Evidence of escape of SARS-CoV-2 variant B.1.351 from natural and vaccine-induced sera.

The race to produce vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began when the first sequence was published, and this forms the basis for vaccines currently deployed globally. Independent lineages of SARS-CoV-2 have recently been reported: UK, B.1.1.7; South Africa, B.1.351; and Brazil, P.1. These variants have multiple changes in the immunodominant spike protein that facilitates viral cell entry via the angiotensin-converting enzyme-2 (ACE2) receptor. Mutations in the receptor recognition site on the spike are of great concern for their potential for immune escape. Here, we describe a structure-function analysis of B.1.351 using a large cohort of convalescent and vaccinee serum samples. The receptor-binding domain mutations provide tighter ACE2 binding and widespread escape from monoclonal antibody neutralization largely driven by E484K, although K417N and N501Y act together against some important antibody classes. In a number of cases, it would appear that convalescent and some vaccine serum offers limited protection against this variant.

The antigenic anatomy of SARS-CoV-2 receptor binding domain.

Antibodies are crucial to immune protection against SARS-CoV-2, with some in emergency use as therapeutics. Here, we identify 377 human monoclonal antibodies (mAbs) recognizing the virus spike and focus mainly on 80 that bind the receptor binding domain (RBD). We devise a competition data-driven method to map RBD binding sites. We find that although antibody binding sites are widely dispersed, neutralizing antibody binding is focused, with nearly all highly inhibitory mAbs (IC50 < 0.1 µg/mL) blocking receptor interaction, except for one that binds a unique epitope in the N-terminal domain. Many of these neutralizing mAbs use public V-genes and are close to germline. We dissect the structural basis of recognition for this large panel of antibodies through X-ray crystallography and cryoelectron microscopy of 19 Fab-antigen structures. We find novel binding modes for some potently inhibitory antibodies and demonstrate that strongly neutralizing mAbs protect, prophylactically or therapeutically, in animal models.

Reduced neutralization of SARS-CoV-2 B.1.1.7 variant by convalescent and vaccine sera.

SARS-CoV-2 has caused over 2 million deaths in little over a year. Vaccines are being deployed at scale, aiming to generate responses against the virus spike. The scale of the pandemic and error-prone virus replication is leading to the appearance of mutant viruses and potentially escape from antibody responses. Variant B.1.1.7, now dominant in the UK, with increased transmission, harbors 9 amino acid changes in the spike, including N501Y in the ACE2 interacting surface. We examine the ability of B.1.1.7 to evade antibody responses elicited by natural SARS-CoV-2 infection or vaccination. We map the impact of N501Y by structure/function analysis of a large panel of well-characterized monoclonal antibodies. B.1.1.7 is harder to neutralize than parental virus, compromising neutralization by some members of a major class of public antibodies through light-chain contacts with residue 501. However, widespread escape from monoclonal antibodies or antibody responses generated by natural infection or vaccination was not observed.

Antibody evasion by the P.1 strain of SARS-CoV-2.

Terminating the SARS-CoV-2 pandemic relies upon pan-global vaccination. Current vaccines elicit neutralizing antibody responses to the virus spike derived from early isolates. However, new strains have emerged with multiple mutations, including P.1 from Brazil, B.1.351 from South Africa, and B.1.1.7 from the UK (12, 10, and 9 changes in the spike, respectively). All have mutations in the ACE2 binding site, with P.1 and B.1.351 having a virtually identical triplet (E484K, K417N/T, and N501Y), which we show confer similar increased affinity for ACE2. We show that, surprisingly, P.1 is significantly less resistant to naturally acquired or vaccine-induced antibody responses than B.1.351, suggesting that changes outside the receptor-binding domain (RBD) impact neutralization. Monoclonal antibody (mAb) 222 neutralizes all three variants despite interacting with two of the ACE2-binding site mutations. We explain this through structural analysis and use the 222 light chain to largely restore neutralization potency to a major class of public antibodies.

Interstitial lung disease in patients with systemic sclerosis: what can we learn from the SENSCIS trial?

