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Biomedical subjects

D L Munz

Publications and source records attributed to D L Munz.

At least 55 records · Page 3Linked to original sources
PubMed1996

[123I]IBZM SPET analysis of dopamine D2 receptor occupancy in narcoleptic patients in the course of treatment.

Elevated levels of central D2 dopamine receptors were found on postmortem examination in cases of human narcolepsy. In vivo investigations using positron emission tomography (PET) and single photon emission tomography (SPET) found no changes of D2 binding in the striatal structures. To investigate whether the elevated D2 receptors in postmortem investigations are due to long-term treatment effects, we applied 123I-labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) ([123I]IBZM, a highly selective CNS D2 dopamine receptor ligand) and SPET in narcoleptic patients in the course of treatment with stimulants and/or antidepressants. Before treatment we found no changes in D2 binding in 10 patients (in comparison to 10 normal controls). After treatment (performed in five patients for 3 months) we found changes in D2 binding in four of them, indicating that the results of the postmortem studies could have been influenced by long-term medications. Human narcolepsy seems not to be related to a striatal D2 dopaminergic disturbance.

Adolescent↗
PubMed1996

Leakage measurement during selective limb perfusion using a gamma probe.

The objective of this study was to establish a probe system for intraoperative quantitative leakage measurement during selective limb perfusion for adjuvant high-dose chemotherapy in patients with malignant melanomas. We used a portable gamma probe with digital display and investigated the physical properties in a phantom study simulating blood pool activity at different angles of the probe to the surface and different distances. In 20 patients the limb circulation was surgically separated from the systemic blood circulation, and the limb was then selectively perfused (cytostatics added) for 60 min. Initially, 15 MBq technetium-99m labelled autologous red blood cells was injected into the limb circulation, and an equal amount was kept as a standard. Every 10 min, blood samples were drawn from the body circulation and count rates were simultaneously measured by the probe system at the lower end of the sternal body. At the end of perfusion, the circulation of the limb was reconnected, the standard injected into the systemic circulation, and a blood sample drawn after 10 min. All blood samples were counted for calculation of leakage in terms of percent of the injected dose, and the results compared with the intraoperative count rates of the probe system. In the range of leakage observed in this study (0%-86%), the count rate of the probe system (corrected for blood volume, i.e. for body surface) correlated with the results of conventional measurement (r=0.92) according to the equation: %leakage=counts per sx[1.2xbody surface (m2)-1.19]. In conclusion, the use of the described probe system is a feasible approach for leakage quantification which continuously yields data during selective limb perfusion.

Antineoplastic Agents↗
PubMed1996

Immunoscintigraphy for the detection of brain abscesses.

The aim of this prospective study was to assess the diagnostic usefulness of a 99Tcm-anti-granulocyte antibody in the early differentiation of the aetiology of a ring-enhancing structure on computed tomography (CT) scans following neurosurgical intervention. In 26 patients (15 males, 11 females) aged 20-82 years with suspected intracranial infection, 29 SPET scans of the head were obtained 4-6 h following the intravenous injection of 555 MBq 99Tcm-anti-granulocyte antibody. The patients had antibiotic, antimycotic or corticosteroid therapy. The diagnosis was confirmed by surgery (19 cases) or subsequent CT/MRI (magnetic resonance imaging) scans and clinical follow-up (10 cases). The immunoscan was true-positive (abscess) in 6 (sensitivity = 100%), true-negative in 19 and false-positive in 4 (specificity 83%) cases. There was no obvious detrimental effect on the results due to the antibiotic, antimycotic or corticosteroid therapy. In conclusion, despite false-positive results, the 99Tcm-anti-granulocyte antibody is a useful tool in the early detection and exclusion of intracranial abscess after neurosurgical interventions.

Adult↗
PubMed1996

[Simultaneous double nucleotide scintigraphy with indium 111 antimyosin Fab and technetium sestamibi for evaluation of myocardial viability after experimental and clinical infarct].

