Spectrally-resolved measurement of concentrated light distributions for Fresnel lens concentrators.

A test method that measures spectrally resolved irradiance distribution for a concentrator photovoltaic (CPV) optical system is presented. In conjunction with electrical I-V curves, it is a means to visualize and characterize the effects of chromatic aberration and nonuniform flux profiles under controllable testing conditions. The indoor characterization test bench, METHOD (Measurement of Electrical, Thermal and Optical Devices), decouples the temperatures of the primary optical element (POE) and the cell allowing their respective effects on optical and electrical performance to be analysed. In varying the temperature of the POE, the effects on electrical efficiency, focal distance, spectral sensitivity, acceptance angle and multi-junction current matching profiles can be quantified. This work presents the calibration procedures to accurately image the spectral irradiance distribution of a CPV system and a study of system behavior over lens temperature.

The value of novel MRI techniques in Parkinson-plus syndromes: diffusion tensor imaging and anatomical connectivity studies.

Conventional MRI is a well-described, highly useful tool for the differential diagnosis of degenerative parkinsonian syndromes. Nevertheless, the observed abnormalities may only appear in late-stage disease. Diffusion tensor imaging (DTI) can identify microstructural changes in brain tissue integrity and connectivity. The technique has proven value in the differential diagnosis of multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and Parkinson's disease (PD). Here, we performed a systematic review of the literature on the main corticosubcortical DTI abnormalities identified to date in the context of the diagnosis of MSA and PSP with diffusion-weighted imaging, diffusion tensor imaging and anatomical connectivity studies. In good agreement with the histological data, increased diffusivity in the putamen (in MSA and PSP), in the middle cerebellar peduncles (in MSA) and in the upper cerebellar peduncles (in PSP) has been reported. Motor pathway involvement is characterized by low fraction anisotropy (FA) in the primary motor cortex in MSA-P and PSP, a high apparent diffusion coefficient (ADC) and low FA in the supplementary motor area in PSP. We then outline the value of these techniques in differential diagnosis (especially with respect to PD). Anatomical connectivity studies have revealed a lower number of fibers in the corticospinal tract in MSA and PSP (relative to PD and controls) and fewer tracked cortical projection fibers in patients with PSP or late-stage MSA (relative to patients with early MSA or PD and controls). Lastly, we report the main literature data concerning the value of DTI parameters in monitoring disease progression. The observed correlations between DTI parameters on one hand and clinical scores and/or disease duration on the other constitute strong evidence of the value of DTI in monitoring disease progression. In MSA, the ataxia score was correlated with ADC values in the pons and the upper cerebellar peduncles, whereas both the motor score and the disease duration were correlated with putaminal ADC values. In conclusion, DTI and connectivity studies constitute promising tools for differentiating between "Parkinson-plus" syndromes.

Structural Connectivity and Cortical Thickness Alterations in Transient Global Amnesia.

BACKGROUND AND PURPOSE: Transient global amnesia (TGA) is a sudden onset of anterograde and retrograde amnesia. We aimed to assess differences in terms of cortical thickness and structural brain connectome between patients with TGA (at acute and delayed postrecovery stages) and matched controls. MATERIALS AND METHODS: We report on 18 consecutive patients with TGA who underwent 3T MR imaging, including DTI and MPRAGE sequences, at the acute (mean delay postonset: 44 hours) and delayed post-recovery (mean delay: 35 days) stages. Structural connectome was assessed in patients with TGA and in 18 age- and sex-matched controls by using probabilistic fiber- tracking and segmentation of 164 cortical/subcortical structures ("nodes"). Connectivity graphs were computed and global network metrics were calculated. Network-based statistical analysis (NBS) was applied to compare patients with TGA at each stage with controls. We also compared cortical thickness between patients with TGA and healthy controls. RESULTS: Global network metrics were not altered in patients with TGA. NBS-analysis showed structural connectome alterations in patients with TGA compared with controls, in core regions involving the limbic network, with 113 nodes and 114 connections (33 left intrahemispheric, 31 right intrahemispheric, and 50 interhemispheric connections) showing significantly decreased structural connectivity (P < .05 NBS corrected, t-values ranging from 3.03 to 8.73). Lower cortical thickness compared with controls was associated with these structural alterations in patients with TGA, involving the orbitofrontal, cingulate, and inferior temporal cortices. All the abnormalities were visible at both acute and delayed postrecovery stages. CONCLUSIONS: Our preliminary study suggests there are structural abnormalities of the limbic network in patients with TGA compared with controls, including decreased structural connectivity and cortical thickness.

