Examination of sclerotial germination in Sclerotinia minor with an in vitro model

1996 ◽  
Vol 74 (3) ◽  
pp. 450-455 ◽  
Author(s):  
D. R. Burgess ◽  
G. Hepworth
Keyword(s):  
In Vitro Model ◽  
Prolonged Exposure ◽  
Soil Microflora ◽  
Acid Mixture ◽  
Sclerotinia Minor ◽  
Germination Response ◽  
Significant Difference ◽  
Vitro Model ◽  
Sclerotial Germination

An in vitro model was developed to examine the effect of surface microflora and exogenous nutrient on sclerotial germination of Sclerotinia minor. Germinated sclerotia were identified by the presence of appressoria on the plastic Petri dish. Surface sterilised field sclerotia germinated at maximum rates on water agar, but unsterilised sclerotia failed to germinate, even after drying and rewetting, indicating that sclerotia of S. minor are unlikely to germinate spontaneously in the presence of soil microflora. Partial surface sterilisation gave intermediate germination rates, which were enhanced two- to four-fold by treatment with sunflower root sap. There was no significant difference in the germination response to root sap from susceptible and resistant sunflower lines, but germination rates were highest with root nutrient obtained from plants during vegetative growth. A positive germination response to peptone and an amino acid mixture implicated amino acids as germination stimuli. Germination of field sclerotia required incubation with root sap for more than 3 days, suggesting that prolonged exposure of sclerotia to root exudates may be required for the onset of stem rot in sunflowers. This is discussed in relation to the dynamics of root growth. Keywords: exogenous nutrient, field sclerotia, germination stimulus.

Performance changes of venous valves following tissue treatment with novel in vitro system

2018 ◽  
Vol 34 (5) ◽  
pp. 347-354
Author(s):  
Garrett Easson ◽  
Megan Laughlin ◽  
Hanna Jensen ◽  
Kevin Haney ◽  
Marc Girardot ◽  
...  
Keyword(s):  
High Speed ◽  
In Vitro Model ◽  
Closing Time ◽  
Venous Valve ◽  
Orifice Area ◽  
Treatment Methods ◽  
Venous Valves ◽  
Significant Difference ◽  
Vitro Model

Objectives The purpose of this study is to test venous valve performance and identify differences between native tissue and replacement devices developed with traditional tissue treatment methods using a new in vitro model with synchronized hemodynamic parameters and high-speed valve image acquisition. Methods An in vitro model mimicking the venous circulation to test valve performance was developed using hydrostatic pressure driven flow. Fresh and glutaraldehyde-treated vein segments were placed in the setup and opening/closing of the valves was captured by a high-speed camera. Hemodynamic data were obtained using synchronized hardware and virtual instrumentation. Results Geometric orifice area and opening/closing time of the valves was evaluated at the same hemodynamic conditions. A reduction in geometric orifice area of 27.2  ± 14.8% (p < 0.05) was observed following glutaraldehyde fixation. No significant difference in opening/closing time following chemical fixation was observed. Conclusions The developed in vitro model was shown to be an effective method for measuring the performance of venous valves. The observed decrease in geometric orifice area following glutaraldehyde treatment indicates a decrease in flow through the valve, demonstrating the consequences of traditional tissue treatment methods.

Gelatin sponge insertion into tympanostomy tubes: An in-vitro study to evaluate postoperative obstruction

2009 ◽  
Vol 140 (5) ◽  
pp. 661-664
Author(s):  
Chad P. Secor ◽  
Robert E. Wilson ◽  
Paul M. Spring ◽  
Richard C. Haydon
Keyword(s):  
In Vitro Model ◽  
In Vitro Study ◽  
The Other ◽  
Gelatin Sponge ◽  
Pressure Equalization ◽  
Significant Difference ◽  
Tympanostomy Tubes ◽  
Ventilation Tubes ◽  
Vitro Model

Objective: To analyze the efficacy of gelatin sponge insertion into lumens of tympanostomy tubes to prevent obstruction in the presence of blood. Study Design: In vitro model. Methods: Absorbable gelatin sponge wicks were placed in the lumen of Ultrasil Collar Button ventilation tubes and Shepherd Grommet ventilation tubes. One half of each group was covered with blood, the other left untreated. Each tube was treated with ofloxacin solution three times daily for seven days. After treatment, the tubes were inspected. Reinspection was performed after brief suctioning. Numerical scores were given based on degree of obstruction. Results: A statistically significant difference in degree of obstruction ( P < 0.0001) was seen between all tubes with wicks alone versus those with blood added. After re-evaluation, there remained a statistically significant difference between tubes with wicks alone and tubes with wicks and blood ( P < 0.0001). Conclusions: Gelatin sponge insertion does not prevent, and may in fact, enhance, obstruction of pressure equalization tube lumens in the presence of blood.

