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Biomedical subjects

P Moretti

Publications and source records attributed to P Moretti.

At least 55 records · Page 3Linked to original sources
PubMed1987

Site-specific integration and excision of pMEA100 in Nocardia mediterranei.

Nocardia mediterranei strain LBG A3136 contains the 23.7 kb element pMEA100 in a chromosomally integrated form as well as in the free state (Moretti et al. 1985). The integrated form of this element can be excised precisely from the Nocardia chromosome without any accompanying rearrangements in flanking chromosomal DNA. After transfer into plasmid-free mutant strains, pMEA100 reintegrates site specifically into its original chromosomal locus. The exact mapping of the pMEA100 integration site was accomplished by restriction analysis and DNA sequencing. The attachment site of pMEA100, the junctions of its integrated form and plasmid-free chromosomal DNA of N. mediterranei contain an identical 47 bp long sequence which is probably required for site-specific recombination connected with integration and excision of pMEA100. Only one such sequence was found in the chromosome of pMEA100-free N. mediterranei derivatives as suggested by the single integration locus.

Base Sequence↗
PubMed1986

Effects of acute benzodiazepine administration on growth hormone, prolactin and cortisol release after moderate insulin-induced hypoglycemia in normal women.

Benzodiazepines are known to affect pituitary hormone release, and it has recently been hypothesized that the adenohypophysial hormone response to stress may be modified by previous benzodiazepine treatment. We investigated, therefore, whether a single dose of triazolam, a short-acting benzodiazepine, and flurazepam, a long-acting one, could influence the response of prolactin (PRL), growth hormone (GH) and cortisol to a mild hypoglycemic stress in young healthy volunteers. Neither triazolam nor flurazepam pretreatment resulted in a significant effect on the pituitary response to hypoglycemic stimulus. The GH, PRL and cortisol peaks after both benzodiazepines were similar to those observed after placebo. Our results seem to exclude, therefore, any relevant effect of acute benzodiazepine administration on the neuroendocrine response to mild stress.

Adult↗
PubMed1986

Carotid artery atherosclerotic disease assessed by flow velocity wave form analysis in hemodialyzed normotensive and hypertensive patients.

Cerebrovascular accidents, often secondary to severe atherosclerotic disease, are very common in uremic patients on long-term hemodialysis. The aim of the present study is to assess asymptomatic carotid artery atherosclerotic disease (CAAD) in hemodialyzed normotensive and hypertensive patients in comparison with age-matched controls, by the use of Doppler ultrasound flow velocity wave form analysis (FVWFA), recorded from the common carotid artery. This study was performed on 47 subjects divided into four groups: 10 young and 10 middle-aged normals were considered in groups I and II, respectively, 5 young uremic normotensive, 6 young uremic hypertensive and 16 middle-aged uremic normotensive patients in groups III, IV and V, respectively. All the examined patients were nonsmokers, without diabetes or cardiopathy. The five wave form dimensions most capable of separating different degrees of atherosclerotic disease were determined on every common carotid tracing and used in a single best fit discriminant equation; the resultant discriminant score (DS) classified each carotid tracing and consequently every group's range. DS of groups I and III were not different, but significantly higher compared to the other three groups; besides DS was statistically not different in groups II, IV and V. In conclusion, FVWFA did not detect a different degree of CAAD between normotensive dialyzed patients and age-matched normals, whereas the blood pressure pharmacological control did not affect the velocity findings of advanced CAAD in young uremic hypertensive patients.

Adult↗
PubMed1985

The effect of biotin on the formation of different types of E-rosettes by human lymphocytes.

Peripheral blood lymphocytes from healthy human donors were cultured with biotin and concanavalin A (Con A) for varying periods up to 48 h. At the end of incubation, the percentages of total, active, and stable E-rosettes were determined. The percentage of total E-rosettes decreased significantly in the course of time in both cultures with biotin and Con A, but more slowly than in the control cultures. Biotin and Con A induced a significant increase in the number of high-affinity E-rosettes (aE-RFC and sE-RFC). Preincubation for 4 h in the presence of puromycin or actinomycin D inhibited biotin, and Con A stimulated E-rosette formation. These results suggest that the effect of biotin on the T lymphocytes might be due to stimulation of protein synthesis and, perhaps, new receptors for sheep red blood cells (SRBC).

Biotin↗
PubMed1985

Isolation and characterization of an extrachromosomal element from Nocardia mediterranei.

