scholarly journals A rapid, parasite-dependent cellular response to Dirofilaria immitis in the Mongolian jird (Meriones unguiculatus)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Christopher C. Evans ◽  
Katherine M. Day ◽  
Yi Chu ◽  
Bridget Garner ◽  
Kaori Sakamoto ◽  
...  
Keyword(s):  
Cellular Response ◽  
Dirofilaria Immitis ◽  
Cell Attachment ◽  
Early Response ◽  
Meriones Unguiculatus ◽  
Filarial Parasite ◽  
Immune Mediated ◽  
Secretory Products ◽  
Species Specific

Abstract Background The Mongolian jird (Meriones unguiculatus) has long been recognized as a permissive host for the filarial parasite Brugia malayi; however, it is nonpermissive to another filarial parasite, canine heartworm (Dirofilaria immitis). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent. Methods Jird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry. Results In vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls (U(9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi, the results were similar (99.4% and 4.72% of D. immitis and B. malayi, respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U(11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U(9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry. Conclusions These results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity.

scholarly journals Antifilarial Activity of Eucalyptus globulus Labill. Leaves Against Brugia malayi

2016 ◽  
Vol 19 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Vijai Lakshmi ◽  
Shailja Misra Bhattacharya
Keyword(s):  
Brugia Malayi ◽  
Ethanolic Extract ◽  
Pharmaceutical Journal ◽  
Oral Route ◽  
Meriones Unguiculatus ◽  
Filarial Parasite ◽  
Mastomys Coucha ◽  
Antifilarial Activity

The present study is aimed to evaluate the antifilarial activity of Eucalyptus globules Labill. (Myrtaceae) against human lymphatic filarial parasite Brugia malayi in vitro and in vivo. The ethanolic extract of the leaves was tested in vitro on adult worms and microfilariae (mf) of B. malayi and the active sample was further evaluated in vivo in B. malayi intraperitoneally (i.p.) transplanted in the jird model (Meriones unguiculatus) and Mastomys coucha subcutaneously infected with infective larvae (L3). The ethanolic extract of the leaves of the E. globulus was tested in vitro on adult worms and microfilariae (mf) of B. malayi and the active sample was further evaluated in vivo in B. malayi. The ethanolic extract was active in vitro (IC50: adult = 62.5 ?g/ml; mf = 31.2. ?g/ml) where it demonstrated 66.7% adulticidal and embryostatic effect on B. malayi in Mastomys at a dose of 5 × 100 mg/kg by oral route. The antifilarial test conducted was at 5 × 100 mg/kg by subcutaneous route revealed excellent adulticidal efficacy resulting in to the death of 66.7% transplanted adult B. malayi in the peritoneal cavity of jirds in addition to noticeable microfilaricidal action on the day of autopsy. The findings revealed that the extract from the leaves of E. globulus contains promising in vitro and in vivo antifilarial activity against human lymphatic filarial parasite B. malayi which may be further explored to new antifilarial agents.Bangladesh Pharmaceutical Journal 19(1): 44-47, 2016

scholarly journals Production of High Silicon-Doped Hydroxyapatite Thin Film Coatings via Magnetron Sputtering: Deposition, Characterisation, and In Vitro Biocompatibility

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 190 ◽  
Author(s):  
Samuel C. Coe ◽  
Matthew D. Wadge ◽  
Reda M. Felfel ◽  
Ifty Ahmed ◽  
Gavin S. Walker ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Silicon Content ◽  
Cellular Response ◽  
Cell Attachment ◽  
Initial Response ◽  
Weight Percent ◽  
Hydroxyl Groups

