[Rosai-Dorfman disease as a rare cause of a pancreatic mass]. / Die Rosai-Dorfman-Erkrankung als seltene Ursache für einen Pankreastumor.

The CT and MRI scans of a 70-year-old male patient revealed a mass in the pancreatic head and a 2.8-cm peripancreatic lymph node. Under steroid therapy the mass did not show regression. Finally, a pancreatoduodenectomy was performed. Histologically, Rosai-Dorfman disease (RDD) was diagnosed. RDD is a rare histiocytic disorder with usually nodal but sometimes also extranodal involvement. Herein we report a rare case of extranodal RDD with intrapancreatic localization.

Purulent myositis of the thigh as a presentation of perforated low rectal cancer.

Purulent myositis is an acute, intramuscular bacterial infection involving abscess formation most commonly affecting the quadriceps, hamstring and gluteal muscles. We present a case of extensive purulent myositis of the thigh and lower leg caused by bowel perforation below the peritoneal reflection secondary to rectal cancer. Cases of lower limb and perineal purulent myositis should raise suspicion of rectal perforation and should prompt investigations to exclude rectal malignancy.

Effect of probiotic on innate inflammatory response and viral shedding in experimental rhinovirus infection - a randomised controlled trial.

Ingestion of probiotics appears to have modest effects on the incidence of viral respiratory infection. The mechanism of these effects is not clear; however, there is evidence from animal models that the probiotic may have an effect on innate immune responses to pathogens. The purpose of this randomised, placebo-controlled study was to determine the effect of administration of Bifidobacterium animalis subspecies lactis Bl-04 on innate and adaptive host responses to experimental rhinovirus challenge. The effect on the response of chemokine (C-X-C motif) ligand 8 (CXCL8) to rhinovirus infection was defined as the primary endpoint for the study. 152 seronegative volunteers who had been supplemented for 28 days, 73 with probiotic and 79 with placebo, were challenged with RV-A39. Supplement or placebo administration was then continued for five days during collection of specimens for assessment of host response, infection, and symptoms. 58 probiotic and 57 placebo-supplemented volunteers met protocol-defined criteria for analysis. Probiotic resulted in higher nasal lavage CXCL8 on day 0 prior to virus challenge (90 vs 58 pg/ml, respectively, P=0.04, ANCOVA). The CXCL8 response to rhinovirus infection in nasal lavage was significantly reduced in the probiotic treated group (P=0.03, ANCOVA). Probiotic was also associated with a reduction in nasal lavage virus titre and the proportion of subjects shedding virus in nasal secretions (76% in the probiotic group, 91% in the placebo group, P=0.04, Fisher Exact test). The administration of probiotic did not influence lower respiratory inflammation (assessed by exhaled nitric oxide), subjective symptom scores, or infection rate. This study demonstrates that ingestion of Bl-04 may have an effect on the baseline state of innate immunity in the nose and on the subsequent response of the human host to rhinovirus infection. Clinicaltrials.gov registry number: NCT01669603.

Functional analysis of -351 interleukin-9 promoter polymorphism reveals an activator controlled by NF-kappaB.

Genetic studies have shown linkages for asthma to the chromosomal region 5q31-q33 in humans that includes the IL-9 gene. An A-to-G base substitution has been identified at bp -351 in the IL-9 promoter. The role of this polymorphism in IL-9 promoter function was assessed utilizing CD4+ T cells purified from individuals with one or two of the G alleles in comparison to those homozygous for the wild-type A. The presence of an A at -351 (A allele) increased mitogen-stimulated IL-9 transcription twofold in comparison to subjects with one or two G alleles at this position. Binding of nuclear extract proteins from IL-9-producing human cell lines to DNA sequences including this base exchange demonstrated specific binding of the transcription factor NF-kappaB. Binding of NF-kappaB to the IL-9 promoter was confirmed in vivo using the chromatin immunoprecipitation assay. Recombinant NF-kappaB bound to a promoter fragment with the A allele with fivefold higher affinity than it did to a promoter with the G allele. Individuals carrying the A allele of the IL-9 promoter display increased synthesis of IL-9, which may result in strong Th2 immune responses and a modulation of their susceptibility to infectious, neoplastic, parasitic or atopic disease.

