An ancient role for nitric oxide in regulating the animal pelagobenthic life cycle: evidence from a marine sponge

In many marine invertebrates, larval metamorphosis is induced by environmental cues that activate sensory receptors and signalling pathways. Nitric oxide (NO) is a gaseous signalling molecule that regulates metamorphosis in diverse bilaterians. In most cases NO inhibits or represses this process, although it functions as an activator in some species. Here we demonstrate that NO positively regulates metamorphosis in the poriferan Amphimedon queenslandica. High rates of A. queenslandica metamorphosis normally induced by a coralline alga are inhibited by an inhibitor of nitric oxide synthase (NOS) and by a NO scavenger. Consistent with this, an artificial donor of NO induces metamorphosis even in the absence of the alga. Inhibition of the ERK signalling pathway prevents metamorphosis in concert with, or downstream of, NO signalling; a NO donor cannot override the ERK inhibitor. NOS gene expression is activated late in embryogenesis and in larvae, and is enriched in specific epithelial and subepithelial cell types, including a putative sensory cell, the globular cell; DAF-FM staining supports these cells being primary sources of NO. Together, these results are consistent with NO playing an activating role in induction of A. queenslandica metamorphosis, evidence of its highly conserved regulatory role in metamorphosis throughout the Metazoa.

Conservation genetics and population history of the threatened European mink Mustela lutreola, with an emphasis on the west European population

In species of great conservation concern, special attention must be paid to their phylogeography, in particular the origin of animals for captive breeding and reintroduction. The endangered European mink lives now in at least three well-separated populations in northeast, southeast and west Europe. Our aim is to assess the genetic structure of these populations to identify 'distinct population segments' (DPS) and advise captive breeding programmes. First, the mtDNA control region was completely sequenced in 176 minks and 10 polecats. The analysis revealed that the western population is characterized by a single mtDNA haplotype that is closely related to those in eastern regions but nevertheless, not found there to date. The northeast European animals are much more variable (pi = 0.012, h = 0.939), with the southeast samples intermediate (pi = 0.0012, h = 0.469). Second, 155 European mink were genotyped using six microsatellites. The latter display the same trends of genetic diversity among regions as mtDNA [gene diversity and allelic richness highest in northeast Europe (H(E) = 0.539, R(S) = 3.76), lowest in west Europe (H(E) = 0.379, R(S) = 2.12)], and provide evidences that the southeast and possibly the west populations have undergone a recent bottleneck. Our results indicate that the western population derives from a few animals which recently colonized this region, possibly after a human introduction. Microsatellite data also reveal that isolation by distance occurs in the western population, causing some inbreeding because related individuals mate. As genetic data indicate that the three populations have not undergone independent evolutionary histories for long (no phylogeographical structure), they should not be considered as distinct DPS. In conclusion, the captive breeding programme should use animals from different parts of the species' present distribution area.

Neovascularization in the human heart is associated with expression of VEGF-A and its receptors Flt-1 (VEGFR-1) and KDR (VEGFR-2). Results from cardiomyopexy in ischemic cardiomyopathy

Cardiomyopexy is a novel means of revascularization in end-stage ischemic heart disease leading to neovascularization and increased perfusion of the damaged heart. So far, the mediators of this process have not yet been identified. However, among others, vascular endothelial growth factor-A (VEGF-A) is a strong candidate for inducing this process. We have performed cardiomyopexy in humans by transplanting a flap of the musculus latissimus dorsi onto the epicardium. One of the patients died 7 weeks after cardiomyopexy due to a septic process unrelated to the underlying cardiac disease. Tissue specimen from the transplanted muscle flap, from the myocardium and from the native musculus latissimus dorsi were analysed by histological and immunohistochemical methods. The transplanted muscle appeared severely degenerated and showed no immunoreactivity for von Willebrandt factor (vWF) and for VEGF-A nor for its receptors KDR and Flt-1. However, a granulation zone had developed next to the transplanted muscle enriched with monocytes and macrophages which is characterized by a network of capillaries reaching into the ischemic myocardium and providing evidence for strong induction of angiogenesis. This process is accompanied by the abundance of VEGF-A expression in the endothelial layer of vessels. In parallel, VEGF-receptor KDR is present in capillaries passing into the subepicardial region supporting the idea of VEGF-A-induced angiogenesis. The spatial expression pattern of VEGF-A and KDR suggests VEGF-A to be a promotor of angiogenesis leading to indirect myocardial revascularization.

Uptake of the ATP-binding cassette (ABC) transporter Ste6 into the yeast vacuole is blocked in the doa4 Mutant

Previous experiments suggested that trafficking of the a-factor transporter Ste6 of Saccharomyces cerevisiae to the yeast vacuole is regulated by ubiquitination. To define the ubiquitination-dependent step in the trafficking pathway, we examined the intracellular localization of Ste6 in the ubiquitination-deficient doa4 mutant by immunofluorescence experiments, with a Ste6-green fluorescent protein fusion protein and by sucrose density gradient fractionation. We found that Ste6 accumulated at the vacuolar membrane in the doa4 mutant and not at the cell surface. Experiments with a doa4 pep4 double mutant showed that Ste6 uptake into the lumen of the vacuole is inhibited in the doa4 mutant. The uptake defect could be suppressed by expression of additional ubiquitin, indicating that it is primarily the result of a lowered ubiquitin level (and thus of reduced ubiquitination) and not the result of a deubiquitination defect. Based on our findings, we propose that ubiquitination of Ste6 or of a trafficking factor is required for Ste6 sorting into the multivesicular bodies pathway. In addition, we obtained evidence suggesting that Ste6 recycles between an internal compartment and the plasma membrane.

