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1.
Gynecol Oncol ; 149(1): 93-100, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29605057

RESUMO

OBJECTIVE: In Canada, Indigenous people have higher human papillomavirus (HPV) infection rates, lower screening rates for cervical cancer, and higher rates of invasive cancer, leading to worse cervical cancer-related outcomes than observed in non-Indigenous Canadian women. Lingering harms from European colonization drive these health inequities and create public health challenges. Policy guidance is needed to optimize HPV vaccination rates and, thereby, decrease the burden of HPV-related illness, including high-morbidity surgical procedures and chemo-radiotherapy. The Enhancing HPV Vaccination In First Nations Populations in Alberta (EHVINA) project focuses on First Nations, a diverse subset of recognized Indigenous people in Canada, and seeks to increase HPV vaccination among girls and boys living in First Nation communities. METHODS: Developing an effective strategy requires partnership with affected communities to better understand knowledge and perceptions about cancer, healthcare, and the HPV vaccine. A 2017 community gathering was convened to engage First Nations community members, health directors, and health services researchers in dialogue around unique barriers and supports to HPV vaccination in Alberta. Voices of community Elders, parents, health directors, and cancer survivors (n=24) are presented as qualitative evidence to help inform intervention design. RESULTS: Key findings from discussions indicate barriers to HPV vaccination include resource constraints and service infrastructure gaps, historical mistrust in healthcare systems, impacts of changing modes of communication, and community sensitivities regarding sexual health promotion. Supports were identified as strengthened inter-generational relationships in communities. CONCLUSIONS AND FUTURE DIRECTION: Ongoing dialogue and co-development of community-based strategies to increase HPV vaccine uptake are required. The identification of possible barriers to HPV vaccination in a Canadian Indigenous population contributes to limited global literature on this subject and may inform researchers and policy makers who work with Indigenous populations in other regions.


Assuntos
Serviços de Saúde Comunitária/métodos , Serviços de Saúde do Indígena/organização & administração , Indígenas Norte-Americanos/psicologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Aceitação pelo Paciente de Cuidados de Saúde/etnologia , Canadá , Feminino , Humanos , Masculino
2.
Phytopathology ; 102(11): 1079-85, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22784252

RESUMO

ABSTRACT With diseases caused by vector-borne plant pathogens, acquisition and inoculation are two primary stages of the transmission, which can determine vector efficiency in spreading the pathogen. The present study was initiated to quantify acquisition and inoculation successes of 'Candidatus Liberibacter solanacearum', the etiological agent of zebra chip disease of potato, by its psyllid vector, Bactericera cockerelli (Hemiptera: Triozidae). Acquisition success was evaluated in relation to feeding site on the host plant as well as the acquisition access period. Inoculation success was evaluated in relation to vector number (1 and 4) on the plants. Acquisition success was influenced by the feeding site on the plant. The highest acquisition success occurred when insects had access to the whole plant. The results of the inoculation study indicated that the rate of successfully inoculated plants increased with the vector number. Plants inoculated with multiple psyllids had higher bacterial titer at the point of inoculation. Although disease incubation period was significantly shorter in plants inoculated with multiple psyllids, this effect was heterogeneous across experimental blocks, and was independent of pathogen quantity detected in the leaflets 3 days postinoculation. Disease progress was not affected by bacterial quantity injected or psyllid numbers.


Assuntos
Hemípteros/microbiologia , Insetos Vetores/microbiologia , Doenças das Plantas/microbiologia , Rhizobiaceae/fisiologia , Solanum tuberosum/microbiologia , Animais , DNA Bacteriano/análise , Hemípteros/fisiologia , Insetos Vetores/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Caules de Planta/microbiologia , Caules de Planta/parasitologia , Solanum tuberosum/parasitologia
3.
Antimicrob Agents Chemother ; 55(1): 211-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21041508

