Incidence and Clinical Impacts of COVID-19 Infection in Patients with Hemodialysis: Systematic Review and Meta-Analysis of 396,062 Hemodialysis Patients.

Hemodialysis (HD) patients are highly susceptible to COVID-19 infection. However, comprehensive assessments of current evidence regarding COVID-19 in HD patients remain incomplete. We systematically searched PUBMED and EMBASE for articles published on incidence or mortality of COVID-19 infection in HD patients until September 2020. Two independent researchers extracted data and study-level risk of bias across studies. We conducted meta-analysis of proportions for incidence and mortality rate. Study heterogeneity and publication bias were assessed. A total of 29 articles with 3261 confirmed COVID-19 cases from a pool of 396,062 HD patients were identified. Incidence of COVID-19 in these HD patients was 7.7% (95% CI: 5.0-10.9%; study heterogeneity: I2 = 99.7%, p < 0.001; risk of publication bias, Egger's test, p < 0.001). Overall mortality rate was 22.4% (95% CI: 17.9-27.1%; study heterogeneity: I2 = 87.1%, p < 0.001; risk of publication bias, Egger's test: p = 0.197) in HD patients with COVID-19. Reported estimates were higher in non-Asian than Asian countries. Quality of study may affect the reported incidence but not the mortality among studies. Both incidence and mortality of COVID-19 infection were higher in HD patients. Available data may underestimate the real incidence of infection. International collaboration and standardized reporting of epidemiological data should be needed for further studies.

Cerebral blood flow autoregulation is impaired in schizophrenia: A pilot study.

Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of the participants had a history of cardiovascular diseases, hypertension, or diabetes. All participants underwent 10-min blood pressure and cerebral blood flow recording through finger plethysmography and Doppler ultrasonography, respectively. Cerebral autoregulation was assessed by analyzing two autoregulation indices: the mean blood pressure and cerebral blood flow correlation coefficient (Mx), and the phase shift between the waveforms of blood pressure and cerebral blood flow determined using transfer function analysis. Compared with the controls, the patients had a significantly higher Mx (0.257 vs. 0.399, p=0.036) and lower phase shift (44.3° vs. 38.7° in the 0.07-0.20Hz frequency band, p=0.019), which indicated impaired maintenance of constant cerebral blood flow and a delayed cerebrovascular autoregulatory response. Impaired cerebral autoregulation may be caused by schizophrenia and may not be an artifact of coexisting medical conditions. The mechanism underlying impaired cerebral autoregulation in schizophrenia and its probable role in the development of cerebrovascular diseases require further investigation.

Increased risk for urological cancer associated with anxiety disorder: a retrospective cohort study.

BACKGROUND: Anxiety disorders (ADs) are common with a high rate of medical comorbidities. Although the association between ADs and the overall cancer risk remains controversial, patients with ADs were found to be more likely to develop specific cancer types. Herein, we estimated the risk of developing urological cancers among patients with ADs in a 5-year follow-up period using a population-based database. METHODS: Two study cohorts were identified from the Taiwan Longitudinal Health Insurance Database 2005: patients with ADs, and comparison subjects selected by one-to-one matching for sex, age, and the year of recruitment. Follow-up was undertaken to determine whether sampled patients and comparison subjects had developed urological cancers in the subsequent 5 years. RESULTS: We found that urological cancers occurred among 0.54% of patients with ADs and 0.13% of comparison subjects. After adjusting for sociodemographic characteristics, medical comorbidities, and alcohol and tobacco use disorder, the stratified Cox proportional hazard regression suggested that patients with ADs were more likely to develop urological cancers relative to comparison subjects (adjusted hazard ratio, 3.67; 95% confidence interval, 2.85 ~ 4.72). The adjusted HR for males with ADs was 3.82 (95% CI: 2.79 ~ 5.23) in comparison to males without ADs. In addition, the adjusted HR for females with ADs was 3.47 (95% CI: 2.26 ~ 5.31) than those females without ADs. CONCLUSIONS: We concluded that during the 5-year follow-up period, there was a significantly increased risk of urological cancers among patients with ADs.

Demethoxycurcumin inhibits energy metabolic and oncogenic signaling pathways through AMPK activation in triple-negative breast cancer cells.

Demethoxycurcumin (DMC), curcumin (Cur), and bisdemethoxycurcumin (BDMC) are major forms of curcuminoids found in the rhizomes of turmeric. This study examined the effects of three curcuminoid analogues on breast cancer cells. The results revealed that DMC demonstrated the most potent cytotoxic effects on breast cancer MDA-MB-231 cells. Compared with estrogen receptor (ER)-positive or HER2-overexpressing breast cancer cells, DMC demonstrated the most efficient cytotoxic effects on triple-negative breast cancer (TNBC) cells. However, nonmalignant MCF-10A cells were unaffected by DMC treatment. The study showed that DMC activated AMPK in TNBC cells. Once activated, AMPK inhibited eukaryotic initiation factor 4E-binding protein-1 (4E-BP1) signaling and mRNA translation via mammalian target of rapamycin (mTOR) and decreased the activity and/or expression of lipogenic enzymes, such as fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC). DMC also targeted multiple AMPK downstream pathways. Among these, the dephosphorylation of Akt is noteworthy because it circumvents the feedback activation of Akt that results from mTOR inhibition. Moreover, DMC suppressed LPS-induced IL-6 production, thereby blocking subsequent Stat3 activation. In addition, DMC also sustained epidermal growth factor receptor (EGFR) activation by suppressing the phosphatases, PP2a and SHP-2. These results suggest that DMC is a potent AMPK activator that acts through a broad spectrum of anti-TNBC activities.

The enhancement of neural growth by amino-functionalization on carbon nanotubes as a neural electrode.

