scholarly journals THE IN VITRO DIFFERENTIATION OF MONONUCLEAR PHAGOCYTES

1965 ◽  
Vol 121 (5) ◽  
pp. 835-848 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Belinda Benson
Keyword(s):  
Acid Phosphatase ◽  
Serum Concentration ◽  
Hydrolytic Enzyme ◽  
Calf Serum ◽  
Hydrolytic Enzymes ◽  
Biochemical Properties ◽  
Mononuclear Phagocytes ◽  
Rabbit Serum ◽  
Granule Formation

The concentration of newborn calf serum in the medium has marked effects on the morphological and biochemical properties of mouse mononuclear phagocytes. At a low serum concentration, the cells developed small numbers of tiny cytoplasmic granules and little or no increase in acid phosphatase, cathepsin, and ß-glucuronidase. As the serum concentration was raised, granules were formed at a more rapid rate and were larger in size. The rate of production and total amount of three hydrolytic enzymes was increased at higher levels of serum. Observations on living cells indicated that the phase-dense granules which accumulated in the perinuclear region were derived from pinocytic vesicles. These clear vesicles fused and migrated to the centrosphere where they underwent a gradual increase in phase density and reacted positively for acid phosphatase. A microscopic technique was described for the evaluation of the pinocytic process. When this method was employed, the rate of pinocytosis increased curvilinearly with elevations in the calf serum concentration of the medium. The comparative influence of bovine, horse, and rabbit serum on mouse cells was evaluated. It is suggested that pinocytosis is a major regulator of granule formation and hydrolytic enzyme production by the mouse macrophage.

scholarly journals THE PARTICULATE HYDROLASES OF MACROPHAGES

1963 ◽  
Vol 118 (6) ◽  
pp. 1009-1020 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Edith Wiener
Keyword(s):  
Acid Phosphatase ◽  
Yeast Cell ◽  
Cell Walls ◽  
Hydrolytic Enzymes ◽  
Neutral Red ◽  
Biochemical Properties ◽  
Extracellular Medium ◽  
Cell Content ◽  
Prolonged Incubation

The influence of phagocytosis on the morphological and biochemical properties of macrophage hydrolase-containing granules has been studied in vitro. Following the uptake of large numbers of heat-killed bacteria, an intracellular rearrangement of hydrolytic enzymes occurred. This was associated with the solubilization of 50 to 60 per cent of the total cell content of acid phosphatase, cathepsin, lysozyme, beta glucuronidase, acid ribonuclease, and acid desoxyribonuclease and with a corresponding decrease in granule-bound enzyme. With more prolonged incubation the majority of the soluble intracellular pool of acid ribonuclease and lysozyme was lost to the extracellular medium. No change in the total content of any of the hydrolases was noted during 180 minutes of incubation in vitro. The morphological fate of the granules was studied by a histochemical method for acid phosphatase. After the phagocytosis of yeast cell walls there was a disappearance of acid phosphatase-positive granules and an accumulation of reaction product about the ingested particle. Experiments employing macrophages which were supravitally stained with neutral red also demonstrated the loss of neutral red-positive granules and the accumulation of the dye about the yeast cell walls. These results strongly suggest that lysis of macrophage granules occurs following phagocytosis and that a portion of the granule contents are then resegregated within the newly formed phagocytic vacuole.

scholarly journals THE IN VITRO DIFFERENTIATION OF MONONUCLEAR PHAGOCYTES

1965 ◽  
Vol 122 (3) ◽  
pp. 455-466 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Belinda Benson
Keyword(s):  
Washout Period ◽  
Serum Proteins ◽  
Calf Serum ◽  
Hydrolytic Enzymes ◽  
Mononuclear Phagocytes ◽  
Cell Protein ◽  
Newborn Calf Serum ◽  
Extracellular Medium ◽  
Dense Granules

Mouse mononuclear phagocytes cultivated in 50 per cent newborn calf serum medium pinocytize actively and form large numbers of phase-dense granules as well as three hydrolytic enzymes. When such cells are then placed in 1 per cent newborn calf serum they illustrate (a) a low level of pinocytic activity, (b) a shrinkage in granule size, and (c) a loss in cell protein, acid phosphatase, ß-glucuronidase, and cathepsin. Examination of the extracellular medium revealed no detectable hydrolase activity. The reintroduction of cells into high levels of serum again resulted in granule and enzyme formation. Cells rapidly incorporated fluorescein-conjugated calf serum proteins into the phase-dense granules. The fluorescence of labeled granules was lost during an 18 hour period in non-fluorescein-containing medium. Crystalline egg white lysozyme was concentrated in the macrophages. Approximately 80 per cent of the cell-associated enzyme was lost during a 24 hour washout period in either 1 or 50 per cent serum medium. No enzymatic activity could be recovered in the medium. Colloidal gold was taken up and concentrated in macrophage granules. Quantitative assays revealed this particle to be conserved during a 24 hour washout period.

