bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic post‐implant needle reconstruction algorithm to characterize and improve implant robustness analyses
Authors: Archambault Louis , Beaulieu Luc , Tubic Dragan
Published: November 2003

Post‐implant analysis in permanent implant brachytherapy is an important process that provides a feedback on treatment quality. Random seed movements, edema, and needle related factors contribute to deteriorate dose coverage. For a complete study of these movements, it is important to reconstruct the post‐implant seeds clusters but, up to now, this task was only possible via a long and difficult manual process. To facilitate post‐implant analysis a simulated annealing algorithm was developed to perform automatic reconstructions. This process is fast (30–60 s on a 1.3 GHz pentium) and has a high level of success, even with up to 5% of seed loss. Tests on 21 clinical cases show that the algorithm yields exactly the same results as manual reconstructions. A realistic simulation tool was used to generate 58 synthetic post‐implant data, in which cases the exact configuration was known. Even if some errors were found, pertinent information was extracted. For medium seed density [corresponding to seeds of 0.6 mCi (0.762 U)], 97% of seeds are matched with their correct needle and 89% are matched with their correct planned position. This method provides pertinent information that can be used to understand inhomogenous dose coverage in specific prostate quadrants; to make realistic post‐implant simulations or to identify seeds belonging to a needle loaded with different seed types or activity.
Micro‐angiography for neuro‐vascular imaging. I. Experimental evaluation and feasibility
Authors: Ganguly Arundhuti , Rudin Stephen , Bednarek Daniel R. , Hoffmann Kenneth R. , Kyprianou Iacovos S.
Published: November 2003

Minimally invasive image‐guided neuro‐vascular interventions require very high image‐resolution and quality, specifically over regions‐of‐interest (ROI) crucial to the procedure. ROI imaging or micro‐angiography, allows limited patient integral radiation dose while permitting rapid frame transfer of high‐resolution images. The design and performance of a charge coupled device (CCD) based x‐ray detector or micro‐angiographic camera was assessed for neuro‐vascular procedures. The detector consists of a 250‐μm‐thick CsI(Tl) phosphor fiber‐optically coupled through a 1.8:1 taper to a CCD chip, with an effective image pixel size of 50 μm and a frame rate of 5 fps in the 2:1 pixel‐binned mode. The characteristics of the camera including the modulation transfer function (MTF), the noise equivalent quanta, the detective quantum efficiency, observer studies, and the effect of geometric magnification were evaluated. The MTF was found to have nonzero (1.7%) value at the Nyquist frequency of 10 cycles/mm, while the DQE(0) had a value of All values were measured using head equivalent attenuating material in the beam at 80 kVp. Human observer studies performed using the 2 Alternative Forced Choice method revealed that iodinated vessels with inner diameter of 100 μm and 2 cm in length can be seen with a confidence level greater than 75%. The observer studies included a comparison with ideal observer performance calculations based on the integral signal to noise ratio in the image. Probabilities of visualization of various objects of interest in a neuro‐intervention, such as stents, were assessed. A geometric magnification of 1 was found to be best for imaging under neuro‐angiographic conditions. The detector appeared to satisfy all the demands of neuro‐angiography and showed promise as an improvement over existing angiographic detectors.
Micro‐angiography for neuro‐vascular imaging. II. Cascade model analysis
Authors: Ganguly Arundhuti , Rudin Stephen , Bednarek Daniel R. , Hoffmann Kenneth R.
Published: November 2003

A micro‐angiographic detector was designed and its performance was previously tested to evaluate its feasibility as an improvement over current x‐ray detectors for neuro‐interventional imaging. The detector was shown to have a modulation transfer function value of about 2% at the Nyquist frequency of 10 cycles/mm and a zero frequency detective quantum efficiency [DQE(0)] value of about 55%. An assessment of the system was required to evaluate whether the current system was performing at its full potential and to determine if any of its components could be optimized to further improve the output. For the purpose, in this study, the parallel cascade theory was used to analyze the performance of the detector under neuro‐angiographic conditions by studying the output at the various stages in the imaging chain. A simple model for the spread of light in the CsI(Tl) entrance phosphor was developed and the resolution degradation due to ‐fluorescence absorption was calculated. The total gain of the system was found to result in (rms) detected at the charge coupled device per absorbed x‐ray photon. The gain and the spread of quanta in the imaging chain were used to calculate theoretically the DQE using the parallel cascade model. The results of the model‐based calculations matched fairly well with the experimental data previously obtained. This model was then used to optimize the phosphor thickness for the detector. The results showed that the area under the DQE curve had a maximum value at 150 μm of CsI(Tl), though when weighted by the squared signal in frequency space of a 100‐μm‐diam iodinated vessel, the integral DQE reached a maximum at 250 μm of CsI(Tl). Further, possible locations for gain increase in the imaging chain were determined, and the output of the improved system was simulated. Thus a theoretical analysis for the micro‐angiographic detector was performed to better assess its potential.
Basic dosimetry of radiosurgery narrow beams using Monte Carlo simulations: A detailed study of depth of maximum dose
Authors: Chaves A. , Lopes M. C. , Alves C. C. , Oliveira C. , Peralta L. , Rodrigues P. , Trindade A.
Published: November 2003

