TMPRSS2:ERG gene fusion associated with lethal prostate cancer in a watchful waiting cohort

The identification of the TMPRSS2:ERG fusion in prostate cancer suggests that distinct molecular subtypes may define risk for disease progression. In surgical series, TMPRSS2:ERG fusion was identified in 50% of the tumors. Here, we report on a population-based cohort of men with localized prostate cancers followed by expectant (watchful waiting) therapy with 15% (17/111) TMPRSS2:ERG fusion. We identified a statistically significant association between TMPRSS2:ERG fusion and prostate cancer specific death (cumulative incidence ratio=2.7, P<0.01, 95% confidence interval=1.3-5.8). Quantitative reverse-transcription-polymerase chain reaction demonstrated high ets-related [corrected] gene (ERG) expression to be associated with TMPRSS2:ERG fusion (P<0.005). These data suggest that TMPRSS2:ERG fusion prostate cancers may have a more aggressive phenotype, possibly mediated through increased ERG expression.

NF-kappaB inhibition ameliorates angiotensin II-induced inflammatory damage in rats

We recently reported that the activation of nuclear factor-kappaB (NF-kappaB) promotes inflammation in rats harboring both human renin and angiotensinogen genes (double-transgenic rats [dTGR]). We tested the hypothesis that the antioxidant pyrrolidine dithiocarbamate (PDTC) inhibits NF-kappaB and ameliorates renal and cardiac end-organ damage. dTGR feature hypertension, severe renal and cardiac damage, and a 40% mortality rate at 7 weeks. Electrophoretic mobility shift assay showed increased NF-kappaB DNA binding activity in hearts and kidneys of dTGR. Chronic PDTC (200 mg/kg SC) treatment decreased blood pressure (162+/-8 versus 190+/-7 mm Hg; P=0.02) in dTGR compared with dTGR controls. The cardiac hypertrophy index was also significantly reduced (4.90+/-0.1 versus 5.77+/-0.1 mg/g; P<0. 001). PDTC reduced 24-hour albuminuria by >95% (2.5+/-0.8 versus 57. 1+/-8.7 mg/d; P<0.001) and prevented death. Vascular injury was ameliorated in small renal and cardiac vessels. Electrophoretic mobility shift assay showed that PDTC inhibited NF-kappaB binding activity in heart and kidney, whereas AP-1 activity in the kidney was not decreased. dTGR exhibited increased left ventricular c-fos and c-jun mRNA expression. PDTC treatment reduced c-fos but not c-jun mRNA. Immunohistochemistry showed increased p65 NF-kappaB subunit expression in the endothelium and smooth muscle cells of damaged small vessels, as well as infiltrating cells in glomeruli, tubules, and collecting ducts of dTGR. PDTC markedly reduced the immunoreactivity of p65. PDTC also prevented the NF-kappaB-dependent transactivation of the intercellular adhesion molecule ICAM-1 and inducible nitric oxide synthase. Monocyte infiltration was markedly increased in dTGR kidneys and hearts. Chronic treatment reduced monocyte/macrophage infiltration by 72% and 64%, respectively. Thus, these results demonstrate that PDTC inhibits NF-kappaB activity, ameliorates inflammation, and protects against angiotensin II-induced end-organ damage.

Magnetic metamaterials at telecommunication and visible frequencies

Arrays of gold split rings with a 50-nm minimum feature size and with an LC resonance at 200 THz frequency (1.5 microm wavelength) are fabricated. For normal-incidence conditions, they exhibit a pronounced fundamental magnetic mode, arising from a coupling via the electric component of the incident light. For oblique incidence, a coupling via the magnetic component is demonstrated as well. Moreover, we identify a novel higher-order magnetic resonance at around 370 THz (800 nm wavelength) that evolves out of the Mie resonance for oblique incidence. Comparison with theory delivers good agreement and also shows that the structures allow for a negative magnetic permeability.

