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1.
Epidemiol Infect ; 149: e120, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33896437

RESUMO

Recently, the antibacterial properties of oestrogen and progestogen were discovered. The aim of this study was to find the cross-sectional association between oral contraceptive use and Helicobacter pylori seroprevalence. Data were obtained from the US National Health and Nutrition Examination Survey (NHANES). The H. pylori immunoglobulin G (IgG) enzyme-linked immunosorbent assays were used to categorise participants as seropositive or seronegative. The study population included 799 female participants who had information on H. pylori seroprevalence and all other covariates and had not been taking any medications (except oral contraceptives). The bivariate Rao-Scott chi-square test indicated a significant association between H. pylori seroprevalence and contraceptive use (P < 0.01). The variables of race, education, poverty income ratio, smoking, and blood lead and cadmium levels were also significantly associated with H. pylori seroprevalence (P < 0.01). Multiple logistic regression analysis of the age-adjusted model revealed that contraceptive users are 65% less likely of being H. pylori seropositive as compared to non-contraceptive users (odds ratio (OR): 0.35, 95% confidence interval (CI): 0.18-0.68). This association is stronger with the final multivariate model (OR: 0.46, 95% CI: 0.23-0.89). Conclusions: This finding reveals the potential protective effect of oral contraceptives against H. pylori infection and serves as a foundation study for further investigations.


Assuntos
Antibacterianos/uso terapêutico , Anticoncepcionais Orais/uso terapêutico , Infecções por Helicobacter/prevenção & controle , Helicobacter pylori/efeitos dos fármacos , Adulto , Anticorpos Antibacterianos/sangue , Estudos Transversais , Bases de Dados Factuais , Feminino , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/imunologia , Humanos , Imunoglobulina G/sangue , Pessoa de Meia-Idade , Razão de Chances , Estudos Soroepidemiológicos , Estados Unidos/epidemiologia , Adulto Jovem
2.
J Laryngol Otol ; 137(12): 1300-1311, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36999550

RESUMO

OBJECTIVE: This review evaluated the safety profile and efficacy of probiotics in chronic rhinosinusitis and was registered with Prospero (Centre for Reviews and Dissemination number: 42020193529). METHOD: Literature databases were searched through inception to August 2022. Randomised, controlled trials exploring adjunctive probiotics in adult chronic rhinosinusitis patients were included. From 948 records screened, 4 randomised, controlled trials were included. RESULTS: Probiotics-associated adverse effects comprised epistaxis and abdominal pain. No reduction in Sino-Nasal Outcome Test values before 4 weeks (p = 0.58) or beyond 8 weeks (p = 0.08) of treatment or reduction of severe symptom frequency (p = 0.75) was observed. Symptom relapse in probiotic-treated patients was significantly lower across all timepoints (p = 0.045). Lower sinusitis relapse risks during treatment (risk ratio = 0.49; p = 0.019) and 8 months post-treatment (risk ratio = 0.56, p = 0.013) were observed. Probiotics demonstrated potential in improving Sino-Nasal Outcome Test symptom subscales, including sleep, psychological and rhinology subscales. CONCLUSION: The optimal mode of probiotic administration, treatment duration and target patient subgroups requires further study to evaluate the utility of probiotics.


Assuntos
Probióticos , Rinite , Sinusite , Adulto , Humanos , Administração Intranasal , Doença Crônica , Probióticos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva , Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico
3.
J Laryngol Otol ; 137(8): 828-839, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36380495

RESUMO

OBJECTIVE: This study was a systematic review to investigate the progression of untreated obstructive sleep apnoea in order to evaluate whether mild obstructive sleep apnoea should be treated from the standpoint of disease progression. METHOD: The database search study outcomes that were collected included Apnea Hypopnea Index and Respiratory Disturbance Index. A meta-analysis of obstructive sleep apnoea severity over time intervals was performed. RESULTS: A total of 17 longitudinal studies and 1 randomised, controlled trial were included for review. For patients with mild obstructive sleep apnoea, mean pre-study and post-study Apnea Hypopnea Index was 5.21 and 8.03, respectively, over a median interval of 53.1 months. In patients with moderate to severe obstructive sleep apnoea, mean pre-study and post-study Apnea Hypopnea Index was 28.9 and 30.3, respectively, over a median interval of 57.8 months. Predictors for disease progression in mild obstructive sleep apnoea are patients aged less than 60 years and those with a baseline body mass index less than 25. CONCLUSION: Mild obstructive sleep apnoea progression is observed, but it does not appear to reach any clinically significant progression to moderate or severe obstructive sleep apnoea.


