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Biomedical subjects

F Girardi

Publications and source records attributed to F Girardi.

48 records · Page 3Linked to original sources
PubMed1988

Piperacillin plus amikacin versus cefotaxime plus amikacin in neutropenic and feverish patients with malignant hemopathies.

Seventy-one neutropenic patients under cytostatic treatment for malignant hemopathies (neutrophil granulocytes less than or equal to/mm3 with feverish episodes in progress (T greater than or equal to 38.5 degrees C) which were probably of an infectious nature were treated according to two antibiotic protocols (piperacillin + amikacin [P + A] or cefotaxime + amikacin [C + A] in a randomized, comparative, prospective study. Of the 71 patients enrolled, 65 could in the end be evaluated for the purposes of this study (36 treated according to the P + A protocol, 29 according to the C + A protocol). In 16 patients the infection was documented bacteriologically. In these cases the percentages of response were, respectively, 77.7% with the P + A and 71.4% with the C + A protocol. The positive clinical results of the two protocols being studied were, considering the entire survey (bacteriologically documented, clinically documented and FUO infections), respectively, 69.4% in the patients treated with P + A and 62.0% in those treated with C + A. The results of the study seem to indicate that the severity of the neutropenia (N.G. less than 500 or greater than 500) does not affect the response to the antibiotic therapy. Modest and transient side effects (hypokalemia and increase of the ClCr) were noted above all in the patients subjected to the therapy with C + A. The results of this study show, therefore, a superimposable effectiveness of the two therapeutic protocols (P + A and C + A) in the empirical treatment of infections in neutropenic patients with malignant hemopathies.

Adolescent↗
PubMed1986

Quantitative microphotometric studies of Feulgen-stained nuclei on sections of the human uterine cervix: optimization of preparation and measuring technique.

The total extinction of apparently normal intermediate cell nuclei was microphotometrically measured in formalin-fixed Feulgen-stained paraffin sections of the uterine cervix. We investigated whether reproducible microphotometric results can be obtained from a histologic section expected to contain a certain amount of sectioned nuclei and stained by a standard technique. The results have shown that exact reproduction of microphotometrically measured mean total extinction values of intermediate cell nuclei can be achieved with a threshold value of 90% transmission in 10 microns sections.

Adult↗
PubMed1984

[Spontaneous microcavitations in the right cardiac chambers. Microcavitations in the right sections].

Spontaneous echocardiographic contrast has been occasionally detected in the left ventricle of patients with mitral valve prosthesis. Only one case has been so far described in which spontaneous microbubbles have been detected in the right ventricle. We report the clinical and echocardiographic findings of five patients in whom spontaneous echocardiographic contrast was detected in right cardiac chambers: one patient had pulmonary embolism, three patients had mitral valve disease and tricuspid regurgitation, one patient had a congestive cardiomyopathy. These microbubbles can be produced by gas development due to lateral pressure drop secondary to tricuspid regurgitation or to gas absorbed from the intestine, that reach the heart through shunts between the portal and the systemic veins.

Adult↗
PubMed1977

Metallobiochemistry of heavy metal pollution: nuclear and radiochemical techniques for long term--low level exposure (LLE) experiments.

The chronic exposure of man to increasing amounts of heavy metals as a consequence of environmental pollution, requires accurate knowledge of how much the homeostatic control of trace elements can stand increased exposure to abnormal amounts of metal pollutants without alteration of the biochemical functions. This topic includes the study of the accumulation of metal pollutants in the body with the identification of metal biocomplexes under long term-low level exposure (LLE) conditions. Extremely sensitive analytical techniques are required for experimentation at the heavy metal levels which are typical of a polluted environment in order to assess the limits of physiological homeostatic controls. The possiblity of applying nuclear and radiochemical techniques, such as neutron activation analysis, multiple tracing, high resolution gamma-ray spectrometry and Cerenkov counting, coupled with biochemical techniques, such as gel filtration, ion-exchange chromatography, polyacrylamide gel electrophoresis and differential centrifugation, has been demonstrated in various typical applications in metallobiochemistry. The subject of the first part of this paper is the development and improvement of the techniques, dealing with potential metal binding components, such as metalloenzymes and nucleic acids chosen as models. The developments refer to: preparation of labelled metal pollutants with very high specific activity to label in vivo nanogram or subnanogram amounts of pollutant metals; neutron activation analysis of enzymes and nucleic acids with the aim of analyzing concentrations of many metal pollutants in the identified metal binding components of the microsamples; radiochemical methods including radiobiochemical techniques for multielement tracer experiments and for studying the interaction of heavy metas and metal binding components; development of complementary counting techniques. The in vivo applications are centered on biochemical studies on cadmium, in particular on the long term-low exposure experiment, which is under investigation at present, with the identification of both critical organs of accumulation and of the cadmium binding components. Results are given for biochemical mechanisms involving cadmium such as the stimulation of the "de novo" biosynthesis of rat liver and intestine cadmium binding proteins (CdBP) and on the systematic study of the interaction of metal pollutants and rat liver cadmium binding proteins itself. Preliminary data are also given for short term experiments dealing with the identification of cellular metal binding components for V, Se, Cd and Pb.

Alkaline Phosphatase↗
PubMed1976

Replacement of metal in metalloenzymes. A lead-alkaline phosphatase.

Lead ions can interact with calf intestine alkaline phosphatase. Experiments using 203Pb-labeled Pb2+ ions showed that Pb2+ ions bind the native protein in a molar ratio of Pb/protein of 1:5 with moderate inhibition of its biochemical activity. The 4 g-atoms of Zn per mol present in the native enzyme may be removed by dialysis against EDTA. The inactive apoenzyme is capable of incorporating Pb2+ ions in a Pb/protein molar ratio of 2:1, giving a lead-protein complex still enzymatically active also when genetic material, such as nucleotides or DNA, has been used a a substrate. The reconstituted lead-protein is capable of binding Zn2+ ions without any release of the Pb2+ ions and with an increase in the catalytic activity of only 10-15%. The absence of Zn in the inactive apoenzyme as well as in the reconstituted lead-protein, the incorporation of Pb2+ ions in stoichiometric amounts in the apoenzyme, and the weak influence of the Zn2+ ions on the enzymatic assay of the lead-enzyme suggest that lead ions partially reactivate the calf intestine alkaline phosphatase apoenzyme.

Alkaline Phosphatase↗
PubMed1976

Multielement and automated radiochemical separation procedures for activation analysis.

In recent years the demand for information about the distribution of elements at trace concentration levels in high purity materials and in biological, environmental and geological specimens has increased greatly. Neutron activation analysis can play an important role in obtaining the required information. Radiochemical separations are required in many of the applications mentioned. A critical review of the progress made over the last 15 years in the development and application of radiochemical separation schemes for multielement activation analysis and in their automation is presented. About 80 radiochemical separation schemes are reviewed. Advantages and disadvantages of the automation of radiochemical separations are critically analysed. The various machines developed are illustrated and technical suggestions for the development of automated machines are given.

Activation Analysis↗