Biomedical subjects

A König

Publications and source records attributed to A König.

At least 19 recordsLinked to original sources

PubMed2003

Automatic capture verification in ICD lead systems using intracardiac ventricular evoked response and reduced coupling capacitance.

AIM: Intracardiac ventricular evoked-response (ER) signals detected by implanted cardioverter defibrillator (ICD) lead systems were investigated for automatic capture verification (AC). METHOD: ER signals were evaluated with an external pacing system equipped with a reduced coupling capacitance (CC=2.2 microF) in the pacing output circuit during ventricular step-down threshold testing at 0.4 ms pulse duration. Real-time pacing markers, surface ECG and intracardiac electrograms pre- and post-filtering were digitally recorded. RESULTS: Twenty consecutive patients, age 61+/-12 years, with leads from two different manufacturers were tested - 10 were implanted with acute leads (AL) and 10 with chronic leads (CL). The analysis was based on the ER amplitude during capture and on the ER-to-afterpotential ratio (SAR), with SAR>2 as the criterion for successful capture detection. ER amplitudes (median and range) were 8.1 mV (2.1-19.5 mV) for AL and 8.3 mV (3.7-14.2 mV) for CL. SAR values (median and range) were 48.0 (2.5-682.6) for AL and 13.2 (6.3-35.9) for CL, indicating that AC could successfully be applied in all patients. CONCLUSIONS: Reducing the pacing CC allows adequate ER detection for automatic capture verification on non-selected ICD lead systems. The effect of high-voltage shock treatment on ER signal detection requires further investigation.

Cardiac Pacing, Artificial↗

PubMed2002

German short musculoskeletal function assessment questionnaire (SMFA-D): comparison with the SF-36 and WOMAC in a prospective evaluation in patients with primary osteoarthritis undergoing total knee arthroplasty.

In a prospective clinical trial, the German short musculoskeletal function assessment (SMFA-D), the short form (SF)-36, and the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) were evaluated in 63 patients with primary osteoarthritis undergoing total knee arthroplasty. All instruments were sensitive to change, demonstrating the effect of total knee arthroplasty at 1-year follow-up. The SMFA-D effect sizes in comparable scales were bigger than in the SF-36 and similar to those of the WOMAC. Significant correlations of the SMFA-D indices with the SF-36 and WOMAC scales preoperatively could be shown. After 1-year follow-up, all correlations between the SMFA-D indices and SF-36 scales were significant. In other comparison, only the correlation between the SMFA-D function index and the WOMAC function scales remained significant. The correlation of the SMFA-D function index with external validation criteria was higher than that using the other instruments. We recommend the SMFA-D for assessing change in functional status of patients with primary osteoarthritis of the knee following arthroplasty.

Arthroplasty, Replacement, Knee↗

PubMed2002

[The juxtaacetabular ganglion].

A juxtaarticular ganglion (JAG) is a rare tumor-like lesion of the acetabulum, causing chronic hip disability. Due to its location, a JAG is a special form of an intraosseous ganglion. There is a lack of histological criteria to differentiate a JAG from an osteoarthritic cyst. The clinical findings of a JAG are determined by its proximity to the joint gap and its extraarticular extension. In a case report the necessary diagnostics as well as the therapeutic consequences are discussed.

Acetabulum↗

PubMed2002

IgVH-genes analysis from psoriatic arthritis shows involvement of antigen-activated synovial B-lymphocytes.

