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Biomedical subjects

J Hierholzer

Publications and source records attributed to J Hierholzer.

At least 55 records · Page 3Linked to original sources
PubMed1997

Renal imaging techniques.

The ancient approach to obtain an image of the kidneys (and other internal organs) was 'section-inspection-imaging' by drawing, painting, sculpturing, and modelling. The present study follows chronologically the development and use of sectioning techniques from ancient (often forbidden) methods to modern microdissection and maceration of silicone-rubber-injected tubules. Inspection evolved from the use of the naked eye to magnifying lenses, microscopes and finally electron microscopy. Pertinent examples such as the description of the kidneys as the site of urine formation, the visualization of loop structures in the renal medulla and the imaging of tight junction strands are discussed. Inspection or visualization of renal structure and function has been revolutionized by modern noninvasive techniques, such as X-ray imaging, imaging by radioisotopes, ultrasound, computer tomography and nuclear magnetic resonance. Pertinent examples are given demonstrating the potency of the various techniques. The contribution of computerized data evaluation is discussed. The development of micropuncture and microperfusion techniques has opened the field for direct imaging not only of renal (sub)structural details but also of functional parameters such as transtubular reabsorption rates, single glomerular capillary filtration and conductance of the paracellular pathway. We focus particularly on techniques specifically designed to visualize renal hemodynamic and transport parameters.

Animals↗
PubMed1996

Epidural lipomatosis: case report and literature review.

We report a case of symptomatic epidural lipomatosis in a 36-year-old man following a heart lung transplant and 3.5 years of steroid medication. A review of the pertinent literature emphasises the importance of including this diagnosis in the differential diagnosis of patients receiving steroid medication or markedly obese patients with back pain or symptoms suggesting spinal cord or cauda equina compression.

Adult↗
PubMed1996

[Magnetic resonance tomography in patients with Parkinson's disease and Parkinson-plus syndromes].

PURPOSE: To define characteristic MR-findings in patients with clinically typical extrapyramidal movement disorders. METHODS: 15 patients with Parkinson's disease (PD), 9 with multisystem atrophy (MSA), and 6 with progressive supranuclear palsy (PSP) underwent MRI using a 1.5 T. Magnetom unit. Two investigators analysed the images with special regard to global and/or focal atrophy and to changes in signal intensity of the CNS in the consensus mode. Normal images of 10 subjects served as controls to patient's images. RESULTS: In all patients with PSP and MSA characteristic pathological findings on MRI were observed including regional changes within the extrapyramidal nuclei. In contrast all patients with PD had an unremarkable MRI study of the CNS. CONCLUSION: MRI enables us to define characteristic morphological changes of the brain in patients with extrapyramidal movement disorders. Early recognition of these findings avoids misdiagnoses in patients who are difficult to diagnose.

Adult↗
PubMed1996

Iodine-123-iodo-lisuride SPECT in Parkinson's disease.

UNLABELLED: Recently, [123I]iodo-lisuride was synthesized for possible applications in SPECT studies. The purpose of this investigation was to compare the striatal binding and kinetics of this radioligand in patients with Parkinson's disease and normal controls. METHODS: Six patients with Parkinson's disease and three normal controls were examined. After intravenous injection of 111 MBq [123I]iodo-lisuride, sequential SPECT examinations at 20, 40, 80 and 120 min were performed. For each SPECT series the basal ganglia-to-cerebellum ratio of tracer accumulation was calculated. In one patient a repeat SPECT examination was undertaken under identical conditions to test the reproducibility of the procedure. In two other patients a second SPECT examination was performed after injection of cold lisuride as a receptor saturation study. In addition, the time course of the radioactivity was measured in the plasma and red blood cells in each individual. RESULTS: In both patients and controls, the highest tracer accumulation was found within the striatum. The basal ganglia-to-cerebellum ratio was 1.182 and 1.303 at 20 min, 1.353 and 1.450 at 40 min, 1.490 and 1.533 at 80 min, 1.550 and 1.583 at 120 min for patients and controls, respectively, which was not statistically different. In the saturation study, 50 micrograms and 100 micrograms cold lisuride led to a 28% and 33% reduction, respectively, of the basal ganglia-to-cerebellum ratio at 120 min. The ligand showed a rapid decline in plasma and red blood cells. The percent injected dose per liter was calculated to be 1.6 and 0.9, respectively, for plasma and red blood cells at 20 min. CONCLUSION: Iodine-123-iodo-lisuride SPECT seems useful for imaging intact striatal dopamine D2 receptors in patients with Parkinson's disease and may provide clinically relevant information for quantitative assessment of the availability and integrity of dopamine D2 receptors.