This study combined In-111 antimyosin Fab (AM) with Tc-99m sestamibi (MIBI) to assess myocardial viability in the subacute stage of infarction. In 9 pigs, the LAD was occluded for 45 min. Seventy-four MBq of AM were injected after 48 h of reperfusion and 740 MBq of MIBI 24 h later. In myocardial specimens, activity relative to normal myocardium (n = 35) in the region of necrosis (n = 35) was found to be 3.96 +/- 2.48 for AM and 0.30 +/- 0.20 for MIBI, in the intermediate zone of macrohistochemically reversibly damaged myocardium (n = 35) 2.79 +/- 1.29 and 0.83 +/- 0.28, respectively. Discriminant analysis classified all 105 specimens with a sensitivity of 83% and specificity of 96%. On the scans, the intermediate zone presented as overlap between both tracers. Twelve patients aged 40 to 76 years with invasively documented acute myocardial infarction (4 x anterior, 8 x inferior) were injected also with 74 MBq of AM 27 to 110 h after the onset of chest pain and with 740 MBq of MIBI 21 to 26 h later. In 8 patients, the infarct vessel was open not later than 5 h after the onset of chest pain. MIBI markedly supported reconstruction of the sections and localization of the lesions with AM on simultaneous double-nuclide single-photon emission computed tomography (SPECT). In 7 patients both tracers overlapped. Four patients showed only faint AM uptake. This demonstrates that in experimental infarction AM overestimates the region of necrosis while the combination with MIBI allows the delineation towards the intermediate zone and normal myocardium. In patients, SPECT shows similar patterns of tracer distribution. MIBI facilitates AM SPECT.

Adult↗
PubMed1996

Assessment of myocardial viability in persistent defects on thallium-201 SPECT after reinjection using gradient-echo MRI.

This prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (+/-SD) was 11.5 +/- 2.7 mm and 5.8 +/- 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 +/- 3.4 mm and 3.7 +/- 3.1 mm in 31 with reversible lesions, 11.3 +/- 2.8 mm and 3.3 +/- 1.9 mm in 10 with mild persistent defects, 9.2 +/- 2.9 mm and 3.2 +/- 2.2 mm in 15 with moderate persistent defects, 5.8 +/- 1.7 mm and 1.3 +/- 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p < 0.0005) and systolic wall thickening (p < 0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.

Adult↗
PubMed1995

[The clinical importance of scintigraphy with the murine monoclonal antigranulocyte antibody BW 250/183 for the diagnosis of prosthesis-related endocarditis].

Thirty-eight patients (16 men, 22 women; median age 62.5, range 7 to 80 years) were enrolled in a prospective study to assess the clinical utility of radioimaging using the antigranulocyte antibody BW 250/183 in suspected valve endocarditis. Eighteen patients had prosthetic valve endocarditis according to clinical criteria (surgical confirmation in 8 patients), the remaining 20 patients served as controls. All patients underwent transthoracic and transesophageal echocardiography. Eight to 10 MBq of technetium-99m-labeled antibody were intravenously injected and single-photon emission computed tomography (SPECT) of the thorax was performed after 20 to 24 h. Echocardiography revealed pathological findings in 16 of 18 patients with endocarditis (sensitivity 89%) and was false positive in one of 20 control subjects (specificity 95%). Scintigraphy was true positive in 14 of 18 patients with endocarditis (sensitivity 78%) and false positive in three of 20 control subjects (specificity 85%). Scintigraphy was true positive in the patients with false negative echocardiography and vice versa (sensitivity for both methods combined 100%, specificity 80%). In all five follow-up patients, scintigraphy became negative parallel to clinical improvement. This suggests that scintigraphy indicates the floridity of the inflammatory process. In clinically suspected prosthetic valve endocarditis with equivocal echocardiographic findings, SPECT using the antigranulocyte antibody BW 250/183 may provide valuable additional diagnostic information.

Adolescent↗
PubMed1995

Single photon emission tomography (SPET) imaging of dopamine D2 receptors in the course of dopamine replacement therapy in patients with nocturnal myoclonus syndrome (NMS).

Single photon emission tomography (SPET) permits the in vivo measurements of regional cerebral radioactivity in the human brain following the administration of compounds labeled with photon-emitting isotopes. According to our SPET findings of a reduced binding of [123I]labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) to D2 dopamine receptors in striatal structures in untreated patients with nocturnal myoclonus syndrome (NMS) it seemed to be of interest to investigate whether there are changes in D2 receptor binding under dopamine replacement therapy or not. We studied the uptake and distribution of [123I]IBZM before and in the course of dopamine replacement therapy in four patients with severe insomnia caused by a nocturnal myoclonus syndrome (NMS). We found an increase of the IBZM binding to D2 receptors in the course of treatment, which was associated with an improvement of sleep quality. Reasons for this are discussed. The [123I]IBZM SPET technique in conclusion offers an intersting tool for in vivo investigations of functional changes in the dopaminergic neurotransmitter system in longitudinal studies.

