bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specificities and Opsonophagocytic Activities of Antibodies to Pneumococcal Capsular Polysaccharides in Sera of Unimmunized Young Children
Authors: Soininen Anu , Karpala Maijastiina , Wahlman Sirkka-Liisa , Lehtonen Hannele , Käyhty Helena 
Published: August 2002

ABSTRACT
An enzyme immunoassay (EIA) for antibodies to pneumococcal capsular polysaccharides (Pnc PSs) detects in some cases antibodies that are cross-reactive within different Pnc PSs. Recently, it has been suggested that for detection of only serotype-specific antibodies, EIA can be modified by removing cross-reactive antibodies by absorption with an irrelevant PS, e.g., the type 22F PS. The opsonophagocytosis assay measures the functional activities of antibodies in vitro, and the results of that assay correlate with in vivo protection better than measurement of the antibody concentration by EIA. We compared these different methods for measuring antibodies to type 1, 6B, 11A, 14, 19F, and 23F Pnc PSs in the sera of unimmunized young children who had been monitored for pneumococcal carriage, acute otitis media, and acquisition of antibodies to Pnc PSs from 2 to 24 months of age. Serum samples with antibody increases after contact with a pneumococcus of a homologous serotype contained specific antibodies and often had opsonophagocytic activity (OPA) (20 of 46). In samples with antibody increases from children who had not had contact with a pneumococcus of a homologous serotype, the antibodies found to be type specific by conventional EIA were usually cross-reactive and infrequently had OPA (10 of 68). When type 22F PS absorption was used in the EIA, most of the false antibody increases were eliminated, but most of the true antibody increases were still detected and the association between the antibody concentration detected by EIA and OPA was improved. However, there were serotype-dependent differences in the frequency of OPA. Use of absorption with a heterologous PS in EIA should be encouraged, and both the specificity of EIA and the sensitivity of opsonophagocytic assays should be further evaluated and improved.
BacillusSpecies Are Present in Chewing Tobacco Sold in the United States and Evoke Plasma Exudation from the Oral Mucosa
Authors: Rubinstein Israel , Pedersen Gerald W. 
Published: August 2002

ABSTRACTFiveBacillusspecies, predominantlyBacillus megateriumandBacillus pumilus, were isolated from two popular brands of commercially available chewing tobacco [(5.0 ± 1) × 106CFU/ml of supernatant; results for four experiments]. Moreover, the supernatant of theBacillusculture evoked plasma exudation from postcapillary venules in the intact hamster cheek pouch, exudation that was mediated by the kallikrein/kinin metabolic pathway. Taken together, these data indicate thatBacillusspecies contaminate chewing tobacco commercially available in the United States and elaborate a potent exogenous virulence factor(s) that injures the oral mucosa.
Affordable CD4
+
-T-Cell Counting by Flow Cytometry: CD45 Gating for Volumetric Analysis
Authors: Janossy George , Jani Ilesh V. , Bradley Nicholas J. , Bikoue Arsene , Pitfield Tim , Glencross Debbie K. 
Published: August 2002

