"Sexual differentiation: From genes to gender"

Amy Wisniewski is Assistant Professor of Biology at Drake University, Des Moines, Iowa. She can be contacted at [email protected] person's sex can be considered across various levels. To illustrate, genes, hormones, and genitalia can all be considered physical markers of a person's sex. In addition to physical markers, behaviors such as gender role, gender identity and sexual orientation can be perceived as stereotypically male or female. The purpose of this review is to summarize current knowledge of sexual differentiation which emphasizes genetic and hormonal mechanisms that result in male and female development of gonads and genitalia. Finally, consideration is given to associations between genetic sex, gonadal sex, and hormonal sex with gender. Copyright 1998 S Karger AG

"Human sex differentiation: From transcription factors to gender"

Amy B. Wiesniewski is an Assistant Professor of Biology at Drake University, Des Moines, Iowa. She can be contacted at [email protected] the past decade, knowledge of the genetic control of human sex differentiation has greately expanded our understanding of the developmental processes needed to form a male or female. The purpose of this review is to discuss how transcription factors are relevant to such processes. Additionally, an attempt is made to relate current knowledge of these factors with gender development of subjects with intersex conditions. Finally, we discuss how information about the genetic control of sex differentiation may contribute to decisions about medical treatment of individuals with conditions of abnormal sex differentiation. Copyright (C) 2000 S. Karger AG, Basel.This work was supported by a grant from The Genentech Foundation for Growth and Development 98-33C to C.J.M., an NIH NRSA grant F32HD08544 to A.B.W. and an NIH, NCRR, GCRC grant RR00052. This work was originally presented as the 1999 Robert L. Ney Memorial Lecture at Johns Hopkins University by C.J.M

Phenotypic Heterogeneity Within Clones Of Fetal Human Cells

The heterogeneity of cell morphology characteristics of some colonies of human fetal kidney and amniotic fluid cells has been analyzed by biochemical and cell-cloning techniques. All the presumed subclones derived from dimorphic colonies were initially epithelioid, but some cells became fibroblastlike as the cell density increased. To determine if the observed heterogeneity occurred within clonal populations of cells, we determined the isozyme phenotype of dimers from renal cells heterozygous for glucose-6-phosphate dehydrogenase (G6PD). Colonies showing mixed cellular morphology expressed only a single G6PD isozyme, thus revealing their single-cell origin. Our results indicate that cell morphology is influenced by the cellular density within the clone, and that a single human renal cell in vitro can yield progeny of two morphological types

Effect of various dopant elements on primary graphite growth

Five spheroidal graphite cast irons were investigated, a usual ferritic grade and four pearlitic alloys containing Cu and doped with Sb, Sn and Ti. These alloys were remelted in a graphite crucible, leading to volatilization of the magnesium added for spheroidization and to carbon saturation of the liquid. The alloys were then cooled down and maintained at a temperature above the eutectic temperature. During this step, primary graphite could develop showing various features depending on the doping elements added. The largest effects were that of Ti which greatly reduces graphite nucleation and growth, and that of Sb which leads to rounded agglomerates instead of lamellar graphite. The samples have been investigated with secondary ion mass spectrometry to enlighten distribution of elements in primary graphite. SIMS analysis showed almost even distribution of elements, including Mg and Al (from the inoculant) in the ferritic grade, while uneven distribution was evident in all doped alloys. Investigations are going on to clarify if the uneven distribution is associated with structural defects in the graphite precipitates

Recent emergence and worldwide spread of the red tomato spider mite, [i]Tetranychus evansi[/i]: genetic variation and multiple cryptic invasions

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699Plant biosecurity is increasingly challenged by emerging crop pests. The spider mite Tetranychus evansi has recently emerged as a new threat to solanaceous crops in Africa and the Mediterranean basin, with invasions characterized by a high reproductive output and an ability to withstand a wide range of temperatures. Mitochondrial (868 bp of COI) and nuclear (1,137 bp of ITS) loci were analyzed in T. evansi samples spanning the current geographical distribution to study the earliest stages of the invasive process. The two sets of markers separate the samples into two main clades that are only present together in South America and Southern Europe. The highest COI diversity was found in South America, consistent with the hypothesis of a South American origin of T. evansi. Among the invaded areas, the Mediterranean region displayed a high level of genetic diversity similar to that present in South America, that is likely the result of multiple colonization events. The invasions of Africa and Asia by T. evansi are characterized by a low genetic variation associated with distinct introductions. Genetic data demonstrate two different patterns of invasions: (1) populations in the Mediterranean basin that are a result of multiple cryptic introductions and (2) emerging invasions of Africa and Asia, each likely the result of propagules from one or limited sources. The recent invasions of T. evansi illustrate not only the importance of human activities in the spread of agricultural pests, but also the limits of international quarantine procedures, particularly for cryptic invasion

