Amantadine prophylaxis during an institutional outbreak of type A (H1N1) influenza.

In January 1984, an outbreak of influenza caused by A/Victoria/7/83-like virus, a new H1N1 variant, occurred in an institution for mentally handicapped children and adults. During the first 18 days of the outbreak, 35 (81%) of 43 residents in two housing modules became ill, nearly all of whom had received influenza vaccine the previous autumn. Amantadine hydrochloride prophylaxis was initiated in two other housing modules and was continued for 28 days. While factors influencing the risk of introduction and secondary spread of influenza virus were comparable in all four modules, only ten (16%) of 63 residents who received amantadine were infected, only one of whom became symptomatic. Most side effects associated with amantadine were mild, but residents with active, preexisting major-motor seizure disorders demonstrated an increase in seizure activity compared with the previous eight-month period; those who took the maximum daily dose of amantadine hydrochloride (200 mg) and those who were also taking anticonvulsants other than phenobarbital were at highest risk.

A novel enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to HIV-1 envelope glycoproteins based on immobilization of viral glycoproteins in microtiter wells coated with concanavalin A.

We have developed a novel method that greatly simplifies the preparation of solid-phase HIV-1 envelope glycoproteins for use in an ELISA that detects serum antibodies to HIV envelope antigens. This method utilizes concanavalin A absorbed to wells of microtiter plates to affinity immobilize detergent-solubilized viral glycoproteins released in culture fluids of HIV-1 infected cell lines grown in serum free medium. Antibodies binding to ConA-immobilized viral antigens are detected by peroxidase-conjugated antibodies and appropriate enzyme substrates. Unlike most commercial HIV ELISAs, which utilize gp120 depleted-purified virus as the source of antigens and thus favor detection of antibodies to core antigens, the ConA envELISA is highly sensitive for detecting antibodies to native gp120, as evidenced by the strong reactivity of gp120-specific human monoclonal antibodies. Our results also suggest that representation of gp41 in the assay varies and depends on which virus infected cell lines are used for antigen production. Since this assay accurately identified 14 HIV-1 antibody positive patient sera and no false positives were detected among 16 HIV-1 negative sera, the ConA envELISA shows promise as an inexpensive assay for the serologic diagnosis of HIV infections.

Disseminated adenovirus serotype 31 infection in an immunocompromised host.

Adenoviruses are ubiquitous organisms but only infrequently have been implicated as a cause of hepatitis and rarely as a cause of fatal disease. A fatal case of disseminated adenovirus serotype 31 infection is described. It occurred in a patient with severe combined immunodeficiency who received a fetal liver transplant and subsequently developed massive hepatic necrosis. To the best knowledge of the authors, this is the first reported case of disseminated disease due to serotype 31.

Isolation of parainfluenza virus type 3 from cerebrospinal fluid associated with aseptic meningitis.

Parainfluenza virus type 3 has been isolated from the cerebral spinal fluid (CSF) from six individuals--four children and two adults--over a 10-year period. All had fever, and four had signs of meningitis. All recovered uneventfully, including one child undergoing chemotherapy for medulloblastoma. The clinical presentation of this child who developed parainfluenza virus type 3 meningitis is described, and the cases of five other individuals with parainfluenza virus type 3 isolated from the CSF are briefly reviewed. The paramyxovirus parainfluenza type 3, in addition to mumps virus, may be considered capable of infecting the central nervous system.

Acute posterior multifocal placoid pigment epitheliopathy associated with an adenovirus type 5 infection.

A 19-year-old black man with acute posterior multifocal placoid pigment epitheliopathy had concurrent positive viral cultures and rising antibodies to adenovirus type 5. This finding, considered together with earlier reports of viral-like syndromes accompanying the disease, supports the implication of a respiratory virus as a possible etiologic factor.

Tolerance development to the arousal effects of nicotine.

To determine if repeated daily doses of nicotine induces tolerance to both its EEG and behavioral activating effects, rats implanted with sets of bipolar cortical elecrodes and carotid cannulae received intracarotid injections of either (1) 6 daily doses of nicotine (as tartrate, 30 mug/kg) (Group 1) or (2) 3 daily doses of saline followed by 4 days of nicotine (Group 2). From an exercise-induced resting state, nicotine produced immediate EEG and behavioral arousal, both of which disappeared in Group 1 by Day 6. Saline administered to Group 2 rats produced little or no response but subsequent nicotine resulted in responses similar to those produced by Group 1 animals. It is concluded that tolerance development to nicotine activation is reflected not only in behavior, but also in the EEG.