In recent years, it has been found that small weight percent additions of silicon to HA can be used to enhance the initial response between bone tissue and HA. A large amount of research has been concerned with bulk materials, however, only recently has the attention moved to the use of these doped materials as coatings. This paper focusses on the development of a co-RF and pulsed DC magnetron sputtering methodology to produce a high percentage Si containing HA (SiHA) thin films (from 1.8 to 13.4 wt.%; one of the highest recorded in the literature to date). As deposited thin films were found to be amorphous, but crystallised at different annealing temperatures employed, dependent on silicon content, which also lowered surface energy profiles destabilising the films. X-ray photoelectron spectroscopy (XPS) was used to explore the structure of silicon within the films which were found to be in a polymeric (SiO2; Q4) state. However, after annealing, the films transformed to a SiO44−, Q0, state, indicating that silicon had substituted into the HA lattice at higher concentrations than previously reported. A loss of hydroxyl groups and the maintenance of a single-phase HA crystal structure further provided evidence for silicon substitution. Furthermore, a human osteoblast cell (HOB) model was used to explore the in vitro cellular response. The cells appeared to prefer the HA surfaces compared to SiHA surfaces, which was thought to be due to the higher solubility of SiHA surfaces inhibiting protein mediated cell attachment. The extent of this effect was found to be dependent on film crystallinity and silicon content.

ELECTROHYDRODYNAMIC PROCESSING OF CALCIUM PHOSPHATES: COATING AND PATTERNING FOR MEDICAL IMPLANTS

Nano LIFE ◽  
2012 ◽  
Vol 02 (01) ◽  
pp. 1250008 ◽  
Author(s):  
GILLIAN MUNIR ◽  
JIE HUANG ◽  
MOHAN EDIRISINGHE ◽  
RAFIQUE NANGREJO ◽  
WILLIAM BONFIELD
Keyword(s):  
Surface Topography ◽  
Cellular Response ◽  
Cell Attachment ◽  
Calcium Phosphates ◽  
Life Time ◽  
Medical Implants ◽  
Osteoblast Cells ◽  
Ha Coating ◽  
Electrohydrodynamic Atomization

Hydroxyapatite (HA)-coated metallic prostheses, which combine the osteoconductivity of HA and high strength of metallic alloys, have been increasingly the choice of joint replacement prostheses by surgeons as the general population lives longer. Surface modification of metallic implant surfaces is one of the key focal points to implantation technology. In addition to material chemistry, surface topography has been found to positively impact cellular response and is able to enhance the life time of the implant. Recently, a new technique, template-assisted electrohydrodynamic atomization (TAEA) spraying, developed using the principles of electrohydrodynamic atomization spraying, which is an electrically driven jet-based deposition method, is of considerable interest in surface topography formation. The process offers the attractive advantages of compatibility with micro-fabrication technology and versatility in pattern specification for advanced implant designs. This technology incorporates nanosized calcium phosphate to mimic the size and chemical composition of bone mineral in a micrometer-dimension pattern configuration to guide cellular responses. In vitro studies showed that both pillar and track nano Silicon-substituted HA (SiHA) patterns were able to encourage the attachment and growth of osteoblast cells, the track patterns provided the favourite surface for the initial cell attachment while a fast cell proliferation rate was found on the pillar pattern from day 1 to day 5 in comparison with that of a SiHA-coated surface. The alignment of actin cytoskeleton of osteoblast cells matched the orientation of the entire cell. The shear peel strength of the patterned interlocking nano-HA coating was found to be at least an order of magnitude higher than the conventional HA coating. Therefore, TAEA offers great potential for producing new coatings with a tailored surface topography, on both the micro- and nano-scale in a more cost effective way to enhance the performance of medical implants.

Characterization of phosphoglycan-containing secretory products ofLeishmania

Parasitology ◽  
1994 ◽  
Vol 108 (S1) ◽  
pp. S63-S71 ◽  
Author(s):  
T. Ilg ◽  
Y.-D. Stierhof ◽  
M. Wiese ◽  
M. J. McConville ◽  
P. Overath
Keyword(s):  
Parasitophorous Vacuole ◽  
Secretory Product ◽  
Flagellar Pocket ◽  
Lesion Development ◽  
Causative Agents ◽  
Secretory Products ◽  
Species Specific ◽  
Modify Protein

