Analysis of the mouse transcriptome based on functional annotation of 60,770 full-length cDNAs

Only a small proportion of the mouse genome is transcribed into mature messenger RNA transcripts. There is an international collaborative effort to identify all full-length mRNA transcripts from the mouse, and to ensure that each is represented in a physical collection of clones. Here we report the manual annotation of 60,770 full-length mouse complementary DNA sequences. These are clustered into 33,409 'transcriptional units', contributing 90.1% of a newly established mouse transcriptome database. Of these transcriptional units, 4,258 are new protein-coding and 11,665 are new non-coding messages, indicating that non-coding RNA is a major component of the transcriptome. 41% of all transcriptional units showed evidence of alternative splicing. In protein-coding transcripts, 79% of splice variations altered the protein product. Whole-transcriptome analyses resulted in the identification of 2,431 sense-antisense pairs. The present work, completely supported by physical clones, provides the most comprehensive survey of a mammalian transcriptome so far, and is a valuable resource for functional genomics.

Prediction of the hip joint centre in adults, children, and patients with cerebral palsy based on magnetic resonance imaging

The location of the hip joint centre (HJC) is required for calculations of hip moments, the location and orientation of the femur, and muscle lengths and lever arms. In clinical gait analysis, the HJC is normally estimated using regression equations based on normative data obtained from adult populations. There is limited relevant anthropometric data available for children, despite the fact that clinical gait analysis is predominantly used for the assessment of children with cerebral palsy. In this study, pelvic MRI scans were taken of eight adults (ages 23-40), 14 healthy children (ages 5-13) and 10 children with spastic diplegic cerebral palsy (ages 6-13). Relevant anatomical landmarks were located in the scans, and the HJC location in pelvic coordinates was found by fitting a sphere to points identified on the femoral head. The predictions of three common regression equations for HJC location were compared to those found directly from MRI. Maximum absolute errors of 31 mm were found in adults, 26 mm in children, and 31 mm in the cerebral palsy group. Results from regression analysis and leave-one-out cross-validation techniques on the MRI data suggested that the best predictors of HJC location were: pelvic depth for the antero-posterior direction; pelvic width and leg length for the supero-inferior direction; and pelvic depth and pelvic width for the medio-lateral direction. For single-variable regression, the exclusion of leg length and pelvic depth from the latter two regression equations is proposed. Regression equations could be generalised across adults, children and the cerebral palsy group.

Actinonin, a naturally occurring antibacterial agent, is a potent deformylase inhibitor

Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian cells, thus making it an attractive target for the discovery of novel antibiotics. We have identified actinonin, a naturally occurring antibacterial agent, as a potent PDF inhibitor. The dissociation constant for this compound was 0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from Staphylococcus aureus gave a similar value. Microbiological evaluation revealed that actinonin is a bacteriostatic agent with activity against Gram-positive and fastidious Gram-negative microorganisms. The PDF gene, def, was placed under control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels in the cell by varying the external arabinose concentration. The susceptibility of this strain to actinonin increases with decreased levels of PDF expression, indicating that actinonin inhibits bacterial growth by targeting this enzyme. Actinonin provides an excellent starting point from which to derive a more potent PDF inhibitor that has a broader spectrum of antibacterial activity.

The fasciated ear2 gene encodes a leucine-rich repeat receptor-like protein that regulates shoot meristem proliferation in maize

The ability to initiate organs throughout the lifecycle is a unique feature of plant development that is executed by groups of stem cells called meristems. The balance between stem cell proliferation and organ initiation is carefully regulated and ensures that organs can be initiated in regular geometric patterns. To understand how this regulation is achieved, we isolated a novel mutant of maize, fasciated ear2 (fea2), which causes a massive overproliferation of the ear inflorescence meristem and a more modest effect on floral meristem size and organ number. We cloned the fea2 gene using transposon tagging, and it encodes a membrane localized leucine-rich repeat receptor-like protein that is most closely related to CLAVATA2 from Arabidopsis. These findings provide evidence that the CLAVATA pathway for regulation of meristem size is functionally conserved throughout the angiosperms. A possible connection of fea2 to the control of crop yields is discussed.

