Possible consequences of Covid-19 on the nervous system

OBJECTIVES

The aim of the survey was to find out what the possible consequences are of the COVID-19 disease on the nervous system and to propose a method of using artificial intelligence.

MATERIAL AND METHODS

Recent research has shown that the risks to patients due to severe acute coronavirus 2 respiratory syndrome (SARS-COV-2) differ most significantly depending on age and the presence of underlying comorbidities such as: cardiovascular disease, hypertension, diabetes and others. The consequences of COVID-19 on the nervous system are especially important. We performed a detailed selection of articles describing the effects of COVID-19 on the nervous system.

RESULTS

We made a clear summary of the main consequences of COVID-19 on the nervous system and suggested a way to use artificial intelligence.

CONCLUSION

We confirmed research that artificial intelligence methods have the potential to accelerate prediction, especially for the possible consequences of COVID-19 on the nervous system.

The influence of mode of anaesthesia for caesarean delivery on neonatal Apgar scores in the Czech Republic and Slovakia: secondary analysis of the results of an international survey in 2015

AIMS

The purpose of this international survey was to describe the impact of current practices and techniques of caesarean section on the neonatal Apgar score in the Czech Republic (CZE) and Slovakia (SVK).

METHODS

All Czech and Slovak departments that provide obstetric anaesthesia were invited to participate in a one-month (November 2015) prospective study that monitored in details all peripartum anaesthetic practices, delivered by anaesthesiologists. Participating centers recorded all data on-line in the CLADE-IS database (Masaryk University, CZE).

RESULTS AND DISCUSSIONS

We collected data of 10119 women who delivered 10226 newborns. A caesarean section was recorded in 25.1% of deliveries (CZE 23.2%; SVK 30%). General anaesthesia was used for caesarean section in 37.5% of the cases (CZE 40%, SVK 33%). There was no statistically significant difference in the Apgar score lower than 7 in the 1, 5 or 10 min in groups of general and regional anaesthesia for caesarean section, when only elective sections of in-term babies with birth weight over 2500 g were analyzed. We found no statistically significant differences in the Apgar score in newborns of women intubated for caesarean section in rocuronium (n=21; 2.2%) and suxamethonium (n=889; 93%).

CONCLUSION

We found no difference in neonatal outcomes in groups of general and regional anaesthesia for caesarean section when only out-of-risk newborns were analyzed. The risk factors were identified as follows: an acute caesarean section, preterm babies, birth weight less than 2 500 g, born in perinatological center and multiple pregnancy - second baby.

TRIAL REGISTRATION

ClinicalTrials.gov (ID: NCT02380586) https://clinicaltrials.gov/ct2/show/NCT02380586.

Abstract P1-03-05: Not presented

This abstract was not presented at the symposium.

Abstract P5-05-02: NEDD9 promotes breast cancer metastasis by regulating mitochondrial functions

NEDD9 has been characterized as a metastasis-promoting gene in various cancer cells including breast. We previously reported that NEDD9 promotes malignant phenotypes of breast cancer cells through distinct and non-overlapped domains. For example, the FAT (Focal Adhesion Targeting) domain of NEDD9 promotes cancer cell growth, while the SH-domain facilitates cell migration. These results suggest that NEDD9 promotes tumor metastasis by enhancing dissemination and growth in the tumor-host microenvironments through distinct and non-overlapped domains. Thus, targeting functions of NEDD9 is a promising approach for breast cancer therapies.

