These novel findings suggest that overnight rostral fluid displacement from the legs, related to prolonged sitting, may play a previously unrecognized role in the pathogenesis of obstructive sleep apnea in nonobese men that is independent of body weight.

The morphology of 50 normal tricuspid valves was studied. The surface of the leaflets was divided into three zones: (1) the rough zone, into which most of the chordae tendineae are inserted, (2) the basal zone, and (3) the clear zone, which lies between the rough and basal zones.Five types of chordae were distinguished by their morphology and mode of insertion: fan-shaped, rough zone, basal, free edge, and deep chordae. The last two types are unique to the tricuspid valve.If fan-shaped chordae, used to define the commissures between the leaflets, are absent, other landmarks may be used for commissural definition. Once defined, all tissue between the commissures was regarded as part of the anterior, posterior, or septal leaflet. The recognition that the free edges of the anterior and septal leaflets contain notches, that rough zone chordae insert into them, and that the posterior leaflet has scallops further aids identification of a leaflet's components. Thus, structures formerly regarded as accessory leaflets were incorporated into one of the three leaflets.RECENTLY, we have reexamined the morphology of the mitral valve and have been able to establish a better clinicopathologic correlation in various types of mitral valve abnormality. By identifying the specific fan-shaped chordae tendineae attached to the mitral valve, we were able to delineate the commissural areas clearly and to divide the valve into anterior and posterior leaflets. We were, thus, also able to identify the clefts of the posterior leaflet and to distinguish them from the true commissures.1 2 This definition of mitral valve anatomy eliminates the need to postulate accessory leaflets of the mitral valve. It proved valuable in enhancing clinicopathologic understanding of the syndrome of mitral regurgitation due to prolapse of the posterior leaflet.3

Fifty normal mitral valves from adults were studied. Commissures, identified by commissural chordae tendineae and the tips of papillary muscles, partition the mitral valvular tissue into anterior and posterior leaflets. This definition incorporates into the posterior leaflet the structures formerly regarded as accessory leaflets. The posterior leaflet is further divided into scallops by clefts in its tissue. Cleft chordae provide a guide to these interscallop indentations or clefts. Partitioned this way, the posterior leaflet was tri-scalloped in 46 hearts. In 42, a large middle scallop was present with two smaller scallops on either side. Rough and clear zones can be defined on the anterior leaflet and rough, clear, and basal zones on the posterior leaflet. Additional Indexing Words: Commissure Prolapsed mitral valve Chordae tendineae Mitral regurgitation

OBJECTIVE To determine if maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30–34 weeks can identify mothers at risk for preeclampsia (PE), stillbirth and small-for-gestational-age neonates (SGA). STUDY DESIGN A prospective cohort study included 1269 singleton pregnant women who had blood samples obtained at 30–34 weeks and delivered after 34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by ELISA. RESULTS The prevalence of late (>34 weeks) PE, severe late PE, stillbirth and SGA was 3.2% (n=40), 1.8% (n=23), 0.4% (n=5) and 8.5% (n=108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late PE [adjusted odds ratio (aOR) 16]; addition of PlGF/sEng to clinical risk factors increased the area under the ROC curve (AUC) from 0.76 to 0.88 (p=0.03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20–25 weeks for the prediction of severe late PE (comparison of AUC; each p≤0.02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false positive rate of 15% for the identification of severe late PE. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30–34 weeks had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80% and specificity 93%) were observed in a separate case-control study. Integrating these biomarkers with clinical data did not improve the prediction of SGA. CONCLUSIONS Risk assessment for severe late PE and stillbirth in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and anti-angiogenic factors at 30–34 weeks of gestation.

No abstract

Background:Neonates have been shown to have a heightened sensitivity to the central depressive effects of opioids compared to older infants and adults. The limited development of P-glycoprotein (P-gp) may limit the ability of the neonate to efflux morphine from the brain back to the systemic circulation. The objective of the study was to determine the ontogeny of P-gp in the human brain. Methods: Postmortem cortex samples from gestational age (GA) 20-26 wk, GA 36-40 wk, postnatal age (PNA) 0-3 mo, PNA 3-6 mo, and adults were immunostained for P-gp. results: The intensity of P-gp staining in adults was significantly higher compared to at GA 20-26 wk (P < 0.05), GA 36-40 wk (P < 0.05), and PNA 0-3 mo (P < 0.05). P-gp intensity at GA 20-26 wk (P < 0.05), GA 36-40 wk (P < 0.05), and PNA 0-3 mo (P < 0.05) was significantly lower compared to at PNA 3-6 mo. conclusion: P-gp expression in the brain is limited at birth, increases with postnatal maturation, and reaches adult levels at ~3-6 mo of age. Given the immaturity of blood-brain barrier (BBB) P-gp after birth, morphine may concentrate in the brain. This provides mechanistic support to life threatening opioid toxicity seen with maternal codeine use during breastfeeding.

Myofibroblast transition from mesenchymal or epithelial precursors triggers loss of the primary cilium. In epithelial cells this requires contact injury and TGFβ and is mediated by Rac- and Smad3-dependent myosin phosphorylation. Thus the myofibroblast is a unique cilium-less cell with markedly reprogrammed ciliary signaling.

Chordae tendineae from 50 normal mitral valves were studied. Four main types can be distinguished by their mode of insertion. Commissural chordae insert into and define the commissures between the anterior and posterior leaflets. Rough zone chordae insert into the ventricular aspect of the distal rough portion of the anterior and posterior leaflets. Such rough zone chordae typically split into three cords before inserting into the leaflet. Two of the anterior leaflet rough zone chordae are thicker than the others and are called strut chordae. They insert at 4 and 8 o'clock positions on the semicircular anterior leaflet. Cleft chordae insert into and define the clefts between the scallops of the posterior leaflet. Basal chordae are single strands that arise from the posterior ventricular wall and insert into the basal zone of the posterior leaflet. This classification permits a clear definition of mitral valve anatomy and forms a sound basis for functional studies of chordae tendineae.