Was ist ?Schock??

Shock, derived from the French "choc", is defined as a syndrome precipitated by a systemic derangement in perfusion leading to widespread cellular hypoxia and vital organ dysfunction. There is an apparently mismatch of oxygen delivery and oxygen uptake on the cellular level. Shock is associated with significant morbidity and mortality. Therefore, rational therapy should rely on the allocation to one of the four primary circulatory defects: cardiogenic, obstructive, distributive and hypovolemic shock. Compensatory mechanisms such as activation of the sympathoadrenal axis and neurohumoral mechanisms act to preserve cardiac output and perfusion of the vital organ systems. Lactate acidosis serves as a marker of critical hypoperfusion. Persistent hypoperfusion und ischemia induce a systemic inflammatory response syndrome which may lead to multiple organ dysfunction or even multiple organ failure.

QRS prolongation on surface ECG and brain natriuretic peptide as indicators of left ventricular systolic dysfunction

OBJECTIVE

To determine whether the combination of prolonged QRS duration and brain natriuretic peptide (BNP) levels predicts left ventricular systolic dysfunction (LVSD) with a higher accuracy compared with QRS duration or BNP alone.

SETTING

University hospital.

METHODS

We studied 128 consecutive patients with suspected cardiac disease. At rest the QRS duration on 12-lead ECG and BNP levels were determined. A left ventricular ejection fraction (LVEF) <50% at echocardiography was defined as LVSD.

RESULTS

QRS duration in the LVSD group (n = 66, LVEF 30 +/- 8%) was longer than in the group without LVSD (n = 62, LVEF 60 +/- 5%; QRS 129 +/- 34 vs. 96 +/- 20 ms, P < 0.001). BNP was higher in the LVSD group compared with controls (467 +/- 397 vs. 169 +/- 242 pg mL(-1), P < 0.001). A QRS duration of >0.1, >0.11 or >0.12 s was highly specific (63, 90 and 98%) but less sensitive (84, 81 and 75%) for the prediction of LVSD. A QRS cut-off value of 106 ms was moderately sensitive (65%) but very specific (87%) for the prediction of LVSD, whereas a BNP cut-off value of >84 pg mL(-1) was highly sensitive (89%) but only modestly specific (58%). The positive likelihood ratio for LVSD of abnormal BNP (2.0) and QRS prolongation >0.1 s (2.3) was improved by the combination of both criteria (5.1). In multivariate analysis, BNP and QRS duration were independent predictors of LVSD.

CONCLUSIONS

The combination of abnormal BNP and QRS prolongation yields a higher positive likelihood ratio for the detection of LVSD compared with the two criteria alone.

Low-Molecular Weight Heparins in Percutaneous Coronary Interventions: Current Concepts, Problems, and Perspectives

A growing body of evidence suggests that low molecular weight heparin (LMWH) is at least as effective as unfractionated heparin (UFH) in the medical management of acute coronary syndromes (ACS) including acute myocardial infarction. Several studies support an early invasive as compared to a conservative (non-invasive) approach utilizing percutaneous coronary intervention (PCI) in these patients. During coronary angiography and PCI systemic anticoagulation usually administering UFH should prevent thrombus formation at the catheter equipment and at the site of vessel injury. The widespread use of UFH as the anticoagulant of choice is explained by low costs, easy reversibility and accepted anticoagulant properties. However, the clinical support for the use of UFH in PCI is largely based on retrospective and observational data only. Compared to UFH, LMWH have distinct pharmacological advantages, including ease of administration and usually no need for monitoring. A major drawback of LMWH is the predominant renal clearance which may lead to unpredictable levels of anticoagulation in patients with impaired renal function. Since LMWH constitute an extremely heterogeneous group of drugs each LMWH should be recognized as an individual pharmaceutical compound. Consequently, pharmacodynamic and pharmacokinetic properties of one LMWH must not be extrapolated for other LMWH. A growing body of evidence supports the use of LMWH in ACS, with or without GPIIb/IIIa receptor antagonists, thrombolysis, or PCI. Although in patients undergoing PCI, LMWH have yet not been shown to be superior to UFH they can safely be administered.

Patellar hypertension syndrome in adolescence: a three-year follow up

INTRODUCTION

Anterior knee pain is one of the major causes of knee pain in an adolescent population. It has been suggested that raised intraosseous pressure may play an important role in the development of anterior knee pain in the young patient.

MATERIAL AND METHODS

A prospective clinical multicentre study with 27 adolescent patients presenting with anterior knee pain was performed. After failure to respond to conservative treatment, all patients agreed to undergo minimally invasive intraosseous pressure measurements in local anaesthesia. All 27 patients demonstrated a positive "pain provocation test" as a response to increased intrapatellar pressure and were decompressed with a new intraosseous drilling technique.

RESULTS

The repeat intraosseous pressure measurement in 27 patients 1 year postoperatively revealed a significant reduction from 43.3+/-13.4 preoperatively to 24.1+/-4.2 mmHg (p<0.001). The pain relief was documented in the form of a reduced VAS from 7.6+/-1.4 to 2.1+/-1.1 cm after 3 years (p<0.001).

CONCLUSION

Patients with anterior knee pain and a positive "pain provocation test" were diagnosed as suffering from a hypertension syndrome of the patella. We conclude that simple extraarticular patellar decompression may offer a valuable new form of treatment in this select group of adolescent patients with anterior knee pain.

Comparison of oesophageal and gastric air tonometry in patients with circulatory failure

BACKGROUND

Gastric PCO2 measured by balloon tonometry can estimate the adequacy of splanchnic perfusion. However, enteral feeding and gastric content can interfere with gastric PCO2 assessment. Tonometry in other sites of the body could avoid these problems. We therefore tested the hypothesis that oesophageal air tonometry would give results similar to gastric tonometry.

METHODS

We studied 20 consecutive patients (mean age 68 (SD 9) [range 49-81] yr, 18 males, SAPS II score 55 (SD 18), ICU mortality 55%) with circulatory disorders during mechanical ventilation in the intensive care unit. Tonometer probes were placed via the nose, one into the stomach and the other in the oesophagus. PCO2 was measured with two automated gas analysers, at admission and 30 min, 1, 2, 3, 32, 40, and 48 h thereafter.

RESULTS

One hundred and forty-eight paired measurements were obtained. Gastric PCO2 was greater than oesophageal PCO2 on admission (7.19 (1.43) vs 5.89 (0.73) kPa, P < 0.01) and subsequently. Differences between the measures correlated (r = 0.67) with the mean absolute value, indicating that overestimation increased as gastric PCO2 increased.

