Adsorption Profile of Commercially Available Adsorbents: An in Vitro Evaluation

Adsorbents from four commercially available devices, Protein A-Sepharose (Immunosorba Protein A-62,5; Excorim KB, Lund Sweden), Tryptophan-PVA (Immusorba TR-350; Asahi Medical Co., Tokyo, Japan), Phenylalanine-PVA (Immusorba PH-350; Asahi Medical Co., Tokyo, Japan), and Dextran sulfate (Liposorber LA-15; Kanegafuchi Chemical Co. Ltd, Osaka, Japan) were tested under optimal in vitro conditions to determine their adsorption capability for several plasma constituents which are usually the target of plasma therapy. The parameters of interest were: double stranded DNA-antibodies (anti-dsDNA), antiglomerular basement membrane antibodies (anti-GBM), antiacetylcholin receptor antibodies (AChRAb), circulating immune complexes (CIC), rheumatoid factor (RF), IgA, IgG, IgM, IgE, C3c, C4, LDL-cholesterol, total cholesterol, erythropoietin (EPO) and β2-microglobulin (β2M). The IgG auto antibodies, CIC and RF can be removed by Protein A-Sepharose, Try-PVA and Phe-PVA. IgG is best adsorbed by Protein A-Sepharose, while IgE can be removed effciently by Try-PVA. Dextran sulfate is without doubt the best adsorbent for LDL-cholesterol. All four adsorbents bind also complement components C3c and C4. No significant adsorption was found for EPO and β2M. The four devices exhibit a quite different adsorption profile which can be used as a guide for the optimal selection of an adsorption column in clinical apheresis.

Upper Blepharoplasty for Areola Reconstruction

Blepharoplasty is one of the most common rejuvenating facial plastic surgery procedures. The procedure has been described many times and has very few complications. The tissue removed from the upper eyelid during blepharoplasty can be used as a skin graft for areola reconstruction due to the tissue's similarity to the areola's natural skin. The present study investigated the use of upper blepharoplasty for areola reconstruction. Criteria were patient satisfaction, objective measurements and the assessment of cosmesis by a panel of physicians. All eight patients included in the study were very satisfied with the cosmetic result. Objective measurements and assessment by a panel of physicians using photographs of the reconstructed nipple-areola complex showed very good aesthetic results.

[Dialysis and ultrafiltration therapy in patients with cardio-renal syndrome: recommendations of the working group "heart-kidney" of the German Cardiac Society and the German Society of Nephrology]

Renal failure is common in patients with severe heart failure. This complex pathophysiological interaction has been classified as cardio-renal syndrome. In these patients hydropic decompensation is the main cause of hospitalization. In patients with refractory heart failure, characterized by diuretic resistance and congestion due to volume overload, ultrafiltration has to be considered. In acute decompensated heart failure with worsening of renal function, extracorporeal ultrafiltration is the preferred treatment modality. On the other hand, patients suffering from chronic decompensated heart failure, particularly patients with ascites, will profit from the treatment specific advantages of peritoneal ultrafiltration. Prerequisite for an optimized care of patients with cardio-renal syndrome is the close collaboration among intensive care doctors, cardiologists and nephrologists.

[Prevention of thromboembolism in patients with atrial fibrillation]

Provided that account is taken of the criteria discussed in the present article, there is no doubt about the therapeutic benefits of effective anticoagulation in patients with chronic atrial fibrillation. Indeed, it is to be expected that the previously valid therapeutic guidelines are more likely to be expanded to reduce feared thromboembolic complications to a minimum, as is exemplified by the recommendation that the application of anticoagulation treatment with vitamin K antagonists should be continued over the longer term, that is, after the restoration of sinus rhythm. Furthermore, there is hope that effective drugs with a calculable (level of) safety and simplicity of administration may soon become available.

Suppressors of cytokine signaling proteins in human preterm placental tissues

Decreased suppressors of cytokine signaling (SOCS) activity in human gestational tissues may play a part in the onset/progression of term labor. Since SOCS proteins negatively regulate cytokine-mediated inflammatory processes, we hypothesized that SOCS proteins are elevated in gestational tissues from spontaneous preterm deliveries with intrauterine infection. SOCS1, -2 and -3 mRNAs and proteins were detectable by RT-PCR and immunoblotting respectively, in preterm amnion, choriodecidua and placenta, irrespective of infection status. Immunoperoxidase staining localized SOCS1, -2 and -3 to all cell types of the gestational membranes, with infiltrating leukocytes reacting strongly in infected tissues. In villous placenta, SOCS was immunolocalized to the syncytiotrophoblast with marked staining of round mesenchymal cells, possibly Hofbauer cells. Nuclear SOCS staining was seen in amnion, chorion and placental syncytiotrophoblasts. SOCS proteins were, in general, significantly more abundant in placenta compared with amnion or choriodecidua. Placental SOCS1 and interleukin-1beta concentrations were positively correlated (r(2)=0.47; P<0.05). However, no changes in SOCS levels in any tissues were observed with intrauterine infection. The relatively large amounts of SOCS proteins in the placenta may reflect a placenta-specific immunoprotective response to minimize the elaboration and effects of cytokines with potential to harm the placenta and fetus. Lack of labor-associated changes in SOCS levels suggests that the regulation of SOCS expression in preterm gestational tissues differs from those at term, perhaps reflecting roles in regulating placental somatotropic responses.

