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Biomedical subjects

R Bettini

Publications and source records attributed to R Bettini.

At least 19 recordsLinked to original sources
PubMed1995

Drug diffusion front movement is important in drug release control from swellable matrix tablets.

Swellable controlled release devices of buflomedil pyridoxalphosphate in hydroxypropyl methylcellulose were prepared, and their swelling and release behavior was investigated. The drug release as a function of time was investigated for various system parameters. Three distinct fronts were observed during the swelling and release processes, i.e., a swelling, a drug diffusion, and an erosion front. The drug diffusion front could be readily determined due to the drug's yellow color. The relative positions of the fronts and the drug release rate were studied as functions of the initial porosity and the molecular weight of the polymer carrier. It was shown that the drug diffusion front best describes the overall release behavior of the system. The fractional drug release was a strong function of the dissolved drug gel layer thickness, which separates the diffusion front from the erosion front. The effect of drug solubility was also investigated by altering the pH and the ionic strength of the dissolution medium. It was shown that as drug solubility increased, the undissolved drug gel layer thickness decreased, again showing the importance of the movement of the diffusion front in controlling the overall release.

Delayed-Action Preparations↗
PubMed1993

Laser nephelometric evaluation of albumin, IgG and alpha 2-macroglobulin: applications to the study of alterations of the blood-brain barrier.

Cerebrospinal fluid and serum levels of albumin, immunoglobulin G and alpha 2-macroglobulin were determined by laser nephelometer in various pathological conditions: Guillain-Barré syndrome amyotrophic lateral sclerosis, lumbar disc herniation. These proteins are different due to their molecular weight, spacial conformation, CSF and serum concentrations and their CSF/serum quotient reflects the status of the blood-brain barrier. In the subjects group comparisons, albumin quotient and IgG quotient show a significant differentiations. The linear regression of albumin quotient compared to alpha 2-macroglobulin quotient behaves differently in the individual groups. The protein CSF/serum quotients are helpful in distinguishing the causes of alterations in the blood-brain barrier.

Adolescent↗
PubMed1992

Life-threatening tachyarrhythmias in athletes.

The arrhythmias in competitive athletes may be classified as "benign," "paraphysiological" due to prolonged athletic training, or "pathological" due to hemodynamic effects on the athletic performance-risk-arrhythmogenic substratum. Pathological arrhythmias include life-threatening forms that are severe enough to produce symptoms (presyncope, syncope, cardiac arrest) during athletic activity. These forms are in particular rapid VT, VF, torsades de pointes, preexcited atrial fibrillation, sinus atrial and AV block. Our study population includes 766 competitive athletes, mean age 21.1 years (74 top international level), investigated with a cardioarrhythmological work-up for symptoms and for arrhythmias from 1974 to June 30, 1991. Three leading categories, represented by 16 aborted sudden death, 8 sudden death, and 7 induced VF (by EES or TAP) athletes, are described. All athletes with life-threatening arrhythmias, previously as asymptomatic or with minor symptoms had an arrhythmogenic substratum due to underlying silent cardiopathy or primary arrhythmic disorders. Athletic activity can be regarded as a trigger of electrical destabilization.

Adolescent↗
PubMed1992

[Epidemiology of pathological cerebral impairment].

Among the over-65 aged patients of our division (848 in all), during a period of little more than a year, we wanted to determine the prevalence of dementia in absolute and per cent terms, using two neuropsychological tests for the evaluation of mental functions, estimating the most frequent forms according to their nature, referring to sex, considering different age groups and trying to find a connection with the pathologies that caused hospitalization and with particular social-environmental conditions. We attended also to the present therapeutical proposals and to the difficult problem of nursing demented people. We estimated the presence of a pathological cerebral impairment in 4% of the over-65 aged population; the prevalence reaches 3.5% in the group between 65 and 74 years and 12% in the one from 75 up to 80 years and over. 50% of dementia is due to Alzheimer's disease, which is more frequent among women, 26.5% to multi-infarction dementia (MID), which strikes more men, and 20.6% to a mixed form, degenerative and vascular; finally other pathologies can be responsible for dementia in the remaining percentage. It is difficult to find a certain relation between dementia and associated diseases, except for MID, which is clearly connected with cerebrovascular and cardiovascular disorders, as well as to consider particular social-environmental conditions as predisposing factors for cognitive impairment. At present, there is no way to remove causes of primary dementia with any kind of therapy, which is therefore only symptomatic. Families bear most of the burden of caring for patients. Most of Alzheimer victims remain at home and subject caregivers to prolonged emotional and physical stress, making them the "hidden victims" of the disease. Clearly, there is a desperate need for day-care help and nursing home-care facilities to make the final institutionalization less frequent or at least to delay it as much as possible.

