Structural and mechanistic insights into the inhibition of respiratory syncytial virus polymerase by a non-nucleoside inhibitor

The respiratory syncytial virus polymerase complex, consisting of the polymerase (L) and phosphoprotein (P), catalyzes nucleotide polymerization, cap addition, and cap methylation via the RNA dependent RNA polymerase, capping, and Methyltransferase domains on L. Several nucleoside and non-nucleoside inhibitors have been reported to inhibit this polymerase complex, but the structural details of the exact inhibitor-polymerase interactions have been lacking. Here, we report a non-nucleoside inhibitor JNJ-8003 with sub-nanomolar inhibition potency in both antiviral and polymerase assays. Our 2.9 Å resolution cryo-EM structure revealed that JNJ-8003 binds to an induced-fit pocket on the capping domain, with multiple interactions consistent with its tight binding and resistance mutation profile. The minigenome and gel-based de novo RNA synthesis and primer extension assays demonstrated that JNJ-8003 inhibited nucleotide polymerization at the early stages of RNA transcription and replication. Our results support that JNJ-8003 binding modulates a functional interplay between the capping and RdRp domains, and this molecular insight could accelerate the design of broad-spectrum antiviral drugs.

High Levels of Interferon-Alpha Expressing Macrophages in Human Breast Milk During SARS-CoV-2 Infection: A Case Report

Introduction: In addition to hand washing and wearing masks, social distancing and reducing exposure time to <15 minutes are the most effective measures against the spread of COVID-19. Unfortunately, three of these guidelines are very difficult, if not impossible, for nursing babies: they cannot wear masks, stay six feet away from the lactating breasts, nor consistently finish within 15 minutes while nursing. We report a case of a nursing mother with SARS-CoV-2 infection, documenting changes of immune cells and cytokines in breast milk with and without the infection. Case Description: With Institutional Review Board (IRB) approval, we obtained expressed breast milk samples from a lactating mother before and during SARS-CoV-2 infection as documented by reverse transcription-PCR. Using flow cytometry analysis, we measured the immune cell profiles and expression of cytokines such as interferon alpha (IFNα) in milk leukocytes before and during infection. Results: There was an eightfold increase in IFNα+ milk leukocytes, from 1% before SARS-CoV-2 infection to 8% when actively infected. The milk macrophages showed the highest increase in IFNα expression. Both T and B lymphocytes showed mild increase. Innate lymphoid cells, neutrophils, and natural killer cells showed no increase in IFNα expression and the dendritic cells actually showed a reduction. Conclusion: We document the presence and high expression of IFNα in the breast milk macrophages of a lactating mother with confirmed COVID-19, compared with her milk before the infection.

Factors Affecting the Composition of Expressed Fresh Human Milk

Breast milk is considered the ideal and preferred feeding for all infants through the first 4-6 months of life. It provides many short and long-term benefits to the infant and mother. In the absence of breastfeeding, expressed breast milk is the best way to provide nutrition. In the United States, the majority of breastfeeding mothers express milk at some point during the course of lactation. Breast milk is a dynamic fluid and its content changes with duration of lactation and varies between and among women. Many factors such as maternal diet and medications affect the constituents of breast milk. In addition, method of breast milk expression, handling, and storage can also influence its contents.

Botulinum Toxin Injections Into the Lateral Cricoarytenoid Muscles for Vocal Process Granuloma

OBJECTIVE

Contact granulomas are benign, exophytic inflammatory lesions of the larynx that typically arise on or near the vocal process of the arytenoid cartilage. The most common management options include voice therapy and antireflux pharmacotherapy, intralesional steroid injections, botulinum toxin injections, and surgical excision. In-office Botox injection into the lateral cricoarytenoid (LCA) muscle can be effective even for recurrent granulomas.

STUDY DESIGN

This is a retrospective chart review and literature review.

METHOD

We reviewed more than 400 charts and included two patients, who underwent in-office injection with botulinum toxin A into LCA muscles bilaterally, after previously failing both conservative and surgical management.

RESULTS

Both cases showed significant improvement of the laryngeal granulomas after 6 months and a single botulinum toxin injection. Both cases were initially grade III granuloma that improved to grade I.

CONCLUSIONS

In-office injection of botulinum toxin A targeting the LCA muscle appears to be a safe and effective treatment modality in refractory laryngeal granuloma.

