Haplotype variation and linkage disequilibrium in 313 human genes

Variation within genes has important implications for all biological traits. We identified 3899 single nucleotide polymorphisms (SNPs) that were present within 313 genes from 82 unrelated individuals of diverse ancestry, and we organized the SNPs into 4304 different haplotypes. Each gene had several variable SNPs and haplotypes that were present in all populations, as well as a number that were population-specific. Pairs of SNPs exhibited variability in the degree of linkage disequilibrium that was a function of their location within a gene, distance from each other, population distribution, and population frequency. Haplotypes generally had more information content (heterozygosity) than did individual SNPs. Our analysis of the pattern of variation strongly supports the recent expansion of the human population.

The mouse snail gene encodes a key regulator of the epithelial-mesenchymal transition

Snail family genes encode DNA binding zinc finger proteins that act as transcriptional repressors. Mouse embryos deficient for the Snail (Sna) gene exhibit defects in the formation of the mesoderm germ layer. In Sna(-/-) mutant embryos, a mesoderm layer forms and mesodermal marker genes are induced but the mutant mesoderm is morphologically abnormal. Lacunae form within the mesoderm layer of the mutant embryos, and cells lining these lacunae retain epithelial characteristics. These cells resemble a columnar epithelium and have apical-basal polarity, with microvilli along the apical surface and intercellular electron-dense adhesive junctions that resemble adherens junctions. E-cadherin expression is retained in the mesoderm of the Sna(-/-) embryos. These defects are strikingly similar to the gastrulation defects observed in snail-deficient Drosophila embryos, suggesting that the mechanism of repression of E-cadherin transcription by Snail family proteins may have been present in the metazoan ancestor of the arthropod and mammalian lineages.

Notch signalling pathway mediates hair cell development in mammalian cochlea

The mammalian cochlea contains an invariant mosaic of sensory hair cells and non-sensory supporting cells reminiscent of invertebrate structures such as the compound eye in Drosophila melanogaster. The sensory epithelium in the mammalian cochlea (the organ of Corti) contains four rows of mechanosensory hair cells: a single row of inner hair cells and three rows of outer hair cells. Each hair cell is separated from the next by an interceding supporting cell, forming an invariant and alternating mosaic that extends the length of the cochlear duct. Previous results suggest that determination of cell fates in the cochlear mosaic occurs via inhibitory interactions between adjacent progenitor cells (lateral inhibition). Cells populating the cochlear epithelium appear to constitute a developmental equivalence group in which developing hair cells suppress differentiation in their immediate neighbours through lateral inhibition. These interactions may be mediated through the Notch signalling pathway, a molecular mechanism that is involved in the determination of a variety of cell fates. Here we show that genes encoding the receptor protein Notch1 and its ligand, Jagged 2, are expressed in alternating cell types in the developing sensory epithelium. In addition, genetic deletion of Jag2 results in a significant increase in sensory hair cells, presumably as a result of a decrease in Notch activation. These results provide direct evidence for Notch-mediated lateral inhibition in a mammalian system and support a role for Notch in the development of the cochlear mosaic.

Defects in limb, craniofacial, and thymic development in Jagged2 mutant mice

The Notch signaling pathway is a conserved intercellular signaling mechanism that is essential for proper embryonic development in numerous metazoan organisms. We have examined the in vivo role of the Jagged2 (Jag2) gene, which encodes a ligand for the Notch family of transmembrane receptors, by making a targeted mutation that removes a domain of the Jagged2 protein required for receptor interaction. Mice homozygous for this deletion die perinatally because of defects in craniofacial morphogenesis. The mutant homozygotes exhibit cleft palate and fusion of the tongue with the palatal shelves. The mutant mice also exhibit syndactyly (digit fusions) of the fore- and hindlimbs. The apical ectodermal ridge (AER) of the limb buds of the mutant homozygotes is hyperplastic, and we observe an expanded domain of Fgf8 expression in the AER. In the foot plates of the mutant homozygotes, both Bmp2 and Bmp7 expression and apoptotic interdigital cell death are reduced. Mutant homozygotes also display defects in thymic development, exhibiting altered thymic morphology and impaired differentiation of gamma delta lineage T cells. These results demonstrate that Notch signaling mediated by Jag2 plays an essential role during limb, craniofacial, and thymic development in mice.

