A replication defective recombinant Ad5 vaccine expressing Ebola virus GP is safe and immunogenic in healthy adults.

Ebola virus causes irregular outbreaks of severe hemorrhagic fever in equatorial Africa. Case mortality remains high; there is no effective treatment and outbreaks are sporadic and unpredictable. Studies of Ebola virus vaccine platforms in non-human primates have established that the induction of protective immunity is possible and safety and human immunogenicity has been demonstrated in a previous Phase I clinical trial of a 1st generation Ebola DNA vaccine. We now report the safety and immunogenicity of a recombinant adenovirus serotype 5 (rAd5) vaccine encoding the envelope glycoprotein (GP) from the Zaire and Sudan Ebola virus species, in a randomized, placebo-controlled, double-blinded, dose escalation, Phase I human study. Thirty-one healthy adults received vaccine at 2×10(9) (n=12), or 2×10(10) (n=11) viral particles or placebo (n=8) as an intramuscular injection. Antibody responses were assessed by ELISA and neutralizing assays; and T cell responses were assessed by ELISpot and intracellular cytokine staining assays. This recombinant Ebola virus vaccine was safe and subjects developed antigen specific humoral and cellular immune responses.

Evaluation of cell substrates for the production of biologicals: Revision of WHO recommendations. Report of the WHO Study Group on Cell Substrates for the Production of Biologicals, 22-23 April 2009, Bethesda, USA.

Evaluating cell substrates for producing vaccines and other biologicals is one of the critical aspects in assuring quality and safety of these products. As part of its mission in setting standards for biological products, WHO provides recommendations for manufacturing and evaluating biologicals. Regular updates of the guidance documents are important to manufacturers and regulators worldwide. WHO Expert Committee on Biological Standardization (ECBS) identified a need for revising the requirements for cell substrates (WHO TRS 878, annex 1). In response, WHO established a Study Group (SG) in 2006 that prepared an updated set of recommendations for using cell substrates for the production of biologicals. A summary of the proposed changes that the SG made in 2007 is available at WHO web site (http://www.who.int/biologicals/publications/meetings/areas/vaccines/cells/en/index.html). Draft revised recommendations were circulated to regulators, manufacturers and other experts for comments in April 2009. The SG held its third meeting on 22-23 April 2009 to review progress in the revision and to propose further improvements. In addition, the experts discussed the need for reference preparations, reference cell banks, and standardization of testing methodologies. The SG proposed clarifications of the rationale for in vivo testing as well as the potential for applying new methods for in vitro testing for detecting microbial agents. In line with this, WHO should conduct review of the current manufacturers' practice in using tests for microbial agents and interpreting these results. Additionally, WHO should take a lead in developing an International Standard for nucleic acid amplification test (NAT) for detecting mycoplasma contamination in cell substrates. WHO Collaborating Centers will lead this initiative, involving other relevant institutions in this area. Finally, advice on the replacement of the WHO Vero reference cell bank 10-87 with respect to the source of cells and re-characterization of the bank was provided. The intended use of the replacement cell bank would be the same as for the current cell bank, which is to serve as a source of well-characterized cells for establishing master cell banks for the production of biologicals. The SG will report outcomes of its discussion to the ECBS at its next meeting in October 2009 for further considerations and advice regarding the proposed course of action.

Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA.

This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150,000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r = 0.91, P < 0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

222Rn emanation from uranium-glazed ceramics.

Orange-red uranium-glazed dinnerware was found to emanate 222Rn to produce an average of less than 0.1 Bq 222Rn decay per piece, which should have no associated health risks. Comparison of 222Rn emanation to 226Ra in glazes (measured by alpha spectrometry) indicated inefficient emanation (<5%) of 222Rn, consistent with the low radon levels observed and with the presence of 222Rn progeny in glazes. These studies also showed that reagent grade uranium compounds may emanate measurable 222Rn.

Environmental impacts of PAH and oil release as a NAPL or as contaminated pore water from the construction of a 90-cm in situ isolation cap.

