Spiral T1 Spin-Echo for Routine Postcontrast Brain MRI Exams: A Multicenter Multireader Clinical Evaluation.

BACKGROUND AND PURPOSE: Spiral MR imaging has several advantages compared with Cartesian MR imaging that can be leveraged for added clinical value. A multicenter multireader study was designed to compare spiral with standard-of-care Cartesian postcontrast structural brain MR imaging on the basis of relative performance in 10 metrics of image quality, artifact prevalence, and diagnostic benefit. MATERIALS AND METHODS: Seven clinical sites acquired 88 total subjects. For each subject, sites acquired 2 postcontrast MR imaging scans: a spiral 2D T1 spin-echo, and 1 of 4 routine Cartesian 2D T1 spin-echo/TSE scans (fully sampled spin-echo at 3T, 1.5T, partial Fourier, TSE). The spiral acquisition matched the Cartesian scan for scan time, geometry, and contrast. Nine neuroradiologists independently reviewed each subject, with the matching pair of spiral and Cartesian scans compared side-by-side, and scored on 10 image-quality metrics (5-point Likert scale) focused on intracranial assessment. The Wilcoxon signed rank test evaluated relative performance of spiral versus Cartesian, while the Kruskal-Wallis test assessed interprotocol differences. RESULTS: Spiral was superior to Cartesian in 7 of 10 metrics (flow artifact mitigation, SNR, GM/WM contrast, image sharpness, lesion conspicuity, preference for diagnosing abnormal enhancement, and overall intracranial image quality), comparable in 1 of 10 metrics (motion artifacts), and inferior in 2 of 10 metrics (susceptibility artifacts, overall extracranial image quality) related to magnetic susceptibility (P < .05). Interprotocol comparison confirmed relatively higher SNR and GM/WM contrast for partial Fourier and TSE protocol groups, respectively (P < .05). CONCLUSIONS: Spiral 2D T1 spin-echo for routine structural brain MR imaging is feasible in the clinic with conventional scanners and was preferred by neuroradiologists for overall postcontrast intracranial evaluation.

The Arabidopsis GORK K+-channel is phosphorylated by calcium-dependent protein kinase 21 (CPK21), which in turn is activated by 14-3-3 proteins.

Potassium (K+) is a vital ion for many processes in the plant and fine-tuned ion channels control the K+-fluxes across the plasma membrane. GORK is an outward-rectifying K+-channel with important functions in stomatal closure and in root K+-homeostasis. In this study, post-translational modification of the Arabidopsis GORK ion channel and its regulation by 14-3-3 proteins was investigated. To investigate the possible interaction between GORK and 14-3-3s an in vivo pull-down from an Arabidopsis protein extract with recombinant GORK C-terminus (GORK-C) indeed identified endogenous 14-3-3s (LAMBDA, CHI, NU) as binding partners in a phosphorylation dependent manner. However, a direct interaction between 14-3-3's and GORK-C could not be demonstrated. Since the pull-down of 14-3-3s was phosphorylation dependent, we determined GORK-C as substrate for CPK21 phosphorylation and identified three CPK21 phospho-sites in the GORK protein (T344, S518 and S649). Moreover, interaction of 14-3-3 to CPK21 strongly stimulates its kinase activity; an effect that can result in increased GORK phosphorylation and change in activity. Using the non-invasive vibrating probe technique, we measured the predominantly GORK mediated salt induced K+-efflux from wild-type, gork, cpk21, aha2 and 14-3-3 mutant roots. The mutants cpk21 and aha2 did not show statistical significant differences compared to WT. However, two (out of six) 14-3-3 isoforms, CHI and PHI, have a clear function in the salt induced K+-efflux. In conclusion, our results show that GORK can be phosphorylated by CPK21 and suggest that 14-3-3 proteins control GORK activity through binding with and activation of CPK21.

Vascular fingerprint and vascular damage markers associated with vascular events in testicular cancer patients during and after chemotherapy.

