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Biomedical subjects

G Franchi

Publications and source records attributed to G Franchi.

At least 37 records · Page 2Linked to original sources
PubMed1997

Bilateral coupling in learned blinking: effects of lesion aimed at callosal disconnection of the cat motor cortex.

The effects of selective transection of the rostralmost portion of the corpus callosum, which contains fibers interconnecting the motor cortices of the two hemispheres, on interocular temporal coupling in the initiation of learned symmetrical blinking were examined in 5 cats trained to blink in response to a 500-ms tone paired with 100-ms airpuffs randomly delivered to either eye (alternate airpuff; 3 animals) or simultaneously directed to both eyes (bilateral airpuff; 2 animals) 400 ms after tone onset. Lesioning had no effect on ability to respond, but did cause a significant increase in the mean conditioned response (CR) latencies of both eyes in all subjects. In the intact cats, a statistically significant difference between the mean CR latencies of the two eyes (hereafter called side superiority) was found in three animals, two of which exhibited superiority of the left eye. After lesioning, it was found that the right eye proved superior to the left eye in four subjects. Both before and after lesioning, side superiority was not due to the ability of one eye to give CRs consistently shorter than those of the other eye, but it crucially depended on the higher proportion of trials in which the superior eye led. A linear correlation between CR latencies of the right and left eye was found in all animals both before and after lesioning. It is suggested that subsequent to lesioning aimed at callosal disconnection of the motor cortex, the effects on initiation of learned symmetrical blinking are the consequences of withdrawal of both bilaterally balanced modulatory influences to both eyes and lateralized modulatory influences to the left eye.

Animals↗
PubMed1997

Bilateral coupling in learned blinking: side superiority, synchrony and temporal coordination in normal cats.

In order to study interocular temporal coupling in the initiation of learned symmetrical blinking, experiments were carried out on cats trained to blink in response to a 500-ms tone paired with 100-ms airpuffs randomly delivered to either eye (alternate airpuff; 6 animals) or simultaneously directed to both eyes (bilateral airpuff; 4 animals) 400 ms after tone onset. In spite of the fact that differences in conditioned response (CR) latencies of the right and left eye varied in a wide range between positive and negative values in all subjects, a statistically significant difference between the mean CR latencies of the two eyes (further called side superiority) was found in 6 animals, of which 4 were trained by alternate airpuff and 2 by bilateral airpuff. Superiority of the right eye was found in 3 animals and the opposite was observed in the other 3. Analysis of the differences between CR latencies of the two eyes showed that side superiority was not due to the ability of one eye to give CRs consistently shorter than those of the other eye, but it crucially depended on the higher proportion of trials in which the superior eye led. The ability to give simultaneous CRs by the two eyes was found inversely related to the mean CR latency per session and subject. Regression analysis showed that power equations best described these relationships. In all animals, the frequency distribution of simultaneous CRs paralleled the frequency distribution of all CRs. In spite of a considerable trial-by-trial variability in the temporal relationships between CR latencies of the two eyes, clear-cut linear correlations were found by plotting the mean CR latencies of the right and left eye per both session and subject. The results reviewed in this paper are best accounted for by suggesting that blink onset of the two eyes is independently controlled by two distinct command signals and is modulated by bilaterally-balanced and lateralized influences.

Air Pressure↗
PubMed1997

Microspectrophotometric evaluation of digestibility of pollen grains.

Digestibility of pollen grains of poppy (Papaver rhoeas) and hazelnut (Corylus avellana) subjected to a human-like in vitro digestion with pancreatic enzymes was evaluated. Pollens showed different types of walls. Digestibility was determined for total protein and insoluble carbohydrate contents by means of a new application of microspectrophotometry. Results demonstrated that pollen grains of both species were only partly digested; after 24 h treatment, only 26% of carbohydrates and 48% of proteins were digested in poppy and only 3% and 59% in hazelnut. This is probably due to the difficulty of enzymes to penetrate the intine of pollen grains. The degree of digestion of insoluble carbohydrates varied in the studied species according to their chemical nature and their storage sites.

