CheekAge: a next-generation buccal epigenetic aging clock associated with lifestyle and health

Epigenetic aging clocks are computational models that predict age using DNA methylation information. Initially, first-generation clocks were developed to make predictions using CpGs that change with age. Over time, next-generation clocks were created using CpGs that relate to both age and health. Since existing next-generation clocks were constructed in blood, we sought to develop a next-generation clock optimized for prediction in cheek swabs, which are non-invasive and easy to collect. To do this, we collected MethylationEPIC data as well as lifestyle and health information from 8045 diverse adults. Using a novel simulated annealing approach that allowed us to incorporate lifestyle and health factors into training as well as a combination of CpG filtering, CpG clustering, and clock ensembling, we constructed CheekAge, an epigenetic aging clock that has a strong correlation with age, displays high test-retest reproducibility across replicates, and significantly associates with a plethora of lifestyle and health factors, such as BMI, smoking status, and alcohol intake. We validated CheekAge in an internal dataset and multiple publicly available datasets, including samples from patients with progeria or meningioma. In addition to exploring the underlying biology of the data and clock, we provide a free online tool that allows users to mine our methylomic data and predict epigenetic age.

Apigenin: a natural molecule at the intersection of sleep and aging

NAD+, a pivotal coenzyme central to metabolism, exhibits a characteristic decline with age. In mice, NAD+ levels can be elevated via treatment with apigenin, a natural flavonoid that inhibits the NAD+-consuming glycoprotein CD38. In animal models, apigenin positively impacts both sleep and longevity. For example, apigenin improves learning and memory in older mice, reduces tumor proliferation in a mouse xenograft model of triple-negative breast cancer, and induces sedative effects in mice and rats. Moreover, apigenin elongates survival in fly models of neurodegenerative disease and apigenin glycosides increase lifespan in worms. Apigenin's therapeutic potential is underscored by human clinical studies using chamomile extract, which contains apigenin as an active ingredient. Collectively, chamomile extract has been reported to alleviate anxiety, improve mood, and relieve pain. Furthermore, dietary apigenin intake positively correlates with sleep quality in a large cohort of adults. Apigenin's electron-rich flavonoid structure gives it strong bonding capacity to diverse molecular structures across receptors and enzymes. The effects of apigenin extend beyond CD38 inhibition, encompassing agonistic and antagonistic modulation of various targets, including GABA and inflammatory pathways. Cumulatively, a large body of evidence positions apigenin as a unique molecule capable of influencing both aging and sleep. Further studies are warranted to better understand apigenin's nuanced mechanisms and clinical potential.

A multimodal cell census and atlas of the mammalian primary motor cortex

Here we report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Our results advance the collective knowledge and understanding of brain cell-type organization1-5. First, our study reveals a unified molecular genetic landscape of cortical cell types that integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a consensus taxonomy of transcriptomic types and their hierarchical organization that is conserved from mouse to marmoset and human. Third, in situ single-cell transcriptomics provides a spatially resolved cell-type atlas of the motor cortex. Fourth, cross-modal analysis provides compelling evidence for the transcriptomic, epigenomic and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types. We further present an extensive genetic toolset for targeting glutamatergic neuron types towards linking their molecular and developmental identity to their circuit function. Together, our results establish a unifying and mechanistic framework of neuronal cell-type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties.

Generation of a DAT-P2A-Flpo mouse line for intersectional genetic targeting of dopamine neuron subpopulations

Dopaminergic projections exert widespread influence over multiple brain regions and modulate various behaviors including movement, reward learning, and motivation. It is increasingly appreciated that dopamine neurons are heterogeneous in their gene expression, circuitry, physiology, and function. Current approaches to target dopamine neurons are largely based on single gene drivers, which either label all dopamine neurons or mark a subset but concurrently label non-dopaminergic neurons. Here, we establish a mouse line with Flpo recombinase expressed from the endogenous Slc6a3 (dopamine active transporter [DAT]) locus. DAT-P2A-Flpo mice can be used together with Cre-expressing mouse lines to efficiently and selectively label dopaminergic subpopulations using Cre/Flp-dependent intersectional strategies. We demonstrate the utility of this approach by generating DAT-P2A-Flpo;NEX-Cre mice that specifically label Neurod6-expressing dopamine neurons, which project to the nucleus accumbens medial shell. DAT-P2A-Flpo mice add to a growing toolbox of genetic resources that will help parse the diverse functions mediated by dopaminergic circuits.