BACKGROUND: Metastatic testicular cancer (TC) can be cured with bleomycin, etoposide and cisplatin (BEP) chemotherapy. This comes at the price of an increased cardiovascular disease risk, not only years afterwards, but also during and shortly after chemotherapy. To prevent cardiovascular events, high-risk patients should be identified. The aim of this study was to assess BEP-chemotherapy induced vascular damage and to find risk factors for early vascular events. PATIENTS AND METHODS: A prospective cohort study was performed in (B)EP treated TC patients. Development of venous and arterial vascular events was assessed. Vascular damage markers (von Willebrand factor [vWF], coagulation factor VIII [FVIII], intima media thickness [IMT]) and cardiovascular risk factors were assessed before and until 1 year after chemotherapy. Before start of chemotherapy a vascular fingerprint was estimated. Presence of ≥3 risk factors was defined as high-risk vascular fingerprint: body mass index >25 kg/m(2), current smoking, blood pressure >140/90 mm Hg, total cholesterol >5.1 and/or low-density lipoprotein >2.5 mmol/L or glucose ≥7 mmol/L. RESULTS: Seventy-three patients were included. Eight (11%) developed vascular events (four arterial events, four pulmonary embolisms). vWF and FVIII increased during chemotherapy, especially in patients with vascular events. Sixteen patients (22%) had a high-risk vascular fingerprint before start of chemotherapy. These patients had arterial events more often (3/16 [19%] versus 1/57 [2%]; p = 0.031) and higher vWF levels and IMT. CONCLUSIONS: Endothelial activation and upregulation of procoagulant activity seem important mechanisms involved in early (B)EP-chemotherapy-induced vascular events. Before chemotherapy, a quarter already had cardiovascular risk factors. A vascular fingerprint could identify patients at risk for arterial events. This vascular fingerprint, when validated, can be used as a tool to select patients who may benefit from preventive strategies.

Long-term exposure to circulating platinum is associated with late effects of treatment in testicular cancer survivors.

BACKGROUND: The success of cisplatin-based (Platinol, Bristol-Myers Squibb Company, New York, NY, USA) chemotherapy for testicular cancer comes at the price of long-term and late effects related to healthy tissue damage. We assessed and modelled serum platinum (Pt) decay after chemotherapy and determined relationships between long-term circulating Pt levels and known late effects. PATIENTS AND METHODS: In 99 testicular cancer survivors, treated with cisplatin-based chemotherapy, serum and 24-h urine samples were collected during follow-up (1-13 years after treatment). To build a population pharmacokinetic model, measured Pt data were simultaneously analysed, together with cisplatin dose, age, weight and height using the NONMEM software. Based on this model, area under the curve between 1 and 3 years after treatment (Pt AUC1-3 years) was calculated for each patient. Predicted long-term Pt exposure was related to renal function and to late effects of treatment assessed median 9 (3-15) years after chemotherapy. RESULTS: Decay of Pt was best described by a two-compartment model. Mean terminal T1/2 was 3.7 (range 2.5-5.2) years. Pt AUC1-3 years correlated with cumulative cisplatin dose, and creatinine clearance before and 1 year after treatment. Patients with paraesthesia had higher Pt AUC1-3 years (30.9 versus 27.0 µg/l month) compared with those without paraesthesia (P = 0.021). Patients with hypogonadism, elevated LDL-cholesterol levels or hypertension also had higher Pt AUC1-3 years. CONCLUSIONS: Renal function before and after cisplatin treatment is an important determinant of long-term Pt exposure. Known long-term effects of testicular cancer treatment, such as paraesthesia, hypogonadism, hypercholesterolaemia and hypertension, are associated with long-term circulating Pt exposure.

Regulation of TRAIL receptor expression by ß-catenin in colorectal tumours.