The placement of a sediment cap was the remedial alternative selected in the Record of Decision for the containment of PAH-contaminated sediments near the Wyckoff/Eagle Harbor Superfund site shoreline, a former log rafting area at this closed wood treatment site. Soft sediments with substantial quantities of nonaqueous phase liquid (NAPL) occurred in this area, which raised a concern that there would be environmental releases or potential cap failure in this area of the site. As part of the investigations to guide cap design, a laboratory bench study was devised to evaluate consolidation-driven NAPL and dissolved phase PAH permeation of the cap. Sediment cores collected from the site were extruded side-by-side into 20 cm diameter, 120 cm high acrylic columns to maintain sediment stratification. Synthetic seawater was added until approximately 60 cm of water covered the site sediment. The simulated cap material was added to each column in such a manner as to fall through the overlying water at a uniform rate to simulate settling velocities expected during a barge wash-off placement event. Vertical loads were applied incrementally to the cap/sediment columns until the total consolidation stress was equivalent to a 90-cm cap. Each column was extruded, inspected visually for the migration of NAPL, and sectioned into three layers with each analyzed for total petroleum hydrocarbons and PAHs. In all three test cylinders, there was no indication of impact to the top 10 cm of the cap (the biologically active zone). The results suggest that the chemicals detected at high concentrations in the native sediments would stay in place and not migrate through a overlying cap via consolidation-induced advection.

Acid extraction of lead and cadmium from newly-purchased ceramic and melamine dinnerware.

Imported dishes can present human health hazards in two ways: (1) dinnerware that contains toxic metals in excessive amounts may gain entry to the US; and (2) imported decorative ceramic plates may be improperly labeled regarding permissible use with food. In the present study, non-random samples of dishes were purchased in new condition in US retail outlets and subjected to 24-h acid leaching tests. Two of 28 patterns of imported ceramic dinnerware were found to release lead in levels that exceed US Food and Drug Administration (FDA) limits, and 10 other patterns released lead in concentrations exceeding California Proposition 65 (CA 65) limits. One imported ceramic dish released cadmium in excess of FDA limits. Samples of new foreign-made melamine (plastic) dinnerware in four patterns released neither lead nor cadmium in detectable concentrations. One of three patterns of imported decorative ceramic plates released lead in concentrations exceeding 2000 micrograms/ml. These plates are not permanently labeled as hazardous and are in noncompliance with FDA regulations.

Laboratory treatability testing of soils contaminated with lead and PCBs using particle-size separation and soil washing.

A soil treatability study was conducted using particle-size separation and soil washing to reduce the volume of material contaminated with polychlorinated biphenyls (PCBs) and lead at a Superfund site. Soil washing using surfactant was effective at removing 95% of PCBs into fine material and residual wash water. Results indicate that almost 80% of the material contaminated with up to 140 mg/kg PCBs could be treated to concentrations below 10 mg/kg using soil washing with surfactant. There did not appear to be a difference in lead removal using either particle size separation or soil washing, although the lead data have high uncertainty because of soil heterogeneity. Lead concentrations in soil were reduced from as high as 1700 to < or =150 mg/kg and from 560 to < or =220 mg/kg in about half of the material using particle size separation.

Use of home test kits for detection of lead and cadmium in ceramic dinnerware.

Commercial home test kits are advertised as a convenient means for assessing heavy metal hazards in old ceramic dinnerware. This paper reports investigations carried out with four commercial kits for detection of lead (Pb) and one for detection of cadmium (Cd) on pre-1970s ceramic dishes subsequently subjected to 24-h leaching tests with 4% acetic acid to determine heavy metal release. With the lead kits, fewer than 10% of dishes leaching greater than 3.0 micrograms Pb/ml yielded negative results (i.e. false negatives). When the cadmium kit was used according to manufacturer's instructions, 29% of dishes leaching greater than 0.5 microgram Cd/ml yielded false negatives. Home lead test kits appear to be useful for screening of old dinnerware, but the cadmium kit may not be suitable for this purpose.

Release of heavy metals from European and Asian porcelain dinnerware.

