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K Hahn

Publications and source records attributed to K Hahn.

At least 145 records · Page 8Linked to original sources
PubMed1997

[Intra-individual comparison of gastric peristalsis after ingestion of a semiliquid and solid test meal].

AIM: Patients with various disorders of gastric function were studied with radiolabeled test meals of different consistency to elaborate the effect of ingested media on gastric peristalsis and emptying. METHODS: In 12 patients parameters of gastric function were intraindividually compared after ingestion of a semiliquid and a solid test meal. In addition to the standard evaluation derived from time activity curves condensed images were established from two fixed time intervals (early and late period). These images were used to evaluate the amplitude and frequency of gastric contractions using Fourier analysis. RESULTS: As expected gastric emptying was influenced by the consistency of the test meal. Mean emptying rates for the solid meal were significant lower than those for the semiliquid one (p < 0.01). The amplitude and frequency of gastric contractions, however, did not depend on the consistency of the test meal. Within the course of the examination contraction amplitudes significantly increased (p < 0.05) from the early to the late period using both, solid as well as semiliquid test meals. The frequency of gastric contractions remained unchanged. CONCLUSION: As shown by an intraindividual data comparison amplitude and frequency of gastric contractions seem to be independent of the consistency of ingested test meals whereas gastric emptying is significantly influenced by the administered media. Semiliquid meals offer advantages with respect to the shorter examination time and simpler preparation and therefore may be preferred for routine use. Since amplitudes seem to vary within the observation period standardized acquisition protocols are recommended for the evaluation of this parameter.

Adult↗
PubMed1997

[Instrumental diagnosis for therapeutic decision: intra-arterial DSA versus 3D CT-angiography in abdominal aortic aneurysms].

Compared to intraarterial DSA, 3D spiral CT-angiography could be an reliable alternative method for preoperative evaluation and planning of abdominal aortic aneurysms. 3D data reconstruction with new rendering techniques (especially "volume rendering") provides unique information about mural thrombus, calcified plaques, vessel kinking and renal/visceral arteries. However, the more invasive intraarterial DSA should be performed in patients with complex occlusive disease of the iliac arteries, renal or visceral artery stenoses, or pathological findings in peripheral duplex sonography or if intraluminal exclusion with endostent placement is planned.

Angiography, Digital Subtraction↗
PubMed1996

MRI and radiographic findings in Currarino's triad.

Currarino's triad is a rare complex of a congenital sacral bony abnormality, anorectal malformation and a presacral mass. Intractable constipation since birth is the leading symptom of this triad, which follows an autosomal dominant mode of heredity. We report conventional radiographic and MR findings in one family consisting of a mother and her two daughters. In all three cases, radiography revealed an abnormality of the os sacrum, the so-called scimitar sacrum. MR examination, undertaken next in our institution, was applied with T1-, T2- and proton density weighted sequences in all three orientations before and after i. v. application of gadolinium diethylene-triamine-pentaacetic acid (Gd-DTPA). In two patients we were able to diagnose the complete form of the triad and in one patient an incomplete form. In any case of a radiographically diagnosed scimitar sacrum in combination with constipation, Currarino's triad should be considered. MRI, as the method of choice, should be the next step to detect a presacral mass and any anomalies of the spinal canal. The importance of early recognition lies in the high morbidity and mortality rates resulting from this disorder.

Adult↗
PubMed1996

Prolactin plasma levels and D2-dopamine receptor occupancy measured with IBZM-SPECT.

By the application of 123([123I]IBZM), an iodine-labelled dopamine D2-receptor antagonist, brain D2 receptors in humans can be visualized with single photon emission computed tomography (SPECT). The ratio of IBZM binding to striatal regions versus binding to frontal cortex (ST/FC ratio) provided a semiquantitative measurement of D2 receptor binding in the striatum. This study investigated the relationship between receptor occupancy and plasma prolactin levels in 12 male patients treated with haloperidol, benperidol or clozapine. Prolactin levels were positively correlated with D2 receptor occupancy, reflecting at least in part a comparable dopamine receptor antagonism in different dopaminergic pathways.

Adult↗
PubMed1996

[The value of 3-phase skeletal scintigraphy for early diagnosis of Sudeck disease].

