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PubMed1996

Vestibular deficits in deaf children.

Considerable knowledge has been accumulated regarding acquired and congenital deafness in children. However, despite the intimate relationship between the auditory and vestibular systems, data are limited regarding the status of the balance system in these children. Using a test population of 15 children, aged 8 to 17 years, we performed electronystagmography testing. The test battery consisted of the eye-tracking (gaze nystagmus, spontaneous nystagmus, saccade, horizontal pursuit and optokinetic) tests, positional/positioning (Dix-Hallpike and supine) tests, and rotational chair tests. With age-matched controls, five children were tested in each of the following three categories: normal hearing, hereditary deafness, and acquired deafness. The children in the hereditary deafness category were congenitally deaf and had a family history of deafness. Those subjects in the acquired deafness category had hearing loss before the age of 2 years, after meningitis. Analysis of variance demonstrated significant differences between the two deaf groups and the control subjects in the gaze nystagmus test, saccade latencies, horizontal pursuit phase, and Dix-Hallpike and supine positionally provoked nystagmus. Also, significant differences were found in rotational chair gain and phase between the deaf and normal-hearing children. The children with acquired deafness exhibited the most profound results. In addition, there were significant differences in rotational chair gain between the acquired and congenitally deaf children. No differences were noted in horizontal pursuit gains, saccade accuracies, or saccade asymmetries. These preliminary data demonstrate that the etiologic factors responsible for congenital and acquired deafness in children may indeed affect the balance system as well. These findings of possible balance disorders in conjunction with the profound hearing loss in this patient population will have prognostic implications in the future evaluation, treatment, and rehabilitation of these patients.

Adolescent↗
PubMed1991

Comparative study of diagnostic testing for feline leukemia virus infection.

Results of commercially available diagnostic test kits and commercial laboratory test results were compared for ability to detect FeLV antigen. Results of the immunofluorescent antibody (IFA) test were compared with test kit ELISA results and with results of a system in which samples were applied to an absorbent material, dried, sent to a laboratory, eluted, and assayed by a plate ELISA. Test kits were generally highly sensitive and specific, compared with the IFA test performed at a commercial laboratory. Feline heterophile antibody, specific for mouse immunoglobulin, was detected in approximately 0.14 to 0.57% of the cat population. Test kits B, E, and D contain reagents that correct for antimouse antibodies. During 1989 and 1990, 2,229 feline serum samples were tested for FeLV antigen (gsa p27); positive ELISA results were obtained for 204 (9%) of the samples. Results for 32 (1.4%) samples were interpreted as equivocal (color development slightly exceeded that of the negative control, but was much less than that of the positive control). Collectively, the data indicate that when testing serum or saliva, a negative test result may be a good predictor that a cat is not infected. In populations of cats in which FeLV prevalence is low, a positive test result may not be reliable and thus, a confirmatory test should be performed.

Animals↗
PubMed1996

Auditory brainstem response screening for hearing loss in high risk neonates.

The present paper reports the findings of a 7 year study evaluating the use of the auditory brainstem response (ABR) as the basis of a hearing screening procedure in a group of newborns at increased risk of hearing impairment. A Special Care Baby Unit (SCBU) population of 417 infants with diverse clinical backgrounds and treatment histories was tested for hearing impairment at birth using ABR audiometry. Some 332 passed the original screen at 30 dBnHL test level in both ears. Of the failure group, 18 did not survive and 32 had some degree of hearing impairment confirmed, nine of which were sensorineural in origin. An increased incidence of persistent middle ear disease was also noted in the failure group. A detailed operational analysis demonstrates that provided appropriate pass/fail criteria are adopted, the ABR technique offers excellent sensitivity and specificity for the detection of significant hearing loss in the test population. Furthermore, the study establishes that implementation of an ABR-based screening programme could reduce the average age at detection of permanent hearing loss by 7 months. A cost assessment shows that the introduction of such a targetted screening procedure could be done at a reasonable outlay.

Cost-Benefit Analysis↗
PubMed1993

Comparison of four second generation kits for detection of IgG antibodies against Helicobacter pylori in adults.

