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Biomedical subjects

M Leone

Publications and source records attributed to M Leone.

At least 199 records · Page 11Linked to original sources
PubMed1987

Disability and quality of life in hereditary ataxias: a self-administered postal questionnaire.

A postal questionnaire was sent to 151 patients affected by Friedreich's disease (FD) and other hereditary ataxias (OHA) to study their disability and quality of life. A 79.5% response rate was obtained. A scoring system based on disability in walking, dressing, personal care, eating and speaking was developed and used. Walking was the most impaired activity. The degree of disability was similar between FD and OHA. Institutionalization, frequency of social contacts, work activity, recreational and social activities were influenced by disability.

Activities of Daily Living↗
PubMed1987

Transmembrane pressures generated by filtrate line suction maneuvers and predilution fluid replacement during in vitro continuous arteriovenous hemofiltration.

A recirculating in vitro CAVH system was designed which generated pulsatile blood and filtrate flows. Monitors recorded hydrostatic pressures simultaneously in the arterial, venous and filtrate lines during varying plasma or blood flow rates and predilution (vs postdilution) replacement fluid flow rates. Similar hydrostatic pressure monitoring was carried out during multiple maneuvers to generate suction on the filtrate side of the hemofilter (Amicon D-20's and Renaflo's). With a plasma flow (Qp) of 100 cc/min and predilution replacement fluid infusion rate of 500 cc/hr, the arterial pressure was 5% greater than during postdilution (p less than 0.05). With a blood flow (Qb) of 50 cc/min, predilution fluid replacement rates of 500 and 1000 cc/hr, and vacuum suction applied to the filtrate compartment, the arterial pressure was 33% lower than during postdilution fluid replacement (p less than 0.03). Nonetheless, the ultrafiltration rate (UFR) was 10 to 30% higher (p less than 0.03). At many other combinations of Qp, Qb and replacement rates and modes, there were no significant changes in arterial pressure. Despite these arterial pressure changes, greater than 70% of the transmembrane hydrostatic pressure (TMP) was due to the negative pressure induced by filtrate suction (gravity, Gomco, wall suction, IMED). The actual pressure in the filtrate compartment measured during Gomco or wall suction was 3/4 of that stated by their gauges, presumably due to leakage. Maximum wall suction never generated TMP's greater than 150 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood↗
PubMed1986

Ataxia clinical rating scale in Friedreich disease.

The "Ataxia Clinical Rating Scale" was used on 22 patients with Friedreich disease. We found a positive correlation (r = 0.64, p less than 0.005) between total score and duration of symptoms. For this reason the scale may be useful in the follow-up of patients affected by Friedreich disease.

Adult↗
PubMed1986

Prevalence of hereditary ataxias and paraplegias in the province of Torino, Italy.

A descriptive epidemiological survey of hereditary ataxias and spastic paraplegias was conducted in the province of Torino, Italy (2,327 996 inhabitants). On prevalence day (31 December 1982) 142 patients were alive. Total prevalence was 6.1 cases/100,000 inhabitants (95% confidence limits = 5.1-7.0). The prevalence rate was 2.6 for recessive or sporadic juvenile ataxias, 1.3 for spastic paraplegias, 1.2 for autosomal dominant cerebellar ataxias, and 1.1 for late onset cerebellar ataxias. The prevalence of hereditary ataxias is similar in our province to that recorded in other populations, but hereditary spastic paraplegias are less frequent than in other populations.

Adult↗
PubMed1986

Quantitative analysis of quadriceps muscle biopsy. Results in 7 definite and 45 possible carriers of Duchenne muscular dystrophy.

Quadriceps muscle biopsy was performed in 7 definite and 45 possible carriers of Duchenne muscular dystrophy. Unequivocal morphological changes were observed in 8 women; all but one of them were already detected as carriers by increased serum CK. Histometric analysis of muscle biopsy was performed on two fibre types (type 1 and type 2) in all 52 women; in 38 of them the two subgroups of type 2 fibres (type 2a and type 2b) were also quantified. Results of histometric analysis were matched with control values obtained from 30 healthy females in the same age as the carriers (20-50 yr). Histometric analysis on two fibre types detected a percentage of carriers (27%) much lower than that detected by serum CK determination (44%). The detection rate of combined serum CK determination and histometric analysis of muscle biopsy was: 100% in definite carriers, 65% in mothers possible carriers, 38% in sisters and 25% in the group of cousins and aunts. The histometric parameters most frequently altered were atrophy factor and variability coefficient of mean diameter. Histometric analysis carried out on three fibre types in 38 women detected 2 more carriers showing atrophy of type 2b fibres. The results indicate that quantitative analysis of muscle biopsy may be used to detect some possible carriers with normal serum CK. However, an adequate number of controls is mandatory; in fact the detection rate of histometric analysis of muscle biopsy decreased by increasing the number of controls, resulting much lower than previously reported.

Adult↗
PubMed1986

Optical absorption spectra of deoxy- and oxyhemoglobin in the temperature range 300-20 K. Relation with protein dynamics.