Tumour-necrosis-factor-related apoptosis-inducing ligand (TRAIL) is being investigated as a targeted cancer therapeutic and the expression of its pro-apoptotic receptors, DR4 and DR5, increases during colorectal carcinogenesis. This study investigated the role of ß-catenin in the regulation of these receptors. In human colorectal adenoma and carcinoma cell lines, downregulation of ß-catenin resulted in lower total DR4 and DR5 protein levels. Similarly, cell membrane expression of DR4 and DR5 was reduced after downregulation of ß-catenin in colon carcinoma cells, whereas induction of ß-catenin in HeLa cells led to increased cell membrane expression of DR4 and DR5. Downregulation of ß-catenin decreased the recombinant human TRAIL sensitivity of human colon carcinoma cells. Activation of the transcription factor T-cell factor-4 (TCF-4) is an important function of ß-catenin. Dominant-negative TCF-4 overexpression, however, did not significantly affect TRAIL receptor expression or recombinant human TRAIL sensitivity. Human colorectal adenomas (N = 158) with aberrant (cytoplasmic and nuclear) ß-catenin expression had a higher percentage of immunohistochemical DR4 and DR5 staining per tumour (mean: 73 and 88%, respectively) than those with membranous ß-catenin staining only (mean: 50 and 70%, respectively, P < 0.01 for both). Furthermore, aberrant ß-catenin staining co-localized with DR4 and DR5 expression in 92% of adenomas. In 53 human colorectal carcinomas, aberrant ß-catenin expression was present in most cases and DR4/5 expression was largely homogenous. Similarly, in adenomas from APC(min) mice, cytoplasmic ß-catenin staining co-localized with staining for the murine TRAIL death receptor. In conclusion, the gradual increase in TRAIL receptor expression during colorectal carcinogenesis is at least partially mediated through increased ß-catenin expression, independently of TCF-4-signalling.

Early development of the metabolic syndrome after chemotherapy for testicular cancer.

BACKGROUND: The metabolic syndrome (MS) might increase the risk of cardiovascular disease in testicular cancer (TC) survivors. We investigated its prevalence, development, vascular implications, and the role of gonadal function. METHODS: TC survivors treated with chemotherapy and follow-up ≥3 years (N = 370, study I) were retrospectively evaluated for the development of cardiovascular risk factors. A subgroup followed 3-20 years (N = 173, study II) was compared with controls (N = 1085) for MS prevalence and evaluated for vascular function. RESULTS: In TC survivors (study I), 24% developed overweight, 24% hypercholesterolemia, and 30% hypertension, after median follow-up of 1.7, 0.9, and 5.1 years, respectively. At the median follow-up of 5 years (study II), 25% of survivors have the MS {odds ratio (OR) 2.2, [95% confidence interval (CI) 1.5-3.3] compared with controls}. Survivors with MS have features of inflammation and prothrombotic state, increased carotid artery intima-media thickness. Survivors with testosterone levels <15 nmol/l (22%) have an increased risk of the MS (OR 4.1, 95% CI 1.8-9.3). CONCLUSIONS: The current data suggest that the MS occurs at earlier age in TC survivors treated with chemotherapy compared with controls and is accompanied by early signs of atherosclerosis. As low testosterone may have a causal role, it is a target for interventions.

Expression of multidrug resistance proteins, P-gp, MRP1 and LRP, in soft tissue sarcomas analysed according to their histological type and grade.

The biological behaviour of different histological types and grades of soft tissue sarcomas (STS) varies. This might result in a differing sensitivity to cytotoxic drugs. Cross-resistance to functionally and structurally distinct natural-product drugs, known as multidrug resistance (MDR), is associated with the overexpression of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and lung resistance-related protein (LRP). The purpose of this study was to evaluate the expression of P-gp, MRP1 and LRP in STS according to their histological type and grade. In 141 chemotherapy-naive STS patients, the expression of the three MDR proteins was detected by immunohistochemistry. Nine histological types were documented. These were 19% grade 1, 34% grade 2 and 47% grade 3 tumours. Expression of P-gp and LRP was observed more frequently than the expression of MRP1 (P<0.0001). P-gp expression was most pronounced in malignant fibrous histiocytoma (MFH), but was low in leiomyosarcomas. MRP1 was expressed in most malignant peripheral nerve sheath tumours (MPNST). LRP was strongly expressed in MFH and unspecified sarcomas, but was low in liposarcomas. MRP1 and LRP expression was significantly more common in grades 2 and 3 compared with grade 1 tumours. P-gp expression was correlated with MRP1, especially in grade 3 STS. In conclusion, P-gp, MRP1 and LRP are expressed in the majority of STS, but this expression varies according to the histological type. MRP1 and LRP, but not P-gp expression, were found to be correlated to tumour grade. MDR might contribute to the observed differences in clinical behaviour within the heterogeneous group of STS.

Calcium affects biomarkers of colon carcinogenesis after right hemicolectomy.

