Analysis of TAF90 mutants displaying allele-specific and broad defects in transcription.

Yeast TAF90p is a component of at least two transcription regulatory complexes, the general transcription factor TFIID and the Spt-Ada-Gcn5 histone acetyltransferase complex (SAGA). Broad transcription defects have been observed in mutants of other TAF(II)s shared by TFIID and SAGA but not in the only two TAF90 mutants isolated to date. Given that the numbers of mutants analyzed thus far are small, we isolated and characterized 11 temperature-sensitive mutants of TAF90 and analyzed their effects on transcription and integrity of the TFIID and SAGA complexes. We found that the mutants displayed a variety of allele-specific defects in their ability to support transcription and maintain the structure of the TFIID and SAGA complexes. Sequencing of the alleles revealed that all have mutations corresponding to the C terminus of the protein, with most clustering within the conserved WD40 repeats; thus, the C terminus of TAF90p is required for its incorporation into TFIID and function in SAGA. Significantly, inactivation of one allele, taf90-20, caused the dramatic reduction in the levels of total mRNA and most specific transcripts analyzed. Analysis of the structure and/or activity of both TAF90p-containing complexes revealed that this allele is the most disruptive of all. Our analysis defines the requirement for the WD40 repeats in preserving TFIID and SAGA function, demonstrates that the defects associated with distinct mutations in TAF90 vary considerably, and indicates that TAF90 can be classified as a gene required for the transcription of a large number of genes.

Iodoquinol associated seizures and radiopacity.

This case report describes seizures and encephalopathy in a nine year-old boy treated with iodoquinol for amebiasis. The toxicity of iodoquinol and other 8-hydroxyquinolines is discussed. The radiopacity of this medication, used worldwide for the treatment of diarrheal illnesses and dermatitis, may be diagnostically useful.

Rational ordering of cervical spine radiographs following trauma.

A retrospective review of 312 hospitalized patients with cervical spine injuries was conducted to identify presenting signs, symptoms, and coexisting conditions, and to determine if any injuries were not diagnosed in the emergency department. Of the 257 (82%) patients who were alert on ED evaluation, 215 (84%) complained of neck pain or tenderness. Of the remaining 42 alert patients without neck pain, 34 had sensory or motor symptoms or signs suggestive of cervical spine injury, and eight had significantly painful other injuries. Of the 284 patients presenting within the first 48 hours after injury, 23 were not diagnosed initially, 21 because radiographs were initially read as negative and two because no radiographs were taken. A significant number of patients had more than one fracture of the spinal column. A stepwise approach to rational ordering of cervical spine radiographs in blunt trauma is proposed.

Relation of body mass to oxygen consumption rate in dental pulp.

Oxygen consumption rates of dentinogenically active dental pulp at 38 C have been determined for 13 different species of mammals ranging from 18.6 gm to 800 kg in mean body mass. The QO2 is inversely related to body mass. The influence of body mass on the oxygen consumption rate seems to be about ten times greater in animals weighing less than 18 kg than it is in larger animals.