An expression vector for the epidermal growth factor (EGF) receptor was introduced into the 32D myeloid cell line, which is devoid of EGF receptors and absolutely dependent on interleukin-3 (IL-3) for its proliferation and survival. Expression of the EGF receptor conferred the ability to utilize EGF for transduction of a mitogenic signal. When the transfected cells were propagated in EGF, they exhibited a more mature myeloid phenotype than was observed under conditions of IL-3-directed growth. Moreover, exposure to EGF led to a rapid stimulation of phosphoinositide metabolism, while IL-3 had no detectable effect on phosphoinositide turnover either in control or EGF receptor-transfected 32D cells. Although the transfected cells exhibited high levels of functional EGF receptors, they remained nontumorigenic. In contrast, transfection of v-erbB, an amino-terminal truncated form of the EGF receptor with constitutive tyrosine kinase activity, not only abrogated the IL-3 growth factor requirement of 32D cells, but caused them to become tumorigenic in nude mice. These results show that a naïve hematopoietic cell expresses all of the intracellular components of the EGF-signaling pathway necessary to evoke a mitogenic response and sustain continuous proliferation.
The typically annelid cuticle of Phallodrilus albidus has an increased population density of epicuticular projections, but this is not thought to be related to its gutless condition. The irregular outline of the apical membrane of the epidermal cells is an inherent feature, possibly enhancing an absorptive function. The cuticle-epidermal interface is characterized by multigranular bodies, rod-shaped bacteria and filiform structures. The multigranular bodies are present in the postclitellar region only, coinciding with the chalkiness of living specimens. The bacteria occur throughout the entire length of the worm, their presence exaggerating the irregularities of the apical membrane. The bacterial cytoplasmic membrane, in contrast to the limiting membrane, was difficult to resolve. Between the two membranes is an amorphous zone. Storage granules of a carbohydrate-rich complex are located peripherally and the bacterial core contains a reticulum of DNA threads. Filiform structures, ultrastructurally similar to the bacterial peripheral region, are numerous, especially where the bacteria are carbohydrate-rich. Connections with the bacterial bodies were observed, but infrequently. The non-pathologic association between the subcuticular bacteria and the gutless tubificid is discussed.
IntroductionThe use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals.Materials and MethodsA set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed.ResultsNone of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR-145 correlated with nadir CD4+ T cell count.DiscussionNo associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection.
This study was carried out in order to compare the multiple cortical response to a photic stimulus and the secondary response to sciatic nerve stimulation. Late responses to flash and to sciatic nerve shock were recorded in acute cat preparations anesthetized with pentobarbital. The responses to the two types of stimuli differed in distribution (visual multiple response confined to primary receiving area, sciatic secondary generalized), form and anesthetic level optimal for their production (deeper anesthesia for the sciatic secondary than for the visual multiple response). In cats with chronically implanted electrodes, it was found that the multiple response to flash was present during natural sleep and was abolished by arousal.
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