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Biomedical subjects

A Belli

Publications and source records attributed to A Belli.

At least 19 recordsLinked to original sources

Flecainide single oral dose for management of paroxysmal supraventricular tachycardia in children and young adults.

The efficacy of a single oral dose of flecainide to terminate paroxysmal supraventricular tachycardia (PSVT) was evaluated in 25 children and young adults. The subjects were selected from a group of 35 patients with recurrent attacks of PSVT evaluated by means of electrophysiologic study and intravenous electropharmacologic testing with flecainide. In all 25 patients the induced PSVT was stopped by intravenous flecainide and was then no longer inducible or nonsustained. All patients had normal hearts. At least 48 hours after acute intravenous testing, 25 patients underwent electrophysiologic study with a transesophageal catheter and PSVT was induced in all of them: atrioventricular reentrant tachycardia in 16 and atrioventricular nodal reentrant tachycardia in nine. During stable tachycardia, a single oral dose of flecainide (2.9 +/- 0.3 mg/kg; 2.5 to 3.3 mg/kg) was administered. This approach was effective for termination of PSVT in 22 patients. The mean plasma level of flecainide at cessation of tachycardia was 277 +/- 92 ng/ml (150 to 500 mg/ml). All 22 patients who responded were given a single oral dose of flecainide for recurrences of PSVT during follow-up. During a period of 12 +/- 7 months (2 to 27 months) a total of 134 spontaneous episodes of PSVT were reported, and 127 of these episodes were terminated with periodic management. Thus oral periodic flecainide seems useful for management of PSVT in selected patients.

Administration, Oral

MDA, oxypurines, and nucleosides relate to reperfusion in short-term incomplete cerebral ischemia in the rat.

Short-term incomplete cerebral ischemia (5 min) was induced in the rat by the bilateral clamping of the common carotid arteries. Reperfusion was obtained by removing carotid clamping and was carried out for the following 10 min. Animals were sacrificed either at the end of ischemia or reperfusion. Controls were represented by a group of sham-operated rats. Peripheral venous blood samples were withdrawn from the femoral vein from rats subjected to cerebral reperfusion 5 min before ischemia, at the end of ischemia, and 10 min after reperfusion. Neutralized perchloric acid extracts of brain tissue were analyzed by a highly sensitive high-performance liquid chromatography (HPLC) method for the direct determination of malondialdehyde, oxypurines, nucleosides, nicotinic coenzymes, and high-energy phosphates. In addition, plasma concentrations of malondialdehyde, hypoxanthine, xanthine, inosine, uric acid, and adenosine were determined by the same HPLC technique. Incomplete cerebral ischemia induced the appearance of a significant amount (8.05 nmol/g w.w.; SD = 2.82) of cerebral malondialdehyde (which was undetectable in control animals) and a decrease of ascorbic acid. A further 6.6-fold increase of malondialdehyde (53.30 nmol/g w.w.; SD = 17.77) and a 18.5% decrease of ascorbic acid occurred after 10 min of reperfusion. Plasma malondialdehyde, which was present in minimal amount before ischemia (0.050 mumol/L; SD = 0.015), significantly increased after 5 min of ischemia (0.277 mumol/L; SD = 0.056) and was strikingly augmented after 10 min of reperfusion (0.682 mumol/L; SD = 0.094). A similar trend was observed for xanthine, uric acid, inosine, and adenosine, while hypoxanthine reached its maximal concentration after 5 min of incomplete ischemia, being significantly decreased after reperfusion. From the data obtained, it can be concluded that tissue concentrations of malondialdehyde and ascorbic acid, and plasma levels of malondialdehyde, oxypurines, and nucleosides, reflect both the oxygen radical-mediated tissue injury and the depression of energy metabolism, thus representing early biochemical markers of short-term incomplete brain ischemia and reperfusion in the rat. In particular, these results suggest the possibility of using the variation of malondialdehyde, oxypurines, and nucleosides in peripheral blood as a potential biochemical indicator of reperfusion damage occurring to postischemic tissues.

