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Biomedical subjects

I Fuchs

Publications and source records attributed to I Fuchs.

At least 19 recordsLinked to original sources
PubMed2006

Platelet function in patients with acute coronary syndrome (ACS) predicts recurrent ACS.

BACKGROUND: Platelet hyperfunction contributes to acute coronary syndromes (ACS). Thus, we hypothesized that platelet function under high shear stress predicts recurrent ACS during long-term follow-up of ACS patients. PATIENTS AND METHODS: Consecutive ACS patients (n = 208) were prospectively followed-up for an average of 28 months. Platelet function was measured with the platelet function analyzer (PFA-100; Dade Behring, Marburg, Germany) at baseline for collagen/adenosine diphosphate closure times (CADP-CT) and for collagen/epinephrine closure times (CEPI-CT) after infusion of a uniform dose of 250 mg aspirin. RESULTS: Of the conventional risk factors, only the prevalence of diabetes was higher in ACS patients with re-events. However, use of clopidogrel and use of beta blockers were also slightly lower in patients with re-events (P < 0.05). The unadjusted risk hazard ratio (HR) for re-events was 3.3 [95% confidence interval (95% CI): 1.4-7.4; P = 0.005] in those patients with the shortest CADP-CT values (lowest quartile). Similarly, the risk was 2.0-fold higher (95% CI: 1.1-3.6; P = 0.02) in ACS patients with CEPI-CT < 300 s as compared with CEPI-CT >or = 300 s. Inclusion of diabetes, clopidogrel and beta blockers in a multivariate Cox regression model enhanced the predictive value of CEPI-CT (HR: 2.7). Inclusion of von Willebrand factor levels did not alter the HR for recurrent ACS (HR: 2.1; 95% CI: 1.1-5.2; P = 0.03) for CEPI-CT < 300 s, but reduced the HR for CADP-CT (HR: 2.8, 95% CI: 0.8-9.8; P = 0.11). CONCLUSION: Shortened CT values reflect biologically relevant platelet hyperfunction in patients with ACS because they predict recurrent ACS.

Acute Disease↗
PubMed2006

Intrapartum translabial ultrasound (ITU): sonographic landmarks and correlation with successful vacuum extraction.

OBJECTIVE: Having studied intrapartum translabial ultrasound (ITU) to define easily obtainable sonographic criteria during maternal pushing, we used it dynamically immediately before vacuum extraction to determine its use in predicting successful operative vaginal delivery. METHODS: In a pilot study, maternal and fetal landmarks were determined sonographically during maternal pushing from a mid-sagittal translabial insonation using a curved array transducer in women delivering singleton fetuses in cephalic presentation spontaneously. With this transducer placed infrapubically ('infrapubic plane'), easily obtainable landmarks and signs were: (i) the 'infrapubic line', perpendicular to the long axis of the pubic joint and extending dorsally from its inferior margin in a mid-sagittal plane, (ii) the widest fetal head diameter and its movement with regard to the infrapubic line during pushing, and (iii) the 'head direction' with respect to the long axis of the symphysis. A three-dimensional reconstruction from a computed tomographic (CT) dataset of a normal female pelvis was then used to quantify accurately the spatial relationship between the infrapubic line and the anatomical landmarks. Finally, 20 pregnant women in spontaneous term labor with normal singleton fetuses in cephalic presentation and clinical indication for vacuum extraction were studied by ITU immediately before operative vaginal delivery. RESULTS: CT reconstruction demonstrated the infrapubic line to be 3 cm cranial to the parallel interspinous plane. Eleven of the 20 vacuum deliveries with the 'head-up' sign (head pointing ventrally) and objective descent of the fetal head below the infrapubic line, both noted at the height of pushing, resulted in successful ('simple' or 'moderately difficult') operative delivery. Lack of descent or lack of passage below the infrapubic line and horizontal or downward head direction were poor prognostic signs. CONCLUSIONS: ITU provides objective information on the dynamics of the second stage of labor, head station and head direction. ITU may be used to assess the prognosis for operative vaginal delivery.

Adolescent↗
PubMed2006

Ion channels meet auxin action.