Cytokines, prostaglandins and parturition--a review

The elaboration of cytokines, chemokines and immunomodulatory proteins in the placenta and gestational membranes has been extensively investigated in the context of both normal and abnormal pregnancy and delivery. Patterns of expression of cytokines in the foetal membranes and decidua suggest that inflammatory activation occurs modestly with term labour, but much more robustly in preterm delivery, particularly in the presence of intrauterine infection. Enhanced chemokine expression, particularly evident in deliveries with an infected amniotic cavity, is presumably responsible for recruiting infiltrating leukocytes into the membranes thereby amplifying the inflammatory process and hastening membrane rupture and delivery. Anti-inflammatory cytokines suppress inflammatory reactions in the placenta, but under some circumstances may act in a pro-inflammatory fashion in the membranes. Intracellular signalling by cytokines is modulated by proteins such as SOCS (Silencer Of Cytokine Signalling)-1, -2 and -3. Changes in the abundance of these proteins occur with term labour, implicating them as modulators of cytokine actions around the time of parturition. Prostaglandins, released by the membranes in response to stretch and the actions of pro-inflammatory cytokines, act not only upon the myometrium and cervix, but may also exert paracrine/autocrine effects on cell viability and matrix protein integrity. The localization and regulation of prostanoid isomerases, responsible for converting PGH(2) (derived from prostaglandin H synthase-1 and -2) to bioactive prostanoids, are being studied in these tissues, particularly in the context of cytokine interactions. Although the gestational tissues are known to be sources of PGD(2), PGJ(2) and its derivatives, the regulation of production of these prostaglandins has yet to be studied in any detail and their actions, which may include apoptosis and suppression of inflammation, remain poorly defined. A more complete understanding of these aspects of cytokine-prostaglandin interactions in pregnancy and parturition will, no doubt, unfold as current studies come to fruition.

Hypoxia inhibits activin A production by term villous trophoblast in vitro

Elevated activin A and inhibin A levels have been associated with pre-eclampsia, a pregnancy-related disorder associated with placental hypoxaemia. We investigated the effect of in vitro hypoxia on the production of inhibin A, activin A and its binding protein follistatin in term villous placental explants (n=4-7) and trophoblast monolayer cultures (n=4). Explants and trophoblasts were incubated for 24-72 h under either normoxic (21 per cent O(2)) or hypoxic (2 per cent O(2)) conditions. Production of activin A, inhibin A, and follistatin was determined by specific ELISA. After 48 h of hypoxia, villous explants exhibited a significant reduction in activin A production rates to 53.2 +/- 8.9 per cent (mean +/- SEM, P<0.05) of normoxic controls which was sustained after 72 h in culture (46.8 +/- 5.9 per cent), whereas production by trophoblast monolayers was not affected by hypoxia. Follistatin production was decreased to 53.7 +/- 9.2 per cent of control (P<0.05) after 48 h of hypoxia. Inhibin A production remained unaltered in both culture systems. Our data demonstrate for the first time that hypoxia lowers term placental activin A and follistatin production in vitro. These findings do not support the notion that elevated circulating activin A levels in pre-eclampsia originate from the placenta as a result of placental hypoxia. Other as yet unknown maternal/placental factors may contribute to elevated activin A production in women with severe pre-eclampsia.

Efficacy and specificity of non-steroidal anti-inflammatory drugs for the inhibition of cytokine-stimulated prostaglandin E(2) secretion by amnion-derived WISH cells

Prostaglandin H synthase-2 (PGHS-II) specific inhibitors have been proposed as a potential treatment in the prevention of preterm birth. We examined the efficacy of PGHS inhibitors on basal and cytokine-stimulated prostaglandin (PG) production by the amnion-like WISH cell line. WISH cells were treated with interleukin (IL)-1 beta and tumour necrosis factor (TNF)-alpha in the presence or absence of indomethacin, etodolac, 5,5-dimethy-3-(3-fluorophenyl)-4-(4-methlysulphonyl) phenyl-2 (5H)-furanone (DFU) or nimesulide (1.6-1000 nM) for 16 h. PG production was then measured using radioimmunoassay. Nimesulide and DFU were the most selective non-steroidal anti-inflammatory drugs (NSAIDs) of IL-beta-stimulated PG production in these studies with an a IC(50)(basal)/IC(50)(stimulated) ratio of, respectively, 142.2 and 113.8, followed by etodolac (25.3) and indomethacin (2.2). Similar results were obtained when cells were stimulated with TNF-alpha. The results of this study suggest that PGHS-II-selective NSAIDs may be effective in the prevention of cytokine-driven amnion PG production associated with preterm labour.

[Atherosclerotic renal artery stenosis]

Only patients with the typical symptoms of a stenosis of the renal artery should be submitted to a screening examination. In elderly patients with suspected atherosclerotic stenosis of the renal artery, color-coded duplex ultrasonography is the diagnostic method of choice. If visualization proves to be poor, and in particular when accessory renal arteries are present, magnetic resonance angiography may be considered. If there is significant stenosis of the renal artery, and if a positive effect on renal function or blood pressure control is to be expected, percutaneous transluminal angioplasty with implantation of a stent is the treatment of first choice. In the case of patients with additional aortic pathology, operative revascularization must be considered.