This paper reports the success of amino-functionalization on multi-walled carbon nanotubes (MWCNTs) to promote neuronal cells growth on MWCNT electrode for extracellular recording, attributed to the formation of positive charge of NH(2) molecules on their surfaces. Besides, the surface of MWCNT electrode becomes hydrophilic after amino-functionalization (AF-MWCNTs) which can enhance electrical conductivity because of lower MWCNT/electrolyte interfacial impedance and higher interfacial capacitance. Durability tests show that electrical characteristics of the MWCNTs treated by 2 wt% 1,4-diaminobutane solution (2 wt%-AF-MWCNTs) can last for at least six months in air ambient. The neural recording of crayfish shows that 2 wt%-AF-MWCNTs can provide better capability on detecting action potentials of caudal photoreceptor (CPR) interneuron compared to suction glass pipette from the evidence of a higher S/N ratio (126 versus 23). The amino-functionalized MWCNT electrode is feasible for long-term recording application according to the results of biocompatibility tests. As the MWCNTs were directly synthesized on Si-based substrates by catalyst-assisted thermal chemical vapor deposition (CVD) at a low temperature (400 °C), these self-aligned MWCNT electrodes could be friendly implemented in integrated circuits fabrications.

An active, flexible carbon nanotube microelectrode array for recording electrocorticograms.

A variety of microelectrode arrays (MEAs) has been developed for monitoring intra-cortical neural activity at a high spatio-temporal resolution, opening a promising future for brain research and neural prostheses. However, most MEAs are based on metal electrodes on rigid substrates, and the intra-cortical implantation normally causes neural damage and immune responses that impede long-term recordings. This communication presents a flexible, carbon-nanotube MEA (CMEA) with integrated circuitry. The flexibility allows the electrodes to fit on the irregular surface of the brain to record electrocorticograms in a less invasive way. Carbon nanotubes (CNTs) further improve both the electrode impedance and the charge-transfer capacity by more than six times. Moreover, the CNTs are grown on the polyimide substrate directly to improve the adhesion to the substrate. With the integrated recording circuitry, the flexible CMEA is proved capable of recording the neural activity of crayfish in vitro, as well as the electrocorticogram of a rat cortex in vivo, with an improved signal-to-noise ratio. Therefore, the proposed CMEA can be employed as a less-invasive, biocompatible and reliable neuro-electronic interface for long-term usage.

Hydrophilic modification of neural microelectrode arrays based on multi-walled carbon nanotubes.

To decrease the impedance of microelectrode arrays, for neuroscience applications we have fabricated and tested MEA based on multi-walled carbon nanotubes. With decreasing physical size of a microelectrode, its impedance increases and charge-transfer capability decreases. To decrease the impedance, the effective surface area of the electrode must generally be increased. We explored the effect of plasma treatment on the surface wettability of MWCNT. With a steam-plasma treatment the surface of MWCNT becomes converted from superhydrophobic to superhydrophilic; this hydrophilic property is attributed to -OH bonding on the surface of MWCNT. We reported the synthesis at 400 °C of MWCNT on nickel-titanium multilayered metal catalysts by thermal chemical vapor deposition. Applying plasma with a power less than 25 W for 10 s improved the electrochemical and biological properties, and circumvented the limitation of the surface reverting to a hydrophobic condition; a hydrophilic state is maintained for at least one month. The MEA was used to record neural signals of a lateral giant cell from an American crayfish. The response amplitude of the action potential was about 275 µV with 1 ms period; the recorded data had a ratio of signal to noise up to 40.12 dB. The improved performance of the electrode makes feasible the separation of neural signals and the recognition of their distinct shapes. With further development the rapid treatment will be useful for long-term recording applications.

A cone-shaped 3D carbon nanotube probe for neural recording.

A novel cone-shaped 3D carbon nanotube (CNT) probe is proposed as an electrode for applications in neural recording. The electrode consists of CNTs synthesized on the cone-shaped Si (cs-Si) tip by catalytic thermal chemical vapor deposition (CVD). This probe exhibits a larger CNT surface area with the same footprint area and higher spatial resolution of neural recording compared to planar-type CNT electrodes. An approach to improve CNT characteristics by O(2) plasma treatment to modify the CNT surface will be also presented. Electrochemical characterization of O(2) plasma-treated 3D CNT (OT-CNT) probes revealed low impedance per unit area (∼64.5 Ω mm(-2)) at 1 kHz and high specific capacitance per unit area (∼2.5 mF cm(-2)). Furthermore, the OT-CNT probes were employed to record the neural signals of a crayfish nerve cord. Our findings suggest that OT-CNT probes have potential advantages as high spatial resolution and superb electrochemical properties which are suitable for neural recording applications.

Interfacing neurons both extracellularly and intracellularly using carbon-nanotube probes with long-term endurance.

This study demonstrates that carbon nanotubes (CNTs) can be fabricated into probes directly, with which neural activity can be monitored and elicited not only extracellularly but also intracellularly. Two types of CNT probes have been made and examined with the escape neural circuit of crayfish, Procambarus clarkia. The CNT probes are demonstrated to have comparable performance to conventional Ag/AgCl (silver/silver cloride) electrodes. Impedance measurement and cyclic voltammetry further indicate that the CNT probes transmit electrical signals through not only capacitive coupling but also resistive conduction. The resistive conduction facilitates the recording of postsynaptic potentials and equilibrium membrane potentials intracellularly as well as the delivery of direct-current stimulation. Furthermore, delivering current stimuli for a long term is found to enhance rather than to degrade the recording capability of the CNT probes. The mechanism of this fruitful result is carefully investigated and discussed. Therefore, our findings here support the suggestion that CNTs are suitable for making biocompatible, durable neural probes of various configurations for diverse applications.