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Purinergic Signalling Mar 2014There is widespread involvement of purinergic signalling in endocrine biology. Pituitary cells express P1, P2X and P2Y receptor subtypes to mediate hormone release.... (Review)
Review
There is widespread involvement of purinergic signalling in endocrine biology. Pituitary cells express P1, P2X and P2Y receptor subtypes to mediate hormone release. Adenosine 5'-triphosphate (ATP) regulates insulin release in the pancreas and is involved in the secretion of thyroid hormones. ATP plays a major role in the synthesis, storage and release of catecholamines from the adrenal gland. In the ovary purinoceptors mediate gonadotrophin-induced progesterone secretion, while in the testes, both Sertoli and Leydig cells express purinoceptors that mediate secretion of oestradiol and testosterone, respectively. ATP released as a cotransmitter with noradrenaline is involved in activities of the pineal gland and in the neuroendocrine control of the thymus. In the hypothalamus, ATP and adenosine stimulate or modulate the release of luteinising hormone-releasing hormone, as well as arginine-vasopressin and oxytocin. Functionally active P2X and P2Y receptors have been identified on human placental syncytiotrophoblast cells and on neuroendocrine cells in the lung, skin, prostate and intestine. Adipocytes have been recognised recently to have endocrine function involving purinoceptors.
Topics: Adenosine Triphosphate; Adipocytes; Adrenal Glands; Animals; Arginine Vasopressin; Endocrine Glands; Humans; Oxytocin; Receptors, Purinergic; Signal Transduction
PubMed: 24265070
DOI: 10.1007/s11302-013-9396-x -
Reproductive Medicine and Biology Jul 2019A mixture of spermatozoa and accessory gland secretions (from seminal vesicles, prostates, and coagulating glands) is ejaculated into the female reproductive tract at... (Review)
Review
BACKGROUND
A mixture of spermatozoa and accessory gland secretions (from seminal vesicles, prostates, and coagulating glands) is ejaculated into the female reproductive tract at copulation. However, the physiological function of accessory glands on male fecundity remains unclear.
METHODS
Publications regarding the physiological functions of male accessory glands were summarized.
MAIN FINDINGS RESULTS
The functions of accessory glands have been studied using male rodents surgically removed coagulating glands (CG), prostates (PR), or seminal vesicles (SV). CG-removed males are fertile or subfertile, while the fecundity of PR-removed males is controversial. SV-removed males show copulatory plug defects, leading to fewer sperm in the uterus and severe subfertility. TGM4, SVS2, and PATE4 were identified as essential factors for copulatory plug formation. When the sufficient number of epididymal spermatozoa was artificially injected into a uterus (AI method), they could efficiently fertilize oocytes, implicating that accessory gland secretions are not essential. Seminal vesicle secretions (SVSs) improved fertilization rates only when low numbers of spermatozoa were used for AI. The changes of uterine environment by SVSs could not improve the pregnancy rate.
CONCLUSION
Accessory gland factors are critical for copulatory plug formation and support sperm fertilizing ability.
PubMed: 31312102
DOI: 10.1002/rmb2.12282 -
Clinics in Perinatology Sep 2016The cardiovascular response to asphyxia involves redistribution of cardiac output to maintain oxygen delivery to critical organs such as the adrenal gland, heart, and... (Review)
Review
The cardiovascular response to asphyxia involves redistribution of cardiac output to maintain oxygen delivery to critical organs such as the adrenal gland, heart, and brain, at the expense of other organs such as the gut, kidneys and skin. This redistribution results in reduced perfusion and localized hypoxia/ischemia in these organs, which, if severe, can result in multiorgan failure. Liver injury, coagulopathy, bleeding, thrombocytopenia, renal dysfunction, and pulmonary and gastrointestinal injury all result from hypoxia, underperfusion, or both. Current clinical therapies need to be considered together with therapeutic hypothermia and cardiovascular recovery.
