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Biomedical subjects

G Gradl

Publications and source records attributed to G Gradl.

At least 19 recordsLinked to original sources
PubMed2006

[Complex proximal humerus fractures--management with a humeral head prosthesis? Clinical and radiological results of a prospective study].

BACKGROUND: Proximal humerus fractures are one of the most common fractures in elderly patients. In the treatment of complex proximal humerus fractures, primary hemiarthroplasty is still discussed controversially. The present study was undertaken to evaluate the results of primary hemiarthroplasty in the treatment of proximal humerus fractures with a modular prosthesis (EPOCA, Fa. Argomedical, Gifhorn, Germany). MATERIAL AND METHODS: A prospective study of 24 patients with complex humerus fracture (NEER: IV/4, V/4, VI/4, and head split fracture) was performed from August 2000 to December 2002. Mean age was 75.6 years (range: 52-92); 18 patients were seen for follow-up after 0.5 and 1 year, respectively. The Constant-Murley score (max. 100 points) and the UCLA Rating System (max. 35 points) were calculated for functional assessment of the operated shoulder. RESULTS: Fifteen patients (83%) were pain free 1 year after the operation. The Constant-Murley score improved from 52 (+/-17) to 56 (+/-18) at the second follow-up after 1 year. On the contralateral side a score of 86 (+/-10) was assessed (p<0.05 vs operated side). Correspondingly, shoulder function according to the UCLA Rating System improved [25 (+/-4); 27 (+/-5)]. CONCLUSIONS: Osteoporotic bone of older patients often may not permit stable internal fixation of complex proximal humerus fractures. In these situations primary hemiarthroplasty is the treatment of choice.

Aged↗
PubMed2005

[Evaluation of sympathicolysis after continuous brachial plexus analgesia using laser Doppler flowmetry in patients suffering from CRPS I].

OBJECTIVE: The aim of this study was to evaluate continuous brachial plexus analgesia in terms of pain relief and sympathicolysis in patients suffering from CRPS I. METHODS: A detailed clinical examination comprised measurement of temperature changes (Infrared Thermometry), pain rating (VAS scale) and assessment of peripheral sympathetic nervous function using laser Doppler flowmetry. A total number of 12 patients (mean age: 56 +/- 9 years, range: 30 to 69 years) received continuous brachial plexus analgesia after placing a catheter in the perineurial sheath of the brachial plexus through an axillary approach. Prior to continuous analgesia (Morphin 0.04 mg/ml, Clonidin 1.5 microg/ml, Bupivacaine 0.0625 %) running at 4 ml/h a test dosis of 20 ml Bupivacaine 0.25 % was applied to establish brachial plexus block. RESULTS: After an equilibration period of 2 hours, consecutive pain measurements revealed sufficient pain relief in 9 out of 12 patients (75 %) with a mean pain rating dropping from 4.7 +/- 0.68 to 1.59 +/- 1.02 (p < 0.001). Pain reduction was accompanied by a significant temperature increase from -0.78 degrees C to 1.7 degrees C (p < 0.05). However measurement of sympathetic function by laser Doppler flowmetry revealed that no significant sympathicolysis occurred. CONCLUSIONS: The study shows that clinical investigation of temperature change is not reliable in the evaluation of sympathicolysis. This is of special interest in patients who are suspected of having sympathically maintained pain (SMP) and are treated by brachial plexus analgesia.

Adult↗
PubMed2004

[Clinical experiences and dosage pattern in subcutaneous single-injection digital block technique].

100 patients with injuries to their fingers were treated using the subcutaneous digital block as described by Low et al.. Different dosages ranging from 2 to 3 millilitres of a local anesthetic were required to obtain appropriate anesthesia according to the location of injury. 108 finger injuries were treated, 18 thumb injuries, 90 finger injuries. The anesthetic was administered using a 0.55 x 25 mm needle and injected strictly subcutaneously into the flexor crease at the base of the finger or thumb. Injuries to the palmar aspect of the fingers were anesthetized using 2 ml of a local anesthetic (1% Lidocain), whereas 3 ml were needed for sufficient pain relief in case of injury to the dorsal aspect of the fingers. Injury to the thumb required a higher dosage (3 ml subcutaneously), and only offered sufficient pain relief for palmar injuries. In the case of dorsal injuries, we found that this technique was not sufficient in providing pain relief. Additionally, we performed a deep local nerve block (Oberst), if the patient still felt discomfort or pain. The severity or type of injury did not play a role according to our findings. The subcutaneous finger block as described by Low et al., therefore, is the method of choice treating injuries to the fingers and to the palmar aspect of the thumb, since it offers a decrease in the amount of anesthetic required and increases patient comfort.