We have studied the optical absorption spectra of human deoxy- and oxyhemoglobin in the temperature range 300-20 K and in the wavelength range 350-1350 nm. By lowering the temperature, a narrowing and a shift of all bands were observed together with a sizeable increase of the integrated intensities of the charge-transfer bands of deoxyhemoglobin. At all temperatures the spectra are in full agreement with the band assignment previously suggested in the literature and no new relevant bands have been detected for both deoxy- and oxyhemoglobin. Analysis of the first and second moment of the bands, within the framework of the harmonic Franck-Condon approximation, gave information on the dynamic properties of the heme in the heme pocket.

Freezing↗
PubMed1986

Effect of glutamine on growth and heterocyst differentiation in the cyanobacterium Anabaena variabilis.

Mutants of the cyanobacterium Anabaena variabilis that were capable of increased uptake of glutamine, as compared with that in the parental strains, were isolated. Growth of these mutants and their parental strains was measured in media containing N2, ammonia, or glutamine as a source of nitrogen. All strains grew well with any one of these sources of fixed nitrogen. Much of the glutamine taken up by the cells was converted to glutamate. The concentrations of glutamine, glutamate, arginine, ornithine, and citrulline in free amino acid pools in glutamine-grown cells were high compared with the concentrations of these amino acids in ammonia-grown or N2-grown cells. All strains capable of heterocyst differentiation, including a strain which produced nonfunctional heterocysts, grew and formed heterocysts in the presence of glutamine. However, nitrogenase activity was repressed in glutamine-grown cells. Glutamine may not be the molecule directly responsible for repression of the differentiation of heterocysts.

Acetylene↗
PubMed1985

A survival analysis of 155 cases of progressive muscular atrophy.

We performed a survival analysis of 155 cases of progressive muscular atrophy (PMA). In about half the cases, hands were involved first, the lower limbs in 30% and the shoulder girdle in 23%. The lifetables of PMA, adjusted to the expected mortality, showed a survival rate of 61.3% and 56.4% at three and five years, respectively. The location of onset symptoms did not modify the life expectancy, whereas the age of the patients at the moment of first diagnosis had a great influence on the course of the disease. The patients were further subdivided in two groups on the basis of the diffusion of the neuromuscular damage at the moment of the diagnosis. The course of the patients with a localized disease was markedly better than that of subjects with widespread disease. Some hypotheses are made about the latter group of cases.

Adult↗
PubMed1983

A rapid and simple assay for the study of thromboxane B2 synthesis by intact human platelets.

Conversion of 1-14C-arachidonic acid (AA) to thromboxane B2 (TXB2) by human platelets was studied by using a new, simple technique. Organic solvent extraction was avoided by spotting aliquots of the reaction mixture directly on thin layer chromatography (TLC) plates. In this way it was possible to study the kinetic parameters of the formation of TXB2. Moreover, the rapidity and simplicity of the assay should be particularly suitable when studying the possible relationships between thromboxane synthesis and aggregation function in human platelets, where a large number of determinations is required.

Blood Platelets↗
PubMed1983

Biomolecular-solvent stereodynamic coupling probed by deuteration.

Thermodynamic interpretation of experiments with isotopically perturbed solvent supports the view that solvent stereodynamics is directly relevant to thermodynamic stability of biomolecules. According with the current understanding of the structure of the aqueous solvent, in any stereodynamic configuration of the latter, connectivity pathways are identifiable for their topologic and order properties. Perturbing the solvent by isotopic substitution or, e.g., by addition of co-solvents, can therefore be viewed as reinforcing or otherwise perturbing these topologic structures. This microscopic model readily visualizes thermodynamic interpretation. In conclusion, the topologic stereodynamic structures of connectivity pathways in the solvent, as modified by interaction with solutes, acquire a specific thermodynamic and biological significance, and the problem of thermodynamic and functional stability of biomolecules is seen in its full pertinent phase space.

Deuterium↗
PubMed1983

Motor neuron disease in the Province of Turin, Italy, 1971-1980.

The incidence and prevalence of motor neuron disease (MND) in the Province of Turin, North-West Italy, were investigated for the period 1971-1980. The crude incidence rate of MND was 0.67/100,000/year. The annual incidence rate, age and sex adjusted to the Italian population in 1971 was 0.69 cases per 100,000 inhabitants, 0.94 for men and 0.45 for women, with a male to female incidence ratio of 2.09:1. The prevalence of MND was 2.62/100,000, 3.57 for males and 1.71 for females. The mean age at the time of diagnosis was 55.6 years. Annual incidence rates increased with advancing age. Amyotrophic lateral sclerosis was found to be 4 times more frequent than progressive muscular atrophy (0.53/100,000/year v. 0.14/100,000/year). The distribution of MND was uneven in the Province suggesting a proportional relationship to the distribution of population density. Possible explanations of this finding are discussed.

Age Factors↗
PubMed1981

Prognosis and clinical varieties of ALS disease.

210 cases of ALS disease in the period 1955-1979 are considered. Different parameters such as sex, age, duration and clinical course have been correlated with four clinical types: conventional, pseudopolyneuritic, pyramidal and bulbar. The age distribution shows a peak in the fifth decade of life. The sex ratio is 2.08:1. Considering together all the clinical types, the mean duration of the disease is 27.05 months. The bulbar variety has the poorest prognosis (19.6 months) and the pyramidal variety the best (37.59 months). Familiarity is evidenced in only 3 cases. All our data are discussed and compared with those of the literature.

Adult↗