Explosive-aggressive behavior related to bilateral subthalamic stimulation.

We describe a patient with Parkinson's Disease who underwent bilateral subthalamic nucleus deep brain stimulation and later presented with episodes of aggressive behavior disorder with disturbed impulse control and an inability to control anger likely related to the deep brain stimulation "switch-on stimulation". We hypothesize that increasing voltage intensity could influence neighboring passing fibers coming from basal limbic system that are involved in the regulation of affect and emotional behavior. We suggest investigating these neuropsychological disturbances considering their influence on quality of life after surgery.

Environmental stress on diving-induced platelet activation.

Platelet activation has been suggested to play an important role in the pathogenesis of prethrombotic states and thus may be responsible for decompression illness during compressed air (scuba) diving. To investigate the effect of physical, mental, and environmental stress on platelet activation during immersion in ice-cold water, we examined 10 male breath-hold divers (BHD), 10 elite BHD (eBHD), and 10 scuba divers during immersion in an ice-covered lake at moderate altitude. Platelet activation was examined by surface expression of activation-dependent glycoproteins CD62p, CD63, and CD42a with flow cytometry 10 min before and 1 min and again 24 h after diving. Plasma epinephrine level was also measured. In addition, the relationship between the activated platelets and the epinephrine level was evaluated. The percentage of platelet activation increased from 2.1 +/- 0.4 to 5.7 +/- 0.3, 1.8 +/- 0.3 to 12.9 +/- 0.8, and 3.7 +/- 0.9 to 31.2 +/- 0.8 in BHD, eBHD, and scuba divers, respectively. The percentage of platelet activation returned to pre-immersion levels in BHD and eBHD divers 24 h after diving, but was still higher in scuba divers. A positive relationship exists between the plasma epinephrine level and the percentage of the platelet activation. This study suggests that physical and mental stress enhance platelet activation during diving in ice-cold water.

Cardiac and humoral changes induced by recreational scuba diving.

The aim of this study was to evaluate the prevalence and the possible clinical relevance of circulating bubbles after a recreational scuba dive. Twenty healthy subjects (18 male, 2 female; age range 25-36 yr) underwent a Doppler-echocardiographic study in basal conditions and 1.9+/-0.2 h after a recreational scuba dive. Venous blood samples were taken just before the two ultrasonic studies to obtain leukocyte and platelet counts and plasma activity of angiotensin-converting enzyme (ACE; assumed as pulmonary endothelial damage marker). Circulating bubbles were observed in the right heart chambers of 12 subjects after the dive. The echocardiographic and humoral data were evaluated before and after diving in subjects with and without circulating bubbles. At the postdive evaluation, a significant increase in right ventricular dimensions (37.4+/-3.9 vs. 40.7+/-4.0 mm; P < 0.01) and a significant reduction of early diastolic filling velocities of both right (59.1+/-16.4 vs. 48.9+/-6.9 cm x s-(-1); P < 0.05) and left (76.2+/-9.9 vs. 67.5+/-10.2 cm x s(-1); P < 0.02) ventricle were observed in the group with circulating bubbles. In the same group, significant increases in ACE activity (92.9+/-41.1 vs. 105.9+/-41.7 U x liter(-1); P < 0.05), platelets (217+/-34 vs. 232+/-35 10(3) x microl(-1); P < 0.01), and granulocytes (3,704+/-715 x microl(-1) vs. 5,212+/-1,995 x microl(-1); P < 0.001) were observed. The bubble-free group showed only a postdive significant decrease of left ventricular early diastolic filling velocity (74+/-6.8 vs. 62.6+/-4.5 cm x s(-1); P < 0.005). These data may indicate that circulating gas bubbles are associated with cardiac changes, suggesting a right ventricular overload and an impairment of ventricular diastolic performance. Postdive humoral and hematologic changes are consistent with the hypothesis that "silent" gas bubbles may damage pulmonary endothelium and activate the reactive systems of the human body.

Effect of acute and chronic cobalt administration on carotid body chemoreceptors responses.