Adolescent↗
PubMed2003

Microdevices for separation, accumulation, and analysis of biological micro- and nanoparticles.

Microfabrication and performance of a novel microsystem for separation, accumulation and analysis of biological micro- and nanoparticles is reported. Versatile chip functions based on dielectrophoresis and microfluidics were integrated to isolate particles from complex sample solutions such as serum. A bead-based assay for virus detection is proposed. Separation of micro- and sub-mum beads employing dielectrophoretic deflector and bandpass structures is demonstrated. Individual antibody coated beads with hepatitis A virus bound to their surface were trapped by negative dielectrophoresis in a field cage and analysed by fluorescence microscopy.

Journal Article↗
PubMed2003

[Radio-radial external fixation in the treatment of distal radius fractures allows for free wrist motion].

INTRODUCTION: Joint bridging external fixation in the treatment of distal radius fractures restores radial length, whereas anatomic reduction of articular fragments is difficult. Immobilisation of the wrist joint is a further disadvantage. An extraarticular hybrid fixation of distal radius fractures was introduced that facilitates fracture reduction, safe retention and allows for free wrist movement. METHODS: 30 consecutive patients with extra- and intraarticular comminuted fractures of the distal radius were treated with an extraarticular radio-radial external fixation employing a modified Ilizarov hybrid fixation technique. The operative procedure is described in detail. A clinical and radiological evaluation was carried out on the first and seventh day as well as 6 weeks postoperatively after implant removal. RESULTS: Anatomic reduction was achieved in 24 cases (80%). On the first postoperative day dorsiflexion was 30%, palmar flexion was 51% and pronation/supination was 60%/70% of the uninjured side. Six weeks postoperatively all fractures united. Wrist motion of the affected side was more than 80% of the unaffected side. Neither extensor tendinitis nor pin loosening in the distal fragment did occur. CONCLUSION: The technique of extraarticular hybrid fixation is safe and reliable in the treatment of comminuted fractures of the distal radius. It allows for early wrist movement in the immediate postoperative period.

Adult↗
PubMed2003

[Acute CRPS I (morbus sudeck) following distal radial fractures--methods for early diagnosis].

INTRODUCTION: CRPS I represents a frequent complication following distal radial fractures. Early diagnosis may prevent chronification of the disease. However posttraumatic pain, swelling and motor disturbances render the differentiation from normal fracture patients more difficult. The incidence of CRPS I in patients at risk and the diagnostic value of clinical evaluation, radiography and thermography in the early posttraumatic phase are analysed. METHODS: 158 consecutive patients with distal radial fractures were followed-up for 16 weeks after trauma. Apart from a detailed clinical examination 8 and 16 weeks after trauma, thermography and bilateral radiographs of both hands were performed. RESULTS: At the end of the observation period 18 patients (11%) were clinically identified as CRPS I. The severity of the preceding trauma and the chosen therapy did not influence the process of the disease. 16 weeks after trauma easy differentiation between normal fracture patients and CRPS I patients was possible. 8 weeks after distal radial fracture clinical evaluation showed a sensitivity of 78% and a specificity of 94%. Thermography (58%) however and bilateral radiography (33%) revealed a poor sensitivity, respectively. The specificity was high for radiography (91%) and again poor for thermography (66%), respectively. CONCLUSION: The results of the study support the importance of clinical evaluation in the early diagnosis of CRPS I. Plain radiographs facilitate the diagnosis as soon as bony changes develop.

Acute Disease↗
PubMed2002

[The femoral neck fracture in the elderly patient - cemented or cementless hip arthroplasty?].

This is a report on the treatment results of femoral neck fractures with a cemented (group 1) and cementless (group 2) type of hip prosthesis, resp. 72 patients were enrolled. 35 patients were treated with a cemented hip prosthesis (mean age: 78 years), and 37 patients with a cementless modular hip prosthesis (mean age: 77 years). In the cemented group we observed 5 cases of hypotension during insertion of the prosthesis in the femoral shaft. One of these patients required mechanical resuscitation during surgery. In the second group 3 cases of proximal femur fissure and one case of distal femoral fracture were recorded. One year after surgery 43 patients presented for follow up evaluation (cemented group: n = 24; cementless group: n = 19). Both groups revealed comparable results according to the Harris Hip Score (75 versus 78,3 points). No prosthesis loosening was observed in either group. In our view the cemented hip prosthesis is the treatment of choice for femoral neck fractures among the old and very old, if no stabile osteosynthesis can be performed. Patients with cardiopulmonary risk factors, however, may profit from cementless hip arthroplasty to avoid the well known cardiodepression during surgery.

