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Biomedical subjects

W Becker

Publications and source records attributed to W Becker.

At least 199 records · Page 11Linked to original sources
PubMed1998

Arthroscintigraphy in suspected rotator cuff rupture.

AIM: In order to evaluate the diagnostic efficiency of arthroscintigraphy in suspected rotator cuff ruptures this new imaging procedure was performed 20 times in 17 patients with clinical signs of a rotator cuff lesion. The scintigraphic results were compared with sonography (n = 20), contrast arthrography (n = 20) and arthroscopy (n = 10) of the shoulder joint. METHODS: After performing a standard bone scintigraphy with intravenous application of 300 MBq 99m-Tc-methylene diphosphonate (MDP) for landmarking of the shoulder region arthroscintigraphy was performed after an intraarticular injection of 99m-Tc microcolloid (ALBU-RES 400 MicroCi/5 ml). The application was performed either in direct combination with contrast arthrography (n = 10) or ultrasound conducted mixed with a local anesthetic (n = 10). Findings at arthroscopical surgery (n = 10) were used as the gold standard. RESULTS: In case of complete rotator cuff rupture (n = 5), arthroscintigraphy and radiographic arthrography were identical in 5/5. In one patient with advanced degenerative alterations of the shoulder joint radiographic arthrography incorrectly showed a complete rupture which was not seen by arthroscintigraphy and endoscopy. In 3 patients with incomplete rupture, 2/3 results were consistent. A difference was seen in one patient with a rotator cuff, that has been already revised in the past and that suffered of capsulitis and calcification. CONCLUSION: Arthroscintigraphy is a sensitive technique for detection of rotator cuff ruptures. Because of the lower viscosity of the active compound, small ruptures can be easily detected, offering additional value over radiographic arthrography and ultrasound, especially for evaluation of incomplete cuff ruptures.

Adult↗
PubMed1997

Anti-carcinoembryonic antigen antibodies versus somatostatin analogs in the detection of metastatic medullary thyroid carcinoma: are carcinoembryonic antigen and somatostatin receptor expression prognostic factors?

BACKGROUND: Surgery is currently the only potentially curative approach in the treatment of medullary thyroid carcinoma (MTC). In many instances however, postsurgically elevated or rising plasma calcitonin and/or carcinoembryonic antigen (CEA) levels indicate persistent metastatic disease, although conventional diagnostic procedures (computed tomography (CT), magnetic resonance imaging (MRI), and invasive venous catheterization) fail to localize the responsible lesions. Recently, anti-CEA antibodies and somatostatin analogs have shown promising results in the staging of MTC. The aim of this study was to compare the sensitivity of both methodologies, especially for the detection of occult MTC, and to assess whether there may be correlations between the scintigraphic behavior and the patients' prognosis. METHODS: A total of 26 patients with medullary thyroid carcinoma were examined at our institution between 1977 and 1996. Ten of them had known disease, 14 had occult metastatic MTC, and 2 were free of disease at the time of presentation. Fourteen patients were investigated with anti-CEA monoclonal antibodies (MAbs) (receiving a total of 35 injections: clones BW431/26, BW431/31, IMACIS, or F023C5, labeled with 99mTc, (111)In or (131)I), and 8 patients were studied with (111)In-labeled octreotide. Two patients received potentially therapeutic doses of (131)I-labeled anti-CEA antibodies. All patients underwent conventional radiologic evaluation (ultrasonography, CT, and MRI) and/or biopsy within 4 weeks. Additional imaging was performed with 99mTc-(V)-DMSA, (131)I-metaiodobenzylguanidine, 201thallium chloride, 99mTc-methylene diphosphate, and/or 18F-fluorodeoxyglucose-positron emission tomography. Clinical follow-up was obtained. RESULTS: All patients with established disease had elevated plasma CEA (range, 6.8-345 ng/mL; calcitonin levels between 92 and 11,497 pg/mL), whereas in 9 of 14 occult cases, levels were < or = 5 ng/mL (range, 0.6-829 ng/mL; calcitonin, 72-2920 pg/mL). In patients with known disease, the overall lesion-based sensitivity was 86% for the anti-CEA MAbs, whereas octreotide was unable to target any tumor in patients with rapidly progressing disease or distant metastases (overall sensitivity, 47%). In all patients with occult MTC, anti-CEA MAbs and octreotide were able to localize at least one lesion (patient-based sensitivity, virtually 100%). In patients with postsurgically persistent hypercalcitoninemia, cervical lymph nodes were identified as the most frequent site of metastases, whereas in patients with occult and slowly progressing disease several years after primary surgery, anti-CEA MAbs and octreotide showed bilateral involvement of mediastinal lymph nodes; however, tumor to nontumor ratios were usually higher with octreotide in these cases. With anti-CEA Mabs, the highest tumor to nontumor ratios were observed in clinically aggressive, rapidly progressing disease. The sensitivity of all other diagnostic modalities was, at < or = 50%, significantly lower. Indication for antitumor effects was observed in a patient receiving 65 mCi of (111)I-labeled F(ab')2 fragments of the clone F023C5. CONCLUSIONS: For the detection of occult MTC, anti-CEA MAbs and octreotide seem to have a sensitivity that is superior to conventional diagnostic modalities, especially also when used in combination. Better detectability with anti-CEA antibodies (which may result in higher CEA expression) seems to be associated with more aggressively growing forms of MTC, whereas somatostatin receptor expression at normal CEA plasma levels and weaker MAb targeting may be associated with a more benign clinical course. This is in accordance with the study of Busnardo et al. (Cancer 1984; 53:278-85), who showed higher CEA serum levels to be associated with a worse prognosis, as well as with the in vitro findings of Reubi et al. (Lab Invest 1991;64:567-73), who demonstrated lower somatostatin receptor expression in less differentiated MTC. Fu

