[Haemostatic management in postpartum haemorrhage : Nationwide survey in Germany]. / Gerinnungstherapie der peripartalen Hämorrhagie : Deutschlandweite Umfrage.

BACKGROUND: In order to ensure evidence-based haemostatic management of postpartum haemorrhage (PPH, blood loss >500 ml) consistent with guidelines appropriate structural conditions must be fulfilled regardless of different levels (1-3) in perinatal care. The aim of the survey was to identify differences in haemostatic management in PPH under consideration of the different levels of perinatal care in Germany. MATERIALS AND METHODS: An electronic questionnaire assessing the structural and therapeutic preconditions for haemostatic management was sent to 533 anaesthesiology departments serving obstetric units. RESULTS: A total of 156 (29 %) questionnaires returned from hospitals of all levels were analysed. PPH occur in all and increase with higher level hospitals (level 1 <5 PPH/year vs. 3 >30 PPH/year). The percentage of PPH requiring red blood cell (RBC) transfusion amounts to <25 % (all levels). A bleeding history (35 %, all levels), laboratory coagulation tests (29 %, all levels) as well as viscoelastic point-of-care coagulation tests (42 %, mainly level 3) are limited in their availability. Blood loss is usually estimated (99 %, all levels), not measured. Tranexamic acid (>80 %, all levels), fibrinogen (>60 %, all levels) and fresh frozen plasma (FFP) (30 %, level 2a) are first line therapeutics. In level 2b and 3 FFP is a second line therapeutic. RBC transfusion is indicated at haemoglobin <5-7 g/dl (57-69 %, all levels), while 15-29 % in level 3 did not base their decision to transfuse RBC on haemoglobin only. CONCLUSIONS: Guideline-consistent haemostatic management of PPH is provided in almost all hospitals independent of the perinatal care level. Deviances from guidelines (measuring blood loss, bleeding history of the patient) affect all levels of perinatal care in Germany.

Advanced glycation end products induce choroidal endothelial cell proliferation, matrix metalloproteinase-2 and VEGF upregulation in vitro.

BACKGROUND: Advanced glycation end products (AGEs) are considered to be important modulators of angiogenesis and accumulate in choroidal neovascularization (CNV). Their effects regarding cells involved in proliferation of CNV [retinal pigment epithelial (RPE) cells, Müller cells and choroidal endothelial cells (CECs)] were investigated. Furthermore, the effects of AGEs on expression of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) by CECs were explored. METHODS: RPE cells, CECs and Müller cells were exposed to AGEs (10 microg/ml, 50 microg/ml and 100 microg/ml) for a time course of three days in their desired medium and proliferation was estimated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. MMP-2 expression of AGE-stimulated CECs was determined by zymography and reverse-transcription polymerase chain reaction (RT-PCR) after 36 h of exposure. Furthermore, VEGF expression of AGE-stimulated CECs (50 microg/ml and 100 microg/ml) was determined by RT-PCR after an exposure time of 36 h. RESULTS: AGEs in a concentration of 50 microg/ml and 100 microg/ml increased the proliferation of CECs (41% vs 46.1%; P<0.005). No AGE effect on RPE cell and Müller cell proliferation was seen. AGEs in all concentrations used upregulated the VEGF mRNA expression of CECs. Zymography and RT-PCR demonstrated the upregulation of MMP-2 by CECs after AGE exposure. CONCLUSION: AGEs stimulate CEC proliferation, MMP-2 secretion and VEGF upregulation and may be important promoters of CNV formation in exudative AMD in vivo.

Direct measurement of VEGF-induced nitric oxide production by choroidal endothelial cells.

Vascular endothelial growth factor (VEGF) and nitric oxide (NO) seem to be involved in the process of angiogenesis, but their interactions are not clearly understood. The aim of this study was to investigate the influence of VEGF on NO production of choroidal endothelial cells (CEC) and its importance in angiogenesis. Experiments were performed using cultured bovine CEC. Basal NO release of unstimulated CEC was measured and compared to NO release of VEGF-stimulated CEC (1, 10, and 100 ng/ml). Further, cells were pretreated with N(omega)-nitro-L-arginine methyl ester (L-NAME, 1 and 2 mM) and incubated with and without VEGF (10 ng/ml) to investigate the effect of blocking NO synthase. NO release into the medium was assessed by an amperometric NO sensor. To show the importance of NO in angiogenesis, proliferation and migration of CEC were measured after VEGF stimulation and in the presence or absence of L-NAME (1 and 2 mM). Unstimulated CEC continuously produced low levels of NO. Stimulation of the cells with VEGF resulted in a dose-dependent increase in NO release. The time course after stimulation with 10 ng/ml VEGF was characterized by a prompt initial rise up to 140% of unstimulated levels and a subsequent sustained increase over 120 min. Pretreatment with L-NAME attenuated the VEGF-induced response. L-NAME incubation alone led to a reduction in basal NO release. L-NAME also significantly diminished the VEGF-enhanced CEC proliferation and migration. The results demonstrate that VEGF enhances the formation of NO in cultured CEC. The blockade of NO production reduces CEC proliferation and migration, an effect which may be important for controlling angiogenesis, especially in reducing neovascularization in age-related macular degeneration in the eye.