scholarly journals CHANGES IN "DROPLET" FRACTIONS FROM RAT KIDNEY CELLS AFTER INTRAPERITONEAL INJECTION OF EGG WHITE

1957 ◽  
Vol 3 (6) ◽  
pp. 933-947 ◽  
Author(s):  
Werner Straus
Keyword(s):  
Acid Phosphatase ◽  
Intraperitoneal Injection ◽  
Rat Kidney ◽  
Hydrolytic Enzymes ◽  
Bottom Layer ◽  
Egg White ◽  
Supernatant Fluid ◽  
Enzyme Content ◽  
Osmotic Effects

1. Kidney homogenates from rats injected with egg white and from control rats were fractionated simultaneously into six fractions and the content of acid phosphatase, ribonuclease, desoxyribonuclease, cathepsin, and ß-glucuronidase in corresponding fractions from treated and untreated animals was compared. These observations were correlated with the amount of dark brown bottom sediments in fractions NDrI, DrII, and DrIII, and with the number of droplets in fraction NDrI. 2. It was found that after injection of egg white the amount of small droplets decreased as indicated by the decrease of the dark brown bottom layer in the sediment of fraction DrIII and by the concomitant decrease of hydrolytic enzymes in the same fraction, and that the number of large droplets increased as indicated by the increase of brown sediment in fraction NDrI and the increase in the number of droplets counted in a bacterial counting chamber in the same fraction. It was concluded that the treatment with egg white induced the transformation of small droplets into large droplets. 3. The decrease of hydrolytic enzymes in the fractions containing the small droplets was accompanied by a marked increase of these enzymes in the supernatant fluid. The enzyme content of fraction NDrI was not increased after treatment, although it contained greatly increased numbers of large droplets. Counting of the droplets in this fraction showed decreased enzymatic activity of the average large droplet after treatment with egg white. It was suggested that during the transformation of small into large droplets, a portion of the hydrolytic enzymes was released into the surrounding cytoplasm, and that this was partly responsible for the increased enzyme content of the supernatant fluid after fractionation of the kidney homogenate. In contrast to the four other hydrolytic enzymes, ß-glucuronidase was not increased in the supernatant fluid. 4. Eighteen hours after intraperitoneal injection of egg white, the specific enzymatic activities of kidney homogenates showed a 25 to 35 per cent increase for cathepsin, ribonuclease, and desoxyribonuclease, no change for acid phosphatase and ß-glucuronidase, and approximately a 7 per cent decrease for cytochrome oxidase. The increase of cathepsin, ribonuclease, and desoxyribonuclease in the total homogenate was interpreted as an indication of the formation of new enzymes, and it was suggested that this partly accounted for the increase of these enzymes in the supernatant fluid. 5. The activation of the enzymes by osmotic effects was investigated in vitro by incubation of droplet fractions in the presence of different concentrations of sucrose.

scholarly journals THE ORIGIN AND KINETICS OF MONONUCLEAR PHAGOCYTES

1968 ◽  
Vol 128 (3) ◽  
pp. 415-435 ◽  
Author(s):  
Ralph van Furth ◽  
Zanvil A. Cohn
Keyword(s):  
Bone Marrow ◽  
Steady State ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Calf Serum ◽  
Peritoneal Macrophages ◽  
Mononuclear Phagocytes ◽  
Sterile Inflammation

The origin and turnover of efferent populations of mouse mononuclear phagocytes has been described. Mononuclear phagocytes were defined as mononuclear cells which are able to adhere to glass and phagocytize. In vitro labeling studies with thymidine-3H showed that monocytes in the peripheral blood and peritoneal macrophages do not multiply and can be considered end cells in a normal, steady state situation. However, the mononuclear phagocytes of the bone marrow appear to be rapidly dividing cells. This conclusion was supported by in vivo labeling experiments. A peak of labeled mononuclear phagocytes of the bone marrow was found 24 hr after a pulse of thymidine-3H. This was followed, 24 hr later, by a peak of labeled monocytes in the peripheral blood. From these experiments it was concluded that the rapidly dividing mononuclear phagocytes of the bone marrow, called promonocytes, are the progenitor cells of the monocytes. Labeling studies after splenectomy and after X-irradiation excluded other organs as a major source of the monocytes. Peak labeling of both the blood monocyte and peritoneal macrophages occurred at the same time. A rapid entry of monocytes from the blood into the peritoneal cavity was observed, after a sterile inflammation was evoked by an injection of newborn calf serum. These data have led to the conclusion that monocytes give rise to peritoneal macrophages. No indications have been obtained that mononuclear phagocytes originate from lymphocytes. In the normal steady state the monocytes leave the circulation by a random process, with a half-time of 22 hr. The average blood transit time of the monocytes has been calculated to be 32 hr. The turnover rate of peritoneal macrophages was low and estimated at about 0.1% per hour. On the basis of these studies the life history of mouse mononuclear phagocytes was formulated to be: promonocytes in the bone marrow, → monocytes in the peripheral blood, → macrophages in the tissue.