Adult↗
PubMed1997

Improved treatment of medullary thyroid cancer in a nude mouse model by combined radioimmunochemotherapy: doxorubicin potentiates the therapeutic efficacy of radiolabeled antibodies in a radioresistant tumor type.

Whereas in advanced metastatic medullary thyroid cancer (MTC), a variety of chemotherapeutic regimens have achieved only limited success clinically, more recently, radioimmunotherapy (RIT) with 131I-labeled anti-carcinoembryonic antigen (CEA) monoclonal antibodies (MAbs) has shown promising results. The aims of this study were to compare, in an animal model, the therapeutic efficacy of RIT to clinically used "standard" chemotherapeutic regimens and to evaluate whether combination strategies of both modalities may be feasible and may help to improve therapeutic results in this rather radioresistant tumor type. Nude mice, bearing s.c. xenografts of the human MTC cell line, TT, were treated either with the 131I-labeled anti-CEA MAb, F023C5 IgG, or were administered chemotherapeutic regimens that had shown promising results in patients with metastatic MTC (doxorubicin and cisplatinum monotherapy, combinations of both agents, and a 5-fluorouracil/dacarbazine/streptozotocin scheme). Control groups were left untreated or were injected with an irrelevant radiolabeled antibody at equitoxic dose levels. The maximum tolerated dose (MTD) of each agent was determined. Combinations of chemotherapy and RIT were evaluated as well. Toxicity and tumor growth were monitored at weekly intervals. From the chemotherapeutic agents and schemes tested, doxorubicin monotherapy was the most effective; combination therapies did not result in an increased antitumor efficacy, but they did result in more severe toxicity. At equitoxic doses, no significant difference was found between the therapeutic efficacy of doxorubicin and that of RIT. Myelotoxicity was dose limiting with radiolabeled MAbs (MTD, 600 microCi), as well as with chemotherapeutic regimens containing alkylating agents (cisplatinum, dacarbazine, or streptozotocin). At its MTD (200 microg), doxorubicin caused only mild myelotoxicity, and despite signs of cardiac toxicity, gastrointestinal side effects were dose limiting. Accordingly, bone marrow transplantation (BMT) enabled dose intensification with RIT (MTD with BMT, 1100 microCi), which led to further increased antitumor efficacy, whereas BMT was unable to increase the MTD of doxorubicin. Due to the complementarity of toxic side effects but an anticipated synergism of antitumor efficacy, combinations of RIT with doxorubicin were tested. Administrations of 500 microCi of 131I-labeled anti-CEA and, 48 h later, 200 microg of doxorubicin (i.e., 83 and 100% of the respective single-agent MTDs), were the highest doses that did not result in an increased lethality; with bone marrow support, 1000 microCi of 131I-labeled anti-CEA could be combined with 200 microg of doxorubicin (i.e., 90 and 100% of the individual MTDs). Therapeutic results of this combined radioimmunochemotherapy were superior to equitoxic monotherapy with either agent, and indication for synergistic antitumor effects is given. At its respective MTD, radioimmunochemotherapy led to a 36% cure rate if it was given without bone marrow support and to a 85% permanent cure rate if it was given with bone marrow support. The animal model, as presented in this study, seems to be useful for the preclinical testing of therapeutic agents for the systemic treatment of MTC. At equitoxic doses, RIT with radiolabeled anti-CEA antibodies seems to be equally as effective as chemotherapy with doxorubicin. Combination of RIT and doxorubicin chemotherapy seems to have synergistic therapeutic efficacy, which may be due to a radiosensitizing effect of doxorubicin.

