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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

Humoral and cell-mediated immune responses in healthy children after one or two doses of varicella vaccine.

This study compared the immune responses of healthy children to one or two doses of Oka/Merck varicella vaccine. Both cell-mediated and humoral immune responses were significantly stronger 1 year later among children given two doses 3 months apart than among those given a single dose. Long-term follow-up studies are needed to determine whether two doses of vaccine indeed provide more complete and more durable protection than a single dose against breakthrough varicella in healthy children.

Antibodies, Viral↗

Saliva and serum as diagnostic media for antibody to hepatitis A virus in adults and in individuals who have received an inactivated hepatitis A vaccine.

Saliva was evaluated as a diagnostic fluid for screening individuals for evidence of previous hepatitis A virus (HAV) infection and for evidence of seroconversion after vaccination with inactivated hepatitis A vaccine. A new and simple saliva collection method and an assay for detection of HAV antibody were used; the assay used an antibody capture format. There was complete concordance between the results of saliva-based assays and those of serum-based assays, both of which were used for determining previous natural HAV exposure. However, for vaccine recipients, 100% concordance for saliva-based and serum-based assays occurred only at serum titers of > 9,000 mIU/mL, which were determined with use of the modified HAVAB assay. Saliva provides adequate sensitivity and specificity for determining naturally acquired HAV infection, although it is not useful in clinical trials for determining seroconversion after HAV vaccination.

Adult↗

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↗

Normative neuropsychological test performance: effects of age, education, gender and ethnicity.

Normative data on neuropsychological test performance for a sample of 131 adults (ages 18-49) is presented. All subjects were native speakers of English screened for past or present medical, neurological and psychiatric disorders, including substance abuse. A broad-based battery including measures of intellectual skills, memory and learning, receptive and expressive language, auditory and visual information processing and attention, sensory processing, motor skills, and self-reported anxiety and depression was administered. Means, standard deviations and percentile rankings for all tests are reported. Regression analyses were computed to consider the concurrent influence of sociodemographic factors on all tests. Significant effects of age (M=27.1 yrs), education (M=14.6 yrs), gender (58% male), and ethnicity (62% white) were observed for relatively few test scores. Younger age at testing was associated with better continuous performance test scores. Higher education levels were associated with higher vocabulary and reading scores. Males had higher WAIS-R Information scores and faster Finger Tapping scores compared to females Ethnicity was associated with Full-scale IQ, and additional tests with a verbal component, e.g., Boston Naming Tests, and non-verbal component, e.g., Drawing Tests. We conclude that sociodemographic factors infrequently account for more than 10% of the variance for many neuropsychological test scores.

Journal Article↗

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↗