Attachment of the flagellate Giardia lamblia: role of reducing agents, serum, temperature, and ionic composition

1982 ◽  
Vol 2 (4) ◽  
pp. 369-377
Author(s):  
F D Gillin ◽  
D S Reiner
Keyword(s):  
Sodium Chloride ◽  
Ionic Strength ◽  
Oxygen Tension ◽  
Giardia Lamblia ◽  
Bovine Serum ◽  
Ionic Composition ◽  
Short Term ◽  
Reduced Temperature

The flagellated protozoan Giardia lamblia has been grown only in highly complex media under reduced oxygen tension. Therefore, the organic and physiological requirements for in vitro attachment and short-term (12-h) survival of this organism were determined. In defined maintenance media, a thiol reducing agent (e.g., cysteine) was absolutely required for attachment and survival of this aerotolerant anaerobe. The crude bovine serum Cohn III fraction greatly stimulated attachment and survival. Attachment was decreased at a reduced temperature (24 degrees C as compared with 35.5 degrees C) and absent at 12 degrees C or below. Attachment and survival were strongly dependent upon pH and ionic strength, with optima at pH 6.85 to 7.0 and 200 to 300 mosmol/kg. Sodium chloride was better tolerated than KC1. Reduction of Ca2+ and Mg2+ to below 10(-8) M did not significantly affect attachment.

scholarly journals Attachment of the flagellate Giardia lamblia: role of reducing agents, serum, temperature, and ionic composition.

1982 ◽  
Vol 2 (4) ◽  
pp. 369-377 ◽  
Author(s):  
F D Gillin ◽  
D S Reiner
Keyword(s):  
Sodium Chloride ◽  
Ionic Strength ◽  
Oxygen Tension ◽  
Giardia Lamblia ◽  
Bovine Serum ◽  
Ionic Composition ◽  
Short Term ◽  
Reduced Temperature

The flagellated protozoan Giardia lamblia has been grown only in highly complex media under reduced oxygen tension. Therefore, the organic and physiological requirements for in vitro attachment and short-term (12-h) survival of this organism were determined. In defined maintenance media, a thiol reducing agent (e.g., cysteine) was absolutely required for attachment and survival of this aerotolerant anaerobe. The crude bovine serum Cohn III fraction greatly stimulated attachment and survival. Attachment was decreased at a reduced temperature (24 degrees C as compared with 35.5 degrees C) and absent at 12 degrees C or below. Attachment and survival were strongly dependent upon pH and ionic strength, with optima at pH 6.85 to 7.0 and 200 to 300 mosmol/kg. Sodium chloride was better tolerated than KC1. Reduction of Ca2+ and Mg2+ to below 10(-8) M did not significantly affect attachment.

scholarly journals Stimulatory Role of Glycated Fetal Bovine Serum Along with Iron on In Vitro Production of Insulin by Differentiated Mouse Embryonic Stem Cells

2011 ◽  
Vol 57 (4) ◽  
pp. 356-361
Author(s):  
Ikuo Nishigaki ◽  
Gowri Rangasamy Gunassekaran ◽  
Panjan Nagappan Venkatesan ◽  
Mandupal Chaco Sabu ◽  
Sabu Priya ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Bovine Serum ◽  
Fetal Bovine Serum ◽  
Embryonic Stem ◽  
In Vitro Production ◽  
Fetal Bovine ◽  
Vitro Production

Adaptation to calcium deprivation in the rat: effects of parathyroidectomy.

1977 ◽  
Vol 232 (3) ◽  
pp. E336
Author(s):  
J T Pento ◽  
L C Waite ◽  
P J Tracy ◽  
A D Kenny
Keyword(s):  
Adaptive Response ◽  
Calcium Transport ◽  
Parathyroid Tissue ◽  
Adaptation Period ◽  
Short Term ◽  
High Calcium

The role of parathyroid hormone (PTH) in the adaptive response in gut calcium transport to calcium deprivation has been studied in the rat using both the in vitro everted duodenal sac and the in situ ligated duodenal segment technique. Intact or parathyroidectomized (PTX) young rats were placed on a low calcium (0.01%) diet for 7-, 14-, or 21-day adaptation periods and compared with control rats maintained on a high calcium (1.5%) diet. Prior PTX (3 days before the start of the adaptation period) abolished the adaptive response (enhanced calcium transport) induced by calcium deprivation for a 7-day adaptation period, but did not abolish a response after a 21-day period. A 14-day adaptation period gave equivocal results. It is concluded that PTH appears to be necessary for short-term (7-day) adaptation, but not for long-term (21-day) adaptation to calcium deprivation. However, if accessory parathyroid tissue is present, the data could be interpreted differently: the essentiality of PTH for the adaptive response might be independent of the length of the adaptation period. The data also contribute to a possible resolution of the controversy concerning the involvement of PTH in the regulation of intestinal calcium transport in the rat.

scholarly journals Triggering DTH and CTL Activity by fd Filamentous Bacteriophages: Role of CD4+ T Cells in Memory Responses