Adenine Nucleotides

Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping.

Six subjects performed a first series of vertical plantar flexions and a second series of vertical rebounds, both involving muscle triceps surae exclusively. Vertical displacements, vertical forces and ankle angles were recorded during the entire work period of 60 seconds per series. In addition, expired gases were collected during the test and recovery for determination of the energy expenditure. Triceps surae was mechanically modelled with a contractile component and with an elastic component. Mechanical behaviour and work of the different muscle components were determined in both series. The net muscular efficiency calculated from the work performed by the centre of gravity was 17.5 +/- 3.0% (mean +/- SD) in plantar flexions and 29.9 +/- 4.8% in vertical rebounds. The net muscle efficiency calculated from the work performed by the contractile component was 17.4 +/- 2.9% in plantar flexions and 16.1 +/- 1.4% in vertical rebounds. These results suggest that the muscular efficiency differences do not reflect muscle contractile component efficiency but essentially the storage and recoil of elastic energy. This is supported by the relationship (P less than 0.01) found in vertical rebounds between the extra work and the elastic component work. A detailed observation of the mechanical behaviour of muscle mechanical components showed that the strategy to maximize the elastic work depends also on the force-velocity characteristics of the movement and that the eccentric-concentric work of the contractile component does not always correspond respectively to the ankle extension-flexion.

Adult

[Appendicitis: microbial interactions and new pathogens].

The Authors present an exhaustive review on microbial agents of appendicitis by means of literature and personal research data. Thus, a detailed analysis is made on common autochthonous agents and their pathogenetic interactions and on less common exogenous bacterial, viral, mycotic, protozoan and helminthic agents with emphasis to the role of Yersinia enterocolitica. In fact this bacterium seems responsible for 3% to 8% of cases in accordance with literature and personal research data (more detailed, Y. enterocolitica has been isolated in 3.8% of 208 inflamed appendices from both pediatric and adults surgical florentine patients). At the end, the pathogenetic role of "new" other bacteria, like Buttiauxella agrestis, Aeromonas hydrophila, Arizona, Streptococcus lactis, is debated on the basis of a personal study.

Acute Disease

[Intestinal absorption of vitamin E in children with atrophy of the jejunal mucosa].

The intestinal absorption of vitamin E is often thought to be closely correlated to that of fatty acids, but the biochemical mechanisms involved in the process are still not clear. For this reason, the present study aimed to assess the absorption of triglycerides and vitamin E, following oral administration, in 11 children with suspected malabsorption syndromes. Intestinal biopsy in 9 children showed the presence of a flat mucosa, whereas no changes were present in 2 patients. The results confirm the inverse correlation between the absorption of triglycerides and vitamin E, as if tocopherols used an independent system of transport. These findings contrast with those reported in the literature perhaps due to the low level of precision of colorimetric techniques previously used to assay vitamin E.

Atrophy

Percutaneous peripheral ultrasonic angioplasty.

We previously reported the initial use of percutaneous catheter delivered ultrasound energy for arterial recanalization in eight patients with peripheral vascular disease. All patients had severe claudication. There were four cases with total occlusion and four with high grade stenoses in a superficial femoral or popliteal artery. A prototype ultrasound probe, with a frequency of 20 kHz and a power output of 20 to 25 watts/cm2 was ensheathed in a 7F catheter and advanced to the occlusions with angiographic guidance. Three of four complete occlusions were recanalized in less than 120 s resulting in a 54 +/- 5% residual diameter stenosis. Ultrasound energy applied to isolated stenoses reduced them by 40%, from 77 +/- 14% to 37 +/- 21%. Further treatment with balloon angioplasty resulted in a mean residual stenosis of 20 +/- 9%. There was no angiographic or clinical evidence of arterial emboli, dissection, spasm, or perforation. Clinical follow-up and Doppler ankle-brachial indices were performed at one, three and six months after combined ultrasound and balloon angioplasty. Two occlusions recurred, both within the first three months, detected by return of claudication and an abnormal ankle/brachial index, and documented by angiography. Repeat balloon angioplasty of standard methods was performed in one, but the vessel again reoccluded. The other five patients with primary technical success have continued patency both clinically and by ankle/brachial index measurement. Percutaneous catheter delivered ultrasound energy appears promising in peripheral vessels to reduce arterial stenoses and recanalize complete arterial obstructions. The long-term findings from this pilot study were insufficient to assess if ultrasound has any effect on restenosis.

