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Biomedical subjects

L J Anderson

Publications and source records attributed to L J Anderson.

At least 145 records · Page 8Linked to original sources

Diarrheal illness among infants and toddlers in day care centers: effects of active surveillance and staff training without subsequent monitoring.

From October 1981 to September 1984, the authors conducted a three-year longitudinal study of diarrhea among infants and toddlers attending day care centers in Maricopa County, Arizona. In the third year of study, they evaluated the effects on diarrhea rates of staff training without external monitoring and of active surveillance conducted throughout the study. From 21 study day care centers, they randomly selected 10 ("intervention day care centers") to receive staff training in procedures to reduce transmission of infectious diarrhea. Continuing active surveillance in the 10 intervention and 11 control day care centers found no difference between diarrhea rates in intervention day care centers in the pre- and posttraining years and no difference between diarrhea rates in the two groups of centers either before or after the training intervention. Biweekly family-based surveys during the two months after training also demonstrated no difference between infant-toddler diarrhea rates in intervention and control day care centers. These surveys found the 21 study day care centers to have significantly higher diarrhea rates than did day care homes or households not using day care, but significantly lower rates than day care centers not included in the active surveillance. Continuous surveillance without training was associated with a significant decrease in diarrheal illness during the course of longitudinal study. One-time staff training without subsequent monitoring did not result in additional decreases and did not lower day care center diarrhea rates to the levels observed in day care homes and households not using day care.

Arizona↗

Aplastic crisis in sickle cell disorders: bone marrow necrosis and human parvovirus infection.

Aplastic crisis in patients with sickle cell disease who develop a parvovirus infection may be associated with extensive bone marrow necrosis as well as acute selective erythroblastopenia. This illness may be manifested by pyrexia, lymphadenopathy, bone tenderness and significant hypoxemia with minimal roentgenographic findings in the lungs. It is uncertain whether the hypoxemia is caused by the effects of the viral infection on the lungs or is secondary to sickling of red blood cells in the pulmonary vasculature or both. The hypoxia may be sufficiently severe to require treatment with both oxygen and transfusion. The physical damage to the bone marrow associated with bone marrow necrosis may be more important than selective acute erythroblastopenia in inducing aplastic crisis in patients with sickle cell disorders. Studies of bone marrow biopsy specimens collected during parvovirus-associated aplastic crisis in patients with nonsickle cell hemolytic disorders would be helpful in determining the pathophysiology of parvovirus-associated disorders.

Acute Disease↗

Neutralization of respiratory syncytial virus by individual and mixtures of F and G protein monoclonal antibodies.

We identified several types of neutralization effected by F and G protein monoclonal antibodies (MAbs) reacted individually or as mixtures against respiratory syncytial virus (RSV). Neutralizing activity was identified by a microneutralization test in which virus replication was determined by enzyme immunoassay. Complete neutralization was seen only with MAbs against the F protein. Strain-specific neutralization, complete neutralization against some strains of RSV, and no neutralization against other strains were seen with an additional MAb against the F protein. Partial neutralization, virus replication significantly reduced but still present, and no neutralization were seen with MAbs against both the F and G proteins. Enhanced neutralization, enhanced efficacy of neutralization, or increased neutralizing titer with a mixture of two MAbs over that for the individual MAbs was seen with all MAbs against the F protein and all but three MAbs against the G protein. Most (10 of 13) of the MAbs that exhibited neutralizing activity reacted with some but not all strains of RSV in an enzyme immunoassay. The epitopes corresponding to these 10 MAbs probably contribute to the strain-specific component of the neutralizing antibody response to RSV. Our results suggest that interpretation of RSV neutralization with MAbs is complex and that studies of such neutralization should include mixtures of MAbs and multiple RSV strains.

Antibodies, Monoclonal↗

Severe anemia caused by human parvovirus in a leukemia patient on maintenance chemotherapy.

A 6-year-old boy on maintenance chemotherapy for acute lymphocytic leukemia developed severe hypoplastic anemia during chemotherapy previously well tolerated. The hypoplastic episode persisted for approximately 30 days. Human parvovirus (B19), the etiologic agent of aplastic crisis in persons with underlying hemolytic syndromes, was detected in the patient's serum 25-30 days after onset of hemoglobin decrease, and B19 IgM seroconversion occurred 1 week later. The patient's hypoplastic anemia was presumably caused by prolonged B19 infection resulting from a blunted immune response. An immune response to the B19 infection and resolution of the illness were temporally associated with brief cessation of chemotherapy.

Anemia, Aplastic↗

Hand splinting for infants in the intensive care and special care nurseries.

Infants in intensive care nurseries often have hand deformities and hand dysfunction. The traditional therapeutic approaches to hand care used in the treatment of adults, young children, and older infants are not always adequate to prevent progressive deformity in preterm and neonatal infants. Medical instability, time constraints, lack of family participation in the therapeutic program, the complexity of the treatment program, and fear of harming the infant are considerations that may indicate the need for splinting as an adjunctive therapeutic intervention. A number of factors are particularly important in making splints for infants, including splint alignment and padding, strap attachment, and thermoplastic malleability.

