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1.
Ann Oncol ; 35(7): 656-666, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38583574

RESUMO

BACKGROUND: The optimal timing of radiotherapy (RT) after radical prostatectomy for prostate cancer has been uncertain. RADICALS-RT compared efficacy and safety of adjuvant RT versus an observation policy with salvage RT for prostate-specific antigen (PSA) failure. PATIENTS AND METHODS: RADICALS-RT was a randomised controlled trial enrolling patients with ≥1 risk factor (pT3/4, Gleason 7-10, positive margins, preoperative PSA≥10 ng/ml) for recurrence after radical prostatectomy. Patients were randomised 1:1 to adjuvant RT ('Adjuvant-RT') or an observation policy with salvage RT for PSA failure ('Salvage-RT') defined as PSA≥0.1 ng/ml or three consecutive rises. Stratification factors were Gleason score, margin status, planned RT schedule (52.5 Gy/20 fractions or 66 Gy/33 fractions) and treatment centre. The primary outcome measure was freedom-from-distant-metastasis (FFDM), designed with 80% power to detect an improvement from 90% with Salvage-RT (control) to 95% at 10 years with Adjuvant-RT. Secondary outcome measures were biochemical progression-free survival, freedom from non-protocol hormone therapy, safety and patient-reported outcomes. Standard survival analysis methods were used; hazard ratio (HR)<1 favours Adjuvant-RT. RESULTS: Between October 2007 and December 2016, 1396 participants from UK, Denmark, Canada and Ireland were randomised: 699 Salvage-RT, 697 Adjuvant-RT. Allocated groups were balanced with a median age of 65 years. Ninety-three percent (649/697) Adjuvant-RT reported RT within 6 months after randomisation; 39% (270/699) Salvage-RT reported RT during follow-up. Median follow-up was 7.8 years. With 80 distant metastasis events, 10-year FFDM was 93% for Adjuvant-RT and 90% for Salvage-RT: HR=0.68 [95% confidence interval (CI) 0.43-1.07, P=0.095]. Of 109 deaths, 17 were due to prostate cancer. Overall survival was not improved (HR=0.980, 95% CI 0.667-1.440, P=0.917). Adjuvant-RT reported worse urinary and faecal incontinence 1 year after randomisation (P=0.001); faecal incontinence remained significant after 10 years (P=0.017). CONCLUSION: Long-term results from RADICALS-RT confirm adjuvant RT after radical prostatectomy increases the risk of urinary and bowel morbidity, but does not meaningfully improve disease control. An observation policy with salvage RT for PSA failure should be the current standard after radical prostatectomy. TRIAL IDENTIFICATION: RADICALS, RADICALS-RT, ISRCTN40814031, NCT00541047.


Assuntos
Prostatectomia , Neoplasias da Próstata , Terapia de Salvação , Humanos , Masculino , Prostatectomia/métodos , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Idoso , Terapia de Salvação/métodos , Pessoa de Meia-Idade , Radioterapia Adjuvante/efeitos adversos , Radioterapia Adjuvante/métodos , Antígeno Prostático Específico/sangue , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/prevenção & controle , Gradação de Tumores , Fatores de Tempo
2.
Ann Oncol ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38852675

RESUMO

BACKGROUND: Upfront primary tumor resection (PTR) has been associated with longer overall survival (OS) in patients with synchronous unresectable metastatic colorectal cancer (mCRC) in retrospective analyses. The aim of the CAIRO4 study was to investigate whether the addition of upfront PTR to systemic therapy resulted in a survival benefit in patients with synchronous mCRC without severe symptoms of their primary tumor. PATIENTS AND METHODS: This randomized phase III trial was conducted in 45 hospitals in The Netherlands and Denmark. Eligibility criteria included previously untreated mCRC, unresectable metastases, and no severe symptoms of the primary tumor. Patients were randomized (1 : 1) to upfront PTR followed by systemic therapy or systemic therapy without upfront PTR. Systemic therapy consisted of first-line fluoropyrimidine-based chemotherapy with bevacizumab in both arms. Primary endpoint was OS in the intention-to-treat population. The study was registered at ClinicalTrials.gov, NCT01606098. RESULTS: Between August 2012 and February 2021, 206 patients were randomized. In the intention-to-treat analysis, 204 patients were included (n = 103 without upfront PTR, n = 101 with upfront PTR) of whom 116 were men (57%) with median age of 65 years (interquartile range 59-71 years). Median follow-up was 69.4 months. Median OS in the arm without upfront PTR was 18.3 months (95% confidence interval 16.0-22.2 months) compared with 20.1 months (95% confidence interval 17.0-25.1 months) in the upfront PTR arm (P = 0.32). The number of grade 3-4 events was 71 (72%) in the arm without upfront PTR and 61 (65%) in the upfront PTR arm (P = 0.33). Three deaths (3%) possibly related to treatment were reported in the arm without upfront PTR and four (4%) in the upfront PTR arm. CONCLUSIONS: Addition of upfront PTR to palliative systemic therapy in patients with synchronous mCRC without severe symptoms of the primary tumor does not result in a survival benefit. This practice should no longer be considered standard of care.