Water availability affects extracellular hydrolytic enzyme production by Aspergillus flavus and Aspergillus parasiticus

2009 ◽  
Vol 2 (3) ◽  
pp. 313-322 ◽  
Author(s):  
S. Alam ◽  
H. Shah ◽  
N. Magan
Keyword(s):  
Acid Phosphatase ◽  
Aspergillus Flavus ◽  
Enzyme Production ◽  
Specific Activity ◽  
Hydrolytic Enzyme ◽  
Hydrolytic Enzymes ◽  
Aflatoxin Production ◽  
Initial Growth ◽  
Wide Range ◽  
Microtitre Plate Assay

The objectives of this study were to examine the effect of different water activities (aw; 0.99, 0.96 and 0.94) and time (up to 120 h) on quantitative and specific enzyme production during germination and initial growth of Aspergillus flavus and A. parasiticus strains at 25 °C. This is an important early indicator of potential for aflatoxin production under conducive conditions. Qualitative API ZYM generic enzyme strips were used to identify key hydrolytic enzymes produced. Subsequently, the temporal effects of aw on the total/specific activity of the key 4-5 hydrolytic enzymes were determined using 4-nitrophenyl substrates in a 96-well microtitre plate assay. The main enzymes produced by germinating conidia of A. flavus were esterase, lipase, acid phosphatase, β-glucosidase and N-acetyl-β-D-glucosaminidase, while for A. parasiticus these were alkaline phosphatase, lipase, acid phosphatase and β-fucosidase for both total (µmol 4-nitrophenol/min/g) and specific activity (nmol 4-nitrophenol/min/µg protein). There were significant increases in the specific activity of all these enzymes of germinating spores of A. flavus (0-120 h) except for β-glucosidase which was maximum at 72 h. The total/specific activities of the enzymes produced by A. flavus were maximum at 0.99 aw, with the exception of acid phosphatase and N-acetyl-β-D-glucosaminidase at 0.94 aw. For A. parasiticus, maximum total activity occurred at 0.99 aw for fucosidase activity, while specific activity was found to be higher at lower aw levels. These enzymes are important in early colonisation of food matrices by these species and single factors (aw, time) and two-way interactions were all statistically significant for the enzymes assayed for both species. These enzymes could be used as an early and rapid indicator of the activity of Aspergillus section flavi species and suggests that rapid infection may occur over a wide range of aw conditions.

QUANTITATIVE STUDIES OF HYDROLYTIC ENZYME ACTIVITY IN THE SALIVARY GLAND OF CHIRONOMUS TENTANS (DIPTERA: CHIRONOMIDAE) DURING METAMORPHOSIS

1971 ◽  
Vol 103 (3) ◽  
pp. 454-457 ◽  
Author(s):  
Hans Laufer ◽  
Ki Ssu Schin
Keyword(s):  
Enzyme Activity ◽  
Salivary Gland ◽  
Acid Phosphatase ◽  
Protein Content ◽  
Lysosomal Enzymes ◽  
Specific Activity ◽  
Hydrolytic Enzyme ◽  
Hydrolytic Enzymes ◽  
Chironomus Tentans ◽  
Quantitative Studies

AbstractChanges in the hydrolytic enzymes, ribonuclease and acid phosphatase were investigated in the salivary gland of Chironomus tentans since these lysosomal enzymes may participate in hormonally stimulated tissue breakdown. Quantitative assays revealed 9- and 12-fold increases in the specific activity of these enzymes during pupation while the protein content of the gland was decreasing. These increases cannot be accounted for by decreased protein but may represent an activation, accumulation, or synthesis which seems to be important in gland breakdown at metamorphosis.

scholarly journals THE DIFFERENTIATION OF MONONUCLEAR PHAGOCYTES

1965 ◽  
Vol 121 (1) ◽  
pp. 153-170 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Belinda Benson
Keyword(s):  
Acid Phosphatase ◽  
Specific Activity ◽  
Total Content ◽  
Progressive Increase ◽  
Neutral Red ◽  
Mononuclear Phagocytes ◽  
In Vitro Differentiation ◽  
Dense Granules