CONCLUSIONS

Oesophageal PCO2 is less than gastric PCO2, and the difference is greater when gastric PCO2 levels are greater. Air tonometry may not measure regional PCO2 levels in the oesophagus satisfactorily. Other methods and sites for carbon dioxide tonometry should be examined.

Treatment of toxoplasmosis in pregnancy: concentrations of spiramycin and neospiramycin in maternal serum and amniotic fluid

Toxoplasma infection during pregnancy is widely treated with oral spiramycin to reduce the risk of congenital toxoplasmosis in the infant. Failures of therapy have been observed, however. In this study, a sensitive high-performance liquid chromatography technique was used to measure concentrations of spiramycin and neospiramycin, one of the major metabolites of spiramycin, in maternal serum and amniotic fluid. Samples were obtained from 18 women who underwent amniocentesis for polymerase chain reaction (PCR) diagnosis of fetal infection 5-109 days following the prescription of spiramycin therapy (3 g/day). Concentrations of spiramycin and neospiramycin in both serum and amniotic fluid were highly variable, ranging from nondetectable values to 1 microg/ml. None of the concentrations measured were within the range reported to inhibit growth of the parasite in vitro. Consistent with previous reports, part of the observed variability in maternal and fetal drug concentrations could be explained by individual differences in several pharmacokinetic parameters: intestinal absorption, tissue distribution, cellular uptake, metabolism, transfer across the placenta, drug accumulation in fetal tissue, and maternal and fetal drug elimination. The heterogeneity of the data could also be related to differences in patient compliance with the medication prescribed. By addressing factors that could impair adequate treatment of toxoplasmosis during pregnancy, the data presented call for a larger-scale controlled study to determine individual and diurnal variations in maternal drug levels, patient compliance, and outcomes of the offspring. The activity of neospiramycin against Toxoplasma gondii should be assessed.

Intracellular calcium in the isolated rat liver: correlation to glucose release, K(+) balance and bile flow

This study correlates whole organ measurements of intracellular calcium concentration ([Ca(2+)](i)) with hormone-induced (epinephrine, vasopressin) changes of liver functions (glucose release, K(+) balance and bile flow). [Ca(2+)](i) was measured in the isolated perfused rat liver using the sensor Fura-2 and applying liver surface fluorescence spectroscopy. The technique was improved by (i) minimizing biliary elimination of the sensor by employing a rat strain deficient in canalicular organic anion transport (TR(-) mutation) and (ii) by correcting for changes of interfering intrinsic organ fluorescence that was shown to depend on the oxidation-reduction state (NAD(P)H content) of the organ. Epinephrine (50 nM) elicits an instantaneous peak rise of [Ca(2+)](i) to approx. 400 nM, followed by a sustained elevation that depends on the presence of extracellular Ca(2+). The rise of [Ca(2+)](i) coincides with initiation of glucose release, transient K(+) uptake, and transient stimulation of bile flow. Vasopressin (2 nM) exerts qualitatively similar effects. The transient rise of bile flow is attributed to Ca(2+)-mediated contraction of the pericanalicular actin-myosin web of hepatocytes.

Helicobacter sp. flexispira bacteremia in an immunocompetent young adult

A young immunocompetent patient was admitted for a febrile illness with malaise, arthralgias, painful leg swelling, and polyserositis. Shortly prior to becoming ill, the patient had traveled to the Northern African desert. The symptoms disappeared during treatment with antibiotics (doxycycline and ceftriaxone) but recurred twice after stopping therapy. A motile gram-negative fusiform rod was isolated from a blood culture taken on the first admission. Analysis of the 16S rRNA gene of the blood culture isolate revealed close similarity with Helicobacter sp. flexispira taxon 8 (99.9% identity), a species that was previously reported as "Flexispira rappini." This is the first reported case of a recurrent Helicobacter sp. flexispira bacteremia in an adult, immunocompetent patient.

Identification of novel polymorphisms in intron 7 of the human p53 gene in acute myeloid leukemia and healthy donors

Screening for mutations by PCR-SSCP in exons 5 to 9 of the p53 gene in 38 bone marrow or peripheral blood specimens of patients with acute myeloid leukemia (AML) showed abnormal shifts in 9 cases. One reflected a mutation in exon 8, whereas in the other cases there were no exonic mutations identified by sequencing. As PCR primers were chosen annealing in the introns flanking the exon region, following sequencing of the encompassing introns identified 5 base substitutions at various sites in intron 7. Two of them have been described previously [1] and 3 novel polymorphisms could be identified. To determine whether these polymorphisms are linked to the pathogenesis of AML, we screened peripheral blood specimens of 26 healthy controls. We found identical base substitutions in 6 out of 26 controls. Our data suggest that these polymorphisms are not related to the pathogenesis of AML.

Thrombosis in Behcet's disease: report of a case followed by a systematic review using the methodology of evidence-based medicine

BACKGROUND

Behcet's disease (BD) is a rare systemic inflammatory disease of unknown aetiology with a variety of organ manifestations.

METHODS

A case of Behcet's disease complicated by deep vein thrombosis (DVT) and inferior vena cava thrombosis referred to our institution is reported. In addition, a structured literature search using the methodology of evidence-based medicine for the localization of venous lesions, treatment modalities, and outcome of patients with Behcet's disease and concurrent thrombosis was performed. A modified validity score was assigned by established methods.

RESULTS

In total, 214 citations were identified using our search strategy. Among these citations, 10 papers including a total of 32 patients (25 male, 7 female) met the inclusion criteria and were incorporated into this overview together with our patient. All studies consisted of serial case reports without control subjects. Neither localization of venous lesions, nor treatment modalities were homogeneous not allowing general recommendations.

CONCLUSIONS

No data are available from controlled studies regarding treatment modalities of patients presenting with Behcet's disease complicated by concurrent thrombosis. This lack of evidence implicates the need for large scale and co-ordinated registries including data on the acute treatment as well as the prevention of future thrombotic events in this clinical setting. The diagnostic criteria of the "International Study Group for Behcet's Disease" may well serve as a basis for this approach.

