Podcasts about pgf2

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.06.23.546291v1?rss=1 Authors: Mellentine, S. Q., Ramsey, A. S., Li, J., Brown, H. N., Tootle, T. Abstract: A key regulator of collective cell migration is prostaglandin (PG) signaling. However, it remains largely unclear whether PGs act within the migratory cells or their microenvironment to promote migration. Here we use Drosophila border cell migration as a model to uncover the cell-specific roles of two PGs in collective migration. Prior work shows PG signaling is required for on-time migration and cluster cohesion. We find that the PGE2 synthase cPGES is required in the substrate, while the PGF2 synthase Akr1B is required in the border cells for on-time migration. Akr1B acts in both the border cells and their substrate to regulate cluster cohesion. One means by which Akr1B regulates border cell migration is by promoting integrin-based adhesions. Additionally, Akr1B limits myosin activity, and thereby cellular stiffness, in the border cells, whereas cPGES limits myosin activity in both the border cells and their substrate. Together these data reveal that two PGs, PGE2 and PGF2, produced in different locations, play key roles in promoting border cell migration. These PGs likely have similar migratory versus microenvironment roles in other collective cell migrations. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

prostaglandins and their related compounds- I prostacyclins (PGl), thromboxanes (TXA), leukotrienes (LT) and lipoxins are collectively known as eicosaniods, since they all contain 20 carbons (Creek : eikosi-twenty). Eicosanoids are considered as locally acting hormones with a wide range of biochemical functions. History : Prostaglandins (PCs) were first discovered in human semen by Ulf von Euler (of Sweden) in 1930. These compounds were found to stimulate uterine contraction and reduce blood pressure. von Euler presumed that they were synthesized by prostate gland and hence named them as prostaglandins. lt was later realized that PCs and other eicosanoids are synthesized in almost all the tissues (exception- erythrocytes). By then, however, the name prostaglandins was accepted worldwide, and hence continued. The prostaglandins E and F were first isolated from the biological fluids. They were so named due to their solubility in ether (PCE) and phosphate buffer (PCF, F for fosfat, in Swedish). All other prostaglandins discovered later were denoted by a letter-PCA, PCH etc. Structure o{ prostaglandins Prostaglandins are derivatives of a hypothetical 2O-carbon fatty acid namely prostanoic acid hence known as prostanoids. This has a cyclopentane ring (formed by carbon atoms 8 to 12) and two side chains, with carboxyl group on one side. Prostaglandins differ in their structure due to substituent group and double bond on cyclopentane ring. The different prostaglandins are given in Fig.32.l. The structures of the most important prostaglandins (PGF2 and PGF2o), prostacyclins (PCl2), thromboxanes (TXA2) and leukotrienes (LTA+) along with arachidonic acid are depicted in Fi9.32.2. A subscript numeral indicates the number of double bonds in the two side chains. A subscript c-denotes that the hydroxyl group at Ce of the ring and the carboxyl group are on thesame side of the ring.Synthesis of prostaglandins Arachidonic acid (5,8,1 1,1 4-eicosatetraenoic acid) is the precursor for most of the prostaglandins inhumans. The biosynthesis of PCs was described by scene Bergstrom and Bengt Samuelsson (1960). lt occurs in the endoplasmic reticulum in the following stages, as depicted in Fi9,32.3. 1. Release of arachidonic acid from membrane bound phospholipids by phospho- lipase A2-this reaction occurs due to a specific stimuli by hormones such as epinephrine or bradykinin. 2. Oxidation and cyclization of arachidonic acid to PGG2 which is then converted to PCH2 by a reduced glutathione dependent peroxidase. 3. PGH2 serves as the immediate precursor for the synthesis of a number of prostaglandins, including prostacyclins and thromboxanes. The above pathway is known as cyclic pathway of arachidonic acid. ln the linear pathway of arachidonic acid, leukotrienes and lipoxins are synthesized (details given later). Cyclooxygenase-a suicide enzyme : lt is interesting to note that prostaglandin synthesis can be partly controlled by suicidal activity ofthe enzyme cyclooxygenase. This enzyme is capable of undergoing self-catalysedestruction to switch off PG synthesis. lnhibition of PG synthesis : A number of structurally unrelated compounds can inhibit prostaglandin synthesis. Corticosteroids (e.g. cortisol) prevent the formation of arachidonic acid by inhibiting the enzyme phospholipase 42. Many non-steroidal anti-inflammatory drugs inhibit the synthesis of prostaglandins, prostacyclins and thromboxanes. They do so by blocking the action of the enzyme cyclo' oxygenase. Aspirin inhibits PG synthesis :Aspirin (acetyl salicylic acid) has been used since nineteenth century as an antipyretic (fever-reducing) and analgesic (pain relieving). The mechanism of action of aspirin however, was not known for a Iong period. lt was only in 1971, John Vane discovered that aspirin inhibits the synthesis of PC from arachidonic acid. Aspirin irreversibly inhibits the enzyme cyclooxygenase.

