Impaired sodium excretion, decreased glomerular filtration rate and elevated blood pressure in endothelin receptor type B deficient rats.

The renal endothelin (ET) system, particularly the ET type B receptor, has been implicated in the regulation of sodium excretion and glomerular filtration rate (GFR). We analyzed kidney morphology and function in a rat strain characterized by complete absence of a functional ETB receptor. Due to Hirschsprung's disease limiting lifetime in these rats, studies were performed in 23-day-old rats. Kidney size and morphology (glomerular and interstitial matrix content, glomerular size and cell density and intrarenal vascular morphology) were normal in ETB-deficient rats. There were also no evidence of altered kidney cell cycle regulation in these rats. GFR was significantly lower, by 72% (P<0.001), in homozygous ETB-deficient rats than in wild-type rats. Fractional sodium excretion was likewise markedly reduced by 84% in homozygous ETB-deficient rats (P<0.001 versus wild-type rats). Treatment with the specific epithelial sodium channel blocker amiloride led to a much higher increase in fractional sodium excretion in ETB-deficient rats (934.2+/-73% in ETB-deficient rats versus 297+/-20% in wild-type rats, expressed as percentage of corresponding placebo treated control; P<0.001). Mean arterial blood pressure was elevated by 7.9 mmHg in homozygous ETB-deficient rats (P<0.05 versus wild-type rats). Our study demonstrates that ETB-deficiency causes early onset kidney dysfunction characterized by a markedly reduced sodium excretion, decreased GFR, and slightly elevated blood pressure. The complete absence of the ETB receptor causes in the kidney--in contrast to the colon--a functional rather than a developmental, neural crest cell dependent disease, since kidney morphology was normal in ETB-deficient rats. The much higher increase in the fractional sodium excretion in ETB-deficient rats after pharmacological blockade of the epithelial sodium channel indicates that the decreased fractional sodium excretion in ETB-deficient rats is most probably due to a lack of the inhibitory property of the ETB receptor on the epithelial sodium channel activity.

Ultrasonography and contrast-enhanced MRA in ICA-stenosis: is conventional angiography obsolete?

BACKGROUND: The standard techniques for the screening and staging of internal carotid artery (ICA) stenosis are Doppler (continuous wave) and Duplex sonography. For the imaging of ICA occlusive disease, magnetic resonance angiography (MRA) is replacing digital subtraction angiography (DSA). The purpose of this observational study was to assess whether contrast enhanced MRA (CE-MRA) combined with ultrasound provided sufficient information for the planning of surgical treatment. METHODS: CE-MRA was performed in 195 patients (mean age 67.5 years) with sonographic evidence of severe ICA stenosis. The MRA examination protocol contained a heavily T1-weighted contrast bolus enhanced 3D-gradient echo sequence. The degree of stenosis was estimated retrospectively by two experienced neuroradiologists who were blinded to the sonographic findings. RESULTS: The consistency of MRA and ultrasound was sufficient to plan thrombendarterectomy in 182/195 patients. The estimations of the degree of stenosis were congruent between MRA and ultrasound in 91% of 197 vessels with high-degree carotid artery stenosis. CE-MRA evaluation had a high interobserver agreement. In 3 cases ultrasound examination diagnosed a filiform ICA stenosis which was not visible with MRA. In all these cases, DSA and the intraoperative findings revealed very short (1-2 mm), high-grade, excentric stenosis. CE-MRA correctly detected patency in 5 patients with high-grade and low-flow carotid artery stenosis, which had been regarded as occluded by ultrasound. Conversely with, in CE-MRA two occluded vessels were falsely considered as open. CONCLUSION: The combination of sonography and CE-MRA is a powerful tool for the non-invasive presurgical evaluation of the carotid arteries. DSA should be reserved for selected cases.

Giant cavernoma of the brain stem: value of delayed MR imaging after contrast injection.