The indeterminate gene encodes a zinc finger protein and regulates a leaf-generated signal required for the transition to flowering in maize

Flowering in plants is a consequence of the transition of the shoot apex from vegetative to reproductive growth in response to environmental and internal signals. The indeterminate1 gene (id1) controls the transition to flowering in maize. We show by cloning the id1 gene that it encodes a protein with zinc finger motifs, suggesting that the id1 gene product functions as a transcriptional regulator of the floral transition. id1 mRNA expression studies and analyses of transposon-induced chimeric plants indicate that id1 acts non-cell-autonomously to regulate the production of a transmissible signal in the leaf that elicits the transformation of the shoot apex to reproductive development. These results provide molecular and genetic data consistent with the florigen hypothesis derived from classical plant physiology studies.

Prediction of protein subcellular locations using Markov chain models

A novel method was introduced to predict protein subcellular locations from sequences. Using sequence data, this method achieved a prediction accuracy higher than previous methods based on the amino acid composition. For three subcellular locations in a prokaryotic organism, the overall prediction accuracy reached 89.1%. For eukaryotic proteins, prediction accuracies of 73.0% and 78.7% were attained within four and three location categories, respectively. These results demonstrate the applicability of this relative simple method and possible improvement of prediction for the protein subcellular location.

Cerebral arterial aneurysm formation and rupture in 20,767 elderly patients: hypertension and other risk factors

Cerebral arterial aneurysms are common in the general population and their rupture is a catastrophic event. Considerable uncertainty remains concerning the conditions that predispose individuals to aneurysm formation or rupture. The role of systemic hypertension in aneurysm formation and rupture has been especially controversial. Demographic variables have rarely been addressed because of the small sample sizes in previous studies. The authors describe the demographics and prevalence of hypertension in 20,767 Medicare patients with an unruptured aneurysm and compared these to a random sample of the hospitalized Medicare population. The prevalence of hypertension in patients with unruptured aneurysms was 43.2% compared with 34.4% in the random sample. Patients who survived their initial hospitalization were separated into two groups: those with an unruptured cerebral aneurysm as the primary diagnosis and those with an unruptured cerebral aneurysm as a secondary diagnosis. Follow-up data for 18,119 patients were examined to determine the risk of subarachnoid hemorrhage (SAH) associated with age, gender, race, hypertension, insulin-dependent diabetes mellitus, and surgical treatment. For patients with an unruptured cerebral aneurysm as the primary diagnosis, hypertension was found to be a significant risk factor for future SAH (risk ratio: 1.46, 95% confidence interval (CI): 1.01-2.11), whereas surgical treatment (risk ratio: 0.29, 95% CI: 0.09-0.97) had a significant protective effect. Advancing age had a small but significant protective effect in both groups. Elderly patients identified with unruptured aneurysms are more likely to have coexisting hypertension than the general hospitalized population. In elderly patients hospitalized with an unruptured cerebral aneurysm as their primary diagnosis, hypertension is a risk factor for subsequent SAH, whereas surgical treatment is a protective factor against SAH.

Frequent requirement of hedgehog signaling in non-small cell lung carcinoma

Although it had previously been suggested that the hedgehog (HH) pathway might be activated in some lung tumors, the dependence of non-small cell lung carcinomas (NSCLC) for HH activity had not been comprehensively studied. During a screen of a panel of 60 human tumor cell lines with an HH antagonist, we observed that the proliferation of a subset of NSCLC cell lines was inhibited. These NSCLC cell lines express HH, as well as key HH target genes, consistent with them being activated through an autocrine mechanism. Interestingly, we also identified a number of NSCLC cell lines that express high levels of the downstream transcription factor GLI1 and harbor enhanced levels of HH activity, but appear insensitive to known HH antagonists. We hypothesized that the high levels of GLI1 in these cells would function downstream of the HH antagonist target, allowing them to bypass the antagonist-mediated block in proliferation. Consistent with this hypothesis, when the levels of GLI1 are knocked down in such cells, they become sensitive to these inhibitors. We go on to show that a large percentage of primary NSCLC samples express GLI1, consistent with constitutive activation of the HH pathway in these samples. Taken together, these results establish the involvement of the HH signaling pathway in a subset of NSCLCs.

Surgery for colorectal cancer: Race-related differences in rates and survival among Medicare beneficiaries

This study examined surgery for colorectal cancer among Medicare beneficiaries 65 years of age or older with an initial diagnosis in 1987 (n = 81 579). Black patients were less likely than White to undergo surgical resection (68% vs 78%), even after age, comorbidity, and location and extent of tumor were controlled for. Among those who underwent resection, Black patients were more likely to die (a 2-year mortality rate of 40.0% vs 33.5% in White patients); this disparity also remained after confounders had been controlled. The disparities were similar in teaching and nonteaching hospitals and in private and public hospitals. These data may indicate racially based differences among Medicare beneficiaries in access to and quality of care for colorectal cancer.