The pathogenesis of psoriatic arthritis (PA), which occurs in 5-7% of patients with psoriasis vulgaris, is enigmatic. There are no molecular data about synovial B-cells of chronic synovitis of PA. In order to understand the B-cell response in PA, we analysed IgVH genes and specified replacement to silent mutation (R/S) ratios of the complementarity determining regions (CDR) and framework regions (FR) as well as VH families. To prove the existence of a common pattern we additionally analysed the IgVH genes at the amino-acid level. From 5 PA patients we took cryo-tissue sections with somatically mutated IgVH genes (sum R/sum S in the CDRs: 2.5-6.8), 62 of which were analysed. In one patient two cases of clonally related IgVH genes were observed. Identical amino-acid replacements in IgVH1 and IgVH4 were found at the same mutational "cold spot". These data indicate that antigen-activated B-cells participate in the formation of chronic synovitis of PA. Since, neither histopathologically nor immunohistochemically, no germinal centres could be detected, the clonally related IgVH genes may be interpreted as residues of a germinal centre reaction that occurred before synovectomy. The existence of identical amino-acid replacement mutations in IgVH1 and IgVH4 genes suggests that a limited number of antigens are common to all PA patients analysed. The recombinant expression of the IgVH could help to define B-cell specificities underlying the pathogenesis of chronic synovitis and dermatitis of PA.

Adult↗

PubMed2002

Microendoscopic lumbar discectomy versus open surgery: an intraoperative EMG study.

This study investigated electromyographic (EMG) activity as a marker of nerve root irritation during two different surgical procedures for lumbar disc herniation. Mechanically elicited EMG activity was recorded during the dynamic stages of surgery in muscle groups innervated by lumbar nerve roots. Confirmation of surgical activity was correlated with the activity of the electromyogram. Fifteen patients with lumbar disc herniations were treated via an endoscopic medial approach, and 15 patients via the open microscopic surgical technique. Results indicated that the endoscopic technique was superior to the open surgical technique and produced less irritation of the nerve root. Significantly less mechanically elicited activity was recorded during both the approach and the root mobilization. The study showed that microendoscopic discectomy allows a smaller incision and less tissue trauma with comparable visualization of the nerve structures than does open surgery.

Adolescent↗

PubMed2002

HID and KID syndromes are associated with the same connexin 26 mutation.

BACKGROUND: Keratitis-ichthyosis-deafness (KID) syndrome is a debilitating ectodermal dysplasia that predisposes patients to develop squamous cell carcinomas in addition to leading to profound sensory deafness and erythrokeratoderma. We recently demonstrated that KID can be caused by a specific missense mutation in connexin 26 (GJB2). Another syndrome, called hystrix-like ichthyosis-deafnesss (HID) syndrome, strongly resembles the KID syndrome. These disorders are distinguished mainly on the basis of electron microscopic findings. We hypothesized that KID and HID syndromes may be genetically related. OBJECTIVE: To demonstrate by mutation analysis that HID and KID syndromes are genetically indistinguishable. METHODS: DNA was extracted from paraffin-embedded tissue samples of the first HID syndrome patient described in the literature. Since the KID syndrome mutation abolishes an AspI restriction site, we were able to screen the patient's DNA by polymerase chain reaction and subsequent restriction enzyme analysis. RESULTS: Restriction analysis of the connexin 26 gene in HID syndrome demonstrated the presence of the KID syndrome mutation that we previously described. This result was confirmed by direct DNA sequencing. CONCLUSIONS: We show that KID and HID syndromes are identical at the molecular level and confirm the clinical impression that these syndromes are one and the same. That previous clinical reports made a distinction may be a consequence of sampling artefacts; alternatively, genetic background effects such as the presence of concurrent mutations in other skin-expressed genes may modify the phenotype.

Connexin 26↗

PubMed2002

Ulcerative colitis in a patient with Wiskott-Aldrich syndrome.

A 30-year-old man with underlying Wiskott-Aldrich syndrome, which is a rare X-linked congenital immunodeficiency syndrome characterized by recurrent infections, thrombopenia, eczema and hematopoietic malignancies, presented with bloody diarrhea. Endoscopic and histological evaluation was compatible with ulcerative colitis. Congenital immune defects are paralleled by enterocolitis mimicking inflammatory bowel disease in a substantial number of patients. Despite therapy with prednisolone and 5-ASA compounds, the patient described here experienced a relapse of the colitis twice. Subsequently a JC virus infection of the central nervous system was diagnosed, and he died due to progressive multifocal leukencephalopathy.