Assuntos
Apneia Obstrutiva do Sono , Humanos , Apneia Obstrutiva do Sono/terapia , Índice de Massa Corporal , Progressão da Doença , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Br J Cancer ; 106(8): 1379-85, 2012 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-22491421

RESUMO

BACKGROUND: PM00104 binds guanines at DNA minor grooves, impacting DNA replication and transcription. A phase I study was undertaken to investigate safety, dose-limiting toxicities (DLTs), recommended phase II dose (RP2D), pharmacokinetics (PKs) and preliminary antitumour activity of PM00104 as a 1- or 3-h infusion three-weekly. METHODS: Patients with advanced solid tumours received PM00104 in a dose escalation trial, as guided by toxicity and PK data. RESULTS: A total of 47 patients were treated; 27 patients on the 1-h schedule (0.23-3.6 mg m(-2)) and 20 patients on the 3-h schedule (1.8-3.5 mg m(-2)). Dose-limiting toxicities comprised reversible nausea, vomiting, fatigue, elevated transaminases and thrombocytopenia, establishing the 1-h schedule RP2D at 3.0 mg m(-2). With the 3-h schedule, DLTs of reversible hypotension and neutropenia established the RP2D at 2.8 mg m(-2). Common PM00104-related adverse events at the RP2D comprised grade 1-2 nausea, fatigue and myelosuppression. In both schedules, PKs increased linearly, but doses over the 1-h schedule RP2D resulted in higher than proportional increases in exposure. A patient with advanced urothelial carcinoma had RECIST shrinkage by 49%, and three patients had RECIST stable disease ≥6 months. CONCLUSION: PM00104 is well tolerated, with preliminary evidence of antitumour activity observed. The 1-h 3-weekly schedule is being assessed in phase II clinical trials.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Tetra-Hidroisoquinolinas/administração & dosagem , Tetra-Hidroisoquinolinas/uso terapêutico , Adulto , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Progressão da Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/classificação , Tetra-Hidroisoquinolinas/efeitos adversos , Tetra-Hidroisoquinolinas/farmacocinética , Adulto Jovem
5.
Mar Environ Res ; 170: 105435, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34385137

RESUMO

Sargassum horneri, a brown macroalga, recently invaded the California coast, including into critical foundational communities such as kelp (Macrocystis pyrifera) forests. Despite its rapid spread, empirical tests that evaluate mechanisms underlying S. horneri's invasion success are lacking. To fill this knowledge gap, we conducted three field experiments on temperate rocky reefs in southern California using growth as a proxy for invasion success. We first tested whether S. horneri success differed with herbivory strength and native diversity by conducting a 2-factor experiment varying site (with different baseline levels of urchin densities and native algal diversity) and urchin access. We found S. horneri growth only differed among urchin treatments and not sites. We then evaluated whether S. horneri could successfully invade established algal canopies as a driver or whether it required open space as a passenger via a 2-factor experiment varying S. horneri size (small, medium, large) and canopy type (S. horneri, kelp, -canopy). We found that all S. horneri sizes grew fastest when canopy was lacking and light was high and slower in both canopy habitats with lower light; overall, small S. horneri grew slowest. Finally, we evaluated whether herbivore consumption for native species could facilitate S. horneri's invasion by conducting a 2-factor experiment varying species (M. pyrifera, S. horneri) and herbivore access. We found uncaged algae were consumed and caged algae grew, but there was no difference between species. Taken together, our results suggest that S. horneri is a "passenger" invader that will take advantage of points in time and space where light is plentiful, such as when M. pyrifera is removed via disturbance. Further, our results suggest that herbivory and native algal diversity are likely not key determining factors of the invasion success of S. horneri.