SUMMARYThis article presents an overview on phosphoglycan-containing components secreted by the insect and mammalian stages of several species ofLeishmania, the causative agents of leishmaniasis in the Old and New World. Firstly, promastigotes of all three species considered,L. mexicana, L. donovaniandL. major, shed lipophosphoglycan (LPG) into the culture medium possibly by release of micelles from the cell surface. Like the cell-associated LPG, culture supernatant LPG is arhphiphilic and composed of a lysoalkylphosphatidylinositol-phosphosaccharide core connected to species-specific phosphosaccharide repeats and oligosaccharide caps. Secondly, all three species release hydrophilic phosphoglycan. Thirdly, all three species appear to secrete proteins covalently modified by phosphosaccharide repeats and oligosaccharide caps. In the case of promastigotes ofL. mexicana, these components are organized as two filamentous polymers released from the flagellar pocket: the secreted acid phosphatase (sAP) composed of a 100 kDa phosphoglycoprotein and a protein- containing high-molecular-weight-phosphoglycan (proteo-HMWPG) and fibrous networks likewise composed of phosphoglycan possibly linked to protein. Structural analyses and gene cloning suggest that the parasites can covalently modify protein regions rich in serine and threonine residues by the attachment of phosphosaccharide repeats capped by oligosaccharides. We propose that the networks formedin vitrocorrespond to fibrous material previously demonstrated in the digestive tract of infected sandflies. In the case ofL. donovani, the sAP is also modified by phosphoglycans but contains neither proteo-HMWPG nor does it aggregate to filaments. Finally,L. mexicanaamastigotes release proteo-HMWPG via the flagellar pocket into the parasitophorous vacuole of infected macrophages. This material appears to be released into the tissue of the infected mammal upon rupture of infected macrophages during lesion development. This secretory product may contribute to the pathology of lesion development.

Designing porous scaffolds for tissue engineering

2005 ◽  
Vol 364 (1838) ◽  
pp. 227-232 ◽  
Author(s):  
William Bonfield
Keyword(s):  
Tissue Engineering ◽  
Cellular Response ◽  
Cell Attachment ◽  
Wide Spectrum ◽  
Porous Scaffolds ◽  
Potential Control ◽  
Biomaterial Scaffold ◽  
Porous Architecture

Biomaterials are either modified natural or synthetic materials, with an appropriate response in the host tissue, which find application in a wide spectrum of implants and prostheses used in reconstructive medicine. The subsequent integration and longevity of the implanted device depends on the effectiveness of the associated biological repair. Hence, there has been considerable interest in the development of novel, second generation, biomaterials, which are favourably bioactive in terms of promoting the desired cellular response in vivo . Such biomaterials in a porous form can also act as cellular scaffolds and allow in vitro , as well as in vivo incorporation of the appropriate tissue cells, with potential control of the sequence of cell attachment, proliferation and the production of extra-cellular matrix. Such generic tissue engineering depends critically on the porous architecture of the biomaterial scaffold so as to allow both the cellular ingress and vascularization required to create a living tissue. The particular requirements of tissue-engineering scaffolds with respect to macro- and micro-porosity, as well as chemistry, are reviewed.

Cellular Response Assessment to Zirconia-Alumina Composite: An In Vitro Experimental Study

2006 ◽  
Vol 309-311 ◽  
pp. 433-436 ◽  
Author(s):  
Dae Joon Kim ◽  
Jung Suk Han ◽  
Young Jun Lim ◽  
Kyung Soo Jang ◽  
Chang-Young Ahn
Keyword(s):  
Cellular Response ◽  
Cellular Proliferation ◽  
Cell Attachment ◽  
Response Assessment ◽  
Rt Pcr ◽  
Mean Values ◽  
Significant Difference ◽  
Term Evaluation ◽  
Alumina Composite

