Comparison of Flow Dynamics of Peripherally and Centrally Inserted Intravenous Catheters Using a Rapid Infusion System (ThermaCor 1200).

The inability to rapidly administer warm intravenous fluids and blood products can potentially threaten a patient's safety and well-being in many clinical settings. Large-bore intravenous catheters and rapid infusion systems are often used in situations where rapid blood loss and massive blood transfusion may be expected. This study examined the maximum flow rate and infusion pressure of various peripherally and centrally inserted intravenous catheters using a rapid infusion system (ThermaCor 1200 Rapid Infusion System, Smisson-Cartledge Biomedical).

Nuclear Magnetic Resonance Structure of the Human Polyoma JC Virus Agnoprotein.

Agnoprotein is an important regulatory protein of the human polyoma JC virus (JCV) and plays critical roles during the viral replication cycle. It forms highly stable dimers and oligomers through its Leu/Ile/Phe-rich domain, which is important for the stability and function of the protein. We recently resolved the partial 3D structure of this protein by NMR using a synthetic peptide encompassing amino acids Thr17 to Gln52, where the Leu/Ile/Phe- rich region was found to adopt a major alpha-helix conformation spanning amino acids 23-39.

Emerging From the Unknown: Structural and Functional Features of Agnoprotein of Polyomaviruses.

Agnoprotein is an important regulatory protein of polyomaviruses, including JCV, BKV, and SV40. In the absence of its expression, these viruses are unable to sustain their productive life cycle. It is a highly basic phosphoprotein that localizes mostly to the perinuclear area of infected cells, although a small amount of the protein is also found in nucleus.

An anti-PCSK9 antibody reduces LDL-cholesterol on top of a statin and suppresses hepatocyte SREBP-regulated genes.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a promising therapeutic target for treating coronary heart disease. We report a novel antibody 1B20 that binds to PCSK9 with sub-nanomolar affinity and antagonizes PCSK9 function in-vitro. In CETP/LDLR-hemi mice two successive doses of 1B20, administered 14 days apart at 3 or 10 mpk, induced dose dependent reductions in LDL-cholesterol (≥ 25% for 7-14 days) that correlated well with the extent of PCSK9 occupancy by the antibody.

A PCSK9-binding antibody that structurally mimics the EGF(A) domain of LDL-receptor reduces LDL cholesterol in vivo.

Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) regulates LDL cholesterol levels by inhibiting LDL receptor (LDLr)-mediated cellular LDL uptake. We have identified a fragment antigen-binding (Fab) 1D05 which binds PCSK9 with nanomolar affinity. The fully human antibody 1D05-IgG2 completely blocks the inhibitory effects of wild-type PCSK9 and two gain-of-function human PCSK9 mutants, S127R and D374Y.

A proprotein convertase subtilisin-like/kexin type 9 (PCSK9) C-terminal domain antibody antigen-binding fragment inhibits PCSK9 internalization and restores low density lipoprotein uptake.

PCSK9 binds to the low density lipoprotein receptor (LDLR) and leads to LDLR degradation and inhibition of plasma LDL cholesterol clearance. Consequently, the role of PCSK9 in modulating circulating LDL makes it a promising therapeutic target for treating hypercholesterolemia and coronary heart disease. Although the C-terminal domain of PCSK9 is not involved in LDLR binding, the location of several naturally occurring mutations within this region suggests that it has an important role for PCSK9 function.

Affinity maturation and characterization of a human monoclonal antibody against HIV-1 gp41.

The human D5 monoclonal antibody binds to the highly conserved hydrophobic pocket on the N-terminal heptad repeat (NHR) trimer of HIV-1 gp41 and exhibits modest yet relatively broad neutralization activity. Both binding and neutralization depend on residues in the complementarity determining regions (CDRs) of the D5 IgG variable domains on heavy chain (VH) and light chain (VL). In an effort to increase neutralization activity to a wider range of HIV-1 strains, we have affinity matured the parental D5 scFv by randomizing selected residues in 5 of its 6 CDRs.

Short communication: In vitro synergy between peptides or neutralizing antibodies targeting the N- and C-terminal heptad repeats of HIV Type 1 gp41.

Class 1 and class 2 fusion peptides bind to the trimeric N-terminal heptad repeat (NHR) and C-terminal heptad repeat (CHR) regions of HIV-1 envelope glycoprotein gp41, respectively, and block its intramolecular folding required for Env-mediated viral and host cell membrane fusion and subsequent viral entry. Using a combination of T-20 (class 1) and (CCIZN17)(3) (class 2), we provide evidence that these classes of fusion peptides work synergistically in an in vitro infectivity assay in inhibiting the entry of primary HIV-1 isolate 89.6 with combination indexes reaching 0.

HIV type 1 vaccines for worldwide use: predicting in-clade and cross-clade breadth of immune responses.