Aged↗
PubMed2001

Clinical and physiologic evaluation of stellate ganglion blockade for complex regional pain syndrome type I.

OBJECTIVE: The efficacy of peripheral sympathetic interruption after stellate ganglion blockade was assessed by a sympathetic function test. Results were compared with clinical signs such as temperature changes, pain reduction, and the development of Horner syndrome to evaluate the correlation with clinical investigations. DESIGN: Stellate ganglion blockade with local anesthetics was carried out via an anterior paratracheal approach in 33 patients suffering from complex regional pain syndrome type I. Patients were examined before and after the procedure. For assessment of sympathetic nervous function, the vasoconstrictor response to sympathetic stimuli was assessed using laser Doppler flowmetry. Clinical parameters like surface temperature changes (thermography), pain relief (visual analogue scale), and Horner syndrome were monitored. RESULTS: Twenty-three (70%) of 33 patients developed an increase in temperature difference between the treated hand and the contralateral hand of more than 1.5 degreesC after the procedure, which is a clinical sign of sympathicolysis. In 48% (n = 11) of these patients, the sympathetic function test showed an undisturbed sympathetic nervous function. In 10 patients, no significant increase in temperature difference was observed. Although these patients presented with a normal sympathetic vasoconstrictor response, 4 felt pain relief of more than 50%, suggesting a placebo effect. Only 7 patients with pain relief revealed both clinical sympathicolysis and extinguished sympathetic nervous function and qualified for sympathetically maintained pain. CONCLUSIONS: Clinical investigation is not reliable in the assessment of stellate ganglion blockade. Proof of sympathetically maintained pain based on pain relief after stellate ganglion blockade is not conclusive.

Adult↗
PubMed2001

cDNA cloning, chromosome assignment, and genomic structure of a human gene encoding a novel member of the RBM family.

We have cloned and characterised a novel human gene mapping to chromosome 20q11.2. A partial transcript was initially isolated from a human cDNA library transcribed from RNA of the colon carcinoma cell line T-84. In order to determine the full coding sequence of this novel mRNA, we isolated seven cDNA clones from a human cDNA library transcribed from RNA of the acute monocytic leukemia cell line THP1 by colony hybridization. On Northern blot analysis of four human cell lines, the cDNAs isolated hybridize with an abundantly expressed mRNA species of 3.5 kb. A full-length cDNA transcript of this novel mRNA has an open reading frame of 2,796 bp encoding a protein with a calculated molecular weight of 97 kDa. Two repetitive structural consensus motifs are contained within the deduced protein sequence, namely five distinct RNA binding motifs and two proline rich regions. The derived protein sequence also contains putative transmembrane domains. These structural motifs identify this novel protein as a member of an expanding protein family containing RNA binding motifs (RBM). As seen from recently completed sequence of the genomic area encoding this novel mRNA by the Sanger Centre Human Genome Project, the coding region of this gene, RBM12, is intronless.

Amino Acid Motifs↗
PubMed2001

Receptor-ligand interactions studied with homogeneous fluorescence-based assays suitable for miniaturized screening.

Cell membrane receptors play a central role in controlling cellular functions, making them the target of drugs for a wide variety of diseases. This report describes how a recently developed method, fluorescence intensity distribution analysis (FIDA), can be used to develop homogeneous, nonradioactive high throughput screening assays for membrane receptors. With FIDA, free ligand and ligand accumulated on receptor-bearing membrane vesicles can be distinguished on the basis of their particle brightness. This allows the concentration of both bound and free ligand to be determined reliably from a single measurement, without any separation. We demonstrate that ligand affinity, receptor expression level, and potency of inhibitors can be determined using the epidermal growth factor and beta(2)-adrenergic receptors as model systems. Highly focused confocal optics enable single-molecule sensitivity, and sample volumes can thus be reduced to 1 microl without affecting the quality of the fluorescence signal. Our results demonstrate that FIDA is an ideal method for membrane receptor assays offering substantial benefits for assay development and high throughput pharmaceutical screening.

