Carbohydrate microarrays and their use for the identification of molecular markers for plant cell wall composition.

Genetic improvement of the plant cell wall has enormous potential to increase the quality of food, fibers, and fuels. However, the identification and characterization of genes involved in plant cell wall synthesis is far from complete. Association mapping is one of the few techniques that can help identify candidate genes without relying on our currently incomplete knowledge of cell wall synthesis. However, few cell wall phenotyping methodologies have proven sufficiently precise, robust, or scalable for association mapping to be conducted for specific cell wall polymers. Here, we created high-density carbohydrate microarrays containing chemically extracted cell wall polysaccharides collected from 331 genetically diverse Brassica napus cultivars and used them to obtain detailed, quantitative information describing the relative abundance of selected noncellulosic polysaccharide linkages and primary structures. We undertook genome-wide association analysis of data collected from 57 carbohydrate microarrays and identified molecular markers reflecting a diversity of specific xylan, xyloglucan, pectin, and arabinogalactan moieties. These datasets provide a detailed insight into the natural variations in cell wall carbohydrate moieties between B. napus genotypes and identify associated markers that could be exploited by marker-assisted breeding. The identified markers also have value beyond B. napus for functional genomics, facilitated by the close genetic relatedness to the model plant Arabidopsis Together, our findings provide a unique dissection of the genetic architecture that underpins plant cell wall biosynthesis and restructuring.

The evolution of host specialization in the vertebrate gut symbiont Lactobacillus reuteri.

Recent research has provided mechanistic insight into the important contributions of the gut microbiota to vertebrate biology, but questions remain about the evolutionary processes that have shaped this symbiosis. In the present study, we showed in experiments with gnotobiotic mice that the evolution of Lactobacillus reuteri with rodents resulted in the emergence of host specialization. To identify genomic events marking adaptations to the murine host, we compared the genome of the rodent isolate L. reuteri 100-23 with that of the human isolate L. reuteri F275, and we identified hundreds of genes that were specific to each strain. In order to differentiate true host-specific genome content from strain-level differences, comparative genome hybridizations were performed to query 57 L. reuteri strains originating from six different vertebrate hosts in combination with genome sequence comparisons of nine strains encompassing five phylogenetic lineages of the species. This approach revealed that rodent strains, although showing a high degree of genomic plasticity, possessed a specific genome inventory that was rare or absent in strains from other vertebrate hosts. The distinct genome content of L. reuteri lineages reflected the niche characteristics in the gastrointestinal tracts of their respective hosts, and inactivation of seven out of eight representative rodent-specific genes in L. reuteri 100-23 resulted in impaired ecological performance in the gut of mice. The comparative genomic analyses suggested fundamentally different trends of genome evolution in rodent and human L. reuteri populations, with the former possessing a large and adaptable pan-genome while the latter being subjected to a process of reductive evolution. In conclusion, this study provided experimental evidence and a molecular basis for the evolution of host specificity in a vertebrate gut symbiont, and it identified genomic events that have shaped this process.

Parallel evolution of genome structure and transcriptional landscape in the Epsilonproteobacteria.