The regulation of cell division and elongation in plants is accomplished by the action of different phytohormones. Auxin as one of these growth regulators is known to stimulate cell elongation growth in the aerial parts of the plant. Here, auxin enhances cell enlargement by increasing the extensibility of the cell wall and by facilitating the uptake of osmolytes such as potassium ions into the cell. Starting in the late 1990s, the auxin regulation of ion channels mediating K+ import into the cell has been studied in great detail. In this article we will focus on the molecular mechanisms underlying the modulation of K+ transport by auxin and present a model to explain how the regulation of K+ channels is involved in auxin-induced cell elongation growth.

Arabidopsis↗
PubMed2005

Long term experience of gamma knife radiosurgery for benign skull base meningiomas.

OBJECTIVES: As most reports on the gamma knife have related only to short or mid-term results, we decided to evaluate the effectiveness and toxicity of radiosurgical treatment for benign skull base meningiomas in 200 patients with a follow up of 5-12 years to define the role of gamma knife radiosurgery (GKRS) for basal meningiomas and to provide further data for comparison with other treatment options. METHODS: In total, 99 patients were treated with a combination of microsurgical resection and GKRS. In 101 patients, GKRS was performed as the sole treatment option. Tumour volumes ranged from 0.38 to 89.8 cm3 (median 6.5 cm3), and doses of 7-25 Gy (median 12 Gy) were given to the tumour borders at covering isodose volume curves (range 20-80%, median 45%). RESULTS: The actuarial progression free survival rate was 98.5% at 5 years and 97.2% at 10 years. Passing radiation induced oedema occurred in two patients (1%). The neurological status improved in 83 cases (41.5%), remained unaltered in 108 (54%), and deteriorated in 9 (4.5%). Worsening was transient in seven patients (3.5%) and unrelated to tumour or treatment in one (0.5%). Repeated microsurgical resection was performed in five patients following GKRS (2.5%). CONCLUSIONS: GKRS has proved to be an effective alternative to microsurgical resection, radiotherapy, and Linac based radiosurgery for adjunctive and primary treatment of selected patients with basal meningiomas. Because of the excellent long term tumour control rate and low morbidity associated with GKRS, this treatment option should be used more frequently in the therapeutic management of benign skull base meningiomas.

Adolescent↗
PubMed2004

Sonographic measurement of cervical length in preterm prelabor amniorrhexis.

OBJECTIVE: To determine whether sonographic measurement of cervical length in pregnancies complicated by preterm prelabor amniorrhexis helps distinguish between those women who deliver within 7 days and those who do not. METHODS: In 101 women with singleton pregnancies presenting with preterm prelabor amniorrhexis at 24-36 (median, 32) weeks of gestation cervical length was measured by transvaginal ultrasound. Exclusion criteria were active labor defined by the presence of cervical dilatation of > or = 3 cm and iatrogenic delivery for fetal or maternal indication when not in active labor. The clinical management was determined by the attending obstetrician. The primary outcome of the study was delivery within 7 days of presentation. RESULTS: Delivery within 7 days of presentation occurred in 58/101 (57%) pregnancies. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length (odds ratio (OR) = 0.91, 95% CI 0.86-0.96, P = 0.001), gestation at presentation (OR = 1.35, 95% CI 1.14-1.59, P = 0.001) and presence of contractions at presentation (OR = 3.07, 95% CI 1.05-8.92, P = 0.039) with no significant independent contribution from ethnic origin, maternal age, body mass index, parity, previous history of preterm delivery, cigarette smoking, vaginal bleeding or the administration of tocolytics, antibiotics or steroids. CONCLUSION: In women with preterm prelabor amniorrhexis prediction of delivery within 7 days is provided by cervical length, gestation and presence of contractions at presentation.

Adolescent↗
PubMed2004

Sonographic measurement of cervical length in twin pregnancies in threatened preterm labor.

