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T Steiner

Publications and source records attributed to T Steiner.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Fiber-optic intubation with non-invasive ventilation with an endoscopic facial mask].

OBJECTIVES: To assess the feasibility and safety of a new technique of fiberoptic bronchoscopy (FOB) tracheal intubation (TI) with noninvasive ventilation (NIV) via an endoscopic full facial mask with two openings, in case of acute respiratory failure (ARF) temporally improved by NIV, but requiring a mechanical ventilation. STUDY DESIGN: Clinical, prospective, open, noncomparative trial of feasibility with direct individual profit. PATIENTS: Sixteen patients with ARF (age: 60 +/- 17 years, PaO2 = 59 +/- 16 mmHg, PaCO2 = 64 +/- 26 mmHg, PaO2/FIO2 = 142 +/- 70 before NIV) (m +/- SD), requiring TI. Including were: TI necessity (SpO2 < 90% or hypercapnic despite NIV, dependence of NIV, exhaustion, septic syndrome), clinical and SpO2 improvement with NIV. METHODS: After i.v. injection of 5 mg midazolam and topical anesthesia (TA) of the nose, the endoscopic mask (modified Fibroxy, Péters) was applied to the face, fixed with elastic straps, then connected to the ventilatory support system with IPAP = 20 cmH2O, EPAP = 5 to 12 cmH2O, FIO2 = 1. A tube was slid on the FOB. As soon as SpO2[[[nbsp] 94%, the extremity of the FOB, was inserted through the lower opening of the mask, slid in the nostril, positioned in front of the glottis for AL, then pushed in the trachea authorizing AL and i.v. injection of 0.15 mg.kg-1 of etomidate (Ramsay[[[nbsp]3). The tube was then slid in the trachea, then, FOB was removed from trachea. RESULTS: The FOB intubation was easy at the patient's, without any failure or any complication. The procedure was 6.7 +/- 2 min. SpO2 significantly improved during TI, from 84 +/- 5% (FIO2 = 0.6 +/- 3) to 97 +/- 1 (FIO2 = 1 +/- 0), without decrease in oxygen saturation off 90%. Arterial pressure decreased only after the 5th min. The quantities of midazolam and of etomidate used were 4.6 +/- 2 mg and 12 +/- 4 mg. Three patients benefited from EPAP > 10 cmH2O. CONCLUSION: Fiberoptic tracheal intubation with NIV via an adapted endoscopic facial mask is a safe technique in patient with ARF temporally improved by NIV. This procedure requires TA and conscious sedation.

Bronchoscopy↗
PubMed2001

Effect and feasibility of controlled rewarming after moderate hypothermia in stroke patients with malignant infarction of the middle cerebral artery.

BACKGROUND AND PURPOSE: Moderate hypothermia has been found to reduce intracranial pressure (ICP) significantly in patients who have severe middle cerebral artery infarction. However, during passive rewarming, ICP continuously rises and some patients suffer transtentorial herniation. METHODS: We investigated the question of whether slower rewarming leads to slower increase in ICP and slower decrease in cerebral perfusion pressure (CPP). Furthermore, we studied feasibility of slow, controlled rewarming. ICP, CPP, and core body temperature were monitored continuously. Achievement of rewarming protocol was assessed by hit rate of temperature target intervals. Side effects of hypothermia were assessed. RESULTS: Rates of change of both ICP and CPP were correlated significantly with increase in temperature (ICP r=0.62, P=0.002; CPP r=-0.50, P=0.017). In feasibility analysis of 13 controlled rewarmed patients, hit rate of temperature target intervals was 63% (median; range 48% to 81%); hit rate within the target interval or below was 79% (median; range 62% to 94%). CONCLUSIONS: Slow, controlled rewarming is feasible and may be used for ICP and CPP control after moderate hypothermia for space-occupying infarction.

Body Temperature↗
PubMed2001

Masking of vertebral artery dissection by severe trauma to the cervical spine.

