RESUMEN

An indoor air quality survey was conducted in Southern Louisiana to determine levels of airborne formaldehyde. Gas chromatography analyses of 419 air samples collected from 53 houses revealed levels of formaldehyde ranging from non-detectable to 6.60 mg/m3. Seventy four percent (312/419) of the samples had detectable amounts of airborne formaldehyde. Of the 312 positive samples, approximately 60% exceeded the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) guideline of 0.123 mg/m3. The highest number of samples exceeding the formaldehyde benchmark were collected in winter. It would appear that in some Southern Louisiana houses, a high level of formaldehyde could serve as a potential upper respiratory irritant.

Asunto(s)

RESUMEN

A four-season, indoor air quality survey was conducted in Southern Louisiana to determine the indoor air levels of the pesticide chlorpyrifos. Gas chromatographic analysis of 213 air samples collected from 53 houses revealed levels of chlorpyrifos ranging from non-detected to 2.13 micrograms/m3. Using the Florida-Pinella exposure guideline (24-hr exposure to chlorpyrifos at 0.48 microgram/m3), it was noted that 14% of the samples exceeded this guideline. The exposure of occupants to the indoor air concentrations of the pesticide, however, were below either the irritation or the odor thresholds, and effects on acute and chronic health responses remains uncertain.

Asunto(s)

RESUMEN

The levels of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), mercury (Hg), and nickel (Ni) were determined in a total of 315 indoor and outdoor dust samples collected from 53 households in Louisiana. Inductively coupled plasma analysis revealed that in many samples, the metal content exceeded the United States Environmental Protection Agency (EPA) Risk-Based Concentration (RBC) guidelines. For example, the number of dust samples above the EPA-RBC included 64 for Cd, 52 for Hg, 43 for As, 4 for Fe, 4 for Cu, 3 for Cr, and 2 for Ni. One-hundred fifty-two samples exceeded the street-dust level for Pb published by the U.S. Agency for Toxic Substances and Disease Registry. The results of this study indicate that exposure to indoor and/or outdoor dust presents a potential health risk for Louisiana residents.

Asunto(s)

Asunto(s)

RESUMEN

The integration of software into special-purpose systems (e.g. for gene sequence analysis) can be a difficult task. We describe a general-purpose software integration tool, the BCE program, that facilitates assembly of VAX-based software into application systems and provides an easy-to-use, intuitive user interface. We describe the use of BCE to integrate a heterogeneous collection of sequence analysis tools. Many BCE design features are generally applicable and can be implemented in other language or hardware environments.

Asunto(s)

Asunto(s)

RESUMEN

We describe computer programs that predict the most energetically favorable secondary structures in growing RNA sequences, generate a sequential display of the growing structures, and monitor the predicted participation of intramolecular sites in secondary structure. These programs may provide insight into the relationships between messenger RNA secondary structure and expressibility.

Asunto(s)

RESUMEN

Secalonic acid D (SAD), a hepatotoxic, teratogenic, and slightly mutagenic metabolite of Penicillium oxalicum has been identified as a natural contaminant of grain dust. Secalonic acid D was administered intraperitoneally to male ICR mice that were exposed to influenza virus aerosols 5 days earlier. The mortality rate was significantly higher (p less than 0.001) in mice subjected to both influenza and SAD than those subjected to influenza alone. Virus titers in lung tissue samples at selected time intervals appeared similar for both influenza and influenza-SAD treated groups of mice for 9 days after exposure to the virus. After 9 days, influenza-SAD treated mice appeared to have higher virus titers. No difference in the pathological progression of pneumonia was discernible between these two groups of mice. The influenza-SAD group, in addition to pneumonia, exhibited severe hepatic necrosis characteristic of SAD administration. Mice infected with influenza virus followed by administration of SAD responded with significantly lower (p less than 0.05) antibody titers to influenza virus than mice exposed to influenza virus alone.

Asunto(s)

RESUMEN

A new serotype of calicivirus, designated as San Miguel sea lion virus type 6 (SMSV-6), was isolated from vesicular lesions on the flipper of a California sea lion pup. Serologic studies show that SMSV-6 neutralizing antibodies (SN) occur frequently among California sea lions and occasionally among northern fur seals. Feral swine, 1- to 6-week elephant seal pups and grey whales tested negative for SMSV-6 antibody.