Hypoxia attenuates PGE(2)but increases prostacyclin and thromboxane production in human term villous trophoblast

Prostanoids have been proposed to play a major role in the regulation of uteroplacental blood flow. We examined the effect of hypoxia on the production of prostaglandin E(2)(PGE(2)) thromboxane B(2)(TXB(2)), and prostacyclin (measured as 6-keto-PGF(1alpha)) by human term trophoblast cells and villous placental explants. Explants (n=8) and purified trophoblast cells (n=5) were incubated for 24-72 h under either normoxic (21 per cent O(2)) or hypoxic (2 per cent O(2)) conditions. In trophoblast monolayer cultures, hypoxia attentuated PGE(2)production rates to 52+/-9.4 per cent (mean+/-sem, P< 0.05) but recovered to control rates within 48 h. In villous explants, PGE(2)production was significantly decreased after 48 and 72 h of hypoxia versus the normoxic control, accompanied by increased production of 6-keto-PGF(1alpha)to 173.9+/-26.7 per cent after 48 h. TXB(2)production was increased to 172.3+/-25.9 per cent and 653.2+/-135.7 per cent (P< 0.05) control after 48 and 72 h of hypoxia, respectively. These results were confirmed in villous explants (n=3) cultured in the presence of exogenous 10 microm arachidonic acid. Hypoxia had no significant effect on TXB(2)and 6-keto-PGF(1alpha)in trophoblast cells. In summary, our findings suggest that hypoxia could be responsible for abnormal profiles of prostanoid production commonly observed in women with pre-eclampsia. These results indicate a putative link between hypoxia and compromised placental perfusion.

Differential regulation in human amnion epithelial and fibroblast cells of prostaglandin E(2) production and prostaglandin H synthase-2 mRNA expression by dexamethasone but not tumour necrosis factor-alpha

Previous studies have identified both pro-inflammatory cytokines and glucocorticoids as positive regulators of amnion prostaglandin (PG) biosynthesis. The stimulatory effects of dexamethasone (Dex), a glucocorticoid agonist, on prostaglandin endoperoxide H synthase (PGHS)-2 mRNA expression and PG biosynthesis in amnion have been attributed to an atypical response by the mesenchymal cells of the amnion. The objective of this study was to confirm previous findings concerning cell type-dependant Dex-induced upregulation of PGHS-2 mRNA expression and PG production using separated amnion cell populations, in comparison with the effects of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha). Amnion cells from placentae delivered at term by caesarian section were isolated by tryptic digestion and epithelial cells were then separated from mesenchymal cells by differential absorption onto plastic. After 24-72 h, the two cell populations were passaged and sub-cultured. Cells were treated with Dex (10(-9)-10(-6) m) or TNF-alpha (0.1-50 ng/ml) or media alone. Thereafter, PGE(2)production was determined and PGHS-2 mRNA content analysed by a competitive quantitative RT-PCR method established and validated for this study. PGE(2)production in fibroblast-enriched cultures was increased to 310+/-41 per cent (mean+/-sem, n=4 wells per treatment point) of control in the presence of 10(-8) m Dex. Conversely, PGE(2)production in Dex-treated amnion epithelial cells was decreased to 67+/-24 per cent of control. Altered PGE(2)biosynthesis was accompanied by the upregulation of PGHS-2 mRNA in amnion fibroblasts but not in epithelial cells. TNF-alpha increased PG output and PGHS-2 expression independent of cell type. Glucocorticoids therefore appear to have opposing effects on PG biosynthesis in the two major cellular components of the human amnion.

Intracisternal A-particle (IAP)-mediated leukemogenesis: levels and stability of IAP mRNA in FDC-P1 cells exposed to the conditions of an irradiated environment

Following injection into sublethally irradiated DBA/2 or BALB/c mice, factor-dependent FDC-P1 cells undergo leukemic transformation due to oncogene activation by insertion of intracisternal A-particle (IAP) genetic elements. Similar events are observed in vitro during coculture of FDC-P1 cells with irradiated bone marrow stroma cells. To elucidate the mechanism of IAP transposition, we studied the level of IAP expression under the growth conditions preceding cell transformation. In vitro experiments showed that the type of growth factor, FDC-P1 cell density, costimulation with steroid hormones or abrupt growth factor withdrawal had no effect on IAP mRNA levels (major transcripts of 7.4, 4.0 and 1.9 kb). By contrast, stimulation with suboptimal concentrations of GM-CSF or IL-3 induced a mean 2. 5-fold increase in the intensity of the 7.4 kb band, and induction of macrophage differentiation with retinoic acid resulted in an increased stability of the 4.0 kb band. Although suboptimal growth stimulation and incipient macrophage differentiation have previously been shown to occur in the process of FDC-P1 cell transformation, an increase in IAP expression could not convincingly be demonstrated in FDC-P1 cell populations isolated from irradiated BALB/c mice or stroma cell cocultures. Further experiments are required to define the role of suboptimal growth stimulation and/or macrophage differentiation in this transformation model.