One of the greatest challenges in HIV vaccine development is accommodating the worldwide sequence diversity of the HIV-1 virus. To understand how viral sequence diversity may affect the potential breadth of HIV-1 vaccines designed to elicit antiviral T cell immunity, we have developed novel approaches to assess sequence conservation at the amino acid level, where vaccine effects are exerted. Taking each sequence from the LANL 2004 amino acid alignments as a potential vaccine or as a challenge virus, all pairwise combinations of sequences were evaluated by two methods: first, a traditional comparison of aligned sequences, and second, by a new walking 9-mer algorithm chosen to emphasize the typical length of an MHC-I epitope.

Evidence for two schizophrenia susceptibility genes on chromosome 22q13.

Objective: Previous linkage scans and meta-analyses for schizophrenia susceptibility loci failed to include the most distal portion of chromosome 22q. Accordingly, 27 families having individuals affected with schizophrenia and schizophrenia-spectrum disorders were analyzed using a set of highly informative markers covering all of chromosome 22q.

Methods: Microsatellite and single nucleotide polymorphism markers were evaluated by nonparametric linkage, parametric linkage, and transmission disequilibrium testing of 22q.

Virological and clinical implications of resistance to HIV-1 protease inhibitors.

Resistance to HIV-1 protease inhibitors is associated with 25 or more amino acid substitutions in the protease and its cleavage sites. These appear in variable combinations and in different orders, and their effects depend on the combinations in which they occur. Substitutions within and away from the enzyme active site may engender resistance by drug-specific or drug-independent mechanisms.

Cross-clade reactivity of HIV-1-specific T-cell responses in HIV-1-infected individuals from Botswana and Cameroon.

An effective HIV type 1 (HIV-1) vaccine will likely require elicitation of broadly reactive cell-mediated immune (CMI) responses against divergent HIV-1 clades. We compared anti-HIV-1 T-cell immune responses among 363 unvaccinated adults infected with diverse HIV-1 clades. Response rates to clade B Gag and/or clade B Nef in Botswana (95%) and Cameroon (98%) were similar when compared with those in countries previously studied, including Brazil (92%), Thailand (96%), South Africa (96%), Malawi (100%), and the United States (100%).

Transmission disequilibrium suggests a role for the sulfotransferase-4A1 gene in schizophrenia.

Previous studies suggest a role for chromosome 22q13 in schizophrenia. This segment of chromosome 22 contains the sulfotransferase-4A1 (Sult4A1) gene, which encodes an enzyme thought to be involved in neurotransmitter metabolism in the central nervous system. To evaluate this candidate, we developed a microsatellite marker targeting a polymorphism in its 5' nontranslated region (D22s1749E).

Cross-reactivity of anti-HIV-1 T cell immune responses among the major HIV-1 clades in HIV-1-positive individuals from 4 continents.

Background: The genetic diversity of human immunodeficiency virus type 1 (HIV-1) raises the question of whether vaccines that include a component to elicit antiviral T cell immunity based on a single viral genetic clade could provide cellular immune protection against divergent HIV-1 clades. Therefore, we quantified the cross-clade reactivity, among unvaccinated individuals, of anti-HIV-1 T cell responses to the infecting HIV-1 clade relative to other major circulating clades.

Methods: Cellular immune responses to HIV-1 clades A, B, and C were compared by standardized interferon- gamma enzyme-linked immunospot assays among 250 unvaccinated individuals, infected with diverse HIV-1 clades, from Brazil, Malawi, South Africa, Thailand, and the United States.

Preclinical study of influenza virus A M2 peptide conjugate vaccines in mice, ferrets, and rhesus monkeys.

A universal influenza virus vaccine that does not require frequent updates and/or annual immunizations will offer significant advantages over current seasonal flu vaccines. The highly conserved influenza virus A M2 membrane protein has been previously suggested as a potential antigen target for such a vaccine. Here, we report systematic evaluation of M2 peptide conjugate vaccines (synthetic peptides of M2 extracellular domain conjugated to keyhole limpet hemocyanin (KLH) or Neisseria meningitidis outer membrane protein complex (OMPC)) in mice, ferrets, and rhesus monkeys.

Efficacy of indinavir-ritonavir-based regimens in HIV-1-infected patients with prior protease inhibitor failures.

Objective: To assess responses to indinavir (IDV)-ritonavir (RTV)-based regimens among HIV-1 infected patients with prior failure of protease inhibitors, and to assess the effects of adherence to therapy and pre-existing genotypic and phenotypic resistance on this response.

Methods: Twenty-eight patients initiating salvage regimens with IDV-RTV (800 mg and 200 mg twice daily, respectively) plus one or more reverse transcriptase inhibitor (RTI) were identified retrospectively. Genotypic and phenotypic susceptibilities to multiple antiretroviral agents were determined on viral samples collected at initiation of the salvage regimens, and adherence to therapy was determined through patient self-reporting.