RESUMO

Neurocysticercosis resulting from Taenia solium infections is a major cause of adult-acquired seizures worldwide. Disease is caused by larval cysts, and treatment consists of the anthelmintic drugs albendazole or praziquantel. There are no standard methods to assess drug activity to T. solium cysts in vitro. Morphological, functional, and biochemical changes that might reflect damaging (inhibiting, cytotoxic) drug effects were analyzed after exposure of cysts to albendazole sulfoxide (ABZ-SO), the major active metabolite of the drug in vivo, praziquantel (PZQ), or combinations of both. PZQ exposure led to a decrease in cyst size and inhibition of evagination, whereas ABZ-SO exposure resulted in minimal changes. Alkaline phosphatase (AP) is normally secreted by cysts, and both drugs inhibited AP secretion at concentrations of 5 and 50 ng/ml for PZQ and ABZ-SO, respectively. Some combinations of both drugs resulted in additive and/or synergistic activities. Parasite-specific antigen, detected in the cerebrospinal fluid and blood of infected patients, is also normally secreted by T. solium cysts. Antigen secretion was similarly inhibited by ABZ-SO and PZQ and a combination of both drugs, suggesting that inhibition of secretion is a common downstream consequence of the activities of both drugs. These studies establish quantitative methods to measure in vitro anthelmintic activity and suggest combination therapy with ABZ-SO and PZQ may have clinical benefit.


Assuntos
Albendazol/farmacologia , Anti-Helmínticos/farmacologia , Praziquantel/farmacologia , Taenia solium/efeitos dos fármacos , Animais , Ensaio de Imunoadsorção Enzimática , Taenia solium/metabolismo
4.
J Exp Med ; 187(12): 1941-51, 1998 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9625754

RESUMO

It is currently believed that latently infected, resting B lymphocytes are central to gammaherpesvirus persistence, whereas mucosal epithelial cells are considered nonessential. We have readdressed the question of nonlymphoid persistence using murine gammaherpesvirus 68 (MHV-68). To dissect lymphoid from nonlymphoid persistence, we used microMT transgenic mice that are defective in B cells. MHV-68 DNA persisted in the lungs of intact and B cell-deficient mice. Both episomal and linear forms of the virus genome were present in lungs, implying the presence of both latency and productive replication. In situ hybridization for virus tRNA transcripts revealed latent MHV-68 in pulmonary epithelial cells. Infectious virus was recovered from the lungs of microMT mice after T cell depletion, showing that the persisting virus DNA was reactivatable. Finally, using adoptive transfer of B cells into B cell-deficient mice, it was shown that virus persisting in lungs seeded splenic B cells, and virus resident in the spleen seeded the lungs. These results show that mucosal epithelia can act as a nonlymphoid reservoir for gammaherpesvirus persistence, and that there is a two-way movement of virus between lymphoid and nonlymphoid compartments during persistence.


Assuntos
Células Epiteliais/virologia , Gammaherpesvirinae , Infecções por Herpesviridae/virologia , Pulmão/virologia , Latência Viral , Animais , DNA Viral/isolamento & purificação , Cadeias mu de Imunoglobulina/genética , Hibridização In Situ , Pulmão/citologia , Camundongos , Camundongos Transgênicos , Plasmídeos , Reação em Cadeia da Polimerase , Ativação Viral
5.
J Exp Med ; 167(1): 109-18, 1988 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-3335828

RESUMO

The WB isolate of Giardia lamblia expresses a cysteine-rich 170-kD surface antigen (CRP170) that undergoes antigenic variation. An (6E7), cytotoxic for isolates expressing CRP170, was used in another study to select antigenic variants from clones of the WB isolate of Giardia. CRP170 was replaced by surface-labeled bands ranging in size from approximately 50 to 170 kD. In this study, mAb 6E7 was used to isolate a 1-kb portion of the CRP170 gene (M2-1) from a lambda gt 11 expression library. The M2-1 clone hybridized to a 5.4-kb transcript from isolates expressing CRP170 but did not hybridize to RNA from antigenic variants. Evidence was found for frequent rearrangements at the CRP170 gene locus. DNA sequencing of the M2-1 clone revealed the presence of long tandem repeats. The putative amino acid sequence of M2-1 reveals a 12% cysteine content, and CRP170 is readily labeled in vivo with cysteine.