How good is prediction of protein structural class by the component-coupled method?

Proteins of known structures are usually classified into four structural classes: all-alpha, all-beta, alpha+beta, and alpha/beta type of proteins. A number of methods to predicting the structural class of a protein based on its amino acid composition have been developed during the past few years. Recently, a component-coupled method was developed for predicting protein structural class according to amino acid composition. This method is based on the least Mahalanobis distance principle, and yields much better predicted results in comparison with the previous methods. However, the success rates reported for structural class prediction by different investigators are contradictory. The highest reported accuracies by this method are near 100%, but the lowest one is only about 60%. The goal of this study is to resolve this paradox and to determine the possible upper limit of prediction rate for structural classes. In this paper, based on the normality assumption and the Bayes decision rule for minimum error, a new method is proposed for predicting the structural class of a protein according to its amino acid composition. The detailed theoretical analysis indicates that if the four protein folding classes are governed by the normal distributions, the present method will yield the optimum predictive result in a statistical sense. A non-redundant data set of 1,189 protein domains is used to evaluate the performance of the new method. Our results demonstrate that 60% correctness is the upper limit for a 4-type class prediction from amino acid composition alone for an unknown query protein. The apparent relatively high accuracy level (more than 90%) attained in the previous studies was due to the preselection of test sets, which may not be adequately representative of all unrelated proteins.

The sensitivity of Medicare claims data for case ascertainment of six common cancers

BACKGROUND

Although Medicare claims data have been used to identify cases of cancer in older Americans, there are few data about their relative sensitivity.

OBJECTIVES

To investigate the sensitivity of diagnostic and procedural coding for case ascertainment of breast, colorectal, endometrial, lung, pancreatic, and prostate cancer.

SUBJECTS

Three hundred and eighty nine thousand and two hundred and thirty-six patients diagnosed with cancer between 1984 and 1993 resided in one of nine Surveillance Epidemiology and End Results (SEER) areas.

MEASURES

The sensitivity of inpatient and Part B diagnostic and cancer-specific procedural codes for case finding were compared with SEER.

RESULTS

The sensitivity of inpatient and inpatient plus Part B claims for the corresponding cancer diagnosis was 77.4% and 91.2%, respectively. The sensitivity of inpatient claims alone was highest for colorectal (86.1%) and endometrial (84.1%) cancer and lowest for prostate cancer (63.6%). However, when Part B claims were included, the sensitivity for diagnosis of breast cancer was greater than for other cancers (93.6%). Inpatient claim sensitivity was highest for earlier years of the study, and, because of more complete data and longer follow up, the highest sensitivity of combined inpatient and Part B claims was achieved in the late 1980s or early 1990s.

CONCLUSIONS

Medicare claims provide reasonably high sensitivity for the detection of cancer in the elderly, especially if inpatient and Part B claims are combined. Because the study did not measure other dimensions of accuracy, such as specificity and predictive value, the potential costs of including false positive cases need to be assessed.

Risk of stroke in patients with atrial flutter

Using a Medicare-based retrospective cohort study, the stroke risk in patients with atrial flutter (RR = 1.41) was determined to be greater than that in a control group (RR = 1.00) but less than that in an atrial fibrillation group (RR = 1.64). Furthermore, patients with atrial flutter who subsequently had an episode of atrial fibrillation had a higher risk of stroke (RR = 1.56) than patients with atrial flutter who never had a subsequent episode of atrial fibrillation (RR = 1.11).

Quality of life for children with fecal incontinence after surgically corrected anorectal malformation

PURPOSE

The aim of this study was to investigate influences of fecal incontinence on children's quality of life after surgically corrected anorectal malformation.

METHODS

Seventy-one children with anorectal malformation underwent follow-up for 8 to 16 years postoperatively. They were divided into good, fair, and poor groups by assessment of anal function. The quality of life was investigated by self-structured disease impact questionnaires and Achenbach's Child Behavior Check List (CBCL). A quality-of-life scoring criteria was established to assess quality of life of the 71 children with operated anorectal malformation and controls.

