Inhibition of bone resorption by Tanshinone VI isolated from Salvia miltiorrhiza Bunge.

During the last decade, a more detailed knowledge of molecular mechanisms involved in osteoclastogenesis has driven research efforts in the development and screening of compound libraries of several small molecules that specifically inhibit the pathway involved in the commitment of the osteoclast precursor cells. Natural compounds that suppress osteoclast differentiation may have therapeutic value in treating osteoporosis and other bone erosive diseases such as rheumatoid arthritis or metastasis associated with bone loss. In ongoing investigation into anti-osteoporotic compounds from natural products we have analyzed the effect of Tanshinone VI on osteoclasts differentiation, using a physiologic three-dimensional osteoblast/bone marrow model of cell co-culture. Tanshinone VI is an abietane diterpene extracted from the root of Salvia miltiorrhiza Bunge (Labiatae), a Chinese traditional crude drug, "Tan-Shen". Tashinone has been widely used in clinical practice for the prevention of cardiac diseases, arthritis and other inflammation-related disorders based on its pharmacological actions in multiple tissues. Although Tanshinone VI A has been used as a medicinal agent in the treatment of many diseases, its role in osteoclast-related bone diseases remains unknown. We showed previously that Tanshinone VI greatly inhibits osteoclast differentiation and suppresses bone resorption through disruption of the actin ring; subsequently, we intended to examine the precise inhibitory mechanism of Tanshinone VI on osteoclast differentiating factor. This study shows, for the first time, that Tanshinone VI prevents osteoclast differentiation by inhibiting RANKL expression and NFkB induction.

Clathrin-dependent endocytosis of membrane-bound RANKL in differentiated osteoclasts.

Bone is continuously repaired and remodelled through well-coordinated activity of osteoblasts that form new bone and osteoclasts, which resorb it. Osteoblasts synthesize and secrete two key molecules that are important for osteoclast differentiation, namely the ligand for the receptor of activator of nuclear factor kappaB (RANKL) and its decoy receptor osteoprotegerin (OPG). Active membrane transport is a typical feature of the resorbing osteoclast during bone resorption. Normally, one resorption cycle takes several hours as observed by monitoring actin ring formation and consequent disappearance in vitro. During these cyclic changes, the cytoskeleton undergoes remarkable dynamic rearrangement. Active cells show a continuous process of exocytosis that plays an essential role in transport of membrane components, soluble molecules and receptor-mediated ligands thus allowing them to communicate with the environment. The processes that govern intracellular transport and trafficking in mature osteoclasts are poorly known. The principal methodological problem that have made these studies difficult is a physiological culture of osteoclasts that permit observing the vesicle apparatus in conditions similar to the in vivo conditions. In the present study we have used a number of morphological approaches to characterize the composition, formation and the endocytic and biosynthetic pathways that play roles in dynamics of differentiation of mature bone resorbing cells using a tri-dimensional system of physiologic coculture.

Effect of recombinant TRAIL in a murine co-culture system of osteoclastogenesis.

Although some experimental evidence has implicated the TRAIL/TRAIL-receptor system in the regulation of osteoclastogenesis, the only available studies performed so far have been performed on isolated pre-osteoclasts, induced to differentiate by the addition of recombinant RANKL and M-CSF. Using a more physiological co-culture system in the absence of exogenous cytokines, we have here demonstrated that recombinant TRAIL inhibits osteoclast formation, but only at relatively high concentrations (500 ng/mL).

In vitro exposure of human chondrocytes to pulsed electromagnetic fields.

The effect of pulsed electromagnetic fields (PEMFs) on the proliferation and survival of matrix-induced autologous chondrocyte implantation (MACI)-derived cells was studied to ascertain the healing potential of PEMFs. MACI-derived cells were taken from cartilage biopsies 6 months after surgery and cultured. No dedifferentiation towards the fibro- blastic phenotype occurred, indicating the success of the surgical implantation. The MACI-derived cultured chondrocytes were exposed to 12 h/day (short term) or 4 h/day (long term) PEMFs exposure (magnetic field intensity, 2 mT; frequency, 75 Hz) and proliferation rate determined by flow cytometric analysis. The PEMFs exposure elicited a significant increase of cell number in the SG2M cell cycle phase. Moreover, cells isolated from MACI scaffolds showed the presence of collagen type II, a typical marker of chondrocyte functionality. The results show that MACI membranes represent an optimal bioengineering device to support chondrocyte growth and proliferation in surgical implants. The surgical implant of MACI combined with physiotherapy is suggested as a promising approach for a faster and safer treatment of cartilage traumatic lesions.

