scholarly journals Free Radicals in Adolescent Varicocele Testis

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Carmelo Romeo ◽  
Giuseppe Santoro
Keyword(s):  
Free Radicals ◽  
Nitrosative Stress ◽  
Antioxidant Defenses ◽  
Seminiferous Tubules ◽  
Oxidative And Nitrosative Stress ◽  
Medline Search ◽  
Morphological Studies ◽  
Hormonal Dysfunction ◽  
And Function ◽  
The Relationship

We examine the relationship between the structure and function of the testis and the oxidative and nitrosative stress, determined by an excessive production of free radicals and/or decreased availability of antioxidant defenses, which occur in the testis of adolescents affected by varicocele. Moreover, the effects of surgical treatment on oxidative stress were provided. We conducted a PubMed and Medline search between 1980 and 2014 using “adolescent,” “varicocele,” “free radicals,” “oxidative and nitrosative stress,” “testis,” and “seminiferous tubules” as keywords. Cross-references were checked in each of the studies, and relevant articles were retrieved. We conclude that increased concentration of free radicals, generated by conditions of hypoxia, hyperthermia, and hormonal dysfunction observed in adolescent affected by varicocele, can harm germ cells directly or indirectly by influencing nonspermatogenic cells and basal lamina. With regard to few available data in current literature, further clinical trials on the pre- and postoperative ROS and RNS levels together with morphological studies of the cellular component of the testis are fundamental for complete comprehension of the role played by free radicals in the pathogenesis of adolescent varicocele and could justify its pharmacological treatment with antioxidants.

scholarly journals Myeloperoxidase-Related Chlorination Activity Is Positively Associated with Circulating Ceruloplasmin in Chronic Heart Failure Patients: Relationship with Neurohormonal, Inflammatory, and Nutritional Parameters

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Aderville Cabassi ◽  
Simone Maurizio Binno ◽  
Stefano Tedeschi ◽  
Gallia Graiani ◽  
Cinzia Galizia ◽  
...  
Keyword(s):  
Heart Failure ◽  
Nitrosative Stress ◽  
Defense Mechanism ◽  
Nyha Class ◽  
Protein Nitration ◽  
Class Iii ◽  
Oxidative And Nitrosative Stress ◽  
Radical Production ◽  
Antioxidant Function ◽  
The Relationship

Rationale. Heart failure (HF) is accompanied by the development of an imbalance between oxygen- and nitric oxide-derived free radical production leading to protein nitration. Both chlorinating and peroxidase cycle of Myeloperoxidase (MPO) contribute to oxidative and nitrosative stress and are involved in tyrosine nitration of protein. Ceruloplasmin (Cp) has antioxidant function through its ferroxidase I (FeOxI) activity and has recently been proposed as a physiological defense mechanism against MPO inappropriate actions.Objective. We investigated the relationship between plasma MPO-related chlorinating activity, Cp and FeOxI, and nitrosative stress, inflammatory, neurohormonal, and nutritional biomarkers in HF patients.Methods and Results. In chronic HF patients (n=81, 76±9 years, NYHA Class II (26); Class III (29); Class IV (26)) and age-matched controls (n=17, 75±11 years, CTR), plasma MPO chlorinating activity, Cp, FeOxI, nitrated protein, free Malondialdehyde, BNP, norepinephrine, hsCRP, albumin, and prealbumin were measured. Plasma MPO chlorinating activity, Cp, BNP, norepinephrine, and hsCRP were increased in HF versus CTR. FeOxI, albumin, and prealbumin were decreased in HF. MPO-related chlorinating activity was positively related to Cp (r= 0.363,P<0.001), nitrated protein, hsCRP, and BNP and inversely to albumin.Conclusions. Plasma MPO chlorinated activity is increased in elderly chronic HF patients and positively associated with Cp, inflammatory, neurohormonal, and nitrosative parameters suggesting a role in HF progression.

Relationship between testicular morphology and sperm production following ischaemia in the ram

1995 ◽  
Vol 7 (1) ◽  
pp. 119 ◽  
Author(s):  
CM Markey ◽  
AM Jequier ◽  
GT Meyer ◽  
GB Martin
Keyword(s):  
Morphological Changes ◽  
Sperm Concentration ◽  
Testicular Biopsy ◽  
Seminiferous Tubules ◽  
Testis Weight ◽  
Infertile Men ◽  
Testicular Morphology ◽  
And Function ◽  
The Relationship ◽  
Spermatogenic Epithelium

Arteriosclerosis was induced in the internal spermatic artery of rams to determine if this condition is implicated in the aetiology of testicular pathology which causes male infertility. Data were collected on sperm concentration and motility for 56 days following surgery to provide an index of testicular function. Testes were then weighed and a testicular biopsy score count was performed on histological sections to assess spermatogenic potential of seminiferous tubules. Vascular disturbance caused focal damage of the seminiferous epithelium, similar to that seen among infertile men, and a reduction in ejaculate volume, sperm concentration and sperm motility. Sperm concentration decreased following ischaemia yet was maintained to some degree by a germ-cell depleted spermatogenic epithelium. Normal testicular morphology was maintained above a testis weight of about 120 g (for an individual testis), but below this threshold spermatogenesis was severely impaired. In conclusion, these data have provided information on the relationship between testicular morphology and function following ischaemia in the ram. Furthermore, the morphological changes induced in the testis were similar to those seen among infertile men and, by their focal nature, could explain the distinction between oligozoospermia and azoospermia in men exhibiting spermatogenic arrest.

