Biomedical subjects

Arpad A Vass

Publications and source records attributed to Arpad A Vass.

5 recordsLinked to original sources

PubMed2005

Antitumor effect of valorphin in vitro and in vivo: combined action with cytostatic drugs.

The action of the cytostatic drugs (epirubicin and vincristine) in combination with the endogenous antiproliferative beta-hemoglobin fragment (33-39), valorphin, was studied in tumor (L929 and A549) cell cultures, primary culture of murine bone marrow cells and in murine model of breast carcinoma in vivo. Simultaneous application of 1 microM valorphin and 1 microM epirubicin, in vitro, did not result in an additive suppressive effect on cell culture growth. Additive effects were achieved with alternating applications of the peptide and the drugs, namely, 0.5 microM (but not 1 microM) epirubicin added 24 h prior to 1 microM valorphin; 1 microM valorphin added 48 h prior to 0.1 microM epirubicin, or 0.1 microM vincristine, or 0.05 microM vincristine, which resulted in 100% cell death in the both series with vincristine and up to 78% cell biomass reduction in the experiments with epirubicin. In the in vivo model (female BLRB mice with subcutaneously inoculated syngeneic mammary carcinoma), simultaneous treatment with 25 mg/m(2) epirubicin and 1 mg/kg valorphin resulted in 42% of tumor growth inhibition, as compared with the negative control group and 22% inhibition as compared with the epirubcin-treated group (at 20th day of treatment). Survival was significantly improved (69% compared to 39% in the group treated with epirubicin only) at day 26 after the treatment beginning.

Adamantane↗

PubMed2004

Decompositional odor analysis database.

This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), describes the establishment of the Decompositional Odor Analysis (DOA) Database for the purpose of developing a man-portable, chemical sensor capable of detecting clandestine burial sites of human remains, thereby mimicking canine olfaction. This "living" database currently spans the first year and a half of burial, providing identification, chemical trends and semi-quantitation of chemicals liberated below, above and at the surface of graves 1.5 to 3.5 ft deep (0.45 to 1.0 m) for four individuals. Triple sorbent traps (TSTs) were used to collect air samples in the field and revealed eight major classes of chemicals containing 424 specific volatile compounds associated with burial decomposition. This research is the first step toward identification of an "odor signature" unique to human decomposition with projected ramifications on cadaver dog training procedures and in the development of field portable analytical instruments which can be used to locate human remains buried in shallow graves.

Adult↗

PubMed2003

A miniature biochip system for detection of aerosolized Bacillus globigii spores.

The feasibility of using a novel detection scheme for the analysis of biological warfare agents is demonstrated using Bacillus globigii spores, a surrogate species for Bacillus anthracis. In this paper, a sensitive and selective enzyme-linked immunosorbent assay using a novel fluorogenic alkaline phosphatase substrate (dimethylacridinone phosphate) is combined with a compact biochip detection system, which includes a miniature diode laser for excitation. Detection of aerosolized spores was achieved by coupling the miniature system to a portable bioaerosol sampler, and the performance of the antibody-based recognition and enzyme amplification method was evaluated. The bioassay performance was found to be compatible with the air sampling device, and the enzymatic amplification was found to be an attractive amplification method for detection of low spore concentrations. The combined portable bioaerosol sampler and miniature biochip system detected 100 B. globigii spores, corresponding to 17 aerosolized spores/L of air. Moreover, the incorporation of the miniature diode laser with the self-contained biochip design allows for a compact system that is readily adaptable to field use. In addition, these studies have included investigations into the tradeoff between assay time and sensitivity.

Aerosols↗

PubMed2003

Stable-isotope fingerprints of biological agents as forensic tools.

Naturally occurring stable isotopes of light elements in chemical and biological agents may possess unique "stable-isotope fingerprints" depending on their sources and manufacturing processes. To test this hypothesis, two strains of bacteria (Bacillus globigii and Erwinia agglomerans) were grown under controlled laboratory conditions. We observed that cultured bacteria cells faithfully inherited the isotopic composition (hydrogen, carbon, and nitrogen) of media waters and substrates in predictable manners in terms of bacterial metabolism and that even bacterial cells of the same strain, which grew in media water and substrates of different isotopic compositions, have readily distinguishable isotopic signatures. These "stable-isotopic fingerprints" of chemical and biological agents can be used as forensic tools in the event of biochemical terrorist attacks.

Bacillus↗

PubMed2002

Decomposition chemistry of human remains: a new methodology for determining the postmortem interval.

This study was conducted to characterize the chemistry associated with the decomposition of human remains with the objective of identifying time-dependent biomarkers of decomposition. The purpose of this work was to develop an accurate and precise method for measuring the postmortem interval (PMI) of human remains. Eighteen subjects were placed within a decay research facility throughout a four-year time period and allowed to decompose naturally. Field autopsies were performed and tissue samples were regularly collected until the tissues decomposed to the point where they were no longer recognizable (encompassing a cumulative degree hour (CDH) range of approximately 1000 (approximately 3 weeks)). Analysis of the biomarkers (amino acids, neurotransmitters, and decompositional by-products) in various organs (liver, kidney, heart, brain, muscle) revealed distinct patterns useful for determining the PMI when based on CDHs. Proper use of the methods described herein allow for PMIs so accurate that the estimate is limited by the ability to obtain correct temperature data at a crime scene rather than sample variability.

Adult↗