Biomedical subjects

Werner Jaschke

Publications and source records attributed to Werner Jaschke.

29 records · Page 2Linked to original sources

PubMed2003

Impact of aging on cardiac high-energy phosphate metabolism determined by phosphorus-31 2-dimensional chemical shift imaging (31P 2D CSI).

Previous echocardiographic and experimental animal studies have shown that cardiac function, structure, and metabolism change with age. The aim of this study was to evaluate the impact of age on left ventricular high-energy phosphate metabolism. Using a 1.5 Tesla whole-body MR scanner 31P 2D CSI (8 x 8 phase encoding steps, 320 mm field of view) was performed in 76 healthy male volunteers (41.7 +/- 13 years) without any history of coronary heart disease. Fourier interpolation, corrections for T1 saturation effects, the nucleus Overhauser effect, and the blood contamination were applied to the spectroscopic data. The volunteers were divided into two groups, younger (n = 37) and older (n = 39) than 41.7 years. In all volunteers, laboratory specimen were sampled, and transthoracal echocardiography was carried out. Significant differences in left ventricular phosphocreatine (PCr) to beta-adenosine-triphosphate (beta-ATP) ratios (2.16 vs. 1.83, p < 0.001), fasting serum glucose levels (83.3 vs. 98.7 mg/dl, p < 0.001), E/A (1.51 vs. 1.14 p < 0.001), and ejection fraction (EF, 65.3 vs. 59.9%, p = 0.005) were detected between the two groups of volunteers, younger and older than 41.7 years. Moreover, age correlated moderately to well with left ventricular PCr to beta-ATP ratios (r = -0.44), fasting serum glucose levels (r = 0.4), E/A (r = -0.7), left ventricular myocardial mass (r = -0.41), and EF (r = -0.55). In conclusion, our study shows that left ventricular PCr to beta-ATP ratios decrease moderately with age, as suggested by previous experimental animal studies. Additionally, age correlates negatively with E/A, left ventricular myocardial mass, and EF, as reported by previous echocardiography studies. The present study is the first to show the impact of age on left ventricular PCr to beta-ATP values in humans.

Adenosine Triphosphate↗

PubMed2003

Medial temporal lobe activation during semantic language processing: fMRI findings in healthy left- and right-handers.

Medial temporal lobe (MTL) areas are well known to serve episodic memory functions; their contribution to semantic memory has been occasionally noticed but not studied in detail. In the present fMRI study, 35 right-handed and 35 left-handed healthy subjects performed a semantic decision paradigm during which subjects heard spoken concrete nouns designating objects and had to decide on whether these objects were available in the supermarket and cost lest then a certain amount of money. The control paradigm consisted of sequences of low and high tones where subjects had to decide whether a sequence contained two high tones. The resulting contrast activation of semantic decision versus tone decision involved neocortical temporal, parietal, and prefrontal areas. Additional significant, bilateral activations in the MTL, the hippocampal formation, and adjacent areas were found. The exact incidence and location of activation was studied in a single-subject analysis for all 70 subjects. At the chosen threshold of P<0.001, 94% of subjects showed activations in the MTL and inferior temporal lobe (ITL). Activations were found along the longitudinal axis of the MTL, including the hippocampal formation and the parahippocampal gyrus. In the ITL, parts of the fusiform and lingual gyri were activated. Activations were similar in right- and left-handers. We conclude from this study that the MTL and parts of the ITL can be added to the areas activated by semantic verbal memory processing.

Acoustic Stimulation↗

PubMed2003

Chemoembolization followed by liver transplantation for hepatocellular carcinoma impedes tumor progression while on the waiting list and leads to excellent outcome.

Orthotopic liver transplantation (OLT) has been considered the best treatment option for patients with hepatocellular carcinoma (HCC). Because of a steadily increasing waiting time, a noteworthy proportion of patients are excluded from OLT because of tumor progression. A 20% and more dropout rate from the waiting list has recently been reported. In this prospective study, we evaluated the effect of preoperative transarterial chemoembolization (TACE) on preventing tumor progression while on the waiting list in patients meeting current selection criteria (solitary lesion < or = 5 cm, three lesions < or = 3 cm). In addition, we analyzed the outcome of a separate group of patients with advanced-stage HCC outside the selection criteria but with at least 50% tumor reduction after TACE (downstaging) to expand current criteria. Forty-eight patients met the selection criteria and were eligible for this study. Seven patients are still on the waiting list; 41 underwent OLT. None of these patients had to be removed from the list because of tumor progression after a mean waiting time of 178 days (23 patients > or =180 days). The 1-, 2-, and 5-year intention-to-treat survival was 98%, 98%, and 94%. The outcome after OLT was also excellent with 1-, 2-, and 5-year survival rates of 98%, 98%, and 93%. Tumor recurrence occurred only in 1 patient (2.4%). Fifteen patients with advanced-stage HCC were included in this study. Three developed a tumor progression and had to be removed from the list (20% dropout rate). Despite tumor reduction before OLT, these patients had a significantly less favorable outcome in the intention-to-treat analysis as well as in the posttransplantation survival. Tumor recurrence was seen in 30% of patients after OLT. In conclusion, TACE followed by OLT is associated with an excellent outcome in selected patients. Furthermore, TACE is highly efficacious in preventing tumor progression while waiting for OLT. Although TACE reduced tumor preoperatively, it failed to show a beneficial effect on patient survival in advanced-stage HCCs.