Carbohydrate Metabolism↗
PubMed1997

Spreading the clinical information system: which users are satisfied?

The present study deals with the assessment of the perceived usefulness and perceived ease of use of the clinical core of the HIS we are building, and progressively spreading into the medical centre, through the use of two questionnaires. The differences in subjective perception among clinical units and professional roles have been analyzed. Results show that the system, in use on a mandatory basis, has been accepted. Most of the users are satisfied, and probable removable causes of dissatisfaction have been identified.

Adult↗
PubMed1997

[Evaluation by bioelectric impedance of body fluid compartments and body mass in cardiosurgical patients before and after total cardiopulmonary bypass].

BACKGROUND: To evaluate the influence of extracorporeal circulation (ECC) on fluid compartments and body mass using impedance measurements. METHODS: A prospective study was performed in 20 consecutive patients undergoing ECC during heart surgery at the Department of Heart Surgery of Verona Hospital. Resistance or reactance measurements at 1-5-10-50-100 KHz were performed in 20 patients undergoing heart surgery for valvular or coronary pathologies in class NYHA I or II, preoperatively and on day 1, 3 and 6 in order to evaluate total body water (TBW), intracellular water (ICW), extracellular water (ECW), thin and fat body mass. Weight, fluid-electrolytic balance and hematochemical parameters relating to electrochemical phenomena and the distribution of volumes in the various compartments, namely sodium, potassium and plasmatic osmolarity, were measured at the same times. Comparisons were made both between the data and during ECC. RESULTS: It was found that there was a mean postoperative weight gain of 2 kg in terms of total body water. Subsequently, this finding tended to decrease to basal values by day 6. Immediately after ECC, the water gain appeared to be predominantly extracellular, whereas the intracellular increase peaked on day 1. The change in total body water was correlated with the weight and fluid balance, but electrical measurements showed values above the corresponding weight gain. The duration of ECC was significantly correlated with bioelectric parameters, but not with absolute weight values. CONCLUSIONS: The method proved useful for the purpose, especially with regard to the overall population examined rather than individual patients. The dual-compartment electric model appears to be more suitable than the single-compartment model for exploring the different compartments. The trend of weight and total body water, which were correlated in pattern but not in absolute values, may be interpreted as a redistribution of fluids, also suggested by changes in electric parameters relating to compartmental distribution.

Aged↗
PubMed1996

Evidence for a facilitatory role of callosal afferents to the cat motor cortex in the initiation of conditioned bilateral movements.

The effects of selective transection of the rostralmost portion of the corpus callosum, which contains fibres interconnecting the motor cortices of the two hemispheres, on frequency of occurrence and latency of conditioned responses (CRs) in both eyes were examined in seven cats trained to blink in response to a 500-ms tone. A 100-ms air-puff delivered to one eye only (ipsilateral eye) 400 ms after tone onset was used as an unconditioned stimulus. Both before and after callosal lesion, bilateral CRs were the most frequent response pattern. Following callosal lesion, a statistically significant reduction in the percentage of CRs in at least one eye was observed in only two cats. In all seven animals, both before and after callosal lesion, the mean CR latencies of the ipsilateral eye were significantly shorter than those of the contralateral eye. Callosal lesion caused a significant increase in the mean CR latencies of both eyes in all subjects. These results provide evidence that the two hemispheres influence each other in controlling conditioned bilateral blinking by reciprocally exchanging facilitatory signals contributing to initiation of CRs in both eyes.

Acoustic Stimulation↗
PubMed1996

Painful vein overdistension in migraine patients: no relationship with serotoninergic parameters.

Overdistension of the hand-forearm veins after a period of ischaemia-induced stasis causes local pain in a high percentage of migraineurs, but never in healthy subjects. To investigate the mechanism of such pain, we compared 5-hydroxytryptamine (5HT) whole blood levels and hand vein 5HT reactivity of migraine subjects who did experience pain during venous overdistension to those who did not. No differences were found in whole blood 5HT levels or in the venoconstrictor activity of 5HT between subjects experiencing pain and those who did not. No correlation was found between whole blood 5HT levels and the degree of 5HT-induced venoconstriction. Our results suggest that, if platelets are considered as a model of central antinociceptive 5HT neurons, pain appearance is not due to reduced 5HT at a central level and, therefore, to increased perception of peripheral nociceptive stimuli. Moreover, the similar 5HT venoconstrictive effect (indirect marker of venous tone and, therefore, of venous distensibility) seems to indicate that a mechanical factor is not involved in pain appearance during the HAVD test.