Topics: Acute Kidney Injury; Asphyxia Neonatorum; Blood Coagulation Disorders; Cardiovascular System; Female; Gastrointestinal Diseases; Hemorrhage; Humans; Hypothermia, Induced; Hypoxia-Ischemia, Brain; Infant, Newborn; Liver Diseases; Lung Diseases; Multiple Organ Failure; Pregnancy; Thrombocytopenia
PubMed: 27524448
DOI: 10.1016/j.clp.2016.04.006 -
Wiener Klinische Wochenschrift May 2017Uncontrolled massive bleeding with subsequent derangement of the coagulation system is a major challenge in the management of both surgical and seriously injured... (Review)
Review
Uncontrolled massive bleeding with subsequent derangement of the coagulation system is a major challenge in the management of both surgical and seriously injured patients. Under physiological conditions activators and inhibitors of coagulation regulate the sensitive balance between clot formation and fibrinolysis. In some cases, excessive and diffuse bleeding is caused by systemic activation of fibrinolysis, i. e. hyperfibrinolysis (HF). Uncontrolled HF is associated with a high mortality. Polytrauma patients and those undergoing surgical procedures involving organs rich in plasminogen proactivators (e. g. liver, kidney, pancreas, uterus and prostate gland) are at a high risk for HF. Antifibrinolytics, such as tranexamic acid (TXA) are used for prophylaxis and treatment of bleeding caused by a local or generalized HF as well as other hemorrhagic conditions. TXA is a synthetic lysine analogue that has been available in Austria since 1966. TXA is of utmost importance in the prevention and treatment of traumatic and perioperative bleeding due to the resulting reduction in perioperative blood loss and blood transfusion requirements. The following article presents the different fields of application of TXA with particular respect to indications and dosages, based on a literature search and on current guidelines.
Topics: Antifibrinolytic Agents; Blood Coagulation; Blood Coagulation Disorders; Dose-Response Relationship, Drug; Fibrinolysis; Hematology; Hemorrhage; Humans; Practice Guidelines as Topic; Tranexamic Acid; Treatment Outcome
PubMed: 28432428
DOI: 10.1007/s00508-017-1194-y -
Journal of Clinical Pathology Jun 2003Intravascular lymphomatosis (IVL) is a rare angiotrophic large cell lymphoma producing vascular occlusion of arterioles, capillaries, and venules. Antigenic phenotyping...
Intravascular lymphomatosis (IVL) is a rare angiotrophic large cell lymphoma producing vascular occlusion of arterioles, capillaries, and venules. Antigenic phenotyping shows that these lymphomas are mostly of B cell type, and less commonly T cell or Ki-1 lymphomas. The central nervous system and skin are the two most commonly affected organs; patients usually present with progressive encephalopathy with mental status changes and focal neurological deficits and skin petechia, purpura, plaques, and discolouration. Other involved organs include adrenal glands, lungs, heart, spleen, liver, pancreas, genital tract, and kidneys. Bone marrow, blood, cerebrospinal fluid, and lymph nodes are typically spared. Fever of unknown origin is another common presentation. Only one case of IVL presenting with disseminated intravascular coagulation and anasarca (generalised oedema) has been reported in the literature. This report describes a postmortem case of a patient with IVL who initially presented with disseminated intravascular coagulation complicated by intracerebral haemorrhage.
Topics: Adult; Cerebral Hemorrhage; Disseminated Intravascular Coagulation; Fatal Outcome; Female; Humans; Lymphoma, Large B-Cell, Diffuse; Male; Vascular Neoplasms
PubMed: 12783976
DOI: 10.1136/jcp.56.6.468 -
Frontiers in Medicine 2022Accidental hypothermia (AH) is an unintended decrease in body core temperature (BCT) to below 35°C. We present an update on physiological/pathophysiological changes... (Review)
Review
BACKGROUND
Accidental hypothermia (AH) is an unintended decrease in body core temperature (BCT) to below 35°C. We present an update on physiological/pathophysiological changes associated with AH and rewarming from hypothermic cardiac arrest (HCA).
TEMPERATURE REGULATION AND METABOLISM
Triggered by falling skin temperature, Thyrotropin-Releasing Hormone (TRH) from hypothalamus induces release of Thyroid-Stimulating Hormone (TSH) and Prolactin from pituitary gland anterior lobe that stimulate thyroid generation of triiodothyronine and thyroxine (T4). The latter act together with noradrenaline to induce heat production by binding to adrenergic β3-receptors in fat cells. Exposed to cold, noradrenaline prompts degradation of triglycerides from brown adipose tissue (BAT) into free fatty acids that uncouple metabolism to heat production, rather than generating adenosine triphosphate. If BAT is lacking, AH occurs more readily.
