PubMed Health⌕ Search

Biomedical subjects

F Schmidt

Publications and source records attributed to F Schmidt.

At least 19 recordsLinked to original sources
PubMed2006

PCV chemotherapy for recurrent glioblastoma.

The authors administered procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU, lomustine), and vincristine (PCV) to 86 patients with recurrent glioblastoma. There were three partial responses, but no complete responses. Median progression-free survival was 17.1 weeks and progression-free survival at 6 months was 38.4%. World Health Organization grade III/IV hematologic toxicity was common (25.6%), but nonhematologic toxicity was mild.

Adult↗
PubMed2006

Efficacy and safety of outpatient alcohol detoxification with a combination of tiapride/carbamazepine: additional evidence.

BACKGROUND: Few medications have been tested for outpatient alcohol detoxification. Previously we had shown a combination of carbamazepine and tiapride to be effective in an open study. This database is an extension of our previous work. METHODS: This was an open prospective study to examine the efficacy, practicability and medical safety of a combination of tiapride and carbamazepine in outpatient detoxification of alcohol dependent patients. Patients were carefully screened for relevant neuropsychiatric disorders and then seen on a daily outpatient basis. RESULTS: A total number of 116 consecutively admitted patients entered the programme; 107 (92%) successfully ended the treatment. The mean initial dose for tiapride was 289 mg and for carbamazepine 502 mg. No serious medical complications or adverse events were observed except for one case of delirium tremens. Only four patients dropped out because of side effects. In general medication was well tolerated. Withdrawal symptomatology as indicated by CIWA-A-scores decreased over time. CONCLUSIONS: Results from this study give further evidence for a combination of tiapride and the anticonvulsant carbamazepine as an effective and safe treatment for outpatient alcohol detoxification in patients with moderate severity of withdrawal syndrome. Further randomized trials are warranted to examine the efficacy of this combination in outpatient alcohol withdrawal.

Adult↗
PubMed2005

Magnetic metamaterials at telecommunication and visible frequencies.

Arrays of gold split rings with a 50-nm minimum feature size and with an LC resonance at 200 THz frequency (1.5 microm wavelength) are fabricated. For normal-incidence conditions, they exhibit a pronounced fundamental magnetic mode, arising from a coupling via the electric component of the incident light. For oblique incidence, a coupling via the magnetic component is demonstrated as well. Moreover, we identify a novel higher-order magnetic resonance at around 370 THz (800 nm wavelength) that evolves out of the Mie resonance for oblique incidence. Comparison with theory delivers good agreement and also shows that the structures allow for a negative magnetic permeability.

Journal Article↗
PubMed2005

Pediatric MR-guided interventions.

MRI guided interventions are a relatively new but steadily growing field within surgery in pediatric age. Besides the advantages of MRI, such as multiplanar capability and excellent soft tissue contrast and spatial resolution, particularly relevant for the pediatric population is the lack of ionizing radiation. There is meanwhile a group of well defined diagnostic or therapeutic indications for applying MR imaging during pediatric interventions. Aim of this review is to give an overview about indications of MR-guided procedures in children as well as the advantages and disadvantages of MR-guided interventions. We also briefly discuss interventional MR-systems and MR-compatible devices. It is our opinion that MR-guidance for pediatric interventions is a promising technique at the beginning of its development.

Child↗
PubMed2005

[MR-guided core biopsy of the shoulder: possibilities and experience with a vertically open 0.5T system].

PURPOSE: The availability of open whole body MRI magnets and MR-compatible instrumentarium were essential conditions for the progression of interventional MRI. The advantages of an MR-guided biopsy at the musculoskeletal system are the visualization of the puncture site of a representative area for tumor histology, the absence of exposure to radiation and the free selection of imaging planes. The purpose of the study was the development of a new technique of a secure MR-guided biopsy of intraosseus lesions in the humeral head. MATERIAL AND METHODS: MR-guided core biopsy of a intraosseus lesion of the humeral head was performed in five male patients on a vertical open, whole body MRI magnet (SIGNA SP/i 0.5T, GE Medical Systems). The technique using interactive MRI and the MR-compatible instrumentarium are described. RESULTS: A secure core biopsy could be obtained from a representative area for tumor histology in all cases. No complications occurred, especially no nerve or vessel lesion, no rotator cuff lesion and no intra-articular contamination of the shoulder joint were observed. CONCLUSION: A new technique is presented to obtain MR-guided core biopsies of intraosseous lesions of the humeral head. Furthermore, clinical indications of this technique are described.

Adult↗
PubMed2005

Anterior sciatic nerve block--new landmarks and clinical experience.

