An Experimental Low-Cost Ultrasonic Phacoemulsifier—A Prototype Test

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Branislav Tomasevic ◽  
Srdjan Glisovic ◽  
Ruzica Jankovic-Tomasevic
Keyword(s):  
Animal Studies ◽  
Heat Dissipation ◽  
Low Cost ◽  
Specific Power ◽  
Surgical Trauma ◽  
In Vitro Experiments ◽  
Original Design ◽  
Prototype Test ◽  
Medium Hardness

The structure and the features of a low-cost ultrasonic phacoemulsification prototype device are described in this paper. The phacoemulsifier was designed to comply with the techniques of modern cataract surgery. The functionality and reliability of the device were confirmed through in vitro experiments and animal studies. The device was designed to minimize surgical trauma: Reduced heat dissipation was achieved by specific power modulation, while the original design of aspiration control assured a reduced surge effect. In order to assess the suitability of the device, phacoemulsification was performed on rabbit eyes with nuclei of medium hardness. Their recovery was closely observed and only mild inflammation caused by surgical trauma was noticed. The device performed well in terms of reliability, ergonomics, and controllability throughout the experiments.

A Prototype Infant Incubator for Heliox Therapy

2006 ◽  
Vol 40 (2) ◽  
pp. 150-163 ◽  
Author(s):  
Clifford J. Singhaus ◽  
Suzanne M. Touch ◽  
Jay S. Greenspan ◽  
Marla R. Wolfson ◽  
Thomas H. Shaffer
Keyword(s):  
Neonatal Intensive Care ◽  
Animal Studies ◽  
Performance Criteria ◽  
In Vitro Tests ◽  
Original Design ◽  
Experimental Conditions ◽  
Infant Incubator ◽  
Opening And Closing

Abstract Heliox (Hx) gas has been shown to improve pulmonary function in infants, but methods for its delivery are invasive and problematic. To this end, we modified an Isolette (Hill-Rom Air-Shields) infant incubator (Hxl) to deliver Hx respiratory gas mixtures noninvasively while providing thermal stability for neonatal care in the Neonatal Intensive Care Unit (NICU). In vitro tests and in vivo animal studies were performed to compare the original design specifications and established baseline performance criteria for the Hxl design. The experimental environments at 50% and 80% relative humidity (RH) consisted of helium (He) with 21% and 50% O2 and control (C) of 21% and 50% O2 with the balance nitrogen (N2). Elapsed times to steady state (SS) and recovery time back to SS (OCDss) due to opening and closing the door were recorded for each variable. All rabbits survived and appeared comfortable during all experimental conditions. These data show that the newly designed Isolette provides similar thermal, O2, CO2, and RH responses as the control incubator. Based on these positive safety/efficacy studies, study of the therapeutic impact of Hxl care on neonatal growth and development is in progress.

scholarly journals Update on the Effects of Antioxidants on Diabetic Retinopathy: In Vitro Experiments, Animal Studies and Clinical Trials

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 561 ◽  
Author(s):  
Jose Javier Garcia-Medina ◽  
Elena Rubio-Velazquez ◽  
Elisa Foulquie-Moreno ◽  
Ricardo P Casaroli-Marano ◽  
Maria Dolores Pinazo-Duran ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Diabetic Retinopathy ◽  
Animal Studies ◽  
Pressure Control ◽  
Vascular Endothelial Growth Factors ◽  
Vascular Endothelial ◽  
In Vitro Experiments ◽  
Current Therapies ◽  
Endothelial Growth Factors

Current therapies for diabetic retinopathy (DR) incorporate blood glucose and blood pressure control, vitrectomy, photocoagulation, and intravitreal injections of anti-vascular endothelial growth factors or corticosteroids. Nonetheless, these techniques have not been demonstrated to completely stop the evolution of this disorder. The pathophysiology of DR is not fully known, but there is more and more evidence indicating that oxidative stress is an important mechanism in the progression of DR. In this sense, antioxidants have been suggested as a possible therapy to reduce the complications of DR. In this review we aim to assemble updated information in relation to in vitro experiments, animal studies and clinical trials dealing with the effect of the antioxidants on DR.

