Factors associated with Pseudomonas pickettii intrinsic contamination of commercial respiratory therapy solutions marketed as sterile.

Laboratory investigations were conducted to study the growth dynamics of Pseudomonas pickettii in commercial 0.9% sodium chloride solution under various environmental conditions and to determine the retention of these organisms after challenge through a 0.2-micron cartridge filter system.

Temporal patterns of ultrastructural alterations in hepatocytes of chimpanzees with experimental non-A, non-B hepatitis.

Non-A, non-B hepatitis was transmitted to eight chimpanzees by intravenous inoculation with antihemophilic materials (factor VIII) that had been implicated in transmission of the disease, with acute-phase liver homogenate from an infected chimpanzee, with acute-phase from an infected chimpanzee, or with chronic-phase plasma from infected chimpanzees. All eight animals developed elevated alanine aminotransferase activity, and all demonstrated unique hepatocyte cytoplasmic tubules at some time during the acute phase of disease. The temporal patterns for tubule appearance in hepatocyte cytoplasm, however, were highly variable, even between chimpanzees given similar inocula.

Non-A/non-B hepatitis in experimentally infected chimpanzees: cross-challenge and electron microscopic studies.

Inoculation of eight chimpanzees with factor VIII, factor IX, or "H" strain plasma resulted in enzymatic and histopathologic evidence of non-A/non-B hepatitis in all eight animals. Challenge of two chimpanzees convalescent from factor VIII-induced disease with either factor IX or "H" strain plasma resulted in non-A/non-B hepatitis only in the animal inoculated with factor IX materials. Reciprocal cross-challenge of a chimpanzee convalescent from factor IX-induced disease with factor VIII also produced unequivocal enzymatic and histopathologic evidence of non-A/non-B hepatitis.

Biochemical and biophysical characterization of light and heavy density hepatitis A virus particles: evidence HAV is an RNA virus.

Heavy density HAV was also shown to be sensitive to low concentrations of RNase. The results of these biophysical and biochemical studies strongly support the notion HAV is an enterovirus.

Cyclic excretion of hepatitis A virus in experimentally infected chimpanzees: biophysical characterization of the associated HAV particles.

Experimental infection of two chimpanzees with the Phoenix Antigen strain of HAV resulted in the cyclic excretion of virus particles on days 9-11, 14-15, and 20-21 postinoculation. Isopycnic banding in CsCl of stool suspensions prepared from 9-11; 14-15; and 17, 19, 21 dav stool pools revealed multiple buoyant densities for the associated HAV particles. Hollow HAV particles found in the 9-11 day pool banded primarily at a buoyant density of 1.

Multiple buoyant densities of hepatitis A virus in cesium chloride gradients.

Hepatitis A virus (HAV) recovered from stools of human cases of hepatitis A and from stools of chimpanzees experimentally infected with HAV was shown to possess multiple buoyant densities in CsCl gradients. The greatest proportion of HAV was most frequently found at a buoyant density of 1.32-1.

Ultrastructural studies of hepatitis A virus by electron microscopy.

Well-defined, core-like structures were visualized in hepatitis A virus particles by a modified microelectron microscopy technique.

"e" Antigen, Dane particles, and serum DNA polymerase activity in HBsAg carriers.

Sera of 103 carriers of hepatitis B surface antigen were assayed for e-antigen and anti-e. Twenty-four were e-antigen-positive, 31 anti-e-positive, and 48 had neither detectable (e-negative). Aminotransferases were elevated in 75% of the e-antigen-positive carriers compared with 25% of e-negative carriers (P less than 0.

Hepatitis A: report of a common-source outbreak with recovery of a possible etiologic agent. II. Laboratory studies.

During investigation of a food-borne outbreak of hepatitis A among university students in a southwestern metropolitan community, immune electron microscopic examination of a concentrated stool suspension pooled from seven acutely ill individuals revealed viruslike particles 17-nm in diameter. These particles were initially coated by antibody contained in the convalescent-phase serum of one of the ill students as well ad by antibody in convalescent plasma of a prison volunteer originally infected with the MS-1 strain of hepatitis A virus. Rises in titer of antibody to this particle were demonstrated by immune electron microscopy in acute and convalescent sera from student patients as well as in pre-inoculation and convalescent sera from the prison volunteer.

Agarose gel filtration of concentrated fecal extracts containing virus-like particles associated with hepatitis A.

Virus-like particles shown to be associated with hepatitis A infection were recently visualized by immune electron microscopy in human and chimpanzee acute-phase fecal extracts. Agarose gel filtration of concentrated chimpanzee fecal extracts containing those 27-nm diameter particles separated more than 99% of the high molecular weight fecal impurities into two major peaks as determined by absorbance at 280 and 260 nm. The hepatitis A-associated particles were found between these two peaks by both immune electron microscopy and a new immunoradiometric assay.

Inability to detect hepatitis B virus or specific antigens in transformed chimpanzee lymphocytes.

Transformed chimpanzee lymphocytes were examined to determine whether they would support the replication of hepatitis B virus. After 5 months, no hepatitis B virus, hepatitis B surface antigen, or antibody to hepatitis B surface antigen was detected.

Cellular transmission of canine lymphoma and leukemia in beagles.

Thirty-four neonatal beagles were inoculated with cells obtained originally from 2 adult beagles, 1 with lymphocytic leukemia, the other with generalized malignant lymphoma. Most of the puppies were irradiated before inoculation; a few were inoculated in utero and were not irradiated. Of the 11 puppies inoculated with buffy coat cells of the blood from the leukemic donor, 2 developed leukemia.