Cellular mechanisms of cyclosporine A-associated side-effects: role of endothelin.

Immunosuppressive therapy with cyclosporine A (CsA) may be associated with severe side-effects such as nephrotoxicity and arterial hypertension. The partial reversability of these effects suggests that they are at least in part functional. We examined the effects of CsA on cellular signaling in cultured vascular smooth muscle cells from rat aorta. Intracellular free calcium concentrations ([Ca2+]i) were measured using fura-2. Total cell calcium was measured by atomic absorption and cellular endothelin production was estimated by radioimmunoassay. In the presence of CsA the calcium mobilizing effect of angiotensin (Ang) II was significantly enhanced. While the ETA receptor antagonist BQ 123 did not affect Ang II-induced calcium mobilization, the potentiating effect of CsA on [Ca2+]i was blocked by BQ 123. Preincubation of the cells with cyclosporine (10 micrograms/ml) for 30 minutes increased total cell calcium from 2.6 +/- 0.5 to 6.9 +/- 0.3 nmol/mg protein (P < 0.01). Within 24 hours endothelin production was significantly enhanced in the presence of cyclosporine (52.2 +/- 2.5 vs. 65.9 +/- 2.7 fmol/mg protein, P < 0.05). Therefore, the cyclosporine-induced rise of total cell calcium in smooth muscle cells is associated with an enhanced production of endothelin. We speculate that cyclosporine induced changes of Ca(2+)-kinetics may be mediated by endothelin. These results indicate that endothelin may play a major role in cyclosporine-associated side-effects.

Cyclosporine A enhances total cell calcium independent of Na-K-ATPase in vascular smooth muscle cells.

The effect of cyclosporine A in enhancing vasconstrictor-induced calcium (Ca2+) mobilization in vascular smooth muscle cells may contribute to important side effects in cyclosporine therapy such as hypertension and nephrotoxicity. As we have previously shown, cyclosporine A stimulates transmembrane Ca2+ influx. Since Ca2+ efflux was not affected by cyclosporine A, we concluded that cyclosporine augments angiotensin II induced Ca2+ mobilization in vascular smooth muscle cells by an increased amount of Ca2+ in angiotensin II sensitive intracellular Ca2+ stores. The present study was therefore designed to examine the effect of cyclosporine A on cellular calcium content and on membrane calcium transport mechanisms. An important mechanism of Ca2+ extrusion from the cell is the Na-Ca exchanger. Its activity is closely related with that of the Na-K-ATPase. By increasing cellular sodium concentration the blockade of Na-K-ATPase would in turn activate cellular calcium uptake bx the Na-Ca exchanger. Therefore, we hypothesized that cyclosporine A might exert its effects in the same manner as a circulating Na-K-ATPase inhibitor. Total cell calcium was measured by atomic absorption and activity of Na-K-ATPase was estimated by an assay measuring phosphate production. Preincubation of the cells with cyclosporine (10 micrograms/ml) for 15 min increased total cell calcium from 31.4 +/- 5.0 to 46.5 +/- 5.3 nmol/mg protein (P < 0.05). Activity of Na-K-ATPase was not affected by cyclosporine A (3.9 +/- 0.2 vs. 4.3 +/- 0.2 mumol Pi h-1 mg-1 protein). Therefore, cyclosporine A induced Ca2+ influx is not mediated by an inhibition of the Na-K-ATPase.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial natriuretic peptide inhibits cyclosporin A-induced endothelin production and calcium accumulation in rat vascular smooth muscle cells.