PURPOSE: In a prospective study the value of the three-phase bone scintigraphy in the early diagnosis of Sudeck's atrophy was analysed. MATERIAL AND METHODS: 137 patients with the clinical suspicion on Sudeck's atrophy in stage I were examined. By means of the clinical course and additional examinations (block response), pain experts confirmed the diagnosis separately. RESULTS: With the findings of hyperperfusion of all 5 phalanges, homogeneous hyperaemia of the affected hand or the foot and periarticular increased uptake of the whole extremity a reliable diagnosis of Sudeck's atrophy was possible. The sensitivity was 95.9%, the specificity 100%. With bone scintigraphy Sudeck's atrophy could be clearly differentiated from an inactivity atrophy. CONCLUSION: Three-phase bone scintigraphy is an excellent tool for the objective diagnosis of Sudeck's atrophy in stage I.

Adult↗
PubMed1996

Infections with various types of organisms stimulate transcription from a short promoter fragment of the potato gst1 gene.

By histochemical GUS staining, we demonstrate that transcription from a short promoter fragment of the potato gst1 gene is locally induced after infection of a host plant with various types of pathogenic or symbiotic organisms. This regulatory unit is not active in noninfected tissues, except root apices and senescing leaves. Measuring the expression of a fusion between the promoter fragment and the gus gene in transgenic plants, therefore, allows comparison of the induction of defense reactions in different types of plant-microbe interactions, in one and the same plant.

Animals↗
PubMed1996

[201Tl myocardial SPECT. First experiences with a simultaneous transmission-emission acquisition protocol for patient-specific attenuated correction].

AIM: In this study our first clinical experiences with simultaneous transmission and emission acquisition in 201 TI myocardial SPECT (T/E-SPECT) are discussed. METHODS: The non-uniform attenuation (AK) was carried out with a triple-head camera (PRISM 3000, Picker Inc.) correction equipped with fanbeam collimators. A line source of 750 MBq 99mTc was used to construct the transmission profile. Prior to investigation patients got 80-120 MBq 201TI-chloride intravenously injected. RESULTS: The study comprises the evaluation of 40 patients, derived from the clinical routine. The investigation followed an usual one day protocol. Our results using T/E-SPECT reveal an almost equilibrated activity distribution between anterior and posterior myocardial wall. CONCLUSION: For this reason it is to be expected that T/E-SPECT provides more reliable information about the posterior myocardial wall, than the usual SPECT technique without attenuation correction.

Gamma Cameras↗
PubMed1996

[111IN-octreotide and 123I-MIBG scintigraphy in the diagnosis of small intestinal carcinoid tumors--results of a comparative investigation].

AIM: This study compares the diagnostic value of 111In-Octreotide- and 123I-MIBG scintigraphy in the diagnostic imaging of carcinoids and correlates the results with CT findings. METHODS: Twenty-eight patients underwent octreotide-, MIBG scintigraphy and CT examination within a short time period. RESULTS: In 13/15 preoperatively examined patients somatostatin receptor expression of the tumor was demonstrated; MIBG-uptake was found in 8/15 cases. Octreotide and MIBG scintigraphy revealed liver metastases in 26 and 19 cases, respectively. CT-examinations detected liver metastases in 22 cases. The number of metastatic lesions found by MIBG and CT was lower than with octreotide. In 3 patients unknown mediastinal lesions were detected by the octreotide scan, 2/3 did not show MIBG uptake. In 5 non-hormone secreting tumors shown by octreotide scintigraphy, no MIBG uptake was found. With respect to the diagnostic accuracy octreotide scintigraphy appeared superior to MIBG. CONCLUSION: MIBG scans do not provide additional diagnostic information compared to octreotide scintigraphy. MIBG scintigraphy may be potentially useful in terms of planning 131I-MIBG therapy only.

3-Iodobenzylguanidine↗
PubMed1996

Reappraisal of quantitative esophageal scintigraphy by optimizing results with ROC analyses.

UNLABELLED: This study investigates whether systematic analyses of methodological issues contribute to improve and renew the diagnostic role of quantitate esophageal scintigraphy. METHODS: Forty-seven patients with normal (n = 26) and pathologic (n = 21) esophageal function were studied with scintigraphy and manometry, using the latter findings as the gold standard. Scintigraphic data were analyzed by receiver operator characteristic (ROC) methods to: establish the optimal decision threshold for six different quantitative parameters, evaluate their inherent discrimination capacity and compare liquid compared with solid bolus data. RESULTS: Quantitative parameters have shown remarkable differences in their potential to discriminate between normal and pathologic findings (percentage of emptying at definite time points > mean time > transit time > mean transit time > Tmax). Sensitivity of 95% at a specificity of 96% was the optimum obtained. At comparable specificity levels, solid bolus studies generally demonstrated higher sensitivity than liquid bolus studies. CONCLUSION: The diagnostic performance of optimized esophageal scintigraphy is close to that of manometry. Our findings do not only renew the role of esophageal scintigraphy as an accurate screening test for esophageal motility disorders but also invalidate recent reservations about the diagnostic potential of this method.