Assuntos
Antígenos de Protozoários/genética , Antígenos de Superfície/genética , Giardia/genética , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Variação Antigênica , Antígenos de Protozoários/imunologia , Antígenos de Superfície/imunologia , Sequência de Bases , Cisteína , Giardia/imunologia , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/imunologia , Sequências Repetitivas de Ácido Nucleico
7.
Microbiol Mol Biol Rev ; 61(3): 294-304, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9293183

RESUMO

Microbiologists have long been intrigued by the ability of parasitic organisms to adapt to changes in the environment. Since most parasites occupy several niches during their journey between vectors and hosts, they have developed adaptive responses which allow them to survive under adverse conditions. Therefore, the life cycles of protozoan and helminthic parasites are excellent models with which to study numerous mechanisms involved in cell differentiation, such as the regulation of gene expression, signal transduction pathways, and organelle biogenesis. Unfortunately, many of these studies are very difficult because the conditions needed to elicit developmental changes in parasites remain undetermined in most cases. Recently, several interesting findings were reported on the process of differentiation of Giardia lamblia trophozoites into cysts. G. lamblia is a flagellated protozoan that inhabits the upper small intestine of its vertebrate host and is a major cause of enteric disease worldwide. It belongs to the earliest identified lineage among eukaryotes and therefore offers a unique insight into the progression from primitive to more complex eukaryotic cells. The discovery of a specific stimulus that induces trophozoites to differentiate into cysts, the identification and characterization of encystation-specific molecules, the elucidation of novel biochemical pathways, and the development of useful reagents and techniques have made this parasite an excellent model with which to study differentiation in eukaryotic cells. In this review, we summarize the most recent fundings on several aspects of Giardia differentiation and discuss the significance of these findings within the context of current knowledge in the field.


Assuntos
Giardia lamblia/crescimento & desenvolvimento , Animais , Transporte Biológico , Parede Celular/metabolismo , Giardia lamblia/citologia , Giardia lamblia/metabolismo
8.
J Clin Invest ; 74(3): 771-82, 1984 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6470140

RESUMO

We have studied the interaction between virulent Legionella pneumophila and human alveolar macrophages, the resident phagocytes at the site of infection in Legionnaires' disease. L. pneumophila multiplied 2.5-5 logs within 3 d, as measured by colony forming units, when incubated with freshly explanted alveolar macrophages in monolayer culture. At the peak of bacterial multiplication, the alveolar macrophage monolayers were destroyed. L. pneumophila multiplied more rapidly in 4-d-old than in freshly explanted alveolar macrophages. Inside alveolar macrophages, L. pneumophila were located within membrane-bound vacuoles whose cytoplasmic sides were studded with ribosomes. Alveolar macrophages that were incubated with concanavalin A (Con A) stimulated human mononuclear cell supernatants (cytokines), inhibited L. pneumophila multiplication, and the degree of inhibition was proportional to the concentration of Con A supernatant added. Anti-L. pneumophila antibody in conjunction with complement promoted phagocytosis of L. pneumophila by alveolar macrophages. By electron microscopy, most (75%) of the phagocytized L. pneumophila were intracellular. However, freshly explanted alveolar macrophages were able to kill only 0-10% of an innoculum of L. pneumophila even in the presence of antibody and complement. At the same time, alveolar macrophages also killed opsonized Escherichia coli poorly. Increasing the ratio of macrophages to bacteria, adhering the macrophages to microcarrier beads, or preincubating the macrophages for 24 or 48 h with Con A supernatants failed to augment alveolar macrophage killing of opsonized E. coli. Corticosteroids appear to increase patient susceptibility to Legionnaires' disease. However, pretreatment of alveolar macrophages and monocytes with hydrocortisone had no influence on intracellular multiplication of L. pneumophila or on the inhibition of that multiplication by activated alveolar macrophages or monocytes. Hydrocortisone did impair cytokine-induced aggregation of alveolar macrophages. These findings demonstrate that L. pneumophila multiplies in human alveolar macrophages and that they do so within a ribosome-lined phagosome; that freshly explanted alveolar macrophages kill few L. pneumophila even in the presence of antibody and complement; that activated alveolar macrophages inhibit L. pneumophila multiplication; and that steroids do not exert a direct suppressive effect on the anti-L. pneumophila activity of activated or nonactivated alveolar macrophages. Our findings indicate that alveolar macrophages may play a central role in both the pathogenesis of Legionnaires' disease and in host defense against it. This paper shows that human resident macrophage can be activated to a higher state of antimicrobial capacity and that the human alveolar macrophage can serve as an effector call in call-mediated immunity.


