Clostridium difficile-associated diarrhea in the elderly.

Objective: It is widely believed that Clostridium difficile (C. difficile)-associated diarrhea is a more severe disease in the elderly than in the young, associated with increased morbidity and mortality. These beliefs are largely anecdotal, and there are few data supporting them.

DNA sequences regulating human beta globin gene expression.

Human delta globin is expressed at approximately 1-2% of the level of human beta globin in erythroid cells despite the marked homology between these two globins. To determine the DNA sequences responsible for this effect, delta and beta globin genes and fusion products of these genes constructed in vitro were transfected and expressed in HeLa cells. The results indicate that when the small intervening sequence of the beta gene (beta IVS 1) is replaced by delta IVS 1, expression of the chimeric gene is the same as that of the normal beta globin gene.

Five nucleotide changes in the large intervening sequence of a beta globin gene in a beta+ thalassemia patient.

A beta globin gene from a patient with homozygous beta+ thalassemia has been cloned and completely sequenced. No changes from normal are found in the 200 nucleotides 5' to the cap site, in the 3' untranslated region up to the poly A addition site, in the small intervening sequence (IVS 1), or in the coding sequence except for a third base change in codon 2. The only other differences are in the large intervening sequence (IVS 2).

Isolation and characterization of cloned DNA: the delta and beta globin genes in homozygous beta + thalassemia.

We have isolated and characterized a clone of human DNA from a patient with beta+ thalassemia containing the entire delta and beta structural genes and their flanking sequences. Partial Eco RI digestion of spleen DNA was used to obtain 15 to 20 kilobase (kb) pieces of human DNA that were then ligated to charon 4A lambda phage DNA. The 8 x 10(5) recombinants obtained were grown and screened for their content of beta gene sequences.