instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: Monocytes are cellular components of wound repair, arteriogenesis, and atherogenesis. Vascular endothelial growth factor (VEGF)-A and placental growth factor recruit monocytes to sites of arteriogenesis via stimulation of VEGF receptor-1 (VEGFR-1). The chemotactic response of monocytes to VEGF-A is attenuated in individuals with diabetes mellitus (DM). This VEGF resistance correlates with impaired collateral growth. The aim of this study is to elucidate the molecular basis of VEGF resistance and impaired monocyte response in DM.', 'Phosphorylation of Akt, p38, and extracellular signal-regulated kinase 1/2 (ERK1/2) could be stimulated with either placental growth factor-1 or VEGF-A in monocytes from non-DM but not DM individuals. In contrast, formyl-methionyl-leucyl-phenylalanine caused a comparable activation of these molecules in both DM and non-DM monocytes. Baseline phosphorylation of Akt, p38, and ERK1/2 was significantly elevated in monocytes from DM compared with non-DM subjects. Of note, H(2)O(2) activated Akt, p38, and ERK1/2 in non-DM monocytes ex vivo. Protein tyrosine phosphatases had stronger oxidative modifications in monocytes from DM than from non-DM individuals, which reflects functional protein tyrosine phosphatase inhibition, similar to that seen after H(2)O(2) challenge. Overall, protein tyrosine phosphatase and protein tyrosine phosphatase-1B activity were reduced in DM monocytes. DM monocytes revealed higher expression of the receptor for advanced glycation end products. Stimulation with advanced glycation end products ligands resulted in activation of non-DM monocytes and inhibition of VEGFR-1-mediated chemotaxis. The elevated baseline phosphorylation/activation of Akt, p38, and ERK1/2 in DM monocytes likely causes the resistance to further stimulation with specific stimuli such as VEGF-A, revealing a molecular explanation of the DM-related signal transduction defect.\Question: Does diabetes mellitus activate signal transduction pathways resulting in vascular endothelial growth factor resistance of human monocytes?
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We propose that elevated advanced glycation end products expression and increased oxidative stress in diabetic monocytes lead to activation of VEGFR-1-related signaling pathways and to desensitization of VEGFR-1 responses. These data establish VEGF resistance as a novel molecular concept for DM-related cellular dysfunction.


question:
Context: Psychostimulants are often used in close temporal proximity to nicotine and have been reported to enhance acutely nicotine's desirability in humans.", 'To investigate the acute associations between amphetamine and nicotine, we examined the potentiative interactions between clinically relevant, low doses of these drugs on locomotor activity, and dopamine overflow in the rat.', 'Locomotor activity was measured by telemetry in the home cage environment, and dopamine overflow was evaluated in striatal slice preparations from female Holtzman rats.', 'When administered simultaneously, nicotine and amphetamine produced a predominantly additive effect on locomotor behavior. However amphetamine, when given 2-4 h before nicotine, strongly potentiated nicotine-induced locomotor activity. Correspondingly, nicotine given 1-4 h before amphetamine robustly enhanced amphetamine-stimulated locomotor activity even when the effects of the nicotine pretreatment dissipated. Acute nicotine pretreatment similarly potentiated the effects of dopamine transporter ligands, cocaine, nomifensine, and methamphetamine but not a direct dopamine receptor agonist. Consistent with the behavioral studies, in vivo nicotine pretreatment exaggerated amphetamine-induced dopamine efflux from rat striatal slices. Likewise, in vivo pretreatment of rats with amphetamine potentiated nicotine-induced dopamine efflux from striatal slices. Direct pretreatment of striatal tissue by nicotine also potentiated subsequent amphetamine-stimulated dopamine overflow, further suggesting that the nicotine-amphetamine interaction occurs at the level of the dopamine terminal.\Question: Do nicotine and amphetamine acutely cross-potentiate their behavioral and neurochemical responses in female Holtzman rats?
answer:
Overall, the present data demonstrate that acute interactions of nicotine and other psychomotor stimulants produce potentiative effects and that these transient interactions may play a role in the frequent co-use and abuse of nicotine and other stimulants.


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Context: Reagent strip testing for microhaematuria has long been used for community diagnosis of Schistosoma haematobium. Sensitivities and specificities are reasonable, and hence, microhaematuria can serve as a proxy for S. haematobium infection. However, assessment of test performance in the context of the underlying S. haematobium prevalence is rare and test parameters other than sensitivity and specificity have been neglected.', 'Data about the association between microhaematuria and urine filtration results from three studies were compared and put into context with findings from a recent Cochrane review. Data were stratified by S. haematobium prevalence to identify prevalence-related differences in test performance. Kappa agreement and regression models were employed to compare data for different S. haematobium prevalence categories.', 'We found a "background" prevalence of microhaematuria (13\xa0%, on average) which does not seem to be associated with schistosomiasis in most settings, irrespective of the prevalence of S. haematobium. This background level of microhaematuria might be due to cases missed with urine filtration, or alternative causes apart from S. haematobium. Especially in very-low prevalence settings, positive results for microhaematuria likely give an inaccurate picture of the extent of S. haematobium, whereas negative results are a sound indicator for the absence of infection.\Question: Is all that blood is not schistosomiasis : experiences with reagent strip testing for urogenital schistosomiasis with special consideration to very-low prevalence settings?
answer:

Reagent strip testing for microhaematuria remains a good proxy for urogenital schistosomiasis, but implications of test results and scope of application differ depending on the setting in which reagent strips are employed. In very-low prevalence settings, microhaematuria is an unstable proxy for urogenital schistosomiasis and treatment decision should not be based on reagent strip test results alone. Our findings underscore the need for highly accurate diagnostic tools for settings targeted for elimination of urogenital schistosomiasis.