BACKGROUND: Anterior sciatic nerve blocks can be complicated by several problems. Pain can be caused by bony contacts and, in obese patients, identification of the landmarks is frequently difficult. METHODS: In a first step, 100 normal anterior-posterior pelvic X-rays were analyzed. The landmarks of the classical anterior approach were drawn on these X-rays and assessed for their sufficiency. Then, in a prospective case study, 200 consecutive patients undergoing total knee replacement were investigated. These patients received femoral and sciatic nerve catheters for postoperative pain management. Using modified anatomical landmarks, sciatic nerve catheters were inserted 5 cm distal from the insertion site of the femoral nerve block perpendicularly in the midline of the lower extremity. This midline connected the insertion site of the femoral nerve catheter to the midpoint between the medial and lateral epicondyle. Correct catheter positioning was verified by magnetic resonance imaging (MRI) in six patients. RESULTS: Evaluation of pelvic X-rays showed that puncture following the classical landmarks pointed in 51% at the lesser trochanter, in 5% medial to the lesser trochanter and in 42% directly at the femur. In the latter patients, location of the sciatic nerve would have been difficult or even impossible. Using our modified anterior approach, the sciatic nerve could be blocked in 196 patients (98%). In nine patients (4.5%) blockade of the posterior femoral cutaneous nerve failed. Vascular puncture happened in 10 (5%) and bony contact in 35 patients (17.5%). Median puncturing depth was 9.5 (7.5-14) cm. Correct sciatic nerve catheter positioning was verified in all patients who underwent MRI. CONCLUSION: Our landmarks for locating the sciatic nerve help to avoid bony contacts and thereby reduce pain during puncture. Our method reliably enabled catheter placement.

Aged↗
PubMed2004

Bilateral Wallerian degeneration of the middle cerebellar peduncles due to paramedian pontine infarction: MRI findings.

Wallerian degeneration is a frequent finding in lesions of the pyramidal tract, but has been observed after damage of the other fibre systems as well. Few reports exist about Wallerian degeneration of cerebellar fibres after distant lesions to the axons. Here, we report on a patient who developed degeneration of both middle cerebellar peduncles after a paramedian pontine infarction.

Aged↗
PubMed2004

Diffusion-weighted MRI in herpes simplex encephalitis: a report of three cases.

Herpes simplex virus encephalitis (HSVE) is the most frequent fatal viral infection of the brain. Because antiviral treatment may improve the prognosis significantly, early diagnosis is mandatory. Imaging diagnosis rests on conventional MRI for the visualization of lesions in the limbic system, the hallmark of HSVE. Diffusion-weighted MRI (DW-MRI) has not been used for the evaluation of HSVE. We report on the DW-MRI findings in three patients with HSVE, who had cortical diffusion abnormalities in affected brain parenchyma, partially as the initial or most sensitive sign of encephalitis. Sequential imaging showed that the diffusion abnormality started to return to normal after 2 weeks in the presence of persistent contrast uptake. Thus, DW-MRI may be a valuable tool for early detection and diagnosis of HSVE whereas contrast-enhanced images are indispensable after the first week.

Aged↗
PubMed2004

Does tumor heterogeneity limit the use of the Weiss criteria in the evaluation of adrenocortical tumors?

Adrenal incidentalomas are detected more frequently with high-resolution imaging modalities. It is difficult to distinguish between benign and malignant lesions despite the so-called histologic Weiss criteria, imaging features, and molecular studies. We here present a 52 yr-old man who was found to have an adrenal incidentaloma during an annual check-up at his urologist. An 8 cm large adrenal lesion was detected on ultrasound, computed tomography, and magnetic resonance imaging with imaging features suggestive of malignancy. The lesion was hormonally inactive. A left-sided adrenalectomy was performed and histologic grading revealed a Weiss score of 2, suggesting a benign tumor. However, on further follow-up, the patient developed a local recurrence and pulmonary metastases diagnosed 6 yr after initial presentation. After repeat surgery in the left adrenal bed adrenocortical tumor tissue had a Weiss score of 8, clearly suggesting histologic malignancy. The patient received adjuvant mitotane therapy. Under this therapy, he developed a right-sided adrenal mass (contralateral from the primary tumor) of 2 cm size which disappeared during the following 9 months, whereas the pulmonary metastases remained unchanged, suggesting tumor clones with a variable response to treatment or spontaneous apoptosis. This case suggests that adrenal incidentalomas larger than 6 cm with imaging features such as intratumoral necrosis suggestive of malignancy, should be managed as potential cancers independent of the so-called Weiss criteria. In such patients, close follow-up examinations including high-resolution imaging (preferably 3 monthly) are needed and should be carried out by a physician familiar/specialized in endocrine oncology.