Adult↗
PubMed1996

[Cerebral SPECT with iodine-123 IBZM in patients with extrapyramidal system disorders: the evaluation of its sensitivity in therapy with dopaminergic drugs].

The functional integrity of striatal post-synaptic dopamine D2 receptors is requested for an effective pharmacologic treatment in patients with extrapyramidal movement disorders. Iodine-123 IBZM Single Photon Emission Computed Tomography (SPECT) is a noninvasive radionuclide technique for the morpho-functional imaging of post-synaptic dopamine D2 receptors. In this study, the results of iodine-123 IBZM SPECT and those of apomorphine tests were compared in 32 patients with extrapyramidal movement disorders--22 patients with idiopathic Parkinson's disease (IPD) and 10 with Parkinson's plus syndrome (PPS). Iodine-123 IBZM uptake was measured as the ratio between striatum and frontal cortex activities. Twenty of 22 IPD patients (91%) responded to apomorphine administration, while in 8 of 10 PPS patients (80%) the apomorphine test was negative. Iodine-123 IBZM uptake was significantly higher (p < 0.01) in IPD patients (1.39 +/- 0.114) than in PPS patients (1.27 +/- 0.078). Similarly, iodine-123 IBZM uptake was significantly higher (p < 0.01) in the patients with positive than in those with negative apomorphine test (1.38 +/- 0.113 vs. 1.26 +/- 0.078). In conclusion, the results of this study demonstrate that iodine-123 IBZM SPECT is a radionuclide technique capable of characterizing the patients with extrapyramidal movement disorders and of selecting the subjects who may respond to pharmacological dopamine treatment.

Adult↗
PubMed1996

[Determining the depth of infiltration in urinary bladder carcinoma with contrast medium enhanced dynamic magnetic resonance tomography. With reference to postoperative findings and inflammation].

OBJECTIVE: The purpose of this study was to evaluate dynamic contrast-enhanced magnetic resonance imaging for the staging of urothelial bladder carcinoma and to compare it with plain and contrast-enhanced spin-echo MRI. METHODS: Pre-operative MRI was carried out in 62 patients. Post-operative histological examination confirmed bladder carcinoma in 50/62 patients. Carcinoma was excluded in 12 patients. Beside spinecho MRI a dynamic contrast-enhanced study was performed immediately after IV application of Gd-DTPA using 10 sequential FLASH-2Dsequences, each with a duration of 15 s. Images were evaluated visually by three radiologists in a blinded fashion. RESULTS: In 41/62 patients pre-operative tumor staging with the dynamic contrast-enhanced study was confirmed by the histological examination after surgery. MRI with spinecho sequences yielded correct staging in 30/62 patients (P = 0.028). Staging of superficial bladder cancer was more accurate with dynamic contrast-enhanced MRI than with conventional MRI (P = 0.024). Overstaging was observed in some patients with stage pT1 tumors. Furthermore, postoperative changes of the bladder wall could be differentiated from cancer due to significantly earlier contrast enhancement of bladder cancer compared with postoperative and inflammatory alterations (P < 0.001). CONCLUSION: Contrast-enhanced dynamic MRI is a helpful addition in the presurgical T-staging of bladder cancer.

Adult↗
PubMed1995

Detection of enteroviruses and rhinoviruses in clinical specimens by PCR and liquid-phase hybridization.

A sensitive method based on PCR followed by liquid-phase hybridization for detection of enterovirus and rhinovirus RNAs in clinical specimens and cell culture supernatants is described. RNA was extracted from stool samples, throat swabs, nasopharyngeal aspirates, cerebrospinal fluid, urine, and plasma with a commercial phenol-guanidinium-chloroform reagent and purified on a polysulfone membrane, on which the reverse transcriptase reaction was also done. Two sets of oligonucleotide primers from the 5' noncoding region of picornaviruses were selected for DNA amplification of 153-bp (enterovirus) and 120-bp (rhinovirus) regions. Double-stranded amplicons were digested into single strands with T7 gene 6 exonuclease and quantitated by an assay using a europium-labeled probe, streptavidin- and biotinylated probe-coated microtitration wells, and time-resolved fluorometry. The sensitivity of the assay was about one template molecule when purified coxsackievirus A9 RNA was used. All enterovirus prototype strains, except echoviruses 22 and 23, and clinical isolates grown in cell culture or suckling mice were strongly positive by the enterovirus PCR-hybridization, as were selected prototype strains and untyped isolates of rhinoviruses by the rhinovirus PCR-hybridization. In a series of 100 clinical specimens tested, the results for 92 agreed with virus culture results. The detection method described will be useful in etiopathogenic studies on enteroviruses and rhinoviruses.