Bone-muscle strength indices for the human lower leg

This cross-sectional study is based on images from the lower leg as assessed by peripheral quantitative computer tomography (pQCT). Measurements were performed in 39 female and 38 male control subjects and 15 female professional volleyball players, all between 18 and 30 years of age. The images were obtained at shank levels of 4%, 14%, 33%, and 66% from the distal end. Bone and muscle cross-sectional areas, and the bones' density-weighted area moment of resistance and of inertia were assessed. From these, muscle-bone strength indices (MBSIs) were developed for compression (CI = 100. bone area/muscle area) and bending (BI = 100. bone area moment of resistance/muscle area/tibia length). Significant correlations between muscle cross-sectional area and bone were found at all section levels investigated. The strongest correlation for compression was observed in the sections at 14% (correlation coefficient r = 0.74), where 4.10 +/- 0.46 cm(2) bone, on average, was related to 100 cm(2) muscle. The compression index (CI) at the 14% level was independent of the tibia length. Interestingly, the 15 athletes had significantly greater CIs than the control subjects. This is most probably due to the greater tension development in the athletes. The highest correlation for bending was for anteroposterior bending at 33% of tibia length (r = 0.81), where the area moment of resistance, R, was on, average, 4.21 +/- 0.54 cm(3)/100 cm(2) muscle/m tibia length. Analysis of the bones' area moment of inertia showed that buckling is a possible cause of bending at the 33% and 66% levels, but not at the 14% level. No gender differences in MBSI were found. Likewise, age was without significant effect. The data show that bone architecture depends critically on muscle cross section and tension development. Moreover, bone geometry (e.g., the tibia length) influences the geometrical distribution of bone mineral, as it was found that long bones adapted to the same compressive strength are wider than short ones. We conclude that MBSIs offer a powerful diagnostic tool for bone disorders and may contribute to improving the treatment of bone metabolic and other diseases.

Positron emission tomography with [(18)F]fluoro-2-deoxy-D-glucose for diagnosis and staging of bile duct cancer

Malignant tumors with high glucose metabolic rates accumulate [18F]-fluorodeoxyglucose (FDG), a positron emitting tracer. The aim of this study was to evaluate FDG positron emission tomography (PET) for detection and staging of human cholangiocarcinoma (CC). Patients with adenocarcinoma of the biliary tree (n = 26), with benign lesions of the bile ducts (n = 8), and 20 control patients underwent FDG-PET (370 MBq [18F]-FDG, Siemens ECAT EXACT HR(+)). In a blinded fashion, 4 independent experts evaluated the PET scans visually and semiquantitatively using the standardized uptake value and a tumor/non-tumor ratio. All adenocarcinomas and benign lesions (sclerosing cholangitis, bile duct adenoma, Caroli's disease) were histologically proven and imaged by magnetic resonance imaging and endoscopic retrograde cholangioscopy. True-positive PET scans were obtained in 24 of 26 CC and false-negative scans in the other 2 (sensitivity 92.3%). The PET scan was true-negative in 18 of 20 controls and in all 8 benign biliary lesions (specificity 92.9%). Visual and semiquantitative evaluation using tumor/non-tumor ratios were equally accurate (accuracy 92.6%) whereas evaluation by standardized uptake value revealed lower accuracy (P <.05). Regional or hepatoduodenal lymph node metastases were detected with PET in only 2 of 15 cases whereas distant metastases (peritoneal carcinomatosis, pulmonary metastases) were diagnosed in 7 of 10 cases. In conclusion, PET is highly sensitive and specific for the detection and localization of CC. It can be helpful for diagnosis of distant metastases but is not suitable for detection of regional lymph node metastases.

Photodynamic therapy for advanced bile duct cancer: evidence for improved palliation and extended survival