Development of an edema factor-mediated cAMP-induction bioassay for detecting antibody-mediated neutralization of anthrax protective antigen

Intoxication of mammalian cells by Bacillus anthracis requires the coordinate activity of three distinct bacterial proteins: protective antigen (PA), edema factor (EF), and lethal factor (LF). Among these proteins, PA has become the major focus of work on monoclonal antibodies and vaccines designed to treat or prevent anthrax infection since neither EF nor LF is capable of inducing cellular toxicity in its absence. Here, we present the development of a sensitive, precise, and biologically relevant bioassay platform capable of quantifying antibody-mediated PA neutralization. This bioassay is based on the ability of PA to bind and shuttle EF, a bacterial adenylate cyclase, into mammalian cells leading to an increase in cAMP that can be quantified using a sensitive chemiluminescent ELISA. The results of this study indicate that the cAMP-induction assay possesses the necessary performance characteristics for use as both a potency-indicating release assay in a quality control setting and as a surrogate pharmacodynamic marker for ensuring the continued bioactivity of therapeutic antibodies against PA during clinical trials.

Comparison of microarray-based mRNA profiling technologies for identification of psychiatric disease and drug signatures

The gene expression profiles of human postmortem parietal and prefrontal cortex samples of normal controls and patients with bipolar disease, or human neuroblastoma flat (NBFL) cells treated with the mood-stabilizing drug, valproate, were used to compare the performance of Affymetrix oligonucleotide U133A GeneChips and Agilent Human 1 cDNA microarrays. Among those genes represented on both platforms, the oligo array identified 26-53% more differentially expressed genes compared to the cDNA array in the three experiments, when identical fold change and t-test criteria were applied. The increased sensitivity was primarily the result of more robust fold changes measured by the oligonucleotide system. Essentially all gene changes overlapping between the two platforms were co-directional, and ranged from 4 to 19% depending upon the amount of biological variability within and between the comparison groups. Q-PCR validation rates were virtually identical for the two platforms, with 23-24% validation in the prefrontal cortex experiment, and 56% for both platforms in the cell culture experiment. Validated genes included dopa decarboxylase, dopamine beta-hydroxylase, and dihydropyrimidinase-related protein 3, which were decreased in NBFL cells exposed to valproate, and spinocerebellar ataxia 7, which was increased in bipolar disease. The modest overlap but similar validation rates show that each microarray system identifies a unique set of differentially expressed genes, and thus the greatest information is obtained from the use of both platforms.

The laparoscopic experience of surgical graduates in the United States

BACKGROUND

Although laparoscopic surgery has become widespread during the past decade, no systematic study of the training needs exists. To obtain guidance for planning, we analyzed the national resident operative experience during the past 8 years.

METHODS

The laparoscopic experiences of all surgical residents graduating between 1994 and 2001 were subjected to regression analysis. The laparoscopic volume of each trainee and change in ratio of laparoscopic/open operation over time were used to estimate the growth of individual laparoscopic operations in training programs.

RESULTS

Laparoscopic surgery constituted only 5.7% of a trainee's total surgical experience in 1994, but comprised 13% by 2001. A resident completing training in 1994 performed 53 laparoscopic operations, of which 79% (42) were cholecystectomies. By 2001, a graduate performed 126 laparoscopic operations, of which 68% (86) were cholecystectomies. During the interim, most laparoscopic operations exhibited growth. Trainee experience in some newer operations has also increased steadily but at a much slower rate.

CONCLUSIONS

This descriptive statistical survey of training experience yields a comprehensive picture of the laparoscopic capability of the young surgeon. The growth potential of some newer operations has also been measured. Using these data, guidelines can be drawn as to which operation programs should focus resources on training residents. Since competence depends on exposure, residency training alone may not provide sufficient depth to allow recent graduates to perform the newer operations independently.

The decline of training in open biliary surgery: effect on the residents' attitude toward bile duct surgery

BACKGROUND

After more than a decade of growth for laparoscopic cholecystectomy and decline in open cholecystectomy, the impact on the training of resident's in other open biliary operations can be analyzed quantitatively.

METHODS

The national operative statistics for residents' operations from 1988 to 2001 (data in the public domain) were analyzed by regression analysis to establish trends and to calculate the rate of change. For laparoscopic biliary operations, the changes in laparoscopic and open operations over time and the number of operations per trainee each year were used to measure the growth of a laparoscopic operation and to predict future trends. A survey of attitude, management algorithm, and self-confidence for coping with unexpected events in laparoscopic cholecystectomy also was conducted for senior residents and recent graduates.

RESULTS

In 2001, open cholecystectomy decreased to 28%, open common duct exploration to 27%, sphincteroplasty to 20%, of 1988 (baseline year) levels. Cholecystostomy and choledochoenteric bypass decreased to 70% and 75%, respectively. The decline began before the era of laparoscopic cholecystectomy, but accelerated after its introduction. Many of the recent graduates surveyed in one program indicated a preference for a nonsurgical, mainly endoscopic, approach for all bile duct conditions, but also for the assistance of senior surgeons in the operative management of unexpected events.

CONCLUSION

The popularity of noninvasive therapy in biliary surgery significantly reduced the resident's exposure to open biliary surgery, adversely affecting their confidence in the management of unexpected events encountered during laparoscopic operations. Supplemental and remedial education measures must be instituted in training programs.