Age Factors↗
PubMed1991

[Supraventricular reentry tachycardia and athletic fitness].

Paroxysmal supraventricular reciprocating tachycardias (PSRT) which are due to a different type of reentry including the atrioventricular reentry circuit of Wolff-Parkinson-White (WPW) syndrome, may disturb the professional career of an athlete. Moreover even severe episodes of preexcited atrial fibrillation of WPW may occur. PSRT in athletes may present various clinical consequences: unimportant symptoms, or severe hemodynamic effects on the athletic performance particularly during sports activity at intrinsic high risk. The athletes are evaluated by clinical protocol which includes Holter monitoring ergometric test, echocardiography study, thyroid check and transesophageal electrophysiologic study at rest and during exercise. The arrhythmological study should be carefully performed in order to exclude an underlying heart disease, to study electrophysiological mechanisms and possible hemodynamic effect sports activity relate of the inducible and clinical tachyarrhythmias. Sometimes, these PSRT may disappear after interruption of athletic activity because of modifications of electrophysiological conditions related to the sports activity.

Electrocardiography, Ambulatory↗
PubMed1991

[Amyloidosis in monoclonal gammapathies. Observations of the authors' own cases].

We have investigated the presence of amyloid in 25 patients with multiple myeloma and in 12 patients with benign monoclonal gammopathies. Ascari's function resulted valid for the screening of patients with amyloidosis. Fine needle biopsy of subcutaneous fat showed the amyloid in 20% of patients with myeloma and in no patient with benign monoclonal gammopathies. The ratio voltage/mass resulted very useful for the diagnosis of cardiac amyloidosis. Sites involved were heart and kidney.

Adipose Tissue↗
PubMed1990

[Cardiac rhythm in athletes: a Holter study of top level and ex-professional football players].

The study we performed aimed at identifying the arrhythmological pattern in the football player. Between 1984 and 1989, 50 top level football players (group A) from the National Olympic team and from the National A team, average age 24.2 years (min. 19, max. 32), underwent Holter monitoring. The recordings were carried out in different environmental conditions according tot he programmes of the team and the number of recordings depended on how long each football player stayed in the National team. Moreover, 40 trainers (group B) from the Italian football teams, average age 38.4 years (min. 32, max. 57), all of whom had formerly been professional high-level football players practising intensive physical exercise for professional reasons, underwent one 24 h Holter monitoring. RESULTS. Group A: 2621 hours of monitoring were able to be analysed in 48/50 football players. Sinus node pauses greater than or equal to 1750 ms were found in 21/48 (43.7%) with a maximum of 3740 ms on altitude in 1/21, second degree atrioventricular block in 8/48 (16.7%) with a maximum of 5400 ms on altitude in 1/8, supraventricular ectopic beats in 13/48 (27%), ventricular ectopic beats in 26/48 (54.1%) which were complex (cl. Lown greater than or equal to 3) in 7/26. Group B: 882.30 hours of monitoring were able to be analysed in 39/40 former football players. Sinus node pauses greater than or equal to 1750 ms were found in 18/39 (46.1%) with a maximum of 2280 ms in 7/18, second degree atrioventricular block in 1/39 (2.6%) with a maximum of 2400 ms, supraventricular ectopic beats in 32/39 (82%), ventricular ectopic beats in 24/39 (61.5%) which were complex in 5/24.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Stable ventricular tachycardia in arrhythmogenic dysplasia of the right ventricle in sportsmen].

