PubMed Health⌕ Search

Biomedical subjects

B Huber

Publications and source records attributed to B Huber.

At least 19 recordsLinked to original sources
PubMed2007

Complete extirpation of benign breast lesions with an ultrasound-guided vacuum biopsy system.

OBJECTIVES: To investigate whether ultrasound-guided vacuum biopsy (VB) with curative intent is suitable for the complete extirpation of selected sonographically detectable benign lesions of the breast, and to establish the limitations of the method with regard to lesion size and complications, the extent of scar formation and the prognostic value. METHODS: One hundred and nine patients underwent hand-held, ultrasound-guided VB (8G or 11G needle) between June 2000 and September 2003. Of these, 45 (41%) women underwent ultrasound-guided extirpation of 46 lesions, and 42 women with 43 lesions were followed up clinically and sonographically for an average of 5.9 months. The complete extirpation rate, residual lesions, and patient satisfaction with the intervention were evaluated. RESULTS: Removal of all sonographic evidence of lesions (median diameter, 13 mm) was achieved in 86% of cases (8G needle, 80%; 11G needle, 89%). 19% of the patients had suspected scar formation at the biopsy site. A palpable lesion in the breast could be removed by VB in 90% of cases. None of the patients developed infections and there were no hemorrhages requiring intervention, or damage to the skin or chest wall. A total of 95% of the patients stated that they would prefer this approach to open excision for possible future intervention. CONCLUSIONS: VB is an ambulatory procedure associated with a low degree of pain. It has a high degree of patient acceptance and, as a minimally invasive biopsy technique for benign lesions, is a good alternative to open excision. The rate of complications is low and is similar to that observed with conventional microbiopsy.

Adolescent↗
PubMed2005

Bifocal disruption of the knee extensor apparatus ("floating patella") in a 13-year-old patient.

We present the unusual case of a traumatic "floating patella" in a 13-year-old healthy boy. No predisposing factors were diagnosed. The obvious bony avulsion was treated by immediate open reduction and screwing, whereas the quadriceps tendon rupture was missed diagnostically in the first step. During the course of the treatment, the extension lag lead to the delayed diagnosis of the concomitant rupture of the quadriceps tendon. After the surgical treatment of the latter, the patient healed with full function of the extensor apparatus and full ROM. Bifocal injury of the knee extensor apparatus is therefore possible in young adolescents without presenting the predisposing factors and should thus be considered.

Adolescent↗
PubMed2004

Psychological problems of cancer patients: a cancer distress screening with a cancer-specific questionnaire.

The purpose of this study was to assess the psychological distress of cancer patients in a disease-specific manner as well as the demographic and medical variables that have an impact on the distress. Psychological distress was assessed with the Questionnaire on Stress in Cancer Patients revised version, which has been developed and psychometrically evaluated in Germany. It consists of items about 23 cancer-specific stress situations, which have to be answered in terms of relevance and amount of distress. A heterogeneous sample of 1721 cancer in- and outpatients was assessed. For the total group, the most important distress is the fear of disease progression. We consider between 23.4% (ca. of the upper gastrointestinal tract) and 40.9% (breast cancer patients) as highly distressed. The most distressed diagnostic subgroups are patients with soft tissue tumours and breast cancer patients. There are no global (general) stress factors, as the relevant demographic and medical 'risk factors' varied between the diagnostic subgroups. Cancer-specific distress questionnaires give a more precise insight into patients' experience than general or psychiatric questionnaires. They are not only used in large screening studies but also in routine medicine, particularly when the objective is to identify patients to whom psycho-oncological support is to be given.

Adult↗
PubMed2004

Efficacy and tolerability of levetiracetam in patients with therapy-resistant epilepsy and learning disabilities.