Kramer et al. generate a DAT-P2A-Flpo mouse line that enables intersectional genetic targeting of dopamine neuron subpopulations using Flp/Cre-dependent constructs. They show that ventral tegmental area dopamine neurons expressing Neurod6 give rise to the majority of dopaminergic projections to the nucleus accumbens medial shell and olfactory tubercle.

Creatine-mediated crosstalk between adipocytes and cancer cells regulates obesity-driven breast cancer

Obesity is a major risk factor for adverse outcomes in breast cancer; however, the underlying molecular mechanisms have not been elucidated. To investigate the role of crosstalk between mammary adipocytes and neoplastic cells in the tumor microenvironment (TME), we performed transcriptomic analysis of cancer cells and adjacent adipose tissue in a murine model of obesity-accelerated breast cancer and identified glycine amidinotransferase (Gatm) in adipocytes and Acsbg1 in cancer cells as required for obesity-driven tumor progression. Gatm is the rate-limiting enzyme in creatine biosynthesis, and deletion in adipocytes attenuated obesity-driven tumor growth. Similarly, genetic inhibition of creatine import into cancer cells reduced tumor growth in obesity. In parallel, breast cancer cells in obese animals upregulated the fatty acyl-CoA synthetase Acsbg1 to promote creatine-dependent tumor progression. These findings reveal key nodes in the crosstalk between adipocytes and cancer cells in the TME necessary for obesity-driven breast cancer progression.

Three-Dimensional Imaging Provides Detailed Atherosclerotic Plaque Morphology and Reveals Angiogenesis After Carotid Artery Ligation

RATIONALE

Remodeling of the vessel wall and the formation of vascular networks are dynamic processes that occur during mammalian embryonic development and in adulthood. Plaque development and excessive neointima formation are hallmarks of atherosclerosis and vascular injury. As our understanding of these complex processes evolves, there is a need to develop new imaging techniques to study underlying mechanisms.

OBJECTIVE

We used tissue clearing and light-sheet microscopy for 3-dimensional (3D) profiling of the vascular response to carotid artery ligation and induction of atherosclerosis in mouse models.

METHODS AND RESULTS

Adipo-Clear and immunolabeling in combination with light-sheet microscopy were applied to image carotid arteries and brachiocephalic arteries, allowing for 3D reconstruction of vessel architecture. Entire 3D neointima formations with different geometries were observed within the carotid artery and scored by volumetric analysis. Additionally, we identified a CD31-positive adventitial plexus after ligation of the carotid artery that evolved and matured over time. We also used this method to characterize plaque extent and composition in the brachiocephalic arteries of ApoE-deficient mice on high-fat diet. The plaques exhibited inter-animal differences in terms of plaque volume, geometry, and ratio of acellular core to plaque volume. A 3D reconstruction of the endothelium overlying the plaque was also generated.

CONCLUSIONS

We present a novel approach to characterize vascular remodeling in adult mice using Adipo-Clear in combination with light-sheet microscopy. Our method reconstructs 3D neointima formation after arterial injury and allows for volumetric analysis of remodeling, in addition to revealing angiogenesis and maturation of a plexus surrounding the carotid artery. This method generates complete 3D reconstructions of atherosclerotic plaques and uncovers their volume, geometry, acellular component, surface, and spatial position within the brachiocephalic arteries. Our approach may be used in a number of mouse models of cardiovascular disease to assess vessel geometry and volume. Visual Overview: An online visual overview is available for this article.