Median survival time of nonresectable hilar bile duct cancer is only 4 to 6 months owing to tumor spread in the biliary tree, refractory cholestasis, and sepsis or liver failure. We explored whether local photodynamic therapy of nonresectable bile duct cancer could improve survival. A sample size of 23 patients is required to detect an increase in 6-month survival rate from less than 50% to greater than 70% in a single-arm phase-II trial with a statistical power of 80% (Fleming's single step procedure; alpha = 0.05). Twenty-three consecutive patients (8 women, 15 men; 67 +/- 14 years) with nonresectable bile duct cancer (Bismuth type III n = 2, type IV n = 21) were treated with photodynamic therapy and biliary endoprosthesis. Photofrin (QLT Pharmaceuticals, Vancouver, Canada) (2 mg/kg body weight intravenously) was photoactivated after 1 to 4 days with laser light (630 nm; 242 J/cm(2)) via endoscopic retrograde access. The 6-month survival rate was 91% after diagnosis and 74% after start of photodynamic therapy (30-day mortality rate was 4%) at a median follow-up time of 10.3 months after diagnosis. Causes of death were tumor progression (n = 9) and bacterial infections (n = 4). The median rate of local tumor response was 74%, 54%, 29%, and 67% after the first, second, third, fourth, and fifth photodynamic therapy. Time to progression ranged from 3 to 8 months. All patients, except 1 with diffuse liver metastases, improved in cholestasis, performance, and quality of life. Photodynamic therapy can prevent tumor occlusion of hilar bile ducts. The apparent benefit in survival time should be confirmed in a controlled trial versus palliation by endoprosthesis only.

Monocyte infiltration and adhesion molecules in a rat model of high human renin hypertension

Hypertension and kidney damage in the double transgenic rat (dTGR) harboring both human renin and human angiotensinogen genes are dependent on the human components of the renin angiotensin system. We tested the hypothesis that monocyte infiltration and increased adhesion molecule expression are involved in the pathogenesis of kidney damage in dTGR. We also evaluated the effects of long-term angiotensin-converting enzyme (ACE) inhibition, AT1 blockade, and human renin inhibition on monocyte recruitment and inflammatory response in dTGR. Systolic blood pressure and 24-hour albuminuria were markedly increased in 7-week-old dTGR as compared with age-matched normotensive Sprague Dawley rats. We found a significant monocyte/macrophage infiltration in the renal perivascular space and increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the interstitium, intima, and adventitia of the small renal vessels. alphaLbeta2 integrin and alpha4beta1 integrin, the corresponding ligands for ICAM-1 and VCAM-1, were also found on infiltrating monocytes/macrophages. The expression of plasminogen activator inhibitor-1 and fibronectin in the kidneys of dTGR were increased and distributed similarly to ICAM-1. In 4-week-old dTGR, long-term treatment with ACE inhibition (cilazapril), AT1 receptor blockade (valsartan), and human renin inhibition (RO 65-7219) (each drug 10 mg/kg by gavage once a day for 3 weeks) completely prevented the development of albuminuria. However, only cilazapril and valsartan were able to decrease blood pressure to normotensive levels. Interestingly, the drugs were all equally effective in preventing monocyte/macrophage infiltration and the overexpression of adhesion molecules, plasminogen activator inhibitor-1, and fibronectin in the kidney. Our findings indicate that angiotensin II causes monocyte recruitment and vascular inflammatory response in the kidney by blood pressure-dependent and blood pressure-independent mechanisms. ACE inhibition, AT1 receptor blockade, and human renin inhibition all prevent monocyte/macrophage infiltration and increased adhesion molecule expression in the kidneys of dTGR.

Mineralocorticoid receptor affects AP-1 and nuclear factor-kappab activation in angiotensin II-induced cardiac injury

Aldosterone is implicated in cardiac hypertrophy and fibrosis. We tested the role of the mineralocorticoid receptor in a model of angiotensin II-induced cardiac injury. We administered spironolactone (SPIRO; 20 mg. kg(-1). d(-1)), valsartan (VAL; 10 mg. kg(-1). d(-1)), or vehicle to rats double transgenic for the human renin and angiotensinogen genes (dTGR). We investigated basic fibroblast growth factor (bFGF), platelet-derived growth factor, transforming growth factor-beta(1), and the transcription factors AP-1 and nuclear factor (NF)-kappaB. We used immunohistochemistry, electrophoretic mobility shift assays, and TaqMan RT-PCR. Untreated dTGR developed hypertension, cardiac hypertrophy, vasculopathy, and fibrosis with a 50% mortality rates at 7 weeks. SPIRO and VAL prevented death and reversed cardiac hypertrophy, while only VAL normalized blood pressure. Both drugs prevented vasculopathy. bFGF was markedly upregulated in dTGR, whereas platelet-derived growth factor-B and transforming growth factor-beta(1) were little changed. VAL and SPIRO suppressed this upregulation. Both AP-1 and NF-kappaB were activated in dTGR compared with controls. VAL and SPIRO reduced both transcription factors and reduced bFGF, collagen I, fibronectin, and laminin in the interstitium. These findings show that aldosterone promotes hypertrophy, cardiac remodeling, and fibrosis, independent of blood pressure. The effects involve AP-1, NF-kappaB, and bFGF. Mineralocorticoid receptor blockade downregulates these effectors and reduces angiotensin II-induced cardiac damage.