In radiosurgery narrow photon beams, the depth of maximum dose in the beam central axis increases as the size of the additional collimator increases. This behavior is the opposite of what is observed in radiotherapy conventional beams. To understand this effect, experimental depth dose curves of the additional collimators were obtained for a Siemens KD2 linear accelerator in 6 MV photon mode and the shift of varied from for the 5 mm collimator to for the 23 mm collimator. Monte Carlo simulations showed that the photons that had no interactions in the additional collimators, contributing more than 90% to the total dose in water, were responsible for the shift in Monte Carlo simulations also showed that electrons originated from these photons and contributing to the dose deposit in water in the beam central axis could be divided in two groups: those that deposit energy far away from their point of origin (the point of the first photon collision in water) and those that deposit energy locally (originated at more than one photon collision in water). Applying a simplified model based on the fact that the photons originating Compton electrons (at the first and subsequent collisions) have similar characteristics in air for all the additional collimators, it was shown that these electrons were also responsible for the shift of in the beam central axis. Finally, it was shown that the changes in the initial gradients of the depth dose curves of the additional collimators were mainly due to electrons originated from the first photon collision in water.
A preliminary investigation of local tomography for megavoltage CT imaging
Authors: Anastasio Mark A. , Shi Daxin , Pan Xiaochuan , Pelizzari Charles , Munro Peter
Published: November 2003

We investigate the problem of reconstructing a two‐dimensional (2‐D) cross‐sectional image of a tumor volume from a set of truncated MV projections that are produced by radiation therapy treatment beams. Our proposed approach is conceptually distinct from previously investigated approaches in that it utilizes a noniterative local tomography reconstruction algorithm. A local tomography reconstruction algorithm is implemented and systematically investigated using several sets of simulated and experimental MV projection data. We demonstrate that the conventional (nonlocal) filtered backprojection reconstruction algorithm cannot, in general, accurately reconstruct the edges and boundaries of low‐contrast features from truncated MV projection data. We demonstrate that the local tomography algorithm is not adversely affected by projection truncation and can reconstruct accurately the boundaries of low‐contrast structures within the region of interest from truncated MV projections.
Two‐dimensional measurement of photon beam attenuation by the treatment couch and immobilization devices using an electronic portal imaging device
Authors: Vieira Sandra C. , Kaatee Robert S. J. P. , Dirkx Maarten L. P. , Heijmen Ben J. M.
Published: November 2003

In our institution, an individualized dosimetric quality assurance protocol for intensity modulated radiotherapy (IMRT) is being implemented. This protocol includes dosimetric measurements with a fluoroscopic electronic portal imaging device (EPID) for all IMRT fields while the patient is being irradiated. For some of the first patients enrolled in this protocol, significant beam attenuation by (carbon fiber) components of the treatment couch was observed. To study this beam attenuation in two‐dimensional, EPID images were also acquired in absence of the patient, both with and without treatment couch and immobilization devices, as positioned during treatment. For treatments of head and neck cancer patients with a 6 MV photon beam, attenuation of up to 15% was detected. These findings led to the development of new tools and procedures for planning and treatment delivery to avoid underdosages in the tumor.
Measurement of Inflammatory Biomarkers in Synovial Tissue Extracts by Enzyme-Linked Immunosorbent Assay
Authors: Rosengren Sanna , Firestein Gary S. , Boyle David L.
Published: November 2003

We developed methods for measuring inflammatory biomarkers (cytokines, chemokines, and metalloproteinases) in synovial biopsy specimens from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Soluble extracts of synovial fragments were prepared with mild detergent and analyzed by enzyme-linked immunosorbent assay (ELISA) for interleukin 1β (IL-1β), IL-6, IL-8, tumor necrosis factor alpha (TNF-α), and matrix metalloproteinase 3. The optimal detergent was 0.1% Igepal CA-630, which interfered minimally with ELISA detection but extracted 80% of IL-6 from synovial tissue. Upon spiking, 81 to 107% of added biomarkers could be recovered. To determine within-tissue variability, multiple biopsy specimens from each RA synovial extract were analyzed individually. A resulting coefficient of variation of 35 to 62% indicated that six biopsy specimens per synovial extract would result in a sampling error of ≤25%. Preliminary power analysis suggested that 8 to 15 patients per group would suffice to observe a threefold difference before and after treatment in a serial biopsy clinical study. The previously described significant differences in IL-1β, IL-6, IL-8, and TNF-α levels between RA and OA could be detected, thereby validating the use of synovial extracts for biomarker analysis in arthritis. These methods allow monitoring of biomarker protein levels in synovial tissue and could potentially be applied to early-phase clinical trials to provide a preliminary estimate of drug efficacy.
Inflammatory Responses of Bovine Polymorphonuclear Neutrophils Induced by Staphylococcal Enterotoxin C via Stimulation of Mononuclear Cells
Authors: Kuroishi Toshinobu , Komine Ken-ichi , Asai Ken-ichi , Kobayashi Jin , Watanabe Kouichi , Yamaguchi Takahiro , Kamata Shin-ichi , Kumagai Katsuo
Published: November 2003