RESULTS

Owing to fecal incontinence, 12 (16.9%) children reported that there were problems in peer relationships; school absences happened in 13 (18.3%) children; 17 (23.9%) children had to restrict themselves to certain food. Based on CBCL, 13 (18.3%) children had behavior problems. The behavior problems in children with poor fecal continence (66.7%) were significantly higher than those of children with good fecal continence (8.6%). According to the quality-of-life scoring criteria, the scores of children with operated anorectal malformation (9.4+/-3.7) were significantly lower than those of the controls (11.2+/-0.9). The scores of children with poor fecal continence (4.8+/-1.4) were significantly lower than those of children with good fecal continence (10.9+/-1.2).

CONCLUSIONS

The children with poor fecal continence have poor quality of life caused by fecal dysfunction. Attention should be paid to the rehabilitation of fecal continence after surgery, such as bowel training and biofeedback therapy. The somatic and psychological care and long-term follow-up are necessary to improve the quality of life.

Agreement of Medicare claims and tumor registry data for assessment of cancer-related treatment

BACKGROUND

Although health claims data are increasingly used in evaluating variations in patterns of cancer care and outcomes, little is known about the comparability of these data with tumor registry information.

OBJECTIVES

To evaluate the agreement between Medicare claims and tumor registry data in measuring patterns of diagnostic and therapeutic procedures for older cancer patients.

RESEARCH DESIGN

Analysis of a database linking Surveillance, Epidemiology and End Results (SEER) registry data and Medicare claims in patients aged > or =65 years with cancer.

SUBJECTS

361,255 Medicare patients with invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancer diagnosed between 1984 and 1993.

MEASURES

Concordance of SEER files with corresponding Medicare claims.

RESULTS

Medicare claims generally identified patients who underwent resection and radical surgery according to SEER (ie, concordance > or =85%-90%) but less likely biopsy or local excision (ie, concordance < or =50%). In some instances, claims also categorized patients as having more invasive surgery than was listed in SEER and also provided incremental information about the use of surgical treatment after 4 months. SEER files and, to a lesser degree, Medicare claims identified radiation therapy not included in the other data source, and Medicare files also captured a significant number of patients with codes for chemotherapy.

CONCLUSIONS

Medicare files may be appropriate for studies of patterns of use of surgical treatment, but not for diagnostic procedures. The potential benefit of Medicare claims in identifying delayed surgical intervention and chemotherapy deserves further study.

Bacterial Peptide deformylase inhibitors: a new class of antibacterial agents

Peptide deformylase (PDF) is a prokaryotic metalloenzyme that is essential for bacterial growth but is not required by mammalian cells. Thus, it represents a selective and promising target for the development of new antibacterial agents. Since deformylase inhibitors have yet to be used clinically as antibacterial drugs, compounds targeting this enzyme should avoid cross-resistance with currently used antibacterial agents. The PDF enzyme is a ferrous ion-containing metallohydrolase, but a nickel-containing surrogate is routinely used in the laboratory for testing inhibitors due to its better stability. Enzymes from several bacterial species have been cloned and both their three-dimensional structures and co-crystal structures with bound inhibitor have been determined. As a metallo enzyme, PDF lends itself to the well-precedented mechanism-based rational drug design approach. Using structural and mechanistic information together with high throughput screening, several types of potent PDF inhibitors have been identified. PDF inhibitors identified to date share a common structural feature of a "chelator + peptidomimetic" scaffold. Although compounds with many different chelators inhibit the cell free enzyme, only compounds containing hydroxamic acid or N-formyl hydroxylamine exhibit appreciable antibacterial activity. Several lead inhibitors have demonstrated in vivo efficacy and an excellent safety profile. Two PDF inhibitors, VIC-104959 (LBM415) and BB-83698, have progressed to Phase I clinical trials. In this review, different PDF inhibitors are compared and their biological activities are discussed. Structure-activity relationships have been established and the implications of this work in the design of future PDF inhibitors are considered.

Peptide deformylase in Staphylococcus aureus: resistance to inhibition is mediated by mutations in the formyltransferase gene