Assuntos
Kelp , Macrocystis , Ecossistema , Florestas , Herbivoria
6.
Br J Cancer ; 103(3): 332-9, 2010 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-20628389

RESUMO

BACKGROUND: This phase Ib trial assessed safety, tolerability, and maximum tolerated dose (MTD) of figitumumab (CP-751,871), a fully human monoclonal antibody targeting the insulin-like growth factor type 1 receptor (IGF-IR), in combination with docetaxel. METHODS: Patients with advanced solid tumours were treated with escalating dose levels of figitumumab plus 75 mg m(-2) docetaxel every 21 days. Safety, efficacy, pharmacokinetics (PKs), and biomarker responses were evaluated. RESULTS: In 46 patients, no dose-limiting toxicities were attributable to the treatment combination. Grade 3 and 4 toxicities included neutropaenia (n=28), febrile neutropaenia (n=11), fatigue (n=10), leukopaenia (n=7), diarrhoea (n=5), hyperglycaemia, lymphopaenia, cellulitis, DVT, and pain (all n=1). The MTD was not reached. Four partial responses were observed; 12 patients had disease stabilisation of > or =6 months. Pharmacokinetic and biomarker analyses showed a dose-dependent increase in plasma exposure, and complete sIGF-IR downregulation at doses of >or =3 mg kg(-1). Pharmacokinetics of docetaxel in combination was similar to when given alone. Out of 18 castration-resistant prostate cancer patients, 10 (56%) had > or =5 circulating tumour cells (CTCs) per 7.5 ml of blood at baseline: 6 out of 10 (60%) had a decline from > or =5 to <5 CTCs and 9 out of 10 (90%) had a > or =30% decline in CTCs after therapy. CONCLUSIONS: Figitumumab and docetaxel in combination are well tolerated. Further evaluation is warranted.


Assuntos
Anticorpos Monoclonais/toxicidade , Neoplasias/tratamento farmacológico , Taxoides/uso terapêutico , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Celulite (Flegmão)/induzido quimicamente , Docetaxel , Relação Dose-Resposta a Droga , Feminino , Humanos , Imunoglobulinas Intravenosas , Linfopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Neoplasias da Próstata/tratamento farmacológico , Receptor IGF Tipo 1/antagonistas & inibidores , Taxoides/farmacocinética
7.
Ann Oncol ; 21(1): 109-13, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19608618

RESUMO

BACKGROUND: Histone deacetylase blockade can promote heat shock protein 90 (HSP90) acetylation, abrogating androgen receptor signaling. A phase II trial of the histone deacetylase inhibitor (HDACi) romidepsin was conducted in patients with progressing, metastatic, castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS: A dose of 13 mg/m(2) was administered i.v. over 4 h on days 1, 8 and 15 every 28 days. The primary end point was rate of disease control defined as no evidence of radiological progression at 6 months. A sample size of 16 assessable patients in stage 1 and nine assessable patients in stage 2 was selected; progression to stage 2 required one or more patients with disease control in stage 1 (H(o) = 0.10, H(a) = 0.30; alpha and beta = 0.10). RESULTS: Thirty-five patients were enrolled. Two patients achieved a confirmed radiological partial response (RECIST) lasting > or = 6 months, along with a confirmed prostate-specific antigen decline of > or = 50%. Eleven patients experienced toxicity necessitating early discontinuation. The commonest adverse events were nausea (30 patients; 85.7%), fatigue (28 patients; 80.0%), vomiting (23 patients; 65.7%) and anorexia (20 patients; 57.1%). There was no significant cardiac toxicity. CONCLUSIONS: At the dose and schedule selected, romidepsin demonstrated minimal antitumor activity in chemonaive patients with CRPC. Further studies of improved HDACi, alone and in combination with other therapies, should nevertheless be investigated.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Depsipeptídeos/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/uso terapêutico , Castração , Resistencia a Medicamentos Antineoplásicos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/patologia
8.
Ann Oncol ; 20(1): 27-33, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18695026

