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Biomedical subjects

L Maestri

Publications and source records attributed to L Maestri.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Treatment with sodium alginate of gastroesophageal reflux disease in childhood: efficacy and tolerance assessment].

OBJECTIVE: Evaluation of efficacy of sodium alginate (Gaviscon) in the treatment of gastroesophageal reflux disease in children 3-12 months old, assessed by 24 hours esophageal continuous pH monitoring. METHOD: 28 children studied by 24 hours pH esophageal continuous monitoring before starting the treatment with Gaviscon 0.5 ml/Kg/dose four times a day, 20 minutes after meal. After 2 months of treatment, a second pH esophageal monitoring was performed, during therapy. Total number of refluxes, number of refluxes longer than 5 minutes and reflux index before and during treatment were evaluated, by multiple regression method. RESULTS: All pHmetric parameters showed a statistically significative improvement after 60 days of treatment.

Alginates↗
PubMedDate not supplied

[High-pressure liquid chromatography (HPLC) with UV developer for the analysis of N-acetyl-S-(N-methylcarbomoyl)cysteine (AMCC)].

N,N-dimethylformamide (DMF) is a solvent widely used to prepare synthetic fibers. Biomonitoring of DMF is usually performed by measuring urinary N-methylformamide, which allows us to estimate exposure during the working day. An alternative biomarker is the mercapturic acid N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) whose excretion accounts for about 13% of the absorbed DMF dose. Owing to its slow excretion (mean half-life = 23 hours) the urinary levels of AMCC at the end of a workweek reflect the cumulative dose of DMF during the whole week. Methods given in literature for measuring AMCC need the derivatization of the molecule before analysis. The paper describes a method for the determination of urinary AMCC by high-performance liquid chromatography (HPLC) with direct UV detection. Samples were purified by solid phase extraction with C18 and ENV+ cartridges, then 10 microliters were directly injected onto an Aminex HPX-87H Ion Exclusion column maintained at a temperature of 37 degrees C. Analyses were performed by isocratic run with 1 mM sulphuric acid delivered at 0.85 mL/min. The detector was set at 196 nm. Under these conditions, AMCC eluted at 11.1 min., and the detection and quantification limits were 1.32 mg/L and 3.96 mg/L, respectively. The performance of the method was evaluated on samples containing 25 mg/L and 400 mg/L of AMCC: each sample was analysed three times. The mean recovery of the extraction procedure was 88.3%. The precision (CV%) and the accuracy (Error%) ranged from 0.8% to 2.9%, and from -1.2% to +3.2%. The calibration curve was linear up to a concentration of 1000 mg/L, the coefficient of correlation was r = 0.9997. AMCC was measured in urine samples from 30 exposed and 20 unexposed (smokers and nonsmokers) subjects. Measurable amounts of AMCC were found in all of the samples from workers exposed to DMF; on the contrary, none of the samples from unexposed subjects contained this metabolite. The proposed method is sufficiently sensitive and specific for the evaluation of occupational exposure to DMF, thus it could be useful for the biological monitoring of workers exposed to this solvent.

Acetylcysteine↗
PubMedDate not supplied

[Chronic idiopathic gastric volvulus in children].

OBJECTIVE: We report clinical, radiograpic and instrumental data about 18 cases of gastric chronic idiopathic volvulus observed since 1997 to june 2000. METHOD: All cases diagnosed by barium meal, performed for vomiting or after a pHmetric esophageal monitoring, in cases of atipical symptoms of gastroesophageal reflux disease. RESULTS: All patients underwent a conservative treatment (antireflux position and procinectics): 5 recovered after 1 year of treatment and 13 were operated on because they did not improve during medical therapy or relapsed after the end of conservative treatment. CONCLUSION: Abnormal position of the stomach is not an absolute indication for surgical treatment. When medical treatment does not obtain improvement in symptoms, surgical option has to be discussed.

Adolescent↗
PubMedDate not supplied

[Small bowel overgrowth: a frequent complication after abdominal surgery in newborns].

