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Biomedical subjects

D L Munz

Publications and source records attributed to D L Munz.

At least 73 records · Page 4Linked to original sources
PubMed1992

Myocardial ischemia and left-ventricular function after ligation of left coronary artery (Bland-White-Garland syndrome): a long-term follow-up.

Left-ventricular function and myocardial perfusion were studied in 8 patients for between 3 and 21 years (mean 16 years) after ligation of the anomalous left coronary artery from the pulmonary artery. While only one patient complained of exercise-dependent stenocardia, 4 patients had abnormal ST-segments in the exercise ECG and all patients showed myocardial ischemia at exercise scintigraphy. At rest, the ejection fraction of the left ventricle was within normal range in all patients. In 5 patients, it failed to increase adequately under exercise conditions, reflecting impaired ventricular function. These results confirm the advantages of surgical procedures establishing a 2-coronary system.

Adolescent↗
PubMed1992

[Imaging and functional parameters in diagnosis of obstructive nephropathy].

Obstruction of the kidney leads to terminal kidney failure within a few years. Therefore, early recognition of such obstruction is of importance. Non-invasive diagnostic ultrasound examination now allows intrauterine visualization of a suspected obstruction. However, the implications of such a dilated ureteral pelvic system are obscure. Whether there is obstruction or dilatation can only be evaluated postnatally by a nuclear technique. The aim of our study was to measure the recovery of kidney function. We investigated 13 kidneys of 9 newborns or small infants (up to 2 years). The follow-up was continuous for up to 29 days. The parameters were: urine output (24-h clearance), glomerular filtration rate, fractional excretion of sodium and potassium, free water clearance, total protein excretion, albumin and alpha 1 microglobulin excretion. The urine output fell from 0.3 to 0.12 ml/min within 14 days after relief of obstruction. The glomerular filtration rate rose from nearly 30 ml/min to about 50 ml/min within a week. The fractional excretion of sodium and potassium indicated recovery of the proximal tubli. The fractional sodium excretion fell below 1% within 4 days. The free water clearance reflects the concentrating ability of the kidney, and in kidneys from newborns it had only positive values, while in kidneys of children older than 6 months there were also negative values. The protein excretion and the albuminuria showed recovery of the glomerular as well as the tubular system.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha-Globulins↗
PubMed1992

[Bone marrow scintigraphy. Principles, clinical results and indications].

After consideration of the anatomical and physiological principles, the radiopharmaceuticals for scintigraphy of the erythropoietic, reticuloendothelial and-as a new development-of the granulopoietic bone marrow are introduced and compared. The data on performing and evaluating bone marrow scans are followed by the presentation of the clinical results. Staging and re-staging of malignant lymphomas, multiple myeloma, breast and lung cancer are considered to be the main indications. 99mTc-labelled monoclonal anti-NCA-95-antibodies are regarded as the radiopharmaceutical of choice.

Bone Marrow↗
PubMed1992

Myocardial distribution of indium-111-antimyosin Fab and technetium-99m-sestamibi in experimental nontransmural infarction.

Early revascularization in acute myocardial infarction results in normal, necrotic and partially damaged and partially salvaged ("intermediate") myocardium. By combining a perfusion tracer and a marker for myocardial injury, we attempted to differentiate between these three types of cardiac tissue. The LAD was occluded in nine pigs for 45 min and then reperfused. After 48 and 72 hr, 74 MBq 111In-antimyosin Fab and 740 MBq 99mTc-sestamibi, respectively, were injected intravenously. Normally perfused myocardium was labeled with fluorescein and the heart excised. Three to four slices were cut from the apex. Tetrazolium staining revealed the zone of necrosis. Tracer distribution on double-nuclide scintigrams of the slices also reflected the three different myocardial zones. Guided by fluorescence and macrohistochemistry, tissue samples were excised from each zone. In relation to normal myocardium, mean activity in the intermediate zone was 0.82 +/- 0.20 for 99mTc-sestamibi and 2.84 +/- 1.31 for 111In-antimyosin Fab. Activity in necrotic myocardium was 0.30 +/- 0.19 and 3.95 +/- 2.47, respectively. These results show that 111In-antimyosin Fab fragments not only accumulate in necrotic but also in intermediate myocardium. Therefore, an overestimation of infarct size may occur if 111In-antimyosin Fab fragments are used alone without a perfusion tracer.

