Upstream regulatory regions required to stabilize binding to the TATA sequence in an adenovirus early promoter

Of the five early adenovirus promoters, the early region 3 (E3) promoter is one of the most strongly induced by the E1A protein. To identify cellular proteins involved in both the basal and E1A-induced transcriptional regulation of the E3 promoter, DNase I footprinting using partially purified Hela cell extracts was performed. Four regions of the E3 promoter serve as binding domains for cellular proteins. These regions are found between -156 to -179 (site IV), -83 to -103 (site III), -47 to -67 (site II), and -16 to -37 (site I), relative to the start of transcription. Examination of the DNA sequences in each binding domain suggests that site III likely serves as a binding site for activator protein 1 (AP-1), site II for the cyclic AMP regulatory element binding protein (CREB), and site I for a TATA binding factor. The factors binding to either site II or III were sufficient to stabilize binding to the TATA sequence (site I). Mutagenesis studies indicated that both sites II and III, in addition to site I, are needed for complete basal and E1A-induced transcription. These results suggest that multiple cellular factors are involved in both the basal and E1A-induced transcriptional regulation of the E3 promoter, and that either of two upstream regions are capable of stabilizing factor binding to the TATA sequence.

Potential pitfall of DMSA scintigraphy in patients with ureteral duplication

A 5-wk-old male presented with radiographic findings of a duplicated collecting system. A [99mTc]DMSA scan was requested to evaluate cortical function. Images obtained immediately. postinjection showed activity restricted to the upper poles; in contrast, delayed images at 4 hr showed activity in the bladder and throughout both kidneys. Catheterizing the patient drained the activity from the bladder but had little effect on the refluxed renal activity. The early [99mTc]DMSA images were critical in making the proper interpretation. Technetium-99m DMSA is excreted into the urine and this fact needs to be considered when interpreting scans of patients with possible reflux or obstruction. When DMSA scans are obtained in pediatric patients with possible reflux, catheterization prior to the study and early images prior to the appearance of DMSA in the collecting system are recommended.

Tn5.7 construction and physical mapping of pRPS404 containing photosynthetic genes from Rhodopseudomonas capsulata

A transposon, Tn5.7, has been constructed incorporating the transposition functions of Tn5 and the antibiotic-resistance factors from Tn7. It was used to mutagenize the plasmid pRPS404 which contains the photosynthetic genes of Rhodopseudomonas capsulata and is KanamycinR . In conjunction with the mutagenesis, physical mapping of the restriction endonuclease recognition sites for XhoI, BglII, KpnI, and SstI has been accomplished.

T, B and K cells in autoimmune thyroid disease

The K-cell cytotoxic activity of peripheral blood lymphoid cells from 104 patients with autoimmune thyroid disease and from age and sex matched control subjects was measured using chicken erythrocytes as target cells. Patients with Hashimoto thyroiditis,primary hypothyroidism and thyrotoxicosis who were either newly diagnosed and untreated or had received therapy for less than or equal to 1 year showed a significant increase in K-cell cytotoxic activity. Patients who had received treatment for greater than 1 year and less than or equal to 5 years showed no such comparable increase in cytotoxic activity. Within the group of patients with untreated thyrotoxicosis it was found that K-cell cytotoxic activity was related to both goitre size and serum antibody titre. Thus patients with little or no goitre showed a highly significant elevation of cytotoxic activity whereas patients with moderate to large goitres gave values within the normal range. Similarly patients with no detectable serum thyroid autoantibodies showed high K-cell activity while patients with positive antibody titres did not. It was also shown that neither the absolute number nor the proportion of circulating T and B lymphocytes in patients with autoimmune thyroid disease as assessed by the sheep red cell rosette method and by indirect immunofluorescence was significantly different from that observed in the normal control population. No correlation was found between peripheral blood K-cell cytotoxic activity and the percentage of circulating null cells, i.e. 100-(percentage T + percentage B) in either patients or control subjects.