Cerivastatin prevents angiotensin II-induced renal injury independent of blood pressure- and cholesterol-lowering effects

BACKGROUND

Statins are effective in prevention of end-organ damage; however, the benefits cannot be fully explained on the basis of cholesterol reduction. We used an angiotensin II (Ang II)-dependent model to test the hypothesis that cerivastatin prevents leukocyte adhesion and infiltration, induction of inducible nitric oxide synthase (iNOS), and ameliorates end-organ damage.

METHODS

We analyzed intracellular targets, such as mitogen-activated protein kinase and transcription factor (nuclear factor-kappaB and activator protein-1) activation. We used immunohistochemistry, immunocytochemistry, electrophoretic mobility shift assays, and enzyme-linked immunosorbent assay techniques. We treated rats transgenic for human renin and angiotensinogen (dTGR) chronically from week 4 to 7 with cerivastatin (0.5 mg/kg by gavage).

RESULTS

Untreated dTGR developed hypertension, cardiac hypertrophy, and renal damage, with a 100-fold increased albuminuria and focal cortical necrosis. dTGR mortality at the age of seven weeks was 45%. Immunohistochemistry showed increased iNOS expression in the endothelium and media of small vessels, infiltrating cells, afferent arterioles, and glomeruli of dTGR, which was greater in cortex than medulla. Phosphorylated extracellular signal regulated kinase (p-ERK) was increased in dTGR; nuclear factor-kappaB and activator protein-1 were both activated. Cerivastatin decreased systolic blood pressure compared with untreated dTGR (147 +/- 14 vs. 201 +/- 6 mm Hg, P < 0.001). Albuminuria was reduced by 60% (P = 0.001), and creatinine was lowered (0.45 +/- 0.01 vs. 0.68 +/- 0.05 mg/dL, P = 0. 003); however, cholesterol was not reduced. Intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression was diminished, while neutrophil and monocyte infiltration in the kidney was markedly reduced. ERK phosphorylation and transcription factor activation were reduced. In addition, in vitro incubation of vascular smooth muscle cells with cerivastatin (0.5 micromol/L) almost completely prevented the Ang II-induced ERK phosphorylation.

CONCLUSION

Cerivastatin reduced inflammation, cell proliferation, and iNOS induction, which led to a reduction in cellular damage. Our findings suggest that 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase inhibition ameliorates Ang II-induced end-organ damage. We suggest that these effects were independent of cholesterol.

Hypertension-induced end-organ damage : A new transgenic approach to an old problem

Angiotensin (Ang) II-induced organ damage has fascinated students of hypertension since the work of Wilson and Byrom. We are investigating a double transgenic rat (dTGR) model, in which rats transgenic for the human angiotensinogen and renin genes are crossed. These rats develop moderately severe hypertension but die of end-organ cardiac and renal damage by week 7. The heart shows necrosis and fibrosis, whereas the kidneys resemble the hemolytic-uremic syndrome vasculopathy. Surface adhesion molecules (ICAM-1 and VCAM-1) are expressed early on the endothelium, while the corresponding ligands are found on circulating leukocytes. Leukocyte infiltration in the vascular wall accompanies PAI-1, MCP-1, and VEGF expression. The expression of TGF-beta and deposition of extracellular matrix proteins follows, which is accompanied by fibrinoid vasculitis in small vessels of the heart and kidneys. Angiotensin-converting enzyme inhibitors and AT1 receptor blockers each lowered blood pressure and shifted pressure natriuresis partially leftward by different mechanisms. When combined, they normalized blood pressure, pressure natriuresis, and protected from vasculopathy completely. Renin inhibition lowered blood pressure partially, but protected from vasculopathy completely. Endothelin receptor blockade had no influence on blood pressure but protected from vasculopathy and improved survival. We show evidence that Ang II stimulates oxidative stress directly or indirectly via endothelin 1 and that NFkappaB is upregulated in this model. We speculate that the transcription factors NFkappaB and AP-1 are involved with initiating chemokine and cytokine expression, leading to the above cascade. The unique model and our pharmacological probes will enable us to test these hypotheses.