CARDIAC OUTPUT
Assuming a 7% drop in metabolism per °C, a BCT decrease of 10°C can reduce metabolism by 70% paralleled by a corresponding decline in CO. Consequently, it is possible to maintain adequate oxygen delivery provided correctly performed cardiopulmonary resuscitation (CPR), which might result in approximately 30% of CO generated at normal BCT.
LIVER AND COAGULATION
AH promotes coagulation disturbances following trauma and acidosis by reducing coagulation and platelet functions. Mean prothrombin and partial thromboplastin times might increase by 40-60% in moderate hypothermia. Rewarming might release tissue factor from damaged tissues, that triggers disseminated intravascular coagulation. Hypothermia might inhibit platelet aggregation and coagulation.
KIDNEYS
Renal blood flow decreases due to vasoconstriction of afferent arterioles, electrolyte and fluid disturbances and increasing blood viscosity. Severely deranged renal function occurs particularly in the presence of rhabdomyolysis induced by severe AH combined with trauma.
CONCLUSION
Metabolism drops 7% per °C fall in BCT, reducing CO correspondingly. Therefore, it is possible to maintain adequate oxygen delivery after 10°C drop in BCT provided correctly performed CPR. Hypothermia may facilitate rhabdomyolysis in traumatized patients. Victims suspected of HCA should be rewarmed before being pronounced dead. Rewarming avalanche victims of HCA with serum potassium > 12 mmol/L and a burial time >30 min with no air pocket, most probably be futile.
PubMed: 35280892
DOI: 10.3389/fmed.2022.824395 -
Life Sciences Oct 2022Severe COVID-19 is associated with the dynamic changes in coagulation parameters. Coagulopathy is considered as a major extra-pulmonary risk factor for severity and... (Review)
Review
Severe COVID-19 is associated with the dynamic changes in coagulation parameters. Coagulopathy is considered as a major extra-pulmonary risk factor for severity and mortality of COVID-19; patients with elevated levels of coagulation biomarkers have poorer in-hospital outcomes. Oxidative stress, alterations in the activity of cytochrome P450 enzymes, development of the cytokine storm and inflammation, endothelial dysfunction, angiotensin-converting enzyme 2 (ACE2) enzyme malfunction and renin-angiotensin system (RAS) imbalance are among other mechanisms suggested to be involved in the coagulopathy induced by severe acute respiratory syndrome coronavirus (SARS-CoV-2). The activity and function of coagulation factors are reported to have a circadian component. Melatonin, a multipotential neurohormone secreted by the pineal gland exclusively at night, regulates the cytokine system and the coagulation cascade in infections such as those caused by coronaviruses. Herein, we review the mechanisms and beneficial effects of melatonin against coagulopathy induced by SARS-CoV-2 infection.
Topics: Angiotensin-Converting Enzyme 2; Blood Platelets; COVID-19; Cytokines; Humans; Melatonin; Peptidyl-Dipeptidase A; Renin-Angiotensin System; SARS-CoV-2
PubMed: 35944663
DOI: 10.1016/j.lfs.2022.120866 -
Journal of Cutaneous Pathology Jan 2022The abundance of publications of COVID-19-induced chilblains has resulted in a confusing situation. (Review)
Review
BACKGROUND
The abundance of publications of COVID-19-induced chilblains has resulted in a confusing situation.
METHODS
This is a prospective single-institution study from 15 March to 13 May 2020. Thirty-two patients received PCR nasopharyngeal swabs. Of these, 28 patients had a thoracic CT-scan, 31 patients had blood and urine examinations, 24 patients had skin biopsies including immunohistochemical and direct immunofluorescence studies, and four patients had electron microscopy.
RESULTS
COVID-19-induced chilblains are clinically and histopathologically identical to chilblains from other causes. Although intravascular thrombi are sometimes observed, no patient had a systemic coagulopathy or severe clinical course. The exhaustive clinical, radiological, and laboratory work-up in this study ruled-out other primary and secondary causes. Electron microscopy revealed rare, probable viral particles whose core and spikes measured from 120 to 133 nm within endothelium and eccrine glands in two cases.
