Ultrastructural study of uptake of monastral blue by the pulmonary intravascular macrophages of sheep in the presence and absence of surface coat

1992 ◽  
Vol 50 (1) ◽  
pp. 702-703
Author(s):  
B. Singh ◽  
D. S. Jassal ◽  
O. S. Atwal ◽  
K. Minhas
Keyword(s):  
Tannic Acid ◽  
Animal Species ◽  
Ultrastructural Level ◽  
Mononuclear Phagocyte ◽  
Surface Coat ◽  
Cell Periphery ◽  
Highly Sensitive ◽  
Pulmonary Intravascular Macrophages

Pulmonary intravascular macrophage (PIM) is an important mononuclear phagocyte of some animal species. In sheep these cells are actively involved in the clearance of microbes and endotoxins. By treating the tissue with tannic acid we have identified at the ultrastructural level a unique globular surface coat, arranged at a distance of 30-40 nm from the cell periphery, This coat is hypothesized to be lipoprotein in nature as tannic acid complexes with the globules to enhance their electron density. This surface coat is highly sensitive to in vitro lipolytic lipase digestion and in vivo heparin treatment.

Depletion of pulmonary intravascular macrophages inhibits acute lung inflammation

2004 ◽  
Vol 286 (2) ◽  
pp. L363-L372 ◽  
Author(s):  
Baljit Singh ◽  
Jacqueline W. Pearce ◽  
Lakshman N. Gamage ◽  
Kyathanahalli Janardhan ◽  
Sarah Caldwell
Keyword(s):  
Lung Inflammation ◽  
Acute Inflammation ◽  
Inflammatory Cells ◽  
Acute Lung Inflammation ◽  
Tnf Α ◽  
Highly Sensitive ◽  
In Vitro Exposure ◽  
Pulmonary Intravascular Macrophages

Pulmonary intravascular macrophages (PIMs) are present in ruminants and horses. These species are highly sensitive to acute lung inflammation compared with non-PIM-containing species such as rats and humans. There is evidence that rats and humans may also recruit PIMs under certain conditions. We investigated precise contributions of PIMs to acute lung inflammation in a calf model. First, PIMs were recognized with a combination of in vivo phagocytic tracer Monastral blue and postembedding immunohistology with anti-CD68 monoclonal antibody. Second, gadolinium chloride depleted PIMs within 48 h of treatment ( P < 0.05). Finally, PIMs contain TNF-α, and their depletion reduces cells positive for IL-8 ( P < 0.05) and TNF-α ( P < 0.05) and histopathological signs of acute lung inflammation in calves infected with Mannheimia hemolytica. The majority of IL-8-positive inflammatory cells in lung septa of infected calves were platelets. Platelets from normal cattle contained preformed IL-8 that was released upon in vitro exposure to thrombin ( P < 0.05). These novel data show that PIMs, as the source of TNF-α, promote recruitment of inflammatory cells including IL-8-containing platelets to stimulate acute inflammation and pathology in lungs. These data may also be relevant to humans due to our ability to recruit PIMs.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

Effect of brefeldin A (BFA) on the unique surface coat of pulmonary intravascular macrophages (PIMs) of sheep: Ultrastructural and cytochemical study

1993 ◽  
Vol 51 ◽  
pp. 18-19
Author(s):  
Baljit Singh
Keyword(s):  
Brefeldin A ◽  
Ultrastructural Feature ◽  
Surface Coat ◽  
Anterograde Transport ◽  
Cytochemical Study ◽  
Active Involvement ◽  
Electron Lucent ◽  
Pulmonary Intravascular Macrophages ◽  
Unique Surface

The PIM of sheep, calf, goat and horse has a characteristic ultrastructural feature in the form of a unique, heparin sensitive, globular surface coat present around the plasma membrane with an intervening electron lucent space of 32-40 nm. We previously showed the active involvement of this surface coat in the phagocytosis of tracer material like monastral blue and cationized ferritin. The surface coat is capable of reconstitution in vivo following disruption with heparin. The present study was aimed to investigate whether PIM is the source of surface coat or not. In the recent years the BFA has been extensively used to understand the secretory pathways in the cells because of its ability to cause a rapid and reversible block to the anterograde transport of proteins from the endoplasmic reticulum to the Golgi.Sheep (n=6) were weighed, their plasma volume was calculated indirectly and based on which a sufficient single intravenous dose of BFA was given so as to reach a concentration of 4-5 microgram/ml of plasma.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

scholarly journals Current Status of Putative Animal Sources of SARS-CoV-2 Infection in Humans: Wildlife, Domestic Animals and Pets

2021 ◽  
Vol 9 (4) ◽  
pp. 868
Author(s):  
Max Maurin ◽  
Florence Fenollar ◽  
Oleg Mediannikov ◽  
Bernard Davoust ◽  
Christian Devaux ◽  
...  
Keyword(s):  
Animal Species ◽  
Biological Properties ◽  
Experimental Models ◽  
Current Data ◽  
The Body ◽  
Receptor Expression ◽  
Current Status ◽  
Susceptible Animal

