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Charis Roussos

Publications and source records attributed to Charis Roussos.

82 records · Page 5Linked to original sources
PubMed2002

Stenotrophomonas maltophilia meningitis, bacteremia and respiratory infection.

Stenotrophomonas maltophilia is an increasingly recognized cause of nosocomial infection of special interest because of its resistance to multiple antimicrobial agents. We report a case of generalized infection by S. maltophilia, including meningitis, bacteremia and respiratory tract infection, in a patient who had undergone multiple neurosurgical procedures and who was treated with trimethoprim-sulphamethoxazole.

Adult↗
PubMed2002

Effects of positive end-expiratory pressure on gas exchange and expiratory flow limitation in adult respiratory distress syndrome.

OBJECTIVE: To assess the effects of different positive end-expiratory pressure (PEEP) levels (0, 5, 10, and 15 cm H2O) on tidal expiratory flow limitation (FL), regional intrinsic positive end-expiratory pressure (PEEPi) inhomogeneity, alveolar recruited volume (Vrec), respiratory mechanics, and arterial blood gases in mechanically ventilated patients with acute respiratory distress syndrome (ARDS). DESIGN: Prospective clinical study. SETTING: Multidisciplinary intensive care unit of a university hospital. PATIENTS: Thirteen sedated, mechanically ventilated patients during the first 2 days of ARDS. INTERVENTIONS: Detection of tidal FL and evaluation of total dynamic PEEP (PEEPt,dyn), total static PEEP (PEEPt,st), respiratory mechanics, and Vrec from pressure, flow, and volume traces provided by the ventilator. The average (+/-sd) tidal volume was 7.1 +/- 1.5 mL/kg, the total cycle duration was 2.9 +/- 0.45 secs, and the duty cycle was 0.35 +/- 0.05. MEASUREMENTS: Tidal FL was assessed using the negative expiratory pressure technique. Regional PEEPi inhomogeneity was assessed as the ratio of PEEPt,dyn to PEEPt,st (PEEPi inequality index), and Vrec was quantified as the difference in lung volume at the same airway pressure between quasi-static inflation volume-pressure curves on zero end-expiratory pressure (ZEEP) and PEEP. RESULTS: On ZEEP, seven patients exhibited FL amounting to 31 +/- 8% of tidal volume. They had higher PEEPt,st and PEEPi,st ( p<.001) and lower PEEPi inequality index ( p<.001) than the six nonflow-limited (NFL) patients. Two FL patients became NFL with PEEP of 5 cm H2O and five with PEEP of 10 cm H2O. In both groups, PaO2 increased progressively with PEEP. In the FL group, there was a significant correlation of PaO2 to PEEPi inequality index ( p=.002). For a given PEEP, Vrec was greater in NFL than FL patients, and a significant correlation of Pao to Vrec ( p<.001) was found only in the NFL group. CONCLUSIONS: We conclude that on ZEEP, tidal FL is common in ARDS patients and is associated with greater regional PEEPi inhomogeneity than in NFL patients. With PEEP of 10 cm H2O, flow limitation with concurrent cyclic dynamic airway compression and re-expansion and the risk of "low lung volume injury" were absent in all patients. In FL patients, PEEP induced a significant increase in PaO2, mainly because of the reduction of regional PEEPi inequality, whereas in the NFL group, arterial oxygenation was improved satisfactorily because of alveolar recruitment.

Adult↗
PubMed2002

Production of interleukin-6 by skeletal myotubes: role of reactive oxygen species.

In the present study we have tested the ability of reactive oxygen species (ROS) to stimulate the production of interleukin (IL)- 6 from skeletal myocytes. Differentiated C2C12 murine skeletal muscle cells (myotubes) exposed to pyrogallol (PYR), xanthine/ xanthine-oxidase (X/XO), or H(2)O(2) for 24 h exhibited a concentration-dependent increase in IL-6 production. Unlike myotubes, incubation of myoblasts and endothelial cells with X/XO or PYR did not result in increased IL-6 release. In myotubes, superoxide dismutase and catalase blocked the ROS-induced IL-6 release. Exposure of myotubes to H(2)O(2) increased steady-state IL-6 mRNA levels, and pretreatment of myotubes with actinomycin D or cycloheximide abolished the ROS-induced IL-6 production. In addition, pretreatment of cells with N-acetyl-cysteine blocked tumor necrosis factor (TNF)-alpha-induced IL-6 release, suggesting that endogenously produced ROS participate in IL-6 production. Myotubes stimulated with H(2)O(2) exhibited increased I kappa B-alpha phosphorylation and degradation, and treatment of C2C12 with ROS-generating agents increased activator protein (AP)-1 and nuclear factor (NF)-kappa B-dependent promoter activity. Finally, preincubation of myotubes with the pharmacologic inhibitor of NF-kappa B, diethyldithiocarbamate, or transient transfection with an I kappa B-alpha mutant, inhibited the ROS-stimulated IL-6 release. In conclusion, ROS stimulate IL-6 production from skeletal myotubes in a manner that involves transcriptional activation of the IL-6 gene through an NF-kappa B-dependent pathway.

Animals↗
PubMed2001

Clinical review: severe asthma.

