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R Anderson

Publications and source records attributed to R Anderson.

At least 181 records · Page 10Linked to original sources
PubMed1998

A simple and rapid method for measuring unconjugated capsular polysaccharide (PRP) of Haemophilus influenzae type b in PRP-tetanus toxoid conjugate vaccine.

The authors developed a simple and rapid method for quantitation of free capsular polysaccharide of Haemophilus influenzae type b (polyribosyl ribitol phosphate, PRP) in PRP-tetanus toxoid conjugate vaccine based on acid precipitation of tetanus toxoid (TT). Acid hydrolysis of PRP during the assay was not detected. The conditions used in the assay did not precipitate unconjugated PRP or adipic acid dihydrazide derivatized PRP. The method was highly reliable, reproducible and sensitive. The accuracy of the assay was confirmed by spiking known amounts of unconjugated PRP to PRP-TT conjugate preparations. A PRP-TT preparation, incubated at 37 degrees C for 6 months showing most of the PRP as unconjugated (87% determined by this method), was not immunogenic in mice for the PRP component even after two injections. In contrast, the same preparation held at 4 degrees C for 20 months, showing 17% unconjugated PRP, induced IgG antibodies to PRP which were boosted after second injection. Therefore, this method is very useful to evaluate the stability of PRP-TT conjugate vaccine. The assay may be useful for characterizing other polysaccharide-protein conjugate vaccines.

Animals↗
PubMed1998

Comparisons of acute toxicity of selected chemicals to rainbow trout and rats.

Median lethal concentration (LC50) and dose (LD50) for 217 chemicals were compared over several exposure routes in rainbow trout and rats. Data were compiled primarily from on-line databases and included octanol-water partition coefficient (Kow), trout LC50, and trout and rat LD50 for oral, dermal, and intraperitoneal (i.p.) routes. Kow and molar lethality data were log-transformed for correlation and regression analyses. Median ratios (rat oral LD50/trout LC50 = 156, rat/trout oral LD50 = 0.80, rat/trout dermal LD50 = 0.43, rat/trout i.p. LD50 = 0.55) demonstrated the effect of similar versus dissimilar exposure routes on lethality, reflecting toxicokinetic differences. Simple linear regressions revealed significant correlations (Bonferroni P < 0.05) for trout LC50 versus rat oral LD50 and for trout LD50 versus rat LD50 when matched on exposure route. When Kow was included with multiple regression to consider the effect of hydrophilic/lipophilic partitioning on uptake and toxicity, correlations improved only for trout LC50 versus rat oral LD50 and for trout i.p. LD50 versus rat i.p. LD50. Stratification of data into pesticides and nonpesticides failed to refine prediction of trout LC50 from rat oral LD50. Simple regressions reported here and in the literature relating fish LC50 and rat oral LD50 exhibited varying degrees of correlation (r = 0.26-0.99), reflecting differences in interspecies sensitivity, chemical group evaluated, and experimental methodologies.

Administration, Cutaneous↗
PubMed1998

The origin and migration of primordial germ cells in the mouse.

Primordial germ cells (PGCs) are the founders of the gametes. They migrate from their origin to combine with the somatic component of the gonad. Progenitors in mice have been recognized in the proximal epiblast. When and how these cells are allocated to the germ line has not been elucidated fully. Numerous growth factors have been described which affect PGC survival, proliferation and directional control during their migration. The extracellular matrix also may play a role in PGC migration, particularly fibronectin and laminin. Once they have arrived at the gonad, PGCs aggregate with one another. The molecules governing this PGC-PGC interaction have yet to be identified.

Animals↗
PubMed1998

Behavioural, physiological and morphological analysis of a line of apolipoprotein E knockout mouse.