BACKGROUND: Gene reshuffling, point mutations and horizontal gene transfer contribute to bacterial genome variation, but require the genome to rewire its transcriptional circuitry to ensure that inserted, mutated or reshuffled genes are transcribed at appropriate levels. The genomes of Epsilonproteobacteria display very low synteny, due to high levels of reshuffling and reorganisation of gene order, but still share a significant number of gene orthologs allowing comparison. Here we present the primary transcriptome of the pathogenic Epsilonproteobacterium Campylobacter jejuni, and have used this for comparative and predictive transcriptomics in the Epsilonproteobacteria. RESULTS: Differential RNA-sequencing using 454 sequencing technology was used to determine the primary transcriptome of C. jejuni NCTC 11168, which consists of 992 transcription start sites (TSS), which included 29 putative non-coding and stable RNAs, 266 intragenic (internal) TSS, and 206 antisense TSS. Several previously unknown features were identified in the C. jejuni transcriptional landscape, like leaderless mRNAs and potential leader peptides upstream of amino acid biosynthesis genes. A cross-species comparison of the primary transcriptomes of C. jejuni and the related Epsilonproteobacterium Helicobacter pylori highlighted a lack of conservation of operon organisation, position of intragenic and antisense promoters or leaderless mRNAs. Predictive comparisons using 40 other Epsilonproteobacterial genomes suggests that this lack of conservation of transcriptional features is common to all Epsilonproteobacterial genomes, and is associated with the absence of genome synteny in this subdivision of the Proteobacteria. CONCLUSIONS: Both the genomes and transcriptomes of Epsilonproteobacteria are highly variable, both at the genome level by combining and division of multicistronic operons, but also on the gene level by generation or deletion of promoter sequences and 5' untranslated regions. Regulatory features may have evolved after these species split from a common ancestor, with transcriptome rewiring compensating for changes introduced by genomic reshuffling and horizontal gene transfer.

Selenium-dependent biogenesis of formate dehydrogenase in Campylobacter jejuni is controlled by the fdhTU accessory genes.

The food-borne bacterial pathogen Campylobacter jejuni efficiently utilizes organic acids such as lactate and formate for energy production. Formate is rapidly metabolized via the activity of the multisubunit formate dehydrogenase (FDH) enzyme, of which the FdhA subunit is predicted to contain a selenocysteine (SeC) amino acid. In this study we investigated the function of the cj1500 and cj1501 genes of C. jejuni, demonstrate that they are involved in selenium-controlled production of FDH, and propose the names fdhT and fdhU, respectively. Insertional inactivation of fdhT or fdhU in C. jejuni resulted in the absence of FdhA and FdhB protein expression, reduced fdhABC RNA levels, the absence of FDH enzyme activity, and the lack of formate utilization, as assessed by (1)H nuclear magnetic resonance. The fdhABC genes are transcribed from a single promoter located two genes upstream of fdhA, and the decrease in fdhABC RNA levels in the fdhU mutant is mediated at the posttranscriptional level. FDH activity and the ability to utilize formate were restored by genetic complementation with fdhU and by supplementation of the growth media with selenium dioxide. Disruption of SeC synthesis by inactivation of the selA and selB genes also resulted in the absence of FDH activity, which could not be restored by selenium supplementation. Comparative genomic analysis suggests a link between the presence of selA and fdhTU orthologs and the predicted presence of SeC in FdhA. The fdhTU genes encode accessory proteins required for FDH expression and activity in C. jejuni, possibly by contributing to acquisition or utilization of selenium.

Alternative spermidine biosynthetic route is critical for growth of Campylobacter jejuni and is the dominant polyamine pathway in human gut microbiota.

The availability of fully sequenced bacterial genomes has revealed that many species known to synthesize the polyamine spermidine lack the spermidine biosynthetic enzymes S-adenosylmethionine decarboxylase and spermidine synthase. We found that such species possess orthologues of the sym-norspermidine biosynthetic enzymes carboxynorspermidine dehydrogenase and carboxynorspermidine decarboxylase. By deleting these genes in the food-borne pathogen Campylobacter jejuni, we found that the carboxynorspermidine decarboxylase orthologue is responsible for synthesizing spermidine and not sym-norspermidine in vivo. In polyamine auxotrophic gene deletion strains of C. jejuni, growth is highly compromised but can be restored by exogenous sym-homospermidine and to a lesser extent by sym-norspermidine. The alternative spermidine biosynthetic pathway is present in many bacterial phyla and is the dominant spermidine route in the human gut, stomach, and oral microbiomes, and it appears to have supplanted the S-adenosylmethionine decarboxylase/spermidine synthase pathway in the gut microbiota. Approximately half of the gut Firmicutes species appear to be polyamine auxotrophs, but all encode the potABCD spermidine/putrescine transporter. Orthologues encoding carboxyspermidine dehydrogenase and carboxyspermidine decarboxylase are found clustered with an array of diverse putrescine biosynthetic genes in different bacterial genomes, consistent with a role in spermidine, rather than sym-norspermidine biosynthesis. Due to the pervasiveness of ε-proteobacteria in deep sea hydrothermal vents and to the ubiquity of the alternative spermidine biosynthetic pathway in that phylum, the carboxyspermidine route is also dominant in deep sea hydrothermal vents. The carboxyspermidine pathway for polyamine biosynthesis is found in diverse human pathogens, and this alternative spermidine biosynthetic route presents an attractive target for developing novel antimicrobial compounds.