Adult↗

PubMed2002

Grading of chronic synovitis--a histopathological grading system for molecular and diagnostic pathology.

The following is a proposition for a simple histopathological classification system to measure inflammation in synovial tissue. This synovitis-score is employed in conventionally stained routine sections, and is applicable to every kind of synovitis, irrespective of etiology and including the following relevant morphological alterations. First: hyperplasia/enlargement of synovial lining cell layer. Second: activation of resident cells/synovial stroma. Third: inflammatory infiltration. All defined histopathological qualities are graded from absent (0), slight (1) and moderate (2) to strong (3), with summaries ranging from 0 to 9. 0 to 1 corresponds to no synovitis (inflammatory grade = 0), 2 to 3 to a slight synovitis (inflammatory grade 1), 4 to 6 to a moderate synovitis (inflammatory grade 2), and 7 to 9 to a strong synovitis (inflammatory grade 3). Using this score, we analyzed 308 random specimens of synovial tissue from degenerative (osteoarthritis (OA)) and inflammatory joint diseases - reactive arthritis (ReA), psoriasis arthritis (PA) and rheumatoid arthritis (RA) - as well as synovial tissue from healthy individuals. The mean grade given to synovitis of RA turned out to be significantly higher than the mean grade of OA (p < 0.0005) and of healthy controls (p < 0.0005). On the contrary, no significant differences could be found between the mean grades of synovitis scores from patients with RA and those with PA and ReA. Another comparison between RA-synovitis types I and II according to the Stiehl classification resulted in type I (p < 0.0005), showing significantly higher values of inflammatory infiltration, and type II (p = 0.037), showing significantly higher values of stroma activation. Since in OA, synovitis is regarded as a result of degenerative cartilage destruction whereas in inflammatory joint diseases (RA, PA, ReA), synovitis is regarded to be the cause of cartilage destruction, it can be concluded that scores with considerable high values indicate the pathogenetic potential of synovitis and that the inflammatory score may be helpful in estimating the destructive potential of synovitis at the same time. Furthermore, the comparison of the score data with the Stiehl RA-synovitis types shows that the score enables us to discriminate the morphological peculiarities of the synovitis types. In experimental pathology, it could provide standardized information on molecular synovial tissue analyses where a correlation of molecular with morphological data is essential. In diagnostic pathology, this synovitis score (in combination with other typing systems) could provide basic and standardized information concerning the degree of inflammatory alterations in synovial tissue.

Arthritis↗

PubMed2001

Randomised trial of acupuncture compared with conventional massage and "sham" laser acupuncture for treatment of chronic neck pain.

OBJECTIVES: To compare the efficacy of acupuncture and conventional massage for the treatment of chronic neck pain. DESIGN: Prospective, randomised, placebo controlled trial. SETTING: Three outpatient departments in Germany. PARTICIPANTS: 177 patients aged 18-85 years with chronic neck pain. INTERVENTIONS: Patients were randomly allocated to five treatments over three weeks with acupuncture (56), massage (60), or "sham" laser acupuncture (61). MAIN OUTCOME MEASURES PRIMARY OUTCOME MEASURE: maximum pain related to motion (visual analogue scale) irrespective of direction of movement one week after treatment. SECONDARY OUTCOME MEASURES: range of motion (3D ultrasound real time motion analyser), pain related to movement in six directions (visual analogue scale), pressure pain threshold (pressure algometer), changes of spontaneous pain, motion related pain, global complaints (seven point scale), and quality of life (SF-36). Assessments were performed before, during, and one week and three months after treatment. Patients' beliefs in treatment were assessed. RESULTS: One week after five treatments the acupuncture group showed a significantly greater improvement in motion related pain compared with massage (difference 24.22 (95% confidence interval 16.5 to 31.9), P=0.0052) but not compared with sham laser (17.28 (10.0 to 24.6), P=0.327). Differences between acupuncture and massage or sham laser were greater in the subgroup who had had pain for longer than five years (n=75) and in patients with myofascial pain syndrome (n=129). The acupuncture group had the best results in most secondary outcome measures. There were no differences in patients' beliefs in treatment. CONCLUSIONS: Acupuncture is an effective short term treatment for patients with chronic neck pain, but there is only limited evidence for long term effects after five treatments.

