Triiodothyronine deiodinating activity in brown adipose tissue after short cold stimulation test in trained and untrained rats.

Interscapular brown adipose tissue (IBAT) activity is controlled by sympathetic nervous system, and factors that influence thermogenesis appear to be centrally connected to the sympathetic outflow to IBAT. Cold exposure produces a rise in BAT temperature, which is associated with an increased thyroid activity, elevated serum levels of 3,5,3'-triiodothyronine (T3), and an increased rate of T3 production. This study evaluated the effect of swimming training on 5'-triiodothyronine deiodinase (5'-D) activity in IBAT under normal environmental conditions and after short (30 min) cold exposure (TST stimulation test). 5'-D activity is lower in trained rats at basal condition, and TST increases 5'-D in IBAT of both untrained and trained rats. However, this increase is lower in trained rats. Training reduces the deiodinating activity in normal environmental conditions as well as after short cold exposure. Probably, other compensatory mechanisms of heat production are active in trained rodents.

Effect of low intensity electrical stimulation on quadriceps muscle voluntary maximal strength.

BACKGROUND: Evaluate the effect of low intensity electrical stimulation (ES) training on strength. We purposefully used a low ES stimulation intensity to have it well accepted by middle aged and low performing people. Relate strength to metabolic parameters. METHODS: Experimental design. Protocol 1: effects of 11 day low intensity ES training on quadriceps muscle maximal voluntary contraction (MVC). Protocol 2: effects of 3 day training at low intensity ES + voluntary contraction at 60% of MVC (co-contraction). VARIABLES MEASURED: maximal voluntary strength (FMAX), strength during ES (FES), strength developed during co-contraction (FES-C), oxygen consumption, heart rate. Experimental design included a basal session, a training program and controls of measured variables during and at the end of the training program. PARTICIPANTS: protocol 1: experiments were done on 13 healthy and sedentary subjects (6 males and 7 women, mean age 50.6 years). Protocol 2: experiments done on 6 healthy sedentary men (mean age 31.5 years). RESULTS: Protocol 1: FMAX increased significantly (p<0.05) to 14 and 19% at day 6 and 11, respectively. During ES, oxygen consumption increased by 20%, but no change in heart rate was observed. Protocol 2: FMAX significantly increased (about 5%) in subjects who trained with co-contraction; conversely, FMAX did not significantly increase in a control group matched for age who trained only with voluntary contractions. CONCLUSIONS: Low intensity ES in sedentary and poorly performing people increases significantly FMAX during MVC possibly via facilitatory neurogenic mechanism.

The effect of a carbohydrate loading on running performance during a 25-km treadmill time trial by level of aerobic capacity in athletes.

The aim of the present study was to examine the influence of a high carbohydrate diet and the level of aerobic capacity on running performance during a 25-km treadmill time trial. The study used a 2*2 design with the factors being training and diet composition. We divided the athletes in 4 groups: 1. Trained athletes with carbohydrate loading (CHO1); 2. Trained athletes without carbohydrate loading (C1); 3. Untrained athletes with carbohydrate loading (CHO2); 4. Untrained athletes without carbohydrate loading (C2). The carbohydrate loading was effected with confectionery. Performance time, running speed, blood glucose and blood lactate concentrations were evaluated during two 25-km treadmill time trial (trial 1 and trial 2) separated by 7 days in which two groups (CHO1 and CHO2) had a carbohydrate loading. The results showed that the athletes with lower level of aerobic capacity had better performance time after carbohydrate loading. They ran faster and had a higher glucose and lactate concentrations in the last 5 km during trial 2. There were no significant differences in the other groups. In conclusion, we can assert that dietary carbohydrate loading can improve running performance and that confectionery can be used as an effective means of supplementing the normal carbohydrate intake in preparation for endurance competitions. But the improvement depends on some factors such as the distance and the level of aerobic capacity.

Thyroid hormone plasmatic levels in rats treated with serotonin in acute and chronic way.

Many experiments show that serotonin (5-HT) controls thyroidal function at hypothalamic level, inhibiting the TRH secretion. The majority of experiments are done in an acute way, consisting of a single serotonin dose injected intraperitoneally (i.p.) or intracerebroventricularly (ic) with the effect registered after a short time (usually 1 h) as in normal environmental conditions similar to the TSH stimulation test, that consists of transfer of the experimental animals from 30 degrees C to 4 degrees C for 30 min, thus inducing stimulation of the hypothalamus-hypophysis-thyroid axis. The aim of the present research was to study the correlation between 5-HT and the thyroidal function, measuring plasmatic thyroid hormone levels in rats i.p. treated in chronic (injected daily for 10 days with different doses of 5-HT), and in acute way (after 1 h from a single 2.0 mg/kg bw 5-HT dose) in normal environmental conditions to evidence the serotonin site action activity outside the blood-brain barrier. The results of the chronic experiment show an inhibitory effect of 5-HT, on T3 and T4 plasmatic level, only when it is injected at medium doses (0.2 and 0.4 mg/kg bw for T3, and 0.2 for T4), while the results of the acute experiment do not evidence any modification. These results show that in normal environmental conditions the outside 5-HT site action is active only when the 5-HT is injected chronically at defined doses, probably for a down-regulation phenomenon.