scholarly journals Pro-Aging Effects of Xanthine Oxidoreductase Products

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 839
Author(s):  
Maria Giulia Battelli ◽  
Massimo Bortolotti ◽  
Andrea Bolognesi ◽  
Letizia Polito
Keyword(s):  
Animal Studies ◽  
Reactive Oxygen ◽  
Genetic Constitution ◽  
Xanthine Oxidoreductase ◽  
In Vitro Experiments ◽  
Nitrogen Species ◽  
Aging Effects ◽  
Physiological Pathways ◽  
Environmental Causes

The senescence process is the result of a series of factors that start from the genetic constitution interacting with epigenetic modifications induced by endogenous and environmental causes and that lead to a progressive deterioration at the cellular and functional levels. One of the main causes of aging is oxidative stress deriving from the imbalance between the production of reactive oxygen (ROS) and nitrogen (RNS) species and their scavenging through antioxidants. Xanthine oxidoreductase (XOR) activities produce uric acid, as well as reactive oxygen and nitrogen species, which all may be relevant to such equilibrium. This review analyzes XOR activity through in vitro experiments, animal studies and clinical reports, which highlight the pro-aging effects of XOR products. However, XOR activity contributes to a regular level of ROS and RNS, which appears essential for the proper functioning of many physiological pathways. This discourages the use of therapies with XOR inhibitors, unless symptomatic hyperuricemia is present.

Neurofilaments and Paired Helical Filaments

1985 ◽  
Vol 43 ◽  
pp. 740-743
Author(s):  
J. Metuzals
Keyword(s):  
Animal Model ◽  
Posttranslational Modifications ◽  
Posttranslational Modification ◽  
Giant Axon ◽  
Paired Helical Filaments ◽  
Squid Giant Axon ◽  
In Vitro Experiments ◽  
Thin Sections ◽  
Structural Relationships

It has been demonstrated that the neurofibrillary tangles in biopsies of Alzheimer patients, composed of typical paired helical filaments (PHF), consist also of typical neurofilaments (NF) and 15nm wide filaments. Close structural relationships, and even continuity between NF and PHF, have been observed. In this paper, such relationships are investigated from the standpoint that the PHF are formed through posttranslational modifications of NF. To investigate the validity of the posttranslational modification hypothesis of PHF formation, we have identified in thin sections from frontal lobe biopsies of Alzheimer patients all existing conformations of NF and PHF and ordered these conformations in a hypothetical sequence. However, only experiments with animal model preparations will prove or disprove the validity of the interpretations of static structural observations made on patients. For this purpose, the results of in vitro experiments with the squid giant axon preparations are compared with those obtained from human patients. This approach is essential in discovering etiological factors of Alzheimer's disease and its early diagnosis.

Decellularized bone extracellular matrix in skeletal tissue engineering

2020 ◽  
Vol 48 (3) ◽  
pp. 755-764
Author(s):  
Benjamin B. Rothrauff ◽  
Rocky S. Tuan
Keyword(s):  
Tissue Engineering ◽  
Bone Regeneration ◽  
Tissue Regeneration ◽  
Animal Studies ◽  
Tumor Resection ◽  
Regenerative Capacity ◽  
Skeletal Tissue ◽  
Large Bone

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms — whole organ, particles, hydrogels — has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.

Modulation of Matrix Metalloproteinases by Plant-Derived Products

2020 ◽  
Vol 20 ◽  
Author(s):  
Nur Najmi Mohamad Anuar ◽  
Nurul Iman Natasya Zulkafali ◽  
Azizah Ugusman
Keyword(s):  
Clinical Trials ◽  
Natural Products ◽  
Matrix Metalloproteinases ◽  
Animal Studies ◽  
Current Knowledge ◽  
In Vitro Models ◽  
In Vivo Studies ◽  
Extracellular Matrix Components

: Matrix metalloproteinases (MMPs) are a group of zinc-dependent metallo-endopeptidase that are responsible towards the degradation, repair and remodelling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic and food industries. This review summarises the current knowledge on plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signalling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviours, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.

