046. FUTURE PROOFING AUSTRALIA'S MAMMALIAN BIODIVERSITY USING GENOME RESOURCE BANKING AND ART: WHERE ARE WE UP TO?

2009 ◽  
Vol 21 (9) ◽  
pp. 11
Author(s):  
S. D. Johnston ◽  
J. Gosalvez ◽  
W. V. Holt
Keyword(s):  
Structural Changes ◽  
Reproductive Tract ◽  
Sperm Chromatin ◽  
Genetic Management ◽  
Lack Of Information ◽  
Gamete Biology ◽  
High Concentrations ◽  
Chromatin Relaxation ◽  
Holding Back

The establishment of a functional genome resource bank for the genetic management and future proofing of Australian native mammals sounds great in theory, but what is the reality of this idea. In order to understand the current rate of progress in this area, we will present an overview of the inherent structural and physiological limitations of non-eutherian mammalian reproduction in terms of gamete biology and ART. For the male, these include (1) an unique mode of spermatid condensation that imparts the need for major structural changes to sperm morphology during epididymal transit, (2) a lack of cysteine protamines and disulphide bonds in the sperm chromatin that predisposes the nucleus to post-thaw chromatin relaxation, (3) an extremely stable acrosome, which to date, has not been possible to experimentally react in vitro, (4) unusual lipid composition in the plasma membrane that potentially makes the sperm cell resistant to cold shock trauma and (5) the need, in some species, for extremely high concentrations of cryoprotectant, that paradoxically, appear to be cytotoxic to the spermatozoon. Female limitations include, (1) the production of a large yolky oocyte and resulting embryo, making it difficult to cryopreserve, (2) a small and technically challenging complex reproductive tract that makes gamete recovery and artificial insemination problematic and (3) a general lack of information on marsupial reproductive physiology and behaviour that has hindered the development of protocols for timed induction of oestrus and ovulation. We shall also identify, socio-political and ethical limitations holding back the application of assisted breeding technology in these species.

scholarly journals Curcumin Protects the Seminal Vesicles from Metronidazole‑induced Reduction of Secretion in Mice

2012 ◽  
Vol 55 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Ali Noorafshan ◽  
Saied Karbalay‑Doust
Keyword(s):  
Body Weight ◽  
Seminal Vesicle ◽  
Structural Changes ◽  
Reproductive Tract ◽  
Anaerobic Bacteria ◽  
Seminal Vesicles ◽  
Female Reproductive Tract ◽  
Sperm Chromatin ◽  
Control Group ◽  
Negative Effects

Seminal vesicle secretion is important for increasing the stability of sperm chromatin, inhibition of the immune activity in the female reproductive tract and so on. Metronidazole (MTZ), a drug used for treatment of infections caused by anaerobic bacteria and protozoa, may have negative effects on the genital gland including the seminal vesicles. Curcumin exhibits antioxidant as well as anti‑inflammatory properties. The present study aims to evaluate the negative effects of MTZ on the seminal vesicle structure and ameliorative effects of curcumin using stereological methods. Thirty balb/c mice were divided into six groups. The control group was received distilled water. The second and the third received higher doses of MTZ (500 mg/kg body weight/day) and MTZ (500 mg/kg/day) + 100 mg/kg/day curcumin, respectively. The fourth and the fifth were treated with lower doses of MTZ (165 mg/kg body weight/day) and MTZ (165 mg/kg body weight/day) + curcumin (100 mg/kg body weight/day), respectively. The sixth group received 100 mg/kg body weight/day curcumin. All the administrations were done by oral gavages for 14 days. After 30 days, seminal vesicles were removed. Stereological study of the seminal vesicle structure revealed a significant reduction in gland and vesicular fluid volume in MTZ‑treated (higher or lower doses) animals. Curcumin protected the reduction of both parameters in therapeutic‑dose treated animals. Metronidazole treatment does not induce structural changes in the seminal gland; however, it can have a significant impact on its secretion ability. Importantly, these deteriorations might be preventable by curcumin co‑treatment.

scholarly journals In Vitro and Vivo Identification, Metabolism and Action of Xenoestrogens: An Overview