Complete genome sequence of the proteolytic Clostridium botulinum type A5 (B3') strain H04402 065.

H04402 065 is one of a very small group of strains of proteolytic Clostridium botulinum that form type A5 neurotoxin. Here, we report the complete 3.9-Mb genome sequence and annotation of strain H04402 065, which was isolated from a botulism patient in the United Kingdom in 2004.

Two respiratory enzyme systems in Campylobacter jejuni NCTC 11168 contribute to growth on L-lactate.

Campylobacter jejuni, a major food-borne intestinal pathogen, preferentially utilizes a few specific amino acids and some organic acids such as pyruvate and L- and D-lactate as carbon sources, which may be important for growth in the avian and mammalian gut. Here, we identify the enzymatic basis for C. jejuni growth on L-lactate. Despite the presence of an annotated gene for a fermentative lactate dehydrogenase (cj1167), no evidence for lactate excretion could be obtained in C. jejuni NCTC 11168, and inactivation of the cj1167 gene did not affect growth on lactate as carbon source. Instead, L-lactate utilization in C. jejuni NCTC 11168 was found to proceed via two novel NAD-independent L-LDHs; a non-flavin iron-sulfur containing three subunit membrane-associated enzyme (Cj0075c-73c), and a flavin and iron-sulfur containing membrane-associated oxidoreductase (Cj1585c). Both enzymes contribute to growth on L-lactate, as single mutants in each system grew as well as wild-type on this substrate, while a cj0075c cj1585c double mutant showed no L-lactate oxidase activity and did not utilize or grow on L-lactate; D-lactate-dependent growth was unaffected. Orthologues of Cj0075c-73c (LldEFG/LutABC) and Cj1585c (Dld-II) were recently shown to represent two novel families of L- and D-lactate oxidases; this is the first report of a bacterium where both enzymes are involved in L-lactate utilization only. The cj0075c-73c genes are located directly downstream of a putative lactate transporter gene (cj0076c, lctP), which was also shown to be specific for L-lactate. The avian and mammalian gut environment contains dense populations of obligate anaerobes that excrete lactate; our data indicate that C. jejuni is well equipped to use L- and D-lactate as both electron-donor and carbon source.

Biofilm formation by Campylobacter jejuni is increased under aerobic conditions.

The microaerophilic human pathogen Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in the developed world. During transmission through the food chain and the environment, the organism must survive stressful environmental conditions, particularly high oxygen levels. Biofilm formation has been suggested to play a role in the environmental survival of this organism. In this work we show that C. jejuni NCTC 11168 biofilms developed more rapidly under environmental and food-chain-relevant aerobic conditions (20% O(2)) than under microaerobic conditions (5% O(2), 10% CO(2)), although final levels of biofilms were comparable after 3 days. Staining of biofilms with Congo red gave results similar to those obtained with the commonly used crystal violet staining. The level of biofilm formation by nonmotile aflagellate strains was lower than that observed for the motile flagellated strain but nonetheless increased under aerobic conditions, suggesting the presence of flagellum-dependent and flagellum-independent mechanisms of biofilm formation in C. jejuni. Moreover, preformed biofilms shed high numbers of viable C. jejuni cells into the culture supernatant independently of the oxygen concentration, suggesting a continuous passive release of cells into the medium rather than a condition-specific active mechanism of dispersal. We conclude that under aerobic or stressful conditions, C. jejuni adapts to a biofilm lifestyle, allowing survival under detrimental conditions, and that such a biofilm can function as a reservoir of viable planktonic cells. The increased level of biofilm formation under aerobic conditions is likely to be an adaptation contributing to the zoonotic lifestyle of C. jejuni.