ABSTRACT

The flow cytometers that are currently supported by industry provide accurate CD4
+
-T-cell counts for monitoring human immunodeficiency virus disease but remain unaffordable for routine service work under resource-poor conditions. We therefore combined volumetric flow cytometry (measuring absolute lymphocyte counts in unit volumes of blood) and simpler protocols with generic monoclonal antibodies (MAbs) to increase cost efficiency. Volumetric absolute counts were generated using CD45/CD4 and CD45/CD8 MAb combinations in two parallel tubes. The percentage values for the various subsets were also determined within the leukocyte and lymphocyte populations utilizing a fully automated protocol. The levels of agreement between the newly developed method and the present industry standards, including both volumetric and bead-based systems using a full MAb panel for subset analysis, were tested by Bland-Altman analyses. The limits of agreement for CD4 counts generated by the volumetric methods using either CD45/CD4 (in a single tube) or the full Trio MAb panel (in three tubes) on the CytoronAbsolute flow cytometer were between −29 and +46 cells/mm
3
with very little bias for CD4 counts (in favor of the Trio method: +8 CD4
+
lymphocytes/mm
3
; 0.38% of lymphocytes). The limits of agreement for absolute CD4 counts yielded by the volumetric CD45/CD4 method and the bead-based method were between −118 and +98 cells/mm
3
, again with a negligible bias (−10 CD4
+
lymphocytes/mm
3
). In the volumetric method using CD45/CD8, the strongly CD8
+
cells were gated and the levels of agreement with the full Trio showed a minor bias (in favor of the Trio; +40 CD8
+
cells/mm
3
; 5.2% of lymphocytes) without a significant influence on CD4/CD8 ratios. One trained flow cytometrist was able to process 300 to 400 stained tubes per day. This workload extrapolates to a throughput of >30,000 samples per year if both CD45/CD4 and CD45/CD8 stainings are performed for each patient or a throughput of >60,000 samples if only CD45/CD4 counts are tested in a single tube. Thus, on the basis of the high efficiency and excellent agreement with the present industry standards, volumetric flow cytometers with automated gating protocols and autobiosamplers, complemented by generic CD45, CD4, and CD8 MAbs used in two-color immunofluorescence, represent the most suitable arrangements for large regional laboratories in resource-poor settings.
Double-Blind Study To Evaluate Flow Cytometry Analysis of Anti-Live Trypomastigote Antibodies for Monitoring Treatment Efficacy in Cases of Human Chagas' Disease
Authors: Martins-Filho Olindo Assis , Eloi-Santos Silvana Maria , Carvalho Andréa Teixeira , Oliveira Rodrigo Corrêa , Rassi Anis , Luquetti Alejandro Ostemayer , Rassi Gustavo Gabriel , Brener Zigman 
Published: August 2002

ABSTRACTThe validation of flow cytometry analysis of anti-live trypomastigote antibodies (FC-ALTA) to monitor cure after treatment of Chagas' disease was evaluated with serum samples from treated and nontreated chagasic patients. After optimization of the original technique, toward better sensitivity and applicability to field surveys, we design a double blind study of 94 coded samples classified into the following categories: patients not treated (NT) and patients treated but not cured (TNC), both presenting positive conventional serology and xenodiagnosis; patients treated and cured (TC), showing negative serology and xenodiagnosis; and patients treated under evaluation (TUE), who presented positive or oscillating conventional serology (CSA) but negative xenodiagnosis. Coded samples, diluted 1:256, were assayed by incubation with live cell culture trypomastigotes, which were subsequently stained with fluorescein isothiocyanate-conjugated anti-human immunoglobulin G, with prior fixation and analysis by flow cytometry. The results were expressed as the percentages of positive fluorescent parasites (PPFP) for each individual sample, establishing 20% PPFP as the cutoff between negative and positive results. Our data demonstrated that all NT and TNC presented positive results while all but one TC had a PPFP lower than 20%. Analysis of TUE demonstrated a wide degree of reactivity, with PPFP values that were negative (PPFP ≤ 20%), low positive (20% < PPFP ≤ 50%), and high positive (PPFP > 50%). As TUE with negative PPFP presented negative xenodiagnosis and positive or oscillating CSA, they were classified as dissociated according to the criteria of Krettli and Brener (J. Immunol.128:2009-2012, 1982) and could indeed be considered cured after chemotherapy. This study demonstrates and validates the use of FC-ALTA to easily identify anti-live trypomastigote membrane-bound antibodies, offering another approach for investigating and monitoring the efficacy of specific chemotherapy in cases of human Chagas' disease.
Modulation of Human Immunodeficiency Virus (HIV)-Specific Immune Response by Using Efavirenz, Nelfinavir, and Stavudine in a Rescue Therapy Regimen for HIV-Infected, Drug-Experienced Patients
Authors: Trabattoni Daria , Lo Caputo Sergio , Biasin Mara , Seminari Elena , Di Pietro Massimo , Ravasi Giovanni , Mazzotta Francesco , Maserati Renato , Clerici Mario 
Published: August 2002

