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Biomedical subjects

M Bonati

Publications and source records attributed to M Bonati.

At least 55 records · Page 3Linked to original sources
PubMed1997

Survival at nine neonatal intensive care units in São Paulo, Brazil. Paulista Collaborative Group on Neonatal Care.

A collaborative effort to assess factors affecting newborn survival at neonatal intensive care units (NICUs) was made by studying 1948 newborns admitted to nine NICUs in the city of São Paulo between 1 June and 30 November 1991. Data on the study subjects were obtained using a standardized form. This was the first activity undertaken by a network of neonatologists (the Paulista Collaborative Group on Neonatal Care) dedicated to jointly evaluating and improving neonatal care in that city. The study results showed an overall mortality of 59 deaths per 1,000 neonates, with survival improving as gestational age and birthweight rose. Other variables significantly affecting survival were a poor maternal obstetric history (a previous stillbirth or neonatal death, or two or more spontaneous abortions); birth asphyxia (Apgar at 5 minutes < 7); respiratory distress syndrome; severe infections; and major malformations. However, multiple logistic regression analysis showed that the rates of neonatal survival in the nine NICUs differed even when these factors were considered. Potential sources of this variability included undetermined population differences in neonatal disease severity and medical care. These results suggest a need for greater efforts to identify and reduce risk factors associated with neonatal mortality, and to adequately evaluate the medical care provided in NICUs. Within this context, the collaborative network of neonatologists established in São Paulo provides a sound organizational structure for evaluating and improving the effectiveness of neonatal care.

Apgar Score↗
PubMed1996

Placental transfer of valproic acid after liposome encapsulation during in vitro human placenta perfusion.

Valproic acid (VPA) is an antiepileptic drug that crosses the placenta freely. Because its use in pregnancy is associated with an increased incidence of fetal malformation and toxic effects, this study was designed to check whether the placental transfer of VPA entrapped in liposomes was reduced. VPA was encapsulated in dehydrated-rehydrated liposomes prepared with equimolar concentrations of phosphatidylcholine, cholesterol and alpha-tocopherol. Liposomes were analyzed for their physicochemical characteristics, their stability and percentage of encapsulation of VPA. A system of dual perfusion of an isolated lobule of term human placenta was used. Six placentas were perfused with liposome-VPA and six with free VPA for 180 min using recirculating maternal and fetal circuits. The rate of transfer and time to reach equilibrium of VPA was similar in placentas perfused with free VPA and with liposome-encapsulated VPA. Liposomes significantly reduced VPA transplacental transfer and placental uptake. This was confirmed by FMM at equilibrium, that was 0.548 +/- 0.058 in free VPA and 0.393 +/- 0.075 in liposome-VPA. The ratio of fetal to maternal concentrations at equilibrium was 0.90 +/- 0.10 in controls and 0.66 +/- 0.13 in liposome-VPA. The amount of VPA recovered in fetal circulation and in placental tissue were 28 +/- 4 and 7 +/- 3% in controls and 19 +/- 4 and 3 +/- 2% in liposome-VPA. In conclusion, our data indicate that encapsulating VPA in liposomes significantly reduces the fetal amount and exposure, and further in vitro and in vivo investigations are needed to optimize the use of liposomes, particularly in pregnancy.

Anticonvulsants↗
PubMed1995

Parental and primary care physicians' views on the management of chronic diseases: a study in Italy. The Italian Collaborative Group on Paediatric Chronic Diseases.

A survey on the burden and quality of care and the parental and primary care physicians' views on management of eight chronic illnesses and disabilities was conducted from 1990 to 1993. Data were collected on 993 children and adolescents from family interviews and physicians' postal questionnaires. Approximately 70% of patients used two or more services for care management and 149 children were treated outside their region. Only 36% of the physicians were case managers and half of these agreed that better communication with other care providers could facilitate their role. A wide difference in parental satisfaction was found between medical and disabling conditions. Approximately 90% of the parents expressed satisfaction with care for children with coeliac disease (112/120), asthma (80/89) and diabetes (98/111), whereas approximately one-third of parents of children with cerebral palsy and Down's syndrome were dissatisfied (88/242 and 72/189, respectively). Primary care physicians expressed similar satisfaction with case management. Distance from hospital, the need for more information on disease management and financial aid were the sources of greatest dissatisfaction. Children with disabling diseases had more problems integrating at school than children with other chronic disorders. Closer interaction between health services, providers and families is necessary to manage the needs of disabled (Italian) children better.