Four serological kits for detection of IgG antibodies against H. pylori were tested on 132 adult patients with dyspeptic symptoms. Presence of H. pylori infection was established when either culture or microscopy of gastric biopsies were positive. The prevalence of H. pylori infection was 55% in the test population. With Anti-H. pylori MTP-assay (Roche), Pylori stat test kit (Whittaker), HM-CAP (Enteric Products Inc.) and Pyloriset EIA-G (Orion) the sensitivities were 97%, 95%, 81% and 68% respectively, the specificities were 53%, 56%, 71% and 69% respectively, the positive predictive values 72%, 74%, 79% and 74% respectively and the negative predictive values were 94%, 92%, 79% and 64% respectively.

Adolescent↗
PubMed2004

Central tolerance to tissue-specific antigens mediated by direct and indirect antigen presentation.

Intrathymic expression of tissue-specific antigens (TSAs) by medullary thymic epithelial cells (Mtecs) leads to deletion of autoreactive T cells. However, because Mtecs are known to be poor antigen-presenting cells (APCs) for tolerance to ubiquitous antigens, and very few Mtecs express a given TSA, it was unclear if central tolerance to TSA was induced directly by Mtec antigen presentation or indirectly by thymic bone marrow (BM)-derived cells via cross-presentation. We show that professional BM-derived APCs acquire TSAs from Mtecs and delete autoreactive CD8 and CD4 T cells. Although direct antigen presentation by Mtecs did not delete the CD4 T cell population tested in this study, Mtec presentation efficiently deleted both monoclonal and polyclonal populations of CD8 T cells. For developing CD8 T cells, deletion by BM-derived APC and by Mtec presentation occurred abruptly at the transitional, CD4high CD8low TCRintermediate stage, presumably as the cells transit from the cortex to the medulla. These studies reveal a cooperative relationship between Mtecs and BM-derived cells in thymic elimination of autoreactive T cells. Although Mtecs synthesize TSAs and delete a subset of autoreactive T cells, BM-derived cells extend the range of clonal deletion by cross-presenting antigen captured from Mtecs.

Animals↗
PubMed2006

Linkage disequilibrium blocks, haplotype structure, and htSNPs of human CYP7A1 gene.

BACKGROUND: Cholesterol 7-alpha-hydroxylase (CYP7A1) is the rate limiting enzyme for converting cholesterol into bile acids. Genetic variations in the CYP7A1 gene have been associated with metabolic disorders of cholesterol and bile acids, including hypercholesterolemia, hypertriglyceridemia, arteriosclerosis, and gallstone disease. Current genetic studies are focused mainly on analysis of a single nucleotide polymorphism (SNP) at A-278C in the promoter region of the CYP7A1 gene. Here we report a genetic approach for an extensive analysis on linkage disequilibrium (LD) blocks and haplotype structures of the entire CYP7A1 gene and its surrounding sequences in Africans, Caucasians, Asians, Mexican-Americans, and African-Americans. RESULT: The LD patterns and haplotype blocks of CYP7A1 gene were defined in Africans, Caucasians, and Asians using genotyping data downloaded from the HapMap database to select a set of haplotype-tagging SNPs (htSNP). A low cost, microarray-based platform on thin-film biosensor chips was then developed for high-throughput genotyping to study transferability of the HapMap htSNPs to Mexican-American and African-American populations. Comparative LD patterns and haplotype block structure was defined across all test populations. CONCLUSION: A constant genetic structure in CYP7A1 gene and its surrounding sequences was found that may lead to a better design for association studies of genetic variations in CYP7A1 gene with cholesterol and bile acid metabolism.

Black or African American↗
PubMed1978

The immunoglobulin allotypes (Gm and Km) of twelve Indian tribes of Central and South America.

