Hemodynamic and biochemical alterations in dogs with lymphoma after induction of chemotherapy.

BACKGROUND: Doxorubicin is a common antineoplastic agent with dose-dependent cardiotoxic adverse effects, and pre-existing myocardial dysfunction is a contraindication to its use. OBJECTIVES: To systematically define the hemodynamic and biochemical alterations in dogs undergoing chemotherapy for newly diagnosed lymphoma and assess the reversibility of these alterations with fluid administration. ANIMALS: Twenty-one client-owned dogs with newly diagnosed lymphoma were evaluated 1 week after induction of chemotherapy. Underlying degenerative valve disease was exclusionary. Eighteen healthy age- and weight-matched dogs were used as controls. METHODS: Physical examination, blood pressure by Doppler, echocardiography, and biochemical evaluation (routine serum biochemistry, plasma renin activity and aldosterone concentrations, plasma and urine osmolalities, and urine electrolyte concentrations) were measured in dogs with lymphoma and compared to controls. Dogs with lymphoma received crystalloids IV at 6 mL/kg/h for 24 hours. All variables were reassessed at 4 and 24 hours. Deuterium oxide dilution and bromide dilution were used to determine total body water and extracellular water space, respectively. RESULTS: Baseline echocardiograms showed significantly smaller chamber dimensions in dogs with lymphoma compared to controls. These changes were reversed by fluid administration. Systolic blood pressure and urine sodium concentration were significantly increased, and bromide dilution space, PCV, urine specific gravity, and urine potassium concentration were significantly decreased compared to controls. CONCLUSION AND CLINICAL IMPORTANCE: Echocardiographic and biochemical abnormalities in dogs with lymphoma appear consistent with volume depletion, and may be the result of systemic hypertension and subsequent pressure natriuresis.

Effect of opioids on CXCL-8 production in healthy cats.

The aim of this study was to evaluate the effect of opioid exposure on CXC chemokine ligand (CXCL)-8 production in cats using whole blood culture. Morphine, buprenorphine, fentanyl, and saline control were administered intravenously to five cats and whole blood pathogen associated molecular pattern motif-induced CXCL-8 production capacity was evaluated. Morphine potentiated CXCL-8 production. To further characterize this effect of morphine, morphine was incubated with whole blood ex vivo and pathogen associated molecular pattern motif-induced CXCL-8 production capacity was measured. There was a time and concentration dependent effect on CXCL-8 production, suggesting the proinflammatory effect of morphine is at least partially mediated by direct stimulatory effects on leukocytes. Additional investigation is indicated to assess the implications of the immunomodulatory actions of opioids in cats.

Comparison of live attenuated and inactivated influenza vaccines in schoolchildren in Russia: I. Safety and efficacy in two Moscow schools, 1987/88.

The performance of two doses of cold-adapted live attenuated vaccine versus one dose of whole-virus inactivated vaccine was compared in 8-15-year-old schoolchildren in two schools in Moscow, Russia, during the winter of 1987/88. Both vaccines gave rise to low frequencies of associated febrile or systemic reactions, but the inactivated vaccine, delivered by jet injector, did cause small local reactions in about half of the children. Immunogenicity was higher for both vaccines in antibody-free children, and higher levels of serum antibody were detected following use of inactivated vaccine. During the winter, influenza A (H3N2) and influenza B viruses circulated in Moscow. A clear outbreak of (H3N2) virus occurred in both schools, and infections with type B virus also occurred in one school. The influenza A/Philippines/2/82 (H3N2) component of both vaccines exhibited protective efficacy of about 40% (p < 0.05) against serologically proven infection caused by the antigenically drifted A/Sichuan/2/87 (H3N2)-like epidemic viruses in one school. In another school where illnesses associated with antibody rise were documented, efficacy was seen for both vaccines in reduction of illnesses, and of illnesses with serological evidence of infection, but statistical significance was not achieved.

Emergence and possible transmission of amantadine-resistant viruses during nursing home outbreaks of influenza A (H3N2).

