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Biomedical subjects

F Ries

Publications and source records attributed to F Ries.

At least 19 recordsLinked to original sources

Clinical benefit from erythropoietin.

Advances continue in erythropoietin biology, and additional data reviewed here have recently become available on complex feedback mechanisms describing the interrelations of hypoxia and its effects on anemia and tumor behavior (eg, apoptosis, angiogenesis). In addition to biology, other clinically relevant data in oncology are included and an attempt is made to identify patients who are most likely to benefit from treatment. The latter aspects will better define the profile of the target patient, probably prevent overtreatment, and improve cost-benefit ratios. Interesting data on radiotherapy results improved by increasing tissue hemoglobin have been published but will need further confirmation.

Anemia↗

Proton magnetic resonance spectroscopy of the primary motor cortex in patients with motor neuron disease: subgroup analysis and follow-up measurements.

OBJECTIVES: To determine the motor cortex degeneration in patients with amyotrophic lateral sclerosis (ALS) using proton magnetic resonance spectroscopy, and to prove that proton magnetic resonance spectroscopy is suited to monitor the course of disease with follow-up examinations. MATERIALS AND METHODS: We studied 33 patients with ALS whose conditions were diagnosed according to the El Escorial World Federation of Neurology criteria. Nine patients with ALS were followed up for up to 2 years. The control group included 20 healthy volunteers and 4 patients with multifocal motor neuropathy. Proton magnetic resonance spectroscopy determined levels of the brain metabolites N-acetylaspartate (NAA), choline, inositol-containing compounds, glutamate/glutamine, and phosphocreatine. RESULTS: Patients with ALS showed a significant reduction in the NAA-choline (P <.001) and NAA-phosphocreatine (P <.005) metabolite ratios and significantly elevated choline-phosphocreatine (P <.005) ratios compared with controls. Inositol-phosphocreatine ratios were also elevated in case patients, but the increase was less pronounced (P <.05). No differences in glutamate/glutamine-phosphocreatine ratios were detected between case patients and controls. An analysis of subgroups demonstrated less significant differences in NAA-choline metabolite ratios (P<.05), even in patients with pure lower motor neuron syndrome (suspected ALS). No changes in metabolite T1 and T2 relaxation times were observed. Patients with multifocal motor neuropathy showed normal metabolic ratios. Progressive alterations in affected metabolite ratios could be documented in the follow-up examinations. CONCLUSIONS: Spectroscopic changes in the motor cortices of patients with ALS correspond with a reduction in levels of NAA and an elevation in levels of choline and inositol compounds. Since NAA is exclusively expressed in neurons, the observed decrease of NAA reflects neuronal loss or dysfunction. Inositol and choline are associated with plasma membrane metabolism, so the release of these compounds may be related to membrane disorders.

Adult↗

Outcome after local intra-arterial fibrinolysis compared with the natural course of patients with a dense middle cerebral artery on early CT.

Our purpose was to relate the outcome after local intra-arterial fibrinolysis (LIF) to the natural course in middle cerebral artery (MCA) occlusion. We retrospectively studied 40 patients with a dense middle cerebral artery on early CT; 20 were treated with LIF within 6 h of onset of symptoms, 20 received "conventional" stroke therapy. The dense middle cerebral artery, which is regarded as a highly specific indicator of thromboembolic MCA occlusion, was chosen as inclusion criterion since patients with "conventional" stroke therapy were not exposed to cerebral angiography. Patients treated with LIF had a significantly better outcome using the Barthel index (P = 0.025): there was a 30% increase in the proportion of patients with minimal or no disability. Mortality, however, did not differ significantly (P = 0.7). Two fatal haemorrhages occurred in the LIF group, and one haemorrhagic transformation in the "conventional" group. Leptomeningeal collateralisation correlated significantly with outcome in the LIF group (P = 0.04). Although the relation between outcome and interval from onset of symptoms to LIF was not significant (P = 0.74), all patients treated within 3 h had an excellent outcome.

Adult↗

High-resolution emboli detection and differentiation by characteristic postembolic spectral patterns.