To elucidate the pathological roles of staphylococcal enterotoxin C (SEC) in bovine staphylococcal mastitis, a histopathological analysis of SEC-inoculated mammary glands was performed. SEC-inoculated mammary glands exhibited interstitial inflammation, and the leukocytes that migrated into the gland were predominantly polymorphonuclear neutrophils (PMN). In the gland cistern tissues dissected from SEC-inoculated mammary glands, epithelial cellular degeneration was observed. We also investigated the physiological effects of SEC on PMN in vitro. PMN migration was induced by culture supernatant of SEC-stimulated peripheral blood mononuclear cells (S-PBMC sup) but not by that of nonstimulated PBMC (N-PBMC sup). The concentration of interleukin-8 was significantly (P< 0.05) higher in S-PBMC sup than N-PBMC sup, and a significantly (P< 0.05) higher mRNA expression of growth-regulated oncogenes was detected in SEC-stimulated PBMC than in nonstimulated PBMC. Milk PMN collected from SEC-inoculated mammary glands produced more than 2 times the amount of superoxide at 1 day postinoculation (dpi) than at 0 dpi in the presence of phorbol 12-myristate 13-acetate (PMA). PMN cultured with S-PBMC sup for 24 h also produced significantly (P< 0.05) larger amounts of superoxide than those cultured with N-PBMC sup in the presence of PMA. Moreover, S-PBMC sup induced the long-time survival of PMN. These results indicate that SEC induces the activation of PMN via the stimulation of mononuclear cells.
Reproducibility of Immunological Tests Used To Assess Multiple Chemical Sensitivity Syndrome
Authors: Hoover Donald R. , Donnay Albert , Mitchell Clifford S. , Ziem Grace , Rose Noel R. , Sabath Daniel E. , Yurkow Edward J. , Nakamura Robert , Vogt Robert F. , Waxdal Myron , Margolick Joseph B.
Published: November 2003

Whether persons with multiple chemical sensitivity syndrome (MCS) have immunological abnormalities is unknown. To assess the reliability of selected immunological tests that have been hypothesized to be associated with MCS, replicate blood samples from 19 healthy volunteers, 15 persons diagnosed with MCS, and 11 persons diagnosed with autoimmune disease were analyzed in five laboratories for expression of four T-cell surface activation markers (CD25, CD26, CD38, and HLA-DR) and in four laboratories for autoantibodies (to smooth muscle, thyroid antigens, and myelin). For T-cell activation markers, the intralaboratory reproducibility was very good, with 90% of the replicates analyzed in the same laboratory differing by ≤3%. Interlaboratory differences were statistically significant for all T-cell subsets except CD4+cells, ranging from minor to eightfold for CD25+subsets. Within laboratories, the date of analysis was significantly associated with the values for all cellular activation markers. Although reproducibility of autoantibodies could not be precisely assessed due to the rarity of abnormal results, there were inconsistencies across laboratories. The effect of shipping on all measurements, while sometimes statistically significant, was very small. These results support the reliability of fresh and shipped samples for detecting large (but perhaps not small) differences between groups of donors in the T-cell subsets tested. When comparing markers that are not well standardized, it may be important to distribute samples from different study groups evenly over time.
Genetic Variation at the Mitochondrial Large-Subunit rRNA Locus of
Pneumocystis
Isolates from Simian Immunodeficiency Virus-Infected Rhesus Macaques
Authors: Norris Karen A. , Wildschutte Hans , Franko Jennifer , Board Kathryn F.
Published: November 2003

The nucleotide sequences of a segment of the
Pneumocystis
mitochondrial large-subunit (mt LSU) rRNA gene from rhesus macaques coinfected with simian immunodeficiency virus (SIV) and
Pneumocystis carinii
were examined. Of 12 isolates examined, 3 were found to be identical and the others showed substantial sequence variation, with up to 13% divergence among variants. We identified two general sequence types that differed at several sites, including a conserved 26-nucleotide insertion. Four monkeys had evidence of two
Pneumocystis
variants present simultaneously, indicative of a mixed infection. There was a high degree of variance between the rhesus macaque-derived
Pneumocystis
mt LSU rRNA gene sequence and the cognate sequences in
Pneumocystis
organisms derived from other hosts. Analysis of the mt LSU rRNA genes of
Pneumocystis
organisms derived from rhesus macaques and several other mammalian hosts supports the observation that rhesus macaque-derived
Pneumocystis
is most closely related to human-derived
Pneumocystis
. In addition, the data identify the mt LSU rRNA gene as an informative locus for transmission and epidemiological studies of the SIV-rhesus macaque model of
Pneumocystis
infection.
Detection of Antibodies toAnaplasma phagocytophilumandEhrlichia chaffeensisAntigens in Sera of Korean Patients by Western Immunoblotting and Indirect Immunofluorescence Assays
Authors: Park Jin-ho , Heo Eun-jeong , Choi Kyoung-seong , Dumler J. Stephen , Chae Joon-seok
Published: November 2003

Two hundred seventy one serum samples from South Korean patients were tested to detect antibodies againstAnaplasma phagocytophilum(the human granulocytic ehrlichiosis agent) andEhrlichia chaffeensis(the human monocytic ehrlichiosis agent) by indirect fluorescent-antibody assay (IFA) and the Western blot assay. These sera were collected from patients with symptoms of high fever. The rate of seropositivity forOrientia tsutsugamushiwas 50.9% by IFA at the Public Health & Environmental Research Institute and National Institute of Health in South Korea. By IFA, 30 (11.1%) and 39 (14.4%) of the serum samples reacted withA. phagocytophilumandE. chaffeensisantigens, respectively. By the Western blot assays, 24 (8.9%) and 29 (10.7%) of the serum samples reacted with purifiedA. phagocytophilumandE. chaffeensisprotein antigens, respectively. This report strengthens other evidence regarding the presence ofA. phagocytophilumandE. chaffeensisinfections in humans in South Korea.
CD56+-T-Cell Responses to Bacterial Superantigens and Immune Recognition of Attenuated Vaccines
Authors: Saikh Kamal U. , Dyas Beverly , Kissner Teri , Ulrich Robert G.
Published: November 2003