Adaptive smoothing for enhancing images

We present a new filter for image enhancement belonging to the family of the Edge Preserving Smoothing Filtering (EPSF). The proposed filter comes from a recent clustering method based on information theory and statistical mechanics developed by YE Wong [191. Its effect is to attenuate noise by smoothing the image within homogeneous regions while it enhances the contrast at their boundaries as anisotropic diffusion filters do . However, this filter performs a more continuous smoothing than anisotropic diffusion filtering which usually produce piecewise constant surfaces. Actually, we show that it is related to a multi-scale anisotropic diffusion process.Cet article présente un nouveau filtre de prétraitement d'image, de la famille des filtres EPSF («Edge Preserving Smoothing Filters »). Il est dérivé d'une récente méthode de classification, basée sur la théorie de l'information et la mécanique statistique, développée par Y.F. Wong [19]. Il permet d' atténuer le bruit en opérant un très bon lissage intra-région, tout en rehaussant les bords flous entre les régions, comme le font les filtres basés sur le principe de la diffusion anisotrope. En revanche, contrairement à ces derniers qui ont pour inconvénient de tendre à produire des surfaces constantes par morceaux, il offre une continuité de lissage très intéressante. Par ailleurs, on montre également que ce filtre est lié à un processus de diffusion anisotrope multi-échelle

Normal sex differences in prenatal growth and abnormal prenatal growth retardation associated with 46,XY disorders of sex development are absent in newborns with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

<p>Abstract</p> <p>Background</p> <p>Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is the most common presentation of a disorder of sex development (DSD) in genetic females. A report of prenatal growth retardation in cases of 46,XY DSD, coupled with observations of below-optimal final height in both males and females with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, prompted us to investigate prenatal growth in the latter group. Additionally, because girls with congenital adrenal hyperplasia are exposed to increased levels of androgens in the absence of a male sex-chromosome complement, the presence or absence of typical sex differences in growth of newborns would support or refute a hormonal explanation for these differences.</p> <p>Methods</p> <p>In total, 105 newborns with congenital adrenal hyperplasia were identified in our database. Gestational age (weeks), birth weight (kg), birth length (cm) and parental heights (cm) were obtained. Mid-parental height was considered in the analyses.</p> <p>Results</p> <p>Mean birth weight percentile for congenital adrenal hyperplasia was 49.26%, indicating no evidence of a difference in birth weight from the expected standard population median of 50th percentile (<it>P </it>> 0.05). The expected sex difference in favor of heavier males was not seen (<it>P </it>> 0.05). Of the 105 subjects, 44 (27%; 34 females, 10 males) had birth length and gestational age recorded in their medical chart. Mean birth length for this subgroup was 50.90 cm (63rd percentile), which differed from the expected standard population median of 50th percentile (<it>P </it>= 0.0082). The expected sex difference in favor of longer males was also not seen (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>The prenatal growth retardation patterns reported in cases of 46,XY disorders of sex development do not generalize to people with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Sex differences in body weight and length typically seen in young infants were not seen in the subjects who participated in this study. We speculate that these differences were ameliorated in this study because of increased levels of prenatal androgens experienced by the females infants.</p

Diagnostische Bedeutung der Proteinbindung von Plasmacortisol, bestimmt durch Dextrangelfiltration

1. Mittels Dextrangelfiltration wurde nach Inkubation von markiertem Cortisol und Plasma der proteingebundene und der sog. freie Anteil (%) des endogenen Plasmacortisols ermittelt und bei gleichzeitiger fluorimetrischer Bestimmung der 11-OHCS auch die Menge proteingebundenen, bzw. sog. freien Cortisols (µg-%) berechnet. 2. Die diagnostische Brauchbarkeit der Methode wurde bei Patienten mit Nebennierenrindeninsuffizienz, mit Hypophysentumoren, nach Hypophysektomie, mit Cushing-Syndrom mit der fluorimetrischen Bestimmung der 11-OHCS verglichen. Die einfache Bestimmung der Cortisolbindung war bei hypophysektomierten Patienten der Bestimmung der 11-OHCS überlegen und entsprach der aufwendigeren ACTH-Belastung. 3. Falsch hohe fluorimetrische 11-OHCS-Spiegel im Plasma unter Spirolacton- oder Oestrogenbehandlung und in der Gravidität lassen sich durch Bestimmung der Cortisolbindung klären. Bei Schilddrüsenüberfunktion war das sog. freie Cortisol im Plasma relativ und absolut vermehrt, bei Schilddrüsenunterfunktion fand sich eine Zunahme des plasmaproteingebundenen Cortisols.1. Following incubation of labeled cortisol and plasma the percentages of protein bound and socalled free endogenous cortisol were determined by means of dextran gel filtration. 2. The diagnostic value of this method was compared with fluorimetric determinations of 11-OHCS for patients with adrenal insufficiency, Cushing-Syndrome, pituitary tumors and after hypophysectomy. In hypophysectomized patients the simple determination of protein bound cortisol was found to correlate well with diagnostic ACTH-infusion tests and to be more sensitive than fluorimetric determinations of 11-OHCS in 9 a.m. plasma. 3. Falsely elevated fluorimetric values of plasma 11-OHCS in patients treated with spirolactone or estrogens, resp. during pregnancy may be recognized through determination of cortisol binding. — In thyrotoxicosis socalled free cortisol was elevated, both relatively and absolutely; in hypothyroidism an increase of protein bound cortisol was found

Sexual dimorphism in cancer.

The incidence of many types of cancer arising in organs with non-reproductive functions is significantly higher in male populations than in female populations, with associated differences in survival. Occupational and/or behavioural factors are well-known underlying determinants. However, cellular and molecular differences between the two sexes are also likely to be important. In this Opinion article, we focus on the complex interplay that sex hormones and sex chromosomes can have in intrinsic control of cancer-initiating cell populations, the tumour microenvironment and systemic determinants of cancer development, such as the immune system and metabolism. A better appreciation of these differences between the two sexes could be of substantial value for cancer prevention as well as treatment