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INTRODUCTION: Noroviruses, together with rotaviruses, are the most common cause of viral gastroenteritis in the Czech Republic (CR). The aim of this study was to analyse data on the incidence of norovirus gastroenteritis in the CR and thus to add to the body of knowledge about its significance. MATERIAL AND METHODS: A descriptive analysis was performed of the basic characteristics of norovirus gastroenteritis reported under ICD-10 code A08.1 to the Epidat or ISIN electronic infectious diseases information system between 2008 and 2020. On the basis of reports from five microbiological laboratories, weekly data on confirmed cases of norovirus infection from 2010-2020 were analysed. Databases of microbiology laboratories from across the Czech Republic were searched to determine the number of the laboratories where norovirus infections were diagnosed and the methods used for this purpose in 2008-2020. RESULTS: From 2008 to 2020, 33,575 cases of norovirus gastroenteritis were reported to the infectious diseases information systems, which equates to an annual incidence of 24.5/100,000 population, varying between years from 8.2 to 77.1/100,000. Men accounted for 40.2% of cases with an incidence of 20.1/100,000 compared to 28.8/100,000 recorded in women. Of the total of reported cases, 14,282 patients (42.5%) required hospital admission. Over the whole study period, 7,431 cases of norovirus gastroenteritis were recorded in children under 5 years of age. This age category accounted for 13.7-38.9% of the annual totals of reported cases. The incidences were 101.8/100,000 in children under 5 years of age, 40.1/100,000 in 5-14-year-olds, 12.7/100,000 in 15-64-year-olds, and 38.2/100,000 in the age group 65 years and over. Twenty-four deaths (case fatality rate of 0.07%) were reported as associated with norovirus gastroenteritis at the ages 42-94. In the age categories 15-64 years and 65 years and over, the case fatality rates were 0.02% and 0.24%, respectively. Over the study period, 274 epidemics occurred, during which 16,893 (50.3%) of the total of 33,575 cases were reported. In the epidemic outbreaks, 1,694 (10.0%) patients required hospital admission. The largest outbreak with 5,248 reported cases in 2015 was associated with contamination of the Prague water supply system. Norovirus infections were laboratory diagnosed year-round, peaking in the autumn and winter months. They are currently diagnosed by 81 laboratories in the Czech Republic, 90.1% of which use immunochromatographic tests. CONCLUSION: The study confirmed the highest incidence of norovirus gastroenteritis among children under 5 years of age and the highest case fatality rate in the age group 65 years and over. Over half of the reported cases were outbreak associated. Most laboratories use immunochromatographic tests. The use of more sensitive laboratory methods would improve diagnosis.
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Infecções por Caliciviridae , Gastroenterite , Norovirus , Infecções por Rotavirus , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Caliciviridae/complicações , Infecções por Caliciviridae/epidemiologia , Criança , Pré-Escolar , República Tcheca/epidemiologia , Surtos de Doenças , Feminino , Gastroenterite/epidemiologia , Gastroenterite/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Rotavirus/complicações , Infecções por Rotavirus/epidemiologia , Adulto JovemRESUMO
Delta Scuti (δSct) stars are opacity-driven pulsators with masses of 1.5-2.5 Mâ, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy through the outer 30 per cent of the star and excites a rich spectrum of resonant acoustic modes. Based on the solar example, with no firm theoretical basis, models predict that the convective envelope in δSct stars extends only about 1 per cent of the radius, but with sufficient energy to excite solar-like oscillations. This was not observed before the Kepler mission, so the presence of a convective envelope in the models has been questioned. Here we report the detection of solar-like oscillations in the δSct star HD187547, implying that surface convection operates efficiently in stars about twice as massive as the Sun, as the ad hoc models predicted.