Aged↗
PubMed1995

99mTc-HMPAO-SPECT in the diagnosis of senile dementia of Alzheimer's type--a study under clinical routine conditions.

This study was designed to evaluate, whether investigations of cerebral blood flow can be a helpful diagnostic tool in the differential diagnosis between (senile) dementia of Alzheimer's type [(S)DAT] and geriatric depression with cognitive impairment. Under clinical routine conditions we performed Single Photon Emission Computed Tomography (SPECT) using 99mTc-Hexamethylpropyleneamine Oxime (HMPAO) in 23 patients with (S)DAT (14f, 9m; mean age 68.9 y), 17 patients with geriatric depression (9 f, 8 m; mean age 66.4 y) and 12 age-matched controls (9 f, 3 m; mean age 69.2 y). Semiquantitative analysis (corticocerebellar ratios) of eight different regions of interest (ROI) revealed a significantly (p < 0.05) reduced perfusion in the (S)DAT patients compared to the control group. The depression group exhibited perfusion values between the (S)DAT and control group. The difference between the depression and (S)DAT group was most prominent in the left parieto-occipital ROI (p = 0.008). We discuss the data with extensive regard to the literature and conclude that 99mTc-HMPAO SPECT is a valuable additional tool in the differential diagnosis of depression and dementia in the elderly.

Aged↗
PubMed1995

Nocturnal myoclonus syndrome (periodic movements in sleep) related to central dopamine D2-receptor alteration.

The nocturnal myoclonus syndrome (NMS) consists of stereotyped, repetitive jerks of the lower limbs that occur during sleep or wakefulness. NMS is often related with restless-legs syndrome (RLS) and can cause severe sleep disturbances and daytime sleepiness. The efficacy of dopamine agonists in the treatment points to a dopaminergic dysfunction in NMS. We investigated the central dopamine D2-receptor occupancy with [123I] labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) ([123I]IBZM) and single photon emission tomography (SPET) in 20 patients with NMS and in 10 healthy controls. In most of the patients with NMS there was a lower [123I]IBZM binding in the striatal structures compared to controls. The results indicate that NMS is related to a decrease of central D2-receptor occupancy.

Adult↗
PubMed1995

Falsely negative 99mTc-antigranulocyte immunoscintigraphy and positive 99mTc-HMPAO-labelled leukocyte scan in active Crohn's disease. Possible effects of immunosuppressive therapy?

A 19-year-old woman with active Crohn's disease under immunosuppressive therapy underwent scintigraphy with 99mTc-anti-NCA-95 antigranulocyte antibodies in order to determine the extent of inflammation. It turned out to be falsely negative whereas a 99mTc-HMPAO-labelled leukocyte scan revealed a marked terminal ileitis and pancolitis. It is assumed that immunosuppressive therapy was the main reason for the falsely negative antibody scan, possibly affecting the red bone marrow where most of the antibodies bind to granulocytes. Peripheral leukocytes labelled in vitro do not seem to be subject to these hypothetical effects on red bone marrow.

Adult↗
PubMed1994

Scintigraphic detection of inflammatory heart disease.

Inflammatory diseases of the heart encompass myocarditis, endocarditis and pericarditis. This paper discusses the diagnostic potential of scintigraphy in these entities. In myocarditis, indium-111 antimyosin Fab imaging can visualize active myocyte damage and thus contribute substantially to the diagnosis. Antimyosin uptake is also seen in a large subset of patients with dilated cardiomyopathy, indicating ongoing myocyte injury in these cases. In endocarditis, immunoscintigraphy using monoclonal technetium-99m-labelled antigranulocyte antibodies provides useful diagnostic information in patients with equivocal echocardiographic findings. Immunoscintigraphy seems to indicate the floridity of the inflammatory process in endocarditis and may be used to monitor antibiotic therapy. In pericarditis, the clinical value of scintigraphy has not been convincingly demonstrated.

Endocarditis↗
PubMed1994

Immunoscintigraphy using technetium-99m-labeled anti-NCA-95 antigranulocyte antibodies as an adjunct to echocardiography in subacute infective endocarditis.

