Early Versus Standard Initiation of Terlipressin for Acute Kidney Injury in ACLF: A Randomized Controlled Trial (eTerli Study)

BACKGROUND AND AIMS

Terlipressin infusion is effective in hepatorenal syndrome (HRS-AKI). However, its efficacy for HRS-AKI resolution in acute-on-chronic liver failure (ACLF) patients has been suboptimal. Progression of AKI is rapid in ACLF. We investigated whether early initiation of terlipressin(eTerli) can improve response rates.

METHODS

Consecutive ACLF patients with stage II/III AKI despite albumin resuscitation (40 g) were randomized to receive terlipressin at 2 mg/24 h plus albumin at 12 h (ET, n = 35) or at 48 h as standard therapy (ST, n = 35). (June 22, 2020 to June 10, 2022). The primary end-point was AKI reversal by day7.

RESULTS

Baseline parameters including AKI stage and ACLF-AARC scores in two arms were comparable. Full AKI response at day 7 was higher in ET [24/35 (68.6%)] than ST arm [11/35 (31.4%; P 0.03]. Day3 AKI response was also higher in ET arm [11/35 (31.4%) vs. 4/35 (11.4%), P 0.04]. Using ST compared to ET [HR 4.3; P 0.026] and day 3 serum creatinine > 1.6 mg/dl [HR 9.1; AUROC-0.866; P < 0.001] predicted HRS-AKI non-response at day 7. ET patients showed greater improvement in ACLF grade, mean arterial pressure, and urine output at day 3, and required lower albumin within 7 days than ET arm (149.1 ± 41.8 g vs. 177.5 ± 40.3 g, P 0.006) and had lower 28-day mortality: 40% vs. 65.7%, P 0.031]. Early use of terlipressin than ST [HR 2.079; P 0.038], baseline HE [HR 2.929; P 0.018], and AKI persistence at day 3 [HR 1.369; P 0.011] predicted 28-day mortality. Fifteen (21.4%) patients had treatment related adverse effects, none was life threatening.

CONCLUSION

In ACLF patients, early initiation of terlipressin for AKI persisting after 12 h of volume expansion with albumin helps in reduced short-term mortality and early AKI reversal with regression of ACLF stage. These results indicate need for change in current practice for terlipressin usage in HRS-AKI.

Tolerance of standard dose albumin infused over 6 hrs for treatment of spontaneous bacterial peritonitis-A randomized controlled trial

BACKGROUND AND AIMS

Twenty per cent albumin (1.5 g/kg at diagnosis and 1 g/kg on day three, infused over six-hour duration) is recommended particularly in high-risk spontaneous bacterial peritonitis (SBP). Whether reduced dose albumin infusion is as effective as the standard dose albumin infusion is not clear. The aim of this study was to compare standard dose albumin infusion with reduced dose albumin infusion in acute kidney injury (AKI) development or progression in patients with cirrhosis and high-risk SBP.

METHODS

Sixty-three patients were randomized to the standard dose albumin arm (n = 31) and reduced dose albumin arm (n = 32, 0.75 g/kg at diagnosis and 0.5 g/kg 48 h later). The albumin was infused over six-hour duration in both groups. When the patient developed respiratory distress, the albumin infusion was stopped and that dose (i.e. of day one or day three) was not restarted and no attempt was made to finish the whole dose of that day. However, the next dose was started at the pre-calculated infusion rate if there was no evidence of respiratory distress at the start of next infusion.

RESULTS

All 31 patients in standard dose and two (6.25%) in the reduced dose group developed symptomatic circulatory overload (p < 0.001), with infusions being stopped prematurely. The actual albumin dose received on day one was similar in both groups and only slightly higher in the standard dose group on day three. Resolution of SBP, progression of AKI to higher stage, in-hospital mortality and 28 days' mortality were similar in both groups.

CONCLUSIONS

For treatment of SBP, standard dose albumin infusion (1.5 g/kg at diagnosis and 1 g/kg 48 hours later) infused over six hours is not tolerated by Indian patients. The effectiveness of standard dose albumin infused over more prolonged periods, as compared to reduced dose albumin, should be evaluated in further studies.

TRIAL REGISTRATION

Clinical Trials.gov Identifier: NCT04273373 .