Aged

[Complications of septorhinoplasty].

A review of the literature on complications in septorhinoplasty is presented. Though rare, complications may arise in the surgical treatment of such a delicate anatomical area as the nasal septum and both theoretical and practical knowledge of the problem is necessary in order to prevent and/or handle such unexpected events. Complications are grouped according to aetiopathogenesis into infectious, haemorrhagic, traumatic, systemic and miscellaneous.

Humans

Lack of oxidative damage in serum polyunsaturated fatty acids before and after dialysis in chronic uremic patients.

We described previously that in the erythrocytes and mononuclear blood cells from uremic patients on chronic hemodialysis, the membrane concentrations of malonyldialdehyde (MDA), resulting from peroxidation of polyunsaturated fatty acids (PUFA) in the membrane itself increased, and the concentrations of vitamin E (VIT E), the major antioxidizing agent, were lower. In the present study we analysed whether similar oxidative damage is seen in the serum from hemodialysis patients and whether the serum fatty acid pattern is affected. No evidence was found of oxidative damage in the serum during hemodialysis, serum concentrations of MDA and VIT E remaining constant before and after dialysis. No change was observed in serum pattern of PUFA, particularly linoleic acid. We therefore assume that the oxidative damage described in uremic patients is mainly intracellular.

Adult

Balloon dilatation of upper gastrointestinal tract strictures.

Balloon dilatation has been performed in a series of 30 patients with strictures of the upper gastrointestinal tract over a period of 28 months. The technique of balloon dilatation is described and the results of follow-up are presented. Sixty per cent of patients have remained symptom-free following balloon dilatation. Twenty-seven per cent of patients have undergone regular repeated dilatations when symptoms have recurred. There were no complications from the technique. Balloon dilatation is a safe and acceptable alternative to conventional methods of bougienage in the management of upper gastrointestinal tract strictures.

Aged

Visceral angiographic findings in pseudoxanthoma elasticum.

Two cases of pseudoxanthoma elasticum are described in brothers who both presented with gastric haemorrhage. The angiographic findings demonstrate the spectrum of vascular abnormalities seen in this condition. Although rare, the combination of angiomatous malformations, aneurysmal dilatation, narrowing and/or occlusion of visceral or peripheral arteries in a relatively young patient with abdominal pain or gastrointestinal bleeding, should alert the radiologist to the diagnosis. Examination will usually reveal the characteristic xanthomatous papular rash and retinal angioid streaks which confirm the diagnosis.

Adult

Pulmonary vasodilator therapy for chronic obstructive pulmonary disease and cor pulmonale. Treatment with nifedipine, nitroglycerin, and oxygen.

The present study was undertaken to evaluate the short-term effects of nitroglycerin, nifedipine, and supplemental oxygen on hemodynamics and gas exchange in 11 patients in stable condition with chronic obstructive pulmonary disease and cor pulmonale. In general, both intravenous nitroglycerin and sublingual nifedipine significantly reduced the pulmonary vascular resistance index. For the group as a whole, nifedipine decreased the pulmonary vascular resistance index by significantly increasing the cardiac index, with minimal reductions in mean pulmonary arterial pressure. Conversely, nitroglycerin decreased the pulmonary vascular resistance index by markedly reducing the mean pulmonary arterial pressure but also decreased the cardiac index in some patients. Nitroglycerin also caused a significant decrease in mixed venous oxygen tension. Administration of oxygen did not cause any clinically significant improvement in resting hemodynamics following short-term administration. During the follow-up period, eight of 11 patients who were treated with pulmonary vasodilators in addition to long-term therapy with low-flow oxygen died within a mean of six months. This rate of survival was not significantly different than an age-matched and sex-matched control group with similar severity of disease who received only long-term therapy with low-flow oxygen. Based on these data, it seems unlikely that a substantial increase in survival will be obtained by combining pulmonary vasodilators with long-term oxygen therapy in patients with stable emphysema who have cor pulmonale and carbon dioxide retention.