Hand Deformities↗

Human parvovirus B19 and pregnancy.

Although B19 infection during pregnancy usually has no adverse effect on the fetus, it can cause fetal death. Recent studies make it possible to estimate risk of infection following different types of exposure and the risk of fetal death after infection. The most common clinical manifestations of B19 infection are erythema infectiosum and aplastic crisis in patients with chronic hemolytic anemias.

Female↗

Day-care center attendance and hospitalization for lower respiratory tract illness.

To identify risk factors associated with hospitalization for acute lower respiratory tract illness, 102 children less than 2 years of age admitted to four Atlanta metropolitan area hospitals between December 1984 and June 1985 with the diagnosis of lower respiratory tract illness were studied. The most common causative agent associated with illness was respiratory syncytial virus, followed by other respiratory viruses, Haemophilus influenzae, and Streptococcus pneumoniae. The 102 case-patients were compared with 199 age- and sex-matched controls. A parent or guardian for each patient and control was interviewed by telephone regarding demographic data, care outside the home, breast-feeding, previous medical history, allergies, and smoking and illness in household members. Five factors were associated with lower respiratory tract illness in both a univariate analysis and a multiple logistic regression model (P less than .05). These factors were the number of people sleeping in the same room with the child, a lack of immunization the month before the patient was hospitalized, prematurity, a history of allergy, and regular attendance in a day-care center (more than six children in attendance). Care received outside of the home in a day-care home (less than or equal to six children in attendance) was not associated with lower respiratory tract illness. The suggestion made by our study and other studies was that for children less than 2 years of age, care outside of the home is an important risk factor for acquiring lower respiratory tract illness, as well as other infectious diseases, and that this risk can be reduced by using a day-care home instead of a day-care center.

Breast Feeding↗

Characterization of the isolated rat flexor digitorum brevis for the study of skeletal muscle phosphorylase kinase phosphorylation.

The flexor digitorum brevis skeletal muscle, a nearly homogeneous fast-twitch oxidative glycolytic fiber type, has been examined for its suitability to explore the regulation of phosphorylase kinase by multisite phosphorylation. A characterization of the adrenergic response of glycogenolytic enzymes, together with the previous data on contractile properties (Carlsen, R. C., Larson, D. B., and Walsh, D. A. (1985) Can. J. Physiol. Pharm. 63, 958-965), has demonstrated that this muscle is stably maintained for the several hours necessary for phosphorylation studies. The phosphorylase kinase in this muscle is primarily the alpha' isozyme, suggesting that the alpha versus alpha' isozyme distribution in muscle is related more to oxidative capacity than to fiber contractile characteristics. Using this muscle system, beta-adrenergic activation of phosphorylase kinase was observed to occur with concomitant phosphorylation of both the alpha' and beta subunits, with the total in the alpha' subunit being approximately 3-fold greater. Similarly, deactivation, following initial adrenergic activation, occurred concomitantly with the dephosphorylation of the two subunits. These results are compatible with the conclusions drawn from previous studies of the isolated enzyme and of the enzyme in perfused rat cardiac muscle, that both alpha' (or alpha) and beta subunit phosphorylation regulate phosphorylase kinase activity.

Adenosine Triphosphate↗

Diagnosis of enterovirus 70 infection by demonstration of IgM antibodies.

Since outbreaks of severe acute hemorrhagic conjunctivitis occur worldwide [Hierholzer and Hatch, 1985] and the majority of the epidemics are caused by enterovirus 70 (EV-70), we developed an EV-70 IgM ELISA to simplify the diagnosis of these outbreaks. The test is based on the capture antibody technique and the use of monoclonal antibodies to EV-70. We detected EV-70 IgM antibodies in 55% of 76 convalescent-phase sera from an outbreak of acute hemorrhagic conjunctivitis in a Brazilian community. Among the 71 acute- and convalescent-phase serum pairs from this outbreak, 49 (69%) demonstrated a 4-fold or greater rise in neutralizing antibody-titer. The titer of IgM antibody began to drop by the fifth week after onset of illness. EV-70 IgM antibodies were not detected in 53 serum pairs with a 4-fold or greater rise in antibodies to other picornaviruses. The EV-70 ELISA proved to simple and relatively rapid to perform, appeared to be specific, and should be sensitive enough to diagnose outbreaks of EV-70 when multiple serum specimens can be tested.

Adolescent↗

Human parvovirus B19 infection during pregnancy.

Human parvovirus B19 (B19) has been implicated as the cause of fifth disease and has been associated with fetal death. We identified pregnant women who were at risk of contracting B19 infection during an outbreak of fifth disease. The sera of 12 women classified at high risk of exposure and 19 classified at low risk were tested during prenatal care, at delivery, or at both times for IgG and IgM antibodies to B19. Four women at high risk but none at low risk were considered infected because they were IgM positive. One IgM-positive woman gave birth to a stillborn hydropic fetus whose tissues were positive for B19 DNA by a nucleic acid hybridization assay. The other three IgM-positive women gave birth to normal offspring, of whom one had IgM-positive cord serum. We conclude that B19 infection during pregnancy can lead to fetal infection with at least two associated outcomes--no adverse effect on the fetus or fetal death.