OBJECTIVE: To determine whether sonographic measurement of cervical length in twin pregnancies presenting with threatened preterm labor helps distinguish between true and false labor. METHODS: In 87 women with twin pregnancies presenting with regular and painful uterine contractions at 24-36 (median, 30) weeks of gestation, cervical length was measured by transvaginal ultrasound. Women presenting in active labor, defined by the presence of cervical dilation of 3 cm or more, with ruptured membranes and those who underwent a prior or subsequent cervical cerclage, were excluded from the study. The clinical management was determined by the attending obstetrician without taking into account the cervical length. Primary outcome of the study was delivery within 7 days of presentation. RESULTS: Delivery within 7 days of presentation occurred in 19/87 (22%) pregnancies and this was inversely related to cervical length, decreasing from 80% (4/5) at 1-5 mm, to 46% (6/13) at 6-10 mm, 29% (4/14) at 11-15 mm, 21% (4/19) at 16-20 mm, 7% (1/15) at 21-25 mm and 0% (0/21) at >25 mm. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length (odds ratio (OR) = 0.78, 95% CI 0.68-0.89, P < 0.001) and use of tocolytics (OR = 0.13, 95% CI 0.02-0.76, P = 0.024), with no significant contribution from gestation at presentation, chorionicity, ethnic origin, maternal age, body mass index, parity, previous history of preterm delivery, cigarette smoking, contraction frequency, vaginal bleeding or the administration of antibiotics or steroids. CONCLUSION: In women with twin pregnancies presenting with threatened preterm labor, sonographic measurement of cervical length helps distinguish between those who deliver within 7 days and those who do not.

Adolescent↗
PubMed2003

Blue light regulates an auxin-induced K+-channel gene in the maize coleoptile.

Auxin redistribution along gravistimulated maize coleoptiles causes differential expression of the auxin-induced K+-channel gene ZMK1 (Zea mays K+ channel 1) and precedes the curvature response. To evaluate the role of ZMK1 during phototropism, we here investigated blue light-stimulated coleoptiles. Four hours of blue light stimulation resulted in phototropic bending (23 degrees ). Rotation on a clinostat, at nominally "zero" gravity, and simultaneous stimulation with unidirectional blue light, however, resulted in up to 51 degrees bending toward the light. Differential ZMK1 transcription reached a maximum after 90 min of blue light stimulation under gravity, whereas ZMK1 expression remained asymmetric for at least 180 min in photostimulated coleoptiles on a clinostat. We therefore conclude that the stronger phototropic bending under nominally "zero" gravity results from prolonged differential expression of ZMK1. Under both conditions, asymmetric expression of ZMK1 could be superimposed on the lateral auxin gradient across the coleoptile tip, whereas the gene for the blue light receptor phototropin 1 (PHOT1), expressed in the tip only, was not differentially regulated in response to blue light. The activation of the two different receptors eliciting the photo- and gravitropic response of the coleoptile thus feeds into a common signaling pathway, resulting in auxin redistribution in the coleoptile tip and finally in differential transcription of ZMK1. In the process of signal integration, gravity transduction restricts the magnitude of the blue light-inducible ZMK1 gradient. The spatial and temporal distribution of ZMK1 transcripts and thus differential K+ uptake in both flanks of the coleoptile seem to limit the stimulus-induced bending of this sensory organ.

Base Sequence↗
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↗
PubMed2002

Gamma Knife radiosurgery of brainstem gliomas.

From August 1992 until December 1999 Gamma Knife radiosurgery (GKRS) was applied to 21 patients (male to female ratio 14:7) with brainstem gliomas. Patient's median age was 23 years (8-56 years). All tumours were histologically confirmed by biopsy or open surgery: 12 low-grade gliomas and 9 malignant growths. Two lesions were located primarily in the medulla, 12 in the pons and 7 in the midbrain. A median dose of 12 Gy (9-20 Gy) was applied to the tumour margin by the median isodose of 45%. Prior to radiosurgery 4 patients were treated by conventional radiotherapy, 1 had radiotherapy and chemotherapy, 1 patient underwent chemotherapy, and 1 patient was shunted due to hydrocephalus. Neuroimaging controls (MR, CT) were obtained from 19 patients. The median interval between radiosurgery and the last neuroimaging control was 11.8 months (1-74 months). Neuroimaging depicted tumour progression in 2 patients, stable disease in 10 patients and regression in 3 cases. Follow-up periods ranged between 3 and 99 months (median 29 months). The neurological state improved in 5 patients. Microsurgical cyst fenestration was performed in 1 patient after GKRS, shunting procedure was necessary for 2 patients. Nine patients died unrelated to radiosurgery within 3 to 45 months (median 20.7 months). GKRS is an effective treatment modality for brainstem gliomas with satisfying tumour control and functional outcome.