Assuntos
Anticorpos Antibacterianos , Legionella/imunologia , Doença dos Legionários/imunologia , Linfocinas/imunologia , Macrófagos/imunologia , Células Cultivadas , Proteínas do Sistema Complemento/imunologia , Concanavalina A/farmacologia , Humanos , Hidrocortisona/farmacologia , Legionella/efeitos dos fármacos , Legionella/crescimento & desenvolvimento , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Macrófagos/ultraestrutura , Microscopia Eletrônica , Monócitos/imunologia , Fagocitose
9.
Mol Cell Biol ; 11(6): 3326-30, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2038335

RESUMO

Giardia lamblia telomeres have been isolated from a library enriched for repaired chromosome ends by (i) screening with a Plasmodium falciparum telomere and (ii) differential hybridization with Bal 31-digested and total G. lamblia DNA. Analysis of three clones isolated by this strategy has identified multiple tandem repeats of the 5-mer TAGGG. An oligonucleotide containing these repeats recognizes Bal 31-sensitive bands in Southern hybridizations and detects all G. lamblia chromosomes in pulsed-field gel electrophoresis separations. An abrupt transition from the G. lamblia rDNA sequence to telomeric repeats has been found in all three clones. In two of the clones the transition occurs at the same site, near the beginning of the large subunit rDNA sequence. In the third clone the transition occurs at a site in the intergenic spacer sequence between the rDNA genes. Hybridization of an rDNA probe to a pulsed-field separation of G. lamblia chromosomes indicates that rDNA genes are present on several chromosomes but vary in location from isolate to isolate. These results suggest that rRNA genes are clustered at telomeric locations in G. lamblia and that these clusters are mobile.


Assuntos
Mapeamento Cromossômico , DNA de Protozoário/genética , DNA Ribossômico/genética , Giardia/genética , Animais , Sequência de Bases , Southern Blotting , Clonagem Molecular , DNA de Protozoário/isolamento & purificação , DNA Ribossômico/isolamento & purificação , Biblioteca Gênica , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Plasmídeos , Mapeamento por Restrição
10.
Mol Cell Biol ; 12(3): 1194-201, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1545800

RESUMO

Giardia lamblia trophozoites demonstrate variable expression of a repertoire of cysteine-rich surface antigens in vitro and in vivo. The size of the repertoire has been estimated at 20 to 184, and specific variants can be detected after approximately 12 generations of in vitro growth for the WB isolate. In earlier studies, we cloned a portion of the gene for a 170-kDa surface antigen (CRP170) and demonstrated by DNA sequencing that it was cysteine rich (12%) and contained 2.6 copies of a tandemly repeated 195-bp pair sequence. The clone hybridized to multiple bands on a Southern blot of G. lamblia DNA in a pattern that was variable among the cloned lines but did not correlate with expression of CRP170. We have now cloned a nearly full length cDNA as well as genomic clones for CRP170 from the WBA6 cloned isolate. In addition, we have isolated a cDNA clone from the WB1269 line (expressing CRP72), an antigenic variant which was derived from WBA6. Sequence analysis of the CRP170 and CRP72 genes revealed marked C-terminal amino acid homology, suggesting a conserved functional role such as membrane anchoring. The CRP170 repeat oligonucleotide hybridized to a stairstep of bands approximately 6 kb in size on HindIII-digested WBA6 DNA representing the expressed copy(ies) of CRP170. In contrast, there was no hybridization to a fragment of similar size in WB1269, suggesting that WB1269 trophozoites have lost the expressed copy of the CRP170 gene.