The biocompatibility of zirconia-alumina composite was evaluated with HOS osteoblast like cell models. A total of 18 zirconia-alumina composite disc (diameter: 19mm and thickness: 1.5mm) were prepared and divided into two groups. Half of the discs were sandblasted with 50µm alumina particles. Mean values of surface roughness (Ra) were 0.1 µm and 0.9-1.48 µm for smooth and sandblasted sample respectively. The cell attachment, proliferation, and differentiation on the specimen were evaluated by the Real-Time Polymerase Chain Reaction (RT-PCR), Methylthiazole Sulfate (MTS) analysis, Alkaline Phosphatase (ALP) activity, and Scanning Electron Microscopy (SEM). There was no significant difference in cellular response between two groups. The analysis of the RT-PCR showed that the amount of Cyclin D1(mRNA expression) was not statistically significant different between two groups after 24 hours as well, however markedly decreased in the smooth surface after 72 hours. This indicated that the rough one might have a more favorable cellular proliferation compared to smooth one in long term evaluation. Further study will be necessary.

Insights into the biochemical and functional characterization of sortase E transpeptidase of Corynebacterium glutamicum

2019 ◽  
Vol 476 (24) ◽  
pp. 3835-3847 ◽  
Author(s):  
Aliyath Susmitha ◽  
Kesavan Madhavan Nampoothiri ◽  
Harsha Bajaj
Keyword(s):  
Protein Engineering ◽  
Cell Attachment ◽  
Functional Characterization ◽  
Protein Structures ◽  
Structural Similarity ◽  
Surface Proteins ◽  
Sortase A ◽  
Peptide Cleavage ◽  
New Findings

Most Gram-positive bacteria contain a membrane-bound transpeptidase known as sortase which covalently incorporates the surface proteins on to the cell wall. The sortase-displayed protein structures are involved in cell attachment, nutrient uptake and aerial hyphae formation. Among the six classes of sortase (A–F), sortase A of S. aureus is the well-characterized housekeeping enzyme considered as an ideal drug target and a valuable biochemical reagent for protein engineering. Similar to SrtA, class E sortase in GC rich bacteria plays a housekeeping role which is not studied extensively. However, C. glutamicum ATCC 13032, an industrially important organism known for amino acid production, carries a single putative sortase (NCgl2838) gene but neither in vitro peptide cleavage activity nor biochemical characterizations have been investigated. Here, we identified that the gene is having a sortase activity and analyzed its structural similarity with Cd-SrtF. The purified enzyme showed a greater affinity toward LAXTG substrate with a calculated KM of 12 ± 1 µM, one of the highest affinities reported for this class of enzyme. Moreover, site-directed mutation studies were carried to ascertain the structure functional relationship of Cg-SrtE and all these are new findings which will enable us to perceive exciting protein engineering applications with this class of enzyme from a non-pathogenic microbe.

The Mechanism of Platelet Aggregation Induced by HLA-Related Antibodies

1996 ◽  
Vol 76 (05) ◽  
pp. 774-779 ◽  
Author(s):  
John T Brandt ◽  
Carmen J Julius ◽  
Jeanne M Osborne ◽  
Clark L Anderson
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Complement Activation ◽  
Thromboembolic Disease ◽  
Clinical Samples ◽  
Hla Antigen ◽  
Aggregation Response ◽  
Immune Mediated ◽  
Dependent Pathway

SummaryImmune-mediated platelet activation is emerging as an important pathogenic mechanism of thrombosis. In vitro studies have suggested two distinct pathways for immune-mediated platelet activation; one involving clustering of platelet FcyRIIa, the other involving platelet-associated complement activation. HLA-related antibodies have been shown to cause platelet aggregation, but the mechanism has not been clarified. We evaluated the mechanism of platelet aggregation induced by HLA-related antibodies from nine patients. Antibody to platelet FcyRIIa failed to block platelet aggregation with 8/9 samples, indicating that engagement of platelet FcyRIIa is not necessary for the platelet aggregation induced by HLA-related antibodies. In contrast, platelet aggregation was blocked by antibodies to human C8 (5/7) or C9 (7/7). F(ab’)2 fragments of patient IgG failed to induce platelet activation although they bound to HLA antigen on platelets. Intact patient IgG failed to aggregate washed platelets unless aged serum was added. The activating IgG could be adsorbed by incubation with lymphocytes and eluted from the lymphocytes. These results indicate that complement activation is involved in the aggregation response to HLA-related antibodies. This is the first demonstration of complement-mediated platelet aggregation by clinical samples. Five of the patients developed thrombocytopenia in relationship to blood transfusion and two patients developed acute thromboembolic disease, suggesting that these antibodies and the complement-dependent pathway of platelet aggregation may be of clinical significance.