The SENSCIS trial of nintedanib versus placebo is the largest trial conducted to date in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD). This trial enrolled 576 patients with an extent of fibrotic ILD on high-resolution computed tomography of >10%. Median time since first non-Raynaud symptom was 3.4 years. Almost half of the patients were receiving a stable dose of mycophenolate at baseline. Key findings of the trial included that at baseline, despite having significant lung fibrosis on HRCT and impairment in lung function, 20% of the patients did not have cough and 30% did not have dyspnoea. Over 52 weeks, a marked decline in forced vital capacity (FVC) was observed (-112.0 mL/year in patients with diffuse cutaneous SSc [dcSSc] and -74.5 mL/year in patients with limited cutaneous SSc [lcSSc] in the placebo group). Loss of FVC was associated with an increased risk of SSc-related hospitalisation or death. Although certain subgroups of patients were at higher risk of progression, it was not possible to make a robust prediction of FVC decline based on baseline characteristics. The relative effect of nintedanib versus placebo on reducing the rate of FVC decline was consistent across subgroups based on factors including anti-topoisomerase I antibody (ATA) status, dcSSc vs. lcSSc, and use of mycophenolate at baseline. The side-effects of nintedanib were mainly gastrointestinal events, particularly diarrhoea. Nintedanib did not have a significant effect on skin fibrosis or health-related quality of life. Overall, the results of the SENSCIS trial support the importance of prompt identification and treatment of SSc-ILD and the consideration of nintedanib as a treatment option.

Severe Acute Respiratory Syndrome Coronavirus 2 and Respiratory Virus Sentinel Surveillance, California, USA, May 10, 2020-June 12, 2021.

State and local health departments established the California Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Respiratory Virus Sentinel Surveillance System to conduct enhanced surveillance for SARS-CoV-2 and other respiratory pathogens at sentinel outpatient testing sites in 10 counties throughout California, USA. We describe results obtained during May 10, 2020‒June 12, 2021, and compare persons with positive and negative SARS-CoV-2 PCR results by using Poisson regression. We detected SARS-CoV-2 in 1,696 (19.6%) of 8,662 specimens. Among 7,851 specimens tested by respiratory panel, rhinovirus/enterovirus was detected in 906 (11.5%) specimens and other respiratory pathogens in 136 (1.7%) specimens. We also detected 23 co-infections with SARS-CoV-2 and another pathogen. SARS-CoV-2 positivity was associated with male participants, an age of 35-49 years, Latino race/ethnicity, obesity, and work in transportation occupations. Sentinel surveillance can provide useful virologic and epidemiologic data to supplement other disease monitoring activities and might become increasingly useful as routine testing decreases.

Chemical Leukoderma Associated with Methylphenidate Transdermal System: Data From the US Food and Drug Administration Adverse Event Reporting System.

OBJECTIVE: To identify and characterize cases of chemical leukoderma, an underrecognized adverse event, associated with the methylphenidate transdermal system (MTS) reported to the US Food and Drug Administration Adverse Event Reporting System (FAERS). STUDY DESIGN: We searched the Food and Drug Administration Adverse Event Reporting System for reports of chemical leukoderma associated with MTS, received by the Food and Drug Administration from April 6, 2006 to December 23, 2014. RESULTS: We identified 51 cases of chemical leukoderma reported with the use of MTS. The median age was 11 years; 43 cases reported leukoderma at or near the application site only, and 7 reported leukoderma at other parts of the body in addition to the application site; 1 case did not provide enough information to confirm the affected site. The time to onset ranged from 2 months to 4 years after the initiation of MTS. MTS was discontinued in 31 cases. Thirteen patients were prescribed treatment for repigmentation. Three cases reported continued spread of leukoderma after MTS was discontinued. Nineteen cases were diagnosed as vitiligo, including 5 cases reporting histologic features consistent with vitiligo. Leukoderma was persistent in all cases. The median follow-up interval after the discontinuation of MTS in 23 cases was 14 months. CONCLUSIONS: As outlined in recent changes to the prescribing information for MTS, health care professionals need to be aware of the potential risk of chemical leukoderma caused by MTS, especially given that chemical leukoderma is often misdiagnosed as idiopathic vitiligo. MTS should be discontinued at the earliest sign of pigment loss and other treatment options considered.