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In high-latitude environments where seasonal changes include periods of harsh conditions, many arthropods enter diapause, a period of dormancy that is hormonally regulated. Diapause is characterized by very low metabolism, resistance to environmental stress, and developmental arrest. It allows an organism to optimize the timing of reproduction by synchronizing offspring growth and development with periods of high food availability. In species that enter dormancy as pre-adults or adults, termination of diapause is marked by the resumption of physiological processes, an increase in metabolic rates and once transitioned into adulthood for females, the initiation of oogenesis. In many cases, individuals start feeding again and newly acquired resources become available to fuel egg production. However, in the subarctic capital-breeding copepod Neocalanus flemingeri, feeding is decoupled from oogenesis. Thus, optimizing reproduction limited by fixed resources such that all eggs are of high quality and fully-provisioned, requires regulation of the number of oocytes. However, it is unknown if and how this copepod limits oocyte formation. In this study, the phase in oocyte production by post-diapause females that involved DNA replication in the ovary and oviducts was examined using incubation in 5-Ethynyl-2'-deoxyuridine (EdU). Both oogonia and oocytes incorporated EdU, with the number of EdU-labeled cells peaking at 72 hours following diapause termination. Cell labeling with EdU remained high for two weeks, decreasing thereafter with no labeling detected by four weeks post diapause, and three to four weeks before spawning of the first clutch of eggs. The results suggest that oogenesis is sequential in N. flemingeri with formation of new oocytes starting within 24 hours of diapause termination and limited to the first few weeks. Lipid consumption during diapause was minimal and relatively modest initially. This early phase in the reproductive program precedes mid-oogenesis and vitellogenesis 2, when oocytes increase in size and accumulate yolk and lipid reserves. By limiting DNA replication to the initial phase, the females effectively separate oocyte production from oocyte provisioning. A sequential oogenesis is unlike the income-breeder strategy of most copepods in which oocytes at all stages of maturation are found concurrently in the reproductive structures.
Em ambientes de alta latitude, onde as mudanças sazonais incluem períodos de condições adversas, muitos artrópodes entram em diapausa, um período de dormência regulado por hormônios. A diapausa é caracterizada por metabolismo muito baixo, resistência ao estresse ambiental e interrupção do desenvolvimento. Ele permite que um organismo otimize a reprodução sincronizando o crescimento e desenvolvimento da prole com períodos de alta disponibilidade de alimentos. Em espécies que entram em dormência como pré-adultos ou adultos, o término da diapausa é marcado pela retomada dos processos fisiológicos, um aumento nas taxas metabólicas e o início da oogênese. Em muitos casos, os indivíduos começam a se alimentar novamente e os recursos recém-adquiridos ficam disponíveis para abastecer a produção de ovos. No oceano subártico, a alimentação do copépode Neocalanus flemingeri é dissociada da oogênese e a reprodução é limitada por recursos fixos obtidos durante a pré-diapausa. No entanto, não se sabe como este copépode regula a formação de ovócitos para garantir que todos os óvulos sejam de alta qualidade e bem fornecidos. Neste estudo, a fase de produção de oócitos por fêmeas pós-diapausa foi examinada usando incubação em 5-Etinil-2'-desoxiuridina (EdU) para caraterizar a replicação do DNA no ovário e nos ovidutos. Tanto as oogônias quanto os oócitos incorporaram EdU, com o número de células marcadas atingindo o pico 72 horas após o término da diapausa. A marcação das células com EdU permaneceu alta por duas semanas, diminuindo na terceira e cessando na quarta semana. Desova da primeira ninhada de ovos ocorre três a quatro semanas depois. Os resultados sugerem que a oogênese é sequencial em N. flemingeri com a formação de novos oócitos começando dentro de 24 horas após o término da diapausa e limitado às primeiras semanas. O consumo de lipídios durante a diapausa foi mínima e relativamente modesto inicialmente. Essa fase inicial do programa reprodutivo precede a vitelogênese 2, quando os ovócitos aumentam de tamanho e acumulam reservas de vitelo e lipídios. Ao limitar a replicação do DNA à fase inicial, as fêmeas efetivamente separam a produção de oócitos do seu fornecimento. Uma oogênese sequencial é diferente da estratégia de reprodução da maioria dos copépodes que mantem oócitos em todos estágios de maturação nas estruturas reprodutivas.
