Tizoxanide Antiviral Activity on Dengue Virus Replication.

Dengue virus is an important circulating arbovirus in Brazil responsible for high morbidity and mortality worldwide, representing a huge economic and social burden, in addition to affecting public health. In this study, the biological activity, toxicity, and antiviral activity against dengue virus type 2 (DENV-2) of tizoxanide (TIZ) was evaluated in Vero cell culture. TIZ has a broad spectrum of action in inhibiting different pathogens, including bacteria, protozoa, and viruses. Cells were infected for 1 h with DENV-2 and then treated for 24 h with different concentrations of the drug. The quantification of viral production indicated the antiviral activity of TIZ. The protein profiles in infected Vero cells treated and not treated with TIZ were analyzed using the label-free quantitative proteomic approach. TIZ was able to inhibit virus replication mainly intracellularly after DENV-2 penetration and before the complete replication of the viral genome. Additionally, the study of the protein profile of infected not-treated and infected-treated Vero cells showed that TIZ interferes with cellular processes such as intracellular trafficking and vesicle-mediated transport and post-translational modifications when added after infection. Our results also point to the activation of immune response genes that would eventually lead to a decrease of DENV-2 production. TIZ is a promising therapeutic molecule for the treatment of DENV-2 infections.

Chemical composition and anti-Mayaro virus activity of Schinus terebinthifolius fruits.

Brazilian traditional medicine has explored the antiviral properties of many plant extracts, including those from the Brazilian pepper tree, Schinus terebinthifolius. In the present study, we investigated the chemical composition and anti-mayaro virus (MAYV) activity of S. terebinthifolius fruit. Extensive virucidal activity (more than 95%) was detected for the ethyl acetate extract and the isolated biflavonoids. From the ethyl acetate extract of Schinus terebinthifolius fruits, two bioflavonoids were isolated ((2S, 2″S)-2,3,2″,3″-tetrahydroamentoflavone and agathisflavone), which showed strong virucidal activity against Mayaro virus. Furthermore, several other compounds like terpenes and phenolics were identified by hyphenated techniques (GC-MS, LC-MS and HPLC-UV), as well as by mass spectrometry. Immunofluorescence assay confirmed antiviral activity and transmission electron microscopy revealed damage in viral particles treated with biflavonoids. The data suggest the direct action of the extract and the biflavonoids on the virus particles. The biflavonoids tetrahydroamentoflavone and agathisflavone had strong virucidal activity and reduced MAYV infection. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13337-021-00698-z.

Antiviral Drug Discovery and Development for Mayaro Fever - What do we have so far?

Tropical infectious diseases cause millions of deaths every year in developing countries, with about half of the world population living at risk. Mayaro virus (MAYV) is an emerging arbovirus that causes Mayaro fever, which is characterized by fever, headache, diarrhea, arthralgia, and rash. These symptoms can be clinically indistinguishable from other arboviruses, such as Dengue, Zika, and Chikungunya, which makes the diagnosis and treatment of the disease more difficult. Though, the Mayaro virus is a potential candidate to cause large-scale epidemics on the scale of ZIKV and CHIKV. Despite this, there is no licensed vaccine or antiviral for the treatment of Mayaro fever and most arboviruses, so the design and development of candidates for antiviral drugs are urgently needed. In this context, this mini-review aims to provide an overview of studies of anti-MAYV derivatives and highlight the importance of the discovery and development of promising drug candidates for Mayaro fever.

Genome Sequence of KP-Rio/2015, a Novel Klebsiella pneumoniae (Podoviridae) Phage.

Klebsiella pneumoniae is a pathogen frequently associated with antibiotic-resistant nosocomial infections. Here, we describe the genome of KP-Rio/2015, a novel phage of K. pneumoniae belonging to the family Podoviridae.

Cytokine kinetics of Zika virus-infected patients from acute to reconvalescent phase.

Zika virus is an emerging mosquito-borne flavivirus currently causing large epidemics in the Pacific Ocean region and Brazil. Clinically, Zika fever resembles dengue fever, but is less severe. Whereas the clinical syndrome and laboratory diagnostic procedures have been described, little attention was paid to the immunology of the disease and its possible use for clinical follow-up of patients. Here, we investigate the role of cytokines in the pathogenesis of Zika fever in travelers returning from Asia, the Pacific, and Brazil. Polyfunctional T cell activation (Th1, Th2, Th9, and Th17 response) was seen during the acute phase characterized by respective cytokine level increases, followed by a decrease in the reconvalescent phase.