BACKGROUND AND PURPOSE: High-intensity transient signals (HITS) detected by transcranial Doppler ultrasonography correspond to microemboli in intracranial arteries. The purpose of this study was to develop new diagnostic criteria for the differentiation of these microembolic signals from artifact, based on a high-resolution analysis of Doppler power spectra in an in vitro model. METHODS: Two hundred seventy-six formed emboli, consisting of different biological and nonbiological materials and as air bubbles, were injected into a flow phantom with artificial blood vessels and perfused in a steady or a pulsatile way. Embolic passage was assessed with a modified 2.5-MHz pulsed Duplex machine and a commercial 2-MHz Doppler system. Embolic HITS were analyzed using internationally accepted criteria for the audiovisual characteristics of HITS. Doppler spectra changes associated with HITS were evaluated by means of a specially developed high-resolution analysis of Doppler raw data. RESULTS: Seventy-seven percent of all embolic events could be identified using conventional audiovisual criteria for embolic HITS. Analysis of Doppler spectra showed that all injected emboli generated high-amplitude signals with a minimum of at least 3 dB above background level. In addition, using high-resolution processing, specific changes in Doppler spectral patterns could be identified after all embolic HITS caused by solid particles. These postembolic spectral patterns were always characterized by a Doppler frequency shift decreasing in time and resembling the letter lambda (lambda). Duration and appearance of the postembolic spectral patterns were mainly influenced by the size and velocity of the embolus. Similar phenomena could not be found in case of embolism by either small air bubbles or in case of provoked artifact registration. Using a commercial Doppler system specific, we documented postembolic spectral patterns in 47% of injected emboli. CONCLUSIONS: In this study, highly specific changes in Doppler spectral patterns associated with microembolic HITS could be characterized, resulting in further criteria for the differentiation between microembolic signals and artifact in Doppler emboli detection. The sensitivity of the detection of these signals can be increased by high-resolution analysis of raw Doppler data.

Animals↗

Congenital myasthenic syndromes in two kinships with end-plate acetylcholine receptor and utrophin deficiency.

We studied two families with five affected members suffering from ptosis and slowly progressive limb-girdle muscle weakness. All patients had abnormal decremental response on low-frequency nerve stimulation, but there were no repetitive responses to single stimuli. The patients improved on anti-acetylcholinesterase drugs. Intercostal muscle was obtained for special studies from one patient of each family. In vitro microelectrode studies were done in Patient 1. Miniature end-plate potentials were of low amplitude, and the quantal content of the evoked end-plate potentials was normal. Light microscopy revealed a marked type 1 fiber predominance. Acetylcholinesterase reactivity was dispersed over increased length of individual fibers in Patient 2. On morphometry of the end-plate ultrastructure, the number of secondary synaptic clefts per neuromuscular junction and the expansion of the postsynaptic area were markedly reduced. In Patient 1, but not in Patient 2, the envelopment of the nerve terminal by Schwann cell was increased. Acetylcholine-receptor (AChR) density was reduced as judged by the reduced immunoreactivity to antibodies against different receptor subunits. Immunohistochemical analysis of proteins known to be involved in orchestrating the end-plate structure showed deficiency of the AChR-associated protein utrophin. These patients appear to have a defect in the development or maintenance of the postsynaptic clefts; whether this defect results from or causes a reduced expression of utrophin or AChR is unclear.

Adult↗

[Spontaneous regression of pulmonary metastases in renal cancer].

Spontaneous regression of lung-metastases in kidney cancer (a case report) A case is reported of a 56-year old woman with renal cell carcinoma operated and treated adjuvantly for a year with Interferon alpha. Ten months thereafter the patient had histologically proven a large pulmonary metastatic disease that regressed spontaneously. Duration of the spontaneous remission was 8 months.

Carcinoma, Renal Cell↗

Local intra-arterial fibrinolysis in thromboembolic "T" occlusions of the internal carotid artery.

Local intra-arterial fibrinolysis (LIF) is considered to support spontaneous recanalisation, which does not usually occur fast enough to prevent an infarct. Therefore, LIF may, at least theoretically, be especially useful in occlusions with large thromboembolic masses. We report our experience of LIF with urokinase in 12 patients with combined occlusions of the distal internal carotid, anterior and middle cerebral arteries (carotid "T" occlusions). There were 4 patients who survived with minor neurological deficits (Barthel index > 90), 4 with major deficits (Barthel index 40-55) and 4 patients died: in one of the last group a haematoma developed in a middle cerebral artery infarct. Recanalisation and clinical outcome were parallel in 10 of 12 patients. A patient with excellent leptomeningeal collaterals had a good clinical outcome despite only moderate recanalisation, and the patient with the parenchymal haematoma had good recanalisation. Recanalisation with urokinase in carotid "T" occlusions is often poor, but outcome can be good if treatment starts early, recanalisation succeeds and leptomeningeal collateral supply is good. Our results therefore encourage us, unlike previously reported series, to perform LIF in this type of occlusion.

Adult↗

Preoperative risk assessment for carotid occlusion by transcranial Doppler ultrasound.

