RESUMO
Despite their perceived inaccessibility, the marine intertidal and benthic environments of Antarctica, southern Africa and South America have continued to provide marine natural products for chemists with unique opportunities to study the secondary metabolite constituents and chemical ecology of a diverse array of marine gastropod molluscs. This review covers the literature up to 31 January 2005 and describes the structures and, where applicable, biological activities of 100 secondary metabolites isolated from 21 species of marine gastropod molluscs. Not unexpectedly, the chemistry of chemically defended shell-less opisthobranchs dominates the natural product studies of molluscs collected from these regions of the southern hemisphere.
Assuntos
Fatores Biológicos/química , Biologia Marinha , Moluscos/química , África Austral , Animais , Regiões Antárticas , Biodiversidade , América do Sul , Especificidade da EspécieRESUMO
Extracts of the endemic nudibranch Leminda millecra collected in Algoa Bay, South Africa, yielded four known metabolites, millecrones A (1) and B (2), isofuranodiene (5), and (+)-8-hydroxycalamenene (9), and nine new compounds, algoafuran (7), cubebenone (8), and a series of seven triprenylquinones and hydroquinones (21-27). A subsequent GC-MS survey of extracts of 21 of L. millecra's possible octocoral prey species in Algoa Bay identified the soft coral Alcyonium fauri as the source of 1 and the gorgonian Leptogorgia palma as the species producing 2 and 8.
Assuntos
Cnidários/química , Furanos/isolamento & purificação , Moluscos/química , Sesquiterpenos/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão , Furanos/química , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estrutura Molecular , Quinonas/química , Quinonas/isolamento & purificação , Sesquiterpenos/química , África do Sul , Espectrofotometria Infravermelho , EstereoisomerismoRESUMO
Two known cembrane diterpenes, flaccidoxide (1) and (1Z,3E,7E,11S, 12S,14S)-11,12-epoxy cembra-1,3,7-trien-14-ol (2), and the new cembrane diterpene flaccidoxide-13-acetate (3) were isolated from specimens of Cladiella kashmani collected off Ponto do Oura, Mozambique. The modified Mosher's method established the previously unassigned absolute configuration of 1 as (1Z,3E,7E,11S,12S,13S, 14R)-14-acetoxy-11,12-epoxy cembra-1,3,7-trien-13-ol. Acetylation of 1 yielded 3 and thus confirmed the structure of 3 as (1Z,3E,7E,11S, 12R,13S,14R)-13,14-diacetoxy-11,12-epoxy cembra-1,3,7-triene. All three diterpenes were toxic to the brine shrimp Artemia salina.
Assuntos
Antineoplásicos/isolamento & purificação , Cnidários/química , Diterpenos/isolamento & purificação , Acetilação , Animais , Antineoplásicos/farmacologia , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Espectroscopia de Ressonância Magnética , Conformação Molecular , África do Sul , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Células Tumorais CultivadasRESUMO
Two new 3,6-epidioxy-7,10-tetrahydrofurano C(26) unsaturated fatty acids, stolonic acids A (1) and B (2), were isolated from a previously undescribed ascidian species, Stolonica sp. collected off the Maldive Islands in the Indian Ocean. The structures and relative stereochemistry of 1 and 2 were determined using conventional spectroscopic methods. Both compounds exhibited antiproliferative activity against selected human melanoma and ovarian tumor cell lines, with IC(50) values of approximately 0.05-0.1 microg/mL.
Assuntos
Antineoplásicos/isolamento & purificação , Ácidos Graxos Insaturados/isolamento & purificação , Furanos/isolamento & purificação , Peróxidos/isolamento & purificação , Urocordados/química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/farmacologia , Furanos/química , Furanos/farmacologia , Humanos , Oceano Índico , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Peróxidos/química , Peróxidos/farmacologia , Células Tumorais CultivadasRESUMO
We have made great strides in understanding the pathophysiology and medical management of hypertension, yet barriers to effective blood pressure control remain. The process of identifying the barriers within the health care system may be as important as the barriers themselves. Our primary purpose was to apply the widely accepted tool, Continuous Quality Improvement (CQI), to identify barriers to the management of hypertension. We wanted to identify the most important factors and (or) persons in effective blood pressure control and to compare costs, satisfaction, and blood pressure control among subgroups of patients to identify those most likely to benefit from interventions. We recruited patients with essential hypertension who came to a university-based clinic staffed by family physicians and residents; 181 patients with hypertension were identified and asked at the time of their visit to complete a questionnaire relating to the management of their blood pressure. Twenty-five physicians and 8 medical assistants were also asked to complete a similar questionnaire regarding their perceptions of barriers to blood pressure management. All other information came from the patients' medical records. Blood pressure control was based on a reading taken on the date the questionnaire was completed. Student's t test was used to determine if statistically significant differences existed in blood pressure control, patient satisfaction, and total costs for certain subgroups; regression analysis was used to determine correlations. We had completed questionnaires from 91 patients, 89 physicians, and 79 staff. The physicians and staff were of course involved; however, we found that the patients' gestalt was extremely important in blood pressure control. Our patients perceived that lifestyle modifications such as exercise and weight loss were the greatest barrier to better blood pressure control. The cost of certain antihypertensive drugs was an obstacle for some patients. African Americans had poorer blood pressure control, and their satisfaction of care was significantly lower than that of other races. Our patients taught us that the 2 major barriers to blood pressure control were changes in lifestyle and reducing the cost of medications. We also found that our African American patients showed the poorest blood pressure control and the greatest dissatisfaction with their care. We surmise that the greatest benefit of any intervention would be expected in this population. We demonstrated that CQI can be used to identify barriers to hypertension management and subgroups of patients likely to benefit from interventions.
