Correlation between 99mTc-(V)-DMSA uptake and constitutive level of phosphorylated focal adhesion kinase in an in vitro model of cancer cell lines

Purpose Although a number of prognostic indicators have been developed, it is still difficult to predict the biological behaviour of all cancer types. ^99mTc-(V)-DMSA (V DMSA) uptake and focal adhesion kinase (FAK) expression and activation level could be potential agents for this purpose. We hypothesised the existence of a correlation between V DMSA, whose uptake is linked to phosphate ions, essential compounds for tumour growth and cell proliferation, and the adhesion protein FAK, whose elevated expression and level of constitutive activation are implicated in cancer progression. The aim of this study was to assess the relationship between V DMSA incorporation rate and FAK expression and activation by phosphorylation on tyrosine 397 residue.Methods We determined V DMSA uptake in six different cancer cell lines and we measured FAK expression and activation by using Western Blotting analysis. Correlations with factors known to be associated with poor prognosis, such as invasive potential, resistance to chemotherapy and proliferation rate, were also investigated. Results The cell lines exhibited different V DMSA incorporation rates. In addition, these cells showed the same FAK expression, but various degrees of activation. A correlation was observed between V DMSA uptake and level of FAK phosphorylation and between V DMSA or constitutive FAK activation and proliferation rate. However, no correlation was shown between these parameters and the other factors tested, i.e. invasive potential and anticancer drug resistance.Conclusion The results of this in vitro study clearly demonstrate that phosphorylation of FAK, proliferation rate and V DMSA uptake are closely related. Because proliferation and a high level of constitutive FAK activation are linked to cancer progression, it can be assumed that in vivo V DMSA uptake reflects tumour aggressiveness.     

Antopol-Goldman lesion: a rare cause of hematuria

An Antopol-Goldman lesion or subepithelial pelvic hematoma of the kidney is a rare cause of hematuria. We described a 26 year-old man hospitalized for macroscopic hematuria associated with a subepithelial hematoma whose development might have been favored by arterial hypertension secondary to a renal artery stenosis.     

Visualization of local Ca2+ dynamics with genetically encoded bioluminescent reporters

Measurements of local Ca2+ signalling at different developmental stages and/or in specific cell types is important for understanding aspects of brain functioning. The use of light excitation in fluorescence imaging can cause phototoxicity, photobleaching and auto-fluorescence. In contrast, bioluminescence does not require the input of radiative energy and can therefore be measured over long periods, with very high temporal resolution. Aequorin is a genetically encoded Ca(2+)-sensitive bioluminescent protein, however, its low quantum yield prevents dynamic measurements of Ca2+ responses in single cells. To overcome this limitation, we recently reported the bi-functional Ca2+ reporter gene, GFP-aequorin (GA), which was developed specifically to improve the light output and stability of aequorin chimeras [V. Baubet, et al., (2000) PNAS, 97, 7260-7265]. In the current study, we have genetically targeted GA to different microdomains important in synaptic transmission, including to the mitochondrial matrix, endoplasmic reticulum, synaptic vesicles and to the postsynaptic density. We demonstrate that these reporters enable 'real-time' measurements of subcellular Ca2+ changes in single mammalian neurons using bioluminescence. The high signal-to-noise ratio of these reporters is also important in that it affords the visualization of Ca2+ dynamics in cell-cell communication in neuronal cultures and tissue slices. Further, we demonstrate the utility of this approach in ex-vivo preparations of mammalian retina, a paradigm in which external light input should be controlled. This represents a novel molecular imaging approach for non-invasive monitoring of local Ca2+ dynamics and cellular communication in tissue or whole animal studies.     

Efficacy and safety of two dosages of cotrimoxazole as preventive treatment for HIV-infected Malawian adults with new smear-positive tuberculosis

OBJECTIVE: To assess the efficacy and safety of two different dosages of cotrimoxazole (CTX) in prophylaxis in HIV-positive new smear-positive pulmonary tuberculosis (TB) patients in Blantyre, Malawi. METHOD: Randomized, double-blind trial using 480 and 960 mg of CTX given to new TB patients, who were followed up until the end of the tuberculosis treatment. The primary outcome was survival. The outcome in the two groups was also compared with an unselected cohort of similar patients registered in Zomba, Malawi in 1995 and new smear-positive patients registered in the National Tuberculosis Programme in 1999. The secondary outcome was the occurrence of (opportunistic) events, especially bacterial pneumonia. RESULTS: There were no statistically significant differences in mortality and bacterial pneumonia between the groups receiving the two different dosages. The case fatality rate at the end of the tuberculosis treatment was 15.4% in the 480 mg group and 14.0% in the 960 mg group. This was lower than the case fatality rate in the Zomba cohort (19.2%, P = 0.10) and lower than the case fatality rate in the national programme (21.0%, P < 0.001). CTX was well tolerated. Compliance was fair. CONCLUSIONS: CTX prophylaxis may have a beneficial effect on mortality and morbidity in HIV-infected smear-positive tuberculosis patients in Malawi. The efficacy of both dosages is not significantly different. The intervention is cheap and easy to implement. These results would support implementation of CTX in this patient group until better strategies are available or evidence is convincingly presented to suggest that its benefit is marginal.     

