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Biomedical subjects

A Rinaldi

Publications and source records attributed to A Rinaldi.

At least 19 recordsLinked to original sources
PubMed1992

[Transesophageal echo-Doppler in children: the importance of the exact measurement of the aortic diameter and its variations over time for estimating the aortic output].

The purpose of the study was to evaluate a new non invasive system of hemodynamic monitoring. The aortic systolic, diastolic and mean diameter have been measured with eco-TM and the aortic blood flow with pulsed Doppler, in order to obtain the aortic output. The aortic systolic diameter and the derived aortic output were then compared to the corresponding values obtained with CT. Ten healthy children were asked to be explored with CT under general anaesthesia and an oesophageal probe was positioned. The mean aortic diameter value was 7.18 +/- 0.91 mm. The systolic and diastolic aortic diameter was 7.87 +/- 0.91 mm and 6.65 +/- 1 mm respectively. The aortic systolic diameter measured with CT was 8.2 +/- 0.92 mm. Correlation analysis with aortic systolic diameter with eco TM as the dependent variable and aortic systolic diameter with CT as the independent variable revealed a highly significant correlation (r = 0.95, coefficient of determination 0.90). The mean percentage difference between systolic and diastolic diameter measured with TM eco scan was 15% with maximum variation 22% and minimum of 10% (p less than 0.003). The aortic blood flow calculated from the systolic aortic diameter was 29% higher than that obtained from diastolic aortic diameter. This would suggest that the correct measurement of the aortic diameter has to be considered in the final evaluation of aortic output especially in children in whom the elasticity of the aortic wall represents a major factor in determining fluctuations of aortic diameter.

Aorta↗
PubMed1991

Description of a home care service for cancer patients through quantitative indexes of evaluation.

Home care (HC) was created and developed in Romagna, as in other parts of Italy, thanks to the endeavor of a private institution, the "Istituto Oncologico Romagnolo". The care is gratis to advanced cancer patients and is based on the palliative philosophy of treatment of the symptoms and the person within the framework of continuity of care permitted by the oncologic approach. To evaluate the intensiveness of the operation in terms of medical and nursing care by means of quantitative indexes, we examined several variables which emerged from a retrospective analysis of our case study. The average duration of care of the 484 patients in the program as of 31 December 1990 was 84.1 days. Four hundred and twenty-three patients of the 484 (87.1% of the total) have died and 61 were still in the HC program at the time of this analysis. The 61 living patients were thus excluded from the descriptive analysis to give greater homogeneity to the study group. The average duration of care for the 423 decreased patients was 68.1 days. Out of a total of 28,759 days of HC for the entire group, the patients actually spent 23,534 days (81.8%) at home. The average duration of hospitalization was 13.5 days, and in 33.2% of the cases it was motivated by psychologic and family causes. The place of death was the home in 44.3% of the cases. A medical or nursing visit was made at the home every 1.4 days, and the average number of visits per patient was 39.0. Although none of the indexes alone can give overall indications of the intensiveness of a HC service, they may constitute a working proposal for the definition of the most objective criteria possible for the quantitative evaluation of such experiences.

Adolescent↗
PubMed1991

Premutation for the Martin-Bell syndrome analyzed in a large pedigree segregating also for G6PD-deficiency. I: A working hypothesis on the nature of the FRAX-mutations.

A large Sardinian family including 13 Martin-Bell syndrome (MBS) patients, several instances of normal transmitting males or females, and the G6PD-Mediterranean mutant segregating in some of its branches, has been thoroughly investigated with the hope of gaining further insight on the nature of the FRAX-mutation. All the MBS patients and the 15 obligate heterozygous women present in the pedigree could be traced back through their X-chromosome lineage to the same ancestress, who must have been heterozygous for a silent premutation at the FRAX-locus. This premutation appears to have turned into a true FRAX-mutation at least 9 times during the gametogenesis of the ancestress' X-related descendants of whom four are males. This finding alone suggests that the transition from the FRAX premutation to the true mutation can be the result of intra- as well as interchromosomal events. This conclusion is supported by the additional observation that the genetic phase between the FRAX and the G6PD loci remained unaltered when the transition occurred in a repulsion double heterozygote for the premutation and the G6PD-Mediterranean mutant. The data described are compatible with the hypothesis that MBS patients and normal transmitting males are, respectively, hemizygous for deletion or duplication products generated by aberrant recombination events at a highly recombinogenic site of the region Xq27-Xqter. The overall message stemming from this report is that no firm conclusion can be drawn on the genetic linkage between the FRAX-locus and other markers of this region until the nature of the FRAX-mutations and the mechanism of their occurrence are fully understood.