ABSTRACT

Analysis of the virologic and immunomodulatory effects of an association of efavirenz (EFV), nelfinavir (NFV), and stavudine (d4T) was performed in 18 human immunodeficiency virus (HIV)-infected and highly active antiretroviral therapy (HAART)-experienced patients who failed multiple therapeutic protocols. Patients (<500 CD4
+
cells/μl; >10,000 HIV copies/ml) were nonnucleoside reverse transcriptase inhibitor (NNRTI)-naive and were treated for 10 months with EFV (600 mg/day) in association with NFV (750 mg three times daily) and d4T (30 or 40 mg twice daily). Measurement of HIV peptide- and mitogen-stimulated production of interleukin-2 (IL-2), gamma interferon (IFN-γ), IL-4, and IL-10 as well as quantitation of mRNA for the same cytokines in unstimulated peripheral blood mononuclear cells were performed at baseline and 2 weeks (t1), 2 months (t2), and 10 months (t3) into therapy. The results showed that HIV-specific (but not mitogen-stimulated) IL-2 and IFN-γ production was augmented and IL-10 production was reduced in patients who received EFV, NFV, and d4T. Therapy was also associated with a reduction in HIV RNA in plasma and an increase in CD4
+
cell count. These changes occurred in the first year of therapy (t2 and t3) and were confirmed by quantitation of cytokine-specific mRNA. Therapy with EFV, NFV, and d4T increases HIV-specific type 1 cytokine production as well as CD4 counts and reduces plasma viremia. This therapeutic regimen may be considered for use in cases of advanced HIV infection.
Immunoblot Analysis of the Humoral Immune Response toLeishmania donovaniPolypeptides in Cases of Human Visceral Leishmaniasis: Its Usefulness in Prognosis
Authors: Kumar Promod , Pai Kalpana , Tripathi Kiran , Pandey H. P. , Sundar Shyam 
Published: August 2002

ABSTRACTSera from Indian patients with parasitologically confirmed visceral leishmaniasis were studied by immunoblot analysis in order to identify a specific pattern forLeishmaniainfection. A soluble extract ofLeishmania donovaniwas used as antigen. At diagnosis the sera from patients with visceral leishmaniasis specifically recognized fractions represented by bands of 201 kDa (50% of serum samples), 193 kDa (60%), 147 kDa (50%), 120 kDa (60%), 100 kDa (50%), 80 kDa (80%), 70 kDa (70%), 65 kDa (100%), 50 kDa (50%), 36 kDa (50%), 20 kDa (70%), and 18 kDa (50%). The 65-kDa band, common to all patients infected withLeishmaniaparasites, was found at the time of diagnosis. However, the immunoblot pattern changed after patients were treated and cured with sodium antimony gluconate (SAG;n=10) or miltefosine (n=10), as was evident from blots of sera obtained pretreatment and at 1, 3, and 6 months posttreatment. At 6 months posttreatment, immunoblots of sera from patients on the SAG regimen showed the disappearance of all bands except the 70-kDa band. Similarly, sera from those on the miltefosine regimen showed the disappearance of all bands except the 65- and 70-kDa bands. This study shows that Western blot analysis is a sensitive test for detection of anti-Leishmaniaantibodies. Moreover, the persistence of reactivity with the 65- and 70-kDa bands in the sera of all groups shows its promise as a diagnostic and prognostic tool.
Helicobacter pylori
-Specific Immune Responses of Children: Implications for Future Vaccination Strategy
Authors: Bode Günter , Piechotowski Isolde , Rothenbacher Dietrich , Brenner Hermann 
Published: August 2002

ABSTRACT

We analyzed the specific anti-
Helicobacter pylori
immunoglobulin G (IgG) antibody profile for a sample of 824 asymptomatic schoolchildren in southern Germany (mean age, 10.7 ± 0.65 years) with an H. pylori-specific IgG enzyme-linked immunosorbent assay and Western blot analysis. The prevalence of infection was 19.8% (95% confidence interval, 17.1 to 22.7%). The immunoresponses were characterized predominantly by antibodies against low-molecular-mass antigens of 14 and 29 kDa, with a significant difference between children of German and Turkish nationalities (
P
= 0.0012 and
P
< 0.0001, respectively).
CD4
+
CD25
+
T-Cell Production in Healthy Humans and in Patients with Thymic Hypoplasia
Authors: Sullivan Kathleen E. , McDonald-McGinn Donna , Zackai Elaine H. 
Published: August 2002

ABSTRACT

Regulatory T cells are found primarily in the CD4
+
CD25
+
fraction of T cells and play an important role in the prevention of autoimmunity. We examined CD4
+
CD25
+
T cells in 33 healthy children and adults and compared them to a population with an inherited form of thymic hypoplasia and a predisposition to autoimmune disease. Absolute numbers of CD4
+
CD25
+
T cells were markedly higher in healthy infants than in infants with chromosome 22q11.2 deletion syndrome.
Peripheral Blood Lymphocyte Subsets in Adolescents: a Longitudinal Analysis from the REACH Project
Authors: Rudy Bret J. , Wilson Craig M. , Durako Stephen , Moscicki Anna-Barbara , Muenz Larry , Douglas Steven D. 
Published: August 2002

