From feedback loop transitions to biomarkers in the psycho-immune-neuroendocrine network: Detecting the critical transition from health to major depression.

BACKGROUND: Biological pathways underlying major depressive disorder (MDD) can be viewed as systems biology networks. The psycho-immune-neuroendocrine (PINE) network comprises central nervous, immune, endocrine and autonomic systems, integrating biological mechanisms of MDD. Such networks exhibit recurrent motifs with specific functions, including positive and negative feedback loops, and are subject to critical transitions, influenced by feedback loop transitions (FLTs). AIMS: We aim to identify critical feedback loops and their FLTs, as well sentinel network nodes (SNNs), key network nodes that drive FLTs, within the PINE network. Examples of biomarkers are provided which may reflect early warning signs of impending critical transition to MDD. RESULTS: Disruption of homeostatic feedback loops reflects the physiological transition to MDD. Putative FLTs are identified within hypothalamic-pituitary-adrenal (HPA) and sympathetic-parasympathetic axes, the kynurenine pathway, gut function and dysbiosis. CONCLUSIONS: Progression from health to disease is driven by FLTs in the PINE network, which is likely to undergo changes characteristic of system instability. Biomarkers of system instability may effectively predict the critical transition to MDD.

[Prevention of thromboembolism in patients with atrial fibrillation]. / Vorhofflimmern bewirkt Thrombenbildung. Effektive Antikoagulation reduziert das Schlaganfallrisiko.

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.

31P NMR studies on the interaction of deoxyuridylate with thymidylate synthase.

The 31P nuclear magnetic resonance signal of deoxyuridylate was studied in the presence and absence of thymidlate synthase. In the absence of enzyme the chemical shift of deoxyuridylate is pH dependent with a pKa of 6.25. In the presence of enzyme, a peak corresponding to the dianioinc form of deoxyuridylate is observed which is independent of pH between pH 5.7 and pH 7.4. The pKa of the phosphate in the deoxyuridylate-thymidylate synthase complex is therefore less than 5. The release of inorganic phosphate from deoxyuridylate catalyzed by contaminating phosphatase was also observed.

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.

IgA1 protease cleaves heavy chains independently in dimeric human IgA1.

Bacterial IgA1 proteases have substrate specificity for human IgA1 immunoglobulin, and cleave both the heavy (alpha) chains where they are paired by disulfide bonds in the hinge region. To determine if the close apposition of the alpha chains allows a single enzyme-substrate-binding event to cleave both hinge region peptides we quantitated the relative levels of intermediate products during the course of complete hydrolysis of an IgA1 paraprotein. The substrate had four Fab regions, analogous to a secretory IgA dimer. The experimental data were then compared to computer-generated models in which various levels of cooperativity among Fab regions were tested. The results most closely conformed to a model in which each individual alpha chain is proteolyzed independently, without regard to the total number of hinge region peptides available in the substrate IgA1. These results will be used to guide the design of IgA1 hinge region peptide analogues as IgA1 protease inhibitors.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Plasma exchange in systemic lupus erythematosus.

Of 20 patients who presented to our hospital with the histologically confirmed diagnosis of SLE, nine met the criteria of presence of both a rapidly progressive disease state and contraindications for conventional therapy required for admission to our plasma exchange programme. Five patients improved; two patients progressed to end-stage renal failure; two patients died as a result of complications of advanced SLE. Severe lupus erythematosus (SLE) is usually treated with a combination of steroids and cytotoxic drugs. Even when treated with high dose therapy some patients develop life-threatening complications, such as renal failure, heart failure and respiratory insufficiency. Moreover, both treatment with high dose of corticosteroids and long lasting cytotoxic therapy may produce troublesome side-effects, including severe infections, gastroduodenal ulcers, bone marrow depressions and lymphomas (1, 2). One of the manifestation of SLE is the presence of antibodies against ds-DNA and ss-DNA. These antibodies can either react with DNA bound to te basement membrane and induce an inflammatory reaction (3), or can form circulating immune complexes which deposit in tissues and may impair the function of lymphocytes or macrophages in the RES (4, 5). The presence of anti-DNA-antibodies appears to be secondary to enhanced B-cell activity along with a depression of suppressor T-cells function proteins mediating the inflammatory process, such as fibrinogen, may deposit in membranes already compromised by the disease. Even though the pathogenic mechanisms operating in SLE are not completely understood, it can be expected, from a theoretical point of view, that the extracorporeal removal of any immunopathogens could improve the disease state.(ABSTRACT TRUNCATED AT 250 WORDS)

Current status of membrane plasma separation and plasma filtration techniques.

Blood and plasma processing by membranes was introduced into clinical medicine in 1979. In the meantime, membrane plasma separation (plasmapheresis) has become very satisfactory and is now a routine therapeutic procedure in many apheresis centers. Plasma fractionation by membranes (plasma filtration or cascade filtration) for unselective removal of high molecular weight pathogens from the separated plasma is technically possible but its routine clinical application is still limited to a few diseases with at least IgM-sized target proteins. The separation of IgG from albumin needed to treat many autoimmune diseases requires further development of both the membranes and the filtration technology.

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.

[Atherosclerotic renal artery stenosis]. / Die atherosklerotische Nierenarterienstenose. Screening nur bei konkretem Verdacht.

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.

[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]. / Dialyse- und Ultrafiltrationsverfahren bei kardio-renalem Syndrom. Empfehlung der Arbeitsgemeinschaft "Herz--Niere" der Deutschen Gesellschaft für Kardiologie--Herz- und Kreislaufforschung e.V. und der Deutschen Gesellschaft für Nephrologie e.V.

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.

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.