Genome-Scale Metabolic Model Driven Design of a Defined Medium for Campylobacter jejuni M1cam.

Campylobacter jejuni, the most frequent cause of food-borne bacterial gastroenteritis, is a fastidious organism when grown in the laboratory. Oxygen is required for growth, despite the presence of the metabolic mechanism for anaerobic respiration. Amino acid auxotrophies are variably reported and energy metabolism can occur through several electron donor/acceptor combinations. Overall, the picture is one of a flexible, but vulnerable metabolism. To understand Campylobacter metabolism, we have constructed a fully curated, metabolic model for the reference organism M1 (our variant is M1cam) and validated it through laboratory experiments. Our results show that M1cam is auxotrophic for methionine, niacinamide, and pantothenate. There are complete biosynthesis pathways for all amino acids except methionine and it can produce energy, but not biomass, in the absence of oxygen. M1cam will grow in DMEM/F-12 defined media but not in the previously published Campylobacter specific defined media tested. Using the model, we identified potential auxotrophies and substrates that may improve growth. With this information, we designed simple defined media containing inorganic salts, the auxotrophic substrates, L-methionine, niacinamide, and pantothenate, pyruvate and additional amino acids L-cysteine, L-serine, and L-glutamine for growth enhancement. Our defined media supports a 1.75-fold higher growth rate than Brucella broth after 48 h at 37°C and sustains the growth of other Campylobacter jejuni strains. This media can be used to design reproducible assays that can help in better understanding the adaptation, stress resistance, and the virulence mechanisms of this pathogen. We have shown that with a well-curated metabolic model it is possible to design a media to grow this fastidious organism. This has implications for the investigation of new Campylobacter species defined through metagenomics, such as C. infans.

Amino acid-dependent growth of Campylobacter jejuni: key roles for aspartase (AspA) under microaerobic and oxygen-limited conditions and identification of AspB (Cj0762), essential for growth on glutamate.

Amino acids are key carbon and energy sources for the asaccharolytic food-borne human pathogen Campylobacter jejuni. During microaerobic growth in amino acid rich complex media, aspartate, glutamate, proline and serine are the only amino acids significantly utilized by strain NCTC 11168. The catabolism of aspartate and glutamate was investigated. An aspartase (aspA) mutant (unable to utilize any amino acid except serine) and a Cj0762c (aspB) mutant lacking aspartate:glutamate aminotransferase (unable to utilize glutamate), were severely growth impaired in complex media, and an aspA sdaA mutant (also lacking serine dehydratase) failed to grow in complex media unless supplemented with pyruvate and fumarate. Aspartase was shown by activity and proteomic analyses to be upregulated by oxygen limitation, and aspartate enhanced oxygen-limited growth of C. jejuni in an aspA-dependent manner. Stoichiometric aspartate uptake and succinate excretion involving the redundant DcuA and DcuB transporters indicated that in addition to a catabolic role, AspA can provide fumarate for respiration. Significantly, an aspA mutant of C. jejuni 81-176 was impaired in its ability to persist in the intestines of outbred chickens relative to the parent strain. Together, our data highlight the dual function of aspartase in C. jejuni and suggest a role during growth in the avian gut.

Domestication of Campylobacter jejuni NCTC 11168.

Reference and type strains of well-known bacteria have been a cornerstone of microbiology research for decades. The sharing of well-characterized isolates among laboratories has run in parallel with research efforts and enhanced the reproducibility of experiments, leading to a wealth of knowledge about trait variation in different species and the underlying genetics. Campylobacter jejuni strain NCTC 11168, deposited at the National Collection of Type Cultures in 1977, has been adopted widely as a reference strain by researchers worldwide and was the first Campylobacter for which the complete genome was published (in 2000). In this study, we collected 23 C. jejuni NCTC 11168 reference isolates from laboratories across the UK and compared variation in simple laboratory phenotypes with genetic variation in sequenced genomes. Putatively identical isolates, identified previously to have aberrant phenotypes, varied by up to 281 SNPs (in 15 genes) compared to the most recent reference strain. Isolates also display considerable phenotype variation in motility, morphology, growth at 37 °C, invasion of chicken and human cell lines, and susceptibility to ampicillin. This study provides evidence of ongoing evolutionary change among C. jejuni isolates as they are cultured in different laboratories and highlights the need for careful consideration of genetic variation within laboratory reference strains. This article contains data hosted by Microreact.