Eosinophil-induced release of acetylcholine from differentiated cholinergic nerve cells

2003 ◽  
Vol 285 (6) ◽  
pp. L1296-L1304 ◽  
Author(s):  
Deborah A. Sawatzky ◽  
Paul J. Kingham ◽  
Niamh Durcan ◽  
W. Graham McLean ◽  
Richard W. Costello
Keyword(s):  
Acetylcholine Receptors ◽  
In Vitro Model ◽  
Acetylcholine Release ◽  
Prolonged Exposure ◽  
Receptor Expression ◽  
Initial Increase ◽  
Cholinergic Nerve ◽  
Release Of Acetylcholine ◽  
Vitro Model

One immunological component of asthma is believed to be the interaction of eosinophils with parasympathetic cholinergic nerves and a consequent inhibition of acetylcholine muscarinic M2 receptor activity, leading to enhanced acetylcholine release and bronchoconstriction. Here we have used an in vitro model of cholinergic nerve function, the human IMR32 cell line, to study this interaction. IMR32 cells, differentiated in culture for 7 days, expressed M2 receptors. Cells were radiolabeled with [3H]choline and electrically stimulated. The stimulation-induced release of acetylcholine was prevented by the removal of Ca2+. The muscarinic M1/M2 receptor agonist arecaidine reduced the release of acetylcholine after stimulation (to 82 ± 2% of control at 10-7 M), and the M2 receptor antagonist AF-DX 116 increased it (to 175 ± 23% of control at 10-5 M), indicating the presence of a functional M2 receptor that modulated acetylcholine release. When human eosinophils were added to IMR32 cells, they enhanced acetylcholine release by 36 ± 10%. This effect was prevented by inhibitors of adhesion of the eosinophils to the IMR32 cells. Pretreatment of IMR32 cells with 10 mM carbachol, to desensitize acetylcholine receptors, prevented the potentiation of acetylcholine release by eosinophils or AF-DX 116. Acetylcholine release was similarly potentiated (by up to 45 ± 7%) by degranulation products from eosinophils that had been treated with N-formyl-methionyl-leucyl-phenylalanine or that had been in contact with IMR32 cells. Contact between eosinophils and IMR32 cells led to an initial increase in expression of M2 receptors, whereas prolonged exposure reduced M2 receptor expression.

scholarly journals Anti-inflammatory Effects of Alcohol Are Associated with JNK-STAT3 Downregulation in an In Vitro Inflammation Model in HepG2 Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Katharina Mörs ◽  
Ramona Sturm ◽  
Jason-Alexander Hörauf ◽  
Shinwan Kany ◽  
Paola Cavalli ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Acute Inflammation ◽  
In Vitro Model ◽  
Prolonged Exposure ◽  
Acute Exposure ◽  
High Dose ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Vitro Model

Background. In several preclinical and in vitro models of acute inflammation, alcohol (ethanol, EtOH) has been described as an immunomodulatory agent. Similarly, in different pathologies, clinical observations have confirmed either pro- or anti-inflammatory effects of EtOH. The liver plays an important role in immunity and alcohol metabolism; therefore, we analysed dose- and time-dependent effects of EtOH on the inflammatory response of human liver cells in an in vitro model of acute inflammation. Methods. HepG2 cells were stimulated with IL-1β and subsequently exposed to EtOH in a low or high dose (85 mM, LoD or 170 mM, HiD) for 1 h (acute exposure) or 72 h (prolonged exposure). IL-6 and TNF-α release was determined by ELISA. Cell viability, adhesion of isolated neutrophils to HepG2 monolayers, their ICAM-1 expression, and the activation of stress-induced protein kinase/c-Jun N-terminal kinase (SAPK/JNK) or signal transducer and activator of transcription 3 (STAT3) were analysed. Results. In this experimental design, EtOH did not markedly change the cell viability. Acute and prolonged exposure to EtOH significantly reduced dose-independent IL-1β-induced IL-6 and TNF-α release, as well as adhesion capacity to pretreated HepG2 cells. Acute exposure to EtOH significantly decreased the percentage of ICAM-1-expressing cells. IL-1β stimulation notably increased the activation of SAPK/JNK. However, low-dose EtOH exposure reduced this activation considerably, in contradiction to high-dose EtOH exposure. Acute exposure to LoD EtOH significantly diminished the IL-1β-induced STAT3 activation, whereas an acute exposure of cells to either HiD EtOH or in a prolonged setting showed no effects on STAT3 activation. Conclusion. EtOH exerts anti-inflammatory potential in this in vitro model of hepatic inflammation. These effects are associated with the reduced activation of JNK/STAT3 by EtOH, particularly in the condition of acute exposure to low-dose EtOH.