Liver injury associated with dimethyl fumarate in multiple sclerosis patients.

BACKGROUND: In pre-approval trials, there was an increased incidence of mild, transient elevations of liver aminotransferases in study subjects treated with dimethyl fumarate (DMF). OBJECTIVE/METHODS: To evaluate post-marketing cases of drug-induced liver injury associated with DMF. RESULTS: We identified 14 post-marketing cases of clinically significant liver injury. Findings included newly elevated serum liver aminotransferase and bilirubin levels that developed as early as a few days after the first dose of DMF. The pattern of liver injury was primarily hepatocellular. No cases resulted in liver failure. CONCLUSION: Health professionals should be alerted to possible serious liver injury in patients receiving DMF.

Effects of Ganoderma Lucidum shell-broken spore on oxidative stress of the rabbit urinary bladder using an in vivo model of ischemia/reperfusion.

Oxidative stress plays an important role in specific disease pathophysiology and the aging process. In the history of human kind, many herbs were utilized for disease prevention and anti-aging treatment. However, there are few direct evidences provided by modern laboratory technology. The current study was designed to evaluate Ganoderma Lucidum's (GL) ability to reduce the damage from in vivo ischemia/reperfusion (I/R) using a rabbit model of I/R that has been effectively utilized to prove the effects of drugs and supplements to reduce oxidative stress. Urinary bladder dysfunction secondary to benign prostatic hyperplasia (BPH) is a major affliction of aging men. One of the major etiologies of obstructive bladder dysfunction (OBD) is oxidative stress induced by I/R. Pharmaceutical studies and clinical research have proven that GL is useful in helping to prevent certain types of pathology and also helpful in prolonging human life in part by acting as an antioxidant. Using an in vivo model of I/R, we have investigated the ability of GL to protect bladder function from oxidative damage mediated by I/R. Our studies demonstrated that ischemia followed by reperfusion resulted in a significant decrease in bladder compliance and decreases in the contractile responses to a variety of forms of contractile stimulation. Pretreatment of rabbits with Ganoderma Lucidum prior to subjecting the rabbits to I/R completely inhibited the negative effects of I/R on both the compliance and contractile responses. These results demonstrate that Ganoderma provides excellent protection of bladder function following I/R (oxidative stress).

The relevance of immune responses to partial bladder outlet obstruction and reversal.

AIMS: Partial bladder outlet obstruction (PBOO) causes tissue inflammation, a significant increase in markers of systemic oxidative stress, and proliferation of circulating myeloid-derived suppressor cells. Here, we investigated the regulatory mechanisms underlying inflammation and helper T cell involvement in PBOO. METHODS: Surgical PBOO was performed in four groups of rats: control (C), obstruction at 2 (O2) and 4 (O4) weeks, and 4 weeks after the relief of PBOO (R4) (n = 6 each). The urinary levels of prostaglandin E metabolite (PGEM), expression of inflammatory cytokines (IL-6 and IL-17) in the bladder, numbers of peripheral blood regulatory T cells (Treg cells), and levels of TGF-ß1 were assessed via immunohistochemistry, flow cytometry, or ELISA. RESULTS: The levels of urinary PGEM, bladder IL-17, and TGF-ß1 and the numbers of peripheral Treg cells (Foxp3) were all significantly increased at 2 and 4 weeks after PBOO. PGEM, IL-17, and Treg cells (Foxp3) were decreased after the relief of PBOO, while the levels of TGF-ß1 continued to increase. CONCLUSIONS: Transient PBOO triggers an acute, reversible increase in inflammatory cytokines and Treg cells. The distinct dynamics of individual inflammatory markers support their potential use as markers for monitoring bladder inflammation.

Adverse event detection using the FDA post-marketing drug safety surveillance system: Cardiotoxicity associated with loperamide abuse and misuse.