Preparation of activated carbons from heavy-oil fly ashes.

The use of heavy oil fly ash with high ash content (45 wt.%) as a precursor for the preparation of activated carbons has been investigated. The raw fly ash and the fly ash with lower ash content, obtained by a HCl/HF washing treatment, have been pyrolyzed at 900 degrees C and then activated with CO(2) in the temperature range of 800-900 degrees C for different times. The activated carbons have been characterised as regards the surface area and the pore volume. The evolution of the porosity has been related to the burn-off degree.

Diacylglycerol kinases in nuclear lipid-dependent signal transduction pathways.

Several independent groups have shown that lipid-dependent signal transduction systems operate in the nucleus and that they are regulated independently from their membrane and cytosolic counterparts. A sizable body of evidence suggests that nuclear lipid signaling controls critical biological functions such as cell proliferation and differentiation. Diacylglycerol is a fundamental lipid second messenger which is produced in the nucleus. The levels of nuclear diacylglycerol fluctuate during the cell cycle progression, suggesting that such a molecule has important regulatory roles. Most likely, nuclear diacylglycerol serves as a chemoattractant for some isoforms of protein kinase C that migrate to the nucleus in response to a variety of agonists. The nucleus also contains diacylglycerol kinases, i.e. the enzymes that, by converting diacylglycerol into phosphatidic acid, terminate diacylglycerol-dependent events. A number of diacylglycerol kinases encoded by separate genes are present in the mammalian genome. This review aims at highlighting the different isotypes of diacylglycerol kinases identified at the nuclear level as well as at discussing their potential function and regulation.

Phosphoinositide-specific phospholipase Cbeta1 expression is not linked to nerve growth factor-induced differentiation, cell survival or cell cycle control in PC12 rat pheocromocytoma cells.

Recent reports have highlighted that phosphoinositide-specific phospholipase Cbeta1 expression is linked to neuronal differentiation in different experimental models. We sought to determine whether or not this is also true for nerve growth factor (NGF)-induced neuronal differentiation of rat PC12 cells. However, we did not find differences in the expression of both the forms of phosphoinositide-specific phospholipase Cbeta1 (a and b) during sympathetic differentiation of these cells. Also, PC12 cell clones stably overexpressing phosphoinositide-specific phospholipase Cbeta1 were not more susceptible to the differentiating effect of NGF. Furthermore, since it is well established that phosphoinositide-specific phospholipase Cbeta1 affects cell proliferation, we investigated whether or not PC12 cell clones stably overexpressing phosphoinositide-specific phospholipase Cbeta1 showed differences in survival to serum deprivation and cell cycle, when compared to wild type cells. Nevertheless, we did not find any differences in these parameters between wild type cells and the overexpressing clones. Interestingly, in PC12 cells the overexpressed phosphoinositide-specific phospholipase Cbeta1 did not localize to the nucleus, but by immunofluorescence analysis, was detected in the cytoplasm. Therefore, our findings may represent another important clue to the fact that only when it is located within the nucleus phosphoinositide-specific phospholipase Cbeta1 is able to influence cell proliferation.

Role of electrothrombosis in aneurysm treatment with Guglielmi detachable coils: an in vitro scanning electron microscopic study.

BACKGROUND AND PURPOSE: In the 1990s, the introduction of the Guglielmi detachable coil (GDC) system in clinical practice was followed by extensive clinical use of this endovascular device in the treatment of brain aneurysms. This technology is based on electrothrombosis and electrolytic detachment of platinum coils. Despite the extensive use of this treatment technique, the role of electrothrombosis has not been fully investigated and clarified. An in vitro electron microscopic study of human blood was performed to elucidate the role that electrothrombosis might play in triggering the biologic response of thrombosis of the aneurysmal sac. METHODS: Human blood from five patients was used to fill plastic containers in which GDCs had been deposited. These five patients had subarachnoid hemorrhage and were similar in age and clinical presentation. Electron microscopic studies were performed on GDCs that had been electrically charged and on GDCs that had not. RESULTS: All electron microscopic studies revealed that the electrically charged GDCs were covered by blood elements and fibrin adherent to the surface of the coil. Noncharged GDCs did not have deposits or adhesions of these blood constituents. CONCLUSION: These findings demonstrated that passage of electric current through the GDC induces attraction of blood constituents. This attraction may trigger a thrombotic reaction on the surface of the coil. The greater the time of current application, the more pronounced the cellular reaction and the deposition of fibrin and blood cells on the GDC.