Post-invasion events after infection with Staphylococcus aureus are strongly dependent on both the host cell type and the infecting S. aureus strain

Host cell invasion is a major feature of Staphylococcus aureus and contributes to infection development. The intracellular metabolically active bacteria can induce host cell activation and death but they can also persist for long time periods. In this study a comparative analysis was performed of different well-characterized S. aureus strains in their interaction with a variety of host cell types. Staphylococcus aureus (strains 6850, USA300, LS1, SH1000, Cowan1) invasion was compared in different human cell types (epithelial and endothelial cells, keratinocytes, fibroblasts, osteoblasts). The number of intracellular bacteria was determined, cell inflammation was investigated, as well as cell death and phagosomal escape of bacteria. To explain strain-dependent differences in the secretome, a proteomic approach was used. Barrier cells took up high amounts of bacteria and were killed by aggressive strains. These strains expressed high levels of toxins, and possessed the ability to escape from phagolysosomes. Osteoblasts and keratinocytes ingested less bacteria, and were not killed, even though the primary osteoblasts were strongly activated by S. aureus. In all cell types S. aureus was able to persist. Strong differences in uptake, cytotoxicity, and inflammatory response were observed between primary cells and their corresponding cell lines, demonstrating that cell lines reflect only partially the functions and physiology of primary cells. This study provides a contribution for a better understanding of the pathomechanisms of S. aureus infections. The proteomic data provide important basic knowledge on strains commonly used in the analysis of S. aureus-host cell interaction.

Effect of bosentan on NF-kappaB, inflammation, and tissue factor in angiotensin II-induced end-organ damage

Reports on the effectiveness of endothelin receptor blockers in angiotensin (Ang) II-induced end-organ damage are conflicting, and the mechanisms involved are uncertain. We tested the hypothesis that endothelin (ET)(A/B) receptor blockade with bosentan (100 mg/kg by gavage after age 4 weeks) ameliorates cardiac and renal damage by decreasing inflammation in rats harboring both human renin and angiotensinogen genes (dTGR). Furthermore, we elucidated the effect of bosentan on tissue factor (TF), which is a key regulator of the extrinsic coagulation cascade. We compared bosentan with hydralazine (80 mg/L in the drinking water for 3 weeks) as a blood pressure control. Untreated dTGR featured hypertension, focal necrosis in heart and kidney, and a 45% mortality rate (9 of 20) at age 7 weeks. Compared with Sprague-Dawley controls, both systolic blood pressure and 24-hour albuminuria were increased in untreated dTGR (203+/-8 versus 111+/-2 mm Hg and 67.1+/-8.6 versus 0.3+/-0.06 mg/d at week 7, respectively). Bosentan and hydralazine both reduced blood pressure and cardiac hypertrophy. Mortality rate was markedly reduced by bosentan (1/15) and partially by hydralazine (4/15). However, only bosentan decreased albuminuria and renal injury. Untreated and hydralazine-treated dTGR showed increased nuclear factor (NF)-kappaB and AP-1 expression in the kidney and heart; the p65 NF-kappaB subunit was increased in the endothelium, vascular smooth muscles cells, infiltrating cells, glomeruli, and tubules. In the heart and kidney, ET(A/B) receptor blockade inhibited NF-kappaB and AP-1 activation compared with hydralazine treatment. Macrophage infiltration, ICAM-1 expression, and the integrin expression on infiltrating cells were markedly reduced. Renal vasculopathy was accompanied by increased tissue factor expression on macrophages and vessels of untreated and hydralazine-treated dTGR, which was markedly reduced by bosentan. Thus, ET(A/B) receptor blockade inhibits NF-kappaB and AP-1 activation and the NF-kappaB- and/or AP-1-regulated genes ICAM-1, VCAM-1, and TF, independent of blood pressure-related effects. We conclude that Ang II-induced NF-kappaB and AP-1 activation and subsequent inflammation and coagulation involve at least in part the ET(A/B) receptors.