Natural killer T (NKT) cells, coexpressing natural killer (NK) and T-cell receptors (TCR), are associated with immunity to viruses, tumors, and parasites. A well-characterized subclass of these NKT cells expresses biased TCR and recognizes glycolipids such as α-galactoceramide, which is found naturally only in marine sponges and presented by the cell surface glycoprotein CD1d. However, a larger number of T cells present in human blood coexpress the NK marker CD56 and unbiased TCR and do not appear to require CD1 for antigen presentation. Observing high frequencies of CD4 and CD8 coreceptor expression in human CD56+T cells, we examined the potential role of major histocompatibility complex (MHC) class II molecules in the activation of these cells. Activation of mononuclear cells with bacterial superantigens presented by MHC class II molecules resulted in increased frequency of CD56+T cells. Primarily, CD4+cells within the CD56+-T-cell population responded to the bacterial superantigens, and cytokine expression profiles were Th1-like. Further, increased levels of T cells expressing CD56 were observed in mononuclear cell cultures responding to aStaphylococcus aureusvaccine or tetanus toxoid. Collectively, our data suggest that a significant number of CD56+T cells recognize pathogen-associated ligands in association with MHC class II molecules.
Diagnosis of Dengue Virus Infection by the Visual and Simple AuBioDOT Immunoglobulin M Capture System
Authors: Vázquez Susana , Lemos Gilda , Pupo Maritza , Ganzón Oscar , Palenzuela Daniel , Indart Adriana , Guzmán María G.
Published: November 2003

The Dengue IgM Capture ELISA (MAC-ELISA) is the immunoenzymatic system recommended by the Pan American Health Organization and the World Health Organization for the serological diagnosis of dengue virus infection due to its high sensitivity, ease of performance, and use of a single acute-phase serum sample. However, tests with this enzyme-linked immunosorbent assay (ELISA) system are time-consuming and require equipment for washing, incubation, and reading of the results. AuBioDOT is a multistep visual diagnostic immunoassay that uses technology based on the immunoglobulin M (IgM) capture ELISA principle. This system uses white polyethylene opaque plates as the solid phase, colloidal gold as the marker, and silver ion amplification. It does not require special equipment, it is totally manually operated, and it can be performed in less than 1 h. The sensitivity and specificity of AuBioDOT for the detection of anti-dengue virus IgM antibodies were studied with a panel of 336 serum samples (150 serum samples from patients with suspected or serologically confirmed dengue virus infection, 186 serum samples from healthy blood donors and patients without dengue virus infection). The results were compared with those obtained by the MAC-ELISA. A sensitivity of 97.7% and a specificity of 97.1% were obtained. The concordance of the two tests was 97.3%, with a kappa index of 0.94. The application of AuBioDOT for the detection of anti-dengue virus IgM antibodies is recommended as an alternative method for the diagnosis of dengue virus infection, both for clinical diagnosis and for seroepidemiological surveillance. The system is useful under field conditions and in laboratories and requires little equipment.
Mimotopes of the Vi Antigen ofSalmonella entericaSerovar Typhi Identified from Phage Display Peptide Library
Authors: Tang Swee-Seong , Tan Wen-Siang , Devi Shamala , Wang Lin-Fa , Pang Tikki , Thong Kwai-Lin
Published: November 2003

The capsular polysaccharide Vi antigen (ViCPS) is an essential virulence factor and also a protective antigen ofSalmonella entericaserovar Typhi. A random 12-mer phage-displayed peptide library was used to identify mimotopes (epitope analogues) of this antigen by panning against a ViCPS-specific monoclonal antibody (MAb) ATVi. Approximately 75% of the phage clones selected in the fourth round carried the peptide sequence TSHHDSHGLHRV, and the rest of the clones harbored ENHSPVNIAHKL and other related sequences. These two sequences were also obtained in a similar panning process by using pooled sera from patients with a confirmed diagnosis of typhoid fever, suggesting they mimic immunodominant epitopes of ViCPS antigens. Binding of MAb ATVi to the mimotopes was specifically blocked by ViCPS, indicating that they interact with the same binding site (paratope) of the MAb. Data and reagents generated in this study have important implications for the development of peptide-base diagnostic tests and peptide vaccines and may also provide a better understanding of the pathogenesis of typhoid fever.
Monoclonal Antibodies That Distinguish Antigenic Variants of
Canine Parvovirus
Authors: Nakamura Masato , Nakamura Kazuya , Miyazawa Takayuki , Tohya Yukinobu , Mochizuki Masami , Akashi Hiroomi
Published: November 2003

