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Biomedical subjects

G P Donzelli

Publications and source records attributed to G P Donzelli.

At least 19 recordsLinked to original sources
PubMed2002

[Esophageal atresia with distal tracheo-esophageal fistula. Evolution of the treatment in the period of 1955-2000 at the Anna Meyer Children's Hospital of Florence].

BACKGROUND: Over the past decades the esophageal atresia (EA) has represented the greatest challenging malformation encountered by the pediatric surgeon. Since then, there have been considerable advancements in the treatment of EA. In this paper the experience at the "Anna Meyer Children's Hospital of Florence" in regards to the surgical treatment of the EA from 1955 to present day is reported, so that the analysis of the various medical and surgical choices followed by the authors and their predecessors in this long period, can be an important learning tool for the EA management. METHODS: From 1955 to 2000, 223 newborns affected by EA with tracheoesophageal fistula (TEF) have been operated on out of a total of 250 cases of EA. Our experience has been subdivided into periods on the basis of homogeneous medical and surgical treatment adopted in that determined time. We have analyzed particularly the data of the last period 1995-2000, where there has been a well standardized protocol of treatment from the medical, surgical and intensive care points of view. RESULTS: The mortality rate has decreased from 44.8 to 3.4% with a significant reduction (p<0.001) between the years 1979-1983 and 1984-2000, due to the introduction of a perioperative treatment in the newborn intensive care unit. Moreover, a significant correlation (p<0.05) has been shown between low birthweight and associated malformations, two risk factors that however do not negatively influence the results of the treatment in the last period 1995-2000. CONCLUSIONS: A full integration between the surgeon and neonatologist is necessary in order to guarantee a good result. The risk connected to EA is not as much the surgical procedure as the presence or absence of associate malformations that are undetected in the prenatal diagnosis. It is suggested that, in order to further reduce the mortality and morbidity rate after EA correction, the number of prenatal diagnoses should be increased.

Esophageal Atresia↗
PubMed2000

[Percutaneous catheterization of the newborn: control of pain and easy insertion with brachial plexus block].

The increasingly prolonged survival of extremely premature infants who required long-term venous access means that this is often a major problem in modern neonatal unit. The insertion of central venous catheters has become an established practice and the development of silastic catheters inserted by newer percutaneous techniques through a peripheral vein is, now, the choice technique in awake non sedated critically-ill infants. Such technique has an high percentage of failure. We have undertaken a retrospective study to determine whether the brachial plexus block performed via the axillary approach could improve the success rate for the insertion of central venous catheter from a peripheral vein of the upper limb in infants minimizing physical and emotional stress to the neonates. Data from 157 low and very low birthweight infants, submitted or not submitted to the axillary block, were examined. The failure rate for the insertion of the central venous catheter was 27% without using the brachial plexus block vs. 9% in the patients that underwent the block. Use of the brachial plexus block via the axillary route, although retrospectively evaluated, improves the success rate and the pain control for the insertion of small diameter central venous silicon catheter from a peripheral vein of the upper limb in low and very low birthweight infants.

Brachial Plexus↗
PubMed1998

Bilirubin photoisomerization products in serum and urine from a Crigler-Najjar type I patient treated by phototherapy.

The relative compositions of the photoisomers of bilirubin-1X alpha (4Z, 15Z-bilirubin) in serum and urine of a patient with Crigler-Najjar type I syndrome treated by phototherapy are reported. High-performance liquid chromatography analysis reveals the presence of high serum levels of the configurational bilirubin photoisomer (4Z,15E-bilirubin) before the beginning of phototherapy (between 12 and 16% of the total bilirubin). The configurational photoisomer value increases during phototherapy with blue fluorescent lamps up to a photoequilibrium of about 25%, similar to that obtained in a bilirubin solution in vitro irradiated by the same lamps. This evidence suggests an inefficient serum excretion of the 4Z,15E-bilirubin. Indeed, its average half-life in serum of the Crigler-Najjar patient is found to be about 8 h. No detectable traces of the bilirubin structural isomer, lumirubin, are found in the serum. On the other hand, lumirubin represents the dominant bilirubin isomer excreted in the urine, as both 15Z and 15E configurations. Smaller amounts of 4Z,15E-bilirubin, 4E,15Z-bilirubin and native 4Z,15Z-bilirubin are observed in urine. The presence in urine of 4Z,15Z-bilirubin is probably due to a fast reversion of the configurational photoisomers to their native form. The half-life of the configurational photoisomers in urine kept at 38 degrees C is found to be of the order of a few minutes. Our study indicates that in Crigler-Najjar type I patients, mechanisms exist to excrete all bilirubin photoisomers. The lumirubin pathway seems to contribute markedly to bilirubin excretion in the urine, as occurs in jaundiced babies under phototherapy. However, the contribution of configurational isomers cannot be neglected.