3.
Br J Surg ; 107(6): 756-766, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31922258

RESUMO

BACKGROUND: It is assumed that conventional laparoscopy (LAP) and robotic-assisted laparoscopic surgery (RALS) differ in terms of the surgeon's comfort. This study compared muscle workload, work posture and perceived physical exertion of surgeons performing LAP or RALS. METHODS: Colorectal surgeons with experience in advanced LAP and RALS performed one of each operation. Bipolar surface electromyography (EMG) recordings were made from forearm, shoulder and neck muscles, and expressed relative to EMG maximum (%EMGmax ). The static, median and peak levels of muscle activity were calculated, and an exposure variation analysis undertaken. Postural observations were carried out every 10 min, and ratings of perceived physical exertion before and after surgery were recorded. RESULTS: The study included 13 surgeons. Surgeons performing LAP showed higher static, median, and peak forearm muscle activity than those undertaking RALS. Muscle activity at peak level was higher during RALS than LAP. Exposure variation analysis demonstrated long-lasting periods of low-level intensity muscle activity in the shoulders for LAP, in the forearms for RALS, and in the neck for both procedures. Postural observations revealed a greater need for a change in work posture when performing LAP compared with RALS. Perceived physical exertion was no different between the surgical modalities. CONCLUSION: Minimally invasive surgery requires long-term static muscle activity with a high physical workload for surgeons. RALS is less demanding on posture.


ANTECEDENTES: Se asume que la cirugía laparoscópica (laparoscopic, LAP) y la cirugía laparoscópica asistida por robot (robotic-assisted laparoscopic surgery, RALS) difieren en cuanto a la comodidad del cirujano. En este estudio se comparó la carga de trabajo muscular, la postura de trabajo y el esfuerzo físico percibido por los cirujanos al realizar LAP o RALS. MÉTODOS: Trece cirujanos colorrectales con experiencia en LAP avanzada y RALS realizaron una operación con cada uno de los abordajes. Se registró la electromiografía de superficie bipolar en los músculos del antebrazo, del hombro y del cuello, y se expresó en relación con el EMG máximo (% EMGmax). Se calculó el nivel de actividad muscular estático, mediano y pico, y se realizó un análisis de variación de la exposición. Las observaciones posturales se llevaron a cabo cada diez minutos y se registraron las valoraciones del esfuerzo físico percibido antes y después de la cirugía. RESULTADOS: La práctica de LAP mostró una mayor actividad muscular estática, mediana y pico del antebrazo en comparación con la práctica de RALS. El hombro izquierdo mostró la mayor actividad muscular en RALS a nivel máximo. El análisis de variación de exposición demostró periodos prolongados de actividad muscular de baja intensidad para LAP en los hombros, para RALS en los antebrazos y para ambos en el cuello. Las observaciones posturales mostraron una mayor necesidad de un cambio en la postura de trabajo al realizar LAP en comparación con RALS. El esfuerzo físico percibido no fue diferente entre ambas modalidades quirúrgicas. CONCLUSIÓN: La cirugía mínimamente invasiva requiere una actividad muscular estática prolongada con una alta carga de trabajo físico para los cirujanos. RALS es menos exigente en el aspecto postural.