Combinatorial Expression of Grp and Neurod6 Defines Dopamine Neuron Populations with Distinct Projection Patterns and Disease Vulnerability

Midbrain dopamine neurons project to numerous targets throughout the brain to modulate various behaviors and brain states. Within this small population of neurons exists significant heterogeneity based on physiology, circuitry, and disease susceptibility. Recent studies have shown that dopamine neurons can be subdivided based on gene expression; however, the extent to which genetic markers represent functionally relevant dopaminergic subpopulations has not been fully explored. Here we performed single-cell RNA-sequencing of mouse dopamine neurons and validated studies showing that Neurod6 and Grp are selective markers for dopaminergic subpopulations. Using a combination of multiplex fluorescent in situ hybridization, retrograde labeling, and electrophysiology in mice of both sexes, we defined the anatomy, projection targets, physiological properties, and disease vulnerability of dopamine neurons based on Grp and/or Neurod6 expression. We found that the combinatorial expression of Grp and Neurod6 defines dopaminergic subpopulations with unique features. Grp+/Neurod6+ dopamine neurons reside in the ventromedial VTA, send projections to the medial shell of the nucleus accumbens, and have noncanonical physiological properties. Grp+/Neurod6- dopamine neurons are found in the VTA as well as in the ventromedial portion of the SNc, where they project selectively to the dorsomedial striatum. Grp-/Neurod6+ dopamine neurons represent a smaller VTA subpopulation, which is preferentially spared in a 6-OHDA model of Parkinson's disease. Together, our work provides detailed characterization of Neurod6 and Grp expression in the midbrain and generates new insights into how these markers define functionally relevant dopaminergic subpopulations.

Voltage-sensitive rhodol with enhanced two-photon brightness

We have designed, synthesized, and applied a rhodol-based chromophore to a molecular wire-based platform for voltage sensing to achieve fast, sensitive, and bright voltage sensing using two-photon (2P) illumination. Rhodol VoltageFluor-5 (RVF5) is a voltage-sensitive dye with improved 2P cross-section for use in thick tissue or brain samples. RVF5 features a dichlororhodol core with pyrrolidyl substitution at the nitrogen center. In mammalian cells under one-photon (1P) illumination, RVF5 demonstrates high voltage sensitivity (28% ΔF/F per 100 mV) and improved photostability relative to first-generation voltage sensors. This photostability enables multisite optical recordings from neurons lacking tuberous sclerosis complex 1, Tsc1, in a mouse model of genetic epilepsy. Using RVF5, we show that Tsc1 KO neurons exhibit increased activity relative to wild-type neurons and additionally show that the proportion of active neurons in the network increases with the loss of Tsc1. The high photostability and voltage sensitivity of RVF5 is recapitulated under 2P illumination. Finally, the ability to chemically tune the 2P absorption profile through the use of rhodol scaffolds affords the unique opportunity to image neuronal voltage changes in acutely prepared mouse brain slices using 2P illumination. Stimulation of the mouse hippocampus evoked spiking activity that was readily discerned with bath-applied RVF5, demonstrating the utility of RVF5 and molecular wire-based voltage sensors with 2P-optimized fluorophores for imaging voltage in intact brain tissue.

A retrospective analysis of severe intraoperative respiratory compliance changes during ophthalmic arterial chemosurgery for retinoblastoma

BACKGROUND AND OBJECTIVES

Ophthalmic arterial chemosurgery for retinoblastoma has been associated with intraoperative decreases in respiratory compliance. Through the analysis of data from computerized records, we objectively defined severe respiratory compliance events and correlated them with demographic and clinical information in patients undergoing this procedure.

METHODS

Data were collected from ophthalmic arterial chemosurgery cases from 2006 to 2013. Intraoperative PIP, PEEP, TV, SpO2 , and EtCO2 were analyzed. Compliance changes, desaturations, decreases in EtCO2 , and clinical outcomes were assessed.