Podoplanin-positive dilated lymphatic vessels in duodenum associates with three-month mortality in patients with cirrhosis

Dilated and dysfunctional gut lymphatic vessels (LVs) have been reported in experimental cirrhosis. Here, we studied LVs in duodenal (D2)-biopsies of liver cirrhosis patients and investigated the prognostic role of a LV marker, podoplanin (PDPN), in predicting the mortality of patients with cirrhosis. A prospective, single-center cohort study was performed in liver cirrhosis patients (n = 31) and matched healthy controls (n = 9). D2-biopsies were obtained during endoscopy procedure, immunostained with PDPN, and scored based on 1) intensity and 2) density of positively-stained LVs per high power field. Gut and systemic inflammation were estimated by quantifying duodenal CD3⁺ intraepithelial lymphocytes (IELs), CD68⁺ macrophages, and serum TNF-α and IL-6 levels, respectively. Gut permeability and inflammation as assessed by quantifying gene expression of TJP1, OCLN, TNF-α, and IL-6 in D2-biopsies. Gene expression of LV markers, PDPN (8-fold), and LYVE1 (3-fold) was enhanced in D2-biopsies of cirrhosis patients compared to control (p < 0.0001). The mean PDPN score in decompensated cirrhosis patients (6.91 ± 1.26, p < 0.0001) was significantly increased as compared to those with compensated (3.25 ± 1.60). PDPN score positively and significantly correlated with the number of IELs (r = 0.33), serum TNF-α (r = 0.35), and IL-6 (r = 0.48) levels, while inversely correlated with TJP1 expression (r = -0.46, p < 0.05 each). In Cox regression, the PDPN score was a significant and independent 3-month-mortality predictor in patients (HR: 5.61; 1.08-29.109; p = 0.04). The area under the curve for the PDPN score was 84.2, and cutoff value for predicting mortality was ≥6.5 with 100% sensitivity and 75% specificity. Collectively, dilated LVs with high PDPN expression in D2-biopsies is a characteristic feature of patients with decompensated cirrhosis. PDPN score correlates with enhanced gut and systemic inflammation and also associates with 3-month mortality in cirrhosis.

Erectile Dysfunction in Cirrhosis: Its Prevalence and Risk Factors

Background

Erectile dysfunction (ED) is common in men with cirrhosis. The aim of this study was to assess the prevalence of ED and the factors associated with ED in men with cirrhosis.

Methods

400 men with cirrhosis [Child-Turcotte-Pugh (CTP) class A, 44.0%; CTP class B, 41.0%; and CTP class C, 15.0%] having high Karnofsky performance score, and living in a stable monogamous relationship with a female partner were included in the study. International Index of Erectile Function (IIEF) questionnaire, and Short-Form (36) Health Survey (SF-36) were used to assess erectile function and the health-related quality of life (HRQOL), respectively.

Results

ED was found in 289 (72.3%) patients. Patients with ED reported significantly lower SF-36 scores across all the eight domains of SF-36 (i.e., physical functioning score, role physical score, bodily pain score, general health perception score, vitality score, social functioning score, role emotional score, and mental health score); physical component summary score, and mental physical component summary score, compared with those without ED. On multivariate analysis, factors associated with ED were older age, longer duration of cirrhosis, CTP-C (vs. CTP-A), higher hepatic venous pressure gradient (HVPG), presence of generalized anxiety disorder (GAD), presence of major depression, and lower appendicular skeletal muscle index measured by dual-energy X-ray absorptiometry (DEXA ASMI).

Conclusion

ED is common in men with cirrhosis, and men with ED have poor HRQOL compared with those without ED. Older age, longer duration of cirrhosis, CTP-C (vs. CTP-A), higher HVPG, presence of GAD, presence of major depression, and lower DEXA ASMI are associated with ED.

Granulocyte-Macrophage Colony-Stimulating Factor Modulates Myeloid-Derived Suppressor Cells and Treg Activity in Decompensated Cirrhotic Patients With Sepsis

Background

Decompensated cirrhosis patients are more prone to bacterial infections. Myeloid-derived suppressor cells (MDSCs) expand in sepsis patients and disrupt immune cell functions. Granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy helps in restoring immune cell functions and resolving infections. Its role in MDSC modulation in cirrhosis with sepsis is not well understood.

Methods

A total of 164 decompensated cirrhotic—62 without (w/o), 72 with sepsis, and 30 with sepsis treated with GM-CSF—and 15 healthy were studied. High-dimensional flow cytometry was performed to analyze MDSCs, monocytes, neutrophils, CD4 T cells, and Tregs at admission and on days 3 and day 7. Ex vivo co-cultured MDSCs with T cells were assessed for proliferation and apoptosis of T cells and differentiation to Tregs. Plasma factors and mRNA levels were analyzed by cytokine-bead assay and qRT-PCR.

