Mégavoltage cone-beam CT : récents développements et applications cliniques pour la radiothérapie conformationnelle avec modulation d'intensité

The Megavoltage cone-beam (MV CBCT) system consists of a new a-Si flat panel adapted for MV imaging and an integrated workflow application allowing the automatic acquisition of projection images, cone-beam CT image reconstruction, CT to CBCT image registration and couch position adjustment. This provides a 3D patient anatomy volume in the actual treatment position, relative to the treatment isocenter, moments before the dose delivery, that can be tightly aligned to the planning CT, allowing verification and correction of the patient position, detection of anatomical changes and dose calculation. In this paper, we present the main advantages and performance of this MV CBCT system and summarize the different clinical applications. Examples of the image-guided treatment process from the acquisition of the MV CBCT scan to the correction of the couch position and dose delivery will be presented for spinal and lung lesions and for head and neck, and prostate cancers.

Characterisation of an isolate of Narcissus degeneration virus from Chinese narcissus (Narcissus tazetta var. chinensis)

A potyvirus from Chinese narcissus was transmitted mechanically to three species of Narcissus and to Lycoris radiata but not to 22 other test species. In western blot, the coat protein reacted strongly with Narcissus degeneration virus (UK isolate) antiserum. Antiserum raised to the Chinese virus did not react with eighteen other potyviruses. The complete nucleotide sequence (9816 nt) had the typical genome organisation for a member of the genus Potyvirus. Sequence comparisons and phylogenetic analysis showed that the Chinese virus was different from all previously sequenced potyviruses but distantly related to onion yellow dwarf and shallot yellow stripe viruses.

Recent advances in the new generation taxane anticancer agents

Recent advances in the design and preclinical evaluations of promising new generation taxane anticancer agents are reviewed in this article. Paclitaxel and docetaxel are two of the most important anticancer drugs today. However, recent reports have shown that treatment with these drugs often encounters undesirable side effects as well as drug resistance. Therefore, it is important to develop new taxane anticancer agents with fewer side effects, superior pharmacological properties, and improved activity against drug-resistant human cancers. Structure-activity relationship (SAR) studies led to the discovery of a series of highly active second-generation taxanes. One of them, "Ortataxel" (SB-T-101131, IDN5109, BAY59-8862), exhibits excellent activity against a variety of drug-sensitive and drug-resistant cancer cell lines, as well as human tumor xenografts in mice. It is orally active and is currently in phase II clinical trials. Photoaffinity labeling of microtubules and P-glycoprotein using photoreactive radiolabeled taxoids has disclosed the drug-binding domain of tubulin as well as Pgp. Together with information on microtubule-bound fluorine-labeled taxoids obtained by solid-state NMR studies, the bioactive conformation of paclitaxel and taxoids appears to emerge. Novel taxane-monoclonal antibody (mAb) immunoconjugates, have shown highly promising results for the tumor-specific delivery and release of an extremely cytotoxic, second-generation taxane. Also, another novel series of second generation taxanes conjugated with n-3 polyunsaturated fatty acids, e.g. decosahexaenoic acid (DHA), has exhibited impressive antitumor activity with minimum general toxicity against the highly drug-resistant DLD-1 human colon cancer xenografts in SCID mice.

Are consecutive nightly recordings required for valid evaluation of sleep-associated erections?

We questioned the need for more than one RigiScan recording for accurate assessment of sleep-associated penile erections and determine the necessity of consecutive nightly recordings for valid evaluation of sleep-associated erections. Men complaining of erectile dysfunction (ED) and referred to RigiScan evaluation for the first time participated. Recordings were performed at the patient's home during two consecutive nights, and data on test time, number of erections, erection duration, minimal and maximal base and tip tumescence and rigidity were retrieved for both nights. Normal erectile function was defined with the recording of at least one erection (70 out of 100% tip rigidity lasting for at least 10 min during either night). The main outcome measures were RigiScan recordings. Group 1 consisted of 29 men (mean age 42.4+/-13.8 years, range 22-71) who had normal erections, all during the first night. Group 2 consisted of 26 men (mean age 48.6+/-13.5 years, range 25-70) who failed to fulfill both criteria for normal erection. In Group 2, only the values for penile base rigidity and erection duration were normal during the first night: the parameters of maximal base tumescence, tip rigidity, number of effective erections and duration of effective erections that were impaired during the first night were significantly worse (P<0.01) during the second night. The required information for the diagnosis of psychogenic ED was obtained during the first night in >50% of the participants. Men with normal erections during the first night can be spared the inconvenience and cost of re-testing. Consecutive night recording should be reserved for patients whose recorded data during the first night did not fulfill the criteria for normal erection.