Adolescent↗
PubMed1997

Effect of pasteurization and storage on some components of pooled human milk.

Pooled human milk was subjected to Holder pasteurization and storage at -20 degrees C up to 90 days and examined for its content of fat and L-lactate and for lipid composition. This treatment reduced fats by 6% and L-lactate by at least 7%. In addition, pasteurization and storage induced triglyceride hydrolysis. The absolute amount of free fatty acids (FFAs) which was 0.5% after collection, doubled after pasteurization and rose even more after storage. Different FFA compositions were found by several authors using the same analytical method even for milk samples subjected to the same treatment. More detailed information on procedures must be given to explain the different results.

Adult↗
PubMed1996

Early-infantile galactosialidosis: clinical, biochemical, and molecular observations in a new patient.

Few patients with the early-infantile form of galactosialidosis have been described to date. Presented here is the first Italian case. Fetal hydrops was detected by ultrasound at week 24 of gestation. At birth, the infant presented with hypotonia, massive edema, a flattened coarse facies, telangiectasias, and hepatosplenomegaly, but no dysostosis multiplex. The patient died 72 days postpartum. Excessive sialyloligosaccharides in urine, as well as vacuolation of lymphocytes and eosinophilic granulocytes in peripheral blood, were indicative of a lysosomal storage disease. In the patient's fibroblasts, both alpha-neuraminidase and beta-galactosidase activities were severely reduced, and cathepsin A activity was < 1% of control levels, confirming the biochemical diagnosis of galactosialidosis. However, in contrast to previously reported early-infantile cases, a normal amount of protective protein/cathepsin A mRNA was detected on Northern blots. This mutant transcript was translated into a precursor protein that was not processed into the mature enzyme and lacked both protective and catalytic activities.

Carboxypeptidases↗
PubMed1996

Fibreoptic phototherapy in the management of jaundice in low birthweight neonates.

A fibreoptic phototherapy device has been compared with conventional white and special blue fluorescent phototherapy lamps to evaluate its efficacy in lowering serum bilirubin levels in low-birthweight neonates. Fibreoptic phototherapy was found to be as effective as white light and less effective than blue light, as assessed by (i) the bilirubin concentration after 24 h of phototherapy and at the end of phototherapy, (ii) the duration of phototherapy, (iii) the percentage daily decline rate and (iv) the overall percentage decline rate (p < 0.05). There were no failures of phototherapy and the need for re-exposure was low (4.7% of the total sample), with no difference between groups. The fibreoptic approach represents a promising way to aggregate synergically the most recent optical technologies and develop a modern, efficient and caring phototherapy system for low-birthweight infants.

Fiber Optic Technology↗
PubMed1994

Computerized cry analysis in infants affected by severe protein energy malnutrition.

A new method of computerized cry analysis has been utilized to evaluate the cries of infants affected by severe protein energy malnutrition. We studied 17 Kenian babies affected by severe malnutrition for more than four months (9 cases of marasmus and 8 of kwashiorkor) and a control group of 17 well-nourished babies. The cries of the malnourished children showed lower inter-utterance variability, formants' frequencies and cry score, assigned by the Infant Cry Modulation Assessment Scale. The melodic pattern was more often flat, rising or falling-rising, when compared to the cries of the well-nourished babies. We hypothesize that these differences reflect the state of brain damage associated with protein energy malnutrition. No differences were found between the cries of infants affected by marasmus and those affected by kwashiorkor, between the cries recorded before and after nutritional therapy and between the first cries of malnourished children who subsequently died during hospitalization and those of infants who survived.

Acoustics↗
PubMed1993

Quantum yield and skin filtering effects on the formation rate of lumirubin.

Photocyclization of bilirubin to lumirubin in the skin of jaundiced infants exposed to blue-green light irradiation is considered to be the most important process for bilirubin elimination from the organism. The quantum yield phi LR of the bilirubin-->lumirubin photoreaction has been recently measured and found to vary with the excitation wavelength, with a peak at about 520 nm. The quantum yield phi ZE for the strongly competing reversible configurational photoisomerization of bilirubin has also been recently shown to be wavelength dependent and to decrease significantly in the long-wavelength part of the absorption band of bilirubin. These new data are taken into account to model the bilirubin photochemistry in vivo by using a simplified skin optical model based on the Kubelka-Munk theory. The rate kappa LR of formation of lumirubin has been evaluated for the case of a four-layer skin and for monochromatic and narrow-band coloured fluorescent lamps. The effects of long-wavelength increase in phi LR, decrease in phi ZE and skin optical losses all combine to shift significantly the optimal rate of formation of lumirubin towards the green. These results suggest that a significant improvement in phototherapy might be obtained with the introduction of new lamps emitting in the blue-green spectral region between 490 and 510 nm.