Defects in development of the kidney, heart and eye vasculature in mice homozygous for a hypomorphic Notch2 mutation

The Notch gene family encodes large transmembrane receptors that are components of an evolutionarily conserved intercellular signaling mechanism. To assess the in vivo role of the Notch2 gene, we constructed a targeted mutation, Notch2(del1). Unexpectedly, we found that alternative splicing of the Notch2(del1) mutant allele leads to the production of two different in-frame transcripts that delete either one or two EGF repeats of the Notch2 protein, suggesting that this allele is a hypomorphic Notch2 mutation. Mice homozygous for the Notch2(del1) mutation died perinatally from defects in glomerular development in the kidney. Notch2(del1)/Notch2(del1)mutant kidneys were hypoplastic and mutant glomeruli lacked a normal capillary tuft. The Notch ligand encoded by the Jag1 gene was expressed in developing glomeruli in cells adjacent to Notch2-expressing cells. We show that mice heterozygous for both the Notch2(del1) and Jag1(dDSL) mutations exhibit a glomerular defect similar to, but less severe than, that of Notch2(del1)/Notch2(del1)homozygotes. The co-localization and genetic interaction of Jag1 and Notch2 imply that this ligand and receptor physically interact, forming part of the signal transduction pathway required for glomerular differentiation and patterning. Notch2(del1)/Notch2(del1)homozygotes also display myocardial hypoplasia, edema and hyperplasia of cells associated with the hyaloid vasculature of the eye. These data identify novel developmental roles for Notch2 in kidney, heart and eye development.

Glucose regulates protein interactions within the yeast SNF1 protein kinase complex

The SNF1 protein kinase is broadly conserved in eukaryotes and has been implicated in responses to environmental and nutritional stress. In yeast, the SNF1 kinase has a central role in the response to glucose starvation. SNF1 is associated with its activating subunit, SNF4, and other proteins in complexes. Using the two-hybrid system, we show that interaction between SNF1 and SNF4 is strongly regulated by the glucose signal. Moreover, this interaction is appropriately affected by mutations in regulators, including protein phosphatase 1. We show that SNF4 binds to the SNF1 regulatory domain in low glucose, whereas in high glucose the regulatory domain binds to the kinase domain of SNF1 itself. Genetic analysis further suggests that the SNF1 regulatory domain autoinhibits the kinase activity and that in low glucose SNF4 antagonizes this inhibition. Finally, these interactions have been conserved from yeast to plants, indicating that homologs of the SNF1 kinase complex respond to regulatory signals by analogous mechanisms.

Remote postconditioning. Brief renal ischemia and reperfusion applied before coronary artery reperfusion reduces myocardial infarct size via endogenous activation of adenosine receptors

OBJECTIVES

A series of brief coronary artery reperfusions and reocclusions applied during the early minutes of coronary artery reflow ("postconditioning") attenuates reperfusion injury. However, it is not known whether brief ischemia-reperfusion applied to a distant organ at the onset of myocardial reperfusion (i.e. "remote postconditioning", remote PostC) reduces infarct size in the reperfused myocardium. In an in vivo anesthetized rat model of myocardial infarction induced by coronary artery occlusion and reperfusion, this study tested the hypothesis that remote postC induced by a single 5 minute episode of renal artery (RA) occlusion and reperfusion applied immediately before the onset of coronary artery reperfusion protects the myocardium from reperfusion injury by mechanisms involving endogenous adenosine receptor activation.

