WordNet

give (hair) the appearance of being fuller by using a rat
a pad (usually made of hair) worn as part of a womans coiffure
any of various long-tailed rodents similar to but larger than a mouse
catch rats, especially with dogs
desert ones party or group of friends, for example, for ones personal advantage
employ scabs or strike breakers in
a yellow phospholipid essential for the metabolism of fats; found in egg yolk and in many plant and animal cells; used commercially as an emulsifier
the relative magnitudes of two quantities (usually expressed as a quotient)

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『ネズミ』 / ひきょう者,裏切り者 / ネズミをつかまえる / 《話》(人を)裏切る,密告する《+『on』+『名』〈人〉》
レシチン(神経細胞や卵黄などに含まれるリン脂質)
『比』,比率,『割合』;『比例』

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/08/02 09:00:44」(JST)

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Sphingomyelin

Phosphatidylcholine, a type of phospholipid in lecithin.

The lecithin–sphingomyelin ratio (aka L-S or L/S ratio) is a test of fetal amniotic fluid to assess for fetal lung immaturity.^[1]^[2]^[3] Lungs require surfactant, a soap-like substance, to lower the surface pressure of the alveoli in the lungs. This is especially important for premature babies trying to expand their lungs after birth. Surfactant is a mixture of lipids, proteins, and glycoproteins, lecithin and sphingomyelin being two of them. Lecithin makes the surfactant mixture more effective.

Evaluation[edit]

The lecithin–sphingomyelin ratio is a marker of fetal lung maturity. The outward flow of pulmonary secretions from the fetal lungs into the amniotic fluid maintains the level of lecithin and sphingomyelin equally until 32–33 weeks gestation, when the lecithin concentration begins to increase significantly while sphingomyelin remains nearly the same. As such, if a sample of amniotic fluid has a higher ratio, it indicates that there is more surfactant in the lungs and the baby will have less difficulty breathing at birth. An L–S ratio of 2 or more indicates fetal lung maturity and a relatively low risk of infant respiratory distress syndrome, and an L/S ratio of less than 1.5 is associated with a high risk of infant respiratory distress syndrome.

If preterm delivery is necessary (as evaluated by a biophysical profile or other tests) and the L–S ratio is low, the mother may need to receive steroids such as betamethasone to hasten the fetus' surfactant production in the lungs.

Procedure[edit]

An amniotic fluid sample is collected via amniocentesis and the sample is spun down in a centrifuge at 1000 rpm for 3–5 minutes. Thin layer chromatography (TLC) is performed on the supernatant, which separates out the components. Lecithin and sphingomyelin are relatively easy to identify on TLC and the predictive value of the test is good.^[4]

References[edit]

^ Gluck L, Kulovich MV, Borer RC, Brenner PH, Anderson GG, Spellacy WN (1971). "Diagnosis of the respiratory distress syndrome by amniocentesis.". Amer. J. Obstet. Gynecol. 109 (3): 440–45. PMID 5107880.
^ Whitfield CR, Chan WH, Sproule WB, Stewart AD (April 1972). "Amniotic fluid lecithin: sphingomyelin ratio and fetal lung development". Br Med J 2 (5805): 85–6. doi:10.1136/bmj.2.5805.85. PMC 1787826. PMID 5018313.
^ Wijnberger LD, de Kleine M, Voorbij HA, et al. (April 2009). "Prediction of fetal lung immaturity using gestational age, patient characteristics and fetal lung maturity tests: a probabilistic approach". Arch. Gynecol. Obstet. 281: 15–21. doi:10.1007/s00404-009-1033-0. PMC 2780670. PMID 19381669.
^ Spillman T, Cotton DB (1989). "Current perspectives in assessment of fetal pulmonary surfactant status with amniotic fluid". Crit Rev Clin Lab Sci 27 (4): 341–89. doi:10.3109/10408368909105719. PMID 2675912.

UpToDate Contents

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1. 胎児肺の成熟度評価 assessment of fetal lung maturity
2. 乳幼児および思春期前の小児における通常の成長パターン normal growth patterns in infants and prepubertal children
3. 妊娠前糖尿病を合併した妊娠の産科的マネージメント obstetrical management of pregnancy complicated by pregestational diabetes mellitus
4. 早産による新生児の罹病および死亡を減少させるための出産前ステロイド療法 antenatal corticosteroid therapy for reduction of neonatal morbidity and mortality from preterm delivery
5. 新生児における呼吸促迫症候群の病態生理および臨床症状 pathophysiology and clinical manifestations of respiratory distress syndrome in the newborn

English Journal

Prediction of fetal lung maturity using the lecithin/sphingomyelin (L/S) ratio analysis with a simplified sample preparation, using a commercial microtip-column combined with mass spectrometric analysis.

Kwak HS1, Chung HJ2, Choi YS3, Min WK4, Jung SY5.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.J Chromatogr B Analyt Technol Biomed Life Sci.2015 Jul 1;993-994:81-5. doi: 10.1016/j.jchromb.2015.05.012. Epub 2015 May 14.
Fetal lung maturity is estimated using the lecithin/sphingomyelin ratio (L/S ratio) in amniotic fluid and it is commonly measured with thin-layer chromatography (TLC). The TLC method is time consuming and technically difficult; however, it is widely used because there is no alternative. We evaluated
PMID 26000861

Arginase activity and lecithin/sphingomyelin (l/s) ratio in the amniotic fluid of pregnant women.

Bjelakovic G1, Miladinovic P2, Jevtovic-Stoimenov T1, Stojanovic I1, Nikolic J1, Pavlovic D1, Kocic G1, Bjelakovic M3, Ilic M4, Sokolovic D1, Basic J1.
Indian journal of clinical biochemistry : IJCB.Indian J Clin Biochem.2015 Jan;30(1):84-8. doi: 10.1007/s12291-013-0398-9. Epub 2013 Nov 20.
Arginase activity is important in polyamines and nitric oxide production which are required for the normal growth of placenta and embryo. A considerable arginase activity is observed in amniotic fluid in women at the end of pregnancy. Lecithin to sphingomyelin (L/S) ratio is widely used in order to
PMID 25646046

Determination of the amniotic fluid lecithin/sphingomyelin ratio using a pipette tip column with a cation-exchange resin and mass spectrometry.

Kwak HS, Chung HJ, Min WK, Chun S, Lee WC, Choi YS, Han JY, Cho DH, Jung SY.
Clinical chemistry and laboratory medicine : CCLM / FESCC.Clin Chem Lab Med.2014 Sep;52(9):e221-3. doi: 10.1515/cclm-2013-0199.
PMID 24781674