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Biomedical subjects

A Weidner

Publications and source records attributed to A Weidner.

At least 19 recordsLinked to original sources
PubMed2006

Current epidemiological aspects of human parvovirus B19 infection during pregnancy and childhood in the western part of Germany.

This investigation was undertaken to provide detailed information on the epidemiology of human parvovirus B19 (B19) infection during pregnancy and childhood in the western part of Germany. Between 1997 and 2004, 40,517 sera from pregnant women aged 17-45 years and 6060 sera from children and young adults were tested for B19 IgG and IgM in our laboratory. In pregnant women, both the history of a 'specific' (OR 7.7, 95% CI 5.2-11.4) and a 'non-specific' rash (OR 3.3, 95% CI 1.5-7.1) was predictive for B19 IgM positivity. The B19 IgG prevalence was 69.2% (4097/5924) in a subgroup of asymptomatic pregnant women screened for B19 antibodies. In children, the age-specific IgG-positivity rate increased from 12.2% (66/541) at 2 years of age to 71.9% (396/551) in those older than 10 years. In conclusion, the prevalence of B19 IgG in pregnant women from the western part of Germany is higher then previously reported. Contact with children aged 3-10 years is a major risk factor for exposure to B19. Pregnant women with the history of a 'non-specific' rash should also be evaluated for acute B19 infection.

Adolescent↗
PubMed2000

Modification of C1-C2 transarticular screw fixation by image-guided surgery.

STUDY DESIGN: This is a feasibility study of image-guided surgery for C1-C2 transarticular screw fixation comparing postoperative screw position in a nonrandomized prospective cohort with a historic control group in which fluoroscopic guidance was used alone. OBJECTIVES: To evaluate the potential benefits and disadvantages of image-guided surgery for C1-C2 screw placement. SUMMARY OF BACKGROUND DATA: C1-C2 transarticular screw fixation is biomechanically superior to other current surgical stabilization procedures. The original technique for C1-C2 screw placement relies on anatomic landmarks and intraoperative fluoroscopy. Screw misplacement or anatomic variations can result in vertebral artery injury. Image-guided surgery involves using computed tomography (CT) data to plan the optimal screw trajectory before surgery and then use this data to guide screw placement during the actual surgery. Promising results of this technique are reported in the literature, but no direct comparison between image-guided surgery and conventional surgical techniques has been previously reported. METHODS: The image-guided surgery group consisted of 37 prospective patients. The historic control group included 78 patients who had similar surgeries performed using only fluoroscopic guidance. For the image-guided surgery group, subluxation was reduced by positioning at the time of CT examination. The CT data were transferred to a StealthStation (Sofamor-Danek, Memphis, TN) surgical planning and guidance computer system, and an optimal screw trajectory was determined for the right and left transarticular screws. After matching the surgical field to the virtual computer field, C2 was drilled according to the planned screw trajectory, and screws were placed. Plain radiographs and CT were used for postoperative evaluation of the image-guided surgery group. RESULTS: Image-guided surgery reduced but did not eliminate the risk of screw misplacement. Surgical time was not increased overall. CONCLUSIONS: Image-guided surgery is an effective tool for the achievement of correct screw placement in C1-C2 transarticular screw fixation procedures. The procedure remains technically demanding.

Axis, Cervical Vertebra↗
PubMed2000

Reviewer's comment.

Explore the source record for details and available documents.

Cervical Vertebrae↗
PubMed2000

[Prognostic value of Fallopian tube endoscopy].

