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Biomedical subjects

M R Ferrari

Publications and source records attributed to M R Ferrari.

7 recordsLinked to original sources
PubMed1992

Impaired circadian modulation of sympathovagal activity in diabetes. A possible explanation for altered temporal onset of cardiovascular disease.

BACKGROUND: Diabetic subjects have a high incidence of cardiovascular accidents, with an altered circadian distribution. Abnormalities in the circadian rhythm of autonomic tone may be responsible for this altered temporal onset of cardiovascular disease. METHODS AND RESULTS: To assess circadian changes of sympathovagal balance in diabetes, we performed 24-hour power spectral analysis of RR interval fluctuations in 54 diabetic subjects (age, 44 +/- 2 years) with either normal autonomic function or mild to severe autonomic neuropathy and in 54 age-matched control subjects. The power in the low-frequency (LF, 0.03-0.15 Hz) and high-frequency (HF, 0.18-0.40 Hz) bands was considered an index of relative sympathetic and vagal activity, respectively. Diabetic subjects with autonomic abnormalities showed a reduction in LF compared with control subjects (5.95 +/- 0.12 In-msec2 versus 6.73 +/- 0.11, p < 0.001) and an even greater reduction in LF, particularly during the night and the first hours after awakening (5.11 +/- 0.18 In-msec2 versus 6.52 +/- 0.14, p < 0.001). Day-night rhythm in sympathovagal balance was reduced or absent in diabetic subjects compared with control subjects. CONCLUSIONS: Diabetic subjects with or without signs of autonomic neuropathy have a decreased vagal activity (and hence a relatively higher sympathetic activity) during night hours and at the same time of the day, during which a higher frequency of cardiovascular accidents has been reported. These observations may provide insight into the increased cardiac risk of diabetic patients, particularly if autonomic neuropathy is present.

Adult↗
PubMed1988

Relationship between fluctuations in heart rate and asymptomatic nocturnal ischaemia.

In order to quantify autonomic changes related to asymptomatic nocturnal myocardial ischaemia, we analyzed heart rate fluctuations recorded during Holter monitoring in 9 subjects with coronary heart disease (21 episodes) and in 11 age-matched controls. R-R interval spectral analysis was computed in sequences of 256 heart beats, taken during the ischaemic episode, 4, 8 and 60 minutes before, and 4 and 60 minutes after. Mean heart rate, R-R interval variability (assessed by R-R interval standard deviation), low and high (respiration-linked) frequency components of R-R interval spectrum were evaluated. Mean heart rate and R-R interval variability increased only during ischaemia (from 62.9 to 73.3 beats/minute, P less than 0.02, and from 39 to 88 msec, P less than 0.01, respectively). While high-frequency components of heart rate variability remained unchanged, low-frequency peak increased during ischaemia (from 9.4 to 43.3 sec2 X 10(-3)/Hz, P less than 0.01) and also 8 minutes (P less than 0.05) and 4 minutes before (P less than 0.05). Despite a moderate increase of heart rate occurring only during ischaemia, the early rearrangement of heart rate fluctuations suggests the occurrence of changes of autonomic tone before the electrocardiographic onset of ischaemia. Due to its limited amount, this phenomenon appears to be a consequence, most likely unspecific, of factors responsible for the genesis of myocardial ischaemia.

Aged↗
PubMedDate not supplied

Chromatin cytophotometric analysis of abnormal bovine spermatozoa.

Sperm head morphology is basically conditioned by the nuclear structure. The aim of the present work was to study the relation between nuclear morphological features, DNA content and chromatin distribution in morphologically normal vs. abnormal bovine spermatozoa. To this end, individual Feulgen-reacted spermatozoa were cytophotometrically studied. Chromatin compactation was evaluated by means of nuclear area, as well as mean and maximal absorbance of each nucleus. Morphological abnormality analysed included large, small, pear, narrow and round shapes, together with presumably 'diploid' sperms. Both large and small spermatozoa have a DNA content that does not differ significantly from normal values, but their area and mean and maximal absorbance are significantly different. Size variation seems basically due to altered chromatin compactation. The pear shapes have a narrower neck and a significant increase in maximal absorbance alone, which is invariably recorded in the neck zone whose increase would indicate a change in distribution and/or compactation. The narrow and round shapes fail to present significant variations in studied parameters. The possible 'diploids' differ significantly from normal cells in all studied variables, with a little area increase.

Animals↗
PubMedDate not supplied

[Evaluation of the appropriateness of hospital use: the case of IRCCS Ospedale Maggiore di Milano, Italy].

In 1999 an Italian version of the AEP was applied to some units of the IRCCS Ospedale Maggiore di Milano and a modified AEP version was used to evaluate the day hospital activity. The main aims of the study were: to establish the appropriateness of the utilisation of beds and of day hospital activity and to calculate the costing of the misuse of hospital resources. 267 admission days were evaluated and 31.5% were not appropriated; whereas of 3,248 days of stay 37% were found not appropriated. The day hospital activity was evaluated through 300 record referred to 570 days of treatment and 13% of them were not appropriated. The cost of the 1,201 not appropriated hospital days was over 351.000. The not appropriated level of hospital utilisation in the IRCCS Ospedale Maggiore di Milano is similar to what is reported in national and international literature. Our study highlights some limits in the application of the AEP protocol at high specialised hospital units.

Adolescent↗
PubMedDate not supplied

[Evaluation of the appropriateness of hospital use: the case of IRCCS Ospedale Maggiore di Milano, Italy].

To measure the level of not appropriated hospital use for some DRG's a Lombardia Region AEP version was applied to two units in the Ospedale Maggiore in Milano. The aims of the study was to evaluate the level of appropriateness in Neurology and Dermatology wards for some DRG's which are at risk to be applied in not appropriated way, to study the reasons of not appropriated use, to educate medical doctors in neurology and dermatology to apply for the right level of care for they patients and to highlight some limits of the Lombardia Regional protocol.

Dermatology↗