RESULTS

Respiratory compliance decreases with a bimodal distribution. Severe events were defined as exhibiting a minimum compliance decrease of 40%. Seventy-eight of 122 children (64%) experienced a severe compliance event during at least one treatment, and it occurred in 137/468 cases (29%). A subset of 94 children had complete or at least the first three records. The incidence of a severe respiratory compliance event in this subgroup was 17/94 (18%) on the first and 84/261 (32%) on subsequent procedures. The probability of developing a severe respiratory compliance event on a subsequent procedure was 0.40 if the child developed it on the first procedure, 0.30 if he did not; this difference was not significant. The incidence of desaturation below 90% with severe respiratory compliance events was 0.20; the incidence of a 30% drop in EtCO2 was 0.34. No morbidity, no extended recovery, and no admissions were associated with intraoperative severe respiratory compliance events. We found no correlation between history, age, sex, weight or allergies, and intraoperative severe respiratory compliance events.

CONCLUSIONS

Here, most patients experienced a severe respiratory compliance event during at least one of their procedures. Overall incidence was 29% and was more likely on subsequent procedures. A severe respiratory compliance event at the initial procedure was poorly predictive of its occurrence on subsequent procedures. No morbidity was associated with intraoperative severe respiratory compliance events.

Distinct, strict requirements for Gfi-1b in adult bone marrow red cell and platelet generation

Strict, lineage-intrinsic requirement for continuous adult Gfi-1b expression at two distinct critical stages of erythropoiesis and megakaryopoiesis.

The zinc finger transcriptional repressor Gfi-1b is essential for erythroid and megakaryocytic development in the embryo. Its roles in the maintenance of bone marrow erythropoiesis and thrombopoiesis have not been defined. We investigated Gfi-1b’s adult functions using a loxP-flanked Gfi-1b allele in combination with a novel doxycycline-inducible Cre transgene that efficiently mediates recombination in the bone marrow. We reveal strict, lineage-intrinsic requirements for continuous adult Gfi-1b expression at two distinct critical stages of erythropoiesis and megakaryopoiesis. Induced disruption of Gfi-1b was lethal within 3 wk with severely reduced hemoglobin levels and platelet counts. The erythroid lineage was arrested early in bipotential progenitors, which did not give rise to mature erythroid cells in vitro or in vivo. Yet Gfi-1b^−/− progenitors had initiated the erythroid program as they expressed many lineage-restricted genes, including Klf1/Eklf and Erythropoietin receptor. In contrast, the megakaryocytic lineage developed beyond the progenitor stage in Gfi-1b’s absence and was arrested at the promegakaryocyte stage, after nuclear polyploidization, but before cytoplasmic maturation. Genome-wide analyses revealed that Gfi-1b directly regulates a wide spectrum of megakaryocytic and erythroid genes, predominantly repressing their expression. Together our study establishes Gfi-1b as a master transcriptional repressor of adult erythropoiesis and thrombopoiesis.

The role of the foreshortening cue in the perception of 3D object slant

Slant is the degree to which a surface recedes or slopes away from the observer about the horizontal axis. The perception of surface slant may be derived from static monocular cues, including linear perspective and foreshortening, applied to single shapes or to multi-element textures. It is still unclear the extent to which color vision can use these cues to determine slant in the absence of achromatic contrast. Although previous demonstrations have shown that some pictures and images may lose their depth when presented at isoluminance, this has not been tested systematically using stimuli within the spatio-temporal passband of color vision. Here we test whether the foreshortening cue from surface compression (change in the ratio of width to length) can induce slant perception for single shapes for both color and luminance vision. We use radial frequency patterns with narrowband spatio-temporal properties. In the first experiment, both a manual task (lever rotation) and a visual task (line rotation) are used as metrics to measure the perception of slant for achromatic, red-green isoluminant and S-cone isolating stimuli. In the second experiment, we measure slant discrimination thresholds as a function of depicted slant in a 2AFC paradigm and find similar thresholds for chromatic and achromatic stimuli. We conclude that both color and luminance vision can use the foreshortening of a single surface to perceive slant, with performances similar to those obtained using other strong cues for slant, such as texture. This has implications for the role of color in monocular 3D vision, and the cortical organization used in 3D object perception.

