Mosquito transgenesis: what is the fitness cost?

The generation of transgenic mosquitoes with a minimal fitness load is a prerequisite for the success of strategies for controlling mosquito-borne diseases using transgenic insects. It is important to assemble as much information as possible on this subject because realistic estimates of transgene fitness costs are essential for modeling and planning release strategies. Transgenic mosquitoes must have minimal fitness costs, because such costs would reduce the effectiveness of the genetic drive mechanisms that are used to introduce the transgenes into field mosquito populations. Several factors affect fitness of transgenic mosquitoes, including the potential negative effect of transgene products and insertional mutagenesis. Studies to assess fitness of transgenic mosquitoes in the field (as opposed to the laboratory) are still needed.     

A billion-fold range in acidity for the solvent-exposed amides of Pyrococcus furiosus rubredoxin

The exchange rates of the static solvent-accessible amide hydrogens of Pyrococcus furiosus rubredoxin range from near the diffusion-limited rate to a billion-fold slower for the non-hydrogen-bonded Val 38 (eubacterial numbering). Hydrogen exchange directly monitors the kinetic acidity of the peptide nitrogen. Electrostatic solvation free energies were calculated by Poisson-Boltzmann methods for the individual peptide anions that form during the hydroxide-catalyzed exchange reaction to examine how well the predicted thermodynamic acidities match the experimentally determined kinetic acidities. With the exception of the Ile 12 amide, the differential exchange rate constant for each solvent-exposed amide proton that is not hydrogen bonded to a backbone carbonyl can be predicted within a factor of 6 (10 (0.78)) root-mean-square deviation (rmsd) using the CHARMM22 electrostatic parameter set and an internal dielectric value of 3. Under equivalent conditions, the PARSE parameter set yields a larger rmsd value of 1.28 pH units, while the AMBER parm99 parameter set resulted in a considerably poorer correlation. Either increasing the internal dielectric value to 4 or reducing it to a value of 2 significantly degrades the quality of the prediction. Assigning the excess charge of the peptide anion equally between the peptide nitrogen and the carbonyl oxygen also reduces the correlation to the experimental data. These continuum electrostatic calculations were further analyzed to characterize the specific structural elements that appear to be responsible for the wide range of peptide acidities observed for these solvent-exposed amides. The striking heterogeneity in the potential at sites along the protein-solvent interface should prove germane to the ongoing challenge of quantifying the contribution that electrostatic interactions make to the catalytic acceleration achieved by enzymes.     

Comprehensive proteome analysis of ovarian cancers using liquid phase separation, mass mapping and tandem mass spectrometry: a strategy for identification of candidate cancer biomarkers

A two-dimensional (2-D) liquid phase separation method, liquid isoelectric focusing followed by nonporous reversed-phase high performance liquid chromatography (HPLC), was used to separate proteins from human ovarian epithelial whole cell lysates. HPLC eluent was interfaced on-line to an electrospray ionization (ESI) time of flight (TOF) mass spectrometer to obtain accurate intact protein molecular weights (Mr). 2-D protein expression maps were generated displaying protein isoelectric point (pI) versus intact protein Mr. Resulting 2-D images effectively displayed quantitative differential protein expression in ovarian cancer cells versus non-neoplastic ovarian epithelial cells. Protein peak fractions were collected from the HPLC eluent, enzymatically digested, and analyzed by matrix-assisted laser desorption/ionization (MALDI) TOF-mass spectrometry (MS) peptide mass fingerprinting and by MALDI-quadrupole TOF tandem mass spectrometry peptide sequencing. Interlysate comparisons of differential protein expression between two ovarian adenocarcinoma cell lines, ES2 and MDAH-2774, and ovarian surface epithelial cells was performed. Five pI fractions from each sample were selected for comparative study and over 300 unique proteins were positively identified from the 2-D liquid expression maps using MS, which covered around 60% of proteins detected by on-line ESI-TOF-MS. This represents one of the most comprehensive proteomic analyses of ovarian cancer samples to date. Protein bands with significant up- or down-regulation in one cell line versus another as viewed in the 2-D expression maps were identified. This strategy may prove useful in identifying novel ovarian cancer marker proteins.     