Adult↗
PubMed1996

Testosterone-induced increase of insulin-like growth factor I levels depends upon normal levels of growth hormone.

Pubertal development is associated with a rise in plasma insulin-like growth factor I (IGF-I) levels that is related both to the increase in sex steroids and/or to the sex steroid-induced augmentation in endogenous growth hormone (GH) secretion. In order to investigate the relationship between IGF-I, GH and testosterone, we examined 42 male subjects with various clinical conditions (classical GH deficiency (CGHD, N = 5), non-classical GH deficiency (NCGHD, N = 7), short idiopathic stature (N = 6), nutritional obesity (N = 8), GH-treated CGHD (N = 4), GH-treated NCGHD (N = 5) and normal stature (N = 7)) in which , for evaluation of hypogonadism (i.e. the absence of one or both testes from the scrotal sac), human chorionic gonadotropin (hCG) tests were performed. We measured IGF-I, total and free testosterone and dehydroepiandrosterone sulfate (DHEAS) by radioimmunoassays before and 48 and 96 h after the start of the test. The values of IGF-I were lower (0.001 < p < 0.005) in CGHD and NCGHD than in the other groups. In comparison to basal levels, IGF-I values increased (0.005 < p < 0.05) both 48 and 96 h after the start of the hCG test in short idiopathic and normal stature children and in GH-treated subjects with NCGHD, but only 96 h in subjects with untreated NCGHD and GH-treated CGHD. No difference was demonstrated in basal values of total testosterone among any of the groups, while basal free testosterone levels were higher (0.001 < p < 0.05) in GH-treated subjects with NCGHD than in all the other groups except nutritional obesity; furthermore, free testosterone was higher (p < 0.05) in nutritional obesity than in CGHD. The values of total and free testosterone obtained both 48 and 96 h after the start of the hCG test were higher (0.001 < p < 0.05) than basal values in all groups. The DHEAS values did not show any significant change during the hCG test. Basal values were higher (0.01 < p < 0.05) in nutritional obesity than in the other groups. Considering all groups, chronological age, bone age and bone age/chronological age ratio were correlated with basal free testosterone, IGF-I and DHEAS levels (0.001 < p < 0.05), while basal free testosterone and IGF-I values were correlated with DHEAS levels (p < 0.005 and < 0.01, respectively). In conclusion, our study during the hCG test in boys with various clinical conditions demonstrated an increase in IGF-I concentrations only in those boys with sufficient GH secretion or GH replacement therapy. These findings indicate that both sex steroids and GH are necessary to allow for the pubertal increase in IGF-I levels.

Body Height↗
PubMed1996

Assessing users' satisfaction through perception of usefulness and ease of use in the daily interaction with a hospital information system.

The present study deals with the assessment of the subjective perception of the clinical core of the hospital information system (HIS) we are building. This HIS is not in use on a voluntary basis, but physicians and nurses use it for all the aspects of their inpatient care that have been informatized. Two questionnaires, aimed at the assessment of users perceived usefulness and ease of use of information technology, were utilized to: obtain feedback of the actual users' satisfaction as a predictive factor for the future life of the system, assess the real influence of the often-mentioned problems of age and unfamiliarity with computers of potential users, learn about the aspects which would enhance users' acceptance. The analysis of answers to the questionnaires has indicated a substantially positive perception of the system in terms of both usefulness and ease of use. This constitutes a good reason to keep on investing in the project. Even though this study has the intrinsic limit of the small dimension of the inquired population (53 users, equivalent to 98% of the personnel of the assessed clinical units), our data confirm the inconsistency of the relationship between perception of usefulness and age, and show "unfamiliarity with computers" as commonplace. On the other hand, it seems that the keystone for usefulness perception is the knowledge the users have of the system. An effort by the technical personnel in establishing a broader collaboration with the users, and in providing more exhaustive training and support may well be worthwhile.