Canine parvovirus
(CPV) is classified as a member of the feline parvovirus (FPV) subgroup. CPV isolates are divided into three antigenic types: CPV type 2 (CPV-2), CPV-2a, and CPV-2b. Recently, new antigenic types of CPV were isolated from Vietnamese leopard cats and designated CPV-2c(a) or CPV-2c(b). CPV-2c viruses were distinguished from the other antigenic types of the FPV subgroup by the absence of reactivity with several monoclonal antibodies (MAbs). To characterize the antigenicity of CPV-2c, a panel of MAbs against CPV-2c was generated and epitopes recognized by these MAbs were examined by selection of escape mutants. Four MAbs were established and classified into three groups on the basis of their reactivities: MAbs which recognize CPV-2a, CPV-2b, and CPV-2c (MAbs 2G5 and 20G4); an MAb which reacts with only CPV-2b and CPV-2c(b) (MAb 21C3); and an MAb which recognizes all types of the FPV subgroup viruses (MAb 19D7). The reactivity of MAb 20G4 with CPV-2c was higher than its reactivities with CPV-2a and CPV-2b. These types of specificities of MAbs have not been reported previously. A mapping study by analysis of neutralization-resistant mutants showed that epitopes recognized by MAbs 21C3 and 19D7 belonged to antigenic site A. Substitution of the residues in site B and the other antigenic site influenced the epitope recognized by MAb 2G5. It was suggested that the epitope recognized by MAb 20G4 was related to antigenic site B. These MAbs are expected to be useful for the detection and classification of FPV subgroup isolates.
Novel Microtechnique for Assessment of Postnatal Maturation of the Phagocytic Function of Neutrophils and Monocytes
Authors: Muniz-Junqueira Maria Imaculada , Peçanha Lídia Maria Figueira , da Silva-Filho Valeriano Luiz , de Almeida Cardoso Maria Cecília , Tosta Carlos Eduardo
Published: November 2003

We describe a simple test for the evaluation of phagocytosis and provide a chart of reference values to evaluate normal phagocytosis by age. We assessed the postnatal maturation of phagocytic function of neutrophils and monocytes. Phagocytosis was evaluated in newborn children delivered vaginally or by cesarean section, infants, preschool children, schoolchildren, and adult subjects. Two drops of blood were placed on a microscope slide and incubated withSaccharomyces cerevisiaeyeasts, and phagocytosis was evaluated by microscopy. Our technique showed results comparable to or better than those obtained by other usual techniques. The neutrophils of newborn children delivered by cesarean section showed a phagocytic capacity 45% higher than those of neonates delivered vaginally, whereas neutrophils from children in the latter group showed the lowest phagocytic capacity of all age groups. Phagocytosis by neutrophils reached the levels seen in adults at about the first year of life, while there were no important variations in phagocytosis by monocytes in the different age groups. The technique described is reliable and fast, uses only a few drops of blood, and allows better preservation of cell function due to the minimal manipulation to which the cells are submitted. The delayed maturation of the phagocytic function by neutrophils may account for the high levels of susceptibility of newborn and infant children to bacterial infections. This practical method of assessment of phagocytosis may allow the diagnosis of primary or secondary phagocytic deficiencies to be made more easily and may allow better monitoring and treatment of those with dysfunctions of these cells.
Evolution of Two Amino Acid Positions Governing Broad Neutralization Resistance in a Strain of Feline Immunodeficiency Virus over 7 Years of Persistence in Cats
Authors: Pistello Mauro , Matteucci Donatella , Giannecchini Simone , Bonci Francesca , Sichi Olimpia , Presciuttini Silvano , Bendinelli Mauro
Published: November 2003

Fresh isolates of lentiviruses are characterized by an outstanding resistance to antibody-mediated neutralization. By investigating the changes that occurred in a neutralization-sensitive tissue culture-adapted strain of feline immunodeficiency virus after it was reinoculated into cats, a previous study had identified two amino acid positions of the surface glycoprotein (residues 481 and 557) which govern broad neutralization resistance (BNR) in this virus. By extending the follow-up of six independently evolving in vivo variants of such virus for up to 92 months, we now show that the changes at the two BNR-governing positions not only were remarkably stereotyped but also became fixed in an ordered sequential fashion with the duration of in vivo infection. In one variant, the two positions were also seen to slowly alternate at determining BNR. Evidence that evolution at the BNR-governing positions was accompanied, and possibly driven, by changes in the antigenic makeup of the viral surface brought about by the mutations at such positions is also presented.
Anti-HBs Cellular Immune Response in Kidney Recipients before and 4 Months after Transplantation
Authors: Aguilar Patricia , Renoult Edith , Jarrosson Loraine , Kolopp-Sarda Marie Nathalie , Mathieu Christine Prin , Faure Gilbert C. , Kessler Michěle , Bene Marie C. , Kohler Chantal , Kennel De March Anne
Published: November 2003