A family of small coiled-coil-forming proteins functioning at the late endosome in yeast

The multispanning membrane protein Ste6, a member of the ABC-transporter family, is transported to the yeast vacuole for degradation. To identify functions involved in the intracellular trafficking of polytopic membrane proteins, we looked for functions that block Ste6 transport to the vacuole upon overproduction. In our screen, we identified several known vacuolar protein sorting (VPS) genes (SNF7/VPS32, VPS4, and VPS35) and a previously uncharacterized open reading frame, which we named MOS10 (more of Ste6). Sequence analysis showed that Mos10 is a member of a small family of coiled-coil-forming proteins, which includes Snf7 and Vps20. Deletion mutants of all three genes stabilize Ste6 and show a "class E vps phenotype." Maturation of the vacuolar hydrolase carboxypeptidase Y was affected in the mutants and the endocytic tracer FM4-64 and Ste6 accumulated in a dot or ring-like structure next to the vacuole. Differential centrifugation experiments demonstrated that about half of the hydrophilic proteins Mos10 and Vps20 was membrane associated. The intracellular distribution was further analyzed for Mos10. On sucrose gradients, membrane-associated Mos10 cofractionated with the endosomal t-SNARE Pep12, pointing to an endosomal localization of Mos10. The growth phenotypes of the mutants suggest that the "Snf7-family" members are involved in a cargo-specific event.

Vascular endothelial growth factor-A-induced chemotaxis of monocytes is attenuated in patients with diabetes mellitus: A potential predictor for the individual capacity to develop collaterals

BACKGROUND

Vascular endothelial growth factor-A (VEGF-A) acts on endothelial cells and monocytes, 2 cell types that participate in the angiogenic and arteriogenic process in vivo. Thus far, it has not been possible to identify differences in individual responses to VEGF-A stimulation because of the lack of an ex vivo assay.

METHODS AND RESULTS

We report a chemotaxis assay using isolated monocytes from individual diabetic patients and from healthy, age-matched volunteers. The chemotactic response of individual monocyte preparations to VEGF-A, as mediated via Flt-1, was quantitatively assessed using a modified Boyden chamber. Although the migration of monocytes from healthy volunteers could be stimulated with VEGF-A (1 ng/mL) to a median of 148.4% of the control value (25th and 75th percentiles, 136% and 170%), monocytes from diabetic patients could not be stimulated with VEGF-A (median, 91.1% of unstimulated controls; 25th and 75th percentiles, 83% and 98%; P<0.0001). In contrast, the response of monocytes to the chemoattractant formylMetLeuPhe remained intact in diabetic patients. The VEGF-A-inducible kinase activity of Flt-1, as assessed by in vitro kinase assays, remained intact in monocytes from diabetic patients. Moreover, the serum level of VEGF-A, as assessed by immunoradiometric assay, was significantly elevated in diabetic patients.

CONCLUSIONS

The cellular response of monocytes to VEGF-A is attenuated in diabetic patients because of a downstream signal transduction defect. These data suggest that monocytes are important in arteriogenesis and that their ability to migrate might be critical to the arteriogenic response. Thus, we resolved a fundamental mechanism involved in the problem of impaired collateral formation in diabetic patients.

Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine

BACKGROUND

The effects of food restriction on energy metabolism have been under investigation for more than a century. Data obtained are conflicting and research has failed to provide conclusive results.

OBJECTIVE

The objective of this study was to test the hypothesis that in lean subjects under normal living conditions, short-term starvation leads to an increase in serum concentrations of catecholamines and thus to an increase in resting energy expenditure.

DESIGN

Resting energy expenditure, measured by indirect calorimetry, and hormone and substrate concentrations were measured in 11 healthy, lean subjects on days 1, 2, 3, and 4 of an 84-h starvation period.

RESULTS

Resting energy expenditure increased significantly from 3.97 +/- 0.9 kJ/min on day 1 to 4.53 +/- 0.9 kJ/min on day 3 (P < 0.05). The increase in resting energy expenditure was associated with an increase in the norepinephrine concentration from 1716. +/- 574 pmol/L on day 1 to 3728 +/- 1636 pmol/L on day 4 (P < 0.05). Serum glucose decreased from 4.9 +/- 0.5 to 3.5 +/- 0.5 mmol/L (P < 0.05), whereas insulin did not change significantly.

CONCLUSIONS

Resting energy expenditure increases in early starvation, accompanied by an increase in plasma norepinephrine. This increase in norepinephrine seems to be due to a decline in serum glucose and may be the initial signal for metabolic changes in early starvation.

Metabolic encephalopathy in critically ill patients suffering from septic or nonseptic multiple organ failure

OBJECTIVE

Evaluation of changes in the peak latencies of sensory evoked potentials in different patient groups, to evaluate differences in metabolic encephalopathy of critically ill patients with multiple organ failure as a result of septic or nonseptic conditions.

DESIGN

Prospective cohort study.

SETTING

Intensive care units of the university hospital, Vienna.

PATIENTS

Patients (n = 103) treated on an intensive care unit because of multiple organ failure with additional metabolic encephalopathy. Multiple organ failure was induced by sepsis (group A; n = 56), surgery (group B; n = 29), or both (group C; n = 18).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Metabolic encephalopathy was determined by measuring median nerve-stimulated short-latency and long-latency sensory evoked potentials. No differences in the peak latencies of the sensory evoked potentials were detected among the groups. Septic patients had a N70 peak latency of 131+/-21 msecs, nonseptic postsurgical patients of 132+/-17 msecs, and septic postsurgical patients of 134+/-17 msecs. The cervicomedullary N13 to cortical N20 conduction times were 6.4+/-1 msec, 6.4+/-1.4 msecs, and 6.8+/-1.2 msecs, respectively. All measured peak latencies were significantly prolonged compared with peak latencies of healthy controls. The severity of illness assessed by the Acute Physiology and Chronic Health Evaluation III score was not different between the three groups. An increase of the delay of N70 peak latencies was significantly correlated with the severity of illness (r2 = .15; p < .00005).

CONCLUSION

There was no difference in sensory evoked potential measurements detectable among septic patients with multiple organ failure, nonseptic postsurgical patients with multiple organ failure, and septic postsurgical patients with multiple organ failure. The N70 peak latency was significantly correlated with the severity of illness but not with the presence or absence of sepsis. In postsurgical patients with multiple organ failure and superimposed sepsis, the N70 peak latencies were not further prolonged compared with postsurgical patients without sepsis.