Administration, Oral

[Radiotherapy of carcinoma of the glottis in the initial stage].

The control of early glottic cancer is equally satisfactory with either surgical resection or radiation therapy; this last method gives the patient good functional results. During the period from 1/1978 to 12/1985, 73 patients with early glottic carcinoma (T1 N0 M0) were treated in the Institute of Radiotherapy L. Galvani, University of Bologna; 45 were stage T1a (tumour limited to one vocal cord) and 28 were stage T1b (tumour of both vocal cords or involving anterior commissure); radiation treatment utilised a 60Co machine and 5 x 5 cm fields; the median dose was 67.2 Gy (range 50-76) with conventional fractionation. Ten patients had local recurrence; the median time of recurrence was 13.4 months; 9/10 were treated by surgery and 2/10 died, so the overall control by radiotherapy with surgery in reserve was 100% in T1a tumours and 90.6% in T1b ones. The 5-years disease free survival rate was 93.1% in T1a tumours and 69% in T1b; lesions involving anterior commissure had the worst prognosis, independent of the dose and time-dose factor (3/10 recurrences in the group treated with TDF less than 110 and 4/18 recurrences in the group with TDF more than 110).

Adult

[A longitudinal entomologic survey on the transmission of malaria in Ouagadougou (Burkina Faso)].

A longitudinal entomological malaria survey was carried out in five zones of the town of Ouagadougou, Burkina Faso, and in three neighbouring villages. The main vector is Anopheles gambiae s.l. with An. funestus having a role in some localities during the dry season. Pyrethrum spray catches were carried out once or twice per month to determine variations in vector density. Inoculation rates were estimated from the number of blood-fed vectors per man and from the sporozoite rates. Larval sampling was routinely carried out all over the urban area in order to map the larval breeding sites. Widely different degrees of malaria transmission were documented in the urban area mainly related to the spatial and temporal distribution of An. gambiae larval breeding sites. Higher inoculation rates, depending both on higher vector densities and sporozoite rates, were documented in the villages.

Animals

[Dispersion of Anopheles gambiae s.l. in an urban zone of Ouagadougou (Burkina Faso)].

Dispersion of Anopheles gambiae s.l. from larval breeding places was examined in the town of Ougadougou, Burkina Faso. A suitable study area was chosen, characterized by high concentration of larval breeding places along a water reservoir. Mosquito density per room was calculated from the results of pyrethrum spray catches carried out on a series of seven groups of collecting stations along a transect from 100 to 1050 m from the water reservoir area. High density and uniform distribution of houses and human host in the urban area appear associated with a remarkably low degree of dispersion since most of An. gambiae s.l. were collected within 200 m (males) or 300 m (females) from the breeding sites. Malaria transmission is consequently very focal in these conditions.

Animals

[Qualitative and quantitative significance of the microbial flora in natural mineral waters during their bottling].

On the basis of data reported in literature concerning the saprophytic bacterial flora of natural mineral waters bottled in glass or in PVC containers and in view of the results obtained during their own investigations, the AA. consider it impossible to establish a limit to the charge of bacterial flora in agar at 20 degrees C and believe that any possible proposal concerning rules limiting the bacterial charge at 37 degrees C requires more detailed study and preliminary controls. In any case, they propose to apply the strictest vigilance in excluding the presence of any sign whatever of fecal contamination or of potentially pathogenic bacterial types (f.i. P. aeruginosa) in all water samples; they also suggest to require that the performance of comparative tests be extended to the stages preceding bottling. Current experimental investigations reveal that the multiplying process seems to be accelerated and more protracted in time in waters bottled in PVC containers than in those kept in glass containers.

Flavobacterium