Right ventricular arrhythmogenic dysplasia (RVAD) is a typical asymptomatic arrhythmogenic cardiopathy in athletes, which is occasionally concurrent with normal ventricular function and life-threatening arrhythmias. A total of 32 athletes (28 males and 4 females, mean age, 23 years, mean follow-up, 6.7 years) were examined for severe cardiac arrhythmias with left bundle branch block. The conclusive diagnosis of RVAD was established from clinical, echocardio-, and angiographic evidence. The protocol of the examination involved Holter monitoring, loading tests, electrophysiological study, two-dimensional echocardiography, cardiac angiography of the right and left ventricles, coronary angiography. The most severe arrhythmias were observed in athletes whose mean age was 23.4 years, 20 patients had sustained ventricular tachycardia (it occurred only in 19 who were indulging in sports), 6 presented with transient ventricular tachycardia, and 1 had ventricular fibrillation. They all had been considered fit for sports. The disease proceeded severely in 16 of 32 athletes (in 13 of 16 while indulging in sports), the conditions close to syncope were seen in 9 patients (8 had sustained ventricular tachycardias and 1 had transient ventricular tachycardias), syncopes were observed in 5 patients (sustained ventricular tachycardias).

Adult↗
PubMed1990

[Stage classification of chronic lymphatic leukemia. A retrospective analysis of 263 cases].

We have analyzed 263 consecutive patients with chronic-lymphocytic leukemia. They all have been studied according to five different staging systems respectively proposed by Rai (1975), Binet (1977), Binet again (1981), Baccarini (1982) and Rozman (1984). All these procedures proved to be effective, because they divided our cases in groups with significant differences in survival time. The paper displays features and usefulness of each staging system.

Adult↗
PubMed1990

[Prognosis in Hodgkin's disease: verification of a new predictive equation].

A retrospective analysis of a series of 114 patients with Hodgkin's disease was carried out. The patient were male, aged greater than or equal to 45 years, histotype mixed cellularity or lymphocytic depletion, advanced stage (III o IV), ESR greater than 45 mm/1h., serum albumin less than or equal to 3.5 gr/dl appeared to be unfavorable parameters at diagnosis. The application of a predictive linear equation recently proposed by Gobbi et al. revealed a agreement between survival and predicted mean survival.

Adolescent↗
PubMed1989

Arrhythmia patterns in athletes with arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is a typical 'silent' arrhythmogenic cardiomyopathy in athletes, with the possibility of normal ventricular performance and life-threatening arrhythmias. We studied 32 athletes (28 M, 4 F), mean age 23 years, follow-up 6.7 years, all previously declared fit for sports activity. They were studied for significant ventricular arrhythmias with LBBB with a final diagnosis of ARVD based on accepted clinical, echocardiographic and angiographic criteria. The study protocol included Holter monitoring (HM), stress test (ST), electrophysiological endocavitary study (EES), 2D echocardiography, RV and LV cardioangiography and coronarography. The most serious arrhythmia appeared at a mean age of 23.4 years, 20 had clinical sustained ventricular tachycardia (VT) (19/20, 95% during sports activity), six non-sustained VT and one ventricular fibrillation (VF). Severe symptoms occurred in 16/32 athletes (50%) during sports activity in 13/16 (81%): presyncope in nine (non-sustained VT in one, sustained VT in eight); syncope in five (sustained VT); aborted sudden death (SD) in one, SD (follow-up) in one. The reproducibility (HM, ST, EES) of clinically severe arrhythmic manifestations which occurred during sports activity was not high. In fact, during sport many factors are at work which may activate several arrhythmogenic mechanisms not easily reproducible in the laboratory. We conclude that a cardioarrhythmological study is mandatory in suspected right ventricular arrhythmias, including morphological study of the RV, to avoid arrhythmic risk during athletic activity.

Adult↗
PubMed1989

[Prognostic significance of skeletal lesions in multiple myeloma].

Prognostic significance of the skeletal lesions in multiple myeloma. Fifty-two patients with multiple myeloma have been analysed and relations between bone X-ray changes and several clinical biohumoral parameters and survival have been found. Our studies show no correlation between the extent of skeletal lesions and the seriousness of anaemia, or between bone marrow infiltration and renal involvement. The results also show that patients with apparently normal bones may also have serious anaemia, wide bone marrow infiltration and serious renal lesions rapidly leading to a poor prognosis. Comparison of survival curves, according to the grade of bone X-ray changes at presentation, shows no significant difference: the grade of bone lesions at diagnosis does not seem to considerably influence survival.

Aged↗
PubMed1989

[Arrhythmologic study of 50 patients with arrhythmogenic disease of the right ventricle: prognostic implications].

