A laser Raman spectroscopic investigation of phospholipid and protein configurations in hemoglobin-free erythrocyte ghosts.

Configurations of both the protein and lipid components of human red blood cell ghosts are examined by laser Raman spectroscopy. Protein configuration is estimated from bands observed in the Amide III region at 1240-1267 cm-1 in water and the Amide I' region at 1630-1670 cm-1 observed in 2H2O. The protein fraction appears to contain 40-55 percent alpha-helix with little beta-configuration. The hydrophobic side chains of the phospholipid component, as interpreted from the 1060-1130 cm-1 C-C stretching region, are estimated to contain 55-65 percent all-trans rigid configuration. These estimated are within the limits set by other physical techniques.

Immunization of high-risk infants younger than 18 months of age with split-product influenza vaccine.

Influenza is an important cause of serious illness in very young children with cardiopulmonary disease. A 4-year study was conducted at two centers to assess immunogenicity and safety of influenza split-product vaccine in children aged 3 to 18 months with bronchopulmonary dysplasia and congenital heart disease. A total of 113 children were studied: 62 children 3 to 5 months of age and 51 children 6 to 18 months of age. Sera were drawn prior to first and second immunization and 3 weeks after second immunization and were tested by hemagglutination inhibition; protection was defined as greater than 1:32. Ninety-five children were surveyed for adverse reactions. Seroresponses were age and antigen specific. Best responses for all ages were to A/Mississippi (H3N2) (97%). Children older than 6 months of age had better seroresponses to A/Leningrad (H3N2) (73%, P less than .03) and B/Victoria (62%, P less than .02) than did children younger than 6 months of age. Seroconversion rates to the remaining antigens were low. Only 9% of children experienced adverse reactions; all but one were mild. The immunologic mechanisms responsible for preventing serious influenzal disease and more effective immunization strategies need to be defined for very young high-risk children.

Unusual outbreak of influenza A in a Wyoming nursing home.

An explosive outbreak of Influenza A (H3N2) occurred during early February 1985 among the 55 residents of a nursing home in Douglas, Wyoming. Thirty of the 55 (55%) had febrile respiratory illnesses. Thirty-six (65%) had received influenza vaccine. The attack rate was 84% in unvaccinated and 39% in vaccinated persons. Vaccine efficacy was estimated to be 54%. There were eight cases of pneumonia in unvaccinated and four in vaccinated persons, three deaths in unvaccinated and one death in vaccinated persons. Complement fixation and hemagglutination inhibition tests on sera from 47 residents confirmed the diagnosis of Influenza A in the great majority of individuals, and furthermore showed very low levels of antibody for the Influenza A H1N1 and Influenza B components of the vaccine.

Effectiveness of influenza vaccine when given during an outbreak of influenza A/H3N2 in a nursing home.

An explosive outbreak of influenza A/H3N2 began in a nursing home in the Denver area early in November, 1987. Residents had not been vaccinated at that time. Vaccine was administered on November 11th. Two weeks after the vaccine was given, the attack rate differed between the vaccinated and unvaccinated individuals. There were 40 cases of influenza among the 98 elderly residents, 12 cases of pneumonia, and seven deaths. Vaccine efficacy two weeks after it was given was estimated to be 65.4% in preventing clinical illness. There were no cases of pneumonia and no deaths among people who were vaccinated more than two weeks before. The virus was identified as influenza A by complement fixation tests with convalescent sera from 16 individuals who had been ill. Many also had hemagglutination inhibition titers for A/Colorado/1/87, which were as high as titers for A/Leningrad/87. A/Colorado/1/87 closely resembled A/Sichuan/87.

Antibody response of an elderly population to a supplemental dose of influenza B vaccine.

Recent reports have suggested that the antibody response of elderly persons to standard doses of influenza vaccine is depressed. We examined the effect of an additional threefold dose of influenza B vaccine on the antibody response in elderly, ambulatory veterans. One hundred thirty-one male subjects aged 70 years and older were randomized to receive one of three influenza vaccine regimens: Group I received standard trivalent influenza vaccine containing 15 micrograms of B/USSR/100/83 in one arm and placebo in the other; Group II received standard trivalent vaccine in one arm and a supplemental dose of 45 micrograms of B/USSR in the other; Group III received the same dose as group II combined in one arm with a placebo in the other. Antibody levels were measured at baseline, 1 month, and 5 months. Nearly 80% of the participants achieved levels of antibody to B/USSR considered protective; seroconversion rates varied from 40% to 61%. No significant differences in antibody response to B/USSR occurred among the vaccine groups, and there were more side effects at higher doses. The higher dose groups did, however, achieve greater antibody levels to the drifted influenza B virus which circulated during the year of the study. Response to the influenza A components of the vaccine, however, may have been blunted in Group III which received a large dose of A and B antigens all at one site.