Platelet-leukocyte aggregates during hemodialysis: effect of membrane type

Hemodialysis is associated with the formation of platelet-leukocyte aggregates. Whether this phenomenon is hemodialysis (HD) membrane dependent is unclear. To evaluate this process, we examined respectively platelet activation (anti-CD41, anti-CD62, and antifibrinogen monoclonal antibodies [MoAb] binding), leukocyte activation (CD11b expression), and the appearance of platelet specific antigens on leukocytes as an index of platelet-leukocyte aggregation during HD using 3 different membrane materials, Cuprophan, Hemophan, and polysulfone. Flow cytometric techniques and specific MoAb were used. All parameters were assayed 5 min after initiation of HD to avoid the confounding variable of leukopenia and resultant cell subpopulation analysis. Platelet activation (anti-CD62 and antifibrinogen binding) occurred only with Cuprophan. All 3 membranes induced equivalent increases in CD11b expression on neutrophils and similarly increased the binding of anti-CD41 to neutrophils, reflecting an increment in the formation of platelet neutrophil aggregates. However, only Cuprophan induced an increase in anti-CD62 binding to neutrophils, suggesting that the aggregated platelets linked to neutrophils were activated. Increased anti-CD41 binding by monocytes was similarly observed with all 3 membranes. However, only polysulfone induced an increase in CD11b expression and fibrinogen binding to monocytes. We conclude that while the formation of platelet leukocyte aggregates appears to be a universal phenomenon in HD occurring with a variety of membrane types, subtypes of this phenomenon consisting of activated platelets and fibrinogen binding may be membrane dependent. This phenomenon may serve as a new biocompatibility parameter and may shed light on some of the biologic consequences of hemodialysis.

Expansion of CD14+CD16+ monocytes in critically ill cardiac surgery patients

We have asked whether critically ill cardiac valve surgery patients identified by a high APACHE II score exhibit an increase in the number of proinflammatory CD14+CD16+ monocytes. A group of 12 patients was studied over a period of 5 days post cardiac valve surgery for changes in blood monocyte populations. Patients were selected on day 1 post surgery to either be in good clinical condition (APACHE II Score of < or = 14; N = 9) or to be critically ill (APACHE II score of > or = 24; N = 3). The < or = 14 patients had an uneventful course and could leave the ICU after 2-3 days. Among the > or = 24 patients two showed a decrease of the score to < or = 14 within the 5 days of observation and they could leave the ICU thereafter. One > or = 24 patient (patient #2) had a persistently high score and finally died on day 28. Analysis of blood monocytes on day 1 post surgery revealed that the < or = 14 patients had normal values of CD14+CD16+ monocytes (44 +/- 9/microliter). By contrast the > or = 24 patients had increased values of these cells with 243 +/- 106 cells per microliter on day 1. The numbers of CD14+CD16+ monocytes returned to the control range over the 5 days of observation in 2 of the > or = 24 patients concomitant with the improvement of the APACHE II score. CD14+CD16+ monocytes remained, however, at a high level in patient #2, the patient with persistently high APACHE II score.

Down-regulation of surface monocyte lipopolysaccharide-receptor CD14 in patients on cardiopulmonary bypass undergoing aorta-coronary bypass operation

OBJECTIVES

Major operative trauma like aorta-coronary bypass operation may lead to postoperative immunodisturbance, putting the patient at an increased risk for infection and sepsis. The monocyte/macrophage system and the endotoxin receptor CD14 are important in the early recognition and elimination of invading bacteria. The aim of this study was to analyze changes in membrane-associated CD14 and soluble CD14 during and after cardiac involving cardiopulmonary bypass.

METHODS

We studied numbers of leukocytes, monocytes, and monocyte subpopulations, expression of monocyte membrane-associated CD14 and plasma levels of soluble CD14 in 10 patients (63 +/- 8 years of age), who underwent elective cardiopulmonary bypass.

RESULTS

Cardiopulmonary bypass induced marked postoperative monocytosis, which was maximal 20 hours after the operation (485 +/- 242 cells/microl before, 1080 +/- 264 cells/microl 20 hours after surgery). Expression of membrane-associated CD14 on classical CD14++ monocytes decreased significantly by 40%, reaching a nadir 20 hours after surgery (p < 0.05). At the time of maximal membrane-associated CD14 suppression, the levels of soluble CD14 measured by enzyme-linked immunosorbent assay were clearly increased (3.2 +/- 1.0 microg/ml before versus 5.6 +/- 1.0 microg/ml 20 hours after, p < 0.001). No significant change of the percentage of small (alpha) and large (beta) forms of soluble CD14 was found.

CONCLUSIONS

Cardiopulmonary bypass leads to reduced membrane-associated CD14 expression on peripheral blood monocytes and increased levels of soluble CD14 through shedding or secretion of membrane-associated CD14 from the cell surface. These findings indicate that bypass is associated with significant monocyte activation.

Dialysis neutropenia: the role of the cytoskeleton

Dialysis neutropenia is the result of pulmonary sequestration of neutrophils after complement activation by the dialyzer membrane. Increased expression of neutrophil adhesion receptors, such as CD11b/CD18, suggests that neutrophil adhesion to the capillary endothelium is a possible mechanism. An alternative hypothesis is that the complement fragment C5a modulates neutrophil mechanical properties via the cytoskeleton-largely filamentous actin (F-actin)-stiffening them and thereby slowing their passage through the pulmonary capillaries. To investigate this hypothesis, we developed an assay to measure the F-actin content of neutrophils in whole blood using flow cytometry and the stain NBD-phallacidin. We measured neutrophil F-actin content during hemodialysis of patients with polysulfone (N = 6), Hemophan (N = 6), and Cuprophan membranes sterilized with either ethylene oxide (N = 5) or steam (N = 6). Cell counts, neutrophil and monocyte CD11b expression and plasma C5a concentrations were also measured. The results confirm the strong relationship between the degree of neutropenia, increases in CD11b expression and plasma C5a levels reported by previous researchers. Modulation of the F-actin content of neutrophils was also strongly related to C5a levels, indicating that the neutrophil cytoskeleton is active during dialysis. Modeling of cell counts suggests that with Cuprophan a substantial fraction of neutrophils and monocytes are sequestered before they even pass through the dialyzer, suggesting some form of systemic activation of these cells. Evidence for systemic activation was also seen in measurements of F-actin content, but not CD11b expression, a finding that strengthens the case for the involvement of the cytoskeleton in dialysis neutropenia.