In order to further characterize NEDD9-mediated breast cancer growth, we performed yeast-two hybrid (Y2H) screening to identify proteins that associate with the FAT domain of NEDD9. Using the FAT domain constructed in pGBKKT7 (Clonetech, CA) as a bait to screen library of human fibroblast (Clonetech, CA), we identified several proteins that associate with the domain. They are small GTPases (i.e. RAB11a and ARF4), cytoskeletal proteins (i.e. Nexilin), and cytosolic proteins (i.e. HAX-1). Among of these potential partner proteins, we focused on the interaction between NEDD9 and HAX-1 in breast cancer cells. Co-immunoprecipitation assays confirm the molecular complex of NEDD9-HAX-1 in both SK-Br3 and SUM149 cells. Importantly, p130cas, which harbors similar domain structures with NEDD9, was not precipitated with NEDD9, suggesting a specific interaction between NEDD9 and HAX-1. Given the fact of NEDD9 as a key metastasis promoting gene, these results suggest that NEDD9-HAX-1 plays a key role breast cancer metastasis by facilitating growth in microenvironments.

While the biological function are not clear at present, previous studies demonstrated that HAX-1 localizes in mitochondria in breast cancer cells, Indeed, we demonstrated that NEDD9 was found in both cytosol and mitochondria fractions in malignant breast cancer cell MDA-MB-231, but not non-metastatic HCC38. These results suggest the presence of NEDD9-HAX1 complex in mitochondria and this complex may facilitate breast cancer metastasis. In addition to HAX-1, several mitochondrial proteins such as EFG1, DCTN6, and MMADHC were found in the Y2H screening system as described above. These results suggest that NEDD9 facilitates breast cancer metastasis through regulating multiple pathways including signaling pathways and mitochondrial functions, thus serving as a promising therapeutic target for cancer patients including breast.

The view expressed in this article are those of the author and do not reflect the official policy of the Department of Defense, or U.S.Government.

Citation Format: Iida J, Dorchak J, Slavik J, Clancy R, Cutler ML, Shriver CD. NEDD9 promotes breast cancer metastasis by regulating mitochondrial functions [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-05-02.

Non-dioxin-like organic toxicant PCB153 modulates sphingolipid metabolism in liver progenitor cells: its role in Cx43-formed gap junction impairment

The non-dioxin-like environmental toxicant 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153), member of a group of persistent organic pollutants wide-spread throughout the environment, reduces gap junction intercellular communication (GJIC), an event possibly associated with tumor promotion. Since very few studies have investigated the signaling effectors and mode(s) of action of PCB153, and it is known that the gap junction (GJ) protein Cx43 can be regulated by the bioactive sphingolipid (SL) sphingosine 1-phosphate (S1P), this in vitro study mainly addresses whether SL metabolism is affected by PCB153 in rat liver epithelial WB-F344 cells. PCB153 treatment obtained significant changes in the S1P/ceramide (Cer) ratio, known to be crucial in determining cell fate. In particular, an increase in S1P at 30 min and a decrease of the bioactive lipid at 3 h were observed, whereas Cer level increased at 1 h and 24 h. Notably, a time-dependent modulation of sphingosine kinase (SphK), the enzyme responsible for S1P synthesis, and of its regulators, ERK1/2 and protein phosphatase PP2A, supports the involvement of these signaling effectors in PCB153 toxicity. Electrophysiological analyses, furthermore, indicated that the lipophilic environmental toxicant significantly reduced GJ biophysical properties, affecting both voltage-dependent (such as those formed by Cx43 and/or Cx32) and voltage-independent channels, thereby demonstrating that PCB153 may act differently on GJs formed by distinct Cx isoforms. SphK down-regulation alone induced GJIC impairment, and, when combined with PCB153, the acute effect on GJ suppression was additive. Moreover, after enzyme-specific gene silencing, the SphK1 isoform appears to be responsible for down-regulating Cx43 expression, while being the target of PCB153 at short-term exposure. In conclusion, we provide the first evidence of novel effectors in PCB153 toxic action in rat liver stem-like cells, leading us to consider SLs as potential markers for preventing GJIC deregulation and, thus, the tumorigenic action elicited by this environmental toxicant.

