Noninvasive grading of untreated gliomas: a comparative study of MR imaging and 3-(iodine 123)-L-alpha-methyltyrosine SPECT

PURPOSE: To compare the accuracy of magnetic resonance (MR) imaging scores with that of 3-(iodine 123)-L-alpha-methyltyrosine ((123)I-IMT) single photon emission computed tomography (SPECT) in the noninvasive grading of untreated gliomas. MATERIALS AND METHODS: The study comprised 15 patients with low-grade gliomas (grades I-II, according to World Health Organization criteria) and 33 patients with high-grade gliomas (grades III-IV). The lesions were evaluated by using an MR imaging score based on nine criteria. The (123)I-IMT uptake was quantified as the ratio between the amino acid uptake in the tumor and that in the contralateral hemisphere. To test for potentially significant differences in diagnostic performance between contrast material-enhanced MR imaging and (123)I-IMT SPECT, binormal receiver operating characteristic curves were fitted to the data and compared by using the area test. RESULTS: The accuracy of MR imaging in the noninvasive grading of untreated gliomas was higher than that of (123)I-IMT SPECT (88% vs 79%). However, the difference in diagnostic performance was not significant on the basis of findings at receiver operating characteristic analysis (P >.2). Neither MR imaging nor (123)I-IMT SPECT allowed differentiation between high-grade gliomas (grades III and IV). CONCLUSION: Although (123)I-IMT uptake is significantly higher in high-grade gliomas than in low-grade gliomas, the performance of (123)I-IMT SPECT adds little to the accuracy of determining tumor grade when MR imaging is performed.     

3-[123I]Iodo-L-alpha-methyl tyrosine transport into human fibroblasts and comparison with Ewing's sarcoma cells

The cellular transport systems and the transport kinetics of [123I]IMT uptake into non-malignant extracranial cells were characterized for the first time. Human fibroblasts were chosen as non-malignant extracranial cells as they are found ubiquitous in the body. [123I]IMT is exclusively transported into fibroblasts via the sodium independent system L. An apparent Michaelis constant K(m) = 116.2 +/- 18.9 microM and a maximum transport velocity V(max) = 191.6 +/- 13.9 pmol x (10(6) cells)(-1) x min(-1) were calculated for the sodium-independent transport. These results were compared with those determined in two malignantly transformed extracranial cell lines, the human Ewing's sarcoma cell lines VH-64 and CADO-ES-1.     

Korean hand acupressure for motion sickness in prehospital trauma care: a prospective, randomized, double-blinded trial in a geriatric population

Patients with trauma or medical illnesses transported to the hospital by ambulance have a frequent incidence of motion sickness. Because the administration of drugs in the ambulance is prohibited by law in Austria, the noninvasive Korean hand acupressure point at K-K9 may be an alternative against nausea and vomiting. We enrolled 100 geriatric patients with minor trauma, randomizing them into a K-K9 group and a sham acupressure group. We recorded visual analog scores (VAS) for nausea and for the patient's overall satisfaction with the treatment, hemodynamic variables, and peripheral vasoconstriction. In the K-K9 group, a significant (P < 0.01) increase in nausea was recorded in all cases: from VAS of 0 mm to 25 +/- 6 mm. A similarly significant (P < 0.01) increase was registered in the sham group: from VAS of 0 mm to 83 +/- 8 mm. However, at the time of arrival in the hospital, nausea scores were significantly different between the K-K9 group and the sham group (P < 0.01). Although all patients had been vasoconstricted at the emergency site before treatment, there was a significant difference (P < 0.01) between groups with regard to the number of vasoconstricted patients at the hospital (4 and 46 constricted and dilated, respectively, in the K-K9 group versus 48 and 2 constricted and dilated, respectively, in the sham group). On arrival in the hospital, a significant difference (P < 0.01) in heart rate was noted between the K-K9 group and the sham group (65 +/- 6 bpm versus 98 +/- 8 bpm). The patients' overall satisfaction with the provided care was significantly higher (P < 0.01) in the K-K9 group (19 +/- 9 mm VAS) than in the sham group (48 +/- 12 mm VAS). Neither group experienced a significant change in blood pressure. K-K9 stimulation was an effective and simple treatment for nausea during emergency care and significantly improved patient satisfaction. IMPLICATIONS: Korean hand acupressure at the K-K9 point was effective in reducing nausea and subjective symptoms of motion sickness in emergency trauma transport of patients at high risk of motion sickness.     