Short-term prognosis in critically ill patients with liver cirrhosis: an evaluation of a new scoring system

OBJECTIVE

The mortality of patients with liver cirrhosis admitted to an intensive care unit (ICU) has been found to be high. This study was performed to assess the physiological and laboratory parameters which are able to identify on ICU admission the cirrhotic patients who are most likely to die.

DESIGN

Prospective clinical trial.

METHODS

Two groups of patients were analysed. Group A consisted of 196 consecutive cirrhotic patients admitted to our medical ICU for various reasons. For the detection of independent outcome predictors, we used a multiple logistic regression model. Based on these variables, the 'intensive care cirrhosis outcome (ICCO) score' was calculated. The ability to discriminate between survivors and non-survivors was determined by receiver operating characteristic curves, and the area under the curve was calculated. Group B consisted of 70 consecutive cirrhotic patients for prospective validation of the ICCO score.

RESULTS

Applying multiple logistic regression analysis, bilirubin, cholesterol, creatinine clearance and lactate were found to be independently associated with the hospital mortality. The ICCO score was 0.3707 + (0.0773 x bilirubin (mg/dl)) - (0.00849 x cholesterol (mg/dl)) -(0.0155 x creatinine clearance (ml/min)) + (0.1351 x lactate (mmol/l)), giving an area under a receiver operating characteristic curve of 0.9. Increasing score values were associated with an increase in mortality. All patients with an ICCO score > +2.6 died.

CONCLUSIONS

Application of the ICCO score is rapid and available at the patient's bedside, and its application is simple and reproducible. In cirrhotic patients, the ICCO score has a high ability to discriminate between survivors and non-survivors. The ICCO score may facilitate estimation on ICU admission of the prognosis of critically ill cirrhotic patients.

Elevation of vascular endothelial growth factor-A serum levels following acute myocardial infarction. Evidence for its origin and functional significance

Following the onset of acute myocardial infarction (AMI), a number of serum parameters show well-defined changes reflecting myocardial injury. During the consecutive repair phase, compensatory processes are initiated including the formation of a collateral circulation on the basis of angiogenesis and arteriogenesis. An important angiogenic factor is vascular endothelial growth factor-A (VEGF-A), shown to be upregulated in the ischemic myocardium. It is unclear, however, whether acute myocardial ischemia leads to a detectable elevation of VEGF-A serum concentrations. With the use of an immunoradiometric assay, we measured the levels of VEGF-A in the serum of patients after AMI at defined time intervals, of patients with unstable angina pectoris (UAP) and of healthy individuals. In addition, in a small group of patients with subacute myocardial infarction VEGF-A concentrations were measured in coronary sinus blood. The data are given as median followed by the 25th and 75th percentiles. In the group with AMI serum VEGF-A measured 105 [78; 176] pg/ml on day 1 and 114 pg/ml [72; 163] pg/ml on day 3 after onset of AMI. Serum levels of VEGF-A significantly increased on day 7 after AMI to 189 [119; 373] pg/ml (P=0.0103) and on day 10 to 255 [162; 371] pg/ml (P=0.0007). The VEGF-A serum level in healthy controls and in patients with UAP measured 98 [75; 137] pg/ml and 116 [57; 140] pg/ml, respectively. Serum at day 10 after AMI contained VEGF-A at a biologically relevant concentration capable of stimulating proliferation of endothelial cells. Surprisingly, VEGF-A serum levels were similar in samples taken from the coronary sinus with 61 [43; 83] pg/ml. Therefore the main source for VEGF-A in the blood stream is not the infarcted myocardium. However, the number of platelets, a rich source of VEGF-A, is significantly increased after myocardial infarction, i.e. 284 [252; 363] x 10(9)/litre v 220 [177; 250] x 10(9)/litre. In conclusion, the time course of VEGF-A elevation following AMI strongly suggests that VEGF-A plays a role as an endogenous activator of coronary collateral formation in the human heart. The most likely source of the elevated VEGF-A are platelets, rather than the infarcted myocardium.

Heavy chronic alcohol abuse has no additional adverse effect on the function of extrahepatic organs and ICU mortality in patients with liver cirrhosis

BACKGROUND AND AIMS

We questioned whether heavy chronic alcohol abuse influences extrahepatic organ failure and ICU mortality in cirrhotic patients admitted to a medical intensive care unit.

PATIENTS AND METHODS

Medical records of 208 consecutive cirrhotic critically ill patients were reviewed. Patients were classified into two groups. Group A comprised 144 patients with liver cirrhosis due to heavy chronic alcohol abuse and group B, 64 patients with liver cirrhosis due to non-alcoholic causes. The presence of extrahepatic organ failures in patients of both groups was assessed with parameters determined on the day of admission to the ICU. Furthermore, ICU mortality was determined.

RESULTS

The occurrence of extrahepatic organ failure was similar in group A and group B (83% vs. 80%; p = NS). The rate of extrahepatic organ failure was 1.7 +/- 1.2 organs in group A, compared to 1.4 +/- 1 organs in group B (p = NS). ICU mortality was 53% in group A and 44% in group B (p = NS). An increase in the number of extrahepatic organ failures was associated with a concomitant increase in ICU mortality in both groups of patients.

CONCLUSION

The occurrence of extrahepatic organ failure and ICU mortality was not different between patients with liver cirrhosis secondary to heavy chronic alcohol abuse and patients with liver cirrhosis due to nonalcoholic causes. Cirrhotic patients should be admitted to a medical intensive care unit for extended intensive care treatment prior to the occurrence of extrahepatic multiple organ failure, independent of the underlying aetiology.

