scholarly journals Quantitative Methods for Measuring DNA Flexibility In Vitro and In Vivo

2011 ◽  
pp. 287-335 ◽  
Author(s):  
Justin P. Peters ◽  
Nicole A. Becker ◽  
Emily M. Rueter ◽  
Zeljko Bajzer ◽  
Jason D. Kahn ◽  
...  
Keyword(s):  
Quantitative Methods ◽  
Dna Flexibility

Aggregation of platelets in damaged vessels

1981 ◽  
Vol 294 (1072) ◽  
pp. 241-250 ◽  
Keyword(s):  
Quantitative Methods ◽  
Small Vessels ◽  
Biochemical Effects ◽  
Chemical Agents ◽  
Low Concentrations ◽  
Experimental Approaches ◽  
Haemostatic Factors ◽  
Aggregation Of Platelets

The only certain physiological function of platelets is their aggregation in injured vessel walls as haemostatic plugs. The association of thrombocytopenia with petechial haemorrhages suggests that platelets are somehow required for the functional integrity of small vessels, but no mechanism has yet been established. The pathological aggregation of platelets as thrombi in atherosclerotic arteries is commonly, if not always, initiated by haemorrhage. In artificial vessels, platelets tend to aggregate on the walls wherever blood flow is non-laminar. The mural aggregation of platelets is not prevented by unphysiologically high wall-shear forces. The facts suggest, on the contrary, that the process depends in some way on abnormal haemodynamic conditions. This contribution is mainly concerned with questions about how haemodynamic conditions in and around vascular leaks affect arriving platelets that aggregate there, and about the chemical agents responsible for making the platelets reactive. The effects of these agents are known mainly from in vitro experiments in which aggregation can be quantitatively correlated with biochemical effects by simple and reproducible methods; the relevance to their reactions in haemostasis and thrombosis is uncertain. It is difficult to devise quantitative methods for analysing these processes in vivo because of the very low concentrations at which endogenous agents can activate platelets and haemostatic factors in the plasma; the rapidity with which platelets aggregate in a damaged blood vessel; and the complexity and inconstancy of the haemodynamic situation. All these facts must be accounted for in hypotheses of haemostasis. New experimental approaches towards analysing the haemostatic mechanism in vivo are described.

Artificial insemination technology for ratites: a review

2008 ◽  
Vol 48 (10) ◽  
pp. 1284 ◽  
Author(s):  
I. A. Malecki ◽  
P. K. Rybnik ◽  
G. B. Martin
Keyword(s):  
Artificial Insemination ◽  
Genetic Improvement ◽  
Quantitative Methods ◽  
Practical Method ◽  
Prolonged Storage ◽  
Female Ratio ◽  
Semen Collection ◽  
Semen Storage

In ratite farming, the low male to female ratio in the mating system restricts genetic improvement and prevents reduction of the number of males kept on-farm for fertilisation of the female flock. These issues can be overcome and the industry can better realise its potential by using artificial insemination (AI) technology. It is the only practical method for intensive genetic improvement of reproduction and the production of eggs, chicks, oil, meat and leather. For AI to be feasible, we need reliable methods for semen collection, artificial insemination, prolonged storage of spermatozoa in the female tract, high rates of lay, efficient protocols for semen storage, and a panel of quantitative methods for measuring true fertility and hatchability, sperm supply rates in vivo and sperm viability in vitro. For both emus and ostriches, prolonged sperm storage in females has already been demonstrated. Methods for semen collection and artificial insemination, using animal-friendly techniques, have also been developed. Semen storage and cryopreservation protocols are yet to be optimised and we still need to overcome the male-dependent rate of lay, but adoption of AI technology by the ratite industries is now feasible. It also seems likely that these technologies will be relevant to wild ratites that need intensive conservation efforts, such as cassowaries, rheas and ostrich subspecies.

Cell adhesion and movement in relation to the developing limb pattern in normal and talpid3 mutant chick embryos

Development ◽  
1968 ◽  
Vol 20 (1) ◽  
pp. 81-100
Author(s):  
D. A. Ede ◽  
G. S. Agerbak
Keyword(s):  
Cell Adhesion ◽  
Quantitative Methods ◽  
Cell Movement ◽  
Genetic Effect ◽  
Mesenchymal Cell ◽  
Cellular Level ◽  
Lethal Mutant ◽  
Wing Bud