2021 ◽  
Vol 22 (8) ◽  
pp. 4013
Author(s):  
Li-Hsuan Wang ◽  
Li-Ru Chen ◽  
Kuo-Hu Chen
Keyword(s):  
Congenital Malformations ◽  
Chemical Structure ◽  
Reproductive Tract ◽  
Chemical Compounds ◽  
Naturally Occurring ◽  
Hormonal Balance ◽  
Industrial Byproducts ◽  
High Concentrations ◽  
Underlying Mechanisms

Xenoestrogens (XEs) are substances that imitate endogenous estrogens to affect the physiologic functions of humans or other animals. As endocrine disruptors, they can be either synthetic or natural chemical compounds derived from diet, pesticides, cosmetics, plastics, plants, industrial byproducts, metals, and medications. By mimicking the chemical structure that is naturally occurring estrogen compounds, synthetic XEs, such as polychlorinated biphenyls (PCBs), bisphenol A (BPA), and diethylstilbestrol (DES), are considered the focus of a group of exogenous chemical. On the other hand, nature phytoestrogens in soybeans can also serve as XEs to exert estrogenic activities. In contrast, some XEs are not similar to estrogens in structure and can affect the physiologic functions in ways other than ER-ERE ligand routes. Studies have confirmed that even the weakly active compounds could interfere with the hormonal balance with persistency or high concentrations of XEs, thus possibly being associated with the occurrence of the reproductive tract or neuroendocrine disorders and congenital malformations. However, XEs are most likely to exert tissue-specific and non-genomic actions when estrogen concentrations are relatively low. Current research has reported that there is not only one factor affected by XEs, but opposite directions are also found on several occasions, or even different components stem from the identical endocrine pathway; thus, it is more challenging and unpredictable of the physical health. This review provides a summary of the identification, detection, metabolism, and action of XEs. However, many details of the underlying mechanisms remain unknown and warrant further investigation.

THE ACTION OF OXYTOCIN AND SYNTHETIC ANALOGUES ON THE ISOLATED MAMMARY-GLAND MYOEPITHELIUM OF THE LACTATING RAT; EFFECT OF SOME IONS

1967 ◽  
Vol 38 (1) ◽  
pp. 13-24 ◽  
Author(s):  
I. POLÁČEK ◽  
I. KREJČÍ ◽  
J. RUDINGER
Keyword(s):  
Mammary Gland ◽  
Time Course ◽  
Structural Changes ◽  
Contractile Response ◽  
Organ Bath ◽  
Synthetic Analogues ◽  
Uterine Smooth Muscle ◽  
Rat Mammary Gland ◽  
High Concentrations

SUMMARY The contractile response of mammary-gland strips from lactating rats to oxytocin varied with the concentration of calcium ions in the organ bath; calcium could be partially substituted by strontium but not by magnesium. High concentrations of potassium did not substantially affect the response to oxytocin. In these and several other respects the mammary gland myoepithelium resembles uterine smooth muscle, notwithstanding the differences in morphology and embryonal origin. The effects of 12 synthetic analogues of oxytocin modified in sequence positions 1, 2, and 3 of the peptide chain on the rat mammary-gland strip were examined. None of the analogues showed a higher potency than oxytocin. However, the mammary-gland strip was less sensitive to the structural changes represented in this series of analogues than the rat uterus in vitro. The action of some of the analogues on the mammary-gland strip differs from that of oxytocin in the time-course of the response.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Aggregation of Cat Platelets in Vitro

1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp
Keyword(s):  
Adenosine Monophosphate ◽  
Blood Collection ◽  
Base Line ◽  
Reversible Aggregation ◽  
Low Concentrations ◽  
Irreversible Aggregation ◽  
High Concentrations ◽  
Two Phases ◽  
Improved Technique

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.

Thrombin Generation Measured Ex Vivo Following Microvasculor Injury Is Increased in SLE Patients with Antiphospholipid-protein Antibodies

1997 ◽  
Vol 78 (04) ◽  
pp. 1173-1177 ◽  
Author(s):  
Jacek Musiał ◽  
Jakub Swadźba ◽  
Miłosz Jankowski ◽  
Marek Grzywacz ◽  
Stanisława Bazan-Socha ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Thrombin Generation ◽  
Ex Vivo ◽  
Skin Incision ◽  
Anticardiolipin Antibodies ◽  
Small Blood Vessel ◽  
Anionic Phospholipids ◽  
Increased Risk ◽  
High Concentrations