CD30-mediated cell cycle arrest associated with induced expression of p21(CIP1/WAF1) in the anaplastic large cell lymphoma cell line Karpas 299

One of the major characteristics of anaplastic large cell lymphomas (ALCL) is the expression of the Ki-1/CD30 antigen. While the receptor mediates NF-kappaB-activation in Hodgkin's lymphomas, some data suggest the CD30-mediated apoptosis of other CD30-expressing cells. We were able to demonstrate that activation of CD30 leads to different effects regarding cell proliferation of the ALCL-derived cell lines Karpas 299 and JB6. Western and Northern blotting analysis revealed that CD30-induced growth inhibition of Karpas 299 cells correlated with a strong upregulation of the cell cycle inhibitor p21(CIP1/WAF1). We found a non activating point mutation at codon 273 in exon 8 of the p53 gene in Karpas 299 cells which indicates an p53-independent mechanism for induced p21 expression. Abundant p21 protein expression resulted in hypophosphorylation of the retinoblastoma protein (Rb) and inhibition of the proliferating cell nuclear antigen (PCNA). CD30-stimulated cells showed no indications of apoptotic cell death, like genomic DNA fragmentation or cleavage of the caspase-3 target protein poly (ADP-ribose) polymerase (PARP). Our results indicate that CD30 is able to mediate an p21-associated cell cycle arrest in ALCL with possible implications for prognosis and clinical treatment.

Ca2+-activated Cl- channels can substitute for CFTR in stimulation of pancreatic duct bicarbonate secretion

This study addresses the mechanisms by which a defect in CFTR impairs pancreatic duct bicarbonate secretion in cystic fibrosis. We used control (PANC-1) and CFTR-deficient (CFPAC-1; DeltaF508 mutation) cell lines and measured HCO3- extrusion by the rate of recovery of intracellular pH after an alkaline load and recorded whole cell membrane currents using patch clamp techniques. 1) In PANC-1 cells, cAMP causes parallel activation of Cl- channels and of HCO3- extrusion by DIDS-sensitive and Na+-independent Cl-/HCO3- exchange, both effects being inhibited by Cl- channel blockers NPPB and glibenclamide. 2) In CFPAC-1 cells, cAMP fails to stimulate Cl-/HCO3- exchange and Cl- channels, except after promoting surface expression of DeltaF508-CFTR by glycerol treatment. Instead, raising intracellular Ca2+ concentration to 1 micromol/l or stimulating purinergic receptors with ATP (10 and 100 micromol/l) leads to parallel activation of Cl- channels and HCO3- extrusion. 3) K+ channel function is required for coupling cAMP- and Ca2+-dependent Cl- channel activation to effective stimulation of Cl-/HCO3- exchange in control and CF cells, respectively. It is concluded that stimulation of pancreatic duct bicarbonate secretion via Cl-/HCO3- exchange is directly correlated to activation of apical membrane Cl- channels. Reduced bicarbonate secretion in cystic fibrosis results from defective cAMP-activated Cl- channels. This defect is partially compensated for by an increased sensitivity of CF cells to purinergic stimulation and by alternative activation of Ca2+-dependent Cl- channels, mechanisms of interest with respect to possible treatment of cystic fibrosis and of related chronic pancreatic diseases.

Ingested blood contributes to the specificity of the symbiosis of Aeromonas veronii biovar sobria and Hirudo medicinalis, the medicinal leech

Hirudo medicinalis, the medicinal leech, usually carries in its digestive tract a pure culture of Aeromonas veronii bv. sobria. Such specificity is unusual for digestive tracts that are normally colonized by a complex microbial consortium. Important questions for the symbiotic interaction and for the medical application after microvascular surgery are whether other bacteria can proliferate or at least persist in the digestive tract of H. medicinalis and what factors contribute to the reported specificity. Using a colonization assay, we were able to compare experimentally the ability of clinical isolates and of a symbiotic strain to colonize H. medicinalis. The symbiotic A. veronii bv. sobria strain proliferated well and persisted for at least 7 days inside the digestive tract. In contrast, the proliferation of Pseudomonas aeruginosa and Staphylococcus aureus was inhibited inside the animal compared to growth in the in vitro control, indicating that the ingested blood was modified within the digestive tract. However, both strains were able to persist in the digestive tract for at least 7 days. For an Escherichia coli strain, the viable counts decreased approximately 1, 000-fold within 42 h. The decrease of viable E. coli could be prevented by interfering with the activation of the membrane-attack complex of the complement system that is present in blood. This suggests that the membrane-attack complex remained active inside H. medicinalis and prevented the proliferation of sensitive bacteria. Thus, antimicrobial properties of the ingested vertebrate blood contribute to the specificity of the A. veronii-H. medicinalis symbiosis, in addition to modifications of the blood inside the digestive tract of H. medicinalis.

Effects of insulin-like growth factor I on basal and stimulated glucose fluxes in rat liver

Effects of insulin-like growth factor I (IGF-I) and insulin on glucose and potassium fluxes were examined by measuring transhepatic glucose and potassium balance in isolated perfused rat livers. At 1 nM, both IGF-I and insulin decreased basal glucose release by approximately 64% (P < 0.05). Adrenaline (epinephrine)-stimulated glucose release (42.6 +/- 4.5 micromol/g of liver within 30 min) was inhibited (P < 0.05) by approximately 32 and approximately 52% during IGF-I and insulin exposure, which was accompanied by reduced cAMP release (-71 and -80%, P < 0.05). IGF-I- and insulin-induced reduction of glucose release only decreased during calcium-free perfusion, but not during inhibition of phosphoinositide 3-kinase by wortmannin. Both IGF-I and insulin induced net potassium uptake, while insulin also attenuated the response to adrenaline. In conclusion, IGF-I causes (i) insulin-like inhibition of hepatic glycogenolysis, even at low, nanomolar concentrations, which is associated with decreased cAMP release, reduced in the absence of Ca(2+), but not mediated by phosphoinositide 3-kinase, (ii) reduction of adrenaline-induced glycogenolysis and (iii) net potassium uptake under basal conditions.

Gastric tonometry in patients with cardiogenic shock and intra-aortic balloon counterpulsation

OBJECTIVE

To study the course of gastric regional PCO2 (PrCO2) in patients with cardiogenic shock requiring intra-aortic balloon (IAB) counterpulsation and the prognostic value of PrCO2 in this patient population.

DESIGN

A prospective, observational clinical study.

SETTING

Medical intensive care unit in a university hospital.

PATIENTS

Twenty-six consecutive patients with cardiogenic shock requiring mechanical support with an IAB counterpulsation undergoing mechanical ventilation

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULT

Hemodynamic variables, tonometric variables, arterial blood gases, and arterial lactate were assessed before insertion of IAB (baseline), and 1, 2, 3, 8, 16, 24, and 48 hrs thereafter. A subset of these patients (n = 14) were studied just before and 1, 8, 24, and 32 hrs after IAB removal; 12/26 patients (46.2%) died. Cardiac index increased from baseline to 1 hr after insertion of IAB (1.7 +/- 0.3 to 2.6 +/- 0.8 L/min/m2, p < .05). PrCO2 did not change between admission (47 +/- 13 torr [6.3 +/- 1.7 kPa]) and 8 hrs after placement of IAB but increased to 63 +/- 22 torr (8.4 +/- 2.9 kPa) at 16 hrs (p < .05) without any further alteration until 48 hrs. CO2 gap showed a similar pattern with 15 +/- 11 torr (2.0 +/- 1.5 kPa) at baseline and an increase to 28 +/- 22 torr (3.7 +/- 2.9 kPa) 16 hrs later. PrCO2 and CO2 gap remained at high levels (59 +/- 11 torr [7.7 +/- 1.5 kPa] and 22 +/- 10 torr [2.9 +/- 1.3 kPa], respectively), before IAB removal without further improvement or deterioration thereafter. PrCO2 values showed no difference between survivors and nonsurvivors at any time point.