Outbreaks of influenza A (H3N2, A/Shanghai/11/87-like) occurred in two partially (60% and 79%) vaccinated nursing home populations in January 1988. A retrospective cohort study using chart review was designed to assess the effectiveness of influenza vaccination and amantadine prophylaxis (100 mg per day) in controlling the outbreaks and to determine the amantadine susceptibility of influenza viruses isolated from case-patients. The point estimate of vaccine efficacy in preventing influenza-like illness was -33% (95% confidence interval -115% to 18%). However, 9% of vaccinated case-patients died within 14 days after onset of influenza-like illness compared with 26% of unvaccinated case-patients (relative risk = 0.4, 95% confidence interval 0.1-1.0). There was no significant difference in illness severity among case-patients who became ill before amantadine prophylaxis was started (n = 84) compared with those who became ill while taking amantadine (n = 34). Four virus isolates obtained before amantadine prophylaxis was started demonstrated 52-68% inhibition by 1 microgram/ml of amantadine; by comparison, six isolates (resistant viruses) obtained from residents who became ill while taking amantadine demonstrated 1-18% inhibition. The resistant viruses had four different RNA sequences in the gene coding for the M2 protein transmembrane region. Three resistant viruses with identical RNA sequences were isolated from residents living in contiguous rooms who had onset of signs and symptoms during a 6-day interval. Further studies are needed to determine how frequently and under what circumstances resistant viruses occur when antiviral agents are used to control institutional influenza A outbreaks. Strategies for antiviral agent administration that limit the emergence and transmission of resistant virus strains may be needed.

Antigenic and genetic variation in influenza A (H1N1) virus isolates recovered from a persistently infected immunodeficient child.

Antigenic and genetic variations have been analyzed in eight consecutive isolates recovered from a child with severe combined immunodeficiency syndrome persistently infected with naturally acquired type A (H1N1) influenza virus over a 10-month period. Hemagglutination inhibition reactions and T1 oligonucleotide fingerprinting demonstrated that these viruses were related to strains causing outbreaks in the United States at that time (1983 to 1984) but that antigenic and genetic differences between consecutive isolates could be detected. This variation between isolates was examined further by sequencing the RNAs encoding the HA1 region of the hemagglutinin (HA) and the nucleoprotein (NP) in five of the consecutive isolates. Multiple point mutations were detected in both genes, and a deletion of one amino acid was detected in the HA. Depending on the isolates compared, 5.8 x 10(-3) to 17 x 10(-3) substitutions per nucleotide site per year were detected in the RNAs encoding the HA1, and 3.5 x 10(-3) to 24 x 10(-3) substitutions per nucleotide site per year were detected in the NP gene. Fifty-four percent of the base changes in the HA1 and 73% in the NP led to amino acid substitutions. A progressive accumulation of mutations over time was not observed, suggesting that the genetic diversity of these viruses may best be interpreted as the result of shifts in the population equilibrium (quasi-species) of replicating variant genomes.

A cluster of meningococcal disease on a school bus following epidemic influenza.

An outbreak of meningococcal disease among children on a school bus offered the opportunity to study a proposed association between this infection and preceding influenza infection. Five students who rode the bus became ill with invasive group C meningococcus. Transmission was limited to the bus; there was no evidence for school transmission. All five students reported influenza-like symptoms within several weeks before the development of meningococcal disease. School absenteeism, principally due to upper respiratory tract illness, was higher during the 3 weeks before the outbreak of meningococcal disease than during any period in the preceding 3 1/2 years, suggesting an unusually severe outbreak of respiratory illness. A case-control study comparing students with and without influenza symptoms revealed that the outbreak of respiratory disease was due to B/Ann Arbor/1/86 influenza (geometric mean titers, 86 for 80 patients and 33 for 47 controls [P = .0007]). These data add to the evidence suggesting that influenza respiratory infection predisposes to meningococcal disease.

Swine influenza virus infections. Transmission from ill pigs to humans at a Wisconsin agricultural fair and subsequent probable person-to-person transmission.

