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C Cimmino

Publications and source records attributed to C Cimmino.

11 recordsLinked to original sources
PubMed1999

Helicobacter pylori: a eubacterium lacking the stringent response.

Accumulation of 16S rRNA and production of guanosine polyphosphates (pppGpp and ppGpp) were studied during amino acid starvation in three wild-type strains of Helicobacter pylori. All strains exhibit a relaxed phenotype with respect to accumulation of 16S rRNA. This constitutes the first example of a wild-type eubacterium showing a relaxed phenotype. The guanosine polyphosphate levels do not rise as a result of amino acid starvation, as expected for relaxed organisms. However, in both growing and starved cells, basal levels of the two polyphosphates appeared to be present, demonstrating that the enzymatic machinery for guanosine polyphosphate production is present in this organism. These findings are discussed within the framework of the hypothesis that stringent control is a physiological control mechanism more important for the fitness of prokaryotes growing in the general environment than for those that inhabit protected niches.

Amino Acids↗
PubMed1997

Antigenic profiles for the differentiation of Mobiluncus curtisii and Mobiluncus mulieris by immunoblotting technique.

The antigenic profile of 30 vaginal isolates of Mobiluncus strains (22 M. curtisii and 8 M. mulieris) was determined by immunoblotting technique using mouse immune ascitic fluids containing polyclonal antibodies against the type strains M. curtisii subsp. holmesii (ATCC 35242) and M. mulieris (ATCC 35243). Two antigenic profiles were identified within M. curtisii isolates, whereas a certain variability was observed among M. mulieris strains where at least three antigens were constantly recognized. The detection of antigenic profiles of Mobiluncus strains by immunoblotting technique provided a simple method to identify Mobiluncus isolates at the species level.

Animals↗
PubMed1995

Ligation of nonmatching DNA molecule ends.

T4 DNA ligase can promote the in vitro ligation of blunt DNA ends to ends bearing a 2-nucleotide single-stranded protrusion. This was shown by digestion of plasmids pBR322 and pSP71 with the appropriate restriction enzymes followed by recircularization of the plasmids and transformation of Escherichia coli. It could be ruled out that such nonmatching ligations are due to the presence of contaminating nucleases. The efficiency of ligation is of the same order of magnitude as that obtained with blunt end ligations. The interaction of a number of different combinations of blunt and sticky ends, the latter bearing both 3' and 5' protrusions, was investigated. Ligation of nonmatching ends was shown to take place in all cases. Several ligation junctions were sequenced, showing that during the ligation process the 2-nucleotide protrusion is trimmed away. In two instances the ligation event was accompanied by the specific loss of either 3 or 15 nucleotide pairs as well as the protrusion. An intermolecular ligation involving nonmatching ends was also performed, demonstrating that this form of ligation can be usefully employed in molecular cloning experiments.

Base Sequence↗
PubMed1995

Lack of production of (p)ppGpp in Halobacterium volcanii under conditions that are effective in the eubacteria.

The stringent halobacterial strain Haloferax volcanii was subjected to a set of physiological conditions different from amino acid starvation that are known to cause production of guanosine polyphosphates [(p)pp Gpp] in eubacteria via the relA-independent (spoT) pathway. The conditions used were temperature upshift, treatment with cyanide, and total starvation. Under none of these conditions were detectable levels of (p)ppGpp observed. This result, in conjunction with our previous finding that (p)ppGpp synthesis does not occur under amino acid starvation, leads to the conclusion that in halobacteria both growth rate control and stringency are probably governed by mechanisms that operate in the absence of ppGpp. During exponential growth, a low level of phosphorylated compounds with electrophoretic mobilities similar, but not identical, to that of (p)ppGpp were observed. The intracellular concentration of these compounds increased considerably during the stationary phase of growth and with all of the treatments used. The compounds were identified as short-chain polyphosphates identical to those found under similar conditions in Saccharomyces cerevisiae.

Culture Media↗
PubMed1993

Stringency and relaxation among the halobacteria.

Accumulation of stable RNA and production of guanosine polyphosphates (ppGpp and pppGpp) were studied during amino acid starvation in four species of halobacteria. In two of the four species, stable RNA was under stringent control, whereas one of the remaining two species was relaxed and the other gave an intermediate phenotype. The stringent reaction was reversed by anisomycin, an effect analogous to the chloroamphenicol-induced reversal of stringency in the eubacteria. During the stringent response, neither ppGpp nor pppGpp accumulation took place during starvation. In both growing and starved cells a very low basal level of the two polyphosphates appeared to be present. In the stringent species the intracellular concentration of GTP did not diminish but actually increased during the course of the stringent response. These data demonstrate that (i) wild-type halobacteria can have either the stringent or the relaxed phenotype (all wild-type eubacteria tested have been shown to be stringent); (ii) stringency in the halobacteria is dependent on the deaminoacylation of tRNA, as in the eubacteria; and (iii) in the halobacteria, ppGpp is not an effector of stringent control over stable-RNA synthesis.

Bacterial Proteins↗
PubMed1992

Dog-transmitted zoonoses: a serological survey in the province of Bologna.

Eight hundred and two sera of owned dogs from four small towns north-west of Bologna were examined for the presence of antibodies against Coxiella burnetii and Leishmania infantum. At the same time, 149 sera of 69 dog owners from the same area were tested for the presence of antibodies to Q fever, leishmaniasis, echinococcosis/hydatidosis and toxocarosis. Of the 802 dog sera, 7 (0.87%) were positive for Q fever. Of the 69 dog owners, 24 (35%) were positive for Q fever, 4 (6%) for echinococcosis/hydatidosis and 3 (4%) for toxocarosis. Some epidemiological evaluations are made on the possible role played by the dog in spreading the zoonoses considered, at least in the area examined.

Animals↗
PubMed1986

Annulus fibrosus calcification in the cervical spine: radiologic-pathologic correlation.

Intervertebral disc calcification can be secondary to a variety of pathologic processes including some of the arthritides, metabolic diseases, and trauma. The annulus fibrosus is the most commonly calcified component and may mimic vertebral body fracture, limbus vertebra, or a persistent ring apophysis. We describe two young patients who developed calcification in the anterior annulus fibrosus and present radiologic-pathologic correlation in this condition in another case. This calcification may actually be secondary to subclinical or chronic stress on the involved intervertebral disc.

Adult↗