CONCLUSION

Patients with cardiogenic shock developed high PrCO2 within the first 24 hrs, which reflects gastric mucosal ischemia. Persistently high levels of PrCO2 were indicative for prolonged hypoperfusion of the gut. Gastric tonometry failed to discriminate between survivors and nonsurvivors.

Computed tomographic angiography findings in 103 patients following vascular events in the posterior circulation: potential and clinical relevance

We studied the diagnostic value of computed tomographic angiography (CTA) in the posterior circulation as a noninvasive substitute for intra-arterial digital subtraction angiography (DSA). We prospectively investigated 103 patients with acute stroke in the posterior circulation. All patients underwent CTA and Doppler ultrasound, and DSA was performed in 22 patients. Vascular findings were classified in categories according to the type of lesion and the location in the vertebral, basilar, or posterior cerebral artery. In the first part of the analysis we examined the correlation between CTA and intra-arterial DSA (n=22), and in the second part that between CTA and Doppler ultrasound (n=103). Intra-arterial DSA identified 11 stenoses, 13 occlusions, and 3 hypoplasias. The correlation between DSA and CTA was best for the basilar artery (all lesions were identified with CTA). Of the 14 lesions detected in the vertebral artery by DSA 13 were also detected by CTA, but the specific type of lesion was identified in only 7 cases. The correlation between CTA and Doppler ultrasound was lower. In conclusion, CTA is thus a reliable method for detecting lesions in the posterior circulation and may replace DSA in many cases. However, particularly in the vertebral artery DSA remains the superior technique.

Lower cardiac troponin T and I results in heparin-plasma than in serum

BACKGROUND

The use of plasma rather than serum for determination of cardiac troponins can improve turnaround time and potentially avoid incomplete serum separation that may produce falsely increased results. We investigated the influence of incomplete serum separation and the effect of heparin-plasma on cardiac troponin concentrations.

METHODS

Serum and heparin-plasma samples were drawn simultaneously from 100 patients (50 patients with acute coronary syndrome and 50 patients after open heart surgery) and measured on three different analytical systems, two for determination of cardiac troponin I (cTnI; Abbott AxSYM and Bayer ACS:Centaur) and one for cardiac troponin T (cTnT; Roche Elecsys cTnT STAT). Serum samples were reanalyzed after a second centrifugation to assess the influence of incomplete serum separation.

RESULTS

Mean results (+/- 95% confidence interval) in heparin-plasma compared with serum were 101% +/- 2% (AxSYM cTnI), 94% +/- 3% (ACS:Centaur cTnI), and 99% +/- 3% (Elecsys cTnT). Differences >20% were seen in 11% of results on the ACS:Centaur, 9% of results on Elecsys cTnT, and 2% of results on the AxSYM. For the Elecsys cTnT assay, the magnitude of the difference between serum and plasma was independent of the absolute concentration and confined to individual samples, and was reversed by treatment with heparinase. A second centrifugation had no effect on serum results by any of the assays.

CONCLUSION

The concentrations of troponins measured in heparin-plasma are markedly lower than in serum in some cases.

Evaluation of the SOFA score: a single-center experience of a medical intensive care unit in 303 consecutive patients with predominantly cardiovascular disorders. Sequential Organ Failure Assessment

OBJECTIVE

To evaluate the use of the Sequential Organ Failure Assessment (SOFA) score, the total maximum SOFA (TMS) score, and a derived variable, the deltaSOFA (TMS score minus total SOFA score on day 1) in medical, cardiovascular patients as a means for describing the incidence and severity of organ dysfunction and the prognostic value regarding outcome.

DESIGN

Prospective, clinical study.

SETTING

Medical intensive care unit in a university hospital.

PATIENTS

A total of 303 consecutive patients were included (216 men, 87 women; mean age 62 +/- 12.6 years; SAPS II 26.2 +/- 12.7). They were evaluated 24 h after admission and thereafter every 24 h until ICU discharge or death between November 1997 and March 1998. Readmissions and patients with an ICU stay shorter than 12 h were excluded.

MAIN OUTCOME MEASURE

Survival status at hospital discharge, incidence of organ dysfunction/failure.

INTERVENTIONS

Collection of clinical and demographic data and raw data for the computation of the SOFA score every 24 h until ICU discharge.

MEASUREMENTS AND MAIN RESULTS

Length of ICU stay was 3.7 +/- 4.7 days. ICU mortality was 8.3% and hospital mortality 14.5%. Nonsurvivors had a higher total SOFA score on day 1 (5.9 +/- 3.7 vs. 1.9 +/- 2.3, p < 0.001) and thereafter until day 8. High SOFA scores for any organ system and increasing number of organ failures (SOFA score > or = 3) were associated with increased mortality. Cardiovascular and neurological systems (day 1) were related to outcome and cardiovascular and respiratory systems, and admission from another ICU to length of ICU stay. TMS score was higher in nonsurvivors (1.76 +/- 2.55 vs. 0.58 +/- 1.39, p < 0.01), and deltaSOFA/total SOFA on day 1 was independently related to outcome. The area under the receiver-operating characteristic curve was 0.86 for TMS, 0.82 for SOFA on day 1, and 0.77 for SAPS II.

CONCLUSIONS

The SOFA, TMS, and deltaSOFA scores provide the clinician with important information on degree and progression of organ dysfunction in medical, cardiovascular patients. On day 1 both SOFA score and TMS score had a better prognostic value than SAPS II score. The model is closely related to outcome and identifies patients who are at increased risk for prolonged ICU stay.

