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Biomedical subjects

B Watson

Publications and source records attributed to B Watson.

At least 55 records · Page 3Linked to original sources

Safety and cellular and humoral immune responses of a booster dose of varicella vaccine 6 years after primary immunization.

Four hundred nineteen children and adolescents immunized with live varicella vaccine 4-6 years earlier were enrolled in a study to evaluate the safety and immune response to a booster dose containing approximately 3300 pfu of virus. Of the subjects, 99% (414/419) maintained antibody to varicella zoster virus (VZV) with a geometric mean titer of 25.7 and mean stimulation index (SI) for VZV-specific lymphoproliferation response of 40.3 +/- 5.3 (SE). Some 7-10 days after the booster immunization, seropositivity rates increased to 100% (302/302), and GMT was 143.6 (anamnestic response). At 6 weeks after the booster inoculation, a subset of subjects had 100% seropositivity (74/74) with a GMT of 218.8 and an SI of 58.6. After 3 months, seropositivity was 100% (358/358), GMT was 119.0, and SI was 61.4.

Adolescent↗

Persistence of cell-mediated and humoral immune responses in healthy children immunized with live attenuated varicella vaccine.

Two hundred fourteen healthy seronegative children immunized with various doses of Oka/Merck varicella vaccine were studied for persistence of varicella-zoster virus (VZV)-specific lymphocyte proliferation and antibodies to VZV as determined by a glycoprotein (gp) ELISA. Of the 140 vaccinees tested for VZV-specific lymphocyte proliferation, 94% had positive responses, with a mean stimulation index of 8.9 (range, 3.0-44.6). Of 214 tested by gpELISA, 95% were positive for up to 6 years after immunization; the geometric mean titer was 30.2 (range, 1.3-3510.0). Of 122 individuals tested both by ELISA and for VZV-specific lymphocyte proliferation, 91% had persistence of both responses. Persistence of cellular and humoral immune responses in a large percentage of vaccinees for up to 6 years after immunization with Oka/Merck varicella vaccine suggests that protection against severe varicella is likely to be similarly long-lasting.

Adolescent↗

Response to hepatitis B immunization by infants exposed to HIV.

OBJECTIVE: To assess the antibody response to hepatitis B immunization in HIV-infected and uninfected infants. DESIGN: Cohort, comparing hepatitis B surface-antibody responses of HIV-infected infants with HIV-exposed but uninfected infants. SETTING: Urban children's hospital outpatient clinic for families with HIV-infected members. INTERVENTION: All infants received hepatitis B vaccine according to the American Academy of Pediatrics and Centers for Disease Control and Prevention recommended schedule. RESULTS: Forty-one HIV-exposed or infected infants were immunized with hepatitis B vaccine in the first year of life. Twenty-two out of 24 (92%) HIV-exposed but uninfected infants demonstrated an antibody response to hepatitis B immunization, compared with six out of 17 (35%) HIV-infected infants (P < 0.0005). CD4 percentage and CD4 counts were significantly lower in the HIV-infected infants than in the uninfected infants, but there was no significant difference in CD4 count or percentage between HIV-infected responders and nonresponders. CONCLUSION: The humoral immune response to hepatitis B immunization, administered before 12 months of age, is significantly reduced in HIV-infected children and is independent of CD4 count. Given the large number of infants born each year to pregnant women coinfected with HIV and hepatitis B, further studies to assess the efficacy of increased doses of antigen and variations in the dosage schedule are urgently needed.

CD4 Lymphocyte Count↗

Comparative study of the immunogenicity and safety of two dosing schedules of Engerix-B hepatitis B vaccine in neonates.