Bilirubin↗
PubMed1989

Food allergy in preterm infants fed human milk.

In 80 preterms aged 9-24 months (mean age: 15.9) and in 80 sex- and age-matched full-terms the frequency of atopic diseases and of positive skin tests to 8 food and 6 inhalant allergens was determined. The two groups did not differ as to overall percentages of cutipositive subjects and patients with atopic diseases. In particular, frequencies of positive skin tests to foods and of atopic dermatitis (the peak prevalence of which occurs early in infancy) were similar in preterm (16.2 and 7.5%, respectively) and full-term (13.7 and 5.0%, respectively) infants. We suggest that preterm infants fed human milk are not at increased risk of developing food allergy and related diseases and that the absorption of antigens through the immature intestine does not seem to favor the development of an IgE sensitization to foods.

Animals↗
PubMed1988

Bilirubin photoconversion induced by monochromatic laser radiation. Comparison between aerobic and anaerobic experiments in vitro.

Structural and geometric photoisomerization of bilirubin bound to human serum albumin was investigated. Solutions were irradiated with monochromatic light emitted by an Ar ion laser, the 457.9, 488.0 and 514.5 nm wavelengths being selected. Photoproducts were separated and analysed by h.p.l.c. Visible-absorption spectra of pure ZZ-bilirubin, ZE-bilirubin and lumirubin in the eluent were registered in the 350-550 nm region by collecting single fractions by h.p.l.c. Wavelength-dependence of bilirubin photoconversion was studied within photoequilibrium and up to a large decrement of the total concentration. Experiments were performed in aerobic and anaerobic conditions in order to assess the contribution of the photo-oxidation to the overall process. The presence of O2 was found to increase the rate of bilirubin degradation and unexpectedly to favour lumirubin production. The ability of 514.5 nm irradiation to induce bilirubin cyclization was definitively confirmed.

Bilirubin↗
PubMed1987

Phototherapy in the management of neonatal hyperbilirubinemia: efficacy with light sources emitting more than 500 nanometers.

The clinical action of green fluorescent lamps, properly filtered to remove wavelengths of less than 500 nm, was investigated in a group of 23 newborns with different initial serum bilirubin concentrations. The serum bilirubin levels were measured at 6, 12, 24, and 48 hours after the beginning of phototherapy. These results are compared with those obtained, under the same experimental conditions, in a group exposed to commercial green lamps. Similar bilirubin decline rates were observed in the two experiments. In general, these data confirm the satisfactory clinical efficacy of the green light in phototherapy and prove, in particular, that the blue component present in the emission spectrum of the commercial green lamps has a negligible effect on the bilirubin degradation process.

Bilirubin↗
PubMed1986

Phototherapy for neonatal jaundice: clinical equivalence of fluorescent green and "special" blue lamps.

The relative efficacy of fluorescent green (Sylvania F20T12/G) and "special" blue (Westinghouse F20T12/BB) lamps in the phototherapy of jaundiced neonates was investigated. Two groups of low birth weight infants with a mean gestational age of 35 weeks and mean birth weight of 1930 gm, who developed hyperbilirubinemia within the first 5 days of life, were given green or blue lamp phototherapy under the same irradiation conditions. No statistically significant difference in plasma bilirubin concentrations was found between the two groups after 24 or 48 hours of treatment. Because recent measurements indicate that green lamps are much less efficient than special blue lamps for the production of Z, E isomers of bilirubin in vitro and in vivo, the clinical equivalence of these two types of lamps seems to support the hypothesis that production of structural photoisomers of bilirubin is the main mechanism of phototherapy in humans. Therefore, fluorescent green lamps provide an alternative to special blue lamps for treatment of neonatal hyperbilirubinemia.

Bilirubin↗
PubMed1983

Green light in phototherapy.

Photodegradation of bilirubin in vivo has been investigated by using green fluorescent sources according to the suggestions obtained in a previous study in vitro. Two groups of 50 jaundiced low-birth-weight infants were exposed to fluorescent light in phototherapy units under similar irradiant conditions. One group was exposed for 24 h to standard green tubes, the other, to daylight lamps. Newborns of the two groups were similar for gestational age, birthweight, and initial bilirubin concentration. A greater decrease in the serum concentration of bilirubin was found in subjects exposed to the green light when compared with infants exposed to daylight lamps. The use of green light is strongly suggested instead of the white, blue, and special blue lamps, because of the real efficiency, power and range of wave lengths.

Bilirubin↗