Betacellulin↗
PubMed2000

Peripheral sympathetic function as a predictor of complex regional pain syndrome type I (CRPS I) in patients with radial fracture.

Complex regional pain syndrome type I (CRPS I) is a frequent complication after injuries of the upper limbs. The pathophysiology of this disease remains unclear, although disturbances of the sympathetic nervous system have been detected in several clinical studies, and sympathetic blocks resolve the symptoms in many of the cases. To investigate the meaning of sympathetic dysfunction at the beginning of the disease, 27 patients with distal radial fracture were examined prospectively during the course of the disease with regard to their clinical symptoms and their peripheral sympathetic nervous function. Sympathetic nervous function was examined by testing the vasoconstrictor response to sympathetic stimuli--recorded with laser Doppler fluxmetry--of the fingertips of both hands. Four patients developed CRPS I during the 12-week observation time and two patients presented an incomplete clinical CRPS I picture ('borderline patients'). The complaints of all patients (normal fracture patients, CRPS I patients, borderline patients) were similar during the first week after trauma with focus on pain, motoric disturbances and autonomic symptoms. After 1 or 2 weeks, a larger clinical difference developed between normal fracture patients and CRPS I or 'borderline patients'. In CRPS I patients and 'borderline patients', the sympathetic vasoconstrictor response was diminished or absent from the first posttraumatic day throughout the observation time, whereas the normal fracture patients revealed slightly impaired sympathetic nervous function on the first posttraumatic day and normal results during the rest of the observation time. With regard to the unaffected contralateral hand, CRPS I patients also showed impaired sympathetic nervous function. The results of the present study suggest that the disturbances in the sympathetic nervous system in CRPS I patients are systemic and not limited to the affected limb. Their occurrence before the clinical breakout of the disease may serve as a marker that might be useful for early therapy and lead to further understanding of the pathophysiology of CRPS I.

Humans↗
PubMed2000

Dielectrophoretic manipulation of suspended submicron particles.

Planar and three-dimensiònal multi-electrode systems with dimensions of 2 - 40 microm were fabricated by IC technology and used for trapping and aggregation of microparticles. To achieve negative dielectrophoresis (repelling forces) in aqueous solution, radiofrequency (RF) electric fields were used. Experimentally, particles down to 100 nm in diameter were enriched and trapped as aggregates in field cages and dielectrophoretic microfilters and observed using confocal fluorimetry. Theoretically, single particles with an effective diameter down to about 35 nm should be trappable in micron field cages. Due to the unavoidable Ohmic heating, RF electric fields can induce liquid streaming in extremely small channels (12 microm in height). This can be used for pumping and particle enrichment but it enhances Brownian motion and counteracts dielectrophoretic trapping. Combining Brownian motion with ratchet-like dielectrophoretic forces enables the creation of Brownian pumps that could be used as sensitive separation devices for submicron particles if liquid pumping is avoided in smaller structures.

Animals↗
PubMed2000

Metastatic lesions of the humerus treated with the isoelastic diaphysis prosthesis.

Between January 1, 1987, and December 31, 1997, an isoelastic polyacetal resin prosthesis was used in 50 patients with metastatic bone disease to reconstruct pathologic or impending fractures of the humeral diaphysis. Fifty-seven operations were performed, including seven revision surgeries. The patients were assessed before and after surgery for limb function and quality of life using a modified Karnofsky scale. The mean survival time was 440 days. Ninety-one percent of the operations resulted in restoration or improvement of quality of life. Limb function was good or excellent in more than 80% of the patients after surgery. Breaking of the implant (n = 3), loosening of the implant (n = 2), periprosthetic fracture (n = 1), hematoma (n = 2), infection (n = 1), and one radial nerve paralysis were the main complications. In the cases of implant failure, the prosthesis broke at the site of a locking screw that was inserted across the prosthetic shaft in the cementless implantation technique. This kind of complication could be avoided by using bone cement for implantation or additional plate osteosynthesis between the prosthesis and humeral shaft. The isoelastic diaphyseal prosthesis offers a promising method of treating patients with metastatic lesions of the humeral shaft.

Adult↗
PubMed1999

Assessment of peripheral sympathetic nervous function for diagnosing early post-traumatic complex regional pain syndrome type I.