ABSTRACT

Flow cytometry analysis of lymphocyte subset markers was performed for a group of sexually active, human immunodeficiency virus (HIV)-negative adolescents over a 2-year period to establish normative data. Data were collected in the REACH Project (Reaching for Excellence in Adolescent Care and Health), a multicenter, longitudinal study of HIV-positive and high-risk HIV-negative adolescents. Two- and three-color flow cytometry data were collected every 6 months for these subjects. We determined the effects of gender, race, and age on the following lymphocyte subset markers: total CD4
+
cells, CD4
+
naïve cells, CD4
+
memory cells, all CD8
+
cells, CD8
+
naïve cells, CD8
+
memory cells, CD16
+
natural killer cells, and CD19
+
B cells. Gender was the demographic characteristic most frequently associated with differences in lymphocyte subset measures. Females had higher total CD4
+
cell and CD4
+
memory cells counts and lower CD16
+
cell counts than males. Age was associated with higher CD4
+
memory cell counts as well as higher CD8
+
memory cell counts. For CD19
+
cells, there was an interaction between age and gender, with males having significantly lower CD19
+
cell counts with increasing age, whereas there was no age effect for females. Race and/or ethnicity was associated with differences in total CD8
+
cell counts and CD8
+
memory cell counts, although both of these associations involved an interaction with gender.
Evaluation of an In-House-Developed Radioassay Kit for Antibody Detection in Cases of Pulmonary Tuberculosis and Tuberculous Meningitis
Authors: Kameswaran M. , Shetty K. , Ray M. K. , Jaleel M. A. , Kadival G. V. 
Published: August 2002

ABSTRACT

A radioassay for the detection of antitubercular antibody has been developed. The technique involves the addition of
125
I-labeled
Mycobacterium tuberculosis
antigen as a tracer, diluted clinical sample (serum or cerebrospinal fluid [CSF]), and heat-inactivated
Staphylococcus aureus
to capture the antibody, incubation for 4 h, and quantitation of the amount of antibody present in the sample. A total of 330 serum samples from patients with pulmonary tuberculosis and 138 control serum samples from individuals who were vaccinated with
M. bovis
BCG and from patients with pulmonary disorders of nontubercular origin were analyzed. Also, 26 CSF samples from patients with tuberculous meningitis and 24 CSF samples as controls from patients with central nervous system disorders of nontuberculous origin were analyzed. Sensitivities of 80 and 73% were observed for patients with pulmonary tuberculosis and tuberculous meningitis, respectively, and specificities of 90 and 88% were seen for the two groups of patients, respectively. The sensitivity was lower, however, for human immunodeficiency virus-infected patients coinfected with
M. tuberculosis
. The control population could be differentiated from the patient population. This assay is rapid and user friendly and, with its good sensitivity and specificity, should benefit the population by providing diagnoses early in the course of disease and, hence, permit the early administration of appropriate chemotherapy.
Functional and Phenotypic Changes in Circulating Lymphocytes from Hospitalized Zambian Children with Measles
Authors: Ryon Judith J. , Moss William J. , Monze Mwaka , Griffin Diane E. 
Published: August 2002