A randomized multicenter study compared the routine hepatitis B vaccine schedule of 0, 1, 6 months with an accelerated schedule of 0, 1, 2 months in newborns. Two hundred ninety-nine infants whose mothers were seronegative for hepatitis B were enrolled in the study and randomized to either the routine or accelerated schedule. All infants had blood drawn for antibody titers to hepatitis B at 2, 3, 6 and 7 months of age. For 222 infants data were evaluable, at least for safety; 193 of these 22 had antibody titers that were evaluable. The infants vaccinated on the accelerated schedule developed seroprotective concentrations of antibody more quickly than the infants vaccinated on the routine schedule; 92.6% vs. 66.1% had seroprotective concentrations (> or = 10 mIU/ml) at 3 months of age (P < 0.001). However, infants in the accelerated schedule had lower geometric mean antibody titers at 7 months, 420.0 vs. 3141.8. We conclude that the accelerated vaccination schedule resulted in the more rapid development of seroprotective concentrations of antibody, but levels of antibodies were not as high as in the routinely vaccinated infants at 7 months. These data suggest that an accelerated vaccine schedule can be used in the newborn period. The effectiveness of the accelerated schedule in preventing perinatal infections compared to the standard schedule and the necessity for booster doses of vaccine remain to be studied.

Drug Administration Schedule↗

Recovery of sensorimotor function after distal middle cerebral artery photothrombotic occlusion in rats.

BACKGROUND AND PURPOSE: The purpose of the present study was to delineate the behavioral correlates of focal thrombotic occlusion of the distal middle cerebral artery in rats and to compare the pattern of deficits and subsequent recovery to that following proximal middle cerebral artery occlusion. METHODS: Ten Sprague-Dawley rats underwent photothrombotic occlusion of the distal middle cerebral artery with tandem occlusion of the common carotid arteries (dMCAO group); 10 animals served as operated controls. Beginning on postischemia day 2, animals were given a battery of five tests that assessed sensorimotor integration, attentional mechanisms, and muscle strength; testing continued twice weekly until day 30. Nine days of cognitive testing on the learning set of the water maze task were then given. Infarct volume and hemispheric atrophy were determined for each dMCAO animal. RESULTS: After ischemia, the dMCAO group exhibited significant behavioral deficits in posture reflex, ability to place a forelimb to various stimuli, limb adduction during rearing, and neglect of contralateral space. These deficits showed variable recovery rates. No deficits were observed in muscle strength or cognitive performance. The deficits and patterns of recovery were related to infarct location and to degree of hemisphere atrophy. CONCLUSIONS: The present study suggests that a battery of tests is necessary to fully characterize the pattern of behavioral deficits after focal cerebral ischemia. Location of infarct damage and associated degree of hemispheric atrophy were important variables in determining behavioral outcome. The present results are compared with those of the more traditional model of electrocoagulation of the proximal middle cerebral artery.

Animals↗

Interventions to improve the AMA-discharge rate for opiate-addicted patients.

1. The nursing staff of a chemical dependency unit were troubled by the unit's high against medical advice (AMA) discharge rate. Almost half (46%) the hospital's total AMA discharges (0.9%) were occurring on this 14-bed unit. 2. It was discovered that opiate-addicted patients comprised 26.5% of the unit's AMAs, while representing only 15% of total admissions. At one point, as high as 50% of the opiate-addicted patients were discharged AMA. 3. Many treatment issues and ethical dilemmas are encountered with AMA discharges, such as staff demoralization and debate over who should pay for AMA discharges. 4. Use of the Endicott-Watson Subjective/Objective Opiate Withdrawal Scale yielded a 60% improvement in the AMA discharge rate. When a community resource link was put into place, there was an additional 1% improvement, making the overall improvement rate 61%.

Ethics, Nursing↗

An investigation of barriers to computer-based patient record implementation.

A study was conducted to verify barriers to implementing computer-based patient record systems as perceived by a random sample of members of the American Health Information Management Association, the American Medical Informatics Association, and the Health Information Management and Systems Society. Study respondents were asked to identify the likelihood of their institution overcoming the barriers and which, if any, strategies would be most helpful in overcoming them. This article discusses the study results.

Analysis of Variance↗

Inactivated hepatitis A vaccine in childhood: implications for disease control.

