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Biomedical subjects

G Serra

Publications and source records attributed to G Serra.

At least 55 records · Page 3Linked to original sources

[Proposal for computer-assisted preparation of parenteral nutrition solutions in neonatal intensive care].

A computer software package was developed to perform the calculation involved in compounding total and partial parenteral nutrition for low-birth-weight and sick newborns. The program requires a minimum of user input and is menu-driven. The flexibility of the algorithm has been increased to a considerable degree. The program calculates the overall balance of fluids, nutrients, calories, electrolytes and minerals. It allows for the possibility of total parenteral nutrition and simultaneous oral feeding. Nutrient amounts per Kg per day and combination of enteral food and parenteral infusions can be completely changed by the operator. In our experience computer-assisted system was more efficient than a manual system and the possibility of computational error was reduced.

Humans↗

[Neonatal hemochromatosis: significance of early identification].

Neonatal hemochromatosis (NH) is a rare clinical-pathologic entity defined by severe neonatal liver failure (NLF) of intrauterine onset associated with extrahepatic siderosis that spares reticuloendothelial elements. Whether this entity is the result of a distinct disease process or is the pathologic end-result of many other forms of NLF remains to be assessed. Death from multisystem organ failure usually occurs in the first few days or weeks of life. We report two sisters with neonatal hemochromatosis with different outcome. The first died at 21 days of life for multiorgan failure and sepsis. The second was diagnosed and treated very early by aggressive support with fresh-frozen plasma, packed red cells, platelets, coagulation factors, diuretics, and pressors, and she is well at 2-year-follow-up. The few therapeutic options are discussed. In general, few patients survived NH. Among patients treated only by medical approachs and that did not undergo orthotopic liver transplantation (OLTX), favorable outcome is only very rarely reported. For management of NH infants early recognition of the disease is critical. Our experience seems to suggest that as early is the start of treatment as high is the possibility of survival. At this moment very early aggressive supportive treatment should appear to be the most useful approach to stabilize the patient hoping in spontaneous liver recovery, or, in turn, to permit OLTX before septic complications bring to clinical decline.

Female↗

Elevated S100 blood level as an early indicator of intraventricular hemorrhage in preterm infants. Correlation with cerebral Doppler velocimetry.

The aim of this study was to assess the use of S100 protein in blood as a means of identifying preterm infants at risk of intraventricular hemorrhage. In 25 preterm newborns, S100 blood concentrations were measured by an immunoradiometric assay during the first 48 h. Cerebral Doppler velocimetry waveform patterns were also tested at the time the blood sample was taken, when clinical and cerebral ultrasound scanning were still normal. Of the 25 newborns studied, 14 were controls and 11 developed intraventricular hemorrhage as revealed by ultrasound scanning more than 72 h after birth, and clinically confirmed by neurological examination on the seventh day of follow-up. S100 blood concentrations were significantly higher (P<0.002) in infants with intraventricular hemorrhage than in control infants and also correlated significantly (r=0.81, P<0.003) with the grade of hemorrhage. A significant correlation (r=0.70, P<0.05) between the S100 blood concentration and the middle cerebral artery pulsatility index was also observed. The present data show that S100 blood concentrations offer a measurable parameter of brain lesion in preterm infants before a radiological assessment of hemorrhage can be performed, when clinical symptoms may be silent and preventive/therapeutic action could be especially useful.

Blood Flow Velocity↗

Visuospatial attention in myopia.

Four experiments were conducted to ascertain whether myopia is associated with deficits of visuospatial attention. In myopic and emmetropic control subjects, we studied: (1) automatic and voluntary orienting of attention, (2) focusing of attention and (3) performance on a visual search task. The results indicated that automatic orienting was defective in myopics and their performance in visual search was less efficient than that of controls. By contrast, myopics showed no deficits in voluntary orienting and in focusing.

Analysis of Variance↗

Diagnosis of neonatal hemochromatosis with MR imaging and duplex Doppler sonography.

Neonatal hemochromatosis is a rare congenital disorder which affects both fetuses and newborns. It is characterized by hepatocellular failure, often appearing on the first day of life in the form of coagulopathy, hypoalbuminemia, hypoglycemia, and jaundice. Most of the affected infants die early in life, and definitive diagnosis has often been made only by post-mortem evaluation. With the help of MRI, plus increasing awareness of the disorder, diagnosis is now often made early, even in utero. Duplex Doppler sonography does not provide information on siderosis but shows abnormalities in the liver or blood-flow patterns associated with liver disease.

Biopsy↗

Cerebral blood-flow monitor for use in neonatal intensive care units.

The implementation of a real-time multichannel system for monitoring cerebral blood-flow is described. The instrument relies on a completely modular architecture and is based on the principle of measuring the electrical impedance between a number of periodically sensed electrode pairs positioned around the subject's head. The whole setup is controlled by a host computer that performs several functions, such as real-time acquisition, analysis, display and data logging. Two operating options can be chosen by the user: a normal mode that allows continuous monitoring and a triggered mode in which the measurement cycle is automatically started by the occurrence of a preset condition in some other circulatory signal, e.g. the permanently available ECG signal. The design is considerably user-friendly and embodies a number of special safety precautions to take account of the peculiar condition of patients, usually newborn infants hospitalized in intensive care units.

Cerebrovascular Circulation↗

Dizocilpine prevents the enhanced locomotor response to quinpirole induced by repeated electroconvulsive shock.

