scholarly journals Elastic Material Damage of Rotational Atherectomy and Orbital Atherectomy: An in Vitro Assessment

Author(s):  
Hirooki Higami ◽  
Yoshifumi Kashima ◽  
Kensuke Yokoi ◽  
Shinnosuke Nomura ◽  
Hikaru Tateyama ◽  
...  

Abstract PurposeRotational atherectomy (RA) and orbital atherectomy (OA) are effective procedures for severe calcified coronary artery disease. Nonetheless, vessel perforation remains an adverse complication of these procedures. This study aimed to evaluate factors affecting elastic material damage caused by RA and OA.MethodsAn in vitro assessment was conducted in which the damage to the rubber latex, an elastic material, after RA was evaluated under various conditions, including burr rotational speed (100,000–220,000 rotations per minute), approaching curve, burr size (1.25 mm, 1.75 mm, and 2.0 mm), and fluid viscosity (water and low-molecular weight dextran). Similarly, the rubber latex damage after OA was evaluated in the same experimental system under various conditions, including crown rotational speed, approaching curve, and fluid viscosity.ResultsIn RA, the rubber latex was damaged at lower rotational speeds (p = 0.003), tighter approaching curves (p < 0.0001), and lower fluid viscosity (p = 0.03). In OA, the rubber latex was generally severely damaged.ConclusionA higher rotational speed, coaxial approach for the wall, and higher viscosity contributed to lesser elastic material damage in RA. The safety mechanism for elastic material in OA proved less effective.

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S223-S246 ◽  
Author(s):  
C. R. Wira ◽  
H. Rochefort ◽  
E. E. Baulieu

ABSTRACT The definition of a RECEPTOR* in terms of a receptive site, an executive site and a coupling mechanism, is followed by a general consideration of four binding criteria, which include hormone specificity, tissue specificity, high affinity and saturation, essential for distinguishing between specific and nonspecific binding. Experimental approaches are proposed for choosing an experimental system (either organized or soluble) and detecting the presence of protein binding sites. Techniques are then presented for evaluating the specific protein binding sites (receptors) in terms of the four criteria. This is followed by a brief consideration of how receptors may be located in cells and characterized when extracted. Finally various examples of oestrogen, androgen, progestagen, glucocorticoid and mineralocorticoid binding to their respective target tissues are presented, to illustrate how researchers have identified specific corticoid and mineralocorticoid binding in their respective target tissue receptors.


2016 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Yohei Sotomi ◽  
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◽  
◽  
◽  
...  

Despite advances in technology, percutaneous coronary intervention (PCI) of severely calcified coronary lesions remains challenging. Rotational atherectomy is one of the current therapeutic options to manage calcified lesions, but has a limited role in facilitating the dilation or stenting of lesions that cannot be crossed or expanded with other PCI techniques due to unfavourable clinical outcome in long-term follow-up. However the results of orbital atherectomy presented in the ORBIT I and ORBIT II trials were encouraging. In addition to these encouraging data, necessity for sufficient lesion preparation before implantation of bioresorbable scaffolds lead to resurgence in the use of atherectomy. This article summarises currently available publications on orbital atherectomy (Cardiovascular Systems Inc.) and compares them with rotational atherectomy.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.


2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.


2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.


1998 ◽  
Vol 39 (4) ◽  
pp. 861-872 ◽  
Author(s):  
Larbi Krimbou ◽  
Michel Tremblay ◽  
Hélène Jacques ◽  
Jean Davignon ◽  
Jeffrey S. Cohn

1963 ◽  
Vol 204 (1) ◽  
pp. 171-175 ◽  
Author(s):  
W. S. Ruliffson ◽  
J. M. Hopping

The effects in rats, of age, iron-deficiency anemia, and ascorbic acid, citrate, fluoride, and ethylenediaminetetraacetate (EDTA) on enteric radioiron transport were studied in vitro by an everted gut-sac technique. Sacs from young animals transported more than those from older ones. Proximal jejunal sacs from anemic animals transported more than similar sacs from nonanemic rats, but the reverse effect appeared in sacs formed from proximal duodenum. When added to media containing ascorbic acid or citrate, fluoride depressed transport as did anaerobic incubation in the presence of ascorbic acid. Anaerobic incubation in the presence of EDTA appeared to permit elevated transport. Ascorbic acid, citrate, and EDTA all enhanced the level of Fe59 appearing in serosal media. These results appear to agree with previously established in vivo phenomena and tend to validate the in vitro method as one of promise for further studies of factors affecting iron absorption and of the mechanism of iron absorption.