Adolescent↗

Norwalk virus antigen and antibody response in an adult volunteer study.

To better define the optimum timing of specimen collection and identify alternate ways to diagnose Norwalk virus outbreaks, we looked at the timing of the antibody response and virus excretion in a human volunteer study. The Norwalk virus antibody titers and antigen in stool specimens were examined by biotin-avidin immunoassay. Our data suggest that in epidemic situations, convalescent-phase sera could be collected as soon as 13 days after the onset of illness and acute-phase sera could be collected as late as 5 days after onset. Our data also suggest that if sufficient serum samples are collected, convalescent-phase case and control serum samples can be used to identify Norwalk virus outbreaks. Antigen detection was much less sensitive than seroconversion for detecting infection.

Acute Disease↗

Comparison of monoclonal time-resolved fluoroimmunoassay with monoclonal capture-biotinylated detector enzyme immunoassay for adenovirus antigen detection.

A sensitive time-resolved fluoroimmunoassay (TR-FIA), adapted from TR-FIA procedures already described, was developed with monoclonal antibodies and compared with several enzyme immunoassays (EIAs) for detecting adenovirus antigens in clinical specimens. The most sensitive EIA was an all-monoclonal assay with biotin-labeled detector antibody and streptavidin-peroxidase conjugate. All tests were evaluated with nasopharyngeal aspirate specimens from respiratory illness, with tissue homogenates from patients with systemic infection, and with stool specimens from gastrointestinal illnesses. For respiratory and tissue specimens, the TR-FIA detected adenovirus in 85% of the specimens positive by culture, which was a sensitivity similar to those of the all-monoclonal biotin-avidin EIA (79%) and the polyclonal-capture biotin-avidin EIA (88%). For stool specimens, the TR-FIA detected adenovirus in 100% of the specimens positive by culture, which was a decidedly higher sensitivity than either EIA format (78 and 75%, respectively). The TR-FIA was shown to be an efficient, flexible, and specific test for large numbers of clinical specimens.

Adenoviridae Infections↗

Right-sided laryngeal dysfunction in a horse.

A two year old Thoroughbred colt was presented after a clinical diagnosis of right sided laryngeal hemiplegia had been made. On endoscopic examination the right arytenoid cartilage was immobile during respiration while the left moved normally. Post-mortem examination revealed an abnormal shape of the cricoid and thyroid cartilages which resulted in absence of the right cricothyroid articulation. The defect was thought to be congenital in origin.

Journal Article↗

Concurrent circulation of antigenically distinct strains of respiratory syncytial virus during community outbreaks.

Respiratory syncytial virus (RSV) is considered to be of a single serotype. Antigenic variants are detectable both by neutralization and monoclonal antibodies and have been divided into two broad categories, groups 1 and 2. Group 2 isolates have been considered to be uncommon. We used indirect immunofluorescence with strain-specific monoclonal antibodies to study RSV isolates from hospitalized infants in the greater Boston area. Of 223 RSV isolates recovered over a five-month period in 1983-1984, 125 (56%) were group 1, 92 (41%) were group 2, and 6 (3%) were of an intermediate character. Among 181 community-acquired RSV isolates, both temporal and geographic clustering was observed: group 1 isolates were common from January through March and predominated in central Boston; group 2 isolates were found principally in February and were acquired in outlying, particularly northern, areas. Strain-specific differences were not found with respect to sex, age, or clinical findings. An analysis of 82 RSV isolates from the 1981-1982 season showed 75 (91%) group 1 isolates and 7 (9%) group 2 isolates. We conclude that at least two antigenically distinct groups of RSV isolates may circulate concurrently in the community and that the prevalence of group 2 isolates appears greater than previously suspected.

Antigens, Viral↗

Temporal and geographic patterns of isolates of nonpolio enterovirus in the United States, 1970-1983.

Surveillance data on nonpolio enterovirus (NPEV) from the Centers for Disease Control (Atlanta, Georgia) for the United States from 1970 to 1983 were analyzed for the temporal and geographic patterns of the most common types of NPEV isolated. The number of isolates varied from year to year, partly because of variation in the number of reporting laboratories and partly because of true variation in the rate of isolation. The most common types isolated also varied from year to year, yet the 15 most common types over the entire 14-year period accounted for 65%-89% of isolates for a given year. The 15 most common types of NPEV had two basic patterns of isolation, one in which a type had periodic epidemic years and the other in which it did not. In 11 of the 14 years there was one or more epidemic types, each accounting for greater than or equal to 20% of all isolates of NPEV that year. The six most common isolates in March, April, and May predicted an average of 59% of the total isolates detected in July-December of that year.

Coxsackievirus Infections↗