Assuntos
Variação Antigênica/genética , Antígenos de Superfície/genética , Cisteína , Giardia lamblia/genética , Família Multigênica , Proteínas de Protozoários/genética , Sequência de Aminoácidos , Animais , Antígenos de Superfície/química , Antígenos de Superfície/imunologia , Sequência de Bases , Northern Blotting , Southern Blotting , Clonagem Molecular , DNA de Protozoário , Eletroforese em Gel de Campo Pulsado , Expressão Gênica , Giardia lamblia/imunologia , Dados de Sequência Molecular , Proteínas de Protozoários/química , Proteínas de Protozoários/imunologia , Mapeamento por Restrição
11.
Transl Psychiatry ; 7(5): e1118, 2017 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-28485725

RESUMO

Visual dysfunction is commonplace in schizophrenia and occurs alongside cognitive, psychotic and affective symptoms of the disorder. Psychophysical evidence suggests that this dysfunction results from impairments in the integration of low-level neural signals into complex cortical representations, which may also be associated with symptom formation. Despite the symptoms of schizophrenia occurring in a range of disorders, the integration deficit has not been tested in broader patient populations. Moreover, it remains unclear whether such deficits generalize across other sensory modalities. The present study assessed patients with a range of psychotic and nonpsychotic disorders and healthy controls on visual contrast detection, visual motion integration, auditory tone detection and auditory tone integration. The sample comprised a total of 249 participants (schizophrenia spectrum disorder n=98; bipolar affective disorder n=35; major depression n=31; other psychiatric conditions n=31; and healthy controls n=54), of whom 178 completed one or more visual task and 71 completed auditory tasks. Compared with healthy controls and nonpsychotic patients, psychotic patients trans-diagnostically were impaired on both visual and auditory integration, but unimpaired in simple visual or auditory detection. Impairment in visual motion integration was correlated with the severity of positive symptoms, and could not be accounted for by a reduction in processing speed, inattention or medication effects. Our results demonstrate that impaired sensory integration is not specific to schizophrenia, as has previously been assumed. Instead, sensory deficits are closely related to the presence of positive symptoms independent of diagnosis. The finding that equivalent integrative sensory processing is impaired in audition is consistent with hypotheses that propose a generalized deficit of neural integration in psychotic disorders.


Assuntos
Transtorno Depressivo Maior/complicações , Esquizofrenia/complicações , Sensação/fisiologia , Percepção Visual/fisiologia , Adulto , Idoso , Percepção Auditiva/fisiologia , Transtorno Bipolar/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos/normas , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos , Esquizofrenia/fisiopatologia
12.
J Neurol Sci ; 372: 202-210, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28017213