Using apolipoprotein E knockout mice derived from the Maeda source [Piedrahita J. A. et al. (1992) Proc. natn. Acad Sci. US.A. 89, 4471 4475], we have studied the influence of apolipoprotein E gene deletion on normal CNS function by neurological tests and water maze learning, hippocampal ultrastructure assessed by quantitative immunocytochemistry and electron microscopy, CNS plasticity, i.e. hippocampal long-term potentiation and amygdaloid kindling, and CNS repair, i.e. synaptic recovery in the hippocampus following deafferentation. In each study there was little difference between the apolipoprotein E knockout mice and wild-type controls of similar age and genetic background. Apolipoprotein E knockout mice aged eight months demonstrated accurate spatial learning and normal neurological function. Synaptophysin and microtubule-associated protein 2 immunohistochemistry and electron microscopic analysis of these animals revealed that the hippocampal synaptic and dendritic densities were similar between genotypes. The induction and maintenance of kindled seizures and hippocampal long-term potentiation were indistinguishable between groups. Finally, unilateral entorhinal cortex lesions produced a marked loss of hippocampal synaptophysin immunoreactivity in both groups and a marked up-regulation of apolipoprotein E in the wild-type group. Both apolipoprotein E knockout and wild-type groups showed immunohistochemical evidence of reactive synaptogenesis, although the apolipoprotein E knockout group may have initially shown greater synaptic loss. It is suggested that either apolipoprotein E is of no importance in the maintenance of synaptic integrity and in processes of CNS plasticity and repair, or more likely, alternative (apolipo)proteins may compensate for the loss of apolipoprotein E in the knockout animals.

Animals↗
PubMed1998

Invisible residents: the chronically mentally ill elderly in nursing homes.

This article presents results from a retrospective study of psychological assessments of elderly persons with chronic mental illness residing in nursing homes. All residents (N = 570) received this assessment as part of federally mandated screening for mentally ill persons residing in long-term care. The process, the Preadmission Screening and Resident Review, was mandated by the Omnibus Budget Reconciliation Act (OBRA 87). These assessments were the first stage in a process to determine if the nursing home was the most appropriate placement for each resident. If nursing home care was deemed appropriate, then a psychological treatment program was to be established within the nursing home setting. The sample ranged in age from 50 to 104 (mean of 70). The majority had a diagnosis of schizophrenia and a history of psychiatric hospitalization occurring early in their life. The assessments did not include any quantifiable data on activities of daily living, cognitive functioning, or level of psychiatric impairment. Therefore, the researchers coded the narrative data so that it could be interpreted. The majority functioned within the none-to-mild range of cognitive impairment, and very few were completely dependent in the need for physical care. The most recorded symptom was social withdrawal. Neuroleptic medications were administered to 64% of elderly persons with chronic mental illness. Importantly, there was no relationship between demographic or clinical information and treatment recommendations. Implications of these findings for psychiatric nurses are discussed.

Activities of Daily Living↗
PubMed1998

Analytical Microscopy in the Real Semiconductor Processing World.

: In the microelectronic semiconductor world we are bombarded with reports of how the drive toward faster, denser, lower power-consuming and more reliable semiconductor products will accelerate with time. This paper discusses the instrumental evolution from visible light microscopy to scanning electron microscopy and on to transmission electron microscopy and scanned probe microscopy. The increased demands placed on specimen preparation of precise locations in a semiconductor chip for microscopy are discussed. Analytical microscopy has to be timely in order to be a viable adjunct to semiconductor manufacturing. The factors governing analysis of turn-around time are explained and an optimum strategy is suggested for effective utilization of finite laboratory resources. The new instrumentation available to the microscopist is introduced along with an overview of the exciting new analyses that will be available in the immediate future.

Journal Article↗
PubMed1998

Responsiveness of the Dermatology-specific Quality of Life (DSQL) instrument to treatment for acne vulgaris in a placebo-controlled clinical trial.

The Dermatology-specific Quality of Life (DSQL) instrument is a new tool which has been developed to address the effects of skin disease and its treatment on physical and social functioning and self-perceptions. Previous reports have demonstrated its cross-sectional validity. The current study examines the DSQL's responsiveness to 12 weeks of acne treatment in a placebo-controlled randomized clinical trial. The DSQL change scores were moderately correlated (r = 0.18 to 0.37) with treatment efficacy parameters including: dermatologist's rating of improvement of acne and a skin irritation score, and highly correlated with patient's global rating of acne severity. Within treatment groups, the DSQL discriminated clinically meaningful changes associated with small and moderate effect sizes. The DSQL total score showed statistically significant differences on nearly all comparisons with placebo. The DSQL dimension scores were sensitive to the most effective therapy compared to placebo. Responsiveness benchmarks are provided for small and moderatesized treatment effects. As a comprehensive instrument, the DSQL is a practical and psychometrically sound tool for use in clinical trials in dermatology.

Acne Vulgaris↗
PubMed1998

Anti-oxidative effects of theophylline on human neutrophils involve cyclic nucleotides and protein kinase A.

