237 research outputs found

    Androgen action via testicular arteriole smooth muscle cells is important for leydig cell function, vasomotion and testicular fluid dynamics

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    Regulation of blood flow through the testicular microvasculature by vasomotion is thought to be important for normal testis function as it regulates interstitial fluid (IF) dynamics which is an important intra-testicular transport medium. Androgens control vasomotion, but how they exert these effects remains unclear. One possibility is by signalling via androgen receptors (AR) expressed in testicular arteriole smooth muscle cells. To investigate this and determine the overall importance of this mechanism in testis function, we generated a blood vessel smooth muscle cell-specific AR knockout mouse (SMARKO). Gross reproductive development was normal in SMARKO mice but testis weight was reduced in adulthood compared to control littermates; this reduction was not due to any changes in germ cell volume or to deficits in testosterone, LH or FSH concentrations and did not cause infertility. However, seminiferous tubule lumen volume was reduced in adult SMARKO males while interstitial volume was increased, perhaps indicating altered fluid dynamics; this was associated with compensated Leydig cell failure. Vasomotion was impaired in adult SMARKO males, though overall testis blood flow was normal and there was an increase in the overall blood vessel volume per testis in adult SMARKOs. In conclusion, these results indicate that ablating arteriole smooth muscle AR does not grossly alter spermatogenesis or affect male fertility but does subtly impair Leydig cell function and testicular fluid exchange, possibly by locally regulating microvascular blood flow within the testis

    Sertoli cell proliferation during the post hatching period in domestic fowl

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    There has been no study aimed at directly determining of the periods of Sertoli cell proliferation in birds even domestic fowl. The aims of this study were to observe the cessation of post-hatching mitotic proliferation of Sertoli cells in domestic fowl, and to determine the volume density of Sertoli and germ cells during this period. A total of 50 Leghorn chicks were used in this study. The testes sections of the animals were immunostained with BrdU to observe the proliferation of cells from one to 10 weeks of age. The volume density of the Sertoli and germ cells were determined using the standard point counting method. The volume density of the germ cell nuclei was initially less than that of the Sertoli cells but the volume density converged by week 6, and remained relatively constant until the commencement of meiosis. Clear labeling of Sertoli and germ cells was observed from week 1 to week 7. The only those cells still labeled after 8 weeks were germ cells, indicating that Sertoli cell proliferation had ceased. Therefore, it is recommended that any research into the testes of domestic fowl should consider the cessation of Sertoli cell proliferation by approximately 8 weeks

    Adipose-derived stem cells as a remedy

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    Adipobiology of stem cells is reaching enthusiastic proportions in today's regenerative medicine. Current interest in the adipose-derived stem cells (ADSC) stems from their multilineage differentiation potential, and ease of derivation in larger quantities using less invasive methods, compared with other stem cell types. The possible benefits of ADSC-based therapy may be mediated by both cell proliferation/differentiation and paracrine secretion. Adipose tissue's secretome includes adipokines (growth factors, cytokines, chemokines, neuropeptides, hypothalamic hormones/releasing factors), steroid hormones, free fatty acids, prostaglandins, and endocannabinoids. The present review, focusing on adipose tissue secretory activity, also highlights the possible implication of ADSC in the therapy of various disorders, particularly neurodegenerative diseases, myocardial infarction and stroke as well as gut, liver and skin diseases.Adipobiology 2010; 2: 51-56

    Emerging properties of financial time series in the “Game of Life”

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    We explore the spatial complexity of Conway’s “Game of Life,” a prototypical cellular automaton by means of a geometrical procedure generating a two-dimensional random walk from a bidimensional lattice with periodical boundaries. The one-dimensional projection of this process is analyzed and it turns out that some of its statistical properties resemble the so-called stylized facts observed in financial time series. The scope and meaning of this result are discussed from the viewpoint of complex systems. In particular, we stress how the supposed peculiarities of financial time series are, often, overrated in their importance

    The adipose tissue: a new member of the diffuse neuroendocrine system?

