Identification and characterization of a matrix protein (PPP-10) in the periostracum of the pearl oyster, Pinctada fucata

AbstractThe periostracum is a layered structure that is formed as a mollusk shell grows. The shell is covered by the periostracum, which consists of organic matrices that prevent decalcification of the shell. In the present study, we discovered the presence of chitin in the periostracum and identified a novel matrix protein, Pinctada fucata periostracum protein named PPP-10. It was purified from the sodium dodecyl sulfate/dithiothreitol-soluble fraction of the periostracum of the Japanese pearl oyster, P. fucata. The deduced amino acid sequence was determined by a combination of amino acid sequence analysis and cDNA cloning. The open reading frame encoded a precursor protein of 112 amino acid residues including a 21-residue signal peptide. The 91 residues following the signal peptide contained abundant Cys and Tyr residues. PPP-10 was expressed on the outer side of the outer fold in the mantle, indicating that PPP-10 was present in the second or third layer of the periostracum. We also determined that the recombinant PPP-10 had chitin-binding activity and could incorporate chitin into the scaffolds of the periostracum. These results shed light on the early steps in mollusk shell formation

Left Ventricular Diastolic Function during the Normal Peripartum Period

Background:Because cardiovascular function and hemodynamics markedly change during pregnancy, our aim was to elucidate left ventricular (LV) diastolic function in pregnant women. Methods and Results:We prospectively collected the data of 397 pregnant women treated between 2012 and 2013. We evaluated their LV systolic and diastolic functions via echocardiography during the 3rd trimester (28–30 weeks’ gestation) and within 4 days of delivery. Additionally, we analyzed the cardiac geometry: relative wall thickness and LV mass index (LVMI). Diastolic dysfunction was defined as early diastolic mitral annulus velocity (e’) 15. The pregnant women were 33.7±5.0 years old and the prevalence of hypertensive disorders in pregnancy (HDP) was 4.0%. LV systolic function was preserved in all pregnant women. However, diastolic function significantly decreased after delivery (mean e’: 12.6 vs. 11.6 cm/s, P<0.0001; median E/e’ ratio: 6.4 vs. 7.3, P<0.0001). Diastolic function after delivery was associated with the prevalence of HDP (P=0.035) and was correlated with age (R=−0.17, P=0.0009) and LVMI (R=−0.30, P<0.0001). However, these changes in diastolic function remained within the normal range and only 1 woman (1/397, 0.3%) had LV diastolic dysfunction after delivery. Conclusions:LV diastolic function decreased after delivery in pregnant women but was within the normal range

Factors associated with increased levels of brain natriuretic peptide and cardiac troponin I during the peripartum period.

BACKGROUND:We aimed to investigate the values and the changes of brain natriuretic peptide (BNP) and cardiac troponin in pregnant women. METHODS AND RESULTS:We prospectively collected the data of 405 pregnant women who were treated at Japanese general hospital between 2012 and 2013. We analyzed their laboratory data and echocardiographic findings during the third trimester (28-30 weeks' gestation) and within 4 days of delivery. In addition, we evaluated the factors associated with elevation of BNP and cardiac troponin I (cTnI) levels. The pregnant women were 33.8 ± 5.0 years old and the prevalence of pregnancy induced hypertension (PIH) and placental abnormality was 4.2% and 2.5%, respectively. BNP levels increased after delivery (13.2 pg/mL vs. 23.5 pg/mL; P <0.001), correlated with increased left ventricular diastolic dimension (P = 0.035), left atrial dimension (P <0.001), and decreased hemoglobin (P <0.001). Moreover, cTnI levels increased to over 0.015 ng/mL after delivery in 4.0% of pregnant women. In multivariate analysis, PIH (OR: 18.71, P = 0.003), placental abnormality (OR: 26.78, P = 0.007), and decreased hemoglobin after delivery (OR: 2.59, P <0.001) were the factors associated with elevated cTnI. CONCLUSIONS:BNP levels increased in association with cardiac chamber enlargement and decreased hemoglobin after delivery. Additionally, the factors affecting elevated cTnI levels were related to labor and delivery