Identification of a novel coronavirus from a beluga whale by using a panviral microarray

The emergence of viruses such as severe acute respiratory syndrome coronavirus and Nipah virus has underscored the role of animal reservoirs in human disease and the need for reservoir surveillance. Here, we used a panviral DNA microarray to investigate the death of a captive beluga whale in an aquatic park. A highly divergent coronavirus, tentatively named coronavirus SW1, was identified in liver tissue from the deceased whale. Subsequently, the entire genome of SW1 was sequenced, yielding a genome of 31,686 nucleotides. Phylogenetic analysis revealed SW1 to be a novel virus distantly related to but most similar to group III coronaviruses.     

Chemo-adoptive immunotherapy of nude mice implanted with human colorectal carcinoma and melanoma cell lines

Summary The antitumor effects of chemotherapy, recombinant human interleukin-2 (IL-2), recombinant human interferon A/D (IFN), allogeneic human lymphokine-activated killer (LAK) cells, and antitumor monoclonal antibody (mAb), administered alone and in various combinations, were tested in athymic nude mice carrying human tumor xenografts. Treatment began 6–18 days after i.v. or i.p. inoculation of colorectal carcinoma or melanoma cell lines, when macroscopic growths were evident. Chemotherapy consisted of two or three courses of 5-fluorouracil (5-FU) or dacarbazine. IL-2 and/or IFN were administered three to five times weekly for 1–3 weeks, usually starting 2–5 days after chemotherapy. Human LAK cells were infused once or twice weekly for 2 or 3 weeks concurrently with IL-2. In some experiments, murine anticolorectal carcinoma mAb (SF25) was administered. In both tumor systems, chemotherapy alone or immunotherapy alone (IL-2, IL-2 + LAK cells, IFN, IL-2 + IFN ± LAK cells) had little or no therapeutic effects. Additive effects were obtained by combining chemotherapy with IL-2 and LAK cells or with IL-2 and IFN. In the majority of the experiments, the most effective combination was chemotherapy + IL-2 + IFN + LAK cells. Treatment with mAb was beneficial in the colorectal carcinoma system when combined with 5-FU + IL-2 or 5-FU + IL-2 + IFN. Homing experiments with radiolabeled human and mouse LAK cells injected i.v. showed increased early accumulation in the liver and lungs, whereas freshly explanted mouse splenocytes localized mostly in the spleen and liver. The tissue distribution pattern of human LAK cells was similar in normal and tumor-bearing mice (with lung metastases). These findings suggest that combination of chemotherapy with cytokines and LAK cells can be partially effective for advanced solid human tumors even in the absence of the host's T-cell immune response. Preliminary experiments showed that tumor-specific, anti-melanoma T-cell clones were effective in local (s.c.) tumor growth inhibition (Winn assay) following coinjection with the autologous tumor cells.     

Graduate education and the role of the physical anthropologist in biomedical teaching and research

There is a place for the physical anthropologist in biomedical teaching and research because of the special and unique skills possessed by this individual. However, eventual success in the health sciences environment requires the student to obtain the knowledge and background for functionally oriented teaching and research. Students interested in a biomedical teaching and research career must prepare themselves methodologically and theoretically. This requires: (1) teaching qualifications, (2) an increased emphasis on methodology and technology, (3) an increased emphasis on research and experimental design, (4) appropriate interdisciplinary courses which provide the background for both teaching and research, (5) increased interaction with graduate faculty active in research, and (6) the latitude to adapt the graduate program to meet these specific needs. Students who finish their graduate training with a marketable skill, and who can apply their unique talents to a specialized area, will have broad appeal in the job market and will considerably strengthen their career opportunities.