Results

Frequencies of MDSCs and Tregs were significantly increased (p = 0.011 and p = 0.02) with decreased CD4 T cells (p = 0.01) in sepsis than w/o sepsis and healthy controls (HCs) (p = 0.000, p = 0.07, and p = 0.01) at day 0 and day 7. In sepsis patients, MDSCs had increased IL-10, Arg1, and iNOS mRNA levels (p = 0.016, p = 0.043, and p = 0.045). Ex vivo co-cultured MDSCs with T cells drove T-cell apoptosis (p = 0.03, p = 0.03) with decreased T-cell proliferation and enhanced FOXP3⁺ expression (p = 0.044 and p = 0.043) in sepsis compared to w/o sepsis at day 0. Moreover, blocking the MDSCs with inhibitors suppressed FOXP3 expression. GM-CSF treatment in sepsis patients significantly decreased MDSCs and FOXP3⁺ Tregs but increased CD4 T-cell functionality and improved survival.

Conclusion

MDSCs have an immunosuppressive function by expanding FOXP3⁺ Tregs and inhibiting CD4⁺ T-cell proliferation in sepsis. GM-CSF treatment suppressed MDSCs, improved T-cell functionality, and reduced Tregs in circulation.

Tadalafil improves erectile dysfunction and quality of life in men with cirrhosis: a randomized double blind placebo controlled trial

BACKGROUND AND AIMS

Patients with cirrhosis have high prevalence of erectile dysfunction (ED). The aim of this study was to study the efficacy and safety of tadalafil for ED in patients with cirrhosis.

METHODS

140 cirrhotic males with ED were randomized into tadalafil 10 mg daily (n = 70) or placebo (n = 70) for 12 weeks. ED was diagnosed if erectile function (EF) domain score was < 25 in International Index of Erectile Function (IIEF) questionnaire. The erectile function domain consists of six questions concerning erection frequency, erection firmness, frequency of partner penetration, frequency of maintaining erection after penetration, ability to maintain erection to completion of intercourse and confidence in achieving and maintaining erection. Primary outcome was proportion of patients having an increase in > 5 points in EF domain of the IIEF. Generalized Anxiety Disorder 7 (GAD-7) questionnaire was used for screening and severity measuring of GAD. The presence of depression was screened using the Patient Health Questionnaire (PHQ-9) and the assessment of health related quality of life was done using the Short Form (36) Health Survey.

RESULTS

At the end of 12 weeks, more patients in tadalafil group achieved > 5 points increase in the EF domain of the IIEF when compared with the placebo group [44(62.9%) vs. 21(30%), p < 0.001]. At the end of 12 weeks, patients receiving tadalafil had significantly more change in scores on the erectile function domain, orgasmic function domain, intercourse satisfaction domain, overall satisfaction domain, erection vaginal penetration rates and successful intercourse; significantly more decline in the GAD-7 and PHQ-9 scores; significantly more improvement in scores of five of the eight domains of SF-36 (general health perception, vitality score, social functioning, role emotional and mental health) and the mental component summary rates when compared with placebo. The development of side effects and the changes in HVPG were not significantly different between the two groups.

CONCLUSIONS

Tadalafil therapy may enhance erectile function, improve anxiety, depression and quality of life; and is well tolerated by men with cirrhosis (CTP score < 10) and ED. However, further larger and long-term studies are needed to confirm these results and look for rarer side effects of using tadalafil in patients with cirrhosis.

TRIAL REGISTRATION

ClinicalTrials.gov identifier number NCT03566914; first posted date: June 25, 2018.

Tracheostomy in critically ill liver disease patients with coagulopathy: A retrospective study at a tertiary center

Introduction

Critically ill patients with liver disease commonly present to the intensive care unit (ICU) with need for prolonged ventilation, difficult weaning, and refractory coagulopathy. These patients experience both bleeding and thrombotic complications with a precariously balanced state of coagulopathy. The purpose of this study was to assess the bleeding complications of tracheostomy in critically ill patients with liver disease.

Methods

A retrospective study was conducted in liver ICU of a tertiary teaching institute. Medical records were analyzed to assess postprocedure complication rate among 73 critically ill liver disease patients who had undergone tracheostomy during the period of October 2017 to September 2018.

Results

Ten out of 73 patients (13%) required transfusion of blood products after 12 h of procedure, despite thromboelastography (TEG)-based correction prior to procedure. Of these, 7 patients (9%) underwent surgical tracheostomy (ST) and three patients (4%) underwent percutaneous tracheostomy. Statistically no significant difference in bleeding was seen among the two groups, but a rising trend was seen with the ST group (P = 0.52). None of the patients experienced procedure-related pneumothorax and subcutaneous emphysema, as observed in the chest X-ray.