STUDY DESIGN: A prospective case study was performed. OBJECTIVES: To illustrate the association of cervical trauma with vertebral artery dissection, and to propose a diagnostic and therapeutic algorithm for suspected traumatic vertebral artery dissection. SUMMARY OF BACKGROUND DATA: Vertebral artery dissection is a recognized but underdiagnosed complication of trauma to the cervical spine. Symptoms of spinal cord injury, however, may obscure those of vertebral artery dissection, presumably causing gross underdiagnosis of this complication. METHODS: All patients with vertebral artery dissection admitted to the authors' facility between 1992 and 1997 were screened for cervical trauma. RESULTS: This article presents four patients with severe trauma to the cervical spine, defined as luxation, subluxation, or fracture, in whom symptoms of vertebral artery dissection developed after a delay ranging from several hours to weeks. The traumatic vertebral artery dissection typically was located at the site of vertebral injury or cranial to it. One patient with fracture of the odontoid process survived symptom free without ischemic brain infarctions. Another patient survived with traumatic quadriplegia in addition to large cerebellar and posterior cerebral artery infarctions. Two patients died as a result of fulminant vertebrobasilar infarctions, both with only moderate impairment from the primary spinal cord injury. CONCLUSIONS: Early signs of vertebral artery dissection include head and neck pain, often localized to the site of intimal disruption, which may be disguised by the signs of the spinal injury. Early Doppler ultrasound and duplex sonography as a noninvasive screening method should be performed for patients with severe trauma to the cervical spine. In cases of vertebral artery dissection, immediate anticoagulation should be initiated. Traumatologists should be aware of this complication in evaluating patients with severe trauma of the cervical spine, and also for a variety of forensic reasons.

Adult↗
PubMed2001

Hydrogen bonds with pi-acceptors in proteins: frequencies and role in stabilizing local 3D structures.

A comprehensive structural analysis of X--H...pi hydrogen bonding in proteins is performed based on 592 published high-resolution crystal structures (< or = 1.6 A). All potential donors and acceptors are considered, including acidic C--H groups. The sample contains 1311 putative X--H...pi hydrogen bonds with N--H, O--H or S--H donors, that is about one per 10.8 aromatic residues. By far the most efficient pi-acceptor is the side-chain of Trp, which accepts one X--H...pi hydrogen bond per 5.7 residues. The focus of the analysis is on recurrent structural patterns involving regular secondary structure elements. Numerous examples are found where peptide X--H...pi interactions are functional in stabilization of helix termini, strand ends, strand edges, beta-bulges and regular turns. Side-chain X--H...pi hydrogen bonds are formed in considerable numbers in alpha-helices and beta-sheets. Geometrical data on various types of X--H...pi hydrogen bonds are given.

Animals↗
PubMed2001

Hypoxic brain damage after intramuscular self-injection of diclofenac for acute back pain.

We present a case of hypoxic brain damage that occurred after intramuscular injection of diclofenac due to a severe anaphylactic reaction. A 38-year-old nurse treated herself for acute lower back pain with 100 mg diclofenac intramuscularly. Five minutes later, she collapsed and developed coma and respiratory arrest. After cardiopulmonary resuscitation she was transferred to hospital. On admission she was comatose and received controlled ventilation of the lungs. Magnetic resonance imaging and computerized tomography showed signs of hypoxic brain injury and the patient died from central cardiopulmonary failure 7 days later. Intramuscular treatment with non-steroidal anti-inflammatory drugs such as diclofenac has rare but potentially severe side-effects. Therefore, intramuscular injections are inappropriate and should be replaced with oral or rectal treatment, which has similar absorption profiles.

Acute Disease↗
PubMed2001

Competition of hydrogen-bond acceptors for the strong carboxyl donor.

A database study on the competition of hydrogen-bond acceptors for the strong carboxyl donor in crystals is reported. The relative success in attracting this donor is determined for 34 types of acceptor (O, N, S, halogen and pi acceptors), and a correlation between the success in competition and the average hydrogen-bond distance is established.

Journal Article↗
PubMed2001

Neurometabolic changes during treatment with moderate hypothermia in a patient suffering from severe middle cerebral artery infarction.