Polymorphisms in Th1-type cell-mediated response genes and risk of gastric cancer

Helicobacter pylori infection, the dominant risk factor for gastric cancers, has been shown to elicit T helper type 1 (Th1) polarized immunological responses. We conducted a population-based study of 305 gastric cancer cases and 427 age- and gender-matched controls in Warsaw, Poland, to evaluate the association with several variants in genes responsible for Th1-cell-mediated response. Genotyping was performed on genomic DNA by TaqMan(TM) assays to determine TNFA (-308 G>A, -417 G>A, -555 G>A, -1036 C>T, -1042 C>A, -1210 T>C), IL1A (-889 C>T), IFNGR2 (Ex7-128 T>C, Ex2-34 C>G and Ex2-16 A>G) and IL12A (IVS2-798 T>A, IVS2-701 C>A and Ex7+277 G>A) polymorphisms. We used unconditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for sex, age, education and smoking status. Out of six single nucleotide polymorphisms (SNPs) tested in TNFA, gastric cancer risk was significantly associated with the TNFA (-308 G>A) polymorphism, with ORs of 1.4 (95% CI: 1.0-2.0) for the G/A and 2.5 (95% CI: 1.3-4.9) for the A/A genotype carriers, when compared with the more frequent genotype (G/G) (P-trend < 0.001). Among the three tested SNPs in the IFNGR2 gene, only the Ex7-128C>T polymorphism was associated with increased risk, with ORs of 1.5 (95% CI: 1.0-2.3) for T/C and 1.7 (95% CI: 1.1-2.7) for C/C carriers when compared with T/T carriers (P-trend = 0.01). Subjects carrying both IFNGR2 Ex7-128 C/C and TNFA -308 A/A genotypes had the highest risk (OR = 5.5, 95% CI: 1.5-19.4), although the interaction was not statistically significant. IL1A (-889 C>T) and the three examined IL12A variants were unrelated to gastric cancer risk. Our findings suggest that two Th1-related polymorphisms (TNFA -308 A>G and IFNGR2 Ex7-128 C>T) may increase the risk of gastric cancer.

Supplementing drinking water with Solutein did not mitigate acute morbidity effects of porcine reproductive and respiratory syndrome virus in nursery pigs

The objective of this study was to determine whether providing nursery pigs drinking water supplemented with spray-dried animal plasma (Solutein, American Protein Corporation Inc., Ankeny, IA) would reduce the detrimental impact of porcine reproductive and respiratory syndrome virus (PRRSV) infection. Sixty-four pigs were subjected to 1 of 4 treatment combinations (2 x 2 factorial arrangement) of Solutein [0 or 2.5% (wt/wt) in drinking water] and PRRSV (sterile medium or 5 mL of tissue culture infectious dose of high-virulence strain ATCC VR-2385). Pigs were provided the water treatments during a 1-wk period before inoculation as well as during a 2-wk period after inoculation. Growth performance was determined throughout the study, and several indicators of the immunological response to PRRSV and disease pathology were assessed in blood and tissue samples collected from pigs killed 7 or 14 d after inoculation. Before inoculation, pigs provided water supplemented with Solutein tended to eat less (P = 0.08) but tended to gain more BW (P = 0.13) than pigs provided tap water. Thus, Solutein markedly improved G:F (P < 0.01), after accounting for the DM provided by Solutein. Inoculation with PRRSV reduced ADG and ADFI (P < 0.01) irrespective of water treatment; however, the beneficial effects of Solutein on G:F persisted. Infection with PRRSV also reduced (P < 0.009) villus height and crypt depth in cranial, medial, and caudal segments of the small intestine and increased (P < 0.05) lung and spleen weight, the number of leukocytes in lung lavage fluid, and serum concentrations of interferon-gamma and IL-1beta regardless of water treatment. Collectively, these results indicate that supplementing water with spray-dried animal plasma improved feed efficiency but did not afford nursery pigs protection from the effects of PRRSV on growth and certain hematological traits.