Neostigmine in the hippocampus increases thermogenesis and T4-to-T3 conversion.

The firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), IBAT and colonic temperatures (TIBAT and TC), and O2 consumption were monitored in urethan-anesthetized male Sprague-Dawley rats. These variables were measured for 40 min before (baseline values) and 40 min after a neostigmine (5 x 10(-7) mol) or saline injection in the hippocampus. The blood level of 3,5,3'-triiodothyronine and L-thyroxine (T3 and T4) and the 5'-deiodinating activity of IBAT, liver, and kidneys were determined in other rats with neostigmine or saline injection. The results showed that neostigmine injection increased firing rate, TIBAT, TC, O2 consumption, blood level of T3, and 5'-deiodinating activity of IBAT. No change was found in the T4 level and in 5'-deiodinating activity of the liver and kidneys. These findings suggest that neostigmine injection in the hippocampus increases heat production by stimulating sympathetic nerves to IBAT and by elevating the blood level of T3.

[Value of continuous electrocardiographic monitoring of patients with syncope. Results of a prospective study]. / Utilità delle registrazioni elettrocardiografiche continue nei pazienti con sincope. Risultati di uno studio prospettico.

AIM: Syncope, a temporary loss of conscience, is a frequent cause for consulting the family doctor or more often being brought to the hospital emergency ward. In order to evaluate the importance of the continuous recording of ECG in the formulation of the diagnosis, the relevant data were extrapolated from more general data in the prospective study. MATERIAL: A total of 194 patients were enrolled whose diagnosis was divided into three distinct stages. Continuous echographic registration using Holter's method and/or bedside monitoring was included in the 2nd stage and was performed in 134 patients. RESULTS: 102 out of 134 patients (76.11%) showed rhythm alterations: varying degrees of atrio-ventricular block were recorded in 6 patients; supraventricular arrhythmia in 73 cases which were divided according to a modified to a modified version of Lawn's classification. Continuous ECG recording alone proved decisive in formulating a diagnosis in 6 patients (one of which together with echocardiogram): in 2 patients due to the presence of complex ventricular extrasystoles; in 4 due to torsion of the tip, sinusal arrest, cardiac arrest, supraventricular tachycardia with aberrant intraventricular conduction, respectively. CONCLUSIONS: Especially when standard surface ECG is carried out rapidly following an acute attack, continuous ECG recording is of scant diagnostic value due to the etiological definition of syncope. But due to its moderate cost and non-invasive character it is worth performing in syncopes of suspected cardiogenic etiology with a more severe prognosis.

[Syncope in a general population: etiologic diagnosis and follow-up. Results of a prospective study]. / La sincope in una popolazione generale: diagnosi eziologica e follow-up. Risultati di uno studio prospettico.

OBJECTIVE: Syncope is a common clinical problem in a general population. A prospective study was performed, in our hospital, to evaluate the incidence of the disease and to standardize the diagnostic and clinical management. METHODS: 194 patients aged 10-92 years were recruited during one year. The diagnostic produce followed the three standard stages: First stage clinical evaluation (a complete history, physical and neurological examination, a base-line laboratory evaluation, a 12-lead electrocardiogram, carotid sinus stimulation); Second stage non invasive investigation (echocardiogram, 24-hour electrocardiographic monitoring, electroencephalography, Doppler echocardiography of epiaortic vessels, head-up tilt test, head CT scan); third stage invasive investigation (electrophysiologic study). RESULTS: Diagnosis was, sometimes, difficult because of the sporadic and transitory nature of the syncope. The etiological diagnosis were the following: cardiovascular causes 68.55% (cardiac 31.95%, reflex syncope 36.59%). Non-cardiovascular causes 10.82% (metabolic 5.15%, neurologic 3.5%, different 2.06%). Unknown cause 20.61%. Diagnosis was determined at the following stages: ist stage 63.40% (complete history and physical examination alone 4072%), 2nd stage 14.43%, 3rd stage 1.54%. The mean follow-up period was 21.71 +/- 6.22 months. Over this period 17 (8.76) patients died; all aged (> 65 years) end in this aged the incidence is 18.08%. If we look at patients with correct diagnosis of syncope (183 patients) the mortality rate is 8.19% (if we consider those aged > 65 the rate is 17.44%). The mortality rate of cardiac syncope of unknown (28.88% for aged > 65 years). 2 deaths among syncope of unknown cause. 17.48% had 1 or more episodes of recurrent syncope during this follow-up period with little prevalence for patients with syncope of unknown origin. Other major cardiovascular events was 18.03% in all patients with little prevalence for cardiac cause of syncope. CONCLUSIONS: 1) Frequently an accurate history, a physical examination and a standard ECG are enough to formulate a correct diagnosis. 2) Head-up tilt test must be considered in patients with a unknown diagnosis, before starting invasive investigation. 3) Prognosis is dependent on the specific cause. Since cardiac syncope has a serious prognosis, when it is not treated correctly, it can even lead to sudden death.