Animals↗
PubMed1995

[Roentgen diagnosis of body packers--radiological and forensic considerations].

The diagnostic value of abdominal ultrasonography and plain abdominal radiographs for the detection or exclusion of body smugglers was investigated prospectively. Both methods showed equally high sensitivity and specificity in the detection of swallowed drug packages. Possibilities for misinterpretation of physiological abdominal contents are illustrated. In addition to the radiological aspects, the legal implications of the subject are discussed.

Adult↗
PubMed1995

[Brain SPECT with 123I-lisuride in patients with Parkinson's disease and controls].

The goal was to visualize cerebral dopamine-D2 receptors in 6 patients with Parkinson's disease and in 3 healthy controls using iodine-123-Lisuride-SPECT. In addition, we performed receptor-replacement studies using 123I-Lisuride and cold Lisuride as competitive ligands. The highest uptake of 123I-Lisuride was observed in the striatum, a region with known high dopamine receptor density. In two patients premedication with cold Lisuride displaced 123I-Lisuride from the dopamine receptor. 123I-Lisuride is valuable as a radiotracer in cerebral dopamine-D2 receptor scintigraphy. Whether or not it is possible to determine dynamic changes of dopamine receptor density or function by receptor replacement studies needs further evaluation in larger patient populations.

Adult↗
PubMed1995

[Estimating patient dosage in radiologic examinations. Effective doses of the most frequent roentgen examinations].

The effective dose (E) measures the stochastic risk of radiation exposure from the viewpoint of the induction of cancer and genetic diseases. In order to compare this risk in roentgen examinations, the effective dose was calculated for the most frequent roentgen examinations. The calculations were performed with a mathematical human phantom for a standard patient. Acquisition parameters were chosen according to national recommendations. The highest values were found for the small bowel enema and lumbar myelography, the lowest values for X-rays of the cervical spine, the paranasal sinuses and the upper thigh.

Body Burden↗
PubMed1994

Johann Lukas Schönlein and his contribution to nephrology and medicine.

Schönlein published few papers, and most of what is known of his achievements in nephrology comes from notes and publications of his students. It seems, however, that he described the combination of rheumatic fever, affection of internal muscular organs, a typical exanthem and oliguria, coining the name purpura rubra to describe this syndrome. Although patients with symptoms of Schönlein's syndrome had been described earlier, Schönlein was the first to describe purpura rheumatica as an entity. Schönlein's greatest contribution was the discovery of the anthropophilic pathogenic fungus Trichophyton schönleinii as the cause of the contagious skin condition favus (honeycomb ringworm). This opened a new field--mycology--and allowed therapy to be aimed specifically at the cause of the disease.

Germany↗
PubMed1994

Dopamine D2 receptor imaging with iodine-123-iodobenzamide SPECT in idiopathic rotational torticollis.

UNLABELLED: The cause of idiopathic rotational torticollis (IRT) is not completely understood to date. However, basal ganglia are believed to be involved in the pathophysiology of IRT. To elucidate this disorder further, the value of iodobenzamide (IBZM) SPECT was studied for the evaluation of striatal dopamine D2 receptors in these patients. METHODS: Striatal dopamine D2 receptor density was assessed in 10 patients with IRT using 123I-IBZM SPECT. The images were interpreted by a nuclear medicine physician initially to determine IBZM binding within the striatum and the cerebellum and, secondly, interstriatal IBZM binding. The results were correlated with the clinical parameters of the patients and compared with the results obtained from normal controls. RESULTS: No difference was found in average, specific striatal IBZM binding (basal ganglia/cerebellum ratio) between patients and controls. However, interstriatal analysis of IBZM binding revealed a significantly higher binding in the striatum contralateral to the direction of the torticollis (p = 0.026, by chi-square test). CONCLUSION: It was concluded that the striatal dopamine D2 receptor status is altered in patients with IRT.

Adult↗
PubMed1994

[Preoperative evaluation of drug resistant focal epilepsies with 123I-iomazenil SPECT. Comparison with vidio/EEG monitoring and postoperative results].