RESUMO

BACKGROUND: A unified set of criteria for neurocysticercosis (NCC) has helped to standardize its diagnosis in different settings. METHODS: Cysticercosis experts were convened to update current diagnostic criteria for NCC according to two principles: neuroimaging studies are essential for diagnosis, and all other information provides indirect evidence favoring the diagnosis. Recent diagnostic advances were incorporated to this revised set. RESULTS: This revised set is structured in absolute, neuroimaging and clinical/exposure criteria. Absolute criteria include: histological confirmation of parasites, evidence of subretinal cysts, and demonstration of the scolex within a cyst. Neuroimaging criteria are categorized as major (cystic lesions without scolex, enhancing lesions, multilobulated cysts, and calcifications), confirmative (resolution of cysts after cysticidal drug therapy, spontaneous resolution of single enhancing lesions, and migrating ventricular cysts on sequential neuroimaging studies) and minor (hydrocephalus and leptomeningeal enhancement). Clinical/exposure criteria include: detection of anticysticercal antibodies or cysticercal antigens by well-standardized tests, systemic cysticercosis, evidence of a household Taenia carrier, suggestive clinical manifestations, and residency in endemic areas. Besides patients having absolute criteria, definitive diagnosis can be made in those having two major neuroimaging criteria (or one major plus one confirmative criteria) plus exposure. For patients presenting with one major and one minor neuroimaging criteria plus exposure, definitive diagnosis of NCC requires the exclusion of confounding pathologies. Probable diagnosis is reserved for individuals presenting with one neuroimaging criteria plus strong evidence of exposure. CONCLUSIONS: This revised set of diagnostic criteria provides simpler definitions and may facilitate its more uniform and widespread applicability in different scenarios.


Assuntos
Neurocisticercose/diagnóstico , Encéfalo/diagnóstico por imagem , Humanos , Neuroimagem
13.
Nucleic Acids Res ; 29(22): 4674-83, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11713317

RESUMO

The protozoan parasite Giardia lamblia synthesizes a diverse and surprisingly abundant array of sterile transcripts unable to code for proteins. Random sampling of cDNAs from two evolutionarily divergent Giardia strains indicates that approximately 20% of cDNAs in the libraries represent polyadenylated sterile transcripts. RNase protection analysis and northern blot hybridization of three sterile transcript loci demonstrated that both the sterile transcript and a complementary mRNA were made in each case, further categorizing these sterile transcripts as antisense transcripts. Investigation of the genomic loci for these same three sterile antisense transcripts showed typical transcription units for the sense transcripts, but still failed to reveal a usable open reading frame for the sterile antisense transcripts. 5'-RACE mapped the transcription start site for one of the sterile antisense transcripts to an AT-rich region, as is typical for GIARDIA: It is unclear whether these sterile transcripts represent errors in transcription or whether they have regulatory functions within the cell, although preliminary investigations failed to reveal evidence for a role in developmental gene regulation. In either case, the presence of such a large pool of sterile antisense transcripts is dramatic evidence of the unusual molecular machinery of the early diverging protist G.lamblia.


Assuntos
Giardia lamblia/genética , RNA não Traduzido/genética , Animais , Sequência de Bases , Northern Blotting , Cisteína Endopeptidases/genética , DNA Complementar/química , DNA Complementar/genética , DNA de Protozoário/química , DNA de Protozoário/genética , Regulação da Expressão Gênica no Desenvolvimento , Giardia lamblia/crescimento & desenvolvimento , Dados de Sequência Molecular , NADH NADPH Oxirredutases/genética , Fases de Leitura Aberta/genética , Biossíntese de Proteínas , RNA Helicases/genética , RNA Mensageiro/genética , Análise de Sequência de DNA , Transcrição Gênica
15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 71(4 Pt 2): 046406, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15903793

