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Biomedical subjects

B Overbeck

Publications and source records attributed to B Overbeck.

8 recordsLinked to original sources
PubMed1992

Technetium-99m-labeled anti-granulocyte antibodies in suspected bone infections.

The introduction of 99mTc-labeled anti-granulocyte antibodies seemed to provide advantages in comparison with formerly used in vitro methods to label autologous white blood cells for inflammation imaging. For this reason, we have undertaken a study to evaluate the clinical significance of this method. Thirty unselected patients with suspected bone infections were studied prospectively using the monoclonal 99mTc-labeled anti-granulocyte antibody. Twenty patients were referred with suspected infections of the peripheral bones (Group I), as well as 10 patients with suspected infections of the spine (Group II). Planar whole-body scans were performed 4 hr and 20 to 24 hr after administration of 500 MBq of the labeled antibody. Scans were considered positive for a bacterial (septic) infection when a focally increased antibody accumulation occurred. All scans were evaluated in blinded fashion by two experienced readers. Of the 20 studies from Group I patients, four false-positive scintigraphic findings were observed, and one false-negative, resulting in a specificity of only 64% and a sensitivity of 89%. In Group II (10 studies), five scans were true-negative, and five false-negative. For both groups, the specificity of the scintigraphic method was quite low (75%), and the sensitivity was also relatively low (57%). The results of this study demonstrate that in an unselected patient population in whom the diagnosis is not known, scintigraphy with 99mTc-anti-granulocyte antibodies is not a reliable method for detecting septic inflammatory lesions: In addition, use of this method excludes septic lesions with only a moderate likelihood (83% negative predictive value).

Adolescent↗
PubMed1992

[99mTc-anti-granulocyte antibodies (BW 250/183) in the detection of appendicitis].

Scintigraphy with 99mTc-labeled anti-granulocyte antibodies (AGAb) was performed in 50 patients with suspected appendicitis. Sequential and static imaging as well as SPECT of the pelvis and abdomen was performed 2 h p.i. In all patients the diagnosis was confirmed either histologically or by long-term follow-up. 13 patients had histologically proven acute appendicitis. In 11 patients the appendix scan had been positive and in 2 patients the scan had shown no significant tracer uptake in the right lower abdomen. The remaining 37 patients turned out not to have acute appendicitis. 29 out of these patients had negative and 3 had positive scan findings. In 5 patients the scan was equivocal. Out of these patients 2 had pathologic findings on the left side of the abdomen which turned out to be acute diverticulitis in one patient and acute peritonitis in the other. The remaining 3 patients with unclear scintigraphic findings had no acute appendicitis. Scintigraphy with AGAb is fast and easy to perform and thus superior to cell labeling methods for diagnosing acute appendicitis. Sensitivity for the diagnosis of acute appendicitis was 85% with a specificity of 91%. Chronic or scarred non-granulocytic appendicitis--in which there is often no definite indication for surgery--was negative in our study except for two cases.

Acute Disease↗
PubMed1991

[HMPAO-SPECT during carotid artery compression (Matas test) in the evaluation of cervical tumor surgery with potential carotid involvement].

For planning the surgical approach in patients with head and neck tumours and extensive cervical metastasis the evaluation of possible vascular involvement is necessary. If the carotid artery is suspected to be infiltrated by the tumour masses its resection or plastic substitute becomes sometimes inevitable. For evaluation of the collateral brain perfusion before a possibly necessary carotid resection we examined 10 patients with neck tumours performing the Matas-Test combined with HMPAO Single-Photon-Emission-Computed-Tomography. During ultrasound-controlled manual compression of the involved common carotid artery 99mTc-labelled HMPAO was injected. The SPECT demonstrated the brain perfusion during the carotid compression time period. 6 patients showed a decreased perfusion of the affected hemisphere with - as far as obtained - normal baseline SPECT-results and balloon occlusion tests. 2 of these patients underwent a carotid artery resection, one of the common carotid artery and one of the internal carotid artery. One patient had a significant perfusion deficit in the SPECT but no pathologic findings in angiography and balloon occlusion test. He suffered from hemiparesis postoperatively. The other patient showed preoperatively a minor decrease in perfusion and had no neurological defects postoperatively. Our findings show that the Matas-Test combined with HMPAO-SPECT is a valuable tool for the preoperative evaluation of the collateral brain perfusion. This technique is not invasive and can be performed in every nuclear medicine department with an ECT camera. The HMPAO-SPECT during carotid compression can add useful information or even replace angiography and the balloon occlusion test.