OBJECTIVES: An endovascular carotid balloon occlusion test with continuous intracranial monitoring by transcranial Doppler sonography was performed in 55 patients for prediction of tolerance of a required permanent occlusion of the carotid artery. METHODS: Blood flow velocities of the ipsilateral middle cerebral artery during occlusion were recorded and compared with clinical tolerance during an occlusion test as well as with postoperative outcome after an eventual permanent occlusion. To stress the capacity of the cerebral circulation to tolerate the occlusion acetazolamide was injected before occlusion in all patients. RESULTS: The onset of neurological symptoms during temporary occlusion was dependent on the percentage fall of mean blood flow velocity relative to baseline rather than on absolute flow velocities during the time of occlusion. Patients with a fall of mean flow velocity of less than 30% tolerated temporary and permanent occlusion, with the exception of two patients who developed an infarction due to thromboembolism after iatrogenic sacrifice of the carotid artery. Patients with a major decrease developed neurological symptoms during occlusion in 55% and, in cases of carotid ligation, a haemodynamic infarction occurred. CONCLUSION: The results show that transcranial Doppler monitoring as a part of an endovascular balloon occlusion test may be a reliable technique for preoperative risk assessment for permanent occlusion of the carotid artery.

Adult↗

Clinical experience with echo-enhanced transcranial Doppler and duplex imaging.

Transcranial Doppler (TCD) and transcranial color-coded duplex sonography (TCCD) are ultrasound neuroimaging modalities that can provide useful diagnostic information on the intracranial vasculature with a high degree of safety. However, the skull can serve as an effective bone barrier, reducing reflected ultrasound signal by up to 100% in some patients and thereby challenging both technical quality and clinical interpretation of TCD and TCCD. Levovist is an IV ultrasound echo-enhancement agent that withstands passage through the heart and lung, increasing signal throughout the entire vascular pool. As part of European phase II and III clinical trials, this agent has been studied for utility of enhancement for TCD and TCCD studies in patients with signs and symptoms of cerebrovascular disease. All patients had either highly insufficient or nonexistent native signal on baseline transcranial ultrasound studies before administration of Levovist. The agent was administered at concentrations of 200, 300, or 400 mg/ml, and studies were repeated. In all studies, 300 to 400 mg/ml was sufficient for enhancement, although in several phase II studies 300 mg/ml Levovist was the preferred dosage in terms of superior imaging with a low level of side effects. In a phase III study, Levovist improved diagnostic utility of TCD and TCCD without compromising safety. Reviews of clinical phase II and III studies show that echo enhancement with Levovist facilitates routine clinical investigation of intracranial vascular anatomy in patients with signs and symptoms of intracranial vascular disease. In patients with no native signal, Levovist-enhanced imaging permits visualization of small peripheral vessels, venous circulation, tissue characteristics, and perfusion data, with no significant loss of safety.

Aged↗

Multidrug resistance: molecular and clinical aspects.

Clinical drug resistance, a common and compromising side-effect during anticancer chemotherapy, is an acquired cellular resistance simultaneously to several cytotoxic drugs. Expression of the multidrug resistance gene (mdr) is one of the most-studied potential underlying mechanisms. The human mdr gene family encompasses two homologous members, the first of which, called the mdr1 gene, is the best-characterized so far. The human mdr1 gene has been shown to encode a membrane P-170 glycoprotein that, on the basis of its structure, is considered to act as a drug-efflux pump excreting various drugs from cells. The human mdr1 gene is thus a major regulated gene playing an important role in the molecular mechanism of multidrug resistance. Its bipartite structure of two similarly organized halves is explained by a gene fusion event during evolution. However, the clinical significance of this particular feature, if it seemed obvious in the 1980s as a factor producing chemoresistance, is currently revised-being a marker of tumor aggressiveness rather than the cause of drug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[New diagnostic approaches to deep venous thrombosis].

This review summarizes a number of recent articles reconsidering the use of phlebography as the golden standard for deep venous thrombosis. Compression ultrasound and color-coded duplex doppler seem to be reasonably sensitive to provide safety in detecting lower limb thrombosis while less invasive. A clinical risk factor panel may further enhance diagnostic security.

Humans↗

Phase I/II clinical trial of epirubicin and paclitaxel followed by granulocyte colony-stimulating factor in a 2-week schedule in patients with advanced or metastatic breast cancer.