ABSTRACTMeasles is associated with immunosuppression and increased susceptibility to secondary infections and is a particular problem in developing countries. Lymphocyte changes accompanying immune activation and regulation of the immune response may contribute to immunosuppression. To evaluate lymphocyte changes during measles, children (n= 274) hospitalized with measles in Lusaka, Zambia, were evaluated at entry, discharge, and 1-month follow-up and compared to healthy Zambian children (n= 98). Lymphopenia was present on hospital admission and reflected decreased CD4 and CD8 T cells but resolved quickly. Lymphopenia was most marked in girls, in those with temperatures of >38.5°C, and in malnourished children. CD4/CD8 ratios were decreased at all time points and were lower in boys than in girls at discharge and follow-up. Spontaneous death occurred in cultured lymphocytes, and the proportions of freshly isolated cells undergoing apoptosis, based on annexin V and propidium iodide staining, were increased. Surface Fas was increased on both CD4 and CD8 T cells compared to controls, and expression was greater on CD4 T cells and was inversely correlated with lymphocyte viability in culture at study entry. Mitogen stimulation of lymphocytes improved viability, but inhibitors of Fas, tumor necrosis factor (TNF)-related apoptosis-inducing ligand, and TNF did not. Plasma levels of β2microglobulin and soluble Fas, Fas ligand, CD8, CD4, and TNF receptor were increased, and soluble CD8 was higher in boys than in girls. The multiple effects of measles on lymphocytes from Zambian children include decreased numbers in circulation, increased activation, and increased susceptibility to cell death, with substantive differences in the magnitude of these changes between boys and girls.
Emergence of
Klebsiella pneumoniae
Isolates Producing Inducible DHA-1 β-Lactamase in a University Hospital in Taiwan
Authors: Yan Jing-Jou , Ko Wen-Chien , Jung Yun-Chih , Chuang Chin-Luan , Wu Jiunn-Jong 
Published: August 2002

ABSTRACT

Ten nonrepetitive clinical isolates of
Klebsiella pneumoniae
exhibiting an unusual inducible β-lactam resistance phenotype were identified between January 1999 and September 2001 in a university hospital in Taiwan. In the presence of 2 μg of clavulanic acid, the isolates showed a one to four twofold concentration increase in the MICs of ceftazidime, cefotaxime, and aztreonam but remained susceptible to cefepime (MICs, ≤0.5 μg/ml) and imipenem (MICs, ≤0.5 μg/ml). PCR, sequence analysis, and isoelectric focusing revealed production by these isolates of TEM-1, SHV-11, and DHA-1, a plasmid-encoded inducible AmpC β-lactamase originally found in a
Salmonella enterica
serovar Enteritidis strain. Transfer of the resistance by conjugation experiments was not successful, but Southern hybridization showed that
bla
DHA-1
was located on 70-kb plasmids, suggesting that the
bla
DHA-1
-containing plasmids in the
K. pneumoniae
isolates were non-self-transmissible. Five isolates were recovered from patients in two surgery wards and two intensive care units. Acquisition of the DHA-1 producers could be traced back to previous hospitalizations 1 to 5 months earlier for the other five patients. Six and seven patterns among the isolates were demonstrated by plasmid analysis and ribotyping, respectively, indicating that the spread of the DHA-1 producers was due to both horizontal transfer of
bla
DHA-1
and dissemination of endemic clones.
Hepatitis C Virus Genotyping: Interrogation of the 5′ Untranslated Region Cannot Accurately Distinguish Genotypes 1a and 1b
Authors: Chen Zhenyu , Weck Karen E. 
Published: August 2002

ABSTRACT
Although the 5′ untranslated region (5′ UTR) is the most conserved region of the hepatitis C virus (HCV) genome, it has been suggested that interrogation of this region is sufficient for determination of the HCV genotype. We compared two methods of determination of the HCV genotype: (i) direct sequencing of the DNA of the NS-5b region and (ii) reverse line probe assay (LiPA; INNO-LiPA HCV II; Innogenetics N.V.) of the 5′ UTR. There was 100% concordance between the two methods for genotype but only 80% concordance for subtype. A significant percentage of genotype 1a isolates were misclassified by LiPA as genotype 1b. Sequence analysis revealed that the only consistent difference in the 5′ UTR for these genotype 1a isolates misclassified as genotype 1b was a single nucleotide (A/G) at position −99 of the HCV genome. All isolates with discordant results analyzed had a G at this position, consistent with LiPA determination of these samples as subtype 1b. However, sequence analysis of 222 nucleotides in the NS-5b region clearly identified all of these isolates as subtype 1a. Population distribution data from the University of Pittsburgh Medical Center of over 200 samples analyzed by sequencing of the NS-5b region and over 1,000 samples analyzed by LiPA also indicated that INNO-LiPA HCV II cannot accurately differentiate HCV genotype 1a isolates from HCV genotype 1b isolates. We provide evidence that the A/G at position −99 represents a sequence polymorphism in the HCV genome that cannot differentiate subtype 1a from subtype 1b isolates. In conclusion, the 5′ UTR is not heterogeneous enough for use in determination of the HCV subtype and cannot be used for differentiation of HCV genotypes 1a and 1b.