Th2 cytokines and asthma. Interleukin-4: its role in the pathogenesis of asthma, and targeting it for asthma treatment with interleukin-4 receptor antagonists.

Interleukin-4 (IL-4) mediates important pro-inflammatory functions in asthma including induction of the IgE isotype switch, expression of vascular cell adhesion molecule-1 (VCAM-1), promotion of eosinophil transmigration across endothelium, mucus secretion, and differentiation of T helper type 2 lymphocytes leading to cytokine release. Asthma is a complex genetic disorder that has been linked to polymorphisms in the IL-4 gene promoter and proteins involved in IL-4 signaling. Soluble recombinant IL-4 receptor lacks transmembrane and cytoplasmic activating domains and can therefore sequester IL-4 without mediating cellular activation. We report the results of initial clinical trials, which demonstrate clinical efficacy of this naturally occurring IL-4 antagonist as a therapeutic agent in asthma.

Rapid spectrophotometric measurements of total bilirubin in intact and hemolyzed neonatal blood: a feasibility study.

BACKGROUND: Conventional methods for measuring the total bilirubin concentration in blood require the use of serum or plasma, but physically separating red blood cells from plasma by centrifugation is a time-consuming and potentially dangerous process that does not lend itself to rapid, near-patient testing. Therefore, we have sought to determine whether spectrophotometric measurements of total bilirubin concentration are feasible in unaltered whole blood. METHODS: We modified an Hb-Quick hemoglobinometer (Avox Systems, Inc., San Antonio, TX), a relatively new, portable, battery-powered instrument that uses disposable cuvettes and a reagentless system to measure total hemoglobin in nonhemolyzed, whole blood. The prototype consisted of an Hb-Quick equipped with light-emitting diodes with emissions at five different wavelengths to measure total bilirubin and total hemoglobin. Using blood samples from neonates with suspected hyperbilirubinemia, we made measurements on plasma from centrifuged samples and on hemolyzed and nonhemolyzed aliquots of the same blood samples. RESULTS: In the first series of experiments, we compared the Unistat bilirubinometer's readings with the prototype's measurements of bilirubin in plasma. There was a close linear correlation between the prototype's measurements and those of the reference instrument (slope=1.01, r(2)=0.991). Subsequently, we used the prototype's measurements on plasma as the reference method and compared them with readings on hemolyzed and nonhemolyzed aliquots of each sample. Readings on hemolyzed and nonhemolyzed aliquots were significantly correlated with the measurements in plasma, but the regression lines did not have a slope of 1. However, when the measurements on hemolyzed and nonhemolyzed blood were scaled appropriately to compensate for the fact that red cells "dilute" the bilirubin in plasma, the correlation coefficients improved, and there was then a 1:1 relationship between the measurements in whole blood and plasma. CONCLUSIONS: These preliminary findings demonstrate the feasibility of developing a portable instrument to measure total bilirubin in unaltered whole blood. The advantages of this method are speed, elimination of centrifugation or other sample preparation, and instrument portability. The disadvantage is that the concentration units are unconventional, i.e., milligrams of bilirubin per volume of whole blood. However, the instrument can be programmed to display the total bilirubin concentration in traditional units, e.g., milligrams of bilirubin per volume of plasma.

A simple method for measuring fetal hemoglobin by co-oximetry.

A simple, rapid method is presented for assessing the fetal hemoglobin fraction (%HbF). The principle of the measurement is straightforward. If two co-oximeters differ in the extent to which fetal hemoglobin interferes with their measurements of a particular analyte and if no other source of interference is present, then the magnitude of the difference in the HbF-induced interference between the two instruments can provide a quantitative measure of the fetal hemoglobin fraction. The present method does not require measuring optical absorbances at specific wavelengths or solving multiple simultaneous equations. On the contrary, the present method requires only one measurement on each instrument and a single simple calculation that yields a useful estimation of %HbF. Finally, it should be noted that this method can also be used for quantifying the concentrations of other compounds if two co-oximeters are available that differ appreciably in the extent to which the compound of interest interferes with their measurements of a particular analyte.