Re-examination of the mechanisms regulating nuclear inositol lipid metabolism.

Although inositol lipids constitute only a very minor proportion of total cellular lipids, they have received immense attention by scientists since it was discovered that they play key roles in a wide range of important cellular processes. In the late 1980s, it was suggested that these lipids are also present within the cell nucleus. Albeit the early reports about the intranuclear localization of phosphoinositides were met by skepticism and disbelief, compelling evidence has subsequently been accumulated convincingly showing that a phosphoinositide cycle is present at the nuclear level and may be activated in response to stimuli that do not activate the inositol lipid metabolism localized at the plasma membrane. Very recently, intriguing new data have highlighted that some of the mechanisms regulating nuclear inositol lipid metabolism differ in a substantial way from those operating at the cell periphery. Here, we provide an overview of recent findings regarding the regulation of both nuclear phosphatidylinositol 3-kinase and phosphoinositide-specific phospholipase C-beta1.

Nuclear apoptotic changes: an overview.

Apoptosis is a form of active cell death essential for morphogenesis, development, differentiation, and homeostasis of multicellular organisms. The activation of genetically controlled specific pathways that are highly conserved during evolution results in the characteristic morphological features of apoptosis that are mainly evident in the nucleus. These include chromatin condensation, nuclear shrinkage, and the formation of apoptotic bodies. The morphological changes are the result of molecular alterations, such as DNA and RNA cleavage, post-translational modifications of nuclear proteins, and proteolysis of several polypeptides residing in the nucleus. During the last five years our understanding of the process of apoptosis has dramatically increased. However, the mechanisms that lead to apoptotic changes in the nucleus have been only partially clarified. Here, we shall review the most recent findings that may explain why the nucleus displays these striking modifications. Moreover, we shall take into consideration the emerging evidence about apoptotic events as a trigger for the generation of autoantibodies to nuclear components.

Morphological features and measurements in a human fetus with karyotype 69, XXX: comparison with fetuses of the same CRL, without chromosomal anomalies.

A triploid fetus (karyotype 69, XXX) with crown-rump length (CRL) 94 mm, presenting micro- and retrognathia, low-set ears and crooked feet, was cleared and double-stained with alizarin red S and alcian blue for detecting the ossification patterns in the vertebral column, ribs, ischium, limbs, and face. Longitudinal measurements of some long bones in the upper (humerus, ulna, radius) and lower (femur, tibia, fibula) limb were taken. The values of both the total length (TL) and the ossified part (OL) of each long bone, as well as the OL/TL per cent ratio were considered. Reference points were located on the mandible, i.e. condylar process (Pcl), coronoid process (Pco), gnathion (GN), gonion (GO), superior symphyseal point (SSP) for measuring linear dimensions. Since the aim of this work was to assess the influence of triploidy 69, XXX the skeletal development and growth patterns, all values obtained in the examined specimen were related with those relative to a group of fetuses, without any detectable malformation and chromosomal anomalies, with a CRL mean value of 93 mm. Results evidenced that the triploid fetus presented growth restriction and that the vertebral centra ossification and the mandibular development were much delayed with the normal ossification patterns.

Further considerations on the intranuclear distribution of HMGI/Y proteins.

We have investigated the intranuclear distribution of High-mobility group proteins I/Y by means of immunofluorescent staining employing a variety of cell lines. Confocal scanning laser microscopy analysis revealed that High-mobility group proteins I/Y are present in an intranuclear fibrogranular network and mitotic chromosomes. In Caski, C4I, Flow 2002, and K562 cell lines, High-mobility group proteins I/Y were absent from nucleoli, whereas in HeLa cells they were present in this nuclear domain. Double immunolabeling studies showed that High-mobility group proteins I/Y co-localize with other key nuclear components such as NuMA, SC-35, and TAF(II)70. Nuclear reactivity for High-mobility group proteins I/Y dramatically decreased in apoptotic nuclei of HL-60 human leukemia cells. Our morphological data correlate well with previous biochemical and functional findings obtained by other investigators, who have demonstrated multiple roles for this class of polypeptides. However, they point to the likelihood that High-mobility group proteins I/Y are involved in as yet unidentified functions, most likely in the speckle domains of the nucleus. They also show that conceivably these proteins are also involved in apoptosis.