Apoptosis and proliferation ofperipheral blood T-cells as alternative processes in pathogenesis of diabetes mellitus type 1

2019 ◽  
Vol 1 (4) ◽  
pp. 16-20 ◽  
Author(s):  
A. V. Lugovaya ◽  
N. M. Kalinina ◽  
V. Ph. Mitreikin ◽  
Yu. P. Kovaltchuk ◽  
A. V. Artyomova ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
T Cells ◽  
High Risk ◽  
Peripheral Blood ◽  
Cellular Response ◽  
Proliferative Potential ◽  
Autoreactive T Cells ◽  
Alternative Processes

Apoptosis, along with proliferation, is a form of lymphocyte response to activating stimuli. In the early stages of cell differentiation, the apoptotic response prevails and it results to the formation of tolerance to inductor antigen. Mature lymphocytes proliferate in response to stimulation and it means the initial stage in the development of the immune response. Since in this case apoptosis and proliferation acts as alternative processes, their ratio can serve as a measure of the effectiveness of the cellular response to activating signals. The resistance of autoreactive T-cells to apoptosis is the main key point in the development of type 1 diabetes mellitus (T1DM). Autoreactive T-cells migrates from the bloodstream to the islet tissue of the pancreas and take an active part in b cells destruction. The resistance of autoreactive effector T-cells to apoptosis may suggest their high proliferative potential. Therefore, the comparative evaluation of apoptosis and proliferation of peripheral blood lymphocytes can give a more complete picture of their functional state and thus will help to reveal the causes of ineffective peripheral blood T-ceiis apoptosis in patients with T1DM and will help to understand more deeply the pathogenesis of the disease. in this article, the features of proliferative response of peripheral blood T-cells in patients with T1DM and in individuals with high risk of developing T1DM have been studied. Apoptosis of T-cell subpopulations has been investigated. The correlation between the apoptotic markers and the intensity of spontaneous and activation- induced in vitro T-cells proliferation of was revealed. it was determined, that autoreactive peripheral blood T-cells were resistant to apoptosis and demonstrated the increased proliferative potential in patients with T1DM and in individuals with high risk of developing T1DM.

The In Vitro Antibiofilm Activity of Water Leaf Extract of Papaya (Carica papaya L.) against Pseudomonas aeruginosa

2017 ◽  
Vol 2 (3) ◽  
pp. 150-163
Author(s):  
Ekajayanti Kining ◽  
Syamsul Falah ◽  
Novik Nurhidayat
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Contact Time ◽  
Cell Attachment ◽  
Water Extract ◽  
Opportunistic Pathogen ◽  
Bacterial Biofilm ◽  
Antibiofilm Activity ◽  
Bacterial Survival ◽  
Optimum Conditions

Pseudomonas aeruginosa is one of opportunistic pathogen forming bacterial biofilm. The biofilm sustains the bacterial survival and infections. This study aimed to assess the activity of water extract of papaya leaves on inhibition of cells attachment, growth and degradation of the biofilm using crystal violet (CV) biofilm assay. Research results showed that water extract of papaya leaves contains alkaloids, tanins, flavonoids, and steroids/terpenoids and showed antibacterial activity and antibiofilm against P. aeruginosa. Addition of extract can inhibit the cell attachment and was able to degrade the biofilm of 40.92% and 48.058% respectively at optimum conditions: extract concentration of 25% (v/v), temperature 37.5 °C and contact time 45 minutes. With a concentration of 25% (v/v), temperature of 50 °C and the contact time of 3 days, extract of papaya leaves can inhibit the growth of biofilms of 39.837% v/v.

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