First Leptophobic Dark Matter Search from the Coherent-CAPTAIN-Mills Liquid Argon Detector.

We report the first results of a search for leptophobic dark matter (DM) from the Coherent-CAPTAIN-Mills (CCM) liquid argon (LAr) detector. An engineering run with 120 photomultiplier tubes (PMTs) and 17.9×10^{20} protons on target (POT) was performed in fall 2019 to study the characteristics of the CCM detector. The operation of this 10-ton detector was strictly light based with a threshold of 50 keV and used coherent elastic scattering off argon nuclei to detect DM. Despite only 1.5 months of accumulated luminosity, contaminated LAr, and nonoptimized shielding, CCM's first engineering run has already achieved sensitivity to previously unexplored parameter space of light dark matter models with a baryonic vector portal. With an expected background of 115 005 events, we observe 115 005+16.5 events which is compatible with background expectations. For a benchmark mediator-to-DM mass ratio of m_{V_{B}}/m_{χ}=2.1, DM masses within the range 9 MeV≲m_{χ}≲50 MeV are excluded at 90% C. L. in the leptophobic model after applying the Feldman-Cousins test statistic. CCM's upgraded run with 200 PMTs, filtered LAr, improved shielding, and 10 times more POT will be able to exclude the remaining thermal relic density parameter space of this model, as well as probe new parameter space of other leptophobic DM models.

Halo effect of a Mediterranean-lifestyle weight-loss intervention on untreated family members' weight and physical activity: a prospective study.

OBJECTIVES: Obesity is subject to strong family clustering. The relatives of participants in weight-loss interventions may also modify their lifestyle and lose weight. The aim of this study was to examine the presence and magnitude of a halo effect in untreated family members of participants enrolled in a randomized, multi-component, lifestyle intervention. METHODS: A total of 148 untreated adult family members of participants in an intensive weight-loss lifestyle intervention (the PREDIMED-Plus study) were included. Changes at 1 and 2 years in body weight, physical activity, and adherence to a traditional Mediterranean diet (MedDiet) were measured. Generalized linear mixed models were used to assess whether the change differed between family members of the intervention group compared to the control. RESULTS: Untreated family members from the intervention group displayed a greater weight loss than those from the control after 1 and 2 years: adjusted 2-year weight change difference between groups was -3.98 (SE 1.10) kg (p < 0.001). There was a halo effect with regard to adherence to the MedDiet at one year which was sustained at two years: 2-year adjusted difference in MedDiet score change +3.25 (SE 0.46) (p < 0.001). In contrast, no halo effect was observed with regard to physical activity, as the untreated family members did not substantially modify their physical activity levels in either group, and the adjusted difference at two years between the 2 groups was -272 (SE 624) METs.min/week (p = 0.665). CONCLUSIONS: In the first prospective study to assess the influence on untreated family members of a diet and physical activity weight-loss intervention, we found evidence of a halo effect in relatives on weight loss and improvement in adherence to a MedDiet, but not on physical activity. The expansion of MedDiet changes from individuals involved in a weight-loss intervention to their family members can be a facilitator for obesity prevention.

Associations of presidential voting preference and gubernatorial control with county-level COVID-19 case and death rates in the continental United States.

OBJECTIVE: To investigate the associations of state gubernatorial party control and 2016 county-level presidential election preference on COVID-19 case and death rates in the United States. STUDY DESIGN: This was a secondary analysis of publicly available data. METHODS: Data including county-level COVID-19 case and death counts through February 9, 2021, 2020 gubernatorial data, and county-level US Census Bureau data, Broadstreet area deprivation index, and 2016 presidential voting tallies were included. Negative binomial regression estimated the adjusted impact of each variable on COVID-19 case and death rates. RESULTS: A total of 3102 counties in the 48 continental United States plus Washington DC were included. County-level case and death rates were higher (12% and 22%, respectively) in Republican vs Democrat controlled states. Case and death rates were higher in counties voting Republican vs Democrat in 2016 and were modified by counties with median ages ≥ 50 years (54% increase in case rate and 91% increase in death rate). CONCLUSIONS: These data further support the need for prevention efforts to focus on public health while extricating guidance and prevention from political agendas.