Conclusion

We conclude that coagulopathy should not be deterrence for the performance of tracheostomy in critically ill patients with liver disease. Adequate clotting support guided by the global tests of coagulation, such as TEG, ensures lesser incidence of bleeding.

Terlipressin Is Superior to Noradrenaline in the Management of Acute Kidney Injury in Acute on Chronic Liver Failure

Hepatorenal syndrome (HRS) carries a high short-term mortality in patients with cirrhosis and acute on chronic liver failure (ACLF). Terlipressin and noradrenaline are routinely used in cirrhosis with HRS and have been found to be equally effective. There are no data comparing the efficacy of terlipressin with noradrenaline in ACLF patients with HRS. In an open-label, randomized controlled trial (RCT), consecutive patients with ACLF diagnosed with HRS acute kidney injury (AKI) were randomized to albumin with infusion of terlipressin (2-12 mg/day; n = 60) or noradrenaline (0.5-3.0 mg/h; n = 60). Response to treatment, course of AKI, and outcome were studied. Baseline characteristics, including AKI stage and sepsis-related HRS-AKI, were comparable between groups. Compared to noradrenaline, terlipressin achieved greater day 4 (26.1% vs. 11.7%; P = 0.03) and day 7 (41.7% vs. 20%; P = 0.01) response. Reversal of HRS was also better with terlipressin (40% vs. 16.7%; P = 0.004), with a significant reduction in the requirement of renal replacement therapy (RRT; 56.6% vs. 80%; P = 0.006) and improved 28-day survival (48.3% vs. 20%; P = 0.001). Adverse events limiting use of drugs were higher with terlipressin than noradrenaline (23.3% vs. 8.3%; P = 0.02), but were reversible. On multivariate analysis, high Model for End-Stage Liver Disease (MELD; odds ratio [OR], 1.10; confidence interval [CI] = 1.009-1.20; P = 0.03) and noradrenaline compared to terlipressin (OR, 3.05; CI = 1.27-7.33; P = 0.01) predicted nonresponse to therapy. Use of noradrenaline compared to terlipressin was also predictive of higher mortality (hazard ratio [HR], 2.08; CI = 1.32-3.30; P = 0.002). Conclusion: AKI in ACLF carries a high mortality. Infusion of terlipressin gives earlier and higher response than noradrenaline, with improved survival in ACLF patients with HRS-AKI.

Correction to: Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

The article Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update, written by [Shiv Sarin], was originally published electronically on the publisher's internet portal (currently SpringerLink) on June 06, 2019 without open access.

Primary and secondary bystander effect and genomic instability in cells exposed to high and low linear energy transfer radiations

Purpose: Non-Targeted effects (NTE), such as bystander effect (BE) and genomic instability (GI) challenge central dogma of radiation biology. Moreover, there is a need to understand its universality in different type of cells and radiation quality.Materials and method: To study BE (primary and secondary) and GI Human adult dermal fibroblast (HADF) and peripheral blood lymphocytes (PBL) were exposed to low fluence of ²⁴¹Am alpha (α) particle and 6 MV X-ray. The BE was carried out by means of co-culture methodology after exposing the cells to both types of radiation and damage was measured using micronucleus assay (MN) and chromosomal aberration assay (CA) in the p1 cells while the GI was followed up in their progeny.Results: A dose-dependent increase in DNA damages (MN and CA) was observed in directly irradiated and bystander cells. The magnitude of BE was higher (6 fold) in cells co-cultured with the α-irradiated cells than that of with X-irradiated cells. Cross exposure of both cell types confirms that radiation induced BE is cell type dependent. In addition, induced DNA damage persisted for a longer population doubling in α-particle irradiated cells.Conclusion: This work adds evidence to secondary bystander response generated from primary bystander normal cells and its dependence to radiation quality.