In September 1988, a previously healthy 32-year-old pregnant woman was hospitalized for pneumonia and died 8 days later. The only pathogen detected was an influenza virus antigenically related to the swine influenza virus (SIV). Four days before illness onset, the patient visited a county fair swine exhibition where there was widespread influenzalike illness among the swine. To detect other persons who were possibly infected by contact with the ill swine, we measured serum SIV hemagglutination-inhibition antibody titer in 25 swine exhibitors who were 9 to 19 years old. Nineteen (76%) had SIV hemagglutination-inhibition titers of 20 or greater. Antibody was undetectable in serum samples from 25 swine exhibitors from a neighboring county. Additional studies suggest that one to three health care personnel who had contact with the patient developed influenzalike illnesses with laboratory evidence of SIV infection. An outbreak of apparent SIV infection in swine resulted in multiple human infections, and, although no recognized community outbreak resulted, there was evidence of virus transmission from the patient to health care personnel.

Expression of influenza A and B virus nucleoprotein antigens in baculovirus.

Full-length cDNA clones of the nucleoprotein (NP) genes of influenza A/Ann Arbor/6/60 and B/Ann Arbor/1/86 viruses were constructed from virion RNA and subsequently expressed in Spodoptera frugiperda (Sf9) cells using the baculovirus vector, Autographa californica nuclear polyhedrosis virus. Western blot analysis of lysates prepared from Sf9 cells infected with the recombinant viruses confirmed that the baculovirus-expressed NP antigens were reactive with monoclonal antibodies specific for either type A or B NP and with anti-NP antibodies in human serum samples. Electrophoretic analysis indicated that the expressed NP antigens comigrated with NP purified from influenza A or B virions and that the recombinant NP antigens represented greater than 10% of total protein in infected cells. Dilutions of clarified Sf9 cell lysates were used as antigens in a standard enzyme immunoassay to detect serum antibody specific for influenza A or B viruses. The results from assays using the baculovirus-expressed NP antigens showed good correlation with the results obtained using bacterially expressed NP antigen as well as complement fixation. Therefore, baculovirus-expressed NP antigens have the potential to be used to develop reproducible and routine assays for the serodiagnosis of influenza virus infections as an alternative to the complement fixation or haemagglutination inhibition tests.

Cocirculation of two distinct evolutionary lineages of influenza type B virus since 1983.

During 1988-1989 two highly distinct antigenic variants of influenza type B were recognized in hemagglutination-inhibition tests with postinfection ferret serum. These viruses were antigenically related to either B/Victoria/2/87, the most recent reference strain, or B/Yamagata/16/88, a variant that was isolated in Japan in May 1988. All influenza B viruses isolated in the United States during an epidemic in the winter of 1988-1989 were antigenically related to B/Victoria/2/87. However, in several countries in Asia, both B/Victoria/2/87-like viruses and B/Yamagata/16/88-like viruses were isolated. Sequence analysis of the hemagglutinin (HA) genes of several influenza B isolates from 1987 to 1988 indicated that the HA1 domains of the B/Yamagata/16/88-like viruses and B/VI/87-like viruses isolated in 1988 differed by 27 amino acids. Evolutionary relationships based on this sequence data indicated that the B/Yamagata/16/88-like viruses were more closely related to epidemic viruses from 1983 (B/USSR/100/83-like viruses) than to more recent reference strains such as B/Victoria/2/87. All other Asian strains, as well as selected isolates from the United States in 1988, were confirmed by sequence analysis as being genetically related to B/Victoria/2/87. These data provide clear evidence that two parallel evolutionary pathways of influenza type B have existed since at least 1983 and that viruses from each of the separate lineages were isolated from cases of influenza B in 1988. This finding is similar to earlier observations for type A H1N1 and H3N2 influenza viruses.

Enhancement of antibody responses to influenza B virus haemagglutinin by use of a new adjuvant formulation.

Mice and guinea pigs were immunized with the haemagglutinin (HA) of influenza B-USSR/100 virus, either in Syntex Adjuvant Formulation-1 (SAF-1) or in saline. Antibody titres were determined by ELISA, haemagglutination inhibition and virus neutralization. Animals immunized with HA in SAF-1 had significantly higher antibody titres than did animals immunized with HA in saline. Both 3-week-old and 13 1/2-month-old mice had greater and more uniform antibody responses to HA in SAF-1 than to HA in saline.