Animals↗
PubMed1997

[Antiviral therapy of HIV infection. A practice-based presentation 1997/1998].

New information on the pathogenesis of HIV infection and the possibility of viral quantification have resulted in significant advances in the treatment of this disease. The triple combination of antiviral medications comprising two reverse transcriptase inhibitors and a proteinase inhibitor has brought about an improvement in the quality of life of the patient together with a slowing down of disease progression. For successful patient management, cooperation based on trust and compliance are equally as important as continual observation of the clinical course and monitoring of the viral burden or the T-helper cells.

Antiviral Agents↗
PubMed1997

Visually-guided saccadic eye movements in adolescents at genetic risk for schizophrenia.

Visually-guided saccades of 21 offspring of schizophrenic parents and 21 individually matched controls were compared with regard to the frequency of occurrence of saccadic hypometria and hypermetria, non-fixations, and omissions of target jumps. Target steps ranged from 10 to 60 degrees, and interstimulus intervals averaged 2.5 s; subjects were promised financial reward depending on performance. Recordings were carried out at the subjects' homes. To screen for cognitive abilities and psychopathological behavior, subjects were tested by means of an intelligence scale and a behavioral checklist. With large target steps (40-60 degrees), the high-risk group made significantly more grossly hypometric saccades (gain < or = 0.8) than the control group; responses to small target steps (10-30 degrees) exhibited a similar, albeit statistically not significant, trend. There were no significant differences with regard to the occurrence of hypermetria. Non-fixations scored marginally higher in the high-risks as compared to controls, but this was again not a significant difference. The incidence of omissions of saccades was very low in both groups. The results of the study suggest that subjects at genetic risk for schizophrenia may differ from controls by an increased incidence of conspicuously hypometric saccades. Clearly, this difference is not caused by a deficit of the saccadic motor circuitry proper; comparison to control data obtained with a similar experimental protocol suggests that it probably reflects an impaired internal control of saccades in the presence of distraction and stress. The relevance of saccades as indicators of a possible schizophrenic vulnerability is discussed.

Adolescent↗
PubMed1997

[Clinical relevance of immunoscintigraphy with 99mTc-labelled anti-CEA antigen-binding fragments in the follow-up of patients with colorectal carcinoma. Assessment of surgical resectability with a combination of conventional imaging methods].