Cavernous angiomas are vascular malformations composed of slowly perfused, sinusoidal vessels which can be located in any part of the central nervous system. Whereas diagnosis is mostly straightforward in typical cases, some lesions may present in unusual locations or with unusual imaging characteristics. Because of the slow perfusion, contrast enhancement is not regarded as a characteristic imaging feature of cavernomas. We report a large brain stem cavernoma with signs of recent bleeding, in which the differential diagnosis against other mass lesions was facilitated by the demonstration of slow, but intense, contrast enhancement on MRI 1 h after contrast injection. We conclude that contrast enhancement in delayed images may contribute to a safe diagnosis of cavernous haemangiomas and should be performed in atypical cases.

Tumor-related venous obstruction and development of peritumoral brain edema in meningiomas.

OBJECTIVE: The exact pathogenesis of peritumoral brain edema (PTBE) in meningiomas is still unknown. A number of different pathophysiological hypotheses have been considered. A detrimental effect of tumor-related venous obstruction has been suggested as one pathogenetic mechanism. We sought to characterize the significance of venous stasis in the development of PTBE in meningiomas. METHODS: Angiograms for 134 patients with 136 intracranial meningiomas were analyzed. Pathological changes affecting cortical veins, sylvian veins, bridging veins, deep veins, transmedullary veins, and dural sinuses were evaluated. From preoperative computed tomographic scans, the total tumor volume, the tumor/PTBE volume ratio (edema index [EI]), and the location of the edema were determined. For statistical evaluation, meningiomas associated with pathological venous drainage were compared with size-matched controls. RESULTS: The edema incidence and the mean EI were not different for meningiomas with unselected signs of obstructed venous drainage, compared with controls. In particular, lesions with involvement of cortical veins, bridging veins, and dural sinuses showed no higher edema incidence. However, meningiomas associated with venous changes in sylvian veins (EI = 4.9 versus EI = 2.7; P < 0.004) and with dysplastic transmedullary veins (EI = 3.3 versus EI = 1.7; P < 0.04) showed significantly higher mean EI values, compared with meningiomas without involvement of these vessels. CONCLUSION: Our data suggest that tumor-related venous obstruction does not play an essential role in the development of PTBE for the majority of meningiomas. For a small subgroup of meningiomas with involvement of sylvian veins or development of dysplastic transmedullary veins, changes in venous drainage may aggravate preexisting PTBE.

Technical performance of the Elecsys CA 72-4 test--development and field study.

Tumor-associated glycoprotein (TAG) 72 is a mucin-like protein of high molecular weight (220-400 kd). Elevated serum levels of TAG72 are preferentially observed in patients suffering from gastric cancer. Additionally the determination of TAG72 may be a helpful tool in the management of patients suffering from mucinous ovarian cancer, in whom the clinical sensitivity of CA125 is low. The new Elecsys CA72-4 assay-available as Elecsys 2010 and 1010--was evaluated in a first field study. The test has a wide measuring range (300 U/ml) and low detection limit (0.5 U/ml) which favours its routine use. Typical precision values are 2% for intra-assay, 4% for inter-assay and 6% for inter-instrument-precision. Method comparisons to Enzymun-Test CA72-4 showed a correlation between 0.91 and 0.96. The correlation to a commercially available RIA was 0.8. With human ascites material no Hook-effect was observed up to 20,000 U/ml. No Hama-interference with clinically relevant HAMA-samples was detected.

Efficacy and tolerability of a new estradiol delivering matrix patch (Estraderm MX) in postmenopausal women.

