DermaPort: A Novel Ported Vascular Access System for Hemodialysis.

Safe, ported access to the body for hemodialysis and other medical uses is increasingly necessary for modern medical therapy. Long-term hemodialysis offers unique challenges with its requirements for high blood flow, chronic implantation, and risks of infection. Although widely used, the polyester, cuffed, delete word and space hemodialysis catheter is far from ideal, and there is a need for an improved vascular access system to allow catheter adjustment and replacement, to reduce infections and to reduce medical costs.

A Prospective Clinical Study of a Percutaneous Vascular Access System for Hemodialysis Catheters.

Introduction: Dysfunctional or infected hemodialysis polyester-cuffed catheters often require removal and are dissected out. The DermaPort™, percutaneous vascular access system (PVAS) permanently integrates a titanium mesh with the skin forming a stable, sterile barrier that allows for catheter placement, adjustment, or catheter exchange. This study aimed to describe the use and clinical outcomes of the DermaPort PVAS.

Adjunctive homeopathic treatment in patients with severe sepsis: a randomized, double-blind, placebo-controlled trial in an intensive care unit.

Background: Mortality in patients with severe sepsis remains high despite the development of several therapeutic strategies. The aim of this randomized, double-blind, placebo-controlled trial was to evaluate whether homeopathy is able to influence long-term outcome in critically ill patients suffering from severe sepsis.

Methods: Seventy patients with severe sepsis received homeopathic treatment (n = 35) or placebo (n = 35).

NB2001, a novel antibacterial agent with broad-spectrum activity and enhanced potency against beta-lactamase-producing strains.

Enzyme-catalyzed therapeutic activation (ECTA) is a novel prodrug strategy to overcome drug resistance resulting from enzyme overexpression. beta-Lactamase overexpression is a common mechanism of bacterial resistance to beta-lactam antibiotics. We present here the results for one of the beta-lactamase ECTA compounds, NB2001, which consists of the antibacterial agent triclosan in a prodrug form with a cephalosporin scaffold.

CPI-0004Na, a new extracellularly tumor-activated prodrug of doxorubicin: in vivo toxicity, activity, and tissue distribution confirm tumor cell selectivity.

The search for cancer therapies that are more selective for tumor cells and spare normal sensitive cells has been very active for at least 20 years. The extracellularly tumor-activated peptidic prodrug of doxorubicin (Dox) CPI-0004Na (N-succinyl-beta-alanyl-L-leucyl-L-alanyl-L-leucyl-Dox) is potentially such a treatment. Here, we report the results of lethality studies performed with this compound in the mouse, showing that it is up to 4.

N-Succinyl-(beta-alanyl-L-leucyl-L-alanyl-L-leucyl)doxorubicin: an extracellularly tumor-activated prodrug devoid of intravenous acute toxicity.

Intravenous administration of N-(beta-alanyl-L-leucyl-L-alanyl-L-leucyl)doxorubicin (4) induces an acute toxic reaction, killing animals in a few minutes. This results from its positive charge at physiological pH combined with its propensity to form large aggregates in aqueous solutions. Negatively charged N-capped versions of 4 such as the succinyl derivative 5 can be administered by the iv route at more than 10 times the LD(50) of doxorubicin without inducing the acute toxic reaction, and they are active in vivo.

Extracellularly tumor-activated prodrugs for the selective chemotherapy of cancer: application to doxorubicin and preliminary in vitro and in vivo studies.

Oligopeptidic derivatives of anthracyclines unable to penetrate cells were prepared and screened for their stability in human blood and their reactivation by peptidases secreted by cancer cells. N-beta-alanyl-L-leucyl-L-alanyl-L-leucyl-doxorubicin was selected as a new candidate prodrug. The NH2-terminal beta-alanine allows a very good blood stability.

Mapping of MCP-1 functional domains by peptide analysis and site-directed mutagenesis.