RESUMO

We present observations for 20-MA wire-array z pinches of an extended wire ablation period of 57%+/-3% of the stagnation time of the array and non-thin-shell implosion trajectories. These experiments were performed with 20-mm-diam wire arrays used for the double- z -pinch inertial confinement fusion experiments [M. E. Cuneo, Phys. Rev. Lett. 88, 215004 (2002)] on the Z accelerator [R. B. Spielman, Phys. Plasmas 5, 2105 (1998)]. This array has the smallest wire-wire gaps typically used at 20 MA (209 microm ). The extended ablation period for this array indicates that two-dimensional (r-z) thin-shell implosion models that implicitly assume wire ablation and wire-to-wire merger into a shell on a rapid time scale compared to wire acceleration are fundamentally incorrect or incomplete for high-wire-number, massive (>2 mg/cm) , single, tungsten wire arrays. In contrast to earlier work where the wire array accelerated from its initial position at approximately 80% of the stagnation time, our results show that very late acceleration is not a universal aspect of wire array implosions. We also varied the ablation period between 46%+/-2% and 71%+/-3% of the stagnation time, for the first time, by scaling the array diameter between 40 mm (at a wire-wire gap of 524 mum ) and 12 mm (at a wire-wire gap of 209 microm ), at a constant stagnation time of 100+/-6 ns . The deviation of the wire-array trajectory from that of a thin shell scales inversely with the ablation rate per unit mass: f(m) proportional[dm(ablate)/dt]/m(array). The convergence ratio of the effective position of the current at peak x-ray power is approximately 3.6+/-0.6:1 , much less than the > or = 10:1 typically inferred from x-ray pinhole camera measurements of the brightest emitting regions on axis, at peak x-ray power. The trailing mass at the array edge early in the implosion appears to produce wings on the pinch mass profile at stagnation that reduces the rate of compression of the pinch. The observation of precursor pinch formation, trailing mass, and trailing current indicates that all the mass and current do not assemble simultaneously on axis. Precursor and trailing implosions appear to impact the efficiency of the conversion of current (driver energy) to x rays. An instability with the character of an m = 0 sausage grows rapidly on axis at stagnation, during the rise time of pinch power. Just after peak power, a mild m = 1 kink instability of the pinch occurs which is correlated with the higher compression ratio of the pinch after peak power and the decrease of the power pulse. Understanding these three-dimensional, discrete-wire implosion characteristics is critical in order to efficiently scale wire arrays to higher currents and powers for fusion applications.

16.
Acta Neurochir Suppl ; 95: 411-4, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16463892

RESUMO

OBJECTIVE: The roles of individual types of cerebral cells in contributing to brain edema are undefined. The objective of this study was to determine the role of cerebral cell-column chromatography in quantifying cell volumes of individual cerebral cell lines, under chemically-induced anoxia/re-oxygenation (A/R). METHODS: Cerebral endothelial cells (4 experiments) or type II astrocytes (4 experiments) were cultured to confluence on microcarrier beads. A chromatographic cell-column of 1.5 cm height was filled with non-treated cell-covered beads. The column was perfused at 1 ml/min with a balanced perfusate for one hour (Baseline). The perfusate was then switched to that containing 5 mM thioglycolic acid for one hour (Anoxia). Then the column was perfused with the normal perfusate for another two hours (Re-oxygenation). The total free space in the column, reversely reflecting cell volumes, was determined by averaged transit time (TTa) of a non-permeable flow tracer blue dextran. Decreased TTa means that cells swell, and vice versa. RESULTS: TTa in endothelial cell columns increased with a peak at 60 minutes of re-oxygenation. TTa in astrocyte columns decreased with a nadir at 30 minutes of re-oxygenation. CONCLUSION: Cell column chromatography can be used to determine the cerebral cell volume changes following chemically-induced anoxia/re-oxygenation.


Assuntos
Edema Encefálico/patologia , Separação Celular/métodos , Cromatografia/métodos , Células Endoteliais/patologia , Traumatismo por Reperfusão/patologia , Edema Encefálico/induzido quimicamente , Contagem de Células/métodos , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Humanos , Traumatismo por Reperfusão/induzido quimicamente , Tioglicolatos
17.
Acta Neurol Scand Suppl ; 173: 36-42; discussion 48-52, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10819090

RESUMO

Diabetic neuropathy is common in patients with diabetes mellitus, and 7.5% of diabetics experience pain from diabetic neuropathy. Complications of diabetes mellitus are more common where control of the disease is not optimal. By improving the control of the disease, both the neuropathy and the pain it can produce may be improved. The pain of diabetic neuropathy can frequently be controlled using analgesics, antidepressants, anticonvulsants, topical capsaicin, and neuromodulation, either alone or in any combination.


