The goal of this study was to exploit molecular recognition of cell surface receptors by viral surface glycoproteins as a means for the selective intracellular delivery of macromolecules. To accomplish this, artificial viral envelopes (AVE) resembling the human immunodeficiency virus-1 (HIV-1) were designed as a model system. Recombinant HIV-1 surface glycoprotein gp160 (HIV-1 rgp160) was inserted in the artificial envelope by a two-step detergent dialysis process. The artificial HIV-1 envelope recognized the CD4 cell surface receptor. FITC-dextran and ricin A were employed as model macromolecules as they cannot passively diffuse across cell membranes. Selective transfer of FITC-dextran encapsulated in HIV-1 rgp160 AVE into a CD4-positive cell line (REX-1B) versus a CD4-negative cell line (KG-1) was demonstrated. Ricin A at concentrations as low as 2 ng/ml arrested cell growth of CD4-positive MOLT-4 cells, whereas 8 ng/ml ricin A in solution had no effect on cell growth. The arrest of cell growth was reverted in the presence of excess anti-gp120 monoclonal antibody. Naked envelopes (without HIV-1 rgp160 inserted) were also found to interact with cells and transfer material, although less efficiently and in a non-specific manner. Viral mimicry using AVE may be a means for targeted intracellular delivery of peptides, proteins, enzymes, toxins, oligodeoxynucleotides, gene constructs, and other non-diffusive, labile or toxic macromolecules.

CD4 Antigens↗

PubMedDate not supplied

Association between the accumulation of hepatitis B virus core gene deletion mutants and progression of liver disease in long-term renal transplant patients.

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Alanine Transaminase↗

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[Percentage of tumor in prostatic biopsy cylinders as prognosis factor of organ-limited disease in candidates for radical prostatectomy].

UNLABELLED: The present study analyzes the prognostic influence of tumor percentage in cylinders of prostatic biopsy in this patient group. MATERIAL AND METHODS: Retrospective study of 68 patients with a diagnosis of adenocarcinoma, clinical stage T1-T2 who had undergone a radical prostatectomy from May 1997 to october 2000. Following preoperative parameters were analyzed: age, PSA, clinical staging, Gleason and six cylinders of ultrasonography-leaded transrectal prostatic biopsy, studying the amount of positive biopsies, the tumor percentage of the total amount of biopsies and the maximum percentage of tumor in one cylinder. Univariate (square-Chi, Student t) and multivariate (multiple logistic regression) analysis are performed in order to study the relationship of these parameters with the presence or not of an organ-located disease. RESULTS: An organ-located disease was shown at 44 patients through the piece of radical prostatectomy. The univariate analysis gave all studied parameters, except age, a prognostic value of the existence or not of an organ-located disease. In the multivariate analysis only the total percentage of biopsy tumors (p = 0.0002) and PSA (p = 0.005) behaved as independent prognostic factors. CONCLUSION: Tumor percentage in prostatic biopsy seems to be a factor with a high predictive value of an organ-located disease, possibly because it is an index of tumoral volume.

Aged↗