BACKGROUND AND OBJECTIVE: Conventional imaging modalities (e.g. ultrasound, computed tomography [CT] and magnetic resonance [MRI]) are used in the routine follow-up of patients with colorectal carcinoma. But they have only limited diagnostic reliability. This study was undertaken to evaluate immunoscintigraphy (IS) with 99mTc-labelled anti-CEA antigen-binding fragments (CEA-Scan) alone or combined with conventional imaging methods. PATIENTS AND METHODS: 22 patients, operated on for colorectal carcinoma and suspected of having a recurrence, underwent scintigraphy with CEA-scan and whole-body single-photon emission computed tomography (SPECT). All results were compared with those by computed tomography (CT) and, in 19 of the patients, with histological findings (surgical specimen or biopsy). The potential influence of the scintigraphic results on surgical management was analysed retrospectively with respect to the preoperative estimate of tumour resectability. RESULTS: Lesion-based sensitivity of IS was 94%, diagnostic accuracy 92%, both being unrelated to the CEA-serum level. When CT and IS were concordant regarding resectability, this estimate was correct in all instances. But in case of discordance the results of IS were verified operatively in 88% of cases. In no patient was there measurable immune reaction with formation of human-mouse-antibodies (HAMA). CONCLUSIONS: These results indicate that IS together with SPECT can achieve reliable and sensitive localisation of tumour lesions. CEA-Scan does not, contrary to other murine antibodies, cause the formation of HAMA. The combination of IS with conventional imaging techniques can improve noninvasively the estimate of surgical resectability.

Adult↗
PubMed1997

Thyroid autonomy with color-coded image-directed Doppler sonography: internal hypervascularization for the recognition of autonomous adenomas.

In a prospective study, we assessed the possibility of recognizing autonomous adenomas of the thyroid with color-coded image-directed Doppler sonography using internal hypervascularization in thyroid nodules for identification. Fifty-three patients with thyroid nodules underwent additional CCDS examination and nuclear scintigraphy (reference). Of 29 patients having autonomous adenomas, 28 patients presented internal hypervascularization in their nodules resulting in a sensitivity of 96% and a specificity was 75%. Interestingly CCDS detected six adenomas in patients showing normal laboratory data (bTSH, TT3, FT4). CCDS could be used to exclude focal adenomas with a negative predictive value of 94%. The positive predictive value for adenoma was 82%.

Adenoma↗
PubMed1997

Enhanced bilateral somatostatin receptor expression in mediastinal lymph nodes ("chimney sign") in occult metastatic medullary thyroid cancer: a typical site of tumour manifestation?

In medullary thyroid cancer (MTC), post-surgically elevated plasma calcitonin and/or carcinoembryonic antigen levels frequently indicate persisting metastatic disease, although conventional diagnostic procedures fail to localize the responsible lesions (occult disease). Somatostatin analogues have been used successfully in disease localization, but recently concerns have been raised that increased thoracic uptake of indium-111 pentetreotide in patients with previous external beam irradiation may represent a false-positive finding, caused by post-irradiation pulmonary fibrosis. We recently examined seven patients with metastatic MTC by somatostatin receptor scintigraphy (six with occult and one with established disease). In four patients, all of whom had stable or slowly rising tumour marker levels over several years, a chimney-like bilateral mediastinal uptake of indium-111 pentetreotide was found. In two patients with persisting hypercalcitonaemia immediately after primary surgery, supraclavicular lymph node metastases were identified as the responsible lesions. None of these seven patients had prior external beam radiation therapy. In two cases, histological confirmation was obtained. In one patient, disease progression could be shown during follow-up. These data suggest that bilateral mediastinal lymph node involvement is a typical site of disease in slowly progressing occult metastatic MTC; the "chimney sign" may represent a typical finding with somatostatin analogues in such cases. Therefore, we believe that even in the case of prior external beam irradiation, mediastinal uptake of octreotide might represent metastatic MTC rather than radiation fibrosis.

Aged↗
PubMed1997

[Realignment, fusion, and staple fixation of the chopart joint in neurogenic foot deformities.].