OBJECTIVE: To examine the efficacy and tolerability of a new matrix patch delivering estradiol (E2 Matrix) at doses of 0.05 and 0.10 mg per day (Estraderm MX 50, 100) in the treatment of moderate to severe postmenopausal symptoms. METHODS: A total of 254 postmenopausal women were randomized to receive treatment with E2 Matrix 0.10 mg (N = 86), E2 Matrix 0.05 mg (N = 82), or placebo (N = 86) in a double-blind, double-dummy fashion for a period of 12 weeks continuously. Patches were applied twice weekly to the buttocks with each patient wearing two patches at all times. The primary efficacy criterion was the difference from baseline of the mean number of moderate to severe hot flushes per 24 h during the last 2 weeks of treatment. Other efficacy variables included reduction in hot flushes at 4 and 8 weeks, reduction in daytime flushing and night sweats, and Kupperman Index at 4, 8, and 12 weeks. RESULTS: E2 Matrix 0.10 and 0.05 mg were both significantly superior to placebo in reducing hot flushes per 24 h after 4, 8, and 12 weeks of treatment (P < 0.001). Also, for all other efficacy parameters studied, both dosage strengths of E2 Matrix were statistically significantly superior to placebo at all time points (P < 0.001). Local tolerability was good in both groups. A slight increase in estrogen related adverse effects (breast tenderness, leukorrhoea) was seen with the 0.10 mg patch. Adhesion of patches and compliance were good. Overall systemic tolerability was good in both treated groups. However, a 4.8% overall incidence of endometrial hyperplasia was observed in patients with an intact uterus. CONCLUSIONS: This new matrix patch offers an effective and well tolerated dosage form for delivery of 0.05 and 0.1 mg estradiol per day. It may be particularly suitable for those women who experience local sensitivity to alcohol-containing systems. In light of the observed hyperplasia after treatment in five patients, estrogen therapy should as yet be supplemented monthly with a progestogen in women with an intact uterus.

Pulmonary nodules in spiral volumetric and single slice computed tomography.

Single slice acquisition of conventional CT and volume scanning of spiral volumetric CT are compared in terms of detection and assessment of pulmonary nodules. Spiral CT is supposed to be superior to conventional CT in detecting all lung nodules by scanning the complete lung volume, while conventional CT may miss nodules due to inconsistent levels of inspiration for single slices. Different technical procedures of spiral CT may change the imaging of nodules and other findings. Fifty-two patients with known or suspected lung nodules were examined by conventional CT and spiral CT. Number and size of lung nodules and imaging of other pulmonary findings were registered independently by two radiologists. Spiral CT showed 15 lung nodules not seen on conventional CT, and missed one nodule. Spiral CT imaging of nodules was superior in some cases (characterisation of benign nodules) because complete scanning provided more information than conventional CT. It was worse in some cases (small nodules, fibrosis, small pleural effusion) due to the greater partial volume effect and less mAs. Technically improved spiral CT with longer scanning facilities and a 180-degree algorithm may be able to replace conventional CT for this indication.

[The characteristic values in the MR study of cerebral blood flow with high spatial and temporal resolution]. / Charakteristische Grössen bei der MR-Untersuchung der zerebralen Durchblutung mit hoher räumlicher und zeitlicher Auflösung.

PURPOSE: Different parameters for the evaluation of perfusion studies with dynamic MR measurements after the administration of paramagnetic contrast agent were compared. METHOD: An echo planar imaging (EPI) sequence was developed that allows dynamic multi-slice data acquisition. Evaluations of the measurements were performed by calculating parameter maps. Phenomenological quantities such as maximal signal reduction and time to peak as well as derived quantities such as approximations of the regional cerebral blood volume were used as parameters. Patients with a low grade astrocytoma, with an acute cerebral infarction and with stenoses of the carotid arteries were examined. RESULTS: On comparison of the derived parameters with the phenomenological parameters no major differences were found in qualitative comparisons of the parameter maps. The comparison of relative parameter values in selected regions within the datasets of 20 patients show a high correspondence between phenomenological and derived parameter values. CONCLUSIONS: Using EPI measurement techniques with high temporal resolution, parameter maps of simple values like maximal signal reduction and time-to-peak are sufficient to visualize relative differences of perfusion within the selected slices. However, the calculation of relative rCBV and rCBF values might be helpful for the detailed characterization of signal courses in selected regions.

[Enhanced MR-angiography (CE-MRA) of the supraaortic arteries: dose reduction with a contrast agent of high relaxivity (Gd-BOPTA)]. / Kontrastmittelverstärkte MR-Angiographie (CE-MRA) der supraaortalen Arterien: Dosisreduktion bei einem Kontrastmittel hoher Relaxivität (Gd-BOPTA).