Localization of the small monomeric GTPases Rab3D and Rab3A in the AtT-20 rat pituitary cell line.

We investigated the cellular localization of the small GTPases Rab3D and Rab3A in AtT-20 cells treated with the drug Brefeldin A. Brefeldin A induces the redistribution of the Golgi complex into the endoplasmic reticulum and tubulation of endosomes. However, in Brefeldin A-treated wild-type AtT-20 cells, both Rab3D and Rab3A retained their distribution, indicating that they belong to a nonendosomal, post-Golgi compartment. Immunoelectron microscopy experiments indicated that both Rab3D and Rab3A localized to the ACTH-containing, large dense core granules. In contrast, in cell clones overexpressing a mutated form of Rab3D (Rab3D N135I), Rab3A did not localize to the dense core granules. Moreover, since our previous results showed that overexpression of Rab3D N135I severely impaired regulated ACTH secretion in AtT-20 cells, we sought to determine whether the impairment could depend on a redistribution of two key components of the regulated exocytosis machinery, synaptotagmin and SNAP-25. As far as synaptotagmin was concerned, in cell clones overexpressing Rab3D N135I, the protein did not localize close to the plasma membrane, in agreement with the previously reported defective docking of dense core granules to the plasma membrane. Immunofluorescence experiments showed that SNAP-25 did not change its localization in these cell clones. All in all, our findings strengthen the notion that both Rab3D and Rab3A are associated with the dense core granule compartment of AtT-20 cells, and that the impairment in the ACTH secretion caused by overexpression of a mutated Rab3D form is likely to be due to a lacking of granule docking to the plasma membrane, possibly because Rab3A fails to associate with the granules.

Immunocytochemical expression of protein kinase C isoenzymes alpha, delta, epsilon and zeta in differentiating chick chondrocytes in vitro.

In our previous work we have investigated the expression of the serine-threonine kinase protein kinase C (PKC) in the vertebral column of mouse foetuses. In the present work we would verify the expression of four PKC-isoenzymes (alpha, delta, epsilon, zeta) in two distinct phases of the chondrogenesis and the endochondral osteogenesis in vitro. We performed primary cultures of chondrocytes collected from tibiae of 6-day old chick embryos. This cells were cultured for 20 days and than collected on coverslips (stage 1 culture). Other cells of the stage 1 were undergone further differentiation towards the phenotype of osteoblast-like cells (stage 2 culture), in accord to the protocol of Descalzi Cancedda et al. (1992). In stage 1 culture, PKC-epsilon was the most expressed isoform, whereas PKC-alpha exhibited the least intense positivity. In stage 2 culture, PKC-alpha was the most expressed isoform, whereas a marked decrease of PKC-epsilon expression was detected compared to stage 1. No relevant differences were evidenced as regards,the expression of PKC-zeta between the two considered cell culture stages. On these bases, it could be reasonable that these PKC-isoenzymes may be involved at different levels in chondrocytes differentiation as well as in the endochondral ossification process.

Biocompatibility evaluation of dental metal alloys in vitro: expression of extracellular matrix molecules and its relationship to cell proliferation rates.

The biocompatibility in vitro of dental biomaterials has been widely studied, with consideration of cell viability and cell proliferation rates. In the present study we evaluated the biocompatibility in vitro of three single-phase dental metal alloys, all provided by the same manufacturer. To this aim, we considered the percentage of proliferating cells revealed by 5-bromodeoxyuridine incorporation in human fibroblast cultures in the presence of these biomaterials, performing a short time test (72 h). These data were correlated with immunocytochemical expression of four molecules of the extracellular matrix, i.e., fibronectin, type I collagen, beta(1)-integrin subunit, and chondroitin sulfate, because the capability of cells to adhere to substrata is widely related to cell proliferation rates. Alloys presenting higher amounts of noble elements were more biocompatible even when they contained significant amount of both Ag and Cu. As regards the expression of the extracellular matrix molecules, the organization level of fibronectin in fibrils was correlated with higher cell proliferation rates, whereas no difference was detected for the expression of the other antigens. On these bases, we assume that expression of fibronectin could be a useful parameter in evaluation of biocompatibility in addition to cell proliferation capability.