Assuntos
Hipertensão/terapia , Aceitação pelo Paciente de Cuidados de Saúde , Gestão da Qualidade Total , Adulto , Negro ou Afro-Americano , Idoso , Anti-Hipertensivos/economia , Feminino , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/economia , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Seleção de Pacientes , População BrancaRESUMO
BACKGROUND: An eight-hour workshop was conducted at a professional meeting in 1996 to introduce medical faculty to the principles of continuous quality improvement (CQI) as they relate to change in medical education and to provide participants with opportunities to use specific tools for applications to education. Four two-hour sessions focused on an introduction to CQI, understanding and mapping processes, identifying change ideas, and testing a change for improvement. TESTING A CHANGE FOR IMPROVEMENT: The goals of the final session were to plan a pilot test of an improvement, identify the steps of the plan-do-study-act (PDSA) cycle, and consider change for improvement in the context of one's own organization. Working in small groups, participants chose a specific change one might try in the following example: improving student performance in a neuroscience course. POSTSESSION EVALUATION AND FOLLOW-UP: Immediately following the workshop sessions, participants represented by administrators in medical education and clinical and basic science teaching faculty completed evaluations on the usefulness and likelihood of their using CQI tools. One year later, of the 32 workshop registrants who were mailed surveys, 15 respondents rated their change in understanding of CQI and their use of CQI techniques. More than 60% of the respondents reported application of CQI principles at their organizations. CQI methods used most frequently included structured team meetings, prioritizing opportunities, and brainstorming. CONCLUSION: The significant application of CQI principles and methods reported by participants one year after a brief intervention supports a need and utility for CQI principles and tools in medical education.
Assuntos
Currículo/normas , Educação Médica/normas , Docentes de Medicina/normas , Ensino/métodos , Gestão da Qualidade Total/métodos , Educação , Humanos , Estados UnidosRESUMO
The known cytotoxic, linear beta-substituted sesterterpenes (18R)-variabilin (1) and 22-deoxyvariabilin (4) and a new variant, 22-deoxy-23-hydroxymethylvariabilin (5), were isolated from the endemic South African nudibranch Hypselodoris capensis together with the known ichthyotoxic sesquiterpenes nakafuran-8 (2) and -9 (3). One of H. capensis' dietary sponges, a Fasciospongia sp. collected simultaneously with the nudibranchs, yielded sesterterpenes 1, 4, and 5 and the ubiquitous prenylated furan derivative, furospinosulin-1 (7).
Assuntos
Furanos/isolamento & purificação , Moluscos/química , Poríferos/química , Terpenos/isolamento & purificação , Animais , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Dados de Sequência Molecular , África do Sul , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Control of sexually transmitted diseases (STDs) in adolescents is a primary responsibility of health care providers. Using the tools of history and physical examination, and drawing on the awareness of different stages of adolescent development, health care providers can define at-risk for STDs. This article discusses screening practices, disease control through reporting and preventive counseling, and treatment guidelines for common STD syndromes.
Assuntos
Adolescente , Infecções Sexualmente Transmissíveis/prevenção & controle , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Anamnese/métodos , Guias de Prática Clínica como Assunto , Atenção Primária à Saúde , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/tratamento farmacológico , Infecções Sexualmente Transmissíveis/etiologiaRESUMO
The purpose of this research was to develop and partially assess a self-report scale for measuring doctors' and patients' perceptions of self-communication and other communication competence during a medical interview. Previous research into the components of communication competence and medical discourse were used to develop the Medical Communication Competence Scale (MCCS). It was hypothesized that the items of the MCCS would form four clusters: information giving, information seeking, information verifying, and socioemotional communication. The cluster analysis results provided support for the hypothesis. Results of several other analyses provided additional support for the validity of the MCCS.
RESUMO
Nonobstetric surgical emergencies may be difficult to recognize in pregnant patients whose normal physiologic state is altered by pregnancy. Early suspicion and serial examination in pregnancy may result in appropriate interventions for appendicitis, cholecystitis, pancreatitis, and bowel obstruction. Treatment in pregnant patients who experience trauma must be systematic so that situations at risk for maternal and fetal loss can be recognized.