Co-oximetry interference by hemoglobin-based blood substitutes.

UNLABELLED: The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-Oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-Oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments' measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes. IMPLICATIONS: We investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different cooximeters. Some blood substitutes caused obvious interference, such as negative carboxyhemoglobin readings; however, the findings indicate that cooximeters will generally give less accurate but clinically useful measurements in the presence of the hemoglobin-based blood substitutes that were tested.

Dissimilar immunogenicities of human papillomavirus E7 and adenovirus E1A proteins influence primary tumor development.

Although human papillomaviruses (HPV) and adenoviruses (Ad) both transform cells by expressing functionally related oncogenes (Ad-E1A/E1B; HPV-E7/E6), only HPV are oncogenic in humans. Prior studies have shown that HPV-transformed cells are resistant to NK cell lysis and E7- and E6-specific CTL are inefficiently generated in women with HPV-induced cervical cancer. Therefore, we postulated that the dissimilar oncogenicities of Ad and HPV may be caused by a protective NK and T cell response that is triggered by transformed cells expressing E1A, but not by E7. To test this hypothesis, mice that were either immunologically intact, lacked T cells, or lacked both NK and T cells were challenged with Ad serotype 5 (Ad5)-E1A- or HPV16-E7-transfected tumor cells. E7-expressing tumor cells were resistant to NK cell lysis in vitro and failed to elicit a measurable anti-tumor NK or T cell response in vivo. The concomitant expression of E6 did not change this phenotype. In contrast, E1A-expressing tumor cells were sensitive to NK lysis in vitro and triggered a protective NK and T cell immune response in vivo. These data suggest differences in the capacities of E1A or E7 oncoproteins to trigger protective anti-tumor immune responses may contribute to the dissimilar oncogenicities of Ad and HPV in humans.

Discrete promoter elements affect specific properties of RNA polymerase II transcription complexes.

The frequency of transcription initiation at specific RNA polymerase II promoters is, in many cases, related to the ability of the promoter to recruit the transcription machinery to a specific site. However, there may also be functional differences in the properties of assembled transcription complexes that are promoter-specific or regulator-dependent and affect their activity. Transcription complexes formed on variants of the adenovirus major late (AdML) promoter were found to differ in several ways. Mutations in the initiator element increased the sarkosyl sensitivity of the rate of elongation and decreased the rate of early steps in initiation as revealed by a sarkosyl challenge assay that exploited the resistance of RNA synthesis to high concentrations of sarkosyl after formation of one or two phospho-diester bonds. Similar, but clearly distinct, effects were also observed after deletion of the binding site for upstream stimulatory factor from the AdML promoter. In contrast, deletion of binding sites for nuclear factor 1 and Oct-1, as well as mutations in the recognition sequence for initiation site binding protein, were without apparent effect on transcription complexes on templates containing the mouse mammary tumor virus promoter.

RNA polymerase II transcription complex assembly in nuclear extracts.

In vitro transcription systems based on nuclear extracts of eukaryotic cells continue to be valuable experimental systems for assessing function of promoter sequences and defining new activities involved in transcription complex assembly and activity, but many aspects of such systems have not been experimentally examined. Here, transcription complex assembly on the promoter from the long terminal repeat of mouse mammary tumor virus was assessed in vitro with a transcription system derived from nuclear extracts of cultured HeLa cells. The extent of preinitiation complex assembly on the promoter was limited by the availability of template, even though only a small fraction of the template present in the assays participated in transcription. These results support a model for transcription complex assembly in which template DNA has two alternative fates, one leading to assembly of a functional transcription complex, and another that leads to irreversible template inactivation. The observed kinetics of assembly reflects loss of template by both pathways and is dominated by a relatively rapid rate of template inactivation. Supplementing nuclear extracts with purified TATA binding protein increased the extent as well as the apparent rate of assembly. Both effects can be explained by a TATA binding protein-dependent increase in the rate of assembly that leads to altered partitioning of template between competing pathways.

CO-oximetry interference by perflubron emulsion: comparison of hemolyzing and nonhemolyzing instruments.