Treatment of an influenza A outbreak in a teaching nursing home. Effectiveness of a protocol for prevention and control.

The safety and efficacy of current ACIP guidelines for the prevention and control of influenza in nursing home populations are uncertain. An outbreak of influenza A/Sichuan (H3N2) in a teaching nursing home during 1988 gave us the opportunity to evaluate the effectiveness of an influenza vaccination and amantadine prophylaxis protocol. Over 13 days, 12 of 60 residents developed influenza. Prior influenza vaccination had been given to 94% of the residents. Protection from infection occurred in those tested who had antibody levels greater than or equal to 1:16 to the A/Leningrad (H3N2) antigen contained in the standard 1987-88 trivalent vaccine. However, five of 17 vaccinated residents who were tested had antibody levels less than or equal to 1:16 at the start of the outbreak. Amantadine (less than or equal to 100 mg/day) was given to all but one resident starting on the third day of the outbreak, and to employees starting on the sixth day of the outbreaks. Seven residents developed illness after the start of amantadine, although amantadine appeared to ameliorate their symptoms. Although amantadine was generally well tolerated by residents, employees receiving amantadine identified a high incidence of side effects and only 44% of employees took at least 70% of the prescribed amantadine. In our opinion, early detection and protocol-directed intervention probably abated a more severe influenza outbreak. Therefore we support existing recommendations that formal nursing home policies be established to ensure that residents and employees receive annual influenza vaccine and that chemoprophylaxis be used when outbreaks of influenza A are suspected.

Serological evidence of Hantaan virus infection in the United States.

We found low titers of fluorescent antibodies against Hantaan virus, the etiologic agent of Korean hemorrhagic fever, in sera from 7 of 1,035 patients with febrile illnesses of unknown origin and from 6 of 664 blood donors in the United States. All but 1 of these individuals possessed neutralizing antibodies against Hantaan virus. This was a 31-year-old research technician who had worked with laboratory rodents with virus-induced tumors, but had not traveled abroad, suggesting that infection with Hantaan virus or a closely related agent was locally acquired. However, the precise source of his infection remains unclear.

Viral respiratory disease at Lowry Air Force Base in Denver, 1952-1982.

Surveillance of febrile respiratory diseases at Lowry Air Force Base, Denver, has been maintained from 1952 to 1982 with laboratory confirmation of diagnosis. Unvaccinated recruit populations were extremely vulnerable to explosive outbreaks of influenza A. Ten controlled trials demonstrated the protective efficacy of inactivated vaccines. Recent military vaccines have raised the hemagglutination-inhibiting antibody levels of most persons into the "protective" range. Despite repeated introduction of influenza viruses onto the base, when all personnel were vaccinated the impact of influenza was reduced to an insignificant level except in one year of antigenic shift (1968) and one of major antigenic drift (1972). Adenovirus disease has been virtually eliminated since live oral types 4 and 7 vaccines have been given to incoming recruits. Rubella and rubeola have disappeared since seronegative recruits have received vaccine. Overall rates of febrile respiratory diseases have been greatly reduced.

Faculty tenure in American medical schools.

Advantages and disadvantages of academic tenure for clinical faculties, including an appraisal of its financial burdens, the utility of modified or alternative systems, and the issue of abolition of tenure, were examined through a questionnaire to which deans and faculty representatives of 106 American medical schools responded during 1975-76. Tenure is valued by most deans and faculty members. A flexible tenure policy permitting appointment of some faculty members to senior academic posts without tenure was endorsed by the deans of 10 selected medical schools who were interviewed. Growth of medical faculties is decelerating; a steady state has not been attained but is imminent. Financial pressures and demands for change will increasingly challenge the tenure system.

Rapid subtyping of influenza A virus isolates by membrane fluorescence.

