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Biomedical subjects

A J Kelly

Publications and source records attributed to A J Kelly.

50 records · Page 3Linked to original sources
PubMed1991

Structure and organization of hip, an operon that affects lethality due to inhibition of peptidoglycan or DNA synthesis.

High-frequency persistence to the lethal effects of inhibition of either DNA or peptidoglycan synthesis, the Hip phenotype, results from mutations at the hip locus of Escherichia coli K-12. The nucleotide sequence of DNA fragments which complement these mutations revealed an operon consisting of a possible regulatory region, including sequences with modest homology to an E. coli promoter, and two open reading frames which are translated both in vitro and in vivo. The stop codon of a 264-bp open reading frame, hipB, and the start codon of a 1,320-bp open reading frame, hipA, share an adenine residue. Assays of promoter strength, the location of the probable promoter with respect to the start of transcription, and codon usage all indicate that hipB and hipA are weakly expressed genes. The activity of the promoter is impaired by an adjacent downstream sequence which includes the coding region of hipB. The impairment is partially relieved by insertion of a premature translation termination signal within the coding region of hipB, suggesting involvement of the HipB protein in the regulation of this promoter. The arrangement of hipB and hipA within the operon and the toxicity of hipA for strains defective in or lacking hipB suggest an important interaction between the products of these genes.

Amino Acid Sequence↗
PubMed1990

Identification of genes expressed in the tobacco shoot apex during the floral transition.

The shoot apex of higher plants contains undifferentiated meristematic cells that serve as the origin of post-embryonic organs. The transition from vegetative to reproductive growth results in the commitment of the apical meristem to floral organ formation. To identify the molecular signals that initiate floral development, we have pursued the isolation of genes that are transcriptionally active in the shoot apex of tobacco during the transition from vegetative to floral growth. The small size of the apex led us to utilize polymerase chain reaction shoot apices. This approach enabled the isolation of the apex-specific and floral apex-specific cDNA clones described in this paper. One clone, A3, detected an equivalent level of transcript in the shoot apex during all developmental stages observed. The second clone, FA2, detected a unique transcript that increased in abundance in the shoot apex during the transition to flowering and showed high levels of expression in developing petals, stamens, and pistils.

Base Sequence↗
PubMed1990

The circadian rhythm of intact parathyroid hormone-(1-84): temporal correlation with prolactin secretion in normal men.

Serum PTH-(1-84), PRL, and adjusted calcium concentrations were determined at 30-min intervals for a 24-h period in six normal adult men. PTH-(1-84) and PRL both exhibited two peaks of increased secretion [1600-1900 and 0200-0600 h for PTH-(1-84); 2000-2200 and 0400-0800 h for PRL]. For each subject there was a striking similarity in the magnitude of secretion of the two hormones and a consistent temporal relationship. Thus, the maximum correlation coefficients of 0.62-0.83 were obtained for the six subjects when the PRL surge lagged that of PTH-(1-84) by 0.5-3.5 h. In contrast, the correlation between PTH-(1-84) and adjusted calcium was weaker (r = -0.36 to -0.66) and showed no consistent temporal relationship (0.0-10.5 h). These data support the concept of higher center control of PTH-(1-84) secretion with the possible involvement of factors common to the control of PRL secretion.

Adult↗
PubMed1981

Technical aspects of bronchopulmonary lavage for alveolar proteinosis: two case reports.

Under general anaesthesia, therapeutic bronchopulmonary lavage was performed in two patients suffering from alveolar proteinosis. In one patient, difficulties were experienced during attempted lavage of the right lung. Fluid trapping occurred when saline was infused down the tracheal (right) lumen of a Carlen's double lumen endobronchial tube and also when a left Robertshaw tube was similarly used. Spillover of saline into the left lung occurred when a right Robertshaw was used. Efficient lavage of the right lung could only be performed after insertion of a White endobronchial tube. In the second patient, both lungs were washed without problem using a left Robertshaw tube after difficulty had been experienced with a Carlen's tube. In both cases venous admixture was least when the lavaged lung was filled with saline. Hypoxaemia increased as the lung was drained. Details of technique are discussed as are problems with double lumen endobronchial tubes used during the procedure.

Adult↗
PubMedDate not supplied

Comparison of torsional strengths of bioabsorbable screws for anterior cruciate ligament reconstruction.

The goals of this study were to evaluate torsional strength and modes of failure in commercially available bioabsorbable interference screws and to test the effect of screw diameter on torsional strength when screws become jammed during insertion. We tested the Arthrex, BioScrew, Endo-Fix, Phantom, and Sysorb screws, all 20 mm in length. Four major modes of failure were encountered. Analysis of variance revealed that both screw type and diameter had a significant effect on failure torque. The Endo-Fix 7-mm screw had the lowest failure torque (1.07 +/- 0.18 N x m) and the Sysorb 8-mm screw had the highest (5.23 +/- 0.24 N x m). The Sysorb was significantly stronger than all the other screws. The failure torques were within the range that has been reported for manual screw insertion. We concluded that technical factors, which can affect insertion torque, assume particular importance with the use of bioabsorbable interference screws.

Absorbable Implants↗