RESUMO

BACKGROUND: The purpose of this study was to evaluate the association of circulating tumour cell (CTC) counts, before and after commencing treatment, with overall survival (OS) in patients with castration-resistant prostate cancer (CRPC). EXPERIMENTAL DESIGN: A 7.5 ml of blood was collected before and after treatment in 119 patients with CRPC. CTCs were enumerated using the CellSearchSystem. RESULTS: Higher CTC counts associated with baseline characteristics portending aggressive disease. Multivariate analyses indicated that a CTC >or=5 was an independent prognostic factor at all time points evaluated. Patients with baseline CTC >or=5 had shorter OS than those with <5 [median OS 19.5 versus >30 months, hazard ratio (HR) 3.25, P=0.012]; patients with CTC >50 had a poorer OS than those with CTCs 5-50 (median OS 6.3 versus 21.1 months, HR 4.1, P<0.001). Patients whose CTC counts reduced from >or=5 at baseline to <5 following treatment had a better OS compared with those who did not. CTC counts showed a similar, but earlier and independent, ability to time to disease progression to predict OS. CONCLUSION: CTC counts predict OS and provide independent prognostic information to time to disease progression; CTC dynamics following therapy need to be evaluated as an intermediate end point of outcome in randomised phase III trials.


Assuntos
Células Neoplásicas Circulantes/patologia , Orquiectomia , Neoplasias da Próstata/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/análise , Biomarcadores/sangue , Contagem de Células , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Análise de Sobrevida , Falha de Tratamento
9.
J Cell Biol ; 115(6): 1701-12, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1661733

RESUMO

We examined pathways which might result in the elevated resting free calcium [( Ca2+]i) levels observed in dystrophic mouse (mdx) skeletal muscle fibers and myotubes and human Duchenne muscular dystrophy myotubes. We found that mdx fibers, loaded with the calcium indicator fura-2, were less able to regulate [Ca2+]i levels in the region near the sarcolemma. Increased calcium influx or decreased efflux could lead to elevated [Ca2+]i levels. Calcium transient decay times were identical in normal and mdx fibers if resting [Ca2+]i levels were similar, suggesting that calcium-sequestering mechanisms are not altered in dystrophic muscle, but are slowed by the higher resting [Ca2+]i. The defect appears to be specific for calcium since resting free sodium levels and sodium influx rates in the absence of Na+/K(+)-ATPase activity were identical in normal and dystrophic cells when measured with sodium-binding benzofuran isophthalate. Calcium leak channels, whose opening probabilities (Po) were voltage independent, could be the major calcium influx pathway at rest. We have shown previously that calcium leak channel Po is significantly higher in dystrophic myotubes. These leak channels were selective for calcium over sodium under physiological conditions. Agents that increased leak channel activity also increased [Ca2+]i in fibers and myotubes. These results suggest that increased calcium influx, as a result of increased leak channel activity, could result in the elevated [Ca2+]i in dystrophic muscle.


Assuntos
Cálcio/metabolismo , Músculos/metabolismo , Distrofias Musculares/metabolismo , Animais , Canais de Cálcio/metabolismo , Células Cultivadas , Humanos , Cinética , Potenciais da Membrana , Camundongos , Sarcolema/metabolismo , Sódio/metabolismo
10.
Science ; 250(4981): 673-6, 1990 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-2173137

RESUMO

Elevated free Ca2+ concentrations found in adult dystrophic muscle fibers result in enhanced protein degradation. Since the difference in concentrations may reflect differences in entry, Ca2+ leak channels in cultures of normal and Duchenne human myotubes, and normal and mdx murine myotubes, have been identified and characterized. The open probability of leak channels is markedly increased in dystrophic myotubes. Other channel properties, such as mean open times, single channel conductance, ion selectivity, and behavior in the presence of pharmacological agents, were similar among myotube types. Compared to the Ca2+ concentrations in normal human and normal mouse myotubes, intracellular resting free Ca2+ concentrations ([Ca2+]i) in myotubes of Duchenne and mdx origin were significantly higher at a time when dystrophin is first expressed in normal tissue. Taken together, these findings suggest that the increased open probability of Ca2+ leak channels contributes to the elevated free intracellular Ca2+ concentration in Duchenne human and mdx mouse myotubes.