MRI of the cervical spinal cord predicts respiratory dysfunction in ALS.

For patients with amyotrophic lateral sclerosis (ALS), the primary therapeutic goal is to minimize morbidity. Non-invasive ventilation improves survival. We aim to assess whether Magnetic Resonance Imaging (MRI) of the cervical spinal cord predicts the progression of respiratory disorders in ALS. Brain and spinal MRI was repeatedly performed in the SOD1G86R mouse model, in 40 patients and in healthy controls. Atrophy, iron overload, white matter diffusivity and neuronal loss were assessed. In Superoxide Dismutase-1 (SOD1) mice, iron accumulation appeared in the cervical spinal cord at symptom onset but disappeared with disease progression (after the onset of atrophy). In ALS patients, the volumes of the motor cortex and the medulla oblongata were already abnormally low at the time of diagnosis. Baseline diffusivity in the internal capsule was predictive of functional handicap. The decrease in cervical spinal cord volume from diagnosis to 3 months was predictive of the change in slow vital capacity at 12 months. MRI revealed marked abnormalities at the time of ALS diagnosis. Early atrophy of the cervical spinal cord may predict the progression of respiratory disorders, and so may be of value in patient care and as a primary endpoint in pilot neuroprotection studies.

Presence of PAF-acether in human breast carcinoma: relation to axillary lymph node metastasis.

PAF-acether (PAF; formerly platelet-activating factor), a potent lipid mediator of inflammation, is involved in multiple cellular functions. To evaluate the role of PAF in human cancer, we obtained specimens from patients with localized breast carcinoma and assayed them for PAF. PAF was found in almost all carcinoma, although it was not detected in most of the matched, nontumor breast tissue samples. Intratumor PAF level was elevated when axillary lymph node involvement was low. Greater axillary extension (two or more positive lymph nodes) was associated with a decreased intratumor PAF level. These findings, along with the independence of other prognostic factors, indicate that PAF is a tumor marker of axillary lymph node involvement.

Mechanisms and kinetics of alpha-linolenic acid uptake in Caco-2 clone TC7.

The uptake kinetics of alpha-linolenic acid (18:3(n - 3)), an essential fatty acid, were investigated in the human intestinal cell line Caco-2. Four clones (PD10, PF11, PD7 and TC7) from the heterogeneous parental Caco-2 cells population were used. After a screening step using isolated cells, the TC7 clone was selected for the study of alpha-linolenic acid uptake. [1-(14)C]linolenic acid dissolved in 10 mM taurocholate was presented to the microvillus plasma membrane (apical side) of TC7 differentiated cells, grown on a semi-permeable polycarbonate membrane. The results show that the initial rate of uptake is not a linear function of the 18:3(n- 3) monomer concentration in the incubation medium. In the monomer concentration range studied (0.2 to 36 microM) apical uptake was saturable and followed Michaelis-Menten kinetics (V(max) = 15.4 +/- 0.6 nmol/mg protein per min, K(m) = 14.3 +/- 1.3 microM). In addition, it was temperature- and energy-dependent but was apparently unaffected by the sodium gradient and intracellular metabolic fate of 18:3(n - 3). Excess of unlabeled saturated or unsaturated long chain fatty acids (C16 to C22) led to a 27-68% reduction of [1-(14)C]linolenic acid uptake. Likewise basolateral uptake was saturable (V(max) = 4.9 +/- 0.7 nmol/mg protein per min, K(m) = 8.7 +/- 2.9 microM). These facts argue in favour of the existence in these human intestinal cells of a carrier-mediated transport system for alpha-linolenic acid and probably other long chain fatty acids as well.

Inhibition of Na+/H+ exchanger activity by an alkyl-lysophospholipid analogue in a human breast cancer cell line.