The in vitro differentiation of homogeneous populations of monocyte-like cells from the unstimulated mouse peritoneal cavity is described. Under the conditions employed, a progressive increase in cell size occurs without significant cell division. This process is characterized morphologically by the accumulation of phase-dense and neutral red-positive granules, mitochondria, and lipid droplets. The phase-dense granules react strongly for acid phosphatase. Biochemical determinations indicate marked increases in the total content and specific activity of acid phosphatase, cathepsin, and ß-glucuronidase. The production of acid phosphatase is more rapid and extensive than that of the other two hydrolases. From these data it appears that the conversion of a monocyte-like cell to a mature macrophage is accompanied by the formation of increased numbers of lysosome-like cytoplasmic organelles. Mouse peritoneal phagocytes stimulated in vivo with a bacterial lipopolysaccharide undergo a similar series of morphological and biochemical events.

Ultrastructural Changes in Tumor Cells During Human Peripheral Blood Monocyte-Mediated Cytotoxicity

1981 ◽  
Vol 39 ◽  
pp. 452-453
Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren
Keyword(s):  
Target Cell ◽  
Human Peripheral Blood ◽  
Mononuclear Phagocytes ◽  
Ultrastructural Changes ◽  
Target Cells ◽  
Limited Information ◽  
Blood Monocytes ◽  
Tumoricidal Activity ◽  
Activated State

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.

In-Vitro Effects of Ricinus Communis Seed Kernel Extract On Some Antioxidant And Hydrolytic Enzymes In Nymph And Adult Zonocerus Variegatus (Grasshopper)

2019 ◽  
Vol 3 (1) ◽  
pp. 129-137
Author(s):  
Gbadebo E . Adeleke ◽  
Olaniyi T. Adedosu ◽  
Rachael O. Adeyi ◽  
John O. Fatoki
Keyword(s):  
Ricinus Communis ◽  
Hydrolytic Enzymes ◽  
Crude Enzyme ◽  
Economic Losses ◽  
Seed Kernel ◽  
Zonocerus Variegatus ◽  
Sod Activity ◽  
Enzyme Preparations ◽  
In Vitro Effects

Background: Many plants have been identified for their insecticidal properties as alternatives to synthetic ones, which are toxic to untargeted organisms and environment. Ricinus communis (Castor) has been re-ported to exhibit insecticidal properties against insect pests. Zonocerus variegatus (Grasshopper) is a notable pest of several crops, and has been linked with great economic losses to farmers. The present study investigates the in-vitro toxicity of R. communis seed kernel extract (RCSKE) on the activities of selected antioxidant and hydrolytic enzymes in nymph and adult Zonocerus variegatus (Grasshopper), using cypermethrin (CYPER-M) and chlorpyrifos (CPF) as standard conventional pesticides. Methods: Seed kernel of Ricinus communis (Castor) was subjected to acidified aqueous extraction to obtain the extract (RCSKE). Crude enzyme preparations were obtained from nymph and adult Z. variegatus grass-hoppers. The in-vitro effects of different concentrations (15, 30, 45, 60, 75, 90 and 105μg/ml) each of RCSKE, CYPER-M and CPF on the activities of superoxide dismutase (SOD), catalase (CAT), acetylcholinesterase (AChE) and carboxylesterase (CES) in crude enzyme preparations were estimated spectrophotometrically. The level of statistical significance was 0.05. Results: The RCSKE significantly reduced the in-vitro SOD activity (p < 0.05) in nymph Z. variegatus at all the concentrations, whereas both CYPER-M and CPF significantly reduced the activity only at certain concentrations. The CAT activity in the nymph was significantly decreased by RCSKE and CPF at all the concentrations, but CYPER-M decreased it only at certain concentrations. In adult Z. variegatus, SOD activity was not significantly affected (p > 0.05), while CAT activity was significantly increased (p < 0.05) by the three agents at all the concentrations. The AChE and CES activities in the nymph were significantly reduced by RCSKE, CYPER-M and CPF at all the concentrations. The RCSKE and CPF significantly increased the CES activity, while CYPER-M caused a significant decrease in the activity in adult Z. variegatus. Conclusion: The seed kernel extract of Ricinus communis is an effective pesticidal agent and hence, it could be a source of biopesticide alternative with greater potential than cypermethrin and chlorpyrifos. In addition, the antioxidant, acetylcholinesterase and carboxylesterase enzymes in the nymphs of Z. variegatus grasshoppers are more susceptible to the effect of the extract than in the adult grasshoppers.

Antifungal Proteins from Plant Latex

2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  
Keyword(s):  
Cell Walls ◽  
Defense Mechanisms ◽  
Hydrolytic Enzymes ◽  
Fungal Species ◽  
Biologically Active ◽  
Protein Classification ◽  
Fungal Cell ◽  
Antifungal Proteins ◽  
Plant Latex

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

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