Respiratory syncytial virus and heart disease. A report of two cases.

Two patients had cardiac disease and serological evidence for respiratory syncytial virus (RSV) infection. The first patient had myocarditis and complete atrioventricular heart block with repeated syncopal episodes two weeks following infection. The second patient had alcoholic cardiomyopathy and worsening congestive heart failure associated with RSV infection. The significance of RSV infection in these two patients may bear a significant relationship to sudden infant death syndrome, chronic cardiomyopathy, and alcohol-related heart disease. Cardiac disease secondary to RSV infection may be more prevalent than is presently recognized.

Influenza, respiratory distress and clear chest films: report of four cases.

Four patients developed severe wheezing and dyspnea with clear chest films during the course of an influenza epidemic. A variety of factors appeared to play a role in the pathogenesis of the respiratory distress. Standard bronchodilator therapy produced no appreciable response. All patients did well with supportive care.

Serum proteins in the plasma membrane of Entamoeba histolytica.

The ability of axenic Entamoeba histolytica, strain 200:NIH, to adsorb serum proteins was studied. Amebae were grown in Diamond's TPS-1 medium. Serological reactivity was observed between the plasma membrane of E. histolytica and rabbit anti-bovine or anti-human serum when the amebae were grown, respectively, with bovine or human serum. Antisera were obtained from rabbits immunized with culture medium, amebal homogenates, and various amebal subcellular fractions: soluble phase, microsomal fraction, and a large vesicle fraction. The presence of serum proteins was demonstrated in the large vesicle fraction by the double diffusion and indirect hemagglutination tests. Immunofluorescence (IF) studies on amebae grown in bovine or human serum showed the surface amebae exhibited IF with specific antibodies against the serum in which they were grown. Rabbit anti-human serum blocked IF on the surface of amebae grown with human serum. From these data we conclude that the plasma membrane of in vitro grown E. histolytica can adsorb human and bovine serum proteins.

A comparison of four commercial test kits for detection of cytomegalovirus antibodies in blood donors.

Four commercial test kits for detecting cytomegalovirus (CMV) antibodies (indirect hemagglutination assay, indirect fluorescent antibody technique, enzyme immunoassay, and passive latex agglutination technique) were compared according to their technical demand, hands-on time, turnaround time, concordance with other techniques, reagent cost per test, and objectivity. The indirect hemagglutination assay, the enzyme immunoassay, and the passive latex agglutination technique produced identical results in 85 donors, detecting 63 positive and 22 negative samples. The indirect fluorescent antibody technique showed discrepant results in four samples. The passive latex agglutination technique rated best overall since it was technically the easiest and required the least hands-on and turnaround times; the short turnaround time (10 minutes) rendered the latex technique a more flexible test for blood bank use because both scheduled and emergency CMV screening of donors could be accommodated. The comparatively high reagent cost of the latex test kit could be offset by savings on technologist time.

Human antibody to influenza C virus: its age-related distribution and distinction from receptor analogs.

Sera from persons of four age groups (1 to 2 years, 2 to 5 years, 20 to 30 years, and 65 to 85 years) were analyzed for hemagglutination inhibition (HI) activity for influenza C virus. Significant HI activity was found in 66% of the 237 sera tested, and titers ranged from 8 to 512. In the yoiung adult group, 96% had antibody and the highest mean titer (74.7) of any age group. Positive sera were far less common in young children (36 to 47%), and relatively low titers (18.3) were common among adults over 65. The high percentage of sera with antibody to influenza C virus suggests that infections with this virus occur at a rate greater than previously recognized. The high percentage of young adults with elevated levels of HI antibody suggested either that an immune response to influenza C infections is common or that the observed HI activity might be attributable, in part at least, to nonspecific inhibitors in the sera. We showed both directly and indirectly that most if not all the inhibitory activity in the human sera we examined was due to specific antibody, mostly immunoglobulin G. This conclusion is based on the finding that the single serum protein fraction with HI activity was found to have a molecular weight equivalent to that of 7S antibody (150,000) and that the HI activity was removed by absorption to staphyloccal protein A. Moreover, immunoglobulin from only HI-positive sera bound specifically to cells infected with influenza C virus, as shown by inhibition of hemadsorption and immunofluorescence. These findings were supported by similar results obtained with chicken antisera to C virus.