[Ac-D-NAL(2)1,4FD-Phe2,D-Trp3,D-Arg6]-LHRH, a potent antagonist of LHRH, produces transient edema and behavioral changes in rats

Acute toxicity studies of [Ac-D-NAL(2)1,4FD-Phe2,D-Trp3,D-Arg6]-LHRH (LHRH-A), a potent antagonist of LHRH were performed. Subcutaneous administration of this peptide to rats induced transient edema of the face and extremities. This effect was maximal 3-5 h after peptide administration and subsided by 24 h. These effects were not seen with an LHRH agonist or two other antagonists. This side effects of LHRH-A was peculiar to rats and not observed in mice, rabbits and rhesus monkeys. Intravenous administration led within minutes to depression of spontaneous activity in rats and monkeys. We conclude that some LHRH antagonists produce species specific effects on vascular permeability and spontaneous activity.

Acute effects of recombinant human interleukin-6 on endocrine and central nervous sleep functions in healthy men

Interleukin-6 (IL-6) is a proinflammatory cytokine that has been shown to mediate, in addition to immune reactions, various endocrine and central nervous components of the acute phase response. In this context, the present study aimed to specify the contributions of IL-6 to the regulation of pituitary-adrenal secretory activity and GH and TSH secretion, as well as to the regulation of central nervous sleep and mood in healthy men. Effects of a low dose of IL-6 (0.5 microgram/kg body weight) were assessed, inducing plasma IL-6 concentrations closely comparable with those typically observed after infectious challenge. Each of the 16 male subjects participated in two 14-h sessions (between 1800 and 0800 h), receiving either placebo or human recombinant IL-6 sc at 1900 h. Blood was collected repeatedly to determine plasma hormone levels, serum concentrations of cytokines, and C-reactive protein. Moreover, mood was assessed, and sleep recordings were obtained between 2300 and 0700 h. The cytokine induced a prolonged increased in plasma concentrations of ACTH and cortisol (P < 0.001), but led to a decrease in TSH concentrations (P < 0.01). In response to IL-6, subjects reported fatigue and felt more inactive and less capable of concentrating than after placebo. Sleep architecture was altered significantly by the cytokine. Slow-wave sleep was decreased during the first half and increased during the second half of sleep. Rapid eye movement sleep during the entire nocturnal sleep time was significantly decreased. After IL-6, body temperature rose slightly. C-reactive protein concentrations were dramatically increased 12.5 h after substance administration (P < 0.001). IL-6 did not affect serum concentrations of IL-2, IL-8, interferon-alpha, and interferon-gamma. The results underscore the importance of IL-6 in the cascade of cytokines for the neuroendocrine response during the acute phase reaction. In addition, IL-6 appears to be involved in changes of sleep and behavior accompanying infection and inflammatory disorders.

Open MRI-guided neurosurgery

OBJECTIVES

A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively.

MATERIAL AND METHOD

The first vertical open 0.5T MRI-scanner for intra-operative MRI-guided neurosurgery in Germany was installed at the University of Leipzig during the summer 1996. Since autumn 1996 a number of surgical procedures including biopsies (n = 31), craniotomies (n = 32), transsphenoidal procedures (n = 8) and interstitial lasertherapies (n = 3) have been performed using intra-operative MR image guidance.

RESULTS

The development of MR-compatible and MR-safe non-magnetic instruments and components had to be solved. Specific surgical instruments were developed to perform biopsies, craniotomies, microsurgical tumour resections and transsphenoidal procedures in the 0.5-T open MRI. Several components required adaptation including the head holder the stereotactic navigation device, the high speed drill, the suction unit, the ultrasonic aspirator, the bipolar coagulation, the laser probe and the surgical microscope. All these newly developed technical features enable the neurosurgeon to perform a large number of surgical procedures under direct control and guidance of intra-operative MR imaging. In contrast to frame-based for framless navigation systems, intra-operative MRI provides accurate and immediate information during the progress of surgery. These intra-operative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery.