The Gm and Km immunoglobulin allotypes are presented, for the first time, for six South American Indian tribes (Baniwa, Kanamari, Kraho, Makiritare, Panoa, and Ticuna) and one Central American tribe (Guaymi). Additional allotype information is presented for five previously reported South American tribes (Cayapo, Piaroa, Trio, Xavante and Yanomama). The distributions of the Gm and Km allotypes among all the tribal populations tested to date are reviewed and evidence is presented for the presence of a north (high)-south(low) cline in Km frequency. The wave theory of the populating of the South American continent was tested by an examination of the distribution of six alleles (Gmax;g, Gma;b0,3,t,Dia,Rx,TFDChi, and 6PGDC), absent in some populations but with polymorphic proportions in others. The present, limited, data failed to confirm the theory.

Alleles↗
PubMed1992

Increased platelet membrane fluidity as a diagnostic marker for Alzheimer's disease: a test in population-based cases and controls.

To test whether increased platelet membrane fluidity as measured by decreased steady state fluorescence anisotropy (rs) of diphenylhexatriene is a biologic/diagnostic marker for Alzheimer's disease (AD), we enrolled 95 clinically diagnosed, probable AD cases from our Alzheimer's Disease Patient Registry and 133 control subjects of similar age and sex randomly selected from the same population base as the cases. We measured rs in platelet membranes following published assay procedures. Laboratory personnel and investigators were blind to the identity of the samples; cases and controls were assayed in random order. Our analyses showed that the distributions of rs values were unimodal and similar for cases and controls. The overall mean differences (control mean-case mean) for the two established assay methods tested were 0.0011 and 0.0003. A nonparametric Wilcoxon rank sum test also showed no difference between cases and controls. Multivariate analysis adjusted for the significant effects of the processing date and analysis platelet recovery led to a final model with the adjusted mean difference of 0.0007 for the principal method. Increased platelet membrane fluidity is not an antemortem diagnostic or biologic marker for AD in our population.

Aged↗
PubMed1999

Detection of HLA-E and -G DNA alleles for population and disease studies.

HLA-E and -G genes show a restricted polymorphism encoding for molecules whose variability is limited at the peptide binding site. Fourteen alleles that give rise to only three productive proteins for HLA-G (*0101, *0103 and *0104) and five alleles with three different proteins for HLA-E (*0101, *0102 and *0103) have been described. Expression of these molecules is low and found in many tissues for HLA-E: HLA-G protein is expressed in extravillous trophoblast cells and thymic epithelium. Molecular studies have shown how HLA-G and HLA-E bind to natural killer (NK) cells immunoglobulin and lectin-type inhibitory receptors. HLA-E may act as a sentinel of the cell; if classical class I and HLA-G are being expressed, HLA-E molecules may reach the cell surface and inhibit the lysis by NK cells. Most findings are consistent with the hypothesis that HLA-E and -G proteins may be tolerogenic molecules at either the T-cell receptor (TcR) (inflammation, graft rejection) or NK level, switching off cells which usually attack foreign (including foetus) or self (autoimmune) antigens. A low HLA-E and -G polymorphism is observed in humans, and their allele frequencies are mostly homogeneous in the populations tested so far. Many studies to detect these alleles are now being performed in isolated populations and also in pregnancy-associated pathologies. In the present paper, standard and detailed techniques to detect HLA-E and -G DNA polymorphism are reported and discussed.

Alleles↗
PubMed2004

A systematic integrative review of infant pain assessment tools.

PURPOSE: To examine the issue of pain assessment in infants by acquiring all available published pain assessment tools and evaluating their reported reliability, validity, clinical utility, and feasibility. DESIGN AND METHODS: A systematic integrative review of the literature was conducted using the following databases: MEDLINE and CINAHL (through February 2004), and Health and Psychosocial Instruments, and Cochrane Systematic Reviews (through 2003). MeSH headings searched included "pain measurement," with limit of "newborn infant"; "infant newborn"; and "pain perception." SUBJECTS: Thirty-five neonatal pain assessment tools were found and evaluated using predetermined criteria. The critique consisted of a structured comparison of the classification and dimensions measured. Further, the population tested and reports of reliability, validity, clinical utility, and feasibility were reviewed. RESULTS: Of the 35 measures reviewed, 18 were unidimensional and 17 were multidimensional. Six of the multidimensional measures were published as abstracts only, were not published at all, or the original work could not be obtained. None of the existing instruments fulfilled all criteria for an ideal measure; many require further psychometric testing. CONCLUSIONS: When choosing a pain assessment tool, one must also consider the infant population and setting, and the type of pain experienced. The decision should be made after carefully considering the existing published options. Confidence that the instrument will assess pain in a reproducible way is essential, and must be demonstrated with validity and reliability testing. Using an untested instrument is not recommended, and should only occur within a research protocol, with appropriate ethics and parental approval. Because pain is a multidimensional phenomenon, well-tested multidimensional instruments may be preferable.