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

The first consensus report of the working party of the Asian Pacific Association for the Study of the Liver (APASL) set up in 2004 on acute-on-chronic liver failure (ACLF) was published in 2009. With international groups volunteering to join, the "APASL ACLF Research Consortium (AARC)" was formed in 2012, which continued to collect prospective ACLF patient data. Based on the prospective data analysis of nearly 1400 patients, the AARC consensus was published in 2014. In the past nearly four-and-a-half years, the AARC database has been enriched to about 5200 cases by major hepatology centers across Asia. The data published during the interim period were carefully analyzed and areas of contention and new developments in the field of ACLF were prioritized in a systematic manner. The AARC database was also approached for answering some of the issues where published data were limited, such as liver failure grading, its impact on the 'Golden Therapeutic Window', extrahepatic organ dysfunction and failure, development of sepsis, distinctive features of acute decompensation from ACLF and pediatric ACLF and the issues were analyzed. These initiatives concluded in a two-day meeting in October 2018 at New Delhi with finalization of the new AARC consensus. Only those statements, which were based on evidence using the Grade System and were unanimously recommended, were accepted. Finalized statements were again circulated to all the experts and subsequently presented at the AARC investigators meeting at the AASLD in November 2018. The suggestions from the experts were used to revise and finalize the consensus. After detailed deliberations and data analysis, the original definition of ACLF was found to withstand the test of time and be able to identify a homogenous group of patients presenting with liver failure. New management options including the algorithms for the management of coagulation disorders, renal replacement therapy, sepsis, variceal bleed, antivirals and criteria for liver transplantation for ACLF patients were proposed. The final consensus statements along with the relevant background information and areas requiring future studies are presented here.

Fast and accurate phylogenetic reconstruction from high-resolution whole-genome data and a novel robustness estimator

The rapid accumulation of whole-genome data has renewed interest in the study of genomic rearrangements. Comparative genomics, evolutionary biology, and cancer research all require models and algorithms to elucidate the mechanisms, history, and consequences of these rearrangements. However, even simple models lead to NP-hard problems, particularly in the area of phylogenetic analysis. Current approaches are limited to small collections of genomes and low-resolution data (typically a few hundred syntenic blocks). Moreover, whereas phylogenetic analyses from sequence data are deemed incomplete unless bootstrapping scores (a measure of confidence) are given for each tree edge, no equivalent to bootstrapping exists for rearrangement-based phylogenetic analysis. We describe a fast and accurate algorithm for rearrangement analysis that scales up, in both time and accuracy, to modern high-resolution genomic data. We also describe a novel approach to estimate the robustness of results-an equivalent to the bootstrapping analysis used in sequence-based phylogenetic reconstruction. We present the results of extensive testing on both simulated and real data showing that our algorithm returns very accurate results, while scaling linearly with the size of the genomes and cubically with their number. We also present extensive experimental results showing that our approach to robustness testing provides excellent estimates of confidence, which, moreover, can be tuned to trade off thresholds between false positives and false negatives. Together, these two novel approaches enable us to attack heretofore intractable problems, such as phylogenetic inference for high-resolution vertebrate genomes, as we demonstrate on a set of six vertebrate genomes with 8,380 syntenic blocks. A copy of the software is available on demand.

Discrimination between Doppler-shifted and non-shifted light in coherence domain path length resolved measurements of multiply scattered light

We show a novel technique to distinguish between Doppler shifted and unshifted light in multiple scattering experiments on mixed static and dynamic media. With a phase modulated low coherence Mach- Zehnder interferometer, optical path lengths of shifted and unshifted light and path length dependent Doppler broadening are measured in a two-layer tissue phantom, with a superficial static layer of different thickness covering a semi-infinite dynamic medium having identical optical properties. No Doppler broadening is observed until a certain optical path length depending on the thickness of the superficial static layer. From the minimum optical path length corresponding to the Doppler-shifted light the thickness of the static layer that overlies the dynamic layer can be estimated. Validation of the experimentally determined thickness of the static layer is done with the Doppler Monte Carlo technique. This approach has potential applications in discriminating between statically and dynamically scattered light in the perfusion signal and in determining superficial burn depths.

Effect of speckles on the depth sensitivity of laser Doppler perfusion imaging

A theoretical model is presented and experimentally validated that allows the prediction of the effect of speckles on the depth sensitivity of laser Doppler perfusion imaging. It is shown that the influence of speckles on depth sensitivity is large. In particular the sensitivity to particle motion in superficial layers is strongly beam diameter dependent: decreasing the beam diameter on the tissue surface increases the sensitivity to superficial motion to a much stronger extent than sensitivity to motion at a larger depth. This can be explained through the effect of beam diameter changes on the fractional coherence areas generated by photons with different penetration depths in the tissue.

Quantification of optical Doppler broadening and optical path lengths of multiply scattered light by phase modulated low coherence interferometry

We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. Water suspensions of Polystyrene microspheres with high scattering and low absorption levels are used as calibrated scattering phantoms. The path length dependent diffusion broadening or Doppler broadening of scattered light is shown to agree with Diffusive Wave Spectroscopy within 5%. The optical path lengths are determined experimentally from the zero order moment of the phase modulation peak around the modulation frequency in the power spectrum and the results are validated with Monte Carlo simulations.