GOAL OF SURGERY: Restoration of a plantigrade foot in adolescents suffering from a neurogenic foot deformity with an important, irreversible malposition of the talocalcaneonavicular joint complex. INDICATIONS: Severe, non reducible hindfoot deformity which cannot be corrected through soft tissue procedures alone. Important tarsal instability. Progressive forefoot deformities. CONTRAINDICATIONS: Presence of supple club foot deformities. Severe deformities necessitating removal of a bone wedge. Important degenerative changes of the subtalar joint. Presence of skin infection or sores. POSITIONING AND ANAESTHESIA: Supine with buttock of operated side slightly elevated. General or regional anaesthesia. Tourniquet at thigh. SURGICAL TECHNIQUE: Two skin incisions, one overlying the talonavicular and the other the calcaneoucuboid joint. Subperiosteal dissection until both approaches meet. Arthrodesis of the calcaneoucuboid and talonavicular joints after resection of articular cartilage and correction of deformity. Temporary fixation with Kirschner wires, visual control of correction and permanent fixation with titanium staples. Long leg cast which is split immediately. Additional tendon surgery may be necessary POSTOPERATIVE MANAGEMENT: Elevation of foot. Low molecular heparin. Well molded fibreglass cast after 2 weeks and heel added 2 weeks later. Orthopaedic shoes 10 to 12 weeks postoperatively. POSSIBLE COMPLICATIONS: Injury of neurovascular structures. Pressure sores. Thrombophlebitis. Wound dehiscence, deep infection. Displacement or breakage of staples. Absence of bony fusion. RESULTS: Between August 1990 and April 1993 the technique was performed 20 times in a total of 15 patients. Follow-up 14 to 36 months. A bony fusion occurred in all patients at 12 weeks. Eighteen times the functional result was good to satisfactory and these patients were free of pain. The following complications were observed: hindfoot varus (2), transient loss of sensation of foot (1), necrosis of the wound edges (2) and breakage of the staple (1).

English Abstract↗
PubMed1997

Radiosynoviorthesis with rhenium-186 in rheumatoid arthritis: a prospective study of three treatment regimens.

The aim of this study was to evaluate the efficiency of radiation synovectomy with rhenium-186 in rheumatoid arthritis. In this prospective, randomized trial we compared three different treatment regimens for shoulder, elbow, wrist, hip and ankle joints: group 1, injection of rhenium-186; group 2, injection of rhenium-186 in combination with triamcinolone hexacetonide; group 3, injection of triamcinolone hexacetonide alone. Each treatment group included 50 joints. Patients included in the study had to fulfil the following criteria: (1) they had to have a diagnosis of rheumatoid arthritis (ARA criteria 1988), (2) their disease-modifying drug had to be methotrexate, started at least 6 months prior to injection therapy and given for the entire study time, (3) their nonsteroidal anti-inflammatory drug had to be diclofenac given at a dose of 150 mg/day or less and (4) they were also given prednisolone at a dose of 7.5 mg/day or less. After 3 years of follow-up, 79 joints met these criteria, i.e. 71 joints were excluded from the study: 26 joints because the patients changed the disease-modifying drug (12 joints from group 1, 4 joints from group 2 and 10 joints from group 3); 45 joints because of recurrent synovitis and second-stage treatment (21 joints from group 1, 5 joints from group 2 and 19 joints from group 3). During the follow-up period, joints were assessed for pain, synovitis, joint motion and stage of radiological destruction. Best clinical results and slowest progression in radiological destruction were achieved with the combined injection of rhenium-186 and triamcinolone hexacetonide. Therefore, we recommend this treatment for articulosynovitis with the exception of severe forms, the latter because of the effective penetration range of rhenium-186.

Adolescent↗
PubMed1997

Gaze stabilization by optokinetic reflex (OKR) and vestibulo-ocular reflex (VOR) during active head rotation in man.

Vestibulo-ocular reflex (VOR)-optokinetic reflex (OKR) interaction was studied in normal human subjects during active sine-like head movements in the horizontal plane for a variety of vestibular-optokinetic stimulus combinations (frequency range, 0.05-1.6 Hz). At low to mid frequencies (< 0.2 Hz) the eyes tended to be stabilized on the optokinetic pattern, independently of whether the head, the pattern, or both were rotated. At higher frequencies, the OKR gain was attenuated and, in each of the differing stimulus combinations, the eyes became increasingly stabilized in space. Qualitatively similar results were obtained when, for the same visual-vestibular combinations, the head was passively rotated at 0.05 and 0.8 Hz. The data could be simulated by a model which assumes a linear interaction of vestibular and optokinetic signals. It considers the OKR with its negative feedback loop of primordial importance for image stabilization on the retina and the VOR only as a useful addition which compensates for the limited bandwidth of the OKR during high frequency/velocity head rotations in a stationary visual environment.