Acupuncture Analgesia↗

PubMed2001

Structure and effective interactions in three-component hard sphere liquids.

Complete and simple analytical expressions for the partial structure factors of the ternary hard sphere mixture are obtained within the Percus-Yevick approximation and presented as functions of relative packing fractions and relative hard sphere diameters. These solutions follow from the Laplace transform method as applied to multicomponent systems by Lebowitz [Phys. Rev. 133, A895 (1964)]. As an important application, we examine effective interactions in hard sphere liquid mixtures using the microscopic information contained in their partial structure factors. Thus the ensuring pair potential for an effective one-component system is obtained from the correlation functions by using an approximate inversion, and examples of effective potentials for three-component hard sphere mixtures are given. These mixtures may be of particular interest for the study of the packing aspects of melts that form glasses or quasicrystals, since noncrystalline solids often emerge from melts with at least three atomic constituents.

Journal Article↗

PubMed2001

Human monoclonal rheumatoid synovial B lymphocyte hybridoma with a new disease-related specificity for cartilage oligomeric matrix protein.

Joint-specific self-Ags are considered to play an important role in the induction of synovial T and B cell expansion in human rheumatoid arthritis (RA). However, the nature of these autoantigens is still enigmatic. In this study a somatically mutated IgG2 lambda B cell hybridoma was established from the synovial membrane of an RA patient and analyzed for its Ag specificity. A heptameric peptide of cartilage oligomeric matrix protein (COMP) could be characterized as the target structure recognized by the human synovial B cell hybridoma. The clonotypic V(H) sequences of the COMP-specific hybridoma could also be detected in synovectomy material derived from five different RA patients but in none of the investigated osteoarthritis cases (n = 5), indicating a preferential usage of V(H) genes closely related to those coding for a COMP-specific Ag receptor in RA synovial B cells. Moreover, the COMP heptamer was preferentially recognized by circulating IgG in RA (n = 22) compared with osteoarthritis patients (n = 24) or age-matched healthy controls (n = 20; both p < 0.0001). Hence, the COMP-specific serum IgG is likely to reflect local immune responses toward a cartilage- and tendon-restricted Ag that might be crucial to the induction of tissue damage in RA.

Antibodies, Monoclonal↗

PubMed2001

Functional MRI of the spine: different patterns of positions of the forward flexed lumbar spine in healthy subjects.

Since the introduction of the technique of vertical open-configuration systems, efforts have been made to obtain functional lumbar spinal magnetic resonance (MR) images. The purpose of this study was to determine the relation between facet joint orientation and flexion patterns in the lower lumbar spine. Thirty-four normal subjects (18 women, 16 men) were examined in a vertical open 0.5-T MR scanner with T1-weighted gradient echo (GE) sequences. Flexion angles were digitally measured in the sagittal plane and facet joint orientation in the axial plane. The population showed three different functional flexion patterns: 17.6% (n=6) had kyphotic angles in all three lower lumbar levels during forward flexion (type 1), 50% (n= 17) had a lordotic angle at L5/S1 but kyphotic angles at L4/L5 and L3/L4 (type 2), and 32.4% (n=11) showed lordotic angles at L5/S1 and L4/L5 but a kyphotic angle at L3/L4 (type 3). There were statistically significant differences between flexion patterns and mean facet joint orientation: at 4/15 33.3 degrees for type 1, 33.5 degrees for type 2 and 46.2 degrees for type 3; at L5/S1 27.2 degrees for type 1, 46.4 degrees for type 2 and 48.1 degrees for type 3. There were no significant differences between the three groups at L3/L4. The three different flexion patterns in normal subjects and their relation to facet joint orientation have not been described previously. Knowledge of these patterns may lead to a better understanding of physiological spinal movement as a base for future investigations in low back pain patients.