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Being able to estimate and predict future microplastic distributions in the environment is one of the major challenges of the rapidly developing field of microplastic research. However, this task can only be achieved if our understanding of the decay of individual microplastic particles is significantly enhanced. Here, we show by using a rate equation model that currently available data of size distributions measured at single times cannot provide useful insights into this process. To analyze what data contains more information we generated more complex artificial data mimicking subsequent measurements using a stochastic simulation algorithm. Applying our model to this data revealed the following minimal requirements for future experimental data: (1) data should be collected as time series at identical spots and (2) size measurements should be combined with mass measurements. In contrast to currently available data, flux rates and decay parameters of individual particles can be extracted from such data.
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BACKGROUND AND STUDY AIMS: Double-balloon enteroscopy (DBE) is the first choice endoscopic technique for small-bowel visualization. However, preparation and handling of the double-balloon enteroscope is complex. Recently, a single-balloon enteroscopy (SBE) system has been introduced as being a simplified, less-complex balloon-assisted enteroscopy system. PATIENTS AND METHODS: This study was a randomized international multicenter trial comparing two balloon-assisted enteroscopy systems: DBE vs. SBE. Consecutive patients referred for balloon-assisted enteroscopy were randomized to either DBE or SBE. Patients were blinded with regard to the type of instrument used. The primary study outcome was oral insertion depth. Secondary outcomes included complete small-bowel visualization, anal insertion depth, patient discomfort, and adverse events. Patient discomfort during and after the procedure was scored using a visual analog scale. RESULTS: A total of 130 patients were included over 12 months: 65 with DBE and 65 with the SBE technique. Patient and procedure characteristics were comparable between the two groups. Mean oral intubation depth was 253 cm with DBE and 258 cm with SBE, showing noninferiority of SBE vs. DBE. Complete visualization of the small bowel was achieved in 18 % and 11 % of procedures in the DBE and SBE groups, respectively. Mean anal intubation depth was 107 cm in the DBE group and 118 cm in the SBE group. Diagnostic yield and mean pain scores during and after the procedures were similar in the two groups. No adverse events were observed during or after the examinations. CONCLUSIONS: This head-to-head comparison study shows that DBE and SBE have a comparable performance and diagnostic yield for evaluation of the small bowel.
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Endoscópios Gastrointestinais , Endoscopia Gastrointestinal/instrumentação , Enteropatias/diagnóstico , Intestino Delgado , Dor Abdominal/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Enteroscopia de Duplo Balão/efeitos adversos , Endoscopia Gastrointestinal/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto JovemRESUMO
Inconsistencies in microplastic quantification are a problem in current microplastic research, leading to difficulties in inter-study comparability. This study proposes a guideline for consistent quantification of microplastic distributions. It contains specific recommendations on how to quantify common microplastic particle parameters, such as size or shape. These recommendations are based on how reliably a parameter can be measured and its importance for inter-study comparability. Furthermore, our study proposes a multidimensional vector approach, where one vector contains the information for the microplastic distribution in one sample. In this way geometric and statistical means can be used to quantitatively compare different studies. In particular, in combination with our proposed quantification procedure, a meaningful comparison of microplastic distributions across different studies becomes possible. Ultimately, this allows comparable long-term and global scale assessments, as well as the development of modeling approaches.
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Plásticos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , MicroplásticosRESUMO
The rapid scientific progress in the past years has evoked debates about ethical limitations of technical innovations. Especially, high-end medicine for patients at the end of life gets in the focus of criticism whereas the idea of palliative care gains more importance. Gastroenterologists are an important partner in the setting of palliative care since many malignant tumors are found in the GI-tract; furthermore, about 80 % of all patients with advanced progressive illnesses being in a palliative care situation suffer from gastrointestinal symptoms. Vice versa the importance of palliative care in gastroenterology is indisputable - in case of an unfavourable prognosis the patients may be accompanied until death. A return to the core values of medical competence is essential. In this paper, the curriculum of "palliative care" in Germany shall be introduced. The aim of this work is to explain why it is worthwhile for physicians and especially for gastroenterologists to be trained in palliative care.