Cell proliferation rates and fibronectin arrangement as parameters for biocompatibility evaluation of dental metal alloys in vitro.

A short-term (72-96 hours) biocompatibility evaluation in vitro of four single phase dental metal alloys was conducted by determining cell proliferation rates correlated to the organization of the extracellular matrix protein fibronectin in human fibroblast cultures. Immunocytochemical methods were performed to detect both cell proliferation rates by 5-bromodeoxyuridine (BrdU) incorporation, and fibronectin arrangement, i.e., diffuse in the extracellular matrix, organized in fibrils or in focal adhesions. We showed that cell proliferation rates were related to fibronectin expression. In particular, a higher percentage of cells in the S-phase were related to a predominance of fibronectin organized both in fibrils and in focal adhesions. The alloy with the highest Au content seemed the most biocompatible among those tested, since it behaved in a very similar manner to the controls. On the contrary, fibroblasts exposed to the alloy with the highest percentage of Ag had the most different behavior as compared to the controls. We can assume that a correlation exists between fibronectin organization and the percentage of BrdU-positive cells and that these parameters are varying with the different metal composition of the alloys. The observation of fibronectin arrangement together with cell proliferation rates could be considered a useful tool to determine the biocompatibility of these biomaterials.

Enhanced nuclear diacylglycerol kinase activity in response to a mitogenic stimulation of quiescent Swiss 3T3 cells with insulin-like growth factor I.

Results from several laboratories have established the existence in the nucleus of an autonomous polyphosphoinositide cycle, which is involved in both cell proliferation and differentiation. A key step of intranuclear polyphosphoinositide metabolism is the phospholipase C-mediated generation of diacylglycerol (DAG). In insulin-like growth factor (IGF)-I-stimulated Swiss 3T3 cells, a transient elevation of intranuclear DAG levels is essential for attracting the alpha isoform of protein kinase C (PKC) to the nucleus. Previous evidence has shown that the nucleus also contains DAG kinase, i.e., the enzyme that yields phosphatidic acid from DAG, thus terminating PKC-mediated signaling events. Here we show that IGF-I treatment of quiescent Swiss 3T3 cells results in the stimulation of nuclear DAG kinase activity. Time course analysis showed an inverse relationship between nuclear DAG mass and DAG kinase activity levels. After IGF-I treatment, maximal enhancement of DAG kinase activity was measured in the internal matrix domain of the nucleus. PKC-alpha remained within the nuclear compartment, even when nuclear DAG mass returned to basal levels. This was conceivably due to interactions with specific nuclear PKC-binding proteins, some of which were identified as lamins A, B, and C and protein C23/nucleolin. Treatment of cells with two DAG kinase inhibitors, R59022 and R59949, blocked the IGF-I-dependent rise in nuclear DAG kinase activity and maintained elevated intranuclear levels of DAG. The two inhibitors also markedly potentiated the mitogenic effect of IGF-I. These results suggest that nuclear DAG kinase plays a key role in regulating the levels of DAG present in the nucleus and that DAG is a key molecule for the mitogenic effect that IGF-I exerts on Swiss 3T3 cells.

In vitro evaluation of the biocompatibility of dental alloys: fibronectin expression patterns and relationships to cellular proliferation rates.

OBJECTIVE: This short-term (72- to 96-hour) in vitro study on fibroblasts evaluated the biocompatibility of 3 single-phase dental alloys by determining cellular proliferation rates and the expression of a glycoprotein, fibronectin, which is involved in cellular adhesion processes. METHOD AND MATERIALS: Flow 2002 fibroblasts were cultured together with 3 single-phase dental alloys of different composition. Proliferation rates were determined by 5-bromodeoxyuridine incorporation. Fibronectin expression was determined by indirect immunofluorescence. RESULTS: At 72 hours, cells cultured with the alloy containing the lowest amount of noble elements (gold, platinum, and palladium) and the highest amount of silver exhibited significantly less proliferation than did controls. At 96 hours, only cultures with the alloy containing the greatest amount of noble elements behaved in a way similar to controls. Fibronectin organization in fibrils and in focal adhesions was correlated to higher cellular proliferation rates. CONCLUSION: Fibronectin organization could be a useful tool to determine the biocompatibility of dental alloys. Among the noble elements, palladium by itself exhibits very good biocompatibility. These indications could be useful for practitioners in the choice of the best alloy for specific clinical applications.