Short communication: Economic impact among 7 reproductive programs for lactating dairy cows, including a sensitivity analysis of the cost of hormonal treatments Find the Big 3 Infographic at otovets.com/cuttingedge Link: https://www.journalofdairyscience.org/article/S0022-0302(20)30275-7/fulltext Big Take Away #1: Improving fertility and breeding efficiency of our dairies can be accomplished via three methods; improved detection of estrus, synchronization of estrus and synchronization of ovulation and timed AI as proven by many different authors. Big Take Away #2: To prove their work the authors used the DairyRepro$ tool form UW-Cornell. Available online after a simple search you can do the same analysis with your own numbers they did! This tool allows you to input all your operations reproductive parameters, drugs costs, labor costs and any other reproductive inputs you could imagine. Big Take Away #3 Ricci found that using Double-Ovsynch over these other Presynch programs it would obtain a $42 dollar greater profit per cow per year than a baseline Presynch-Ovsynch with 35% conception rate and no cherry picking. The next closest program used the automated heat detection system in conjunction with Presynch and that came in at more than 50% less profit than Double-Ovsynch with PGF. Ultimate Message: All that said OTO’er ultimately it comes down to this….can you get a big enough conception rate bump to justify the switch? Many times, the only change to reproduction a dairy will make will be the first breeding program; so use this DairyRepro$ tool to facilitate this discussion. This is the true reason I brought you this article. Objective: This study had 2 major objectives: (1) to analyze the profitability of an intensive reproductive program involving more injections (i.e., Double Ovsynch) compared with less intensive ones (Presynch-Ovsynch) in different geographic areas (i.e., the United States and Europe) depending on variation of hormonal treatment costs, and (2) to estimate how high the cost of hormonal treatments would have to be to render intensive synchronization programs unprofitable. Location: University of Torino and University of Wisconsin-Madison Methods: A reproductive economic analysis simulation model was used to compare the economic impact of pairs of reproductive management programs. We simulated sets of scenarios for 2 analyses. In the first analysis, we calculated the economic impact of switching from a Presynch-Ovsynch program to a Double-Ovsynch program that included a second PGF2α treatment during the Breeding-Ovsynch portion of the program (Double-Ovsynch+PGF). In the second analysis, we conducted a break-even analysis in which the cost of hormonal treatments was incrementally increased within various reproductive management programs.