Speckles in laser Doppler perfusion imaging

We report on the quantitative influence of speckles in laser Doppler perfusion imaging. The influence of speckles on the signal amplitude and on the Doppler spectrum is demonstrated experimentally for particle suspensions with different scattering levels and various beam widths. It is shown that the type of tissue affects the instrumental response through the effect of lateral light diffusion on the number of speckles involved in the detection process. These effects are largest for narrow beams.

Genetic contribution to high neonatally lethal malformation rate in the United Arab Emirates

OBJECTIVES

We examined the contribution of genetic disorders to congenital anomalies (CA) causing neonatal deaths in the Al Ain Medical District (AMD) in the United Arab Emirates (UAE) because of the high consanguineous marriage rate in the community.

METHODS

Charts of all neonatal deaths in the three perinatal units, which accounted for 99% of all births in AMD (1992-2000), were studied. Data regarding pregnancy, a family history including the level of parental consanguinity, the results of genetic evaluations and neonatal outcomes were recorded as part of an ongoing malformation surveillance system. Causes of death were based on clinical, laboratory and imaging findings.

RESULTS

Of the 508 neonates who died, 212 (42%) had CA, which were the leading cause of death. Forty-four percent of the CA were due to definite genetic disorders and 75% of these were single gene defects. Multisystem malformations were the commonest congenital malformations. Parental consanguinity was associated with a 2-fold increased risk of non-chromosomal multisystem malformations.

CONCLUSIONS

Lethal malformations were the leading cause of neonatal deaths, and parental consanguinity was associated with an increased risk of autosomal recessive disorders. The results underscore the importance of genetic screening and counseling in strategies for further significant reductions in the neonatal mortality rate in the UAE.

Vasopeptidase inhibitors, neutral endopeptidase inhibitors, and dual inhibitors of angiotensin-converting enzyme and neutral endopeptidase

Vasopeptidase inhibitors represent a new class of cardiovascular drugs. They function as a combined angiotensin-converting enzyme (ACE) inhibitor and neutral endopeptidase (NEP) inhibitor, the latter of which potentiates the actions of atrial natriuretic peptide (ANP) by minimizing its degradation in the circulation. The consequence of such dual inhibition is a synergistic reduction of vasoconstriction and enhancement of vasodilation, thereby serving to more effectively reduce blood pressure. Furthermore, inhibition of the renin-angiotensin-aldosterone system (RAAS) prevents physiologic compensatory responses in vivo seen with NEP inhibition alone. Vasopeptidase inhibitors have also shown to potentiate bradykinin and adrenomedullin, which additionally contribute to cardiovascular regulation. The most extensively researched and promising agents within the class of VP inhibitors is omapatrilat, a mercaptoacyl derivative of a bicyclic thiazepinone dipeptide. It is a single molecule with equal potency and affinity for ACE and NEP inhibition. Although ACE inhibition tends to more selectively benefit high-renin models of hypertension, vasopeptidase inhibition has been shown to be equally efficacious in low-, normal-, and high-renin models. Contrary to NEP inhibition alone, omapatrilat has also demonstrated the ability to significantly reduce blood pressure in spontaneously hypertensive rats, the equivalent of essential hypertension in humans. Studies also suggest that omapatrilat has cardioprotective properties, especially in the setting of congestive heart failure. More specifically, animal models have demonstrated omapatrilat to be more effective than ACE inhibition alone in remodeling the heart and improving its contractile function. Human studies have documented the efficacy of omapatrilat in the treatment of both hypertension and, to a lesser extent, heart failure. Safety concerns (specifically angioedema) are currently being addressed before the widespread utilization of this promising new agent.