Prenatal malnutrition and adult cognitive impairment: a natural experiment from the 1959-1961 Chinese famine.

The current measures of cognitive functioning in adulthood do not indicate a long-term association with prenatal exposure to the Dutch famine. However, whether such association emerges in China is poorly understood. We aimed to investigate the potential effect of prenatal exposure to the 1959-1961 Chinese famine on adult cognitive impairment. We obtained data from the Second National Sample Survey on Disability implemented in thirty-one provinces in 2006, and restricted our analysis to 387 093 individuals born in 1956-1965. Cognitive impairment was defined as intelligence quotient (IQ) score under 70 and IQ of adults was evaluated by the Wechsler Adult Intelligence Scale - China Revision. Famine severity was defined as excess death rate. The famine impact on adult cognitive impairment was estimated by difference-in-difference models, established by examining the variations of famine exposure across birth cohorts. Results show that compared with adults born in 1956-1958, those who were exposed to Chinese famine during gestation (born in 1959-1961) were at greater risk of cognitive impairment in the total sample. Stratified analyses showed that this effect was evident in males and females, but only in rural, not in urban areas. In conclusion, prenatal exposure to famine had an enduring deleterious effect on risk of cognitive impairment in rural adults.

Clinical significance and outcome of Aeromonas spp. infections among 204 adult patients.

The objectives of this investigation were to analyze the clinical patterns, risk groups, prognostic factors, and mortality of infections caused by Aeromonas spp. This was a retrospective study of adult patients with Aeromonas spp. isolates attended at the Hospital del Mar in Barcelona, Spain, between January 2006 and December 2012. Epidemiological data, antimicrobial susceptibility, clinical patterns, underlying illnesses, type of infection, admission to the intensive care unit (ICU), number of episodes, coinfection, antimicrobial therapy, and evolution were analyzed. A total of 221 clinical samples from 204 patients were positive for Aeromonas spp. The mean age of the patients was 67.6 years. The main clinical form of presentation was gastrointestinal (78.4%). Malignancy was the main risk group in 69 (33.8%) patients, and 48 (23.5%) were previously healthy. Twenty-one patients (10.3%) were admitted to the ICU. Infections were acquired in the hospital in 52.5% of the patients, and 28.9% were polymicrobial. The overall mortality (after 1 year of follow-up from the first positive culture) was 26.5%. Univariate analysis identified an association between increased mortality and the following variables: age ≥80 years, hospitalization, admission to the ICU, malignancy, extraintestinal infection, and appropriate antimicrobial therapy. In the multivariate analysis, age ≥80 years [odds ratio (OR), 4.37 [95% confidence interval (CI), 1.68-11.35; p = 0.002]], admission to the ICU (OR, 6.59 [95% CI, 2.17-19.99; p = 0.001]), and malignancy (OR, 3.62 [95% CI, 1.32-9.90; p = 0.012]) were significantly associated with mortality. Aeromonas infections are mainly gastrointestinal. The 1-year follow-up mortality rate was high. Old age (age ≥80 years), admission to the ICU, and malignancy were identified as independent risk factors for mortality.

Trends in Rehabilitation Services Use in Chinese Children and Adolescents With Intellectual Disabilities: 2007-2013.