Humans↗
PubMed2006

Comparison of naturally acquired antibody responses against the C-terminal processing products of Plasmodium vivax Merozoite Surface Protein-1 under low transmission and unstable malaria conditions in Sri Lanka.

We report here, for the first time, a comparison of naturally acquired antibody responses to the 42 and 19 kDa C-terminal processing products of Plasmodium vivax Merozoite Surface Protein-1 assayed by ELISA using p42 and p19 baculovirus-derived recombinant proteins, respectively. Test populations comprised patients with microscopy confirmed acute P. vivax infections from two regions endemic for vivax malaria where low transmission and unstable malaria conditions prevail, and a non-endemic urban area, in Sri Lanka. The antibody prevalence to the two proteins, both at the individual and population levels, tend to respond more to p42 than to p19 in all test areas, where >14% of individuals preferentially recognized p42, compared with <2% for p19. In patients with no previous exposure to malaria, 21% preferentially recognized p42, whereas none exclusively recognized p19. A significantly lower prevalence of anti-p19 IgM, but not anti-p42 IgM, was observed among residents from endemic areas compared with their non-endemic counterparts. Individuals from both endemic areas produced significantly less anti-p19 IgM compared with anti-p42 IgM. IgG1 was the predominant IgG isotype for both antigens in all individuals. With increasing exposure to malaria in both endemic areas, anti-p19 antibody responses were dominated by the functionally important IgG1 and IgG3 isotypes, with a concurrent reduction in IgM that was lacking in the non-endemic residents. This antibody switch was also reflected for PvAMA-1 as we previously reported with the identical battery of sera. In contrast, the antibody switch for p42 was restricted to endemic residents with more extensive exposure. These results suggest that an IgM-dominated antibody response against the p42 polymorphic region in endemic residents may interfere with the development of an IgG-dominated "protective" isotype shift to p19, that may complicate vaccine development.

Adolescent↗
PubMed2004

Managing genital infection in community family planning clinics: an alternative approach to holistic sexual health service provision.

OBJECTIVE: To pilot and evaluate sexually transmitted infection (STI) management in community family planning clinics (FPCs). METHODS: Number of STI tests taken, positive results, infections treated, contacts traced/treated, referrals to specialist services and time from testing to treatment were documented as well as age and sex of the population tested. RESULTS: STI tests taken increased from 233 to 308/month and male clients seen increased from 114 to 147/month across all clinics. Chlamydia prevalence rates in one large clinic increased from 6.7% to 11.9%. 82% of those with STIs in this clinic were treated. Of 44 clients treated for chlamydia, 84% had partner notification performed, 0.43 contacts were treated for every client with chlamydia and referrals to specialist services decreased. 70% of STIs were detected in clinic users under the age of 25 and 45.5% of clients tested under the age of 16 had an STI. Before STI treatment was available at FP clinics 52% of clients with STIs attended specialist services after referral and time from testing to treatment was 19 days. Managing STIs in the community increased treatment rates to 82% with a testing to treatment time of 10 days. CONCLUSIONS: The management of uncomplicated genital infection in community FPCs working in partnership with specialist services is a feasible and effective approach to holistic sexual health service provision.

Adult↗
PubMed1989

Arterial oxygen saturation in sedated patients undergoing gastrointestinal endoscopy and a review of pulse oximetry.

