Chemoprevention of Tumors: The Role of RAR-Beta

2003 ◽  
Vol 18 (1) ◽  
pp. 78-81 ◽  
Author(s):  
S. Toma ◽  
L. Emionite ◽  
G. Fabia ◽  
N. Spadini ◽  
L. Vergani
Keyword(s):  
Animal Model ◽  
Invasive Cancer ◽  
Model Studies ◽  
Chemical Agents ◽  
Different Types ◽  
Scientific Rationale ◽  
Cellular Alterations

Chemoprevention can be defined as the use of specific natural or synthetic chemical agents to reverse, suppress, or prevent carcinogenic progression to invasive cancer. The knowledge of carcinogenic mechanisms provides the scientific rationale for chemoprevention. Epithelial carcinogenesis proceeds through multiple discernible stages of molecular and cellular alterations. Understanding of the multistep nature of carcinogenesis has evolved through highly controlled animal carcinogenesis studies, and these studies have identified three distinct phases: initiation, promotion and progression. Animal model studies have provided evidence that the development of cancer involves many different factors, including alterations in the structures and functions of different genes. Transitions between successive stages can be enhanced or inhibited in the laboratory by different types of agents, such activities providing the fundamental basis for chemoprevention.

scholarly journals The Role of Osteopontin in Amyotrophic Lateral Sclerosis: A Systematic Review

2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Seyed Vahid Mousavi ◽  
Elmira Agah ◽  
Abbas Tafakhori
Keyword(s):  
Animal Model ◽  
Amyotrophic Lateral Sclerosis ◽  
Cortical Neurons ◽  
Human Studies ◽  
Cochrane Library ◽  
Control Group ◽  
Model Studies ◽  
Als Patients ◽  
Lateral Sclerosis

Context: Osteopontin (OPN) is a matrix phosphoprotein expressed by a variety of tissues and cells, including the immune system and the nervous system. Previous studies have shown that OPN may have a role in neurodegenerative diseases, including multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease. Objectives: The present study aimed to systematically review studies investigating the role of OPN in amyotrophic lateral sclerosis (ALS) patients or the disease animal model. Evidence Acquisition: We searched the Cochrane Library, PubMed, Web of Science, and Scopus to find relevant articles published up to January 20, 2019. Both human and animal model studies of ALS were considered. Results: A total of nine articles (four human studies and five animal model studies) were included. Two of the human studies reported that the CSF levels of OPN were higher among ALS patients compared to controls. The other two human studies found that OPN levels in cortical neurons did not differ significantly between ALS cases and the non-neurological control group. One of the studies found that the expression level of OPN in astrocytes was similar between ALS patients and the control group, but the level of microglial OPN significantly increased in ALS cases. Four of the animal model studies reported that the expression of OPN mRNA in spinal cord microglia significantly increased during the disease progression. The remaining animal model study found that OPN was selectively expressed by fast fatigue-resistant and slow motor neurons (MNs), which are resistant to ALS, and that the OPN expression was low among fast-fatigable MNs. Conclusions: Prompt microglial activation is a hallmark pathology of ALS, and OPN is among the most widely expressed proteins by these activated glial cells. Therefore, OPN might have a role in ALS pathogenesis. The existing evidence is not sufficient to justify whether OPN has a neurotoxic or neuroprotective role in ALS. We encourage researchers to investigate the role of OPN in ALS pathogenesis more extensively.

scholarly journals Regulating Retinoic Acid Availability during Development and Regeneration: The Role of the CYP26 Enzymes

2020 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Catherine Roberts
Keyword(s):  
Animal Model ◽  
Cytochrome P450 ◽  
Retinoic Acid ◽  
Receptor Binding ◽  
Genetic Disease ◽  
Signalling Pathway ◽  
Human Genetic Disease ◽  
Model Studies ◽  
And Function

This review focuses on the role of the Cytochrome p450 subfamily 26 (CYP26) retinoic acid (RA) degrading enzymes during development and regeneration. Cyp26 enzymes, along with retinoic acid synthesising enzymes, are absolutely required for RA homeostasis in these processes by regulating availability of RA for receptor binding and signalling. Cyp26 enzymes are necessary to generate RA gradients and to protect specific tissues from RA signalling. Disruption of RA homeostasis leads to a wide variety of embryonic defects affecting many tissues. Here, the function of CYP26 enzymes is discussed in the context of the RA signalling pathway, enzymatic structure and biochemistry, human genetic disease, and function in development and regeneration as elucidated from animal model studies.