CONCLUSION

Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step forward in the field of neurosurgery.

Modafinil for excessive daytime sleepiness in myotonic dystrophy

The authors conducted an open-label trial of modafinil for excessive daytime sleepiness in myotonic dystrophy. Eleven patients were evaluated: two were not treated because of obstructive sleep apnea, and nine received 200 to 400 mg modafinil/day for an average of 16.4 weeks. There were no major side effects. Average sleep latency as measured by the Multiple Sleep Latency Test increased from 7.3 to 22.7 minutes ( p = 0.00013), and average Epworth Sleepiness Scale score decreased from 13.25 to 7.75 (p = 0.01028). Modafinil shows evidence of effectiveness for excessive daytime somnolence in myotonic dystrophy and should be investigated further.

Evidence for a melatonin receptor within pancreatic islets of neonate rats: functional, autoradiographic, and molecular investigations

In a recent perifusion investigation, we showed that the pineal secretory product melatonin reduces insulin secretion from isolated pancreatic islets of neonate rats stimulated with potassium chloride (KCl), glucose, and forskolin. This effect of melatonin was reproduced with doses ranging from 200 pmol/L to 5 micromol/L. Because it is generally accepted that melatonin exerts some of its biological effects through specific, high-affinity pertussis-toxin-sensitive G-protein-coupled receptors, we blocked the putative melatonin receptor of pancreatic islets using both the non-hydrolyzable guanosine triphosphate analog guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS, 30 micromol/L) and the melatonin antagonist luzindole (10 micromol/L). Both GTPgammaS and luzindole caused a near normalization of the melatonin-induced inhibition of the forskolin-stimulated insulin secretion. To localize putative melatonin receptors within the pancreatic islets autoradiographic studies were additionally carried out. These investigations showed specific binding of 2-[125I]iodomelatonin, which were in exact correspondence with the localization of the islets. In addition, gray-level analysis showed that unlabeled melatonin was able to reduce the binding of 2-[125I]iodomelatonin in a dose-dependent manner. Concentrations of unlabeled melatonin of 10(-9) mol/L produced a 50% reduction in specific binding, whereas concentrations of 10(-6) mol/L displaced the binding completely. Likewise, the results of molecular investigations showed that the rat pancreas contains a melatonin receptor, since reverse transcription polymerase chain reaction (RT-PCR) experiments, using specific primers for the rat melatonin receptor Mel1a, showed that mRNA for this melatonin receptor type is expressed in pancreatic tissue of newborn rats. In summary, it may be said that our functional. autoradiographic, and molecular results indicate that the Mel1a receptor is located on the pancreatic islets, possibly in the beta cells.

Blood pressure-independent effects in rats with human renin and angiotensinogen genes

The blood pressure-independent effects of angiotensin II (Ang II) were examined in double transgenic rats (dTGR) harboring human renin and human angiotensinogen genes, in which the end-organ damage is due to the human components of the renin angiotensin system. Triple-drug therapy (hydralazine 80 mg/L, reserpine 5 mg/L, and hydrochlorothiazide 25 mg/L in drinking water) was started immediately after weaning. Triple-drug therapy normalized blood pressure and coronary resistance, only partially prevented cardiac hypertrophy, and had no effect on ratio of renal weight to body weight. Although triple-drug therapy delayed the onset of renal damage, severe albuminuria nevertheless occurred. Semiquantitative scoring of ED-1-positive and MIB-5-positive (nuclear cell proliferation-associated antigen Ki-67) cells showed profound perivascular monocyte/macrophage infiltration and cell proliferation in kidneys and hearts of untreated dTGR. Triple-drug therapy had only a minimal effect on local inflammatory response or vascular cell proliferation. In contrast, a novel orally active human renin inhibitor (HRI), 30 mg/kg by gavage for 4 weeks, normalized blood pressure and coronary resistance and also prevented cardiac hypertrophy and albuminuria. ED-1-positive cells and MIB-5-positive cells were decreased by HRI in hearts and kidneys almost to levels observed in normotensive Sprague-Dawley rats. The renoprotective effects of HRI were at least in part due to improved renal hemodynamics and distal tubular function, since HRI shifted renal pressure-diuresis/natriuresis curves leftward by approximately 35 mm Hg, increased glomerular filtration rate and renal blood flow, and shifted the fractional water and sodium excretion curves leftward. In untreated dTGR, plasma Ang II was increased by 400% and renal Ang II level was increased by 300% compared with Sprague-Dawley rats. HRI decreased plasma human renin activity by 95% and normalized Ang II levels in both plasma and kidney compared with triple-drug therapy. Our findings indicate that in dTGR harboring human renin and angiotensinogen genes, Ang II causes end-organ damage and promotes inflammatory response and cellular growth largely independent of blood pressure.

