Biomedical subjects
Publications and source records attributed to G Antonini.
A group of Babinga Pygmies from the Central African Republic have been analyzed for the acid phosphatase polymorphism with special reference to the ACPR allele. The frequency of this allele (17%) is one of the highest observed in Africa and is comparable only with those reported for the Khoikhoi and the San.
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Myotonic dystrophy (MD) is associated with a wide spectrum of cardiac abnormalities, but only a few longitudinal studies have investigated the natural course of heart disease in MD. To assess whether neuromuscular involvement significantly predicts cardiac disorders in MD, 83 patients with various grades of disease severity were enrolled in a 13-year follow-up study (mean, 60.6 +/- 37.8 months) that included periodic physical and instrumental cardiac examinations (standard and Holter electrocardiography, echocardiography). During follow-up, muscular disease worsened clinically in 9 patients (11%) whose baseline severity grade changed accordingly; only 3 of them demonstrated parallel worsening of cardiac disturbance, however, compared with a large number of patients who showed additional cardiac abnormalities. These included further worsening of pre-existing pathologic features (19/83) and the appearance de novo of serious arrhythmias and/or conduction defects (23/83). Pacemaker implantation was necessary in 11 of 83 patients (13.2%) who had symptomatic bradyarrhythmias, bifascicular block, and P-R prolongation with a His-to-ventricle interval exceeding 55 ms, as documented by electrophysiologic study. Eight (9.6%) patients died: 2 from noncardiac and 1 from unknown causes, 1 from heart failure, and 4 from sudden death closely related to documented ventricular tachycardia. The incidence and seriousness of arrhythmic and conduction disturbances correlated with the severity of the muscular involvement. Nevertheless, cardiac and muscular disease did not show a linear progression. Cardiac involvement generally worsened more rapidly than did skeletal muscle disease.
The identification of two functionally distinct states, called pulsed and resting, has led to a number of investigations on the conformational variants of the enzyme. However, the catalytic properties of cytochrome oxidase may depend on a number of experimental conditions related to the solvent as well as to the protocol followed to determine the turnover number of the enzyme. This paper reports results which illustrate that the steady-state differences between pulsed and resting oxidase may, or may not, be detected depending on experimental conditions.
The transient kinetics of proton pumping and the electron transfer properties of cytochrome oxidase inserted into small unilamellar vesicles have been investigated by stopped-flow spectrophotometry. In the presence of valinomycin, proton pumping and cytochrome c oxidation by cytochrome oxidase are synchronous up to rate constants of approximately 9 sec-1. Moreover, the enzyme depleted of subunit III ("three-less oxidase") was also shown to pump protons, although with a significantly smaller stoichiometry. Thus, subunit III is not the only (or even the main) proton channel, although it may be involved in the regulation of activity. The kinetics of cytochrome c oxidation by COV in the absence and in the presence of ionophores have been investigated. Analysis of the time course of the process in the transient and steady state phases indicates that the onset of control by the electrochemical gradient follows the transfer of four electrons, i.e., one complete turnover of the oxidase. Two possible alternative interpretations for the control of the turnover phase are presented and discussed.
We utilized Doppler echocardiography to characterize left ventricular diastolic function in 42 patients with myotonic dystrophy (mean age 37 +/- 12 years, 64% male) who had no symptoms of heart failure and had normal left ventricular systolic function. Data were compared with those in 41 normal control subjects of similar age and gender. Heart rate, systemic blood pressure, and cardiac dimensions (wall thickness, left atrial and left ventricular cavity dimensions) were similar and not significantly different in patients and controls. As a group, patients showed significantly increased deceleration time and decreased rate of decline of flow velocity in early diastole (p < 0.0001 and p < 0.01, respectively) when compared to controls. Individual patient analysis showed that 10 (24%) of the 42 patients with myotonic dystrophy had 2 or more abnormal Doppler indexes of diastolic function consistent with a pattern of impaired left ventricular relaxation. The most common abnormalities were increased deceleration time (> 224 ms; 9 patients), prolonged isovolumic relaxation time (> 103 ms; 8 patients) and reduced rate of decline of flow velocity in early diastole (< 2.1 m/s2; 5 patients). In addition, peak early diastolic flow velocity was reduced (< 43 cm/s) in 3 patients and early to atrial peak flow velocity ratio was reduced (< 1) in 2 patients. Comparison of subgroups of patients with and without abnormal Doppler indexes showed no significant differences with regard to age, gender, heart rate, systemic blood pressure, severity of neuromuscular disease, and cardiac dimensions. After study, patients were clinically followed up for a mean period of 20 +/- 7 months (range 12-35). During observation no patients died and none experienced symptoms of heart failure. This Doppler echocardiographic analysis demonstrates that diastolic abnormalities may be present in patients with myotonic dystrophy, even in the absence of symptoms of cardiac failure or left ventricular systolic dysfunction. These diastolic abnormalities suggest an intrinsic myocardial abnormality in patients with myotonic dystrophy; however, whether they represent a preclinical phase of myocardial involvement or an intrinsic feature of the primary myocardial disease process in myotonic dystrophy remains to be elucidated.
