Solvation: how to obtain microscopic energies from partitioning and solvation experiments.

Oil-water partitioning, solubilities, and vapor pressure experiments on small-molecule compounds are often used as models to obtain energies for biomolecular modeling. For example, measured partition coefficients, K, are often inserted into the formula -RT in K to obtain quantities thought to represent microscopic contact interaction free energies. We review evidence here that this procedure does not always give microscopically meaningful free energies.

Human and fungal 3' splice sites are used by Trypanosoma brucei for trans splicing.

In Trypanosoma brucei, pre-mRNAs are joined to a 5' 39 nt spliced leader sequence by trans splicing, a process that has not been well characterized. We have asked whether the 3' splice site regions of human and yeast introns are able to substitute in vivo for the 3' spliced leader acceptor regions of trypanosome pre-mRNA sequences. The ability of heterologous sequences to participate in trans splicing in trypanosomes was assayed by chloramphenicol acetyltransferase (CAT) enzyme activity and/or the detection of spliced CAT mRNA.

Rochalimaea henselae infection. A new zoonosis with the domestic cat as reservoir.

Objective: To determine the reservoir and vector(s) for Rochalimaea henselae, a causative agent of bacillary angiomatosis (BA) and cat scratch disease, and to estimate the percentage of domestic cats with R henselae bacteremia in the Greater San Francisco Bay Region of Northern California.

Design: Hospital-based survey of patients diagnosed with BA who also had significant exposure to at least one pet cat, as well as a convenience sampling of pet or impounded cats for prevalence of Rochalimaea bacteremia.

Setting: Community and university hospitals and clinics; veterinary clinics treating privately owned or impounded cats.

Heat-inducible ATP-binding proteins of Candida albicans are recognized by sera of infected patients.

Four proteins from Candida albicans extracts have been isolated by ATP affinity chromatography. These proteins were found to be at elevated levels in extracts of cells raised from 25 degrees C to 37 degrees C, but were present at low levels in cells grown at 25 degrees C. The molecular masses of the proteins (38-42 kDa, 66-68 kDa, 70-72 kDa and 74-76 kDa) correspond to the published sizes of C.

Ribosomal protein L25 from Trypanosoma brucei: phylogeny and molecular co-evolution of an rRNA-binding protein and its rRNA binding site.

The gene encoding ribosomal protein L25, a primary rRNA-binding protein, was isolated from the protozoan parasite Trypanosoma brucei. Hybridization studies indicate that multiple copies of the gene are present per T. brucei haploid genome.

Three distinct secreted aspartyl proteinases in Candida albicans.

The secreted aspartyl proteinases of Candida albicans (products of the SAP genes) are thought to contribute to virulence through their effects on Candida adherence, invasion, and pathogenicity. From a single strain of C. albicans (WO-1) which expresses a phenotypic switching system, three secreted aspartyl proteinases have been identified as determined by molecular weight and N-terminal sequence.

Isolation of Rochalimaea species from cutaneous and osseous lesions of bacillary angiomatosis.

Background: Bacillary angiomatosis is characterized by vascular lesions, which occur usually in patients infected with the human immunodeficiency virus (HIV). A newly described gram-negative organism, Rochalimaea henselae, has been associated with cutaneous bacillary angiomatosis, but no organism has been isolated and cultivated directly from cutaneous tissue.

Methods: We used two methods to isolate the infecting bacterium from four HIV-infected patients with cutaneous lesions suggestive of bacillary angiomatosis: cultivation with eukaryotic tissue-culture monolayers and direct plating of homogenized tissue onto agar.