The effects were studied of the non-specific phosphodiesterase inhibitor, theophylline (37.5-300 microM), on intracellular levels of cyclic adenosine monophosphate (cAMP) and superoxide generation following exposure of human neutrophils to four different stimuli of neutrophil membrane-associated oxidative metabolism, each of which utilizes a different transductional mechanism to activate NADPH-oxidase, in vitro. Exposure of neutrophils to FMLP (1 microM), the calcium ionophore A23187 (1 microM), and opsonized zymosan (OZ, 0.5 mg/ml) was accompanied by activation of superoxide production and increased concentrations of intracellular cAMP. Inclusion of theophylline resulted in augmentation of cAMP and inhibition of superoxide production by these stimuli. These negative effects of theophylline on neutrophil superoxide generation were mimicked by dibutyryl cAMP and 8-bromo-cGMP, while the inhibitory activity of all 3 agents was antagonized by the protein kinase A inhibitor KT 5720, but not by the G-kinase inhibitor KT 5823. Unlike FMLP, OZ and A23187, intracellular cAMP levels did not increase in cells activated with phorbol-12-myristate-13-acetate (PMA, 25 ng/ml), while oxidant production activated by this stimulus was insensitive to the inhibitory effects of theophylline. These observations suggest that the beneficial, anti-inflammatory interactions of theophylline with human neutrophils are related to the phosphodiesterase inhibitory properties of this agent, and are selective for those pro-inflammatory stimuli which elevate cAMP, resulting in enhanced activity of protein kinase A and inhibition of the production of potentially harmful reactive oxidants by these cells.

Alkaloids↗
PubMed1998

The quality of life of older adults with urinary incontinence: determining generic and condition-specific predictors.

Urinary incontinence (UI) is an unpleasant problem for many adults. This study determined the importance of demographic, health and incontinence variables for the generic and incontinence-specific quality of life (QoL) of older adults (age > or = 60 years). Telephone surveys of adults reporting at least weekly episodes of UI (n = 435) were conducted as part of a randomized, controlled trial. Logistic regression analyses showed that the predictors of generic and incontinence-specific QoL differed. Life satisfaction, a generic outcome, was predicted by education, the number of days in bed due to health problems, the number of days not feeling well and the amount of urine lost. Generic health was related to education, the number of days sick in the previous 30 days and the number of days health issues restricted activities. The incontinence-specific QoL outcomes were predicted by age, mobility difficulties, the amount of urine lost, the frequency of UI, and the number of daytime and night-time voids. The specific QoL measures provide a different profile of those most affected in this sample than that obtained by the generic measures. The most affected are younger persons with severe urine loss. Older persons may have other conditions impinging on QoL and may have adapted behaviourally and psychologically to urine loss.

Aged↗
PubMed1998

Effect of rolipram and dibutyryl cyclic AMP on resequestration of cytosolic calcium in FMLP-activated human neutrophils.

1. We have investigated the effects of the selective phosphodiesterase (PDE) type 4 inhibitor, rolipram (0.01-1 microM) on cytosolic Ca2+ fluxes in FMLP-activated human neutrophils, as well as on superoxide production by, and release of elastase from, these cells. 2. Cytosolic Ca2+ fluxes were measured by use of fura-2 spectrofluorimetry in combination with a radiometric procedure that enables distinction between net efflux and influx of the cation. Superoxide production and elastase release were measured by lucigenin-enhanced chemiluminescence and a colorimetric procedure, respectively. 3. Pretreatment of neutrophils with rolipram did not affect the FMLP-activated release of Ca2+ from intracellular stores, but was associated with dose-related acceleration of the rate of decline in fura-2 fluorescence and with decreased efflux, as well as store-operated influx of 45Ca2+, indicative of enhancement of resequestration of the cation by the endo-membrane Ca2+-ATPase. 4. Inhibition of superoxide production and elastase release was observed at concentrations of rolipram which accelerated the clearance of Ca2+ from the cytosol of FMLP-activated neutrophils. 5. These effects of rolipram on FMLP-activated Ca2+ fluxes, superoxide generation and elastase release were mimicked by pretreatment of neutrophils with dibutyryl cyclic AMP (0.5-4 mM), while theophylline (10-150 microM), a non-specific PDE inhibitor, as well as the beta2-agonist, salbutamol, were less effective. 6. We conclude that rolipram deactivates FMLP-stimulated human neutrophils by enhancement of cyclic AMP-dependent resequestration of cytosolic Ca2+.

Adrenergic beta-Agonists↗
PubMed1998

Polyoxoanions are cytotoxic to malignant glioma cells.