A genomic sequence analysis of the mouse and human microtubule-associated protein tau

Microtubule associated protein tau (MAPT) encodes the microtubule associated protein tau, the primary component of neurofibrillary tangles found in Alzheimer's disease and other neurodegenerative disorders. Mutations in the coding and intronic sequences of MAPT cause autosomal dominant frontotemporal dementia (FTDP-17). MAPT is also a candidate gene for progressive supranuclear palsy and hereditary dysphagic dementia. A human PAC (201 kb) and a mouse BAC (161 kb) containing the entire MAPT and Mtapt genes, respectively, were identified and sequenced. Comparative DNA sequence analysis revealed over 100 conserved non-repeat potential cis-acting regulatory sequences in or close to MAPT. Those islands with greater than 67% nucleotide identity range in size from 20 to greater than 1700 nucleotides. Over 90 single nucleotide polymorphisms were identified in MAPT that are candidate susceptibility alleles for neurodegenerative disease. The 5' and 3' flanking genes for MAPT are the corticotrophin-releasing factor receptor (CRFR) gene and KIAA1267, a gene of unknown function expressed in brain.

Validation of a digital color Doppler flow measurement method for pulmonary regurgitant volumes and regurgitant fractions in an in vitro model and in a chronic animal model of postoperative repaired tetralogy of Fallot

OBJECTIVES

The purpose of this study was to validate a digital color Doppler (DCD) automated cardiac flow measurement method for quantifying pulmonary regurgitation (PR) in an in vitro and a chronic animal model of the right ventricular outflow tract of postoperative tetralogy of Fallot (TOF).

BACKGROUND

There has been no reliable ultrasound method that can accurately quantitate PR.

METHODS

We developed an in vitro model of mild pulmonary stenosis and wide-open PR that mimics the patterns of flow seen in patients with postoperative TOF. Thirteen different forward and regurgitant stroke volumes (RSVs) across the noncircular shaped cross-sectional outflow tract flow area were estimated using the DCD method in two orthogonal planes. In six sheep with surgically created PR, 24 different hemodynamic states with PR strictly quantified by electromagnetic probes were also studied.

RESULTS

The RSVs and regurgitant fractions (RFs) obtained by the DCD method using average values from two orthogonal planes correlated well with reference values (RSV: r = 0.99, mean difference = 0.02 +/- 0.39 ml/beat for in vitro model; r = 0.97, mean differences = 1.79 +/- 1.84 ml/beat for animal model, RF: r = 0.98, mean difference = -1.10 +/- 4.34% for in vitro model; r = 0.94, mean difference = 2.73 +/- 6.75% for animal model). However, the DCD method using a single plane had limited accuracy for estimating pulmonary RFs and RSVs.

CONCLUSIONS

The DCD method using average values from two orthogonal planes provides accurate estimation of RSVs and RFs and should have clinical importance for serially quantifying PR in patients with postoperative TOF.

Identification of a high-affinity anti-phosphoserine antibody for the development of a homogeneous fluorescence polarization assay of protein kinase C

In the last few years, fluorescence polarization (FP) has been applied to the development of robust, homogeneous, high throughput assays in molecular recognition research, such as ligand-protein interactions. Recently, this technology has been applied to the development of homogeneous tyrosine kinase assays, since there are high-affinity anti-phosphotyrosine antibodies available. Unlike tyrosine kinases, application of FP to assay development for serine/threonine kinases has been impeded because of lack of high-affinity anti-phosphoserine/threonine antibodies. In the present study, we report the discovery of a high-affinity, monoclonal anti-phosphoserine antibody, 2B9, with a Kd of 250 +/- 34 pM for a phosphoserine-containing peptide tracer, fluorescein-RFARKGS(PO(4))LRQKNV. Our data suggest that 2B9 is selective for fluorescein-RFARKGS(PO(4))LRQKNV. The antibody and tracer have been used for the development of a competitive FP assay for protein kinase C (PKC) in 384-well plates. Phosphatidylserine, which enhances the kinase activity of PKC in a Ca(2+)-dependent manner and has a structure similar to that of phosphoserine, did not interfere with binding of the peptide tracer to the antibody in the FP assay. The data indicate that the FP assay is more sensitive and robust than the scintillation proximity assay for PKC. The FP assay developed here can be used for rapid screening of hundreds of thousands of compounds for discovery of therapeutic leads for PKC-related diseases.

The role of lipoproteins in the transport and uptake of cyclosporine and dihydro-tacrolimus into HepG2 and JURKAT cell lines

OBJECTIVES

We wish to examine the role of lipoproteins in the transport and cellular uptake of cyclosporine (CsA) and tacrolimus.