METHODS

All rats were subjected to a total of 30 minutes of left coronary artery occlusion (LCAO) and 3 hours of reperfusion. The rats were randomized to one of six groups: 1) CONTROL: LCAO and reperfusion only with no other intervention; 2) Remote PostC: after 24 minutes of LCAO the RA was occluded for 5 minutes and released 1 min before coronary artery reperfusion; 3) Permanent RA occlusion: the RA was permanently occluded after 24 minutes LCAO continuing to the end of reperfusion; 4) Delayed Remote PostC: after 26 minutes LCAO the RA was occluded for 5 minutes, and its release was delayed until 1 min after coronary artery reperfusion; 5) CON + SPT: rats with LCAO and reperfusion received 10 mg/kg IV of the non-selective adenosine receptor antagonist 8-sulfophenyl theophylline [SPT] administered 5 minutes before coronary artery reperfusion; and 6) Remote PostC + SPT: after 24 minutes of LCAO the RA was occluded for 5 minutes and released 1 minute before coronary artery reperfusion in the presence of 10 mg/kg SPT given 5 min before coronary artery reperfusion.

RESULTS

Myocardial infarct size (percentage necrosis/area at risk, mean +/- SEM) was reduced by 50% in Remote PostC (25 +/- 4%) compared to CONTROL (49 +/- 4%, p = 0.003), consistent with a reduction in plasma CK activity (44 +/- 5 vs. 67 +/- 6 U/ml, p = 0.023). In contrast, permanent RA occlusion before LCAO and reperfusion failed to reduce myocardial infarct size (47 +/- 5%) vs CONTROL. Delaying the release of the RA occlusion (delayed Remote PostC) abrogated the myocardial infarct reduction observed with Remote PostC (48 +/- 6%). SPT alone had no effect on infarct size (47 +/- 4% in CON + SPT vs. 49 +/- 4% in CON); however, Remote PostC+SPT abrogated the myocardial infarct size reduction in Remote PostC (50 +/- 3% in Remote PostC + SPT vs. 25 +/- 4% in Remote PostC).

CONCLUSIONS

Remote renal postconditioning applied immediately before the onset of coronary artery reperfusion provides potent myocardial infarct size reduction likely exerted during the first minutes of coronary artery reperfusion. This inter-organ remote postconditioning phenomenon is likely mediated in part by release of adenosine by the ischemic-reperfused kidney and subsequent activation of adenosine receptors.

The Snf1 protein kinase and its activating subunit, Snf4, interact with distinct domains of the Sip1/Sip2/Gal83 component in the kinase complex

The Snf1 protein kinase plays a central role in the response to glucose starvation in the yeast Saccharomyces cerevisiae. Previously, we showed that two-hybrid interaction between Snf1 and its activating subunit, Snf4, is inhibited by high levels of glucose. These findings, together with biochemical evidence that Snf1 and Snf4 remain associated in cells grown in glucose, suggested that another protein (or proteins) anchors Snf1 and Snf4 into a complex. Here, we examine the possibility that a family of proteins, comprising Sip1, Sip2, and Gal83, serves this purpose. We first show that the fraction of cellular Snf4 protein that is complexed with Snf1 is reduced in a sip1delta sip2delta gal83delta triple mutant. We then present evidence that Sip1, Sip2, and Gal83 each interact independently with both Snf1 and Snf4 via distinct domains. A conserved internal region binds to the Snf1 regulatory domain, and the conserved C-terminal ASC domain binds to Snf4. Interactions were mapped by using the two-hybrid system and were confirmed by in vitro binding studies. These findings indicate that the Sip1/Sip2/Gal83 family anchors Snf1 and Snf4 into a complex. Finally, the interaction of the yeast Sip2 protein with a plant Snf1 homolog suggests that this function is conserved in plants.

Preparation, characterization, adsorption kinetics and thermodynamics of novel magnetic chitosan enwrapping nanosized gamma-Fe2O3 and multi-walled carbon nanotubes with enhanced adsorption properties for methyl orange