We studied the cytotoxicity of five polyoxoanions on two human malignant glioma cell lines (T98G and 86HG39), a rat glioma cell line (C6) and a human fibroblast cell line (NIH-3T3) using MTT tests to measure the drug concentration killing 50% of the cells (LC50). Cisplatin was used as a reference agent. Cisplatin had the highest efficacy in three of the four cell lines. Only in T98G cells, one of the components (POA5) had a lower LC50 value (1.3 x 10(-6) mol/l) than cisplatin (2.5 x 10(-6)). POA5 was also the most cytotoxic polyoxoanion when the LC50 values of all four cell lines were averaged (6.6 x10(-6)). Average LC50 values of the other compounds were 10.9, 12.6, 19.0 and 19.2 x 10(-6) mol/l in POA1, POA2, POA3 and POA4, respectively. When the benign fibroblasts were used to calculate a therapeutic index as LC50 in fibroblasts divided by LC50 in glioma cells, POA5 was superior to cisplatin. These results indicate that polyoxoanions are cytotoxic for malignant glioma cells and that the most promising compound investigated here was POA5.

3T3 Cells↗
PubMed1998

Effect of tamoxifen on bone fractures in older nursing home residents.

OBJECTIVES: To evaluate the association between tamoxifen (TAM) treatment and rate of bone fractures in older, nursing home residents. PARTICIPANTS: A total of 93,031 women, aged 65 years and older, whose data were part of the 1993 New York State MDS and for whom there was documentation of treatment with at least one medication. SETTING: New York State long-term care facilities. DESIGN: Cross-sectional study via secondary analysis of 1385 matched sets of residents. Each set included one resident who was receiving TAM treatment and up to four residents who were not. MEASUREMENTS: Measurements included age, ethnicity, TAM treatment, hormone replacement therapy, vision impairment, any bone fractures, and, specifically, hip fractures. RESULTS: During the 1.5-year period for which bone fractures are documented in the 1993 MDS, the fracture rates were: 7.62% in women not treated with TAM, 3.20% in women receiving 10 mg TAM daily, and 6.73% in women receiving 20 mg TAM daily. The odds ratio (OR) for bone fractures among women receiving 20 mg TAM daily compared with nontreated women was 0.916 (95% confidence interval (CI): 0.720-1.164; P = .472), and was 0.312 (95% CI: 0.112-0.865; P = .025) for those receiving 10 mg daily. The rates of hip fracture were 4.98%, 2.40%, and 4.57% for controls and women receiving 10 mg and 20 mg TAM daily, respectively. Whereas the hip fracture rate for women receiving 20 mg daily was statistically similar to that of the controls (OR = .963; 95% CI: 0.718-1.291; P = .800), the difference between the controls and those receiving 10 mg daily approached significance (OR: 0.313; 95% CI: 0.096-1.018; P = .054). CONCLUSION: Although standard treatment of 20 mg TAM daily offers no apparent protection against bone fracture in older nursing home residents, a daily 10 mg dose seems to be protective.

Aged↗
PubMed1998

Early stages in male germ cell differentiation in the mouse. Review article.

Primordial germ cells arise during gastrulation and migrate from the hindgut into the gonad primordium during early organogenesis. In this article, we discuss factors that control migration, proliferation and targeting of the PGCs. In particular we discuss how changes in adhesiveness control germ cell positioning in the gonad, and the molecules involved.

Animals↗
PubMed1998

Evaluation of the Abbott LCx ligase chain reaction assay for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine and genital swab specimens from a sexually transmitted disease clinic population.