Adult↗

PubMed2003

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors improve myocardial high-energy phosphate metabolism in men.

PURPOSE: We intended to prove that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors or statins have a beneficial impact on the human myocardial, high-energy, phosphate metabolism. METHODS: The present study included 18 male patients (mean age 49.8 +/- 10.3) with statin-treated, familiar hypercholesterolemia (FH) and 13 male patients with untreated FH (mean age 44.6 +/- 9.5). Twenty-six healthy male volunteers served as controls (mean age 44.2 +/- 12.1). Phosphorus-31, two-dimensional chemical shift imaging (31P 2D CSI) of the heart was performed in all subjects using a 1.5 Tesla whole-body magnetic resonance (MR) scanner. The ratios between phosphocreatine (PCr) and beta-adenosine-triphosphate (beta-ATP) were calculated for the left ventricular myocardium. Furthermore, echocardiographic evaluation and stress tests were performed in all individuals. RESULTS: The untreated patients with FH exhibited a significant decrease in left ventricular PCr to beta-ATP ratios (1.78 +/- 0.34) compared with statin-treated FH patients (2.15 +/- 0.26, p < 0.001) and healthy controls (2.04 +/- 0.26, p = 0.009). The left ventricular PCr-to-beta-ATP ratios of the treated FH patients were in the range of the healthy controls. CONCLUSIONS: Our study shows for the first time an-improvement of the high-energy, phosphate metabolism in the left ventricular myocardium of patients with statin-treated FH compared with untreated FH patients.

Adenosine Triphosphate↗

PubMed2003

Hyperperfusion syndrome of the deltoid muscle after subclavian artery angioplasty and stenting.

PURPOSE: To report a case of hyperperfusion syndrome of the deltoid muscle after percutaneous transluminal angioplasty of a symptomatic high-grade subclavian artery stenosis. CASE REPORT: Immediately after balloon dilation of a left-sided subclavian artery stenosis, a 53-year-old man developed severe ipsilateral shoulder pain and swelling. Computed tomographic angiography revealed no extravasation or hematoma. Sonography showed massive edema and increased anteroposterior diameter of the left deltoid muscle (3.5 cm compared to 2.0 cm on the right). Hyperperfusion syndrome was suspected, and decompression by anterolateral fasciotomy was performed. Subsequently, both pain and swelling decreased. At day 3, the skin incision, which was temporarily covered with a synthetic skin substitute, was sutured; the wound healed uneventfully. Two weeks after surgery, both muscle strength and shoulder movements showed no restrictions. CONCLUSIONS: Hyperperfusion syndrome after endovascular treatment of subclavian artery stenosis should be considered in the differential diagnosis of atypical muscle pain in the upper extremity. It may present as a compartment syndrome requiring surgical decompression.

Angioplasty, Balloon↗

PubMed2002

Resolution requirements for monitor viewing of digital flat-panel detector radiographs: a contrast detail analysis.

With the introduction of digital flat-panel detector systems into clinical practice, the still unresolved question of resolution requirements for picture archiving communication system (PACS) workstation monitors has gained new momentum. This contrast detail analysis was thus performed to define the differences in observer performance in the detection of small low-contrast objects on clinical 1K and 2K monitor workstations. Images of the CDRAD 2.0 phantom were acquired at varying exposures on an indirect-type digital flat-panel detector. Three observers evaluated a total of 15 images each with respect to the threshold contrast for each detail size. The numbers of correctly identified objects were determined for all image subsets. No significant difference in the correct detection ratio was detected among the observers; however, the difference between the two types of workstations (1K vs 2K monitors) despite less than 3% was significant at a 95% confidence level. Slight but statistically significant differences exist in the detection of low-contrast nodular details visualized on 1K- and 2K-monitor workstations. Further work is needed to see if this result holds true also for comparison of clinical flat-panel detector images and may, for example, exert an influence on the diagnostic accuracy of chest X-ray readings.

Computer Terminals↗

PubMed2002

Storage phosphor radiography of wrist fractures: a subjective comparison of image quality at varying exposure levels.

