Preimplantation human embryos and embryonic stem cells show comparable expression of stage-specific embryonic antigens.

Cell-surface antigens provide invaluable tools for the identification of cells and for the analysis of cell differentiation. In particular, stage-specific embryonic antigens that are developmentally regulated during early embryogenesis are widely used as markers to monitor the differentiation of both mouse and human embryonic stem (ES) cells and their malignant counterparts, embryonic carcinoma (EC) cells. However, there are notable differences in the expression patterns of some such markers between human and mouse ES/EC cells, and hitherto it has been unclear whether this indicates significant differences between human and mouse embryos, or whether ES/EC cells correspond to distinct cell types within the early embryos of each species.

Identification of putative interaction partners for the Xenopus Polycomb-group protein Xeed.

The extra sex combs (esc) gene of Drosophila and its mammalian homologue embryonic ectoderm development (eed) play pivotal roles in establishing Polycomb-group (Pc-G) mediated transcriptional silencing of regulatory genes during early development. We have carried out a two-hybrid screen in yeast to identify maternally expressed proteins that interact directly with the product of the Xenopus eed homologue, Xeed. Xeed-interacting proteins that were recovered in this screen included a maternal Xenopus histone deacetylase (HDACm), the Xeed protein itself, and a Xenopus homologue of Enhancer of zeste (XEZ) - a second member of the Pc-G that is closely related by sequence similarity to histone methyltransferases.

Planar polarity: photoreceptors on a high fat diet.

Differential activity of Frizzled in the R3/R4 photo-receptors of Drosophila regulates the orientation of ommatidia. New evidence suggests that the cadherins Dachsous and Fat act upstream of Frizzled in this process.

Smoking history, knowledge, and attitudes among older residents of a long-term care facility.

In the absence of empirical literature from the resident perspective, this study provided a first assessment of smoking history, knowledge of the risks of smoking, the risks of environmental tobacco exposure, and the benefits of quitting among older (age 50+) nursing home unit residents, as well as readiness to quit, barriers to quitting, frequency of cessation advice by healthcare givers, and quit-attempt history of residents who smoke. Subjects were 25 smokers and 70 non-smokers housed on long-term nursing home units in a county hospital. Results indicated that smoking status for the majority of residents was similar to when they were admitted, although smokers smoked fewer cigarettes (M = 11.

Complete rescue of the nude mutant phenotype by a wild-type Foxn1 transgene.

In this paper we describe the production and analysis of mice carrying a 110-kb transgene that encompasses the wild-type Foxn1 genomic locus. Mutations in Foxn1 cause the nude phenotype. We show that in the hair follicles, transgenic mice with increased Foxn1 gene dosage exhibited increased Foxn1 expression that was restricted correctly to the nascent, post-mitotic cells of the differentiating hair cortex and hair cuticle lineages.

Asymmetric localization of frizzled and the determination of notch-dependent cell fate in the Drosophila eye.

Background: During patterning of the Drosophila eye, a critical step is the Notch-mediated cell fate decision that determines the identities of the R3/R4 photoreceptor pair in each ommatidium. Depending on the decision taken, the ommatidium adopts either the dorsal or ventral chiral form. This decision is directed by the activity of the planar polarity genes, and, in particular, higher activity of the receptor Frizzled confers R3 fate.

Development of the zebrafish inner ear.

Abstract Recent years have seen a renaissance of investigation into the mechanisms of inner ear development. Genetic analysis of zebrafish has contributed significantly to this endeavour, with several dramatic advances reported over the past year or two. Here, we review the major findings from recent work in zebrafish.

Opponent activities of Shh and BMP signaling during floor plate induction in vivo.

We performed in vivo experiments in chick embryos that examined whether application of an exogenous source of Shh protein mimics the ability of the notochord to induce ectopic floor plate cells in the neural tube. Shh cannot act alone to induce a floor plate. However, coapplication of Shh and chordin, a BMP antagonist normally coexpressed with Shh in the notochord, results in a marked switch from dorsal to ventral cell fate, including a dramatic and widespread induction of floor plate cells.

Linear growth characteristics of congenitally GH-deficient infants from birth to one year of age.