Assuntos
Laparoscopia , Músculo Esquelético/fisiopatologia , Esforço Físico , Postura , Procedimentos Cirúrgicos Robóticos , Cirurgiões , Carga de Trabalho , Adulto , Fenômenos Biomecânicos , Eletromiografia , Ergonomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
J Exp Biol ; 213(Pt 18): 3237-46, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20802127

RESUMO

The behavior of the ubiquitous estuarine planktotrophic spionid polychaete larvae Polydora ciliata was studied. We describe ontogenetic changes in morphology, swimming speed and feeding rates and have developed a simple swimming model using low Reynolds number hydrodynamics. In the model we assumed that the ciliary swimming apparatus is primarily composed of the prototroch and secondarily by the telotroch. The model predicted swimming speeds and feeding rates that corresponded well with the measured speeds and rates. Applying empirical data to the model, we were able to explain the profound decrease in specific feeding rates and the observed increase in the difference between upward and downward swimming speeds with larval size. We estimated a critical larval length above which the buoyancy-corrected weight of the larva exceeds the propulsion force generated by the ciliary swimming apparatus and thus forces the larva to the bottom. This modeled critical larval length corresponded to approximately 1 mm, at which, according to the literature, competence for metamorphosis and no more length increase is observed. These findings may have general implications for all planktivorous polychaete larvae that feed without trailing threads. We observed bell shaped particle retention spectra with a minimum prey size of approximately 4 microm equivalent spherical diameter, and we found that an ontogenetic increase in maximum prey size add to a reduction in intra-specific food competition in the various larval stages. In a grazing experiment using natural seawater, ciliates were cleared approximately 50% more efficiently than similar sized dinoflagellates. The prey sizes retainable for P. ciliata larvae covers the microplankton fraction and includes non-motile as well as motile prey items, which is why the larvae are trophically positioned among the copepods and dinoflagellates. Not only do larval morphology and behavior govern larval feeding, prey behavior also influences the feeding efficiency of Polydora ciliata.


Assuntos
Larva/fisiologia , Poliquetos/fisiologia , Comportamento Predatório/fisiologia , Natação/fisiologia , Animais , Hidrodinâmica , Larva/anatomia & histologia , Tamanho da Partícula , Poliquetos/anatomia & histologia
5.
Sci Adv ; 6(37)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32917704

RESUMO

Growing evidence suggests that sexual reproduction might be common in unicellular organisms, but observations are sparse. Limited knowledge of sexual reproduction constrains understanding of protist ecology. Although Teleaulax amphioxeia and Plagioselmis prolonga are common marine cryptophytes worldwide, and are also important plastid donors for some kleptoplastic ciliates and dinoflagellates, the ecology and development of these protists are poorly known. We demonstrate that P. prolonga is the haploid form of the diploid T. amphioxeia and describe the seasonal dynamics of these two life stages. The diploid T. amphioxeia dominates during periods of high dissolved inorganic nitrogen (DIN) and low irradiance, temperature, and grazing (winter and early spring), whereas the haploid P. prolonga becomes more abundant during the summer, when DIN is low and irradiance, temperature, and grazing are high. Dimorphic sexual life cycles might explain the success of this species by fostering high genetic diversity and enabling endurance in adverse conditions.

6.
Int J Clin Pharmacol Ther ; 47(12): 744-51, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19954713

RESUMO

BACKGROUND: Combination of xylometazoline and ipratropium in a nasal spray provides fast, effective symptomatic relief of nasal congestion and rhinorrhea in adults with common cold. OBJECTIVES: To gather data in a non-prescription setting regarding the safety, pattern of use, patients' general assessment of treatment and suitability of making available without medical prescription of this topical combination nasal spray. DESIGN: Post-marketing, non-interventional, non-controlled study reflecting normal over-the-counter (OTC) use of the spray in adults with common cold (n = 1,019). Main outcome measures included pattern of use (patient-reported effectiveness, compliance with treatment) and safety (adverse drug reaction (ADR) reports). RESULTS: Over 92% of patients used the product for the intended indication, 81.4% used it 2 - 3 times/day and the median duration of treatment was 6 days. In total, 39.7% of patients reported 585 ADRs (mean 1.45 ADR/patient) while 60.3% reported no ADRs. Most common side effects were nasal dryness (12.4%), blood tinged mucus (9.3%), nasal discomfort (6.2%), epistaxis (4.2%), generally harmless and of mild severity. Patients who used the product outside the approved indication did not seem to have a higher risk of ADRs. Mean general impression score was 3.4, with 79% of patients rating treatment as "good" to "excellent". CONCLUSIONS: The topical combination nasal spray (xylometazoline plus ipratropium) for the symptomatic relief of nasal congestion and rhinorrhea in adults with common cold has a good safety profile and results in high patient satisfaction in an OTC setting. No reasons could be found to oppose the assertion that the combination spray is suitable for classification as a product not subject to medical prescription.