Perflubron emulsion is expected to be in clinical use soon as a non-hemoglobin blood substitute. A preliminary report indicates that this new oxygen-carrying fluorocarbon interferes with the measurements of CO-oximeters. Therefore, we have quantified the interference that perflubron causes in the measurements of eight widely used oximeters and CO-oximeters. The AVL Omni 6, CC270, IL482, IL682, and OSM3 are conventional CO-oximeters that hemolyze blood samples before analyzing them. In contrast, the AVOXimeters 1000 and 4000 and the IL Synthesis 35 make their measurements without hemolyzing the samples. Because perflubron is expected to be used most frequently on surgical patients in a hemodiluted state, we conducted all tests on human erythrocytes suspended in plasma at a hemoglobin concentration standardized to 70 g/L (7 g/dL) and with oxyhemoglobin saturation set at 97%. When perflubron was added to the blood samples, the nonhemolyzing CO-oximeters were not seriously affected by perflubron concentrations in and above the therapeutic range. In contrast, some of the hemolyzing CO-oximeters experienced concentration-dependent interference in their measurements of all analytes except total hemoglobin concentration. Thus, we conclude that the nonhemolyzing CO-oximeters provide an effective means for determining whether a hemolyzing CO-oximeter is experiencing clinically important interference in blood from patients receiving perflubron.

Effect of oximetry error on the diagnostic value of the Qp/Qs ratio.

As a quantitative assessment of the magnitude of shunting, the ratio of pulmonary to systemic blood flow (Qp/Qs) plays an important role not only in the oximetric diagnosis of intracardiac and great-vessel shunts but also in the treatment of the patient. However, the oxygen saturation measurements used to compute the Qp/Qs ratio contain errors due to physiological variability and measurement error of the oximeter used to analyze the blood samples. We have developed a mathematical model to describe the variability that oximetry errors contribute to the uncertainty in the Qp/Qs ratio. Using this model, we compute the probability of making an inappropriate recommendation regarding corrective surgery when a particular value of the ratio is the criterion for surgery, e.g. a Qp/Qs ratio >2. This report also contains a spreadsheet that readers can use to analyze their own oximetry data by computing confidence intervals for the Qp/Qs ratio. The results presented here support the following conclusions. First, because the Qp/Qs ratio is calculated from saturation measurements at four different sites, oximetry errors make the Qp/Qs ratio less effective at detecting the presence of a shunt than the conventional step-up method that depends on samples from only two sites. Second, although oximetry errors are equally likely to cause the calculated Qp/Qs ratio to overestimate the true Qp/Qs ratio as to underestimate it, the overestimations on average have greater magnitudes than the underestimations. Third, in comparison with an oximeter that has 2.5% measurement error, using an oximeter with 1% or less error greatly reduces the uncertainty in the Qp/Qs ratio and thus increases the probability of reaching the right decision regarding corrective surgery. Fourth, the variability in apparent Qp/Qs ratios is also greatly diminished by taking multiple blood samples from each of the four requisite sites and averaging them before calculating the Qp/Qs ratio. Although increasing the number of blood samples from each site can compensate for the error of an oximeter, this approach can be impractical, particularly if the oximeter error is 2.5% or greater.

Evaluation of two oximeters for use in cardiac catheterization laboratories.

We evaluated two whole-blood oximeters designed for use in the cardiac catheterization laboratory: the Oxicom 3000 and the AVOXimeter 1000. Unlike the larger CO-Oximeters, which hemolyze a blood sample before analysis, these simple instruments use disposable cuvettes to allow determination of oxyhemoglobin saturation of whole blood. Thus they eliminate the need for cleaning solutions and considerable maintenance. We evaluated the accuracy of these instruments in comparison with a Radiometer OSM3 and found them both to work well on routine samples. Of note, the AVOXimeter performed better than the Oxicom when the sample was hemolyzed and when green dye was present. In addition, the AVOXimeter measures the total hemoglobin concentration and the oxygen content of each sample, eliminating errors that hemodilution introduces into the determination of cardiac output by the Fick principle. We conclude that whole-blood oximeters are accurate and useful instruments for use in the cardiac catheterization laboratory.

Effects of temperature on optical absorbance spectra of oxy-, carboxy-, and deoxyhemoglobin.