OBJECTIVE: Progress in sterility-therapy demands diagnostic methods, that ensure the right indication for certain therapies in order to avoid unsuccessful attempts. In this retrospective study we tried to find out, whether we could predict and influence the success rate of therapies with the use of falloposcopy prior to further treatment. MATERIAL AND METHODS: In 62 sterile patients the endotubal state was evaluated with a falloposcope (Imagyn, Irvine, USA), a system of linear everting catheter (LEC) and microendoscope, prior to further treatment. RESULTS: Twenty of the 62 patients had endotubal pathology of both tubes, 15 patients showed pathology of one tube and 25 patients were diagnosed to have a normal endotubal morphology. In 2 patients falloposcopy could not be performed because of blockage due to intramural myomas. Pregnancy rate of those patients with a normal endosalpinx was 52% altogether, following microsurgery 80% and following insemination even 100%. No extrauterine pregnancies were described in this group. Pregnancy rate of those patients with endotubal pathology of both tubes was 35%. In this group no pregnancy followed microsurgery and following insemination one extrauterine pregnancy could be noticed. Furthermore, IVF results were improved if morphologic evaluation showed normal mucosa. CONCLUSIONS: The falloposcopy is a helpful diagnostic procedure to evaluate endotubal pathology prior to microsurgery and insemination.

Adult↗
PubMed2000

Comparative immunoglobulin G antibody profiles between mother and child (CGMC test) for early diagnosis of congenital toxoplasmosis.

Early diagnosis of congenital toxoplasmosis is rendered difficult when specific immunoglobulin M (IgM) and/or IgA antibodies are absent in the blood of the newborn infant. Since maternal IgG antibodies can cross the placenta, determination of IgG antibodies in newborn infants has hitherto not been used routinely for the diagnosis of congenital infection. The aim of this study was to assess the diagnostic usefulness of an immunoblot assay which compares the early IgG profiles between the mother and her child (comparative IgG profile between mother and child; CGMC test) directed against a total cell lysate of Toxoplasma gondii tachyzoites. Serum samples from 97 newborn infants at risk of toxoplasma infection were obtained from umbilical cord blood at birth or postnatally until 3 months of life and were directly compared with serum samples from the respective mothers. Congenital toxoplasmosis was diagnosed only when IgG-reactive protein bands that were present in any newborn serum samples were absent in the corresponding maternal serum sample. Congenital infection was defined by conventional serological assays when IgM and/or IgA antibodies were present in newborn infant blood or when IgG titers rose within the first 12 months or were persistently stable for more than 8 months. Using these criteria, congenital infection was definitely confirmed in 11 cases. Three additional cases were diagnosed based on indicative data. The CGMC test, which was performed without knowledge of the results of conventional serologal assays, had sensitivity and specificity of 82.4 and 93.0%, respectively, and positive and negative predictive values of 73.7 and 95.7%, respectively. When true positives and true negatives were considered, the comparative IgG profile had a ratio of 90.9% true results. The CGMC test thus is useful as an additional assay for the rapid diagnosis of congenital toxoplasmosis when paired serum samples from mother and child are available.

Animals↗
PubMed1993

Abnormalities of circulating T-cell subpopulations in patients with cutaneous T-cell lymphoma: cutaneous lymphocyte-associated antigen expression on T cells correlates with extent of disease.

The recent characterization of the cutaneous lymphocyte-associated antigen (CLA) as a skin-selective homing receptor for skin-associated memory T cells has suggested a possible mechanism for the tropism demonstrated by the neoplastic T cells in cutaneous T-cell lymphoma (CTCL). In this study, we used five parameter flow cytometry to evaluate expression of CLA and the peripheral lymph node homing receptor L-selectin on circulating T cells in a series of patients with CTCL. Because CTCL cells were previously shown to be CD7-, we looked at expression of these receptors on the CD7- T-cell subset as well as on total T cells. Our results indicate that CTCL patients have increased levels of both CLA+ and CD7- cells in their peripheral blood and that these abnormalities are not seen in patients with other cutaneous disorders. The levels of the CLA-bearing subset correlated with extent of cutaneous but not lymph node disease. By contrast, the CD7- L-selectin+ subset correlated with peripheral lymph node involvement by CTCL. Only the CD7- L-selectin- subset correlated with the number of morphologically abnormal lymphocytes in the peripheral blood. The results support the hypothesis that expression of tissue-selective homing receptors contributes to the unique pattern of tissue involvement seen in patients with CTCL.