Percutaneous endoscopic gastrostomy is an interesting method of providing enteral nutrition or gastric decompression in patients who are candidates for operative gastrostomy or nasoenteric tube feeding. We report our experience with percutaneous endoscopic gastrostomy with gastropexy (Introducer T-Fastener) in 41 patients. This method uses a technique in which the anterior gastric wall is non-surgically sutured to the anterior abdominal wall before catheter insertion. This technique was successful in all patients, including one subject with a Billroth II hemigastrectomy. Enteral nutrition was started in all cases within 24 hours of the end of the procedure. The medium enteral nutrition period to date is 482.5 days. There were no deaths related to the procedure and no patients had major specific abdominal complications requiring urgent surgical repair. Eight patients complained of minor specific complications which were successfully resolved in all cases with simple conservative procedures and/or therapies. These results indicate that the Introducer T-Fastener method for performing percutaneous endoscopic gastrostomy is rapid, safe, and inexpensive.
Bovine lactoferrin (BLf) is an iron binding protein folded in two lobes, N- and C-lobes. In this study we have reported the inhibitory activity towards herpes simplex virus type 1 (HSV-1) in vitro infection of BLf tryptic digested N- and C-lobes in comparison with the whole protein. The N-lobe and C-lobe exerted an anti-herpesvirus activity 50- and 10-fold lower than native BLf, respectively. In order to assess the phase of viral replication affected, lactoferrin-derived lobes were added to the cells at different non cytotoxic concentrations, during the whole cycle of viral infection or during viral attachment step, demonstrating that both lobes interfered with the early phases of infection. Among the BLf tryptic digested fragments, two negatively-charged small peptides deriving from N-lobe, previously shown effective towards HSV-1, have been further studied. We assessed that the net negative charge of these peptides was not responsible for the antiviral activity since their activity was not modified when the aspartic and glutamic acidic residues of these peptides were replaced with asparagine and glutamine, respectively. The experiments here reported confirm a pivotal role of N-lobe in inhibiting viral infection. However, the residual inhibiting activity of C-lobe and the similar efficacy shown by negatively or positively charged peptides strongly support the idea that the antiviral activity of bovine lactoferrin cannot be fully explained simply on the basis of competition between the protein and viral recognition sites for binding to glycosaminoglycans.
Deep peroneal nerve mononeuropathy is rarely observed in clinical practice. We describe a case in which the syndrome was caused by a clinically not detectable ganglion within the anterior compartment of the leg. Electrophysiological data allowed us to localize the site of the lesion for a correct planning of CT scan. CT scan showed a low density tissue occupying the anterior compartment of the leg and its relationships to muscles, septa, bones and vessels. Electrophysiological data and CT scan utilities are discussed.
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Starting from a case they observed and from similar cases of literature, the authors underline the variability of clinical aspects of MDCF which in this case was associated with absence of both motorial acquisitions and skeletal alterations. They underline how their case is characterized by the presence and consistence of musculotendinous retractions and by muscular weakness.
On the ground of preceding researches carried out about myodystrophias, the authors studied the melituric symptomatology in both a group of myasthenic patients and a group of control. The chromatographic analysis and the dosage of some urinary carbohydrates, showed that there are not statistically significant differences between the group of myasthenic patients and that of controls.
The Authors, referring to a clinical case, make a revision of the so-called atypic or intermediate forms of the heredo-atazies diseases and try to resolve the problem of their nosology, underlining the fact that these clinical forms tend to reveal themselves as different phenotypes, starting from a basic genotypes.
Authors refer to a clinical case in which they observed the association of bilateral cervical ribs with aneurism of subclavian artery. They underline the high frequencey of occasional observations of anomalies of the thoracic outlet, and consider the possible pathogenetic mechanisms of the thoracic outlet syndrome and associated vascular damages.
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