Birth length has been reported to be either normal or reduced in infants with congenital GH deficiency (CGHD). We evaluated 46 infants with CGHD followed in a single regional medical center. All were born full term and had peak GH of less than 10 microg/liter after provocative stimulation.

Hedgehog signaling: a tale of two lipids.

Hedgehog proteins constitute one of the major classes of intercellular signals that control inductive interactions during animal development. These proteins undergo unusual lipid modifications and signal through an unconventional transmembrane protein receptor that is characterized by a sequence motif implicated in sterol sensing. Recent studies suggest that the lipid adducts regulate the range and potency of the signals, whereas the sterol-sensing domain is essential for receptor activity.

The zebrafish neckless mutation reveals a requirement for raldh2 in mesodermal signals that pattern the hindbrain.

We describe a new zebrafish mutation, neckless, and present evidence that it inactivates retinaldehyde dehydrogenase type 2, an enzyme involved in retinoic acid biosynthesis. neckless embryos are characterised by a truncation of the anteroposterior axis anterior to the somites, defects in midline mesendodermal tissues and absence of pectoral fins. At a similar anteroposterior level within the nervous system, expression of the retinoic acid receptor a and hoxb4 genes is delayed and significantly reduced.

A phenomenologic assessment of relapsing MS patients' experiences during treatment with interferon beta-1a.

The purpose of this study was to describe the experiences of patients with relapsing multiple sclerosis (MS) who are being treated with interferon beta-1a. MS patients often experience fear and uncertainty about their future and derive benefit from understanding their diagnosis as well as learning about their anticipated disease course. Interferon beta-1a treatment can delay the accumulation of physical disability that naturally occurs over time in patients with untreated relapsing MS and thus offer hope for their future.

Expression of BMP signalling pathway members in the developing zebrafish inner ear and lateral line.

In this paper we describe the mRNA expression patterns of members of the bone morphogenetic protein (BMP) signalling pathway in the developing zebrafish ear. bmp2b, 4, and 7 are expressed in discrete areas of otic epithelium, some of which correspond to sensory patches. bmp2b and 4 mark the developing cristae before and during the appearance of differentiated hair cells.

The trappist's approach to pathfinding: elucidating brain wiring using secretory-trap mutagenesis.

A key problem in using genetics to dissect the wiring of the mammalian brain lies in discovering which of the billions of neural connections have been disrupted by a particular mutation. A novel gene-trap approach targets the genes involved in brain wiring and labels the axons of neurons expressing those genes, enabling the effects of mutations to be observed directly.

Hedgehog signaling pathway is essential for pancreas specification in the zebrafish embryo.

Recent studies have implicated the signaling factor Sonic hedgehog (Shh) as a negative regulator of pancreatic development, but as a positive regulator of pancreas function in amniotes [1-4]. Here, using genetic analysis, we show that specification of the pancreas in the teleost embryo requires the activity of Hh proteins. Zebrafish embryos compromised in Hh signaling exhibit disruption in the expression of the pancreas-specifying homeobox gene pdx-1 and concomitantly show almost complete absence of the endocrine pancreas.

Olfaction preservation in anterior cranial base approaches: an anatomic study.

Objective: To study the anatomic basis for olfaction-sparing anterior cranial base approaches.

Methods: The medial anterior skull base containing the olfactory unit and delimited by the inner table of the frontal sinus, the lesser wing of the sphenoid bone, and the medial orbital walls was removed from six cadaveric specimens. Histological methods were used to investigate the location, distribution, and depth of penetration of olfactory nerves.

The viral RNA polymerase H4L subunit is required for Vaccinia virus early gene transcription termination.

Vaccinia virus early gene transcription is catalyzed by a multisubunit virion form of RNA polymerase that possesses a unique subunit, H4L. Prior studies from this laboratory showed that the NH(2)-terminal domain of H4L, containing amino acids 1-195, interacts with the COOH-terminal end of nucleoside triphosphate phosphohydrolase I (NPH I), an ATPase that is employed in early gene transcription termination. Carboxyl-terminal deletion mutations of NPH I lose both the ability to mediate transcription termination and binding to H4L, providing evidence that the interaction between NPH I and H4L is required for termination.

Interaction between the J3R subunit of vaccinia virus poly(A) polymerase and the H4L subunit of the viral RNA polymerase.