A novel magnetic composite bioadsorbent composed of chitosan wrapping magnetic nanosized gamma-Fe(2)O(3) and multi-walled carbon nanotubes (m-CS/gamma-Fe(2)O(3)/MWCNTs) was prepared under relative mild conditions and was characterized. Adsorption of methyl orange (MO) onto m-CS/gamma-Fe(2)O(3)/MWCNTs was investigated with respect to pH, initial MO concentration, coexisting anions and temperature. Results of characterizations indicated that magnetic nanosized gamma-Fe(2)O(3) and MWCNTs have been wrapped by crosslinked chitosan. Introduction of MWCNTs could obviously increase the adsorption capacity (q(e)) of MO onto bioadsorbent by 2.2 times. Kinetics data and adsorption isotherm were better fitted by pseudo-second-order kinetic model and by Langmuir isotherm, respectively. Values of activation parameters such as free energy ( big up tri, openG degrees ), enthalpy ( big up tri, openH degrees ) and entropy (DeltaS degrees ) were determined as 3.15-3.78 kJ mol(-1), -9.94 kJ mol(-1) and -20.65 J mol(-1)k(-1), respectively, indicating that the adsorption was feasible, spontaneous and exothermic process in nature. After adsorption, m-CS/gamma-Fe(2)O(3)/MWCNTs could be effectively and fleetly separated by applying a magnetic field.

Downregulation of Wnt2 and beta-catenin by siRNA suppresses malignant glioma cell growth

Increasing evidence suggests that aberrant activation of Wnt signaling is involved in tumor development and progression. Our earlier study on gene expression profile in human gliomas by microarray found that some members of Wnt family were overexpressed. To further investigate the involvement of Wnt signaling in gliomas, the expression of core components of Wnt signaling cascade in 45 astrocytic glioma specimens with different tumor grades was examined by reverse transcription-PCR and immunohistochemistry. Wnt2, Wnt5a, frizzled2 and beta-catenin were overexpressed in gliomas. Knockdown of Wnt2 and its key mediator beta-catenin in the canonical Wnt pathway by siRNA in human U251 glioma cells inhibited cell proliferation and invasive ability, and induced apoptotic cell death. Furthermore, treating the nude mice carrying established subcutaneous U251 gliomas with siRNA targeting Wnt2 and beta-catenin intratumorally also delayed the tumor growth. In both in vitro and in vivo studies, downregulation of Wnt2 and beta-catenin was associated with the decrease of PI3K/p-AKT expression, indicating the interplay between Wnt/beta-catenin and PI3K/AKT signaling cascades. In conclusion, the canonical Wnt pathway is of critical importance in the gliomagenesis and intervention of this pathway may provide a new therapeutic approach for malignant gliomas.

Minimal enteral nutrient requirements for intestinal growth in neonatal piglets: how much is enough?

BACKGROUND

Parenterally nourished preterm infants commonly receive minimal enteral feedings, the aim being to enhance intestinal function. Whether this regimen increases intestinal growth has not been established.

OBJECTIVE

Our objective was to determine the minimal enteral nutrient intakes necessary to stimulate and to normalize neonatal intestinal growth.

METHODS

Intestinal growth and cell proliferation were quantified in neonatal pigs given equal amounts of an elemental nutrient solution for 7 d. Different groups (n = 5-7 per group) received 0%, 10%, 20%, 40%, 60%, 80%, or 100% of total nutrient intake enterally, with the remainder given parenterally.

RESULTS

In the jejunum, wet weight, protein mass, and villus height were significantly greater at enteral intakes >40%. Stimulation of ileal protein mass required a higher enteral intake (60%). In both segments, abrupt increases in DNA mass, crypt depth, ornithine decarboxylase activity, and crypt cells in S-phase occurred between enteral intakes of 40% and 60%. Circulating concentrations of glucagon-like peptide-2 and peptide YY, but not gastrin, increased significantly between enteral intakes of 40% and 60% and closely paralleled indexes of cell proliferation.

CONCLUSIONS

The minimal enteral nutrient intake necessary to increase mucosal mass was 40% of total nutrient intake, whereas 60% enteral nutrition was necessary to sustain normal mucosal proliferation and growth. Our results imply that providing <40% of the total nutrient intake enterally does not have significant intestinal trophic effects.