Adult↗
PubMed1991

DNA methylase from Pisum sativum.

DNA methylase activity was detected in nuclei from pea shoots. The enzyme can only be extracted by low-salt treatment if the nuclei are pretreated with micrococcal nuclease. Only a single enzyme was detected, and it was purified to a specific activity of 1620 units/mg of protein. It has an Mr of 160,000 on gel filtration and SDS/PAGE. Pea DNA methylase methylates cytosine in all four dinucleotides, and this is interpreted to show that it acts on CNG trinucleotides. Although it shows a strong preference for hemi-methylated double-stranded DNA, it is also capable of methylation de novo. Homologous DNA is the best natural substrate. In vitro the enzyme interacts with DNA to form a salt-resistant complex with DNA that is stable for at least 4 h.

Base Sequence↗
PubMed1991

Olive milling wastewater as a medium for growth of four Pleurotus species.

Four species of Pleurotus were adapted to grow on olive milling wastewater, and in certain conditions produced high yield of fruit bodies. Some biochemical transformations were observed in the olive milling wastewater owing to the growth of Pleurotus. In particular, the fungi actively excreted large amounts of laccase in the medium, and at the same time the concentration of phenolics and other toxic compounds significantly decreased, as revealed by HPLC analysis and toxicity tests on standard cultures of human cell lines.

Culture Media↗
PubMed1991

Microassay for DNA methyltransferase.

A microassay for DNA methylase is described which can detect activity in as few as 50 tissue culture cells. The cells are lysed and incubated for 2 h at 37 degrees C with 3 microCi high specific activity [3H]AdoMet and 0.5 microgram poly[d(I-C).d(I-C)] in a volume of 23 microliters. Ribonuclease is present during the assay and the product DNA is isolated by phenol extraction after protease digestion.

DNA Modification Methylases↗
PubMed1991

Social competence and positive and negative symptoms: a longitudinal study of children and adolescents at risk for schizophrenia and affective disorder.

OBJECTIVE: The authors longitudinally examined social competence and positive and negative symptoms in children at risk for schizophrenia, children at risk for affective disorder, and matched normal subjects. METHOD: The subjects were offspring of parents with schizophrenia or affective disorder and normal comparison subjects matched on age, sex, and socioeconomic status. Ratings of social competence (Premorbid Adjustment Scale), affective flattening and poverty of speech (Scale for the Assessment of Negative Symptoms), and positive formal thought disorder (Scale for the Assessment of Positive Symptoms) were based on videotaped psychiatric interviews conducted in childhood (N = 144), early adolescence (N = 127), and adolescence (N = 106). RESULTS: In childhood, there were no significant group differences. In early adolescence, the subjects at risk for schizophrenia had poorer social competence than those at risk for affective disorder and the normal subjects. In early adolescence, the subjects at risk for schizophrenia also had greater positive thought disorder than those at risk for affective disorder but did not differ significantly from the normal subjects; there were no differences in negative symptoms. In adolescence, the subjects at risk for schizophrenia had poorer social competence and greater positive and negative symptoms than the adolescents at risk for affective disorder and the normal subjects. CONCLUSIONS: During early adolescence and adolescence, poor social competence may be more characteristic of children at risk for schizophrenia than those at risk for affective disorder. Higher levels of positive and negative symptoms may also be specific to subjects at risk for schizophrenia, but only during adolescence.