Novel effects of a transposon insertion in the Vibrio fischeri glnD gene: defects in iron uptake and symbiotic persistence in addition to nitrogen utilization

Vibrio fischeri is the sole species colonizing the light-emitting organ of the Hawaiian squid, Euprymna scolopes. Upon entering the nascent light organ of a newly hatched juvenile squid, the bacteria undergo morphological and physiological changes that include the loss of flagellation and the induction of bioluminescence. These and other events reveal a pattern of genetic regulation that is a response to the colonization of host tissue. In this study, we isolated and characterized a glnD:mTn5Cm mutant of V. fischeri. In addition to the predicted defects in the efficiency of nitrogen utilization, this glnD mutant had an unexpected reduction in the ability to produce siderophore and grow under iron-limiting conditions. Although the glnD mutant could colonize juvenile squid normally over the first 24 h, it was subsequently unable to persist in the light organ to the usual extent. This persistence phenotype was more severe if the mutant was pregrown under iron-limiting conditions before inoculation, but could be ameliorated by the presence of excess iron. These results indicate that the ability to respond to iron limitation may be an important requirement in the developing symbiosis. Supplying the glnD gene in trans restored normal efficiency of nitrogen use, iron sequestration and colonization phenotypes to the glnD:mTn5Cm mutant; thus, there appears to be a genetic and/or metabolic linkage between nitrogen sensing, siderophore synthesis and symbiosis competence in V. fischeri that involves the glnD gene.

Ultrastructural findings after intraarticular application of hyaluronan in a canine model of arthropathy

We investigated the effect of intraarticularly applied hyaluronic acid (hyaluronan) on the cartilaginous structure of experimentally induced chondromalacia patellae in dogs. For the induction of chondromalacia, we used the Pond-Nuki technique, which involved severance and resection of the anterior cruciate ligament, as a canine model of arthropathy in 27 foxhounds (three groups of nine animals each). In a pilot study, we evaluated the effect of resection of the anterior cruciate ligament with no therapy. Patellar specimens were retrieved at 3, 6, and 12 weeks postoperatively. Subsequently, we compared a treatment group that received intraarticular injections of hyaluronan with a placebo group that received saline solution. The groups were compared at 3, 6, and 12 weeks postoperatively. Three animals from the treatment and placebo groups received five injections of hyaluronan during one of the 4-week intervals (weeks 3-6, 6-9, or 12-15). Specimens were retrieved 5 weeks after the last injection. In both groups, the uninvolved contralateral knee served as a control. The specimens were taken from the medial and lateral patellar poles. Histological analysis included light microscopy and transmission electron microscopy. The structural and ultrastructural changes were assessed qualitatively and were quantified with use of a modified Mankin score. Our results indicate that chondromalacia patellae may be induced with the Pond-Nuki technique. We found a significant reduction (p < 0.01) of cartilaginous lesions in the hyaluronan group compared with the placebo group. Our results suggest that intraarticularly applied hyaluronan is effective in delaying the degenerative process of cartilage degradation. Therefore, we conclude that the use of hyaluronan may be indicated during the early stages of chondromalacia.

Herbal anti-inflammatory agents for skin disease

Herbs have been used in clinical medicine for thousands of years. However, it is only in recent times that we have been able to employ scientific methods to prove the efficacy of many of these herbs and to give us a better understanding of their mechanisms of action. This article will focus on the use of herbs in various dermatological conditions characterized by inflammation and pruritus. Topical preparations of many of these herbs are more commonplace in Europe. However, their availability is increasing in the US. As this is occurring we are witnessing a growing marriage between alternative and traditional medicines.

A new concept in the treatment of anterior knee pain: patellar hypertension syndrome

This prospective clinical study evaluated 69 patients (136 knees) presenting with anterior knee pain after failure to respond to conservative treatment. All patients agreed to undergo minimally invasive intraosseous pressure measurements of the patella under local anesthesia. Forty patients (50 knees) demonstrated a positive pain provocation test (the typical pain sensation could be reproduced by raising intrapatellar pressure) and were treated with a new method of intraosseous drilling and decompression. Ninety percent of the patients treated experienced pain relief >3 years postoperatively. Repeated intraosseous pressure measurements in 33 knees 1 year postoperatively confirmed objective intraosseous pressure reduction in 88%. Patients with anterior knee pain and a positive pain provocation test were labeled as hypertension syndrome of the patella. These results indicate simple extra-articular patellar decompression may offer a valuable new form of treatment in select patients with anterior knee pain, ie, hypertension syndrome of the patella.

Severe transmyocardial ischemia in a patient with tension pneumothorax

OBJECTIVE

To report tension pneumothorax (TP) as a cause of severe myocardial ischemia.

DESIGN

Clinical case report.

SETTING

Medical intensive care unit of a university hospital.

PATIENTS

One patient with severe shock attributable to right TP after unsuccessful percutaneous central venous catheterization.

INTERVENTIONS

Blood pressure, electrocardiogram (ECG), chest radiograph, and echocardiography during and after shock.

MEASUREMENTS AND MAIN RESULTS

On admission the patient was in profound state of shock (heart rate 140 beats/min, blood pressure 65/30 mm Hg). Twelve-lead ECG showed pronounced ST segment elevation in leads II, III, aVF, and V4-V6. Chest radiograph revealed right TP with complete displacement of the mediastinum and the heart to the left side. Immediate right-sided tube thoracostomy resulted in reexpansion of the lung followed by instantaneous hemodynamic and respiratory improvement as well as nearly complete resolution of the ECG changes. Peak value of the creatine phosphokinase was 4140 U/L without significant elevation of the MB isoenzyme at any time. Moreover, the initial hypokinesia of the posterior and lateral left ventricular wall resolved completely, as demonstrated by echocardiography.

CONCLUSION

The specific condition of TP may lead to impaired systolic and diastolic coronary artery blood flow affecting ventricular repolarization and T-wave configuration in ECG indicative of transmyocardial ischemia. General symptoms, namely hypotension, tachycardia, and hypoxemia, are likewise typical for cardiogenic shock attributable to myocardial infarction. Yet any therapeutic measure directed toward revascularization, such as thrombolysis or even percutaneous transluminal coronary angioplasty, would have had devastating consequences. Therefore, thorough physical examination of our patient was pivotal in disclosing the true origin of profound shock.

In vitro validation of gastric air tonometry using perfluorocarbon FC 43 and 0.9% sodium chloride

Monitoring splanchnic perfusion by means of gastric intramucosal tonometry is carried out using saline, or more recently, air tonometry using the Tonocap. The objective of this study was the validation of the Tonocap in saline and perfluorocarbon FC 43. The two methods underestimated the predefined PCO2 value by an average of 10%, with clinically acceptable precision. Accuracy of the Tonocap improved at high PCO2 values (9.33 and 9.94 kPa), whereas saline tonometry was superior at low PCO2 values (3.99 and 3.75 kPa). The Tonocap provides a fast and reliable estimation of the PCO2, and with the revised software requiring only 10 min of equilibration, will increase the comparability of future studies.