The Abbott LCx ligase chain reaction (LCR) assay for the simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae was evaluated by using swab and urine specimens from 562 patients. C. trachomatis results by LCR were compared to those by the Gen-Probe PACE 2 assay, whereas N. gonorrhoeae results by LCR were compared to those by culture. The Gen-Probe and LCR assays were performed according to the manufacturers' instructions. Gram-negative diplococci growing on modified Thayer-Martin medium were confirmed as N. gonorrhoeae by the GonoGen II assay. Supplemental data analysis was performed by major outer membrane protein PCR for C. trachomatis and probes for pilin gene detection for N. gonorrhoeae. A true-positive result for each pathogen was defined as a positive result for all three or two of three assays. Overall agreement among the six assays was 94.8%. C. trachomatis prevalence was 16.2%; N. gonorrhoeae prevalence was 5.5%. The overall sensitivity and specificity, respectively, for each test (after supplemental data analysis) were as follows: for C. trachomatis, Gen-Probe, 65.9 and 100%; LCR on urine, 90.1 and 100%; LCR on swab specimens, 96.7 and 100%; and for N. gonorrhoeae, culture, 80.6 and 100%; LCR on urine, 93.5 and 99.8%; and LCR on swab specimens, 96.8 and 100%. For women, the N. gonorrhoeae culture was very insensitive compared to its performance in men (58.3 versus 94.7%, respectively). For C. trachomatis, the Gen-Probe assay's sensitivity was lower for men than for women (62.3 versus 71.1%, respectively). The sensitivity for C. trachomatis detection by LCR on urethral and cervical swab specimens was 96.2 and 97.4% for men and women, respectively. For men, swab results were slightly better than urine results for both pathogens (sensitivity for C. trachomatis in swab and urine specimens, 96.2 and 92.5%, respectively; sensitivity for N. gonorrhoeae in swab and urine specimens, 100 and 94.7%, respectively), while for women, cervical swabs were superior in sensitivity to urine samples for detecting C. trachomatis (swab, 97.4%; urine, 81.6%) and equivalent for N. gonorrhoeae (swab, 92.3%; urine, 91.6%). The LCx LCR appears to be both sensitive and specific for the detection of C. trachomatis and N. gonorrhoeae when performed on urine or genital swab samples. Swab samples had better sensitivity than urine samples for the detection of both pathogens.

Adolescent↗
PubMed1998

Why do symptomatic patients delay obtaining care for tuberculosis?

The resurgence of tuberculosis (TB) has coincided with deteriorating access to care for high-risk populations. We sought to determine what perceived access barriers delayed symptomatic TB patients from obtaining care. In order to do this, we conducted a survey in Los Angeles County, California, using a consecutive sample of patients with active TB as confirmed by the county TB control authority. The measures used in the study were a self-reported delay in seeking care of more than 60 d from symptom onset, a period sufficient to cause skin-test conversion in exposed contacts, and self-reported access barriers. The county TB registry provided supplementary clinical data. We found that one in five of the 248 symptomatic respondents (response rate: 60%) delayed obtaining care for > 60 d (mean = 74 d, SD = 216 d). During the delay, patients exposed an average of eight contacts. As compared with the rest of the sample, delay was more common in those who were unemployed (25% versus 14%), concerned about cost (27% versus 14%), anticipated prolonged waiting-room time (26% versus 14%), believed they could treat themselves (31% versus 14%), anticipated difficulty in getting an appointment (28% versus 16%), were uncertain about where to get care (33% versus 16%), and feared immigration authorities (47% versus 18%) (p < 0.05). Logistic regression revealed that uncertainty about where to get care, unemployment, and belief in the efficacy of self-treatment independently predicted delay > 60 d. Illness severity as measured by chest radiography, sputum smears, and symptoms had little impact on delay. We conclude that because access variables such as lack of employment and knowledge about where to obtain care were more closely associated with clinically significant delay than was severity of illness, these results raise concerns about the equity of access to care among TB patients. The results suggest that improving the availability of services for high-risk groups may substantially reduce TB patients' delay in obtaining care, and thus may limit the spread of the disease.

Adult↗
PubMed1998

Ankle fracture classification: a comparison of reliability of three X-ray views versus two.

Our hypothesis was that malleolar ankle fractures could be classified with two radiographic views as reliably as with three views. Four different observers independently evaluated 99 sets of ankle radiographs. The examiners classified the ankle fractures by using both the Lauge-Hansen and Danis-Weber systems. The interobserver and intraobserver variations were analyzed by kappa statistics. With regard to intraexaminer reliability, the examiners demonstrated excellent accord in classifying the fractures in the Danis-Weber system with either three views or two views. The kappa values were comparable. In the Lauge-Hansen system, three examiners demonstrated excellent accord and one examiner demonstrated good accord in classifying the fractures. Similar kappa values were generated when examiners classified fractures with either three views or two views. With regard to interexaminer reliability, good to excellent accord was demonstrated overall among the four examiners when they used the Danis-Weber system with either three views or two views. The examiners were in good agreement when they used the Lauge-Hansen system. Similar kappa values were generated whether the examiners used three views or two views. Three radiographic views are usually ordered for evaluation of an acute ankle injury. Previous studies have shown that only two views are needed for diagnosis of a malleolar ankle fracture. This study demonstrates that malleolar ankle fractures can be classified with two views, lateral or mortise, with a reliability as good as that achieved with three views. The best agreement is achieved with lateral and mortise views.

Ankle Injuries↗