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Biomedical subjects

M Antonelli

Publications and source records attributed to M Antonelli.

At least 127 records · Page 7Linked to original sources

Changes in the levels of coenzyme Q homologues, alpha-tocopherol and malondialdehyde in human tissue during the course of circulatory shock.

Following our previous findings on mitochondrial oxidative damage during the course of circulatory shock in human muscular tissue, in the present work we examined the pathogenic connections between the electron-transport-chain enzymic activity and the ubiquinone metabolism. The effects of the oxidative damage on the alpha-tocopherol content and malondialdehyde (MDA) levels were also studied. The results reveal an involvement of cytochrome oxidase and coenzyme Q10 in the oxidative damage due to shock; alpha-tocopherol seems to show a particularly increased antioxidant activity contemporary with the marked increase in MDA levels. These findings suggest that the significant fall in the mitochondrial oxidative capacity could generate an oxygen free-radical production with subsequent peroxidative damage of the mitochondrial inner-membrane bilayer.

Blood Pressure↗

Asolectin decreases progesterone inhibition of oocyte adenylate cyclase.

Asolectin, a naturally occurring mixture of soybean phospholipids, causes a small (10-25%) but reproducible stimulation on the activity of oocyte adenylate cyclase measured in the presence of guanine nucleotides. This phospholipid preparation, at a concentration of 0.5-1 mg/ml, greatly reduces the inhibition of this enzyme caused by progesterone. The reversal of the progesterone inhibition is due in part to the effect of asolectin in reducing the hysteresis of the enzymatic reaction which is enhanced by progesterone. The asolectin effect is not due to trapping of the progesterone and making it unavailable for interaction with its receptor, because similar concentrations of the phospholipid do not prevent the induction of meiotic maturation of the oocytes by progesterone. This finding suggests that the phospholipids interfere with the transduction of the hormonal signal to the adenylate cyclase catalytic subunit.

Adenylyl Cyclase Inhibitors↗

Leukocyte locomotory function in children with the immotile cilia syndrome.

The random motility of polymorphonuclear leucocytes (PMN), cellular chemotaxis and chemokinesis in kinetic fashion in 4 patients with immotile cilia syndrome (ICS) have been evaluated. No impairment of granulocyte ability of orientation and migration was found. Ultrastructural alterations of cilia which are the primary factor in the pathogenesis of respiratory tract disease in patients with ICS do not impair the PMN function.

Adolescent↗

Shock-induced damage to mitochondrial function and some cellular antioxidant mechanisms in humans.

The effects of circulatory shock on skeletal muscle mitochondrial oxidative activity in various substrates and cytochrome oxidase activity have been investigated using samples of muscle obtained by the needle biopsy technique from human subjects. The effect of shock on superoxide dismutase activity and glutathione content of skeletal muscle was also examined. The results show that there is a large decrease in cytochrome oxidase activity during shock and also in the capacity of the mitochondria to oxidize either succinate, or pyruvate, or palmitoyl carnitine. There is a fall in the tissue content of superoxide dismutase and in the total glutathione present. Furthermore, an increased oxidized glutathione content causes a decrease in the molar ratio of reduced to oxidized glutathione present in the muscle. These findings suggest that mitochondrial electron transport chain (ETC) oxidative damage can play a relevant role in the pathogenesis of circulatory shock and support the hypothesis of oxygen-free radical involvement in the cellular injury.

Biopsy, Needle↗

Effects of L-carnitine administration on mitochondrial electron transport activity present in human muscle during circulatory shock.

Carnitine was administered to a group of patients in shock, and the activities of cytochrome oxidase and succinate cytochrome c reductase in muscle needle biopsies from these patients were compared to those activities present in a non-carnitine treated control group of patients. Carnitine seemingly exerted a significant protective action on cytochrome oxidase activity during the initial phases of shock, but not to such an extent on succinate cytochrome c reductase activities.

Carnitine↗

Incidence in Italy, genetic heterogeneity, and segregation analysis of cystic fibrosis.

Taking advantage of the availability of an archive of consanguineous marriages that gives accurate estimates of consanguinity in Italy, it has been possible to calculate the increase of first- and second-cousin marriages among 624 couples of cystic fibrosis (CF) parents over the general population. From these estimates, the incidence of CF in Italy has been found to correspond approximately to 1/2,000. In turn, the same data have been used to test the hypothesis of genetic heterogeneity of CF, recently proposed, which is based on the presence of two distinct genetic disorders having similar frequencies. If such a hypothesis were true, the number of first-cousin marriages among CF parents should be significantly higher than that observed in our present study. Finally, the segregation analysis of 624 CF sibships has yielded under multiple selection a segregation ratio of 0.252, confirming the recessive mode of inheritance.

Consanguinity↗

Transferrin subtypes in cystic fibrosis.

The molecular polymorphism and quantitative data of serum transferrin (Tf) were ascertained in a group of fibrocystic patients, their parents and controls. Quantitative rates of pre-albumin, retinol binding globulin (RBG) and alpha-1-glycoprotein were also investigated as a reference for the evaluation of Tf quantitative data. Neither different allele distributions nor abnormal electrophoretic patterns were observed among CF patients. A slight lowering of Tf, pre-albumin and RBG, probably due to malnutritional condition in CF subjects was found.

Adolescent↗

Partial monosomy for a 21 chromosome. Report of a new case of r(21) and review of the literature.

A 21-month-old male infant with 46,XY,r(21) constitution identified by G and R banding is reported. The main clinical features were mental and physical retardation, microcephaly, antimongoloid slant of eyelids, malformed and low set ears. The clinical and cytogenetic findings of previously reported cases of r(21) are reviewed. Clinical resemblance to the eleven cases described in the literature is striking. The assays for superoxide dismutase (SOD-1) activity in the red blood cells from patient and his parents gave normal results. This findings is compatible with the hypothesis that only the segment distal to the SOD-1 locus, i.e. 21q22.2 leads to qter, has been lost during ring formation.

Aneuploidy↗

Supernumerary microtubules in the cilia of two siblings causing "immotile cilia syndrome".

The function and ultrastructure of nasal cilia in 2 siblings with unexplained chronic sinusitis and bronchitis were investigated. Both patients lacked nasal mucociliary clearance (greater than 30 min). On electron microscopy, the ultrastructure of nasal cilia showed an extra doublet or supernumerary microtubules with disorganized microtubular network. Other axonemal components were normally present. It is conceivable that an "extra" component of the axoneme may be added to those "defects" already recognized as a cause of the "immotile-cilia syndrome".

Adolescent↗

Constipation and obesity: a statistical analysis.

Constipation frequency was investigated among 1897 subjects (874 males and 1023 females), ranging in age from 6 to 70 years, chosen at random between city inhabitants and farmers. Bowel habit was studied in 966 obese patients (390 males and 576 females). The authors followed for the diagnosis of constipation either the commonest and restrictive criterion of the weekly bowel actions or the clinical one which implies also others parameters, like hard or small stools, difficulties of expulsion or feeling of incomplete evacuation after defecation. The statistical analysis showed that constipation frequency is 8.3% in obese patients and 1.5% in normal-weighting, according to weekly bowel actions criterion: the difference is statistically significative (p less than 0.001).

Adolescent↗