The mechanisms by which ET-18-OCH3 (1-O-octadecyl-2-O-methyl-sn-glycero-3 -phosphocholine) and other analogues of alkyl-lysophospholipids exert their antineoplastic effects are not yet fully elucidated. Possible interference with mechanisms involving intracellular pH (pHi) regulation was examined by measuring the effect of ET-18-OCH3 on the activity of the Na+/H+ exchanger in the breast cancer-derived cell line MCF-7. When ET-18-OCH3 was added to culture medium at 10 muM (determined as a noncytotoxic but cytostatic concentration), it led to an intracellular acidification (0.15 pH unit). It also decreased the rate of pHi recovery by Na+/H+ exchange following artificial acidification. Kinetic parameters of the exchange indicated that this was due to a decrease in the affinity of the exchanger for both transported ions, rather than to a decrease in the number of exchanger proteins in the membrane (same maximal efflux rate for treated and untreated cells). These results suggest that Na+/H+ exchanger inhibition and subsequent cytoplasmic acidification participate in the mode of action of ET-18-OCH3, and could be used for modulation of tumor-cell chemosensitivity or their subsequent commitment into programmed cell death.

Use of the Modified Mini-Mental State Examination with children.

The validity and reliability of the modified version of the Mini-Mental State Examination with children was examined. The Modified Mini-Mental State Examination was administered to 99 children between 4 and 12 years of age (45 males and 54 females) to assess expected scores for nonclinical children and with a clinical sample. Concurrent validity was assessed through correlations of Modified Mini-Mental State Examination scores with Wechsler Intelligence scores and Child Behavior Checklist scores. The Modified Mini-Mental State Examination was administered to 26 children on two occasions to determine test-retest reliability. Means and standard deviations of scores are reported by age and grade level. Test-retest reliability coefficients were positively significant. For the nonclinical sample, Modified Mini-Mental State Examination scores were significantly and positively correlated with Verbal IQ and Child Behavior Checklist scores. Modified Mini-Mental State Examination scores were significantly correlated with Verbal IQ scores in the total and clinical samples.

A psychometric analysis of the California Card Sorting Test.

The purpose of this study is to begin to characterize performance on the California Card Sorting Test (CCST), a relatively new measure of executive function specifically designed to fractionate problem-solving ability into its cognitive components. Data describing the performance of 135 neurologically intact young adults on the CCST and four other common measures of executive function are presented. Factor analyses indicated that the CCST is a valid measure of concept formation and abstract ability and that the CCST taps abilities different from those measured by commonly used tests of executive function. While further work must be done, the CCST seems to hold promise as a neuropsychological assessment instrument.

Autovagotomy by esophageal carcinoma. An unusual cause of gastric retention without outlet obstruction.

A case of gastric retention without outlet obstruction in a 44-year-old patient with esophageal carcinoma is reported. Radiological (and particularly C.T.) examinations support the opinion that the gastric motility disorders were due to the autovagotomy secondary to malignant involvement of the intrathoracic vagus nerve.

[Predictive value of preoperative abdominopelvic CT for optimal cytoreduction surgery in ovarian carcinoma]. / Valeur prédictive du scanner abdomino-pelvin pour la chirurgie optimale des carcinomes de l'ovaire.

Some patients underwent laparoscopy without optimal debulking surgery as initial treatment for advanced ovarian carcinoma. The amount of residual tumor following primary surgery was an important prognosis factor. Neoadjuvant chemotherapy is a new therapeutic approach. Secondary, optimal surgery could be done in better conditions. The purpose was to access the ability of preoperative abdominopelvic CT to predict success of debulking surgery for ovarian carcinoma: less than 1 cm of residual tumor size after initial surgery. We reviewed 39 patients (2 stages Ic, 1 stage IIc, 22 stages III and 14 stages IV) operated on for ovarian carcinoma between January 1992 and December 1997. Surgical criteria of inability to perform optimal surgical cytoreduction were compared with abdominopelvic CT done the month before. CT scans were prospectively assessed by radiologist A and retrospectively (3 months to 6 years delay) rewiewed separately by radiologists A and B without surgical data. Nineteen patients underwent optimal debulking surgery: 13 no residual tumor and 6 with residual lesions under 1 cm. The interreader (0.73) and intrareader (0.9) agreement, worked out by Kappa coefficient, was juged good to very good. The sensitivity of CT was 91% with a specificity of 95%. These results allowed us to determine wich CT criteria were accurate and reproducible to be a helpfull for therapeutic choice and to avoid laparotomy without optimal surgery.