Adolescent↗
PubMed2002

Preservation of cranial nerve function following Gamma Knife radiosurgery for benign skull base meningiomas: experience in 121 patients with follow-up of 5 to 9.8 years.

INTRODUCTION: Microsurgical excision with preservation of juxtaposed neurovascular structures is considered the treatment of choice for skull base meningiomas, but there exists a great controversy regarding surgical resectability, potential risk for subsequent postoperative Cranial Nerve Deficit (CND) and the role of adjuvant or adjunctive treatment options. In this study we evaluated the effect of Gamma Knife Radiosurgery (GKRS) in 121 patients with benign basal meningiomas after a follow-up of 5 to 9.8 years. METHODS: Sixty patients had undergone open resections prior to radiosurgical treatment and 61 patients were treated by GKRS alone. Tumour volumes of 0.5 to 89.9 ccm (median 6.8 ccm) received a median marginal dose of 13 Gy (range 7-25 Gy) at the covering 25% to 80% isodose volume curves (median 45%). RESULTS: Neuroradiological controls demonstrated decreased tumour size in 73 patients (60.3%), stable meningioma volume in 47 cases (38.9%) and tumour enlargement in one patient (0.8%). Clinically, 54 patients (44.6%) improved and 61 cases (50.4%) remained unchanged. Four patients (3.3%) showed temporary and two patients (1.7%) permanent neurological deterioration (unrelated to tumour or treatment in one patient). Two patients (1.7%) developed radiation induced new or aggravated pre-existent CND (1 transient, 1 permanent) and two patients (1.7%) required further surgical resection. CONCLUSION: In our long-term experience, GKRS proved to be an attractive additional and save alternative primary treatment option in selected patients with basal meningiomas. The tumour control rate of 98.3% associated with excellent clinical outcome and low incidence for treatment related CND (1.7%) compares favourably with the reported microsurgical series.

Adolescent↗
PubMed2002

Endoscopic percutaneous transforaminal treatment for herniated lumbar discs.

BACKGROUND: The prevailing percutaneous treatment options for herniated non-contained lumbar discs have not reliably achieved the same good results as the conventional microsurgical techniques. In this study we evaluated clinical outcome and complication rate following endoscopic percutaneous transforaminal treatment of extruded or sequestrated herniated lumbar discs in 122 patients with a follow-up period of more than one year. METHOD: Between October 1997 and December 2000, 86 male and 36 female patients with a median age of 55 years (range 18 to 89 years) underwent endoscopic treatment for non-contained herniated lumbar discs at our department. Neurological controls were conducted after 4 to 8 weeks routinely and the clinical result was reassessed at a follow-up of 15 to 53 months (median 35 months) according to the Macnab scale and Prolo outcome score. FINDINGS: On follow-up examination, 96 patients were found with permanently ameliorated or normal clinical status following endoscopy alone. The remaining 26 cases with unchanged or only temporarily improved neurological disorders were submitted to conventional microsurgical interventions. Spinal nerve root injury during endoscopic treatment occurred in two patients but no additional neurological deficits or aggravation of pre-existing disorders were observed. INTERPRETATION: Due to the minimal invasivity, the good functional outcome (78.7% clinical amelioration) and the low complication rate (1.6%), this procedure represents an attractive and efficient treatment alternative especially for foraminal and extraforaminal herniated lumbar discs and reduces the indications for open surgery in selected cases.

Adolescent↗
PubMed2002

Antenatal diagnosis of placenta percreta with planned in situ retention and methotrexate therapy in a woman infected with HIV.