Disruption of four-and-a-half LIM 2 decreases bone mineral content and bone mineral density in femur and tibia bones of female mice

Four-and-a-half LIM 2 (FHL2) is a member of a family of LIM domain proteins which mediate protein-protein interactions. FHL2 acts as a coactivator and binds to important regulators of bone formation such as insulin-like growth factor binding protein (IGFBP)-5, androgen receptor, and beta-catenin. We hypothesized that FHL2 is an important regulator of bone formation. We evaluated growth and skeletal parameters in FHL2 knockout (KO) and wild-type (WT) mice at 4, 8, and 12 weeks of age. At 4 weeks of age, lack of FHL2 reduced femur, tibia, and total bone mineral content (BMC) and body weight in all mice. A gender-by-treatment interaction (P <or= 0.05) was observed for several parameters due to a greater reduction in females. Specifically, femur BMC was reduced 11-27% at 8 and 12 weeks of age and BMD was reduced 7-13% at all ages in female KO mice (P < 0.05). A similar reduction was observed in the tibias at 8 weeks of age. A 6% reduction (P = 0.07) in femur cortical thickness was observed at 12 weeks of age in female KO mice. Interestingly, a gender-specific reduction in IGFBP-5 expression was observed in the femurs of female KO mice. During differentiation of bone marrow stromal cells into osteoblasts, expression of osteocalcin, alkaline phosphatase, and bone sialoprotein was reduced 47-96% in FHL2 KO cells (P < 0.001). In conclusion, FHL2 is an important regulator of peak bone mass, lack of FHL2 produces gender- and site-specific effects on bone accretion and IGFBP-5 expression, and FHL2 is important for optimal osteoblast differentiation in vitro.

Vitamin E attenuates crystal formation in rat kidneys: Roles of renal tubular cell death and crystallization inhibitors

We previously reported that oxidative stress and renal tubular damage occur in chronic hyperoxaluric rats. However, the in vivo responses of renal epithelial cells after vitamin E administration and their correlations with calcium oxalate (CaOx) crystal formation have not been evaluated. Male Wistar rats received 0.75% ethylene glycol (EG) for 7, 21, or 42 days to induce CaOx deposition (EG group). Another group of EG-treated rats received 200 mg kg(-1) of vitamin E intraperitoneally (EG+E group) to evaluate its effect on hyperoxaluria. Urinary electrolytes and biochemistry and levels of lipid peroxides and enzymes were examined, together with serum vitamin E levels. Levels of the tubular markers, alpha and mu glutathione S-transferase, proliferating cell nuclear antigen (PCNA), osteopontinin (OPN), and Tamm-Horsfall protein (THP) were also measured, and TUNEL staining was performed to examine the viability of the tubular epithelium. There were no significant differences between the two age-matched controls either untreated or given vitamin E. Compared to untreated controls, tubular cell death was increased at all time points in EG rats with a gradual increase in CaOx crystals, whereas the number of PCNA-positive cells was only significantly increased on day 21. In EG+E rats, tubular cell death was decreased compared to the EG group, and cell proliferation was seen at all time points, while CaOx crystal deposition was decreased, but hyperoxaluria, urinary lipid peroxides, and enzymuria were unaffected. Vitamin E supplement prevented the loss of OPN and THP in renal tissues by EG and the reduction in their levels in the urine. The beneficial effect of vitamin E in reducing CaOx accumulation is due to attenuation of tubular cell death and enhancement of the defensive roles of OPN and THP.

Improved glutathione production by gene expression in Escherichia coli

AIMS

To improve glutathione (GSH) production in Escherichia coli by different genetic constructions containing GSH genes.

METHODS AND RESULTS

GSH production was very low in E. coli by the expression of gshI gene. An increase of GSH production was achieved by the expression of both gshI and gshII genes in E. coli. A higher GSH production, namely 34.8 mg g(-1) wet cell weight, was obtained by simultaneous expression of two copies of gshI gene and one copy of gshII gene.

CONCLUSIONS

The simultaneous expression of two copies of gshI gene and one copy of gshII gene resulted in a significant increase in GSH production.

SIGNIFICANCE AND IMPACT OF THE STUDY

The expression strategy for GSH production described here can be used to increase gene expression and obtain high production rates in other multienzyme reaction systems.

The regulation of adiponectin receptors in human prostate cancer cell lines

Obesity is a risk factor for prostate cancer, and plasma levels of the adipokine, adiponectin, are low in the former but high in the latter. Adiponectin has been shown to modulate cell proliferation and apoptosis, suggesting that adiponectin and its receptors (Adipo-R1, Adipo-R2) may provide a molecular association between obesity and prostate carcinogenesis. We show for the first time, the protein distribution of Adipo-R1 and Adipo-R2 in LNCaP and PC3 cells, and in human prostate tissue. Using real-time RT-PCR we provide novel data demonstrating the differential regulation of Adipo-R1 and Adipo-R2 mRNA expression by testosterone, 5-alpha dihydrotestosterone, beta-estradiol, tumour necrosis factor-alpha, leptin, and adiponectin in LNCaP and PC3 cells. Our findings suggest that adiponectin and its receptors may contribute to the molecular association between obesity and prostate cancer through a complex interaction with other hormones and cytokines that also play important roles in the pathophysiology of obesity and prostate cancer.