Transoral laser microsurgery for recurrent laryngeal and pharyngeal cancer.

STUDY DESIGN AND SETTING: A two-center prospective case series analysis. PATIENTS: One hundred fourteen patients with previously treated laryngeal or pharyngeal squamous cell carcinoma who underwent salvage transoral laser microsurgery (TLM). INTERVENTIONS: TLM in 114 patients, neck dissection in 22 (19%) patients, adjuvant radiotherapy in 12 (11%) patients. RESULTS: Ninety-one (80%) patients had recurrent primary tumors whereas 23 (20%) patients had second primary tumors occur within a previously irradiated field. The minimum follow-up was 1 year (median, 3 years). The distribution of tumor location was oropharynx 52 (46%), glottic and subglottic larynx 44 (39%), supraglottic larynx 11 (10%), and pyriform/hypopharynx 7 (6%). Overall, three-year local and locoregional control estimates were 70 percent and 67 percent, respectively; and three-year survival and disease-free survival estimates were 62 percent and 64 percent, respectively. The average duration of hospitalization was 2.3 days. Four (3.5%) patients had significant postoperative bleeding. Two (<2%) patients had treatment-related deaths. CONCLUSIONS: Transoral laser microsurgery offers select patients an attractive alternative salvage surgical therapy to the recurrent and second primary tumor site.

The complete genome sequence of Campylobacter jejuni strain 81116 (NCTC11828).

Campylobacter jejuni is a major human enteric pathogen that displays genetic variability via genomic reorganization and phase variation. This variability can adversely affect the outcomes and reproducibility of experiments. C. jejuni strain 81116 (NCTC11828) has been suggested to be a genetically stable strain (G. Manning, B. Duim, T. Wassenaar, J. A. Wagenaar, A. Ridley, and D. G. Newell, Appl. Environ. Microbiol. 67:1185-1189, 2001), is amenable to genetic manipulation, and is infective for chickens. Here we report the finished annotated genome sequence of C. jejuni strain 81116.

Transoral laser microsurgery for advanced laryngeal cancer.

OBJECTIVE: To report the oncologic and functional outcomes of transoral laser microsurgery (TLM) in the treatment of advanced laryngeal cancer. DESIGN: Prospective case series study. SETTING: Multi-institution (academic, tertiary referral centers). PATIENTS: A total of 117 patients with pathologically confirmed T2 to T4 lesions, stage III or stage IV, glottic or supraglottic carcinoma of the larynx were treated with TLM from 1997 to 2004. All patients had a minimum follow-up period of 2 years. INTERVENTIONS: Transoral laser microsurgery in 117 patients, neck dissection in 91 patients, and adjuvant radiotherapy in 45 patients. MAIN OUTCOME MEASURES: End points analyzed included laryngeal preservation, overall survival, disease-free survival, local control, locoregional control, and distant metastases. Postoperative complications, tracheotomy rate, and feeding-tube dependence were also examined. RESULTS: The median follow-up period among surviving patients was 5 years. At 2 years, the percentage of patients with an intact larynx after treatment was 92%. The 2-year local control and locoregional control rates were 82% and 77%, respectively. The 2-year disease-free and overall survival rates were 68% and 75%, respectively. The 5-year Kaplan-Meier estimates were local control, 74%; locoregional, control, 68%; disease-free survival, 58%; overall survival, 55%; and distant metastases, 14%. Four patients (3%) experienced treatment-related deaths. Seven patients (6%) experienced a postoperative hemorrhage. Of those patients with organ preservation and no disease recurrence, 2 patients (3%) were tracheotomy dependent, and 4 patients (7%) were feeding-tube dependent. CONCLUSIONS: In patients with advanced laryngeal cancer, TLM with or without radiotherapy is a valid treatment strategy for organ preservation. Furthermore, low morbidity and mortality and excellent oncologic and functional outcomes make TLM an attractive therapeutic option.