Aged↗
PubMed1991

[A comparison of 201Tl and 99mTc-MIBI in the follow-up of differentiated thyroid carcinomas].

12 patients with suspected recurrence of differentiated thyroid carcinoma following thyroidectomy, radioiodine therapy and, in some cases, external radiation therapy had 201Tl and 99mTc-MIBI scintigraphy. Except in one case, the findings concerning tumor localization and extension were identical. In all cases, locoregional lymph node metastases as well as osseous metastases were imaged by 201Tl and 99mTc-MIBI scintigraphy. MRI images obtained in all patients with suspected lymph node metastases revealed inoperable situations in 2 cases, whereas there was no correlation in 1 patient with positive 201Tl and 99mTc-MIBI scintigraphy. In contrast, the sensitivity of the two methods was relatively low in the detection of pulmonary metastases which were imaged in 1 out of 3 patients only. Discrepancies between 201Tl and 99mTc-MIBI were observed in a case of axillary lymph node metastasis. Although tumor-/background ratios were slightly higher for 201Tl, 99mTc-MIBI SPECT showed a higher imaging quality compared to 201Tl SPECT, especially in deeply situated tumor lesions. In conclusion, 99mTc-MIBI seems to be a promising alternative imaging agent in the follow-up of differentiated thyroid carcinomas.

Adenocarcinoma↗
PubMed1990

[Increased sensitivity of whole-body scintigraphy with I131 for the detection of iodine-accumulating metastases by means of delayed imaging].

In the follow-up of thyroid cancer patients we sometimes observed discrepancies between elevated thyroglobulin levels and negative results of posttherapeutic or diagnostic scans 48 h and 72 h after oral application of 131I routinely. Consequently, delayed 131I scans (96 h and later) were performed in addition. In all cases, delayed 131I scans either showed a higher imaging quality or additional metastatic lesions. Thus, posttherapeutic (and diagnostic) scans should include late images (4 d and later).

Administration, Oral↗
PubMed1990

[Early and late HMPAO-SPECT during an epileptic seizure].

For presurgical evaluation of epilepsy a 44-year old patient with complex-partial seizures underwent HMPAO-SPECT. The morphology of the seizures, the MRI-scan, psychometry and ictal as well as interictal EEGs showed a left temporal origin of the seizures. Early images were obtained 20 min and late images 24 h following injection. On both scans a marked hyperperfusion was observed in the left temporal area. A crossed cerebellar diaschisis was also seen on both SPECTs. It could be shown that during ictal examinations there is no bloodflow-dependent wash-out from brain tissue.

Adult↗
PubMed1987

Cholecystokinin octapeptide, caerulein, substance P, neurotensin, and angiotensin II: species-typical effects on the isolated portal vein of guinea pig and rat.

The isolated, spontaneously active portal vein of guinea pig was stimulated by the following compounds (the pD2 is given in parentheses): caerulein (CER, 8.02), cholecystokinin octapeptide (CCK-8, 7.59), substance P (SP, 4.68), and carbachol (5.37), whereas neurotensin (NT) was ineffective and angiotensin II (AII) produced inhibition. On the portal vein of the rat, CER and CCK-8 were ineffective, whereas stimulation occurred with SP (5.72), NT (6.79), AII (7.89), and carbachol (5.50). Tetrodotoxin did not modify these effects in both types of preparation. Cyclic dibutyryl guanosine monophosphate reduced the effect of CCK-8 and CER but not that of carbachol. It is concluded that the peptides stimulate the portal vein in a way independent from intramural neurons. It may be speculated that receptors for CCK-8 and CER are absent in the portal vein of rat and those for NT in the guinea pig vein.

Angiotensin II↗