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Stress ossidativo e stato antiossidante in pazienti sottoposti a ossigeno terapia iperbarica

Serena Benedetti¹, Antonio Lamorgese², Michele Piersantelli¹, Silvia Pagliarani¹, Francesca Benvenuti¹, Franco Canestrari¹

¹Istituto di Chimica Biologica "G. Fornaini", Università degli Studi di Urbino "Carlo Bo"
²Medicina Iperbarica, Centro di Terapia e Ricerca, Fano (PU)

Biochimica Clinica: 2003; 27(5-6): 312-317 [Article in italian]

ABSTRACT. Exposure to hyperbaric oxygen (HBO) favourably leads to an increase of dissolved oxygen in the blood; however, increased formation of toxic reactive oxygen species has also been observed. The aim of this study was to evaluate the condition of oxidative stress and the possible modifications of the antioxidant defense systems in twelve patients exposed to 15 HBO treatments not receiving antioxidant supplementation. We found that the prolonged exposure to HBO led to a condition of medium-high oxidative stress with reactive oxygen metabolite and malondialdehyde accumulation. At the same time, a decrease in erythrocyte superoxide dismutase and catalase activities was observed at the 15th HBO session when compared to the 1st treatment. This preliminary study seems to indicate that, in absence of antioxidant supplementation, the prolonged exposure to HBO leads to a condition of oxidative stress which negatively affect the enzymatic antioxidant defense system.

Alleli G20210A e G1691A dei geni della protrombina e del fattore V:la complessità della patologia tromboembolica

Raffaella Sibillo, Francesca Pizza, Angela Sibillo, Antonella Fuccio
Laboratorio di emostasi e trombosi Hermes S.r.l. Centro Medico Polispecialistico, Caserta

Biochimica Clinica: 2003; 27(5-6): 318-322 [Article in italian]

ABSTRACT. We described three pedigrees including heterozygous and homozygous subjects for prothrombin and factor V mutations. The probands of each family, heterozygous for factor V Leiden and homozygous for G20210A prothrombin mutation, soffered of deep-vein thrombosis, recurrent phlebitis and one event of cerebral ischemia. None of relatives in all families have had thromboembolic disease, even if have been exposed to genetic risk factors and circumstantial risk factor such as pregnancy, surgical procedures and use of oral contraceptive. These cases suggest that the genotype/phenotype correlation may not be as strong as described and support the complexity of thromboembolic disease. Individuals heterozygous or homozygous for the same mutant gene exhibit symptoms or non although they have been exposed to risk factors.

La mutazione Q109X del gene SDHD causa tumori ereditari cromaffini caratterizzati da un'alta variabilita' fenotipica

Lisa Simi1, Pietro Ferruzzi2, Roberta Sestini3, Pamela Pinzani1, Maurizio Genuardi3, Mario Pazzagli1, Mario Serio2, Massimo Mannelli2, Claudio Orlando1

Dipartimento di Fisiopatologia Clinica, Unità di Biochimica Clinica1, di Endocrinologia2 e di Genetica Medica3, Università degli Studi di Firenze

Biochimica Clinica: 2003; 27(5-6): 323-325 [Article in italian]

ABSTRACT. Familial chromaffin tumors are caused by mutations in VHL, RET, NF1 or in mitochondrial complex genes SDHB, SDHC, SDHD. We studied three families (negative for VHL, RET, NF1 mutations) and affected by chromaffin tumors with a high clinical variability, presenting carotid tumors, paragangliomas and pheochromocytomas. In each family a nonsense germline mutation (Q109X) was found in exon 4 of the SDHD gene, that causes a stop codon and the synthesis of a truncated protein. In affected patients, the heterozygous mutation was in germline as well as in tumor DNA and was always inherited through fathers. This study shows that this germline mutation is associated to different clinical pictures and suggests that genomic analysis should be performed in patient affected by a chromaffin tumor especially if present in young age, with multiple or extraadrenal localization.

L'impiego della succinilditiocolina come substrato rappresenta il metodo d'elezione per la misura dell'attività catalitica della colinesterasi nel siero nella diagnosi della sensibilità alla succinildicolina

Andrea Mosca¹, Roberto Bonora², Ferruccio Ceriotti³, Carlo Franzini⁴, Giuliana Lando⁵, Renata Paleari¹, Maria Cristina Patrosso⁵, Martina Zaninotto⁶, Mauro Panteghini²** per il Gruppo di Studio 'Enzimi' della Società Italiana di Biochimica Clinica e Biologia Molecolare Clinica (SIBioC)
¹Dipartimento di Scienze e Tecnologie Biomediche, Università degli Studi, Segrate, Milano
²Laboratorio Analisi Chimico Cliniche 1, Azienda Ospedaliera "Spedali Civili", Brescia
³Laboratorio Standardizzazione, Istituto Scientifico H. San Raffaele, Milano
⁴Dipartimento di Scienze Cliniche Luigi Sacco, Università degli Studi, Milano
⁵Laboratorio Analisi Chimico Cliniche Patologia Clinica, Ospedale Niguarda Ca' Granda, Milano
⁶Dipartimento di Medicina di Laboratorio, Università - Ospedale, Padova*Questo articolo è basato su uno studio in precedenza riportato in Clinical Chemistry & Laboratory Medicine (Clin Chem Lab Med 2003;41:317-22), anche se in forma e contenuti parzialmente diversi.Il presente lavoro è stato in parte presentato durante il 32É Congresso Nazionale SIBioC, 12-15 settembre 2000, Rimini (Biochim Clin 2000;24:303), e il 34É Congresso Nazionale SIBioC, 17-20 settembre 2002, Rimini (Biochim Clin 2002;26:297).

** Coordinatore del Gruppo di Studio, a cui inviare la corrispondenza (e-mail: panteghi@bshosp.osp.unibs.it)
Biochimica Clinica: 2003; 27(5-6): 326-331 [Article in italian]

ABSTRACT. No comparative information is available concerning the ability of various cholinesterase (ChE) methods to identify succinyldicholine-sensitive patients, purely based on the enzyme activity recorded in serum. Here, we evaluated six different methods for the measurement of ChE activity; 131 subjects were subdivided according to ChE phenotype and, therefore, to succinyldicholine sensitivity. ChE phenotype was determined by measuring dibucaine and fluoride numbers. DNA analysis was performed to confirm correlation between the phenotype classification used in the study and the ChE genotype. The tested methods were significantly different in their ability to discriminate between the subjects with and without succinyldicholine-sensitive phenotypes. The succinyldithiocholine/5,5'-dithio-bis(2-nitrobenzoate) (DTNB) method showed the highest accuracy [area under the receiver operating characteristic (ROC) curve 0.97] followed by the propionylthiocholine/DTNB method (area under the ROC curve 0.94). On the other hand, the two methods using butyrylthiocholine as substrate and that employing benzoylcholine showed limited clinical utility in discriminating subjects at risk of prolonged apnea (area under the ROC curve â0.9). Using the succinyldithiocholine method, a value â23 U/L was approximately five times as likely to occur in a sensitive individual as in a normal one.

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