Volumetric modulated arctherapy for locally advanced nasopharyngeal carcinoma: Clinical efficacy and late toxicity.

PURPOSE: We report our experience of 86 consecutive patients with locally advanced nasopharyngeal carcinoma who were treated with volumetric modulated arc therapy. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 86 patients with histologically proven primary nasopharyngeal carcinoma treated with volumetric modulated arctherapy technique radiotherapy. Primary endpoints were local, regional, distant control, and overall survival, second endpoint was late toxicity. RESULTS: The median age was 47.5 years (range: 13-79 years) with sex ratio 1.09. At diagnosis, rhinologic symptoms represented the most common clinical presentation, reported by 61 patients (70.9%). Almost 88.4% of patients presented non-keratinizing undifferentiated carcinoma histology (n=76). Most of the patients presented a locally advanced disease defined by stage III and IVa (95.3%). Therefore, 31 patients were treated by concurrent chemoradiation (36%), 52 patients received induction chemotherapy followed by concurrent chemoradiotherapy (57%), three patients received induction chemotherapy followed by exclusive radiotherapy (3.5%). and three patients treated with exclusive irradiation (3.5%). With a median follow up of 15.7 months (range: 4-33.3 months), nine patients died (10.4%), three presented local or locoregional relapse (3.4%), while nine patients presented distant recurrences (10.4%). The two years overall and disease-free survival rates were 88.7% and 83.1% respectively, locoregional control was 100% at 12 months and 96.2% at 24 months, and the two years distant failure-free survival was 86.7%. Time to relapse was the only prognostic factor in univariate analysis for overall survival in our study. The therapeutic tolerance was good with 61.7% of grade 3 and 2.3% grade 4 hyposialia respectively, 46.5% of otological disorders and no radionecrosis was noted. CONCLUSION: Volumetric modulated arctherapy technique with concurrent chemoradiotherapy is an effective treatment for nasopharyngeal carcinoma with excellent overall and locoregional control without severe toxicity. Distant metastasis is the major site of failure, so induction chemotherapy added to chemoradiotherapy must be discussed in multidisciplinary consultation meeting because it significantly improved recurrence-free survival and overall survival, as compared with chemoradiotherapy alone.

Evaluation of margins in pelvic lymph nodes and prostate radiotherapy and the impact of bladder and rectum on prostate position.

PURPOSE: The aims of this study were: determination of the CTV to PTV margins for prostate and pelvic lymph nodes. Investigation of the impact of registration modality (pelvic bones or prostate) on the CTV to PTV margins of pelvic lymph nodes. Investigation of the variations of bladder and rectum over the treatment course. Investigation of the impact of bladder and rectum variations on prostate position. PATIENTS AND METHODS: This study included 15 patients treated for prostate adenocarcinoma. Daily kilo voltage images and weekly CBCT scans were performed to assess prostate displacements and common and external iliac vessels motion. These data was used to calculate the CTV to PTV margins using Van Herk equation in the setting of a daily bone registration. We also compared the CTV to PTV margins of pelvic lymph nodes according to registration method; based on pelvic bone or prostate. We delineated bladder and rectum on all CBCT scans to assess their variations over treatment course at 4 anatomic levels [1.5cm above pubic bone (PB), superior edge, mid- and inferior edge of PB]. RESULTS: Using Van Herk equation, the prostate CTV to PTV margins (bone registration) were 8.03mm, 5.42mm and 8.73mm in AP, ML and SI direction with more than 97% of prostate displacements were less than 5mm. The CTV to PTV margins ranged from 3.12mm to 3.25mm for external iliac vessels and from 3.12mm to 4.18mm for common iliac vessels. Compared to registration based on prostate alignment, bone registration resulted in an important reduction of the CTV to PTV margins up to 54.3% for external iliac vessels and up to 39.6% for common iliac vessels. There was no significant variation of the mean bladder volume over the treatment course. There was a significant variation of the mean rectal volume before and after the third week of treatment. After the third week, the mean rectal volume seemed to be stable. The uni- and multivariate analysis identified the anterior wall of rectum as independent factor acting on prostate motion in AP direction at 2 levels (superior edge of, mid PB). The right rectal wall influenced the prostate motion in ML direction at inferior edge of PB. The bladder volume tends toward significance as factor acting on prostate motion in AP direction. CONCLUSIONS: We recommend CTV to PTV margins of 8mm, 6mm and 9mm in AP, ML and SI directions for prostate. And, we suggest 4mm and 5mm for external and common iliac vessels respectively. We also prefer registration based on bony landmarks to minimize bowel irradiation. More CBCT scans should be performed during the first 3weeks and especially the first week to check rectum volume.

Characterization of the harmful effect of olive mill wastewater on spearmint.