The coronary endothelium: a target for vascular endothelial growth factor. Human coronary artery endothelial cells express functional receptors for vascular endothelial growth factor in vitro and in vivo

Vascular endothelial growth factor (VEGF) is an angiogenic peptide that can stimulate endothelial cell proliferation and migration in vitro and collateral development in ischemic organs in vivo. Although postulated, the expression of functional VEGF receptors in the heart has not been demonstrated yet. To prove this hypothesis and to extend the molecular basis of myocardial angiogenesis, we have characterized the expression and function of VEGF receptors in human coronary artery endothelial cells (HCAEC) and in human heart tissue. VEGF strongly induces proliferation and migration of HCAEC. These cells express transcripts of the two VEGF receptors KDR and Flt-1. Their expression levels are higher in HCAEC as compared with human umbilical vein endothelial cells. In HCAEC, VEGF stimulates phosphorylation of KDR in a concentration-dependent manner proving that KDDR is a functional receptor tyrosine kinase. Scatchard analysis demonstrated the presence of the high affinity receptor Flt-1 in HCAEC with a kd of 8 pM. Flt-1 protein could be visualized as a single band corresponding to a size of 210 kd. In addition mature KDR protein could be detected in adult human heart. Taken together, HCAEC and human heart tissue express high levels of functional VEGF receptors. These results broaden the molecular basis for understanding and manipulating VEGF-induced endothelial function and angiogenesis in the coronary circulation.

Molecular mediators of tumor angiogenesis: enhanced expression and activation of vascular endothelial growth factor receptor KDR in primary breast cancer

The progression of breast cancer growth and its ability to metastasize are associated with the process of angiogenesis. In this study, we examined the protein expression of vascular endothelial growth factor (VEGF) and its specific and functional receptor KDR in human breast tissue. We investigated a total of 13 mammary carcinomas, 3 fibroadenomas, 5 specimens with fibrocystic breast disease as well as normal (adjacent to malignant) breast tissue using immunohistochemistry and Western blot analysis. In all carcinomas examined, functional KDR protein was present independent of tumor type, tumor stage and histological grade as demonstrated by tyrosine phosphorylation analysis of KDR. When malignant tissues were compared with their neighboring non-neoplastic regions, activated KDR was found to be expressed to a much higher extent within the malignant tissue samples. In fibroadenomas, KDR was barely detectable, whereas in fibrocystic breast disease KDR expression was variable. Immunostaining of KDR was localized to endothelium and epithelium of mammary ducts in malignant and benign breast tissue, while VEGF immunoreactivity was primarily found in the endothelium and also in tumor cells and macrophages. Our data demonstrate that KDR activation is enhanced in breast cancer in vivo and emphasize the functional role of VEGF and KDR in the development of malignant breast disease.

Transient left ventricular failure following bilateral lung transplantation for pulmonary hypertension

BACKGROUND

Bilateral lung transplantation is an established therapy for end-stage pulmonary hypertension. Its early postoperative outcome may be biased by various complications resulting in unexpected deterioration of the patient in terms of hemodynamics and blood gases.

METHODS

We have reviewed the early postoperative course of patients who underwent bilateral lung transplantation for pulmonary hypertension at our institution and analyzed all available data, especially hemodynamic measurements, echocardiographic documentation and therapeutical strategies, in those cases where cardiac dysfunction was found to be responsible for clinical deterioration.

RESULTS

Three out of 20 lung transplant recipients operated for pulmonary hypertension experienced severe respiratory insufficiency accompanied by hemodynamic decompensation during the first days after surgery. Clinical and laboratory findings together with results of echocardiography and pulmonary artery catheterism helped establish the diagnosis of left ventricular failure. This proved to be transitory, but the response to therapy (inotropic drugs, afterload reduction and eventually prostaglandins) was very variable. Adequately treated, this complication did not preclude the outcome of transplantation by itself.

CONCLUSION

Left ventricular failure is a possible complication after lung transplantation for pulmonary hypertension. Echocardiography and pulmonary artery catheterism may be useful adjuvant diagnostic tools, beside routine physical examination, chest X-ray, and laboratory analysis. Therapy of this complication must be adapted individually and may be complex.

Inhalation of nitric oxide as a life-saving therapy in a patient after pulmonary embolectomy

We describe a 54-yr-old man with cardiogenic shock caused by acute right heart failure after pulmonary embolectomy. Inhalation of nitric oxide led to immediate improvement in respiratory and haemodynamic variables. Inhaled nitric oxide can be used to reduce acute right heart failure until conventional therapy can provide successful haemodynamic stability.

Catheter-induced thrombus in the superior vena cava diagnosed by transesophageal echocardiography

BACKGROUND

To present the role of transesophageal echocardiography (TEE) in the diagnosis and management of catheter-related superior vena cava thrombosis.

CASE HISTORY

A 42-year-old woman with severe Crohn's disease presented with septic shock and pulmonary embolism three weeks after emergency laparotomy and ileocolic resection for small-bowel perforation with peritonitis. Cardiopulmonary evaluation with ECG, pulmonary artery catheter and TEE demonstrated no evidence of acute myocardial ischemia or ventricular dysfunction; hemodynamic indices were consistent with severe sepsis. TEE revealed a large sheathing thrombus surrounding a central venous catheter used for parenteral nutrition. A spiral CT scan of the chest confirmed multiple peripheral pulmonary emboli. Treatment consisted of systemic anticoagulation and antibiotics. To avoid further pulmonary embolism, the central venous catheter was not removed until six days later under TEE monitoring, which revealed that the thrombus was firmly adherent to the superior vena cava. The patient made an uneventful recovery and was discharged from hospital on long-term anticoagulant therapy.

CONCLUSION

In a case of catheter-induced superior vena cava thrombosis with septicemia and pulmonary embolism, bedside TEE was very helpful to make the correct diagnosis early, assess thrombus size during anticoagulation, and monitor cardiac performance and thrombus disposition during central venous catheter removal.