Assuntos
Antagonistas Colinérgicos/uso terapêutico , Resfriado Comum/tratamento farmacológico , Imidazóis/uso terapêutico , Ipratrópio/uso terapêutico , Descongestionantes Nasais/uso terapêutico , Medicamentos sem Prescrição/uso terapêutico , Administração Intranasal , Adolescente , Adulto , Antagonistas Colinérgicos/administração & dosagem , Antagonistas Colinérgicos/efeitos adversos , Quimioterapia Combinada , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Imidazóis/administração & dosagem , Imidazóis/efeitos adversos , Ipratrópio/administração & dosagem , Ipratrópio/efeitos adversos , Masculino , Descongestionantes Nasais/administração & dosagem , Descongestionantes Nasais/efeitos adversos , Medicamentos sem Prescrição/efeitos adversos , Satisfação do Paciente/estatística & dados numéricos
7.
Scand J Surg ; 98(3): 143-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19919918

RESUMO

BACKGROUND AND AIMS: Self-expanding metallic stents (SEMS) have since 1991 established themselves as an option in the treatment of large bowel obstruction. The aim of this study was to evaluate the use of SEMS in management of acute colorectal obstructions at a Danish Surgical Gastroenterology center. MATERIAL AND METHODS: Retrospective review of charts from all patients who, in the period Marts 2002 to December 2007 underwent insertion of a SEMS for an acute large bowel obstruction. RESULTS: Of 45 patients included, SEMS was intended as a bridge to surgery in 20 patients and as palliation in 25 patients. For malignant etiology, the SEMS procedure was a technical and clinical success in 97.4% of the cases. Complications occurred in 21%, mortality rate 2,6%. For benign etiology, the SEMS procedure was a technical success in 85.7%, and a clinical success in 71.4%. Complications occurred in 71.4% of the benign cases with a mortality rate of 28,6%. CONCLUSIONS: Placement of SEMS for acute large bowel obstruction with malignant etiology is an effective and safe procedure with low mortality and morbidity. However results for benign obstructions are questionable and more research is needed to determine the role of SEMS.


Assuntos
Neoplasias Colorretais/patologia , Endoscopia , Obstrução Intestinal/patologia , Obstrução Intestinal/terapia , Stents , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Neoplasias Colorretais/cirurgia , Dinamarca , Desenho de Equipamento , Feminino , Humanos , Obstrução Intestinal/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
8.
Food Chem Toxicol ; 46(9): 3099-105, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18639604

RESUMO

A risk benefit assessment in Norway on the intake of added sugar, intense sweeteners and benzoic acid from beverages, and the influence of changing from sugar sweetened to diet beverages was performed. National dietary surveys were used in the exposure assessment, and the content of added sugar and food additives were calculated based on actual contents used in beverages and sales volumes provided by the manufactures. The daily intake of sugar, intense sweeteners and benzoic acid were estimated for children (1- to 13-years-old) and adults according to the current intake level and a substitution scenario where it was assumed that all consumed beverages contained intense sweeteners. The change from sugar sweetened to diet beverages reduced the total intake of added sugar for all age groups but especially for adolescent. This change did not result in intake of intense sweeteners from beverages above the respective ADIs. However, the intake of acesulfame K approached ADI for small children and the total intake of benzoic acid was increased to above ADI for most age groups. The highest intake of benzoic acid was observed for 1- to 2-year-old children, and benzoic acid intake in Norwegian children is therefore considered to be of special concern.