Monocyte chemoattractant protein-1 (MCP-1) is a member of the beta chemokine family which acts through specific seven transmembrane receptors to recruit monocytes, basophils, and T lymphocytes to sites of inflammation. To identify regions of the human MCP-1 protein which are important for its biological activity, we have synthesized domain-specific peptides and tested their ability to antagonize MCP-1 binding and chemotaxis in THP-1 cells. We have found that an intercysteine first loop peptide encompassing amino acids 13-35 inhibits MCP-1 binding and chemotactic activity, while peptides representing the amino-terminus (amino acids 1-10), second loop (amino acids 37-51), and carboxy-terminus (amino acids 56-71) of MCP-1 have no effect.

Cyclic RGD peptide inhibits alpha 4 beta 1 interaction with connecting segment 1 and vascular cell adhesion molecule.

The integrin supergene family includes receptors for a variety of extracellular matrix as well as cell surface proteins. Integrin alpha 4 has been shown to play an important role in leukocyte adhesion and extravasation during immune and inflammatory reactions. One recognition sequence known to interact with alpha 4 is the Leu-Asp-Val (LDV) site contained in the connecting segment 1 region of fibronectin.

Emergency intubation with the Combitube: comparison with the endotracheal airway.

Study Objective: To evaluate the safety and effectiveness of the Combitude as used by ICU nurses under medical supervision compared with endotracheal airway established by ICU physicians during CPR.

Design: Prospective study of ICU patients over a seven-month period.

Setting: Medical ICU.

A novel cyclic pentapeptide inhibits alpha 4 beta 1 and alpha 5 beta 1 integrin-mediated cell adhesion.

Lymphocytes and monocytes initiate and modulate inflammatory and immune responses for host defense. This process is dependent upon extravasation of leukocytes from the circulation to sites of antigenic challenge and is controlled, in part, by various integrins, including alpha 4 beta 1 and alpha 5 beta 1. A small cyclic pentapeptide that inhibits, in vitro, both alpha 4 beta 1 and alpha 5 beta 1 activity is described.

The collagen receptor alpha 2 beta 1, from MG-63 and HT1080 cells, interacts with a cyclic RGD peptide.

Several receptors for the extracellular matrix protein collagen have been described which belong to the superfamily of receptors collectively known as integrins. Although several integrins have been shown to interact with extracellular matrix molecules via a common recognition site, arginine-glycine-aspartic Acid (RGD), within the beta 1 integrin subfamily, only the fibronectin receptor (alpha 5 beta 1) has been convincingly shown to interact with RGD. In the present study, we tested whether a collagen receptor could interact with RGD.

SV40 large T-antigen nuclear signal analogues: successful nuclear targeting with bovine serum albumin but not low molecular weight fluorescent conjugates.

The signal sequence of a nuclear-directed protein encodes the necessary information for targeting the attached proteins to the cell nucleus. The sequence/structural requirements for a functional transport signal were explored with a series of peptides derived from the simian virus 40 large T-antigen nuclear signal 126-134 (CPKKKRKVED-NH2, wild type) conjugated to bovine serum albumin (BSA) through an N-terminal Cys (1) with m-maleimidobenzoyl-N-hydroxysuccinimide ester. Nuclear accumulation was virtually complete 15 min after microinjection into green monkey kidney cells (TC-7).

Characterization of monoclonal antibodies against human prorenin profragment and identification of active prorenins in plasma.

Monoclonal antibodies were raised against a synthetic peptide (43 amino acid residues) that corresponds to the complete profragment of human prorenin. Seven monoclonal antibodies were chosen for further characterization. Two antibodies, 2-X-C1 and 4-X-E1, reacted with the middle region and C-terminus of the profragment and were isotyped IgG1.

Use of the Membrane Invasion Culture System (MICS) as a screen for anti-invasive agents.