Abstract P2-05-16: Tumor-associated glycans as key molecules to promote growth of triple-negative breast cancer cells

Enhanced invasion and migration into the surrounding tissues are hallmarks of the malignancy of tumor cells. To successfully metastasize, a cancer cell has to detach from the primary tumor, invade into surrounding tissues, and intravasate into blood or lymphatic vessels. These processes are composed of complex mechanisms involving tumor recognition, degradation of extracellular matrix (ECM) proteins and migration into tissue. Triple negative (TN) breast cancers are defined by a lack of expression of estrogen, progesterone, and HER2 receptors. It is widely recognized that TN breast cancers have a poorer prognosis than any other subtype of breast cancer. Given the lack of effective targeted therapies for TN breast cancer patients, understanding of the mechanisms of migration and invasion of these tumors will provide insight into developing novel approaches to lower the mortality from TN breast cancer.

Previous studies demonstrated that NEDD9 plays a key role facilitating progression and metastasis of various tumor cells including breast. We previously demonstrated that NEDD9 plays a critical role in promoting migration and growth of MDA-MB-231. In order to further characterize the mechanisms of NEDD9-mediated cancer migration and growth, we established stable cell lines expressing NEDD9 using HCC38 as a parental cell line which expresses low level of endogenous NEDD9. Microarray studies demonstrated that enzymes (CHST11, CHST15, and CSGALNACT1) involved in biosynthesis of chondroitin sulfate (CS) but not heparan sulfate (HS) were markedly upregulated in HCC38(NEDD9) compared to control HCC38(Vector) cells. These results suggest that NEDD9 regulates specific structures of tumor-associated glycans such as chondroitin sulfate. Core proteins of CD44 and Serglycin were markedly upregulated in HCC38(NEDD9) cells compared to HCC38(Vector) cells, while those of Syndecan-1, Syndecan-2, and Versican were downregulated in HCC38(NEDD9). Immunofluorescence studies using specific antibody, GD3G7, confirmed the enhanced expression of CS-E subunit in HCC38(NEDD9). Immunoprecipitation and western blotting analysis demonstrated that CS-E was attached to Serglycin and CD44 core proteins. We demonstrated that removing CS by chondroitinase ABC significantly inhibited anchorage-independent growth of HCC38(NEDD9) in methylcellulose. Importantly, the fact that GD3G7 significantly inhibited colony formation of HCC38(NEDD9) cells suggest that CS-E subunit plays a key role in this process. Furthermore, treatment of HCC38(NEDD9) cells with chondroitinase ABC or GD3G7 significantly inhibited mammosphere formation. Exogenous addition of CS-E enhanced colony formation and mammosphere formation of HCC38 parental and HCC38(Vector) cells. These results suggest that NEDD9 regulates the synthesis and expression of tumor associated glycocalyx structures including CS-E, which plays a key role in promoting and regulating breast cancer progression metastasis and possibly stem cell phenotypes.

The opinion and assertions contained herein are the private views of the authors and are not to be construed as official or as representing the views of the Department of the Army or the Department of Defense.

Citation Format: Iida J, Dorchak J, Clancy R, Slavik J, Cutler ML, Shriver CD. Tumor-associated glycans as key molecules to promote growth of triple-negative breast cancer cells. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-16.

Microenvironment of the high affinity ATP-binding site of Na+/K+-ATPase is slightly acidic

Fluorescein-5'-isothiocyanate (FITC) was used to study the high-affinity ATP-binding site of Na+/K+-ATPase. The molar ratio of specifically bound FITC per alpha-subunit of Na+/K+-ATPase was found to be 0.5 as followed from pretreatment experiments with another specific E1ATP-inhibitor Cr(H2O)4AdoPP[CH2]P. This indicated an existence of one high affinity ATP-binding site (E1ATP-binding site) in the native (alphabeta)2-diprotomer of Na+/K+-ATPase. Fluorescence dual-excitation ratio of specifically bound FITC revealed that at external pH 7.5, the pH value inside the E1ATP-binding site is 6.95 +/- 0.18. In addition, FITC fluorescence quenching by anti-fluorescein and by iodide choline indicated the limited access of water into the small pocket of the E1ATP-binding site.