Prevalence of anxiety in an outpatient clinic sample of type 2 diabetics in Trinidad

OBJECTIVE: To examine the prevalence of anxiety in an outpatient clinic sample type 2 diabetics in Trinidad. Additionally, this study aims to examine gender differences in anxiety, whether anxiety levels differed among age groups and whether anxiety was related to hyperglycemia and having a coexisting medical complication such as hypertension and heart disease. DESIGN AND METHODS: 128 type 2 diabetics attending outpatient clinics on designated clinic days for their routine appointment were surveyed. Their demographics, levels of anxiety, blood glucose levels and coexisting medical complications were measured. Pearson’s correlations and t-tests were used to analyse the data. RESULTS: 19.5% of the sample population had mild to moderate levels of anxiety. The analyses indicated that diabetics with coexisting medical conditions had higher anxiety levels (p = .038); and women were more likely to have higher levels of anxiety than men (p = .002). CONCLUSION: Anxiety may potentially exacerbate the complications associated with diabetes. Attention should be given to the psychological symptoms associated with type 2 diabetes and the implementation of screening for anxiety at health clinics in an effort to effectively treat type 2 diabetes in Trinidad.

Assessing positivity and circulating levels of NS1 in samples from a 2012 dengue outbreak in Rio de Janeiro, Brazil.

Dengue virus (DENV) represents a major threat to public health worldwide. Early DENV diagnosis should not only detect the infection but also identify patients with a higher likelihood to develop severe cases. Previous studies have suggested the potential for NS1 to serve as a viral marker for dengue severity. However, further studies using different sera panels are required to confirm this hypothesis. In this context, we developed a lab-based ELISA to detect and quantitate NS1 protein from the four DENV serotypes and from primary and secondary cases. This approach was used to calculate the circulating NS1 concentration in positive samples. We also tested the NS1 positivity of DENV-positive samples according to the Platelia Dengue NS1 Ag assay. A total of 128 samples were positive for DENV infection and were classified according to the WHO guidelines. The overall NS1 positivity was 68% according to the Platelia assay, whereas all samples were NS1-positive when analyzed with our lab-based ELISA. Fifty-four samples were positive by PCR, revealing a co-circulation of DENV1 and DENV4, and the NS1 positivity for DENV4 samples was lower than that for DENV1. The circulating NS1 concentration ranged from 7 to 284 ng/mL. Our results support previous data indicating the low efficiency of the Platelia assay to detect DENV4 infection. Moreover, this work is the first to analyze NS1 antigenemia using retrospective samples from a Brazilian outbreak.

Full inactivation of human influenza virus by high hydrostatic pressure preserves virus structure and membrane fusion while conferring protection to mice against infection.

Whole inactivated vaccines (WIVs) possess greater immunogenicity than split or subunit vaccines, and recent studies have demonstrated that WIVs with preserved fusogenic activity are more protective than non-fusogenic WIVs. In this work, we describe the inactivation of human influenza virus X-31 by high hydrostatic pressure (HHP) and analyze the effects on the structure by spectroscopic measurements, light scattering, and electron microscopy. We also investigated the effects of HHP on the glycoprotein activity and fusogenic activity of the viral particles. The electron microscopy data showed pore formation on the viral envelope, but the general morphology was preserved, and small variations were seen in the particle structure. The activity of hemagglutinin (HA) during the process of binding and fusion was affected in a time-dependent manner, but neuraminidase (NA) activity was not affected. Infectious activity ceased after 3 hours of pressurization, and mice were protected from infection after being vaccinated. Our results revealed full viral inactivation with overall preservation of viral structure and maintenance of fusogenic activity, thereby conferring protection against infection. A strong response consisting of serum immunoglobulin IgG1, IgG2a, and serum and mucosal IgA was also detected after vaccination. Thus, our data strongly suggest that applying hydrostatic pressure may be an effective method for developing new vaccines against influenza A as well as other viruses.

Envelope lipid-packing as a critical factor for the biological activity and stability of alphavirus particles isolated from mammalian and mosquito cells.

Alphaviruses are enveloped arboviruses. The viral envelope is derived from the host cell and is positioned between two icosahedral protein shells (T = 4). Because the viral envelope contains glycoproteins involved in cell recognition and entry, the integrity of the envelope is critical for the success of the early events of infection. Differing levels of cholesterol in different hosts leads to the production of alphaviruses with distinct levels of this sterol loaded in the envelope. Using Mayaro virus, a New World alphavirus, we investigated the role of cholesterol on the envelope of alphavirus particles assembled in either mammalian or mosquito cells. Our results show that although quite different in their cholesterol content, Mayaro virus particles obtained from both cells share a similar high level of lateral organization in their envelopes. This organization, as well as viral stability and infectivity, is severely compromised when cholesterol is depleted from the envelope of virus particles isolated from mammalian cells, but virus particles isolated from mosquito cells are relatively unaffected by cholesterol depletion. We suggest that it is not cholesterol itself, but rather the organization of the viral envelope, that is critical for the biological activity of alphaviruses.