Descriptive studies of the talpid3 chick embryonic lethal mutant (ta3/ta3) have suggested that the multiple effects produced by this gene are of mesodermal origin, and that they arise from defective mesenchymal cell movement and condensation (Ede & Kelly, 1964 a, b). It may be argued that condensation in vivo is comparable to cell reaggregation of dissociated cells in vitro, and that defects in the former are likely to be reflected in the latter. In this case it should be possible to obtain experimental verification of this effect of the gene at the cellular level, using the quantitative methods for assessing aggregation developed by Moscona (1961 a, b) and Curtis & Greaves (1965). The experiments reported here show a clear genetic effect upon cell adhesion in the wing-bud mesenchyme of the talpid3 mutant. The wing-bud was chosen because it was hoped to establish a connexion between the effect of the gene at the cellular level and its dramatic effect on limb morphogenesis.

scholarly journals Studying the Degree of Tooth Enamel Mineralization through Raman Spectroscopy in Various Spectral Ranges

Biophysica ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 269-278
Author(s):  
Diana V. Prikule ◽  
Vladimir I. Kukushkin ◽  
Aleksandr V. Mitronin ◽  
Vladislav F. Prikuls
Keyword(s):  
Raman Spectroscopy ◽  
Raman Scattering ◽  
Quantitative Methods ◽  
Tooth Enamel ◽  
Incisal Edge ◽  
Enamel Mineralization ◽  
Spectral Ranges ◽  
Good Agreement

In vitro and in vivo methods of Raman spectroscopy have been developed to assess the degree of mineralization of the enamel of different functional groups. This article presents comparative studies that were carried out using scanning Raman microspectroscopy with various sources of laser excitation with wavelengths of 532, 785, and 1064 nm. It is shown that the intensity of Raman scattering of enamel can be a measure of its thickness. The obtained dependence of the Raman scattering intensity on the distance from the incisal edge is in good agreement with the literature data, where two independent methods (computer tomography and electron microscopy) are used to determine the enamel thickness values. The proposed methods can be considered as potential quantitative methods for express diagnostics of the state of tooth enamel in vivo.

scholarly journals SensitiveIn VitroSystem To Assess Morphological and Biochemical Effects of Praziquantel and Albendazole onTaenia soliumCysts

2010 ◽  
Vol 55 (1) ◽  
pp. 211-217 ◽  
Author(s):  
S. Mahanty ◽  
A. Paredes ◽  
M. Marzal ◽  
E. Gonzalez ◽  
S. Rodriguez ◽  
...  
Keyword(s):  
Active Metabolite ◽  
Quantitative Methods ◽  
Taenia Solium ◽  
Specific Antigen ◽  
Drug Effects ◽  
Anthelmintic Activity ◽  
Cyst Size ◽  
Biochemical Effects

ABSTRACTNeurocysticercosis resulting fromTaenia soliuminfections is a major cause of adult-acquired seizures worldwide. Disease is caused by larval cysts, and treatment consists of the anthelmintic drugs albendazole or praziquantel. There are no standard methods to assess drug activity toT. soliumcystsin vitro. Morphological, functional, and biochemical changes that might reflect damaging (inhibiting, cytotoxic) drug effects were analyzed after exposure of cysts to albendazole sulfoxide (ABZ-SO), the major active metabolite of the drugin vivo, praziquantel (PZQ), or combinations of both. PZQ exposure led to a decrease in cyst size and inhibition of evagination, whereas ABZ-SO exposure resulted in minimal changes. Alkaline phosphatase (AP) is normally secreted by cysts, and both drugs inhibited AP secretion at concentrations of 5 and 50 ng/ml for PZQ and ABZ-SO, respectively. Some combinations of both drugs resulted in additive and/or synergistic activities. Parasite-specific antigen, detected in the cerebrospinal fluid and blood of infected patients, is also normally secreted byT. soliumcysts. Antigen secretion was similarly inhibited by ABZ-SO and PZQ and a combination of both drugs, suggesting that inhibition of secretion is a common downstream consequence of the activities of both drugs. These studies establish quantitative methods to measurein vitroanthelmintic activity and suggest combination therapy with ABZ-SO and PZQ may have clinical benefit.

scholarly journals Rheologycal Parameters in Patients with Brain Infarct During COVID-19

2020 ◽  
pp. 53-66
Keyword(s):  
Quantitative Methods ◽  
Blood Rheology ◽  
Research Area ◽  
Plasma Viscosity ◽  
Rheological Parameters ◽  
Disease Group ◽  
Brain Infarct ◽  
Rbc Aggregation

In the description of the analytical clinical data of the patients with COVID-19 from difference country. In article shows detailed description of the rheological situation in patients with neuropathic during COVID-19. This data was compared with results of rheological study in analogical disease group patients without COVID-19. The article describes the effect of various anticoagulants on blood rheology, also describing protocols. In vivo, in vitro experiments, that studied a range of rheological parameters different anticoagulants. Measurement of RBC aggregation, RBC deformities, plasma viscosity were study with innovative technologies, quantitative methods. The work presents a scientific focus, after deep and increase research area is able to transport the newest conclusion to the clinical practice to treatment management of COVID-19.

