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Biomedical subjects

E Keller

Publications and source records attributed to E Keller.

At least 19 recordsLinked to original sources
PubMed2006

Decompressive hemicraniectomy in patients with subarachnoid hemorrhage and intractable intracranial hypertension.

BACKGROUND AND PURPOSE: To evaluate the outcome of patients with aneurysmal subarachnoid hemorrhage (aSAH) developing intractable intracranial hypertension and treated by decompressive hemicraniectomy (DHC). METHODS: Of 193 patients with aSAH 38 patients were treated with DHC after early aneurysm clipping. Indications for DHC were 1. Signs of brain swelling during aneurysm surgery (group 1: primary DHC). 2. Intracranial pressure- (ICP)-elevation and epidural, subdural or intracerebral hematoma after aneurysm surgery (group 2: secondary DHC due to hematoma) 3. Brain edema and elevated ICP without radiological signs of infarction (group 3: secondary DHC without infarction). 4. Brain edema and elevated ICP with radiological signs of infarction (group 4: secondary DHC with infarction). RESULTS: Thirty-one patients (81.6%) suffered from high grade aSAH Hunt & Hess 4-5. 21 belonged to group 1, five to group 2, six to group 3 and six to group 4. Of a total of 38 patients a good functional outcome according to Glasgow Outcome Score (GOS 4 & 5) could be reached in 52.6% of the cases. 26.3% survived severely disabled (GOS 3), no case suffered from a vegetative state (GOS 2) but 21.1% died (GOS 1). After 12 months good functional outcome could be achieved in 52.4% of the cases in group 1, in 60% in group 2, in 83.3% in group 3 and in 16.7% in group 4. CONCLUSIONS: In more than half of the patients with intractable intracranial hypertension after aSAH a good functional outcome could be achieved after DHC. Patients with progressive brain edema without radiological signs of infarction and those with hematoma may benefit most. The indication for DHC should be set restrictively if secondary infarcts are manifest.

Adult↗
PubMed2006

Clinical and functional characteristics of the human Arg59Ter insulin-like growth factor i receptor (IGF1R) mutation: implications for a gene dosage effect of the human IGF1R.

CONTEXT: Signaling via the IGF-I receptor (IGF-IR) is crucial for normal prenatal and postnatal growth. The heterozygous IGF-IR mutation Arg59Ter resulted in reduced IGF-IR expression and represents haploinsufficiency of the human IGF1R gene. OBJECTIVE: We studied clinical and in vitro aspects of a human IGF1R gene dosage effect. We provide detailed clinical data on the two half-brothers and their mother with the Arg59Ter mutation. Arg59Ter and control fibroblasts were examined for functionality of IGF-I and insulin-stimulated receptor phosphorylation and signal transduction. RESULTS: The two brothers presented with primary microcephaly, mild mental retardation, and intrauterine as well as postnatal growth deficits. After GH therapy (30 microg/kg.d) for 24 months, the growth deficit in the propositus decreased by +1.0 sd. There was no clinical evidence for impaired glucose tolerance or hypoglycemia in all Arg59Ter subjects. In vitro, IGF-IR-deficient Arg59Ter cells expressed less IGF-IR and unchanged insulin receptor (IR) protein. Receptor autophosphorylation and phosphorylation of downstream protein kinase B/Akt exhibited resistance to IGF-I but showed an augmented response to insulin in Arg59Ter cells. Decreased IGF-IR content was accompanied by a reduction of IGF-IR/IR receptor hybrids, and therefore, increased levels of IR/IR homodimers probably explain increased insulin-stimulated receptor autophosphorylation and Akt phosphorylation. CONCLUSIONS: In vivo and in vitro IGF-I resistance in Arg59Ter subjects and fibroblasts indicates a human IGF1R gene dosage effect involving not only the IGF-IR, but also IGF-IR/IR hybrids. The abundance of both the IGF-IR protein and IGF-IR/IR hybrid receptors may have an impact on human growth, organ function, and glucose metabolism.

Body Weight↗
PubMed2006

Neuropsychological problems after paediatric stroke: two year follow-up of Swiss children.