OBJECTIVES: To investigate trends in rehabilitation services use in children and adolescents with intellectual disabilities, and to explore factors potentially contributing to the trends. DESIGN: A population-based study using a multistage, randomized cluster-sampling process to ascertain participants in 2006. A subsample was selected for follow-up surveys from 2007 to 2013. SETTING: Thirty-one provinces of China. PARTICIPANTS: Children (N=5432) aged 0 to 17 years with intellectual disabilities were followed up for 7 years. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The outcome variable was whether individuals received at least 1 of the following rehabilitation services in the past 12 months: occupational therapy, physical therapy, and speech or communication therapy. RESULTS: Overall, the utilization rates of rehabilitation services significantly increased from 14.4% in 2007 to 37.1% in 2013. The trends were also significant in children aged 0 to 10 and 11 to 17 years, in boys and girls, and in rural participants. From 2007 to 2013, rehabilitation services utilization increased at an annual rate of 22.39% (95% confidence interval, 18.11%-26.82%) in the total sample. The rise was only significant in rural rather than urban individuals, resulting in the urban-rural gap in rehabilitation services use being narrowed. However, minority populations and those without health insurance still received fewer rehabilitation services than their respective counterparts. CONCLUSIONS: There were upward trends in rehabilitation services use in participants over time, and the urban-rural gap was narrowed. However, there were still socioeconomic differences on rehabilitation services use among children and adolescents with intellectual disabilities.

Lieb-Liniger-like model of quantum solvation in CO-(4)HeN clusters.

Small (4)He clusters doped with various molecules allow for the study of "quantum solvation" as a function of cluster size. A peculiarity of quantum solvation is that, as the number of (4)He atoms is increased from N = 1, the solvent appears to decouple from the molecule which, in turn, appears to undergo free rotation. This is generally taken to signify the onset of "microscopic superfluidity." Currently, little is known about the quantum mechanics of the decoupling mechanism, mainly because the system is a quantum (N + 1)-body problem in three dimensions which makes computations difficult. Here, a one-dimensional model is studied in which the (4)He atoms are confined to revolve on a ring and encircle a rotating CO molecule. The Lanczos algorithm is used to investigate the eigenvalue spectrum as the number of (4)He atoms is varied. Substantial solvent decoupling is observed for as few as N = 5 (4)He atoms. Examination of the Hamiltonian matrix, which has an almost block diagonal structure, reveals increasingly weak inter-block (solvent-molecule) coupling as the number of (4)He atoms is increased. In the absence of a dopant molecule the system is similar to a Lieb-Liniger (LL) gas and we find a relatively rapid transition to the LL limit as N is increased. In essence, the molecule initially-for very small N-provides a central, if relatively weak, attraction to organize the cluster; as more (4)He atoms are added, the repulsive interactions between the identical bosons start to dominate as the solvation ring (shell) becomes more crowded which causes the molecule to start to decouple. For low N, the molecule pins the atoms in place relative to itself; as N increases the atom-atom repulsion starts to dominate the Hamiltonian and the molecule decouples. We conclude that, while the notion of superfluidity is a useful and correct description of the decoupling process, a molecular viewpoint provides complementary insights into the quantum mechanism of the transition from a molecular cluster to a quantum solvated molecule.

Disability and disability benefit seeking in chronic low back pain.

BACKGROUND: Numerous studies suggest psychosocial factors contribute to functional disability in patients with chronic low back pain (CLBP). However, less is known about the association of psychosocial factors, such as depression, with seeking medical disability benefits and their prevalence in benefit seekers compared with patients already receiving such payments. AIMS: To determine if characteristics of disability benefit seekers differ from patients receiving disability benefits and if both differ from patients not dependent on such payments. METHODS: Questionnaire data on pain, health-related quality of life, depression, social support, substance abuse, adverse childhood experiences and disability seeking were obtained from CLBP respondents recruited at 10 primary care clinics throughout Texas. A multinomial logistic regression model was computed using variables significantly associated with disability status and pain severity in univariate models. RESULTS: There were 213 participants. In full models, compared with those not on disability benefits, only depression symptoms were significantly associated with seeking disability benefits (odds ratio [OR] = 1.13; 95% confidence interval [CI] 1.01-1.26) and only duration of pain was significantly associated with being on such benefits (OR = 1.05; 95% CI 1.01-1.09). CONCLUSIONS: Patient characteristics differ between disability benefit seekers and those established on disability benefit payments. Depression may be a modifiable correlate of disability benefit seeking that if treated may reduce the number of patients who eventually come to depend on disability benefits. Additional data collection involving other pain syndromes is warranted to determine if these results are unique to CLBP or apply to other painful conditions.