SummaryAntiphospholipid-protein antibodies (APA) include lupus-type anticoagulant (LA) and antibodies recognizing complexes of anionic phospholipids (e.g. cardiolipin) and proteins (e.g. prothrombin and (β2-glycoprotein I). The presence of APA is associated with an increased risk of both arterial and venous thrombosis. However, the pathogenic mechanism leading to thrombosis in patients with APA remains unclear. We studied 32 patients with systemic lupus erythematosus (SLE) who were divided into two groups depending on the presence (n = 19) or absence (n = 13) of APA. Healthy volunteers (n = 12) matched by age and sex served as controls. In all subjects LA and IgG class anticardiolipin antibodies (ACA) were determined. Thrombin generation was monitored ex vivo measuring fibrinopeptide A (FPA) and prothrombin fragment F1 + 2 (F1 + 2) in blood emerging from a skin microvasculature injury, collected at 30 second intervals. In subjects with antiphospholipid antibodies mean FPA and F1 + 2 concentrations were signiF1cantly higher at most blood sampling times than in controls. In some SLE patients with APA the process of thrombin generation was clearly disturbed and very high concentrations of F1brinopeptide A were detected already in the F1rst samples collected. Two minutes after skin incision SLE patients without APA produced slightly more FPA, but not F1 + 2, as compared to healthy subjects. Mathematical model applied to analyze the thrombin generation kinetics revealed that APA patients generated signiF1cantly greater amounts of thrombin than healthy controls (p = 0.02 for either marker). In contrast, in the same patients generation of thrombin in recalciF1ed plasma in vitro was delayed pointing to the role of endothelium in the phenomenon studied. In summary, these data show for the F1rst time that in SLE patients with antiphospholipid-protein antibodies thrombin generation after small blood vessel injury is markedly increased. Enhanced thrombin generation might explain thrombotic tendency observed in these patients.

Inhibition of Platelet Function by Antiarrhythmic Drugs, Verapamil and Disopyramide

1982 ◽  
Vol 47 (02) ◽  
pp. 150-153 ◽  
Author(s):  
P Han ◽  
C Boatwright ◽  
N G Ardlie
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Antiarrhythmic Drugs ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Second Phase ◽  
Ionophore A23187 ◽  
High Concentrations ◽  
Artery Disease

SummaryVarious cardiovascular drugs such as nitrates and propranolol, used in the treatment of coronary artery disease have been shown to have an antiplatelet effect. We have studied the in vitro effects of two antiarrhythmic drugs, verapamil and disopyramide, and have shown their inhibitory effect on platelet function. Verapamil, a calcium channel blocker, inhibited the second phase of platelet aggregation induced by adenosine diphosphate (ADP) and inhibited aggregation induced by collagen. Disopyramide similarly inhibited the second phase of platelet aggregation caused by ADP and aggregation induced by collagen. Either drug in synergism with propranolol inhibited ADP or collagen-induced platelet aggregation. Disopyramide at high concentrations inhibited arachidonic add whereas verapamil was without effect. Verapamil, but not disopyramide, inhibited aggregation induced by the ionophore A23187.

Native Ubiquitin Structural Changes Resulting from Complexation with β-methylamino-L-alanine (BMAA)

2020 ◽  
Author(s):  
Katie Mae Wilson ◽  
Aurora Burkus-Matesevac ◽  
Samuel Maddox ◽  
Christopher Chouinard
Keyword(s):  
Structural Changes ◽  
Noncovalent Complex ◽  
Unfolded Protein ◽  
Protein Size ◽  
High Concentrations ◽  
The Unfolded Protein Response ◽  
Critical Binding ◽  
Protein Response ◽  
The Brain ◽  
Lateral Sclerosis