Biocompatibility in vitro of titanium dental implants. Immunocytochemical expression of fibronectin and extracellular matrix receptors.

BACKGROUND: Cell-substratum interactions play a peculiar role in cell proliferation, differentiation and migration. They are regulated by various glycoproteins, among which fibronectin, and by receptors connecting cells to the extracellular matrix, i.e. integrins. Therefore, the aim of this study was to correlate the proliferation rates of the human fibroblast line WI-38 cultured in presence of titanium dental implants to cell adhesion capability to substrata. METHODS: WI-38 fibroblasts were cultured in presence of four dental implants in titanium (one hydroxyapatite coated) for 48, 72 and 96 hours. Cell proliferation was evaluated by detecting 5-bromodeoxyuridine incorporation. Fibronectin organization and alpha5beta1 integrin expression were evidenced by indirect immunofluorescence. RESULTS: A correlation between fibronectin organization and cell proliferation rates was demonstrated: cultures showing fibronectin mainly organized in fibrils presented the highest cell proliferation degrees. After 96 hours, the observed decrease of the number of proliferating cells corresponded to a different fibronectin organization. In presence of the hydroxyapatite coated implant, colocalization of fibronectin and alpha5beta1 integrin was represented in focal contacts in cultures exhibiting the highest proliferation rate, while cells with the lowest proliferation one expressed alpha5beta1 integrin in point contacts. CONCLUSIONS: Evidences obtained in this work showed that both the organization of fibronectin and the expression of alpha5beta1 integrin are strictly correlated to cell proliferation rates. Therefore, these parameters could be useful for evaluating the biocompatibility of dental materials in vitro.

Prognostic value of 24-hour blood pressure in pregnancy.

CONTEXT: Elevated blood pressure (BP) measured at the physician's office may reflect true hypertension or white coat hypertension (WCH). The prognostic value of WCH among pregnant women is unknown. OBJECTIVE: To assess the prognostic value of WCH in pregnancy. DESIGN: Prospective cohort study conducted between September 1994 and October 1997. SETTING: Community hospital. PATIENTS: Women without preexisting hypertension and not treated with antihypertensive drugs aid with high (n = 148) or normal (n = 106) office BP (high office BP was defined as > or =140 mm Hg systolic and/or > or =90 mm Hg diastolic) matched for gestational age during their third trimester of pregnancy. All women underwent 24-hour noninvasive BP monitoring, and women without hypertension on 24-hour monitoring (125/74 mm Hg or less for average 24-hour BP) with office hypertension were classified as having WCH. Women were followed up through the end of pregnancy. MAIN OUTCOME MEASURES: Duration of pregnancy, gestational hypertension, preeclampsia or eclampsia, cesarean delivery, placental and neonatal weight, and length of maternal and neonatal hospital stays for those with and without elevated office BP. RESULTS: After application of exclusion criteria, data for 7 women were removed from the analysis. For the remaining subjects, in the group with elevated BP, prevalence of WCH was 29.2% (42/144). Duration of pregnancy was similar in the normotensive and WCH groups (39.6 vs 39.8 weeks; P = .50), but shorter (38.3 weeks; P<.001) in the true hypertension group. Incidence of preeclampsia was similar in the normotensive and WCH groups (5.8% vs 7.1 %; P = .86) but higher in the true hypertension group (61.7%; P<.001). Frequency of cesarean delivery was lower in the normotensive (12.4%) than in the WCH (45.2%; P = .008) and true hypertension (41.1 %; P = .009) groups. Neonatal weight was lower (P<.001) in the true hypertension (mean, 2911 g) than in the normotensive (3336 g) and WCH groups (3435 g), which did not differ (P = .68). The duration of neonatal hospital stay did not differ between the normotensive and the WCH group (5.3 vs 6.9 days; P = .13) but was longer in the true hypertension group (12.3 days; P<.001). CONCLUSIONS: In women with elevated BP during their third trimester of pregnancy, 24-hour BP was superior to office BP (distinguishing true hypertension from WCH) for prediction of the outcome of pregnancy. Outcomes in the normotensive and WCH group were comparable, but the increased incidence of cesarean delivery in the WCH group may reflect decision-making processes influenced by office BP.