Autoimmune neutropenia: clinical and laboratory studies in 143 patients

Summary Clinical and laboratory data of 143 patients with primary or secondary autoimmune neutropenia (AIN) were evaluated. Primary AIN was found predominantly in children below 3 years, whereas secondary AIN was more frequent in patients 40–60 years of age. Female patients with primary AIN were slightly more prevalent (54%) than male patients (46%). The peripheral blood count showed normal or diminished leukocyte counts with median absolute neutrophil counts of 250 cells/l. In 38% of the patients neutropenia was accompanied by monocytosis. Bone marrow examination revealed in 95% a normo- or hypercellular marrow with a marked reduction of mature neutrophils in 56% of the specimens. Twenty-three percent of the sera showed specificity for the NA1 antigen. Patients were usually affected by benign bacterial infections of the skin and of the upper respiratory tract, as well as by recurrent otitis media. Infections were treated symptomatically, and only six patients required continuous administration of antibiotics. Remission of neutropenia during treatment occurred in three of six patients treated with intravenous immunoglobulin G and in three of four patients who received steroid therapy. Except for one patient neutropenia relapsed after discontinuation of therapy. During a follow-up of 6–36 months, spontaneous remission has been observed in four patients.This work was supported by theDeutsche Forschungsgemeinschaft (Mu 277/9-7)     

Proteinase-activated receptor-2-mediated signaling and inhibition of DNA synthesis in human pancreatic cancer cells

Summary Conclusion Proteinase-activated receptor-2 (PAR-2)-mediated effects contribute to the intracellular signaling network in pancreatic tumor cells. A role of PAR-2 as negative regulator in human pancreatic tumor growth might be implied. Background Using the human pancreatic tumor cell line MIA PaCa-2, we evaluated cellular effects of trypsin and the PAR-2-activating peptide SLIGRL on [Ca²⁺]_i mobilization, Ins(1,4,5)P₃ level, and protein kinase (PKC) activation. Furthermore, PAR-2 involvement in the regulation of cell proliferation has been estimated by measurement of [³H]thymidine incorporation in MIA PaCa-2 cells. Results Trypsin and the PAR-2 synthetic peptide agonist SLIGRL induced [Ca²⁺]_i mobilization, transient increase in inositol (1,4,5) triphosphate level, and PKC translocation in MIA PaCa-2 cells. In addition, SLIGRL induced a decrease in DNA synthesis in MIA PaCa-2 cells.     

Analysis of temporal requirements for myocardial tissue velocity imaging.

AIMS: Movements of myocardial walls include components of high velocity and short duration calling for a high sampling rate in the acquisition of tissue velocity imaging data. This study aims at establishing the optimal sampling requirements for tissue velocity imaging measurements. METHODS AND RESULTS: In 16 healthy individuals, tissue velocity imaging data were acquired at a frame rate of 141-203 frames/s for a subsequent off-line analysis using software enabling a reduction of the sampling rate to 50%, 25% and 12.5% of the initial frame rate. Different components of the myocardial velocity profile were measured at each of these frame rates. The deviation of the results from the initial values increased markedly at decreasing frame rates, producing an underestimation of peak systolic and diastolic velocities, most other measured parameters being overestimated. A cut-off point for an acceptable < or =10% deviation of the results corresponded to at least 70 frames/s for peak systolic and early diastolic velocity, and to at least 100 frames/s for other systolic and diastolic parameters. CONCLUSION: A high sampling rate is essential for a proper rendering of tissue velocity imaging signals, too low frame rates resulting in inferior accuracy of the results. This should be kept in mind while viewing reported tissue velocity imaging data.     

Studies in experimental animals on disseminated intravascular coagulation (DIC).

Changes in the clotting system, as well as morphological and functional alterations corresponding to that of the pathologic phenomenon of disseminated intravascular coagulation (DIC) or consumption coagulopathy, were produced by thrombin infusion (550 NIH U X kg-1 X h-1) in rats and simultaneous inhibition of fibrinolysis by PAMBA (100 mg/kg). Changes in the fibrinogen level and platelet count as well as the appearances of fibrin monomers and the formation of microthrombi in several organs were evaluated. Simultaneously, the function of the respiratory system was investigated by continuous measurement of oxygen consumption as well as elasticity and water content of the lung. From the time course of the alterations in the several parameters, conclusions can be drawn for the pathogenesis and the possible therapeutic influence on DIC.     

Allergen immunotherapy decreases specific allergen-induced expression of Fas and FasL on CD4+ and CD8+ cells.

Apoptosis programmed cell death without induction of an inflammatory response. It is mediated by Fas--a cell surface protein which is expressed on activated lymphocytes. Interaction with its counterpart--the Fas ligand induces the apoptosis of Fas bearing cells. The mechanism underlying successful immunotherapy has not been identified. The aim of this study was to investigate whether specific immunotherapy (SIT) might affect Fas and FasL expression after stimulation with specific allergen. The study was conducted on 8 allergic subjects and 8 healthy volunteers as controls. The allergic patients were treated with conventional SIT (Pollinex). Blood samples were collected before the first day and 7 days after the last injection. Isolated CD4+ and CD8+ cells were incubated in various concentrations of specific allergen (1, 10, 100 ng/ml) or in medium alone. Indirect immunofluorescence test with rabbit IgG against human Fas and FasL was performed. The percentage of positive cells was determined under fluorescence microscope. The expression of Fas and FasL before SIT was significantly increased on CD4+ and CD8+ cells under the influence of specific allergen (10, 100 ng/ml). After SIT, significant decrease in the expression of both molecules was observed, although elimination of allergen-reactive cells was not complete and their number was still higher than in the controls. CONCLUSION: The exposure of CD4+ and CD8+ cells on allergen may induce the Fas-FasL apoptotic pathway. Significant decrease in number of allergen-reactive CD4+, CD8+ cells after SIT suggests participation of the phenomenon in deletion of clones, which may be a part of the allergen tolerance mechanism achieved naturally or during SIT.     