Natural Bioactive Compounds As Adjuvant Therapy For Hepatitis C Infection

2020 ◽  
Vol 16 ◽  
Author(s):  
Moema S. Santana ◽  
Rute Lopes ◽  
Isabela H. Peron ◽  
Carla R. Cruz ◽  
Ana M. M. Gaspar ◽  
...  
Keyword(s):  
Hepatitis C ◽  
Bioactive Compounds ◽  
Low Cost ◽  
Chemical Diversity ◽  
Acute Hepatitis C ◽  
Hepatitis C Infection ◽  
Middle Income ◽  
Broad Perspective ◽  
Cost Of Production

Background: Hepatitis C virus infection is a significant global health burden, which causes acute or chronic hepatitis. The acute hepatitis C is generally asymptomatic and progresses to cure, while persistent infection can progress to chronic liver disease and extrahepatic manifestations. Standard treatment is expensive, poorly tolerated, and has variable sustained virologic responses amongst the different viral genotypes. New therapies involve direct acting antivirals; however, it is also very expensive and may not be accessible for all patients worldwide. In order to provide a complementary approach to the already existing therapies, natural bioactive compounds are investigated as to their several biologic activities, such as direct antiviral properties against hepatitis C, and effects on mitigating chronic progression of the disease, which includes hepatoprotective, antioxidant, anticarcinogenic and anti-inflammatory activities; additionally, these compounds present advantages, as chemical diversity, low cost of production and milder or inexistent side effects. Objective: To present a broad perspective on hepatitis C infection, the chronic disease, and natural compounds with promising anti-HCV activity. Methods: This review consists of a systematic review study about the natural bioactive compounds as a potential therapy for hepatitis C infection. Results: The quest for natural products have yielded compounds with biologic activity, including viral replication inhibition in vitro, demonstrating antiviral activity against hepatitis C. Conclusion: One of the greatest advantages of using natural molecules from plant extracts is the low cost of production, not requiring chemical synthesis, which can lead to less expensive therapies available to low and middle-income countries.

Protective Effect of Isothiocyanates from Cruciferous Vegetables on Breast Cancer: Epidemiological and Preclinical Perspectives

2020 ◽  
Vol 20 ◽  
Author(s):  
Suong N.T. Ngo ◽  
Desmond B. Williams
Keyword(s):  
Breast Cancer ◽  
Protective Effect ◽  
Animal Studies ◽  
Cancer Survival ◽  
Breast Cancer Survival ◽  
Human Studies ◽  
In Vitro Studies ◽  
Cochrane Library ◽  
Cruciferous Vegetables

Background: The effect of cruciferous vegetable intake on breast cancer survival is controversial at present. Glucosinolates are the naturally occurring constituents found across the cruciferous vegetables. Isothiocyanates are produced from the hydrolysis of glucosinolates and this reaction is catalysed by the plant-derived enzyme myrosinase. The main isothiocyanates (ITCs) from cruciferous vegetables are sulforaphane, benzyl ITC, and phenethyl ITC, which had been intensively investigated over the last decade for their antibreast cancer effects. Objective: The aim of this article is to systematically review the evidence from all types of studies, which examined the protective effect of cruciferous vegetables and/or their isothiocyanate constituents on breast cancer. Methods: A systematic review was conducted in Pubmed, EMBASE, and the Cochrane Library from inception to 27 April 2020. Peerreviewed studies of all types (in vitro studies, animal studies, and human studies) were selected. Results: The systematic literature search identified 16 human studies, 4 animal studies, and 65 in vitro studies. The effect of cruciferous vegetables and/or their ITCs intake on breast cancer survival was found to be controversial and varied greatly across human studies. Most of these trials were observational studies conducted in specific regions, mainly in the US and China. Substantial evidence from in vitro and animal studies was obtained, which strongly supported the protective effect of sulforaphane and other ITCs against breast cancer. Evidence from in vitro studies showed sulforaphane and other ITCs reduced cancer cell viability and proliferation via multiple mechanisms and pathways. Isothiocyanates inhibited cell cycle, angiogenesis and epithelial mesenchymal transition, as well as induced apoptosis and altered the expression of phase II carcinogen detoxifying enzymes. These are the essential pathways which promote the growth and metastasis of breast cancer. Noticeably, benzyl ITC showed a significant inhibitory effect on breast cancer stem cells, a new dimension of chemoresistance in breast cancer treatment. Sulforaphane and other ITCs displayed anti-breast cancer effects at variable range of concentrations and benzyl isothiocyanate appeared to have a relatively smallest inhibitory concentration IC50. The mechanisms underlying the cancer protective effect of sulforaphane and other ITCs have also been highlighted in this article. Conclusion: Current preclinical evidence strongly supports the role of sulforaphane and other ITCs as potential therapeutic agents for breast cancer, either as adjunct therapy or combined therapy with current anti-breast cancer drugs, with sulforaphane appeared to display the greatest potential.

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