Glucose-regulated interaction of a regulatory subunit of protein phosphatase 1 with the Snf1 protein kinase in Saccharomyces cerevisiae

The Snf1 protein kinase family has been conserved in eukaryotes. In the yeast Saccharomyces cerevisiae, Snf1 is essential for transcription of glucose-repressed genes in response to glucose starvation. The direct interaction between Snf1 and its activating subunit, Snf4, within the kinase complex is regulated by the glucose signal. Glucose inhibition of the Snf1-Snf4 interaction depends on protein phosphatase 1 and its targeting subunit, Reg1. Here we show that Reg1 interacts with the Snf1 catalytic domain in the two-hybrid system. This interaction increases in response to glucose limitation and requires the conserved threonine in the activation loop of the kinase, a putative phosphorylation site. The inhibitory effect of Reg1 appears to require the Snf1 regulatory domain because a reg1Delta mutation no longer relieves glucose repression of transcription when Snf1 function is provided by the isolated catalytic domain. Finally, we show that abolishing the Snf1 catalytic activity by mutation of the ATP-binding site causes elevated, constitutive interaction with Reg1, indicating that Snf1 negatively regulates its own interaction with Reg1. We propose a model in which protein phosphatase 1, targeted by Reg1, facilitates the conformational change of the kinase complex from its active state to the autoinhibited state.

A novel biomarker Linc00974 interacting with KRT19 promotes proliferation and metastasis in hepatocellular carcinoma

Location-associated long noncoding RNA (lncRNA) was reported to interact with target protein via a cis-regulatory process especially for the Flank10kb class lncRNA. Based on this theory, we aimed to explore the regulatory mechanisms of Linc00974 and KRT19 (an lncRNA beyond the Flank10kb class with protein) when we first confirmed the aberrant expression in hepatocellular carcinoma in a previous study. Knockdown of Linc00974 resulted in an inhibition of cell proliferation and invasion with an activation of apoptosis and cell cycle arrest in vitro, which was also validated by a subcutaneous and tail vein/intraperitoneal injection xenotransplantation model in vivo. We further investigated the interaction pattern of Linc00974 and KRT19. MiR-642 was identified, by acting as the competing endogenous RNA in regulating Linc00974 and KRT19. Linc00974 was increased owing to an abnormal hypomethylation promoter, which induced the upregulation of KRT19 via ceRNA interaction, resulting in the activation of the Notch and TGF-β pathways as detected by cDNA microarray. We also discovered Linc00974F-1 stably expressed in the plasma. By the combined analysis of Linc00974F-1 with CYFRA21-1, we found that these joint indicators predicted growth and metastasis of tumor in HCC patients. In conclusion, the combination of Linc00974 and KRT19 may be novel indices for clinical diagnosis of tumor growth and metastasis in HCC, while Linc00974 may become a potential therapeutic target for the prevention of HCC progression.

Novel magnetic chitosan/poly(vinyl alcohol) hydrogel beads: preparation, characterization and application for adsorption of dye from aqueous solution

Novel magnetic chitosan/poly(vinyl alcohol) hydrogel beads (m-CS/PVA HBs) were prepared by an instantaneous gelation method and characterized by X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). Results of characterization indicated that m-CS/PVA HBs have been prepared successfully without damaging the crystal structure of Fe(3)O(4) and their saturation magnetization were about 21.96 emu g(-1). The adsorption capacity of Congo Red on the m-CS/PVA HBs was 470.1 mg g(-1). The adsorption was well described by pseudo-second-order kinetics and Langmuir equation. Positive value of enthalpy change (ΔH(∘)) (13.32 kJ mol(-1)) showed that the adsorption was endothermic and physical in nature. The values of Gibbs free energy change (ΔG(∘)) were found to be -3.321 kJ mol(-1) at 298 K for m-CS/PVA HBs, indicating the spontaneity of Congo Red adsorption. Therefore, the m-CS/PVA HBs could be employed as a low-cost alternative to other adsorbents in the removal of dyes from aqueous solution.

Androgenetic/biparental mosaicism causes placental mesenchymal dysplasia

BACKGROUND

Placental mesenchymal dysplasia (PMD) is a distinct syndrome of unknown aetiology that is associated with significant fetal morbidity and mortality. Intrauterine growth restriction is common, yet, paradoxically, many of the associated fetuses/newborns have been diagnosed with Beckwith-Wiedemann syndrome (BWS).

