PubMed Health⌕ Search

Biomedical subjects

C Kunze

Publications and source records attributed to C Kunze.

At least 19 recordsLinked to original sources
PubMed2004

Anatomic basis for a minimally invasive approach to the subtalar joint.

INTRODUCTION: An isolated arthrodesis of the talocalcaneonavicular joint is a common indication in cases of pain and post-traumatic arthroses. MATERIALS AND METHODS: Because of the high infection rate after surgery with the lateral incision, the authors decided to evaluate an alternative, minimally invasive procedure. Joint destruction was carried out via a posterolateral access after the insertion of two guidewires. For an evaluation of the risk for vessel and nerve structures, 102 ankle joint specimens preserved in formalin/alcohol were examined. Additionally, the minimally invasive access was evaluated in ten ankle joint specimens. RESULTS: Neither in the specimen nor during evaluation of the minimally invasive access could injuries of vessels or nerve structures larger than 1 mm in diameter be found. The authors did not encounter any problems when drilling open the articular surface with a destruction of 65% of the overall surface and when performing the following arthrodesis using a plug technique. Using a posterolateral, minimally invasive access between the Achilles tendon and lateral malleolus, it is possible to resect about 65% of the subtalar articular surface for arthrodesis without impact on major vessels and nerves. Postoperative complications such as sensitive and sensory failure as well as wound healing impairment at the lateral side of the foot are not to be expected when choosing the minimally invasive access. CONCLUSION: It has to be said, however, that this technique does not offer the opportunity of performing a corrective arthrodesis as the hindfoot cannot be displayed during surgery. As the result of this study was positive, clinical evaluation was started.

Arthrodesis↗
PubMed2004

[Prolactinoma of the sphenoid sinus. Case report and literature review].

In this case study, we report on a patient complaining of headache who, after CT and MRI, was found to have a neoplasia of the left sphenoid sinus. After a transnasal biopsy and histological examination, a prolactinoma was diagnosed. Based on this case, we discuss important aspects of tumor biology, diagnostic procedures, histology as well as differential diagnosis. Prolactinoma has to be considered as a differential diagnose in all sphenoid sinus neoplasias with close contact to the pituitary gland.

Diagnosis, Differential↗
PubMed2004

[Thrombosis of the iliac artery in a premature neonate: thrombolytic therapy using rt-PA].

Thromboembolic events in neonates are very rare. They are often associated with severe disease affecting the newborn or are secondary to central venous lines or arterial catheters. Most of the described cases of thromboses of the iliac or femoral arteries are associated with cardiac catheterisation or femoral invasive blood pressure monitoring. The relationship between single umbilical arteries and an increased incidence of structural and chromosomal anomalies is well known, but a higher rate of thromboembolic disease in infants with single umbilical arteries has not been described. Rt-PA (recombinant tissue plasminogen activator) has been successfully used in small studies and numerous case reports. To date controlled clinical trials giving guidelines for antithrombotic therapy using rt-PA are still lacking. We report the clinical course of a 700 g premature male, who was born by Caesarean section at 29 + 6 gestational weeks. On the fifth day the baby suffered from arterial thrombosis of the right pelvis axis. Antenatally a single umbilical artery was identified. Iliac arteries on the involved site appeared hypoplastic. Additionally, the prothrombin G20210A mutation was found. The patient was treated successfully using recombinant tissue plasminogen activator. In the case of a high risk of limb or organ loss due to arterial thrombosis, thrombolysis using rt-PA is justified. Appropriate rt-PA treatment has been studied for the adult but not the paediatric population. Hence, well-designed clinical trials are necessary to determine the pharmacokinetics and dynamics of thrombolytic agents in children.

Dandy-Walker Syndrome↗
PubMed2002

[Poly-beta-hydroxybutyric acid (PHB) films and plates in defect covering of the osseus skull in a rabbit model].

BACKGROUND: Titan plates have proven a success in the operative assistance of middle face fractures for stabile osteosynthesis. Also bioresorbant materials are being used increasingly. METHOD: Films and plates made from poly-beta-hydroxybutyric acid (PHB) with two holes and bolts are tested subperiostally on the osseus skull of 15 rabbits or respectively on cut trough zygomatic arches. The test bodies and the surrounding tissue are explantated after a defined period and are clinically and histologically prepared. RESULTS: All implants healed well. There were no macroscopic or microscopic signs of inflammation. A very slow, clinically not recordable decomposition followed. A "leap" in the decomposition evidently took place between the 20th and 25th month. Only initial signs of resorbation were to be found microfocally on the surface of the implant until 20 months after implantation but no more test body could be detected after 25 months. CONCLUSION: PHB is suitable for defect covery of the osseus skull or respectively as osteosynthesis material for fractures of the visceral cranium.

Animals↗
PubMed2002

Application of ubiquitous computing in personal health monitoring systems.

A possibility to significantly reduce the costs of public health systems is to increasingly use information technology. The Laboratory for Information Processing Technology (ITIV) at the University of Karlsruhe is developing a personal health monitoring system, which should improve health care and at the same time reduce costs by combining micro-technological smart sensors with personalized, mobile computing systems. In this paper we present how ubiquitous computing theory can be applied in the health-care domain.

