Search PubMed⌕ Search

Biomedical subjects

S Petros

Publications and source records attributed to S Petros.

13 recordsLinked to original sources
PubMed2006

[Identification of patients suitable for therapy with activated Protein C].

Drotrecogin alpha (recombinant human activated protein C, rhAPC; Xigris) is an immune modulating treatment principle that has been shown to significantly reduce mortality in patients with severe sepsis. Currently, the identification of patients in intensive care that may benefit from such a treatment is insufficient. The importance of this evidence-based treatment modality is commonly ignored for reasons of increased cost. A medically justified and economically acceptable strategy with a medico-legal backing would be a procedure based on the design and the results of the PROWESS study. This may benefit patients with severe sepsis of not longer than 48 h duration, an APACHE II score of > or =25 or > or =2 failing organs and no exclusion criteria. Extending the indication beyond this group should be discussed as a last resort in patients with a fulminant clinical course, such as in meningitis, and based on data from retrospective subgroup analyses. Patients with severe sepsis following community-acquired pneumonia with progressive organ dysfunction may also benefit from activated protein C treatment in addition to an otherwise best standard of care.

Antifibrinolytic Agents↗
PubMed2006

Platelet-dependent coagulation assays for factor VIII efficacy measurement after substitution therapy in patients with haemophilia A.

FVIII therapy for haemophilia A is safe and effective, with the problem of individually sufficient efficacy unsettled. Routine one-stage clotting assays and tests employing chromogenic substrates poorly detect individual haemostatic effects of FVIII due to artificial test conditions. In particular, the use of cell-free and diluted plasma samples neglect the crucial role of platelets for thrombin and fibrin formation. To optimize FVIII substitution therapy, we measured in 40 patients with severe to mild haemophilia A before and after FVIII substitution the FVIII activity in cell-free plasma samples using a one-stage clotting assay as well a chromogenic substrate assay and compared the data with those obtained with cell-based coagulation tests, i.e. thrombin generation in platelet-rich plasma (PRP) and thromboelastography (TEG) in samples of citrated whole blood (WB). To determine the maximum ex vivo haemostatic effect we added 1 unit/ml of FVIII to samples of PRP and WB and measured the maximum thrombin generation in the thrombin generation test (TGT) and the maximum clot firmness (MCF) in TEG. After FVIII substitution we observed a nearly linear relation between the individual FVIII activities administered to the patients and the activities measured in the plasma samples. However, data obtained with TGT and TEG revealed a high inter-individual variation and a very poor correlation to the administered FVIII activity. Actually, it could be shown that FVIII substitution yielding in a FVIII plasma activity of about 30% is sufficient to get an ex vivo haemostatic effect of more that 90% as measured by maximum thrombin generation and MCF. FVIII substitution up to a plasma activity of more than 90% did not further enhance the haemostatic effect. Our data clearly demonstrate that the haemostatic effect of FVIII is not only dependent on the activity that is measured in plasma but also depends on the interplay between coagulation and blood cells, in particular with platelets. The use of cell-based coagulation tests such us TGT or TEG may help to optimize FVIII therapy by determining the individual FVIII dosage that produces a maximum haemostatic effect.

Adult↗
PubMed2004

A severe case of systemic lupus erythematosus with cerebral involvement.

We describe an 18-year-old girl who presented with severe systemic lupus erythematosus with multiple organ involvement. The disease was further complicated by recurrent seizures and intracerebral left parieto-occipital bleeding that required neurosurgical treatment. Postoperative rebleeding occurred due to disseminated intravascular coagulation and platelet dysfunction. Catastrophic antiphospholipid syndrome was suspected, but could not be confirmed during follow-up. Additional treatment with plasmapheresis and intravenous pulse cyclophosphamide in combination with corticosteroids was started. Liquor drainage via a ventriculo-peritoneal (vp)-shunt was necessary because of a hydrocephalus malresorptivus. The patient's recovery was slow and incomplete (cachexia and amaurosis persisted). Follow-up was further complicated by an intraperitoneal vp-shunt cyst, which was initially treated conservatively, but finally had to be revised operatively.

Adolescent↗
PubMed2001

Validity of an abbreviated indirect calorimetry protocol for measurement of resting energy expenditure in mechanically ventilated and spontaneously breathing critically ill patients.

OBJECTIVE: To test a short indirect calorimetry protocol with five stable 1-min readings (5-min steady state) against the commonly used protocol of 30 1-min readings (30-min steady state) in critically ill patients with various modes of ventilation. DESIGN: A prospective clinical study. SETTING: A medical ICU of a university hospital. SUBJECTS: Forty-six mechanically ventilated patients (group A and B), and 16 spontaneously breathing patients (group C). INTERVENTION: Indirect calorimetry with the Deltatrac II MBM-200 Metabolic Monitor. RESULTS: Mechanically ventilated patients were classified into group A (controlled) and B (assisted) depending on the ventilation mode. All patients in group A, but only 48.8% of those in group B, received some form of analgosedation, and the doses were significantly higher in group A. The 30-min steady state test was 100.0%, 83.7%, and 75.0% successful in group A, B, and C, respectively. The corresponding rate for the 5-min steady state test was 100.0%, 81.4%, and 100.0%, respectively. The coefficient of determination (r2) for resting energy expenditure between the two protocols ranged between 0.972 and 0.994. The time required to collect the 5-min steady state data was 5.5+/-1.1, 9.9+/-5.7, and 6.5+/-3.3 min for group A, B, and C, respectively. CONCLUSION: Indirect calorimetry with 5-min steady state test correlated very well with the 30-min steady state test in both mechanically ventilated and spontaneously breathing patients. The time required varies depending on the mode of ventilation, and it is influenced by the level of sedation in mechanically ventilated patients. The abbreviated protocol may be more acceptable to spontaneously breathing patients.