2004 ◽  
Vol 22 (2) ◽  
pp. 300-304 ◽  
Author(s):  
Patricia N. Bordallo ◽  
Derly H. Silva ◽  
José Maria ◽  
Cosme D. Cruz ◽  
Elizabeth P. Fontes

Synthetic seeds can be an alternative for those species in which botanical seeds are not viable. One of the major problems of in vitro plant cultivation is the high level of somaclonal variation. The most common factors affecting somaclonal variation are genotype, explant source, in vitro period and cultivation conditions in which the culture is established. In this work, calli were induced using leaf and stem explants of the commercial potato cultivars Achat, Baraka, Baronesa, Bintje, and Contenda in MS culture media supplemented with 1.65 mM of picloram and 11.5 mM of 2,4-D. Seventy and 90 days after induction, DNA samples of 40 calli were compared concerning the effects of the two explant (leaf and stem) and two growth regulator sources on five potatoes cultivars. A total of 20 arbitrary sequence primers were evaluated. The RAPD pattern generated by these primers suggested a high percentage of polymorphic fragments among the five genotypes, indicating a high level of genetic variation among cultivars. Cultivar Baronesa showed the highest number of polymorphic fragments for all treatments. The cultivar Contenda showed the smallest somaclonal variation, for most of the treatments, except for the treatment which consisted of stem explants, picloram (1.65 mM) application, and a 70-day period of callus formation. 'Contenda' is, therefore, the most suitable cultivar for synthetic seed production.


Sarcoma ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaodong Mu ◽  
Christian Isaac ◽  
Trevor Schott ◽  
Johnny Huard ◽  
Kurt Weiss

Osteosarcoma (OS) is the most common primary malignancy of bone. Mortality is determined by the presence of metastatic disease, but little is known regarding the biochemical events that drive metastases. Two murine OS cell lines, K7M2 and K12, are related but differ significantly in their metastatic potentials: K7M2 is highly metastatic whereas K12 displays much less metastatic potential. Using this experimental system, the mammalian target of rapamycin (mTOR) pathway has been implicated in OS metastasis. We also discovered that aldehyde dehydrogenase (ALDH, a stem cell marker) activity is higher in K7M2 cells than K12 cells. Rapamycin treatment reduces the expression and enzymatic activity of ALDH in K7M2 cells. ALDH inhibition renders these cells more susceptible to apoptotic death when exposed to oxidative stress. Furthermore, rapamycin treatment reduces bone morphogenetic protein-2 (BMP2) and vascular endothelial growth factor (VEGF) gene expression and inhibits K7M2 proliferation, migration, and invasionin vitro. Inhibition of ALDH with disulfiram correlated with decreased mTOR expression and activity. In conclusion, we provide evidence for interaction between mTOR activity, ALDH activity, and metastatic potential in murine OS cells. Our work suggests that mTOR and ALDH are therapeutic targets for the treatment and prevention of OS metastasis.


2015 ◽  
Vol 36 (5) ◽  
pp. 1961-1970 ◽  
Author(s):  
Dong-dong Cheng ◽  
Tu Hu ◽  
Hui-zhen Zhang ◽  
Jin Huang ◽  
Qing-cheng Yang

Background/Aims: This aim of the present study was to identify specific markers determining the recurrence of the giant cell tumor of bone (GCTB). Methods: This study involved the clinicopathological analysis of 80 cases. All of the clinical features, pathological fracture, Campanacci grade, histological features and surgical methods were reviewed. Immunohistochemistry was used to detect the expression of Ki-67, CD147, mutant p53 and p63 in GCTB. Comparisons between different groups were performed using the Chi-square test. The risk factors affecting recurrence were analyzed using a binary logistic model. Kaplan-Meier analysis was employed for the survival analysis between the groups. Cell proliferation assays, migration and invasion assays were used to detect the function of CD147 on GCTB in vitro. Results: The univariate analysis showed that Ki-67 and CD147 expression, pathological fracture, Campanacci grade and surgical method were associated with recurrence. The multivariate analysis revealed that CD147 expression, Campanacci grade and surgical method were the factors affecting GCTB recurrence. In addition, the Kaplan-Meier analysis revealed that these factors affected tumor-free survival time. In vitro study revealed that the CD147 knockdown by small interfering RNA (siRNA) technique dramatically reduced the proliferation, migration and invasion of GCTB. Conclusion: Our results suggest that CD147 may serve as an adequate marker for GCTB recurrence. Campanacci grade is a risk factor for GCTB recurrence, which is also affected by the surgical method used.


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