The experience to date with the Merck inactivated hepatitis A vaccine in healthy children 2-16 years old is reviewed. Comparison of response to increasing doses indicates that an intramuscular dose of 25 units results in seroconversion of 99% of children by week 4 following a single dose. Antibody persistence rate is nearly 100% six months later, whether or not a second priming dose is given at week 8. This vaccine has proven highly immunogenic in children and has a favourable safety/tolerability profile. It should be useful for pre-exposure prophylaxis and control of hepatitis A, and should eventually replace immune globulin (Ig) for this indication.

Adolescent↗

Helicobacter pylori infection in elderly people: correlation between histology and serology.

A hundred elderly dyspeptic patients were studied to assess the prevalence of Helicobacter pylori infection and the correlation between histological and serological findings. Eighty-one per cent of the patients with gastritis and 63% with gastric ulcer were H. pylori positive. All patients who had H. pylori negative gastritis and gastric ulcers were on nonsteroidal anti-inflammatory drugs (NSAIDs). There were 24 patients who had evidence of H. pylori infection and were on NSAIDs. H. pylori positive patients had more dyspeptic symptoms in comparison with those who were H. pylori negative. In patients who were taking NSAIDs, the presence of severe active gastritis seemed to correlate with the presence of H. pylori but not with the use of NSAIDs. Serology had a sensitivity of 90% and a specificity of 93% with a negative predictive value of 86%. There was a significant correlation between IgG titre and the degree of inflammation and H. pylori infection. We conclude that H. pylori gastritis is the commonest histopathological finding in elderly dyspeptic patients. H. pylori infection may be an important risk factor in elderly patients who take NSAIDs, increasing their risk of gastric ulcer. H. pylori serology in elderly people has a high sensitivity and specificity comparable with those in young age groups.

Aged↗

Role of serology in monitoring treatment for Helicobacter pylori infection in elderly patients.

Fifteen elderly patients with type B gastritis caused by Helicobacter pylori infection were treated with triple therapy consisting of colloidal bismuth subcitrate, amoxycillin and metronidazole. All were followed up every 6 weeks for 3 months. After triple therapy, eradication of the infection was confirmed in 12 patients (85%) by histology and bacteriology. In this group, a significant reduction in IgG antibody levels against H. pylori was detected (p < 0.001). In a control group of 15 patients with type B gastritis who received no antibacterial treatment, the specific IgG antibody titre remained unchanged during 3 months of follow-up. We conclude that this simple and noninvasive serological test would be suitable for follow-up after treatment of H. pylori infection in elderly patients.

Aged↗

The effect of decreasing amounts of live virus, while antigen content remains constant, on immunogenicity of Oka/Merck varicella vaccine.

The purpose of the study was to establish the minimum immunizing dose of stored Oka/Merck varicella vaccine and mimic effects of prolonged storage of vaccine at freezer temperatures. Ninety children were randomized to one of three groups: group A (1770 pfu/dose), group B (400-500 pfu/dose), or group C (80-160 pfu/dose). Seroconversion rates for groups A-C were 97%, 96%, and 92%, respectively. Group A and B vaccinees had higher antibody titers at 1 year than did group C subjects (P = .01). The difference between groups B and C approached significance (P = .058). At 1 year after immunization, 73%, 83%, and 80% in groups A-C, respectively, demonstrated cell-mediated responses. Since freshly reconstituted vaccine contains 1770 pfu/dose, vaccine failure from loss of potency is unlikely if vaccine is stored properly and administered promptly after reconstitution.

Antibodies, Viral↗

Physical, physiological and performance differences between Canadian national team and universiade volleyball players.