Image quality of storage phosphor radiographs acquired at different exposure levels was compared to define the minimal radiation dose needed to achieve images which allow for reliable detection of wrist fractures. In a study on 33 fractured anatomical wrist specimens image quality of storage phosphor radiographs was assessed on a diagnostic PACS workstation by three observers. Images were acquired at exposure levels corresponding to a speed classes 100, 200, 400 and 800. Cortical bone surface, trabecular bone, soft tissues and fracture delineation were judged on a subjective basis. Image quality was rated according to a standard protocol and statistical evaluation was performed based on an analysis of variance (ANOVA). Images at a dose reduction of 37% were rated sufficient quality without loss in diagnostic accuracy. Sufficient trabecular and cortical bone presentation was still achieved at a dose reduction of 62%. The latter images, however, were considered unacceptable for fracture detection. To achieve high-quality storage phosphor radiographs, which allow for a reliable evaluation of wrist fractures, a minimum exposure dose equivalent to a speed class of 200 is needed. For general-purpose skeletal radiography, however, a dose reduction of up to 62% can be achieved. A choice of exposure settings according to the clinical situation (ALARA principle) is recommended to achieve possible dose reductions.

Fractures, Bone↗

PubMed2002

Endotoxin and its binding proteins in chronic liver disease: the effect of transjugular intrahepatic portosystemic shunting.

BACKGROUND: Gut-derived endotoxin is insufficiently cleared by the diseased liver, and thus, is elevated in plasma of patients with chronic liver disease (CLD). Endotoxin action might be modified by binding to soluble CD14 (sCD14) and lipopolysaccharide-binding protein (LBP), both of which have not yet been sufficiently studied in CLD. METHODS: Endotoxin, sCD14 and LBP have been determined in peripheral blood of 72 patients and 39 control subjects, and in portal and hepatic venous blood of 12 patients during transjugular intrahepatic portosystemic shunt (TIPS) implantation. RESULTS: Peripheral endotoxin (average 3-fold increased compared to controls), LBP, and sCD14 plasma levels were elevated in chronic liver disease irrespective of Child stage m, preserve/absence of cirrhosis or aetiology. LBP, and sCD14. Furthermore, endotoxin levels in the portal vein (38.1 +/- 6.1 pg/ml) were only slightly elevated compared to the hepatic vein (29.2 +/- 4.4 pg/ml), and peripheral endotoxin levels did not increase after TIPS. CONCLUSIONS: Decreased hepatocellular function rather than hepatic blood shunting might be responsible for endotoxemia. The elevation in LBP and sCD14 levels may be a consequence of endotoxemia.

Acute-Phase Proteins↗

PubMed2002

Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures.

AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon flat panel detector exceeds state of the art storage phosphor radiography. This makes it well suited for skeletal imaging particularly in trauma as seen in the detection of wrist fractures.

Analysis of Variance↗

PubMed2002

Nontumorous vascular malformations in the liver: color Doppler ultrasonographic findings.

OBJECTIVE: To investigate color Doppler and spectral wave characteristics of nontumorous vascular malformations in the liver. METHODS: From September 1995 to January 2001, 32 cases of vascular malformations were identified by means of color Doppler ultrasonography and spectral wave analysis. Computed tomography, angiography, or both were performed in all cases. RESULTS: Five arterioportal and 14 portovenous malformations, 1 arteriovenous malformation, and 4 portoportal and 8 venovenous shunts were detected. Associations with Rendu-Osler-Weber syndrome in 6 cases and with cirrhotic liver in 12 cases were found Fourteen patients were liver disease free. In 3 cases, interventional procedures were necessary to reduce portal hypertension or cardiac dysfunction. The incidence of finding vascular malformations in 12,000 patients was 0.1%. CONCLUSIONS: Nontumorous vascular malformations are rare disorders in the liver. They may appear in patients with healthy livers and in patients with portal hypertension. Color Doppler ultrasonography and spectral wave analysis are capable of showing and differentiating different types of hepatic vascular malformations.

Adolescent↗

PubMed2002

Persistent median artery in the carpal tunnel: color Doppler ultrasonographic findings.

OBJECTIVE: To describe the ultrasonographic and color Doppler ultrasonographic findings in 2 patients with carpal tunnel syndrome associated with a persistent median artery and to report the frequency of this anatomic variation in healthy volunteers. METHODS: Two patients with the clinical appearance of carpal tunnel syndrome and 100 wrists and distal forearms of 50 asymptomatic volunteers were examined with ultrasonography and color Doppler ultrasonography. The frequency and size of a persistent median artery and its relationship to median nerve anatomy in the carpal tunnel were evaluated. RESULTS: A large persistent median artery of 3 mm in diameter was found in the affected hands in both patients with carpal tunnel syndrome. Findings were confirmed at surgery. Among the asymptomatic volunteers, a persistent median artery could be found in 13 (26%, 10 [20%] unilateral and 3 [6%] bilateral), with a mean diameter of 1.1 mm (range, 0.5-1.7 mm). In 10 (63%) of 16 hands, the persistent median artery was associated with high division of the median nerve or a bifid nerve configuration in the carpal tunnel. CONCLUSIONS: A persistent median artery is a common condition in healthy individuals and in most cases is related to median nerve variations such as high division or a bifid nerve. Because a persistent median artery has a superficial course close to the transverse carpal ligament, preoperative diagnosis of this anatomic variation may be of clinical importance.

Adult↗