INTRODUCTION: The purpose was to evaluate the effects of levetiracetam (LEV) in routine therapy in learning disabled patients with therapy-resistant epilepsy. METHODS: In an open observational add-on study design, 46 patients (residents of the Bethel Epilepsy Centre) with severe therapy-resistant epilepsy and different degrees of learning disabilities, who were treated with LEV between its introduction in Autumn 2000 and February 2002, were evaluated retrospectively. Information on monthly seizure frequencies, seizure severity and psychiatric status was extracted from the current patient case records. A 3 months baseline and a 3 months LEV treatment period (after 3 months of titration) were compared. Responders were defined as having a 50% reduction in seizure frequency and being evaluated as good or very good in an ad hoc global clinical efficacy scale. When only one criterion was positive, a careful individual decision was made based on the impact on the patients' daily activities. RESULTS: The responder rate was 41.3% (34.8 for 50% seizure reduction). It was higher in focal and multifocal epilepsy as compared to symptomatic generalised epilepsy/Lennox Gastaut Syndrome (P<0.05). Antiepileptic response occurred in doses between 500 and 4000 mg/day. Changes in seizure severity were rare. Nine patients experienced positive psychotropic effects (mostly improved vigilance and mood); six of these patients had antiepileptic effects as well. Twelve patients had adverse effects, mostly mild; in three cases, however, more severe effects led to discontinuation. CONCLUSIONS: LEV is an effective and generally well-tolerated drug for this patient group, especially in focal and multifocal epilepsy.

Adolescent↗
PubMed2004

[Atypical epilepsy symptomatology as cause of a dementia like state in a mentally and physically retarded patient].

We report on a 50-year-old man with mental retardation and right-sided hemi-paresis. He seemed to be cured from epilepsy. In a short time a mental and physical deterioration developed which looked like a dementia, which was suggested by vascular risk factors. The EEG showed marked epileptic activity characterized by spikes appearing every 10 seconds over the left temporal lobe. After introduction of carbamazepine, a fast and long-term improvement of symptoms was noticed resulting in self sufficiency. The fast and marked effect of an antiepileptic drug being given to the patient with an non-typical reactivation of epilepsy in which the dementia-syndrome was caused by a transitory cognitive impairment due to sub-clinic electric seizures or non-convulsive status epilepticus.

Anticonvulsants↗
PubMed2002

[Effects of topiramate in patients with epilepsy and intellectual deficits].

There is little knowledge about the effects of topiramate in intellectually impaired epileptic patients. This open prospective study compares seizure frequencies during a 3-month period of topiramate add-on therapy (after 3 months of titration) compared with a 3-month baseline period. An intention-to-treat analysis was made on the first 24 consecutive topiramate-treated adult patients (residents of the Bethel epilepsy centre, therapy-resistant epilepsy, intellectual impairment of different degrees, one half with neurological deficits). The responder rate (at least a 50% reduction in seizure frequency) was 37.5%. One patient became completely seizure-free during post-evaluation (up to 24 months). Efficacy was not different between different epileptic syndromes or seizure types (case number too small). Responders had topiramate dosages above 200 mg/day and serum concentrations above 2.2 micrograms/ml. Six patients (25%) experienced serious neuropsychiatric complications such as confusion and severe deceleration of thinking and acting, up to complete helplessness (at topiramate dosages from 50 mg/day to 900 mg/day and serum concentrations from 2.2 micrograms/ml to 8.0 micrograms/ml). Preexisting brain damage may enhance the risk of unwanted central nervous effects.

Adult↗
PubMed2001

[Correction of the leg axis after epiphyseal fracture and progressive abnormal growth of the proximal tibia].

Development of an angular deformity around the knee joint, following a posttraumatic premature epiphyseal closure is a rare but serious complication. We present a case report of this complication following a proximal tibial epiphyseal injury in a 9 year old child initially treated conservatively with plaster immobilization. Subsequently, partial closure of epiphysis on medial side resulted in genu varum of 20 degrees, which was treated with medial open wedge osteotomy of the proximal tibia combined with resection of a segment from the proximal fibula, and a percutaneous epiphysiodesis of the proximal tibia and fibula. At three years follow up, the child had shortening of the leg by 1 cm, but no angular deformity. Significance of regular follow-up after an epiphyseal injury to detect the condition and role of operative management with various modalities is discussed.