Time course of catch-up in adiposity influences adult anthropometry in individuals who were born small for gestational age

Although necessary for a normal final height in individuals who were born small for gestational age (SGA), catch-up growth is associated with drastic changes in body composition that have been suspected to favor the later development of the long-term metabolic complications by promoting central adiposity; however, the specific contribution of catch-up itself on these later complications remains unclear. Therefore, the aim of the study was to characterize the dynamic changes in adiposity during childhood in individuals who were born SGA and to investigate their consequences on adulthood. The magnitude and the time course of postnatal changes in body mass index (BMI) relative to birth and their consequences on adult adiposity were investigated in 127 adults who were born SGA and had available serial anthropometric data in childhood (0-6 y) and adulthood. Catch-up in BMI, observed in 91% of individuals who were born SGA, was mostly completed within the first or second year of age. Overall, adult BMI was correlated with the magnitude of gain in BMI during childhood. However, this effect was significant only when this gain persisted after the first year of life. Similarly, the influence of the magnitude in gain in BMI on the risk for adult BMI >25 kg/m(2) was significantly influenced by the age at which the gain in BMI occurred. In summary, although the extent of catch-up in BMI affects adiposity in adulthood, this effect is mostly deleterious when occurring after 1 y of age, suggesting that a rapid catch-up process should be more suitable than a delayed one. Whether this observation holds through regarding the metabolic syndrome remains to be elucidated.     

Therapeutic schedules influence the pattern of intellectual decline after irradiation of posterior fossa tumors

BACKGROUND: To evaluate intellectual decline in children with posterior fossa (PF) tumors treated with different therapeutic protocols. PROCEDURE: Forty children had a complete neuropsychological evaluation prospectively twice, at least 6 months year (y) after the end of their treatment. Patients were classified into four groups according to treatment schedules: Group 1 (n = 7) PF radiotherapy (PFRT) alone at 50 Gy; Group 2 (n = 13) reduced-dose cranio-spinal irradiation (CSI) at 25 Gy with a PF boost; Group 3 (n = 9) standard CSI at 35 Gy and a PF boost; and Group 4 (n = 11) high-dose chemotherapy with stem cell support followed by PFRT at 50 Gy. RESULTS: At the first evaluation (mean interval since diagnosis 3.7 y), the mean Full-Scale Intellectual Quotient (FSIQ) was 80 (SD = 19). Only patients in Group 1 had a normal mean IQ score of 92 (SD = 14). At the second evaluation (mean interval since diagnosis 6.3 y), the mean FSIQ scores were significantly lower with a mean difference of 2.4 points, i.e., a yearly decline of one point. The magnitude of the FSIQ decline was positively correlated with the first IQ score (P = 0.0001) and inversely correlated with age at diagnosis (P = 0.0005). A FSIQ decline was observed in all treatment groups except Group 1 (P = 0.005). The differences in FSIQ observed initially between the four treatment groups persisted at the second evaluation. CONCLUSIONS: This study shows that FSIQ continues to decline more than 4 years after the diagnosis but this yearly decline seems to decrease with time from diagnosis. Therapeutic schedules influence the magnitude of this decline. Long-term follow-up into adulthood is necessary to effectively adapt patient rehabilitation.     

Accessing key steps of human tumor progression in vivo by using an avian embryo model

Experimental in vivo tumor models are essential for comprehending the dynamic process of human cancer progression, identifying therapeutic targets, and evaluating antitumor drugs. However, current rodent models are limited by high costs, long experimental duration, variability, restricted accessibility to the tumor, and major ethical concerns. To avoid these shortcomings, we investigated whether tumor growth on the chick chorio-allantoic membrane after human glioblastoma cell grafting would replicate characteristics of the human disease. Avascular tumors consistently formed within 2 days, then progressed through vascular endothelial growth factor receptor 2-dependent angiogenesis, associated with hemorrhage, necrosis, and peritumoral edema. Blocking of vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor signaling pathways by using small-molecule receptor tyrosine kinase inhibitors abrogated tumor development. Gene regulation during the angiogenic switch was analyzed by oligonucleotide microarrays. Defined sample selection for gene profiling permitted identification of regulated genes whose functions are associated mainly with tumor vascularization and growth. Furthermore, expression of known tumor progression genes identified in the screen (IL-6 and cysteine-rich angiogenic inducer 61) as well as potential regulators (lumican and F-box-only 6) follow similar patterns in patient glioma. The model reliably simulates key features of human glioma growth in a few days and thus could considerably increase the speed and efficacy of research on human tumor progression and preclinical drug screening.     