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Giovanna Del Pozzo ◽  
Dina Mascolo ◽  
Rossella Sartorius ◽  
Alessandra Citro ◽  
Pasquale Barba ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Long Term Memory ◽  
Short Term ◽  
Filamentous Bacteriophages ◽  
Ctl Responses

The ability of fd bacteriophage particles to trigger different arms of the immune system has been previously shown by us with particular emphasis on the ability of phages to raise CTL responses in vitro and in vivo. Here we show that fd virions in the absence of adjuvants are able to evoke a DTH reaction mediated by antigen specific CD8+ T cells. In addition, we analyzed the induction of CTL responses in mice depleted of CD4+ T cells, and we observed that short-term secondary CTL responses were induced in the absence of CD4+ T cells while induction of long-term memory CTLs required the presence of CD4+ T lymphocytes. These results examine the cellular mechanism at the basis of fd efficiency and provide new elements to further validate the use of fd particles for eliciting and monitoring antigen-specific CTLs.

scholarly journals Activity of ketoconazole against Mycobacterium tuberculosis in vitro and in the mouse model

2007 ◽  
Vol 56 (8) ◽  
pp. 1047-1051 ◽  
Author(s):  
Sean T. Byrne ◽  
Steven M. Denkin ◽  
Peihua Gu ◽  
Eric Nuermberger ◽  
Ying Zhang
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Term Treatment ◽  
New Drugs ◽  
Bacteriostatic Effect ◽  
Short Term ◽  
Short Term Treatment ◽  
Neutral Conditions

There is an urgent need for the development of new drugs that are active against drug-resistant Mycobacterium tuberculosis strains and can shorten tuberculosis (TB) therapy. It has previously been reported that the azole class of antifungals has anti-TB activity in vitro. This study evaluated ketoconazole (KTC) for activity against M. tuberculosis. The MIC of KTC for different M. tuberculosis strains ranged from 8 to 16 μg ml−1 under both acidic and neutral conditions, with the minimum bactericidal concentration being about twofold higher than the MIC. KTC had enhanced activity against old, non-growing bacilli in vitro when combined with pyrazinamide (PZA) and rifampicin (RIF). A single oral dose of KTC at 75 mg kg−1 led to an inhibitory serum concentration 2 h after administration. The in vivo activity of KTC was evaluated in established pulmonary TB in the murine model, compared alone and in combination with isoniazid (INH), PZA and RIF. KTC alone exhibited little effect after short-term treatment, with a borderline bacteriostatic effect on spleen colony counts but not on lung counts. KTC, when added in combination with INH, PZA and RIF, significantly improved the treatment outcome in the lungs (compared with treatment with INH, PZA and RIF). The lowest numbers of bacilli in lungs were found in mice treated with KTC, PZA and RIF. Further investigation is necessary to determine the role of KTC in the treatment of TB.

The in vitro perifused rat ovary: II. Role of oxygen tension in the whole and quartered ovary

1992 ◽  
Vol 6 (4) ◽  
pp. 239-245 ◽  
Author(s):  
T. Soendoro ◽  
M. P. Diamond ◽  
J. R. Pepperell ◽  
F. Nafiolin
Keyword(s):  
Oxygen Tension ◽  
Rat Ovary

scholarly journals Control of neurotransmitter release by two distinctmembrane-binding faces of the Munc13-1 C­1C2B region

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Marcial Camacho ◽  
Bradley Quade ◽  
Thorsten Trimbuch ◽  
Junjie Xu ◽  
Levent Sari ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Point Mutations ◽  
Short Term ◽  
In Vitro Reconstitution ◽  
Presynaptic Plasticity ◽  
Hippocampal Cultures

Munc13-1 plays a central role in neurotransmitter release through its conserved C-terminal region, which includes a diacyglycerol (DAG)-binding C1 domain, a Ca2+/PIP2-binding C2B domain, a MUN domain and a C2C domain. Munc13-1 was proposed to bridge synaptic vesicles to the plasma membrane through distinct interactions of the C­1C2B region with the plasma membrane: i) one involving a polybasic face that is expected to yield a perpendicular orientation of Munc13-1 and hinder release; and ii) another involving the DAG-Ca2+-PIP2-binding face that is predicted to result in a slanted orientation and facilitate release. Here we have tested this model and investigated the role of the C­1C2B region in neurotransmitter release. We find that K603E or R769E point mutations in the polybasic face severely impair Ca2+-independent liposome bridging and fusion in in vitro reconstitution assays, and synaptic vesicle priming in primary murine hippocampal cultures. A K720E mutation in the polybasic face and a K706E mutation in the C2B domain Ca2+-binding loops have milder effects in reconstitution assays and do not affect vesicle priming, but enhance or impair Ca2+-evoked release, respectively. The phenotypes caused by combining these mutations are dominated by the K603E and R769E mutations. Our results show that the C1-C2B region of Munc13-1 plays a central role in vesicle priming and support the notion that two distinct faces of this region control neurotransmitter release and short-term presynaptic plasticity.