Interactions between endothelin and nitric oxide in the regulation of vascular tone in obesity and diabetes

Endothelial dysfunction reflects an imbalance of vasodilators and vasoconstrictors. Endogenous endothelin activity seems to be increased in human obesity and type 2 diabetes, and cellular studies suggest that this factor may itself reduce bioavailable nitric oxide (NO). We studied 20 lean, 20 obese, and 14 type 2 diabetic individuals under three protocols, measuring leg vascular responses to intra-arterial infusions of NG-monomethyl-l-arginine (l-NMMA; an inhibitor of NO synthase) alone or in combination with BQ123 (an antagonist of type A endothelin receptors) or phentolamine (used as a control vasodilator). NO synthase inhibition alone (study 1) produced an approximately 40% increase in leg vascular resistance (LVR) in all three participant groups, which was not statistically different across groups (increase in LVR: lean, 135 +/- 28; obese, 140 +/- 32; type 2 diabetic, 184 +/- 51 units; NS). By design, BQ123 at the infused rate of 3 micromol/min produced equivalent approximately 35% reductions in LVR across groups. The subsequent addition of l-NMMA produced a greater increase in LVR among obese participants than lean or type 2 diabetic participants (study 2: lean, 182 +/- 48; obese, 311 +/- 66; type 2 diabetic, 186 +/- 40; P = 0.07). Compared with study 1, the effect of l-NMMA was magnified by BQ123 in obese participants but not in lean or type 2 diabetic participants (P = 0.005, study 1 vs. 2; P = 0.03 for group effect). Phentolamine (75 mg/min) produced vasodilation in obese participants comparable to that seen with BQ123 but failed to augment the L-NMMA response. Endothelin antagonism unmasks or augments NO synthesis capacity in obese but not type 2 diabetic participants. This suggests that impaired NO bioavailability as a result of endogenous endothelin may contribute to endothelial dysfunction in obesity, in addition to direct vasoconstrictor effects of endothelin. In contrast, endothelin antagonism alone is insufficient to restore impaired NO bioavailability in diabetes.     

Comparison of hydraulic and hemolytic properties of different impeller designs of an implantable rotary blood pump by computational fluid dynamics

A mixed-flow blood pump for long-term applications has been developed at the Helmholtz-Institute in Aachen, Germany. Central features of this implantable pump are a centrally integrated motor, a blood-immersed mechanical bearing, magnetic coupling of the impeller, and a shrouded impeller, which allows a relatively wide clearance. The aim of the study was a numerical analysis of hydraulic and hemolytic properties of different impeller design configurations. In vitro testing and numerical simulation techniques (computational fluid dynamics [CFD]) were applied to achieve a comprehensive overview. Pressure-flow charts were experimentally measured in a mock loop in order to validate the CFD data. In vitro hemolysis tests were performed at the main operating point of each impeller design. General flow patterns, pressure-flow charts, secondary flow rates, torque, and axial forces on the impeller were calculated by means of CFD. Furthermore, based on streak line techniques, shear stress (stress loading), exposure times, and volume percentage with critical stress loading have been determined. Comparison of CFD data with pressure head measurements showed excel-lent agreement. Also, impressive trend conformity was observed between in-vitro hemolysis results and numerical data. Comparison of design variations yielded clear trends and results. Design C revealed the best hydraulic and hemolytic properties and was chosen as the final design for the mixed-flow rotary blood pump.     

Surgical epicardial left ventricular lead versus coronary sinus lead placement in biventricular pacing.