Computer Communication Networks↗
PubMed2000

Elevated levels of calcitonin gene-related peptide in aqueous humor of patients with proliferative vitreoretinopathy.

PURPOSE: To detect the levels of the sensory peptide calcitonin gene-related peptide in aqueous humor of patients with proliferative vitreoretinopathy and to compare them with those of uninflamed eyes (cataract and uncomplicated rhegmatogenous retinal detachment). MATERIALS AND METHODS: Using a highly specific and sensitive radioimmunoassay the concentration of calcitonin gene-related peptide was detected in fresh samples of aqueous humor obtained via paracentesis. Furthermore, calcitonin gene-related peptide-like immunoreactivities were characterized by high-pressure liquid chromatography. RESULTS: The mean level of calcitonin gene-related peptide was 6.11 fmol/ml in cataract controls and 14.77 fmol/ml in uncomplicated rhegmatogenous retinal detachment. In the cataract group, 9 of 18 cases were below the detection limit and in the retinal detachment group, 5 of 16. In proliferative vitreoretinopathy, the peptide averaged 76.92 fmol/ml and none of the samples was below the detection limit. High-pressure liquid chromatography revealed one major peak corresponding to synthetic calcitonin gene-related peptide. CONCLUSION: In recent studies, we found elevated levels of the sensory peptide substance P in aqueous humor of patients with proliferative vitreoretinopathy. This fact and the present result, the elevation of calcitonin gene-related peptide in aqueous humor of eyes with proliferative vitreoretinopathy, clearly point to an involvement of sensory peptides in the pathobiology of the disease. The source of the elevation is not clear, but we hypothesize that it originates from a neurogenic mechanism, i.e. an acceleration of the peptides by their enhanced release from the iris/ciliary body complex subsequent to sensitization of sensory neurons, thus representing a very interesting epiphenomenon of proliferative vitreoretinopathy. Our results constitute novel aspects in the pathophysiological concept of proliferative vitreoretinopathy and extend the knowledge about the pathobiology of the disease process.

Adolescent↗
PubMed1999

The effect of streptozotocin-induced diabetes mellitus on substance P and calcitonin gene-related peptide expression in the rat trigeminal ganglion.

Substance P (SP) and calcitonin gene-related peptide (CGRP) constitute the main sensory peptides in the trigeminal ganglion (TG). The objective of this study was to characterize peptidergic changes in the streptozotocin-induced diabetes mellitus rat model both quantitatively and qualitatively. Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (65 mg/kg) and the levels of SP and CGRP were measured by means of radioimmunoassay (RIA) in a time-dependent manner. Peptide immunoreactivities were characterized by high pressure liquid chromatography (HPLC). The expression of both neuropeptides was examined 5 weeks after streptozotocin injection using in situ hybridization with 35S-labelled oligonucleotides. Saline-injected rats served as controls. SP was significantly decreased in the diabetic rat TG, i.e. , a 44.6% (+/-10.9) decrease after 1 week, 40.2% (+/-11.8) after 3 weeks and 72.3% (+/-14.6) after 5 weeks. CGRP was decreased only after 5 weeks (19.6% decrease +/-3.9), whereas at later stages, both peptide levels returned to normal values. HPLC revealed one major peak coeluting with the synthetic peptides. By using in situ hybridization, a significantly increased signal of both peptide-encoding mRNAs was found (43.8%), which seems to act to restore a diabetes-associated depletion of neuropeptides in the diabetic rat TG. The decreased SP- and CGRP levels in the diabetic rat TG reflect a diabetes-associated deficit which may be clinically relevant. Diabetes mellitus is associated with a variety of ocular complications, even corneal complications, including decreased corneal sensitivity, which in many ways resemble those after interruption of the normal trophic innervation of the eye. Our results point to reduced availability of neuropeptides for corneal innervation and may thus support the idea of a partial loss of trophic influences from the trigeminal nerve in diabetics.

Animals↗
PubMed1999

Topography of evoked brain activity during mental arithmetic and language tasks: sex differences.

We studied visual information processing using two different tasks in a group of 10 female and 10 male healthy, right-handed adults. Subjects solved arithmetic tasks shown sequentially on a computer monitor, and they also compared words presented as anagrams. The experimental design allowed us to compare the effects of reading or actively processing a given stimulus. Task difficulty was varied in three steps ('easy', 'medium', 'hard') after an independent group of 81 young adults had judged the stimulus material according to difficulty by answering questionnaires. Brain activity was recorded from an array of 30 electrodes extending from the inion to 5% anterior of F2. For each subject mean potentials were averaged off-line after screening the EEG for artifacts. Components were determined quantitatively as epochs of stable topography resulting in 10 independent components occurring within 1200 ms after stimulus onset. Significant effects were seen with field strength and scalp topography: simply reading the stimuli yielded significantly smaller amplitudes than when the subjects actively processed the same stimuli. Females had consistently larger global field power than males, and they also displayed different scalp field topography of various components. In addition, processing anagrams was accompanied by larger field strength than mental arithmetic. The scalp field distributions were also affected by sex, task type and difficulty indicating the activation of different neuronal assemblies during visual information processing of males and females. Many effects were seen at short latencies in the order of 70-120 ms indicating very early selective processing of visual stimuli where specific differences were introduced by sex and task parameters.