OBJECTIVES: This study was performed to assess the clinical value of immunoscintigraphy in subacute infective endocarditis. BACKGROUND: Radiolabeled granulocytes can reveal inflammatory lesions. METHODS: Using technetium-99m-labeled anti-NCA-95 anti-granulocyte antibodies, planar scintigraphy and single-photon emission computed tomography of the thorax were performed in 72 consecutive patients with suspected endocarditis. Each patient also underwent transthoracic and, if findings were negative, transesophageal echocardiography. RESULTS: Thirty-three patients were found to have endocarditis on the basis of clinical criteria (surgical confirmation in 17 patients), and the remaining 39 served as control subjects. Initial scintigraphy was true positive in 26 patients (sensitivity 79%) and false positive in 7 (specificity 82%). Echocardiography was true positive in 29 patients (sensitivity 88%) and false positive in 1 (specificity 97%). Scintigraphy was positive in the four patients with false negative echocardiography, and echocardiography was positive in the seven patients with false negative scintigraphy. Thus, the combination of scintigraphy and echocardiography yielded a sensitivity of 100% and a specificity of 82%. In 10 of the 11 patients with two to three follow-up studies, scintigraphy became negative parallel to clinical improvement, indicating decreasing floridity of the inflammatory process. CONCLUSIONS: Immunoscintigraphy in patients with subacute infective endocarditis provides valuable diagnostic information in equivocal echocardiographic findings and may be used to monitor antibiotic therapy.

Adolescent↗
PubMed1994

[Nightly myoclonus syndrome (NMS) and restless legs syndrome (RLS)--review and case report].

The paper gives a brief review of the existing literature concerning the nocturnal myoclonus syndrome (NMS). The clinical symptomatology, criteria for differential diagnosis and the relation to the restless legs syndrome (RLS) are discussed. Recently we investigated central dopamine receptor density with 123I-labeled 3'-iodo-6-methoxybenzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) and single photon emission tomography (SPECT) in patients with NMS and found a reduced density of dopamine D2-receptors in the striatal structures, indicating a dopaminergic dysfunction in NMS and RLS. We present a report concerning a 58-year old female with NMS-associated insomnia and present IBZM SPECTs and hypnograms before and after a 3-month treatment with L-dopa and discuss the results with regard to pathophysiological theories.

Epilepsies, Myoclonic↗
PubMed1994

Bone marrow immunoscintigraphy versus conventional bone scintigraphy in the diagnosis of skeletal metastases in urogenital malignancies.

Bone marrow immunoscintigraphy using a 99mTc-labelled anti-NCA-95 monoclonal antibody and conventional bone scintigraphy with 99mTc-methylene-diphosphonate were compared in the diagnosis of skeletal metastases in 58 patients with urogenital tumours. In 13 patients with metastatic disease, bone marrow immunoscintigraphy proved to be superior to bone scintigraphy, detecting 431 metastatic lesions on immunoscans as compared to 261 lesions on bone scans. However, on a patient-by-patient basis bone marrow immunoscintigraphy did not demonstrate a clinical advantage over conventional bone scanning, as in this study no patient was identified with metastatic disease still confined to the marrow space, with bone scintigraphy and bone X-ray being normal.

Adult↗
PubMed1993

Clinical value of combined contrast and radionuclide arthrography in suspected loosening of hip prostheses.

Combined contrast and radionuclide arthrography was performed in 71 cemented, non-cemented and hybrid hip arthroplasties for diagnosis of component loosening. In 31 cases, either one or two prosthesis components were clearly loose upon clinical and radiological diagnosis, with subsequent intraoperative confirmation. The other 40 cases had doubtful component loosening, with discrepancy between clinical and radiological findings, and were investigated for clarification. Contrast and radionuclide arthrograms were compared with sequential plain radiographs and their ability to indicate component loosening was evaluated. The combined contrast and radionuclide arthrograms proved in 90.9% of the cases whether a loose component existed as confirmed by intraoperative findings. They had a high sensitivity, specificity and predictive accuracy for both the acetabular and the femoral component. Sensitivity and predictive accuracy were remarkably precise in comparison to those of plain radiographs on the acetabular side. In nearly all patients with contradictory clinical and radiological findings, conclusive diagnosis was possible on the basis of the contrast and radionuclide arthrograms. Coinciding positive results in both contrast and radionuclide arthrograms were verified in each operated case. The combination of contrast and radionuclide arthrography is an useful method to diagnose doubtful loosening of hip arthroplasty components, especially in addition to routine sequential plain radiographs.

