular-matrix collagens considerably alters their ability to modulate PMN migration and production of reactive oxygen species. This imbalance in PMN metabolism may be a major event in the increased oxidative status that characterizes diabetes mellitus.

scholarly journals Transcription of bacteriophage T4 deoxyribonucleic acid in vitro

1969 ◽  
Vol 115 (3) ◽  
pp. 353-361 ◽  
Author(s):  
John O. Bishop ◽  
Forbes W. Robertson
Keyword(s):  
Rna Polymerase ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Deoxyribonucleic Acid ◽  
Bacteriophage T4 ◽  
Rna Sequences ◽  
Experimental Conditions ◽  
E Coli ◽  
New Methods

1. RNA was synthesized in vitro from a template of bacteriophage T4 DNA, in the presence of Mn2+. A comparison was made of the RNA synthesized by purified RNA polymerase from two sources, Micrococcus lysodeikticus and Escherichia coli; these are referred to as Micrococcus cRNA and E. coli cRNA respectively (where cRNA indicates RNA synthesized in vitro by using purified RNA polymerase and a DNA primer). 2. Both types of RNA were self-complementary as judged by resistance to digestion with ribonuclease after self-annealing, Micrococcus cRNA being more self-complementary (40%) than was E. coli cRNA (30%). The cRNA was found to be much less self-complementary if Mg2+ was present during RNA synthesis instead of Mn2+. 3. Micrococcus cRNA hybridized with a larger part of bacteriophage T4 DNA than did E. coli cRNA. The E. coli cRNA competed with only part (70%) of the Micrococcus cRNA in hybridization-competition experiments. It is concluded that more sequences of bacteriophage T4 DNA are transcribed by Micrococcus polymerase than by E. coli polymerase. 4. The RNA sequences synthesized by Micrococcus RNA polymerase but not by E. coli RNA polymerase are shown by hybridization competition to compete with specifically late bacteriophage T4 messenger RNA sequences. The relevance of this finding to the control of transcription is discussed. 5. In an Appendix, new methods are described for the analysis of hybridization-saturation and -competition experiments. Particular attention is paid to the effects produced if different RNA sequences are present at different relative concentrations. 6. By using cRNA isolated from an enzymically synthesized DNA–RNA hybrid, it is estimated that, of the DNA that is complementary to cRNA, only about half can become hybridized with cRNA under the experimental conditions used.

scholarly journals Modulation of extracellular matrix biosynthesis by bovine retinal pericytes in vitro: effects of the substratum and cell density

1990 ◽  
Vol 96 (1) ◽  
pp. 159-169
Author(s):  
A.E. Canfield ◽  
T.D. Allen ◽  
M.E. Grant ◽  
S.L. Schor ◽  
A.M. Schor
Keyword(s):  
Extracellular Matrix ◽  
Type Iv Collagen ◽  
Type I Collagen ◽  
Single Cells ◽  
Collagen Gel ◽  
Type Iii Collagen ◽  
Type I ◽  
Experimental Conditions ◽  
Type Iv ◽  
Retinal Pericytes

Bovine retinal pericytes plated on a two-dimensional substratum display a characteristic stellate morphology. In post-confluent cultures these cells aggregate spontaneously to form multicellular nodules. The same cells plated within a three-dimensional collagen matrix display an elongated sprouting morphology. Sprouting pericytes may be embedded within a gel either as individual cells or as multicellular aggregates. We have compared the nature of the matrix proteins synthesised by pericytes displaying these different phenotypes. Stellate pericytes cultured on plastic dishes synthesised predominantly type I collagen, some type III collagen and only traces of type IV collagen. The same collagen types were secreted when nodules had formed in postconfluent cultures on plastic, and by sprouting cells plated as single cells within the collagen gel. By contrast, sprouting pericytes plated as aggregates within the collagen gel secreted increased levels of type IV collagen and reduced amounts of type I collagen. Fibronectin was synthesized by pericytes under all experimental conditions examined; thrombospondin was produced in relatively large amounts by cells grown on plastic dishes, whereas only trace amounts could be detected in the medium when the cells were cultured within a collagen gel matrix. Transmission electron microscopy revealed that pericyte aggregates within a collagen gel contained cells in close apposition surrounded by a dense extracellular matrix. In contrast, cells in the centre of a nodule on plastic appeared to be separated from each other by loose extracellular material. These results suggest that the morphological and biosynthetic phenotypes of retinal pericytes are modulated by cell-matrix and/or cell-cell interactions.

scholarly journals Antimicrobial effects of fruit sauces on some pathogenic bacteria in vitro and on chicken breast meat

2021 ◽  
Vol 72 (1) ◽  
pp. 2703
Author(s):  
I VAR ◽  
S UZUNLU ◽  
I DEĞIRMENCI
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Diffusion Method ◽  
Chicken Breast ◽  
Type I ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Agar Diffusion

The use of natural food additives is currently a rising trend. In the present study, the aim was to determine the antimicrobial effects of plum, pomegranate, Seville orange and sumac sauces on E. coli O157:H7,E. coli type I,Listeriamonocytogenes, Listeria ivanovii, Salmonella Typhimurium and Staphylococcus aureus. Different concentrations (1%, 10%, 100%, v/v) of the sauces were tested on the studied bacteria in vitro using the agar diffusion and minimal inhibition concentration (MIC) methods. The results showed that the sumac sauce had the highest antimicrobial activity. The Seville orange, plum and pomegranate sauces also exerted antimicrobial activity in descending order. The antimicrobial activity of the fruit sauces was more effective at a concentration of 100% than at 10% and 1%, v/v. The most inhibitory effect was recorded for sumac sauce at a concentration of 100% (v/v) on L.monocytogenesand E. coli O157:H7. The findings of the MIC method aligned with the agar diffusion method. In addition, the in situ(food method) antimicrobial effect of the sauces on the indigenous microflora of chicken breast samples sold in stores was determined. Chicken samples hosting aerobic mesophilic bacteria, coliforms and E. coli were treated for two hours at 4 °C with plum, pomegranate, Seville orange and sumac sauces and were then monitored. The findings revealed that the Seville orange and sumac sauces were the most effective in reducing the indigenous microbial growth on the chicken samples. The plum sauce showed higher antimicrobial activity than pomegranate sauce. The phenolic content and acidity of the samples significantly (P< 0.05) affected the antimicrobial activity both in vitro (agar diffusion and MIC) and in situ (chilled chicken breast). In conclusion, the sumac and Seville orange sauces were found to be the most promising natural antibacterial agents, and their use could be recommended, for example, in catering services to reduce the risk of foodborne illness.

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