Diverse restriction fragment length polymorphism patterns of the PCR-amplified 16S rRNA genes in Aeromonas veronii strains and possible misidentification of Aeromonas species

Restriction fragment length polymorphism analysis after PCR amplification (RFLP-PCR) of the 16S rRNA gene has been previously proposed as a rapid method to identify Aeromonas species. In the present study, the precision of RFLP-PCR was evaluated with 62 Aeromonas reference strains. The analysis revealed that Aeromonas veronii biovar sobria strains produce various patterns, possibly leading to its misidentification as an environmental species. For most other Aeromonas species little variation was noted. This study supports the usefulness of RFLP-PCR analysis to separate three clinically important species but also reveals possible misidentifications that necessitate further biochemical tests to validate the preliminary identification.

Acute troglitazone action in isolated perfused rat liver

1. The thiazolidinedione compound, troglitazone, enhances insulin action and reduces plasma glucose concentrations when administered chronically to type 2 diabetic patients. 2. To analyse to what extent thiazolidinediones interfere with liver function, we examined the acute actions of troglitazone (0.61 and 3.15 microM) on hepatic glucose and lactate fluxes, bile secretion, and portal pressure under basal, insulin- and/or glucagon-stimulated conditions in isolated perfused rat livers. 3. During BSA-free perfusion, high dose troglitazone increased basal (P < 0.01), but inhibited glucagon-stimulated incremental glucose production by approximately 75% (10.0 +/- 2.5 vs control: 40.0 +/- 7.2 micromol g liver(-1), P < 0.01). In parallel, incremental lactate release rose approximately 6 fold (13.1 +/- 5.9 vs control: 2.2 +/- 0.8 mmol g liver(-1), P < 0.05), while bile secretion declined by approximately 67% [0.23 +/- 0.02 vs control: 0.70 +/- 0.05 mg g liver(-1) min(-1)), P < 0.001]. Low dose troglitazone infusion did not enhance the inhibitory effect of insulin on glucagon-stimulated glucose production, but rapidly increased lactate release (P < 0.0005) and portal venous pressure (+0.17 +/- 0.07 vs +0.54 +/- 0.07 cm buffer height, P < 0.0001). 4. These results indicate that troglitazone exerts both insulin-like and non-insulin-like hepatic effects, which are blunted by addition of albumin, possibly due to troglitazone binding.

Symbiosis of Aeromonas veronii biovar sobria and Hirudo medicinalis, the medicinal leech: a novel model for digestive tract associations

Hirudo medicinalis, the medicinal leech, is applied postoperatively in modern medicine. Infections by Aeromonas occur in up to 20% of patients unless a preemptive antibiotic treatment is administered. The associated infections demonstrate the need for a better understanding of the digestive tract flora of H. medicinalis. Early studies reported the presence of a single bacterial species in the digestive tract and suggested that these bacteria were endosymbionts contributing to the digestion of blood. In this study, we cultivated bacteria from the digestive tract and characterized them biochemically. The biochemical test results identified the isolates as Aeromonas veronii biovar sobria. This species identification was supported by sequence comparison of a variable region of the genes coding for 16S rRNA. In a colonization assay, a rifampin-resistant derivative of a symbiotic isolate was fed in a blood meal to H. medicinalis. The strain colonized the digestive tract rapidly and reached a concentration similar to that of the native bacterial flora. For the first 12 h, the in vivo doubling time was 1.2 h at 23 degreesC. After 12 h, at a density of 5 x 10(7) CFU/ml, the increase in viable counts ceased, suggesting a dramatic reduction in the bacterial growth rate. Two human fecal isolates, identified as Aeromonas hydrophila and A. veronii biovar sobria, were also able to colonize the digestive tract. These data demonstrate that the main culturable bacterium in the crop of H. medicinalis is A. veronii biovar sobria and that the medicinal leech can be used as a model for digestive tract association of Aeromonas species.

Three-dimensional echocardiographic determination of left ventricular volumes and function by multiplane transesophageal transducer: dynamic in vitro validation and in vivo comparison with angiography and thermodilution

The goal of this study was to validate 3-dimensional echocardiography by multiplane transesophageal transducer for the determination of left ventricular volumes and ejection fraction in an in vitro experiment and to compare the method in vivo with biplane angiography and the continuous thermodilution method. In the dynamic in vitro experiment, we scanned rubber balloons in a water tank by using a pulsatile flow model. Twenty-nine measurements of volumes and ejection fractions were performed at increasing heart rates. Three-dimensional echocardiography showed a very high accuracy for volume measurements and ejection fraction calculation (correlation coefficient, standard error of estimate, and mean difference for end-diastolic volume 0.998, 2.3 mL, and 0.1 mL; for end-systolic volume 0.996, 2.7 mL, and 0.5 mL; and for ejection fraction 0.995, 1.0%, and -0.4%, respectively). However, with increasing heart rate there was progressive underestimation of ejection fraction calculation (percent error for heart rate below and above 100 bpm 0.59% and -8.6%, P < .001). In the in vivo study, left ventricular volumes and ejection fraction of 24 patients with symmetric and distorted left ventricular shape were compared with angiography results. There was good agreement for the subgroup of patients with normal left ventricular shape (mean difference +/-95% confidence interval for end-diastolic volume 5.2+/-6.7 mL, P < .05; for end-systolic volume -0.5+/-8.4 mL, P = not significant; for ejection fraction 2.4%+/-7.2%, P = not significant) and significantly more variability in the patients with left ventricular aneurysms (end-diastolic volume 23.1+/-56.4 mL, P < .01; end-systolic volume 5.6+/-41.0 mL, P = not significant; ejection fraction 4.9%+/-16.0%, P < .05). Additionally, in 20 critically ill, ventilated patients, stroke volume and cardiac output measurements were compared with measurement from continuous thermodilution. Stroke volume as well as cardiac output correlated well to thermodilution (r = 0.89 and 0.84, respectively, P < .001), although both parameters were significantly underestimated by 3-dimensional echocardiography (mean difference +/-95% confidence interval = -6.4+/-16.0 mL and -0.6+/-1.6 L/min, respectively, P < .005).