DESIGN AND METHODS

The distribution of tritiated CsA and tacrolimus among lipoproteins was determined in normo- and hypertriglyceridemic sera. The uptake of these two drugs into HepG2 and JURKAT cell lines was assessed in the presence of various concentrations of low density lipoproteins. (LDL).

RESULTS

Our data showed that about 60% of these drugs were transported by high density lipoprotein in normolipidemic sera, while about 50-60% were carried by very low density lipoprotein in hypertriglyceridemic sera. Almost 80% of CsA and 70% of tacrolimus entered HepG2 and JURKAT cells within the first hour of incubation in lipoprotein free media. However, the uptake was decreased (CsA by 60% and tacrolimus by 40%) in the presence of LDL.

CONCLUSIONS

Lipoproteins play a major role in the transport of CsA and tacrolimus, but not in their cellular uptake.

Regulation of pituitary vasopressin receptors during chronic stress: relationship to corticotroph responsiveness

The relationship between vasopressin (VP) receptor levels in the anterior pituitary and VP-stimulated ACTH release in vitro was studied in rats subjected to various chronic stress paradigms. The stress models used were water deprivation for 60 h and administration of 2% NaCl in the drinking water (both of which are associated with decreased pituitary ACTH responsiveness), and repeated i.p. hypertonic saline injections or repeated daily immobilization for 14 days (associated with increased ACTH responsiveness to novel stimuli). VP receptors were measured by binding of [3H]arginine-VP to anterior pituitary membrane-rich fractions, and ACTH responses to VP in collagenase dispersed anterior pituitary cells. In control rats, binding of [3H]AVP was saturable and high affinity, with a Kd of 0.45 +/- 0.05 nM and a Bmax of 138.8 +/- 8.1 fmol/mg. In pituitary membranes from stressed rats, binding affinity was unchanged, but Bmax changed according to the type of stress. While VP binding was markedly reduced after water deprivation and 2% saline (25% and 49%, respectively), it was significantly increased after repeated i.p. hypertonic saline injections and repeated immobilization (126% and 154% of controls, respectively). The changes in VP binding were associated to parallel changes in maximum VP-stimulated ACTH production in vitro, with a 34% decrease in water deprived rats and a 25% increase in hypertonic saline injected rats. The potentiating effect of VP on corticotropin releasing hormone-stimulated ACTH was also reduced in cells from water-restricted rats, and increased in cells from rats given repeated injections of hypertonic saline. The data show a direct relationship between changes in corticotroph responsiveness and changes in pituitary VP receptors during chronic stress, suggesting that pituitary VP receptor regulation is involved in the adaptation of the HPA axis during chronic stress.

Peptide mapping of neutralizing and nonneutralizing epitopes of duck hepatitis B virus pre-S polypeptide

Antibodies to the envelope proteins of duck hepatitis B virus neutralize viral infection in vitro. Using a library of murine monoclonal antibodies (Mabs) against the envelope proteins, we previously identified four neutralizing and two non-neutralizing epitopes on the pre-S region of the large envelope proteins. In this study we report the localization of all but one of these epitopes at the amino acid level. All but 28 nucleotides of the pre-S and S genes were cloned in pUC vectors and expressed in Escherichia coli. All Mabs in this study reacted with the expressed gene products in Western blots. Deletion mutants of the pre-S region were generated and their expressed products tested on Western blots for reactivity with the Mabs. Of the three epitopes involved in neutralization, the epitope found to be immunodominant in convalescent ducks was localized to nine amino acids of the middle portion of the pre-S gene product, while a second epitope was mapped to nine amino acids upstream of the immunodominant epitope and the third epitope to seven amino acids adjacent to the S gene. One of the two non-neutralizing epitopes was located between the two groups of neutralizing epitopes while the other mapped to the same region as one of the neutralizing epitopes. Our data indicate that several regions of the pre-S polypeptide may play a role in neutralization of hepadnaviruses.

T-cell involvement in benign phase chronic myelogenous leukemia

T cells from the peripheral blood of patients with chronic myeloid leukemia (CML) were cultured with phytohemagglutinin and T-cell growth factor (TCGF) in agar culture. These T-cell colonies were pooled and expanded further in liquid culture with TCGF and then simultaneously analysed for the E-rosette receptor with the monoclonal antibody OKT11 and for the presence of the Philadelphia (Ph1) chromosome. OKT11 analysis showed these populations to be composed 99.5% or more of T cells. In four of the seven patients the T-cell suspension showed 7/50 (14%), 3/36 (8%), 2/34 (6%), and 4/44 (9%) Ph1 metaphases. Furthermore, Ph1 metaphases were demonstrated in T-cell cultures in two patients when bone marrow metaphases simultaneously showed 90 and 100% Ph1 negative metaphases secondary to human leukocyte interferon therapy or combination chemotherapy. A minority of T cells in benign phase CML have the Ph1 abnormality despite reduced number of Ph1 metaphases in bone marrow from therapy.