Adult↗
PubMed1999

Spatial extent of pigment epithelial detachments in age-related macular degeneration.

OBJECTIVE: To quantify the spatial extent of pigment epithelial detachment (PED) associated with age-related macular degeneration (AMD) using a rapid, noninvasive method. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: The authors tested 32 eyes of 21 patients (13 women and 8 men) with AMD 56 to 91 years of age (mean = 72.8 years). The authors retested seven eyes of six patients. INTERVENTION: Three-dimensional imaging and quantification of PED were performed in each subject using confocal infrared imaging (790 nm) with a Topographic Scanning System (TopSS). The data consisted of a series of 32 images within a 3-mm-depth range requiring 0.9 second. Three-dimensional calculations were made from the series. MAIN OUTCOME MEASURE: Height, diameter, area, volume, and slope of each PED were obtained with two calculation methods. The Ellipse Method used a graphics tool to draw elliptical borders circumscribing the region of interest in the image. The software automatically calculated the values for all parameters for the region inside the ellipse, with the retinal reference plane adjusted to match the height of the surrounding retina. The User-Defined Region Method differed in that the region of interest was drawn manually. RESULTS: PEDs were easily detected in all patients using the TopSS. Maximum height of all PEDs above the reference plane ranged from 0.204 to 1.818 mm (mean = 0.57 mm). The diameter was 0.501 to 5.151 mm (mean = 2.711 mm), area was 0.179 to 20.402 mm2 (mean = 6.585 mm2), and volume was 0.012 to 13.981 mm3 (mean = 2.173 mm3). Intraobserver variability was low, with correlations between first and second measurements for the first visit ranging from r = 0.906 to 0.997 for slope and diameter, respectively. CONCLUSIONS: Three-dimensional analysis with the TopSS provides objective outcome measures not obtainable with typical clinical methods such as fundus photography and angiography. Height and volume are crucial in determining whether neovascularization is worsening or persistent after photocoagulation. More longitudinal data are needed to determine whether tomographic data reduce the need for angiography. Unique to scanning laser tomography, exudative features were imaged at different depths.

Aged↗
PubMed1999

Differential gene expression after implantation of biomaterials into rat gastrointestine.

Two biodegradable materials, polyglycolide-copoly(L)-lactide/poly-dioxanone composite and poly(3-hydroxybutyrate), have been employed for surgery in the gastrointestine of laboratory rats. The tissue response was analyzed at distinct time intervals up to 2 months by differential mRNA display. Two specific PCR fragments were transiently present 7 and 14 days after contact with poly(3-hydroxybutyrate). Both fragments represent distinct rat lipases which might play a role in poly(3-hydroxybutyrate) degradation.

Journal Article↗
PubMed1996

Complexation capacity of aquatic systems in dependence on different ligands and heavy metals - Electroanalytical investigations and statistical evaluation.

Heavy metals exist in natural waters in different species. Mobility and bioavailability of bound metals can be influenced by some complex factors in the aquatic environment. Therefore, it is useful to determine the complexation properties of various ligands influenced by different metals. The copper and zinc complexation capacity was determined for a natural ligand (fulvic acid) and anthropogenic pollutants (e.g. nitrilotriacetic acid and ethylenediaminetetraacetic acid). The interactions between several ligands and metal ions and their effects on the complexation capacity were analyzed in particular. Applying methods of experimental design, such as multifactorial plans, it is possible to determine influence and interaction of various parameters (e.g. concentration of zinc or copper) by a minimum number of experiments. Differential pulse polarography was used for the determination of the complexation capacity. Methods of parametric and robust multiple linear regressions were applied for the interpretation of the measured values.

Journal Article↗
PubMed1996

Grid pattern photocoagulation for diabetic macular edema--long-term visual results.

The authors reviewed the data of 226 eyes in 124 patients with clinically significant diabetic macular edema treated by grid pattern photocoagulation from 1986 to 1994 at the Ophthalmological Clinic of Innsbruck University Hospital. On the basis of baseline visual acuity (VA), eyes were classified in four groups: group 1 = VA < 0.1; group 2 = VA 0.1-0.2; group 3 = VA > 0.2-0.5; group 4 = VA > 0.5. The development of VA from the baseline examination until the last checkup in treated eyes is reported. This classification showed a better visual outcome after photocoagulation in eyes with a decreased VA at baseline (groups 1, 2) compared with eyes with a good initial VA (groups 3, 4). The difference in visual outcome between the second and third groups as well as between the third and fourth groups was statistically significant (p < or = 0.001). A correlation of initial VA with visual outcome after treatment was demonstrated (R = -0.558; p = 0.0001). Clinical conclusions of these results are discussed.

Adult↗