Endothelin receptor antagonists for pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a devastating disease, which leads to right heart failure and premature death. Pulmonary arterial hypertension can be classified into five categories according to Venice classification: (1) Idiopathic PAH; (2) Familial PAH; (3) PAH associated with collagen vascular disease, congenital systemic-to-pulmonary shunts, portal hypertension, HIV infection, drugs and toxins or other (thyroid disorders, glycogen storage disease, Gaucher disease, hereditary hemorrhagic telangiectasia, hemoglobinopathies, myeloproliferative disorders, splenectomy); (4) PAH associated with significant venous or capillary involvement, which includes pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis (PCH); (5) Persistent pulmonary hypertension of the newborn. PAH can also be secondary to chronic hypoxic lung disease as part of the "cor-pulmonale" syndrome, and also secondary to left sided heart disease, but these conditions are usually distinguished from those listed here.

OBJECTIVES

To evaluate the efficacy of endothelin receptor antagonists in pulmonary arterial hypertension.

SEARCH STRATEGY

A search was carried out using the CENTRAL (Cochrane Central Register of Controlled Trials), MEDLINE, EMBASE, and the reference section of retrieved articles. Searches are current as of August 2005.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-randomised controlled trials involving patients with pulmonary arterial hypertension (PAH) were selected by two reviewers.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies; assessed study quality; and extracted data. We analysed outcomes as continuous and dichotomous data.

MAIN RESULTS

In this updated version of the review, we added two RCTs. Altogether, five RCTs met the entry criteria of the review (reporting eight group comparisons). The studies were of short duration (12-16 weeks), recruiting a total of 482 participants. Three studies compared a non-selective ERA (bosentan) with placebo, one compared bosentan with sildenafil (a phosphodiesterase inhibitor) , and one compared a selective ERA (sitaxsentan) with placebo. Over a 12-16 week period ERAs improved exercise capacity, improve Borg dyspnoea score, some measures of cardiopulmonary haemodynamics (pulmonary artery pressure, pulmonary vascular resistance, and cardiac index) in symptomatic patients with mainly idiopathic PAH. The effect of ERAs on mortality was not significant. The most severe side effect, hepatic toxicity, was not common.

AUTHORS' CONCLUSIONS

ERAs in conjunction with conventional therapy over 12 to 16 weeks can improve exercise capacity, Borg dyspnoea scores and several cardiopulmonary haemodynamics variables in patients mainly with idiopathic PAH. The data on mortality do not currently show a benefit of this class of drugs on this endpoint. Additional assessment of this outcome is important in order to establish whether there is evidence that ERAs have an impact on the risk of death. Longer studies are required.

Role of colanic acid exopolysaccharide in the survival of enterohaemorrhagic Escherichia coli O157:H7 in simulated gastrointestinal fluids

AIM

This study evaluated the production of colanic acid (CA) exopolysaccharide (EPS) by Escherichia coli O157:H7 in relation to the pathogen's ability to survive under acidic conditions simulating the environment in the human gastrointestinal tract.

METHODS AND RESULTS

Escherichia coli O157:H7 W6-13 and its CA-deficient mutant M4020 were examined for their resistance to bile salts, and their ability to survive in simulated gastric fluid containing pepsin (pH 2.0) and simulated intestinal fluid containing pancreatin (pH 8.0). The effect of acid adaptation at pH 5.5 on the survival of E. coli O157:H7 in simulated gastric fluid was also determined. The results indicated that the survivability of M4020, under conditions simulating the environment in the human gastrointestinal tract, reduced more drastically than the viability of W6-13. The presence of bile salts had a slight effect on both types of E. coli O157:H7 cells. The loss of CA did not change the ability of M4020 to respond to acid adaptation.

CONCLUSION

The EPS CA may serve as a protective barrier to E. coli O157:H7 for its survival in the human gastrointestinal tract.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study contributes to a better understanding of the EPS affecting the ability of E. coli O157:H7 to combat acid stress.

Suppression of tumor growth by intra-muscular transfer of naked DNA encoding adrenomedullin antagonist

We have recently reported that the intra-tumoral injection of adrenomedullin (AM) antagonist (AMA; AM (22-52)) peptides significantly reduced the in vivo growth of a pancreatic cancer cell line in severely combined immunodeficient (SCID) mice. In the present study, we examined the effects of intra-tumoral and intra-muscular transfers of naked DNA encoding AMA on the in vivo growth of cancer cell lines. We demonstrate that these treatments induce the regression of a pancreatic cancer cell line and a breast cancer cell line inoculated in SCID mice. Furthermore, CD31-positive cells disappear completely from tumor tissues, following treatment, indicating that neo-vascularization is entirely inhibited. These results suggest that the intra-tumoral or intra-muscular transfer of naked DNA encoding AMA might be a promising alternative modality for treating human cancers.

