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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

699 records · Page 39Linked to original sources
PubMedDate not supplied

Pathogenicity of different serogroups of avian salmonellae in specific-pathogen-free chickens.

The pathogenicity of one isolate of Salmonella typhimurium, four isolates of Salmonella heidelberg, three isolates of Salmonella kentucky, two isolates of Salmonella montevideo, one isolate of Salmonella hadar, and two isolates of Salmonella enteritidis (SE), one belonging to phage type (PT)13a and the other to PT34, was investigated in specific-pathogen-free chicks. Three hundred eighty-four chicks were separated into 16 equal groups of 24 chicks. Thirteen groups were inoculated individually with 0.5 ml of broth culture containing 1 x 10(7) colony-forming units (CFU) of either S. typhimurium (one source), S. heidelberg (four sources), S. montevideo (two sources), S. hadar (one source), S. kentucky (three sources), SE PT 13a (one source) or SE PT 34 (one source) by crop gavage. Two groups of 24 chicks were inoculated in the same way with 1 x 10(7) CFU of SE PT4 (chicken-CA) and Salmonella pullorum. Another group of 24 chicks was kept as an uninoculated control group. The chicks were observed daily for clinical signs and mortality. Isolation of salmonella was done from different organs at 7 and 28 days postinoculation (DPI). All the chicks were weighed individually at 7, 14, 21, and 28 DPI. Two chicks chosen at random from each group were euthanatized and necropsied at 7 and 14 DPI and all the remaining live chickens, at 28 DPI. Selected tissues were taken for histopathology at 7 and 14 DPI. Dead chicks were examined for gross lesions and tissues were collected for histopathology. Chicks inoculated with S. pullorum had the highest mortality (66.66%), followed by S. typhimurium (33.33%). Chicks inoculated with S. heidelberg (00-1105-2) and SE PT4 (chicken-CA) had 12.5% mortality and 8.3% mortality, respectively, with SE PT 13a. Ceca were 100% positive for salmonellae at acute or chronic infection compared with other organs. Mean body weight reduction ranged from 0.67% (inoculated with S. kentucky 00-926-2) to 33.23% (inoculated with S. typhimurium 00-372) in the inoculated groups at different weeks compared with uninoculated controls. Gross and microscopic lesions included peritonitis, perihepatitis, yolk sac infection, typhilitis, pneumonia, and enteritis in some groups, especially those inoculated with S. typhimurium, S. heidelberg (00-1 105-2), SE PT4 (chicken-CA), and S. pullorum.

Animals↗
PubMedDate not supplied

Theories and models supporting prevention approaches to alcohol problems among youth.

The Alcohol, Drug Abuse, and Mental Health Administration's Office for Substance Abuse Prevention (OSAP) was established to initiate programs to provide prevention and early intervention services for young people, especially high-risk youth. OSAP's starting point was the theories and models that provide the background body of knowledge. The models summarized here guide new prevention efforts and provide a framework for analyzing diverse experiences in the field. The goal has been to develop strategies based on theories and models of prevention that can reverse or prevent adolescent alcohol use. Among the psychosocial models, research in social learning theory is the theoretical basis for prevention efforts using the team approach among individuals, small groups, families, and communities. A prevention technique based on cognitive dissonance theory proposes verbal inoculations to establish or strengthen beliefs and attitudes, helping a young person to resist drinking, which may be in conflict with another, more desirable goal. In the developmental concept adolescence is a period of role confusion out of which the person's identity should emerge. Prevention efforts built on this view seek to help adolescents to form positive identities by achievement as students, athletes, and in community roles. Behavioral intention theory provides a framework for understanding the role of perceived social norms in directing behaviors. In the social development model, prevention programs should create positive peer groups and ensure that the social environment does not give mixed messages. Health behavior theory is the basis for prevention strategies directed toward a person's entire behavior instead of one aspect. The stages of the drug involvement model form the basis for prevention programs providing early intervention directed at the so-called gateway drugs.Among the communications models, the health promotion concept advocates a comprehensive approach in developing health campaigns and attention to the five major elements of the communications process. Mass media campaigns based on the communication-behavior change concept address the steps required to move a target population from initial awareness of interest in a problem to the adoption and maintenance of advocated attitudes or behaviors.Among public policy models, researchers have concluded that higher real prices on alcohol and restricted availability have the effect of lowering alcoholic beverage consumption among young people and the incidence of heavy and frequent drinking.Raising the minimum age for purchase has been found to reduce the rate of automobile accidents involving young persons. Essential components of prevention strategies and approaches are presented.

Adolescent↗
PubMedDate not supplied

Carotid endarterectomy. The timing of perioperative antiplatelet therapy by indium 111 labelled platelets study in canines.

Bilateral carotid endarterectomy (CEA) was performed in a series of 16 dogs, one of the arteriotomies being closed by direct suture and the other with an autologous vein patch. Platelets obtained at the induction of the anaesthetic were labelled with Indium 111 Oxine and subsequently re-infused prior to restoration of blood flow. Post-operative sequential platelet counts using a Selo CSZ counter were undertaken, which demonstrated a substantial rise at the sites of CEA. These counts rose to peak levels between 7-88 minutes after declamping with a median peak time of 20 minutes. Continued high levels of labelled platelet accumulation persisted for 48-96 hours following CEA and in some instances persisted for three weeks. These studies suggest that antiplatelet agents should therefore be active when carotid declamping occurs and administered for at least three weeks following CEA.