Adult↗
PubMed1993

Platelet and fibrin deposition on coronary stents in minipigs: effect of hirudin versus heparin.

OBJECTIVES: The present study was designed to test the hypothesis that the direct thrombin hirudin is more efficient than heparin in reducing thrombus formation after coronary stenting. BACKGROUND: Despite aggressive anticoagulation, subacute thrombosis of coronary stents is a major complication associated with these new devices. METHODS: In 19 minipigs indium-111-labeled thrombocytes and iodine-125-labeled fibrinogen were injected 14 to 19 h before coronary implantation of tantalum balloon-expandable stents. In group 1 (n = 6, seven stents), a bolus of heparin (100 U/kg body weight) was given before stenting. Group 2 (n = 6, 11 stents) received both dextran (500 ml) and heparin (a 100-U/kg bolus followed by a continuous infusion of 50 U/kg per h). In group 3 (n = 7, 13 stents), hirudin (recombinant desulphatohirudin HV 1 [CGP 39393] [1 mg/kg]) was given before stent implantation, followed by an infusion of 1 mg/kg per h. All animals were pretreated with aspirin (250 mg intravenously). RESULTS: Activated partial thromboplastin time was prolonged to > 1.8 times control values in groups 2 and 3. Histologic examination after perfusion fixation 12 h after stenting showed a variable extent of thrombus on all stents. Medial tear was observed in three stents in group 1, six stents in group 2 and six stents in group 3. The number of platelets on all stents averaged 116.2 (range 22 to 522) x 10(6) in group 1, 64.3 (range 11 to 169) x 10(6) in group 2 and 19.7 (range 9 to 38) x 10(6) in group 3 (p < 0.05 vs. group 1 and vs. group 2). The increase in platelet deposition, associated with medial tear in all groups, was lowest in the hirudin group. Similarly, fibrin deposition was lowest on stents in hirudin-treated animals. CONCLUSIONS: Recombinant hirudin significantly reduces platelet and fibrin deposition on coronary stents compared with the reduction achieved with combined heparin, dextran and aspirin.

Angioplasty, Balloon, Coronary↗
PubMed1993

Myocardial indium-111 antimyosin uptake in patients with idiopathic dilated cardiomyopathy: its relation to haemodynamics, histomorphometry, myocardial enteroviral infection, and clinical course.

The myocardial uptake of indium-111 antimyosin indicates the presence of ongoing myocyte damage. To evaluate the role of this finding in patients with idiopathic dilated cardiomyopathy (IDC), 36 patients were studied by planar and SPECT antimyosin imaging. The diagnosis of IDC was based on coronary angiography and left ventricular endomyocardial biopsy. The antimyosin scan was evaluated qualitatively from SPECT images and assessed quantitatively by a count density index (CDI) which measured the tracer activity over the heart relative to the lung and sternal region (normal value less than 1.20). Group 1 consisted of 13 patients (36%) with an increased myocardial antimyosin uptake, while 23 patients had a normal antimyosin scan (group 2). Clinical data, pulmonary artery pressures, gated blood pool ejection fraction and histomorphometry of endomyocardial biopsies were similar in both groups. During a follow-up of 21 +/- 12 months there were two cardiac deaths in group 1 and 10 deaths in group 2 (P = 0.12). The 2-year survival rate was 81% and 59%, respectively. During follow-up, there was no significant change in haemodynamic parameters in either group, but there was a slight improvement in functional NYHA class in group 1 (P < 0.05). No association was found between the presence of myocardial enterovirus infection, determined in 17 patients by in situ hybridization and the antimyosin scan (P = 0.5 g). Myocardial antimyosin uptake was found in a high percentage of patients with IDC, indicating ongoing myocyte damage. This finding was not related to any clinical, haemodynamic, morphological parameter, or enterovirus infection. Myocyte damage is a distinct feature in a subgroup of patients with IDC unrelated to any known causes of myocellular destruction. This subgroup showed a trend towards a more favourable clinical outcome.

Actuarial Analysis↗