During the winter of 1977-1978 three influenza A virus serotypes (A/Vic/3/75, A/Texas/1/77 [both H3N2], and A/USSR/90/77 [H1N1]) circulated in Denver, offering us the opportunity to apply fluorescent antibody techniques to the specific identification of these viruses. Surface antigens of infected, unfixed primary monkey kidney cells were stained in suspension by an indirect immunofluorescence technique with anti-H3N2 and anti-H1N1 antisera. In tests of cells infected with known viruses, the members of the H3N2 family could not be distinguished from one another, but were easily distinguished from H1N1 strains. A total of 101 hemadsorption-positive clinical specimens were evaluated over a 6-month period. Forty-five of 48 influenza A H3N2 and 24 of 29 H1N1 specimens confirmed by hemagglutination inhibition were correctly identified by membrane fluorescence of cultured cells, with no misidentifications among influenza strains and with 1 false positive among 24 non-influenza isolates. The average time to identification by this technique was 4 days compared to 7 days by hemagglutination inhibition. Live cell membrane fluorescence is a simple, rapid, and accurate method for identifying and grouping influenza A viruses.

Antibody response of young adults to experimental influenza A/New Jersey/76 virus vaccines.

In military personnel aged 17-25 years, only one of four experimental influenza A/New Jersey/76 virus vaccines produced a satisfactory hemagglutination-inhibiting (HAI) antibody response when a dose of 200 chick cell-agglutinating (CCA) units was used. A second injection of 400 CCA units of vaccine caused seroconversion in all persons. Although an early comparison of experimental split-product and whole-virus vaccines suggested that the former were relatively ineffective, a later comparison with different lots of the vaccines showed no difference between vaccines of these two types. The influenza A/NJ/76 virus vaccine evoked a high HAI antibody response to influenza A/PR/8/34 (H0N1) virus but not to H1N1 or H3N2 strains.

Anti-influenza A activity of combinations of amantadine and ribavirin in ferret tracheal ciliated epithelium.

The anti-influenza A activities of amantadine and ribavirin were investigated separately and in combination. Ferret tracheal ciliated epithelium was continuously exposed to the drugs at concentrations (0.25, 0.5, and 1 mg/l) comparable to those found in human serum after oral administration. Each drug alone produced a modest delay in A/Alaska/6/77 (H3N2) induced cytopathic effect. The combination of drugs synergistically delayed cytopathic effect. At 1 mg/l of each, cytopathic effect was prevented in 75% of rings for the 28-day duration of the experiment. This effect was greater than that of 32 mg/l of amantadine or 64 mg/l of ribavirin as single antiviral drugs. Peak virus production was suppressed 4.4 log-fold by the combination of 1 mg/l of each drug. This is in contrast to amantadine alone which suppressed peak virus production by 1 log-fold and ribavirin along which at 1 mg/l suppressed peak virus production by 1.9 log-fold. At lower concentrations, the drugs were at least additive in suppression of virus production.

Anti-influenza A virus activity of amantadine hydrochloride and rimantadine hydrochloride in ferret tracheal ciliated epithelium.

The activities and toxicities of amantadine hydrochloride and rimantadine hydrochloride against influenza A/Alaska/6/77 (H3N2) and A/Bangkok/1/79 (H3N2) viruses were compared in organ cultures and ferret tracheal ciliated epithelium. Pretreatment of cultures with concentrations (0.5 and 1 micrograms/ml) comparable to those found in human serum after oral administration of amantadine revealed that rimantadine produced significantly longer protection than amantadine against virus-induced cytopathic effects. Correspondingly, rimantadine produced a comparable protective effect at four- to eight-fold-lower concentrations than amantadine. Both drugs produced increasing and similar effects at higher concentrations, which were comparable to those reported in nasal washings after aerosol administration of amantadine. At the concentrations tested, amantadine was nontoxic. However, at concentrations of 16 and 32 micrograms/ml, rimantadine was toxic to the ciliated epithelium after 10 to 21 days of continuous exposure. When the drugs were added 24 h or more after infection, protection against cytopathic effects decreased markedly. Both drugs moderately suppressed virus production at concentrations of 0.5 to 16 micrograms/ml. However, no dose response or difference between the drugs was observed. Because of comparable antiviral activity at lower concentrations and greater activity at similar concentrations, rimantadine may be more useful than amantadine for oral prophylaxis and therapy of influenza.