Adult↗
PubMed1996

[Lymphoscintigraphy for non-invasive long term follow-up of functional outcome in patients with autologous lymph vessel transplantation].

AIM: Autologous lymph vessel transplantation significantly improves the lymphdrainage in patients with primary and secondary lymphedema. The aim of the present study was to answer the question, whether scintigraphic long-term follow up and semiquantitative evaluation of lymphatic flow could prove the persisting success of this sophisticated microsurgical technique. METHODS: In this study visual and semiquantitative lymphoscintigraphy was used to prove the function of lymphatic vessel grafts in 20 patients (17 females, 3 males) comparing a preoperative baseline study with postoperative follow up investigations for a period of 7 years. The reason for microsurgical lymph vessel transplantation was in 4 patients a primary and in 16 patients a secondary lymphedema. In 12 cases the transplantation site was at the upper extremity, in 8 cases at the lower limb. RESULTS: In 17/20 patients lymphatic function significantly improved after autologous lymph vessel transplantation compared to the preoperative findings, as verified by visual improvement of lymph drainage and decrease of a numeric transportindex. In 5 cases the vessel graft could be directly visualized. In these patients with scintigraphic visualization of the vessel graft the transportindex decreases to a significantly greater extent compared to the preoperative baseline study. Only 3 patients did not benefit from microsurgical treatment CONCLUSION: Lymphoscintigraphy combined with semiquantitative estimation of lymphatic transport kinetics has shown to be an easy, reliable and readily available technique to assess lymphatic function before and after autologous lymph vessel transplantation. Thus, the method is not only helpful in planning microsurgical treatment but also in monitoring the postoperative improvement of lymph drainage. Patients with scintigraphic visualization of the vessel graft showed a significant better postoperative outcome than those without. The scintigraphic visualization of the vessel graft therefore seems to indicate a favourable prognosis regarding to lymph drainage.

Adult↗
PubMed1995

Congenital clavicular pseudoarthrosis associated with vascular thoracic outlet syndrome: case presentation and review of the literature.

Thoracic outlet syndrome (TOS) associated with congenital clavicular pseudoarthrosis is rare in adults and often misdiagnosed. In this case report, we describe an adult female who was found to have thrombosis of the subclavian and axillary arteries with embolization documented by invasive angiography. This unusual vascular manifestation of TOS should remind physicians that anatomic derangements may predispose to upper extremity ischemia.

Adult↗
PubMed1995

Transesophageal echocardiographically guided atrial transseptal catheterization in patients with normal-sized atria: incidence of complications.

The incidence of cardiac complications from atrial transseptal catheterization has never been quantified in patients with normal-sized atria. Series defining the complication rate are derived from diseased hearts with structural changes that may alter the complication rate of the procedure. The generation of a standardized incidence of perforation in a population of structurally normal atria has important implications. A total of 46 atrial transseptal catheterizations guided by transesophageal echocardiography (TEE) for radiofrequency ablation of left-sided accessory pathways was performed in 42 patients during a 3-year period (1990-1993). Clinical and echocardiographic data were analyzed, with special attention given to TEE reports pre- and post-transseptal catheterization. Only one complication occurred in the 46 procedures (2.2%): a perforation of the left atrium that led to pericardial effusion and cardiac tamponade. In a small series of patients with normal sized atria, we have demonstrated that TEE-guided transseptal catheterization in a procedure with a low complication rate.

Adult↗
PubMed1995

Technetium-99m mercaptoacetyltriglycine clearance: reference values for infants and children.

Six hundred and thirty-nine clearance studies performed in children aged 7 days to 19 years utilizing technetium-99m mercaptoacetyltriglycine (MAG 3) were retrospectively analysed. Standardized conditions for the investigation included: parenteral hydration (60 ml/hxm2 body surface) in addition to normal oral fluid intake, weight-related dose of 99mTc-MAG 3 (1 MBq/kg body weight, minimum 15 MBq) and calculation of clearance according to Bubeck et al. Of the 513 children, 169 included in this analysis could be classified as "normal" with regard to their renal function. Normal kidney function was judged by the following criteria: normal GFR for age, normal tubular function (absence of proteinuria and glucosuria), normal renal parenchyma (on ultrasonography, MAG 3 scan and intravenous pyelography), absence of significant obstruction and gross reflux (>grade I), no single kidney and no difference in split renal function >20%. Results showed increasing MAG 3 clearance values for infants during the first months of life, reaching the normal range for older children and adults between 7 and 12 months.