Microdialysis is a means of measuring neurochemical changes in the extracellular space and has been applied in acute brain trauma, subarachnoid hemorrhage and stroke patients. In this study, we monitored neurochemical changes in the extracellular space using microdialysis in a patient with left-sided hemispheric infarction treated with moderate hypothermia (33 degrees C). Microdialysis probes were obtained from the infarcted and noninfarcted hemisphere during hypothermia and rewarming. Concentrations of extracellular substances in the infarcted hemisphere (glutamate, glycerine, lactate/pyruvate) decreased with hypothermia and remained stable (glutamate) or increased (glycerine, lactate/pyruvate) during rewarming. Concentrations of these substances in the noninfarcted hemisphere remained at normal levels. Microdialysis monitoring of therapeutic hypothermia in severe hemispheric infarction might be a useful additional monitoring tool to assess the status of the brain and to predict further deterioration.

Adult↗
PubMed2001

Interferon-alpha suppresses the antiapoptotic effect of NF-kB and sensitizes renal cell carcinoma cells in vitro to chemotherapeutic drugs.

BACKGROUND: Immunochemotherapy (ICT) with interleukin-2 (IL-2) and interferon-alpha (IFNalpha) with a secondary effector (5-fluorouracil, 5 FU) is the only promising treatment for advanced renal cell carcinoma (RCC). With IFNalpha, besides the activation mechanisms of the immunosystem, a direct antitumor effect on tumor cells is expected. MATERIALS AND METHODS: NF-kB activity in three permanent cell lines (Hep2, HepG2, HT29) and in primary RCC cell lines was measured after incubation with tumor necrosis factor-alpha (TNFalpha), IFNalpha, IFN-gamma, TNFalpha+IFNalpha, and IFNgamma+TNFalpha, respectively. NF-kB activity and induction of apoptosis by chemotherapeutic drugs (5FU and doxorubicin) were determined in cells transfected with a constitutively active NF-kB p65 or a dominant negative IkB. RESULTS: NF-kB signaling induced by TNFalpha is suppressed by IFNalpha and IFNgamma in the permanent cell lines and in the primary RCC tumor cell cultures. In an in vitro ICT model we show that pretreatment of RCC with IL-2 and IFNalpha leads to a diminished NF-kB response to TNFalpha. In certain tumors, this correlates with increased susceptibility to investigated chemotherapeutic drugs as shown by annexin stain and cell elimination. Modulation of the cellular NF-kB state by a constitutively active p65 or a dominant negative IkB mimics this effect. The IkB construct leads to the same effects as IL-2/IFNalpha pretreatment as shown by predominant elimination of the transfected cells from the overall population, while introduction of p65 leads to a partial rescue from the effect of IL-2 and IFNalpha. The described effect, however, applies only to a selection of primary cell cultures. CONCLUSIONS: Besides the immunomodulation effects, treatment of RCC with IL-2/IFNalpha leads to a proapoptotic state in certain tumors. The relevant mediator seems to be IFNalpha by suppression of the antiapoptotic effect of NF-kB. These data can provide an experimental base for correlation with real patient outcome after ICT.

Antineoplastic Agents↗
PubMed2001

Differential expression of cytokines and cytokine receptors in renal cell carcinoma.

Modulation of immunomechanisms by tumor cells can be caused by secretion of cytokines. In vitro data are usually gained in culture systems. It is debatable whether these systems are representative of the conditions inside the respective tumor tissues. Immunohistochemical studies of tumor tissue cryostats were compared with those in matched primary renal cell carcinoma tumor cell cultures. Results were correlated with histopathological characteristics and the in vitro cytotoxic effect of autologous tumor infiltrating lymphocytes (TILs). Expression of all studied cytokines and cytokine receptors could be shown in cryostats and cell cultures, but the detection pattern varied individually. The immunohistochemical results in cryostats were in good accordance with those in cell cultures. Expression of TGFbeta1 both in cryostats and cell cultures significantly correlated with the lack of cytotoxic activity of autologous TILs. Representative data can be obtained in tumor culture systems of primary renal cell carcinoma. TGFbeta1 secretion could play an important role in the interactions between tumor and cytotoxic cells.

Carcinoma, Renal Cell↗
PubMed2001

Hemorrhagic transformation of ischemic brain tissue: asymptomatic or symptomatic?