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Currículo , Gastroenterologia/educação , Neoplasias Gastrointestinais/enfermagem , Cuidados Paliativos/métodos , Assistência Terminal/métodos , Alemanha , HumanosAssuntos
Ciclofosfamida/uso terapêutico , Imunossupressores/uso terapêutico , Vasculite Sistêmica/diagnóstico por imagem , Vasculite Sistêmica/tratamento farmacológico , Idoso , Azatioprina/uso terapêutico , Isquemia Encefálica/etiologia , Enterite/etiologia , Feminino , Humanos , Artéria Mesentérica Inferior/diagnóstico por imagem , Artéria Mesentérica Superior/diagnóstico por imagem , Radiografia , Vasculite Sistêmica/complicaçõesRESUMO
BACKGROUND AND STUDY AIMS: Double-balloon enteroscopy (DBE) has been proven effective for deep intubation of the small bowel. However, intubation depth is limited by distention of the small bowel due to air insufflation during the procedure. The present trial investigated whether carbon dioxide (CO (2)) instead of standard air insufflation would improve intubation depth during DBE, as well as reduce postprocedure pain. PATIENTS AND METHODS: One hundred and twelve consecutive patients scheduled for DBE at two centers were randomly assigned to either CO (2) or air insufflation during DBE. Patients and endoscopists were blinded with regard to the type of gas used. Intubation depth was registered using a validated form. Patients scored pain and discomfort during and after the examination on a 100-mm visual analog scale. RESULTS: One hundred patients were eligible for data analysis (48 in the CO (2) group and 52 in the air group). The mean small-bowel intubation depth was extended by 30 % in the CO (2) group compared to the air group (230 vs. 177 cm, P = 0.008). The superiority was most pronounced for oral DBE, with a 71-cm improvement in intubation depth when using CO (2) (295 cm in the CO (2) group vs. 224 cm in the air group, P < 0.001). Patient pain and discomfort were significantly reduced in the CO (2) group at 1 and 3 hours after the examination. CONCLUSIONS: CO (2) insufflation significantly extended intubation depth in DBE. CO (2) insufflation also reduces patient discomfort. CO (2) insufflation may lead to a higher diagnostic and therapeutic yield of DBE, with reduced patient discomfort.
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Endoscopia por Cápsula/métodos , Dióxido de Carbono/administração & dosagem , Intubação Gastrointestinal/métodos , Pneumoperitônio Artificial/métodos , Adulto , Idoso , Ar , Análise de Variância , Método Duplo-Cego , Endoscopia Gastrointestinal/métodos , Feminino , Humanos , Insuflação/métodos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Projetos Piloto , Probabilidade , Valores de Referência , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: Acute pancreatitis is a disease with an increasing incidence in the Western countries associated with a high mortality depending on severity of disease. Etiology is often biliary or due to alcoholism. Incidence of etiology varies between regions depending on risk-factor prevalence. Several risk scores are available to estimate mortality. The aim of the study is to identify the risk factors most relevant for patients being treated for severe acute pancreatitis in an ICU of a tertiary medical center. PATIENTS AND METHODS: The retrospective cohort study included 91 patients (61.2% men, mean age 52 years) with severe acute pancreatitis who were treated between 2002 and 2013 at the medical ICU of a tertiary medical center. Risk factors were identified using COX regression analysis and associations were assessed with the χ2 test. RESULTS: Pulmonary failure necessitating ventilator support, renal failure requiring renal replacement therapy, need for vasopressor therapy, positive blood cultures, and bleeding complications were identified as risk factors for high mortality in severe acute pancreatitis. Low calcium and high lactate levels are independent risk factors for mortality. CONCLUSION: Critically ill patients with severe pancreatitis have high mortality rates that can be estimated using risk scores. Weighting of risk factors may differ depending on region and severity of disease. For patients included in our study, the Ranson Criteria and the APACHE II Score may be most applicable.