Repeated administration of electroconvulsive shock, as expected, potentiated the locomotor stimulant response to quinpirole (0.3 mg/kg s.c.), a dopamine D2-like receptor agonist. Chronic, but not acute, treatment with the NMDA receptor non-competitive antagonist dizocilpine (0.3 mg/kg i.p.) prevented electroconvulsive shock-induced potentiation of quinpirole locomotor response. These results suggest that NMDA receptor activation is necessary for the development of supersensitivity to dopamine receptor agonists produced by repeated electroconvulsive shock. The relevance of this observation in regard to the mechanism of electroconvulsive shock therapeutic effect is discussed.

Animals↗

Behavioural sensitization of mesolimbic dopamine D2 receptors in chronic fluoxetine-treated rats.

A common action of chronic antidepressant treatments is the potentiation of dopaminergic transmission in the limbic system. We now report that chronic, but not acute, treatment with fluoxetine (2.5 mg/kg by intragastric gavage once a day for 21 days) potentiates the locomotor stimulant effect of quinpirole, a selective dopamine D2/D3 receptor agonist. However, neither quinpirole-induced stereotypies nor the sedative effects elicited by low doses of this dopamine receptor agonist are influenced by chronic fluoxetine. These results suggest that fluoxetine, as well as classical antidepressants, sensitize postsynaptic dopamine D2/D3 receptors in the mesolimbic system.

Animals↗

Severe complex I deficiency in a case of neonatal-onset lactic acidosis and fatal liver failure.

We report a newborn admitted to our service on the 2nd day of life because of hypotonia and metabolic acidosis. A progressive hepatocellular dysfunction dominated the clinical picture and the patient died at 13 months of age because of severe hepatic failure. Persistent lactic acidosis, high ketone bodies levels and high-normal lactate/pyruvate and 3-hydroxybutyrate/acetoacetate molar ratios in plasma were found. Investigation of a liver biopsy revealed low activities of all the mitochondrial respiratory chain enzymes but in particular a marked decrease of complex I (NADH cytochrome c reductase) activity. All respiratory chain enzyme activities were normal in cultured skin fibroblasts. Mitochondrial DNA analysis failed to detect any major rearrangements. Although only a few cases have been reported so far, it is becoming clear that liver should be considered as one of the organs involved in oxidative phosphorylation disorders. The finding of unexplained progressive liver failure with poor neurological conditions, lactic acidaemia and ketonuria strongly warrants investigation for a respiratory chain disorder. Moreover, the finding of normal respiratory enzyme activities in a tissue other than liver does not rule out the existence of an oxidative phosphorylation disorder in patients with hepatocellular disease of unexplained origin.

Acidosis, Lactic↗

Fatty acid composition of human milk in Italy.

The fatty acid composition of breast milk from 20 Italian women, delivering at term and on ad libitum diets, was analyzed with high-resolution gas chromatography. Milk samples were collected twice a day, on the 1st, 4th, 7th, 14th, 21st and 28th day after colostrum appearance. No significant differences were detected between the two daily samples. During the maturation process a significant reduction in long-chain polyunsaturated fatty acids of the n-6 series (p = 0.002) and n-3 series (p = 0.005) was recorded, particularly in arachidonic acid (p = 0.035), docosatetraenoic acid (p = 0.035) and docosahexaenoic acid (p = 0.032). The linoleic acid/n-6 and alpha-linolenic acid/n-3 ratios increased (p = 0.024 and p = 0.037), while the docosatetraenoic/docosahexaenoic acid ratio decreased (p = 0.032). The fatty acid composition of mature milk was the following: saturated 45.50%; unsaturated 54.51%; monounsaturated 42.69%; polyunsaturated 11.82%; long-chain polyunsaturated 1.27%; linoleic acid 9.79%, and alpha-linolenic acid 0.36%. The fatty acid composition of milk collected from Italian women appears similar to that of women in other southern European countries and, therefore, could reflect dietary habits.

Adult↗

Role of D1 and alpha1 receptors in the enhanced locomotor response to dopamine D2-like receptor stimulation induced by repeated electroconvulsive shock.

We previously reported that, in rats chronically treated with the antidepressant drug imipramine, the enhanced locomotor response to the D2-like receptor agonist quinpirole became less sensitive to the inhibitory effect of the D1 receptor antagonist SCH 23390 and more sensitive to the inhibitory effect of the alpha1 receptor antagonist prazosin. In this study, we show that in electroconvulsive shock-treated rats these antagonists behave in the opposite manner to that observed in imipramine-treated rats, with SCH 23390 being highly effective and prazosin ineffective in antagonizing the locomotor response to quinpirole. The possibility that these differences may reflect some of the clinical characteristics of these antidepressant treatments is discussed.

Animals↗

Biochemical and electrophysiological effects of 7-OH-DPAT on the mesolimbic dopaminergic system.

Systemic administration of the putative selective D3 receptor agonist 7-hydroxy-2-(N,N-di-n-propylamino)tetralin (7-OH-DPAT) consistently decreased extracellular dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the nucleus accumbens and dopaminergic neuronal activity in the ventral tegmental area. 7-OH-DPAT inhibited dopamine release in the nucleus accumbens also when locally perfused through the dialysis probe. The results suggest the possibility that stimulation of dopamine D3 receptors with 7-OH-DPAT mimic biochemical and electrophysiological actions previously ascribed to D2 autoreceptor stimulation; however the lack of selective D3 antagonist precludes any firm conclusion in this sense.

Animals↗