Assuntos
Bebidas/análise , Carboidratos/administração & dosagem , Carboidratos/efeitos adversos , Ingestão de Energia/efeitos dos fármacos , Edulcorantes/efeitos adversos , Edulcorantes/farmacologia , Adolescente , Adulto , Fatores Etários , Idoso , Aspartame/efeitos adversos , Aspartame/análise , Ácido Benzoico/toxicidade , Bebidas/efeitos adversos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Inquéritos Nutricionais , Medição de Risco , Fatores Sexuais , Tiazinas/efeitos adversos , Tiazinas/análise
9.
Surg Endosc ; 21(11): 2012-6, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17705082

RESUMO

BACKGROUND: Trocar incisions are important sources of pain the first days after laparoscopic cholecystectomy. Radially expanding trocars may cause less pain than conventional cutting trocars. METHODS: In a patient- and observer-blinded trial, 80 patients were randomized to undergo laparoscopic cholecystectomy using either radially expanding trocars (radial group) or conventional cutting trocars (cutting group). Two 10-mm and two 5-mm trocars were used in both treatment groups. All the patients received standardized anesthetic and analgesic treatment. The primary outcome was incisional pain. Pain was registered during mobilization using a visual analog scale (VAS) and a verbal rating scale (VRS) before and 6 h after the operation, and at postoperative days 1 and 2. The needs for a fascial incision to retract the gallbladder, active surgical hemostasis, and supplementary requirements of opioids during the hospital stay were registered. In addition, 2 days after the operation, the incidence and severity of suggilations at the trocar incisions were measured. RESULTS: Data from 77 patients were available for statistical analysis. In the radial group, 23 patients needed fascial incision for gallbladder retraction compared with 11 patients in the cutting group (p = 0.006). No significant intergroup differences in VAS or VRS pain scores or any other variable were found. CONCLUSIONS: The use of radially expanding trocars has no effect on incisional pain after laparoscopic cholecystectomy.


Assuntos
Colecistectomia Laparoscópica/efeitos adversos , Colecistectomia Laparoscópica/instrumentação , Doenças da Vesícula Biliar/cirurgia , Dor Pós-Operatória/etiologia , Instrumentos Cirúrgicos/efeitos adversos , Adolescente , Adulto , Idoso , Desenho de Equipamento , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Medição da Dor , Dor Pós-Operatória/diagnóstico , Hemorragia Pós-Operatória/diagnóstico , Hemorragia Pós-Operatória/etiologia
10.
Leukemia ; 6(3): 209-14, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1564958

RESUMO

Similar to interferon alpha, pentostatin is highly effective in hairy cell leukemia and moderately active in other chronic lymphoid malignancies. In ten patients with hairy cell leukemia (HCL) and seven patients with other B-cell chronic leukemias (BCL), we have studied the intracellular 2',5'-oligoadenylate synthetase (2,5OAS) activity of the mononuclear cells before, 4 h, 24 h, and 48 h after pentostatin administration. In patients with HCL the median level of intracellular 2,5OAS increased 4.6-fold at 4 h and 11.5-fold at 24 h compared to the pretreatment value. Among the other seven patients, the median intracellular 2,5OAS remained unchanged in three patients and rose slightly by 2 to 14 times in four patients. Eleven patients (eight with HCL and two with BCL) responded to pentostatin. The median increase in 2,5OAS among the responders was 13.0-fold (range 4.8-30.0) whereas that among non-responders was 2.2-fold (range 0.2-6.3). The difference was highly significant (p less than 0.0001). In five of the total seventeen patients, the plasma levels of 2,5OAS activity were also determined and changes in plasma levels paralleled those measured intracellularly. To determine if the elevation of 2,5OAS is mediated by induction of interferon alpha, the expressions of mRNA for interferon alpha and beta were investigated by means of reverse transcription and polymerase chain reaction using the corresponding sense primers. In none of the five patients thus studied could we find an induction of mRNA for interferon alpha or beta in the leukemic cells during treatment with pentostatin. Thus, response to pentostatin correlates with induction of 2,5OAS directly and the 2',5'-oligoadenylate system seems to be involved in cytotoxicity.