Diffusion-weighted MRI in herpes simplex encephalitis: a report of three cases

Herpes simplex virus encephalitis (HSVE) is the most frequent fatal viral infection of the brain. Because antiviral treatment may improve the prognosis significantly, early diagnosis is mandatory. Imaging diagnosis rests on conventional MRI for the visualization of lesions in the limbic system, the hallmark of HSVE. Diffusion-weighted MRI (DW-MRI) has not been used for the evaluation of HSVE. We report on the DW-MRI findings in three patients with HSVE, who had cortical diffusion abnormalities in affected brain parenchyma, partially as the initial or most sensitive sign of encephalitis. Sequential imaging showed that the diffusion abnormality started to return to normal after 2 weeks in the presence of persistent contrast uptake. Thus, DW-MRI may be a valuable tool for early detection and diagnosis of HSVE whereas contrast-enhanced images are indispensable after the first week.

Shear field mapping in actin networks by using magnetic tweezers

An improved magnetic bead microrheometer based on phase contrast microscopy allowing high resolution measurements of local deformations within macromolecular network is applied to study local viscoelastic properties of cross-linked actin networks. By embedding nonmagnetic colloidal beads as probes into the networks, the spatial variation of the strain field within cross-linked actin networks can be mapped. Moreover, the Poisson ratio and shear modulus can be measured locally.

A placebo-controlled crossover trial of creatine in mitochondrial diseases

To test the efficacy and safety of creatine (Cr) monohydrate in mitochondrial diseases, 16 patients with chronic progressive external ophthalmoplegia or mitochondrial myopathy were randomized in a crossover design to receive double-blind placebo or 20 g Cr/day for 4 weeks. Cr was well tolerated, but there were no significant effects with regard to exercise performance, eye movements, or activities of daily life. The power of this pilot study was limited and future multicenter trials are needed.

A phase II study of pegylated liposomal doxorubicin for treatment of advanced hepatocellular carcinoma

BACKGROUND

Pegylated liposomal doxorubicin has an enhanced efficacy and reduced toxicity compared with free doxorubicin. The efficacy and toxicity of pegylated liposomal doxorubicin was investigated in patients with hepatocellular carcinoma.

PATIENTS AND METHODS

Patients with histologically confirmed, locally advanced or metastatic hepatocellular carcinoma and a Karnofsky index > 60% were included in this prospective single-arm study. Exclusion criteria were liver cirrhosis stage Child-Pugh C, previous chemotherapy, or chemoembolization. Pegylated liposomal doxorubicin was given in a dose of 30 mg/m2 every three weeks until progression of disease. After inclusion of five patients the dose could be escalated to 40 mg/m2 in absence of toxicity grade 3 and 4.

RESULTS

Sixteen patients were evaluable for response. No objective response was achieved. The median survival time was 140 days (95% confidence interval: 126-154 days). Treatment toxicities grade > or = 3 comprised increased liver enzymes in patients with preexisting grade 1 or 2 elevation (n = 6), hematologic toxicity (n = 5), and hypersensitivity (n = 2).

CONCLUSIONS

Pegylated liposomal doxorubicin is not effective for treatment of advanced hepatocellular carcinoma. The favorable toxicity profile was confirmed even in patients with underlying liver disease.