Indirect radiation leukemogenesis in DBA/2 mice: increased expression of B2 repeats in FDC-P1 cells transformed by intracisternal A-particle transposition

We have previously reported that granulocyte-macrophage colony-stimulating factor (GM-CSF)- and interleukin-3 (IL-3)-dependent FDC-P1 cells undergo leukemic transformation when injected into sublethally irradiated DBA/2 mice. Transformation is related to aberrant activation of growth-regulatory genes by insertion of intracisternal A-particle (IAP) genomes. To elucidate the transformation process further, a subtracted cDNA library was constructed from a factor-independent leukemic FDC-P1 variant and the parental FDC-P1 cells. Screening for clones that were preferentially recognized by a total cDNA probe from the transformed cell line (in comparison to a similar probe from untransformed FDC-P1 cells) led to the isolation of 14 clones, of which six contained cDNA inserts encoding so-called B2 repeats, a class of short interspersed nucleotide elements. The expression of B2 repeats was significantly increased not only in the cell line from which the subtracted library was constructed, but also in all other leukemic FDC-P1 variants analyzed. B2 repeats can act as insertional mutagens and may have a role in the stabilization of certain oncogene and cytokine mRNAs. Interestingly, B2 repeats contain a 14-nucleotide region that is almost completely complementary to an AU-rich sequence in a region of the IAP mRNA encoding the enzyme reverse transcriptase. Although preliminary experiments to demonstrate stabilization of IAP mRNA by hybridization to B2 repeat sequences remained inconclusive, it is intriguing to speculate that B2 repeat sequences may have a causative role in the transformation process.

Cytokine production precedes the expansion of CD14+CD16+ monocytes in human sepsis: a case report of a patient with self-induced septicemia

We describe a patient with self-induced disease who presented with repeated urinary tract infection and sepsis due to intravesical and intravenous injection of feces. Sepsis occurred repeatedly such that the patient exhibited 10 bouts of fever > 40 degrees C in a single month. This bacterial challenge led to massive activation of the monocyte system with high levels of TNF-alpha, IL-6, and monocyte colony-stimulating factor (M-CSF). This cytokine response was followed by strong expansion of the novel CD14+CD16+ monocyte subset. These results suggest that cytokines induce the development of CD14+CD16+ cells in human septicemia and that CD14+CD16+ cells may serve as indicator for previous bouts of excessive inflammation.

Plasma therapy at Klinikum Grosshadern: a 15-year retrospective

Immediately after the availability of highly permeable membranes in 1979, membrane plasma separation was introduced as a mode of extracorporeal blood purification by the nephrology group at Klinikum Grosshadern of the Ludwig Maximilians University of Munich (F.R.G.). The new therapy was applied primarily in the management of immunologically mediated renal and extrarenal disorders as well as in paraproteinemias. We also have witnessed a widespread application of this extracorporeal treatment as a last resort in otherwise refractory clinical conditions. Over the years, the group at Grosshadern has contributed to the development, as well as to the laboratory and clinical testing, of new plasma separation membranes, simplified plasmapheresis formats (e.g., spontaneous membrane plasma separation), and several plasma fractionation procedures (e.g., cascade filtration, adsorption). Whenever indicated and possible, plasma fractionation procedures, rather than unselective plasma exchange, are performed in an appropriate clinical situation.

The novel subset of CD14+/CD16+ blood monocytes is expanded in sepsis patients

Staining with CD14 and CD16 monoclonal antibodies will identify two monocyte subpopulations in human blood: a major population of regular monocytes, which strongly expresses the CD14 antigen (CD14++), and a minor population with weak expression of CD14 and expression of the CD16 antigen (CD14+/CD16+ cells). As shown herein, the latter cells account for 45 +/- 22 cells/microL and 9% +/- 5% of the monocytes in healthy control donors (n = 35). In septicemia patients, the CD14+/CD16+ cells can become a major population, with more than 50% of all monocytes in 3 of 18 patients and with more than 500 cells in 4 of 18 cases. There was no correlation of CD14+/CD16+ cells to any clinical parameter except for CD14+/CD16+ percentage and body temperature (P = .013). The CD14++ regular monocytes showed a substantial decrease in CD14 antigen density in 9 of 11 patients. Three-color immunofluorescence shows that the CD14+/CD16+ monocytes in septicemia patients when compared with the CD14++ monocytes exhibit a higher level of class II antigen and a lower level of CD11b and CD33 antigens, consistent with a more mature nature of the CD14+/CD16+ cells. Levels of interleukin-6 (IL-6) were increased in septicemia patients; 3 of 5 patients with high numbers of CD14+/CD16+ cells (> 200/microL) had high levels of IL-6 (> 250/U/mL). These data suggest that septicemia may lead to substantial changes in blood monocyte composition and this may be related to elevated levels of cytokines such as IL-6.