Bond strength of photocured composite resin facings: clinical versus laboratory procedures

The tensile strengths of laboratory versus clinical photocured composite resins have been investigated. Metal surfaces were bonded to photocured composite resin by either retentive beads, Sebond or Silicoating. The bond strengths were measured by an Instron machine and the fracture sites observed. Following repair with the adhesives Dentacolor Opaquer, Fusion and Cover up 2, the Instron measurements were repeated. The metal/facing bond strength was the highest in samples fabricated by the Silicoating technique, the bond strength exceeding the cohesive forces in the composite resin facing. The tensile strengths of metal/facing bonded by Sebond and retentive beads were similar. Fractures that include the facing and partially reveal the metal are the least resistant to tension after repair. Renewal of the Opaque layer and completion of the facing is superior to any of the repair methods used in this paper. The original fracture point is the weakest after repair. All the repair kits tested were inferior to the original restoration materials.

Changes in serum copper and zinc during treatment with anticancer drugs interfering with pyridoxal phosphate

Hexamethylmelamine, pentamethylmelamine and procarbazine are anticancer drugs known to interfere with pyridoxal phosphate. This paper presents results on copper and zinc serum levels during the treatment with each of these drugs used as single agents. Six NZW rabbits weighing 2.7-4.5 kg were used in these experiments. Hexamethylmelamine and procarbazine were administered by gastric gavage and pentamethylmelamine by intravenous route at the daily doses of 100 mg, 30 mg and 50 mg/kg of body weight respectively for up to four days. Blood samples were collected in metal free tubes at fasting state before and during the treatment. Student's paired t-test was used for statistical analysis. The pretreatment serum copper concentration significantly (p = 0.05) increased and conversely the serum zinc concentration significantly (p = 0.05) decreased during each drug treatment. Consequently the copper/zinc ration significantly increased from 0.32, 0.33 and 0.27 to 1.16, 0.63 and 1.13 for hexamethylmelamine, pentamethylmelamine and procarbazine respectively. These results indicate, that daily administration of three anticancer drugs interfering with pyridoxal phosphate causes changes in serum copper and zinc levels with inversed relationship between both changes.

6-azauridine triacetate induced hyper beta-alaninemia and its decrease by administration of pyridoxine

The effect of pyridoxine on 6-azauridine triacetate (6-AzUrd-TA) induced hyper beta-alaninemia was studied in New Zealand albino rabbits in three experiments. In each of the three experiments the animals were administered by gavage: Group 1 (Control), drinking water; Group 2, 6-AzUrd-TA; and Group 3, 6-AzUrD-TA with pyridoxine. While no beta-alanine was found in the control group or in pretreatment samples of the 6-AZUrd-TA and 6-AzUrd-TA + pyridoxine treated animals, high concentrations of this amino acid (191.0 +/- 91.6, 220.2 +/- 116.3, 103.2 +/- 64.4 nmol/ml) were found on the fourth and seventh days of 6-AzUrd-TA treatment with daily doses of 1.0 g/kg and 0.5 g/kg B.W. respectively. The drug induced hyper beta-alaninemia was significantly (p less than or equal to 0.05) reduced in all three experiments by simultaneous pyridoxine administration in daily doses of 50 mg/kg B. W. These results indicate, that daily repeated oral administration of 6-AzUrd-TA causes elevation of serum beta-alanine, which can be partially prevented by oral administration of pyridoxine. They also indirectly support the hypothesis, that 6-AzUrd-TA induced hyper beta-alaninemia is at least partially caused by the inhibition of beta-alanine degrading enzymes, that use pyridoxal phosphate as a coenzyme. Direct measurement of the enzyme activity is planned in our future studies.