Evaluation in children of cold-adapted influenza B live attenuated intranasal vaccine prepared by reassortment between wild-type B/Ann Arbor/1/86 and cold-adapted B/Leningrad/14/55 viruses.

A reassortant cold-adapted (ca) influenza B experimental live attenuated intranasal vaccine was evaluated for safety and immunogenicity in children by means of a blind, placebo controlled study. The vaccine contained the haemagglutinin and neuraminidase genes, and the gene for its non-structural proteins from wild-type (wt) B/Ann Arbor/1/86 virus, the contemporary strain at the time of the study. Other genes were derived from ca B/Leningrad/14/55 virus. No increase in illness rates was seen in the children from ages 3-15 years given vaccine at maximum potency (a one in two dilution of infectious allantoic fluid, having a titre of 10(7.0) EID50) compared to children given placebo. About 60% of seronegative children, ages 3-7 years, exhibited a detectible antibody response following one dose of intranasal vaccine, with the seroresponse rate rising to greater than 70% after two doses of vaccine. Immunogenicity was lowest in seropositive children age 8-15 years, reaching a maximum of 36% after two doses. Results indicated that the vaccine was highly attenuated, and probably of adequate immunogenicity for kindergarten age children. The lower immunogenicity in older children suggests the vaccine might be overly attenuated for use in school-age children who are more likely to have a history of prior natural infection with influenza B virus. Further clinical and epidemiological studies of protection are needed to fully assess this.

Laboratory characterization of a swine influenza virus isolated from a fatal case of human influenza.

A swine influenza virus-like type A (H1N1) virus, designated A/Wisconsin/3523/88, was isolated in September 1988 from a Wisconsin woman who had died with primary viral pneumonia. Antigenic analyses with hemagglutinin-specific monoclonal antibodies and postinfection ferret serum indicated that the hemagglutinin of A/Wisconsin/3523/88 was antigenically closely related to viruses currently circulating in swine. Genetic analysis of the A/Wisconsin/3523/88 virus by RNA fingerprinting and partial RNA sequence analysis of seven of the eight segments indicated that the genome of the human isolate was similar to that of enzootic swine viruses. These laboratory data supported the epidemiologic findings that this human infection occurred by transmission of an enzootic swine influenza virus and that the virus showed no major genetic changes potentially related to increased pathogenesis.

An outbreak of influenza A/Taiwan/1/86 (H1N1) infections at a naval base and its association with airplane travel.

In late October 1986, an outbreak of influenza-like illness was detected at the Naval Air Station in Key West, Florida. Between October 10 and November 7, 1986, 60 active duty personnel reported experiencing a respiratory illness characterized by fever, cough, sore throat, and myalgia. Influenza A/Taiwan/1/86 (H1N1) virus was recovered from three symptomatic patients. Forty-one (68%) of 60 case-patients belonged to a 114-person squadron that had traveled to Puerto Rico for a temporary assignment from October 17-28, 1986. Among squadron members, the attack rate for persons previously vaccinated with the 1986-1987 trivalent influenza vaccine and for those unvaccinated was the same (37%). Transmission of infection among squadron personnel appeared to have commenced in Key West and continued in a barracks in Puerto Rico and aboard two DC-9 aircraft that transported the squadron back to Key West on October 28. There was no evidence that the outbreak spread to the surrounding civilian communities in Puerto Rico or Key West. This was the first reported outbreak of respiratory illness due to influenza A/Taiwan/1/86 (H1N1) in the continental United States in the 1986-1987 influenza season.

Immunoassay for serologic diagnosis of influenza type A using recombinant DNA produced nucleoprotein antigen and monoclonal antibody to human IgG.