Transoral laser microsurgery for untreated glottic carcinoma.

OBJECTIVES: To report the oncology and functional outcomes of transoral laser microsurgery (TLM) for untreated glottic carcinoma. STUDY DESIGN: A 2 center prospective case series analysis. SETTING: Academic, tertiary referral centers. RESULTS: Seventy-six patients underwent TLM. Pathologic T stages were: T1, 45 (59%); T2, 21 (28%); T3, 5 (7%); and T4, 5 (7%). Five (7%) patients had neck dissections. Five (7%) patients received adjuvant radiotherapy. Mean follow-up was 42 months. Respective T1 and T2 5-year Kaplan-Meier estimates were: local control, 90% and 93%; loco-regional control, 90% and 93%; disease specific survival, 90% and 93%; and overall survival, 94% and 93%. The average hospital stay was 2 days. Two (3%) patients experienced major complications. The overall laryngeal preservation rate was 95% (72 of 76). CONCLUSIONS: TLM is a safe and effective treatment in select carcinoma of the glottic larynx. Low morbidity and mortality and short periods of hospitalization make TLM an attractive therapeutic option. SIGNIFICANCE: TLM is an emerging strategy in the treatment of laryngeal cancer.

Transoral laser microsurgery for carcinoma of the supraglottic larynx.

OBJECTIVES: The study goal was to report the oncologic outcomes of transoral laser microsurgery (TLM) in the treatment of squamous cell carcinoma of the supraglottic larynx. STUDY DESIGN AND SETTING: A two-center prospective case series analysis. RESULTS: Thirty-eight patients underwent TLM for previously untreated carcinoma of the supraglottic larynx between 1997 and 2005. Pathological T stages were T1 in 8 (21%), T2 in 14 (37%), T3 in 8 (21%), and T4 in 8 (21%). Twenty-six patients (68%) had neck dissections. Thirteen patients (34%) received adjuvant radiotherapy. The mean follow-up for all patients was 31 months. The 2-year Kaplan-Meier estimates for local control were 97%; locoregional control, 94%; disease-specific survival, 80%; and overall survival, 85%. The overall functional laryngeal preservation rate was 79% (19 of 24). CONCLUSIONS: TLM is a safe and effective treatment for cancer of the supraglottic larynx. SIGNIFICANCE: TLM is an emerging strategy in the management of laryngeal cancer.

Carcinoma of the tongue base treated by transoral laser microsurgery, part one: Untreated tumors, a prospective analysis of oncologic and functional outcomes.

OBJECTIVES: To report the oncologic and functional outcomes of transoral laser microsurgery (TLM) in the management of untreated primary carcinoma of the tongue base. STUDY DESIGN: A two center prospective case series analysis. METHODS: Fifty-nine patients with pathologically confirmed squamous cell carcinoma of the tongue base were treated with TLM between 1997 and 2005. The pathological T stage distribution was: T1, 16; T2, 23; T3, 12 and T4, 8. Thirty-six patients presented with stage IV disease, 12 with stage III, 7 with stage II and 4 with stage I disease. Neck dissections were performed in 49 patients (83%). Twenty-eight patients (47%) underwent adjuvant radiotherapy. End points analyzed were local control, loco regional control, disease specific survival, and overall survival. Organ function was assessed before and after treatment using a clinical Functional Outcome Swallowing Scale (FOSS) and Communication Scale (CS) staging system. RESULTS: The mean follow up for all patients was 31 months. The 2 and 5-year Kaplan-Meier estimates were: local control, both 90%; loco-regional control, both 88%; recurrence free survival, both 84% and overall survival 91% and 69% respectively. For all patients the median stay in hospital was 4 days. The median length of hospital visit for TLM alone was 2.5 days and 4 days for TLM with neck dissection. Three patients (5%) suffered minor post-operative hemorrhage. The median pre-operative FOSS stage was 0 (normal function.) The median post-operative FOSS stage was stage 1 (Normal function with episodic or daily symptoms of dysphagia.) There were no clinically significant changes in communication function after treatment. CONCLUSIONS: Transoral laser surgery is a safe and effective treatment for select early and advanced previously untreated squamous cell cancer of the tongue base. In addition, the low morbidity and mortality and shortened duration of hospitalization associated with TLM make it an attractive therapeutic alternative.