Catechol-o-methyltransferase enzyme activity and protein expression in human prefrontal cortex across the postnatal lifespan

The prefrontal cortex (PFC) dopamine system, which is critical for modulating PFC function, undergoes remodeling until at least young adulthood in primates. Catechol-o-methyltransferase (COMT) alters extracellular dopamine levels in PFC, and its gene contains a functional polymorphism (Val(158)Met) that has been associated with variation in PFC function. We examined COMT enzyme activity and protein immunoreactivity in the PFC during human postnatal development. Protein was extracted from PFC of normal individuals from 6 age groups: neonates (1-4 months), infants (5-11 months), teens (14-18 years), young adults (20-24 years), adults (31-43 years), and aged individuals (68-86 years; n = 5-8 per group). There was a significant 2-fold increase in COMT enzyme activity from neonate to adulthood, paralleled by increases in COMT protein immunoreactivity. Furthermore, COMT protein immunoreactivity was related to Val(158)Met genotype, as has been previously demonstrated. The significant increase in COMT activity from neonate to adulthood complements previous findings of protracted postnatal changes in the PFC dopamine system and may reflect an increasing importance of COMT for PFC dopamine regulation during maturation.

Late and early C4d-positive acute rejection: Different clinico-histopathological subentities in renal transplantation

This study was performed to investigate the clinical and pathologic features of C4d-positive steroid-resistant acute rejection (AR) at different phases after renal transplantation. Fifty-six kidney allograft recipients with C4d-positive AR were divided into three groups, very early rejection (VER, occurring < or =14 days following transplantation, n=28), early rejection (ER, occurring 15-180 days following transplantation, n=5), and late rejection (LR, occurring >180 days following transplantation, n=23). Clinical and pathological features were evaluated. Significantly more patients in the ER and LR groups were associated with a reduction or withdrawal of immunosuppressants. More patients in the ER and LR groups experienced a significant (>3 g/l) decrease in serum albumin (80% ER, 91.3% LR, 7.1% VER, P<0.001) and a decrease in hemoglobin (>1 g/dl) (80, 100 vs 17.9%, P<0.001). Most VER patients reported a fever and had very rapid graft dysfunction requiring dialysis. Significantly more patients (87%) had interstitial fibrosis and tubular atrophy in the LR group compared with the other groups and 13% had transplant glomerulopathy. Most cases of VER were reversed with tacrolimus and mycophenolate mofetil treatment, with or without immunoadsorption, with a 1-year survival rate of 96.4%, compared with only 60 and 52.2% in the ER and LR groups. In conclusion, C4d-positive steroid-resistant AR at different time points is associated with unique clinico-histopathological manifestations requiring distinct treatment strategies. Late episodes are usually associated with significantly reduced serum albumin and hemoglobin levels and a poorer outcome. A more specialized treatment protocol should be established for these patients.

Effect of phospholipid composition on characterization of liposomes containing 9-nitrocamptothecin

9-Nitrocamptothecin (9-NC), a newly developed camptothecin derivative, had poor solubility in any pharmaceutically acceptable solvents. One way of improving the solubility is to formulate the drug into liposomes. However, 9-NC has low affinity to lipid membranes resulting in a very low drug-to-liposome entrapment. We developed a novel liposome-based 9-NC formulation which was composed of soybean phosphatidylcholine (SPC), hydrogenated soybean phosphatidylcholine (HSPC), and cholesterol. Compared with conventional liposomes composed of only SPC and cholesterol, 9-NC/lipid molar ratio increased from 1:72 to 1:18 while incorporation efficiency was still maintained about 80%. In addition, after 9-NC was encapsulated into novel liposomes, pharmacokinetic results revealed an increase in area under the plasma concentration-time curve (AUC) and a decrease in distribution volume of 9-NC following intravenous administration to rats. Increased stability in plasma may account for the improved pharmacokinetic behavior of the novel liposomes. Effect of HSPC/SPC molar ratio on characterization of the novel liposomes was also investigated. Except for drug/lipid molar ratio and encapsulation efficiency, HSPC/SPC molar ratio had only a little effect on other properties of novel liposomes. In conclusion, the study suggests that the novel liposomes can act as promising carriers for hydrophobic substances such as 9-NC.