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Biomedical subjects

G Perona

Publications and source records attributed to G Perona.

At least 73 records · Page 4Linked to original sources

Ceftazidime and amikacin as empiric antibiotic therapy of febrile granulocytopenic patients with hematological malignancies. Report of 171 consecutive episodes.

One hundred and seventy-one consecutive febrile episodes occurring in 130 neutropenic adult patients with hematological malignancies (mainly acute leukemia) were empirically treated with a combination antibiotic therapy consisting of ceftazidime (100 mg/kg/day) + amikacin (15 mg/kg/day). Of these, 161 were evaluable. In the majority of episodes (75 per cent) documented infections were identified as a cause of fever. There were 73 bacteremias (34 Gram-negative, 29 Gram-positive, 10 polymicrobial). One third of patients had pneumonia. Cure without change of the initial regimen was achieved in 45/73 (62 per cent) bacteremic episodes and in 12/13 episodes of microbiologically documented infections without bacteremia. There were 35 clinically documented infections and 26 (74 per cent) of these were cured. Of the 40 patients presenting with possible infections 26 (65 per cent) were cured. Overall, cure without modification of the initial antibiotic combination was achieved in 109/161 episodes (68 per cent). In spite of the frequent occurrence of persistent neutropenia (82 per cent), the infectious mortality was low (8.6 per cent), and often due to superinfection. The deaths due to primary infections were 6/161 (3.7 per cent). Side effects were mild and rare. In our experience ceftazidime + amikacin was an effective and safe empirical regimen for this population of hematologic patients with persistent neutropenia and severe documented infections.

Agranulocytosis↗

Selenium enhances glutathione peroxidase activity and prostacyclin release in cultured human endothelial cells. Concurrent effects on mRNA levels.

Selenium (Se) is an essential component of glutathione peroxidase (GSH-Px), an enzyme that protects cells by reducing intracellular peroxides. Impaired Se status and GSH-Px activity seem associated with increased risk of atherosclerotic vascular diseases. This study reports the effects of Se supplementation on GSH-Px activity, on prostacyclin (PGI2) production, on 12-hydroxy-eicosatetraenoic acid (12-HETE) levels, and on GSH-Px mRNA expression in cultured human umbilical vein endothelial cells (HUVEC). Se-enriched HUVEC showed significant increase of both GSH-Px activity and thrombin-stimulated production of PGI2 in the presence of stable concentrations of 12-HETE. On the other hand, an inverse correlation between Se concentrations in culture media and GSH-Px mRNA levels in Northern blot analysis was shown; this suggests that a major degree of regulation for GSH-Px expression by Se is most likely exerted at the posttranscriptional level. These observations may help to explain the increased incidence of atherosclerosis described in Se-deficient individuals.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

Improved prognosis of Pseudomonas aeruginosa bacteremia in 127 consecutive neutropenic patients with hematologic malignancies.

OBJECTIVES: Although decreasing in frequency, Pseudomonas aeruginosa bacteremia is still a major challenge for neutropenic cancer patients. In patients with hematologic malignancies, the prognosis of P. aeruginosa bacteremia is particularly poor due to the prolonged and severe neutropenia, mucosal damage, and other defects in immunity related both to the underlying disease and to the cytotoxic therapy. METHODS: To verify the outcome of P. aeruginosa bacteremia and to try to define possible prognostic factors, the authors reviewed the medical records of 127 consecutive episodes of P. aeruginosa bacteremia observed in the hematologic unit of the Verona University School of Medicine. RESULTS: Presence of pneumonia and septic shock, persistence and severity of neutropenia, delayed and inappropriate antibiotic therapy, and unresponsive underlying disease had negative impact on clinical outcome of P. aeruginosa bacteremia. CONCLUSIONS: With recognition of the risk factors and more careful management, the prognosis of P. aeruginosa bacteremia in neutropenic patients with hematologic malignancies has improved in recent years.

Adolescent↗

Amino acid concentrations in blood serum of horses performing long lasting low-intensity exercise.

The aim of this work was to evaluate the changes in the concentrations, after two rides different for distance covered, of different amino acids in endurance horses. Blood samples have been collected from horses just before the start, at the top of a steep slope (819 m difference in height) and just at the end of a 32-km endurance ride. A second group, competing in a 72 km endurance ride, has also been sampled immediately before and after the race. In serum samples, the concentrations of alanine, arginine, asparagine, glycine, isoleucine, histidine, leucine, lysine, methionine, ornithine, phenylalanine, tryptophan, tyrosine and valine have been measured by high-performance liquid chromatography (HPLC). anova and t-test have been used to study the differences in the concentrations of the amino acids. The pre-ride concentrations of the free amino acids were different between the two races, except for methionine and leucine. Differences between start and end race have been found for both groups for all the considered parameters except asparagine, isoleucine, leucine and lysine for the 72 km ride. Increases have been recorded for the shorter and decreases for the longer ride in the blood serum concentrations. Significant increases have also been found between the starting sampling and the second, at the top of the slope, only for alanine, arginine, asparagines, phenylalanine and lysine. The ride length has a significant impact on blood serum amino acids mobilization and uptake; in the shorter race the increases stand only for mobilization, whereas in the longer the decrease can be considered the effect of the onset of the amino acids catabolism.

Amino Acids↗

Different suppression of Ph1 positive hemopoiesis induced by intensive chemotherapy in lymphoid and myeloid blast crisis of CML.

BACKGROUND: The suppression of Ph1-positive hemopoiesis is a major goal in the treatment of CML; in this context the CML patients in blast crisis obtaining a complete clinical remission represent a useful model to investigate the behavior of the Ph1-positive and negative clones during bone marrow repopulation after ablative therapy. METHODS: Seven CML patients in blast crisis (four lymphoid and three myeloid) who obtained a complete clinical remission after an intensive polychemotherapy treatment were evaluated by cytogenetic and molecular analysis both in blast and remission phases. Standard cytogenetic and Southern techniques were employed; in addition, minimal residual disease status (MRD) was ascertained by amplification (PCR) of the specific bcr-abl chimeric transcripts. RESULTS: After a single cycle of induction, all lymphoid cases displayed a complete restoration of Ph1-negative hemopoiesis; by contrast, one myeloid blast crisis showed a partial suppression of Ph1-positive hemopoiesis only after two cycles of chemotherapy, and in the remaining two cases the hematological remission was indeed a reversion to the chronic phase. CONCLUSIONS: Ph1-positive chronic clones present in lymphoid blast crisis showed a higher degree of sensitivity to intensive chemotherapy than those present in the myeloid cases. This observation further suggests that the growth properties of the Ph1-positive clones are highly variable from case to case and probably tend to progress during the time-course of the disease.

Antineoplastic Combined Chemotherapy Protocols↗