Patients with renal failure represent a population at risk for hepatitis B, since only 50 to 60% of them develop protective humoral responses after vaccination. As this could be due to an altered regulation of cellular immune responses, the objectives of the present study were to evaluate the proliferative abilities of lymphocytes from patients with chronic renal failure after stimulation in vitro with a mitogen (pokeweed mitogen [PWM]) or HBsAg. In order to differentiate between the immunodeficiency associated with renal failure and that due to immunosuppression posttransplantation, the same subjects were tested before and 4 months after kidney transplantation. The lymphoproliferation assay used was performed by flow cytometry, which is based on sequential analysis of the cell cycle and which allows analysis of cytokine production. Serologically, the group of 36 patients tested comprised 22% nonresponders, 30% poor responders, and 48% responders. Lymphocyte growth was observed for all patients after stimulation with PWM, indicating that these cells had the capacity to proliferate in vitro. The level of lymphoproliferation in response to PWM was significantly reduced after transplantation, yet both before and after transplantation, all serologic nonresponders developed cellular responses to at least two vaccines. No correlation between humoral and cellular responses was shown. Proliferating cells were lymphocytes, which mostly secreted interleukin 4 (IL-4) and IL-10 for the three serologic groups. This study suggests that even when repeated vaccination fails to induce significant antibody levels in patients with renal failure, specific HBs cellular responses develop, and these may prove to be efficient in protecting these patients against hepatitis B.
Quantification of CCR5 mRNA in Human Lymphocytes and Macrophages by Real-Time Reverse Transcriptase PCR Assay
Authors: Lai Jian-Ping , Yang Ji-Hong , Douglas Steven D. , Wang Xu , Riedel Eric , Ho Wen-Zhe
Published: November 2003

CCR5, a β-chemokine receptor, plays an important role in human immunodeficiency virus (HIV) infection of human immune cells, as it is a primary coreceptor for HIV entry into macrophages. We have applied a newly developed real-time reverse transcriptase PCR (RT-PCR) assay for the quantification of CCR5 mRNA in human blood immune cells. The CCR5 real-time RT-PCR assay has a sensitivity of 100 mRNA copies, with a dynamic range of detection between 10
2
and 10
6
copies of the CCR5 mRNA transcripts per reaction. The assay is highly reproducible, with an intra-assay coefficient of variation of the threshold cycle of less than 2.07%. When used for quantification of CCR5 mRNA in human monocyte-derived macrophages (MDM) and peripheral blood lymphocytes (PBL), the assay has precision and reproducibility. MDM expressed higher levels of CCR5 mRNA than did PBL. Thus, this assay has the potential and a wide application for the investigation of the role of CCR5 in inflammatory diseases and viral infections, including HIV disease.
Effect of Antigen Coating Conditions on Enzyme-Linked Immunosorbent Assay for Detection of Immunoglobulin G Antibody to
Neisseria meningitidis
Serogroup Y and W135 Capsular Polysaccharide Antigens in Serum
Authors: Giardina Peter C. , Evans Renee E. , Sikkema Daniel J. , Madore Dace , Hildreth Stephen W.
Published: November 2003

Human sera collected from 28 consenting adult volunteers were used to define assay conditions for meningococcal vaccine clinical trial serology. Immunoassay parameters were optimized with these test sera and the standard reference serum, CDC1992. Coating conditions for serogroup Y and W135 polysaccharide antigens were found to influence the predicted serum immunoglobulin G (IgG) antibody concentrations. Sera that displayed IgG antibody binding profiles most unlike that of CDC1992 were influenced the most by coating conditions. Our results suggest that presentation of specific epitopes is influenced by antigen-coating concentrations for serogroup Y and W135 polysaccharides.
ImmunochromatographicBrucella-Specific Immunoglobulin M and G Lateral Flow Assays for Rapid Serodiagnosis of Human Brucellosis
Authors: Smits Henk L. , Abdoel Theresia H. , Solera Javier , Clavijo Encarnacion , Diaz Ramon
Published: November 2003

To fulfill the need for a simple and rapid diagnostic test for human brucellosis, we used the immunochromatographic lateral flow assay format to develop two assays, one for the detection ofBrucella-specific immunoglobulin M (IgM) antibodies and one for the detection ofBrucella-specific IgG antibodies. The diagnostic values of these tests were examined. The tests are shown to detect acute, persistent, and relapsing disease and can be used to monitor treatment. The sensitivity ofBrucellaIgM and IgG flow assays calculated for the combined assay results is 96%, and specificity amounts to 99%. The flow assay requires neither specialized training nor equipment, the assay is very easy to perform and to read, and the components are stable without a requirement for refrigeration and well standardized. Together these characteristics indicate that theBrucellaIgM and IgG flow assays are ideal for use in clinical settings in rural and suburban areas in which brucellosis is endemic.
Cell-Mediated Immune Responses of Healthy Laboratory Volunteers to Sonicate Antigens Prepared from the Most Prevalent Strains ofMycobacterium tuberculosisfrom South India Harboring a Single Copy of IS6110
Authors: Rajavelu Priya , Das Sulochana D.
Published: November 2003

Our restriction fragment length polymorphism (RFLP) studies have shown that the most prevalent (40%) strains ofMycobacterium tuberculosisfrom South India contain a single copy of the IS6110insertion sequence and are of importance in studying virulence and immunity. Sonicate antigens from seven such strains were used to study in vitro T-cell proliferation and gamma interferon (IFN-γ) and interleukin-12 (IL-12) secretion as markers of protective immunity in 25 healthy subjects positive for purified protein derivative (PPD). The standard PPD and heat-killed H37Rv antigens induced the maximum levels of T-cell proliferation and IFN-γ secretion but low levels of IL-12. All sonicate antigens induced T-cell proliferation and IFN-γ secretion with strong positive correlation. Our results suggest that sonicate antigens from the most prevalent and recent strains ofM.tuberculosisfrom clinical isolates have the potential to induce T-cell activation and may allow newer and specific antigens to be further characterized for diagnosis and vaccine development.
Prokaryotic Expression and Antigenic Characterization of Three RecombinantLeishmaniaAntigens for Serological Diagnosis of Canine Leishmaniasis
Authors: Rosati S. , Ortoffi M. , Profiti M. , Mannelli A. , Mignone W. , Bollo E. , Gradoni L.
Published: November 2003