Samples of porcelain dinnerware manufactured in five European and three Asian countries before the mid-1970s and subsequently brought into the US were subjected to acid leaching tests to investigate the release of heavy metals. Forty-six dishes decorated with decals or hand painted designs applied over the glaze were examined. Included in the selection were dishes from major manufacturers of fine dinnerware (Haviland Limoges, Rosenthal, Noritake) as well as samples from lesser-known or unidentified factories. During 24-h tests with 4% acetic acid, half of the samples (23 dishes) released lead in concentrations exceeding the US Food and Drug Administration (FDA) allowable maximum of 3.0 micrograms/ml and another 17 dishes released lead in concentrations ranging from 0.1 to 2.9 micrograms/ml. Five dishes released cadmium, but only one value exceeded the FDA limit of 0.5 microgram/ml. Zinc, cobalt, copper and chromium were also released by some of the dishes. None of the acetic acid solutions contained measurable concentrations of nickel although this metal, as well as those named above, could be extracted from some samples with 6 M nitric acid. The FDA has not established dinnerware extraction limits for any metals except lead and cadmium. All overglaze-decorated dishes imported into the US before the mid-1970s should be tested for lead release before they are used in the preparation, serving, or storage of food.

Traditional approach preventive HIV vaccines: What are the cell substrate and inactivation issues?

A workshop was convened to discuss safety issues for traditional-approach HIV vaccines, especially inactivated vaccines. The topics included issues pertaining to (1) cell substrates used for production and (2) vaccine virus inactivation. The use of cell substrates such as tumor-derived continuous cell lines (TCLs) or virus-transformed. CLs may be the most feasible approach to provide commercial-scale virus yields. However, especially because of concerns about tumorigenicity, TCLs have not been used to produce preventive vaccines for human trials with healthy subjects in the United States. Residual TCL material (e.g., DNA, cellular proteins, viruses) may not be removed during purification of intact HIV virions to the same extent achievable for a recombinant protein. Manufacturing processes, e.g., physicochemical methods of destroying DNA, could decrease tumorigenicity risk. Methods to assess potential for tumorigenicity may need further development. Another potential substrate for viral production that merits further study is human peripheral blood mononuclear cells (PBMCs). Regardless of the cell substrate used, extensive testing for adventitious agents (including non-HIV retroviruses) is needed. Vaccine virus inactivation can be considered in statistical terms, i.e., the probability of a surviving infectious particle. One formula to determine a "safety margin" (SM) is reduction of titer in log10 for all inactivation steps minus initial viral infectivity in log10. Calculations for appropriate SMs should include all sources of variability (e.g., lot-to-lot differences). Ensuring a specified SM, as the lower bound of the 95% confidence interval, for production lots was discussed. Sensitivity and specificity of infectivity assays may present limitations.

Spinal extramedullary hematopoiesis secondary to hepatocellular carcinoma. Case report and literature review.

A 38-year-old man, with hepatitis C and a history of intravenous drug use had hepatocellular carcinoma. Severe low back pain was the result not of metastases but of extramedullary hematopoiesis. This was not confirmed by biopsy but seemed unequivocal on magnetic resonance imaging.

Extraction of lead, cadmium and zinc from overglaze decorations on ceramic dinnerware by acidic and basic food substances.

Dinnerware decorated with overglaze designs can release toxic metals into food substances in amounts high enough to constitute health hazards. When dishes made in the US before 1970 were filled with 4% acetic acid for 24 h, lead concentrations of up to 610 micrograms/ml and cadmium concentrations of up to 15 micrograms/ml were measured. Acetic acid leachates from more than half the dishes tested for lead (78 of 149) contained levels exceeding the US Food and Drug Administration (FDA) allowable concentration of 3.0 micrograms/ml. One-fourth of dishes tested for cadmium (26 of 98) exceeded the FDA limit of 0.5 microgram/ml. High concentrations of lead, cadmium and zinc were also released into 1% solutions of citric and lactic acids. Significant amounts of these metals were extracted by basic solutions of sodium citrate and sodium tripolyphosphate, as well as by commercial food substances including sauerkraut juice, pickle juice, orange juice, and low-lactose milk. Relative concentrations of lead, zinc and cadmium released depend on the leaching agent used. Citric acid leachates contain higher lead:cadmium and zinc:cadmium (but lower lead:zinc) ratios than do acetic acid leachates from nominally identical dishes. Repeated extractions with acetic acid show that even after 20 consecutive 24-h leachings many dishes still release lead in concentrations exceeding FDA limits.