CONCLUSION
This study provides further clinicopathologic evidence of COVID-19-related chilblains. Negative PCR and antibody tests do not rule-out infection. Chilblains represent a good prognosis, occurring later in the disease course. No systemic coagulopathy was identified in any patient. Patients presenting with acral lesions should be isolated, and chilblains should be distinguished from thrombotic lesions (livedo racemosa, retiform purpura, or ischemic acral necrosis).
Topics: Adolescent; Adult; Aged; Biopsy; COVID-19; Chilblains; Child; Diagnosis, Differential; Eccrine Glands; Endothelium; Female; Humans; Livedo Reticularis; Male; Microscopy, Electron; Middle Aged; Prognosis; Prospective Studies; Purpura; SARS-CoV-2; Skin; Toes; Young Adult
PubMed: 34272741
DOI: 10.1111/cup.14099 -
Thrombosis Research May 2014The hemostatic system plays pleiotropic roles in cancer progression by shaping the tumor microenvironment and metastatic niches through thrombin-dependent fibrin... (Review)
Review
The hemostatic system plays pleiotropic roles in cancer progression by shaping the tumor microenvironment and metastatic niches through thrombin-dependent fibrin deposition and platelet activation. Expanding experimental evidence implicates coagulation protease receptors expressed by tumor cells as additional players that directly influence tumor biology. Pro-angiogenic G protein-coupled signaling of TF through protease activated receptor 2 and regulation of tumor cell and vascular integrins through ligation by alternative spliced TF are established pathways driving tumor progression. Our recent work shows that the endothelial protein C receptor (EPCR), a stem cell marker in hematopoietic, neuronal and epithelial cells, is also crucial for breast cancer growth in the orthotopic microenvironment of the mammary gland. In aggressive triple-negative breast cancer cells, EPCR expression is a characteristic of cancer stem cell-like populations that have tumor initiating properties in vivo. Blocking antibodies to EPCR attenuate in vivo tumor growth and proliferation specifically of EPCR(+) cells on defined integrin matrices in vitro. We also showed that tumor-associated macrophages are a source for upstream coagulation proteases that can activate TF- and EPCR-dependent cellular responses, suggesting that tumor cells utilize the tumor microenvironment for tumor promoting coagulation protease signaling.
Topics: Animals; Antigens, CD; Blood Coagulation; Breast Neoplasms; Disease Progression; Endothelial Protein C Receptor; Female; Humans; Receptors, Cell Surface; Signal Transduction; Tumor Microenvironment
PubMed: 24862151
DOI: 10.1016/S0049-3848(14)50014-X -
Scientific Reports Dec 2022Among the different polymers (proteins, polysaccharides, etc.) that make up natural fibers, fibroin is a protein produced by silk spinning animals, which have developed...
Among the different polymers (proteins, polysaccharides, etc.) that make up natural fibers, fibroin is a protein produced by silk spinning animals, which have developed an optimized system for the conversion of a highly concentrated solution of this protein into high-performance solid fibers. This protein undergoes a self-assembly process in the silk glands that result from chemical gradients and by the application of mechanical stresses during the last step of the process. In the quest for a process that could mimic natural spinning at massive scales, we have discovered that turbulence offers a novel and promising solution: a turbulent liquid jet can be formed by a chemically green and simple coagulating liquid (a diluted solution of acetic acid in etanol) co-flowing with a concentrated solution of fibroin in water by the use of a Flow Blurring nebulizer. In this system, (a) the co-flowing coagulant liquid extracts water from the original protein solution and, simultaneously, (b) the self-assembled proteins are subjected to mechanical actions, including splitting and stretching. Given the non-negligible produced content with the size and appearance of natural silk, the stochastic distribution of those effects in our process should contain the range of natural ones found in animals. The resulting easily functionalizable and tunable one-step material is 100% biocompatible, and our method a perfect candidate to large-scale, low-cost, green and sustainable processing of fibroin for fibres and textiles.
Topics: Animals; Fibroins; Biocompatible Materials; Bombyx; Silk; Water
PubMed: 36536025
DOI: 10.1038/s41598-022-26137-7