Assuntos
2',5'-Oligoadenilato Sintetase/biossíntese , Leucócitos Mononucleares/efeitos dos fármacos , Pentostatina/uso terapêutico , 2',5'-Oligoadenilato Sintetase/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Indução Enzimática/efeitos dos fármacos , Feminino , Humanos , Interferon-alfa/metabolismo , Interferon beta/metabolismo , Leucemia de Células Pilosas/tratamento farmacológico , Leucemia de Células Pilosas/enzimologia , Leucemia de Células Pilosas/metabolismo , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/enzimologia , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucócitos Mononucleares/enzimologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Indução de Remissão
11.
Clin Pharmacol Ther ; 60(6): 679-86, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8988071

RESUMO

OBJECTIVES: To evaluate the efficacy of a combination of ephedrine and caffeine on smoking cessation rates, postcessation weight gain, and withdrawal symptoms and to examine changes in glycosylated hemoglobin (HbA1c) after smoking cessation. METHODS: This randomized double-blind placebo-controlled study with a 1-year follow-up period was carried out at the Department of Pulmonary Medicine in Denmark. Study subjects were 225 heavy smokers who wanted to quit smoking without gaining weight. Two-thirds of the subjects were randomized to receive 20 mg ephedrine plus 200 mg caffeine three times a day; one-third of the subjects received placebo treatment. The dosage was gradually decreased from week 12 to discontinuation at week 39. Group support and control were performed at entry and after 1, 3, 6, 12, 26, 39, and 52 weeks. Main outcome measures were (1) self-reported abstinence with validation by carbon monoxide in expired air and serum cotinine and (2) weight gain. RESULTS: The success rates after 1 year were 17% in the group treated with ephedrine plus caffeine and 16% in the group treated with placebo; the success rates were not significantly different at any time. The success rates for the four counseling physicians varied between 7% and 27% after 1 year (p < 0.05). The weight gain was significantly lower in the ephedrine plus caffeine-treated group during the first 12 weeks, but weight gains were similar after 1 year. No differences in the smoking withdrawal symptoms could be observed between the treatment groups. HbA1c was lower 6 weeks and 1 year after smoking cessation (p < 0.05). CONCLUSIONS: We found an effect of this combination of ephedrine and caffeine on weight gain during the first 12 weeks, but we found no effect on the success rates or craving for cigarettes.


Assuntos
Depressores do Apetite/farmacologia , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Efedrina/farmacologia , Abandono do Hábito de Fumar , Aumento de Peso/efeitos dos fármacos , Adulto , Glicemia/metabolismo , Testes Respiratórios , Monóxido de Carbono/metabolismo , Colesterol/sangue , Cotinina/sangue , Dinamarca , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
12.
J Magn Reson ; 142(2): 379-81, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10648158

RESUMO

Time savings by a factor of between 20 and 30 in the acquisition of multinuclear single-crystal (SC) NMR spectra have been obtained for submillimeter-size (0.01 to 0.03 mm(3)) single crystals when compared to recent results for (31)P and (87)Rb SC NMR. This gain in sensitivity is achieved by optimizing the filling factor using the smallest possible rf coil (2.0 mm inner diameter) for the specific SC probe design. Furthermore, this small coil is particularly useful for variable-temperature SC NMR studies. A probe design for such studies is presented and demonstrated experimentally.


Assuntos
Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Temperatura
13.
J Magn Reson ; 139(2): 314-33, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10423369

RESUMO

New methods for optimum separation of (2)H MAS NMR spectra are presented. The approach is based on hypercomplex spectroscopy that is useful for sign discrimination and phase separation. A new theoretical formalism is developed for the description of hypercomplex experiments. This exploits the properties of Lie algebras and hypercomplex numbers to obtain a solution to the Liouville-von Neumann equation. The solution is expressed in terms of coherence transfer functions that describe the allowed coherence transfer pathways in the system. The theoretical formalism is essential in order to understand all the features of hypercomplex experiments. The method is applied to the development of two-dimensional quadrupole-resolved (2)H MAS NMR spectroscopy. The important features of this technique are discussed and two different versions are presented with widely different characteristics. An improved version of two-dimensional double-quantum (2)H MAS NMR spectroscopy is developed. The conditions under which the double-quantum experiment is useful are discussed and its performance is compared with that observed for the quadrupole-resolved experiments. A general method is presented for evaluating the optimum pulse sequence parameters consistent with maximum sensitivity and resolution. This approach improves the performance of the experiments and is essential for any further development of the techniques. The effects of finite pulse width and hypercomplex data processing may lead to both intensity and phase distortions in the spectra. These effects are analyzed and general correction procedures are suggested. The techniques are applied to polycrystalline malonic-acid-(2)H(4) for which the spinning sideband manifolds from the carboxyl and methylene deuterons are separated. The spinning sideband manifolds are simulated to determine the quadrupole parameters. The values are consistent with previous results, indicating that the techniques are both accurate and reliable.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Cristalização , Deutério/análise , Malonatos/química
14.
J Magn Reson ; 136(1): 6-14, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9887283