Peptide deformylase, a bacterial enzyme, represents a novel target for antibiotic discovery. Two deformylase homologs, defA and defB, were identified in Staphylococcus aureus. The defA homolog, located upstream of the transformylase gene, was identified by genomic analysis and was cloned from chromosomal DNA by PCR. A distinct homolog, defB, was cloned from an S. aureus genomic library by complementation of the arabinose-dependent phenotype of a P(BAD)-def Escherichia coli strain grown under arabinose-limiting conditions. Overexpression in E. coli of defB, but not defA, correlated to increased deformylase activity and decreased susceptibility to actinonin, a deformylase-specific inhibitor. The defB gene could not be disrupted in wild-type S. aureus, suggesting that this gene, which encodes a functional deformylase, is essential. In contrast, the defA gene could be inactivated; the function of this gene is unknown. Actinonin-resistant mutants grew slowly in vitro and did not show cross-resistance to other classes of antibiotics. When compared to the parent, an actinonin-resistant strain produced an attenuated infection in a murine abscess model, indicating that this strain also has a growth disadvantage in vivo. Sequence analysis of the actinonin-resistant mutants revealed that each harbors a loss-of-function mutation in the fmt gene. Susceptibility to actinonin was restored when the wild-type fmt gene was introduced into these mutant strains. An S. aureus Deltafmt strain was also resistant to actinonin, suggesting that a functional deformylase activity is not required in a strain that lacks formyltransferase activity. Accordingly, the defB gene could be disrupted in an fmt mutant.

Deformylase as a novel antibacterial target

Bacterial genomics has revealed a plethora of previously unknown targets of potential use in the discovery of novel antibacterial drugs. However, so far little has emerged from this approach. Peptide deformylase is an interesting target that was discovered more than 30 years ago, but was not exploited until recently. The reawakening of interest in this target resulted from an improved understanding of the enzyme, making it a more tractable and attractive target. Information on the properties of the enzyme, such as its three-dimensional structure, the activity of inhibitors, its resistance and suitability as a target are discussed.

The Continual Reassessment Method for Multiple Toxicity Grades: A Bayesian Quasi-Likelihood Approach

We consider the case of phase I trials for treatment of cancer or other severe diseases in which grade information is available about the severity of toxicity. Most dose allocation procedures dichotomize toxicity grades based on being dose limiting, which may not work well for severe and possibly irreversible toxicities such as renal, liver, and neurological toxicities, or toxicities with long duration. We propose a simple extension to the continual reassessment method (CRM), called the Quasi-CRM, to incorporate grade information. Toxicity grades are first converted to numeric scores that reflect their impacts on the dose allocation procedure, and then incorporated into the CRM using the quasi-Bernoulli likelihood. A simulation study demonstrates that the Quasi-CRM is superior to the standard CRM and comparable to a univariate version of the Bekele and Thall method (2004, Journal of the American Statistical Association 99, 26-35). We also present sensitivity analysis of the new method with respect to toxicity scores, and discuss practical issues such as extending the simple algorithmic up-and-down designs.

Free ammonia and free nitrous acid inhibition on the anabolic and catabolic processes of Nitrosomonas and Nitrobacter

The inhibitory effects of free ammonia (FA) and free nitrous acid (FNA) on the catabolic and anabolic processes of Nitrosomonas and Nitrobacter were investigated using a method that allows decoupling the growth and energy generation processes. Lab-scale sequencing batch reactors (SBRs) were operated for the enrichment of Nitrosomonas and Nitrobacter. Fluorescent In-Situ Hybridization (FISH) analysis showed that the reactors were 82% and 73% enriched with Nitrosomonas and Nitrobacter, respectively. Batch tests were carried out to measure the oxygen uptake rate (OUR) by the enriched cultures at various FA and FNA levels, in the presence (OUR with CO2 ) or absence (OUR without CO2) of inorganic carbon (CO2, HCO*3 and CO 2*3). FA up to 16.0 mgNH3-N.L(-1) was not found to have any inhibitory effect on either the catabolic or anabolic processes of the Nitrosomonas culture, but both these processes were inhibited by FNA. While an FNA level of 0.40-0.63 mgHNO2-N.L(-1) inhibited the energy production capability of Nitrosomonas by 50%, the growth process of the culture was completely inhibited by FNA at a concentration of 0.40 mgHNO2-N.L(-1). Both FA and FNA were found to have strong inhibition on the anabolic processes of Nitrobacter, but with limited inhibitory effects on the catabolism of this culture. The biosynthesis of Nitrobacter was totally inhibited at an FA level of 6.0 mgNH3-N.L(-1) (or above) or an FNA level of 0.02 mgHNO2-N.L(-1) (or above). At the same level of FA, the energy production capability of Nitrobacter was only inhibited by 12%, whereas an FNA level of up to 0.024 mgHNO2-N.L(-1) did not show any inhibition on the energy production of Nitrobacter. Further, these inhibitory effects appears to be much stronger on Nitrobacter than on Nitrosomonas, supporting that FA and FNA inhibition may play a major role in the elimination of nitrite oxidizing bacteria in processes treating wastewater containing a high level of nitrogen.