[Xanthogranulomatous cholecystitis. X-ray computed tomographic study of a pseudotumoral form]. / Cholécystite xanthogranulomateuse. Etude scanographique d'une forme pseudo-tumorale.

The authors report a case of xanthogranulomatous cholecystitis in a 63-year-old woman hospitalized because of a right hypochondrium mass. Ultrasonography, computed tomography, and celiac arteriogram showed a gallbladder tumour. Surgical management allowed subtotal tumour resection. Diagnosis of xanthogranulomatous cholecystitis was established by histological examination. Twenty-two months later, patient is in good health. From this observation and a world-wide literature review (90 previously reported cases), the authors analyse the clinical, pathological, and pathophysiological features of this very unusual entity.

[Value of MRI in symptomatic patients treated with tamoxifen]. / Apport de l'IRM chez les patientes symptomatiques traitées par tamoxifène.

PURPOSE: To assess the MR imaging (MRI) findings in symptomatic tamoxifen treated-women with abnormal transvaginal sonography. PATIENTS AND METHODS: From january 1997 to june 2000, 32 consecutive symptomatic tamoxifen treated-women with abnormal transvaginal sonography were prospectively studied by MRI. T1-weighted, T2-weighted, post-contrast T1-weighted and dynamic gradient-echo T1-weighted sequences were used. All patients underwent uterine sampling within one month of MRI. RESULTS: Endometrial thickness at sonography ranged from 5 to 48 mm (mean thickness 19 mm), and on T2-weighted imaging ranged from 3 to 50 mm (mean=25 mm). Three MRI patterns were found. Pattern 1 (13 patients) was defined as homogeneous high signal intensity of the endometrium on T2W images, and signal void in the lumen on gadolinium-enhanced images. Pattern 2 (8 patients) was defined as heterogeneous endometrial signal on T2W images, and latticelike enhancement traversing the endometrial canal on gadolinium-enhanced images. Pattern 3 (11 patients) was defined as heterogeneous signal on T2W images with masses or nodules which were better seen on dynamic gadolinium-enhanced images. In pattern 1 we found 13 atrophic endometrium, in addition there were 4 polypoid glandulo-cystic proliferation (PGCP), and 1 adenomyosis. In pattern 2 we found 3 PGCP, 4 atrophy and 1 polyp without hyperplasia. The 2 carcinomas and the polyps with hyperplasia were found in pattern 3 (11 patients). CONCLUSION: In our experience MRI allows differentiation of lesions which may require surgery from other lesions in which noninvasive follow-up is possible.

[Computed tomography-guided transthoracic biopsy after negative fiber-optic endoscopy; apropos of 134 patients]. / Biopsies transthoraciques sous contrôle tomodensitométrique après fibroscopie négative; à propos de 134 patients.

PURPOSE: To evaluate the diagnostic accuracy of transthoracic needle biopsy (TNB) in patients being treated for cancer in order to compare results from small and large pulmonary nodules and to study the efficiency of pathology versus cytology analysis. PATIENTS AND METHODS: 141 consecutive CT-guided TNBs were performed in 134 patients. Cancer had been diagnosed in all cases. From the CT images, nodules were classified as small (< or = 15 mm) (n = 63; 47%) or large (> 15 mm) (n = 71; 53%). RESULTS: There were 16 benign and 118 malignant lesions (92 metastasis, 18 primary, 8 unspecified). There was no statistically significant difference for sensitivity and for prevalence of pneumothorax between small or large nodules. For the 107 true-positive and 16 true-negative results, the cytology examination was positive alone in 41 cases (33.3%), the pathology examination in 24 cases (19.5%) and both in 58 cases (47.2%). CONCLUSION: The diagnostic efficiency of CT-guided transthoracic needle biopsy is as good for small pulmonary nodules (> or = 15 mm) as for larger lesions. This technique is particularly useful in the diagnosis of secondary lesions and does not increase the risk of complications, even in case of small nodules. Ordering both pathology and cytology examinations improves the efficacy of TNB.