UNLABELLED: Arrhythmogenic right ventricular disease is a syndrome which involves a wide spectrum of anatomo-clinical features. It is characterised by different levels of right ventricle anomaly, and by life-threatening "right" hyperkinetic ventricular arrhythmias. Fifty consecutive pts were retrospectively examined at the Arrhythmological Centre in Trento between 1977 and 1988. The results of rigorous arrhythmological, echocardiographic and angiographic criteria showed that all pts were affected by arrhythmogenic right ventricular disease. CASE STUDY: 39/50 (78%) males, 11/50 (22%) females; age 30.6 years (11-78) at the time of the first study. METHODS: clinical history in 50/50 pts, electrocardiogram in 50/50 pts, Holter monitoring in 50/50 pts, ergometric test in 49/50 pts, non-invasive analysis using signal-averaging QRS in 17/50 pts, 2D echocardiogram in 50/50 pts, angiography in 38/50 pts, electrophysiological endocavitary study in 35/50 pts. RESULTS: familial 2/50 (4%); 1/50 (2%) was in class II NYHA; first arrhythmia at 24.6 years (8-60); most severe arrhythmia at 27.7 years (9-74). Forty-three out of fifty patients (86%) were symptomatic for arrhythmias: 28/50 (56%) as a result of stress; 20/50 (40%) had life-threatening symptoms; 6/50 (12%) had aborted sudden death. Arrhythmogenic right ventricular disease was "localized" in 42/50 (84%) and "diffused" in 8/50 (16%) and was associated with anomalies of the left ventricle in 30/50 (60%). Electrocardiogram showed: right bundle branch block in 10/50 (20%), negative T wave on the right precordial leads in 19/50 (38%), delayed ventricular potentials in 4/17 (23.5%). Using the electrocardiogram, Holter monitoring and electrophysiological endocavitary study the following were documented: a) clinical ventricular tachycardia in 40/50 (80%): non-sustained ventricular tachycardia in 10/50 (20%), sustained ventricular tachycardia in 30/50 (60%); b) electrically induced ventricular tachycardia in 26/35 (74.2%): non-sustained ventricular tachycardia in 8/35 (22.8%), sustained ventricular tachycardia in 18/35 (51.4%) (clinical sustained ventricular tachycardia in 18/18); c) multiform ventricular tachycardia in 12/50 (24%) (diffused arrhythmogenic right ventricular disease in 3/12 and associated anomalies of the left ventricle in 11/12); d) pleomorphic sustained ventricular tachycardia in 9/30 (30%) (diffused arrhythmogenic right ventricular disease in 2/9, and associated anomalies of the left ventricle in 8/9). Forty-two out of fifty patients (84%) underwent antiarrhythmic treatment. When the study was carried out 6.6 years (1 month-22 years) had passed since the first symptom; follow-up was 2.1 years (1 month-11 years) while the interval between the first symptom and the last check-up was 8.4 years (1-30 years); 2/50 dropped out and 2/50 died suddenly.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Induction of supraventricular tachyarrhythmia at rest and during exercise with transoesophageal atrial pacing in the electrophysiological evaluation of asymptomatic athletes with Wolff-Parkinson-White syndrome.

Even today there is controversy as regards the best approach to asymptomatic or slightly symptomatic athletes with the WPW syndrome as regards fitness for sports activity, especially in some countries where the doctor is responsible for certifying sports fitness. This study concerns 84 asymptomatic or slightly symptomatic athletes (66 males, 18 females, mean age 21.7 years, range 12-44 years) who underwent a stimulation protocol the end-point of which was the induction of atrial fibrillation (or, if not possible, atrial tachyarrhythmia) in the basal state and during bicycle stress test with transesophageal atrial pacing. The 81 athletes in whom the end-point was reached were divided into two groups: Group I includes the 32 athletes with the shortest R-R interval between pre-excited beats less than or equal to 240 ms in the basal state and/or less than or equal to 210 ms during bicycle ergometer test, Group II includes the other 49 patients. The evaluation during exercise was not carried out in four athletes because of serious haemodynamic compromise due to the arrhythmia induced in the basal state. Only 21/32 athletes would have been included in Group I if only evaluated in the basal state. In 30/81 athletes (37%), there was discrepancy between the result of stimulation and the result of the usual non-invasive evaluation (Holter monitoring, ergometric stress test, ajmaline test). On average, 40 min are required for the performance of the study protocol except when the induced arrhythmia lasts more than 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