Participation of peripheral polymorphonuclear leukocytes in the oxidative stress and inflammation in patients with essential hypertension.

Oxidative stress and inflammation have recently been linked to endothelial damage in essential hypertension (EH). Activated peripheral polymorphonuclear leukocytes (PMN) damage surrounding tissue by releasing reactive oxygen species (ROS) and proteolytic enzymes before self-necrosis. PMN necrosis further exacerbates inflammation and promotes chemotaxis and PMN recruitment. The number and properties of PMN from untreated EH patients is the focus of the present study. Oxidative stress was assessed by measuring the rate of superoxide anion release from separated, phorbol ester-stimulated PMN and the redox state of plasma glutathione. Inflammation was estimated indirectly by determining PMN number and their in vitro survival. PMN from EH patients (n = 37) released superoxide anion faster (P < .0001) than those of normotensives (NC, n = 37), 17.7 +/- 1.14 v 9.54 +/- 0.51 nmol/10 min/10(6) cells. The redox state of glutathione was twofold higher in EH plasma (P < .02) indicating systemic oxidative stress. PMN survival in vitro correlates linearly with the rate of superoxide release (r2 = 0.60, P < .02) and PMN count of EH patients, although in the normal range, were significantly higher (P < .0001), indicating necrosis and recruitment. Hypertensive plasma significantly reduced NC PMN viability, whereas normal plasma significantly increased EH PMN viability. What our studies show is that EH is accompanied by a primed state PMN that does not correlate with the levels of blood pressure. PMN priming in EH patients reflects an in vivo exposure to a constant stimulus ending in oxidative stress, increased self-necrosis, and cell recruitment. Oxidative stress and inflammation will result in endothelial damage and atherosclerosis in the long run.

Paroxysmal nocturnal hemoglobinuria associated with in vitro inhibition of erythropoiesis by bone marrow T lymphocytes.

BACKGROUND: The etiology of bone marrow failure, a prominent feature of paroxysmal nocturnal hemoglobulinuria, is presently unknown. OBJECTIVES: To evaluate the possible influence of cellular immune mechanisms in the bone marrow failure of PNH. METHODS: We studied marrow erythroid colony formation in a patient with paroxysmal nocturnal hemoglobinuria without hypoplastic/aplastic marrow complications. RESULTS: In vitro assays revealed a pronounced inhibition of primitive erythroid (BFU-E) progenitor cell growth by marrow T lymphocytes. Removal of T cells prior to culture resulted in a 4.5-fold enhancement of BFU-E numbers. Reevaluation of in vitro erythropoiesis during steroid administration indicated a persistent, albeit less prominent, T cell inhibitory effect. CONCLUSION: Our findings provide the first direct evidence for a cellular immune inhibitory phenomenon accompanying PNH.

The use of the Hansen-Street intramedullary nail in midshaft fractures of the femur.

A retrospective study was conducted on 75 consecutive femoral midshaft fractures treated with intramedullary nailing using the solid-diamond-shape Hansen-Street nail with an open technique. The average age of patients was 32.5 years. Road accidents accounted for 43 cases. The average operative time was 40 minutes. There were two systemic complications. No infection occurred. Fifty-six cases could be gathered for this study, with an average follow-up of 5 years; 19 were followed for at least 6 months. At 4 months, all the fractures were united except one. The average time to sound bony union was 4 months. There was no residual deformity in varus-valgus or in the sagittal plane. Malrotation was rare and did not exceed 5 degrees. Shortening of 2 cm was found in 3 patients where the fracture was comminuted. All followed patients returned to regular daily function. The use of the Hansen-Street nail in an open procedure is an accurate method for anatomic reduction. As opposed to closed techniques, the procedure proved in our hands to be simple and quick, without undue exposure to radiation of the surgical team, and without such other complications as nerve complications due to traction. The procedure with this device is indicated for mid-third fractures of the femoral shaft only.

Immunophenotypic characterization of myelopoiesis in early and late myelodysplastic syndromes: use of CD44 as an aid in early diagnosis.

We investigated the possibility that myeloid cells from the bone marrow (BM) of myelodysplastic patients differ in their expression of CD44 antigen compared with expression of the antigen in normal controls. In addition, two triple-surface marker assays incorporating, respectively, CD44/CD33/CD66 and CD33/CD34/HLA-DR were used to evaluate the degree of myeloid maturation and assess the number of blasts in BM by flow cytometry. Patients with early-stage myelodysplastic syndrome (MDS; RA [FAB classification]) have significantly decreased expression of CD44 on gated myeloid cells. In contrast, patients with late-stage MDS (RAEB and RAEB-T [FAB classification]) showed an elevated expression of CD44 and an increased number of CD34 blasts compared with early-stage MDS patients and normal controls. Late-stage MDS patients also had an increase in the immature myeloid compartment (CD66 weak expression) compared with early-stage MDS patients and normal controls. We have already included this assay as part of our MDS evaluation protocol alongside BM morphology and cytogenetics.

Serum immunoglobulin-lipid complexes in plasma cell dyscrasia.

Immunoglobulin-lipid complexes (SILC) are found in the serum of all patients with monoclonal gammopathy. Fractionation by density gradient ultracentrifugation, Sephadex G-200 chromatography and Sepharose protein A affinity, followed by extensive immunoassaying for immunoglobulins and lipoproteins, does not confirm the accepted assumption that SILC are immune complexes between monoclonal immunoglobulins and lipoproteins. Lipid extraction of monoclonal fractions isolated on protein A columns followed by thin-layer chromatography shows a lipid pattern characteristic of the one found in cellular membranes. It is proposed that SILC are hydrophobic complexes between immunoglobulins and lipids, as described in membranes of B lymphocytes.

Heparin induces apoptosis in human peripheral blood neutrophils.

Programmed cell death, by apoptosis, has been shown to play an important role in the regulation of haemopoiesis. Using trypan blue exclusion for distinguishing intact membranes, flow cytometry for detection of sub G1 peak and in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL), this study shows that heparin induces apoptosis in vitro in human peripheral blood neutrophils. The known anti-proliferative effect of heparin in several in vitro cell systems has therefore to be interpreted in the light of apoptosis. In addition, apoptosis may help explain the anti-inflammatory effects resulting from the interaction between vessel wall heparan sulphate and chemoattracted peripheral blood neutrophils.

The polymorphonuclear leukocyte--a new target for erythropoietin.

A previous study from our laboratory has shown that erythropoietin (EPO), beside its traditional role in erythropoiesis, acts as an alleviator of oxidative stress and inflammation in chronic hemodialysis (HD) patients, conferred in part by activated polymorphonuclear leukocytes (PMNLs). To substantiate this phenomenon, the existence of EPO receptors (EPO-Rs) on PMNL membrane was examined at the transcriptional and translational levels. mRNA for EPO-R was detected in PMNLs using specific primers directed towards the extracellular region of human EPO-R cDNA. The predicted 300-bp fragment was amplified by reverse transcriptase-polymerase chain reaction. Subcloning and sequence analysis revealed 100% homology of this fragment with human EPO-R. The receptor protein was detected on the surface of intact PMNLs using (125)I-EPO. The protein was further demonstrated by flow cytometric analysis using a fluorescent monoclonal anti-EPO-R. The percentage of PMNLs expressing EPO-R showed a strong correlation with the level of EPO in the serum, suggesting an upregulation of the receptor by the hormone. Taken together with our recent findings that EPO attenuates the oxidative stress and inflammation contributed by PMNLs in HD patients, the detection of functional EPO-R expression in PMNLs places these cells among the nonerythroid, EPO-responsive target populations.