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Stefano Martelossi

Publications and source records attributed to Stefano Martelossi.

7 recordsLinked to original sources
PubMed2007

Glutathione-S-transferase genotypes and the adverse effects of azathioprine in young patients with inflammatory bowel disease.

BACKGROUND: Adverse drug reactions to azathioprine, the prodrug of 6-mercaptopurine, occur in 15%-38% of patients and the majority are not explained by thiopurine-S-methyltransferase (TPMT) deficiency. Azathioprine is known to induce glutathione depletion and consumption of glutathione is greater in cells with high glutathione-S-transferase (GST) activity compared with those with low activity; moreover, some reports indicate that GST might play a direct role in the reaction of glutathione with azathioprine. The association between polymorphisms of GST-M1, GST-P1, GST-T1, and TPMT genes and the adverse effects of azathioprine was therefore investigated. METHODS: Seventy patients with inflammatory bowel disease (IBD), treated with azathioprine, were enrolled and clinical data were retrospectively determined. TPMT and GST genotyping were performed by polymerase chain reaction (PCR) assays on DNA extracted from blood samples. RESULTS: Fifteen patients developed adverse effects (21.4%); there was a significant underrepresentation of the GST-M1 null genotype among patients developing adverse drug reactions to azathioprine (odds ratio [OR] = 0.18, 95% confidence interval [CI] = 0.037-0.72, P = 0.0072) compared with patients who did not develop adverse effects. Patients heterozygous for TPMT mutations presented a marginally significant increased probability of developing adverse effects (OR = 6.38, 95% CI = 0.66-84.1, P = 0.062). Moreover, among the 55 patients who did not develop adverse effects, there was a significant underrepresentation of the GST-M1 null genotype among patients who displayed lymphopenia as compared with those that did not display this effect of azathioprine (OR = 0.15, 95% CI = 0.013-1.08, P = 0.032). CONCLUSION: Patients with IBD with a wildtype GST-M1 genotype present increased probability of developing adverse effects and increased incidence of lymphopenia during azathioprine treatment.

Adolescent↗
PubMed2006

Prevalence of methylenetetrahydrofolate reductase polymorphisms in young patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) has been related to mutations of methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in the metabolism of folate and methionine, both of which are important factors in DNA methylation and synthesis. A mutated MTHFR genotype was associated with increased toxicity of methotrexate treatment. The objective of this study was to verify, in a population of young patients with IBD, the presence of an association among mutations in the MTHFR gene, the incidence of IBD, and the risk of adverse events during the treatment with thiopurines azathioprine (AZA) or 6-mercaptopurine (6MP). Ninety-two patients with IBD were enrolled; 63 were treated with thiopurines; patients and 130 controls were genotyped for MTHFR mutations by PCR-based methods. The incidence of mutations in the MTHFR gene was not different between patients with IBD and control subjects; the mutated genotype was not associated with an increased risk of toxicity during thiopurine treatment.

Adolescent↗
PubMed2006

Diagnostic challenge of hyper-IgD syndrome in four children with inflammatory gastrointestinal complaints.

OBJECTIVE: Hyper-IgD syndrome (HIDS) is a rare autosomal recessive disease characterized by recurrent fever, lymphadenopathy, diarrhoea, abdominal pain, headache, arthralgia and skin rash. Abdominal symptomatology may mimic inflammatory bowel disease. We report on four patients with HIDS who had been previously investigated for Crohn's disease (CD). The levels of IgD were measured in a series of patients with CD to evaluate the specificity of this assay in the differential diagnosis between the two conditions. MATERIAL AND METHODS: Diagnosis of HIDS was based on clinical criteria as well as immunological or genetic data. IgD levels were measured in the four subjects affected by HIDS, in 59 patients with CD and in a group of 160 healthy controls. RESULT: All patients underwent a variety of gastroenterological investigations because inflammatory bowel disease was suspected. Ultrasonography was pathologic in all the patients, showing enlargement of mesenteric lymph nodes. Abdominal leucocyte scintigraphy displayed diffuse signals of mild to moderate degree. IgD and IgA levels were elevated in three out of four patients. No difference in IgD values was found in CD patients as compared to the control group. CONCLUSIONS: Gastrointestinal complaints associated with recurrent fever and mesenteric adenopathy warrant genetic investigation for HIDS, in order to avoid unnecessary invasive investigations and treatment.

Child↗
PubMed2006

Network approach to the child with primary intestinal failure.

Intestinal failure (IF) is a rare condition resulting from short gut and other heterogeneous intestinal diseases. Major centers in Italy merged in a national network to build common diagnostic and management approaches and to investigate the natural history of IF. Gastroenterological reference centers with specific expertise in intestinal morphology, diagnosis of autoimmune conditions, intestinal microbiology and parenteral nutrition were identified to act as consultants to the network. These centers of expertise provided specific diagnostic approaches while ensuring high technical standards. The approach allowed each center to learn from a larger cohort of patient samples. A database was set up to investigate etiology, epidemiology and natural history of IF. A common diagnostic algorithm for intractable diarrhea was designed. This process was largely based on electronic communication among centers and specimen shipping. Etiologic diagnosis was obtained in almost all cases of IF secondary to severe protracted diarrhea. The study of the natural history of IF showed a close association between etiology of IF and its outcome. The natural history of IF also provided the starting point for specific therapeutic approaches to its complications such as parenteral nutrition-associated cholestasis and catheter-related sepsis. The network approach to IF provides an effective model to optimize resources and prospectively investigate the natural history of IF, essential steps to design interventions, including intestinal transplantation and improve the outcome of IF.

Child↗
PubMed2003

Deep sedation with propofol by nonanesthesiologists: a prospective pediatric experience.

BACKGROUND: The need to perform procedural sedation for children has increased in recent years, and so has the experience of nonanesthesiologists in this field. The use of propofol increases the success of satisfactory deep sedation, but it can produce rapid and profound decreases in level of consciousness and cardiorespiratory function. Data are needed to assess the safety of this drug outside an anesthesiology setting. OBJECTIVE: To assess safety and efficacy of procedural sedation with propofol in a pediatric ward of a tertiary-care pediatric teaching hospital with trained personnel and monitoring facilities. METHODS: Patients admitted to the hospital who needed invasive procedures underwent procedural sedation by the pediatric sedation unit with intravenous propofol. A training protocol was developed to educate nurses and residents. RESULTS: We performed 1059 procedures. Sedation was achieved in all procedures, and all but 1 were successfully performed. No patient required intubation. Transient desaturation resolving spontaneously occurred in 134 (12.7%) of 1059 patients. Major desaturation requiring a short course of ventilation occurred in 4 (0.8%) of 483 patients undergoing upper endoscopies, in 1 (0.3%) of 287 patients undergoing painful procedures, and in none of the 289 patients undergoing colonoscopies. Laryngospasm occurred in 10 (2.1%) of 483 patients undergoing upper endoscopies. CONCLUSIONS: In this experience, the use of propofol with concurrent oxygen administration allowed sedations in children with no significant complications for colonoscopies and painful procedures. Complications in the group of upper endoscopies appear too high for recommending propofol in a sedation unit with residents in attendance. This protocol of procedural sedation by nonanesthesiologists allowed a significant increase in the number of procedures performed with sedation and saved anesthesiology resources.

Adolescent↗