Adrenal Cortex↗
PubMed2004

Twenty-four-hour ambulatory urodynamics in healthy young men.

OBJECTIVE: To describe normal natural fill urodynamics in young men during normal and increased fluid intake. MATERIAL AND METHODS: Thirty healthy males aged 21-32 years volunteered for an ambulatory urodynamic 24 h investigation with a suprapubic catheter. The recorded micturition data were: frequency (f), voided volume (VV), voiding time, maximal flow rate (Qmax) and time to Qmax. The number of sensed and not-sensed bladder contractions, duration and time in relation to voiding were also recorded. During the recording day subjects were randomized to normal (30 ml/kg body weight per day) or larger (60 ml/kg body weight per day) fluid intake. RESULTS: As expected there was a larger urine production and an increased voiding frequency in the fluid-loaded group (p<0.0001). The detrusor pressure (Pdet) Qmax was significantly higher in the fluid-loaded group (73 cmH2O, range 57-94) than in the normal fluid intake group (60 cmH2O, range 45-86) (p=0.003). No other urodynamic data differed significantly between the two groups. When comparing the ambulatory urodynamic data with previously obtained home flowmetry recordings from the same volunteers differences were only found in voiding frequency. The majority of participants had detrusor contractions, felt and unfelt, during the filling phase. Three types of detrusor activity during voiding phase could be described: type 1, with one micturition contraction, type 2, with several small contractions before micturition, and type 3, with large prolonged contractions leading to micturition. CONCLUSIONS: Ambulatory urodynamics in normal young men showed a large interindividual variation. Bladder contractions during filling were frequently recorded, and premicturition contractions were consistently found. The data found in this study were similar to previous home flow recordings in the same group.

Adult↗
PubMed2003

Response to combination therapy with interferon alfa-2a and ribavirin in chronic hepatitis C according to a TNF-alpha promoter polymorphism.

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is involved in the pathogenesis of chronic active hepatitis C. Polymorphisms in the promoter region of the TNF-alpha gene can alter the TNF-alpha expression and modify the host immune response. The present study aimed at the correlation of the G308A TNF-alpha polymorphism with the response to antiviral combination therapy in chronic hepatitis C. PATIENTS AND METHODS: 62 patients with HCV and 119 healthy unrelated controls were genotyped for the G308A TNF-alpha promoter polymorphism. The patients received 3 x 3 million units of interferon alfa-2a and 1,000-1,200 mg ribavirin daily according to their body weight. A response was defined as absence of HCV-RNA and normalization of S-ALT after 6 months of combination therapy. RESULTS: With respect to the allele and genotype frequency, a significant difference was not observed between controls and patients with chronic hepatitis C. Furthermore, such a difference was also not observed if responders and non-responders to antiviral therapy were compared. CONCLUSIONS: The promoter polymorphism of the TNF-alpha gene investigated herein is equally distributed in healthy individuals and patients with hepatitis C and does not seem to predict the response to therapy with interferon alfa-2a and ribavirin.

Adult↗
PubMed2003

Progressive multifocal leukoencephalopathy: analysis of lesion development with diffusion-weighted MRI.

Progressive multifocal leukoencephalopathy (PML), caused by replication of JC virus in oligodendrocytes of immunocompromised patients, is diagnosed by polymerase chain reaction-based demonstration of JC virus DNA. We investigated whether MRI might be used to assess disease activity. Diffusion-weighted imaging (DWI) was obtained in two patients with PML, in whom it was the only MRI sequence on which we could identify areas of progressive disease. The extent of abnormal diffusion appeared to correlate with the speed of clinical progression. DWI would thus seem to be of value in patients with PML.

Brain↗
PubMed2003

The effects of working conditions and antenatal leave for the risk of premature birth in Berlin.

OBJECTIVES: The influence a job--including its physical and psychological aspects--has on pregnant woman's chances of delivering prematurely. METHODS: Seven hundred and seven women who had given birth participated. Statements regarding her job and its stresses were obtained with a standardised questionnaire. RESULTS: Two hundred and thirty-seven of the 707 women delivered prematurely (<37 weeks), 471 at term. No increased incidence of premature deliveries was observed in working mothers or found in relation to physical stress. A link was observed due to a mother's dissatisfaction with her job ( p<0.001). CONCLUSION: With changes in the workplace and adherence to laws protecting pregnant women, effective factors are in place that help prevent premature births. A prerequisite for this is the pregnant woman's contentment with her work.

Berlin↗
PubMed2003

The Delta 32 mutation of the chemokine-receptor 5 gene neither is correlated with chronic hepatitis C nor does it predict response to therapy with interferon-alpha and ribavirin.