BACKGROUND/PURPOSE: Surgery for congenital or acquired gastroenterological disorders, and particularly that associated with short bowel, is not infrequently complicated by Small Bowel Bacterial Over growth (SBBO). Aim of this study is to evaluate the clinical course of children undergoing bowel surgery in the newborn period, assessing the development of SBBO and the response to intensive treatment with a "bowel cocktail" of gentamycin, metronidazole and cholestyramine. METHODS: 17 children with various conditions were studied clinically and by Breath Hydrogen Test (fasting and after glucose). 14 children underwent more than one procedure. All children were treated with overall "bowel cocktail" of gentamycin, metronidazole and cholestyramine. RESULTS: 5 children recovered after one course of treatment and 11 children relapsed at least once and required further courses of therapy. One child died from TPN related liver failure and another following a liver and small bowel transplant for short bowel syndrome. A third child required total intestinal tube splinting according to Sauer and another one required a tapering of the preatretic enlarged jejunal loop. CONCLUSIONS: Our study suggests that children undergoing bowel surgery in the neonatal period and those having more than one procedure are at greater risk of developing small bowel bacterial overgrowth postoperatively. Interestingly, loss of the ileocecal valve was not associated with an increased risk of bacterial overgrowth.

Child↗
PubMedDate not supplied

[Monitoring air dispersed concentrations of aldehydes during the use of ortho-phthalaldehyde and glutaraldehyde for high disinfection of endoscopes].

Solutions of glutaraldehyde (GTA) and ortho-phthalaldehyde (OPA) can both be used for low-temperature disinfection of endoscopes. Currently, GTA is being replaced by OPA (an aromatic dialdehyde) at the San Matteo Hospital, as OPA is less dangerous for health care workers than GTA, but has a similar capacity to kill viruses, bacteria and spores. The aim of the study was to compare air levels of GTA and OPA in several endoscopy units at our hospital. The air samples were analysed by means of both Infrared Spectroscopy (IR) and HPLC-UV (High Performance Liquid Chromatography with UV detection). The HPLC method gave a much lower aldehyde value when using OPA (8.4 micrograms/m3) compared to that obtained when GTA was used to disinfect endoscopes (21.279.3 micrograms/m3). Both HPLC and IR methods detected low levels of OPA in air, the mean values being below 10 micrograms/m3. In addition, we studied the resistance of various types of gloves to OPA. Tests showed that OPA permeated vinyl gloves more rapidly (26,628 ng/cm2 per hour) than nitrile gloves (13.9 ng/cm2 per hour).

Air Pollution, Indoor↗
PubMedDate not supplied

[Biological monitoring of occupational exposure to desflurane].

In these last years Desflurane (D) has become used, alone or in combination with nitrous oxide, in surgical procedures. Occupational exposed groups include anesthesiologists, other physicians, (e.g. surgeons) and operating room nurses. Desflurane is a halogenated methylethylether which is administered by inhalation. Desflurane is halogenated exclusively with fluorine. The blood/gas partition coefficient of Desflurane is 0.42. Changes in the clinical effects of Desflurane rapidly follow changes in the inspired concentration. Studies in man indicate that Desflurane washes into the body rapidly. It also washes out of the body rapidly, allowing flexibility in adjustment of the depth of anaesthesia. Desflurane is eliminated via the lungs, undergoing only minimal metabolism (0.02%). In order to investigate the role of urinary D as an indicator of occupational exposure to Desflurane (CI, ppm), CI was measured in 21 members of operating room staffs. For the measurement of environmental concentration of Desflurane (CI), the ambient air was sampled using personal passive dosimeters. The analyte was desorbed by a water-methanol mixture and was analysed by means a gas chromatograph--mass spectrometer (GC-MSD) and headspace technique. The biological monitoring of exposed workers was conducted by determining the concentration of Desflurane in urine (Cu, microgram/L). Urine concentrations of Desflurane were determined by headspace analysis using GC-MSD. Significant correlations were found between the environmental Desflurane concentration and the urinary concentrations. The correlation between CI (ppm) and Cu (microgram/L) was: Log D (Cu, microgram/L) = .191 + .922 * LogCI; r = .916 On the basis of the equation it was possible to establish tentatively the biological limit values corresponding to the respective occupational exposure limit values proposed for Desflurane.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Spontaneous regression of an adrenal mass detected in utero].

The case of a left adrenal mass detected by ultrasonography in a male fetus at the 37th week of gestation is presented. After an uneventful delivery at the 38th gw, the newborn was sonographically monitored, and during the follow-up clinical evaluations were performed, in order to make a differential diagnosis between an adrenal hemorrhage and a congenital neuroblastoma. VMA and HVA were within normal levels, and MIGB scan was negative. A MNR of the the abdomen performed at the age of one month was suggestive for an adrenal hemorrhage in involution. We therefore decided to keep monitoring the mass by ultrasound, avoiding any surgical approach. The sonographic complete disappearance of the disease was documented at the end of the fourth month.