[Otitis media in the child. Follow-up study and control of 104 cases]. / L'otite media nel bambino. Studio e controllo a distanza di 104 casi.

The authors report a case-study on 104 children admitted for many reasons to the I Department of Pediatrics of the A. Meyer Hospital in the period 1979-81. During their hospitalization, otitis media was diagnosed in all these cases. The children later underwent two check-ups including otorhinolaryngologic and tympanometric tests and in some cases an audiometric examination. A correlation between otitis media and enlarged adenoids was noticed and the results of the present case-study are compared with other international publications, following the short bibliography.

[Interrelation of blood glucose and serotonin in rats]. / Rapporto tra glicemia e serotonina nei ratti.

Previous experiments have put in evidence that the 5-HT injected intraperitoneally in rats elicits remarkable variations of some enzymatic activities of glycolytic pathways and it is an iperglicemic factor as in function of dose that of time. For that the AA. have measured the glycemia in different starting glicemic conditions, to control if the 5-HT effect persists. The results have evidenced the 5-HT effect (20 mg/kg i.p.) there is also in fasting rats as drinking water as a water solution of glucose (20%).

[Changes in liver and muscle glycogen in rats treated with serotonin]. / Variazioni del glicogeno epatico e muscolare in ratti trattati con serotonina.

The authors have put in evidence that the 5-HT (20 mg/Kg b.w.) injected intraperitoneally in four days fasting rats and drinking water, causes an almost complete glycogenolysis in liver and muscles. When the 5-HT is injected in four days fasting rats but drinking a water solution (20%) of glucose, the amount of glycogen, in both organs, is marked increased.

[Time course of blood glucose levels in rats after intraperitoneal injection of a dose of serotonin]. / Andamento temporale della glicemia nei ratti dopo iniezione intraperitoneale di una dose di serotonina.

The injection of 20 mg/Kg of serotonin intraperitoneally, in rats, elicits a progressive and marked increase of blood glucose after 30, 60 and 90 minutes. These results, according with previous experiments of the same authors, put yet in evidence that the serotonin has a clear influence on glucose metabolism.

[Serotonin action of CPK and alpha-HBDH activities in the heart and muscle of rats]. / Attività CPKasica e alpha-HBDHasica nel cuore e nel muscolo di ratti iniettati con serotonina.

Serotonin injected intraperitoneally in rats (20 mg/Kg of body weight) doesn't modify remarkably the enzymatic activities CPK and alpha-HBDH of the heart and muscle at different times from the injection (30, 60 and 90 min).

[Serotonin action on plasma total lipids, triglycerides and NEFA in rats]. / Lipidi totali, trigliceridi e NEFA nel plasma di ratti iniettati con serotonina.

Serotonin injected intraperitoneally in rats (20 mg/Kg of body weight) doesn't modify remarkably the plasmatic level of total lipids, of triglycerides and of non esterified fatty acids (NEFA) at different times from the injection (30, 60 and 90 min).

[Xeroradiography in nasal bones fractures (author's transl)]. / L'indagine xeroradiografica nelle fratture delle ossa del naso.

Traumatic lesions of nasal bones were investigated by xerography in 44 patients. "Negative", rather than "positive", method is preferred. Soft tissues can be accurately inspected too; these lesions can exactly evaluated and possible contraindications to surgical reduction of such fractures are easily detected.

[Influence of serotonin on some serum enzyme activities in rats]. / Influenza della serotonina su alcune attivita' enzimatiche sietiche in ratti.

The serotonin injected intraperitoneally in rats (20 mg/Kg of body weight) modifies some seric enzymatic activities (LDH, alpha-HBDH and CPK) at different times from the injection (30, 60, 90 min.), acting probably on membrane permeability and on intracellular metabolism.