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Unidades de Terapia Intensiva , Pancreatite Necrosante Aguda/diagnóstico , Índice de Gravidade de Doença , Cálcio/sangue , Estudos de Coortes , Feminino , Mortalidade Hospitalar , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Pancreatite Necrosante Aguda/classificação , Pancreatite Necrosante Aguda/mortalidade , Pancreatite Necrosante Aguda/terapia , Estudos Retrospectivos , Fatores de RiscoRESUMO
Constitutive activation of the antiapoptotic nuclear factor-κB (NF-κB) signaling pathway is a hallmark of the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphomas (DLBCL). Recurrent oncogenic mutations are found in the scaffold protein CARMA1 (CARD11) that connects B-cell receptor (BCR) signaling to the canonical NF-κB pathway. We asked how far additional downstream processes are activated and contribute to the oncogenic potential of DLBCL-derived CARMA1 mutants. To this end, we expressed oncogenic CARMA1 in the NF-κB negative DLBCL lymphoma cell line BJAB. By a proteomic approach we identified recruitment of ß-catenin and its destruction complex consisting of APC, AXIN1, CK1α and GSK3ß to oncogenic CARMA1. Recruitment of the ß-catenin destruction complex was independent of CARMA1-BCL10-MALT1 complex formation or constitutive NF-κB activation and promoted the stabilization of ß-catenin. The ß-catenin destruction complex was also recruited to CARMA1 in ABC DLBCL cell lines, which coincided with elevated ß-catenin expression. In line, ß-catenin was frequently detected in non-GCB DLBCL biopsies that rely on chronic BCR signaling. Increased ß-catenin amounts alone were not sufficient to induce classical WNT target gene signatures, but could augment TCF/LEF-dependent transcriptional activation in response to WNT signaling. In conjunction with NF-κB, ß-catenin enhanced expression of immunosuppressive interleukin-10 and suppressed antitumoral CCL3, indicating that ß-catenin can induce a favorable tumor microenvironment. Thus, parallel activation of NF-κB and ß-catenin signaling by gain-of-function mutations in CARMA1 augments WNT stimulation and is required for regulating the expression of distinct NF-κB target genes to trigger cell-intrinsic and extrinsic processes that promote DLBCL lymphomagenesis.
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Proteínas Adaptadoras de Sinalização CARD/genética , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Carcinogênese , Guanilato Ciclase/genética , Guanilato Ciclase/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , beta Catenina/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Linfoma Difuso de Grandes Células B/patologia , Mutação , Estabilidade Proteica , Fatores de Transcrição TCF/metabolismo , Proteínas rho de Ligação ao GTP/metabolismoAssuntos
Doenças da Aorta/cirurgia , Fístula Esofágica/cirurgia , Esôfago/lesões , Corpos Estranhos/cirurgia , Stents , Fístula Vascular/cirurgia , Adulto , Doenças da Aorta/complicações , Deglutição , Fístula Esofágica/complicações , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/cirurgia , Humanos , Masculino , Prisioneiros , Tentativa de Suicídio , Fístula Vascular/complicaçõesRESUMO
Calanus finmarchicus, the dominant mesozooplankter of the North Atlantic, is an important food source for many fishes and other planktivores. This species, which has limited diel vertical migration, depends on its fast-start escape response to evade predators. It has myelinated neuronal axons, which contribute to its rapid and powerful escape response. The thermal environment that C. finmarchicus inhabits ranges from below 0 degrees C to 16 degrees C. Previous studies have shown that respiration, growth, and reproductive rates are strongly dependent on temperature, with Q10 > 2.5. A comparable dependence of the escape response could place the animal at higher risk for cold-compensated predators. Our work focused on the temperature dependence of the behavioral response to stimuli that mimic predatory attacks. We found that in contrast to other biological processes, all aspects of the escape response showed a low dependence on temperature, with Q10 values below 2. This low temperature dependence was consistent for escape parameters that involved neural as well as muscle components of the behavioral response. These findings are discussed in the contexts of the predator-prey relations of copepods and the thermal dependence of behavior in other taxa.