Adrenal Gland Diseases↗
PubMedDate not supplied

[Spontaneous regression of an adrenal mass detected in utero].

The case of a left adrenal mass detected by ultrasonography in a male fetus at the 37th week of gestation is presented. After an uneventful delivery at the 38th gw, the newborn was sonographically monitored, and during the follow-up clinical evaluations were performed, in order to make a differential diagnosis between an adrenal hemorrhage and a congenital neuroblastoma. VMA and HVA were within normal levels, and MIGB scan was negative. A MR of the the abdomen performed at the age of one month was suggestive for an adrenal hemorrhage in involution. We therefore decided to keep monitoring the mass by ultrasound, avoiding any surgical approach. The sonographic complete disappearance of the disease was documented at the end of the fourth month.

Adrenal Gland Diseases↗
PubMedDate not supplied

[Excretion kinetics of phenylhydroxyethyl mercapturic acids (PHEMAs), ethanol consumption, and chronic exposure to styrene: preliminary data on humans].

Styrene (S) is a widely used aromatic hydrocarbon, responsible for several adverse effects. In humans, the metabolism of S is well characterized: besides the major metabolites (mandelic and phenylglyoxylic acid), a minor metabolic pathway leads to phenylhydroxyethyl mercapturic acids (PHEMAs) [N-acetyl-S-(1-phenyl-2-hydroxyethyl)-L-cysteine (M1) and N-acetyl-S-(2-phenyl-2-hydroxyethyl)-L-cysteine (M2)], that are potentially useful for biomonitoring purposes. A pilot study on a volunteer exposed under controlled conditions to S, with or without ethanol administration, allowed us to characterize the excretion profile of PHEMAs and the ethanol-induced interference on PHEMAs metabolic pathway. We further considered a group of 9 workers exposed to S during the working week to determine the confounding role of chronic exposure. Our results confirm the wide interindividual variability of both the biotransformation rate of S into PHEMAs and of the excretion rate of these metabolites. Moreover, both the above parameters changed during the working week, suggesting the existence of a large intraindividual variability as a consequence of the exposure to S and to other solvents. As a practical rule, the data indicate that it is necessary to collect samples at the beginning of the working week when studies on the correlation between genotype and phenotype are carried out. Finally, the results emphasise the importance of excluding an even extemporary ethanol assumption when practicing a biological monitoring programme based on the determination of urinary PHEMAs.

Acetylcysteine↗
PubMedDate not supplied

[New biomarkers of exposure].

In this paper we have defined the new biomarkers of exposure (NBE) as those biomarkers discovered in the last five years and, among previously validated biomarkers, also those applied in different ranges of doses or those determined in biological matrices which differ from matrices originally considered. We examined the results from the surveys carried out by the main Italian research units involved in biological monitoring, i.e. those from the Universities of Brescia, Milan, Naples, Padua, Parma, Pavia, Turin and Verona. The data were collected using a standardized model and included the following: type of element or organic compound, type of biomarker, analytical technique and method, their relationship with environmental monitoring data, their relationship with effect indicators or effects in general, improvement with respect to old biomarkers, reference values. Twenty two NBEs were identified: 14 elements and chemical compounds as such or as metabolites, 4 examples of mixtures, 3 of new matrices, one of speciation. Among the others, aspects such as interest in requiring NBE, quality assurance, availability, cost-benefit ratio were discussed. We conclude that development of this specific field of research appears to be a crucial point for future improvement in risk assessment and health surveillance procedures.

Animals↗
PubMedDate not supplied

[The significance of enviromental and biological monitoring in workers employed in service stations after the elimitation of tetraethyl lead from gasoline].