scholarly journals Analysis of Vipadenant and Its In Vitro and In Vivo Metabolites via Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 260 ◽  
Author(s):  
Seok-Ho Shin ◽  
Min-Ho Park ◽  
Jin-Ju Byeon ◽  
Byeong Lee ◽  
Yuri Park ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Drug Metabolism ◽  
Quantitative Methods ◽  
Checkpoint Inhibitors ◽  
Time Of Flight ◽  
Drug Clearance ◽  
Precipitation Method ◽  
Experimental Conditions

A simple and sensitive liquid chromatography–quadrupole-time-of-flight–mass spectrometric (LC-QTOF-MS) assay has been developed for the evaluation of drug metabolism and pharmacokinetics (PK) properties of vipadenant in rat, a selective A2a receptor antagonist as one of the novel immune checkpoint inhibitors. A simple protein precipitation method using acetonitrile was used for the sample preparation and the pre-treated samples were separated by a reverse-phase C18 column. The calibration curve was evaluated in the range of 3.02 ~ 2200 ng/mL and the quadratic regression (weighted 1/concentration) was used for the best fit of the curve with a correlation coefficient ≥0.997. The in vivo PK studies in rats showed that vipadenant bioavailability was 30.4 ± 8.9% with a low to moderate drug clearance. In addition, in vitro/in vivo metabolite profiles in rat were also explored. Five different metabolites were observed in our experimental conditions and the major metabolites were different between in vitro and in vivo conditions. As far as we know, there has been no report on the development of quantitative methods for its PK samples nor the identification of its metabolites since vipadenant was developed. Therefore, this paper would be very useful to better understand the pharmacokinetic and drug metabolism properties of vipadenant in rat as well as other species.

scholarly journals Enhancement of DNA Flexibility in Vitro and in Vivo by HMGB Box A Proteins Carrying Box B Residues†

Biochemistry ◽  
2009 ◽  
Vol 48 (10) ◽  
pp. 2125-2134 ◽  
Author(s):  
Nadia T. Sebastian ◽  
Emily M. Bystry ◽  
Nicole A. Becker ◽  
L. James Maher
Keyword(s):  
Dna Flexibility

scholarly journals Graphene–Oxide Porous Biopolymer Hybrids Enhance In Vitro Osteogenic Differentiation and Promote Ectopic Osteogenesis In Vivo

2022 ◽  
Vol 23 (1) ◽  
pp. 491
Author(s):  
Aida Șelaru ◽  
Hildegard Herman ◽  
George Mihail Vlăsceanu ◽  
Sorina Dinescu ◽  
Sami Gharbia ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Osteogenic Differentiation ◽  
Quantitative Methods ◽  
Bone Cells ◽  
Osteogenic Potential ◽  
Specific Cell ◽  
Collagen Formation ◽  
Calcium Deposits

Over the years, natural-based scaffolds have presented impressive results for bone tissue engineering (BTE) application. Further, outstanding interactions have been observed during the interaction of graphene oxide (GO)-reinforced biomaterials with both specific cell cultures and injured bone during in vivo experimental conditions. This research hereby addresses the potential of fish gelatin/chitosan (GCs) hybrids reinforced with GO to support in vitro osteogenic differentiation and, further, to investigate its behavior when implanted ectopically. Standard GCs formulation was referenced against genipin (Gp) crosslinked blend and 0.5 wt.% additivated GO composite (GCsGp/GO 0.5 wt.%). Pre-osteoblasts were put in contact with these composites and induced to differentiate in vitro towards mature osteoblasts for 28 days. Specific bone makers were investigated by qPCR and immunolabeling. Next, CD1 mice models were used to assess de novo osteogenic potential by ectopic implantation in the subcutaneous dorsum pocket of the animals. After 4 weeks, alkaline phosphate (ALP) and calcium deposits together with collagen synthesis were investigated by biochemical analysis and histology, respectively. Further, ex vivo materials were studied after surgery regarding biomineralization and morphological changes by means of qualitative and quantitative methods. Furthermore, X-ray diffraction and Fourier-transform infrared spectroscopy underlined the newly fashioned material structuration by virtue of mineralized extracellular matrix. Specific bone markers determination stressed the osteogenic phenotype of the cells populating the material in vitro and successfully differentiated towards mature bone cells. In vivo results of specific histological staining assays highlighted collagen formation and calcium deposits, which were further validated by micro-CT. It was observed that the addition of 0.5 wt.% GO had an overall significant positive effect on both in vitro differentiation and in vivo bone cell recruitment in the subcutaneous region. These data support the GO bioactivity in osteogenesis mechanisms as being self-sufficient to elevate osteoblast differentiation and bone formation in ectopic sites while lacking the most common osteoinductive agents.

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