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    Adipose tissue is a sophisticated module, consisting of adipocytes and non-adipocyte cellular elements including stromal, vascular, nerve and immune cells. There is at present evidence that sharing of ligands and their receptors constitutes a molecular language of the human's body, which is also the case for adipose tissue and hypothalamus-pituitary gland. Historically, Nikolai Kulchitsky's identification of the enterochromaffin cell in 1897 formed the basis for the subsequent delineation of the diffuse neuroendocrine system (DNES) by Friedrich Feyrter in 1938. In DNES paradigm, the secretion of hormones, neuropeptides and neurotrophic factors is executed by cells disseminated throughout the body, for example, Kulchitsky (enterochromaffin) cells, testicular Leydig cells, and hepatic stellate cells. Here we propose that the adipose tissue might be a new member of DNES. Today (dnes, in Bulgarian), adipose tissue is "getting nervous" indeed: (i) synthesizes neuropeptides, neurotrophic factors, neurotransmitters, hypothalamic hormones/releasing factors and their receptors, (ii) like brain expresses endocannabinoids and amyloid precursor protein and, for steroidogenesis, the enzyme aromatase (P450arom), (iii) adipocytes may originate from the neural crest cells, and (iv) adipose-derived stem cells may differentiate into neuronal cells. Further molecular profiling of adipose tissue may provide new biological insights on its neuroendocrine potential. Overall this may frame a novel field of study, neuroadipobiology; its development and clinical application may contribute to the improvement of human's health.Adipobiology 2009; 1: 87-93

    Conifers phytochemicals: A valuable forest with therapeutic potential

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    Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.This research was funded by University of Hradec Kralove (Faculty of Science VT 2019-2021)

    Apium plants: Beyond simple food and phytopharmacological applications

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    Apium plants belong to the Apiaceae family and are included among plants that have been in use in traditional medicine for thousands of years worldwide, including in the Mediterranean, as well as the tropical and subtropical regions of Asia and Africa. Some highlighted medical benefits include prevention of coronary and vascular diseases. Their phytochemical constituents consist of bergapten, flavonoids, glycosides, furanocoumarins, furocoumarin, limonene, psoralen, xanthotoxin, and selinene. Some of their pharmacological properties include anticancer, antioxidant, antimicrobial, antifungal, nematocidal, anti-rheumatism, antiasthma, anti-bronchitis, hepatoprotective, appetizer, anticonvulsant, antispasmodic, breast milk inducer, anti-jaundice, antihypertensive, anti-dysmenorrhea, prevention of cardiovascular diseases, and spermatogenesis induction. The present review summarizes data on ecology, botany, cultivation, habitat, medicinal use, phytochemical composition, preclinical and clinical pharmacological efficacy of Apium plants and provides future direction on how to take full advantage of Apium plants for the optimal benefit to mankind.N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)

    Performance of the Linear Ion Trap Mass Spectrometer for the Mars Organic Molecule Analyzer (MOMA) Investigation on the 2018 Exomars Rover

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    The 2018 ExoMars rover mission includes the Mars Organic Molecule Analyzer (MOMA) investigation. MOMA will examine the chemical composition of samples acquired from depths of up to two meters below the martian surface, where organics may be protected from degradation derived from cosmic radiation and/or oxidative chemical reactions. When combined with the complement of instruments in the rover's Pasteur Payload, MOMA has the potential to reveal the presence of a wide range of organics preserved in a variety of mineralogical environments, and to begin to understand the structural character and potential origin of those compounds. The MOMA investigation is led by the Max Planck Institute for Solar System Research (MPS) with the mass spectrometer subsystem provided by NASA GSFC. MOMA's linear ion trap mass spectrometer (ITMS) is designed to analyze molecular composition of: (i) gas evolved from pyrolyzed powder samples and separated in a gas chromatograph; and, (ii) ions directly desorbed from crushed solid samples at Mars ambient pressure, as enabled by a pulsed UV laser system, fast-actuating aperture valve and capillary ion inlet. Breadboard ITMS and associated electronics have been advanced to high end-to-end fidelity in preparation for flight hardware delivery to Germany in 2015
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