OBJECTIVE: The purpose of this investigation was to identify and characterize post-marketing reports of cardiotoxicity, including torsades de pointes (TdP), associated with loperamide use. METHODS: We searched the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) database for post-marketing reports of serious cardiac adverse events associated with loperamide use from December 28, 1976 (U.S. drug approval date), through December 14, 2015. We also conducted a Pubmed and Google Scholar search to identify additional published reports of cardiotoxicity associated with loperamide in the medical literature through February 11, 2016. RESULTS: Forty-eight cases of serious cardiac adverse events associated with loperamide use composed the case series. The most frequently reported cardiac adverse events were syncope (n = 24), cardiac arrest (n = 13), QT-interval prolongation (n = 13), ventricular tachycardia (n = 10), and TdP (n = 7). There were 10 cases that resulted in death. Of the 48 cases, the most commonly reported reasons for use can be characterized as drug abuse (n = 22) and diarrhea treatment (n = 17). More than one-half of the 48 cases were reported after 2010. Of the 22 drug abuse cases, the median daily dose was 250 mg (range 70 mg to 1600 mg) and events occurred as early as 6 hours after a dose and as long as 18 months after initiation of loperamide. Thirteen of the 22 cases reported using loperamide for euphoric or analgesic effects, and 9 reported use to prevent opioid withdrawal symptoms. CONCLUSION: The FAERS case reports provide evidence to suggest that high doses of loperamide are associated with TdP and other serious cardiac adverse events. The majority of cases in this series occurred in the setting of drug abuse for the purpose of preventing opioid withdrawal or to produce euphoric effects. It is important for both clinicians and patients to be aware of this potential risk, because prompt therapy and discontinuation of the offending agent are often essential to management and prevention of loperamide-induced cardiac arrhythmias.

Aflatoxin M1: Prevalence and decontamination strategies in milk and milk products.

Aflatoxin M1 (AFM1) in milk is among the most carcinogenic compounds, relatively high levels being consumed, especially by the most vulnerable age groups, i.e. infants and the elderly. Reports on its prevalence are constantly being received from various parts of the world compelling nations to establish their own standard limits for AFM1. Global review of the literature indicates the existence of methods of partial decontamination of AFM1, however; evidence based studies do not suggest that any single strategy as a coherent and complete solution to the issue. Microbial decontamination of AFM1 has emerged as the most suitable method up to now but the stability of toxin-microbial cell complexes still remains questionable. This review discusses the chemical nature, established maximum permissible limits and prevalence of AFM1 in various countries from 2009 to 2014. Moreover, the possible mechanisms for AFM1 reduction mainly the microbial decontamination and the stability and bioaccessibility of microbial-AFM1 complexes are also discussed.

Comparative biochemical responses and antioxidant activities of the rabbit urinary bladder to whole grapes versus resveratrol.

The objective of this study is to compare the antioxidant activity of a whole-grape suspension with the antioxidant activity or pure resveratrol on the effect of hydrogen peroxide (H2O2) on malondialdehyde (MDA) generation, choline acetyltransferase (ChAT) activity, calcium ATPase activity, and sarcoendoplasmic reticular ATPase (SERCA) of the male rabbit urinary bladder. MDA was used as a model for the effect of H2O2 on lipid peroxidation. ChAT, SERCA, and calcium ATPase were evaluated based on their importance in urinary bladder physiology and pathology. Four male rabbit bladders were used. Each bladder was separated into muscle and mucosa, frozen under liquid nitrogen and stored at -80 °C for biochemical evaluation. The effect of H2O2 on the enzymes listed above was determined in the presence and absence of either resveratrol or a whole-grape suspension. (1) Resveratrol was significantly more effective than the grape suspension at protecting the bladder muscle and mucosa against peroxidation as quantitated by MDA formation. (2) The grape suspension was significantly more effective at protecting ChAT activity against oxidative stress of the muscle than resveratrol. (3) Neither the grape suspension nor resveratrol were particularly effective at protecting the bladder muscle or mucosa calcium ATPase or SERCA against oxidative stress. (4) ChAT was significantly more sensitive to oxidative stress than either calcium ATPase or SERCA. These data support the idea that the grape suspension protects the mitochondria and nerve terminals to a significantly greater degree than resveratrol which suggests that the activities of the grape suspension are due to the combination of active components found in the grape suspension and not just resveratrol alone.