[Comparative study of tumor evaluation with computerized tomography and surgery in ovarian cancer]. / Etude comparative de l'évaluation tumorale par TDM et par chirurgie dans le cancer de l'ovaire.

PURPOSE: To evaluate the results of an abdomino-pelvic scan in cancers of the ovary in comparison with surgery. MATERIAL AND METHODS: We reviewed the observations concerning patients operated on for malignant tumors of the ovary between January 1992 and April 1995 in our anti-cancer center. We selected 32 patients who had had both a complete surgical abdominal exploration (laparotomy or laparoscopy) and an abdominal pelvic scan in the preceding months. We divided the abdomen into 33 areas and compared the scan of each with the surgical findings. Two cancer radiologists, including one gynecology specialist, studied the imaging separately. Neither knew the results of the surgical observations. RESULTS: Imaging findings varied with localization tumor size and presence or not of ascites radiologists. For certain localization, detection of lesions was difficult for both readers (pancreas, spleen, stomach), for others, recognition improved with experience (bowel, diaphragm, colon). CONCLUSION: The clinician must be aware of the variability of ovarian cancer assessment by CT scan, particularly if imaging alone is being used to guide treatment.

[Predictive value of abdominopelvic scan for optimal surgery of ovarian carcinoma]. / Travail original présenté lors de la Société Françaiseurgie d'oncologie Gynécologique des 5 et 6 novembre 1999. Valeur prédictive du scanner abdomino-pelvien pour la chirurgie optimale des carcinomes de l'ovaire.

BACKGROUND: Some patients undergo laparoscopy without optimal debulking surgery as initial treatment for advanced ovarian carcinoma. The amount of residual tumor following primary surgery is an important prognosis factor. Neoadjuvant chemotherapy is a new therapeutic approach. Secondary, optimal surgery could be done in better conditions. PURPOSE: To access the ability of preoperative abdominopelvic CT to predict success of debulking surgery for ovarian carcinoma: less than 1cm of residual tumor size after initial surgery. MATERIALS AND METHODS: We reviewed 39 patients (two stage Ic, 1 stage IIc, 22 stage III and 14 stage IV) operated on for ovarian carcinoma between January 1992 and December 1997. Surgical criteria of inability to perform optimal surgical cytoreduction were compared with abdominopelvic CT done the month before. CT scans were prospectively assessed by radiologist A and retrospectively (3 months to 6 years delay) reviewed separately by radiologists A and B without surgical data. RESULTS: Nineteen patients underwent optimal debulking surgery: 13 no residual tumor and 6 with residual lesions under 1cm. The interreader (0.73) and intrareader (0.9) agreement, worked out by Kappa coefficient, was judged good to very good. The sensitivity of CT was 91% with a specificity of 95%. CONCLUSION: These results allowed us to determine which CT criteria were accurate and reproducible to be a helpful for therapeutic choice and to avoid laparotomy without optimal surgery.

[Clinically localized cancers of the breast. Therapeutic consequences of the evaluation of extension]. / Cancers du sein cliniquement localisés. Conséquences thérapeutiques du bilan d'extension.

The therapeutic modifications induced by pretreatment evaluation were studied in a consecutive series of 852 asymptomatic women with newly diagnosed primary breast cancer attending our center between 1980 and 1984. Staging tests included chest X-rays in 851 patients, bone X-rays in 831, alkaline phosphatase in 826, hepatic enzymes in 818, liver echography in 750 and bone scintigraphy in 504. The intended local treatment was changed for a systemic one in 8 patients due to suspicious abnormalities. The follow-up confirmed evidence of metastases in 6 out of 8 patients (bone: 4; liver: 1; lung: 1). Mastectomy, initially avoided in these 6 patients, was subsequently performed in 2 of them owing to slow progression of distant metastases. On the basis of the current study, pretreatment staging in asymptomatic primary breast cancer cannot be recommended due to the low prevalence of detectable metastases.

Pulse-triggered DTI sequence with reduced FOV and coronal acquisition at 3T for the assessment of the cervical spinal cord in patients with myelitis.