Antigens, CD↗
PubMed1990

[Spinal fusions in rheumatic dislocation of the cranio-cervical transition].

In 37 patients suffering from rheumatoid arthritis fusions of the cranio-cervical region were performed. The different techniques of fusions are reported and their complications and rate of pseudoarthrosis are mentioned. In detail a modified technique of transarticular screwing according to the method of Magerl are given.

Adult↗
PubMed1982

[Lumbar spinal stenosis].

Lumbar spinal stenosis is a condition of polyetiologic origin. It is defined as narrowing of the spinal canal, the nerve root canals or the intervertebral canals. For clinical, diagnostic and therapeutic reasons it may be divided into two main types: central and lateral stenosis with obstruction of the lateral recesses. Plain radiographs may be suggestive in central or generalized narrowing only. Diagnosis is confirmed by additional investigations, i.e. myelography and CT. Lumbar myelography allows definitive diagnosis of central spinal stenosis. However, validity regarding visualization of the lateral recesses is limited and a decision on the nature of the obstruction, bony or soft tissue, cannot be made. In contrast, CT does support information on the bony outline of the lateral recess as related to the facet and soft tissue structures in particular. Treatment of choice should be conservative-supportive if clinical symptoms permit. Surgery is indicated when there is intolerable pain, progressive muscle weakness or sphincter dysfunction. Surgery seeks to attain complete decompression of neural elements, if instability is present or imminent spinal fusion has to be considered. Shape, size and configuration of the spinal canal have to be determined prior to any surgical approach. CT fulfills these requirements most admirably.

Aged↗
PubMed1981

Benign fibrous histiocytoma of bone. Light- and electron-microscopic observations.

Case report of a patient with an unusual, rapidly growing bone tumor in the third and fourth cervical vertebrae. Histological and electron-microscopic investigations reveal a tumor composed of histiocytic cells, xanthomatous cells, giant cells of Touton type, and fibroblastic cells. No cellular features of malignancy are observed. From its cytologic appearance the tumor has to be classified as a benign fibrous histiocytoma. Regarding its ultrastructural features, the tumor may not be distinguished from non-ossifying fibroma of bone, but its clinical pattern shows obvious differences of localization and growth potential. the term "benign fibrous histiocytoma of bone" is proposed for these tumors which must be differentiated from non-ossifying fibroma.

Adult↗
PubMed1981

[Arachnoiditis after lumbar spine surgery (author's transl)].

21 postoperative myelograms after lumbar spine surgery were analysed in respect to intradural scarring. 13 of these cases showed roentgenological features of arachnoiditis. The postoperative complaints are related to the myelographic evaluation. The conditions forming arachnoiditis are described.

Adolescent↗
PubMed1980

[The effect of ketamine on the lysosomal enzymes of the brain tissue (author's transl)].

The action of ketamine on the lysosomal of the white and gray matter was studied by estimating the ratio: free acid hydrolase beta-glucuronidase/total activity. Administration of ketamine was followed within 24 hours by stabilization of the lysosomal membrane of the white matter. Despite this protective effect on the subcellular structures of the white matter ketamine cannot, because of its excitometabolic action, be recommended as an anaesthetic agent with brain-protecting properties.

Anesthesia↗
PubMed1979

The protective effect of steroid treatment on lysosomal enzymes after cold lesion of the cat brain.

The effect of posttraumatic steroid treatment (6-methylprednisolone) on the stability of lysosomal membranes in the cat brain is studied. The share of free activity of the lysosomal enzymes beta-glucuronidase and N-acetylhexosaminidase indicates the grade of membrane stability. The results demonstrate an increased stability of lysosomal membranes in grey as well as in white matter after posttraumatic steroid treatment. This regarded as an important aspect of the protective effects of steroid treatment in posttraumatic brain edema.

Animals↗