RESUMO
Lethal 3 malignant brain tumor 1 (L3MBTL1), a homolog of the Drosophila polycomb tumor suppressor l(3)mbt, contains three tandem MBT repeats (3xMBT) that are critical for transcriptional repression. We recently reported that the 3xMBT repeats interact with mono- and dimethylated lysines in the amino termini of histones H4 and H1b to promote methylation-dependent chromatin compaction. Using a series of histone peptides, we now show that the recognition of mono- and dimethylated lysines in histones H3, H4 and H1.4 (but not their trimethylated or unmodified counterparts) by 3xMBT occurs in the context of a basic environment, requiring a conserved aspartic acid (D355) in the second MBT repeat. Despite the broad range of in vitro binding, the chromatin association of L3MBTL1 mirrors the progressive accumulation of H4K20 monomethylation during the cell cycle. Furthermore, transcriptional repression by L3MBTL1 is enhanced by the H4K20 monomethyltransferase PR-SET7 (to which it binds) but not SUV420H1 (an H4K20 trimethylase) or G9a (an H3K9 dimethylase) and knockdown of PR-SET7 decreases H4K20me1 levels and the chromatin association of L3MBTL1. Our studies identify the importance of H4K20 monomethylation and of PR-SET7 for L3MBTL1 function.
Assuntos
Regulação da Expressão Gênica , Histona-Lisina N-Metiltransferase/química , Histonas/química , Proteínas de Neoplasias/metabolismo , Transcrição Gênica , Sítios de Ligação , Ciclo Celular , Cromatina/química , Cromatina/metabolismo , Proteínas Cromossômicas não Histona , Humanos , Células K562 , Lisina/química , Metilação , Ligação Proteica , Proteínas Repressoras , Proteínas Supressoras de TumorRESUMO
Toxic strains of the finely filamentous, velvety, dark-olive green to black algal organism, Microcolus Lyngbyaceus, (formerly Lyngbya majuscula Gomont, or "lyngbya") have been recognized as etiologic agent of "stinging seaweed" dermatitis (one of several forms of "swimmer's itch") in Hawaii since the late 1950s as reviewed. Lymphadenopathy, pustular folliculitus, and local infections have been reported in some persons.
Assuntos
Dermatite de Contato/etiologia , Alga Marinha , Vibrio/isolamento & purificação , Microbiologia da Água , Cianobactérias , Dermatite de Contato/microbiologia , Surtos de Doenças , Humanos , Toxinas de Lyngbya/efeitos adversosRESUMO
The known and theoretical pharmacology of poisons involved in toxic marine ingestions has assisted in the development of specific therapeutics for these afflictions. The clinical manifestations of several toxic marine ingestions have suggested toxins/cogeners that may be involved in the poisoning process, providing direction for the development of diagnostic laboratory tests, including those for cyclic ethers. Future investigations should involve utilization of acetaminophen and indomethacin for chronic ciguatera fish poisoning, and the evaluation of the role of polycyclic ethers in the temperature sensation reversal phenomenon of both ciguatera and neurotropic shellfish poisoning.
Assuntos
Peixes Venenosos , Toxinas Marinhas/farmacologia , Animais , Ciguatera , Ciguatoxinas/farmacologia , Alucinógenos/farmacologia , Alucinógenos/intoxicação , Humanos , Toxinas Marinhas/intoxicação , Neurotoxinas/farmacologia , Neurotoxinas/intoxicação , Pepinos-do-Mar , Frutos do Mar , Tetrodotoxina/farmacologia , Tetrodotoxina/intoxicaçãoRESUMO
A 45-year-old man ate the liver of the toxic pufferfish (Diodron hystrix) and developed mild tetrodotoxication consisting of hyperemesis, bradycardia, hypotension, generalized numbness, and a generalized paresis. He was treated with atropine, normal saline IV infusions, nasogastric suction, and oxygen, and he recovered after six days.
Assuntos
Emergências , Peixes Venenosos , Tetrodotoxina/intoxicação , Animais , Atropina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Peixes Venenosos , Doenças Transmitidas por Alimentos/etiologia , Idoso , Animais , Havaí , Humanos , MasculinoRESUMO
Of the hundreds of species of bacteria in seawater, in marine sediments, and associated with marine organisms, more than 20 are known human pathogens. Based on published data, wherein a variety of marine bacteria have been cultured from open wounds (eg, coral cuts) and from near-drowning pneumonias, it is hypothesized that these bacteria can provide a primary infectious inoculation of open marine wounds and of the respiratory tract of near-drowners.
Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/etiologia , Afogamento/microbiologia , Pneumonia/etiologia , Água do Mar , Microbiologia da Água , Ferimentos e Lesões/microbiologia , Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia/tratamento farmacológico , Água do Mar/efeitos adversos , Escarro/microbiologiaAssuntos
Toxinas de Lyngbya , Alga Marinha , Estomatite/etiologia , Alcaloides/efeitos adversos , Alcaloides/análise , Dermatite/etiologia , Humanos , Lactonas/efeitos adversos , Lactonas/análise , Masculino , Toxinas Marinhas/efeitos adversos , Pessoa de Meia-Idade , Alga Marinha/análise , Estomatite/terapia , NataçãoRESUMO
Selected invasive diagnostic and therapeutic techniques were taught to emergency physicians through modular Advanced Trauma Life Support (ATLS) animal laboratory courses presented in the fall of 1977. Thirty-seven emergency physicians participated in the four pilot ATLS laboratories in which the average trainee:animal:instructor ratio was 2:1:0.75. The animals consisted of 15 large baboons and five large rhesus monkeys. Cost accounting on these pilot ATLS courses revealed that the total program cost was $15,581.86, for an average of $3,895.46 per trauma laboratory course and $421.13 per emergency physician trained. The ATLS concept is ready for development into a nationally-standarized ATLS series.