The pulse oximeter is a widely used noninvasive monitor which provides a continuous reading of arterial oxygen saturation. We sought to determine if patients with cardiopulmonary disease were at higher risk of oxygen unsaturation than controls during gastrointestinal endoscopy. Patients presenting for upper gastrointestinal endoscopy and/or colonoscopy were placed into one of two groups: A. control population:patients with no history of cardiac and/or pulmonary disease (N = 11); B. test population:patients with a history of cardiac and/or pulmonary disease (N = 39). The procedure was performed by one of 14 equally experienced physicians. The Nellcor N-100 Pulse Oximeter and D-25 finger probe were used to monitor arterial oxygen saturation which was recorded at five minute intervals from commencement of intravenous sedation analgesia to 15 minutes post-procedure. In both groups, the oxygen saturation fell to statistically significant. A: 98.3% to 90.2%; B: 97.7% to 89.5%. However, the amount of unsaturation which occurred in Group B was not statistically different from Group A. Therefore, history of prior cardiac and/or pulmonary disease does not increase the degree of unsaturation from that occurring in patients with no such history. In addition, the effects of age, procedure, duration, I.V. sedation, and individual tolerance on oxygen unsaturation were studied by regression analysis and analysis of variance (ANOVA). Only the upper GI endoscopy patients showed a dependence of oxygen unsaturation upon one of the variables, specifically patient tolerance. It is concluded that patients at risk for hypoxemia during endoscopy or colonoscopy cannot be determined prior to the initiation of the procedure, and it is recommended that all of these patients be given supplemental oxygen as well as monitored with a pulse oximeter.

Endoscopy↗
PubMed1998

Urinary tract infections may trigger relapse in multiple sclerosis.

Multiple Sclerosis (MS), a demyelinating disease of the central nervous system, is the most common neurological disease affecting young adults in North America and, in the majority of cases, is associated with accumulating disability. Urinary tract dysfunction affects up to 90% of the MS population, and urinary tract infections are encountered in up to 74% of the tested population. Viral infections have previously been shown to trigger acute exacerbation and it is our experience that urinary tract infection also commonly precedes relapse, and, when recurrent, is associated with neurologic progression. We present three case studies from our MS Clinic where recurrent UTI was associated with acute exacerbation and neurologic progression refractory to intravenous steroid treatment. Interferons, protein signaling molecules, have recently been found to play a role in acute exacerbation and disease progression in individuals with MS. Viral infections induce interferon release which may activate T cells to produce gamma-interferon. Interferon-gamma precipitates relapse and stimulates production of tumour necrosis factor-alpha, a cytokine directly toxic to oligodendrocytes. Bacterial infections similarly induce interferon release and may activate immune pathways that result in MS exacerbation and neurologic progression.

Acute Disease↗
PubMed2001

A retrospective analysis of contact allergy to lanolin.

BACKGROUND: Lanolin is often stated to be an important sensitizer but some of the available literature is based on the analysis of high-risk patients. OBJECTIVES: To analyse the frequency of contact allergy to lanolin (wool alcohols) in a central London teaching hospital patch-test population. METHODS: Review of 24,449 patients recorded on our database during 1982--96 who were tested with a standard series containing 30% wool alcohols. RESULTS: The mean annual rate of sensitivity to this allergen was 1.7%. The wool alcohols-allergic group contained a higher proportion of females (P < 0.05), and the mean age of both males and females (48.4 and 49.2 years) was higher than that of non-wool alcohols-allergic patients (41.4 and 35.9 years; P < 0.0005). There was no difference in atopic eczema status between these groups. The highest prevalence of allergy to wool alcohols was among patients with lower leg dermatitis (6.0%; 95% confidence interval, CI 4.46--7.54), followed by those with anogenital dermatitis (3.23%; 95% CI 1.81--4.65). There was an unexplained decline in the rate of positive patch tests to Amerchol L-101. However, some patients who reacted to this were negative with wool alcohols, so it may be a useful additional test reagent. The mean rates of allergy to Eucerin (0.65% per annum) and 50% hydrogenated lanolin in petrolatum (1% per annum) were low, and we no longer use these as test reagents. CONCLUSIONS: This study illustrates that lanolin sensitization has remained at a relatively low and constant rate even in a high-risk population (i.e. patients with recent or active eczema).

Adolescent↗
PubMed1984

Ten years of "civilization": fitness of Canadian Inuit.