Absenteeism↗
PubMed1995

Subgroups of Graves' patients identified on the basis of the biochemical activities of their immunoglobulins.

Graves' patient immunoglobulins (IgG) are known to activate adenylyl cyclase. Recently, we have shown that they also stimulate phospholipase A2 (PLA2). Here we analyze the relationship of these biochemical activities of Graves' IgG to thyroid growth in vitro ([3H]thymidine incorporation) and in vivo (patient goiter size) as well as to clinical indicators of severity of the disease, such as ophthalmopathy, T3 levels, T3/T4 molar ratio, and TSH binding-inhibiting IgG activity. A cluster analysis of the biochemical parameters referring to the whole population (158 subjects) led to the identification of 4 subgroups of Graves' patients based on the different capabilities of IgG to stimulate adenylyl cyclase, PLA2, and [3H]thymidine incorporation. Importantly, a trend of increasing severity of the disease from group 1 to group 4 could be identified. In particular, patients in group 4 (characterized by elevated stimulation of adenylyl cyclase, PLA2, and [3H]thymidine incorporation) had the largest goiter, highest serum concentration of T3, highest T3/T4 molar ratio, and highest prevalence of ophthalmopathy. These results indicate that Graves' IgG induce thyroid growth by stimulating both adenylyl cyclase and PLA2, and suggest a method for the subclassification of Graves' patients that identifies four groups with different degrees of severity of the disease. Moreover, this classification might lead to the targeted use of a novel therapeutic approach based on the inhibition of PLA2 and arachidonic acid metabolism.

Adult↗
PubMed1994

Epidemiologic evaluation of drug use in children.

To define and evaluate the attention devoted to drug use in children rather than just review existing reviews, the present attempt is to seek out the primary sources of information in the hope that this effort would not only yield more reliable data, but would also provide an opportunity for reconsidering methodological problems which are possibly even more important. An English-language literature search for drug use in children from 1988 was conducted on two databases and a manual search was made of the literature, with a check of references quoted in main original articles, reviews and textbooks. The review was then organized in two main sections: an overall evaluation of the recent literature concerning drug use in children; the epidemiological profile of drug exposure as described cumulatively by the drug-utilization studies. A substantial lack of systematic attention to this area of drug epidemiology was found: drug use in the children is a 'hidden' reality in the literature; the wealth of methodologic developments that have taken place in the general field of drug use monitoring has scantly reached children. Children can be considered still "methodologic orphans" with respect to the transferable knowledge on the benefit/risk profile of therapies they receive. A network has to be developed to monitor clinical problems, including drug use, as part of an "audit" of the overall management of children.

Adolescent↗
PubMed1994

Episodic changes of serum procollagen type I carboxy-terminal propeptide levels in fertile and postmenopausal women.

The aim of the present study was to optimize the use of serum procollagen type I carboxy-terminal propeptide (PICP) as a possible marker of postmenopausal-376lted changes of bone metabolism. Postmenopausal (n = 20) and healthy fertile young (n = 4) women were studied after informed consent. The postmenopausal women were subdivided in 4 groups: (1) nontreated; (2) treated with estrogen-progestogen replacement therapy; (3) treated with calcitonin, or (4) with kidney or liver diseases. Blood samples were collected at 15-min time intervals for 4, 6 or 8 h. Serum concentration of PICP was measured by radioimmunoassay, in duplicate at two different dilutions. In postmenopausal women mean +/- SEM serum PICP levels were slightly but nonsignificantly higher than in fertile women. Serum PICP levels in estrogen-progestogen or calcitonin-treated women were significantly lower than in non-treated postmenopausal women. Episodic changes of circulating PICP level were observed in fertile and postmenopausal women. The pulses of serum PICP levels did not show significant differences among the groups of women studied. The present study showed that the measurement of serum PICP levels is a useful marker for investigating the changes of bone metabolism. In particular, low PICP levels in postmenopausal women under steroid hormone or calcitonin treatment in part reflect the changes of bone turnover. The pulses of serum PICP levels during a time interval suggest that collagen metabolism in women undergoes a rapid turnover.

Adult↗
PubMed1994

Mefloquine transfer during in vitro human placenta perfusion.