Adult↗

PubMed2001

Hepatitis A virus: a test method for virucidal activity.

Hepatitis A virus (HAV) is closely related to the genus enterovirus. HAV is very stable and resistant to acid pH and elevated temperature, as well as to chemicals and environmental influences. Human poliovirus is still one of the model viruses for testing disinfectants but there are discussions about changing to hepatitis A virus. The purpose of this study was to develop a method for using adapted hepatitis A virus to test hand disinfectants. Using HAV strains HM175/24a and FRhK-4 cytopathic effects were visible rarely, and not before 14 days. To verify virus growth in cells a RT-PCR was developed. Two disinfectants tested did not show the required virucidal activity to satisfy current German guidelines.

2-Propanol↗

PubMed2001

Reduction of pacing output coupling capacitance for sensing the evoked response.

Sensing of the intracardiac evoked response (ER) after a pacing stimulus has been used in implantable pacemakers for automatic verification of capture. Reliable detection of ER is hampered by large residual afterpotentials associated with pacing stimuli. This led to the development of various technological solutions, like the use of triphasic pacing pulses and low polarizing electrode systems. This study investigated the effect of reducing the coupling capacitance (CC) in the pacemaker output circuitry on the magnitude of afterpotential, and the ability to automate detection of ventricular evoked response. A CC of 2.2 microF and four different blanking and recharge time settings were clinically tested to evaluate its impact on sensing of the ventricular ER and pacing threshold. Using an automatic step-down threshold algorithm, 54 consecutive patients, aged 70 +/- 10 years with acutely (n = 27) or chronically (n = 27) implanted ventricular pacing leads were enrolled for measurement testing. Routine measurements, using a standard pacing system analyzer (PSA), were (mean +/- SD) impedance 569 +/- 155 omega, R wave amplitude baseline to peak 9.8 +/- 3.7 mV and threshold 0.9 +/- 0.7 V at 0.4-ms pulse width. This new capture verification scheme, based on a CC of 2.2 microF and recharge/blanking timing setting of 10/12 ms, was successful in 52 patients which is equivalent to a success rate of 96%. In a subgroup of 26 patients implanted with bipolar ventricular leads (10 chronic, 16 acute), data were collected in unipolar (UP) and bipolar (BP) pace/sense configurations. Also, ER signals were recorded with two different band-pass filters: a wider band (WB) of 6-250 Hz and a conventional narrow band (NB) of 20-100 Hz. WB sensing from UP lead configuration yielded statistically significant larger signal to artifact ratios (SAR) than the other settings (P < 0.01). A dedicated unipolar ER sensing configuration using a small output capacitor and a wider band-pass filter enables adequate automatic capture verification, without any restrictions on pacing lead models or pacing/sensing configurations.

Aged↗

PubMed2001

Stent design related neointimal tissue proliferation in human coronary arteries; an intravascular ultrasound study.