Lipid apheresis by hemoperfusion: in vitro efficacy and ex vivo biocompatibility of a new low-density lipoprotein adsorber compatible with human whole blood

To date, selective extracorporeal low-density lipoprotein (LDL) removal can only be performed from plasma; that is, a plasma-cell separation step using a centrifuge or a plasma membrane separator is necessary initially. This article characterizes a new polyacrylate-based LDL adsorber directly applicable to whole blood. In vitro single-pass hemoperfusion tests using pooled donor blood showed quantitative adsorption of atherogenic LDL-cholesterol (LDL-C) and complete recovery of protective high-density lipoprotein C. Fibrinogen, another independent risk factor of atherosclerosis, was also adsorbed to a lesser extent. Single-pass ex vivo biocompatibility using fresh donor blood on-line was excellent and resulted in minimal cell loss. Neither signs of hemolysis nor activation of monocytes (interleukin-1 production) were detected. Only slight activation of leukocytes (elastase release) and thrombocytes (platelet factor 4 secretion) as well as of coagulation (thrombin-antithrombin complex formation) and complement (C3a, C5a generation) was observed. Under the experimental conditions used, the optimal anticoagulation regimen was 0.5 IU heparin plus 0.375 mg citrate/ml blood. Priming the column with a buffer of pH 7.4 containing heparin, citrate, and Ca2+ is recommended. In conclusion, this new adsorber exhibited selective LDL-C adsorption in vitro combined with excellent ex vivo biocompatibility and thus holds great promise for a successful clinical application in a closed-loop system in patients.

A beta-turn is present in the 392-411 segment of the human fibrinogen gamma-chain. Effects of structural changes in this segment on affinity to antibody 4A5

The interaction between fibrinogen gamma-peptide 392-411, LTIGEGQQHHLGGAKQAGDV, and monoclonal antibody 4A5, an antibody with a high affinity for both for the peptide and native fibrinogen, is being studied as a model for peptide-antibody interaction. Two-dimensional NMR studies of the free peptide at pH 5.2 indicated the presence of a significant population, about 60%, of type II beta-turn, spanning residues Gln407-Asp410. At pH 2.7, little, if any, turn structure is present. The D-Ala409 analog, which, for steric reasons, would be expected to preserve the beta-turn, and the L-Ala409 analog, which would not be expected to have this conformational feature, were synthesized, and NMR studies confirmed the respective structural predictions. The affinity of the D-Ala analog for antibody 4A5 is even greater than that displayed by native gamma 392-411, while the affinity of the L-Ala analog is less than one-tenth that of the native peptide. Both conformational and steric effects involving residues 407-410 may be important in recognition by antibody 4A5. Since gamma 392-411 includes a platelet receptor binding locus of fibrinogen, and this and related peptides are inhibitors of platelet aggregation, the D-Ala409 and L-Ala409 analogs were tested for platelet binding. Neither of the analogs displays any measurable platelet binding, indicating that the recognition requirements for the platelet receptor differ considerably from those for antibody 4A5.

Adsorption profile of commercially available adsorbents: an in vitro evaluation

Adsorbents from four commercially available devices, Protein A-Sepharose (Immunosorba Protein A-62,5; Excorim KB, Lund Sweden), Tryptophan-PVA (Immusorba TR-350; Asahi Medical Co., Tokyo, Japan), Phenylalanine-PVA (Immusorba PH-350; Asahi Medical Co., Tokyo, Japan), and Dextran sulfate (Liposorber LA-15; Kanegafuchi Chemical Co. Ltd, Osaka, Japan) were tested under optimal in vitro conditions to determine their adsorption capability for several plasma constituents which are usually the target of plasma therapy. The parameters of interest were: double stranded DNA-antibodies (anti-dsDNA), antiglomerular basement membrane antibodies (anti-GBM), anti-acetylcholin receptor antibodies (AChRAb), circulating immune complexes (CIC), rheumatoid factor (RF), IgA, IgG, IgM, IgE, C3c, C4, LDL-cholesterol, total cholesterol, erythropoietin (EPO) and beta 2-microglobulin (beta 2M). The IgG auto antibodies, CIC and RF can be removed by Protein A-Sepharose, Try-PVA and Phe-PVA. IgG is best adsorbed by Protein A-Sepharose, while IgE can be removed efficiently by Try-PVA. Dextran sulfate is without doubt the best adsorbent for LDL-cholesterol. All four adsorbents bind also complement components C3c and C4. No significant adsorption was found for EPO and beta 2M. The four devices exhibit a quite different adsorption profile which can be used as a guide for the optimal selection of an adsorption column in clinical apheresis.

In vitro desensitization to lipopolysaccharide suppresses tumour necrosis factor, interleukin-1 and interleukin-6 gene expression in a similar fashion