Assuntos
Canais de Cálcio/fisiologia , Cálcio/metabolismo , Distrofias Musculares/metabolismo , Distrofia Muscular Animal/metabolismo , Animais , Canais de Cálcio/efeitos dos fármacos , Distrofina/genética , Humanos , Potenciais da Membrana , Camundongos , Músculos/metabolismo , Nifedipino/farmacologia
11.
Nanotechnology ; 20(44): 445201, 2009 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-19801783

RESUMO

Light emitting diodes (LEDs) consisting of p-GaN epitaxial films and n-ZnO nanorods have been fabricated and characterized. The rectifying behavior and emission spectra were strongly dependent on the electronic properties of both GaN film and ZnO nanorods. Light emission under both forward and reverse bias was obtained in all cases, and emission spectra could be changed by annealing the ZnO nanorods. The emission spectra could be further tuned by using a GaN LED epiwafer as a substrate. Both forward and backward diode behavior has been observed and the emission spectra were significantly affected by both the properties of the GaN substrate and the annealing conditions for the ZnO nanorods.

12.
Occup Environ Med ; 66(8): 517-22, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19286683

RESUMO

OBJECTIVES: To investigate modifiable risk and preventive factors of work-related eye injuries. METHODS: A case-crossover study conducted to explore the associations between transient risk factors and work-related eye injuries. Patients seen at seven medical centres in Taiwan with work-related eye injuries over a 4-year period were enrolled in the study. Clinical information was collected from medical charts and detailed information on exposure to eight potentially modifiable factors during the 60 minutes prior to the occurrence of each injury, as well as during the same time interval on the last work day prior to the injury, were obtained using questionnaire surveys. Matched-pair interval analysis was adopted to assess the odds ratios (ORs) for work-related eye injuries given exposure to the eight modifiable factors. RESULTS: A total of 283 subjects were interviewed. Most of these injured workers were young, male, and self-employed or small enterprise workers. The most common injury type was photokeratitis (33.2%), mainly caused by welding (30.4%). The OR for a work-related eye injury was increased with the performance of an unfamiliar task (57.0), operation of a faulty tool or piece of equipment (48.5), distractions (24.0), being rushed (13.0), or fatigued (10.0), and a poor work environment (4.3). Wearing eye protection devices was found to have a significant protective effect on workers who might otherwise have been exposed to eye injuries (OR = 0.4; 95% CI 0.2 to 0.7). CONCLUSION: Potential modifiable risk and preventive factors for work-related eye injuries were identified using a case-crossover study. This information should be helpful in the development of preventive strategies.


Assuntos
Acidentes de Trabalho , Traumatismos Oculares/etiologia , Exposição Ocupacional/efeitos adversos , Acidentes de Trabalho/prevenção & controle , Acidentes de Trabalho/estatística & dados numéricos , Adolescente , Adulto , Idoso , Estudos Cross-Over , Traumatismos Oculares/epidemiologia , Traumatismos Oculares/prevenção & controle , Dispositivos de Proteção dos Olhos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/estatística & dados numéricos , Razão de Chances , Estudos Retrospectivos , Fatores de Risco , Taiwan/epidemiologia , Adulto Jovem
15.
Bioinformatics ; 23(1): 129-31, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17060359

RESUMO

UNLABELLED: We have developed an online program, WCLUSTAG, for tag SNP selection that allows the user to specify variable tagging thresholds for different SNPs. Tag SNPs are selected such that a SNP with user-specified tagging threshold C will have a minimum R2 of C with at least one tag SNP. This flexible feature is useful for researchers who wish to prioritize genomic regions or SNPs in an association study. AVAILABILITY: The online WCLUSTAG program is available at http://bioinfo.hku.hk/wclustag/