Gastric tonometry: in vivo comparison of saline and air tonometry in patients with cardiogenic shock

Measurement of gastric intramucosal pH (pHi) has been advocated to assess gastric perfusion. Regional PCO2 (rPCO2) values are measured using saline tonometry (rsPCO2) and more recently using air tonometry (raPCO2). We compared 237 measurements of saline and air tonometry in 19 consecutive, severely ill patients (mean age 59 (range 31-76) yr, 19 males, APACHE II 22 +/- 7) with cardiogenic shock. Equilibration period was set to 90 min. Nineteen independent paired samples of mean raPCO2 and mean rsPCO2 of each patient showed good correlation (r = 0.93, P < 0.001). Mean raPCO2 was 6.5 (1.8) kPa and mean rsPCO2 6.8 (2.4) kPa. PCO2 measured by saline was significantly higher than that measured by air (P < 0.05). Bland and Altman analysis showed a bias (mean rsPCO2-mean raPCO2) of 0.3 kPa and a precision of 1.2 kPa. Agreement between the two methods decreased with increasing rPCO2 concentrations. Although air tonometry of rPCO2 is a promising technique, a systematic disagreement with saline tonometry at high rPCO2 values requires further investigation and cautious interpretation of these values.

Electrogenicity of hepatocellular fatty acid uptake

Sensitivity of cellular fatty acids uptake to the membrane potential difference is still a matter of controversy. For direct evaluation of potential sensitivity the effect of changing membrane potential on uptake of a fluorescent long chain fatty acid derivative, 12-NBD-stearate, in isolated rat hepatocytes, was examined. Changes in membrane potential were achieved by patch clamp procedures. Fatty acid influx was simultaneously determined by recording of cell fluorescence. Hyperpolarization from -30 to -70 mV accelerated fatty acid influx whereas depolarization to +50 mV reduced uptake. After obtaining equilibrium hyperpolarization increased cell fluorescence, whereas depolarization pushed NBD-stearate out of cells. Potential sensitivity of uptake was dependent on the fatty acid concentrations in the medium with most prominent effects at low unbound concentrations. These data show that, at low fatty acid concentrations, uptake is, in part, driven by an intracellular negative electric membrane potential.

[Effectiveness of intra-articular application of hyaluronic acid on early forms of femoropatellar arthrosis--an experimental study in dogs]

PURPOSE

We investigated the effects of intraarticularly applied hyaluronic acid on the cartilage-integrity with early-forms of retropatellar cartilage degeneration (chondromalacia patellae) in dogs.

METHODS

We used the Pond-Nuki model (tenotomy and resection of the anterior cruciate ligament = ACL) in 27 dogs (foxhounds) (3 groups of 9 animals) PILOT STUDY: ACL-tenotomy and resection, no therapy, specimens retrieval after 3, 6, 12 weeks (3 animals each period). VERUM: ACL-tenotomy and resection, hyaluronic acid (start after 3, 6, 12 weeks), 5 injections in 4 weeks, specimens retrieval after 5 weeks following final injection (12, 15, 21 weeks postoperatively, 3 dogs each period). PLACEBO: same procedure as verum, but saline-injections. Specimens were taken from the medial/lateral patellar pole from both, the operated and the normal knee and examined histologically using various staining methods (HE, Azan, Toluidin, Masson-Goldner, Safranin-O). A modified Mankin score was used to grade cartilage degeneration.

RESULTS

Our results demonstrate that the Pond-Nuki model is suitable to experimentally induce chondromalacia patellae. There were significantly less degenerative cartilage changes in the knees treated with hyaluronic acid compared to the placebo-group.

CONCLUSION

Our results let assume that hyaluronic acid could be indicated i.e. after arthroscopically diagnosed early cartilage-degeneration, the final conclusions concerning the actual mechanisms and therapeutical effectiveness need however further prospective clinical and experimental investigations.

Metabolism of the anticancer drug flavopiridol, a new inhibitor of cyclin dependent kinases, in rat liver

Flavopiridol (FLAP) is a promising novel chemotherapeutic agent currently undergoing clinical phase I trials. To examine hepatic metabolism and biliary disposition of FLAP we applied the isolated perfused rat liver system. Besides FLAP two metabolites were detected by high performance liquid chromatography in bile and perfusate. Twenty-five min after FLAP (30 microM) addition to the perfusion medium, biliary secretion of metabolite 1 and 2 reached a maximum of 1.04 +/- 0.52 and 11.34 +/- 4.72 nmol/g.liver.min, respectively. Biliary excretion of parent FLAP, however, continuously increased for 60 min up to 406 +/- 134 pmol/g liver.min. In the perfusate, metabolite 1 was below detection limit and release of metabolite 2 was low (2.8 +/- 0.7 pmol/g liver.min after 60 min). Enzymatic hydrolysis with beta-glucuronidase, mass spectroscopy and electron absorption spectroscopy revealed that both metabolites are monoglucuronides with the glucuronide in position 5 and 7 of the flavonoid core, respectively. The amount of FLAP, metabolite 1 and metabolite 2 excreted into bile during the 60 min of perfusion was 1.94 +/- 0.91, 5.15 +/- 1.95 and 57.29 +/- 23.60% of FLAP cleared from the perfusate during 60 min, respectively. In contrast to the structurally similar flavonoids genistein and daidzein, no inhibition of UDP-glucuronyltransferase with methylumbelliferone as a substrate was observed indicating that different UDP-glucuronyltransferase isoforms are involved in FLAP metabolism. In conclusion, we find that glucuronidation is the major mechanism of hepatic FLAP biotransformation. Metabolites are mainly excreted into bile but also released into systemic circulation. The pharmacological and toxicological effects of these metabolites remain to be elucidated.

Hot spices influence permeability of human intestinal epithelial monolayers

Indirect evidence suggests that hot spices may interact with epithelial cells of the gastrointestinal tract to modulate their transport properties. Using HCT-8 cells, a cell line from a human ileocoecal carcinoma, we studied the effects of spices on transepithelial electrical resistance (TER), permeability for fluorescein isothiocyanate (FITC)-labeled dextrans with graded molecular weight, and morphological alterations of tight junctions by immunofluorescence using an anti-ZO-1 antibody, a marker for tight junction integrity. Two different reactivity patterns were observed: paprika and cayenne pepper significantly decreased the TER and increased permeability for 10-, 20- and 40-kDa dextrans but not for -70 kDa dextrans. Simultaneously, tight junctions exhibited a discontinuous pattern. Applying extracts from black or green pepper, bay leaf or nutmeg increased the TER and macromolecular permeability remained low. Immunofluorescence ZO-1 staining was preserved. In accordance with the above findings, capsaicin transiently reduced resistance and piperine increased resistance, making them candidates for causing the effects seen with crude spice extracts. The observation that Solanaceae spices (paprika, cayenne pepper) increase permeability for ions and macromolecules might be of pathophysiological importance, particularly with respect to food allergy and intolerance.