Influenza type A nucleoprotein (NP) derived from the full length cloned gene expressed in E. coli was evaluated in a solid phase enzyme immunoassay (EIA) for detection of human antibody to influenza. Monoclonal antibody to human IgG was used for detection. Direct and indirect assays were developed and sera were tested in serial and single dilution formats. Preliminary results indicated that recombinant-and virion-derived NP antigens were comparable in binding ability to plastic and binding human antibody. Eighty-seven paired sera from influenza patients were tested. The most sensitive assay (indirect-serial dilution) detected 56 (64%) rises and the simplest assay (direct-single dilution) detected 43 (49%) rises, compared to 36 (41%) for complement fixation. Paired sera from 18 control patients showed no evidence of antibody rises by any of the assays. Forty-nine paired sera from influenza B infected patients were negative for antibody rises except for one borderline rise by the indirect-serial dilution assay. These results indicate that the use of recombinant DNA derived nucleoprotein for immunoassay is feasible. The sensitivity of immunoassays using NP adsorbed to the solid phase and monoclonal antibody specific for human IgG to detect bound antibody exceeded that of conventional complement fixation testing for establishing serologic evidence of influenza type A infection.

Protection against virulent H5 avian influenza virus infection in chickens by an inactivated vaccine produced with recombinant vaccinia virus.

A cloned cDNA copy of the haemagglutinin (HA) gene of A/Chicken/Scotland/59 (H5N1) influenza virus has been expressed in vaccinia virus. This pox virus is poorly infectious or non-infectious for chickens. However, immunization of chickens with lysates of cell cultures infected with the recombinant vaccinia virus, that had been emulsified with adjuvant and which contained an estimated 0.5 microgram influenza HA, elicited a substantial neutralizing antibody response to influenza virus. Challenges of immunized and non-immunized adult chickens with virulent A/Chicken/Scotland/59 influenza virus showed that the immunized animals were highly protected while the non-immunized controls died. Immunized birds were also protected against infection with the recent virulent H5 avian influenza virus, A/Chicken/Pennsylvania/83 (H5N2).

The roles of vaccination and amantadine prophylaxis in controlling an outbreak of influenza A (H3N2) in a nursing home.

An outbreak caused by influenza A/Philippines/2/82 (H3N2)-like viruses occurred in a partially vaccinated nursing home population in January 1985. During the first six days of the outbreak, 14 (25%) of 55 residents developed influenzalike illness. The risk of illness was most strongly associated with undetectable levels of antibody against the epidemic strain, with unvaccinated case-patients having more severe illnesses and a higher rate of hospitalization than vaccinated case-patients (5/8 vs 0/6). During the period of amantadine hydrochloride prophylaxis (100 mg/d) from days 7 to 35, only two (5%) of the remaining 41 residents became ill, even though 11 (27%) had no detectable antibody. Serum amantadine levels obtained on day 35 ranged from 117 to 737 ng/mL (mean 309 ng/mL), similar to therapeutic levels documented in younger adults who have taken the standard regimen of 200 mg/d; there were few clinically significant side effects. These findings illustrate the benefits of influenza vaccination and support the use of amantadine hydrochloride at a dosage of 100 mg daily for outbreak control among elderly persons.

Class-specific antibody responses in school children vaccinated with an A/Brazil/11/78 (H1N1)-like recombinant influenza virus prepared from the A/Leningrad/134/57 paediatric cold-adapted donor strain.

Forty-three school children from 8 to 11 years old were vaccinated intranasally with two doses of a paediatric attenuated influenza vaccine developed by reassortment between cold-adapted A/Leningrad/134/57(H2N2) and an A/Brazil/11/78(H1N1)-like strain. Two vaccine doses were administered 1 month apart in a randomized, blind, placebo-controlled study. Although the first vaccine dose had a low infectivity titre, overall 65% of children who received two doses of vaccine showed serological evidence of infection by HI tests. Serum IgA antibody responses against the vaccine strain were detected in nearly 50% of the vaccines and serum IgG antibody responses were detected in approximately equal to 40% by an enzyme immunoassay.

Antibody response in humans to influenza virus type B host-cell-derived variants after vaccination with standard (egg-derived) vaccine or natural infection.

