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Biomedical subjects

R Agostino

Publications and source records attributed to R Agostino.

54 records · Page 3Linked to original sources
PubMed1984

Recovery cycle of the masseter inhibitory reflex in man.

The masseter inhibitory reflex from stimulation of the mental nerve has been recorded electromyographically in 10 healthy subjects. The recovery cycle of the two silent periods interrupting the tonic contraction of the masseter muscles have been studied with the paired shock technique. There was a clear dissociation between the recovery of early and late inhibition, the latter being far more affected by a preceding impulse. It is concluded that the two silent periods are mediated by separate neural nets. The differences with the recovery curves of the two components of the blink reflex are discussed.

Adult↗
PubMed1982

Evaluation of an automatic oscillometric method and of various cuffs for the measurement of arterial pressure in the neonate.

We compared simultaneous measurement of aortic, direct (Dir) and of indirect (Ind) systolic (S), mean (M) and diastolic (D) arterial pressure (AP) determined by an automatic oscillometric instrument (DINAMAP) in neonates with birthweight of 1000-3680 g. DINAMAP measurements were performed with cuffs of increasing width and length, recommended by the manufacturer for increasing arm circumference, and with a Standard sized cuff (2.5 X 15 cm), previously considered as suitable for neonates of any body size. In addition, we compared simultaneous measurements of Dir SAP and of Ind SAP determined by a Doppler technique and the Standard cuff. In DINAMAP SAP measurements with the Standard cuff, a statistically significant correlation between arm circumference and delta Ind-Dir SAP values (i.e. the difference between simultaneous Ind and Dir SAP measurements) was found. In DINAMAP MAP measurements with the cuff recommended for arm circumference, a statistically significant difference of the mean delta Ind-Dir MAP values was observed in infants whose arm was or was not completely encircled by the bladder of the cuff. In SAP as well as in MAP DINAMAP determinations, the overall error of measurement with the Standard cuff was smaller than with the recommended cuff. The Doppler method was found considerably more accurate than the DINAMAP method for the determination of SAP. In spite of these limitations, the DINAMAP method with the Standard cuff was considered to be reasonably accurate for the clinical determination of SAP and MAP, provided that several consecutive measurements are performed and averaged in order to minimize the error of measurement. When considering DAP measurements the error was so unacceptably high that the DINAMAP method cannot be recommended for clinical use. The need for a careful consideration of the cuff characteristics when evaluating new methods for the indirect measurement of AP in the neonate is emphasized.

Blood Pressure Determination↗
PubMed1981

Prolonged intermittent positive pressure ventilation by nasal prongs in intractable apnea of prematurity.

In order to avoid endotracheal intubation in very small newborn infants requiring prolonged intermittent positive pressure ventilation (IPPV), a method was developed allowing delivery of IPPV by means of nasal prongs (nasal IPPV). A series of 10 newborn infants weighing 1 200 g or less, and requiring nasal IPPV for 5 to 14 days because of intractable apnea has been reported. Five infants survived. With the exception of hearing defects in two survivors, no lesions possibly due to the ventilation procedure were observed. Follow-up examination showed severe mental and motor handicap in one infant, and apparently normal mental and motor development in 3 infants examined at the age of 12-27 months. It is suggested that nasal IPPV is an effective and safe method for prolonged ventilation of very small newborn infants with normal or not severely affected lungs, whereas it appears of very limited use in patients with stiff lungs, such as in severe HMD.

Apnea↗
PubMed1975

Genetic differentiation among Sardinian villages.

The present study reports an analysis of genetic differentiation among 14 Sardinian villages located mainly in the center of the island. Chi-square tests show significant genetic heterogeneity among villages, and analyses by F- and R- statistics indicate an essentially random pattern of differentiation for all alleles. Using the kinship methods of Morton, a matrix, R, with elements rij describing the correlations between the gene frequencies of villages i and j is obtained. Use of Malécot's formula relating the rij to the geographic distances between villages shows a rapid decline of kinship with increasing distance but reveals essentially no relationship for distances over 40 km. Rotation of a two-dimensional reduction of the kinship matrix to maximum congruence with the geographic distances indicates that about 25% of the genetic distances can be accounted for by the geographic location of the villages. Isolation due in part to cultural factors, genetic drift, and special local or regional patterns of villages associations appear to be involved in the pattern of genetic variation.

Adolescent↗
PubMed1975

Red cell acid phosphatase: another polymorphism correlated with Malaria?

The frequency of PC allele for acid phosphatase in fourteen Sardinian villages correlates positively with the altitude and negatively with past malarial morbidity and GdMed prevalence. The susceptibility towards hemolytic favism in Sardinian males with G6PD deficiency is dependent on the erythrocyte acid phosphatase and thalassemia phenotypes. Thalassemia trait exerts a protective action only in subjects carrying PA allele for acid phosphatase. The data suggest that the gradient for malaria morbidity directly or indirectly, through interactions with thalassemia and G6PD polymorphisms, mediated by the habit of eating Vecia faba, may have had a significant role in determining the heterogeneous distribution of acid phosphatase polymorphism in Sardinia. Besides malaria, other environmental factors related with altitude seem to have been very important in shaping the present pattern of distribution of both acid phosphatase and G6PD polymorphisms in Sardinia.

Acid Phosphatase↗
PubMed1971

Favism: association with erythrocyte acid phosphatase phenotype.

The frequency of carriers of the P(a)and P(c) alleles of the gene for acid phosphatase in the erythrocyte is significantly higher in male subjects deficient in glucose-6-phosphate dehydrogenase and having hemolytic clinical favism than it is in the general population. This observation seems to indicate that alleles (P(a) and P(c)) of a gene polymorphic in all human populations affect the fitness of the involved phenotypes in special genotypic and nongenotypic conditions.

Acid Phosphatase↗