DOT1A-dependent H3K76 methylation is required for replication regulation in Trypanosoma brucei.

Cell-cycle progression requires careful regulation to ensure accurate propagation of genetic material to the daughter cells. Although many cell-cycle regulators are evolutionarily conserved in the protozoan parasite Trypanosoma brucei, novel regulatory mechanisms seem to have evolved. Here, we analyse the function of the histone methyltransferase DOT1A during cell-cycle progression. Over-expression of DOT1A generates a population of cells with aneuploid nuclei as well as enucleated cells. Detailed analysis shows that DOT1A over-expression causes continuous replication of the nuclear DNA. In contrast, depletion of DOT1A by RNAi abolishes replication but does not prevent karyokinesis. As histone H3K76 methylation has never been associated with replication control in eukaryotes before, we have discovered a novel function of DOT1 enzymes, which might not be unique to trypanosomes.

Interleukin-6 as a predictor of cardiovascular events in troponin-negative non-ST elevation acute coronary syndrome patients.

AIM: Risk stratification in acute coronary syndrome without ST-segment elevation (NSTE-ACS) and troponin-negative remains a challenge. We evaluated the value of interleukin-6 (IL-6) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) in the prognosis assessment of low-moderate risk NSTE-ACS and troponin-negative, and whether these biomarkers could improve the predictive performance of the established thrombolysis in myocardial infarction (TIMI) risk score. METHODS: A total of 212 low-moderate risk patients with NSTE-ACS and troponin-negative were prospectively studied. Clinical follow up at 6 months was performed for adverse endpoints. RESULTS: A total of 28 patients (13.5%) presented adverse clinical events. Those with adverse clinical events were associated with higher levels of IL-6 [8.58 (5.13-20.95) ng/l vs. 6.12 (4.16-9.14) ng/l, p = 0.043] and NT-proBNP [275.3 (108.6-548.2) ng/l vs. 126.8 (55.97-430.20) ng/l, p = 0.046]. In moderate risk group, we observed a higher event rate in patients with troponin-negative but elevated levels of IL-6 (p = 0.024). Only elevated IL-6 (> 12.40 ng/l) was an independent predictor of adverse outcomes [hazard ratios: 3.62, 95% confidence interval (CI) 1.69-7.75, p = 0.001]. The addition of IL-6 and history of ischaemic heart disease (IHD) to TIMI risk score significantly improved both the discrimination (integrated discrimination improvement, p = 0.003) and reclassification (Clinical Net reclassification improvement, p = 0.010) of the model for adverse events. CONCLUSIONS: Interleukin-6 is an independent predictor of adverse events in low-moderate risk patients with NSTE-ACS and troponin-negative. Its use identifies a higher risk population in moderate-risk patients. This provides together with history of IHD a better discrimination and reclassification beyond that achieved with clinical risk variables from TIMI risk score in these patients.

Seismic response of 3D steel buildings considering the effect of PR connections and gravity frames.

The nonlinear seismic responses of 3D steel buildings with perimeter moment resisting frames (PMRF) and interior gravity frames (IGF) are studied explicitly considering the contribution of the IGF. The effect on the structural response of the stiffness of the beam-to-column connections of the IGF, which is usually neglected, is also studied. It is commonly believed that the flexibility of shear connections is negligible and that 2D models can be used to properly represent 3D real structures. The results of the study indicate, however, that the moments developed on columns of IGF can be considerable and that modeling buildings as plane frames may result in very conservative designs. The contribution of IGF to the lateral structural resistance may be significant. The contribution increases when their connections are assumed to be partially restrained (PR). The incremented participation of IGF when the stiffness of their connections is considered helps to counteract the no conservative effect that results in practice when lateral seismic loads are not considered in IGF while designing steel buildings with PMRF. Thus, if the structural system under consideration is used, the three-dimensional model should be used in seismic analysis and the IGF and the stiffness of their connections should be considered as part of the lateral resistance system.