Anthracyclines and taxanes are the most potent cytotoxic agents available for treating breast cancer. With combined therapy (either epirubicin or doxorubicin with paclitaxel [Taxol; Bristol-Myers Squibb Company, Princeton, NJ]), response rates of 70% to 90% have been reported. To achieve a maximal dose intensity per week, we decided to combine epirubicin 100 mg/m2 with escalating doses of paclitaxel, at successive dose levels of 135, 150, 165, and 180 mg/m2 in a 2-week schedule, with administration of subcutaneous granulocyte colony-stimulating factor 5 microg/kg from days 2 through 10. To date, 16 patients have been included, with six patients treated at level 1 (100/135 mg/m2 epirubicin/paclitaxel), four at level 2 (100/150 mg/m2), four at level 3 (100/165 mg/m2), and two at level 4 (100/180 mg/m2). The median age of all subjects is 55 years (range, 41 to 65 years). Five patients had received chemotherapy in the adjuvant setting. Of 79 treatment courses, 78 are evaluable for toxicity. The mean number of courses per patient is six (range, two to six courses). At dose level 1, one episode of febrile neutropenia with grade 4 thrombocytopenia occurred. No grade 4 extrahematologic adverse event has been noted so far. At dose level 2, we achieved a dose intensity per week of epirubicin 50 mg/m2 and paclitaxel 75 mg/m2, as expected. At dose level 3, the dose intensity per week was 47.5 mg/m2 and 78.8 mg/m2, respectively (expected 50 and 82.5 mg/m2). The current response rate, evaluated in 14 of 16 patients, is four complete remissions and eight partial remissions, for an overall response rate of 85%. Two patients had stable disease. Granulocyte colony-stimulating factor following epirubicin/paclitaxel on a 2-week schedule permits a very high dose intensity per week for both drugs and produces a high response rate in patients with advanced or metastatic breast cancer.

Adult↗

Epirubicin cardiotoxicity: a study comparing low- with high-dose-intensity weekly schedules.

Epirubicin is one of the less cardiotoxic alternatives to doxorubicin. We were interested in studying the cardiotoxic effect of the total cumulative dose, and weekly schedules of low compared to high dose intensity. Fifty-seven patients were treated with different epirubicin-containing regimens. We confirm the classical notion that total cumulative doses of less than 600 mg/m2 do not induce significant cardiotoxicity, whereas doses above 600 mg/m2 are associated with a trend towards cardiotoxicity. Patients receiving a high weekly dose intensity (> 40 mg/m2), however, did have a significantly lower incidence of cardiotoxicity than those receiving a low dose intensity per week (< 40 mg/m2) (22.8% versus 50%; P < 0.05). We identified the association of a dose intensity of more than 40 mg m-2/ week-1 and a cumulative dose of 400-899 mg/m2 or a dose intensity of less that 40 mg m-2/week-1 and a cumulative dose of less than 400 mg/m2 to have the lowest incidence rate of cardiotoxicity. We conclude from this study that epirubicin in weekly schedules of high dose intensity is not more cardiotoxic than in weekly schedules of low dose intensity.

Adult↗

[Endovascular balloon occlusion test of the internal carotid artery with increased hemodynamic monitoring for determination of circulatory reserve before planned carotid occlusion].

PURPOSE: To evaluate stroke risk assessment of balloon test occlusion of the internal carotid artery (ICA) with enlarged haemodynamic monitoring prior to permanent ICA occlusion. MATERIAL AND METHODS: 24 patients with cervical metastasis (n = 18), cavernous meningiomas (n = 3) or inoperable cavernous aneurysms (n = 3) were examined. The test occlusion was monitored by EEG, neurological examinations and transcranial Doppler sonography of the ipsilateral middle cerebral artery with evaluation of the cerebrovascular reserve capacity. Additionally 99mTc-HMPAO-SPECT imaging was added showing the perfusion during test occlusion. RESULTS: In one (4%) patient the test occlusion had to be interrupted previously due to an acute neurological deficit. This patient and two (8%) patients with highly pathological test results in SPECT and TCD were excluded from permanent carotid occlusion. In 6 (25%) patients quantitative TCD monitoring could improve the stroke risk assessment by differentiating the patients in a low and high risk group. 6 (25%) patients were definitely occluded without haemodynamic complications, but two patients suffered from embolic infarctions which cannot be predicted by this procedure. CONCLUSIONS: The multimodal balloon test occlusion with enlarged haemodynamic monitoring allows haemodynamic stroke risk assessment prior to permanent occlusion of the ICA.

Adult↗

ALS.

The cause of ALS is not known but there are four main hypotheses about its etiology. First, an excess of extracellular glutamate in the CNS of patients with ALS resulting from a defect in glutamate reuptake may have excitotoxic effects on motor neurons. Clinical trials suggest the antiglutamate agent riluzole improves survival of patients with the disease. Second, ALS may be an autoimmune disease, but immunologically-based treatments have been unsuccessful. The third hypothesis is that ALS results from a lack of neurotrophic growth factors. Preliminary results from clinical trials indicate recombinant human insulin-like growth factor I offers therapeutic promise. Finally, familial ALS is sometimes linked to a gene encoding a Cu/Zn-binding superoxide dismutase; the mutations in ALS are thought to result in gain of function of dismutase activity. The involvement of superoxide dismutase in sporadic ALS is unclear.

Amyotrophic Lateral Sclerosis↗