Transient increase in circulating myeloid-derived suppressor cells after partial bladder outlet obstruction.

PURPOSE: Partial bladder outlet obstruction causes a significant increase in tissue and systemic oxidative stress markers and tissue inflammatory cytokine levels. Myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone are believed to be associated with oxidative stress and inflammation. We investigated alterations in plasma myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone levels in partial bladder outlet obstruction and after its reversal. MATERIALS AND METHODS: Rats with surgically induced partial bladder outlet obstruction were divided into 4 groups of 3 each, including sham treated, 4-week obstruction, and 4 and 8-week obstruction with relief. Plasma levels of circulating myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone were assessed by flow cytometry or enzyme-linked immunosorbent assay. RESULTS: The circulating myeloid-derived suppressor cell level was markedly increased in the obstruction group compared to the sham treated group and it returned to normal in the 4 and 8-week obstruction with relief groups. Plasma IFN-γ, IL-10 and aldosterone were similarly increased in the obstruction group and returned to normal in the 4 and 8-week obstruction with relief groups. CONCLUSIONS: Levels of circulating myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone were increased in rats with partial bladder outlet obstruction but returned to normal after reversal. This suggests that an increase in these parameters may be a good predictive indicator of patients at increased risk for urinary symptoms.

Effect of hydrogen peroxide on contractility and citrate synthase activity of the rabbit urinary bladder in the presence and absence of resveratrol and a whole-grape suspension.

One etiology related directly to obstructive urinary bladder dysfunction is ischemia/reperfusion resulting in significant oxidative stress to the bladder. Grapes, a natural source of antioxidants, have been proven effective in preventing obstructive and ischemic bladder dysfunction. Many investigators believe that resveratrol is the primary active antioxidant ingredient in grapes. We compared the ability of a whole-grape suspension with pure resveratrol in their ability to protect the bladder from in vitro oxidative stress mediated by hydrogen peroxide (H2O2). Four male rabbit bladders were used. Two strips from each bladder were incubated in the presence of 1 mg/mL grape suspension for 30 min, another two strips were incubated in the presence of 1 mg/mL resveratrol solution, and the last two strips were incubated in the presence of 1 mg/mL sucrose/and fructose as controls. The rest of the bladder was separated into muscle and mucosa, frozen and stored for biochemical evaluation. (1) Chemically, resveratrol has about 20 times the antioxidant capacity of the grape suspension. (2) The grape suspension had significant protective effects when the rate of tension was quantitated at all concentrations of H2O2, while the resveratrol had no effect. (3) Citrate synthase activities of the muscle and mucosa were significantly protected by the grape suspension but not by resveratrol. These data demonstrate that the grape suspension protects the mitochondria to a significantly greater degree than resveratrol, which suggests that the antioxidant activities are due to the combination of active components found in the grape suspension and not just resveratrol.

Effect of partial bladder outlet obstruction and reversal on rabbit bladder physiology and biochemistry: duration of recovery period and severity of function.

OBJECTIVES: To use a rabbit model of partial bladder outlet obstruction (BOO) to investigate the point at which obstructive bladder dysfunction becomes irreversible. METHODS: Partial BOO was induced in New Zealand White rabbits. It was then reversed and the rabbits were allowed to recover for 4, 8 or 12 weeks. Both at the time of reversal and at the end of the study, the rabbits were grouped according to bladder decompensation level (mild, intermediate or severe) based on bladder mass (weight). RESULTS: A strong correlation was observed between the production and distribution of collagen and the reduction of smooth muscle contractile function. We found that only in the bladders that were severely decompensated at the time of reversal did collagen levels not decrease. CONCLUSION: The data show that recovery of function after reversal of partial BOO is directly related primarily to collagen levels at the time of reversal.

Effect of estrogen and ovariectomy on response of the female rabbit urinary bladder to two forms of in vitro oxidative stress.

