PubMed Health⌕ Search

Biomedical subjects

A Locatelli

Publications and source records attributed to A Locatelli.

At least 145 records · Page 8Linked to original sources
PubMed1990

Effect of transport loading or noise on blood biochemical variables in calves.

The influence of 2 transport stressors (loading and noise) on several serum and plasma biochemical variables was studied in 4 calves. When calves were loaded and kept for 30 minutes on a motionless transport simulator or were exposed to the noise of the working simulator, increases in plasma epinephrine and serum cortisol and nonesterified fatty acids concentrations were similar to changes observed in calves subjected to simulated transport for 30 minutes. Results indicate that loading and noise have an important role in transport stress.

Animals↗
PubMed1989

[The medical team and the campaign for primary prevention of cardiovascular diseases in the Tessin canton].

This study presents the results of a questionnaire research into the subjective perception of the free-practicing doctors in Ticino concerning the primary prevention programme against cardiovascular risk factors, directed to the whole cantonal population by the Social Welfare Department. 93% of the doctors (82% of the population) are aware of the programme and 82% of those interviewed judged it to be useful or very useful. Furthermore, the single initiatives of the programme (TV-advertisements and information-Leaflets) were also evaluated, as well as the frequency of preventive practices during medical visits (information on tobacco risks, blood pressure measurement, treatment of hypercholesterolemia). This study was also analyzed on the basis of questionnaire received before (response rate 41%) and after having sent out a further reminder (final response rate 61%). The results and conclusions did not differ with an increase in the reply rate.

Adult↗
PubMed1989

Clinical evaluation of the effect of acetylcholine on the corneal endothelium.

A transient corneal edema is often seen after the injection of acetylcholine solution in the anterior chamber during cataract surgery. Ninety eyes of 90 patients scheduled for extracapsular cataract extraction with posterior chamber intraocular lens implantation were randomly assigned to two groups: one which received acetylcholine solution in the anterior chamber and one, a control group, which received only external conjunctival pilocarpine drops as a miotic. At three days, endothelial folds (P = .04) and corneal edema (P = .01) were more pronounced in the acetylcholine group; at seven days, endothelial folds were more severe (P = .04) in the acetylcholine group. At 30 days, the acetylcholine group showed a 37.2% increase (P = .01) of the endothelial cell area, whereas the control group showed a 7.08% increase. The difference between the groups was statistically significant (P = .05). Anterior chamber fluorophotometry at 30 days showed an increase of the corneal transfer coefficient that was higher but not significant in the acetylcholine group. We suggest caution in the intraoperative use of acetylcholine solution, particularly in those eyes showing a preoperative compromise of the endothelium.

Acetylcholine↗
PubMed1989

Mental arithmetic stress as a test for evaluation of diabetic sympathetic autonomic neuropathy.

The effects of a 1-min mental arithmetic stress test on heart rate change were studied in 72 Type 1 diabetic patients, 36 without and 36 with diabetic autonomic neuropathy (mean age 33 and 44 yr, respectively), and in 80 matched normal subjects. Variation in hand skin temperature was also recorded in 25 normal subjects and 30 diabetic patients without and 32 with autonomic neuropathy. While mental arithmetic rapidly reduced skin temperature of normal volunteers and of patients without autonomic neuropathy, no effect was found in autonomic neuropath (a drop of 0.63 +/- 0.05 (+/- SE), 0.52 +/- 0.04 and 0.16 +/- 0.02 degrees C (p less than 0.001), respectively). In control subjects and in diabetic patients without and with autonomic neuropathy the heart rate increase was 22.9 +/- 6.8 (+/- SD), 21.4 +/- 8.4 and 7.0 +/- 3.7 beats min-1, respectively (p less than 0.001). The ratio between maximum mental arithmetic-induced heart rate and basal heart rate was 1.29 +/- 0.10, 1.24 +/- 0.10 and 1.07 +/- 0.05 (p less than 0.001) for healthy subjects, non-neuropathic patients, and neuropathic patients. Cut-off values (the low normal limit for these variables) are proposed: skin temperature 0.23 degrees C, heart rate increase 11.6 beats min-1 and heart rate ratio 1.12. Anxiety state, blood glucose concentration (excluding hypoglycaemia), body position, basal heart rate, and age did not interfere with responses to mental arithmetic stress.

Adult↗
PubMed1989

Non-involvement of the accessory olfactory system in the LH response of anoestrous ewes to male odour.

In anoestrous ewes, male chemosignals elicit rapid increases in luteinizing hormone (LH) secretion that can ultimately lead to ovulation. To assess the possible involvement of the accessory (vomeronasal) olfactory system in the mediation of those chemical cues, we destroyed this pathway by vomeronasal organ electrocauterization (Exp. I) and vomeronasal nerve section (Exp. II). Neither of these lesions inhibited the LH response of ewes to the odour of the male. These results suggest that the vomeronasal system is not necessary to mediate the neuroendocrine response of the ewe to the male odour. As both surgical methods spared the main olfactory system but destroyed the vomeronasal system, it is likely that the main olfactory system is involved in the LH response to chemical stimulation in sexually experienced ewes.