Host-derived amino acids support the proliferation of symbiotic bacteria

Animals are typically colonized by diverse bacterial symbionts, many of which are commensal and, in numerous cases, even essential for their host's proper development and growth. In exchange, the host must supply a sufficient array and quantity of nutrients to support the proliferation and persistence of its microbial community. In this investigation, we have examined such a nutritional environment by determining the symbiotic competence of auxotrophic mutants of the bioluminescent bacterium Vibrio fischeri, and have demonstrated that the host squid Euprymna scolopes provides at least 9 aa to the growing culture of symbiotic V. fischeri present in its light-emitting organ. We also collected and analyzed the extracellular fluid from this organ, in which the symbionts reside, and confirmed that it contained significant amounts of amino acids. The combined results suggested that host-derived free amino acids, as well as peptides or proteins, are a source of the amino acids that support the growth of the symbionts. This work describes a technique to sample the symbionts and their surrounding environment without contamination by host tissue components and, in combination with molecular genetic studies, allows the characterization of the nutritional conditions that support a cooperative animal-bacterial symbiosis.

Vitamin D increases tight-junction conductance and paracellular Ca2+ transport in Caco-2 cell cultures

We investigated the effects of 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] on paracellular intestinal Ca2+ absorption by determination of transepithelial electric resistance (TEER), as a measure of tight-junction ion permeability and bidirectional transepithelial 45Ca2+ fluxes in confluent Caco-2 cell cultures. The rise of TEER to steady-state levels of approximately 2,000 omega.cm2 was significantly attenuated by 1,25(OH)2D3 (by up to 50%) in a dose-dependent fashion between 10(-11) and 10(-8) M. Synthetic analogs of 1,25(OH)2D3, namely, 1 alpha,25-dihydroxy-16-ene,23-yne-vitamin D3 and 1 alpha,25-dihydroxy-26,27-hexafluoro-16-ene,23-yne-vitamin D3, exhibited similar biopotency, whereas their genomically inactive 1-deoxy congeners were only marginally effective. Enhancement of transepithelial conductance of Caco-2 cell monolayers by vitamin D was accompanied by a significant increase in bidirectional transepithelial 45Ca2+ fluxes. Although 1,25(OH)2D3 also induced cellular 45Ca2+ uptake from the apical aspect of Caco-2 cell layers and upregulated the expression of calbindin-9kDa mRNA, no significant contribution of the Ca(2+)-adenosinetriphosphatase-mediated transcellular pathway to transepithelial Ca2+ transport could be detected. Therefore stimulation of Ca2+ fluxes across confluent Caco-2 cells very likely results from a genomic effect of vitamin D sterols on assembly and permeability of tight-junctional complexes.

Regulation of ion channels in rat hepatocytes

Patch-clamp studies have been performed to elucidate single ion channels in rat hepatocytes. In rat hepatocytes two types of ion channel have been identified: an inwardly rectifying K+ channel with a mean inward conductance of 55 +/- 6.5 pS (n = 20) and a mean outward conductance of 25 +/- 3.2 pS (n = 20) in the inside-out configuration with 145 mmol/l KCl on either side of the patch as well as an outwardly rectifying Cl- channel with a mean outward conductance of 30 +/- 4.5 pS (n = 8) and a mean inward conductance of 10 +/- 2.3 pS (n = 6) in the inside-out configuration with symmetrical 145 mmol/l KCl. The open probability of these channels is virtually insensitive to Ca2+ activity on the intracellular side. Accordingly, the Ca2+ ionophore ionomycin had no effect on cell membrane potential. Dibutyryl-cAMP (db-cAMP) hyperpolarizes the cell membrane and increases the activity of the 55-pS inwardly rectifying K+ channel by reducing the duration of closure between bursts. Forskolin similarly hyperpolarizes the cell membrane. The inwardly rectifying K+ channel is inhibited by progesterone, while the outwardly rectifying Cl- channel is insensitive to progesterone.

Muscular involvement in the Holt-Oram syndrome

Holt-Oram syndrome is an autosomal dominant disorder characterised by radial ray and congenital heart defects. Recently, a gene for this disorder has been identified on chromosome 12q24.1, encoding a T box transcription factor. However, the functional role of the gene product is not completely understood. We present results of neurological, radiological, and muscle magnetic resonance imaging (MRI) investigations in 13 patients from eight unrelated families. Besides heart defects, clinical signs ranged from thenar abnormalities to bilateral phocomelia. The former were present in all patients. MRI showed hypoplasia of discrete muscles which clinically showed as non-progressive weakness. The structural pattern of residual muscles was normal on MRI, which together with normal muscular power, electromyography, and muscle enzyme investigations excluded a progressive neuromuscular disorder. The number and location of hypoplastic muscles correlated with the severity of skeletal involvement. Thus, patients with hypoplasia of large and proximal muscles had phocomelia, and those with mere intrinsic hand muscle hypoplasia had only a triphalangeal thumb or no skeletal malformation. On the basis of these observations, we conclude that disturbed fetal limb muscle development is involved in the bony malformations of the upper limbs.

Modulation of liver canalicular transport processes by the tyrosine-kinase inhibitor genistein: implications of genistein metabolism in the rat

Rat liver cells express the multispecific organic anion transporter (cmoat, cmrp, mrp2) and P-glycoprotein (Pgp) in their canalicular membranes, proteins that are homologous to the multidrug-resistance related protein (MRP) and multidrug resistance (MDR) gene products in multidrug resistant tumor cells. We tested whether genistein, a modulator of drug resistance in tumor cells, affects biliary secretion of substrates of canalicular multispecific organic anion transporter (cmoat) (glucuronides of bilirubin and rhodamine, glutathione conjugate of bromsulphthalein) and of P-glycoprotein (Pgp) (rhodamine), respectively. Using the isolated perfused rat liver of control Wistar rats (TR+) and of a mutant strain (TR-) that expresses Pgp but not cmoat, we show that genistein effectively inhibits the secretion of anionic substrates of cmoat in Wistar rats but stimulates secretion of cationic rhodamine in TR- rats. Genistein is subject to glucuronidation and sulfatation and secretion of genistein and its metabolites stimulates bile flow in Wistar rats, but secretion is nearly absent in TR- rats. Because genistein and its metabolites are substrates for cmoat, inhibition of anion secretion by genistein is partially explained by competition for this transporter. Genistein is also a substrate of uridindiphosphate (UDP)-glucuronyltransferase isoenzyme(s). Inhibition of glucuronidation reduces the availability of bilirubin and rhodamine glucuronates for transport via cmoat, but unconjugated cationic rhodamine becomes available for transport via Pgp at an increased cellular concentration. Daidzein, a genistein analogue with no effect on protein tyrosine kinase (PTK) shows Similar effects on secretion of organic anions and cations supporting the conclusion that genistein affects transport in liver mainly through competition with other substrates at the sites of glucuronidation and transport via cmoat.