Tomography diagnostic of plasma radiated power on the spherical tokamak Globus-M.

A diagnostic system for plasma radiated power tomography on Globus-M was upgraded with a new linear array based on silicon photodiodes. The hardware of the diagnostic system based on a 256-channel tangential matrix array and a 24-channel linear array is described. The algorithm for 2D tomographic reconstruction of plasma emissivity is presented. It uses the Tikhonov regularization method and anisotropic diffusion functional as a side constraint. Simulated plasma emissivity profiles were used to test and assess the capabilities of the developed algorithm. Data analysis was carried out in ohmic and neutral beam heated discharges to demonstrate the performance of the tomography diagnostic in plasmas with different parameters. The presented results illustrate the proper functioning of the tomography system that allowed to reveal and study various plasma phenomena, including magnetohydrodynamic mode.

Normocapnic high frequency oscillatory hyperventilation increases oxygenation in pigs.

High frequency oscillatory ventilation (HFOV), contrary to conventional ventilation, enables a safe increase in tidal volume (V(T)) without endangering alveoli by volutrauma or barotrauma. The aim of the study is to introduce the concept of normocapnic high frequency oscillatory hyperventilation and to assess its effect upon oxygen gain under experimental conditions. Laboratory pigs (n = 9) were investigated under total intravenous anesthesia in three phases. Phase 1: Initial volume controlled HFOV period. Phase 2: Hyperventilation--V(T) was increased by (46 +/- 12) % when compared to normocapnic V(T) during phase 1. All other ventilatory parameters were unchanged. A significant increase in PaO(2) (by 3.75 +/- 0.52 kPa, p < 0.001) and decrease in PaCO(2) (by -2.05 +/- 0.31 kPa, p < 0.001) were obtained. Phase 3: Normocapnia during hyperventilation was achieved by an iterative increase in the CO(2) fraction in the inspiratory gas by a CO(2) admixture. All ventilatory parameters were unchanged. A significant increase in PaO(2) (by 3.79 +/- 0.73 kPa, p < 0.001), similar to that which was observed in phase 2, was preserved in phase 3 whereas normocapnia was fully re-established. The concept of high frequency normocapnic hyperventilation offers a lung protective strategy that significantly improves oxygenation whilst preserving normocapnia.

Normocapnic high-frequency oscillatory ventilation affects differently extrapulmonary and pulmonary forms of acute respiratory distress syndrome in adults.

The recently reported differences between pulmonary and extrapulmonary acute respiratory distress syndromes (ARDS(p), ARDS(exp)) are the main reasons of scientific discussion on potential differences in the effects of current ventilatory strategies. The aim of this study is to assess whether the presence of ARDS(p) or ARDS(exp) can differently affect the beneficial effects of high-frequency oscillatory ventilation (HFOV) upon physiological and clinical parameters. Thirty adults fulfilling the ARDS criteria were indicated for HFOV in case of failure of conventional ventilation strategy. According to the ARDS type, each patient was included either in the group of patients with ARDS(p) or ARDS(exp). Six hours after normocapnic HFOV introduction, there was no significant increase in PaO2/F(I)O2 in ARDS(p) group (from 129+/-47 to 133+/-50 Torr), but a significant improvement was found in ARDS(exp) (from 114+/-54 to 200+/-65 Torr, p<0.01). Despite the insignificant difference in the latest mean airway pressure (MAP) on conventional mechanical ventilation (CMV) between both groups, initial optimal continuous distension pressure (CDP) for the best PaO2/F(I)O2 during HFOV was 2.0+/-0.6 kPa in ARDS(p) and 2.8+/-0.6 kPa in ARDS(exp) (p<0.01). HFOV recruits and thus it is more effective in ARDS(exp). ARDS(exp) patients require higher CDP levels than ARDS(p) patients. The testing period for positive effect of HFOV is recommended not to be longer than 24 hours.

Changes in alveolar-arterial oxygen difference and oxygenation index during low-dose nitric oxide inhalation in 15 newborns with severe respiratory insufficiency.