Descriptive analysis of the economic costs of periprosthetic joint infection of the knee for the public health system of Andalusia.

This study offers a descriptive analysis of the economic costs of Periprosthetic joint infection (PJI) of the knee for the public health system of Andalusia (Spain) The data are based on consecutive patients with PJI treated in our Bone and Joint Infection Unit between January 2005 and January 2010. The total cost for all patients with knee PJI was 4,151,843 $ (3,202,841 €), i.e., a mean cost per patient of 52,555 $ (40,542 €). The mean cost per patient was 24,980 $ (19,270.80 €) for patients with early PJI and rose to 78,111 $ (60,257 €) for those with late PJI. The main cost was for the hospital stay and the specific in-hospital care received, followed by the cost of the surgical procedure.

Demographic change and urban health: Towards a novel agenda for delivering sustainable and healthy cities for all.

The focus is on the demographic drivers and demographic implications of urban health and wellbeing in towns and cities across the globe. The aim is to identify key linkages between demographic change and urban health - subjects of two largely disparate fields of research and practice - with a view to informing arguments and advocacy for urban health while identifying research gaps and priorities. The core arguments are threefold. First, urban health advocates should express a globalized perspective on demographic processes, encompassing age-structural shifts in addition to population growth and decrease, and acknowledging their uneven spatial distributions within and between urban settings in different contexts. Second, advocates should recognize the dynamic and transformational effects that demographic forces will exert on economic and political systems in all urban settings. While demographic forces underpin the production of (intra)urban inequities in health, they also present opportunities to address those inequities. Third, a demographic perspective may help to extend urban health thinking and intervention beyond a biomedical model of disease, highlighting the need for a multi-generational view of the changing societal bases for urban health, and enjoining significant advances in how interested parties collect, manage, analyse, and use demographic data. Accordingly, opportunities are identified to increase the availability of granular and accurate data to enable evidence-informed action on the demographic/health nexus.

Telomeric repeat factor 1 protein levels correlates with telomere length in colorectal cancer.

BACKGROUND: colorectal cancer is the third cancer cause of death in Spain. It is important to investigate new tumoral markers for early diagnosis, disease monitoring and prevention strategies. Telomeres protect the chromosome from degradation by nucleases and endto-end fusion. The progressive loss of the telomeric ends of chromosomes is an important mechanism in the timing of human cellular aging. Telomeric Repeat Factor 1 (TRF1) is a protein that binds at telomere ends. PURPOSE: to measure the concentrations of TRF1 and the relationships among telomere length, telomerase activity, and TRF1 levels in tumor and normal colorectal mucosa. METHOD: from normal and tumoral samples of 83 patients who underwent surgery for colorectal cancer we analyzed TRF1 protein concentration by Western Blot, telomerase activity, by the fluorescent-telomeric repeat amplification protocol assay and telomere length by Southern Blot. RESULTS: high levels of TRF1 were observed in 68.7% of tumor samples, while the majority of normal samples (59%) showed negative or weak TRF1 concentrations. Among the tumor samples, telomere length was significantly associated with TRF1 protein levels (p = 0.023). CONCLUSIONS: a relationship was found between telomere length and TRF1 abundance protein in tumor samples, which means that TRF1 is an important factor in the tumor progression and maybe a diagnostic factor.

Chaos and thermalization in a classical chain of dipoles.