Casts, Surgical↗
PubMed2001

Interferon-alpha-induced endogenous superantigen. a model linking environment and autoimmunity.

We earlier proposed that a human endogenous retroviral (HERV) superantigen (SAg) IDDMK(1,2)22 may cause type I diabetes by activating autoreactive T cells. Viral infections and induction of interferon-alpha (IFN-alpha) are tightly associated with the onset of autoimmunity. Here we establish a link between viral infections and IFN-alpha-regulated SAg expression of the polymorphic and defective HERV-K18 provirus. HERV-K18 has three alleles, IDDMK(1,2)22 and two full-length envelope genes, that all encode SAgs. Expression of HERV-K18 SAgs is inducible by IFN-alpha and this is sufficient to stimulate V beta 7 T cells to levels comparable to transfectants constitutively expressing HERV-K18 SAgs. Endogenous SAgs induced via IFN-alpha by viral infections is a novel mechanism through which environmental factors may cause disease in genetically susceptible individuals.

Antigens, CD↗
PubMed2001

[10 years experience with extracorporeal membrane oxygenation].

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is a supportive therapy used for severe acute respiratory distress syndrome (ARDS). We present outcome, clinical parameters, and complications in a cohort of 245 ARDS patients of whom 62 were treated with ECMO. METHODS: Data of all ARDS patients were prospectively collected between 1991 and 1999. Outcome and clinical parameters of patients treated with and without ECMO were evaluated. RESULTS: Hundred-thirty-eight patients were referred from other hospitals, 107 were primarily located in our hospital. About one fourth of these patients was treated with ECMO. The survival rate was 55% in ECMO patients and 61% in non-ECMO patients. ECMO resulted in very few complications, one of them was fatal. No parameter before or during ECMO could be used to predict the individual prognosis. CONCLUSION: ECMO is a therapeutic option for patients with severe ARDS, likely to increase survival. However, a randomized controlled study proving its benefit is still awaited. Until the development of a causal or otherwise superior therapy ECMO should be used in selected patients.

Adult↗
PubMed2001

Synthesis of multiple N-acylhomoserine lactones is wide-spread among the members of the Burkholderia cepacia complex.

Seventy strains of the Burkholderia cepacia complex, which currently comprises six genomic species, were tested for their ability to produce N-acylhomoserine lactone (AHL) signal molecules. Using thin layer chromatography in conjunction with a range of AHL biosensors, we show that most strains primarily produce two AHLs, namely N-octanoylhomoserine lactone (C8-HSL) and N-hexanoylhomoserine lactone (C6-HSL). Furthermore, some strains belonging to B. vietnamiensis (genomovar V) produce additional long chain AHL molecules with acyl chains ranging from C10 to C14. For B. vietnamiensis R-921 the structure of the most abundant long chain AHL was confirmed as N-decanoylhomoserine lactone (C10-HSL) by liquid chromatography-mass spectrometry (LC-MS) in combination with total chemical synthesis. Interestingly, a number of strains, most notably all representatives of B. multivorans (genomovar II), did not produce AHLs at least under the growth conditions used in this study. All strains were also screened for the production of extracellular lipase, chitinase, protease, and siderophores. However, no correlation between the AHL production and the synthesis of these exoproducts was apparent. Southern blot analysis showed that all the B. cepacia complex strains investigated, including the AHL-negative strains, possess genes homologous to the C8-HSL synthase cepI and to cepR, which encodes the cognate receptor protein. The nucleotide sequence of the cepI and cepR genes from one representative strain from each of the six genomovars was determined. Furthermore, the cepI genes from the different genomovars were expressed in Escherichia coli and it is demonstrated that all genes encode functional proteins that direct the synthesis of C8-HSL and C6-HSL. Given that cepI from the B. multivorans strain encodes a functional AHL synthase, yet detectable levels of AHLs were not produced by the wild-type, this suggests that additional regulatory functions may be present in members of this genomovar that negatively affect expression of cepI.