Assuntos
Internet , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único/genética , Software , Interface Usuário-Computador , Algoritmos , Mapeamento Cromossômico/métodos , Análise por Conglomerados , Marcadores Genéticos , Sitios de Sequências Rotuladas
16.
Bull Environ Contam Toxicol ; 81(6): 535-8, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18787749

RESUMO

Fluoxetine, a commonly prescribed antidepressant (Prozac), has been detected in sewage effluent. Its active metabolite norfluoxetine is more potent and has been detected in sewage influent and in fish tissues. We tested the effects of norfluoxetine on spawning and parturition in bivalves. Norfluoxetine induced significant spawning in zebra mussels and dark false mussels at concentrations as low as 5 microM. Norfluoxetine induced significant parturition in fingernail clams at 10 microM. Fluoxetine also induced spawning in dark false mussels at concentrations as low as 100 nM. Implications for environmental impacts of norfluoxetine and fluoxetine on native and exotic bivalves are discussed.


Assuntos
Bivalves/efeitos dos fármacos , Dreissena/efeitos dos fármacos , Fluoxetina/análogos & derivados , Comportamento Sexual Animal/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Bivalves/fisiologia , Dreissena/fisiologia , Feminino , Fluoxetina/química , Fluoxetina/toxicidade , Masculino , Esgotos/química , Poluentes Químicos da Água/química
17.
Mar Environ Res ; 140: 1-9, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29807625

RESUMO

Recent evidence suggests macroalgal blooms may play a role in the worldwide decline in seagrass, but the shape of the functional relationship between seagrass health and dominant bloom-forming macroalgae is poorly characterized. We tested whether the impact of varying abundances of two cosmopolitan bloom-forming macroalgal genera caused linear/quasi-linear or sudden threshold changes in measures of eelgrass, Zostera marina, meadow health. We conducted two caging experiments in a shallow Z. marina bed (∼1 m depth) in Bodega Harbor, California, USA where we maintained six densities within the range of natural abundances of macroalgae, Ulva (0-4.0 kg m-2) and Gracilariopsis (0-2.0 kg m-2), as well as uncaged controls over a 10-week period. Shoot density, blade growth, and epiphyte load were measured every two weeks and algal treatments reset. We did not find support for threshold transitions between algal abundance and measures of seagrass bed health using sigmoidal and broken-stick regression analyses for each data set; these models are commonly used to identify threshold patterns in ecological shifts. Instead, final measurements of shoot density and epiphyte load were best modelled as linear or slightly non-linear declines with increasing Ulva abundance. A negative linear relationship also existed between shoot density and Gracilariopsis abundance and a trend towards linear negative effects on epiphyte load. The similar shape of these functional relationships across different types of algae suggests the relationship may be generalizable. At algal abundances that are commonly observed, we found smooth and predictable negative impacts to Z. marina by decline in shoot density and potential impacts to food webs by loss of epiphytes rather than sudden threshold shifts or "ecological surprises". Our work contrasts with the growing body of literature suggesting highly non-linear shifts in response to human impact; thus, it is important to broaden understanding of shifts to more than just pattern but to the processes that drive different patterns of shifts.


Assuntos
Ecossistema , Monitoramento Ambiental , Eutrofização , Alga Marinha/fisiologia , Zosteraceae/fisiologia , Biomassa , California , Cadeia Alimentar , Ulva
18.
Mol Cell Biol ; 17(3): 1714-21, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9032298