SPECT with the benzodiazepine receptor antagonist 123I-Iomazenil was performed in 33 patients with intractable partial seizures for pre-operative evaluation. The results combined with MRI and 99mTc-HMPAO-SPECT findings were compared with the video-assisted EEG monitoring ("gold standard") which localised the focus in 25 patients. 11 patients underwent surgical resection of the epileptogenic area and became seizure-free for a period up to 13 months. The Iomazenil SPECT had a significantly higher sensitivity compared to 99mTc-HMPAO in the visualization of an epileptogenic area and should be regularly used in the diagnostic of medically intractable partial seizures.

Adolescent↗
PubMed1994

[123I-iomazenil- and 99mTc-HMPAO in the diagnosis of focal epilepsies: a comparison of untreated and treated patients].

The purpose of this study was to compare HMPAO- and IMZ-SPECT findings in treated and untreated patients with focal epilepsies. We examined 20 patients (untreated 13; treated 7). All patients had a normal CT and/or MRI scan. In all patients both whole-brain activity and regional count density (rcd) were evaluated by SPECT. Furthermore, the specific and non-specific binding of IMZ were calculated for each ROI and the results of both, treated and untreated patients were compared. Our data indicate that the normalized cerebral total binding of IMZ was significantly increased in all regions in the group of treated patients (p < 0.001). In contrast, no difference in the tracer binding was found with HMPAO-SPECT. We conclude that the difference in the IMZ-binding might be due either to exogenous or endogenous factors. In our study IMZ-SPECT had a higher sensitivity and a lower specificity in the detection of decreased rcd in areas with EEG findings that indicate an epileptogenic focus compared with HMPAO-SPECT.

Adolescent↗
PubMed1993

Correlation of clinical response in apomorphine test with D2-receptor status as demonstrated by 123I IBZM-SPECT.

The knowledge of functional capacities of postsynaptic dopaminergic receptors in parkinsonian syndromes is important for differential diagnosis and for planning therapeutic approaches. Subcutaneous apomorphine challenges serve as a pharmacological tool in testing dopaminergic responsiveness, but discrepancies between results of the apomorphine test and long-term levodopa treatment remain. 123I IBZM (I-123 labeled iodobenzamide) as a dopaminergic receptor ligand allows depiction of D2-receptors by means of SPECT methods. The correlation between dopaminergic responsiveness and D2-receptor status as demonstrated by 123I IBZM-SPECT imaging was assessed by applying an apomorphine test to 41 patients with parkinsonian syndromes. All subsequently underwent an 123I IBZM-SPECT. Apomorphine responders showed a significantly higher binding of 123I IBZM than nonresponders, and patients with idiopathic Parkinson's disease (IPD) had higher D2-receptor density as visualized by SPECT than patients with other parkinsonian syndromes. The marked overlap between the groups allowed a reliable prediction only in patients with an abnormally low basal ganglia/frontal cortex ratio of 123I IBZM binding.

Adult↗
PubMed1993

[The differential diagnosis of Parkinson diseases--123I-IBZM-SPECT vs. the apomorphine test].

The aim of our study was to compare the striatal dopamine D2-receptor density as measured by 123I-IBZM-SPECT with the results of the apomorphine-test. 30 patients were studied; 21 with idiopathic Parkinson's disease (IPD), 9 with Parkinson plus syndromes (PPS). Patients with IPD showed a significantly higher striatal IBZM binding as compared to patients with PPS (p = 0.006). A good correlation between IBZM binding and outcome of the apomorphine-test was found (p = 0.006). Low striatal IBZM binding indicates reduced dopamine D2-receptor density. This compromises successful dopaminergic medical therapy and is indicative of non-IPD disease. 123I-IBZM-SPECT could be diagnostic aid in the work-up of patients with extrapyramidal movement disorders. The response to dopaminergic drug treatment might be precluded by IBZM-SPECT in patients with Parkinsonian syndromes.

Adult↗
PubMed1993

[Neurotransmitter-receptor-imaging].

The importance of neuroreceptor imaging in vivo using single photon emission tomography (SPECT) and positron emission tomography (PET) has increased enormously. The principal neurotransmitters, such as dopamine, GABA/benzodiazepine, acetylcholine, and serotonin, are presented with reference to anatomical, biochemical, and physiological features. The main radioligands for SPECT and PET are introduced, and methodological characteristics of both PET and SPECT are summarized. Finally, the results of neurotransmitter receptor imaging obtained so far will be discussed.

Animals↗