OBJECTIVE: Biventricular pacing has demonstrated improvement in cardiac function in treating congestive heart failure (CHF). Two different operative strategies (coronary sinus vs. epicardial stimulation) for left ventricular (LV) pacing were compared. METHODS: Since April 1999, a total of 86 patients (pts, age: 63+/-10 years) with depressed systolic LV function (mean ejection fraction 24+/-9%), left bundle-branch-block (mean QRS 182+/-22 ms) and congestive heart failure NYHA III or higher were enrolled. For biventricular stimulation coronary sinus (CS) leads were placed in 79 pts. Nine of these devices were converted to surgical epicardial LV-leads, because of CS-lead failure. In 7 patients epicardial LV-leads were initially implanted surgically, accounting for a total of 16 pts with surgical placed epicardial steroid-eluting LV-leads. For these, a limited left-lateral thoracotomy (7+/-4 cm) was used. Thirty-three (38%) pts had an indication for a defibrillator. The mean follow-up time was 16.4+/-15.4 months (0.1-45 months), representing 107.1 patient-years. RESULTS: In the biventricular pacing mode, QRS duration decreased to 143+/-16 ms (P<0.001). Threshold capture of the CS-leads increased significantly compared to surgically placed epicardial leads (18 month control: 2.2+/-1.4V/0.5 ms vs. 0.7+/-0.3V/0.5 ms), which had no increase in threshold (P<0.001). At the 18 month follow-up 7 CS-leads had a threshold of >4V/0.5 ms vs. epicardial leads which were under 1.1V/0.5 ms, except for one (1.8V/0.5 ms). After CS-lead implantation 25 LV-lead related complications occurred, (failed implantation, CS-dissection, loss of pacing capture, diaphragm stimulation or lead dislodgment), vs. one dislodgement after surgical epicardial lead placement (P<0.05). Correct lead positioning (obtuse marginal branch area) was achieved in all surgical epicardial placements but only in 70% with CS-leads (P<0.03). In the follow up period, 9 pts died (4 cardiac related). Heart transplantation was necessary in 4 pts due to deterioration of the cardiomyopathy. CONCLUSIONS: Surgical epicardial lead placement revealed excellent long-term results and a lower LV-related complication rate compared to CS-leads. Although, the approach via limited thoracotomy for biventricular pacing is associated with 'more surgery', it is a safe and reliable technique and should be considered as an equal alternative.     

Cortical Thinning Correlates with Cognitive Change in Multiple Sclerosis but not in Neuromyelitis Optica

Objectives

To compare spatial patterns of cortical thickness alterations in neuromyelitis optica (NMO) and multiple sclerosis (MS); and to investigate the correlations between cortical thinning and clinical variables in NMO and MS.

Methods

We studied 23 patients with NMO, 27 patients with MS and 26 healthy controls (HCs). The global, brain region and vertex-based cortical thickness (CTh) were analysed and compared among the three groups. A general linear model was used to investigate the correlations between cortical thinning and clinical measures.

Results

A limited number of cortical regions in visual cortex were found to be significantly thinner in NMO patients than in HCs. The MS patients exhibited more widespread cortical thinning compared with HCs, and significantly greater cortical thinning in the insula and the parahippocampus compared with NMO. The extent of cortical thinning in several brain regions correlated with cognitive measures in MS, but not in NMO.

Conclusions

Neocortical thinning in NMO mainly affects visual cortex, while MS patients show much more extensive cortical thinning. Cognitive changes are correlated with cortical atrophy in MS not in NMO. The substrates of cognitive changes in MS and NMO could therefore be different.

Key Points

? MS patients show much more extensive cortical thinning than NMO. ? Cortical thinning of insula and parahippocampus particularly distinguishes MS from NMO. ? Cognitive changes are correlated with cortical atrophy in MS but not in NMO.     

Gallstone ileus: rare and still controversial

BACKGROUND: Gallstone ileus is a rare disease and accounts for about 1-3% of mechanic ileus of the small bowel, but for 25% of all small bowel obstructions in patients older than 65 years. Concomitant cardiorespiratory diseases or diabetes are frequent in older patients and responsible for the high mortality rate. The aim of the present study was to evaluate and discuss different surgical approaches and to analyze the clinical outcome. METHODS: Four patients with a mean age of 72 years were treated for gallstone ileus at our hospital in the last 10 years. Patients history, operative strategy and their outcome is elucidated and a review of the recent literature is given. RESULTS: In all patients the operative strategy was a one-stage procedure including enterolithotomy, cholecystectomy and closure of the fistula. The 30-day mortality rate was 25%. CONCLUSION: One-stage procedure prevents from cholangitis, cholecystitis and recurrent ileus caused by further gallstones but bears the risk of enteric or biliary leakage after fistula closure. It should therefore be reserved for patients presenting in good general condition with a low degree of cholecystitis.