Airborne lead in the Springfield, Missouri, area during a 19-year period (1975-1993).

Concentrations of airborne lead at Springfield, Missouri, in 1975-1993 have been determined by analysis of particulate material collected on glass-fiber filters during the 19-year period. Nitric acid-soluble lead in 1100 samples collected at a total of 19 monitoring stations was determined by atomic absorption spectroscopy and by differential pulse polarography. Ambient concentrations of airborne lead were found to decrease steadily (by more than 90%) during this period in spite of increases in area population and in automobile traffic. The decrease is significantly correlated with national trends in total emissions of lead to the atmosphere and with US ambient lead levels. Airborne lead from a coal-fired power plant was small compared with that from gasoline burning.

Effect of microwave heating on leaching of lead from old ceramic dinnerware.

When samples of pre-1950s U.S.-made ceramic dinnerware, purchased in antique shops and flea markets, were filled with 4% acetic acid or 0.5% citric acid and heated in a microwave oven for 2-5 min, lead was leached in amounts of up to 5 mg per dish. Concentrations of lead in the leachates were not significantly correlated with, and could not be predicted from, concentrations in leachates measured during 24-h room temperature acid leaching tests. Unsafe lead concentrations (>3 microg/ ml) were found in microwave leachates of dishes with uranium-containing glazes, with copper-containing glazes, and with floral over-the-glaze decals. This evidence suggests that use of such dishes to microwave common foods could result in the ingestion of dangerously large amounts of lead.

Accidental contamination from uranium compounds through contact with ceramic dinnerware.

Examination of orange-colored dinnerware samples purchased in antique stores and flea markets has revealed the occasional presence of surface uranium compounds that are readily transferred to the hands and clothing. We have further been able to produce soluble uranium compounds on the surfaces of clean dishes by exposing them to household vinegar or bleach. We estimate that handling of a contaminated dish can transfer up to 1-2 becquerels or more of uranium compounds to the hands. Uranium contamination is of concern because the element is not only an alpha emitter but also a chemical nephrotoxin. Although the amount of uranium likely to be ingested as a result of casual handling may be small, it could still exceed by several times the amount occurring in the average diet (about 40 mBq/day). Furthermore, since fresh surface compounds are readily formed, it is possible that a person who regularly handles or eats from uranium-glazed dinnerware can accidentally ingest significant amounts of uranium.

Recombinant feline leukemia virus genes detected in naturally occurring feline lymphosarcomas.

Using a polymerase chain reaction strategy aimed at detecting recombinant feline leukemia virus (FeLV) genomes with 5' env sequences originating from an endogenous source and 3' env sequences resulting from FeLV subgroup A (FeLV-A), we detected recombinant proviruses in approximately three-fourths of naturally occurring thymic and alimentary feline lymphosarcomas (LSAs) and one-third of the multicentric LSAs from cats determined to be FeLV capsid antigen positive by immunofluorescence assay. In contrast, only 1 of 22 naturally arising FeLV-negative feline LSAs contained recombinant proviruses, and no recombinant env gene was detected in seven samples from normal tissues or tissues from FeLV-positive animals that died from other diseases. Four preferred structural motifs were identified in the recombinants; one is FeLV-B like (recognizing that FeLV-B itself is a product of recombination between FeLV-A and endogenous env genes), and three contain variable amounts of endogenous-like env gene before crossing over to FeLV-A-related sequences: (i) a combination of full-length and deleted env genes with recombination at sites in the middle of the surface glycoprotein (SU), (ii) the entire SU encoded by endogenous-like sequences, and (iii) the entire SU and approximately half of the transmembrane protein encoded by endogenous-like sequences. Additionally, three of the thymic tumors contained recombinant proviruses with mutations in the vicinity of the major neutralizing determinant for the SU protein. These molecular genetic analyses of the LSA DNAs correspond to our previous results in vitro and support the occurrence and association of viral recombinants and mutants in vivo in FeLV-induced leukemogenesis.