Transjugular intrahepatic portosystemic shunt and cardiac arrhythmias

The approach to the liver for a transjugular intrahepatic porto-systemic shunt (TIPS) is through the venous system. Because catheter and guidewire system traverses the heart, cardiac arrhythmias may be expected during the procedure. We have prospectively investigated the incidence of such dysrhythmias during TIPS implantation. Twelve consecutive patients, 4 women and 8 men aged 26 to 75 years (mean, 58 +/- 13 years), were studied. Before and on the day of TIPS implantation, a 24-hour Holter recording was performed. Transjugular intrahepatic portosystemic shunt implantation was performed under local anesthesia (lidocaine) and sedoanalgesia (midazolam and fentanyl). None of the patients had concomitant cardiac disease or electrolyte disturbances. In all patients except one, TIPS implantation was successful without any technical complications. A mean of 43 +/- 5.3 hours of Holter recording was performed before and after TIPS implantation. All recordings obtained during this control period were considered inconspicuous. The mean heart rate was significantly higher during the implantation procedure of 136 +/- 37 minutes' duration (83 +/- 20 beats per minute vs 70 +/- 19 beats per minute; p < 0.01). Nine of the 12 patients experienced episodes of nonsustained supraventricular tachycardias, and one patient had two sustained supraventricular tachycardias. Frequent episodes of nonsustained ventricular tachycardias developed in 75% of the patients. It seems clear that TIPS implantation is frequently associated with supraventricular and ventricular tachyarrhythmias even in patients with apparently good cardiac condition at the beginning of the procedure. Thus close cardiac monitoring with resuscitation equipment immediately available throughout the procedure is mandatory.

Effect of prostaglandin E1 on extravascular lung water in patients with severe heart failure

Prostaglandin E ( 1 ) (PGE ( 1 ) ) is a naturally occurring paracrine hormone that is used pharmacologically for treatment of peripheral occlusive arterial disease and to maintain ductus-arteriosus patency in neonates with congenital heart disease until the primary condition is operable. PGE ( 1 ) treatment also has been associated with reduction in pulmonary arterial pressure and increase in cardiac output in patients with left ventricular failure. In contrast, in isolated cases, patients with heart failure reportedly have developed pulmonary edema while receiving PGE ( 1 ). Therefore, to better define the effect of PGE ( 1 ) in heart failure, this double-blind study investigated the effect of PGE ( 1 ) on extravascular lung water in intensive-care patients with severe heart failure (New York Heart Association [NYHA] classes III and IV) and slightly above-normal extravascular lung water. Intravenous infusion of 60 microg PGE ( 1 ) (Prostavasin; Schwarz Pharma, Monheim, Germany) over a period of 2 hours caused no significant change in lung water relative to the baseline values (9.8 +/- 4.3 mL/kg before the infusion, 9.3 +/- 3.2 mL/kg after 1 hour, and 9.4 +/- 3.5 mL/kg after 2 hours) or to values observed in placebo-treated patients (6.5 +/- 3.3 mL/kg before the infusion, 7.1 +/- 2.7 mL/kg after 1 hour, and 7.0 +/- 3.2 mL/kg after 2 hours). Thus, administration of PGE ( 1 ) is unlikely to cause or worsen pulmonary edema in patients with severe heart failure (NYHA classes III and IV).

Studies on rat and human thymus to demonstrate immunoreactivity of calcitonin gene-related peptide, tyrosine hydroxylase and neuropeptide Y

The peptidergic and noradrenergic innervation of rat and human thymus was investigated by immunohistochemistry at the light and electron microscopical level (avidin-biotin-complex, sucrose-phosphate-glyoxylic-acid, and immunogold techniques). The distribution of noradrenergic neural profiles, and positive immunoreactivity for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH) and neuropeptide Y (NPY) is described in female rats during ageing, and in human children. In the neonatal rat thymus, the arteries and septa are well supplied by fine varicose nerves. In older animals (2 wk-1 y) the number of septa and blood vessels increase and consequently also the innervation. No nerves were found in the cortex. Apart from the innervation of the septal areas, immunoreactivity for CGRP and TH was present in thymic cells. Except for the young rats (neonatal-14 d), all rats showed CGRP positivity in subcapsular/perivascular epithelial cells (type 1 cells). All rat thymuses also contained a few TH positive cells in the medulla, which could only be confirmed as epithelial cells (type 6 cells) in children. Type 1 cells in the human thymus were not CGRP positive, but as in the rat, there were similar TH positive cells in the medulla. It was concluded that in addition to nerves containing CGRP, noradrenaline or dopamine, epithelial cells also contain these transmitters. They could therefore act on different cells (compared with neural targets) in a paracrine manner.

Modulation of dye-coupling and proliferation in cultured rat thymic epithelium by factors involved in thymulin secretion

Cultures of rat thymic epithelium were used to measure the effect of thymulin secretagogues on dye-coupling and proliferation. Dye-coupling was assessed after the injection of lucifer yellow dextran which cannot permeate the connexin pore of gap junctions and the smaller, permeant cascade blue. In addition to gap junctional communication, larger intercellular bridges were demonstrated by the transfer of lucifer yellow dextran between cells. The extent of intercellular communication was found to be influenced by both cell density and the number of passages. In control cultures, intercellular communication was reduced in cell groups of low (< 20 cells/group) or high cell densities (> 100 cells/group) compared with groups of 20-60 cells. The highest coupling indices were found in subcultures 20-30. Taking these factors into account, significant decreases in coupling index were observed after pretreatment of test cultures with factors known to influence the secretion of thymulin (5 U/ml interleukin 1 (alpha and beta), 1 microM progesterone, 1 microM oestrogen, 1 microM testosterone, 1 ng/ml adrenocorticotropic hormone, 100 nM rat growth hormone) but 7.5 ng/ml thymulin had no effect on dye-coupling. The nonspecific gap junction uncoupler, octanol, abolished dye-coupling. Cellular proliferation, as measured by the uptake of tritiated thymidine, showed that the same factors that reduced coupling also increased proliferation. None of these factors affected the number of multinucleate cells present, except interleukin-1beta which caused a significant reduction in the average number of nuclei per cell. Thus rat thymic epithelium in vitro provides a model for the study of the direct action of factors on cells of the thymic microenvironment.

Blood groups Lewis(b) and ABH expression in gastric mucosa: lack of inter-relation with Helicobacter pylori colonisation and occurrence of gastric MALT lymphoma

BACKGROUND

Blood group Lewis(b) antigens mediate Helicobacter pylori attachment to gastric mucosa with attachment being particularly strong in subjects with ABH blood group O.

AIMS

To determine whether H pylori colonisation or the occurrence of gastric mucosa associated lymphoid tissue (MALT) lymphomas might be related to gastric Lewis(b) expression or occurrence of particular ABH blood groups on gastric mucosa.