Find a complete typed summary at otovets.com/cuttingedge Find the full article at https://www.journalofdairyscience.org/article/S0022-0302(11)00025-7/fulltext The use of plastic cover sheaths at the time of artificial insemination improved fertility of lactating dairy cows Revisiting a technology and technique developed in the 80’s with a new research model. Published by: S. Bas, A. Hoet, P. Rajala-Schultz, D. Sanders, G.M. Schuenemann Objective: To to evaluate the effectiveness of using protective plastic sheaths (PS) to minimize contamination of the AI catheter (AIC) on pregnancies per AI (PAI) in lactating dairy cattle. Hypothesis: The hypothesis of this study was that the use of protective PS (clean AI technique) would minimize vaginal contamination of the AIC and improve PAI in lactating dairy cows. Location: Unknown April – June 2009 Methods: Lactating cows housed in freestall barns on a commercial dairy farm were presynchronized with 2 injections of PGF2α given 14 d apart (starting at 26 ± 3 d postpartum) followed by Ovsynch (GnRH-7 d-PGF2α-56 h-GnRH-16 h-timed-AI; TAI) 12 d later. Cows presenting signs of standing heat any time during the protocol received AI, whereas the remaining animals were subjected to TAI 16 h after second Ovsynch GnRH. At the time of AI (1 AI technician), 996 services from 773 lactating dairy cows were randomly assigned to 1 of the 2 groups; with (TRT, n = 487) or without (CON, n = 509) the use of disposable PS. In the TRT group, the AIC protected with a PS was introduced into the vagina; once in the cranial portion of the vagina adjacent to the cervical os, the PS was pulled back and only the AIC was manipulated through the cervix into the uterine body for semen deposition. In the CON group, cows were inseminated without the use of PS. Samples were taken with a sterile cotton swab from the tip of the AIC (n = 51) after AI from both treatment groups. Pregnancy diagnosis was determined by ultrasonography 39 ± 3 d after AI. Outcomes: Cultured swab samples revealed that the use of PS was effective in minimizing contamination of the AIC (positive bacterial growth: TRT = 61.53% vs. CON = 100%). Overall, the proportion of cows pregnant was greater for cows in TRT (42.7) compared with the CON group (36.1). For first services postpartum, PAI did not differ between CON (43.01%, n = 194) and TRT (43.8%, n = 182) groups. However, PAI for second or greater services were greater in TRT (43.8%, n = 305) than in CON cows (32.3%, n = 315). Results from this study provided evidence that the use of PS during AI improved PAI for second or greater services in lactating dairy cows. Performing a clean AI technique through the use of PS may be an effective strategy to improve reproductive outcomes in dairy cattle.

Heat detection is a key factor for the economic viability of dairy herds. However, it is becoming more difficult for farmers to detect and use the heat for a successful artificial insemination. There are various reasons for this development. On the one hand, cows are showing progressively fewer behavioral signs of oestrus and, on the other hand, due to economic necessity leading to growing herds, the herd managers do not have enough time for adequate oestrus detection. The result is a considerable loss of profit. For these reasons, the development and use of new and above all workable oestrus detection methods are imperative. The objective of this study was to establish a new heat detection method which allows the farmer to automatically observe his herd on a 24/7-basis. The recommended system is based on the continuous detection of the moving cows in a freestall barn, which involves machine vision. The information received about the positions as well as the locomotion within the freestall barn enables a precise view of the moving patterns. With this system, we analyzed the duration and the intensity of activity as well as the social interactions of cows in oestrus with other members of the herd. As gold standard for the validation of the method, we used an enzyme immuno assay test to measure the amount of progesterone in skimmed milk. As part of the extensive preparation, we selected appropriate video cameras, designed suitable markers and implemented special software. Finally, we used high-resolution GigE-cameras and markers we made ourselves out of fabric-reinforced PVC with printed 2D matrix codes. Our study demonstrated that the new method is able to correctly show the increased activity which is typical of cows in oestrus. The median of the increase in