The effect of gonadotropins on the in vitro growth of the free-living nematode Cephalobus sp. Bastian

1971 ◽  
Vol 49 (7) ◽  
pp. 1059-1061 ◽  
Author(s):  
Cyril H. S. Thong ◽  
John M. Webster
Keyword(s):  
In Vitro Growth ◽  
Environmental Condition ◽  
Stress Reactions ◽  
Free Living ◽  
Rate Of Development ◽  
Free Living Nematode ◽  
The Mean ◽  
Gravid Females ◽  
As Stress

Cephalobus sp. was exposed to four concentrations of testosterone and oestradiol in an in vitro culture. The rate of development was not affected. There was a significant increase in the mean body lengths of gravid females and mature males at concentrations of oestradiol between 0.001 and 0.05 mg and at concentrations of testosterone between 0.01 and 0.05 mg. These changes are interpreted as stress reactions of the nematodes to an unnatural environmental condition.

Isolation and translation in vitro of poly(A)+ RNA from the free-living nematode Panagrellus silusiae

1979 ◽  
Vol 57 (4) ◽  
pp. 330-335 ◽  
Author(s):  
J. Scott Noble ◽  
J. Pasternak
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Mean Value ◽  
Amino Acid Incorporation ◽  
Free Living ◽  
Free Living Nematode ◽  
Rnase Digestion ◽  
Fold Stimulation ◽  
Cellulose Column

Polysomal RNA was isolated from the free-living nematode Panagrellus silusiae. Passage of this RNA through a cellulose column resulted in the fractionation of the input RNA into poly(A)− RNA (ca. 97.5% of the total) and poly(A)+ RNA (ca. 2.5% of the total). RNase digestion, followed by polyacrylamide gel electrophoresis, revealed that the poly(A)+ RNA contained poly(A) tracts that ranged from 75 to 104 nucleotides in length with a mean value of about 90 residues. There was no evidence of poly(A) sequences in the poly(A)− RNA fraction. Poly(A)+ RNA gave a 25- to 50-fold stimulation (over background) of amino acid incorporation in the wheat germ cell-free protein-synthesizing system. At least 26 proteins were evident after electrophoresis in cylindrical sodium dodecyl sulfate – polyacrylamide gels. Poly(A)− RNA was capable of stimulating protein synthesis in vitro with about five discrete proteins being produced. In summary, the properties of mRNA from a simple organism such as P. silusiae are very similar to those of more complex eukaryotes.

Spatial and seasonal variations of subtidal free-living nematode assemblages in the northern Beibu Gulf, South China Sea

2011 ◽  
Vol 92 (2) ◽  
pp. 255-264 ◽  
Author(s):  
S.J. Fu ◽  
L.Z. Cai ◽  
J. Yang ◽  
X.P. Zhou ◽  
X. Peng ◽  
...  
Keyword(s):  
Organic Matter ◽  
South China Sea ◽  
Water Depth ◽  
Environmental Variables ◽  
Beibu Gulf ◽  
Free Living ◽  
Deposit Feeders ◽  
Free Living Nematode ◽  
Offshore Station ◽  
The Mean

This study determined the spatial and seasonal density, number of genera, genera composition, maturity index and trophic structure of free-living nematode assemblages in the subtidal waters of the northern Beibu Gulf, South China Sea, and explored whether these five biotic characteristics were related to various environmental variables. Based on the data derived from samples collected seasonally at nine stations, the mean densities of nematodes decreased from alongshore to offshore station in the northern Beibu Gulf. However, the number of nematode genera increased from alongshore to offshore station. Non-parametric multidimensional scaling analysis showed no clear seasonal changes for nematode assemblages in most sampling stations. Higher densities of the generaElzaliaandTricomawere found in offshore sampling stations, and a higher density of the genusCheironchuswas found in alongshore sampling stations. The mean percentage of each feeding type compared to the total numbers was highest in epigrowth feeders (2A), second highest in non-selective deposit feeders (1B), third highest in predators (2B), and lowest in selective deposit feeders (1A). There were significant negative correlations between nematode density and water depth and temperature; significant positive correlations between the number of nematode genera and water depth and salinity; and significant negative correlation between the maturity index of the nematode assemblage and organic matter. BIOENV analysis indicated that water depth, salinity, pH, median sediment particle size and organic matter were the most correlated combination of environmental variables affecting the nematode assemblages.

scholarly journals In Vitro Antileishmanial Effects of Saffron Compounds, Crocin and Stigmasterol, on Iranian Strain of Leishmania major (MHOM/IR/75/ER)

2021 ◽  
Author(s):  
Reza RANJBAR ◽  
Peyman SHAYANFAR ◽  
Mahmood MANIATI
Keyword(s):  
Leishmania Major ◽  
Inhibitory Effect ◽  
In Vitro Growth ◽  
Fatality Rate ◽  
Pasteur Institute ◽  
Inhibitory Effects ◽  
Therapeutic Approaches ◽  
New Therapeutic Approaches ◽  
The Mean

Background: Due to numerous side effects of common drugs in treatment of leishmaniasis, new therapeutic approaches focus on herbal compounds. Therefore, we aimed to determine the effect of crocin and stigmasterol on in-vitro growth of promastigotes and amastigotes of Leishmania major in the Department of Parasitology, Pasteur Institute, Tehran, Iran in 2018. Methods: The effect of different concentrations of crocin and stigmasterol were evaluated by determining their in-vitro inhibitory effects on promastigotes and amastigotes of the L. major using MTT assay. Results: The fatality rate was 65.27% and 71.96% for crocin and stigmasterol respectively at 24 h post-culture in concentration of 50 μg/mL. The mean inhibitory effect of crocin and stigmasterol on L major amastigotes after 72 h were 52.22% and 38.96%. Conclusion: The crocin and stigmasterol had efficient adverse effects on promastigote and amastigotes of L. major, hence, further studies on the anti-leishmanial effects of these herbal compounds in human and animal models are recommended.