Volleyball has been described as an 'interval' sport with both anaerobic and aerobic components. At the higher skill levels, technical performance may be limited by physical characteristics as well as physical fitness, and performance characteristics such as speed and vertical jump. This investigation compared teams at the two uppermost levels of men's volleyball in Canada for differences in physical, physiological and performance characteristics. The subjects were members of the national (n = 15) and universiade teams (n = 24). The parameters examined included percent body fat, maximal oxygen uptake (VO2 max), anaerobic power, bench press, 20-m sprint time and vertical jumping ability. The only significant difference in physical characteristics between the two teams was in age. Despite similarities in standing and reach height, the national team players had significantly higher block (3.27 vs 3.21 m) and spike (3.43 vs 3.39 m) jumps. An evaluation of anaerobic power measures produced similar power outputs during a modified Wingate test, yet the national team members had higher scores (P less than 0.05) for spike and block jump differences as well as 20-m sprint time. The large aerobic component of elite volleyball play was supported by the high VO2 max value recorded for the national team players (56.7 vs 50.3 ml kg-1 min-1). The results suggest that either years of specific physical conditioning and playing or the selection of individuals for the national team who possess more desirable characteristics as a consequence of genetic endowment, plays a significant role in the preparation of international calibre volleyball players.

Anthropometry↗

Safety and immunogenicity of acellular pertussis vaccine combined with diphtheria and tetanus toxoids in 17- to 24-month-old children.

A double-blind, randomized, controlled trial comparing 4 lots of acellular pertussis-diphtheria tetanus toxoids vaccine (APDT) to whole cell DTP vaccine in 397 children was conducted at 7 clinical centers. Children were immunized at 17 to 24 months of age and sera were obtained pre- and postimmunization. Sera were analyzed for antibody to pertussis antigens (pertussis toxin, filamentous hemagglutinin, with a molecular weight of 69,000 (69k) outer membrane protein and agglutinogens) and to diphtheria and tetanus toxoids. Information concerning local reactions and systemic events was collected daily for 10 days postimmunization. The acellular vaccine produced significantly fewer local reactions than whole cell DTP. Parents reported that drowsiness or fretfulness occurred significantly less often in APDT vaccine recipients compared with whole cell DTP recipients. Fever greater than or equal to 38.3 degrees C occurred in 8% of APDT vaccine recipients and in 15% of whole cell DTP vaccine recipients (P = 0.06). The only significant difference in immune response to pertussis antigens between the two vaccines was for filamentous hemagglutinin (P less than 0.01) for which significantly higher antibody concentrations were found in the APDT vaccine group. We conclude that this APDT vaccine is safe and immunogenic when administered as a booster dose to 18-month-old children.

Antibodies, Bacterial↗

Safety and immunogenicity of acellular pertussis vaccine, combined with diphtheria and tetanus as the Japanese commercial Takeda vaccine, compared with the Takeda acellular pertussis component combined with Lederle's diphtheria and tetanus toxoids in two-, four- and six-month-old infants.

A double blind, randomized, controlled trial compared the safety and immunogenicity of an acellular pertussis vaccine formulated at Lederle using the Takeda acellular pertussis component combined with Lederle diphtheria and tetanus toxoids vaccines (APDT), with the commercially available Japanese Takeda vaccine (APDT-T/J) as a three-dose series to 2-, 4-, and 6-month-old children. Sera were analyzed for antibody to pertussis antigens: lymphocytosis-promoting factor; filamentous hemagglutinin; 69-kDa outer membrane protein; pertussis agglutinogens; neutralizing antibodies to LPF; and to diphtheria and tetanus toxoids. Information concerning local reactions and systemic events were collected daily for 10 days postimmunization. The overall reaction rate was low for both groups. There were no reactions that contraindicated subsequent vaccine and no serious adverse events. For local reactions statistically significant differences between the groups were seen only for a greater incidence of induration in the APDT group at 2 months (12% vs. 0%, P < 0.01), and at 4 months (8% vs. 0%, P = 0.4) compared to the APDT-T/J group. Of the few systemic reactions the only statistically significant difference between the vaccine groups was a greater incidence of fretfulness in the APDT group after the initial immunization (12% vs. 2%, P = 0.05). There were no statistically significant differences in the immune response between the two vaccines at the 7-month visit. We conclude that APDT is equivalent to the commercially available Takeda vaccine (APDT-T/J).

Antibodies, Bacterial↗