We explore the connection between chaos, thermalization, and ergodicity in a linear chain of N interacting dipoles. Starting from the ground state, and considering chains of different numbers of dipoles, we introduce single site excitations with excess energy ΔK. The time evolution of the chaoticity of the system and the energy localization along the chain is analyzed by computing, up to a very long time, the statistical average of the finite-time Lyapunov exponent λ(t) and the participation ratio Π(t). For small ΔK, the evolution of λ(t) and Π(t) indicates that the system becomes chaotic at approximately the same time as Π(t) reaches a steady state. For the largest considered values of ΔK the system becomes chaotic at an extremely early stage in comparison with the energy relaxation times. We find that this fact is due to the presence of chaotic breathers that keep the system far from equipartition and ergodicity. Finally, we show numerically and analytically that the asymptotic values attained by the participation ratio Π(t) fairly correspond to thermal equilibrium.

Bifurcations of dividing surfaces in chemical reactions.

We study the dynamical behavior of the unstable periodic orbit (NHIM) associated to the non-return transition state (TS) of the H(2) + H collinear exchange reaction and their effects on the reaction probability. By means of the normal form of the Hamiltonian in the vicinity of the phase space saddle point, we obtain explicit expressions of the dynamical structures that rule the reaction. Taking advantage of the straightforward identification of the TS in normal form coordinates, we calculate the reaction probability as a function of the system energy in a more efficient way than the standard Monte Carlo method. The reaction probability values computed by both methods are not in agreement for high energies. We study by numerical continuation the bifurcations experienced by the NHIM as the energy increases. We find that the occurrence of new periodic orbits emanated from these bifurcations prevents the existence of a unique non-return TS, so that for high energies, the transition state theory cannot be longer applied to calculate the reaction probability.

Differences in the presentation and treatment of primary liver tumors at a hepatology center and an oncology center.

INTRODUCTION AND AIMS: Primary liver cancer is a public health problem in Mexico and the world. Liver transplantation (LT) is the ideal treatment for early hepatocellular carcinoma (HCC). Our aim was to evaluate the characteristics of patients with HCC and cholangiocarcinoma (CC) at two centers and identify transplantation candidates. MATERIALS AND METHODS: A retrospective observational study was conducted at the Hepatology Center (HC) and the University Center Against Cancer (UCAC), within the time frame of 2012-2018. HCC or intrahepatic CC was confirmed in 109 patients. Staging classifications, transplant selection models, and a predictive model for post-LT recurrence were applied to the HCC patients. RESULTS: Of the total population, 93% (n=102) presented with cirrhosis, 86% (n=94) had HCC (HC: 58%, UCAC: 42%), and 14% (n=15) had intrahepatic CC (HC: 40%, UCAC: 60%). Of the HC patients with HCC, Okuda I-II, BCLC A-B, and AFP levels <100ng/m predominated, whereas Okuda II-III, BCLC C-D, and AFP levels >1000ng/mL predominated in the UCAC patients. Half of the HC population with HCC met the criteria for LT, in contrast to 23% of the UCAC patients. Fifteen patients were evaluated for LT, and at present, six have undergone transplantation. CONCLUSIONS: The most frequent primary liver tumor was HCC. Patients from the HC presented with earlier-stage disease and a high number of them met the criteria for LT. Only patients from the HC underwent transplantation.

Differences in the presentation and treatment of primary liver tumors at a hepatology center and an oncology center. / Diferencias de la presentación y tratamiento en las neoplasias primarias de hígado en un centro de hepatología y un centro oncológico.