SARS-CoV-2 is currently considered to have emerged from a bat coronavirus reservoir. However, the real natural cycle of this virus remains to be elucidated. Moreover, the COVID-19 pandemic has led to novel opportunities for SARS-CoV-2 transmission between humans and susceptible animal species. In silico and in vitro evaluation of the interactions between the SARS-CoV-2 spike protein and eucaryotic angiotensin-converting enzyme 2 (ACE2) receptor have tentatively predicted susceptibility to SARS-CoV-2 infection of several animal species. Although useful, these data do not always correlate with in vivo data obtained in experimental models or during natural infections. Other host biological properties may intervene such as the body temperature, level of receptor expression, co-receptor, restriction factors, and genetic background. The spread of SARS-CoV-2 also depends on the extent and duration of viral shedding in the infected host as well as population density and behaviour (group living and grooming). Overall, current data indicate that the most at-risk interactions between humans and animals for COVID-19 infection are those involving certain mustelids (such as minks and ferrets), rodents (such as hamsters), lagomorphs (especially rabbits), and felines (including cats). Therefore, special attention should be paid to the risk of SARS-CoV-2 infection associated with pets.

scholarly journals Immunocompatibility of a new dual modality contrast agent based on radiolabeled iron-oxide nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria-Argyro Karageorgou ◽  
Dimosthenis Stamopoulos
Keyword(s):  
Complete Blood Count ◽  
Morphological Characteristics ◽  
Mononuclear Phagocyte ◽  
Dual Modality ◽  
Immunodeficient Mice ◽  
Force Microscopy ◽  
Magnetic Resonance Imaging Mri ◽  
Diagnostic Applications

AbstractRadiolabeled magnetic nanoparticles are promising candidates as dual-modality-contrast-agents (DMCA) for diagnostic applications. The immunocompatibility of a new DMCA is a prerequisite for subsequent in vivo applications. Here, a new DMCA, namely Fe3O4 nanoparticles radiolabeled with 68Ga, is subjected to immunocompatibility tests both in vitro and in vivo. The in vitro immunocompatibility of the DMCA relied on incubation with donated human WBCs and PLTs (five healthy individuals). Optical microscopy (OM) and atomic force microscopy (AFM) were employed for the investigation of the morphological characteristics of WBCs and PLTs. A standard hematology analyzer (HA) provided information on complete blood count. The in vivo immunocompatibility of the DMCA was assessed through its biodistribution among the basic organs of the mononuclear phagocyte system in normal and immunodeficient mice (nine in each group). In addition, Magnetic Resonance Imaging (MRI) data were acquired in normal mice (three). The combined OM, AFM and HA in vitro data showed that although the DMCA promoted noticeable activation of WBCs and PLTs, neither degradation nor clustering were observed. The in vivo data showed no difference of the DMCA biodistribution between the normal and immunodeficient mice, while the MRI data prove the efficacy of the particular DMCA when compared to the non-radiolabeled, parent CA. The combined in vitro and in vivo data prove that the particular DMCA is a promising candidate for future in vivo applications.

scholarly journals DNAJB6b is Downregulated in Synucleinopathies

2021 ◽  
pp. 1-13
Author(s):  
Jonas Folke ◽  
Sertan Arkan ◽  
Isak Martinsson ◽  
Susana Aznar ◽  
Gunnar Gouras ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Substantia Nigra Pars Compacta ◽  
Endogenous Protein ◽  
Highly Sensitive ◽  
Brain Material ◽  
Health And Disease ◽  
Isoform B

Background: α-synuclein (α-syn) aggregation contributes to the progression of multiple neurodegenerative diseases. We recently found that the isoform b of the co-chaperone DNAJB6 is a strong suppressor of a-syn aggregation in vivo and in vitro. However, nothing is known about the role of the endogenous isoform b of DNAJB6 (DNAJB6b) in health and disease, due to lack of specific antibodies. Objective: Here we generated a novel anti-DNAJB6b antibody to analyze the localization and expression this isoform in cells, in tissue and in clinical material. Methods: To address this we used immunocytochemistry, immunohistochemistry, as well as a novel quantitative DNAJB6 specific ELISA method. Results: The endogenous protein is mainly expressed in the cytoplasm and in neurites in vitro, where it is found more in dendrites than in axons. We further verified in vivo that DNAJB6b is expressed in the dopaminergic neurons of the substantia nigra pars compacta (SNpc), which is a neuronal subpopulation highly sensitive to α-syn aggregation, that degenerate to a large extend in patients with Parkinson’s disease (PD) and multiple system atrophy (MSA). When we analyzed the expression levels of DNAJB6b in brain material from PD and MSA patients, we found a downregulation of DNAJB6b by use of ELISA based quantification. Interestingly, this was also true when analyzing tissue from patients with progressive supranuclear palsy, a taupathic atypical parkinsonian disorder. However, the total level of DNAJB6 was upregulated in these three diseases, which may indicate an upregulation of the other major isoform of DNAJB6, DNAJB6a. Conclusion: This study shows that DNAJB6b is downregulated in several different neurodegenerative diseases, which makes it an interesting target to further investigate in relation to amyloid protein aggregation and disease progression.