β-methylamino-L-alanine (BMAA) has been linked to the development of neurodegenerative (ND) symptoms following chronic environmental exposure through water and dietary sources. The brains of those affected by this condition, often referred to as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), have exhibited the presence of plaques and neurofibrillary tangles (NFTs) from protein aggregation. Although numerous studies have sought to better understand the correlation between BMAA exposure and onset of ND symptoms, no definitive link has been identified. One prevailing hypothesis is that BMAA acts a small molecule ligand, complexing with critical proteins in the brain and reducing their function. The objective of this research was to investigate the effects of BMAA exposure on the native structure of ubiquitin. We hypothesized that formation of a Ubiquitin+BMAA noncovalent complex would alter the protein’s structure and folding and ultimately affect the ubiquitinproteasome system (UPS) and the unfolded protein response (UPR). Ion mobility-mass spectrometry revealed that at sufficiently high concentrations BMAA did in fact form a noncovalent complex with ubiquitin, however similar complexes were identified for a range of additional amino acids. Collision induced unfolding (CIU) was used to interrogate the unfolding dynamics of native ubiquitin and these Ubq-amino acid complexes and it was determined that complexation with BMAA led to a significant alteration in native protein size and conformation, and this complex required considerably more energy to unfold. This indicates that the complex remains more stable under native conditions and this may indicate that BMAA has attached to a critical binding location.

Native Ubiquitin Structural Changes Resulting from Complexation with β-methylamino-L-alanine (BMAA)

2020 ◽  
Author(s):  
Katie Mae Wilson ◽  
Aurora Burkus-Matesevac ◽  
Samuel Maddox ◽  
Christopher Chouinard
Keyword(s):  
Structural Changes ◽  
Noncovalent Complex ◽  
Unfolded Protein ◽  
Protein Size ◽  
High Concentrations ◽  
The Unfolded Protein Response ◽  
Critical Binding ◽  
Protein Response ◽  
The Brain ◽  
Lateral Sclerosis

β-methylamino-L-alanine (BMAA) has been linked to the development of neurodegenerative (ND) symptoms following chronic environmental exposure through water and dietary sources. The brains of those affected by this condition, often referred to as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), have exhibited the presence of plaques and neurofibrillary tangles (NFTs) from protein aggregation. Although numerous studies have sought to better understand the correlation between BMAA exposure and onset of ND symptoms, no definitive link has been identified. One prevailing hypothesis is that BMAA acts a small molecule ligand, complexing with critical proteins in the brain and reducing their function. The objective of this research was to investigate the effects of BMAA exposure on the native structure of ubiquitin. We hypothesized that formation of a Ubiquitin+BMAA noncovalent complex would alter the protein’s structure and folding and ultimately affect the ubiquitinproteasome system (UPS) and the unfolded protein response (UPR). Ion mobility-mass spectrometry revealed that at sufficiently high concentrations BMAA did in fact form a noncovalent complex with ubiquitin, however similar complexes were identified for a range of additional amino acids. Collision induced unfolding (CIU) was used to interrogate the unfolding dynamics of native ubiquitin and these Ubq-amino acid complexes and it was determined that complexation with BMAA led to a significant alteration in native protein size and conformation, and this complex required considerably more energy to unfold. This indicates that the complex remains more stable under native conditions and this may indicate that BMAA has attached to a critical binding location.

Needleless electrospinning of PVP/PGS fibrous scaffolds for skin tissue engineering applications

2018 ◽  
Author(s):  
Antonios Keirouz ◽  
Giuseppino Fortunato ◽  
Anthony Callanan ◽  
Norbert Radacsi
Keyword(s):  
Tissue Engineering ◽  
Tensile Modulus ◽  
Dermal Fibroblasts ◽  
Skin Tissue ◽  
Skin Substitute ◽  
Electrospinning Technique ◽  
Skin Tissue Engineering ◽  
Needleless Electrospinning ◽  
High Concentrations

Scaffolds and implants used for tissue engineering need to be adapted for their mechanical properties with respect to their environment within the human body. Therefore, a novel composite for skin tissue engineering is presented by use of blends of Poly(vinylpyrrolidone) (PVP) and Poly(glycerol sebacate) (PGS) were fabricated via the needleless electrospinning technique. The formed PGS/PVP blends were morphologically, thermochemically and mechanically characterized. The morphology of the developed fibers related to the concentration of PGS, with high concentrations of PGS merging the fibers together plasticizing the scaffold. The tensile modulus appeared to be affected by the concentration of PGS within the blends, with an apparent decrease in the elastic modulus of the electrospun mats and an exponential increase of the elongation at break. Ultraviolet (UV) crosslinking of PGS/PVP significantly decreased and stabilized the wettability of the formed fiber mats, as indicated by contact angle measurements. In vitro examination showed good viability and proliferation of human dermal fibroblasts over the period of a week. The present findings provide important insights for tuning the elastic properties of electrospun material by incorporating this unique elastomer, as a promising future candidate for skin substitute constructs.

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