Three recombinant antigens ofLeishmania chagasi(=L. infantum) were expressed in prokaryotic systems and evaluated (using a panel of dog sera characterized by parasitological and serological immunofluorescent antibody test [IFAT] techniques) as diagnostic markers of infection. The whole open reading frame encoding K9, the gene fragment encoding the repetitive sequence of K26, and the 3′-terminal gene fragment encoding a single 39-amino-acid subunit of the kinesin-related protein K39 (K39sub) were amplified fromL. infantumDNA and cloned into a pGEX-2T expression vector in frame with glutathioneS-transferase (GST). The sensitivity and specificity of enzyme-linked immunosorbent assays (ELISAs) using K26 as an antigen (evaluated with sera from 20 parasitologically positive and 20 parasitologically negative dogs) were both 100% (95% confidence interval [CI] = 83.2 to 100). When K9 and K39sub were used, sensitivity was 95% (95% CI = 75.1 to 99.9) and specificity was 100% (95% CI = 83.2 to 100). Using 182 field sera, a good agreement was found between the recombinant K26 ELISA and IFAT (K= 0.92; 95% CI = 0.86 to 0.98) results and between the K9 and K39sub ELISA (used in parallel) and IFAT (K= 0.87; 95% CI = 0.80 to 0.95) results. The results demonstrate that each antigen carries immunodominant epitopes and that their combination may further increase the sensitivity of currently available serological tests.
Cytokines as Mediators for or Effectors against Rotavirus Disease in Children
Authors: Jiang B , Snipes-Magaldi L. , Dennehy P. , Keyserling H. , Holman R. C. , Bresee J. , Gentsch J. , Glass R. I.
Published: November 2003

Rotavirus is the most common cause of severe gastroenteritis in young children, but the pathogenesis and immunity of this disease are not completely understood. To examine the host response to acute infection, we collected paired serum specimens from 30 children with rotavirus diarrhea and measured the levels of nine cytokines (interleukin-1β [IL-1β], IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, gamma interferon [IFN-γ], and tumor necrosis factor alpha [TNF-α]) using a microsphere-based Luminex Flowmetrix system. Patients with acute rotavirus infection had elevated median levels of seven cytokines in serum, and of these, the levels of three (IL-6, IL-10, and IFN-γ) were significantly (
P
< 0.05) higher than those in serum from control children without diarrhea. Patients with fever had significantly (
P
< 0.05) higher levels of IL-6 in serum than control children, and those with fever and more episodes of diarrhea had significantly (
P
< 0.05) higher levels of TNF-α than those without fever and with fewer episodes of diarrhea. We further demonstrated a negative association (
P
< 0.05) between the levels of IL-2 and the number of stools on the day on which the first blood sample was collected. Finally, patients with vomiting had significantly (
P
< 0.05) lower levels of IFN-γ than those without vomiting. Our pilot study provides evidence that the types and magnitudes of cytokine responses to rotavirus infection in children influence or reflect the clinical outcome of disease. These findings suggest that certain cytokines may play an important role in the pathogenesis of and the protection against rotavirus disease in children and, consequently, may provide directions and insights that could prove critical to the prevention or treatment of this important disease.
Histopathologic Patterns of Nephropathy in Naturally Acquired Canine Visceral Leishmaniasis
Authors: Costa F. A. L. , Goto H. , Saldanha L. C. B. , Silva S. M. M. S. , Sinhorini I. L. , Silva T. C. , Guerra J. L.
Published: November 2003

Although the nephropathy of visceral leishmaniasis (VL) is known both in humans and dogs, histopathologic alterations have not been thoroughly studied. We examined renal alterations in 55 dogs with naturally acquired VL compared with five noninfected dogs from an endemic area in northeastern Brazil. Glomerulonephritis was found in 55 dogs, interstitial alterations in 53 dogs, and tubular changes in 43 dogs with VL. The glomerular alterations found were minor glomerular abnormalities ( n = 8, 14.5%), focal segmental glomerulosclerosis ( n = 10, 18.2%), mesangial proliferative glomerulonephritis ( n = 17, 32.7%), membrano-proliferative glomerulonephritis ,(n = 18, 30.9%), crescentic glomerulonephritis ( n = 1, 1.8%), and chronic glomerulonephritis ( n = 1, 1.8%). Morphometric and ultrastructural studies complemented the analysis. The five control animals exhibited no glomerular alterations. The glomerular lesions were related to functional alterations. Considering that the alterations of canine and human nephropathy in VL are very similar, the data obtained in this study constitute an important contribution to the understanding of canine and human VL nephropathy.
Necrotizing Enterotyphlocolitis in Dogs Treated with a Potent Antimuscarinic
Authors: Rudmann D. G. , VanderEide S. L.
Published: November 2003