The optical absorbance spectra of oxy-, carboxy-, and deoxyhemoglobin were recorded at wavelengths from 479 to 651 nm and at temperatures of 20, 30, and 40 degrees C. As noted in earlier reports, a major effect of lowering the temperature was an increase in the absorptivities at or near the absorbance maxima. However, at other wavelengths, reducing the temperature increased, decreased, or caused no change in absorbance. At wavelengths where temperature-induced shifts did occur, the absorbance change appeared to be a linear function of temperature. Unlike previous reports, the data presented here are quantitative and thus can be used to predict temperature-induced errors in spectrophotometric measurements of the relative concentrations of these hemoglobin species. Examples are given of the error that would occur in a widely used CO-Oximeter, the IL482, if it were not temperature controlled. Thus, the data presented here should be particularly useful to the operators and designers of spectrophotometric instruments such as oximeters, CO-Oximeters, and hemoglobinometers.

An oximeter for measuring hemoglobin concentration and oxygen content.

We have developed an oximeter that measures both the total hemoglobin concentration in whole blood and the percentage of the hemoglobin saturated with oxygen. The oximeter uses red and infrared light-emitting diodes to illuminate a capillary tube filled with a sample of whole blood. Light scattered by the blood travels a short distance down the length of the capillary tube and reaches a photodetector, the output of which is amplified, digitized, and fed into a microprocessor. The microprocessor computes the total hemoglobin concentration as a nonlinear function of the infrared light intensity. Oxyhemoglobin saturation is computed from the ratio of the logarithms of the intensities of red and infrared light. Our instrument has the following advantages over existing oximeters: 1) it provides a measurement of total hemoglobin concentration, 2) it is immune to the calibration shifts that fluctuations in total hemoglobin concentration cause in other oximeters, 3) it is accurate over a wide range of oxygen saturation, and 4) the blood samples are not diluted and can thus be preserved for further analysis. A detailed parts list and circuit diagram are presented, and sources of error are discussed.

An optical hemoglobinometer for whole blood.

To overcome the disadvantages of the presently available hemoglobinometers, we have developed an optical instrument that measures the total hemoglobin (Hb) concentration in whole, undiluted blood. The device uses an infrared light-emitting diode to illuminate a capillary tube filled with a sample of whole blood. Light scattered in the blood travels a short distance down the length of the capillary tube, passes through a second light path, and reaches a photodetector, the output of which is amplified, digitized, and fed into a microprocessor. The microprocessor computes the Hb concentration as a nonlinear function of the light intensity. The optical device yielded Hb content measurements that correlated well with standard methods (r = 0.99, slope = 0.94, mean absolute difference = 0.75 g Hb/dl). Thus the accuracy appears to be less than 1 g Hb/dl. The advantages of the present device are as follows: 1) no chemical reaction is required (hence neither accurate dilutions nor toxic reagents are necessary); 2) it reads Hb concentration within a few seconds; 3) it can be operated by unskilled personnel; 4) it could be made portable and thus could be operated in the field, in rural settings, or at accident sites; 5) sample size is small (25-70 microliters); and 6) the same capillary tube can be centrifuged if a measure of hematocrit is also desired. A detailed parts list and circuit diagram are presented, and sources of error are discussed.

Diffusion model of the optical absorbance of whole blood.

Photon-diffusion theory has had limited success in modeling the optical transmittance of whole blood. Therefore we have developed a new photon-diffusion model of the optical absorbance of blood. The model has benefited from experiments designed to test its fundamental assumptions, and it has been compared extensively with transmittance data from whole blood. The model is consistent with both experimental and theoretical notions. Furthermore, when all parameters associated with a given optical geometry are known, the model needs no variational parameters to predict the absolute transmittance of whole blood. However, even if the exact value of the incident light intensity is unknown (which is the case in many situations), only a single additive constant is required to scale experiment to theory. Finally, the model is shown to be useful for simulating scattering effects and for delineating the relative contributions of the diffuse transmittance and the collimated transmittance to the total optical density of whole blood. Applications of the model include oximetry and measurements of the arteriovenous oxygen difference in whole, undiluted blood.