Inhibition of vesicular stomatitis virus replication by prostaglandin A1 in Aedes albopictus cells.

Cyclopentenone prostaglandins (PGs) exhibit antiviral activity against RNA and DNA viruses in mammalian cell lines, and this effect has been associated with the induction of a heat shock protein (hsp70). We investigated the effect of prostaglandin A1 (PGA1) on the replication of vesicular stomatitis virus (VSV) in Aedes albopictus (mosquito) cells. PGA1 was found to inhibit VSV replication dose dependently. Virus yield was reduced to 50% (3 microg PGA1/ml) and to 95% with 8 microg PGA1/ml. Even with the dramatic reduction of virus production observed in cells treated with PGA1, VSV-specific protein synthesis was unaltered. Treatment of cells with PGA1 (5 microg/ml) stimulated the synthesis of a polypeptide identified as a heat-shock protein (hsp) by immunoblot analysis. PGA1 induced hsp70 synthesis in uninfected cells. However, in VSV-infected cells the induction of hsp70 by PGA1 was reduced. This is the first report of antiviral effects of PGs affecting the replication of VSV in a mosquito cell line.

Interferon selectively inhibits the synthesis of Mayaro virus glycoproteins

We have previously observed that interferon(recIFNa2b) blocks the process of mophogenesis of Mayaro virus in TC7 cells (monkey kidney). In this work we show that IFNa inhibits preferentially virus glycoproteins and their precursors, and this effects is probably correlated to the alterations in the morphogenesis process previously observed

Recent time trends in uterine cancer.

Recent trends in corpus uterine cancer incidence rates were explored using 1979-86 data from the Surveillance and End Results Program (SEER); recent trends in hospitalizations for corpus uterine cancer were explored using 1979-86 data from National Hospital Discharge Surveys (NHDS); and recent trends in exogenous hormone use were delineated using data from the 1980, 1981, and 1985 National Ambulatory Medical Care Surveys (NAMCS). Uterine cancer incidence rates using SEER data have continued to decline since 1979. An acceleration in the decline since 1983-84 is suggested in all women and in women with intact uteri ages 45-64. Hospitalizations for uterine cancer have also declined since 1979, with a marked acceleration in the decline since 1983-84 for all women and for women ages 40-79 has increased 22 percent and use of unopposed exogenous estrogens in women of similar age has increased 7 percent, while use of exogenous progesterones have shown much more substantial increases of approximately 700 percent. Possible relationships between trends in exogenous hormone use and incidence rates of corpus uterine cancer are discussed.

Organ donation in three major American cities with large Latino and black populations.

It has been suggested that areas with large inner-city Black and Latino populations have worse organ donation rates than those with large suburban and rural White populations. Yet data are sparse. We studied family refusal rates (FRRs) to cadaver organ donation between 1/84 and 5/87 in three United States city-areas (New York, Los Angeles, and Miami) with large Black and distinct Latino populations. Blacks are at least 18% and Latinos at least 25% of the combined general population of the three cities, totaling over three and four million people, respectively. In addition, Blacks and Latinos represent 42% of cadaver transplant recipients, 49% of patients on waiting lists, and 57% of the patients on dialysis in the three cities. Combining the data from the three cities, Black (45%) and Latino (43%) FRRs were similar (P = .78), and each was significantly higher than that in the White population (17%) (P less than 0.0001). The overall refusal rate in NYC (42%) was significantly higher (P less than .0001) than in LA (26%) or Miami (21%), and LA's refusal rate was significantly higher than Miami (P = .03). The refusal rates for the White (31%) and Black (55%) populations in NYC were each significantly higher than their respective populations in LA (14% and 33%) or Miami (11% and 36%) (P less than .05). Although Miami Latinos had a lower FRR (35%) than Latinos in NYC (46%) or LA (45%), the difference was not statistically significant (P = .19 and P = .20, respectively). In the three cities combined, 515 of a possible 1772 medically and legally eligible organ donors were lost during the 40 months studied due to families' refusal of consent. This represents approximately 1000 transplantable kidneys and large numbers of extrarenal organs. Further studies are needed to elucidate the reasons for differences in donation rate among groups and regions in the United States.