Influence of anthropometric features on graft diameter in ACL reconstruction

BACKGROUND

There is a paucity of literature regarding the influence of anthropometric features on the hamstring graft obtained in ACL reconstruction. This study was undertaken to assess the influence of anthropometric measurements on the graft diameter obtained at ACL reconstruction surgery within the European population. We hypothesise that anthropometric features do influence graft thickness in ACL reconstruction.

MATERIALS AND METHODS

Data from 121 consecutive patients who had undergone ACL reconstruction by the same surgeon using quadruple hamstring grafts were analysed. The body mass index (BMI), height and weight of these patients were correlated with the graft diameter obtained during surgery. Regression analysis was undertaken to assess the influence of individual anthropometric variables on the graft diameter.

RESULTS

There were 121 patients with mean age of 32 years (14-55). There was a statistically significant positive correlation individually between the height and graft diameter (r = 0.38, p < 0.01) as well as between the body weight and graft diameter (r = 0.29, p < 0.01). However, when the body mass index was calculated, the correlation was not statistically significant (r = 0.08, p > 0.1). Regression analysis confirmed that BMI was not statistically significant as a predictor of hamstring graft diameter whereas height was statistically the most important predictor (F = 20.1; p < 0.01).This yielded the predictive equation, graft diameter = 4.5 + 0.02 x Ht (in cm).

CONCLUSION

Although body mass index did not significantly correlate, body height may be a predictive variable in predicting the graft diameter in ACL reconstruction and provide useful pre operative information.

Disposition and metabolism of cumene in F344 rats and B6C3F1 mice

Cumene is a high-production volume chemical that has been shown to be a central nervous system depressant and has been implicated as a long-term exposure carcinogen in experimental animals. The absorption, distribution, metabolism, and excretion of [(14)C]cumene (isopropylbenzene) was studied in male rats and mice of both sexes after oral or intravenous administration. In both species and sexes, urine accounted for the majority of the excretion (typically ≥ 70%) by oral and intravenous administration. Enterohepatic circulation of cumene and/or its metabolites was indicated because 37% of the total dose was excreted in bile in bile duct-cannulated rats with little excreted in normal rats. The highest tissue (14)C levels in rats were observed in adipose tissue, liver, and kidney with no accumulation observed after repeat dosing up to 7 days. In contrast, mice contained the highest concentrations of (14)C at 24 h after dosing in the liver, kidney, and lung, with repeat dosing accumulation of (14)C observed in these tissues as well as in the blood, brain, heart, muscle, and spleen. The metabolites in the expired air, urine, bile, and microsomes were characterized with 16 metabolites identified. The volatile organics in the expired air comprised mainly cumene and up to 4% α-methylstyrene. The major urinary and biliary metabolite was 2-phenyl-2-propanol glucuronide, which corresponded with the main microsomal metabolite being 2-phenyl-2-propanol.

64Cu-labeled affibody molecules for imaging of HER2 expressing tumors

INTRODUCTION

The development of molecular probes based on novel engineered protein constructs is under active investigation due to the great potential of this generalizable strategy for imaging a variety of tumor targets.

DISCUSSION

In this report, human epidermal growth factor receptor type 2 (HER2)-binding Affibody molecules were radiolabeled with (64)Cu and their imaging ability was further evaluated in tumor mice models to understand the promise and limitations of such probes. The anti-HER2 Affibody molecules in monomeric (Z(HER2:477)) and dimeric [(Z(HER2:477))(2)] forms were site specifically modified with the maleimide-functionalized chelator, 1,4,7,10-tetraazacyclododecane-1,4,7-tris(acetic acid)-10-acetate mono (N-ethylmaleimide amide) (Mal-DOTA). The resulting DOTA-Affibody conjugates were radiolabeled with (64)Cu and evaluated in nude mice bearing subcutaneous SKOV3 tumors. Biodistribution experiments showed that tumor uptake values of (64)Cu-DOTA-Z(HER2:477) and (64)Cu-DOTA-(Z(HER2:477))(2) were 6.12 +/- 1.44% and 1.46 +/- 0.50% ID/g, respectively, in nude mice (n = 3 each) at 4 h postinjection. Moreover, (64)Cu-labeled monomer exhibited significantly higher tumor/blood ratio than that of radiolabeled dimeric counterpart at all time points examined in this study. MicroPET imaging of (64)Cu-DOTA-Z(HER2:477) in SKOV3 tumor mice clearly showed good and specific tumor localization. This study demonstrates that (64)Cu-labeled Z(HER2:477) is a promising targeted molecular probe for imaging HER2 receptor expression in living mice. Further work is needed to improve the excretion properties, hence dosimetry and imaging efficacy, of the radiometal-based probe.