Like blood monocytes, the human monocytic cell line Mono Mac 6 can be stimulated by lipopolysaccharide (LPS) at 1 microgram/ml to produce high levels of cytokines. When Mono Mac 6 cells are stimulated for 4-6 hr at 1 x 10(6)/ml, supernatants contain tumour necrosis factor (TNF) at an average of 60 U/ml and interleukin-6 (IL-6) at an average of 1000 U/ml. IL-1 is not detected in the supernatant, but after three freeze-thaw cycles cell-associated IL-1 can be detected (100 U/ml) and with similar amounts of IL-alpha and -beta. Preculture of Mono Mac 6 cells with LPS at 10 ng/ml for 3 days results in cells refractory to subsequent stimulation by LPS at 1 microgram/ml. In the refractory desensitized cells, production of all three cytokines is down-regulated, with a more than 10-fold reduction in protein production. For all three cytokines, this desensitization appears to be regulated at the transcript level, with a strong reduction in specific mRNA as detected by Northern blot analysis. Furthermore, Mono Mac 6 cells can be stimulated by Staphylococcus aureus (LPS contamination less than 10 pg/ml) to produce cytokines. This type of stimulus is unable to overcome desensitization, in that the secretion of TNF in LPS-precultured Mono Mac 6 cells was 10- to 100-fold lower than in Mono Mac 6 cells without LPS preculture. These data show that desensitization in Mono Mac 6 cells affects all three cytokines tested and that it extends to other activating signals, such as staphylococci.

Differential expression of cytokines in human blood monocyte subpopulations

Cytokine expression was analyzed in CD14++ regular monocytes and in the novel subset of CD14+/CD16+ small monocytes. Biologic activity for tumor necrosis factor (TNF), interleukin-1 (IL-1), and IL-6 in the supernatant of elutriator-enriched, cell sorter-purified small monocytes was about 10-fold lower compared with regular monocytes when stimulated with lipopolysaccharide (LPS) for 12 hours. In CD14++ regular monocytes levels were 1,157 U x 10(-3)/mL, 158 U/mL, and 1,337 U/mL for TNF, IL-1, and IL-6, respectively. By contrast, CD14+/CD16+ small monocytes exhibited 137 U x 10(-3)/mL, 14 U/mL, and 60 U/mL for TNF, IL-1, and IL-6, respectively. Additional treatment with interferon-gamma enhanced production of TNF in both subsets, but CD14+/CD16+ small monocytes still exhibited lower levels. Stimulation of the monocyte subsets by platelet-activating factor gave the same pattern of results. Hybridization with 32P-labeled oligonucleotides specific for the respective cytokine messenger RNAs (mRNAs) showed a 10-fold lower prevalence of transcripts for TNF, IL-1, and IL-6, as well. By contrast, the constitutive expression of Glyceraldehyde-3-phosphate-dehydrogenase mRNA was 1.7-fold higher in the CD14+/CD16+ small monocytes. These data indicate that the novel subset of small monocytes is selectively suppressed in the expression of the cytokines TNF, IL-1, and IL-6, suggesting that these cells may comprise a deactivated type of cell. The expression of class II transcripts in the small monocytes is, however, similar to the regular monocytes, and the cell surface expression of class II protein about threefold increased. Thus, the novel subset of small monocytes appears to be a functionally distinct type of cell.

Monocyte phenotype and interleukin-1 production in patients undergoing haemodialysis

The expression of MHC class II (HLA-DR) and complement receptor (CR1) surface molecules on CD 14+ monocytes were compared with the production of the monokine interleukin-1 beta (IL-1 beta) in patients with endstage renal disease undergoing maintenance haemodialysis (HD) with hollow fibre dialyzers containing cellulose (CE, n = 8) and polysulfone (PS, n = 7) membranes. Monocyte staining was performed in blood samples obtained at the beginning and after 3 h of HD. Analysis of surface marker expression was done by immunofluorescence staining and flow cytometry analysis. Specific fluorescence intensity for both CR1 and class II (HLA-DR) antigens was increased in patients treated with CE membranes at the beginning of a dialysis treatment when compared to healthy control values. Interestingly, after 3 h on dialysis a further increase was noted for CR1 complement receptor expression whereas the increased HLA-DR expression was no longer detectable. In contrast, specific fluorescence intensity for both antigens was not significantly different from controls, either before or after dialysis, in patients treated with PS. The capacity of peripheral blood mononuclear cells to produce IL-1 beta spontaneously in vitro in the two patient groups was found to parallel results on phenotypic expression of surface molecules. The present study demonstrates that functional signs of monocyte activation, as evidenced by an augmented IL-1 beta production, in some patients on long-term HD correlate with an increased expression of two functionally important monocyte surface marker molecules.

Small (CD14+/CD16+) monocytes and regular monocytes in human blood

Compared to the obvious phenotypic and functional heterogeneity of tissue macrophages, little information is available on subsets of blood monocytes. We have employed two-color immunofluorescence and flow cytometry for the definition of regular and small monocytes, the latter characterized by the low-density expression of CD14 and the strong expression of the CD16 (Fcy-RIII) antigen. These cells comprise 15% of the blood monocytes and they appear to be similar in phenotype to the alveolar macrophage. The CD14+/CD16+ small monocytes can perform phagocytosis and they produce reactive oxygen, while their capacity for cytokine production is strongly reduced when compared to regular monocytes. At this point it is still unclear as to whether the CD14+/CD16+ small monocytes comprise a specific level of activation or differentiation or a distinct sublineage of human blood monocytes.

