Influence of mechanical ventilation and inhalation of pulmonary vasodilators, upon pulmonary blood flow and pulmonary vascular resistance

Peer Reviewe

Xenon prevents cellular damage in differentiated PC-12 cells exposed to hypoxia

BACKGROUND: The neuroprotective effect of xenon has been demonstrated for glutamatergic neurons. In the present study it is investigated if dopaminergic neurons, i.e. nerve-growth-factor differentiated PC-12 cells, are protected as well against hypoxia-induced cell damage in the presence of xenon. RESULTS: Pheochromocytoma cells differentiated by addition of nerve growth factor were placed in a N(2)-saturated atmosphere, a treatment that induced release of dopamine, reaching a maximum after 30 min. By determining extracellular lactate dehydrogenase concentration as marker for concomitant cellular damage, a substantial increase of enzymatic activity was found for N(2)-treated cells. Replacement of N(2 )by xenon in such a hypoxic atmosphere resulted in complete protection against cellular damage and prevention of hypoxia-induced dopamine release. Intracellular buffering of Ca(2+ )using the Ca-chelator 1, 2-bis(2-Aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl) ester (BAPTA) reduced the neuroprotective effect of xenon indicating the essential participation of intracellular Ca(2+)-ions in the process of xenon-induced neuroprotection. CONCLUSIONS: The results presented demonstrate the outstanding property of xenon to protect neuron-like cells in a hypoxic situation

Mild hypothermia after near drowning in twin toddlers

INTRODUCTION: We report a case of twin toddlers who both suffered near drowning but with different post-trauma treatment and course, and different neurological outcomes. METHODS AND RESULTS: Two twin toddlers (a boy and girl, aged 2 years and 3 months) suffered hypothermic near drowning with protracted cardiac arrest and aspiration. The girl was treated with mild hypothermia for 72 hours and developed acute respiratory dysfunction syndrome and sepsis. She recovered without neurological deficit. The boy's treatment was conducted under normothermia without further complications. He developed an apallic syndrome. CONCLUSION: Although the twin toddlers experienced the same near drowning accident together, the outcomes with respect to neurological status and postinjury complications were completely different. One of the factors that possibly influenced the different postinjury course might have been prolonged mild hypothermia

Altered immune parameters in chronic alcoholic patients at the onset of infection and of septic shock

INTRODUCTION: Chronic alcoholic patients have a threefold to fourfold increased risk for developing a severe infection or septic shock after surgery, which might be due to altered immune response. The aim of this outcome matched study was to investigate proinflammatory and anti-inflammatory immune parameters during the course of infection and subsequent septic shock in chronic alcoholic patients, and to compare these parameters with those in nonalcoholic patients. METHODS: Twenty-eight patients from a cohort of fifty-six with either pneumonia or peritonitis and subsequent septic shock were selected. Fourteen patients were chronic alcoholics whereas fourteen were nonalcoholic patients. Chronic alcoholic patients met criteria (Diagnostic and Statistical Manual of Mental Disorders IV, of the American Psychiatric Association) for alcohol abuse or dependence. Measurements were performed during the onset of infection (within 24 hours after the onset of infection), in early septic shock (within 12 hours after onset of septic shock) and in late septic shock (72 hours after the onset). Blood measurements included proinflammatory and anti-inflammatory cytokines. RESULTS: Chronic alcoholic patients exhibited significantly lower plasma levels of IL-8 (P < 0.010) during the onset of infection than did matched nonalcoholic patients. In early septic shock, chronic alcoholic patients had significantly decreased levels of IL-1β (P < 0.015), IL-6 (P < 0.016) and IL-8 (P < 0.010). The anti-inflammatory parameters IL-10 and tumour necrosis factor receptors I and II did not differ between alcoholic and nonalcoholic patients. CONCLUSION: At the onset of infection and during early septic shock, chronic alcoholic patients had lower levels of proinflammatory immune parameters than did nonalcoholic patients. Therefore, immunomodulatory therapy administered early may be considered in chronic alcoholic patients at the onset of an infection because of their altered proinflammatory immune response

Effects of dopexamine on the intestinal microvascular blood flow and leucocyte activation in a sepsis model in rats

INTRODUCTION: Dopexamine may be a therapeutic option to improve hepatosplanchnic perfusion in sepsis. To investigate this possibility, we administered dopexamine in an experimental sepsis model in rats. METHODS: This prospective, randomized, controlled laboratory study was conducted in 42 Wistar rats. The animals were divided into three groups. Group 1 served as the control group (CON group). The animals in both groups 2 (LPS group) and 3 (DPX group) received an endotoxin (lipopolysaccharide from Escherichia coli – LPS) infusion (20 mg/kg for 15 minutes). DPX group additionally received dopexamine (0.5 μg/kg per minute over four hours). One half of the animals in each group underwent studies of intestinal microvascular blood flow (IMBF) using laser Doppler fluxmetry. In the other half an intravital microscopic evaluation of leucocyte-endothelial cell interaction in intestinal microcirculation was conducted. Functional capillary density (FCD) in the intestinal mucosa and in the circular as well as longitudinal muscle layer was estimated. RESULTS: One hour after endotoxin challenge, IMBF decreased significantly in LPS group to 51% compared with baseline (P < 0.05). In DPX group (endotoxin plus dopexamine) we found IMBF values significantly higher than those in LPS group (approximately at the level of controls). The impaired FCD following endotoxin challenge was improved by dopexamine in the longitudinal muscle layer (+33% in DPX group versus LPS group; P < 0.05) and in the circular muscle layer (+48% in DPX group versus LPS group; P < 0.05). In DPX group, dopexamine administration reduced the number of firmly adherent leucocytes (-31% versus LPS group; P < 0.05). Plasma levels of tumour necrosis factor-α were reduced by dopexamine infusion (LPS group: 3637 ± 553 pg/ml; DPX group: 1933 ± 201 pg/ml) one hour after endotoxin challenge. CONCLUSION: Dopexamine administration improved IMBF and FCD (markers of intestinal microcirculation) and reduced leucocyte activation (a marker of inflammation) in experimental sepsis

Light-Ion-Induced Multifragmentation: The ISiS Project

An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid-gas phase transition has been performed with the Indiana Silicon Sphere (ISiS)4 pi detector array. Measurements were performed with 5-15 GeV/c p, pbar, and pion beams incident on $^{197}$Au and 2-5 GeV $^3$He incident on $^{nat}$Ag and $^{197}$Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of E*/A = 4-5 MeV per residue nucleon. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20-50 fm/c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid-gas phase transition.Comment: 67 pages, 44 figures, all included in tar fil

Xenon prevents cellular damage in differentiated PC-12 cells exposed to hypoxia-5

<p><b>Copyright information:</b></p><p>Taken from "Xenon prevents cellular damage in differentiated PC-12 cells exposed to hypoxia"</p><p>BMC Neuroscience 2004;5():55-55.</p><p>Published online 8 Dec 2004</p><p>PMCID:PMC544856.</p><p>Copyright © 2004 Petzelt et al; licensee BioMed Central Ltd.</p>s, in N, or in xenon. Mesencephalic cells containing dopaminergic neurons were exposed on day 14 after preparation for two hours either to normal atmosphere, or xenon or nitrogen. Dopamine was not released from cells maintained under normal conditions or in xenon whereas a significant amount of dopamine was liberated from cells maintained in nitrogen. B. Cellular damage in mesencephalic dopaminergic cells after two-hour incubation. If cells were kept in normal air, or in xenon, only a small amount of LDH was released. Much higher cellular damage was found when cells were incubated in nitrogen. (n = 4; **P < 0.01)