scholarly journals B-1 cell: the precursor of a novel mononuclear phagocyte with immuno-regulatory properties

2009 ◽  
Vol 81 (3) ◽  
pp. 489-496 ◽  
Author(s):  
José Daniel Lopes ◽  
Mario Mariano
Keyword(s):  
Mammalian Cells ◽  
Giant Cells ◽  
Mononuclear Phagocyte ◽  
Different Types ◽  
Series Of Experiments ◽  
B1 Cells ◽  
Regulatory Properties

Characterization of the origin, properties, functions and fate of cells is a fundamental task for the understanding of physiological and pathological phenomena. Despite the bulk of knowledge concerning the diverse characteristics of mammalian cells, some of them, such as B-1 cells, are still poorly understood. Here we report the results obtained in our laboratory on these cells in the last 10 years. After showing that B-1 cells could be cultured and amplified in vitro, a series of experiments were performed with these cells. They showed that B1 cells reside mostly in the peritoneal and pleural cavities, migrate to distant inflammatory foci, coalesce to form giant cells and participate in granuloma formation, both in vitro and in vivo. They are also able to present antigens to immunologically responsive cells and are endowed with regulatory properties. Further, we have also shown that these cells facilitate different types of infection as well as tumor growth and spreading. These data are presently reviewed pointing to a pivotal role that these cells may play in innate and acquired immunity.

scholarly journals Clearance and binding of native and defucosylated lactoferrin

1983 ◽  
Vol 212 (2) ◽  
pp. 249-257 ◽  
Author(s):  
M J Imber ◽  
S V Pizzo
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Specific Binding ◽  
Gel Filtration ◽  
Peritoneal Macrophages ◽  
Mononuclear Phagocyte ◽  
Stable Complex

These studies explore the role of carbohydrate recognition systems and the direct involvement of terminal alpha 1-3-linked fucose in the clearance of lactoferrin from the murine circulation and in the specific binding of lactoferrin to receptors on murine peritoneal macrophages. As previously reported, radiolabelled lactoferrin cleared very rapidly (t1/2 less than 1 min) after intravenous injection into mice. However, competing levels of ligands specific for the hepatic galactose receptor (asialo-orosomucoid), the hepatic fucose receptor (fucosyl-bovine serum albumin), and the mononuclear-phagocyte system pathway recognizing mannose, N-acetylglucosamine and fucose (mannosyl-, N-acetylglucosaminyl- and fucosyl-bovine serum albumin) did not block radiolabelled lactoferrin clearance in vivo or binding to mouse peritoneal macrophage monolayers in vitro. Almond emulsin alpha 1-3-fucosidase was used to prepare defucosylated lactoferrin in which 88% of the alpha 1-3-linked fucose was hydrolysed. No difference in clearance or receptor binding was observed between radiolabelled native and defucosylated lactoferrin. Fucoidin, a fucose-rich algal polysaccharide, completely inhibits the clearance in vivo and macrophage binding in vitro of lactoferrin. This effect, however, is probably not the result of competition for binding to the fucose receptor, since gel-filtration studies demonstrated formation of a stable complex between lactoferrin and fucoidin. The present results indicate that the lactoferrin-clearance pathway is distinct from several pathways mediating glycoprotein clearance through recognition of terminal galactose, fucose, N-acetylglucosamine or mannose. Furthermore, alpha 1-3-linked fucose on lactoferrin is not essential for lactoferrin clearance in vivo or specific binding to macrophage receptors in vitro.

STATEMENT BY COMMITTEE ON FETUS AND NEWBORN

PEDIATRICS ◽  
1961 ◽  
Vol 28 (4) ◽  
pp. 678-678
Author(s):  
Keyword(s):  
Dose Response ◽  
Animal Species ◽  
Older Children ◽  
Human Species ◽  
Basic Premise ◽  
Newborn Animal ◽  
Physical Size ◽  
Human Adults

IT IS A BASIC PREMISE of pediatrics that physical size is not the most important difference between children and adults. There is increasing awareness that it is also necessary to make more than a quantitative distinction between infants and children. The fetus and the newborn infant often behave so differently as to warrant consideration as separate categories of the human species. This necessitates re-evaluation of the effects of drugs independently in each category of the human so that they may be used safely. Existing drugs and agents that are developed in the future for use in the fetus and in infants must be subjected to more extensive preclinical investigation than is being carried out at the present time. The pharmacologic responses of the immature human may differ greatly both quantitatively and qualitatively from those of the adult. As a result, data obtained from tests in mature animals and human adults or older children cannot be accepted as a satisfactory basis for recommendations concerning the fetus and infant. The pharmacologic properties of drugs should be studied in vitro and in vivo in the fetus and newborn animal and compared with those in the adult of the same animal species. Of particular importance would be a knowledge of the LD50, dose response, metabolism, and distribution and disposition of the drug.

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