Animals↗
PubMedDate not supplied

Stress reduction prior to oral surgery.

Patients about to undergo oral surgical procedures may be fearful and anxious. It is thought that stress reduction can be attained by relaxation and reassurance. One time stress reduction techniques were tested on 100 patients prior to oral surgery and measurements of stress were made prior to and during the procedures. Patients were divided randomly into four groups: group one patients received general surgical information about tooth removal; group two patients listened to a relaxation tape; group three patients listened to a combination of surgical information and relaxation information tape; and group four patients had no intervention. The day of oral surgery, patients were administered Corah's Dental Anxiety Scale. In addition, measurements of peripheral skin temperature, frontalis EMG for facial muscle tension and blood pressure recordings were made. The measurements were taken prior to and after the patients listened to the information mentioned above on audio tapes, (groups 1-3) or relaxed in their own way (group 4). Self assessment of anxiety reduction was recorded and evaluation of relaxation was made by the oral surgeon during the surgical procedure. Observations were made relating to age, sex, degree of surgical difficulty and presence or absence of preoperative pain. A significant decrease in blood pressure (p_.01 was noted between the experimental and control group. Reduction of anxiety was notably seen with group three patients, where EMG and temperature differences varied from the control group. It was also noted that all patients perceived some degree of relaxation.

Adult↗
PubMedDate not supplied

DNA characterization of Lyme disease spirochetes.

Lyme disease spirochetes (LDS) have phenotypic characteristics of both treponemes and borreliae. To ascertain whether one or more species of LDS exist, as well as their taxonomic status, we determined the DNA base (G + C) content for three strains of LDS, the DNA relatedness of ten strains isolated in the United States or Europe, and the DNA relatedness of LDS to other spirochetes. The G + C content of the three LDS strains was 28.1-29.0 mol%, most similar to those of Borellia hermsii (30.6 mol %) and Treponema hyodysenteriae (25.6 mol %) among the other spirochetes tested. DNA hybridization studies of nine LDS strains to a reference strain isolated from human blood revealed divergence (unpaired bases) within related nucleotide sequences of only 0.0-1.0 percent, indicating the strains were one species. Similarly, relatedness values of seven strains to the reference strain were high: 58-98 percent (mean, 71 percent) in 50 degrees C reactions and 50-93 percent (mean, 69 percent) in 65 degrees C reactions. Labeled DNA from B. hermsii was 30-40 percent related to three Lyme disease spirochete strains in 50 degrees C reactions and 8-10 percent related in 65 degrees C reactions. In contrast, DNA from the reference LDS strain showed relatedness of only 1 percent to DNAs of two leptospires and only 16 percent to DNA from T. hyodysenteriae. We conclude that LDS are a single species, genetically unlike treponemes or leptospires, which belong in the genus Borrelia.

Borrelia↗
PubMedDate not supplied

Effects of child visitation in adult critical care units: a pilot study.

OBJECTIVE: To examine the behavioral and emotional responses of the child and of the nonhospitalized adult family member (NHAFM) to facilitated child visitation in the critical care setting. DESIGN: Quasi-experimental, posttreatment design. SETTING: An adult surgical intensive care unit at a large Midwestern teaching hospital. PARTICIPANTS: Twenty families participated in the study, 10 families in a restricted and 10 families in a facilitated visitation group. Each family unit had a child, an NHAFM, and a critically ill family member. In the control group the NHAFMs visited the patient in the customary routine, but children were restricted from visiting. After a 2-week waiting period a facilitated child visitation intervention was implemented for the experimental group. OUTCOME MEASURES: The child completed measures on anxiety as measured by the Manifest Anxiety Scale and behavioral and emotional changes as measured by the Perceived Change Scale. The NHAFM completed measures on anxiety as measured by the State-Trait Anxiety Inventory and mood as measured by the Mood Adjective Check List. Family functioning, as measured by the Feetham Family Functioning Survey, and life event changes, as measured by the Life Event Scale, were examined as extraneous variables. INTERVENTION: The Child Visitation Intervention encompassed systematic facilitation and supervision of children visiting a critically ill adult family member in a surgical intensive care unit and provision of emotional support before, during, and after visitation (the intervention protocol may be obtained from the investigators on request). RESULTS: Children in the facilitated visitation group had a greater reduction (t = 4.0, df = 18, p = 0.0004) in negative behavioral and emotional changes as measured by the Child-Perceived Change Scale when compared with children in the restricted visitation group. CONCLUSION: Facilitated child visitation may help children deal with the critical illness of an adult family member and deserves further study.

Adolescent↗
PubMedDate not supplied

Racial differences in late prenatal care visits.

The purpose of this study was to examine potential racial disparities in the use of prenatal care beyond what could be measured by the Kessner Index. The data were obtained from the 1986 Massachusetts Prenatal Care Survey, a follow-back study of 2587 postpartum women, which had as its primary objective the identification of barriers to adequate use of prenatal care. This investigation examined the number of prenatal visits reported for each month of pregnancy and found that white women reported significantly more visits than black women only in the eighth and ninth months of pregnancy. This racial difference remained after we controlled for gestational age, sociodemographic factors, reported barriers to care, payor status, and access to care. This study suggests that racial differences in use of late prenatal visits need direct attention if the gaps in use of prenatal care and adverse birth outcomes are to be lessened.

Adolescent↗