AIM: The aim of this study was to obtain information about neurological and cognitive outcome for a population-based group of children after paediatric ischaemic stroke. METHODS: Data from the Swiss neuropaediatric stroke registry (SNPSR), from 1.1.2000 to 1.7.2002, including children (AIS 1) and neonates (AIS 2). At 18-24 months after a stroke, a follow-up examination was performed including a history, neurological and neuropsychological assessment. RESULTS: 33/48 children (22 AIS 1, 11 AIS 2) participated in the study. Neurological outcome was good in 16/33. After childhood stroke mean IQ levels were normal (94), but 6 children had IQ < 85 (50-82) and neuropsychological problems were present in 75%. Performance IQ (93) was reduced compared to verbal IQ (101, p = 0.121) due to problems in the domain of processing speed (89.5); auditory short-term memory was especially affected. Effects on school career were common. Outcome was worse in children after right-sided infarction. Children suffering from stroke in mid-childhood had the best prognosis. There was no clear relationship between outcome and localisation of the lesion. After neonatal stroke 7/11 children showed normal development and epilepsy indicated a worse prognosis in the remaining 4. CONCLUSION: After paediatric stroke neuropsychological problems are present in about 75% of children. Younger age at stroke as well as an emergence of epilepsy were predictors for worse prognosis.

Adolescent↗
PubMed2006

Surgical removal and immediate reattachment of coronal fragment embedded in lip.

This case describes a patient with a traumatic crown fracture of an upper incisor, associated with a laceration wound in the lower lip, showing local oedema. While palpating the tissues of the lower lip we felt the presence of a foreign body. This was confirmed by a radiograph of the lip that showed a radiopaque material, being similar to the coronal fragment of the fractured incisor. It was successfully surgically removed and immediately reattached using a composite adhesive technique. At the follow-up of 1 year later the vitality test on the teeth was positive and neither one of the two traumatized teeth showed any sign of discoloration.

Adolescent↗
PubMed2006

Diagnostic value of fine-needle aspiration biopsy of thyroid nodules in children and adolescents.

From 1971 to 2001, 188 fine-needle aspiration biopsies (FNAB) of the thyroid gland were performed in 169 children and adolescents with thyroid nodules. In 65.4% the results of FNAB were classified as benign. In 13.8% FNAB was considered insufficient for diagnosis, due to the absence or small number of cells. The results of FNAB were classified as suspicious or malignant in 17.6% (n = 33). Surgery was performed in 118 patients (69.8%) and the results of cytological evaluation and histopathology were compared. The accuracy of FNAB was 77.2%, specificity 63.6%, and sensitivity 78.9%, which is less than reported for adults. Histopathological evaluation showed 13 malignant tumors. In two of the 13 malignancies, FNAB was inadequate because of a lack of thyroid cells. Of the remaining 11 malignancies, seven were detected by FNAB but four of these were classified as benign. Because of the lower accuracy of FNAB, we suggest a more aggressive diagnostic and therapeutic approach in children and adolescents than for adults.

Adolescent↗
PubMed2005

Fatal traffic injuries among pedestrians, bicyclists and motor vehicle occupants.

The objective of this study was to investigate characteristic injuries of pedestrians and bicyclists (unprotected) compared to motor vehicle occupants' (protected) in fatal traffic accidents. Cases of 664 fatal traffic accidents (371 pedestrians, 45 bicyclists, and 248 motor vehicle occupants) were collected from 1999 to 2001 using the database of the Forensic Institute in Budapest. Autopsy reports were analyzed. Location of injuries, blood alcohol levels, seasonal distribution and natural diseases influencing accident outcome were evaluated. For statistical analysis, odds ratio (OR) with 95% confidence interval (CI) was used by a conditional logistic regression. There were substantial differences in distribution of injuries suffered by pedestrians, bicyclists and motor vehicle occupants. Among pedestrians and bicyclists there was a higher rate of head injuries, such as skull fractures, epidural haemorrhage, subdural haemorrhage, brain contusion, and injuries of the lower extremities. Thoracic damages, such as traumatic aortic rupture, hemothorax, and abdominal damages, like liver rupture were dominant in motor vehicle occupants. Considering existing natural diseases, coronary artery disease was the only one with higher occurrence among motor vehicle occupants 24 (9.7%) compared with pedestrians and bicyclist 36 (8.6%). These results underline the importance of preventive strategies in transportation, pointing out that different methods are necessary to reduce fatal injuries of various traffic participants.

Accidents, Traffic↗
PubMed2005

Histologic analysis of gonadal tissue in patients with Ullrich-Turner syndrome and derivative Y chromosomes.