RESUMO

We explore the time-translational relation between one of the powder angles (gamma) and the sample rotation angle (omegart) in NMR spectroscopy of rotating solids. Averaging over the gamma powder angle is shown to be generally equivalent to a cross correlation of two periodic functions. This leads to a fundamental relation concerning the phases of NMR spectra of rotating solids as well as improved strategies for efficient simulation of experimental spectra. Using these results in combination with the frequency-domain simulation procedure COMPUTE (M. Edén et al., J. Magn. Reson. A 120, 56 (1996)), it proves possible to reduce the computation time for spectral simulations by typically a factor 10-30 relative to the state-of-the-art calculations using the original COMPUTE algorithm. The advantage and the general applicability of the new simulation procedure, referred to as gamma-COMPUTE, are demonstrated by simulation of single- and multiple-pulse MAS NMR spectra of 31P-31P and 1H-1H spin pairs influenced by anisotropic chemical shielding and homonuclear dipolar interactions.


Assuntos
Algoritmos , Simulação por Computador , Espectroscopia de Ressonância Magnética , Pós/química , Anisotropia , Análise de Fourier , Estrutura Molecular
15.
J Magn Reson ; 148(2): 298-308, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11237635

RESUMO

This work explores the utility of simple rotary resonance experiments for the determination of the magnitude and orientation of (13)C chemical shift tensors relative to one or more (13)C--(14)N internuclear axes from (13)C magic-angle-spinning NMR experiments. The experiment relies on simultaneous recoupling of the anisotropic (13)C chemical shift and (13)C--(14)N dipole--dipole coupling interactions using 2D rotary resonance NMR with RF irradiation on the (13)C spins only. The method is demonstrated by experiments and numerical simulations for the (13)C(alpha) spins in powder samples of L-alanine and glycine with (13)C in natural abundance. To investigate the potential of the experiment for determination of relative/absolute tensor orientations and backbone dihedral angles in peptides, the influence from long-range dipolar coupling to sequential (14)N spins in a peptide chain ((14)N(i)--(13)C(alpha)(i)--(14)N(i+1) and (14)N(i+1)--(13)C'(i)--(14)N(i) three-spin systems) as well as residual quadrupolar-dipolar coupling cross-terms is analyzed numerically.

16.
J Magn Reson ; 135(1): 126-32, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9799686

RESUMO

Design of state-of-the-art instrumentation and software for acquisition and analysis of single-crystal NMR spectra is presented. The design involves highly accurate rotation of a goniometer, and the acquisition of all the spectra for each rotation axis is automatically controlled by the host computer of the spectrometer using a homebuilt interface between the computer and the single-crystal probe. Moreover, a software package (ASICS) for fast and routine assignment/analysis of complex single-crystal spectra has been developed. Employing this equipment, the acquisition and complete analysis of single-crystal NMR spectra may be performed in about the same time as required for powder methods (spinning or static). The hardware and software are compared to recent alternative approaches within single-crystal NMR. Finally, it has been observed that single-crystal NMR techniques may provide the desired data for samples where powder methods fail.


Assuntos
Computadores , Processamento de Imagem Assistida por Computador/instrumentação , Espectroscopia de Ressonância Magnética , Software , Espectroscopia de Ressonância Magnética/métodos
17.
J Magn Reson ; 131(1): 144-7, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9533917

RESUMO

By combination of fast magic-angle spinning (MAS) and detection of the free-induction decay during a rotor-synchronized quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) train of refocusing pulses, the sensitivity of quadrupolar-echo MAS NMR spectra for the central transition of half-integer quadrupolar nuclei exhibiting large quadrupolar couplings may be significantly enhanced. Enhancements by an order of magnitude may easily be realized while maintaining information about the anisotropic interactions. In the present study the so-called QCPMG-MAS experiment is demonstrated experimentally and by numerical simulations for the two 87Rb sites in Rb2SO4.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Anisotropia , Fenômenos Químicos , Físico-Química , Simulação por Computador , Espectroscopia de Ressonância de Spin Eletrônica , Aumento da Imagem/métodos , Modelos Químicos , Rubídio/química , Radioisótopos de Rubídio/química , Sulfatos/química , Difração de Raios X
18.
J Magn Reson ; 156(1): 152-4, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12081453