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Comportamento Animal/fisiologia , Copépodes/fisiologia , Reação de Fuga/fisiologia , Temperatura , Envelhecimento , Animais , Feminino , Masculino , Atividade Motora , Fatores SexuaisRESUMO
Antibody drug conjugates (ADCs), in which cytotoxic drugs are linked to antibodies targeting antigens on tumor cells, represent promising novel agents for the treatment of malignant lymphomas. Pinatuzumab vedotin is an anti-CD22 ADC and polatuzumab vedotin an anti-CD79B ADC that are both linked to the microtubule-disrupting agent monomethyl auristatin E (MMAE). In the present study, we analyzed the activity of these agents in different molecular subtypes of diffuse large B-cell lymphoma (DLBCL) both in vitro and in early clinical trials. Both anti-CD22-MMAE and anti-CD79B-MMAE were highly active and induced cell death in the vast majority of activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCL cell lines. Similarly, both agents induced cytotoxicity in models with and without mutations in the signaling molecule CD79B. In line with these observations, relapsed and refractory DLBCL patients of both subtypes responded to these agents. Importantly, a strong correlation between CD22 and CD79B expression in vitro and in vivo was not detectable, indicating that patients should not be excluded from anti-CD22-MMAE or anti-CD79B-MMAE treatment because of low target expression. In summary, these studies suggest that pinatuzumab vedotin and polatuzumab vedotin are active agents for the treatment of patients with different subtypes of DLBCL.
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Anticorpos Monoclonais/farmacologia , Antígenos CD79/imunologia , Imunoconjugados/farmacologia , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Apoptose/efeitos dos fármacos , Western Blotting , Antígenos CD79/genética , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ensaios Clínicos Fase I como Assunto , Estudos de Coortes , Citometria de Fluxo , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Linfoma Difuso de Grandes Células B/classificação , Linfoma Difuso de Grandes Células B/patologia , Mutação/genética , Estadiamento de Neoplasias , Prognóstico , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Células Tumorais CultivadasRESUMO
The immunogenicity of an allograft correlates with the number of MHC class II+ antigen-presenting cells (dendritic cells) that it contains. To determine whether these antigen-presenting cells induce not only MHC class II-mediated immune responses, but also physiologically relevant levels of MHC class I immunity, we took advantage of a unique MHC class I+/class II-/CD80+ dendritic cell line (80/1 DC) derived from murine (C3H, H-2k) fetal skin. The 80/1 DC sensitized H-2-disparate recipients for specific transplantation immunity, as evidenced by significantly accelerated rejection (second set) of skin allografts from C3H mice, but not of third-party allografts. As few as 10(2) 80/1 DC, administered by the subcutaneous route, were effective, indicating their high potency as stimulator cells. Several lines of evidence support the hypothesis that the immunization observed was mediated primarily by direct presentation of allo-class I: (i) Blockage of the co-stimulatory molecule CD80 on 80/1 DC abrogated their sensitizing capacity; (ii) equal numbers of a nonprofessional antigen-presenting cell line (L929, C3H origin) as well as dead 80/1 DC failed to accelerate graft rejection; and (iii) injection of syngeneic (BALB/c) Langerhans cells pulsed with 80/1 DC fragments induced a delayed-type hypersensitivity reaction to these fragments but failed to accelerate rejection of C3H skin grafts. We conclude that direct allo-class I immunity can occur in the absence of class II expression when induced by a professional antigen-presenting cell and that this mechanism has biologic relevance in transplantation immunity.
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Apresentação de Antígeno/imunologia , Antígeno B7-1/imunologia , Rejeição de Enxerto/imunologia , Células de Langerhans/imunologia , Transplante de Pele/imunologia , Animais , Linhagem Celular , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Transplante HomólogoRESUMO
CD16, the low affinity receptor for monomeric IgG (Fc gamma RIIIA), is a well characterized activation molecule on NK cells. In this study we investigated the role of CD16 in NK cell-mediated regulation of immunoglobulin production. Cocultures of the CD16+ human NK clone CNK6 and highly purified SAC/IL-2-activated B lymphocytes with various CD16 antibodies showed significantly diminished NK-enhanced immunoglobulin production in a dose-dependent manner, indicating that CD16 is relevant in NK-B cell interaction. Similarly, recombinant soluble CD16 incubated with B cells before cultures, suppressed the NK cell-stimulated B cell antibody response. Enhanced immunoglobulin production was also inhibited by Fc-specific F(ab')2 anti-body fragments. Coculture of NK cells with B lymphocytes resulted in induction of mRNA for IFN-gamma and TNF-alpha. The accumulation of mRNA for these cytokines was prevented by addition of CD16 and Fc-specific antibodies. It is proposed that interaction of CD16 on NK cells with B cell bound immunoglobulin leads to induction of cytokines in NK cells which stimulate immunoglobulin production by B cells.