PATIENTS

Gastric resection specimens from 89 cases with gastric MALT lymphoma and gastric mucosal biopsy specimens from 95 patients undergoing upper endoscopy due to upper gastrointestinal complaints, including five cases with gastric MALT lymphoma, were studied.

METHODS

H pylori was visualised with the Warthin-Starry stain. Immunostaining (Lewis(b), Lewis(a), A, B) was performed by applying a three step immunoperoxidase technique and indirect immunofluorescence staining on formalin fixed and paraffin wax embedded tissue. In 40 patients red blood cell Lewis phenotype and ABH blood groups were additionally determined by haemagglutination assay.

RESULTS

Gastric surface epithelial cells showed an immunoreactivity to blood groups A, B, and AB in 80 (43.5%), 22 (12%), and 11 (6%) cases respectively and no immunoreactivity to any of these blood group substances (blood group O) in 71 (38.5%) patients. Lewis(b) expression of all gastric surface epithelial cells (secretor status) was found in 130 (70.7%) cases. Lewis(a) expression of all gastric surface epithelial cells (non-secretor status) was found in 36 (19.6%) cases, secretor status remained unclassified in 18 (9.8%) patients. Colonisation with H pylori was found in 134 (72.8%) cases. The occurrence of H pylori was neither significantly associated with secretor status nor with certain ABH blood groups. The infiltration of gastric mucosa with MALT lymphoma was highly significantly associated with H pylori colonisation (p < 0.0003) but neither with secretor status nor with certain ABH blood groups. There was no inter-relation between secretor status or ABH blood groups and type, stage, grade of, and survival after MALT lymphoma.

CONCLUSION

This study failed to show an inter-relation between secretor status or particular ABH blood groups and either H pylori infection or the occurrence of gastric MALT lymphomas.

Beta-adrenoceptor-mediated effects in rat cultured thymic epithelial cells

1. Sympathetic nerves were visualized in sections from rat thymus by immunostaining of tyrosine hydroxylase, the rate-limiting enzyme of catecholamine biosynthesis, and by glyoxylic acid-induced fluorescence of catecholamines. Catecholaminergic nerve fibres were detected in close connection to thymic epithelial cells which therefore might be preferred target cells. To evaluate this, rat immunocytochemically defined, cultured thymic epithelial cells were investigated for adrenoceptors and adrenergic effects. 2. In rat cultured thymic epithelial cells mRNA for beta 1- and beta 2-adrenoceptors was detected by reverse transcription-polymerase chain reaction by use of sequence-specific primers. Specific, saturable binding to the cultivated cells was observed with the beta-adrenoceptor agonist CGP 12177. 3. Adrenaline, noradrenaline or the beta-adrenoceptor agonist, isoprenaline, increased intracellular adenosine 3':5'-cyclic monophosphate (cyclic AMP) levels in cultivated thymic epithelial cells dose-dependently about 25 fold. The pharmacological properties revealed that this response was mediated by receptors of the beta 1- and the beta 2-subtypes. The selective beta 3-adrenoceptor agonist BRL 37344 had no effect on cyclic AMP levels. The increase in cyclic AMP was downregulated by preincubation with glucocorticoids like dexamethasone or cortisol which also changed the relative importance of beta 1-/beta 2-adrenoceptors to the response. 4. Incubation with isoprenaline or the adenylate cyclase activator forskolin decreased basal and serum-stimulated proliferation of thymic epithelial cells. However, adrenergic stimulation of thymic epithelial cells did not induce interleukin 1 production. Since thymic epithelial cells create a microenvironment which influences the maturation and differentiation of thymocytes to T-lymphocytes, their observed capacity to respond to catecholamines provides novel evidence for the suggestion that adrenergic stimulation may interfere with the regulation of immune functions.

Impairment of citrate metabolism in acute hepatic failure

AIMS

To compare the utilization of citrate employed as anticoagulant in patients with acute hepatic failure and subjects with normal liver function.

PATIENTS AND METHODS

Three patients in acute hepatic failure and normal renal function were studied during therapeutic plasma exchange with citrate containing fresh frozen plasma. Six patients receiving immunapheresis or LDL-apheresis anticoagulated with citrate served as controls. Determinations of serum citrate concentrations, of ionized calcium and blood pH were performed before, during, and after the extracorporeal treatment. Total body clearance and elimination half life were calculated in a two compartment model.

RESULTS

Preinfusion citrate levels were higher in the patients with acute hepatic failure than in the controls (n.s.). The citrate level rose to 1.73 +/- 0.2 mmol/l in the liver patients versus 0.99 +/- 0.1 mmol/l in the healthy subjects (p < 0.03). Total body clearance was markedly reduced in patients with acute hepatic failure (3.31 +/- 0.03 ml/kg/min) as compared with the controls (6.34 +/- 0.16 ml/kg/min) (p < 0.02), the elimination half life (t/2 k1e) was prolonged (49.7 +/- 5.4 vs. 32.9 +/- 1.02 min, p < 0.05). In the controls blood pH rose from 7.4 +/- 0.01 to 7.45 +/- 0.01 (p < 0.05) after citrate infusion, whereas in the liver patients no rise in pH was observed, again reflecting the impairment of citrate metabolism. Ionized calcium was lower in the patients with acute hepatic failure at the beginning (1.01 +/- 0.05 vs. 1.21 +/- 0.04 mmol/l, p < 0.05) and the end (0.68 +/- 0.02 vs. 0.93 +/- 0.04 mmol/l, p < 0.05) of the citrate infusion.

CONCLUSIONS

Citrate metabolism is severely impaired and the plasmatic calcium stores are reduced in acute hepatic failure and, thus, the risk of adverse effects is high. Therapeutic infusions of citrate should be restricted in patients with acute hepatic failure and, if necessary, therapy should be closely monitored by repeated measurements of ionized calcium to avoid the development of potentially hazardous hypocalcemia.