4-Butyrolactone↗
PubMed2001

N-acylhomoserine-lactone-mediated communication between Pseudomonas aeruginosa and Burkholderia cepacia in mixed biofilms.

Pseudomonas aeruginosa and Burkholderia cepacia are capable of forming mixed biofilms in the lungs of cystic fibrosis patients. Both bacteria employ quorum-sensing systems, which rely on N-acylhomoserine lactone (AHL) signal molecules, to co-ordinate expression of virulence factors with the formation of biofilms. As both bacteria utilize the same class of signal molecules the authors investigated whether communication between the species occurs. To address this issue, novel Gfp-based biosensors for non-destructive, in situ detection of AHLs were constructed and characterized. These sensors were used to visualize AHL-mediated communication in mixed biofilms, which were cultivated either in artificial flow chambers or in alginate beads in mouse lung tissue. In both model systems B. cepacia was capable of perceiving the AHL signals produced by P. aeruginosa, while the latter strain did not respond to the molecules produced by B. cepacia. Measurements of extracellular proteolytic activities of defined quorum-sensing mutants grown in media complemented with AHL extracts prepared from culture supernatants of various wild-type and mutant strains supported the view of unidirectional signalling between the two strains.

Animals↗
PubMed2001

Radial nerve palsy associated with humeral shaft fracture: evaluation with US--initial experience.

PURPOSE: To determine the feasibility of using ultrasonography (US) for evaluation of a radial nerve injury associated with humeral shaft fracture. MATERIALS AND METHODS: In a prospective study, 11 consecutive patients with sensorimotor radial deficiency after distal humeral fracture were evaluated with conventional radiography, US, electroneurography, and electromyography. Surgical repair of the fracture and nerve inspection were performed in five patients. The remaining six patients were successfully treated conservatively. The US appearance of the radial nerve was studied in 10 healthy volunteers and in the noninjured arm of the 11 patients for comparison. RESULTS: In five patients, US findings of a severely damaged radial nerve were confirmed at surgical nerve inspection. In one patient, the nerve was entrapped between fragments. One patient had a complete nerve dissection, one had a lacerated nerve from a loose compression plate, and one had a nerve riding on the edge of a bone fragment. In the fifth patient who underwent surgical inspection, the nerve was buried in the callus. In the six patients treated conservatively, US showed continuity of the nerve. CONCLUSION: US may be useful for accurate evaluation of the radial nerve in patients with nerve palsy associated with humeral shaft fracture.

Adult↗
PubMed2000

Characterization of the alpha(2)-adrenoceptor subtype, which functions as alpha(2)-autoreceptor in human neocortex.

The pharmacological properties of the alpha(2)-adrenergic receptors regulating the release of norepinephrine were investigated in human neocortex. Slices were preincubated with [(3)H]norepinephrine, superfused under blockade of transmitter reuptake, and stimulated electrically. First, the autoinhibitory circuit of [(3)H]norepinephrine release was analyzed quantitatively by estimation of the K(d) of norepinephrine at the alpha(2)-autoreceptor (10(-7.99) M), the concentration of the endogenous transmitter causing this autoinhibition at a stimulation frequency of 3 Hz (10(-7.61) M), and the maximum inhibition obtainable through the autoreceptor (83%). Second, antagonist pK(b) values of nine antagonists were determined by using their pEC(50) values (negative logarithms of antagonist concentrations that increased the electrically evoked overflow of tritium by 50%) against the release-inhibiting effect of the endogenous transmitter. When compared with binding or functional data from the literature, the pK(b) values correlated best with the antagonist affinities at alpha(2A) binding sites. In contrast, the correlations with alpha(2B), alpha(2C), and alpha(2D) sites were not as good. It is concluded that in human neocortex prejunctional autoreceptors are alpha(2A).