Animals↗
PubMed1991

[201Thallium reinjection after exertion-redistribution myocardial scintigraphy. A new method for distinguishing between scars and vital myocardium].

In a prospective study 38 patients (35 men, 3 women; median age 56 [37-71] years) with known coronary heart disease in whom conventional thallium-201 exercise-redistribution myocardial scintigraphy (ERMS) had demonstrated segments with diminished activity, thallium-201 was again injected ("reinjection scintigraphy"). Its purpose was to test whether in myocardial segments with persisting diminished radioactivity improved activity after reinjection provided evidence for still viable myocardium. Seven myocardial segments were evaluated in each patient, i.e. a total of 266 segments. Activity in the conventional ERMS was diminished in 94 of the 166 abnormal segments, but improved on reinjection in 21 of the 94 segments (22.3%). Nine of the 38 patients (23.7%) benefitted from the reinjection: only scar tissue without any viable myocardium would have been diagnosed by conventional ERMS in four patients, while extent and spread of ischaemic myocardium was better visualized in five.

Adult↗
PubMed1991

Radioimmunoimaging of subacute infective endocarditis using a technetium-99m monoclonal granulocyte-specific antibody.

Immunoscintigraphy with a technetium-99m murine monoclonal IgG1 antibody directed against non-specific cross-reacting antigen (NCA-95) and carcinoembryonic antigen was performed with 20 patients with suspected subacute infective endocarditis (SIE) and 6 controls with suspected inflammatory/infectious disease elsewhere in the body. Immunoscintigraphy and echocardiography localised SIE in 11 of 15 patients in whom the disease could be confirmed. In 4 patients with validated SIE, the immunoscan was abnormal, and the echocardiogram was normal. In another 4 patients, the result was exactly the opposite. These findings suggest that the combination of immunoscintigraphy and echocardiography improves diagnostic efficacy in patients with suspected SIE.

Adolescent↗
PubMed1991

Immunoscintigraphy using different methods of applying a 99mTc labeled monoclonal anti-CEA-antibody in the staging of patients with liver metastases before partial hepatectomy.

It was the aim of this study to determine the value of portal-venous (p.v.), intra-arterial (i.a.) or intravenous (i.v.) IS in the detection of liver metastases. Immediately after angiography and i.a. CT (20 patients) or p.v. CT (6 patients), 0.7-1.2 GBq of the 99mTc labeled anti-CEA MoAb were injected via the i.a. catheter, and in 10 patients i.v. Planar scanning was performed. Using IS in the detection of liver metastases a total sensitivity of 61% was established. However, IS was still found to be the decisive method of excluding extrahepatic tumor deposits.

Adult↗
PubMed1990

Immunoscintigraphy with 111In antimyosin Fab.

Monoclonal 111In antimyosin Fab is a marker for myocytes which have lost their membrane integrity. Because of the slow blood pool clearance of the radiopharmaceutical, imaging is usually started 24-48 h after intravenous injection of 74 MBq of the tracer. This long postinjection interval restricts its utilization in the primary diagnosis of acute myocardial infarction. However, antimyosin may help to differentiate between necrotic and viable myocardium in the subacute stage of incomplete myocardial infarction. Serial endomyocardial biopsy for early detection of transplant rejection after heart transplantation may be partially replaced or supplemented by antimyosin scintigraphy. The compound may facilitate the diagnosis of myocarditis. Other potential indications may be prognostic assessment of dilated cardiomyopathy, monitoring cardiotoxic side-effects of chemotherapeutics, recognition of cardiac contusion as well as diagnosis of rhabdo- and leiomyosarcoma. In specific clinical situations 111In antimyosin Fab immunoscintigraphy may provide valuable diagnostic information.

Antibodies, Monoclonal↗
PubMed1989

Contribution of different scintigraphic techniques to the management of medullary thyroid carcinoma.