Placenta percreta is a rare obstetric condition associated with potentially life-threatening hemorrhage. Diagnosis in advance of delivery permits a planned delivery and preparation for blood transfusions and planned Cesarean hysterectomy, which is the common treatment. We report a case of placenta percreta in an HIV-positive patient which was diagnosed in the second trimester using conventional and extended field of view ultrasound imaging and color Doppler. At 36 weeks the infant was delivered by Cesarean section and the placenta was left in situ. Postoperatively the patient was treated with methotrexate. Four weeks later, the patient delivered the placenta spontaneously. Early or late postpartum hemorrhage did not occur and postoperative recovery was uneventful.

Adult↗
PubMed2000

Solid- and liquid-phase extraction for the gas chromatographic-tandem mass spectrometric quantification of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-oxo-prostaglandin F1 alpha in human urine.

Whole body synthesis of thromboxane A2 is best assessed by quantifying non-invasively its major urinary metabolite, i.e., 2,3-dinor-thromboxane B2 (2,3-dn-TxB2), by gas chromatography-mass spectrometry (GC-MS) or GC-tandem MS. Methods based on these techniques usually require a series of extraction and purification procedures including solid-phase extraction (SPE) and thin-layer chromatography (TLC) or liquid chromatographic separation of authentic or derivatized 2,3-dn-TxB2. Taking advantage of the inherent accuracy of GC-tandem MS and the high selectivity of the extraction of methoximated 2,3-dn-TxB2 on phenylboronic acid SPE cartridges we developed a method that involves only SPE steps prior to quantification by GC-tandem MS. The method was validated by performing in parallel an additional TLC step. Method mean accuracy and precision were of the order of 103% and 95%, respectively. The method allows furthermore co-processing of the same urine sample to quantify accurately and rapidly the major urinary metabolite of prostacyclin, i.e., 2,3-dn-6-oxo-prostaglandin (PG) F1 alpha, by GC-tandem MS. The limit of detection of the method was below each 5 pg of 2,3-dn-TxB2 and 2,3-dn-6-oxo-PGF1 alpha per 5 ml of urine. Our study suggests that dinor metabolites of isothromboxanes and isoprostacyclins are not abundantly present in human urine.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

Auxin-induced K+ channel expression represents an essential step in coleoptile growth and gravitropism.

Auxin-induced growth of coleoptiles depends on the presence of potassium and is suppressed by K+ channel blockers. To evaluate the role of K+ channels in auxin-mediated growth, we isolated and functionally expressed ZMK1 and ZMK2 (Zea mays K+ channel 1 and 2), two potassium channels from maize coleoptiles. In growth experiments, the time course of auxin-induced expression of ZMK1 coincided with the kinetics of coleoptile elongation. Upon gravistimulation of maize seedlings, ZMK1 expression followed the gravitropic-induced auxin redistribution. K+ channel expression increased even before a bending of the coleoptile was observed. The transcript level of ZMK2, expressed in vascular tissue, was not affected by auxin. In patch-clamp studies on coleoptile protoplasts, auxin increased K+ channel density while leaving channel properties unaffected. Thus, we conclude that coleoptile growth depends on the transcriptional up-regulation of ZMK1, an inwardly rectifying K+ channel expressed in the nonvascular tissue of this organ.

Animals↗
PubMed1999

[Torticollis spasmodicus, blepharospasm and hemifacial spasm. Subjective evaluation of therapy by patients].

Injections with botulinum toxin type A (BTX) are considered the first-line treatment for spasmodic torticollis (ST), blepharospasm (BL) and hemifacial spasm (HFS). Because BTX brings only temporary and partial relief, patients frequently try other additional therapies to minimize their symptoms. The subjective rating of all therapies ever tried by patients with ST, BL and HFS was evaluated by using a simple questionnaire. Two hundred questionnaires were considered (112 TS, 54 BL, 34 HFS). BTX was rated subjectively the best therapy in all three diagnostic groups (median: 2 = good effect). Despite Citalopram and physiotherapy (median: 3 = average effect), all other therapies were rated with a median of > or = 4 (= minimal effect). Patients with ST tried 7.7, patients with BL 2.4 and patients with HFS 2.6 different types of therapy. In conclusion, BTX is the most effective treatment for patients with ST, BL and HFS, as rated subjectively. Further evaluation of therapies additional to BTX injections is recommended.

Blepharospasm↗