Pharmacodynamic effects and pharmacokinetic profile of continuous infusion fentanyl in newborn piglets

The objective of this study was to determine hemodynamic effects and pharmacokinetic profiles of fentanyl with continuous infusion in 1- to 3-day-old newborn piglets. The piglets (n = 6) were administered a loading dose of fentanyl at 30 microg/kg i.v. over 15 min followed by a continuous i.v. infusion at 10 microg/kg/h for 6 h. The control group (n = 8) received equivalent volume bolus and infusion of 5% dextrose. Blood samples were obtained serially from systemic circulation and sagittal sinus vein for measurement of plasma fentanyl, pH and blood gases. Plasma fentanyl achieved steady state levels by 30 min of infusion both in the systemic (202.7 +/- 39.1 ng/ml) and sagittal sinus vein (136.7 +/- 20.7 ng/ml). Fentanyl caused a transient increase in respiratory rate at 2 h. Heart rate was significantly elevated at 30 min and 6 h during infusion but systemic and sagittal sinus vein blood pressure remained unchanged. Systemic and sagittal sinus vein PO2 were significantly decreased from 2 through 6 h of infusion. Compared to the control group, there was a 56% (p < 0.01) decrease in sagittal sinus vein O2 content at 30 min of infusion, an effect which lasted up to 6 h (47%, p < 0.01). Fractional O2 extraction by the brain increased significantly at 30 min (26%, p < 0.01) and remained elevated throughout the infusion time (22%, p < 0.05 at 6 h). Brain fractional O2 extraction increased as a function of brain fractional fentanyl extraction (r2 = 0.40, p < 0.001). Mean clearance was estimated as 56.2 +/- 13.7 ml/kg/h (range 43.5-76.9 ml/kg/h), mean volume of distribution at steady state was 1.29 +/- 0.6 liters/kg (range 0.78-2.15 liters/kg) and the mean half-life was 15.7 +/- 5.7 h (range 9.4-22.5 h). These data suggest that increased systemic oxygen may be necessary to maintain normal cerebral oxygen extraction during fentanyl anesthesia/analgesia.

C/EBP regulates hepatic transcription of 11beta -hydroxysteroid dehydrogenase type 1. A novel mechanism for cross-talk between the C/EBP and glucocorticoid signaling pathways

Glucocorticoid action within individual cells is potently modulated by 11beta-hydroxysteroid dehydrogenase (11beta-HSD), which, by interconverting active and inert glucocorticoids, determines steroid access to receptors. Type 1 11beta-HSD (11beta-HSD1) is highly expressed in liver where it regenerates glucocorticoids, thus amplifying their action and contributing to induction of glucocorticoid-responsive genes, most of which are also regulated by members of the C/EBP (CAAT/enhancer-binding protein) family of transcription factors. Here we demonstrate that C/EBPalpha is a potent activator of the 11beta-HSD1 gene in hepatoma cells and that mice deficient in C/EBPalpha have reduced hepatic 11beta-HSD1 expression. In contrast, C/EBPbeta is a relatively weak activator of 11beta-HSD1 transcription in hepatoma cells and attenuates C/EBPalpha induction, and mice that lack C/EBPbeta have increased hepatic 11beta-HSD1 mRNA. The 11beta-HSD1 promoter (between -812 and +76) contains 10 C/EBP binding sites, and mutation of the promoter proximal sites decreases the C/EBP inducibility of the promoter. One site encompasses the transcription start, and both C/EBPalpha and C/EBPbeta are present in complexes formed by liver nuclear proteins at this site. The regulation of 11beta-HSD1 expression, and hence intracellular glucocorticoid levels, by members of the C/EBP family provides a novel mechanism for cross-talk between the C/EBP family of transcription factors and the glucocorticoid signaling pathway.

Focal neurological manifestations following aberrant central venous catheter placement

An infant developed focal tonic clonic movements of both lower limbs while receiving total parenteral nutrition through a left saphenous percutaneous central venous catheter. Radiographic studies using a contrast confirmed that the catheter tip was located in the ascending lumbar vein in close proximity to the epidural space. Withdrawal of the catheter abated all clinical symptoms. This case emphasizes the need to confirm central venous catheter placement and illustrates yet another risk associated with the infusion of parenteral alimentation.

11 beta-Hydroxysteroid dehydrogenase in cultured hippocampal cells reactivates inert 11-dehydrocorticosterone, potentiating neurotoxicity