Antigenic drift and efficacy of influenza virus vaccines, 1976--1977.

A unique opportunity occurred in February 1977 to assess the efficacy of an influenza virus vaccine given to military personnel in doses of 400 chick cell-agglutinating (CCA) units of A/Victoria/3/75, 400 CCA units of A/New Jersey/76, and 500 CCA units of B/Hong Kong/72 viruses. After cessation of all influenza virus vaccine administration in mid-December 1976, approximately 200 unvaccinated U.S. Air Force personnel arrived per week beginning February 1, 1977, at Lowry Air Force Base, Denver, Colorado. Arriving unvaccinated personnel were assigned to one of 12 units with previously vaccinated personnel. A sharp outbreak of influenza A occurred on the base during February that was due to an A/Texas/1/77-like virus, a variant of the A/Victoria/3/75 prototpye. Fifty-four cases of influenza A were documented in the student population on the base. During the two-week peak of the outbreak, attack rates were 10-fold higher in unvaccinated than in vaccinated students, and the overall estimate of vaccine efficacy was 80%. Thus, despite animal tests suggesting considerable antigenic drift, a vaccine containing influenza A/Victoria/3/75 virus provided good protection against the variant strain.

Impaired serum antibody response to inactivated influenza A and B vaccine in renal transplant recipients.

Before and after vaccination with a commercial inactivated influenza vaccine containing A/Aichi/2/68 (H3N2) and B/Massachusetts/1/71 antigens, the serum hemagglutination inhibition antibody titers to homologous and heterologous strains of A and B influenza viruses were measured in 45 renal transplant patients and 66 healthy controls (62 for the B strains). At least a fourfold titer rise to the homologous A strain occurred in 14 of 45 transplant patients (31%) versus 37 of 66 controls (56%). Fourfold or greater heterologous A rises occurred in only 8 of 45 transplant patients (18%) compared with 40 of 60 controls (61%). In both the homologous and heterologous B responses, at least fourfold hemagglutination inhibition titer rises were seen in significantly fewer transplant patients than control subjects. In the transplant group, no correlation was observed between degree of antibody response and age, previous influenza vaccination, percentage of patients initially seronegative, time since transplantation, dose of immunosuppressive drugs, level of renal function, or nature of original renal disease.

Cryptic epidemic of Q fever in a medical school.

Pregnant sheep used in perinatel research were the source of a large outbreak of Q fever in 1980 among the faculty and staff of a medical school. Complement-fixation tests with phase II Coxiella burnetii antigen were positive in 81 persons, of whom 58 (71.6%) had Q fever during the first eight months of 1980. Microagglutination and/or indirect immunofluorescence tests of 485 sera were positive in an additional 56 persons. Only 41 of the 137 seropositive persons were involved in caring for or working with sheep; the remaining 96(70.1%) persons were located along the routes followed by sheep carts or had been exposed to sheep in other ways. Early in the outbreak few patients sought medical help. Later, most patients reported promptly and responded favorably to therapy with tetracycline. Sheep were removed from the campus in July 1980; cases ceased one month later. Other medical centers engaged in research with pregnant sheep should be alert to the risk of Q fever.

Comparison of sevral wild-type influenza viruses in the ferret tracheal organ culture system.

Several strains of wild-type influenza A virus were studied in the ferret tracheal organ culture system. Ciliary activity and viral replication were measured. Ciliary activity was reduced more rapidly by A/Hong Kong/45/68 (H3N2) (A/HK) and A/Victoria/3/75 (H3N2) (A/Vic) than by A/New Jersey/8/76 (Hsw1N1) (A/NJ), A/Scotland/840/74(3HN2) (A/Scot), or A/USSR/90/77 (H1N1) (A/USSR). A/HK, A/Vic, and A/Scot produced titers of virus higher than A/USSR or A/NJ during the first three days after infection. Differences in effects of the five viruses on cilia were not related to history of egg passage. The two strains that destroyed ciliary activity rapidly had caused excess mortality in the United States, whereas the three that destroyed ciliary activity more slowly had not. A relationship may exist between the properties contributing to virulence in humans and the destruction of ciliary activity in vitro in this culture system.