BACKGROUND AND PURPOSE: DTI is a promising technique for imaging of the spinal cord, but the technique has susceptibility-induced artifacts. We evaluated a pulse-triggered DTI sequence with an rFOV technique and coronal acquisition for the assessment of the cervical spinal cord in patients with myelitis at 3T. MATERIALS AND METHODS: A rFOV acquisition was established by a noncoplanar application of the excitation and the refocusing pulse in conjunction with outer volume suppression. The DTI sequence was performed in the coronal plane in 12 healthy volunteers and 40 consecutive patients with myelitis. Probabilistic tractography of the posterior and lateral funiculi was performed from the C1 to C7 levels. FA, MD, aD, rD, and ratios of aD and rD were measured. RESULTS: In healthy volunteers, mean DTI indices within the whole-fiber pathways were the following: FA = 0.61, MD = 1.17 × 10(-3) mm(2)/s, aD = 1.96 × 10(-3) mm(2)/s, rD = 0.77 × 10(-3) mm(2)/s, and ratios of aD and rD = 2.5. Comparison of healthy controls and patients with myelitis identified statistically significant differences for all DTI parameters. Different patterns of myelitis, including spinal cord atrophy and active inflammatory lesions, were recognized. There was a significant correlation between clinical severity and DTI parameters. CONCLUSIONS: The present work introduces a new approach for DTI of the cervical spinal cord at 3T, enabling a quantitative follow-up of patients with myelitis.

Na(V)1.5 enhances breast cancer cell invasiveness by increasing NHE1-dependent H(+) efflux in caveolae.

Na(V)1.5 sodium channels enhance the invasiveness of breast cancer cells through the acidic-dependent activation of cysteine cathepsins. Here, we showed that the Na(+)/H(+) exchanger type 1 (NHE1) was an important regulator of H(+) efflux in breast cancer cells MDA-MB-231 and that its activity was increased by Na(V)1.5. Na(V)1.5 and NHE1 were colocalized in membrane rafts containing caveolin-1. The inhibition of Na(V)1.5 or NHE1 induced a similar reduction in cell invasiveness and extracellular matrix degradation; no additive effect was observed when they were simultaneously inhibited. Our study suggests that Na(V)1.5 and NHE1 are functionally coupled and enhance the invasiveness of cancer cells by increasing H(+) efflux.

The SK3/K(Ca)2.3 potassium channel is a new cellular target for edelfosine.

BACKGROUND AND PURPOSE: The 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine (edelfosine) is an ether-linked phospholipid with promising anti-cancer properties but some side effects that preclude its full clinical therapeutic exploitation. We hypothesized that this lipid could interact with plasma membrane ion channels and modulate their function. EXPERIMENTAL APPROACH: Using cell migration-proliferation assays, patch clamp, spectrofluorimetry and ¹²5I-Apamin binding experiments, we studied the effects of edelfosine on the migration of breast cancer MDA-MB-435s cells, mediated by the small conductance Ca²(+) -activated K(+) channel, SK3/K(Ca)2.3. KEY RESULTS: Edelfosine (1 µM) caused plasma membrane depolarization by substantially inhibiting activity of SK3/K(Ca)2.3 channels, which we had previously demonstrated to play an important role in cancer cell migration. Edelfosine did not inhibit ¹²5I-Apamin binding to this SK(Ca) channel; rather, it reduced the calcium sensitivity of SK3/K(Ca)2.3 channel and dramatically decreased intracellular Ca²(+) concentration, probably by insertion in the plasma membrane, as suggested by proteinase K experiments. Edelfosine reduced cell migration to the same extent as known SK(Ca) channel blockers. In contrast, K+ channel openers prevented edelfosine-induced anti-migratory effects. SK3 protein knockdown decreased cell migration and totally abolished the effect of edelfosine on MDA-MB-435s cell migration. In contrast, transient expression of SK3/K(Ca)2.3 protein in a SK3/K(Ca)2.3-deficient cell line increased cell migration and made these cells responsive to edelfosine. CONCLUSIONS AND IMPLICATIONS: Our data clearly establish edelfosine as an inhibitor of cancer cell migration by acting on SK3/K(Ca)2.3 channels and provide insights into the future development of a new class of migration-targeted, anti-cancer agents.