Calorimetry, Indirect↗
PubMed2000

Mutant envelope residues confer a transactivation function onto N-terminal sequences of the v-Rel oncoprotein.

The retroviral oncoprotein v-Rel is a member of the Rel/ NF-kappaB family of transcription factors. v-Rel has multiple changes as compared to the proto-oncoprotein c-Rel, and these changes render v-Rel highly oncogenic in avian lymphoid cells. Previous results have shown that three mutant residues in the eleven helper virus-derived Envelope (Env) amino acids (aa) at the N-terminus of v-Rel are required for its full oncogenicity. In this report, we show that these mutant Env aa also enable sequences in the N-terminal half of v-Rel to activate transcription in yeast and chicken cells, under conditions where the analogous sequences from c-Rel either do not or only weakly activate transcription. Removal of the Env aa from v-Rel or site-directed mutations that revert the three mutant residues to the residues present in the Rev-A helper virus Env protein abolish this transactivation ability of v-Rel. Addition of mutant Env aa onto c-Rel is not sufficient to fully restore the transactivation function; other sequences in the N-terminal half of v-Rel are needed for full transactivating ability. A C terminally-truncated form of NF-kappaB p100 (p85), produced in HUT-78 human leukemic cells, also activates transcription in yeast, under conditions where the normal p52 and p100 proteins do not. Furthermore, transcriptional activation by p85 in yeast is likely to occur through N-terminal sequences. Taken together, these results are consistent with a model in which transactivation by N-terminal Rel Homology (RH) domain sequences in oncogenic Rel family proteins is influenced by sequences outside the RH domain.

Animals↗
PubMed2000

Serum procalcitonin and proinflammatory cytokines in a patient with acute severe leptospirosis.

Leptospirosis is a zoonosis, with clinical manifestations ranging from the imperceptible to severe, potentially fatal renal and liver failure accompanied by haemorrhage and jaundice. In this case report of a patient with severe leptospirosis, serum levels of procalcitonin decreased ahead of any obvious clinical improvement, and thus may be useful as a prognostic marker. Levels of soluble IL-2 receptor were very high and correlated well with the clinical course.

Acute Disease↗
PubMed1999

Percutaneous tracheostomy.

BACKGROUND: Percutaneous tracheostomy (PT) has gained an increasing acceptance as an alternative to the conventional surgical tracheostomy (ST). In experienced hands, and with proper patient selection, it is safe, easy and quick. COMPLICATIONS: Perioperative complications are comparable with those of ST and these are mostly minor. An important advantage of PT over ST is that there is no need to move a critically ill patient to the operating room and the rate of stomal infection is very low. Although data on late complications of PT are not yet sufficient, available reports show a favourable result. TECHNIQUES: Ciaglia's method is the most commonly applied, but no study has shown superiority of any of the percutaneous techniques described. The decision on which method to use should solely be made depending on the clinical situation and the experience of the operator. The learning curve demands caution, attention to detail and adequate experience on the part of the intensive care physician. Although PT is unfortunately declared 'easy', it must be left in the hands of experienced physicians to avoid unnecessary complications, and the risk of overimplementation should be kept in mind.

Journal Article↗
PubMed1997

Percutaneous dilatational tracheostomy in a medical ICU.

OBJECTIVE: To evaluate the safety of percutaneous dilatational tracheostomy. DESIGN: A prospective clinical study. SETTING: The intensive care unit of a university medical clinic. PATIENTS: 137 critically ill patients admitted between May 1993 and September 1996. INTERVENTION: Percutaneous dilatational tracheostomy at the bedside. RESULTS: The median duration of translaryngeal intubation prior to tracheostomy was 8 days. Tracheostomy was carried out within 12.8 min (range 7-30 min). Acute complications were documented in 11.0% of the patients. There was one case of severe bleeding with transient asphyxia. Four patients had tracheal mucosal laceration treated conservatively. The postoperative in-hospital complication rate was 5.1%, the sole problem being stomal bleeding. Only two cases of stomal infection were documented. There was no procedure-related mortality. CONCLUSION: In the hands of the experienced, percutaneous dilatational tracheostomy is a safe and quick bedside procedure. It is also less expensive and incurs minimal stress for the patient compared with the surgical method. The technique can be easily mastered by non-surgical physicians and we feel that it is the method of choice for elective tracheostomy in the majority of intensive care patients.

Adolescent↗
PubMed1991

[Diagnosis of biliary dyskinesia after cholecystectomy].

In patients with upper abdominal complaints after cholecystectomy the normal and disordered bile flow was evaluated using quantitative scintigraphy after initially excluding organic etiology. A continuous intravenous infusion of cholecystokinin and secretin for one hour resulted in an accelerated bile flow in the majority of these patients, which is the normal reaction of the biliary system under stimulation. On the contrary, a bolus injection of these hormones led to marked delay of flow in a group of the study population, a condition taken as a paradoxical reaction to cholecystokinin. Although all of the patients with this paradoxical reaction did complain of typical biliary pain, a causal association is, however, yet to be proved. Nitrates can be helpful in the differential diagnosis of impeded bile flow, a lack of response being a possible sign of organic hindrance at the papilla of Vater.

Biliary Dyskinesia↗