The Relationship of Form and Function of Minute Characters of Lepidopterous Larvae, and its Importance in Life-History Studies

1964 ◽  
Vol 96 (7) ◽  
pp. 991-1004 ◽  
Author(s):  
Margaret Rae MacKay
Keyword(s):  
Life History ◽  
Chemical Control ◽  
Life Histories ◽  
The Other ◽  
Taxonomic Study ◽  
Form And Function ◽  
Morphological Studies ◽  
And Function ◽  
Relationship Of ◽  
The Relationship

AbstractThe information to be obtained from thorough life-history studies is an extremely useful tool, perhaps especially so when ecology is being emphasized, as it is to-day, by the life-table and other mathematical approaches to the study of population processes. This information is desired by workers in many fields of entomology – by the biological and chemical control experts, the biomathematicians, the theorists and even the taxonomists. However, much of the knowledge that these workers require, for instance the fine distinctions of behaviour and environment, has been overlooked in most life-history studies, and I strongly suspect that one of the weaknesses of studies of this nature has been the failure to analyse the mode of living of an insect (or, in the case of Lepidoptera, of the immature forms) in relation to the anatomy on one hand and environmental circumstances on the other. To look for these relationships, I believe that one requires (a) the ability and perseverance to perceive detail as minute as that required for a taxonomic study, and (b) a considerable knowledge of the taxonomic detail that is to be obtained from basic morphological studies. Therefore, in this paper, attention is drawn to pertinent structural characters of lepidopterous larvae and their probable connection with the behaviour and microhabitats of the larvae, in the hope that some guidance may be offered to future students of life-histories, at least in Lepidoptera.

Ouabain decreases sarco(endo)plasmic reticulum calcium ATPase activity in rat hearts by a process involving protein oxidation

2006 ◽  
Vol 291 (6) ◽  
pp. H3003-H3011 ◽  
Author(s):  
David J. Kennedy ◽  
Sandeep Vetteth ◽  
Miaorong Xie ◽  
Sankaridrug M. Periyasamy ◽  
Zijian Xie ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Nitrosative Stress ◽  
Spectrometric Analysis ◽  
Oxidative And Nitrosative Stress ◽  
Cardiac Inotropy ◽  
Plasmic Reticulum ◽  
Rat Hearts ◽  
Developed Pressure ◽  
And Function ◽  
Rat Cardiac Myocytes

The effect of cardiac glycosides to increase cardiac inotropy by altering Ca2+ cycling is well known but still poorly understood. The studies described in this report focus on defining the effects of ouabain signaling on sarcoplasmic reticulum Ca2+-ATPase function. Rat cardiac myocytes treated with 50 μM ouabain demonstrated substantial increases in systolic and diastolic Ca2+ concentrations. The recovery time constant for the Ca2+ transient, τ[Formula: see text], was significantly prolonged by ouabain. Exposure to 10 μM H2O2, which causes an increase in intracellular reactive oxygen species similar to that of 50 μM ouabain, caused a similar increase in τ[Formula: see text]. Concurrent exposure to 10 mM N-acetylcysteine or an aqueous extract from green tea (50 mg/ml) both prevented the increases in τ[Formula: see text] as well as the changes in systolic or diastolic Ca2+ concentrations. We also observed that 50 μM ouabain induced increases in developed pressure in addition to diastolic dysfunction in the isolated perfused rat heart. Coadministration of ouabain with N-acetylcysteine prevented these increases. Analysis of sarcoplasmic reticulum Ca2+-ATPase protein revealed increases in both the oxidation and nitrotyrosine content in the ouabain-treated hearts. Liquid chromatography-mass spectrometric analysis confirmed that the sarcoplasmic reticulum Ca2+-ATPase protein from ouabain-treated hearts had modifications consistent with oxidative and nitrosative stress. These data suggest that ouabain induces oxidative changes of the sarcoplasmic reticulum Ca2+-ATPase structure and function that may, in turn, produce some of the associated changes in Ca2+ cycling and physiological function.

scholarly journals Antioxidant potentials of Miyan Kuka (Baobab leaves)

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Eduitem S. Otong ◽  
Sunday A. Musa
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Vitamin C ◽  
Singlet Oxygen ◽  
Nitrosative Stress ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Antioxidant Defenses ◽  
Oxygen Species