motion activity with regard to a moving average of the 10 days before the oestrus was +430 % for cows in natural oestrus and +338 % for cows in PGF2α-induced oestrus. Overall, the median was +397 %. We found a statistically significant difference (p < 0.001) in increased motion activity between cows in oestrus and cows not in oestrus (median: +153 %). There was no statistically significant difference in increased motion activity between cows in natural oestrus and cows in PGF2α-induced oestrus (p = 0.290). In our study we used ROC analysis to find the optimum between sensitivity and specificity of the method. We identified an ideal threshold value of +225 %. The outcome was a sensitivity of 85 % and a specificity of 83 %. To enhance the efficiency of the machine vision method, we established a completely new parameter. This parameter is used for the detection and evaluation of social interactions between cows in heat and peri-oestrus herd members. We named the new parameter “variance of social interactions”. This measure of scale makes sexual contacts of observed cows (in heat) with other likewise sexually active herd members apparent. The median of the variance of social interactions was 1.598 for cows in natural heat, 1.478 for cows in PGF2α-induced oestrus and 1.52 overall. For cows not in oestrus (in dioestrus or gestating), we found a measure of scale of 1.10. We found a statistically significant difference (p = 0.003) between the cows in oestrus and the cows not in oestrus. There was no statistically significant difference in the variance of social interactions between cows in heat naturally and cows in PGF2α-induced oestrus (p = 0.881). With ROC analysis, we determined a heat detection rate (sensitivity) of 74 %. The specificity was 83 %. By means of a regression analysis, we combined the two parameters of increased motion activity and variance of social interactions. This resulted in a sensitivity of 82 % and a specificity of 87 %. Heat detection in dairy herds with the use of machine vision is not only a functional alternative to the pedometers that have been commonly used so far. With the newly introduced and automatically included parameter “variance of social interactions”, the recommended system offers real additional value for the farmer and can thus help to optimize fertility rates in dairy herds. Moreover, the method provides supplemental data such as length of food intake, lying times, average speed, etc.). This data has the potential to help farmers prevent impending diseases such as lameness or ketosis as well as to indicate problems with animal husbandry at an early stage and therefore provide a contribution to animal-oriented management of dairy herds.

The aim of the present study was to estimate the influence of uterine NOS-system and the sexual steroids estrogen and progesterone on the blood supply of the uterus and the ovaries. Five trotter mares were examined in total during four estrous cycles and one early pregnancy. The investigations contained color Doppler- and ultrasound recordings as soon as the extraction of blood samples and endometrial biopsies. The first cycle was medically uninfluenced and investigations were carried out on Days 0 (= ovulation), 1, 5, 11, 15 and daily during estrous, whereas in estrous only one endometrial biopsy was taken. In the second cycle luteal regression was induced on Day 5 of diestrous with the PGF2α-analogon Tiaprost (Ilirenâ, 450 mg i.m.) and in estrous ovulation was induced with hCG (Choriolutinâ, 2500 IE i.v.), when the size of one follicle reached 35 mm. Investigations were carried out in this cycle immediately before giving PGF2α and 0.5, 1, 3, 6, 12, 24, 36, 48 hours after that and then once a day up to ovulation. Endometrial biopsies were taken in each case before induction of luteolysis, 12 and 36 hours after that, before injection of hCG and immediately after ovulation. During the further two cycles the mares were treated orally with the NO donor ISDN (ISDN 40â, 30 mg, twice a day). Investigations were carried out on Days 0, 1 and 5 of the first cycle (ISDN I), as well as on Days 11, 15 and during estrous of the second cycle (ISDN II). During early pregnancy color Doppler recordings and blood samples were taken on Days 0, 1, 5, 11 and 15 of pregnancy, while endometrial biopsies were only gained on day 15. The analysis of uterine blood flow was based on the time-averaged maximum velocity (TAMV). Estrogens and progesterone were measured by an enzyme immunoassay. Nitrate concentrations were evaluated using Griess