INTRODUCTION AND AIMS: Primary liver cancer is a public health problem in Mexico and the world. Liver transplantation (LT) is the ideal treatment for early hepatocellular carcinoma (HCC). Our aim was to evaluate the characteristics of patients with HCC and cholangiocarcinoma (CC) at two centers and identify transplantation candidates. MATERIALS AND METHODS: A retrospective observational study was conducted at the Hepatology Center (HC) and the University Center Against Cancer (UCAC), within the time frame of 2012-2018. HCC or intrahepatic CC was confirmed in 109 patients. Staging classifications, transplant selection models, and a predictive model for post-LT recurrence were applied to the HCC patients. RESULTS: Of the total population, 93% (n = 102) presented with cirrhosis, 86% (n = 94) had HCC (HC: 58%, UCAC: 42%), and 14% (n = 15) had intrahepatic CC (HC: 40%, UCAC: 60%). Of the HC patients with HCC, Okuda I-II, BCLC A-B, and AFP levels < 100 ng/m predominated, whereas Okuda II-III, BCLC C-D, and AFP levels > 1,000 ng/mL predominated in the UCAC patients. Half of the HC population with HCC met the criteria for LT, in contrast to 23% of the UCAC patients. Fifteen patients were evaluated for LT, and at present, six have undergone transplantation. CONCLUSIONS: The most frequent primary liver tumor was HCC. Patients from the HC presented with earlier-stage disease and a high number of them met the criteria for LT. Only patients from the HC underwent transplantation.

Characterization of the acyl-ACP thioesterases from Koelreuteria paniculata reveals a new type of FatB thioesterase.

Koelreuteria paniculata is a deciduous tree, popular in temperate regions for its ornamental value, which accumulates unusual cyanolipids in its seeds. The seed oil of this plant is rich in the unusual cis-11-eicosenoic fatty acid (20:1, or gondoic acid), a monounsaturated oil of interest to the oleochemical industry. In higher plants, de novo fatty acid biosynthesis takes place in the plastids, a process that is terminated by hydrolysis of the thioester bond between the acyl moiety and the ACP by acyl-ACP thioesterases. The specificity of acyl-ACP thioesterases is fundamental in controlling the fatty acid composition of seed oil. To determine the mechanisms involved in fatty acid biosynthesis in K. paniculata seeds, we isolated, cloned and sequenced two cDNAs encoding acyl-ACP thioesterases in this plant, KpFatA and KpFatB. Both of them were expressed heterologously in Escherichia coli and characterized with different acyl-ACP substrates. The K. paniculata FatB2 displayed unusual substrate specificity, so that unlike most FatB2 type enzymes, it displayed preference for oleoyl-ACP instead of palmitoyl-ACP. This specificity was consistent with the changes in E. coli and N. benthamiana fatty acid composition following heterologous expression of this enzyme. KpFatB also showed certain genetic divergence relative to other FatB-type thioesterases and when modelled, its structure revealed differences at the active site. Together, these results suggest that this thioesterase could be a new class of FatB not described previously.

Telomerase activity and telomere length in the colorectal polyp-carcinoma sequence.

OBJECTIVE: The role of telomerase activity and telomere length in the adenoma-carcinoma sequence of colon carcinogenesis has not been well established. The objective of this study was to determine telomerase activity and telomere length patterns in patients with adenomatous polyps either associated or not with colorectal cancer, as well as the role of telomeric instability in the adenoma-carcinoma sequence. PATIENTS AND METHODS: We included in the study 14 patients who underwent surgery for colorectal cancer and/or polyps. In 6 of these patients fresh samples of tumor tissue, polyps, and normal mucosa were obtained; in the 8 remaining cases, we collected only polyps and normal mucosa. We used the fluorescent-telomeric repeat amplification protocol assay (TRAP-F) to determine telomerase activity and telomere length using Southern-blot testing. RESULTS: Telomerase activity was detected in 86% of polyps and 50% of associated normal mucosa. Mean telomerase activity in polyp tissue was 5.85; in the normal mucosa it was 0.58 TPG. Mean telomere length was 6.78 Kbp and 7.78, respectively. Polyps in patients without synchronous cancer had a telomerase activity that was significantly higher (9.4) than in those with cancer (1.1). CONCLUSIONS: Telomerase activity increases in the colorectal adenoma-carcinoma sequence, concurrently with a decrease in telomere length. The presence of synchronous cancer modifies telomerase activity in polyps.