Genotypic analysis methods for detection of drug resistance mutations in the HIV-1 proteinase and reverse transcriptase genes.

Understanding the basis of human immunodeficiency virus (HIV) drug resistance represents a key requirement for individualized HIV patient care. The genotypic data generated to date have already provided significant insight. However, it is clear that the relationship between genotype, phenotype and clinical outcome is complex and still poorly defined.

Treatment with indinavir, efavirenz, and adefovir after failure of nelfinavir therapy.

A prospective, open-label study was conducted to assess the response to indinavir, efavirenz, and adefovir in human immunodeficiency virus (HIV)-infected patients experiencing viral rebound while receiving therapy with nelfinavir-containing regimens, to determine whether the protease genotype influenced the outcome of the salvage regimen. Genotyping from 29 nelfinavir failures revealed D30N in 17 (59%) and L90M in 11 (38%) cases. Suppression to <400 viral RNA copies/mL was achieved at week 48 in 56% of patients with the D30N virus versus 18% of patients with the L90M virus.

Potential new therapies for the treatment of HIV-1 infection.

The development and clinical use of chemotherapeutic agents for the treatment of persistent HIV-1 infection over the past decade has profoundly and favorably affected the course of HIV-1 disease for many infected individuals. Unfortunately, the long-term use of these therapies is complicated by unwanted metabolic side effects, by issues of adherence, and by the selection of viral variants with reduced susceptibility. These complications have spurred the search for new anti-HIV-1 agents having improved pharmacological properties and expressing activity against viral variants resistant to the currently available agents.

Prevalence and predictive value of intermittent viremia with combination hiv therapy.

Context: In HIV-infected patients having virologic suppression (plasma HIV RNA <50 copies/mL) with antiretroviral therapy, intermittent episodes of low-level viremia have been correlated with slower decay rates of latently infected cells and increased levels of viral evolution, but the clinical significance of these episodes is unknown.

Objective: To determine if HIV-infected patients with intermittent viremia have a higher risk of virologic failure (confirmed HIV RNA >200 copies/mL).

Design And Setting: Retrospective analysis of subjects in well-characterized cohorts, the AIDS Clinical Trials Group (ACTG) 343 trial of induction-maintenance therapy (August 1997 to November 1998) and the Merck 035 trial (ongoing since March 1995).

Drug resistance and predicted virologic responses to human immunodeficiency virus type 1 protease inhibitor therapy.

The extent to which human immunodeficiency virus (HIV) type 1 drug resistance compromises therapeutic efficacy is intimately tied to drug potency and exposure. Most HIV-1 protease inhibitors maintain in vivo trough levels above their human serum protein binding-corrected IC(95) values for wild-type HIV-1. However, these troughs are well below corrected IC(95) values for protease inhibitor-resistant viruses from patients experiencing virologic failure of indinavir and/or nelfinavir.

Baseline human immunodeficiency virus type 1 phenotype, genotype, and RNA response after switching from long-term hard-capsule saquinavir to indinavir or soft-gel-capsule saquinavir in AIDS clinical trials group protocol 333.

AIDS Clinical Trials Group protocol 333 was an open-label trial of a switch from saquinavir (SQV) hard capsules (SQVhc) to indinavir (IDV) or saquinavir soft-gel capsules (SQVsgc) after >48 weeks of prior treatment with SQVhc. Eighty-nine subjects received IDV or SQVsgc or continued to receive SQVhc and continued unchanged treatment with non-protease-inhibitor antivirals for 8 weeks. Subjects receiving SQVhc then switched treatment to IDV.

3-year suppression of HIV viremia with indinavir, zidovudine, and lamivudine.

Background: Antiretroviral regimens containing HIV protease inhibitors suppress viremia in HIV-infected patients, but the durability of this effect is not known.

Objective: To describe the 3-year follow-up of patients randomly assigned to receive indinavir, zidovudine, and lamivudine in an ongoing clinical trial.

Design: Open-label extension of a randomized, double-blind study.

Associations between amino acids in the evolution of HIV type 1 protease sequences under indinavir therapy.

Significant diversity exists in amino acid sequences encoding HIV-1 protease in individuals naive for protease inhibitors, which could influence the rate of evolution of resistance. High-level resistance to indinavir requires multiple substitutions among at least 11 amino acid sites, and no single substitution was observed in all of 29 resistant isolates obtained from patients on long-term indinavir monotherapy. We have analyzed the evolution of PR in these sequences.

Resistance to HIV protease inhibitors.

Resistance to the HIV-1 protease inhibitor indinavir involves the accumulation of multiple amino acid substitutions in the viral protease. A minimum of 11 amino acid positions have been identified as potential contributors to phenotypic resistance. Three or more amino acid substitutions in the protease are required before resistance becomes measurable (> or = four-fold).