We compared three different scintigraphic techniques for the localization of neck recurrences and metastases in seven patients with medullary thyroid carcinoma one month to eight years after the first surgical intervention. Three successive scintigraphic studies were performed in five patients (6 x 3 studies) within two weeks using 201Tl chloride, 111In-labeled F(ab')2 fragments of the anti-carcinoembryonic antigen (anti-CEA) monoclonal antibody (MoAb) BW 431/31, and 131I meta-iodo-benzylguanidine (MIBG). Additionally, 11 studies were performed with the 111In-labeled MoAb fragment BW 431/31 (seven studies) or the 99mTc-labeled intact anti-CEA MoAb BW 431/26 (four studies). The gold standards for classifying scintigraphic results were biopsy, histology, surgery, and cytology. Six regions were classified as positive or negative in each study: thyroid region, four quadrants (lymph node regions) around the thyroid, and the region of the upper mediastinum. Of 36 sites, 201Tl was true positive (TP) in seven sites, false-positive (FP) in one site, true negative (TN) in 22 sites, and false-negative (FN) in six sites, resulting in a sensitivity of 54% and a specificity of 96%. 131I MIBG was TP in four sites, FP in none of the sites, TN in 23 sites, and FN in nine sites, with a sensitivity of 31% and a specificity of 100%. Immunoscintigraphy (102 sites overall) was TP in 16 sites, FP in five sites, TN in 77 sites, and FN in four sites, resulting in a sensitivity of 80% and a specificity of 94%. Immunoscintigraphy with 111In/99mTc anti-CEA F(ab')2 fragment/intact antibody is superior to scintigraphy with 201Tl and 131I MIBG.

3-Iodobenzylguanidine↗
PubMed1986

Radioimmunodetection of human tumor xenografts by monoclonal antibody F(ab')2 fragments.

Experimental procedures are described for the radiolocalization of human tumors by murine monoclonal antibodies (MAb) in animal model systems. Visualization of tumor xenografts was clearer in nude mice as compared to experimentally immunosuppressed mice due to the higher viability of the tumors in nude mice. MAb localization in tumor tissue was greatly enhanced when F(ab')2 fragments rather than intact antibody molecules were used. Although tumors could be visualized with either 131I-, 123I- or 111In-labeled MAb fragments without using background subtraction, tumor-to-background ratios of radioactivity were highest for 131I-labeled fragments. 131I-labeled F(ab')2 fragments of eight MAb against human colorectal carcinoma, melanoma or lung carcinoma localized specifically only in those tumors that bound the MAb in vitro and not in unrelated tumors. Radiolabeled fragments of MAb with other specificities (anti-hepatitis virus MAb) did not localize in tumors. All MAb that inhibited tumor growth in nude mice effectively localized these tumors by gamma-scintigraphy. On the other hand, some MAb were effective in localizing tumors but ineffective in inhibiting their growth. The ability of the specific radiolabeled F(ab')2 fragments to localize in tumor grafts correlated significantly with MAb binding affinity and density of antigenic sites on tumor cells together, but not with either in vitro binding parameter alone. Thus, Scatchard analysis of MAb binding to tumor cells may be an effective means to screen for MAb with tumor radiolocalization potential.

Animals↗
PubMed1986

New aspects of cellular thallium uptake: Tl+-Na+-2Cl(-)-cotransport is the central mechanism of ion uptake.

Cellular uptake mechanisms of 201Tl+ were studied in Ehrlich mouse ascites tumor cells. 201Tl+ passes the cell membrane of tumor cells using three transport systems: the ATPase, the Tl+-Na+-2Cl(-)-cotransport, and the Ca++-dependent ion channel. In the case of 201Tl+ the main route for entering the cells was the cotransport, its importance increasing with the age of the cells; in parallel, the ATPase activity was reduced. In contrast, the transport capacities of the ATPase and the cotransport were of the same magnitude in the case of 42K+ and 86Rb+. This change in ion distribution was not brought about by varying velocity relations but by changing the number of transport systems in the cell membrane. There was no relationship between transport rates and diameters of the ions. 201Tl+ distribution is proportional to that of K+ with a higher intracellular concentration of about 30%. Under physiological conditions the cotransport was reversible suggesting the ability to regulate steady state during varying extracellular ion concentrations. Cells and medium were two compartments, kinetically seen. Due to the significant difference of transport capacities between the three systems with the respective ions the term "potassium-thallium-analogy" may be misleading as it erroneously assumes identical uptake conditions.

Adenosine Triphosphatases↗