Anestrus↗
PubMed1989

Biphasic response in the secretion of gonadotrophin-releasing hormone in ovariectomized ewes injected with oestradiol.

In ovariectomized ewes, an injection of oestrogen initially inhibits the tonic secretion of LH, and then induces a large release of LH similar to the preovulatory surge in intact ewes. The pattern of hypothalamic secretion of gonadotrophin-releasing hormone (GnRH) into the pituitary portal blood during this biphasic response to oestrogen was investigated in conscious, unrestrained, ovariectomized adult Ile-de-France ewes during the breeding season. The ewes were ovariectomized and implanted with cannulae for portal blood collection on the same day. Seven days later, portal and peripheral blood samples were collected simultaneously every 5 min for 25 h. The ewes were injected with oestradiol-17 beta (25 micrograms i.v. and 25 micrograms i.m.) 6.25 h after the start of sampling. GnRH and LH were measured by radioimmunoassay in portal and jugular plasma samples respectively. A clear pulsatile pattern of LH secretion was observed before the oestradiol injection in all the ewes, followed by the typical biphasic decrease (negative feedback) and increase (positive feedback) in mean concentrations. The sampling period was divided, for analysis, into pretreatment, negative feedback and positive feedback phases. Before injection with oestradiol, the GnRH pulses were clearly defined in portal blood and were always synchronized with LH pulses in the peripheral circulation. The frequency was 5.9 +/- 0.6 pulses/6 h (mean +/- S.E.M.), and the amplitude was 31.6 +/- 7.6 pmol/l. During negative feedback, both the frequency (4.2 +/- 0.5 pulses/6 h, P less than 0.01) and amplitude (15.2 +/- 4.6 pmol/l, P less than 0.05) of the GnRH pulses decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Role of creatine phosphate in myocardial protection in heart surgery].

The Authors report their experience with the use of Creatine Phosphate (CP) in cardiac surgery. Forty patients undergoing mitral valve replacement are randomly divided into two groups: the former is treated with plain cardioplegia, the latter with CP-enriched cardioplegia at a concentration of 10 mmol/l. A sample of papillary muscle, obtained from the removed valve, is studied by means of spectrophotometric analysis in order to assess the enzyme activities and the intermediate metabolites of the different biochemical pathways of the myocardial cell. Our results suggest a possible interaction of exogenous CP with the cellular metabolism: all the mechanisms involved with the production of energy seem to be shifted towards a better preservation of the available pool of high-energy compounds.

Aged↗
PubMed1988

Secretion of corticotropin releasing factor (CRF) and vasopressin (AVP) into the hypophysial portal blood of conscious, unrestrained rams.

The secretion of Corticotropin-Releasing Factor (CRF) and Arginine Vasopressin (AVP) into sheep hypothalamo-hypophysial portal blood was investigated in conscious, unrestrained castrated rams. One to two hours after the onset of the collection, peripheral ACTH and cortisol levels were within the basal range in all the animals and portal CRF and AVP concentrations were low ranging between 5 and 90 pg/ml. After acute hemorrhage, a sharp increase in portal CRF and AVP was observed, inducing a sustained elevation of peripheral ACTH and cortisol. These data show that measurements of CRF and AVP in the portal blood of conscious sheep provide a good methodology to study the regulation of basal and stress-induced ACTH secretion.

Animals↗
PubMed1988

Effect of time after castration on secretion of LHRH and LH in the ram.

Hypophysial portal blood and peripheral blood were obtained from conscious, unrestrained rams to measure simultaneously the secretion of LHRH and LH in entire rams and rams which had been castrated for 2-15 days (short-term castration) and for 1-6 months (long-term castration). The apparatus for portal blood collection was surgically implanted using a transnasal trans-sphenoidal approach and, 4-5 days later, portal blood and peripheral blood were collected simultaneously at 10-min intervals for 8-9 h from 15 sheep. LHRH was clearly secreted in pulses in all three physiological conditions, but there were marked differences in pulse frequencies, which averaged 1 pulse/2-4 h in entire rams, 1 pulse/70 min in short-term castrated rams and 1 pulse/36 min in long-term castrated rams. In entire and short-term castrated animals, LH profiles were also clearly pulsatile and each LHRH pulse in hypophysial portal blood was associated with an LH pulse in the peripheral blood. In long-term castrated animals, LH pulses were not as well defined, because of the high basal levels and small pulse amplitudes, and the temporal relationship between LHRH and LH pulses was not always clear. These results demonstrate the pulsatile nature of LHRH secretion under the three physiological conditions and suggest that the irregular LH profiles characteristic of long-term castrates are due to an inability of the pituitary gland to transduce accurately the hypothalamic signal. The very high frequency of the LHRH pulses may be one of the major reasons for this, and is probably also responsible for the high rate of LH secretion in the long-term castrated animal.