Adult↗
PubMed1997

Diagnostic value of 123iodine scintigraphy and perchlorate discharge test in the diagnosis of congenital hypothyroidism.

AIM: Forty children suffering from congenital primary permanent hypothyroidism were studied to determine the diagnostic impact of 123I scintigraphy in comparison to laboratory findings and ultrasonography. METHODS: In all patients 123I scintigraphy was performed after intravenous administration of 3.7 MBq 123I. If accumulation of the radiotracer in thyroid tissue occurred a perchlorate discharge test was performed subsequently. RESULTS: Scintigraphy revealed athyrosis in 7 children. In 11 children a lingual thyroid was observed. Deficiency in iodine organification was diagnosed by a significant discharge of 123I in 15 patients. In four of these children the diagnosis of Pendred's syndrome could be established. Ectopic thyroid tissue could be demonstrated only by scintigraphy where clinical examination and sonography failed in the diagnosis in all cases. Hypoplasia of the thyroid gland as it was diagnosed in 2 cases by ultrasonography appeared to be unlikely because a normal 123I uptake was seen in these patients. In 2 patients with scintigraphic proven athyrosis an orthotopic gland had been considered by ultrasound. In 50% of our patients the final diagnosis could only be established if 123I scintigraphy and perchlorate discharge test were performed. CONCLUSION: This findings suggest that scintigraphy is indispensible in the correct diagnostic work up of congenital hypothyroidism.

Child↗
PubMed1997

Autoimmune thyreoiditis in childhood--epidemiology, clinical and laboratory findings in 61 patients.

Autoimmune thyroiditis (AT) is the most common cause of nonendemic goiter and acquired hypothyroidism in children and adolescents. In 61 patients AT was diagnosed following clinical, ultrasonographic, biochemical and cytological examinations. Girls were more often affected than boys, the female/male ratio in our patients was 9:1. Clinically the vast majority of patients had a goiter. Approximately half of the patients were euthyroid (n = 29). In the other patients hyperthyrotropinaemia (n = 16), hypothyroidism (n = 9) and hyperthyroidism (n = 7) were evident. Thyroid microsomal and peroxidase antibodies were elevated in most of the patients, while thyroglobin antibodies were less frequently elevated. As AT without detectable thyroid antibodies can occur, a fine-needle aspiration cytology of the thyroid is important in nontypical cases. This type of cytologic examination should also be considered in patients with euthyroid nonendemic goiter, thyroid nodules and hyperthyroid goiter.

Adolescent↗
PubMed1997

Alveolar bone anatomic profiles as measured from dry skulls. Clinical ramifications.

The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 111 dry skulls were evaluated at Baylor College of Dentistry (Dallas, Texas). The skulls were arbitrarily divided into flat, scalloped and pronounced scalloped anatomic profiles according to alveolar bone anatomy. The number of buccal dehiscences and fenestrations was determined for each skull according to their anatomic morphotype. 10 skulls from each group were selected for bone height measurements. The measurements were made with a periodontal probe and ruler from the height of the interproximal bone to the buccal alveolar crest. Kodachrome slides were used to measure mesial-distal tooth width and length from ten skulls from each anatomic category. The average number of fenestrations for each group was 3.5. The mean number of dehiscences for flat and scalloped skulls was 0.5. The average number of dehiscences for pronounced scalloped was 1.2. There were no significant differences when the groups were compared. The mean distance from the height of the interdental bone to the alveolar crest was statistically significant when the groups were compared (flat 2.1 mm, scalloped 2.8 mm, pronounced 4.1 mm) (Tukey, p = 0.05). There were no significant differences when tooth shapes were compared with bone anatomy. Pronounced scalloped anatomic profiles were slightly narrower when compared with the other groups. The observations reported have treatment ramifications when patients with scalloped or pronounced scalloped morphotypes are being considered for dental implant placement.

Adult↗