1. As we have previously shown, cyclosporin A enhances the vasoconstrictor-induced rise in intracellular free calcium in vascular smooth muscle cells. This effect may contribute to important side-effects in cyclosporin therapy, such as hypertension and nephrotoxicity. Atrial natriuretic peptide has been shown to inhibit this effect as well as the cyclosporin-stimulated transmembrane calcium influx in smooth muscle cells. 2. The present study, therefore, was designed to examine the effect of cyclosporin and atrial natriuretic peptide on total cellular calcium content in the rat. Furthermore, since cyclosporin was recently shown to induce endothelin production in smooth muscle cells, we investigated the effect of atrial natriuretic peptide on this potentially adverse cellular effect of cyclosporin therapy. 3. Total cell calcium was measured by atomic absorption, and cellular endothelin production was estimated by radioimmunoassay. 4. Preincubation of the cells with cyclosporin (10 micrograms/ml) for 30 min increased total cell calcium from 2.6 +/- 0.5 to 6.9 +/- 0.3 nmol/mg of protein (P < 0.01). Within 24 h endothelin production was significantly enhanced in the presence of cyclosporin (52.2 +/- 2.5 versus 65.9 +/- 2.7 fmol/mg of protein, P < 0.05). Therefore, the cyclosporin-induced rise in total cell calcium in smooth muscle cells is associated with enhanced production of endothelin. Thus, it is tempting to speculate that the cyclosporin-induced changes in calcium kinetics may be mediated by endothelin. 5. In the presence of atrial natriuretic peptide (10(-8) mol/l), the cyclosporin-induced rise in total cell calcium was significantly reduced (6.9 +/- 0.3 versus 5.1 +/- 0.2 nmol/mg of protein, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular signaling by cyclosporine A in contractile cells: interactions with atrial natriuretic peptide.

Immunosuppressive therapy with cyclosporine A (CyA) may be associated with severe side effects such as nephrotoxicity and arterial hypertension. The partial reversibility of these effects suggests that they are at least in part functional. The present study examined the effects of CyA on cellular signaling in vascular smooth muscle cells and in glomerular mesangial cells and the interactions with the endogenous vasodilator atrial natriuretic peptide (ANP). Intracellular free calcium concentrations ([Ca2+]i) were measured using Fura-2. 45Ca2+ was used to measure Ca2+ efflux and cellular Ca2+ influx. In the presence of cyclosporine (10 micrograms/ml), the Ca(2+)-mobilizing effects of angiotensin II (10(-8)M) in smooth muscle cells and of arginine vasopressin (AVP) in mesangial cells were significantly enhanced. CyA significantly stimulated cellular Ca2+ uptake in both cell types. ANP blocked the Ca2+ mobilization by angiotensin II and AVP and also completely inhibited the potentiating effect of CyA on angiotensin II- and AVP-induced Ca2+ mobilization. ANP also completely blocked the CyA-stimulated Ca2+ uptake. These findings suggest that CyA stimulates transmembrane Ca2+ influx, thereby increasing vasopressor-sensitive intracellular Ca2+ stores and augmenting vasopressor-induced Ca2+ mobilization. This cellular effect of CyA in vitro was markedly diminished by ANP. The effects of CyA on intracellular signaling may directly enhance the contractile response of smooth muscle and the glomerular mesangium to vasopressor stimuli and may also contribute to other disturbances of cell metabolism associated with CyA.

Human blood dendritic cells exhibit a distinct T-cell-stimulating mechanism and differentiation pattern.

In this study, the mechanisms underlying stimulation of T-cell proliferation by human blood dendritic cells (BDC) and their differentiation have been defined with a panel of monoclonal antibodies (MoAbs). It was found that the MoAbs against LFA-1 (CD11a), CD11c, LFA-3 (CD58), ICAM-1 (CD54) or HLA-DR could significantly suppress T-cell proliferation in an allogeneic mixed lymphocyte reaction (P < 0.05), while being unable to inhibit clustering of BDC with T cells. Addition of anti-CD18 or CD45 MoAbs increased the size of clusters after 18 h of culture, but had no effect on the proliferation of T cells (P < 0.05). The suppressive effect of the MoAbs may be viewed not as an inhibition of contact between BDC and T cells, but rather as a blocking of co-stimulatory signals for T-cell activation, which are mediated by interaction of the adhesion molecules. After depleting the BDC preparations of monocytes, we used a double staining in FACS analysis to demonstrate that BDC do not express specific T (CD3), B (CD20 and CD21) and myeloid cell markers (CD11b, CD13 and CD14), but abundant class II antigens. This pattern remained unaltered after 8 days of culture in the presence of 100 U/ml GM-CSF, although a threefold increase of HLA-DQ and ICAM-1 molecules on the cultured cells was observed.

[Hyperlipoproteinemia and pancreatitis (author's transl)]. / Hyperlipoproteinämie und Pankreatitis.

Exocrine pancreatic function was tested in 8 patients with pancreatitis and hyperlipoproteinemia type I, IV and V. Three young patients with HLP I and V and 2 patients with alcoholic HLP type V exhibited in most cases a distinctly reduced pancreatic function (chronic relapsing pancreatitis). Three patients with primary or secondary HLP type IV and V did not present pancreatic insufficiency (acute pancreatitis, acute relapsing pancreatitis). Taking into account the literature data and our own experience it can be stated that all forms of excessive hypertriglyceridemia can give rise to acute pancreatitis. Different possible causal relationships between HLP and pancreatitis are discussed. Concomitant occurrence of HLP and pancreatitis is observed most often in alcoholics.