METHODS

We report two cases of PMD with high levels of androgenetic (complete paternal uniparental isodisomy) cells in the placenta and document, in one case, a likely androgenetic contribution to the fetus as well.

RESULTS

The same haploid paternal complement found in the androgenetic cells was present in coexisting biparental cells, suggesting origin from a single fertilisation event.

CONCLUSIONS

Preferential allocation of the normal cells into the trophoblast explains the absence of trophoblast overgrowth, a key feature of this syndrome. Interestingly, the distribution of androgenetic cells appears to differ from that reported for artificially created androgenetic mouse chimeras. Androgenetic mosaicism for the first time provides an aetiology for PMD, and may be a novel mechanism for BWS and unexplained intrauterine growth restriction.

Absorption of sunscreens across human skin: an evaluation of commercial products for children and adults

AIMS

Topical sunscreens are routinely applied to the skin by a large percentage of the population. This study assessed the extent of absorption of a number of common chemical sunscreen agents into and through human skin following application of commercially available products.

METHODS

Sunscreen products were applied to excised human epidermis in Franz diffusion cells with the amount penetrating into and across the epidermis assessed by h.p.l.c. for 8 h following application.

RESULTS

All sunscreen agents investigated penetrated into the skin (0.25 g m-2 or 14% of applied dose), but only benzophenone-3 passed through the skin in significant amounts (0.08 g m-2 or 10% of the applied dose). With one exception, suncreen agents in corresponding products marketed for adults and children had similar skin penetration profiles.

CONCLUSIONS

Whilst limited absorption across the skin was observed for the majority of the sunscreens tested, benzophenone-3 demonstrated sufficiently high penetration to warrant further investigation of its continued application.

GLP-2 stimulates intestinal growth in premature TPN-fed pigs by suppressing proteolysis and apoptosis

We wished to determine whether exogenous glucagon-like peptide (GLP)-2 infusion stimulates intestinal growth in parenterally fed immature pigs. Piglets (106-108 days gestation) were given parenteral nutrient infusion (TPN), TPN + human GLP-2 (25 nmol. kg(-1). day(-1)), or sow's milk enterally (ENT) for 6 days. Intestinal protein synthesis was then measured in vivo after a bolus dose of [1-(13)C]phenylalanine, and degradation was calculated from the difference between protein accretion and synthesis. Crypt cell proliferation and apoptosis were measured in situ by 5-bromodeoxyuridine (BrdU) and terminal dUTP nick-end labeling (TUNEL), respectively. Intestinal protein and DNA accretion rates and villus heights were similar in GLP-2 and ENT pigs, and both were higher (P < 0.05) than in TPN pigs. GLP-2 decreased fractional protein degradation rate, whereas ENT increased fractional protein synthesis rate compared with TPN pigs. Percentage of TUNEL-positive cells in GLP-2 and ENT groups was 48 and 64% lower, respectively, than in TPN group (P < 0.05). However, ENT, but not GLP-2, increased percentage of BrdU-positive crypt cells above that in TPN piglets. We conclude that GLP-2 increases intestinal growth in premature, TPN-fed pigs by decreasing proteolysis and apoptosis, whereas enteral nutrition acts via increased protein synthesis and cell proliferation and decreased apoptosis.

Subclinical atherosclerosis, airflow obstruction and emphysema: the MESA Lung Study