Adolescent↗
PubMed1991

Decrease in DNA methylase activity during preimplantation development in the mouse.

During early mouse development, there are large-scale changes in DNA methylation. These changes may be due to the availability or stability of the enzyme, DNA methyltransferase (methylase), which is responsible for maintenance of DNA methylation. A microassay for methylase activity in preimplantation embryos shows that the level of maternally inherited enzyme is extremely high in the egg and that this activity is stable for the first three cleavage divisions. However, from the 8-cell to the blastocyst stage, there is a marked and absolute decrease in enzyme activity.

Animals↗
PubMed1990

DNA demethylation in erythroleukaemia cells.

Despite a fall in the proportion of CGs methylated, evidence has not been obtained for significant demethylation of prelabelled DNA when mouse erythroleukaemia cells are induced to differentiate. There is, however, a delay in the methylation of the DNA that is synthesised in the early period of induction, leading to its undermethylation by 30-50% and this may be a contributory cause of the observed fall in CG methylation.

Animals↗
PubMed1990

Eukaryotic DNA methylases and their use for in vitro methylation.

DNA methylases from mouse and pea have been purified and characterized. Both are high molecular mass enzymes that show greater activity with hemimethylated than unmethylated substrate DNA. Both methylate cytosines in CpG preferentially, but not exclusively and show similar kinetics of methylation, which makes it difficult to saturate all possible sites on the DNA, but procedures are described that circumvent this problem.

Animals↗
PubMed1990

Hemodynamic effects of decompressive craniectomy in cold induced brain oedema.

An experimental model of cold induced brain oedema was carried out in 7 albino rabbits by topic application of fluid N2 on the skull to examine the favourable effects of an appropriate tailored craniodural opening both on the whole brain perfusion and on the local dynamics of the oedematous fluid. After positioning the animals in a stereotactic frame the following parameters were recorded: ICP, carotid blood pressure and flow velocity, EEG, EKG. Histological staining with Evan's blue was utilized to check fluid extravasation. In all the animals the lesion was followed both by an ICP increase and a reduction in the carotid blood flow velocity so indicating an increase in the cerebrovascular resistances. In 4 animals the removal of the craniodural flap over the lesion dramatically reduced the ICP values and normalized the blood flow velocity. No difference in the Evan's blue distribution was noticed between the two groups of animals.

Animals↗
PubMed1990

[Noninvasive hemodynamic monitoring via the integration of data obtained by ECG, aortic flow by Doppler esophageal probe and by finger plethysmography].

The aims of this work are to describe the general and technical characteristics of a new device for the noninvasive monitoring of patients in intensive care and during general anaesthesia, and the results concerning the reliability of this method. An ultrasonic esophageal probe and an echo-Doppler device have been used to obtain continuous data of the aortic diameter and of blood velocity. Aortic output is calculated automatically. This method, together with other non-invasive monitoring techniques (blood pressure, heart rate, rhythm and cardiac conduction), gives on the one hand the data of aortic output, systemic peripheral resistance and stroke volume; on the other, through a computerized elaboration, the systolic time intervals (PEP pre-ejection period, LVET left ventricular ejection time, QS2 electromechanical systole, PEP/LVET ratio of PEP to LVET). The validation of STI data, has been obtained through 125 comparative measurements for each of the three parameters. The data obtained through the aortic velocity waveform in descending aorta (pulsed Doppler) have been compared with those obtained through the aortic pressure waveform (intra aortic catheter). The correlation was: PEP 0.92, LVET 0.95, QS2 0.93. The clinical application of this method supplies data concerning cardiac load, after-load and indirectly cardiac pre-load. This non-invasive procedure gives us a continuous measurement of hemo-dynamic situation, which allows the physician to plan and evaluate the therapeutical efficacy. Finally new pathologic events may be opportunely faced.

Anesthesia, General↗
PubMed1990

[Non-invasive monitoring of hemodynamic profile during general anesthesia].