In this study, changes in viability, biomass production, essential oil yield and essential oil composition of Mentha spicata L. (spearmint) exposed to olive mill wastewater (OMW) were investigated. Spearmint cuttings were sensitive to OMW and, after 6h of incubation in raw or diluted OMW, their viability was null. The short contact of raw OMW with mint cuttings caused an irreversible damage in rhizogenesis and shoots development. Roots were more sensitive to phytotoxicity than shoots. In a field essay, spearmint showed a good capability to recover when OMW was spread at 8 l m(-2) at the vegetative phase of growth (45 days after plantation). At this dose, a slight increase of mostly of the mint essential oil constituents was obtained. When the dose applied was 16 l m(-2), phytotoxicity was manifested by a high reduction of biomass and essential oil yield. The essential oil composition was also affected and a disappearance of many of mint essential oil constituents was observed with an increase of 59% for carvone, the major compound of spearmint essential oil. As far as we know, this is the first report on the effect of field application of OMW on an aromatic plant essential oil yield and composition.

Effect of prefermentation on denitrifying phosphorus removal in slaughterhouse wastewater.

An anaerobic-anoxic sequencing batch reactor (A2 SBR) coupled with a fixed-bed nitrification reactor for simultaneous carbon, nitrogen and phosphorus removal was evaluated using slaughterhouse wastewater. Whereas the treatment could not be successfully carried out on the raw wastewater, the process showed very good nutrient removal performances after prefermentation. The removals of COD, N-NH4 and P-PO4 achieved were 99%, 85% and 99%, respectively. The increase in volatile fatty acid (VFA) and phosphate concentrations in the effluent after prefermentation may explain the high levels of biological carbon, nitrogen and phosphorus removal observed. A simple prefermentation is, therefore, necessary but sufficient to ensure good performances of the denitrifying enhanced biological phosphorus removal (EBPR) process.

Effect of operating parameters on anoxic biological phosphorus removal in anaerobic anoxic sequencing batch reactor.

Optimizing anoxic biological phosphorus removal in the anaerobic-anoxic sequencing batch reactor (A2 SBR) was observed to depend greatly on three parameters: the amount of added nitrate, the sludge retention time (SRT) and the phosphorus/carbon feeding ratio (P/C, wt/wt). The concentration of 120 mg N-NO3 l-1 in the anoxic medium corresponding to 800 mg COD l-1 acetic acid and 60 mg P-PO4 l-1 in the synthetic wastewater, the SRT of 15 days and the P/C feeding ratio of 20/100 were determined as optimal for complete phosphorus removal in the A2 SBR. The acetate uptake, the phosphorus release and the phosphorus removal increased with the P/C feeding ratio and the phosphorus sludge content (Ps). The polyphosphate-accumulating organisms (PAO) were dominant under operation at all P/C feeding ratios tested except 2/100. At a P/C feeding ratio of 20/100, PAO could accumulate a high content of polyphosphate compared with other P/C ratios. In contrast, the P/C ratio of 2/100 caused a decrease in the polyphosphate content in PAO, the deterioration of enhanced biological phosphorus removal (EBPR) activity, and the dominance of glycogen-accumulating organisms (GAO). This study was completed by microscopic observations which revealed three morphological types of PAO. This is the first time that an oval form of PAO could be observed in the A2 SBR.

Biological denitrifying phosphorus removal in SBR: effect of added nitrate concentration and sludge retention time.

Optimizing anoxic biological phosphorus removal in the anaerobic-anoxic sequencing batch reactor (A2 SBR) was observed to depend on two parameters: the amount of added nitrate and the sludge retention time (SRT). The concentration of 120 mg N-NO3.l-1 in the anoxic medium and the SRT of 15 days were determined as optimal for a complete phosphorus removal in the A2 SBR. The reactor was supplied with synthetic wastewater containing 800 mg COD.l-1 acetic acid, 240 mg N-NH4.l-1 and 30 mg P-PO4.l-1. This study was completed by microscopic observations which revealed three morphological types of phosphate-accumulating bacteria (PAB).

Genetic analysis of early onset cerebellar ataxia with retained tendon reflexes in four Tunisian families.

Spinocerebellar ataxias comprise a poorly understood group of inherited degenerative neurological diseases. Attempts to classify hereditary ataxias on the basis of the neurological features or specific clinical signs such as tendon reflex changes have proven to be unsatisfactory. Early onset cerebellar ataxia (EOCA) is generally inherited as an autosomal-recessive trait. Thus far, we do not have accurate answers to several questions about its classification. However, significant clinical heterogeneity observed in four Tunisian families with typical EOCA clinical features reinforces the hypothesis of genetic heterogeneity underlying this phenotype. We have demonstrated that three of the four families studied were not linked to Friedreich's ataxia (FA), vitamin E deficiency ataxia (AVED), and autosomal dominant cerebellar ataxia (ADCA) loci. The fourth family showed homozygosity for a large pathological expansion of GAA repeat in all patients, the parents being heterozygous for this mutation. We have also noted, in the case of the family studied, that there was instability in the transmission of the mutation, along with a phenomenon of anticipation comparable to that observed in dominant triplet repeat diseases. EOCA is thus clinically indistinguishable from FA, yet genetically independent of all known candidate genes. Genetic mapping is required for research into the causal gene and an understanding of the disease's physiopathologic mechanisms.