Severe asthma, although difficult to define, includes all cases of difficult/therapy-resistant disease of all age groups and bears the largest part of morbidity and mortality from asthma. Acute, severe asthma, status asthmaticus, is the more or less rapid but severe asthmatic exacerbation that may not respond to the usual medical treatment. The narrowing of airways causes ventilation perfusion imbalance, lung hyperinflation, and increased work of breathing that may lead to ventilatory muscle fatigue and life-threatening respiratory failure. Treatment for acute, severe asthma includes the administration of oxygen, beta2-agonists (by continuous or repetitive nebulisation), and systemic corticosteroids. Subcutaneous administration of epinephrine or terbutaline should be considered in patients not responding adequately to continuous nebulisation, in those unable to cooperate, and in intubated patients not responding to inhaled therapy. The exact time to intubate a patient in status asthmaticus is based mainly on clinical judgment, but intubation should not be delayed once it is deemed necessary. Mechanical ventilation in status asthmaticus supports gas-exchange and unloads ventilatory muscles until aggressive medical treatment improves the functional status of the patient. Patients intubated and mechanically ventilated should be appropriately sedated, but paralytic agents should be avoided. Permissive hypercapnia, increase in expiratory time, and promotion of patient-ventilator synchronism are the mainstay in mechanical ventilation of status asthmaticus. Close monitoring of the patient's condition is necessary to obviate complications and to identify the appropriate time for weaning. Finally, after successful treatment and prior to discharge, a careful strategy for prevention of subsequent asthma attacks is imperative.

Acute Disease↗
PubMedDate not supplied

Novel recurrent structural chromosomal aberrations in primary bladder cancer.

BACKGROUND: Bladder cancer is a heterogeneous genetic disease and, to date, no specific cytogenetic abnormality has been established. The detection of recurrent genetic changes with common breakpoints is of special interest, facilitating the identification of genes implicated in carcinogenesis. The aim of this study was to investigate recurrent structural chromosomal aberrations with common breakpoints and to correlate them with the histological stage of tumors. MATERIALS AND METHODS: Fifteen patients with transitional cell carcinoma of the bladder were cytogenetically studied by direct culture of primary tumor cells and G-banding technique. RESULTS: Most of the cases studied exhibited very complex karyotypes. Recurrent structural aberrations were observed involving, according to frequency, chromosomal regions 11p15, 3p12, 14q32, 19q13 and 6q23. Isochromosomes i(8q), i(17q) and i(6p) were also observed. CONCLUSION: Conventional cytogenetics continues to be valuable in cancer study, detecting common chromosomal breakpoints. Of interest was the detection of novel recurrent structural chromosomal aberrations including involvement of 11p15, 14q32 and 19q13, while a correlation of recurrent abnormalities observed with tumor stage was also evaluated.

Carcinoma, Transitional Cell↗
PubMedDate not supplied

Sex chromosome abnormalities in bladder cancer: Y polysomies are linked to PT1-grade III transitional cell carcinoma.

BACKGROUND: Bladder cancer is a heterogeneous group of tumors from both the biological and clinical points of view. Conventional cytogenetics and molecular genetic techniques have shown non-random aberrations in bladder cancer, while certain chromosomal changes have been found to be highly correlated with tumor grade or stage. The aim of this study was to evaluate, by fluorescence in situ hybridization (FISH), the numerical aberrations of chromosomes X and Y in bladder cancer, comparing the incidence of nuclei with aneusomies in different grades or histological stages of the tumors. MATERIALS AND METHODS: The FISH technique, using DNA probes specific for chromosomes X and Y, was applied to 35 male bladder tumor specimens directly processed for cytogenetic study. RESULTS: Polysomies of chromosome X were observed in 25 out of the 35 cases examined (71.43%), while numerical aberrations of chromosome Y were observed in 22 out of the 35 cases (62.86%). Of those cases with numerical aberrations of chromosome Y, 13 had polysomy (37.14%), while in 9 cases, loss of Y was observed (25.71%). Statistical analysis showed that numerical aberrations on chromosomes X or Y were not linked to histological stage, while a probable correlation was observed between aneusomies X or Y and tumor grade. Comparing the results of PT1-grade III tumors with those of PT1-grade II, statistical analysis showed that aneusomies Y and, especially, polysomy Y were correlated with PT1-grade III tumors, p = 0.023 and p = 0.010, respectively. An uncertain correlation between polysomy X and PT1-grade III tumors was found, p = 0.070. CONCLUSION: Our results may suggest that the genetic instability associated with PT1-grade III tumors may account for the considerable potential for aggression of these tumors. However, to draw definite conclusions, a large number of cases must be studied.

Aneuploidy↗
PubMedDate not supplied

Is aneusomy of chromosome 9 alone a valid biomarker for urinary bladder cancer screening?

BACKGROUND: Detection of genetically-changed tumor cells in the urine is one of the new approaches for the screening of bladder carcinomas. In a previous study, numerical aberrations of chromosome 9 were found in 85.18% of bladder tumors studied by the fluorescence in situ hybridization (FISH) technique. The purpose of the present study was to investigate whether chromosome 9 aneusomy alone is a valid, cost effective, biomarker for bladder cancer screening. MATERIALS AND METHODS: Twenty-seven voided urine specimens obtained from 22 bladder cancer patients, either at initial diagnosis or at the follow-up, were analyzed by the FISH technique with the centromeric probe specific for chromosome 9. RESULTS: In all except 2 out of the 13 specimens with a histological confirmation of cancer, FISH analysis showed aneusomy 9 (sensitivity 84.61%). Among 6 cases with a negative cystoscopy but a positive FISH analysis, 3 recurred within the following 2 months, while 2 no-recurrent patients continued to show positive FISH findings after 6 months. One patient was considered to be false-positive. Four cases with a negative cystoscopy showed disomy 9 and 2 of them recurred. CONCLUSION: Aneusomy 9 has a high sensitivity (84.61%) for the detection of bladder cancer. Patients with a negative cystoscopy but with aneusomy 9 should be kept under close clinical surveillance for potential disease recurrence. However, negative FISH results might not be a negative predictor for disease recurrence. Our results encourage further studies with a large number of patients and a long-term follow-up with concurrent FISH analysis.

Aged↗