Age Factors↗
PubMed1995

Effect of combined treatment with gonadotropin releasing hormone analogue and growth hormone in patients with central precocious puberty who had subnormal growth velocity and impaired height prognosis.

Growth hormone-insulin-like growth factor-I status and response to growth hormone therapy (0.6 IU/kg/week sc, six times a week for 12 months) were evaluated in 12 girls (chronological age 9.4 +/- 1.6 years) suffering from central precocious puberty with growth velocity less than 4 cm/year and no substantial increase or decrease in predicted adult height during gonadotropin releasing hormone Bn-RH) analogue treatment (D-Trp6-LH-RH, 60 micrograms/kg im/28 days). At baseline, large variations were observed in nocturnal growth hormone (GH) means (pathological values stimulated levodopa GH peaks (pathological values (< 10.0 micrograms/l) 28.6%) and serum insulin-like growth factor-I (IGF-I) levels. Neither GH-nor IGF-I levels were correlated with growth velocity. During recombinant GH therapy, growth velocity increased significantly (baseline 3.0 +/- 0.9 cm/year; 6 months 6.4 +/- 1.9 cm/year, p < 0.001 versus baseline; 12 months 6.0 +/- 1.3 cm/year, p < 0.0001 versus baseline). There was a significant increase in height SDS for bone age (baseline -1.6 +/- 0.5 SDS; 12 months -1.04 +/- 0.6 SDS; p < 0.002) and in predicted adult height (baseline 152.0 +/- 3.6 cm; 12 months 155.9 +/- 3.4 cm; p < 0.002). Our results suggest that combined therapy with Gn-RH analogues and recombinant GH can improve growth velocity and predicted adult height in girls with central precocious puberty and impaired height prognosis during Gn-RH analogue treatment.

Age Determination by Skeleton↗
PubMed1995

[Fracture of the medial wall of the orbit. Apropos of 4 cases].

Fractures or the medial wall of the orbit are uncommon and clinical signs are often discreet. This report was focused on isolated fractures of the medial wall of the orbit. Blow-out trauma is usually the cause. In these cases the clinical signs ranged from simple ecchymosis to blindness by haematoma of the orbital cone. Computed tomography is a major tool for diagnosis and making therapeutic indications for these fractures. Treatment depends on the oculomotor involvements as measured by forced duction tests.

Blindness↗
PubMed1995

Interaction and dialogue between the users and the patient record core of hospital information system: looking for a solution.

The lack of good user interface, in terms of both modality of dialogue and system behaviour is the major impediment to the acceptance and routine use of the computer based patient record (CPR) core of a hospital information system. We describe here the adopted approach to face the daily users' needs, overcoming the pitfalls of the paper based patient record (PPR), and giving the physicians an exhaustive modality for CPR inspection.

Hospital Information Systems↗
PubMed1994

Comparison between venoconstrictor effects of sumatriptan and ergotamine in migraine patients.

The vasoconstrictor activity of sumatriptan and ergotamine were compared by injecting these drugs in the hand vein of migraine subjects. We used the "venotest method", which permits the evaluation of the venoconstrictor effect of small doses of drugs, acting locally in the hand vein. Sumatriptan injected at increasing doses in the hand vein provoked contraction only at high doses (500 micrograms): venoconstriction lasted 5-15 minutes and was similar in intensity and duration to that induced by 0.5-1 micrograms of 5-hydroxytryptamine (5-HT). Likewise, ergotamine induced contraction only at a dose of 50 micrograms: this venoconstrictor effect was long lasting (at least 1 hour). Ergotamine-induced hand vein contraction, almost completely inhibited by ketanserin, seems mediated at least in part by 5-HT2 receptors, like the one induced by 5-HT and sumatriptan, already observed in a previous study. Clinical doses of ergotamine (0.25 mg intramuscular) and of sumatriptan (6 mg subcutaneous) do not provoke hand vein contraction for at least 1 hour: this could be due to a low activity of these drugs on the 5-HT2 vein receptors or a technique that is unsuitable to detect the vasoconstrictor effect of drugs given by the systemic route. The long lasting venoconstrictor effect of ergotamine may be due to a slow dissociation from receptor sites. The short vasoconstriction induced by sumatriptan could account for the recurrence of headache in many sumatriptan-treated migraine subjects.