More efficient allopatric combinations of Fasciola hepatica and Lymnaea truncatula due to modification of redial development?

Experimental infections of two susceptible French populations of Lymnaea truncatula (Courcelles and Saint Ours) with an allopatric (Fès, Morocco) or a semi-sympatric (Limoges, France) isolate of Fasciola hepatica miracidia were performed to determine the effect of allopatric miracidia on redial and cercarial production. In both populations, cercarial release was significantly greater in allopatric than in semi-sympatric snails. Compared to semi-sympatric snails, the examination of allopatric snails killed from day 14 to day 35 post-exposure demonstrated (1) a significant decrease after day 28 in the number of daughter rediae (R2a group) exiting from the first-appearing mother redia (R1a redia), and (2) the differentiation of numerous daughter rediae (R2b group) in the body of second-appearing mother rediae (R1b group). These experiments demonstrated that the exposure of L. truncatula to an allopatric isolate of miracidia disturbed the usual developmental pattern of redial generations and caused the formation of numerous R2b rediae. The authors hypothesized that the increase in cercarial release noted in allopatric snails would be assured by the rediae from the R2b group after their emergence from the body of R1b mother rediae.

Cloning of a Leishmania major gene encoding for an antigen with extensive homology to ribosomal protein S3a.

Following purification by affinity chromatography, a Leishmania major S-hexylglutathione- binding protein of molecular mass 66kDa was isolated. The immune serum against the parasite 66kDa polypeptide when used to screen a L. major cDNA library could identify clones encoding for the human v-fos transformation effector homologue, namely ribosomal protein S3a, and thus was named LmS3a-related protein (LmS3arp). A 1027bp cDNA fragment was found to contain the entire parasite gene encoding for a highly basic protein of 30kDa calculated molecular mass sharing homology to various ribosomal S3a proteins from different species. Using computer methods for a multiple alignment and sequence motif search, we found that LmS3arp shares a sequence homology to class theta glutathione S-transferase mainly in a segment containing critical residues involved in glutathione binding. These new findings are discussed in the light of recent published data showing multiple function(s) of the ribosomal proteins S3a.

Kinetic behavior of some polyphosphate-accumulating bacteria isolates in the presence of nitrate and oxygen.

This paper studies the phosphate uptake by pure cultures of Aeromonas hydrophila, Klebsiella oxytoca, Agrobacterium tumefaciens, and Aquaspirillum dispar in the presence of both nitrate and oxygen. It is shown that species were able to respire both electron acceptors for phosphate accumulation. A. tumefaciens and A. dispar accumulated overall phosphate both in oxic and anoxic culture conditions, whereas A. hydrophila and K. oxytoca eliminated overall phosphate only in oxic conditions. A. dispar was able to remove phosphate by reducing oxygen and nitrate simultaneously with the production of dinitrogen gas. The anoxic denitrification observed in the cultures of adapted and nonadapted cells to nitrate showed that only A. dispar have a denitrification rate superior when the cells were adapted to nitrate.

Polyphosphate-accumulating and denitrifying bacteria isolated from anaerobic-anoxic and anaerobic-aerobic sequencing batch reactors

In this study, phosphate-accumulating bacteria achieved complete phosphate removal in two different systems: an anaerobic-anoxic sequencing batch reactor and an anaerobic-aerobic sequencing batch reactor. This result shows that phosphate-accumulating bacteria in the A2 SBR can use nitrate as terminal electron acceptor instead of oxygen. Phosphate-accumulating bacteria accumulated phosphate with a rates between 30 and 70 mg P/L/h in the A/O SBR and between 15 and 32 mg P/L/h in the A2 SBR. Twenty denitrifying isolates were screened from A2 SBR and nine from A/O SBR. Identification of these isolates by the Biolog system and the API 20 NE identification kit revealed that the most active denitrifiers in both SBRs reactors were species of Ochrobactrum, Pseudomonas, Corynebacterium, Agrobacterium, Aquaspirillum, Haemophilus, Xanthomonas, Aeromonas, and Shewanella. The most active phosphate accumulating and denitrifying bacteria were identified as Agrobacterium tumefaciens B, Aquaspirillum dispar, and Agrobacterium radiobacter. This study showed that the active phosphate accumulating-bacteria were also the most efficient denitrifying bacteria in both reactors.