scholarly journals Role of ClC-K and barttin in low potassium-induced sodium chloride cotransporter activation and hypertension in mouse kidney

2018 ◽  
Vol 38 (1) ◽  
Author(s):  
Naohiro Nomura ◽  
Wakana Shoda ◽  
Yuanlong Wang ◽  
Shintaro Mandai ◽  
Taisuke Furusho ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sodium Chloride ◽  
Ex Vivo ◽  
Extracellular Potassium ◽  
Sodium Chloride Cotransporter ◽  
Low Potassium ◽  
Wnk Kinases

The sodium chloride cotransporter (NCC) has been identified as a key molecule regulating potassium balance. The mechanisms of NCC regulation during low extracellular potassium concentrations have been studied in vitro. These studies have shown that hyperpolarization increased chloride efflux, leading to the activation of chloride-sensitive with-no-lysine kinase (WNK) kinases and their downstream molecules, including STE20/SPS1-related proline/alanine-rich kinase (SPAK) and NCC. However, this mechanism was not studied in vivo. Previously, we developed the barttin hypomorphic mouse (Bsndneo/neo mice), expressing very low levels of barttin and ClC-K channels, because barttin is an essential β-subunit of ClC-K. In contrast with Bsnd−/− mice, Bsndneo/neo mice survived to adulthood. In Bsndneo/neo mice, SPAK and NCC activation after consuming a low-potassium diet was clearly impaired compared with that in wild-type (WT) mice. In ex vivo kidney slice experiment, the increase in pNCC and SPAK in low-potassium medium was also impaired in Bsndneo/neo mice. Furthermore, increased blood pressure was observed in WT mice fed a high-salt and low-potassium diet, which was not evident in Bsndneo/neo mice. Thus, our study provides in vivo evidence that, in response to a low-potassium diet, ClC-K and barttin play important roles in the activation of the WNK4-SPAK-NCC cascade and blood pressure regulation.

ROLE OF TAMM-HORSFALL PROTEIN (THP) IN LITHOGENIC PROCESS : ANIMAL STUDIES

2019 ◽  
pp. 1-2
Author(s):  
Varsha Choudhary
Keyword(s):  
Ionic Strength ◽  
Guinea Pigs ◽  
Animal Studies ◽  
Dual Role ◽  
Urinary Oxalate ◽  
Crystal Aggregation ◽  
Physico Chemical ◽  
Low Ionic Strength

One of the defenses against nephrolithiasis is provided by macromolecules that modulate the nucleation, growth, aggregation and retention of crystals in the kidneys.According to its well-known physico-chemical properties.THP has a dual role in modifying crystal aggregation: at high pH and low ionic strength (IS),THP is a powerful crystal aggregation inhibitor.Upon lowering pH and rasing ionic strength THP viscosity increases,leading to reduced crystal aggregation inhibition.For this purpose eight guinea pigs were made hyperoxaluric.The treatment was given for fifteen days;then urine samples were collected before treatment ;then on 5,10,15and 25 day( after treatment) and in vitro addition of THP on 30th day which was isolated from hyperoxaluric and normal animals.The effect of EG+GM on urinary oxalate,THP and TBAR levels increases but after treatment the urine chemistry revert to normal profile,though plasma TBAR levels were appreciably high.The crystallization of calcium was almost double when THP was isolated from hyperoxaluric animals rather than normals.Our study suggested that THP act as a promoter

Pseudobase formation in 2-methylpapaverinium cations and their biotransformation by enzymes of rat liver homogenates in vitro

1980 ◽  
Vol 45 (3) ◽  
pp. 956-965 ◽  
Author(s):  
Daniela Walterová ◽  
Vladimír Preininger ◽  
Ladislav Dolejš ◽  
František Grambal ◽  
Miroslav Kyselý ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Aqueous Medium ◽  
Rat Liver ◽  
Carbonyl Compounds ◽  
Liver Enzymes ◽  
Aqueous Ethanol ◽  
Equilibrium Constants ◽  
Liver Homogenates

2-Methylpapaverinium iodide (I), 2'-hydroxymethyl-2-methylpapaverinium iodide (IX), and 2-methyl-3,4-dihydropapaverinium iodide (X. CH3I) form pseudobase by addition of hydroxide ions to the C(1)=N(+) bond. 2'-Hydroxymethyl-2-methyl-3,4-dihydropapaverinium iodide (XV) and 2'-hydroxymethyl-2-methyl-9-oxo-3,4-dihydropapaverinium iodide (XVI) react with hydroxide ions in aqueous medium under formation of cyclic pseudobases XVII and XVIII. The equilibrium constants (KR+) of pseudobase formation have been measured in aqueous ethanol (1 : 1 w/w, 25°C, ionic strength 0.1). The quaternary papaverinium derivatives are metabolized to isoquinilones and carbonyl compounds by means of rat liver enzymes. The role of pseudobases in these biotransformations has been discussed and biogenetic conclusions have been drawn.

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