PURPOSE: Reducing the amount of contrast medium in contrast-enhanced MR-angiography (CE-MRA) of the cervical vessels could lead to considerable cost reduction. This study investigates whether the amount of contrast medium possessing high relaxivity can be reduced without loss of diagnostic information. MATERIALS AND METHODS: In a prospective study the supraaortic vessels of 40 patients were examined on a 1.5 T MR-system using 10 or 20 ml Gd-BOPTA (MultiHance). The examinations were evaluated by measurement of the signal increase in the common carotid arteries in 38 patients. Furthermore, CE-MRA was rated by two independent observers, who were blinded to the amount of contrast medium and degree of stenosis. Rating criteria were quality of arterial contrast and image impression. RESULTS: Signal increase in the carotid artery was identical for 10 and 20 ml Gd-BOPTA in 12 patients with optimal bolus timing (10 ml: 454 +/- 58; 20 ml: 458 +/- 63). Signal intensities were significantly lower for 10 ml when bolus timing was suboptimal (281 +/- 80 vs 353 +/- 65; p < 0.02). The quality of the CE-MRA using 10 and 20 ml Gd- BOPTA was rated as identical by the observers, and the amount of contrast medium used could not be deduced from the images. CONCLUSION: Image quality and signal values of the carotid arteries did not differ in CE-MRA performed with either 10 ml or 20 ml Gd-BOPTA (MultiHance) as long as the examination is adequate. Thus, cost reduction can be achieved with a reduced standard dose of 10 ml Gd-BOPTA without loss of diagnostic information.

[Contrast enhanced MR-angiography (CE-MRA): do contrast media with higher T1 relaxation improve imaging of carotid stenoses?]. / Kontrastangehobene MR-Angiographie (CE-MRA): Verbessern Kontrastmittel mit höherer T1-Relaxivität die Darstellung von Karotisstenosen?

PURPOSE: CE-MRA is a powerful tool for the non-invasive evaluation of carotid artery occlusive disease. However, due to certain drawbacks, it has not completely replaced DSA. The purpose of this study was to evaluate if Gd-BOPTA, a contrast agent with high T1 relaxivity, can increase the diagnostic accuracy of CE-MRA. MATERIAL AND METHODS: The CE-MRA examinations of 54 consecutive patients were evaluated by two experienced radiologists, independently. The examinations of 27 patients were contrasted either with 20 ml Gd-BOPTA or with 20 ml Gd-DTPA. The reviewers were blinded to the contrast agent chosen and to the ultrasound results. They rated the overall image quality and the degree of the ICA stenoses. RESULTS: For the estimation of the degree of the ICA stenoses there was a high interrater validity. In comparison to the ultrasound findings, 6 of 50 high-degree stenoses were underestimated as moderate stenoses. In one of seven sonographically occluded vessels, MRA revealed residual patency in the vessel lumen. It was not possible to identify the contrast agent that was taken for a study. Subjective estimation of the image quality (arterial contrast of the ICA, contrast of the other vessels, and general impression) did not significantly change with the contrast agent employed. CONCLUSION: The diagnostic accuracy of CE-MRA for the evaluation of internal carotid artery stenoses is not improved by Gd-BOPTA if identical volumina of contrast media are applied. The potential of this contrast agent can be the reduction of the amount of contrast without loss of diagnostic information. Further studies are necessary.

Objects, decision considerations and self-image in men's and women's impulse purchases.