Assuntos
Apendicite/diagnóstico , Colecistite/diagnóstico , Obstrução Intestinal/diagnóstico , Pancreatite/diagnóstico , Complicações na Gravidez/diagnóstico , Ferimentos e Lesões/terapia , Apendicite/cirurgia , Colecistite/cirurgia , Feminino , Morte Fetal/etiologia , Morte Fetal/prevenção & controle , Humanos , Obstrução Intestinal/cirurgia , Pancreatite/cirurgia , Gravidez , Complicações na Gravidez/cirurgia , Ferimentos e Lesões/complicações , Ferimentos e Lesões/diagnósticoRESUMO
The known diterpenoids zahavin A and 9-deacetoxy-14,15-deepoxyxeniculin and the two new diterpenoids 7,8-epoxyzahavin A and xeniolide C were isolated from specimens of Eleutherobia aurea collected from Aliwal Shoal off the southern Kwazulu-Natal coast, South Africa. Standard spectroscopic methods were used for the structure determinations. The former three diterpenoids inhibit superoxide production in rabbit-cell neutrophils.
Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Cnidários/metabolismo , Diterpenos/isolamento & purificação , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Cromatografia Líquida de Alta Pressão , Cristalização , Diterpenos/química , Diterpenos/farmacologia , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Peso Molecular , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Coelhos , Superóxidos/metabolismoRESUMO
Nonobstetric medical emergencies of hypoxia may be difficult to recognize in pregnant patients whose normal physiologic condition is altered by the pregnant state. Keys to early recognition of hypoxia in pregnancy may result in appropriate medical interventions for treatment of asthma and seizures that minimize ill effects to mother and fetus. Preventive measures and patient education are important to reducing the incidence of emergencies such as status asthmaticus and status epilepticus.
Assuntos
Asma/complicações , Epilepsia/complicações , Hipóxia/etiologia , Complicações na Gravidez/etiologia , Asma/epidemiologia , Asma/prevenção & controle , Epilepsia/epidemiologia , Epilepsia/prevenção & controle , Feminino , Humanos , Hipóxia/epidemiologia , Incidência , Gravidez , Complicações na Gravidez/epidemiologiaRESUMO
Extracts of the dorid nudibranchTritoniella belli and stoloniferan coralClavularia frankliniana were chromatographed and analyzed by(1)H NMR and thin-layer chromatography. Three glycerol ethers were detected inT. belli, primarily 1-O-hexadecyl glycerol (chimyl alcohol). Chimyl alcohol was also detected after gradient flash chromatography and reverse-phase HPLC purification in the tissues ofC. frankliniana. The common omnivorous predatory Antarctic sea starOdontaster validus, a likely predator of benthic invertebrates, showed feeding deterrence to small cubes ofT. belli mantle tissue placed on the tube feet along the ambulacral feeding groove, while always extruding the cardiac stomach when presented with cubes of shrimp tissue of similar size. Filter-paper disks soaked in an aqueous shrimp solution and then dried were found to elicit a broad range of feeding behaviors inO. validus, including movement of the shrimp disk to the mouth, extrusion of the cardiac stomach, and the assumption of a humped feeding posture. Chimyl alcohol-treated shrimp disks caused significant feeding deterrence in sea stars when compared with control disks (solvent plus shrimp treated disks alone).T. belli andC. frankliniana appear to employ a defensive compound that has been found in a variety of temperate and tropical mollusks, where it has been demonstrated to deter fish predators. We provide evidence for further deterrent capabilities of chimyl alcohol and of its trophic relationship in the polar ecosystem of McMurdo Sound, Antarctica.
RESUMO
PIP: Despite the very rich theoretical literature on marital power, recent empirical investigations on this subject have, in general, relied on disappointing measures of power. The empirically testable model developed in this article is an application of Blumberg's general theory of gender stratification to the contemporary American heterosexual couple. In the model, the authors concur with prior studies that identify economic power as the key variable in the power balance within a marital relationship. Their conceptualization of economic power, however, attempts to reflect the extremely complex nature of marital power. Thus, they offer the notion of overall economic power and then suggest that there are a number of discount factors operating at both the macro and micro levels that affect the power balance, resulting in what is termed net economic power. The fully elaborated model is dynamic, taking into account birth cohort differences, stable versus transitional relationships, and cross-class differences.^ieng
Assuntos
Renda , Relações Interpessoais , Casamento , Modelos Teóricos , Poder Psicológico , Fatores Socioeconômicos , América , Comportamento , Países Desenvolvidos , Economia , América do Norte , Política , Pesquisa , Estados UnidosAssuntos
Piranos , Pironas , Animais , Fungos/análise , Humanos , Conformação Molecular , Estrutura Molecular , Plantas/análise , Análise Espectral , Terminologia como AssuntoRESUMO
Cells cultured in vitro from normal human white matter and 3 individual brain tumors exhibited the following population doubling times: cells from normal human white matter, 64 +/- 22 h, glioblastoma multiforme, 43 +/- 11 h; malignant astrocytoma, 98 +/- 19 h; and anaplastic oligodendroglioma, 81 +/- 24 h. Cells were seeded at subconfluent density, pulse-labelled for 24 h with the ganglioside precursor D-[1-14C]glucosamine and harvested. Radioactive patterns of extracted gangliosides showed that incorporation of label into disialoganglioside was significantly higher in the samples with longer population doubling times than in samples with shorter population doubling times. These findings suggest gangliosides may play a role in regulation of cell growth.