BACKGROUND AND PURPOSE: The term symptomatic hemorrhage secondary to ischemic stroke implies a clear causal relationship between clinical deterioration and hemorrhagic transformation (HT) regardless of the type of HT. The aim of this study was to assess which type of HT independently affects clinical outcome. METHODS: We used the data set of the European Cooperative Acute Stroke Study (ECASS) II for a post hoc analysis. All patients had a control CT scan after 24 to 96 hours or earlier in case of rapid and severe clinical deterioration. HT was categorized according to radiological criteria: hemorrhagic infarction type 1 and type 2 and parenchymal hematoma type 1 and type 2. The clinical course was prospectively documented with the National Institutes of Health Stroke Scale and the modified Rankin Scale: The independent risk of each type of HT was calculated for clinical deterioration at 24 hours and disability and death at 3 months after stroke onset and adjusted for possible confounding factors such as age, severity of stroke syndrome at baseline, and extent of the ischemic lesion on the initial CT. RESULTS: Compared with absence of HT, only parenchymal hematoma type 2 was associated with an increased risk for deterioration at 24 hours after stroke onset (adjusted odds ratio, 18; 95% CI, 6 to 56) and for death at 3 months (adjusted odds ratio, 11; 95% CI, 3.7 to 36). All other types of HT did not independently increase the risk of late deterioration. CONCLUSIONS: Only parenchymal hematoma type 2 independently causes clinical deterioration and impairs prognosis. It has a distinct radiological feature: it is a dense homogeneous hematoma >30% of the ischemic lesion volume with significant space-occupying effect.

Age Factors↗
PubMed2001

Multimodal online monitoring in middle cerebral artery territory stroke.

BACKGROUND AND PURPOSE: Patients with large middle cerebral artery infarction and elevated intracranial pressure (ICP) who are undergoing invasive intensive care therapy require technical monitoring. However, the effectiveness of the current gold standard, measurement of ICP, is limited. Furthermore, the effects of what is considered to be standard antiedema medical treatment are not fully understood. We studied whether multimodal monitoring can help to overcome this problem. METHODS: ICP, cerebral perfusion pressure (CPP), and partial brain tissue oxygen pressure (PbrO(2)) were continuously measured within the white matter of the frontal lobe unilaterally or bilaterally. We analyzed the effects of antiedema drugs and looked for pattern changes in the PbrO(2) before transtentorial herniation in patients in whom this could not be prevented. Furthermore, complications were registered. RESULTS: We performed 27 measurements in 21 patients. A total of 297 antiedema drug administrations were analyzed in 11 patients. Hyper-HAES and mannitol were most often associated with an increase in CPP and PbrO(2), whereas the use of thiopental and tromethamine led to negative or contrary effects, although ICP was decreased in every case. Pattern changes in the PbrO(2) curve could be observed between 6 to 18 hours before transtentorial herniation. No bleeding complication or infections were observed. CONCLUSIONS: Multimodal monitoring can be used to monitor antiedema drug effects. Our data suggest that with multimodal monitoring, pathophysiological changes could be predicted considerably in advance. ICP alone is of questionable use. Furthermore, this method might help to optimize the timing of invasive therapy in space-occupying infarction.

Brain Edema↗
PubMed2001

Treatment options for large hemispheric stroke.

Some stroke patients suffering acute middle cerebral artery (MCA) infarction develop massive brain edema and herniation, a condition known as malignant MCA infarction. Severe swelling increases intracranial pressure (ICP) and leads to progressive brainstem dysfunction. Once ICP reaches critical values (>30 mm Hg) herniation occurs, usually within 2 to 5 days. Patients rarely survive (80% mortality) with standard treatment, and those who do are often severely disabled. Malignant MCA infarction is often missed by neurologists, despite well-defined clinical and neuroimaging (CT scan) diagnostic criteria. After diagnosis, conventional treatments such as osmotherapy, barbiturates, buffers, and hyperventilation center on reducing ICP. The goal of hyperosmolar therapy is to increase the serum osmolarity to approximately 315-320 mOsm/L. Enteric glycerol is used routinely to reduce ICP. In more severe cases and when glycerol fails, mannitol may be administered. Other therapies are also available, including hypertonic saline solution, THAM (Tris-hydroxy-methyl-aminomethane) buffer, and high-dose barbiturates. Hyperventilation also helps reduce ICP. All measures work effectively for a short time only. Other approaches to control elevated ICP, including decompression surgery and hypothermia, have shown promising results. In the Heidelberg decompression surgery trial, mortality in surgically treated patients was significantly lower (32%) than in non-treated patients (76%) despite conventional treatment. Importantly, of the surviving treated patients, 66% were rated independent with only mild to moderate disability. Moderate hypothermia (33-36 degrees C) has recently been shown to be effective in severe MCA infarction. Hypothermia induction within 14 hours of ischemic injury and maintained for 72 hours significantly reduced ICP and mortality (44%).