Digestion of invertebrate neuropeptides by preparations from the free-living nematodePanagrellus redivivus

2008 ◽  
Vol 82 (3) ◽  
pp. 279-285 ◽  
Author(s):  
E.P. Masler
Keyword(s):  
Serine Proteases ◽  
Free Living ◽  
Peptide Substrates ◽  
Protease Cleavage ◽  
Rp Hplc ◽  
Panagrellus Redivivus ◽  
Free Living Nematode ◽  
Aminopeptidase P ◽  
Hydrolysis Of

AbstractProteases in the soluble fraction of homogenates prepared from the free-living nematodePanagrellus redivivushydrolysed the amidated invertebrate neuropeptides FMRFa and FLRFa, and nematode FMRFa-like peptides (FLPs) KPNFLRFa (FLP-1-H), APKPKFIRFa (FLP-5-A), KNEFIRFa (FLP-8), KPSFVRFa (FLP-9), RNKFEFIRFa (FLP-12) and KHEYLRFa (FLP-14)in vitro. Results were assessed by analysing reaction components with RP-HPLC, UV detection at 210 nm and peak integration. Based upon substrate peak size, more than 90% of most of the peptide substrates was consumed after 1 h at 27°C, but digestion was not complete even with a crude protease mixture. Two peptides, FLP-12 and FLP-14, were significantly less susceptible to digestion than the others. FLP-12 was the least susceptible of all sequences (71% loss;P < 0.0001), while FLP-14 was digested less (84% loss;P < 0.0004) than all but FLP-12. Product peak digestion patterns of FLP-12, a second nonapeptide (FLP-5-A), and FMRFa, incubated with aminopeptidase (amastatin) and serine endoprotease (AEBSF) inhibitors, demonstrated highly specific behaviours of each sequence to protease cleavage. Amastatin significantly (P < 0.03) reduced digestion of FLP-12 (54% loss) and FMRFa (61% loss;P < 0.0005), but had no effect on FLP-5-A. AEBSF had no protective effect on FMRFa but significantly decreased hydrolysis of FLP-5-A (77% loss;P < 0.0001) and FLP-12 (59% loss;P < 0.03). The combination of both inhibitors had additive effects only for FMRFa (34% loss;P < 0.0005). Further analysis of FMRFa digestion using peptides withd-amino acid substitutions demonstrated nearly complete protection of FdMRFa (2% loss;P < 0.0001) from all proteolytic digestion, whereas digestion of FMRdFa was complete. Results suggest that in addition to aminopeptidase and serine proteases, both deamidase and aminopeptidase P participate in neuropeptide metabolism inP. redivivus.

Effect of in Vivo Oxidized Cellulose on in Vitro Growth of Human Respiratory Mucosa and Sub-mucosa During Endoscopic Skull Base Approaches

2016 ◽  
Vol 77 (S 01) ◽  
Author(s):  
Ezequiel Goldschmidt ◽  
Jorge Rasmussen ◽  
Joseph Chabot ◽  
Monica Loressi ◽  
Marcelo Ielpi ◽  
...  
Keyword(s):  
Skull Base ◽  
Oxidized Cellulose ◽  
In Vitro Growth ◽  
Respiratory Mucosa

Influence of Platelet Membrane Sialic Acid and Platelet-Associated IgG on Ageing and Sequestration of Blood Platelets in Baboons

1993 ◽  
Vol 70 (04) ◽  
pp. 676-680 ◽  
Author(s):  
H F Kotzé ◽  
V van Wyk ◽  
P N Badenhorst ◽  
A du P Heyns ◽  
J P Roodt ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Life Span ◽  
Blood Platelets ◽  
Senescent Cell ◽  
Platelet Membrane ◽  
Antigen Complex ◽  
The Mean ◽  
Aggregation Of Platelets

SummaryPlatelets were isolated from blood of baboons and treated with neuraminidase to remove platelet membrane sialic acid, a process which artificially ages the platelets. The platelets were then labelled with 111In and their mean life span, in vivo distribution and sites of Sequestration were measured. The effect of removal of sialic acid on the attachment of immunoglobulin to platelets were investigated and related to the Sequestration of the platelets by the spleen, liver, and bone marrow. Removal of sialic acid by neuraminidase did not affect the aggregation of platelets by agonists in vitro, nor their sites of Sequestration. The removal of 0.51 (median, range 0.01 to 2.10) nmol sialic acid/108 platelets shortened their life span by 75 h (median, range 0 to 132) h (n = 19, p <0.001), and there was an exponential correlation between the shortening of the mean platelet life span and the amount of sialic acid removed. The increase in platelet-associated IgG was 0.112 (median, range 0.007 to 0.309) fg/platelet (n = 25, p <0.001) after 0.79 (median, range 0.00 to 6.70) nmol sialic acid/108 platelets was removed (p <0.001). There was an exponential correlation between the shortening of mean platelet life span after the removal of sialic acid and the increase in platelet-associated IgG. The results suggest that platelet membrane sialic acid influences ageing of circulating platelets, and that the loss of sialic acid may have exposed a senescent cell antigen that binds IgG on the platelet membrane. The antibody-antigen complex may then provide a signal to the macrophages that the platelet is old, and can be phagocytosed and destroyed.

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