J3R, the 39-kDa subunit of vaccinia virus poly(A) polymerase, is a multifunctional protein that catalyzes (nucleoside-2'-O-)-methyltransferase activity, serves as a poly(A) polymerase stimulatory factor, and acts as a postreplicative positive transcription elongation factor. Prior results support an association between poly(A) polymerase and the virion RNA polymerase. A possible direct interaction between J3R and H4L subunit of virion RNA polymerase was evaluated.

Interaction between nucleoside triphosphate phosphohydrolase I and the H4L subunit of the viral RNA polymerase is required for vaccinia virus early gene transcript release.

Signal-dependent termination is restricted to early poxvirus genes whose transcription is catalyzed by the virion form of RNA polymerase. Two termination factors have been identified. Vaccinia termination factor/capping enzyme is a multifunctional heterodimer that also catalyzes the first three steps of mRNA cap formation and is an essential intermediate gene transcription initiation factor.

Prognostic factors in infants and very young children with intracranial ependymomas.

The Pediatric Oncology Group (1986-1990) conducted a study in which 48 children <3 years of age with intracranial ependymomas were treated with prolonged postoperative chemotherapy (CT) and delayed RT. Thirty-one children, 0-23 months of age at diagnosis (Gp A) received 2 years of CT followed by RT; while 17 children, 24-36 months of age at diagnosis (Gp B) received CT for 1 year followed by radiation. One-year survivals were 87% (Gp A) and 94% (Gp B) and 2-year survivals were 67% (Gp A) and 82% (Gp B).

Maternal cigarette smoking, regular use of multivitamin/mineral supplements, and risk of fetal death: the 1988 National Maternal and Infant Health Survey.

Data from the 1988 National Maternal and Infant Health Survey were used to examine whether regular use of multivitamin/mineral supplements could modify the relation between maternal smoking and fetal death. Maternal smoking was defined as the self-reported average number of cigarettes smoked after recognition of pregnancy. Regular supplement use was defined as use of multivitamin/mineral supplements for at least 3 days per week during the 3 months before and/or after recognition of pregnancy.

Can regular multivitamin/mineral supplementation modify the relation between maternal smoking and select adverse birth outcomes?

Purpose: The purpose of this study was to examine whether or not regular multivitamin/mineral supplementation can modify the relation between maternal smoking and preterm birth (gestational age < 37 weeks), very-low-birthweight (VLBW) (< 1500 g), moderately-low-birthweight (MLBW) (< 2499 g), or small-for-gestational-age (SGA) (< 10th percentile of birth weight for gestational age).

Methods: Live birth data from the 1988 National Maternal and Infant Health Survey (NMIHS) were used for the analysis. Maternal smoking referred to self-reported average number of cigarettes smoked after recognition of pregnancy, while regular multivitamin/mineral supplementation referred to use of multivitamin/mineral supplements for at least three days per week during the three months before and/or after recognition of pregnancy.

Clinical features of bleb disorder of the cornea.

Background: Bleb disorder of the cornea is a rare corneal epithelial disorder that has previously been described in asymptomatic patients or those with recurrent nontraumatic corneal erosions.

Methods: We report two cases of bleb disorder, each presenting with blurred vision from irregular astigmatism secondary to the bleb changes. We also report on the detection of bleb disorder in siblings.

Nitric oxide in single-breath exhalation in humans.

This study was performed to test the hypothesis that the amount of nitric oxide (NO) in exhaled air (VNO) is the net result of both NO formation in the conducting airway and its clearance by diffusion in the alveoli. It's so difficult to collect the gas in the alveoli in volunteers that we made the following consideration from the profile of CO2 fraction (FECO2): the late fraction of exhaled air coming mainly from the alveoli while the early fraction representing mixed gas from both the conducting airway and/or the transition zone, and the alveoli. We compared the FECO2, NO concentration, and VNO in the early and late fractions of exhaled air after subjects inspiring either NO-free gas or NO-containing gas (510 ppb) using a single-breath technique (n = 5).

Infection of the conjunctiva by Rhinosporidium seeberi.

Rhinosporidiosis is an unusual fungal disease that rarely affects the eye. It was first described as a pathogen in humans at the turn of the century. The etiologic agent, Rhinosporidium seeberi, commonly produces granulomatous inflammation of the upper respiratory mucosa.