Airflow obstruction is an independent risk factor for cardiovascular events in the general population. The affected vascular bed and contribution of emphysema to cardiovascular risk are unclear. We examined whether an obstructive pattern of spirometry and quantitatively defined emphysema were associated with subclinical atherosclerosis in the carotid, peripheral and coronary circulations. The Multi-Ethnic Study of Atherosclerosis recruited participants aged 45-84 yrs without clinical cardiovascular disease. Spirometry, carotid intima-media thickness (IMT), ankle-brachial index (ABI) and coronary artery calcium (CAC) were measured using standard protocols. Percentage of emphysema-like lung was measured in the lung windows of cardiac computed tomography scans among 3,642 participants. Multiple linear regression was used to adjust for cardiac risk factors, including C-reactive protein. Decrements in forced expiratory volume in 1 s (FEV(1)) and FEV(1)/forced vital capacity ratio were associated with greater internal carotid IMT, particularly among smokers (p=0.03 and p<0.001, respectively) whereas percentage emphysema was associated with reduced ABI regardless of smoking history (p=0.004). CAC was associated with neither lung function (prevalence ratio for the presence of CAC in severe airflow obstruction 0.99, 95% CI 0.91-1.07) nor percentage emphysema. An obstructive pattern of spirometry and emphysema were associated distinctly and independently with subclinical atherosclerosis in the carotid arteries and peripheral circulation, respectively, and were not independently related to CAC.

β-catenin is Required in Odontoblasts for Tooth Root Formation

The tooth root is an important part of the tooth that works together with the surrounding periodontium to maintain the tooth in the alveolar socket. The root develops after crown morphogenesis. While the molecular and cellular mechanisms of early tooth development and crown morphogenesis have been extensively studied, little is known about the molecular mechanisms controlling tooth root formation. Here, we show that β-catenin is strongly expressed in odontoblast-lineage cells and is required for root formation. Tissue-specific inactivation of β-catenin in developing odontoblasts produced molars lacking roots and aberrantly thin incisors. At the beginning of root formation in the mutant molars, the cervical loop epithelium extended apically to form Hertwig’s epithelial root sheath (HERS), but root odontoblast differentiation was disrupted and followed by the loss of some HERS inner layer cells. However, the outer layer of the HERS extended without the root, and the mutant molars finally erupted. The periodontal tissues extensively invaded the dental pulp. These results indicate that there is a cell-autonomous requirement for Wnt/β-catenin signaling in the dental mesenchyme for root formation.

A family of proteins containing a conserved domain that mediates interaction with the yeast SNF1 protein kinase complex

The SNF1 protein kinase is required for the regulatory response to glucose starvation in Saccharomyces cerevisiae. SNF1 is a protein serine/threonine kinase that has been widely conserved in both plants and mammals. Previously, we identified SIP1 and SIP2 as proteins that interact with SNF1 in vivo by the two-hybrid system. We have cloned the SIP2 gene and the encoded protein is homologous to SIP1 and to GAL83, which affects glucose repression of the GAL genes. We show that SIP2 and GAL83, like SIP1, co-immunoprecipitate with SNF1 and are phosphorylated in vitro. An 80 amino acid sequence, designated the ASC domain, is highly conserved at the C-termini of all three proteins. We show that this small domain can mediate protein-protein interaction with the SNF1 kinase complex. Thus, SIP1, SIP2 and GAL83 define a family of homologous proteins that are tightly associated with the SNF1 kinase, probably in alternative forms of the complex. Genetic evidence suggests that the three proteins have distinct, but related, functions in the SNF1 pathway, and deletion of GAL83 dramatically reduces SNF1 activity in immune complex assays. We propose that SIP1, SIP2 and GAL83 act as adaptors that promote the activity of SNF1 towards specific targets.

Use of non-cross-linked polyacrylamide for four-color DNA sequencing by capillary electrophoresis separation of fragments up to 640 bases in length in two hours

Four-color DNA cycle sequencing was performed on an M13mp18 template using dye-labeled primers. Sequencing fragments were separated by capillary electrophoresis at 60 degrees C and at an electric field of 150 V/cm. The sieving medium was 5%T, non-cross-linked polyacrylamide in 7 M urea. The use of high temperature for the separation reduces formation of secondary structures in the sequencing fragments, generating a sequence that is free of compressions without the use of strongly denaturing gels. The use of high temperatures also increases the separation rate compared with room-temperature operation. Fragments up to 640 bases are separated in less than 2 h.

Predictors of survival in patients with recurrent ovarian cancer undergoing secondary cytoreductive surgery based on the pooled analysis of an international collaborative cohort

BACKGROUND

This study aims to identify prognostic factors and to develop a risk model predicting survival in patients undergoing secondary cytoreductive surgery (SCR) for recurrent epithelial ovarian cancer.

