Safe urodynamic practices in times of COVID-19: What can be accomplished and what can be added?

AIM: To present feedback, after applying national and international urodynamic study (UDS) recommendations for safe practice during the COVID-19 pandemic. METHODS: We created a checklist to assess the feasibility of performing UDS recommendations for safe practice during the COVID-19 pandemic from the first week of May 2021 to the last week of July 2021. RESULTS: One hundred patients were analyzed during the study period. We observed that all preventive recommendations for the steps that precede UDS could be followed in full. However, some guidelines for performing the exam were not feasible in all patients. We have successfully adopted other safety measures for all patients. CONCLUSIONS: The COVID-19 pandemic will likely persist for several more years. We believe that continuous improvement, revision, and updating of existing protocols and guidelines for the safe practice of UDS in times of COVID-19, as we propose in this study, should be encouraged.

Standardizing the influenza neuraminidase inhibition assay among United States public health laboratories conducting virological surveillance.

BACKGROUND: Monitoring influenza virus susceptibility to neuraminidase (NA) inhibitors (NAIs) is vital for detecting drug-resistant variants, and is primarily assessed using NA inhibition (NI) assays, supplemented by NA sequence analysis. However, differences in NI testing methodologies between surveillance laboratories results in variability of 50% inhibitory concentration (IC50) values, which impacts data sharing, reporting and interpretation. In 2011, the Centers for Disease Control and Prevention (CDC), in collaboration with the Association for Public Health Laboratories (APHL) spearheaded efforts to standardize fluorescence-based NI assay testing in the United States (U.S.), with the goal of achieving consistency of IC50 data. METHODS: For the standardization process, three participating state public health laboratories (PHLs), designated as National Surveillance Reference Centers for Influenza (NSRC-Is), assessed the NAI susceptibility of the 2011-12 CDC reference virus panel using stepwise procedures, with support from the CDC reference laboratory. Next, the NSRC-Is assessed the NAI susceptibility of season 2011-12 U.S. influenza surveillance isolates (n = 940), with a large subset (n = 742) tested in parallel by CDC. Subsequently, U.S. influenza surveillance isolates (n = 9629) circulating during the next three influenza seasons (2012-15), were independently tested by the three NSRC-Is (n = 7331) and CDC (n = 2298). RESULTS: The NI assay IC50s generated by respective NSRC-Is using viruses and drugs prepared by CDC were similar to those obtained with viruses and drugs prepared in-house, and were uniform between laboratories. IC50s for U.S. surveillance isolates tested during four consecutive influenza seasons (2011-15) were consistent from season to season, within and between laboratories. CONCLUSION: These results show that the NI assay is robust enough to be standardized, marking the first time IC50 data have been normalized across multiple laboratories, and used for U.S. national NAI susceptibility surveillance.

Sorption interactions between imazaquin and a humic acid extracted from a typical Brazilian oxisol.

Soil sorption of most hydrophobic organic compounds (e.g., nonpolar pesticides) is directly related to soil organic matter (SOM) content. Humic substances are the major SOM components, containing carboxylic, phenolic, amine, quinone, and other functional groups, and specific structural configurations. In this paper, sorption interactions between imazaquin (2-[4,5-dydro-4-methyl-4-(1-methylethyl)-5-oxo-1H- imidazol-2-yl]-3-quinoline-carboxylic acid) herbicide (IM) and a humic acid (HA) extracted from a typical Brazilian Oxisol were studied with electron paramagnetic resonance (EPR) and Fourier-transform infrared (FTIR) spectroscopic techniques. A polarographic technique was used to quantify sorption. The IM amount sorbed on the HA was much higher than that on the whole soil within the pH range studied, emphasizing the prominent role played by SOM on IM sorption. Moreover, IM sorption increased as the soil-solution pH decreased. This enhancement in sorption was attributed to the hydrophobic affinity of the herbicide by the HA and to the electrostatic interaction between the protonated quinoline group of IM and the negative sites of the HA. Hydrophobic regions in the HA's interior at low pH (< 5.0) were recently demonstrated by an EPR detectable spin-label molecule. The FTIR and EPR spectroscopy and polarography data indicated weak interaction between IM and the soil and its HA, involving hydrogen bonding, proton transfer, and cation exchange (at low pH), and mainly hydrophobic interactions. However, no strong reaction mechanism, such as charge transfer, was involved. In addition, this research suggested that soil amendment with organic material might increase magnitude of IM sorption, consequently avoiding leaching and carryover problems usually found for mobile and persistent herbicides such as imazaquin.

Overcoming original (antigenic) sin.

Original antigenic sin describes a phenomenon in which the antibody response elicited in an individual after a secondary viral infection reacts more strongly to the viral variant that originally infected the individual. As T helper cells play critical roles in promoting antibody responses, a similar phenomenon may hold true for T helper cell responses. This concept is particularly relevant to the development of vaccines against viruses such as human immunodeficiency virus and hepatitis C virus, in which myriad viral variants are present throughout the human population. We have compared the effects of priming the immune system with a single peptide epitope or with a cocktail of related peptides based on the epitope. Our data demonstrate that immunization with multiple peptide variants expands a more broadly reactive and durable T helper cell response than does immunization with a single peptide. This vaccine strategy may circumvent original antigenic sin.

Morphine induces gene expression of CCR5 in human CEMx174 lymphocytes.