Brain Edema↗
PubMed2001

Suboptimum hemicraniectomy as a cause of additional cerebral lesions in patients with malignant infarction of the middle cerebral artery.

OBJECT: The goal of this study was to determine the frequency of hemicraniectomy-associated lesions and their potential effect on the risk of mortality in patients suffering from malignant infarction of the middle cerebral artery MCA). METHODS: The authors evaluated serial computerized tomography scans obtained in 60 patients with complete infarction of the right MCA who were treated using hemicraniectomy. The maximum diameter of the hemicraniectomy was determined and the hemicraniectomy-associated lesions were classified as ischemic lesions or hemorrhages. The category of hemorrhages was composed of parenchymal, subdural, or epidural/subgaleal hematomas. Parenchymal hemorrhages and infarcts associated with hemicraniectomy occurred with frequency rates of 41.6% and 28.4%, respectively. The occurrence of hemicraniectomy-associated bleeding was related to the size of the hemicraniectomy performed; that is, the smaller the hemicraniectomy, the more often lesions occurred (p < 0.05). Hemicraniectomy-associated bleeding was also related to an increased risk of mortality. CONCLUSIONS: Hemicraniectomy is an effective therapy in patients with malignant infarction of the MCA. However, a hemicraniectomy that is too small in diameter may cause the formation of additional lesions and adversely affect the risk of mortality and the quality of survival. In addition, the size and shape of the edges of the bone defect are important factors relating to its efficacy.

Adult↗
PubMed2001

Stroke magnetic resonance imaging within 6 hours after onset of hyperacute cerebral ischemia.

We studied the diagnostic and prognostic value of diffusion- and perfusion-weighted magnetic resonancce imaging (DWI and PWI) for the initial evaluation and follow-up monitoring of patients with stroke that had ensued less than 6 hours previously. Further, we examined the role of vessel patency or occlusion and subsequent recanalization or persistent occlusion for further clinical and morphological stroke progression so as to define categories of patients and facilitate treatment decisions. Fifty-one patients underwent stroke magnetic resonance imaging (DWI, PWI, magnetic resonance angiography, and T2-weighted imaging) within 3.3 +/- 1.29 hours, and, of those, 41 underwent follow-up magnetic resonance imaging on day 2 and 28 on day 5. In addition, we assessed clinical scores (on the National Institutes of Health Stroke Scale, Scandinavian Stroke Scale, Barthel Index, and Modified Rankin Scale) on days 1, 2, 5, 30, and 90 and performed volumetric analysis of lesion volumes. In all, 25 patients had a proximal, 18 a distal, and 8 no vessel occlusion. Furthermore, 15 of 43 patients exhibited recanalization on day 2. Vessel occlusion was associated with a PWI-DWI mismatch on the initial magnetic resonance imaging, vessel patency with a PWI-DWI match (p < 0.0001). Outcome scores and lesion volumes differed significantly between patients experiencing recanalization and those who did not (all p < 0.0001). Acute DWI and PWI lesion volumes correlated poorly with acute clinical scores and only modestly with outcome scores. We have concluded on the basis of this study that early recanalization saves tissue at risk of ischemic infarction and results in significantly smaller infarcts and a significantly better clinical outcome. Patients with proximal vessel occlusions have a larger amount of tissue at risk, a lower recanalization rate, and a worse outcome. Urgent recanalization seems to be of utmost importance for these patients.

Aged↗