Clinical diagnosis of complex regional pain syndrome type I (CRPS I) in post-traumatic patients is often delayed since the clinical appearance of this disease resembles normal post-traumatic states to a certain extent (pain, edema, loss of function). The purpose of this study was to assess the incidence of specific clinical features in CRPS I patients and normal post-traumatic patients and to evaluate the diagnostic value of a bedside test that measures the sympathetic nervous function. Fifty patients with post-traumatic CRPS I of the upper limb and 50 patients 8 weeks after distal radius fracture with an undisturbed course of disease were subjected to a detailed clinical examination. Pain was assessed using the VAS (visual analog scale), skin temperature measured with an infrared camera and grip-strength with a pneumatic manometer. In CRPS I patients, motor disturbances defined as an impaired active range of motion of the hand, were most frequent (96%, fracture patients: 40%), followed by edema (88%, fracture patients: 80%) and spontaneous pain (VAS 4.0 +/- 2.3, fracture patients: VAS 1.3 +/- 0.6). Systematic temperature differences (>1 degree C) between the affected and unaffected limbs were seen in only 42% of CRPS I patients and in 34% of the fracture patients. Further sensory, sudomotor or trophic changes of the hands were rare. As expected, there were significant differences in the quantity of edema, motor disturbances and sensory disturbances between CRPS I patients and normal fracture patients. However, normal fracture patients still suffered from several of the evaluated symptoms 8 weeks after trauma, which makes an early clinical diagnosis of the complication more difficult. Using a newly developed bedside test, the peripheral sympathetic nervous function was assessed in both groups of patients and in 50 age-matched healthy controls. The decrease in skin blood flow following sympathetic provocation maneuvers, detected by laser Doppler flowmetry, was quantified as sympathetic reactivity. In the affected hands of CRPS I patients, as well as in the contralateral hands, the sympathetic reactivity was obliterated or diminished in contrast to the age-matched controls and normal fracture patients. A multivariate analysis did not reveal any correlation between sympathetic function and the severity of any clinical symptom. Sympathetic reactivity seems to be an independent variable in CRPS I and the test presented may facilitate the difficult clinical diagnosis of this disease.

Adult↗
PubMed1996

pLEF, a novel vector for expression of glutathione S-transferase fusion proteins in mammalian cells.

An expression vector, pLEF, has been used to produce the intracellular domain (IC) of the human CD95 (Fas/APO-1) apoptosis receptor as a glutathione S-transferase (GST) fusion protein in murine L929 fibroblasts. GST::CD95IC was affinity-purified in a single step using glutathione-Sepharose. Purification of GST::CD95IC from 32P-labelled L929 cells and cleavage with thrombin revealed that CD95IC was phosphorylated in vivo when produced as a GST fusion protein. Therefore, pLEF may facilitate the mapping of in vivo-modified sites of eukaryotic proteins.

Amino Acid Sequence↗
PubMed1996

A standardized bedside test for assessment of peripheral sympathetic nervous function using laser Doppler flowmetry.

In spite of increasing knowledge about the role of the sympathetic nervous system in autonomic disturbances like reflex sympathetic dystrophy, no functional test for the peripheral sympathetic system has been introduced into the clinical routine so far. In the development of a standardized bedside test, effects of arousal stimuli [inspiratory gasp (IG) and contralateral cooling (CC)] on blood flow in the fingertips (FTBF) were studied, using laser Doppler flowmetry (LDF). Fifty-two healthy subjects (ages 17 to 75) and 15 patients with sympathetic reflex dystrophy (SRD) underwent the diagnostic procedure. FTBF of healthy subjects during arousal maneuvers showed a reproducible decrease, which is related to a sympathetic vasoconstrictor response. The standardized test procedure with external body heating made interindividual test results comparable. Examination trials with 4 healthy subjects on 10 subsequent days showed good reproducibility. Mathematical analysis of the LDF curves was performed to calculate the degree of FTBF decrease (SRF = (Fmean - Fmin)/Fmean, QI = integral pre/integral post). In contrast to absolute flow values like Fmean and Fmin or time-related parameters like tdecrease and tregeneration, SRF and QI values presented small coefficients of variation (IG test, SRF 25.7, QI 21.7; CC test, SRF 20.0, QI 15.3). The typical decrease of the LDF signal after sympathetic stimulation was absent or diminished in patients with SRD. SRF and QI values showed statistically highly significant differences (P < 0.001) compared to healthy subjects. The presented test appears reliable for the assessment of peripheral sympathetic nervous function. The narrow physiological range of SRF and QI values enabled the differentiation of pathological sympathetic reactions. The test procedure is easy to perform, noninvasive, and practical even in patients with injuries of the upper limbs.

Adolescent↗