All HIV-1 strains studied to date use CCR5, CXCR4, or both receptors to enter cells. Simian immunodeficiency virus (SIV) infection of non-human primates has served as a useful model for understanding AIDS pathogenesis in humans. Research on several genetically divergent SIV isolates has revealed that SIV uses CCR5, and not CXCR4, for entry. CEM x174, a human lymphoid cell line, has been routinely used to cultivate and maintain various SIV strains. However, questions have arisen about how CEM x174, which reportedly was unable to express detectable amounts of CCR5 transcripts, efficiently supports the growth of SIV. In searching for an answer, we resorted to a sensitive competitive reverse transcriptase-polymerase chain reaction procedure in an attempt to detect as well as quantify the amount of CCR5 expression. Here we present our findings, which indicate that CEM x174 indeed expresses CCR5 and that the amount of CCR5 is increased in cells pretreated with morphine. These results correlate well with our previous observations that morphine treatment causes CEM x174 cells to be more susceptible to SIV infection. Similar morphine effect was not observed on CEM x174 cells infected with simian retroviruses, which do not depend on CCR5 for entry. These findings suggest a plausible mechanism whereby opiate drug users render themselves more susceptible to HIV infection, thereby explaining the vast prevalence of HIV infection among endemic drug use populations.

Immunogenicity of a vaccine preparation representing the variable regions of the HIV type 1 envelope glycoprotein.

Variability of the major antigenic sites of the envelope glycoprotein of HIV-1 constitutes a major problem in the formulation of effective vaccines. We have prepared a synthetic peptide vaccine that represents the major hypervariable epitopes (V1 through V5) of the clade B HIV-1 envelope glycoprotein (gp120). We refer to this preparation as variable epitope immunogen or VEI vaccine. This construct takes into consideration the type and frequency of amino acid substitutions found at each epitope during the evolution of the virus in individual patients and in the target population. Immunization of mice, rabbits, and rhesus macaques with the VEI vaccine resulted in the induction of long-lasting, high-titered HIV-1 antibodies, including antibodies that neutralize primary isolates. We also documented lymphocyte proliferative responses to the VEI vaccine, its individual components, analogs, and subtype-specific peptides representing the major hypervariable regions of HIV-1 gp120. Delayed-type hypersensitivity responses to these antigens were also demonstrated in mice. Our results show that this vaccine is highly immunogenic and safe in animals. Our data suggest that this formulation could become an important component of combination vaccine approaches against HIV-1 and other antigenically variable pathogens.

The kinetics of specific immune responses in rhesus monkeys inoculated with live recombinant BCG expressing SIV Gag, Pol, Env, and Nef proteins.

Development of an effective preventive or therapeutic vaccine against HIV-1 is an important goal in the fight against AIDS. Effective virus clearance and inhibition of spread to target organs depends principally on the cellular immune response. Therefore, a vaccine against HIV-1 should elicit virus-specific cytotoxic lymphocyte (CTL) responses to eliminate the virus during the cell-associated stages of its life cycle. The vaccine should also be capable of inducing immunity at the mucosal surfaces, the primary route of transmission. Recombinant Bacille Calmette-Guérin (BCG) expressing viral proteins offers an excellent candidate vaccine in view of its safety and ability to persist intracellularly, resulting in the induction of long-lasting immunity and stimulation of the cellular immune response. BCG can be administered orally to induce HIV-specific immunity at the mucosal surfaces. The immunogenicity of four recombinant BCG constructs expressing simian immunodeficiency virus (SIV) Gag, Pol, Env, and Nef proteins was tested in rhesus macaques. A single simultaneous inoculation of all four recombinants elicited SIV-specific IgA and IgG antibody, and cellular immune responses, including CTL and helper T cell proliferation. Our results demonstrate that BCG recombinant vectors can induce concomitant humoral and cellular immune responses to the major proteins of SIV.

Effect of human immunodeficiency virus type 1 on intracellular activation and superoxide production by neutrophils.

The immunopathogenesis of AIDS is associated with the development of opportunistic infections by intracellular pathogens that can invade and reproduce freely because of impaired cellular functions. Neutrophils from asymptomatic human immunodeficiency virus (HIV) type 1-infected persons and from symptomatic patients with AIDS were found to retain normal phagocytosis activity while producing significantly less superoxide than neutrophils from HIV-1-negative subjects, when stimulated through Fc receptors or protein kinase C. After priming with a synthetic HIV-1 envelope peptide and stimulation via the Fc receptor, the neutrophils from HIV-1-negative controls had suppressed superoxide production, reduced phosphorylation of two unidentified cellular proteins, and increased expression of a third phosphoprotein. These results suggest that HIV-1 can produce direct functional damage of neutrophils through binding of envelope components to the cell membrane.

Antibodies from HIV-positive and AIDS patients bind to an HIV envelope multivalent vaccine.

A major problem impeding development of an effective HIV vaccine is the rapid antigenic variability that is characteristic of several envelope glycoprotein epitopes. Frequent mutations alter the composition of the most immunogenic regions of the envelope glycoprotein. We have prepared a synthetic immunogen representing the evolution of the major hypervariable epitopes on the envelope glycoprotein (gp120) of HIV-1. Five synthetic constructs, representing each of the HIV-1 gp120 hypervariable epitopes were tested for recognition by antibodies from patients infected with HIV-1 from different geographic regions worldwide. An HIV-1 human plasma panel provided a representation of the antibodies recognizing subtype-specific epitope sequences prevalent at different parts of the world. The vaccine construct was recognized by antibodies from HIV-1-positive individuals infected with subtypes A, B, C, D, E, and F. Antibodies in pooled HIV-1 patient sera from San Francisco also recognized all five constructs. This complex immunogen was recognized by antibodies in sera from individual HIV-1-positive and AIDS patients from Puerto Rico and Canada, with a strong binding to the complete vaccine and the V3 component. Altogether, our results demonstrate that antibodies from seropositive patients infected with different HIV-1 clades recognize and bind to the HIV hypervariable epitope construct vaccine preparation and its individual components.