Mefloquine (MQ) is highly effective in the treatment and prophylaxis of chloroquine-resistant Plasmodium falciparum malaria. Despite its widespread use, scant information is available on the transplacental profile and time course of MQ transfer across the human placenta. Six human placentas were perfused with human plasma for 180 min using recirculating maternal and fetal circuits. The viability of the placental preparation was validated measuring oxygen and carbon dioxide balance and the rates of glucose consumption and lactate production. MQ data were compared with antipyrine, a routine marker in placental perfusions. Disappearance of MQ from the maternal circulation after a dose of 0.8 mg/liter was biexponential, with a first, rapid distribution phase into the placental tissue. The apparent first-order distribution (lambda 1) and elimination (lambda z) rate constants were 0.043 +/- 0.014 min-1 and 0.020 +/- 0.007 min-1, respectively. The fetomaternal mass ratio became constant (0.46 +/- 0.07) after 120 min of perfusion and the time needed to achieve equal concentrations on both sides of the placenta was 178 +/- 31 min. MQ clearance was 3.36 +/- 0.38 ml/min. About 40% of the MQ maternal dose was recovered in tissue and 11% appeared in the fetal circulation. These data provide support for using MQ in pregnant women for both the treatment and prophylaxis of Plasmodium malaria, although comparison with other compounds are needed.

Antipyrine↗
PubMed1993

Simultaneous determination of retinol, alpha-tocopherol and retinyl palmitate in plasma of premature newborns by reversed-phase high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of retinol, alpha-tocopherol and retinyl palmitate in plasma. Plasma containing an internal standard (tocol) was deproteinized with ethanol, then extracted with n-hexane. The organic layer was removed and evaporated under a nitrogen stream, and chromatographed on a reversed-phase RP-18 column using a water/acetonitrile-ethyl acetate/2-propanol gradient solvent system over 15 min at 305 nm. The recovery exceeded 93%. The detection limit was 0.1 microgram/ml for retinol, 1.3 micrograms/ml for alpha-tocopherol and 0.95 micrograms/ml for retinyl palmitate. The reproducibility, precision (expressed as coefficients of variation) and accuracy were less than 8% for all analytes. The small sample requirement, the simplicity of extraction, the short run-time and the good reproducibility make this procedure particularly useful for monitoring retinol and alpha-tocopherol supplementation in premature newborns.

Chromatography, High Pressure Liquid↗
PubMed1993

Use of psychotropic drugs during pregnancy. A report of the international co-operative drug use in pregnancy (DUP) study. Collaborative Group on Drug Use in Pregnancy (CGDUP).

Drug Use in Pregnancy (DUP) is an international epidemiological survey of drug use in pregnancy conducted from 1988 to 1990 in 148 maternity wards, representing the general delivery practices of 22 countries. Data on exposure of pregnant women to psychotropic drugs, the indications for their use and their correlation with maternal characteristics are reported. Of the 14,778 women interviewed, 520 (3.5%) reported 562 courses of psychotropic drugs. Benzodiazepines (BDZ) accounted for the greatest number of the exposures (444/520 women); neuroleptics and antidepressants were prescribed to tiny minorities of women (83 and 17 respectively), mostly in those few countries were the overall prevalence of use of those drugs was highest. Throughout the majority of the other countries, overall rates were in the low range and were rather heterogeneous. With the exception of small clusters of "unexpected" indications, prescriptions of BDZ were found to be consistent with the target symptoms of anxiety and insomnia; chronic use was reported in 31/444 women. The study was not targeted to the detection of malformations; no suspected clustering was found, however, among the 130 women exposed during the first trimester of pregnancy. The collaborative network now established provides a framework for periodically replicated surveillance to monitor the evolution of this field of knowledge and care in order to provide reliable information for women and society.

Adolescent↗
PubMed1993

Tetany and rhabdomyolysis due to surreptitious furosemide--importance of magnesium supplementation.

Diuretics may induce hypokalemia, hypocalcemia and hypomagnesemia. While severe hypokalemia may cause muscle weakness, severe hypomagnesemia is associated with muscle spasms and tetany which cannot be corrected by potassium and calcium supplementation alone (1,2). Surreptitious diuretic ingestion has been described, mainly in women who are concerned that they are obese or edematous. Symptomatic hypokalemia has been reported in such patients (3-7) and in one case hypocalcemia was observed (8), but the effects of magnesium depletion were not noted in these patients.

Adult↗