Data on the cardiorespiratory fitness of the Canadian Inuit has been obtained before and after 10 yr exposure to "white civilization." The population tested comprises 201 males (aged 9-76 yr) and 143 females (aged 10-69 yr), about 70% of the eligible population of Igloolik (69 degrees 40'N). During direct maximum tests to exhaustion, a higher maximum heart rate was attained in 1980-81 (194.4 beats X min-1) than in 1970-71 (184.5 beats X min-1); this probably reflects a closer approach to a centrally limited maximum as the Inuit have become familiar with white investigators. The Astrand nomogram currently underestimates the directly measured maximum O2 intake (VO2max) by some 3% in subjects making a good maximum effort. Comparing the 1980-81 data with results for 1970-71, there has been a 15% decrease of predicted VO2max, accompanied by a 2- to 4-kg increase of body mass, accumulation of subcutaneous fat, and a decrease of leg extension strength, these changes affecting all subjects except boys aged 9-15 yr. It is suggested that the loss of personal fitness is related to adoption of a more sedentary lifestyle, particularly the use of tracked vehicles in place of walking through deep snow.

Adolescent↗
PubMed1998

[Clinical profile of cryptosporidiosis in a pediatric hospital environment in Burkina Faso].

Data concerning Cryptosporidium parvum infection in Black Africa are highly fragmentary. A 12-month study was carried out on 1392 stool specimens from children under 36 months of age with (n = 756) or without diarrhea (n = 629) in the Pediatric Department of Bobo Dioulasso Hospital in Burkina Faso. In 558 children HIV blood tests were also performed. The phenicated fuchsin technique was used to identify Cryptosporidia oocysts. Results were positive in 72 of the 1392 stool specimens tested (5.2%) and in 59 of the 756 stool samples from children with diarrhea (7.8%). Oocysts were not detected in any child under the age of 6 months and the highest incidence of infection was between 6 and 23 months. Detection of oocysts during this year long study was significantly higher from April to June, which corresponds to the beginning of the rainy season in Burkina Faso. Occurrence of diarrhea was not significantly correlated with parasite density. Presence of oocysts was correlated with malnutrition (p < 0.01) and rotavirus infection (p < 0.05). Of the 558 children who underwent HIV testing, only one was positive. In contrast the incidence of HIV infections in the overall population tested was 7%. This study indicates that cryptosporidiasis is a major factor in development of diarrhea and dehydration in the pediatric hospital setting of Burkina Faso. Two other notable findings are that occurrence of cryptosporidiosis is closely linked to hygiene in the population but is not significantly correlated with HIV infection in the pediatric setting in Africa.

Animals↗
PubMed1991

Formulation of a flowable liquid concentrate of Bacillus thuringiensis serotype H-14 spores and crystals as mosquito larvicide.

Bacillus thuringiensis serotype H-14 spores and crystals, produced in 51 fermenters, were centrifuged and resuspended in emulsified palm olein to give 3.2 x 10(11) colony forming units (cfu)/ml. The suspension was mixed with a cassava-molasses-palm olein-charcoal (CMPC-2) mixture which served as the carrier, adhesive, dispersant and protectant. The final concentration of the formulation was 3.2 x 10(9) cfu/ml. The lethal concentrations capable of killing 50% of the test population (LC50) of CMPC-2 during 0, 1 and 2 years of storage at 32 +/- 4 degrees C were 0.056, 0.058 and 0.058 mg/ml respectively as against 0.054, 0.051 and 0.054 mg/ml for the Institut Pasteur Standard-1978 (IPS-78) during the corresponding period. The chi 2 tests showed that the results were homogeneous at P = 0.05. The relative potencies of the preparations were 964.3, 879.3 and 931 International toxic units (ITU) Aedes aegypti as compared with the 1000 ITU assigned to IPS-78. At 95% confidence limits there was no significant difference between the potencies of CMPC-2 and IPS-78. Field tests showed that CMPC-2 provided between 87.5 and 100% control of natural populations of Aedes spp. and Cutex spp. Sedimentation tests showed that CMPC-2 settled markedly during storage. This, therefore, required that the product be thoroughly shaken before use.

Aedes↗