INTRODUCTION AND HYPOTHESIS: There are several lower urinary tract dysfunctions (LUTD) that are more common in women than in men including incontinence, interstitial cystitis, and recurrent urinary tract infection. There is increasing evidence that these dysfunctions are associated with reduced blood flow, ischemia, hypoxia, and reperfusion resulting in free radical generation and oxidative damage. The goal of the current study was to determine if the level of circulating estrogen affects the response of the bladder muscle and mucosa to two in vitro models of oxidative stress: Incubation in the presence of hydrogen peroxide (H(2)O(2)) is the first model; the second is ischemia followed by reperfusion which results in the direct production of damaging free radicals. The motivation for this study is the current literature linking female-related LUTD with oxidative stress. METHODS: Eighteen female New Zealand white rabbits were divided into three groups: control, ovariectomized, and ovariectomized receiving continuous estrogen. Eight bladder strips from each of three rabbits per group were taken for in vitro ischemia/reperfusion (I/R) physiological experiments, while eight strips from the three remaining rabbit bladders per group were taken for in vitro H(2)O(2) experiments. All tissue was analyzed for total antioxidant activity (AA) and malondialdehyde (MDA) levels. In addition, the organ bath buffer was also analyzed for AA. RESULTS: In vitro H(2)O(2) was found to target the nerve, muscarinic receptor, and membrane equally causing more damage to bladder tissue than in vitro I/R. Ovariectomy resulted in lower contractility and higher lipid peroxidation. However, estrogen supplementation following ovariectomy protected the bladder against both models of oxidative stress by maintaining contractile responses to stimulation and decreasing lipid peroxidation. CONCLUSIONS: The primary conclusion from this study is high estrogen protects the bladder from oxidative stress, whereas low estrogen makes the bladder more susceptible.

Use of ß-cyclodextrin and activated carbon for quantification of Salmonella enterica ser. Enteritidis from ground beef by conventional PCR without enrichment.

The high level of PCR inhibitors present in ground beef is a major factor that affects molecular based techniques, such as the polymerase chain reaction (PCR), for the detection of Salmonella enterica. In this study, the use of ß-cyclodextrin and milk protein coated activated carbon (MP-CAC) allowed the PCR to detect low numbers of Salmonella seeded into ground beef without enrichment of samples. invA was used as target gene in the conventional PCR protocol. With 25 g samples of ground beef containing 7.0, 15, and 27% fat, treatment of stomached samples with 5.0, 10, and 15% ß-cyclodextrin respectively followed by treatment with MP-CAC, resulted in the detection of 3 CFU/g (equivalent to 75 CFU in a 25 g sample). The total assay time was 4.5 h. The methodology described in this study for the detection of S. enterica in ground beef without enrichment is rapid, sensitive, and has the potential to be applied to a number of complex food matrices to detect low numbers of food-borne bacterial pathogens.

Purification and characterization of iso-ribonucleases from a novel thermophilic fungus.

A thermophilic fungus previously isolated from composted horse manure was found to produce extracellular iso-RNases that were purified 127.6-fold using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined electrophoretically using 4%-15% gradient polyacrylamide gels. RNase activity was dependent on the presence of a metal co-factor with significantly more activity with Zn2+ or Mn2+ than Mg2+. The RNases exhibited maximum activity at both pH 3.0 and pH 7.0 with no activity at pH 2.0 or 10.0. The optimal temperature for the iso-RNase was 70 °C. The molecular weight of the iso-RNase was determined to be 69 kDa using a Sephadex G-75 column.

Purification of an inducible DNase from a thermophilic fungus.

The ability to induce an extracellular DNase from a novel thermophilic fungus was studied and the DNAse purified using both traditional and innovative purification techniques. The isolate produced sterile hyphae under all attempted growing conditions, with an average diameter of 2 µm and was found to have an optimal temperature of 45 °C and a maximum of 65 °C. Sequencing of the internal transcribed region resulted in a 91% match with Chaetomium sp., suggesting a new species, but further clarification on this point is needed. The optimal temperature for DNase production was found to be 55 °C and was induced by the presence of DNA and/or deoxyribose. Static growth of the organism resulted in significantly higher DNase production than agitated growth. The DNase was purified 145-fold using a novel affinity membrane purification system with 25% of the initial enzyme activity remaining. Electrophoresis of the purified enzyme resulted in a single protein band, indicating DNase homogeneity.