Align the text in enumerate (or itemize) with the item number

Question

How can we align the text in enumerate (or itemize) with the item number?
Also, how to add a parenthesis after the item number and make the two in bold and italic?

An example of what I am looking for:

1) AAAA: bbbb
cccc
2) DDDD: eeee
ffff

Answer 1

Using itemindent from enumitem you could do something along the lines of this...

Code:

\documentclass{amsart}
\usepackage{enumitem}
\newcommand{\sample}[1]{\textit{\textbf{#1:}}}
\begin{document}
\begin{enumerate}[itemindent=.5cm,label={\textbf{\textit{\arabic*}})}]
\item \sample{AAAA} bbbb\\cccc
\item \sample{DDDD} eeee\\ffff
\end{enumerate}
\end{document}

Yields:

Answer 2

With enumitem, you have to use:

\begin{enumerate}[label=\emph\bfseries\arabic*),wide=0pt]
\item ...
\end {enumerate}

for a single enumerate, or, for each enumerate (1st level),

\setlist[enumerate]{label=\emph\bfseries\arabic*)},wide=0pt}

in your preamble.