Asunto(s)

RESUMEN

In a 5-year study (1972-1977) of microbial agents isolated from both clinically normal and diseased marine mammals, it was shown that certain disease agents are widespread in a diversity of ocean populations and that some are also transmissible to a number of terrestrial mammal species. Leptospira interrogans serovar pomona has been isolated repeatedly from 2 species of pinnipeds (Zalophus californianus califonianus and Callorhinus ursinus). Some of the more important bacterial pathogens for land mammals that were isolated from wild marine mammals are Pseudomonas mallei, Clostridium chauvoei, C novyi, Neisseria mucosa var heidelbergensis, Klebsiella pneumoniae, Salmonella spp, and Pasteurella multocida. Numerous serotypes of viruses classified as caliciviruses were isolated from a variety of marine mammals. Some of these are known to infect several land mammal species including swine horses, and primates. For this reason., precautions should be taken to ensure that disease agents shed by captive marine mammals are not transmitted to susceptible terrestrial mammals, including animal handlers and other human beings.

Asunto(s)

RESUMEN

Three populations of wild foxes were sampled for serum neutralizing antibody to calicivirus (San Miguel sea lion virus) types 1-5. Neutralizing activity was detected in serum from gray foxes resident on Santa Cruz Island, California, but not in Arctic foxes from Alaska. The results indicate that foxes may be naturally infected with caliciviruses, but their role in the transmission cycle is unknown.

RESUMEN

Vesicular exanthema of swine (VES) was first recognized in 1932. At the time, eradication measures and, later, quarantine procedures were instituted and extension of the disease to surrounding farms appeared to have been prevented. Between 1932 and 1936, however, seemingly unrelated epizootics continued among swine herds being fed raw garbage. In 1936, VES disappeared only to reappear in 1939. The disease was contained within California until 1952, at which time it spread to all the major swine producing areas of the United States. The disease was eradicated in 1959, through the enforcement of laws prohibiting the feeding of raw garbage to swine. Other than the association with raw garbage, a reservoir for VES virus (VESV) was never found. In 1972, a virus isolated from California sea lions--and thus named the San Miguel sea lion virus (SMSV)--proved to be distinguishable from VESV. When SMSV was injected into swine, clinical signs of vesicular exanthema developed, leading to the conclusion that, for all practical purposes, SMSV and VESV were the same. To date, 5 species of marine mammals and 2 species of terrestrial mammals, including feral swine, have been shown to possess antibodies to 1 or more of the 4 distinct SMSV serotypes. Current evidence suggests that SMSV infections occur among both terrestrial and marine mammals inhabiting the California coastal zones. This and the practice of shipping frozen meats known to contain SMSV to mink ranches in Utah point to the possibility that domestic swine in the United States are occasionally being exposed to SMSV. Although marine mammals are a source of SMSV, the primary virus reservoir is thought to be 1 or more submammalian marine species common to the southern California coastline. Such a primary reservoir presumably is the source of a new SMSV serotypes infecting marine mammals and may have been the original source of the VESV serotypes that infected swine through the intermediary of raw garbage.

Asunto(s)

RESUMEN

Serum neutralizing antibodies to four serotypes of San Miguel Sea Lion Virus (SMSV) were demonstrated in a variety of marine and terrestrial species. These results show a wide geographic distribution of SMS viruses in the marine environment and indicate that certain terrestrial mammals have been infected with these so-called marine viruses. Evidence is presented supporting the theory that unidentified submammalian marine species are a reservoir for SMSV.

Asunto(s)

Asunto(s)

RESUMEN

An interaction between sarcoma-180/TG cells and vesicular stomatitis virus in adult mice resulted in the rapid onset of extensive mortality. This interaction, termed lethal synergy, occurred only at early stages of ascites induction in animals with no prior virus contact. A significant sparing effect conferred by the serotonin antagonist dibenamine was reversed by the administration of serotonin. The cause of death was not determined, but a mechanism involving hypersensitivity is indicated.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

The influence of relative humidity on the airborne survival of simian virus 40 (SV40) was studied by allowing virus aerosols to age in rotating drums at 21 or 32 C and at a relative humidity (RH) value ranging from 22 to 88%. Airborne SV40 virus was stable at every RH tested at 21 C, but aerosols maintained at 32 C were inactivated within 60 min at mid-range RH values. The unusual stability at 21 C over a broad RH range indicates that potentially biohazardous situations may occur under laboratory conditions if this virus becomes accidentally airborne.

Asunto(s)

Asunto(s)