Azygos arch cannulation by central venous catheters: radiographic detection of malposition and subsequent complications

The aim of this study was to determine the frequency of radiographically evident central venous catheter misplacement in the azygos arch and to analyze whether the frequency of azygos arch cannulation is dependent on the anatomical site of catheter insertion. We reviewed 1,287 postprocedural examinations and 3,441 follow-up examinations. Catheters had been inserted through the left (6%) or right (15%) internal jugular veins and through the left (32%) or right (46%) subclavin veins. Radiographs were analyzed for possible catheter malposition in the azygos arch and for complications related to this malposition. Catheter malposition in the azygos arch was seen on 16/1,287 (1.2%) postprocedural radiographic examinations. Of the 16 malpositioned catheters, 11 (69%) had been inserted in the left subclavian vein, three (19%) in the left jugular vein, two (12%) in the right subclavian vein, and none (0%) in the right jugular vein. There was a statistically significant difference in the frequency of azygos arch cannulation between left- and right-sided catheters (p = 0.001). All complications consisted of venous perforations and were seen in three of 16 cases (19%). Azygos arch cannulation is a rare but hazardous central venous catheter malposition that occurs early after catheter insertion and carries a substantial risk for complication. The risk for azygos arch cannulation is substantially increased if catheters are inserted in left-sided veins. Because of the severity of subsequent complications, radiologists should be vigilant in the detection of this rare malposition.

Detection of nontraumatic comatose patients with no benefit of intensive care treatment by recording of sensory evoked potentials

OBJECTIVES

To determine the predictive ability of sensory evoked potential recordings in nontraumatic comatose patients. To evaluate the hypothesis that patients with bilateral absent cortical responses ultimately die despite long-term intensive care treatment.

DESIGN

Prospective cohort study.

SETTING

Medical intensive care unit (ICU) of a university hospital.

PATIENTS

Four hundred forty-one adult nontraumatic comatose patients (unarousable unresponsiveness to external stimulation, Glasgow Coma Score < or = 7) from various causes. Six hundred seventy-six sensory evoked potential measurements were performed within 7 days after onset of coma.

MAIN OUTCOME MEASURES

Death or survival to hospital discharge.

RESULTS

Eighty-six patients (20%) had a bilateral loss of the cortical evoked potential N20 peak. Despite long-term intensive care treatment, all died without awakening from coma (mortality rate, 100%; 95% confidence interval, 96-100). The mean stay at the ICU after evoked potential measurement until death was 8.1 days (697 patient days). The overall cost of ICU management for these 86 patients accounted for approximately $1,324,300. In the remaining 355 comatose patients with preserved cortical N20 peak, 148 (42%) survived and 207 (58%) died. In this latter group of patients, cervicomedullary N13 to cortical N20 conduction time was prolonged in nonsurvivors (mean +/- SD, 6.7 +/- 1.3 milliseconds) compared with that in survivors (mean +/- SD, 6.4 +/- 1.2 milliseconds, P < .05) and healthy controls (mean +/- SD, 5.5 +/- 0.4 milliseconds, P < .05). Although this difference is statistically significant, a preserved N20 peak is not useful to discriminate whether the individual patient will survive (N13-N20 conduction time of > 7 milliseconds had a positive predictive value of correct prediction of death of 0.67).

CONCLUSIONS

Recording of sensory evoked potentials identifies a subgroup of adult nontraumatic comatose patients with a mortality rate of 100% in our sample. In these patients, advanced intensive care treatment should be withdrawn to provide limited ICU resources for patients with higher probability of favorable outcome. We emphasize that these results are not applicable to comatose patients following closed head trauma and particularly not to children.

Outcome prediction for patients with cirrhosis of the liver in a medical ICU: a comparison of the APACHE scores and liver-specific scoringsystems

OBJECTIVE

To find the most adequate prognostic scoring system for predicting ICU-outcome in patients with decompensated liver cirrhosis in a medical intensive care unit (ICU).

DESIGN

Retrospective analysis of patients' records over a 10-year period.

SETTING

A medical ICU at the university medical center of Vienna.

PATIENTS AND PARTICIPANTS

94% (n = 198) of all patients with cirrhosis admitted to our medical ICU throughout the 10-year study period.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

From data obtained at admission and at 48 h after admission, scores were calculated using the following scoring systems: Acute Physiology and Chronic Health Evaluation (APACHE) II and III, Scale for Composite Clinical and Laboratory Index Scoring (CCLI), Mayo Risk Score, and Child's Classification. Statistical analysis for the prognostic variables was performed using the chi-square test, t-test, Youden index, and area under a receiver operating characteristic (ROC) curve. APACHE III was found to be the most reliable outcome predictor at admission and after 48 h for patients with decompensated liver cirrhosis (AUC = 0.75 and 0.8, respectively).

CONCLUSIONS

To predict the outcome for patients with decompensated cirrhosis of the liver admitted to a medical ICU liver failure alone is not decisive. Liver-specific scoring systems (Mayo Risk Score, CCLI) are adequate, but the APACHE II and III proved to be more powerful, because they include additional physiologic parameters and therefore also take into account additional complications associated with this liver disorder.

Vasomotion, regional cerebral blood flow and intracranial pressure after induced subarachnoid haemorrhage in rats

The objective of our study was to examine the relation of the intracranial pressure (ICP), cerebral perfusion pressure (CPP), regional cerebral blood flow (rCBF), and vasomotion in the acute phase in rats after having induced subarachnoid haemorrhage (SAH). The experiments were carried out on a total of 21 Wistar rats by means of neuroleptanalgesia and controlled mechanical ventilation. In 16 animals SAH was induced according to the method described by Solomon et al. with a fractionated application of 0.5 ml autologous blood into the cisterna magna. In a control group 0.5 ml of physiological saline solution was injected under identical conditions. The parameters were registered continuously before, during and at least 3 hours after the bolus application. The rCBF and vasomotion were recorded by laser-doppler fluxmetry. The ICP and the systemic arterial blood pressure were registered simultaneously. In the course of the experiment blood gas analyses were carried out regularly for documentary reasons of normoventilation. Our results show that the Cushing-response-after having induced SAH-led to a deterioration of the cerebral perfusion. In the control group however an increase in ICP and rCBF was recorded. The frequency and amplitude of the oscillations of Doppler signals, described as vasomotion, were significantly reduced in the SAH group as compared to the control group (p = 0.0004) during the course of the experiment. After having induced SAH an impairment of the cerebral autoregulation becomes apparent which seems to manifest itself on the level of microvascular structures as a suppressed behaviour pattern of vasomotion. Although basal vessels may constrict distal parenchymal vessels tend to dilate after SAH. The dilation-described as a reduction of vasomotion-could also be measured in clinical situations by means of laserdoppler fluxmetry.

