Differentiation of exudate from transudate ascites based on the dipstick values of protein, glucose, and pH

Differential diagnosis of ascites: etiologies, ascitic fluid analysis, diagnostic algorithm

Ascites is the pathological accumulation of fluid within the peritoneal cavity. It often occurs as results of liver cirrhosis, malignant neoplasia, tuberculous infection, cardiac insufficiency, renal diseases, etc. Determining the etiology is an essential step in the management of patients with new-onset ascites. Abdominal paracentesis with appropriate ascitic fluid analysis is probably the most cost-effective method of determining the cause of ascites. We performed a literature search of PubMed and identified articles published in the field of ascites, to evaluate diagnostic values of various parameters in defining the etiologies of ascites and then provides diagnostic algorithm for patients with new-onset ascites. In patients with ascites, the constituent ratio of underlying etiology varies between developed and developing countries. It is a challenge to define the etiologies of ascites in developing countries. Routine ascitic fluid analysis should include the serum ascites albumin gradient (SAAG), total protein concentration, cell count and differential. Optional ascitic fluid analysis includes cholesterol, fluid culture, cytology, tumor markers, lactate dehydrogenase, adenosine deaminase (ADA), triglyceride, amylase, glucose, brain natriuretic peptide (BNP), etc. Our review evaluated diagnostic values of the above parameters in defining the etiologies of ascites. Diagnostic algorithm established in this review would provide a practical and convenient diagnostic strategy for clinicians in diagnosing patients with new-onset ascites.

Smartphone-Based Electrochemical Systems for Glucose Monitoring in Biofluids: A Review

As a vital biomarker, glucose plays an important role in multiple physiological and pathological processes. Thus, glucose detection has become an important direction in the electrochemical analysis field. In order to realize more convenient, real-time, comfortable and accurate monitoring, smartphone-based portable, wearable and implantable electrochemical glucose monitoring is progressing rapidly. In this review, we firstly introduce technologies integrated in smartphones and the advantages of these technologies in electrochemical glucose detection. Subsequently, this overview illustrates the advances of smartphone-based portable, wearable and implantable electrochemical glucose monitoring systems in diverse biofluids over the last ten years (2012-2022). Specifically, some interesting and innovative technologies are highlighted. In the last section, after discussing the challenges in this field, we offer some future directions, such as application of advanced nanomaterials, novel power sources, simultaneous detection of multiple markers and a closed-loop system.

Glucose availability limits microglial nitric oxide production

Metabolic intermediates influence inflammation not only through signaling effects, but also by fueling the production of pro-inflammatory molecules. Microglial production of nitric oxide (NO) requires the consumption of NADPH. NADPH consumed in this process is regenerated from NADP⁺ primarily through the hexose monophosphate shunt, which can utilize only glucose as a substrate. These factors predict that glucose availability can be rate-limiting for glial NO production. To test this prediction, cultured astrocytes and microglia were incubated with lipopolysaccharide and interferon-γ to promote expression of inducible nitric oxide synthase, and the rate of NO production was assessed at defined glucose concentrations. Increased NO production was detected only in cultures containing microglia. The NO production was markedly slowed at glucose concentrations below 0.5 mM, and comparably reduced by inhibition of the hexose monophosphate shunt with 6-aminonicotinamide. Reduced NO production caused by glucose deprivation was partly reversed by malate, which fuels NADPH production by malate dehydrogenase, and by NADPH itself. These findings highlight the role of the hexose monophosphate shunt in fueling NO synthesis and suggest that microglial NO production in the brain may be limited at sites of low glucose availability, such as abscesses or other compartmentalized infections.

Implantable platinum nanotree microelectrode with a battery-free electrochemical patch for peritoneal carcinomatosis monitoring

As a severe stage of cancers, peritoneal carcinomatosis should be frequently monitored by means of ascites analysis. Nevertheless, the analysis process is traumatic and time-consuming in clinical practice. In this study, an implantable platinum nanotree microelectrode with a wireless, battery-free and flexible electrochemical patch was developed for in vivo and real-time peritoneal glucose detection to monitor peritoneal carcinomatosis. As the core of implantable microelectrode, platinum trees were synthesized by one-step electrodeposition method and highly sensitive to glucose detection. The platinum nanotree microelectrode was implantable in peritoneal cavity in minimally invasive way. A flexible circuit patch could execute electrochemical test and realize wireless power harvesting and data interaction with a near field communication (NFC)-enabled smartphone. The whole system could detect glucose dynamics in vivo in rat peritoneal cavity. Furthermore, the accuracy of this system was validated in ascites of patients. In this way, the system could offer hassle-free, rapid and minimally invasive opportunities toward peritoneal carcinomatosis monitoring.