This article presents a general vision of a new non-invasive cardiovascular monitoring technique applied to patients during general anaesthesia. This method employs an esophageal eco-Doppler, able to supply a continuous measurement of the aortic diameter (eco-TM) and of the velocity of aortic blood flow (pulsed Doppler) for the calculation of aortic output; a monitor to survey the ECG and a noninvasive device for the measurement of blood pressure. The resulting data, opportunely processed by the computer, supply the values of aortic output, of systemic peripheral resistances and of stroke volume. The last two parameters are indexed with aortic output. Through the computer analysis of ECG and of the aortic velocity curve, it is possible to trace back the systolic time intervals and find out the left ventricular ejection time, the pre-ejection period and the electromechanical systole. All these values are indexed with heart rate. The validation of this method gave good results. The comparison between aortic output, measured by the eco-Doppler, and the value obtained with the thermodilution gave a correlation of r = 0.97, and comparing it with the one obtained with the electromagnetic ring, the correlation was r = 0.96. The aortic diameter was calculated with computerized tomography and the correlation between the two diameters resulted in 0.978. This method is quite useful because it supplies continuous parameters in an automatic and noninvasive way. Therefore it is possible, through a compete hemodynamic profile, to diagnose the variations and control the evolutions of the hemodynamic profile induced by the therapeutical treatments, on the basis of a correct physiopathological interpretation.

Anesthesia, General↗
PubMed1990

Mental retardation in heterozygotes for the fragile-X mutation: evidence in favor of an X inactivation-dependent effect.

The still debated question of whether the expression of mental retardation in heterozygous carriers of the Martin-Bell syndrome is influenced by X inactivation has been investigated in a group of phase-known double heterozygotes for the FRA-X mutant and the G6PD Mediterranean variant. In these individuals, the number of somatic cells (fibroblasts or red cells) with an active FRA-X chromosome could be assessed through the G6PD phenotype at the single-cell level. The data reported indicate a significant inverse correlation between the IQ level (as measured by the Wechsler-Bellevue test) and the percentage of fibroblast cells with an FRA-X active chromosome. In contrast, no significant correlation was found when the IQ level and red cell data were compared, thus suggesting the occurrence of somatic selection against hematopoietic stem cells with an active FRA-X chromosome.

Dosage Compensation, Genetic↗
PubMed1989

Amine oxidase from Lathyrus cicera and Phaseolus vulgaris: purification and properties.

Cu-Amine oxidases (amine oxygen oxidoreductase deaminating, copper containing E.C. 1.4.3.6.) are found in all forms of life (1). They catalyze the following general reaction: R-CH2-NH2 + O2 + H2O----R-CHO + NH3 + H2O2. Cu-amine oxidases (Cu-AOs) have been extracted from different leguminosae: Pisum sativum (2-3), Lathyrus sativus (4), Lens esculenta (5), Vicia faba (6), Cicer arietinum (7), Glycine max (8) but not from Phaseolus vulgaris. Palavan and Galston (9), in a study of polyamine biosynthesis during developmental stages of Phaseolus vulgaris, did not detect diamine or polyamine oxidase activity in Phaseolus. The present paper describes the purification of Phaseolus vulgaris seedlings amine oxidase (PhSAO) and also compares the properties of this enzyme to the Lathyrus cicera enzyme (LcSAO), obtained with the same method of purification.

Amine Oxidase (Copper-Containing)↗
PubMed1988

Hypomethylation of host cell DNA synthesized after infection or transformation of cells by herpes simplex virus.

Infection of rat embryo cells with herpes simplex virus type 2 caused undermethylation of host cell DNA synthesized during infection. DNA made prior to infection was not demethylated, but some of its degradation products, including methyl dCMP, were incorporated into viral DNA. The use of mutant virus showed that some viral DNA synthesis appears to be required for the inhibition of methylation. Inhibition of methylation cannot be explained by an absence of DNA methyltransferase as the activity of this enzyme did not change during the early period of infection. Inhibition of host cell DNA methylation may be an important step in the transformation of cells by herpesviruses, and various transformed cell lines tested showed reduced levels of DNA methylation.

Animals↗