The chemical risk in service stations may be due to toxic compounds present in fuel (particularly benzene and additives) and to the emission of exhausts and fine particulate from vehicles. Owing to the elimination of lead (Pb) from fuel and to the necessity of lowering CO emission, several oxygenated additives have been added to fuel, in particular methyl-tert-butyl-ether (MTBE), whose toxic properties are at present under investigation. The introduction of reformulated gasoline (RFG) and the use of catalytic converters (with possible release of platinum (Pt) in the environment) may have modified the risks for workers employed in service stations. The paper shows data collected from 26 subjects (divided into three specific tasks, namely: fuel dispenser, "self-service" attendant and controller, and cashier) to estimate the actual chemical risk and to compare it with the previous data taken from literature. For this purpose, besides performing the usual medical surveillance, we measured the environmental concentrations of benzene, MTBE and formaldehyde, the urinary levels of benzene metabolites S-phenylmercapturic acid (S-PMA) and t,t-muconic acid (MA) and of unmodified MTBE, and the blood concentrations of Pb and Pt for each subject. Mean values of these compounds were, respectively: 38.81 microg/m3; 174.04 microg/m3; 10.38 microg/m3; 2.36 microg/g creatinine; 96.57 microg/g creatinine; 1.41 microg/L; 7.00 microg/100 mL; 0.0738 ng/ml. The above values were much lower than the corresponding limit values reported by ACGIH and DFG. In particular, after the introduction of vapour recycle systems and the widespread use of "self-service" systems, airborne benzene concentration dropped from 300/400 microg/m3 to lower than 100 microg/m3, without noticeable increasing of exposure to formaldehyde. The disappearing of Pb from gasoline leads to a progressive lowering of its blood levels, while the possible risks due to the very low amounts of Pt released from catalytic converters have still to be defined exactly. Taken all in all, our results seem to indicate that, after the elimination of tetraethyl lead, the chemical risk for workers employed in service stations is now lower than in the past.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Intestinal intussusception: easy diagnosis in the 21st Century? Outcome of five years experiences].

UNLABELLED: Intussusception is an entity well codify in pediatric surgery, with guidelines well defined since years in terms of imaging and procedures. MATERIAL: From January '99 to Dec. '03, 25 children were admitted to the Department of Pediatric Surgery of the Children's Hospital of Milan. All the aspects related to the pathology have been evaluated in the study. RESULTS: 25 patients have been studied. 23/25 presented severe pain, 19/25 normal bowel movements in the last 3 hours and in 9/25 a mass were detected at clinical examination.19/25 were submitted to laparotomy after failure of reduction through barium enema, and in 17/19 a manual reduction were performed. Only 2 patients required a bowel resection with primary anastomosis. The analysis of the delay of diagnosis, the delta-T between beginning of the symptoms and first medical evaluation was of 16,23 h. (3-72), and the delta-T between the first evaluation and diagnosis was 18,7 h. The interval between diagnosis and surgery was of 4,3. CONCLUSION: Authors believe that intussusception still represent a challenge for medical and surgical emergency team, supported by the data in literature. Imaging procedures must not be constricted in case of minimal suspicions of intestinal intussusception.

Child↗
PubMedDate not supplied

[Our experience in the subject of gastroesophageal reflux disease].

From January 1st, 1983 to March 31st, 1988, 66 children with GER were tested with barium esophagogram, esophageal pH monitoring and esophagoscopy. A medical therapy was given to 49 children and 46 had a clinical improvement; 13 were operated. Early diagnosis is very important to prevent complications: in fact our data show that older children have the worst complications, while infants with GER and severe esophageal pH monitoring have only I-II grade esophagitis.

Adolescent↗
PubMedDate not supplied

[HPLC determination of low concentrations of benzene].

A laboratory study, using generated atmosphere containing 0.14/23.3 mg/m3 of Benzene, was conducted to adapt an existing industrial hygiene monitoring method for measuring low concentrations of Benzene. This method was developed to determine concentrations of Benzene in the ambient air and around refinery/petrochemical plant. The air sample is collected on a diffusive personal sampler (Zambelli-TK 200) and analyzed by desorption with a mixture of methylene chloride and ethyl acetate followed by quantification using HPLC-Fluorescence detector. The method used did not detect aliphatic or alicyclic hydrocarbons. The HPLC-Fluorescence method is compared with a gas chromatographic method that uses capillary column and flame ionization detection after a collection of air sample on a Carbotrap 100 tube and following thermal desorption.

Air Pollutants↗
PubMedDate not supplied

[Congenital segmental dilatations of the intestines].

Four cases of this rare disease are presented and the reports of the literature are reviewed. The anamnestic, clinical, roentgenologic and anatomo-pathologic findings are discussed mainly in view of aetiopathogenesis and differential diagnosis with numerous congenital obstructive diseases.

Child↗