To identify patients who had Ullrich-Turner syndrome (UTS) and were at risk for gonadoblastoma or associated germ cell tumors, molecular genetic analysis was carried out to detect Y chromosomal sequences. From peripheral blood samples of 5 patients who had cytogenetically confirmed UTS, genomic DNA was extracted and screened for Y chromosomal sequences by polymerase chain reaction. The morphology of the gonadal tissues was compared with results from polymerase chain reaction. Three phenotypic females showed UTS mosaicism with normal X chromosome accompanied by Y chromosomal material, and 2 patients showed marker chromosomes. Molecular analysis represented loci PABY, SRY, ZFY, TSPY, DYZ3, DYZ1 DXYS, 19Y, DYS-273, DYS-148, DYS218, DYS224, and DYZ1. Three patients showed gonadal tumors (1 with unilateral gonadoblastoma, 1 with unilateral dysgerminoma, and 1 patient had both tumors in 1 gonad). Molecular genetic screening for Y chromosomal sequences may be useful as an additional tool for the identification of patients at risk for a gonadal tumor. Careful, complete processing, including step sectioning, of the gonadectomy specimens to detect small lesions is recommended.

Adolescent↗
PubMed2005

Cerebral vasospasm: results of a structured multimodal treatment.

Symptomatic cerebral vasospasm (CVS) with delayed ischemic neurologic deficits affects about one third of the patients after aneurysmal subarachnoid hemorrhage (SAH). In spite of the lack of definite evidence of large clinical trials, the devastating outcome of the natural history of symptomatic CVS demands an aggressive CVS treatment in a practically oriented, structured multimodal treatment regimen. With our treatment protocol good functional outcome could be reached in 66% of the patients with symptomatic CVS. This policy requires close and fast multidisciplinary collaboration between neurosurgeons, neuroradiologists, competent in endovascular interventions, and specialists for neurointensive care. We report on our experience with 79 cases with symptomatic CVS and delayed ischemic neurologic deficit (DIND) after aneurysmal SAH. The different treatment options with CVS are reviewed and practical guidelines for a step by step treatment are given.

Brain Ischemia↗
PubMed2005

Decompressive craniectomy in severe cerebral venous and dural sinus thrombosis.

OBJECTIVE: To evaluate the outcome of patients with most severe cerebral venous and dural sinus thrombosis (CVT) after decompressive craniectomy. Indications and techniques for decompressive craniectomy and intensive care regimen are discussed. METHODS: Between 2000 and 2004 15 patients with CVT and intracerebral hemorrhage were treated at the Department of Neurosurgery, University Hospital Zurich. Among them, four patients with the most severe illness course were treated with decompressive craniectomy. Indications for decompressive craniectomy were deterioration of level of consciousness with CT signs of space occupying brain edema, venous infarction and congestional bleeding with mass effect, midline shift and obliteration of the basal cisterns. RESULTS: Among 15 patients with CVT and intraparenchymatous hemorrhage four patients were treated with decompressive craniectomy. Glasgow Coma Scale (GCS) immediately before the operation was in mean 10.2 (range 6 to 13). No patient showed signs of unilateral or bilateral third nerve palsy before surgery. No surgical complications were observed. All four patients who underwent decompressive craniectomy recovered with favourable functional outcome (Glasgow Outcome Scale; GOS 4 and 5). Anticoagulation therapy with heparin was reconvened 12 hours postoperatively with half dosage and 12 hours later with full dosage. No enlargement of existing intraparenchymatous hematoma or other intracranial bleeding complications occurred. CONCLUSIONS: Favorable functional outcome in selected patients with most severe courses of CVT can be achieved after decompressive craniectomy. Postoperative anticoagulation therapy with full dose heparin 24 hours after craniotomy seems to be safe. Precise indications and techniques for combined surgical decompression and thrombectomy deserve to be evaluated in future studies.

Adult↗
PubMed2005

Tissue-interface pressures on three different support-surfaces for trauma patients.

The purpose of this study was to evaluate and compare tissue-interface pressures on three different support-surfaces for trauma patients. The support-surfaces were a semi soft overlay mattress, a vacuum mattress and a spine board. Tissue-interface pressures were measured in a standardised way between the scapulae, the sacrum, the heels and the different support-surfaces in 20 healthy volunteers. Appreciation of comfort of the support-surface was assessed using a 10-point visual analog scale. High and potentially ischaemic interface pressures were found on all three support-surfaces, with the highest pressures (exceeding 170 mmHg) measured on the spine board. The spine board got the worst comfort score. It was also noted that no support was given to the normal lumbar lordosis by the spine board. There is a need for new support-surfaces for trauma patients, which reduce interface pressures and are comfortable.

