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Standard heparin, an effective treatment for antepartum thromboembolic disease, is thought to be safe for the fetus since it does not cross the placenta. Recently, a number of low molecular weight heparins have been prepared which have been shown to produce less bleeding than standard heparin for an equivalent antithrombotic effect in experimental animals. These observations suggest that the low molecular weight heparins may also provide superior antithrombotic therapy in antepartum thromboembolic disease. However, it is not known whether the low molecular weight heparins cross the placenta. To determine this, we examined the pharmacokinetics of 125I-labelled standard heparin and a low molecular weight heparin, and their anticoagulant effects in mother and fetus, using a pregnant sheep model. Catheters were inserted into maternal and fetal femoral arteries at 108-119 d gestation (term: 147 d). 1-3 days later the mothers were given a bolus i.v. injection of 5000 anti-Xa units of 125I-labelled standard heparin or low molecular weight heparin, CY 222. Nine serial blood samples were collected over 4 h from both mother and fetus for measurements of radioactivity, anti-Xa activity (chromogenic) and activated partial thromboplastin times. When therapeutic levels of standard and CY 222 heparins were achieved in the mother, there was no detectable radioactivity or anticoagulant effect in the fetus. We conclude that standard heparin and the low molecular weight CY 222 do not cross the placenta in the pregnant sheep.

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How can you reduce Melt flow index of hdpe granules?

To reduce the melt flow index of HDPE granules, you can increase the molecular weight of the polymer by using a higher molecular weight grade of HDPE, incorporating chain extenders or cross-linking agents, or blending with a lower molecular weight polymer. These methods can help decrease the flowability of the material, resulting in a lower melt flow index.


Why polymers don't have uniform or fixed molecular weight?

Polymers do not have a uniform or fixed molecular weight due to their inherent nature of being composed of long chains of repeating units, or monomers, which can vary in length. During the polymerization process, the reaction conditions and the presence of different types of monomers lead to the formation of chains of varying lengths, resulting in a distribution of molecular weights. Additionally, factors such as branching, cross-linking, and incomplete reactions contribute to this variability, making it difficult to achieve a single, uniform molecular weight in a polymer sample.


How do you convert 20mM NaH2PO4 into gram per liter?

Get the MR of the NaH2PO4 molecule. Now use the 1M = (MR)g/L to work out the equation. The last equation you need is 20mM = (X)g/L Now you make the units the same, cross multiply and get your answer for X. Once you do this a few times it becomes second nature.


How does molecular size affect the drug?

Molecular size can influence how a drug is absorbed, distributed, metabolized, and excreted in the body. Smaller molecules may be more easily absorbed but can have a shorter duration of action, while larger molecules may have slower absorption but longer-lasting effects. Additionally, molecular size can impact the drug's ability to cross cell membranes and interact with target molecules.


What is the most abundant type if immunoglobulin?

IgG is the most abundant type of immunoglobulin in the blood, making up about 75% of all immunoglobulins. It plays a key role in immune response by helping to neutralize pathogens and toxins, and is the only antibody class that can cross the placenta from mother to fetus.

Related Questions

Does iga cross placenta?

No.


What impacts the properties of hydrocarbon polymers?

its structure whether its linear or cross linked its molecular weight


What vitamin doesn't cross placenta?

vitamin a,vitamin d,usually cross placenta during pregnancy.exept vitamin c


Can warfarin cross placenta?

yes


How can you reduce Melt flow index of hdpe granules?

To reduce the melt flow index of HDPE granules, you can increase the molecular weight of the polymer by using a higher molecular weight grade of HDPE, incorporating chain extenders or cross-linking agents, or blending with a lower molecular weight polymer. These methods can help decrease the flowability of the material, resulting in a lower melt flow index.


Which antibodies can cross placental barrier?

IgG is the only antibody small enough to cross he placenta.


Why immunoglobulin G alone can cross placenta?

IgG is an immunoglobluin monomer, meaning that it is one immunoglobulin that is small enough to cross the placenta. An example would be the Rh antibody that causes isoimmunization between Rh negative mothers and Rh positive fetuses. In constrast, ABO blood group immunoglobulins are IgM which is a pentamer, meaning it is composed of 5 immunoglobulins and is too large to cross the placenta.


Is semon good for a baby in the womb?

semen does not cross into the placenta and has no effect on baby in womb.


Does a baby inherit the blood if the mother has a blood transfusion?

No. Red blood cells do not cross the placenta.


Which immunoglobulin class is able to cross the placenta from the mother to the fetus?

This is called natural passive immunity.


Which situation occurs when drugs cross the placenta during pregnancy?

babies may be born with a drug dependency


What substance can cross the placenta?

The embryo gets all the oxygen, and all the nutrients that it needs from the mother's blood supply, all of which crosses the placenta, through the umbilical cord into the embryonic blood system.