Animals↗
PubMed1988

Are differences in FSH concentrations involved in the control of ovulation rate in Romanov and Ile-de-France ewes?

Despite differences in FSH concentrations ranging from 1.5 ng/ml (Romanov ewes) to 4 ng/ml (Ile-de-France ewes) between the follicular and luteal phases, follicular growth (numbers of follicles growing, growth rates, maximum size reached) was morphologically similar between the two stages of the cycle. Injection of 750 i.u. hCG at Day 6 or 16 of the cycle triggered ovulation of 4.1 +/- 0.7 and 4.0 +/- 1.3 follicles in Romanov and 2.2 +/- 0.5 and 1.7 +/- 0.5 follicles in Ile-de-France ewes, respectively, demonstrating that functional differentiation was similar between the two stages of the cycle. As gonadotrophin environment differs between these two stages of the cycle, this suggests that there is a wide flexibility in the amount of gonadotrophins required to trigger terminal follicular growth and that ovarian requirements for gonadotrophins might work through thresholds. When Romanov and Ile-de-France ewes were given similar amounts of exogenous gonadotrophins (1250 i.u. PMSG, 750 i.u. hCG) after hypophysectomy, ovulation rates were close to the usual values (Romanov, 5.5 +/- 3.9; Ile-de-France, 1.4 +/- 0.5), demonstrating that differences in gonadotrophin concentrations during the follicular phase do not play a major role in the high ovulation of the Romanov compared to the Ile-de-France ewes.

Animals↗
PubMed1987

[Insulin therapy with microinfusion devices. Review of the literature].

The aim of the present work is to review the most recent data in the literature about the problems, true advantages and limits of continuous infusion of insulin in the therapy of insulin-dependent diabetes mellitus. After a report on the kinds of microinfusors available today and the possible ways of continuously administering insulin, some aspects of CSII (continuous subcutaneous insulin infusion) are reviewed: indications, side effects, patterns of insulin flow programming and psychological aspects. The need for preliminary selection of the patients who are to undergo instructive courses is emphasized. Then the data from the literature about the effects of continuous infusional therapy in relation to metabolic alterations and the later complications of diabetes are analysed. These important aspects are compared with the results of conventional insulin therapy. Finally, the effects of continuous infusional therapy during pregnancy, on brittle diabetes, on insulin sensitivity and on the "down phenomenon" are analysed. It is concluded that, even if you cannot formulate a definitive opinion about this topic, microinfusors can be a functional means of achieving excellent metabolic control. Nevertheless, their greater efficiency in comparison with the so-called optimized insulin therapy has not been unequivocably demonstrated, and the real need for them at the present time appears to be exceptional.

Diabetes Mellitus, Type 1↗
PubMed1987

[Pseudoaldosteronism caused by licorice. Review of the literature and description of 4 clinical cases].

Metabolic and toxic effects caused by prolonged daily ingestion of Liquorice are well known in the literature. Such acquisition doesn't seem to be known enough by practitioners and by common people. Besides active substances such as Glycyrrhizin , Liquorice contains even steroids similar to the adrenocortical ones; among these the most important is Beta-Glycyrrhetinic acid. This one, in vivo and in vitro, produces salt and water retention by means of a "DOCA-like" mineral-corticoid mechanism, and clear suppression of the Renin-Angiotensin-Aldosterone axis. A low plasmatic level of Renin and Aldosterone is a common feature. The clinical picture in many ways is similar to the primary Aldosteronism and for this reason the above mentioned syndrome is usually called "Pseudoaldosteronism". Symptoms and signs can be classified into the following main groups: symptoms linked with water and salt retention: oedemas, hypertension, cardiac involvement. Symptoms linked with serum Potassium depletion: asthenia, paralysis (due to Potassium deficiency), myopathy with myoglobinuria. The diagnosis is essential based on an accurate pharmacological dietetic history, aimed to recognise an excessive use of Liquorice (pure or more often as substitute) in the screening of hypertension with or without hypopotassemia. Finally, the more or less quick normalisation of blood pressure and biochemical signs--as an "ex juvantibus" criterion--is the most important reason for the diagnosis. After a wide survey of the literature, the clinical and biological picture in four patients with chronic Liquorice ingestion and Pseudoaldosteronism syndrome is described.

Adult↗
PubMed1987

A continuous flow intermittent mandatory ventilation with continuous positive airway pressure circuit with high-compliance reservoir bag.

Unstable inspiratory pressure may reduce the benefits of intermittent mandatory ventilation and impose a greater work of breathing than some patients can tolerate. The authors evaluated a continuous flow intermittent mandatory ventilation with continuous positive airway pressure apparatus provided with a 10-L high compliance reservoir bag, separated from the ventilator circuit by a one-way valve. A pulmonary simulator was tested to generate a wide range of inspiratory peak flow rates. Pressures and flow rates were examined in different sections of the system, using PEEP levels up to 15 mm Hg and different fresh gas flow rates. The circuit offers many advantages, particularly considering the low inspiratory pressure drop and the low fresh gas flow rates needed for optimal function.

Equipment Design↗