Adult↗
PubMed2005

The first three years of the Swiss Neuropaediatric Stroke Registry (SNPSR): a population-based study of incidence, symptoms and risk factors.

We report the results of three years of the population-based, prospective Swiss NeuroPaediatric Stroke Registry (SNPSR) of children (up to 16 years) with childhood arterial ischaemic stroke (AIS1), neonatal stroke (AIS2), or symptomatic sinus venous thrombosis (SVT). Data on risk factors (RF), presentation, diagnostic work-up, localisation, and short-term neurological outcome were collected. 80 children (54 males) have been included, 40 AIS1, 23 AIS2, and 17 SVT. The data presented will be concentrated on AIS. The presentation for AIS1 was hemiparesis in 77% and cerebellar symptoms and seizures in 20%, respectively. AIS2 presented in 83% with seizures and in 38% with abnormality of muscle tone. Two or more RF were detected in 54%, one RF in 35%. The most prominent RF for AIS1 were infections (40%), followed by cardiopathies and coagulopathies (25% each). AIS2 were frequently related to birth problems. Neurological outcomes in AIS1 and AIS2 were moderate/severe in 45 % and 32 %, respectively. The outcome correlated significantly with the size of infarction (p = 0.013) and age at stroke (p = 0.027). The overall mortality was 6%. Paediatric stroke is a multiple risk problem, which leads to important long-term sequelae.

Adolescent↗
PubMed2004

Seasonal variations in hospital admissions due to aneurysmal subarachnoid haemorrhage in the state of Zurich, Switzerland.

INTRODUCTION: In clinical practice, the occurrence of aneurysmal subarachnoid haemorrhage (SAH) often coincides with a particular season. Our objective was to examine seasonal variations in hospital admissions due to aneurysmal SAH. METHODS: The study population consisted of 489 patients with aneurysmal SAH who were admitted to the Department of Neurosurgery, University Hospital of Zurich, Switzerland, between 1st of January 1996 and 31st of December 2002. Statistical significance of seasonal variation was determined by applying Roger's r test. RESULTS: Statistically significant seasonal variation was only found among patients younger than 60 years, showing a first peak in spring and second lower peak in autumn (Roger's r=6.89, p<0.05). A borderline significance was found in men younger than 60 years (Roger's r=5.96, p=0.051). A trend was observed in patients presenting with Fisher grade 1-2 (Roger's r=5.70, p=0.058). CONCLUSIONS: Previous studies from different countries have shown significant seasonal variations, with the peak period for aneurysmal SAH differing widely. There appears to be some link between aneurysmal SAH and the season of the year or variations in weather conditions. Further investigations are desirable to evaluate which weather or climatic parameters correlate well with SAH.

Adult↗
PubMed2004

Video-assisted gonadectomy in children with Ullrich Turner syndrome or 46,XY gonadal dysgenesis.

Patients with dysgenetic gonads carry a high risk for the development of gonadal neoplasia. The aim of the study is to evaluate indications and feasibility of laparoscopy and video-assisted prophylactic gonadectomy in children with Ullrich Turner syndrome (UTS) or 46,XY gonadal dysgenesis (GoDy). Between 1996 and December 2002 five girls with UTS and nine patients with 46,XY GoDy (female gender role) were explored by laparoscopy. Video-assisted salpingo-oophorectomy or gonadectomy was performed using a three-port technique. Prophylactic salpingo-oophorectomy was exclusively performed in UTS patients with proven presence of translocated parts of the Y chromosome. In three patients with 46,XY GoDy laparoscopy was followed by surgical revision of the groin and open gonadectomy in four patients. In two cases with UTS the removed streak gonads contained small unilateral tumours stage pT1a, and in four cases of 46, XY GoDy histopathological investigation revealed bilateral neoplasms stage pT1b. We found the following tumour types: gonadoblastoma, dysgerminoma, testicular intraepithelial neoplasia, and mature teratoma. In conclusion, investigative laparoscopy gives a good image of the internal genital structures and allows the safe removal of the dysgenetic gonads during the same operation. The high rate of gonadal tumours underlines the indication for early gonadectomy in these patients.