The In Vitro Evaluation of Preosteoblast Migration From 3-D-printed Scaffolds to Decontaminated Smooth and Minimally Rough Titanium Surfaces: A Pilot Study

2021 ◽  
pp. 026119292110221
Author(s):  
Vitor de Toledo Stuani ◽  
David Minjoon Kim ◽  
Masazumi Nagai ◽  
Chia-Yu Chen ◽  
Adriana Campos Passanezi Sant’Ana
Keyword(s):  
Cell Migration ◽  
Pilot Study ◽  
In Vitro Model ◽  
Cellular Migration ◽  
Bone Implant ◽  
Significant Difference ◽  
Animal Use ◽  
Titanium Surfaces ◽  
Vitro Model

In vitro evaluations are essential to gaining a better understanding of re-osseointegration, while reducing animal use and the overall costs of peri-implantitis studies. This pilot study evaluated preosteoblast migration from 3-D-printed scaffolds to decontaminated titanium microimplants, creating a system that tries to mimic the bone–implant interface. Smooth (S) and minimally rough (R) titanium microimplants were incubated in Escherichia coli cultures and divided into six groups according to the decontamination protocol applied: EDTA gel (EDTA); chlorhexidine (CHL); chlorhexidine-soaked gauze (GCHL); scaling (SC); titanium brush (TiB); and implantoplasty (IP). Pristine S and R microimplants were used as the controls (C). After the decontamination procedures, the microimplants were inserted in 3-D-printed polyurethane-based scaffolds previously inoculated with preosteoblast cell cultures. Cellular migration was assessed after 24, 72 and 120 hours by ATP quantification. At the 120-hour time point, there was no statistically significant difference between S-C, S-EDTA, S-CHL, S-GCHL and S-SC ( p > 0.05), and between R-C, R-EDTA and R-GCHL ( p > 0.05). The in vitro model developed in this pilot study successfully demonstrated cell migration on the different decontaminated surfaces. This methodology suggests that on smooth microimplants, EDTA, GCHL, SC and TiB decontamination may have a reduced impact on preosteoblast migration, while on minimally rough microimplants, EDTA and GCHL decontamination affected cell migration the least. However, when selecting a decontamination protocol, the effectiveness of the decontamination per se must also be considered.

Ascorbate prevents cell death from prolonged exposure to glutamate in an in vitro model of human dopaminergic neurons

2013 ◽  
Vol 91 (12) ◽  
pp. 1609-1617 ◽  
Author(s):  
Santiago Ballaz ◽  
Ingrid Morales ◽  
Manuel Rodríguez ◽  
José A. Obeso
Keyword(s):  
Cell Death ◽  
Dopaminergic Neurons ◽  
In Vitro Model ◽  
Prolonged Exposure ◽  
Vitro Model

A standardized model for in vitro testing of sutures and patches for watertight dural closure

2021 ◽  
pp. 1-10
Author(s):  
Florian Ebel ◽  
Stefan Wanderer ◽  
C. Marvin Jesse ◽  
Ralph T. Schär ◽  
Irena Zubak ◽  
...  
Keyword(s):  
Double Layer ◽  
In Vitro Model ◽  
Infusion Pump ◽  
Suture Technique ◽  
Suture Techniques ◽  
Interrupted Suture ◽  
Dural Closure ◽  
Significant Difference ◽  
Vitro Model

OBJECTIVE CSF leaks are common complications of spinal and cranial surgeries. Several dural grafts and suture techniques are available to achieve watertight dural closure, but the effectiveness of these techniques remains unclear. The authors developed a standardized in vitro model to test available grafts and suture techniques alone or in combination to find the technique with the most watertight dural closure. METHODS A fluid chamber with a dural fixation device, infusion pump, pressure gauge, and porcine pericardium as a dural equivalent was assembled to provide the reusable device for testing. The authors performed dural closure in 4 different fashions, as follows: A) using running versus simple interrupted suture technique and different suture materials to close a 3-cm incision; B) selecting commonly used sealants and dural patches in combination with a running suture; C) performing duraplasty (1.5 × 1.5–cm square defect) with different dural substitutes in a stand-alone fashion; and D) performing duraplasty with different dural substitutes in a double-layer fashion. Each technique was tested 6 times. The hydrostatic burst pressure (BP) was measured and compared using the Kruskal-Wallis test or the Mann-Whitney U-test. Values are reported as mean ± SD. RESULTS There was no significant difference between the running and simple interrupted suture technique (p = 0.79). Adding a patch or sealant to a suture resulted in a 1.7- to 14-fold higher BP compared to solitary suture closure (36.2 ± 24.27 cm H2O and 4.58 ± 1.41 cm H2O, respectively; p < 0.001). The highest BP was achieved by adding DuraSeal or TachoSil (82.33 ± 12.72 cm H2O and 74.17 ± 12.64 cm H2O, respectively). For closing a square defect, using a double-layer duraplasty significantly increased BP by a factor of 4–12 compared to a single-layer duraplasty (31.71 ± 12.62 cm H2O vs 4.19 ± 0.88 cm H2O, respectively; p < 0.001). The highest BP was achieved with the combination of Lyomesh and TachoSil (43.67 ± 11.45 cm H2O). CONCLUSIONS A standardized in vitro model helps to objectify the watertightness of dural closure. It allows testing of sutures and dural grafts alone or in combination. In the authors’ testing, a running 6-0 monofilament polypropylene suture combined with DuraSeal or TachoSil was the technique achieving the highest BP. For the duraplasty of square defects, the double-layer technique showed the highest efficacy.

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

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