Chronic cobalt exposure leads to release and production of erythropoietin and consequently to polycythemia. Accordingly, cellular elements sensitive to oxygen in the carotid body, would manifest responses during acute and chronic cobalt administration. The carotid body, detects gas changes (PO2, PCO2/pH) in the arterial blood and regulates ventilation and circulation by the afferent nerve discharge. We hypothesized that cobalt interacts with an oxygen sensitive mechanism in the carotid chemoreception and in erythropoietin producing cells. Twelve cats were anesthetized, paralysed and artificially ventilated; few fiber preparation of carotid sinus nerve were recorded during close intraarterial injection of cobalt. In another protocol, 12 rats received an intraperitoneal dose of CoCl2 (10 mg/kg) daily for 6 weeks. At the end, the carotid body was fixed in situ by superfusion. Ultrastructural and morphometric studies were made. Acute administration (0.08-2.3 mumol) promptly stimulated the chemoreceptor afferents. Type I cells increased significantly along with erythropoiesis in the chronic cobalt treated rats. The stimulatory effects of cobalt on the carotid body chemoreceptor showed that sensitive mechanisms in the kidney and in the carotid body are similar, and cobalt interacts with the physiological responses of oxygen.

Potentiometric determination of carbonic anhydrase activity in rabbit carotid bodies: comparison among normoxic, hyperoxic and hypoxic animals.

The catalytic activity of carbonic anhydrase (CA) contained in the glomus cells of mammalian carotid bodies has been determined in vitro by a potentiometric method. Experiments performed on whole rabbit carotid bodies have shown a very low variability, in terms of the overall CA activity, among organs belonging to different animals maintained in normoxic conditions. Repeated assays performed on each carotid body have shown a marked decrease of the overall CA activity after the first assay, thus suggesting the presence of at least two different forms of enzyme. Experiments performed on carotid bodies belonging to rabbits maintained in normal, hyperoxic and hypoxic conditions have shown that the overall CA activity follows the sequence: hypoxic > normoxic > hyperoxic, matching with the corresponding physiological activity of the carotid body.

Chemosensitivity and regulation of ventilation during sleep at high altitudes.

The paper presents new observations on young high altitude natives (Andes and Himalayas), testing the hypothesis that periodic breathing with apnea during sleep is determined by their ventilatory sensitivity to hypoxia and its interaction with the sleep state. The hypothesis is in general supported by the evidence. But, contrary to expectation, the ventilatory sensitivity to hypoxia in the Sherpa children was significantly lower than those in the Andes. Despite that departure, the magnitude of ventilatory periodicity among the subjects was internally consistent with their ventilatory sensitivity to hypoxia. Although the carotid chemosensory input is the pacesetter for the reflexive periodicity, mechanisms in the central nervous system can influence it significantly.

Chronic cobalt causes hypertrophy of glomus cells in the rat carotid body.

We tested the hypothesis that chronic cobalt administration would induce carotid body cellular response along with polycythemia as found in chronic hypoxia if common oxygen-sensitive mechanisms were involved in the two instances. Morphometric studies were performed on carotid bodies in male rats that were chronically treated with cobalt chloride (0.17 mumol/kg, ip, daily for 6 wk) and in control rats that received blank saline injections. The rats were anesthetized, blood samples were collected for hematocrit, and the carotid bodies were surgically exposed and were perfused and superfused with the buffered fixative (3% glutaraldehyde plus 1% paraformaldehyde, pH 7.40, 330-340 mosM). The carotid bodies were processed, and ultrathin sections were cut for electron microscopy and morphometry of type I (glomus) and type II cells. Hematocrit increased from 44% in the control to 74% in the cobalt-treated rats, and the mean volume of type I cells increased from 424 to 1,061 microns 3. Type II cells did not show any significant change in size. The results suggest that cobalt stimulated oxygen-sensitive mechanism in the glomus cells of the carotid body and that the glomus cell is a site of oxygen chemosensing.

Pulmonary blood flow distribution in erect man in air and during breathhold diving.