Adolescent↗
PubMed2004

Priming with testosterone enhances stimulated growth hormone secretion in boys with delayed puberty.

BACKGROUND AND OBJECTIVE: Tests for growth hormone (GH) deficiency are not always helpful in the differential diagnosis of physiological delay of growth and puberty and GH deficiency. PATIENTS AND METHODS: To enhance diagnostic specificity, we used a single dose testosterone priming before repeating the arginine stimulation test in 26 boys with short stature and only early signs of puberty who failed to show an adequate response of serum GH in the first test. RESULTS: 77% (20/26 patients) increased their serum GH peak to more than 10 ng/ml, whereas six patients were still below this concentration. CONCLUSION: We propose that testosterone priming is a useful tool to distinguish between physiological delay of growth and puberty and GH deficiency and should be included in the diagnostic procedure.

Adolescent↗
PubMed2004

Addison's crisis in adolescent patients with previously diagnosed diabetes mellitus as manifestation of polyglandular autoimmune syndrome type II--report of two patients.

We report on two female adolescents--both diagnosed with type 1 diabetes mellitus in early childhood--who presented with signs of severe metabolic decompensation. In both cases recompensation was difficult, and during the stay in hospital increasing discoloration of palmar creases was observed. ACTH testing demonstrated cortisol deficiency in both patients. In addition, autoimmune thyroiditis was diagnosed in one patient. As a polyglandular autoimmune syndrome was suspected, autoantibody studies were performed and the presence of autoantibodies against thyroid and adrenal tissue was established. Polyglandular autoimmune syndrome (PGA) type II can lead to subsequent manifestation of deficiencies of several endocrine glands. Although PGA type II usually presents at a more advanced age, adolescents may also present with the full spectrum of the disease. Especially in the presence of Addison's disease, life-threatening situations can develop rapidly. Coloration of palmar skin creases of patients with known type I diabetes mellitus should serve as a warning sign to be followed up with investigation of endocrine functions.

Acute Disease↗
PubMed2003

50-Hz magnetic field exposure influences DNA repair and mitochondrial DNA synthesis of distinct cell types in brain and kidney of adult mice.

Despite several recent investigations, the impact of whole-body magnetic field exposure on cell-type-specific alterations due to DNA damage and DNA repair remains unclear. In this pilot study adult mice were exposed to 50-Hz magnetic field (mean value 1.5 mT) for 8 weeks or left unexposed. Five minutes after ending exposure, the mice received [(3)H]thymidine and were killed 2 h later. Autoradiographs were prepared from paraffin sections of brains and kidneys for measuring unscheduled DNA synthesis and mitochondrial DNA synthesis, or in situ nick translation with DNA polymerase-I and [(3)H]dTTP. A significant (P<0.05) increase in both unscheduled DNA synthesis and in situ nick translation was only found for epithelial cells of the choroid plexus. Thus, these two independent methods indicate that nuclear DNA damage is produced by long-lasting and strong magnetic field exposure. The fact that only plexus epithelial cells were affected might point to possible effects of magnetic fields on iron transport across the blood-cerebrospinal fluid barrier, but the mechanisms are currently not understood. Mitochondrial DNA synthesis was exclusively increased in renal epithelial cells of distal convoluted tubules and collecting ducts, i.e., cells with a very high content of mitochondria, possibly indicating increased metabolic activity of these cells.

Animals↗
PubMed2003

A new subdural probe for combined intracranial pressure (ICP) and cerebral blood flow (CBF) monitoring.

We report the development of a new subdural probe for combined intracranial pressure (ICP) and cerebral blood flow (CBF) monitoring with near infrared spectroscopy (NIRS) and indocyanine green (ICG) dye dilution. For NIRS a conventional subdural ICP monitoring probe was supplied with two fiber bundles and 90-degree prisms. Injections of 25 mg ICG were performed. Regional values for the mean transit time of ICG (rmtt(ICG)), cerebral blood flow (rCBF) and cerebral blood volume (rCBV) were calculated. With prototypes of the probe in two patients with intracerebral haemorrhage 18 comparative measurements obtained simultaneously with conventional NIRS (optodes placed on the skin) and the subdural NIRS probe were performed. The new subdural NIRS probe allows combined monitoring of ICP and cerebral hemodynamics in the brain directly, without the influence of extracerebral tissue.

Blood Flow Velocity↗