RESUMO

The design of a broadband 4-mm magic-angle spinning (MAS) X-(1)H/(19)F double resonance probe for cross-polarization (CP)/MAS NMR studies at 21.15 T ((1)H at 900 MHz) is described. The high-frequency (1)H/(19)F channel employs a new and efficient transmission line tuning design. The first (13)C CP/MAS NMR spectra recorded at 21.15 T have been obtained with this probe and exhibit the best S/N per milligram sample of hexamethylbenzene achieved so far for a 4-mm rotor.


Assuntos
Espectroscopia de Ressonância Magnética/instrumentação , Derivados de Benzeno/química , Desenho de Equipamento , Espectroscopia de Ressonância Magnética/métodos
19.
Arch Dermatol Res ; 291(7-8): 425-31, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10482013

RESUMO

The air around intact feverfew (Tanacetum parthenium) plants was examined for the presence of airborne parthenolide and other potential allergens using a high-volume air sampler and a dynamic headspace technique. No particle-bound parthenolide was detected in the former. Among volatiles emitted from the aerial parts of feverfew plants and collected by the dynamic headspace technique a total of 41 compounds, mainly monoterpenes, were identified and quantified by GC and GC-MS. Alpha-Pinene, camphene, limonene, gamma-terpinene, (E)-beta-ocimene, linalool, p-cymene, (E)-chrysanthenol, camphor and (E)-chrysanthenyl acetate were the predominant monoterpenes accounting for nearly 88% of the total volatiles emitted. The average total yield of volatiles emitted over 24 h was 18,160 ng/g fresh weight of leaves and flowers, corresponding to the emission of approximately 8 mg volatiles per day from one full-grown feverfew plant. No parthenolide or other sesquiterpene lactones were detected. The present investigation does not support the theory of airborne sesquiterpene lactone-containing plant parts or of direct release of sesquiterpene lactones from living plants as the only explanations for airborne Compositae dermatitis. Potential allergens were found among the emitted monoterpenes and their importance in airborne Compositae dermatitis is discussed.


Assuntos
Poluentes Atmosféricos/imunologia , Asteraceae/imunologia , Asteraceae/metabolismo , Dermatite de Contato/imunologia , Sesquiterpenos/metabolismo , Terpenos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Humanos
20.
Eur J Obstet Gynecol Reprod Biol ; 50(1): 71-6, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8365539

RESUMO

Three hundred eighty-five women treated with conization due to repeated CIN I, CIN II or CIN III of the cervix uteri have been followed up for 5 years. All cones were classified according to diagnosis and status of the resection margins. A significantly greater recurrence rate of 16.2% was found in the group with neoplasia in the resection margins, in contrast to 3.9% in the group with normal resection margins. However, 83.8% (75.4-92.2%) of patients with neoplasia in the resection margins can be expected to be free of recurrence after a 5-year postoperative follow-up period. Whether the non-free resection margins were endocervical, ectocervical or both, did not influence the recurrence rate. While the prevalence of non-free resection margins increased significantly with increasing dysplasia, this could not be found with increasing age. The risk of recurrence could not be correlated with the grade of dysplasia. We conclude that neoplasia in the resection margins of the cone represents an increased risk of recurrence. Therefore, we changed the normal smear check-up with a cotton-swab to smear with cyto-brush, supplemented with colposcopy in the non-free resection margin group, but it remains to be proven that this procedure is safer.


Assuntos
Carcinoma in Situ/patologia , Recidiva Local de Neoplasia/patologia , Neoplasias do Colo do Útero/patologia , Carcinoma in Situ/cirurgia , Feminino , Seguimentos , Humanos , Recidiva Local de Neoplasia/epidemiologia , Fatores de Risco , Neoplasias do Colo do Útero/cirurgia , Esfregaço Vaginal/métodos
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