Current theories in economics, marketing, and psychology fail to explain underlying reasons for impulse buying and, crucially, why certain goods (e.g., clothes) are bought impulsively more than others (e.g., basic kitchen equipment). We propose and examine a social psychological model, which predicts that people impulse buy to acquire material symbols of personal and social identity. We predict that consumers will differ systematically in the goods they buy on impulse, and in their reasons for doing so, depending on their attitudes towards shopping, and also along important social categories, such as gender. Specifically, our theoretical model-drawing on a social constructionist model of material possessions (e.g., Dittmar, 1992) and symbolic self-completion theory (e.g. Wicklund and Gollwitzer, 1982)-leads to three sets of hypotheses: (i) some consumer durables are more likely to be bought on impulse than others, and there may be gender differences in object choices, (ii) differences will emerge in the buying considerations (e.g., functional, emotional, symbolic) that are used for impulse and planned buying, and (iii) magnitude of self-discrepancies will predict relative impulse buying frequency and the buying considerations used, if the individual uses consumption as a self-completion strategy. These predictions were expected to hold particularly strongly for individuals high in compulsive shopping tendencies. We test our model in a questionnaire study with a sample of British consumers (n = 61). The results lend support to all three sets of hypotheses. The implications of these findings are discussed with respect to economic and consumer theory, and the treatment offered to the increasing number of 'addicted' shoppers.

Abnormally adherent placentation: a life-threatening complication.

Two cases are presented illustrating the potential danger of abnormal placentation. Placenta accreta is frequently associated with placenta praevia and/or a history of previous caesarean section. As there are no obvious specific symptoms before or during delivery, one should consider the possibility of this anomaly in the third stage of labour when manual removal of the placenta is very arduous. The treatment of choice is immediate abdominal hysterectomy, for this is followed by the lowest maternal mortality. If abnormal placentation is suspected, one should be prepared to deal with it as necessitated, including the possible performance of an emergency caesarean hysterectomy.

Single-dose prophylaxis in gynaecological surgery: amoxycillin/clavulanic acid versus the combination of cefuroxim and metronidazole in a randomized prospective comparison.

A prospective randomized study was conducted comparing a single 2.2 g preoperative dose amoxycillin/clavulanic acid with a regimen of 1.5 g cefuroxim combined with 0.5 g metronidazole. Two hundred and fifty-one women were evaluated in this comparative study. The febrile morbidity, the incidence of urinary tract infections and the hospital stay were similar in both regimens. A single preoperative dose of amoxycillin/clavulanic acid was as effective as a combined regimen of cefuroxim and metronidazole and less expensive.

Central pontine myelinolysis in a normonatraemic alcoholic patient.

Central pontine myelinolysis (CPM) is a rare disease which has been associated with hyponatraemia and its rapid correction. We describe a malnourished 32-year-old alcohol-dependent woman suffering from an infection who had developed CPM without any known prior derangement in serum electrolytes or its iatrogenic correction. Computerized tomography (CT) and magnetic resonance imaging (MRI) played an important role in the diagnosis. Even when an electrolyte derangement is absent, alcoholism, malnourishment and infection should be considered as important possible aetiological factors of CPM.

Congenital bilateral perisylvian syndrome (CBPS): do concomitant esophageal malformations indicate a poor prognosis?

Congenital bilateral perisylvian syndrome (CBPS) is a syndrome of cortical malformation characterized by faciopharyngoglossomasticatory diplegia. We report on two cases of CBPS with associated esophageal malformations and a poor mental and motor development. The association of CBPS and esophageal malformations may indicate a subgroup of patients with a very early prenatal injury, characterised by a bad prognosis due to severe cortical disorganization. However, it can not be excluded that the association of CBPS and esophageal malformation is purely coincidental.

[Not Available]. / Medulloblastom des Kleinhirnwurms mit Liquorraumaussaat Ungewöhnliche klinische und MRT-Präsentation : Ungewöhnliche klinische und MRT-Präsentation.

Medulloblastoma, the most frequent pediatric brain tumor, has known propensity for subarachnoid dissemination. Spinal metastases indicate a poor prognosis. Intraventricular spread is much less common.We report a case of primary intraventricular dissemination with precocious puberty as the first clinical symptom due to a metastasis at the infundibulary stalk. This has not been reported so far as initial symptom of a medulloblastoma. Furthermore, we encountered an unusually mild contrast enhancement of the spinal and intraventricular metastases. Delayed scanning after contrast administration and FLAIR sequences proved to be particularly valuable in this case.