Antioxidant is any substance that directly scavenges reactive oxygen species (ROS) or indirectly acts to up-regulate antioxidant defenses or inhibit ROS production. The review is aimed at highlighting the components of baobab leaves with antioxidant capabilities. Articles were searched from the Directory of Open Access Journals, PubMed, Google Scholar, Science Direct using key words such as composition of baobab leaves, antioxidant properties of baobab leaf, reactive oxygen species, oxidative stress and antioxidant. The result showed that boabab leaves are good sources of food with a lot of antioxidant components such as vitamin C, carotenes, flavonoids, zinc etc. These antioxidant components help to regulate ROS including free radicals such as superoxide anion, hydroxyl radical, as well as non-radical molecules like hydrogen peroxide, singlet oxygen. Baobab leaves carry out the antioxidant activities through the following processes: scavenging and neutralizing free radicals, singlet oxygen quenching, superoxide radical scavenging, hydrogen donation, metal chelating, enzymes inhibition, peroxide decomposing and synergies. They also help in activating antioxidant enzymes, reduce α-tocopherol radicals, reduce nitrosative stress, prevent oxidases, and increase levels of uric acid and low molecular weight molecules which ultimately help to reduce oxidation in the long run. Baobab leaves are rich in phytochemicals with a lot of antioxidant capabilities due to the present of several components like vitamin C, carotenes, flavenoids, etc. These components work in different ways to regulate reactive oxygen species and by extension prevent oxidative stress.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

Physicianship and the Rebirth of Medical Education

2018 ◽  
Author(s):  
J. Donald Boudreau ◽  
Eric Cassell ◽  
Abraham Fuks
Keyword(s):  
Medical Education ◽  
Educational Process ◽  
Medical Attention ◽  
Patient Centeredness ◽  
Goals Of Medicine ◽  
The Subject ◽  
Definition Of ◽  
And Function ◽  
William Osler ◽  
The Relationship

This book reimagines medical education and reconstructs its design. It originates from a reappraisal of the goals of medicine and the nature of the relationship between doctor and patient. The educational blueprint outlined is called the “Physicianship Curriculum” and rests on two linchpins. First is a new definition of sickness: Patients know themselves to be ill when they cannot pursue their purposes and goals in life because of impairments in functioning. This perspective represents a bulwark against medical attention shifting from patients to diseases. The curriculum teaches about patients as functional persons, from their anatomy to their social selves, starting in the first days of the educational program and continuing throughout. Their teaching also rests on the rock-solid grounding of medicine in the sciences and scientific understandings of disease and function. The illness definition and knowledge base together create a foundation for authentic patient-centeredness. Second, the training of physicians depends on and culminates in development of a unique professional identity. This is grounded in the historical evolution of the profession, reaching back to Hippocrates. It leads to reformulation of the educational process as clinical apprenticeships and moral mentorships. “Rebirth” in the title suggests that critical ingredients of medical education have previously been articulated. The book argues that the apprenticeship model, as experienced, enriched, taught, and exemplified by William Osler, constitutes a time-honored foundation. Osler’s “natural method of teaching the subject of medicine” is a precursor to the Physicianship Curriculum.

scholarly journals Mitochondrial Sirtuins in Reproduction

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1047
Author(s):  
Giovanna Di Emidio ◽  
Stefano Falone ◽  
Paolo Giovanni Artini ◽  
Fernanda Amicarelli ◽  
Anna Maria D’Alessandro ◽  
...  
Keyword(s):  
Stress Responses ◽  
Metabolic Pathways ◽  
Redox Balance ◽  
Antioxidant Defenses ◽  
Metabolic Abnormalities ◽  
Female Reproduction ◽  
Mitochondrial Dysfunctions ◽  
Early Embryos ◽  
The Relationship

Mitochondria act as hubs of numerous metabolic pathways. Mitochondrial dysfunctions contribute to altering the redox balance and predispose to aging and metabolic alterations. The sirtuin family is composed of seven members and three of them, SIRT3-5, are housed in mitochondria. They catalyze NAD+-dependent deacylation and the ADP-ribosylation of mitochondrial proteins, thereby modulating gene expression and activities of enzymes involved in oxidative metabolism and stress responses. In this context, mitochondrial sirtuins (mtSIRTs) act in synergistic or antagonistic manners to protect from aging and aging-related metabolic abnormalities. In this review, we focus on the role of mtSIRTs in the biological competence of reproductive cells, organs, and embryos. Most studies are focused on SIRT3 in female reproduction, providing evidence that SIRT3 improves the competence of oocytes in humans and animal models. Moreover, SIRT3 protects oocytes, early embryos, and ovaries against stress conditions. The relationship between derangement of SIRT3 signaling and the imbalance of ROS and antioxidant defenses in testes has also been demonstrated. Very little is known about SIRT4 and SIRT5 functions in the reproductive system. The final goal of this work is to understand whether sirtuin-based signaling may be taken into account as potential targets for therapeutic applications in female and male infertility.

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