Unlike in HIV, homozygosity for a 32-bp deletion (Delta 32) of the chemokine receptor 5 (CCR5) gene was recently described in increased frequency in patients with chronic hepatitis C (HCV). Thus, it was speculated that this mutation might be relevant for disease susceptibility and influence the response to antiviral therapy. The present study sought to confirm the association between HCV and the Delta 32 mutation of the CCR5 gene and to correlate it with the response to therapy with interferon-alpha-2a and ribavirin. Sixty-two patients with HCV and 119 healthy unrelated controls were genotyped for the Delta 32 mutation. For the correlation between the Delta 32 mutation and response to therapy, only patients (n = 59) who completed 6 months of combination therapy as part of a prospective study were evaluated. The Delta 32 mutation was not observed in increased frequency in HCV. Furthermore, a significant difference of the HCV load or aminotransferase concentrations was not observed in carriers versus noncarriers of the Delta 32 mutation. After stratification for potentially confounding factors such as gender or HCV genotype, a significant difference was also not detected with respect to treatment outcome. These observations argue strongly against a role of CCR5 for susceptibility to HCV infection or response to combination therapy.

Antiviral Agents↗
PubMed2003

[MRI-guided pediatric interventions].

AIM: There are only a few diagnostic or therapeutic procedures where MR imaging is applied during pediatric interventions. This study will describe indications, complications as well as the advantages and disadvantages of MRI-guided interventions based on a case study in an open MRI scanner. MATERIALS AND METHODS: 14 procedures were performed in an open MRI scanner (Signa SP/i, GEMS) on 13 children (1 - 16 yr) with bone, soft tissue and brain lesions (1 - 4 cm diameter). Localization of the pathology, targeting and final control of the result were based on images acquired with SE-, 3D-, GE-sequences pre- and post-contrast as well as FSE-sequences. Interactive MRI-guided instrument navigation was performed using a multiplanar T1w GE-sequence. RESULTS: Eight biopsies (incl. 1 rebiopsy), two tumor resections, one removal of a free joint mouse and three tumor-markings were performed without complications. Five biopsies provided appropriate sample quality for a histological diagnosis while two samples were too fragmented requiring a second biopsy (one of them MRI-guided). Surgical progress during tumor resection and marking could be controlled during the intervention without repositioning the patient. DISCUSSION: MR image guided pediatric interventions combine the advantage of an imaging system without ionizing radiation and the high soft-tissue contrast. The low number of these kinds of procedures can be explained by the relatively high costs for the intervention, the increased duration for each procedure and the limited availability of open MRI systems. The integrated localization-system helps during planning of the access path when facing complex anatomical structures and provides safe navigation in sensitive regions like the epiphyseal cartilage. Recent and expected developments of the required MR-compatible biopsy instruments could provide higher efficiency for appropriate sample size and quality. Summarizing, MRI-guided pediatric interventions have shown to be a promising method at the beginning of its development.

Adolescent↗
PubMed2002

Thyroid hypoechogenicity in patients with chronic hepatitis receiving interferon-alpha therapy: evaluation by standardized grey scale ultrasonography.

BACKGROUND: Recombinant human interferon-a therapy of chronic hepatitis B and C is associated with the induction of thyroid dysfunction in up to 15%. Little is known about morphological changes of the thyroid gland, especially about its tissue echogenicity under this immunomodulative drug treatment. METHODS: 116 patients with chronic hepatitis B or C were consecutively investigated. 53 patients qualified for treatment with interferon-a alone or in combination with ribavirin. Patients with normal serum aminotransferase levels, advanced liver cirrhosis, hepatocellular carcinoma, active intravenous drug or alcohol abusus and with focal thyroid lesions (nodes, cysts, calcifications) were excluded. Thyroid function was determined by measurements of FT4, TSH and thyroidal autoantibodies. Ultrasonography was performed before, during and after interferon-a therapy including volumetry and standardized grey scale analysis. The data were compared with values of 100 euthyroid volunteers as control group. RESULTS: After six months of therapy patients differed from controls by significant TSH elevation (12.8 +/- 9.34 vs. 2.8 +/- 1.1 microU/ml, p<0.02). Six patients (11%) developed overt hypothyroidism with detectable thyroidal autoantibodies. Thyroid volume in patients was similar (13.0 +/- 4.1 ml) to that in the control group (12.6 +/- 4.7 ml). However, thyroid echogenicity of the patients was significantly lower after 6 months of therapy (21.9 +/- 2.5 grey scales) compared to the status before (25.6 +/- 2.3 grey scales) and compared to the values of controls (25.4 +/- 2.1 grey scales, p <0.002). CONCLUSION: Beside of functional disorders interferon-alpha leads to thyroid hypoechogenicity suggesting relevant morphological changes of the organ.

Adult↗