Adolescent↗
PubMed1995

Melanocyte-stimulating hormone release-inhibiting factor-1 (MIF-1) can be formed from Tyr-MIF-1 in brain mitochondria but not in brain homogenate.

Two samples of the peptide tyrosine-melanocyte-stimulating hormone release-inhibiting factor-1 (Tyr-MIF-1; Tyr-Pro-Leu-Gly-NH2) were tritiated on different amino acids (Tyr or Pro) and incubated together at 37 degrees C with fractions of rat brain. The amount of intact tetrapeptide remaining was determined by HPLC. By 3 min, most of the Tyr-MIF-1 was degraded. Because similar amounts of [3H]Pro and [3H]Tyr appeared after incubation of the Tyr-MIF-1 peptides in brain homogenate, even as early as 30 s, examination of only this crude preparation would misleadingly indicate that Tyr-MIF-1 is not a precursor of melanocyte-stimulating hormone release-inhibiting factor-1 (MIF-1; Pro-Leu-Gly-NH2) in brain tissue. However, incubation of the mitochondrial fractions of brain under the same conditions resulted in more than three times as much [3H]Tyr being formed as [3H]Pro, with accompanying accumulation of MIF-1. Addition of excess MIF-1 to the mitochondrial fraction completely suppressed the formation of MIF-1 and more than doubled the amount of Tyr-MIF-1 remaining intact. When Tyr-MIF-1 tritiated only on the Tyr was added to the mitochondrial fraction, the main peaks of radioactivity appeared only at the positions of Tyr and Tyr-MIF-1, not at the position of Tyr-Pro. The results indicate that Tyr-MIF-1 can serve as a precursor of MIF-1 in brain mitochondria, an effect not evident when crude brain homogenate is used.

Animals↗
PubMed1995

Diagnostic approach in acute pulmonary embolism: perfusion scintigraphy versus spiral computed tomography.

For diagnosing acute pulmonary embolism, perfusion scintigraphy in combination with ventilation studies is a well-established and sensitive method. Recently, computed tomography (CT) incorporating an angiographic technique was introduced for evaluating the pulmonary arterial system without breathing artefacts. The present study compared lung scans with spiral CT data to establish the diagnostic value of the latter approach. Twenty-five patients with a clinical suspicion of acute pulmonary embolism were examined using both methods. Perfusion and ventilation lung scans were done and spiral volumetric CT studies were performed. In 18 patients, pulmonary embolism was diagnosed using both methods. However, the results were interpreted differently. Particularly when centrally localized emboli were present in both pulmonary arteries, assessment of the more affected side was difficult on CT and depended on the experience of the physicians interpreting the scans. Small, (sub-)segmental emboli could not be demonstrated on CT. This may explain the false-positive and false-negative results, respectively. Spiral CT enables an exact demonstration of thrombosis in severe, centrally localized emboli. In incompletely occluded vessels, estimation of the degree and the location of perfusion defects is better with scintigraphy. Based on the present results and the technical equipment necessary for spiral CT, it is concluded that perfusion scintigraphy remains the method of choice for diagnosing acute pulmonary emboli.

Acute Disease↗
PubMed1995

[Post-antibiotic effect and post-exposure polyene antagonism of azole antimycotics in Candida albicans: dependency on lipophilia].

With the lipophilic azoles itraconazole (ICZ), ketoconazole (KCZ), and miconazole (MCZ) two effects, occurring in parallel, on Candida albicans were observed: Firstly, these azoles caused a growth inhibition which persisted for at least 24 hours (post-antibiotic effect, found regularly with KCZ and MCZ, with ICZ only occasionally). Furthermore, the fungicidal activity of amphotericin B (AMB, 1 mg/1) after exposure to the azoles was reduced. In contrast, to this, fluconazole (FCZ) produced neither of these effects. Additional experiments indicate that both actions of the three lipophilic azoles may be related to their noncovalent binding to lipophilic cytoplasmatic components of the yeast cells. In the case of fluconazol such bonds seem to be much weaker. Presumably, the amount of the relatively hydrophilic fluconazole, which will be bound to the cell, is too low as to produce long lasting post-exposure effects like those caused by the lipophilic azoles.

Amphotericin B↗