Assuntos
Analgésicos/administração & dosagem , Neuropatias Diabéticas/tratamento farmacológico , Neuralgia/tratamento farmacológico , Analgésicos/efeitos adversos , Ensaios Clínicos como Assunto , Neuropatias Diabéticas/diagnóstico , Humanos , Neuralgia/diagnóstico , Medição da Dor , Resultado do Tratamento
18.
Clin Pharmacol Ther ; 22(5 Pt 1): 568-72, 1977 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-913024

RESUMO

Niridazole, an antischistosomal drug, caused a 44% decrease in the serum uric acid (SUA) concentration in 11 patients with schistosomiasis. The mean SUA (+/- SE) was 6.3 +/- 1.4 mg/100 ml at baseline and 3.5 +/- 1.5 mg/100 ml (p less than 0.01) on day 7 of treatment. There was a significant increase in the urinary uric acid/creatinine ratio, from 0.446 +/- 0.165 at baseline to 0.550 +/- 0.145 on day 3. There was no significant difference on day 7. The fractional clearance of uric acid rose from 7.2 +/- 6.8% to 13.9 +/- 17.3% (p less than 0.01), indicating a uricosuric effect. Oxypurine excretion was unchanged. In a separate study on 7 other patients, the SUA remained low for 4 to 7 days after the last dose. Niridazole, although not an organic acid, has uricosuric effects.


Assuntos
Niridazol/farmacologia , Uricosúricos , Creatinina/urina , Depressão Química , Humanos , Fatores de Tempo , Ácido Úrico/sangue , Ácido Úrico/urina
19.
Neurology ; 53(4): 777-81, 1999 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-10489040

RESUMO

OBJECTIVE: To determine serial MRI and CT abnormalities around calcified cysts due to cysticercosis in previously treated patients during periods of seizure activity. BACKGROUND: Some patients with calcified lesions due to cysticercosis have seizures. How and why seizures occur in this setting are unknown. METHODS: Three patients with known, treated cysticercosis were studied prospectively by serial MRI and CT before, during, and after seizure activity. RESULTS: All three patients demonstrated edema surrounding calcified lesions. Two of three patients had repeated episodes involving the same calcified lesions, and their symptoms corresponded to the location of the lesion. Enhancement was present in the lesions demonstrating edema, but was also present surrounding other nonsymptomatic calcified lesions. CONCLUSIONS: Perilesional edema surrounding calcified lesions due to cysticercosis occurs in some patients at the time of seizure activity. Repeated seizure episodes tend to be associated with the same lesions. Although the mechanisms involved are unknown, long-term antiseizure medication is likely indicated in these patients. Current evidence does not support the use of specific antiparasitic treatment in these patients.


Assuntos
Edema Encefálico/complicações , Calcinose/complicações , Neurocisticercose/complicações , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
20.
Neurology ; 57(2): 177-83, 2001 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-11480424

RESUMO

Neurocysticercosis is the most common helminthic infection of the CNS but its diagnosis remains difficult. Clinical manifestations are nonspecific, most neuroimaging findings are not pathognomonic, and some serologic tests have low sensitivity and specificity. The authors provide diagnostic criteria for neurocysticercosis based on objective clinical, imaging, immunologic, and epidemiologic data. These include four categories of criteria stratified on the basis of their diagnostic strength, including the following: 1) absolute--histologic demonstration of the parasite from biopsy of a brain or spinal cord lesion, cystic lesions showing the scolex on CT or MRI, and direct visualization of subretinal parasites by funduscopic examination; 2) major--lesions highly suggestive of neurocysticercosis on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after therapy with albendazole or praziquantel, and spontaneous resolution of small single enhancing lesions; 3) minor--lesions compatible with neurocysticercosis on neuroimaging studies, clinical manifestations suggestive of neurocysticercosis, positive CSF enzyme-linked immunosorbent assay for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the CNS; and 4) epidemiologic--evidence of a household contact with Taenia solium infection, individuals coming from or living in an area where cysticercosis is endemic, and history of frequent travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: 1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiologic criterion; and 2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiologic criterion, and in those who have three minor plus one epidemiologic criterion.


Assuntos
Neurocisticercose/diagnóstico , Humanos
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