The Membrane Invasion Culture System (MICS) assay was adapted for relatively rapid screening of compounds and used to identify anti-invasive drugs that inhibit human and murine tumor cell migration through a reconstituted basement membrane in vitro. Cell lines demonstrating low and high invasive and metastatic potentials were tested with all compounds for tumoricidal effects prior to evaluation in MICS at non-cytotoxic doses. The effect on invasive potential in the MICS assay was determined in 3 categories: (1) 48 hr drug pre-treatment prior to seeding in the MICS (exceptions: 90 min pre-treatment with pertussis toxin and, for some studies, continuous exposure for 2-7 days); (2) peptide or prostaglandins 2 hr after seeding and attachment to the membranes in MICS followed by continuous exposure; and (3) cells receiving neither drug nor peptide treatment and serving as controls in each MICS chamber.

A technique for rapid purification of low yield products: biotinylation of chemically synthesized proteins on-resin.

We report here straightforward methodology for the purification of chemically synthesized proteins which are produced in low yield. The methodology is generally applicable to all proteins still on-resin and fully protected except for the terminal amino group. The protein is treated in order with the following steps: Biotinylation with NHS-biotin, HF cleavage, and avidin-agarose affinity chromatography.

Identification of specific binding proteins for a nuclear location sequence.

The nuclear envelope is a selective barrier against the movement of macromolecules between the nucleus and cytoplasm. Nuclear proteins larger than relative molecular mass 20,000-40,000 are probably actively transported across the envelope through the nuclear pore complex and are directed by specific nuclear location sequences (NLS) in the proteins. NLS mediate the nuclear import of isolated nuclear proteins after microinjection into whole cells and the nuclear accumulation of chimaeric proteins or of non-nuclear proteins conjugated to synthetic peptides.

Peptides as potential virus inhibitors. Synthesis and bioassay of five respiratory syncytial virus peptide analogs with antimeasles activity.

Five carbobenzoxylated and D-amino acid containing-peptide analogs of the respiratory syncytial virus (RSV) F1 glycoprotein amino terminus were chemically synthesized by solution and FMOC-solid phase peptide synthesis methods. Several of these peptides, ranging from 3 to 6 residues in length, raised the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine. None of these peptides were specific inhibitors of RSV or herpes simplex virus infection.

On-resin biotinylation of chemically synthesized proteins for one-step purification.

A general, convenient, one-step purification procedure for chemically synthesized proteins present in low yields using on-resin biotinylation is reported. The protein, terminally deprotected and neutralized on-resin, is stirred in dimethylformamide and then biotinylated with N-hydroxysuccinimidobiotin (2 mg/mg protein on-resin) for 24 h at 45 degrees C. Following low/high hydrogen fluoride cleavage (J.

Bilayer stabilizing peptides and the inhibition of viral infection: antimeasles activity of carbobenzoxy-Ser-Leu-amide.

A number of carbobenzoxy-dipeptide-amides raise the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine (stabilizes the bilayer). The potency of the peptides in stabilizing the bilayer phase is Z-Tyr-Leu-NH2 = Z-Gly-Phe-NH2 greater than Z-Ser-Leu-NH2 greater than Z-Gly-Leu-NH2 greater than Z-Gly-Gly-NH2. A linear correlation was found between the respective HPLC retention time parameter k' for the peptide and the slope of the bilayer stabilization curve determined with model membranes by differential scanning calorimetry.

Affinity labeling of the androgen receptor in rat prostate cytosol with 17 beta-[(bromoacetyl)oxy]-5 alpha-androstan-3-one.

An androgen affinity label, 17 beta-[(bromoacetyl)-oxy]-5 alpha-androstan-3-one, has been synthesized in both radioactive and nonradioactive forms. The affinity label (170 Ci/mmol) was characterized and found to have a high degree of purity. Affinity labeling of the androgen receptor from rat ventral prostate was androgen specific and appeared to be directed at the steroid binding site of the protein.

Molecular properties of the androgen receptor in rat ventral prostate.

Results from these studies demonstrate that we have purified a protein from rat prostate cytosol that is similar to the beta-protein (complex II) but different from the alpha-protein (complex I) reported by Liao et al. The purified receptor was different from androgen binding protein (ABP) in that ABP has a faster dissociation rate (6 min), a lower pI value (4.6), and requires higher concentrations of ammonium sulfate for precipitation (40-50%) than the prostatic androgen receptor.