We used intravenously administered 99mTc-labelled macroaggregates and a gamma camera attached to a computer for measuring distribution of pulmonary blood flow per unit lung volume in eight healthy subjects sitting erect in air and also during breathhold diving to 1 or 10 m of depth. We measured distribution of perfusion in the supine position and substituted regional lung volume with regional perfusion in the supine for calculating regional perfusion per lung volume erect in air and during diving. The perfusion per unit lung increased rectilinearly down the lung in subjects below 30 years of age but decreased in the lowermost regions in older subjects. This decrease showed a strong correlation to closing capacity. An age-related decrease in transpulmonary pressure may influence both basal perfusion and closing capacity. During submersion, perfusion became equal in all regions with the exception of the lung apex which became hyperperfused. Close to the diaphragm, small inconsistent changes were noted. Redistribution was the same at surface (1 m of depth) with the lung volume being close to total lung capacity and at 10 m of depth when lung volume was compressed to functional residual capacity. During breathhold diving, high intrapulmonary blood volume and pressure became more important for blood flow distribution than gravity or lung volume, while differences in regional hypoxic vasoconstriction and in transpulmonary pressure seem to explain interindividual variation.

[Protective effect of hyperbaric hypoxygenation for paraquat poisoning in the rat]. / Effet protecteur de l'hypoxygénation hyperbarique au cours de l'intoxication par le paraquat, chez le rat.

The effect to paraquat in normobaric conditions and hyperbaric conditions with either a normal or low (10%) oxygen percentage was investigated in rats. Results showed that hyperbaric conditions increased the toxic effect of paraquat on the lung. By contrast, in hypoxic-hyperbaric conditions, the toxic effect of paraquat was decreased either clinically or macro-/microscopically, and lung injury was reduced.

Change in plasma amino acid concentrations during breath-hold diving at high altitude.

We studied the plasma concentration of various amino acids in 6 Italian sport divers in Italy and at approximately 4,500 m altitude in Peru; 6 Peruvian inhabitants were examined for comparison. We attempted to create a situation of pronounced hypoxia in muscles by breath-hold diving at altitude. The diving reflex diverts blood away from muscles while diving increases central oxygen tension and prevents loss of consciousness. Differences in certain amino acids, probably related to diet, were noted between Italy and Peru. Increases in concentration of plasma alanine and some branched-chain amino acids occurred after breath-hold diving. These changes were similar to those seen after prolonged hard exercise, even though physical work was low. Hypoxia in muscles, common during hard work and during breath-hold diving at altitude, might thus be the stimulus for amino acid release from working muscles.

[Inappropriate gonadotropin secretion in the polycystic ovary syndrome]. / Studio sulla inappropriata secrezione di gonadotropine nella sindrome dello ovaio policistico.

In this study was investigated the diagnostic significance of double stimulation test with (that is of 25 micrograms rapid injection intravenously twice at an interval of 120 minutes and the misure of maximal net increment of serum LH after the first GnRH injection expressed as delta 1 and after the second injection, expressed as delta 2) to discriminate patients with idiopatic hirsutism. This test was effectuated on 8 patients with PCO (presence of polycystic ovaries on Ecografya and/or Laparoscopy) and 8 patients with idiopatic hirsutism (presence of normal morphology ovaries). Basal LH, FSH, E1, E2 and delta 4 levels were also measured. The value of LH delta 2 were more elevated in patients with PCO (p less than 0,0002) than the patients with idiopatic hirsutism. Consequently it as been value of LH delta 2 to discriminate the two different groups of patients. In PCO patients were also found: -a positive linear correlation between LH delta 1 and basal concentration serum of E2 (p less than 0,001); -a significant increase of basal levels serum of delta 4 (p less than 0,02); while the values of basal LH and LH delta 1 were found superior only on 4 of the initial 8 patients, the basal values of E1 and E2 were at the superior found of the norm and basal FSH, FSH delta 1 and FSH delta 2 values were found normals.

[Computerized system for the acquisition and analysis of bioelectric waves]. / Sistema computerizzato per l'acquisizione ed analisi di onde bioelettriche.

With collaboration of medicals, electronics and informatics; we have evaluated a method destined to be a potent instrument for the analysis and store of bioelectrical signal. The signal can be taken directly from the subjects or from a tape recorder; we can call again stored for evaluating the gradient grade, the integral and other mathematical evaluations of traits of a curves; in example EEG, EOG, PEV, etc.