METHODS

Individual data of 1100 patients with recurrent ovarian cancer of a progression-free interval at least 6 months who underwent SCR were pooled analysed. A simplified scoring system for each independent prognostic factor was developed according to its coefficient. Internal validation was performed to assess the discrimination of the model.

RESULTS

Complete SCR was strongly associated with the improvement of survival, with a median survival of 57.7 months, when compared with 27.0 months in those with residual disease of 0.1-1 cm and 15.6 months in those with residual disease of >1 cm, respectively (P<0.0001). Progression-free interval (≤23.1 months vs >23.1 months, hazard ratio (HR): 1.72; score: 2), ascites at recurrence (present vs absent, HR: 1.27; score: 1), extent of recurrence (multiple vs localised disease, HR: 1.38; score: 1) as well as residual disease after SCR (R1 vs R0, HR: 1.90, score: 2; R2 vs R0, HR: 3.0, score: 4) entered into the risk model.

CONCLUSION

This prognostic model may provide evidence to predict survival benefit from secondary cytoreduction in patients with recurrent ovarian cancer.

Dietary plasma protein reduces small intestinal growth and lamina propria cell density in early weaned pigs

ABSTRACT We quantified the effects of a diet containing animal plasma protein on small intestinal growth and mucosal morphology in early weaned pigs. Ninety-six pigs [14 d old, 4 kg body weight (BW)] were assigned in groups of 32 to three dietary treatments as follows: 1) free access to control diet (C), 2) free access to plasma protein diet (P), and 3) plasma protein, pair-fed to C (PPF). Eight pigs from each group were killed at 2, 4, 8 or 16 d. Over a 16-d period, weight gain in the P group was 43% greater (P < 0.05) than that in C pigs; weight gain was similar in C and PPF groups. Protein intake in the P group was 33% higher (P < 0.05) than that in the PPF group; no significant difference was observed between the C and P groups. Dietary protein conversion efficiencies in both the P and PPF groups were approximately 18% greater (P < 0.05) than those in the C group. Intestinal masses in the three groups did not differ at 2, 4 and 8 d. By 16 d, the jejunal and ileal protein and DNA masses (mg/kg BW) in both the P and PPF groups were lower than those in the C group (P < 0.05). Dietary plasma protein did not affect crypt cell proliferation, crypt depth or villous height in either the jejunum or ileum. However, the intravillous lamina propria cell density in the jejunum was significantly lower (P < 0.05) in P and PPF pigs than in C pigs. Plasma urea concentrations were also 40 and 42% lower (P < 0.05) in the P and PPF groups, respectively, than in the C group. Our results indicate that dietary plasma protein reduces the cellularity of the lamina propria, but not epithelial cell surface of the small intestine. Feeding plasma protein also increased the efficiency of dietary protein utilization, in part, by decreasing amino acid catabolism.

Osr2, a new mouse gene related to Drosophila odd-skipped, exhibits dynamic expression patterns during craniofacial, limb, and kidney development

We have isolated a new mouse gene, odd-skipped related 2 (Osr2), that encodes a zinc finger containing protein related to Drosophila Odd-skipped. The putative OSR2 protein shares 65% amino acid sequence identity overall and 98% sequence identity in the zinc finger region, respectively, with the previously reported Osr1 gene product. During mouse embryonic development, Osr2 expression is first detected at E9.25, specifically in the mesonephric vesicles. By E10.0, Osr2 expression is also observed in the rostro-lateral mandibular mesenchyme immediately adjacent to the maxillary processes. In the developing limb buds, Osr2 is expressed in a unique mesenchymal domain and the onset of Osr2 expression follows a distinct dorsal to ventral developmental time sequence beginning in the forelimb and then in the hindlimb. Osr2 exhibits a dynamic expression pattern during craniofacial development, in the mandibular and maxillary processes as well as the developing palate. Osr2 is also expressed at sites of epithelial-mesenchymal interactions during tooth and kidney development.