RESUMO

The 5' untranslated regions (UTRs) of the Drosophila Ubx and Antp genes were tested for their ability to promote cap-independent translation initiation. The Ubx and the Antp 5' UTR were inserted between the CAT and lacZ coding sequences in a dicistronic gene and tested for IRES activity in transgenic Drosophila. Northern analysis of the mRNAs showed the presence of the predicted full-length dicistronic mRNAs. High CAT activity was expressed from the first cistron from all of the dicistronic constructs introduced into the fly genome. The dicistronic transgenic strains bearing the Ubx and Antp IRES elements expressed significant levels of beta-galactosidase (betaGAL) from the second cistron whereas little or no betaGAL was expressed in the controls lacking the IRESs. In situ analysis of betaGAL expression in the transgenic strains indicates that expression of the second cistron is spatially and temporally regulated. Although the developmental patterns of expression directed by the Antp and Ubx IRESs overlap, they exhibit several differences indicating that these IRESs are not functionally equivalent.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Drosophila , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Homeodomínio/genética , Proteínas Nucleares , Iniciação Traducional da Cadeia Peptídica/genética , Fatores de Transcrição , Animais , Animais Geneticamente Modificados , Proteína do Homeodomínio de Antennapedia , Cloranfenicol O-Acetiltransferase/genética , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Óperon Lac/genética , Larva , RNA Mensageiro/análise , Sequências Reguladoras de Ácido Nucleico/genética , Transfecção
19.
Swiss Med Wkly ; 137(19-20): 286-91, 2007 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-17594541

RESUMO

PRINCIPLES: Current methods for detecting vascular invasion in pancreatic cancer can be inaccurate, invasive, and expensive. The aim of this study is to assess the value of current imaging modalities in determining vascular invasion by pancreatic cancer. METHODS: The results of Endoscopic Ultrasonography (EUS), Computed Tomography (CT), Ultrasonography (US), and Angiography performed in 170 patients, suffering from pancreatic cancer, were retrospectively studied and correlated with intra-operative findings and surgical anatomopathological diagnosis after resection. We assessed sensitivity, specificity, positive and negative predictive values, and accuracy for detecting vascular invasion. RESULTS: EUS turned out to be the most reliable imaging technique for detecting vascular invasion in pancreatic cancer, with a sensitivity of 55%, specificity of 90%, positive predictive value of 61.1%, negative predictive value of 87.5%, and accuracy of 82.2%. CT results were 39.4%, 90%, 52%, 84.4%, and 79.1% for the respective categories, with however, better results with multislice CT. The US results were 3.7% for the sensitivity, 96.3% for the specificity, 25% for the positive predictive value, 75.2% for the negative predictive value, and 73.4% for the accuracy. For angiography, the sensitivity, the specificity, the positive predictive value, the negative predictive value, and the accuracy were 52.6%, 72.3%, 43.5%, 79.1%, and 66.7% respectively. CONCLUSION: In this study, EUS was the most valuable imaging modality in assessing vascular invasion (especially for venous invasion) for pancreatic cancer, with an accuracy of more than 80%. A further prospective study should be carried out to evaluate the combination of imaging modalities for the detection of vascular involvement, especially with multi-slice CT which almost reached the performances obtained by EUS.


Assuntos
Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Vasculares/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia/normas , Endossonografia/normas , Feminino , Humanos , Masculino , Artérias Mesentéricas/diagnóstico por imagem , Artérias Mesentéricas/patologia , Veias Mesentéricas/diagnóstico por imagem , Veias Mesentéricas/patologia , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias/métodos , Neoplasias Pancreáticas/patologia , Veia Porta/diagnóstico por imagem , Veia Porta/patologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Suíça , Tomografia Computadorizada por Raios X/normas , Neoplasias Vasculares/secundário
20.
Genet Mol Res ; 6(4): 1131-41, 2007 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-18273807

RESUMO

The human genome has linkage disequilibrium (LD) blocks, within which single-nucleotide polymorphisms show strong association with each other. We examined data from the International HapMap Project to define LD blocks and to detect DNA sequence features inside of them. We used permutation tests to determine the empirical significance of the association of LD blocks with genes and Alu repeats. Very large LD blocks (>200 kb) have significantly higher gene coverage and Alu frequency than the outcome obtained from permutation-based simulation, whereas there was no significant positive correlation between gene density and block size. We also observed a reduced frequency of Alu repeats at the gaps between large LD blocks, indicating that their enrichment in large LD blocks does not introduce recombination hotspots that would cause these gaps.


Assuntos
Elementos Alu , Genoma Humano , Desequilíbrio de Ligação , Bases de Dados de Ácidos Nucleicos , Genética Populacional , Humanos , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Recombinação Genética
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