BACKGROUND: In Western societies colonic cancer most frequently develops in the distal colon, largely as a result of the composition of the diet. Modulation of dietary factors is therefore an attractive modality to reduce colorectal cancer risk. This study aims to evaluate the potentially protective effects of calcium in right hemicolectomy patients. MATERIALS AND METHODS: A randomized controlled cross-over intervention trial was performed with 1000 mg of elemental calcium per day for 2 months in 15 right hemicolectomy patients. Primary endpoints were proliferative activity, determined by immunohistochemical detection of BrdU-labeled cells (LI) in rectal biopsies, and cytotoxicity and alkaline phosphatase activity of faecal water. Secondary endpoints were bile acid composition in faeces. RESULTS: Calcium-reduced LI in the superficial one-third of the crypt (from 0.84 +/- 0.27% to 0.37 +/- 0.08%, P = 0.04) and a trend towards a lower total LI and LI in the mid one-third of the crypt was observed. Alkaline phosphatase activity was reduced from 6.2 +/- 2.6 U mL-1 in the placebo period to 4.6 +/- 2.2 in the calcium period (P = 0.02), and a trend toward a lower cytotoxicity of faecal water was observed. No effect on total bile acids in faeces was observed, but calcium increased the percentage of deoxycholic acid (from 49.6 +/- 7.0% to 56.5 +/- 6.2%, P = 0.03) and decreased the percentages of cholic acid (from 10.3 +/- 4.7% to 5.8 +/- 2.7%, P = 0.05) and lithocholic acid (from 26.7 +/- 3.4% to 23.9 +/- 2.9%, P = 0.04). CONCLUSION: Calcium may have a protective effect against colorectal cancer risk in right hemicolectomy patients.

Apoptosis induction by sennoside laxatives in man; escape from a protective mechanism during chronic sennoside use?

Chronic sennoside use induces melanosis coli (MC) and possibly increases colorectal cancer risk. Sennosides alter colonic crypt length, proliferative activity, and bcl-2 expression 18 h after administration. To investigate possible mechanisms for carcinogenesis, the effects of acute sennoside use and the presence of MC on colorectal epithelium were studied. Colorectal biopsies from 15 subjects receiving sennosides 6 h before sigmoidoscopy (Sen), 15 controls (NSen), and 27 with MC [11 moderate (MMC) and 16 severe (SMC)]. were analysed for degree of apoptosis (H&E staining), immunohistochemical p53, p21/WAF and bcl-2 expression, and proliferative activity (labelling index, LI). Apoptosis (p=0.0004), intensity of p53 staining (p=0.01), and p21/WAF expression (p=0.008) were increased in Sen and SMC compared with NSen and MMC. p53 expression was increased in Sen (p=0.004). No difference in bcl-2 expression or LI was observed. Crypts were shorter in Sen (p=0.05) and longer in SMC (p=0.04) than in NSen. It is concluded that sennosides acutely induce apoptosis of colonic epithelial cells, presumably by a p53, p21/WAF-mediated pathway, resulting in shorter crypts. In severe melanosis coli, apoptosis seems to be delayed, causing longer crypts without a rise in proliferative activity or bcl-2 expression. This escape from a presumably protective mechanism may enhance the risk of carcinogenesis during chronic sennoside use.

Role of metallothionein in cisplatin sensitivity of germ-cell tumours.

Cisplatin (CDDP) is an extremely active drug in the treatment of germ-cell tumours. Earlier, we found an unexpected inverse correlation between the total amount of sulfhydryl groups and CDDP sensitivity in a panel of 3 human germ-cell-tumour and 3 colon-carcinoma cell lines. Major components of the sulfhydryl groups are glutathione and metallothionein (MT). We further investigated a possible role of MT in the CDDP sensitivity of germ-cell tumours. MT levels and functionality of the germ-cell-tumour and colon-carcinoma cell lines were found to be inversely correlated with CDDP sensitivity. No difference in sub-cellular localization of MT could be observed among the types of cell lines. In agreement with the in vitro data, immunohistochemical detection of MT was high in 11/14 primary human germ-cell tumours and low in 7/7 human colon carcinomas. MT-protein expression in primary germ-cell tumours did not discriminate between responding and non-responding patients. As compared with the primary tumours, MT-protein expression decreased in 5/7 post-chemotherapy residual vital tumours or remained undetectable (2/7). MT-protein expression in the germ-cell tumours was not related to total p53-protein expression. In summary, over-expression of MT was found in germ-cell tumours, both in cell lines and in human tumours. Although MT-protein over-expression seems to be associated with the CDDP sensitivity of germ-cell tumours, MT-protein expression in primary germ-cell tumours did not differ between responding and non-responding patients and therefore cannot be used to predict response to chemotherapy.

