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Biomedical subjects

A Hirsch

Publications and source records attributed to A Hirsch.

At least 199 records · Page 11Linked to original sources
PubMed1975

[Pleural calcifications].

Pleural fibro-hyaline calcification and plaques were noted in about 1% of chest Xrays carried out as a routine in adults. The etiological diagnosis is often difficult taking into consideration the considerable delay between the discovery of the lesion of the disease responsible. These abnormalities follow inflammatory pleural effusion affecting the visceral layer of the pleura. The autors recall certain possible complications, such as, functional disturbance, secondary infection, fistula formation and malignant change. The calcified plaques of the parietal pleura represent an excellent sign of exposure to asbestos in a population. Their characteristics, significance and mechanisms are discussed.

Asbestosis↗
PubMed1972

Effect of dibutyryladenosine 3':5'-cyclic monophosphate on growth and differentiation in Caulobacter crescentus.

Caulobacter crescentus goes through a series of morphological changes during its life cycle, including the coincident expression of synthesis of flagella, pili, and receptor sites for DNA bacteriophage. Upon transfer of a mixed population of cells to medium containing lactose as the sole carbon source, these changes were blocked for about 20 hr until beta-galactosidase activity became apparent. The addition of dibutyryl cyclic AMP to the blocked cultures brought about the resumption of cell differentiation, growth, and the appearance of beta-galactosidase activity within 1 hr. Unlike Escherichia coli, the intracellular and extracellular concentrations of cyclic AMP in C. crescentus did not vary under several growth conditions, including catabolite repression. It would appear, therefore, that although there is an effect of cyclic AMP on the induction of beta-galactosidase and differentiation in C. crescentus, regulation of these processes occurs without consistent changes in the cellular level of this nucleotide.

Bacteria↗