Forensics on wild animals: differentiation between otter and pheasant blood using electrophoretic methods

Electrophoretic techniques were used to prove illegal hunting of a protected species as small amounts of dried blood stains could be clearly identified as of otter origin. Species differentiation between the otter (Lutra lutra) and pheasant (Phasianus colchicus) was based mainly on small differences in electrophoretic mobilities of the respective albumins and hemoglobins in one-dimensional separations. Additional differences in minor proteins of the two species were revealed by two-dimensional electrophoresis. Electrophoresis thus also proved to be a valuable tool for forensic purposes.

Calcitonin gene-related peptide and its receptor in the thymus

Calcitonin gene-related peptide (CGRP), a 37-amino acid residue neuropeptide, was immunostained in rat thymus at two sites: a subpopulation of thymic epithelial cells, namely subcapsular/perivascular cells, were heavily stained besides some nerve fibers surrounding arteries and arterioles. The administration of nanomolar concentrations of rat alpha-CGRP dose-dependently raised intracellular cyclic adenosine monophosphate (cAMP) levels in isolated rat thymocytes (half-maximum stimulation 1 nM) but not in cultured rat thymic epithelial cells. Peptides structurally related to CGRP (i.e., rat calcitonin or amylin) had no effect. CGRP(8-37), an N-terminally truncated form, acted as an antagonist. Peripheral blood lymphocytes did not respond to CGRP, suggesting that receptors are present only on a subpopulation of thymocytes but not on mature T cells. This was substantiated by visualization of CGRP receptors on single cells by use of CGRP-gold and -biotin conjugates of established biological activity: only a small proportion of isolated thymocytes was surface labeled. In situ, the CGRP conjugates labeled receptors on large thymocytes residing in the outer cortical region of rat thymus pseudolobules. Thus, immunoreactive CGRP is found in subcapsular/perivascular thymic epithelial cells and acts via specific CGRP receptors on thymocytes by raising their intracellular cAMP level. It is suggested that CGRP is a paracrine thymic mediator that might influence the differentiation, maturation, and proliferation of thymocytes.

Energy metabolism in acute hepatic failure

BACKGROUND

Conflicting data are available concerning energy metabolism in liver disease. Changes should be most pronounced in acute hepatic failure in which loss of 85% of liver cell mass is reported. Metabolic rate could be decreased due to impairment in liver mass but may also be increased as a result of systemic-mediator actions. To clarify this issue we studied energy metabolism in acute hepatic failure.

METHODS

Energy metabolism was evaluated by indirect calorimetry in 12 patients with acute liver failure and 22 sex-, age-, and body size-matched healthy individuals. In controls and 5 patients, studies were performed in the postabsorptive state; the remaining 7 patients received glucose at a rate of 8 mumol/kg body weight.min to prevent hypoglycemia.

RESULTS

Resting energy expenditure was increased in acute liver failure compared with healthy controls (5.1 +/- 0.14 kJ.min-1 x 1.73 m-2 vs. 3.97 +/- 0.08 kJ.min-1 x 1.73 m-2; mean +/- SEM; P < 0.001). Respiratory quotient and oxidation rates for major fuels were not different between the total patient-group and controls. In patients without glucose supply, energy derived from fat was higher and from carbohydrate lower than in healthy controls and patients with glucose supply.

CONCLUSIONS

Energy expenditure is increased in acute liver failure. Altered substrate oxidation can be normalized by glucose supply.

Effect of immunoglobulin administration on blood rheology in patients with septic shock

The hemorrheological determinants plasma fibrinogen, plasma viscosity, red cell aggregation, and hematocrit were studied in 11 patients before and 4 and 24 hr after a 15 g immunoglobulin infusion to assess the effect of intravenous immunoglobulin administration on blood rheology in septic shock. Four hr after the immunoglobulin administration, plasma fibrinogen decreased significantly [472 (175-950) vs. 522 (182-1,050) mg/dl before administration; median (range); P < 0.01]; after 24 hr, plasma fibrinogen tended to increase again [501 (185-980); n.s.]. No changes were seen in plasma viscosity, red cell aggregation, hematocrit, and coagulation status 4 and 24 hr after immunoglobulin administration. In patients with septic shock, intravenous immunoglobulin administration leads to a decrease in plasma fibrinogen, whereas plasma viscosity and red cell aggregation remain unaffected. The explanation for the decrease in fibrinogen remains speculative.

Early prediction of individual outcome after cardiopulmonary resuscitation

Prediction of individual outcome after cardiopulmonary resuscitation is of major medical, ethical, and socioeconomic interest but uncertain. We studied the early predictive potency of evoked potential recording after cardiac arrest in 66 resuscitated patients who returned to spontaneous circulation but were unconscious and mechanically ventilated. Detailed long-latency and short-latency sensory evoked potentials were recorded and neurological evaluations were done 4-48 h after admission to intensive care. In all 17 patients with favourable outcome (cerebral performance categories 1 and 2) the cortical evoked potential N70 peak, a reliable measure of cortical function, was detected between 74 and 116 ms. In 49 patients with bad outcome (categories 4 and 5) the N70 peak was absent in 35 or found with a delay between 121 and 171 ms in 14 (p < 0.05 vs favourable outcome). Thus the predictive ability was 100% with cutoff of 118 ms. To confirm reproducibility and validity, repeated tracings, and linked-earlobe referenced techniques were done and gave similar results. Early recording of long-latency evoked potentials after cardiopulmonary resuscitation is highly predictive of outcome.