Adrenergic alpha-Antagonists↗
PubMed1999

N(epsilon)-(carboxymethyl)lysine adducts of proteins are ligands for receptor for advanced glycation end products that activate cell signaling pathways and modulate gene expression.

Recent studies suggested that interruption of the interaction of advanced glycation end products (AGEs), with the signal-transducing receptor receptor for AGE (RAGE), by administration of the soluble, extracellular ligand-binding domain of RAGE, reversed vascular hyperpermeability and suppressed accelerated atherosclerosis in diabetic rodents. Since the precise molecular target of soluble RAGE in those settings was not elucidated, we tested the hypothesis that predominant specific AGEs within the tissues in disorders such as diabetes and renal failure, N(epsilon)-(carboxymethyl)lysine (CML) adducts, are ligands of RAGE. We demonstrate here that physiologically relevant CML modifications of proteins engage cellular RAGE, thereby activating key cell signaling pathways such as NF-kappaB and modulating gene expression. Thus, CML-RAGE interaction triggers processes intimately linked to accelerated vascular and inflammatory complications that typify disorders in which inflammation is an established component.

Animals↗
PubMed1999

Immunochemical detection of oxalate monoalkylamide, an ascorbate-derived Maillard reaction product in the human lens.

Carbohydrates with reactive aldehyde and ketone groups can undergo Maillard reactions with proteins to form advanced glycation end products. Oxalate monoalkylamide was identified as one of the advanced glycation end products formed from the Maillard reaction of ascorbate with proteins. In these experiments, we have analyzed human lens proteins immunochemically for the presence of oxalate monoalkylamide. Oxalate monoalkylamide was absent in most of the very young lenses but was present in old and cataractous lenses. The highest levels were found in senile brunescent lenses. Incubation experiments using bovine lens proteins revealed that oxalate monoalkylamide could form from the ascorbate degradation products, 2,3-diketogulonate and L-threose. These data provide the first evidence for oxalate monoalkylamide in vivo and suggest that ascorbate degradation and its binding to proteins are enhanced during lens aging and cataract formation.

Adolescent↗
PubMed1999

Experimental investigation of a fast Monte Carlo photon beam dose calculation algorithm.

An experimental verification of the recently developed XVMC code, a fast Monte Carlo algorithm to calculate dose distributions of photon beams in treatment planning, is presented. The treatment head is modelled by a point source with energy distribution (primary photons) and an additional head scatter contribution. Utility software is presented, allowing the determination of the parameters for this model using a single measured depth dose curve in water. The simple beam model is considered to be a starting point for more complex models being planned for future versions of the code. This paper is mainly focused on the influence of the different techniques on variance reduction and material property determination for dose distributions. It is demonstrated that XVMC and the simple beam model reproduce measured (by a diamond detector) relative dose distributions with an accuracy of better than +/-2% in various homogeneous and inhomogeneous phantoms. Furthermore, relative dose distributions in solid state phantoms have been measured by film. Also for these cases, measured and calculated dose distributions agree within experimental uncertainty. The short calculation time (depending on voxel resolution, statistical accuracy, field size and energy, a span of 1 min to 1 h using a present-day personal computer) and an interface to a commercial planning system will allow the implementation of the code for routine treatment planning of clinical electron and photon beams.

Algorithms↗
PubMed1999

Sonographic detection of radial nerve entrapment within a humerus fracture.

Radial neuropathy is frequently associated with fracture of the middle third of the humerus owing to the course of the nerve adjacent to the humeral shaft. The prevalence varies from 2 to 18% of humeral fractures. The therapeutic management is still controversial. Some authors recommend initial surgical exploration, whereas others prefer observation and intervention only if the injured nerve failed to recover after a period of more than 4 months. According to the literature, verification of an entrapped radial nerve in a fracture gap requires surgical exploration, but diagnostic tools to verify the existence of a pathologic condition are limited. We describe the sonographic findings of an entrapped radial nerve and review the literature regarding diagnosis and treatment of entrapped radial nerve in cases of humeral fracture.

Adult↗