reacting. Total RNA was isolated from endo-metrial biopsies. Transcriptes encoding the estrogen receptors a and b and the endothelial as well as the inducible nitric oxide-synthase (eNOS and iNOS) were quantified by RT-PCR-analysis. The expression of eNOS-mRNA in control, as well as in the PGF2a-induced cycle, followed a consistent wavelike pattern (p < 0.05 and p < 0.0001). Both, eNOS and iNOS, showed their maximum of expression especially on Day 5 of diestrous and during estrous, when the highest levels of either progesterone or estrogen were measured. In the PGF2a-induced cycle, a significant connection between eNOS and progesterone was proved (p < 0.05). There was a positive correlation between the expression of the eNOS-mRNA and the uterine blood flow (p < 0.05) in the control cycle. In the PGF2a-induced cycle these two parameters also showed a similar cyclic pattern. The levels of estrogen-receptors in the endometrium or concentrations of estrogen in plasma were not related to the endometrial NO-synthases or to TAMV values. Plasma concentrations of nitrate were independent from the stage of estrous cycle and consequently were proved as unsuitable for the question raised here (in this case). The application of the NO donor ISDN leaded to a marked decrease of the uterine NOS-expression when compared with control cycle (p < 0.0001). An increase of uterine or ovarian perfusion during the application of ISDN was not provable (p > 0.05). In result of the biopsies on day 5 and of simultaneous ISDN application luteolysis was induced next to all mares. On day 15 of pregnancy, an increase in uterine and ovarian perfusion as well as an enhancement in iNOS-mRNA expression was observed. In conclusion, the results of this study indicate that the endometrial NO-synthases play an important role in the regulation of uterine blood supply during estrous cycle and pregnancy of the mare. Progesterone as well as estrogen seem to stimulate the endometrial expression of eNOS and iNOS, by which these hormones may indirectly influence uterine and ovarian blood flow.

The integrin heterodimer CD11b/CD18 (alpha M beta 2, Mac-1, CR3) expressed on monocytes or polymorphonuclear leukocytes (PMN) is a receptor for iC3b, fibrinogen, heparin, and for intercellular adhesion molecule (ICAM)-1 on endothelium, crucially contributing to vascular cell interactions in inflammation and atherosclerosis. In this report, we summarize our findings on the effects of lipid mediators and lipid-lowering drugs. Exposure of endothelial cells to oxidized low density lipoprotein (oxLDL) induces upregulation of ICAM-1 and increases adhesion of monocytic cells expressing Mac-1. Inhibition experiments show that monocytes use distinct ligands, i.e. ICAM-1 and heparan sulfate proteoglycans for adhesion to oxLDL-treated endothelium. An albumin-transferable oxLDL activity is inhibited by the antioxidant pyrrolidine dithiocarbamate (PDTC), while 8-epi-prostaglandin F2 alpha (8-epi-PGF2 alpha) or lysophosphatidylcholine had no effect, implicating yet unidentified radicals. Sequential adhesive! and signaling events lead to the firm adhesion of rolling PMN on activated and adherent platelets, which may occupy areas of endothelial denudation. Shear resistant arrest of PMN on thrombin-stimulated platelets in flow conditions requires distinct regions of Mac-1, involving its interactions with fibrinogen bound to platelet alpha llb beta 3, and with other platelet ligands. Both arrest and adhesion strengthening under flow are stimulated by platelet-activating factor and leukotriene B4, but not by the chemokine receptor CXCR2. We tested whether Mac-1-dependent monocyte adhesiveness is affected by inhibitors of hydroxy-methylglutaryl-Coenzyme A reductase (statins) which improve morbidity and survival of patients with coronary heart disease. As compared to controls, adhesion of isolated monocytes to endothelium ex vivo was increased in patients with hypercholesterolemia. Treatment with statins decreased total and low density lipoprotein (LDL) cholesterol plasma levels, surface expression of Mac-1, and resulted in a dramatic reduction of Mac,mediated monocyte adhesion to endothelium. The inhibition of monocyte adhesion was reversed by mevalonate but not LDL in vitro,indicating that isoprenoid precursors are crucial for adhesiveness of Mac-1. Such effects may crucially contribute to the clinical benefit of statins, independent of cholesterol-lowering, and may represent a paradigm for novel, anti-inflammatory mechanisms of action by this class of drugs.