Effects of topical and general anesthetic agents on tracheal mucous velocity of sheep

1975 ◽  
Vol 38 (5) ◽  
pp. 946-948 ◽  
Author(s):  
J. F. Landa ◽  
J. A. Hirsch ◽  
M. I. Lebeaux
Keyword(s):  
Animal Model ◽  
Average Velocity ◽  
General Anesthetic ◽  
Tracheal Mucosa ◽  
Transnasal Approach ◽  
Anesthetic Agents ◽  
Chemical Agents ◽  
Different Types ◽  
Conscious Sheep ◽  
Physical And Chemical

Tracheal mucous velocity was estimated in eleven sheep by means of cine-bronchofiberscopic technique in which Teflon discs placed on the tracheal mucosa were filmed as markers. The procedure was done using a transnasal approach in conscious nonanesthetized sheep, and in the same sheep using topical and/or general anesthetic agents. The average mucous velocity in conscious sheep was 17.3 plus or minus 6.2 (SD) mm/min; in sheep anesthetized with intravenous pentobarbital or thioamylal, the average velocity was significantly depressed to 11.1 plus or minus 3.6 mm/min. No Significant differences in tracheal mucous velocity were found when 10 ml of 2 percent lidocaine was instilled into the tracheas of either conscious sheep or sheep under general anesthesia. Sheep as an animal model appear to be ideal in the study of the responses of tracheal mucous velocity to physical and chemical agents since they tolerate bronchofiberscopy quite well without the use of topical or general anesthetic agents. The basis for the depression of tracheal mucous velocity by barbiturates cannot be ascertained from the present study but the model should be useful for comparing different types of anesthetic agents.

Controversies Surrounding the Pathophysiology of Tics

2019 ◽  
Vol 34 (13) ◽  
pp. 851-862 ◽  
Author(s):  
Harvey S. Singer ◽  
Farhan Augustine
Keyword(s):  
Animal Model ◽  
Basal Ganglia ◽  
Tourette Syndrome ◽  
Model Studies ◽  
Complex Interactions ◽  
Motor Movements ◽  
Premonitory Urge ◽  
Underlying Pathophysiology

Tics are sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations (phonic productions) that are commonly present in children and are required symptoms for the diagnosis of Tourette syndrome. Despite their frequency, the underlying pathophysiology of tics/Tourette syndrome remains unknown. In this review, we discuss a variety of controversies surrounding the pathophysiology of tics, including the following: Are tics voluntary or involuntary? What is the role of the premonitory urge? Are tics due to excess excitatory or deficient inhibition? Is it time to adopt the contemporary version of the cortico-basal ganglia-thalamocortical (CBGTC) circuit? and Do we know the primary abnormal neurotransmitter in Tourette syndrome? Data from convergent clinical and animal model studies support complex interactions among the various CBGTC sites and neurotransmitters. Advances are being made; however, numerous pathophysiologic questions persist.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

The Diagnosis of Lupus Anticoagulants by the Activated Partial Thromboplastin Time - The Central Role of Phosphatidyl Serine

1984 ◽  
Vol 52 (02) ◽  
pp. 172-175 ◽  
Author(s):  
P R Kelsey ◽  
K J Stevenson ◽  
L Poller
Keyword(s):  
Screening Method ◽  
Coagulation Factors ◽  
Phosphatidyl Serine ◽  
Test System ◽  
Specific Factor ◽  
Marginal Effect ◽  
Constant Composition ◽  
Lupus Anticoagulants ◽  
Different Types

SummaryLiposomes of pure phospholipids were used in a modified APTT test system and the role of phosphatidyl serine (PS) in determining the sensitivity of the test system to the presence of lupus anticoagulants was assessed. Six consecutive patients with lupus anticoagulants and seven haemophiliacs with anticoagulants directed at specific coagulation factors, were studied. Increasing the concentration of phospholipid in the test system markedly reduced the sensitivity to lupus anticoagulants but had marginal effect on the specific factor inhibitors. The same effect was achieved when the content of PS alone was increased in a vehicle liposome of constant composition.The results suggest that the lupus anticoagulants can best be detected by a screening method using an APTT test with a reagent of low PS content. The use of a reagent rich in PS will largely abolish the lupus anticoagulant’s effect on the APTT. An approach using the two different types of reagent may facilitate differentiation of lupus inhibitors from other types of anticoagulant.

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