AIMS: Histological restenosis models in animals have indicated that stent design has a significant impact on vessel trauma during stent implantation and on the amount of subsequent neointimal tissue proliferation. The impact of different stent designs on intimal hyperplasia in human atherosclerotic coronary arteries has not been determined. METHODS AND RESULTS: Angiographic and intravascular ultrasound studies were performed at the 6 month follow-up in 131 consecutive native coronary lesions of 131 patients treated with 50 Multi-Link stents, 40 InFlow stents and 41 Palmaz-Schatz stents. Lumen and stent cross-sectional areas (CSA) were measured at 1 mm axial increments. Mean intimal hyperplasia cross-sectional area (stent CSA-lumen CSA) and mean intimal hyperplasia thickness were calculated. Intravascular ultrasound demonstrated different levels of intimal hyperplasia proliferation for the three stents. Mean intimal hyperplasia thickness was 0.16+/-0.08 mm for Multi-Link stents, 0.26+/-0.19 mm for Palmaz-Schatz stents and 0.39+/-0.14 mm for Inflow stents (P<0.001). Multivariate analysis proved that stent type was the only independent predictor of intimal hyperplasia thickness at follow-up (P<0.001). CONCLUSION: Coronary stent design has a significant impact on subsequent intimal hyperplasia after implantation into atherosclerotic human coronary arteries. The corrugated ring design of the Multi-Link stent proved to result in less tissue proliferation at 6-month follow-up than the tubular slotted design of Palmaz-Schatz and InFlow stents.

Coronary Disease↗

PubMed2001

Safety considerations of DNA in food.

Recombinant DNA techniques are capable of introducing genetic changes into food organisms that are more predictable than those introduced through conventional breeding techniques. This review discusses whether the consumption of DNA in approved novel foods and novel food ingredients derived from genetically modified organisms (GMOs) can be regarded as being as safe as the consumption of DNA in existing foods. It concludes that DNA from GMOs is equivalent to DNA from existing food organisms that has always been consumed with human diets. Any risks associated with the consumption of DNA will remain, irrespective of its origin, because the body handles all DNA in the same way. The breakdown of DNA during food processing and passage through the gastrointestinal tract reduces the likelihood that intact genes capable of encoding foreign proteins will be transferred to gut microflora. The review does not specifically address food safety issues arising from the consumption of viable genetically modified microorganisms but it shows that the likelihood of transfer and functional integration of DNA from ingested food by gut microflora and/or human cells is minimal. Information reviewed does not indicate any safety concerns associated with the ingestion of DNA per se from GMOs resulting from the use of currently available recombinant DNA techniques in the food chain.

Consumer Product Safety↗

PubMed2001

Didymosis aplasticosebacea: coexistence of aplasia cutis congenita and nevus sebaceus may be explained as a twin spot phenomenon.

BACKGROUND: Co-occurrence of aplasia cutis congenita and nevus sebaceus has sometimes been observed. OBJECTIVE: We propose a genetic mechanism that may explain this coexistence of two different congenital skin disorders. METHODS AND RESULTS: We review 15 cases as reported in the literature and present an additional case. To explain the temporal and spatial proximity of the two skin lesions we advance the concept of twin spotting for which we propose the term didymosis (Greek didymos = twin). In an embryo heterozygous for two different recessive mutations localized on either of a pair of homologous chromosomes, an event of somatic recombination would occur at an early developmental stage, giving rise to two different cell clones homozygous for either mutation. CONCLUSION: The concept of didymosis aplasticosebacea is so far hypothetical. Future molecular research may show whether this concept holds true.

Child↗

PubMed2001

Paradominant inheritance may explain familial occurrence of Cutis marmorata telangiectatica congenita.

Cutis marmorata telangiectatica congenita (CMTC) is a rare congenital vascular anomaly that virtually always occurs sporadically and in a patchy, quadrant, unilateral or otherwise segmental manifestation. This would suggest mosaicism of a postzygotic mutation. Some authors, however, described CMTC occurring in several members of a family. This paradox may be explained by the concept of paradominant inheritance. Heterozygous individuals carrying a 'paradominant' mutation are, as a rule, phenotypically normal. The mutation can therefore be transmitted unperceived through many generations. The trait only becomes manifest when a postzygotic mutation occurring during early embryogenesis gives rise to loss of heterozygosity and forms a mosaic population of cells being either homozygous or hemizygous for the mutation. This concept may explain the occasional familial occurrence of CMTC.

Child, Preschool↗