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) catalyzes the conversion of the glucocorticoid corticosterone (cortisol in humans) to inert 11-dehydrocorticosterone (cortisone). 11 beta-HSD activity is present in the hippocampus, where it is induced by glucocorticoids and stress in vivo, prompting suggestions that the enzyme may attenuate the deleterious effects of chronic glucocorticoid excess on neuronal function and survival. Two isoforms exist: 11 beta-HSD1, a bidirectional NADPH-dependent enzyme, and 11 beta-HSD2, an NAD(+)-dependent exclusive 11 beta-dehydrogenase (corticosterone-inactivating enzyme). In this study, 11 beta-HSD1 activity and mRNA synthesis were demonstrated in primary fetal hippocampal cell cultures. Unexpectedly, the reaction direction in intact hippocampal cells was 11 beta-reduction (reactivation of inert 11-dehydrocorticosterone), although homogenization revealed that the enzyme was capable of 11 beta-dehydrogenation when removed from its normal cellular context. Dexamethasone (10(-7) M) increased 11 beta-HSD activity in homogenates of hippocampal cultures (102% increase). In intact hippocampal cells, dexamethasone induced 11 beta reductase, not dehydrogenase. To determine the functional relevance of hippocampal 11 beta-reductase, glucocorticoid potentiation of kainic acid neurotoxicity was examined. Pretreatment of hippocampal cells with corticosterone reduced survival on kainate exposure. Hippocampal cell 11 beta-HSD activity was potently inhibited by carbenoxolone. Carbenoxolone had no effect on cell survival after kainate alone and did not alter the effect of corticosterone. 11-Dehydrocorticosterone also potentiated kainate neurotoxicity; this effect was lost, however, if 11 beta-HSD was inhibited with carbenoxolone. Thus, hippocampal 11 beta-HSD seems to be a functional 11 beta-reductase in intact cells. Measures to attenuate hippocampal 11 beta-reductase may reduce neuronal vulnerability to glucocorticoid toxicity.

Cloning, sequencing and tissue-distribution of mouse 11 beta-hydroxysteroid dehydrogenase-1 cDNA

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) reversibly converts physiological glucocorticoids (cortisol, corticosterone) to inactive 11-dehydro forms, and thus controls glucocorticoid access to receptors in a variety of tissues. We have cloned a cDNA encoding 'liver-type' 11 beta-HSD (11 beta-HSD1) from the mouse using PCR, and have determined its nucleotide sequence. Mouse 11 beta-HSD1 cDNA showed 91% identity to rat 11 beta-HSD1 cDNA. There was 87% amino acid identity with rat 11 beta-HSD1 with conservation of the putative cofactor and substrate binding domains. Northern blot analysis of mouse tissues demonstrated abundant 11 beta-HSD1 message in the liver, kidney and lung, with lower expression in brain subregions and gonads. 11 beta-HSD1 mRNA was below the level of detection in the murine colon. 11 beta-HSD1 mRNA levels in kidney was higher in males than in females, but in contrast to the rat, there was no sexual dimorphism in the mouse liver. Although males and females showed different mRNA levels in the kidney, there was no sex difference in 11 beta-HSD enzyme activity. Thus, despite the high inter-species conservation of 11 beta-HSD1, there are clear species and tissue-specific differences in its expression.

Regulation of 11 beta-hydroxysteroid dehydrogenase by sex steroids in vivo: further evidence for the existence of a second dehydrogenase in rat kidney

11 beta-Hydroxysteroid dehydrogenase (11 beta-OHSD) catalyses the reversible conversion of corticosterone to inactive 11-dehydrocorticosterone, thus regulating glucocorticoid access to mineralocorticoid and perhaps glucocorticoid receptors in vivo. 11 beta-OHSD has been purified from rat liver and an encoding cDNA isolated from a liver library. However, several lines of indirect evidence suggest the existence of at least two isoforms of 11 beta-OHSD, one found predominantly in glucocorticoid receptor-rich tissues and the other restricted to aldosterone-selective mineralocorticoid target tissues and placenta. Here we have examined the effects of chronic (10 day) manipulations of sex-steroid levels on 11 beta-OHSD enzyme activity and mRNA expression in liver, kidney and hippocampus and present further evidence for the existence of a second 11 beta-OHSD isoform in kidney. Gonadectomized male and female rats were given testosterone, oestradiol or blank silicone elastomer capsules, controls were sham-operated. In male liver, gonadectomy+oestradiol treatment led to a dramatic decrease in both 11 beta-OHSD activity (69 +/- 8% decrease) and mRNA expression (97 +/- 1% decrease). Gonadectomy and testosterone replacement had no effect on male liver 11 beta-OHSD. However, in female liver, where 11 beta-OHSD activity is approximately 50% of that in male liver, gonadectomy resulted in a marked increase in 11 beta-OHSD activity (120 +/- 37% rise), which was reversed by oestradiol replacement but not testosterone treatment. In male kidney, gonadectomy+oestradiol treatment resulted in a marked increase in 11 beta-OHSD activity (103 +/- 4% rise). By contrast, 11 beta-OHSD mRNA expression was almost completely repressed (99 +/- 0.1% decrease) by oestradiol treatment.(ABSTRACT TRUNCATED AT 250 WORDS)