Modulation of cytotoxicity of cytostatic drugs by hemodialysis in vitro and in vivo

For most cytotoxic substances there are no established guidelines on how to deal with overdosage. Little is known about the dialysability of cytostatic drugs. To obtain further information, human plasma was incubated with cytostatic drugs and dialysed in vitro, using 'minimodules' with capillaries identical to those in clinical use. Cytotoxicity before and after dialysis was measured in a biological test system using permanent human lymphoblast cultures (LS2). The 20 cytostatic drugs studied were categorized as follows: (1) Dialysability in vitro. Good: methotrexate (MTX), 5-fluorouracil (5-FU/5-FUdR), cytarabine (ARAC), actinomycin D (DACT), mitomycin C (MMC), 4-OH-cyclophosphamide (4-OH-CPM), ifosfamide (IFO), melphalan (L-PAM), dacarbazine (DTIC), cisplatin (DDP). Intermediate: Adriamycin (ADM), 4'-epi-doxorubicin (4'-EA), carmustine (BCNU). Ineffective: daunorubicin (DNR), vincristine (VCR), vinblastine (VBL), vindesine (VDS), etoposide (VP-16), teniposide (VM-26), mitoxantrone (MITOX). These in vitro results cannot be transferred automatically into the in vivo situation because of specific drug distribution and metabolic rates. Considering pharmacokinetic data from the literature, the following recommendations can be made for practical clinical purposes. (2) Detoxification by hemodialysis in vivo. Possibly effective: MTX, 5-FU, MMC, CPM, IFO, L-PAM, BCNU, DTIC. Ineffective: ADM, 4'-EA, DNR, MITOX, DACT, VP-16, VM-26, VCR, VBL, VDS, ARAC, DDP.

[Dialysability of cytostatic drugs. Experimental studies in vitro]

There are no established guidelines for detoxification for most cases of overdosage or intoxication with cytostatic drugs. Little is known about the dialysability of cytostatic drugs. To obtain further information on the dialysability of cytostatic drugs, human plasma was incubated with cytostatic drugs and dialysed in vitro using "mini-modules" with capillaries identical to clinical use. Cytotoxicity before and after dialysis was measured in a biological test system using permanent human lymphoblast cultures (LS2). The 20 cytostatic drugs studied could be categorised as follows: Good dialysability in vitro: methotrexate, 5-fluorouracil, cytarabine, actinomycin D, mitomycin C, 4-OH-cyclophosphamide, ifosfamide, melphalan, dacarbazine, cisplatin. Intermediate dialysability in vitro: adriamycin, epirubicin, carmustine. Ineffective dialysability in vitro: daunorubicin, vincristine, vinblastine, vindesine, etoposide, teniposide, mitoxantrone. These in vitro results cannot be transferred automatically into the in vivo situation because of specific drug distribution and metabolic rates. Considering pharmacokinetic data, the following recommendations can be made for practical clinical purposes: Detoxification by hemodialysis in vivo: Possibly effective: Methotrexate, 5-fluorouracil, mytomicin C, cyclophosphamide, ifosfamide, melphalan, carmustine, dacarbazine. Ineffective: Adriamycin, epirubicin, daunorubicin, mitoxantrone, actinomycin D, etoposide, teniposide, vincristine, vinblastine, vindesine, cytarabine, cisplatin.

Differential activation of monocytes in haemodialysis patients exposed to different types of membranes

Peripheral blood mononuclear cells (PBMC) from haemodialysis patients treated with different types of membranes were isolated, incubated in vitro, and extracellular and cell-associated interleukin I (IL-1) assayed by radioimmunological methods. Extracellular IL-1 was low and not different from controls, regardless of the dialyser used. In contrast, cell-associated IL-1 was increased in patients treated with dialysers containing low-flux Cuprophan (CU, n = 5) and polyacrylonitrile sheet membrane (AN69, n = 5). Patients treated with dialysers containing high-flux polysulphone (PS, n = 7), and polymethylmethacrylate (PMMA, n = 8), exhibited no increase in cell-associated IL-1 under these conditions. To elucidate the mechanism of the activation, aqueous extracts of dialysers containing CU, PS, and AN69 were tested for their ability to induce IL-1 generation in PBMC from healthy donors. Extracts from unrinsed CU-containing dialysers caused significant IL-1 synthesis and release, whereas incubation with extracts from dialysers containing PS and AN69 sheet membranes did not. Hence, although both CU and AN69 sheet-type dialysers result in activation of blood monocytes the mechanism of action appears to be different. We speculate that functional signs of PBMC activation as evidenced by increased spontaneous IL-1 production observed in some patients on long-term haemodialysis may result from extractable dialyser membrane material while in other instances direct cell membrane interactions or endotoxin transfer from the dialysate may be relevant.

B cell lymphokines in human systemic lupus erythematosus

B lymphocytes of patients with systemic lupus erythematosus were studied to determine if they were intrinsically hyperresponsive to lymphokine mediators. Peripheral blood B cells from 25 lupus patients and 16 normal individuals matched for age and sex were cultured with recombinant lymphokines. B cells both from patients and normal subjects did not show increased [3H]thymidine uptake when cultured with interleukins 1, 2, and 4. The addition of Staphylococcus aureus Cowan I as costimulant increased [3H]thymidine uptake by B cells of patients and normal subjects. In the absence of T cells these recombinant lymphokines did not increase in vitro IgG or IgM production by lupus or normal B cells. Other recombinant lymphokines, interleukin 3, interferon gamma, lymphotoxin, tumour necrosis factor, and colony stimulating factors for granulocytes and macrophages were tested on lymphocytes from smaller numbers of patients and controls. Most patients in this study had inactive disease and all data suggested that B cells from patients with inactive lupus were not hyperresponsive to the lymphokines tested. In addition, the use of lymphokine gene probes for interleukins 2, 3, and 4 did not show spontaneous expression of these genes in circulating lymphocytes.