Expressed isolated integrin beta1 subunit cytodomain induces endothelial cell death secondary to detachment

Expression of isolated beta integrin cytoplasmic domains in cultured endothelial cells was reported to induce cell detachment and death. To test whether cell death was the cause or the consequence of cell detachment, we expressed isolated integrin beta1 cytoplasmic and transmembrane domains (CH1) in cultured human umbilical vein endothelial cells (HUVEC), and monitored detachment, viability, caspase activation and signaling. CH1 expression induced dose-dependent cell detachment. At 24 h over 90% of CH1-expressing HUVEC were detached but largely viable (>85%). No evidence of pro-caspase-8,-3, and PARP cleavage or suppression of phosphorylation of ERK, PKB and Ikappa-B was observed. The caspase inhibitor z-VAD did not prevent cell detachment. At 48 h, however, CH1-expressing cells were over 50% dead. As a comparison trypsin-mediated detachment resulted in a time-dependent cell death, paralleled by caspase-3 activation and suppression of ERK, PKB and Ikappa-B phosphoyrylation at 24 h or later after detachment. HUVEC stimulation with agents that strengthen integrin-mediated adhesion (i.e. PMA, the Src inhibitor PP2 and COMP-Ang1) did not prevent CH1-induced detachment. Expression of CH1 in rat carotid artery endothelial cells in vivo caused endothelial cell detachment and increased nuclear DNA fragmentation among detached cells. A construct lacking the integrin cytoplasmic domain (CH2) had no effect on adhesion and cell viability in vitro and in vivo. These results demonstrate that isolated beta1 cytoplasmic domain expression induces caspase-independent detachment of viable endothelial cells and that death is secondary to detachment (i.e. anoikis). They also reveal an essential role for integrins in the adhesion and survival of quiescent endothelial cells in vivo.     

Involvement of the basal ganglia in refractory epilepsy: an 18F-fluoro-L-DOPA PET study using 2 methods of analysis.

Studies in animal models and epileptic patients have led to the suggestion that the basal ganglia (BG) are involved in seizures. PET with 6-18F-L-3,4-fluorodihydroxyphenylalanine (18F-fluoro-L-DOPA) has recently demonstrated a reduction of striatal dopamine uptake in drug-resistant epileptic patients with ring chromosome 20 (r20) using a multiple-time graphical analysis. The aim of the present study was to evaluate the involvement of dopamine in other epileptic syndromes using a multiple-time graphical analysis and the all-brain statistical parametric mapping (SPM) analysis. METHODS: Patients with drug-resistant epilepsy were divided into 3 groups: group 1, with r20 epilepsy (n = 16; mean age +/- SD, 21.5 +/- 5.4 y); group 2, with resistant generalized "absence-like" epilepsy (n = 10; mean age, 32.3 +/- 11.4 y); and group 3, with drug-resistant temporal lobe epilepsy with hippocampal sclerosis (n = 9; mean age, 35.2 +/- 10.3 y). We compared 2 strategies of analysis of the 18F-fluoro-L-DOPA uptake constant (K(i), min(-1)) in BG using a multiple-time graphical analysis using regions of interest (the gold-standard method) and an SPM analysis using a voxel-by-voxel statistical t test to avoid a priori hypotheses in the analysis. Each epileptic group was compared with a group of healthy volunteers (n = 10; mean age, 45.1 +/- 16.5 y). RESULTS: A decrease of the mean K(i) value was observed in the striatum in all groups of patients with both types of analysis. With multiple-time graphical analysis, the reduction was evident using the averaged K(i) values over both hemispheres in each BG. Unilateral decreases in each BG were detected in SPM analysis. A ratio of decrease of 18F-fluoro-L-DOPA uptake was observed in the 3 groups of patients. Only the SPM analysis showed a decrease of 18F-fluoro-L-DOPA uptake ipsilateral to the seizure side in patients with temporal lobe epilepsy. Moreover, the all-brain SPM analysis showed a decrease of 18F-fluoro-L-DOPA uptake in the substantia nigra bilaterally (P < 0.001). CONCLUSION: This result confirms the involvement of dopamine neurotransmission in seizure control related to the type of epileptic syndrome. The difference in epileptic types may depend in part on the seizure frequency.     

Prenatal molecular diagnosis in hypertrophic cardiomyopathy: report of the first case

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease that may cause premature sudden death, especially in teenagers and young adults. The recent progress in the molecular genetics of the disease has made genetic testing sometimes available in clinical practice. We report the case of a couple who still requested prenatal molecular testing after detailed information had been given through a multidisciplinary consultation. Prenatal diagnosis in HCM is associated with complex medical and psychological implications, in addition to general ethical considerations, as the potential value of the diagnosis is counterbalanced by the highly variable expression of the disease and the difficulty in predicting its evolution. The R403L mutation in the MYH7 gene had been previously identified in this family, characterized by a malignant form of HCM. In the specific context of this case, we decided to agree to the request of the parents and performed the prenatal diagnosis. To the best of our knowledge, this is the first report of a prenatal molecular diagnosis performed in the context of HCM.