To assess the safety of a potent muscarinic receptor antagonist (antimuscarinic) for human clinical testing, repeat-dose oral toxicity studies were conducted in the Beagle dog. Treatment resulted in unexpected gastrointestinal system effects that were likely mediated by the exaggerated pharmacologic effects of the anti-muscarinic on intestinal motility. Dogs developed profound anorexia followed by severe bloody diarrhea, and at necropsy, the intestinal tract was distended, filled with red-tinged fluid, and the mucosa was reddened. Histologically, intestinal lesions consisted of severe epithelial necrosis and mucosal atrophy localized predominantly to the ileum and large intestine. Feces from dogs with diarrhea were culture-positive for Clostridium perfringens (CP), suggesting that CP might be the etiologic agent; however, the intestinal lesions were not consistent with histologic findings reported in dogs with hemorrhagic canine enteritis.
Consumers' Search and Use of Nutrition Information: The Challenge and Promise of the Nutrition Labeling and Education Act
Authors: Balasubramanian Siva K. , Cole Catherine
Published: November 2003

Four studies investigate the Nutrition Labeling and Education Act's (NLEA's) impact on how consumers use nutrition information. Field and laboratory studies compare, but do not detect any changes in, consumers' search for nutrition information or their recall of this information in the pre- and post-NLEA periods. However, the search activities of a select group (highly motivated and less knowledgeable consumers) benefited more from the NLEA than did other groups. Additional results from the field and lab studies indicate that the NLEA changed attention to negative nutrition attributes (such as fat and sodium, of which less is better) more than it changed attention to positive attributes such as calcium and vitamins. Analyses of scanner databases confirm this trend (with the exception of calories). Focus group results also reflect these findings. The authors discuss implications for public policy, management, academic research, and consumer welfare.
How Firms Relate to Their Markets: An Empirical Examination of Contemporary Marketing Practices
Authors: Coviello Nicole E. , Brodie Roderick J. , Danaher Peter J. , Johnston Wesley J.
Published: November 2003

The authors examine 308 firms in the United States and four other Western countries to understand how different types of firms relate to their markets. Comparative analysis shows that though there is some support for consumer and goods firms being more transactional and business and service firms being more relational, there are many exceptions. The results also show that firms can be grouped into those whose marketing practices are predominantly transactional, predominantly relational, or a transactional/relational hybrid. Each group constitutes approximately one-third of the sample and includes all types of firms (consumer goods, consumer services, business-to-business goods, and business-to-business services). This suggests that marketing practices are pluralistic and managerial practice has not shifted from transactional to relational approaches per se.
The Role of the Institutional Environment in Marketing Channels
Authors: Grewal Rajdeep , Dharwadkar Ravi
Published: November 2003

Set within the political economy framework, marketing channels literature predominantly has used an efficiency-based task environment perspective and largely overlooked a legitimacy-based institutional environment approach in studying channel attitudes, behaviors, processes, and structures. The purpose of this article is to highlight the importance of the institutional environment and develop a comprehensive conceptual framework that incorporates the institutional environment into current marketing channels research. The institutional environment perspective relies on the primacy of (1) regulatory institutions (e.g., laws), (2) normative institutions (e.g., professions), and (3) cognitive institutions (e.g., habitual actions) in influencing the legitimacy of channel members. Using institutional theory, the authors augment the current task environment approach by developing three institutional processes and their underlying mechanisms and elaborating on how these institutions might influence channel relationships. The article ends by laying out a research agenda and highlighting managerial implications.
The Hidden Minefields in the Adoption of Sales Force Automation Technologies
Authors: Speier Cheri , Venkatesh Viswanath
Published: November 2003

Sales force automation technologies are increasingly used to support customer relationship management strategies; however, commentary in the practitioner press suggests high failure rates. The authors use identity theory as a lens to better understand salesperson perceptions associated with technology rejection. They collected survey data from 454 salespeople across two firms that had implemented sales force automation tools. The results indicate that immediately after training, salespeople had positive perceptions of the technology. However, six months after implementation, the technology had been widely rejected, and salesperson absenteeism and voluntary turnover had significantly increased. There were also significant decreases in perceptions of organizational commitment, job satisfaction, person–organization fit, and person–job fit across both firms. Finally, salespeople with stronger professional commitment indicated more negative job-related perceptions as experience with the technology increased.
A Longitudinal Study of Complaining Customers' Evaluations of Multiple Service Failures and Recovery Efforts
Authors: Maxham James G. , Netemeyer Richard G.
Published: November 2003

The authors report a repeated measures field study that captures complaining customers' perceptions of their overall satisfaction with the firm, likelihood of word-of-mouth recommendations, and repurchase intent during a 20-month span that includes two service failures and recovery attempts. The findings suggest that though satisfactory recoveries can produce a “recovery paradox” after one failure, they do not trigger such paradoxical increases after two failures. Furthermore, “double deviations” can occur following two consecutive unsatisfactory recoveries or following an unsatisfactory recovery in response to a second failure. The findings indicate that customers reporting an unsatisfactory recovery followed by a satisfactory recovery reported significantly higher ratings at the second postrecovery period than did customers reporting the opposite recovery sequence. The outcome of the second recovery also demonstrated a significant influence on customer ratings (positively if the recovery was satisfactory, negatively if the recovery was unsatisfactory), regardless of whether the customer found the first recovery satisfactory or unsatisfactory. In addition, although the increased change in recovery expectations and failure severity ratings from the first failure to the second is more dramatic for customers who previously reported a satisfactory recovery, the increase in attributions of blame toward the firm is more pronounced for customers who previously reported an unsatisfactory recovery. Last, the results show that recovery efforts are attenuated when two similar failures occur and when two failures happen in close time proximity.