Adult↗
PubMed1993

Reduction of bone density: an effect of gonadotropin releasing hormone analogue treatment in central precocious puberty.

Gonadal steroids drive the significant bone mineral increase that occurs at puberty. Oestrogen deprivation in women results in bone loss. We investigated bone mineralization by single photon absorptiometry in girls with central precocious puberty (n = 13, age 3.8-8.5 years) before and during 1 year of treatment with gonadotropin releasing hormone analogue (GnRH-a = long-acting D-Trp6-GnRH, 60 micrograms i.m. every 28 days). Before GnRH-a therapy, bone mineral density (BMD) was significantly higher in patients than in ten control girls matched for chronological age (patients 0.575 +/- 0.097 g/cm2, controls 0.433 +/- 0.049 g/cm2, P < 0.001). Patient BMD was not significantly different from that of ten control girls matched according to patient bone, age (0.550 +/- 0.046 g/cm2, P = NS). During GnRH-a treatment, pituitary-gonadal axis was suppressed and patient BMD significantly decreased (6 months: -6.0%, P < 0.002 vs baseline; 12 months: -8.0%, P < 0.001 vs baseline). We conclude that in girls with precocious puberty the activation of gonadal steroid secretion induces an increase in bone mineralization and that oestrogen deprivation by GnRH-a treatment caused a significant decrease in BMD.

Absorptiometry, Photon↗
PubMed1993

Amplifying effect of sumatriptan on noradrenaline venoconstriction in migraine patients.

The venoconstrictive activity of sumatriptan and its interaction with noradrenaline (NA)- and 5-hydroxytryptamine (5HT) venoconstriction was studied in vivo in the hand vein of migraineurs. Sumatriptan, injected at increasing doses into the vein, caused local venoconstriction after a 500 microgram dose, comparable to that induced by 0.5-1 micrograms of 5HT. This venoconstriction was completely inhibited by low doses of ketanserin (5 micrograms). Subcutaneous sumatriptan (6 mg) provoked a minor increase in vein tone, lasting less than 30 min. Non-venoconstrictive doses of sumatriptan (10-100 micrograms), injected in the hand vein, produced an amplification of NA-venoconstriction but not of 5HT-induced venoconstriction. A similar increased effect was displayed by subcutaneous sumatriptan (6 mg) for at least 1 h. Sumatriptan appears to cause peripheral venoconstriction only at high doses locally applied (in the hand vein), by acting on 5HT2 receptors. Clinical subcutaneous doses (6 mg) do not show significant venoconstrictive effects. The amplifying effect on NA venoconstriction, also caused by 5HT, ergotamine and dihydroergotamine in human cranial arteries, may be important in explaining the therapeutic action of sumatriptan in migraine attacks.

Adolescent↗
PubMed1993

Time stability of a drug molecule sterilized through gamma rays.

In a previous work, we studied the possibility to process a drug molecule through a gamma rays sterilizing treatment. Optimal process conditions were studied and the related effects on the treated molecule were analyzed, as well. From obtained results, we concluded that there are not any contraindications to apply this sterilization process to the molecule treated. In this second paper we examined the time stability of the active ingredient treated with a gamma rays sterilization process. Among treated and untreated samples, stored in the refrigerator as well as room temperature, or slightly above, we did not observe any time-related in behaviour differences. Instead, samples stored at higher temperature (80 degrees C) showed behavioural differences between gamma treated and gamma untreated samples. This phenomenon, that at the beginning we found unexplainable, subsequently could be explained owing to further tests of "molecule stabilization" with temperature.

Carnitine↗