A high-resolution physical map of human chromosome 11.

The development of a highly reliable physical map with landmark sites spaced an average of 100 kbp apart has been a central goal of the Human Genome Project. We have approached the physical mapping of human chromosome 11 with this goal as a primary target. We have focused on strategies that would utilize yeast artificial chromosome (YAC) technology, thus permitting long-range coverage of hundreds of kilobases of genomic DNA, yet we sought to minimize the ambiguities inherent in the use of this technology, particularly the occurrence of chimeric genomic DNA clones. This was achieved through the development of a chromosome 11-specific YAC library from a human somatic cell hybrid line that has retained chromosome 11 as its sole human component.To maximize the efficiency of YAC contig assembly and extension, we have employed an Alu-PCR-based hybridization screening system. This system eliminates many of the more costly and time-consuming steps associated with sequence tagged site content mapping such as sequencing, primer production, and hierarchical screening, resulting in greater efficiency with increased throughput and reduced cost. Using these approaches, we have achieved YAC coverage for >90% of human chromosome 11, with an average intermarker distance of <100 kbp. Cytogenetic localization has been determined for each contig by fluorescent in situ hybridization and/or sequence tagged site content. The YAC contigs that we have generated should provide a robust framework to move forward to sequence-ready templates for the sequencing efforts of the Human Genome Project as well as more focused positional cloning on chromosome 11.     

Electrocardiogram signal variance analysis in the diagnosis of coronary artery disease—A comparison with exercise stress test in an angiographically documented high prevalence population

Variance electrocardiography (variance ECG) is a new resting procedure for detection of coronary artery disease (CAD). The method measures variability in the electrical expression of the depolarization phase induced by this disease. The time-domain analysis is performed on 220 cardiac cycles using high-fidelity ECG signals from 24 leads, and the phase-locked temporal electrical heterogeneity is expressed as a nondimensional CAD index (CAD-I) with the values of 0–150. This study compares the diagnostic efficiency of variance ECG and exercise stress test in a high prevalence population. A total of 199 symptomatic patients evaluated with coronary angiography was subjected to variance ECG and exercise test on a bicycle ergometer as a continuous ramp. The discriminant accuracy of the two methods was assessed employing the receiver operating characteristic curves constructed by successive consideration of several CAD-I cutpoint values and various threshold criteria based on ST-segment depression exclusively or in combination with exertional chest pain. Of these patients, 175 with CAD (≥ 50% luminal stenosis in 1 + major epicardial arteries) presented a mean CAD-I of 88 ± 22, compared with 70 ± 21 in 24 nonaffected patients (p < 0.01). Variance ECG provided a stochastically significant discrimination (p < 0.01) which was matched by exercise test only when chest pain variable was added to ST-segment depression as a discriminating criterion. Even then, the exercise test diagnosed single-vessel disease with a significantly lower sensitivity. At a cutpoint of CAD-I ≥ 70, compared with ST-segment depression ≥ 1 mm combined with exertional chest pain, the overall sensitivity of variance ECG was significantly higher (p < 0.01) than that of exercise test (79 vs. 48 %). When combined, the two methods identified 93% of coronary angiography positive cases. Variance ECG is an efficient diagnostic method which compares favorably with exercise test for detection of CAD in high prevalence population.     

N-Terminal Pro–B-Type Natriuretic Peptide in the Emergency Department: The ICON-RELOADED Study

Background

Contemporary reconsideration of diagnostic N-terminal pro–B-type natriuretic peptide (NT-proBNP) cutoffs for diagnosis of heart failure (HF) is needed.

Effect of nifedipine on interdigestive gallbladder volume and postprandial gallbladder emptying in man

The effect of two oral doses (10 and 20 mg) of nifedipine versus placebo on the fasted gallbladder volume and on the meal-induced gallbladder emptying was assessed according to a double-blind study protocol in 12 healthy volunteers. Eight subjects underwent three studies (with placebo and with both nifedipine doses), whereas in two subjects the effect of a 10-mg nifedipine dose, vs placebo and in two others the effect of a 20-mg nifedipine dose vs placebo was examined. The studies were performed on separate days, and the gallbladder volume was measured by means of real-time ultrasonography. Neither placebo nor 20 mg nifedipine per os elicited any significant change in the fasted gallbladder vlume. With 10 mg nifedipine per os a significant increase in the interdigestive gallbladder volume was observed: 22.9±2.9 cm³ before and 26.2±3.2 cm³ after the drug receipt (P<0.005). A trend towards an inhibition of the postprandial gallbladder emptying was observed with 10 mg nifedipineper os without, however, reaching the level of statistical significance. Following 20 mg nifedipineper os, a marked delay in the meal-stimulated gallbladder emptying occurred as reflected by a decrease in the gallbladder ejection fraction from 48.1±4.5% (placebo) to 26.4±5.0% (nifedipine) (P<0.02) at 30 min and from 54.0±3.6% (placebo) to 33.2±4.6% (nifedipine) (P<0.02) at 40 min after the test meal. We conclude that a therapeutic oral dosage of nifedipine has a significant relaxing effect on the human gallbladder.