UNLABELLED: We evaluated changes in alveolar-arterial oxygen differences (AaDO2) and oxygenation index (OI) during inhalation of low-dose nitric oxide (INO) in 15 newborns with severe respiratory insufficiency: congenital diaphragmatic hernia (CDH) -6, asphyxial lung disease -4, meconium aspiration syndrome (MAS) -2, respiratory distress syndrome -2, persistent pulmonary hypertension of newborn -1. Their mean birth weight was 2522 g (1030-3200 g, SD +/- 575), mean gestational age 36 weeks (29-39 weeks, SD +/- 3.2), mean initial AaDO2 = 607 mm Hg (574-628 mm Hg, SD +/- 14) and mean initial OI = 32 (6-57, SD +/- 12). INO was performed using the Pulmonox system (Messer Griesheim, Austria) at conventional regimens of mechanical ventilation. The initial value of 20 ppm nitric oxide (NO) was decreased 6 h later, first to 15 ppm and then, as quickly as possible, to 3 ppm. The mean inhalation period was 51 h (6-131 h, SD +/- 42). The initial value of AaDO2 and OI decreased significantly within the first 6 h of INO (P < 0.001). After the first 6 h, 4 patients died: 1 with MAS of an extrapulmonary cause and 3 CDH patients because of pulmonary hypoplasia. In the remaining 11 patients the decrease in AaDO2 and OI during the first 24 h of INO was highly significant (P < 0.0001). CONCLUSION: In a heterogeneous group of 15 newborns with severe respiratory insufficiency, the initial AaDO2 and OI decreased significantly within the first 6 h of INO.

Endothelial desquamating activity of rat synthetic fibrinopeptide B and its analogues "in vivo": identification of responsible sequence.

The endothelial desquamating activity of the synthetic rat fibrinopeptide B (ATTDSDKVDLSIAR-OH), and its analogues was studied "in vivo" after intravenous administration to rats. Rat fibrinopeptide B (FPB) caused a significant increase in the count of circulating endothelial cell carcasses at the dose of 100 nmol/kg. Maximal effect reaching about 270% of the normal value was achieved with the dose of 600 nmol/kg in 30 min. after the injection. No significant thrombocytopenia, no hemolysis and no other life-threatening complications were observed. The same endothelial desquamating effect was achieved with N-terminal FPB(1-7) peptide ATTDSDK-OH, but very low activity exhibited the two FPB mutant peptides: ATDSDKVDLSIAR-OH and ATTNSNK-OH. Our results indicate that N-terminal sequence (1-7) consisting of N-terminal "pig tail" (ATT), acid region (DSD) and basic amino acid (K) is responsible for endothelial desquamating activity of rat FPB. Similar corresponding sequences may be recognized in FPB of different species. The conservation of this common "active site" sequence is less apparent in primates.

[Tracheobronchography in neonates and infants with obstruction of the upper respiratory tract]. / Tracheobronchografie novorozencu a kojencu s obstrukcí horních dýchacích cest.

In the period of 1980 to 1989 the authors performed contrast examinations of tracheobronchial tree in 38 children up to one year of age, three of them being newborns. In 29 examined children (74.4%) there was an anatomical defect causing the obstruction of upper respiratory pathways. In 15 of them the trachea compression was caused by pressure of hyperplastic thymus on the brachiocephalic arterial truncus crossing trachea. For visualization of upper respiratory pathways Hexabrix 320 (Byk Gulden) was used in 30 children, administered in 10 cases by jet ventilation. The filling was recorded by radiocinematographic method.

[Thrombosis of the inferior vena cava with successive lung embolization in a 15-year-old boy with the nephrotic syndrome]. / Thrombosis der Vena cava inferior mit sukzessiver Lungen-Embolisation bei einem 15jährigen Jungen mit nephrotischem Syndrom.

The authors report on a boy with typical course of recent nephrotic syndrome, who developed massive thrombosis involving the iliac inferior holden veins during the standard therapy with corticosteroid. The first sign of this complication was pulmonary embolism. Thrombosis was treated by surgery, during which 3 large thrombi from veins were removed. The patient developed recurrent thrombosis occurring at the previous sites in the later stage and he died 23 days after the first sign of thromboembolic complication. Autopsy showed only minimal glomerular changes. The cause of the death was massive pulmonary embolisation. The aethiopathogenesis of the complication and preventive approach in children with nephrotic syndrome are discussed.

[Thrombosis of the inferior vena cava with successive lung embolization in a 15-year-old boy with nephrotic syndrome]. / Thrombosis der Vena cava inferior mit sukzessiver Lungen-Embolisation bei einem 15jährigen Jungen mit nephrotischem Syndrom.

The authors report on a boy with typical course of recent nephrotic syndrome, who developed massive thrombosis involving the iliac inferior holden veins during the standard therapy with corticosteroid. The first sign of this complication was pulmonary embolism. Thrombosis was treated by surgery, during which 3 large thrombi from veins were removed. The patient developed recurrent thrombosis occurring at the previous sites in the later stage and he died 23 days after the first sign of thromboembolic complication. Autopsy showed only minimal glomerular changes. The cause of the death was massive pulmonary embolisation. The aethiopathogenesis of the complication and preventive approach in children with nephrotic syndrome are discussed.