Hemagglutination inhibition (HI) and neutralization tests were used to determine antibody responses to egg-derived and Madin-Darby canine kidney (MDCK)-derived influenza B virus (B/England/222/82) in paired sera from persons naturally infected with influenza B and in persons vaccinated with standard egg-derived inactivated influenza vaccine. When tested by HI, the MDCK-derived antigen gave significantly higher (8- to 12-fold) geometric mean titers (GMT) in convalescent-phase sera from persons naturally infected during community outbreaks, as well as more 4-fold titer rises, than did tests with egg-derived antigen. When tested by neutralization, however, the convalescent-phase sera GMTs were only threefold higher with the MDCK-derived antigen and an equivalent number of fourfold titer rises were detected with both antigens. With postvaccine sera, the MDCK-derived antigen gave GMTs that were threefold higher than those obtained with egg-derived antigen in both the HI and neutralization tests and both antigens detected an equivalent number of fourfold titer rises in HI and neutralization tests. Sucrose gradient-fractionated egg-derived antigen showed a single peak of hemagglutinin activity corresponding to whole virions, whereas MDCK-derived antigen contained two distinct peaks of hemagglutinin activity, one of which had a lower sedimentation rate. The overall findings indicate that the egg-derived antigen in the vaccine induced HI and neutralizing antibody to both egg- and MDCK-derived variants and suggest that titers of antibody to MDCK-derived virus may be affected by the physical form of the hemagglutinin antigen.

Time-resolved fluoroimmunoassay with monoclonal antibodies for rapid diagnosis of influenza infections.

Monoclonal antibodies that are broadly reactive with either influenza A or influenza B viruses were used to develop a 2- to 3-h antigen capture time-resolved fluoroimmunoassay (TR FIA) for detecting influenza viral antigens in both original nasopharyngeal aspirate specimens and in tissue cultures inoculated with nose or throat swab specimens. The lower limit of sensitivity of the assay was about 10 pg of protein as determined with purified influenza A nucleoprotein expressed by recombinant DNA. When the TR FIA was performed with 96 nasopharyngeal aspirate specimens collected during outbreaks of influenza A (H3N2) virus and the results were compared with serodiagnosis results with paired sera, the specificity and sensitivity of TR FIA for the demonstration of influenza A infections were 95 and 85%, respectively. In culture confirmation assays, more than 80% of the swab specimens that grew influenza A or B virus within 7 days could be identified by the TR FIA within 48 h of the inoculation of cells. The results are consistent with those previously reported for respiratory syncytial virus and extend the applicability of monoclonal antibody-based TR FIA for the rapid diagnosis of acute respiratory viral infections.

Isotype-specific enzyme immunoassay for influenza antibody with monoclonal antibodies to human immunoglobulins.

Mouse monoclonal antibodies specific for human immunoglobulin isotypes were investigated for use in an isotype-specific enzyme immunoassay for detection of antibody to influenza type A hemagglutinin (H1 and H3). The monoclonal antibody reagents were compared with isotype-specific, hyperimmune rabbit antisera from the National Institutes of Health. Endpoint titers for immunoglobulin G (IgG) obtained with the two reagents were within fourfold of each other 84% of the time (79 of 84) and within eightfold of each other 95% of the time (89 of 94). Regression analysis of the data gave a multiple correlation coefficient (r2) of 0.77 and a Spearman rank value of 0.83 (P less than 0.001). For IgA reagents, endpoint titers agreed within fourfold 77% of the time (88 of 114) and within eightfold 92% of the time (105 of 114). The r2 was 0.73, and Spearman rank was 0.83 (P less than 0.001). IgM antibody was detected in only 17 of 114 sera by either monoclonal or polyclonal reagents. Of these sera, 14 (82%) gave titers with the two reagents that were within fourfold of each other. A similar number of fourfold titer rises were detected with each reagent in paired sera showing hemagglutination inhibition titer rises. Monoclonal antibody reagents detected 27 IgA, 29 IgG, and 6 IgM rises, while polyclonal antisera detected 26 IgA, 31 IgG, and 7 IgM rises. These results show that monoclonal antibodies specific for human immunoglobulin isotypes are suitable as reagents for diagnostic assays. The advantages of monoclonal antibodies are their high degree of specificity and the ability to be standardized and produced in unlimited quantities. Moreover, the availability of immunoglobulin subclass- and allotype-specific monoclonal antibodies will enable a more detailed analysis of the antibody response to influenza as well as other infectious agents.