Electrochemical determination of dopamine using a poly(2-picolinic acid) modified glassy carbon electrode

A poly(2-picolinic acid) chemically modified electrode (CME) for the determination of dopamine (DA) by cyclic voltammetry is described. Compared with a bare glassy carbon electrode, the CME exhibits a 200 mV shift of the oxidation potential of DA in the cathodic direction and a marked enhancement of the current response. In pH 7.0 buffer solution, a linear calibration graph is obtained over the range from 2.5 x 10(-7) to 1.0 x 10(-5) mol dm-3 with a correlation coefficient of 0.998. The detection limit is 3.0 x 10(-8) mol dm-3. The modified electrode eliminated efficiently the interference from ascorbic acid (AA) when present in a 150-fold concentration ratio. It also showed excellent stability and reproducibility.

Lumbar spine surgery and mortality among Medicare beneficiaries, 1986

OBJECTIVES

The purpose of this study was to compare lumbar spine surgical procedures by age, gender, and number of comorbidities with respect to mortality in patients 65 years of age and older in the United States.

METHODS

A 100% sample of the 1986 Medicare inpatient Health Care Financing Administration claims files databases involving lumbar spine surgical procedures was analyzed.

RESULTS

Lumbar spine surgery in 34,418 patients (median age = 71 years) was associated with a significant increase in in-hospital and 1-year cumulative mortality only beyond 80 years of age. When adjusted for age, in-hospital and 1-year cumulative mortality with both decompression and excision procedures were significantly higher in men than in women. When adjusted for both age and gender, mortality increased significantly as the number of comorbidities increased.

CONCLUSIONS

With lumbar spine surgery in elderly patients, mortality did not significantly increase until 80 years of age and was consistently associated with decompression and excision, with male gender, and with an increase in number of comorbidities.

A national population-based study of incidence of colorectal cancer and age. Implications for screening in older Americans

BACKGROUND

Population-based screening programs with flexible sigmoidoscopy have been advocated as a means to reduce the death rate from colorectal cancer. Because other studies have suggested a greater prevalence of lesions inaccessible to sigmoidoscopy in older patients, the expected yield of this procedure may differ in these subgroups.

METHODS

A 100% sample of Medicare beneficiaries 65 years or older with a first known diagnosis of colorectal cancer in 1987 was studied. Tumor site was divided into rectum, distal colon (distal to splenic flexure) and proximal colon. The analysis was also stratified by sex, race, and presence or absence metastatic disease, and incidence rates at each site by 5-year age group were calculated.

RESULTS

Among the 75,266 patients studied, the incidence of colorectal cancer increased from 1.59 patients/1000 in patients age 65-69 years to 3.87 patients/1000 in patients age 85 years and older. Although the incidence rates at all three sites increased, the increment was greatest for proximal tumors. The incidence trends with age also persisted in an analysis of only metastatic lesions. Moreover, incidence rates were consistently higher in men than in women and higher in whites than in blacks at all sites, though the age-related increase in incidence was consistent among all four groups.

CONCLUSIONS

The proportion of tumors beyond the reach of sigmoidoscopy increased with age, as did the actual incidence of accessible lesions. These patterns were also consistent in subgroup analyses. As the age-related increase in incidence was observed for metastatic tumors at all sites in the colon, age-related differences in screening and diagnostic evaluation alone do not adequately explain the findings. These data underscore the need for further studies of the relative benefits of cancer screening and pathogenic factors in tumor development in different subgroups of the older population.

Enhancing aerobic granulation for biological nutrient removal from domestic wastewater

This study focuses on the enhancement of aerobic granulation and biological nutrient removal maintenance treating domestic wastewater. Two sequencing batch reactors (SBRs) were inoculated with either only floccular sludge (100%-floc SBR) or supplemented with 10% crushed granules (90%-floc SBR). Granules developed in both reactors. The 100%-floc SBR achieved 75% of nitrogen and 93% of phosphorus removal at the end of the performance, but some floccular sludge remained in the system. The 90%-floc SBR became fully granulated and finished with 84% and 99% of nitrogen and phosphorus removal, respectively. Regarding biological phosphorus removal, nitrite was identified as an inhibitor of the process. Nitrite levels lower than 5 mg N-NO2-L(-1) were used for anoxic phosphate uptake while higher concentrations inhibited the process.