\documentclass[english,german]{scrartcl}
\usepackage[latin1]{inputenc}
\usepackage{geometry}
\geometry{verbose,a4paper,tmargin=1.75cm,bmargin=2cm,lmargin=2cm,rmargin=2cm,headheight=0.8cm,headsep=0.5cm,footskip=0.5cm}
\usepackage{babel}
\usepackage{url}
\urlstyle{same}
\newcommand\email{\begingroup \urlstyle{same}\Url}\usepackage{graphicx}
\usepackage{units}
\usepackage{tabularx}
\usepackage{wasysym} % enable use of \permil instead of \textperthousand
\usepackage{marvosym}
\usepackage{arabtex}
\usepackage{hyphenat}
\usepackage{booktabs}
\usepackage{mdwlist}
\renewcommand{\thefootnote}{\relax}
\usepackage{index}
\newindex{key}{kdx}{knd}{Keywords}
\newindex{author}{idx}{ind}{Authors}
\usepackage{fancyhdr}
\pagestyle{fancy}
\renewcommand{\headrulewidth}{0pt}
\fancyfoot{}
\usepackage{ifpdf}
\ifpdf
%\usepackage[activate]{pdfcprot}
%\usepackage[owner=Tapioka, print=true, copy=true, edit=false, annotate=false,set]{pdfcrypt}
%encryption: not supported any more (since pdftex 1.10)
\usepackage[pdftex]{thumbpdf}
\usepackage[pdftex]{hyperref}
\hypersetup{pdftitle={Repeated Vitrification of Mouse Blastocysts Using the Open Pulled Straw (OPS) Method},pdfauthor={Moataz El-Gayar, Matthias Gauly, Wolfgang Holtz},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Cryopreservation, embryo transfer, mouse, open pulled straw, repeated vitrification},pdfpagemode=None,colorlinks=true}
\else
\usepackage{ae}
\usepackage{textcomp}
\fi
\begin{document}
\ifpdf
\parbox[b]{2.5cm}{\resizebox*{2.5cm}{!}{\includegraphics{dtt2010.jpg}}}
\else
\parbox[b]{2.5cm}{\resizebox*{2.5cm}{!}{\includegraphics{dtt2010.eps}}}
\fi
\hfill
\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
\hspace{0.1cm}
\begin{center}
\Large{\textbf{Repeated Vitrification of Mouse Blastocysts Using the Open Pulled Straw (OPS) Method\footnote{\textbf{Contact Address:} Wolfgang Holtz, Georg-August-Universität Göttingen, Department of Animal Sciences, Albrecht-Thaer-Weg 3, 37075~Göttingen, Germany, \mbox{e-mail}: \email{wholtz@gwdg.de}}\\[0.8ex]}}
\normalsize{\textsc{Moataz El-Gayar$^{1}$, Matthias Gauly$^{2}$, Wolfgang Holtz$^{2}$}}
\end{center}
\begin{itemize*}
\item[]{\small{\textit{$^{1}$Suez Canal University, Faculty of Agriculture, Department of Animal Production, Egypt}}}
\item[]{\small{\textit{$^{2}$Georg-August-Universität Göttingen, Department of Animal Science, Germany}}}
\end{itemize*}
\index[author]{El-Gayar, Moataz}
\index[author]{Gauly, Matthias}
\index[author]{Holtz, Wolfgang}
\begin{center}
\vspace{1.1cm}
\textbf{Abstract}
\begin{abstract}
\normalsize{
Vitrification by the OPS technique has been shown to be an effective means of embryo cryopreservation, though little is known about the repeated use of the technique. In the present investigation, morphologically intact mouse blastocysts from 40 superovulated 5 to 8 week"=old virgin female NMRI mice (blastocysts were pooled from 3 to 5 donors at a time) were vitrified using the open pulled straw (OPS) method. After warming to 37oC, one third of the embryos (n = 75) was cultured \textit{in~vitro}, the remaining two thirds were subjected to re"=vitrification. After the second warming, another third was put to culture whereas the last third was vitrified once again. These embryos too were re"=warmed and cultured. No embryos were lost in the process. Of blastocysts vitrified once, \mbox{97\,\%} developed to the expanded blastocyst stage and \mbox{81\,\%} proceeded to hatching. The corresponding values for embryos re"=vitrified once were 93 and \mbox{72\,\%}, respectively. These differences were not significant ($p > 0.05$). After the third vitrification, expansion and hatching rates were 57 and \mbox{35\,\%} respectively. These values differed significantly from those recorded after first and second vitrification ($p < 0.01$). Blastocysts vitrified once and twice were transferred to recipients (\unitfrac[10]{embryos}{recipient}) to examine their potential to continue development \textit{in~vivo}. Of 10 recipients provided with embryos vitrified once, 8 remained pregnant, bearing 5.5 $\pm$ 0.3 (mean $\pm$ SEM) fetuses. Of 10 recipients receiving embryos that had been vitrified twice, 8 remained pregnant with 5.0 $\pm$ 0.3 fetuses. Of all embryos transferred, \mbox{44\,\%} of those vitrified once and \mbox{40\,\%} of re"=vitrified embryos survived to the fetal stage. It may be concluded that, in mice, repeated OPS-vitrification is feasible. If it were possible to translate these finding to domestic animals and man, it would offer new possibilities for future application. }

\vspace{0.5cm}
\end{abstract}
\end{center}
\noindent \textbf{Keywords:} Cryopreservation, embryo transfer, mouse, open pulled straw, repeated vitrification
\index[key]{Cryopreservation}
\index[key]{Embryo transfer}
\index[key]{Mouse}
\index[key]{Open pulled straw}
\index[key]{Repeated vitrification}
\end{document}