Carcinoma of the tongue base treated by transoral laser microsurgery, part two: Persistent, recurrent and second primary tumors.

OBJECTIVES: To report the oncologic and functional outcomes of transoral laser microsurgery (TLM) in the treatment of persistent, recurrent, and second primary squamous cell carcinoma of the tongue base. STUDY DESIGN: A two-center prospective case series analysis. METHODS: Twenty-five patients with persistent, recurrent, or second primary squamous cell carcinoma of the tongue base were treated with TLM between 1997 and 2005. Four (16%) patients with persistent disease at the primary site were considered TX. Eleven (44%) patients with recurrent disease were pathologically staged rT1 3/11, rT2 2/11, rT3 4/11, T4 1/11, and TX 1/11. Ten (40%) patients with second primary tumors were staged pT1, 4/10; pT2, 3/10; pT3, 2/10; and pT4, 1/10. Eight (32%) patients underwent neck dissection. Three (12%) patients received adjuvant radiotherapy. Pre- and post-treatment organ function was assessed using a clinical Functional Outcome Swallowing Scale (FOSS) and Communication Scale. RESULTS: The mean follow-up period was 26 months. The 2-year Kaplan-Meier local control and locoregional control estimate was 69%. For those patients presenting with persistent/recurrent or second primary disease, the 2 year local control estimates were 75% and 68%, respectively. For all patients, the respective 2 and 5 year overall survival estimates were 54% and 26%. Two (8%) patients suffered postoperative hemorrhage. The average duration of hospitalization was 3.6 days. The median pretreatment and posttreatment FOSS stage was stage 2 and stage 3, respectively. CONCLUSIONS: Transoral laser surgery is a rational and effective treatment in appropriately selected patients with persistent, recurrent, or second primary tongue base cancer. The low morbidity and mortality and shortened duration of hospitalization associated with TLM make it an attractive therapeutic alternative.

Inverse structure functions.

While the ordinary structure function in turbulence is concerned with the statistical moments of the velocity increment Deltau measured over a distance r , the inverse structure function is related to the distance r where the turbulent velocity exits the interval Deltau. We study inverse structure functions of wind-tunnel turbulence which covers a range of Reynolds numbers Re(lambda) = 400-1100. We test a recently proposed relation between the scaling exponents of the ordinary structure functions and those of the inverse structure functions [S. Roux and M. H. Jensen, Phys. Rev. E 69, 16309 (2004)]. The relatively large range of Reynolds numbers in our experiment also enables us to address the scaling with Reynolds number that is expected to highlight the intermediate dissipative range. While we firmly establish the (relative) scaling of inverse structure functions, our experimental results fail both predictions. Therefore, the question of the significance of inverse structure functions remains open.

Finite-size scaling of two-point statistics and the turbulent energy cascade generators.

Within the framework of random multiplicative energy cascade models of fully developed turbulence, finite-size-scaling expressions for two-point correlators and cumulants are derived, taking into account the observationally unavoidable conversion from an ultrametric to an Euclidean two-point distance. The comparison with two-point statistics of the surrogate energy dissipation, extracted from various wind tunnel and atmospheric boundary layer records, allows an accurate deduction of multiscaling exponents and cumulants, even at moderate Reynolds numbers for which simple power-law fits are not feasible. The extracted exponents serve as input for parametric estimates of the probabilistic cascade generator. Various cascade generators are evaluated.