Shock-prod burying test in rats: autonomic and behavioral responses.

Heart rate (HR), core temperature (CT) and gross locomotor activity (GLA) were recorded in rats by a computerized telemetry system before, during and after 15-min exposure to a constantly electrified (2mA) or nonelectrified (0mA) prod which was presented through a hole in the home cage with woodshavings on the floor [shock-prod burying (SPB) test]. Measurement of both autonomic and behavioral response continued up to 60 min after introduction of the prod in the home cage. Twenty-four h after the SPB test, rats were tested for retention. During the SPB test, significant increases in HR, respective to baseline values, were observed in both the 2mA and 0mA group, but the tachycardiac response in the former group significantly outweighed that in the latter group. In shocked rats, HR remained elevated during the entire 45-min posttest period, whereas HR declined immediately after removal of the prod in nonshocked animals. An onset in rise in CT was observed in the 2mA, but not in the 0mA group, during prod exposure time, which eventually resulted in an additional-more than two-fold--increase after termination of the test and outlasted total recording time. Marked behavioral activation was observed in the 2mA group, whereas the 0mA responded to a lesser extent. Approach and exploration of the prod was reduced when the prod was electrified. The total time spent by rats burying the prod was significantly longer in the shocked than in the nonshocked group. When exposed to the nonelectrified prod after 24 h, total burying time was reduced in the 2mA group but still significantly longer than in the 0mA group.(ABSTRACT TRUNCATED AT 250 WORDS)

Proliferation rate of colonic mucosa in normal subjects and patients with colonic neoplasms: a refined immunohistochemical method.

An increased colonic epithelial proliferation rate and an increase of the cryptal proliferative zone are probable markers of increased susceptibility to colonic cancer. In this study an immunohistochemical method using 5-bromo-deoxyuridine (BrdUrd) to measure the proliferation rate of colonic mucosa in vitro was used. Fresh endoscopic colonic biopsy specimens were incubated with BrdUrd and then processed for immunohistochemistry using a monoclonal antibody. Essential procedures with respect to the equal distribution of nuclei stained with BrdUrd in the biopsy specimens proved to be the cutting of the specimens before incubation and the use of a microwave oven at the beginning of incubation. The use of the procedure of the running average showed that 12 length cut crypts are sufficient to determine reliably the proliferation rate, expressed as the labelling index (LI). This was determined in the biopsy specimens of 10 subjects without organic colonic disease, eight patients with adenomatous colonic polyps, and in six patients with (recent) colonic carcinoma. Mean LI in the controls was significantly lower than in patients with colonic polyps and in those with colon cancer. It is concluded that this method is promising for screening persons at risk for colon cancer and will be of great potential in performing dietary intervention studies in these subjects.

Effect of human cord and postoperative serum on experimental inflammation in the rat.

Human cord and postoperative serum depressed the oedema provoked by mediators of the inflammatory reaction such as bradykinin, histamine, serotonin and prostaglandin E2 and also the experimental inflammation caused by carrageenin. Normal human and pregnancy serum did not have such an effect. In two cases of open neural tube defect, one of anencephaly and another of spina bifida, human amniotic fluid also had a strongly depressing effect on the experimental oedema provoked by serotonin. Human amniotic fluid from normal pregnancies did not inhibit this experimental inflammation. A protein-fraction of mol. wt 30,000--100,000 has been isolated from the inhibiting sera and shows the anti-inflammatory activity to be dose-related towards all the oedema-provoking substances used. Immunological studies showed that the inhibiting factor could be a protein in the pre-albuminic region, while alpha-foetoprotein did not appear to be responsible for the anti-inflammatory activity. Our conclusion is that human serum contains a protein of foetal origin with an acute-phase character and strong anti-inflammatory activities analogous to rat alpha 2-macrofoetoprotein.