Strain LBG A3136 of Nocardia mediterranei (ETH Collection) was found to contain a low-copy-number covalently closed circular extrachromosomal element, pMEA 100, which could only be isolated from mycelium grown on agar plates. pMEA 100 could not be isolated from the closely related strain ATCC 13685. Hybridization experiments showed that pMEA 100 is present in strain LBG A3136 in the free as well as in the integrated form whereas in strain ATCC 13685 only an integrated form was detected. Excision and reintegration in strain LBG A3136 seemed to be site specific. pMEA100 was found to be self-transmissible, eliciting the lethal zygosis phenotype, and is possibly involved in fertility in N. mediterranei.

Chromosome Mapping↗
PubMed1985

Relationships between biotin and DNA contents and DNA turnover in lymphoid organs: thymus, lymph nodes and spleen.

Biotin-deficient rats show a slower growth rate and a reduction in thymus, intestinal lymph nodes and spleen weight. The effect is reversible. Biotin administration to normal rats (1 mg/rat/day) causes an increase in intestinal lymph nodes and spleen, while there is no effect on body and thymus weight. The amount of thymus and spleen DNA is lower for deficient than control rats. No difference was noticed between the levels of DNA from normal control and biotin-deficient rat lymph nodes, and between the levels of DNA from normal rats treated and untreated with biotin. The time-course of the specific radioactivity of DNA and the DNA turnover shows that biotin increases both the incorporation of labelling in DNA and DNA turnover rate.

Animals↗
PubMed1984

Arginine degradation in Pseudomonas aeruginosa mutants blocked in two arginine catabolic pathways.

Pseudomonas aeruginosa mutants defective in agmatine utilization (agu) were isolated. The genes encoding agmatine deiminase (aguA) and N-carbamoylputrescine amidinohydrolase (aguB) were 98% cotransducible and mapped between gpu and ser-3 in the 30 min region of the chromosome. Constructed agu arc double mutants (blocked in the arginine decarboxylase and arginine deiminase pathways) used arginine efficiently as the sole carbon and nitrogen source. This suggests the existence of a further arginine catabolic pathway in P. aeruginosa. The mapping data of this study confirm that in P. aeruginosa the chromosomal genes with catabolic functions do not show supraoperonic clustering as found in P. putida.

Arginine↗
PubMed1984

[Weight increase and chronic experimental poisoning by tobacco smoke in the albino rat. Effect of protection with mineral waters].

The Authors refer to the results of an experiment conducted on albino rats chronically intoxicated with tobacco smoke. Several groups of animals were contemporaneously protected, by drinking or by inhaling or by both methods, by a beneficial sulphureous water with a varying sulphydrometric degree, and in one experiment, by inhaling a hypertonic salso-bromo-iodic water. In all cases, it was possible to observe that in the adopted experimental conditions, the chronic intoxication from tobacco smoke slowed the weight increase of albino rats subjected to intoxication and not protected, both as regards non-intoxicated animals and as regards intoxicated animals protected by one of the studied waters. There were no statistically significant differences between the weight increase of the animals protected by the drinking or inhaling methods while protection via both methods resulted statistically more efficacious than protection by one single method.

Animals↗
PubMed1980

Behaviour in biotin-deficient rats of thymic peptides controlling DNA transcription.

Biotin-deficient rats show a slowing down of the growth and an involution of the thymus. The amount of the thymic peptides controlling DNA template, if referred to the thymus weight is higher in deficient than in control rats; no significant difference is noticed among the contents of the active peptides when evaluated per rat. The inhibiting activity on RNA synthesis is the same for the peptides extracted from normal and from biotin-deficient rat thymus.

Animals↗
PubMed1979

Intracellular distribution of biotin-14COOH in rat liver.

Biotin clearance, its distribution in liver and liver fractions after intravenous administration of 5 muCi/100 g body weight (21.55 microgram) of biotin-14COOH in normal and biotin-deficient rats are reported. In the biotin deficient animal there is a more rapid disappearance of the labeled biotin from the blood stream. Biotin-14COOH incorporation in the liver of the deficient rat is more rapid and larger than the incorporation in normal rat liver. Almost all the biotin recovered from liver homogenate is found in the mitochondria and in the pH 5.2 cytosol fraction; whereas in the microsomes only a very small amount is present. The intracellular distribution of biotin is in agreement with its known metabolic roles.

Animals↗