Kidney allocation to liver transplant candidates with renal failure of undetermined etiology: role of percutaneous renal biopsy

The feasibility, value and risk of percutaneous renal biopsy (PRB) in liver transplant candidates with renal failure are unknown. PRB was performed on 44 liver transplant candidates with renal failure of undetermined etiology and glomerular filtration rate (GFR) <40 mL/min/1.73 m(2) (n = 37) or on renal replacement therapy (RRT) (n = 7). Patients with >or=30% interstitial fibrosis (IF), >or=40% global glomerulosclerosis (gGS) and/or diffuse glomerulonephritis were approved for simultaneous-liver-kidney (SLK) transplantation. Prebiopsy GFR, urinary sodium indices, dependency on RRT and kidney size were comparable between 27 liver-transplant-alone (LTA) and 17 SLK candidates and did not relate to the biopsy diagnosis. The interobserver agreement for the degree of IF or gGS was moderate-to-excellent. After a mean of 78 +/- 67 days, 16 and 8 patients received LTA and SLK transplants. All five LTA recipients on RRT recovered kidney function after transplantation and serum creatinine was comparable between LTA and SLK recipients at last follow-up. Biopsy complications developed in 13, of these, five required intervention. PRB is feasible in liver transplant candidates with renal failure and provides reproducible histological information that does not relate to the pretransplant clinical data. Randomized studies are needed to determine if PRB can direct kidney allocation in this challenging group of liver transplant candidates.

N-(2-Mercaptoethyl)picolylamine as a diaminomonothiolate ligand for the "fac-[Re(CO)3]+" core

N-(2-Mercaptoethyl)picolylamine (MEPAH) was studied as a potentially biologically relevant ligand for the "fac-[M(CO)(3)](+)" core (M = Re, (99)Tc, (99m)Tc). To this end, the complex Re(CO)(3)(MEPA) was synthesized. The reaction of MEPAH with fac-[Re(CO)(3)(MeCN)(3)](+) took place over the course of seconds, showing the high affinity possessed by this ligand for the "fac-[Re(CO)(3)](+)" core. A single-crystal X-ray diffraction study was performed confirming the nature of Re(CO)(3)(MEPA), a rare mononuclear rhenium(I) thiolate complex. Additional exploration into derivatization of the ligand backbone has afforded the analogous N-ethyl complex, Re(CO)(3)(MEPA-NEt). The high affinity of the ligand for the metal coupled with the ease of its derivatization implies that utilization of this ligand system for the purposes of (99m)Tc-radiopharmaceutical development is promising.

Clinical and laboratory evaluation of the safety of a bioartificial liver assist device for potential transmission of porcine endogenous retrovirus

BACKGROUND

The potential risk of transmission of porcine endogenous retroviruses (PERV) from xenogeneic donors into humans has been widely debated. Because we were involved in a phase I/II clinical trial using a bioartificial liver support system (BLSS), we proceeded to evaluate the biosafety of this device.

MATERIALS AND METHODS

The system being evaluated contains primary porcine hepatocytes freshly isolated from pathogen-free, purpose-raised herd. Isolated hepatocytes were installed in the shell, which is separated by a semipermeable membrane (100-kD nominal cutoff) from the lumen through which the patients' whole blood is circulated. Both before and at defined intervals posthemoperfusion, patients' blood was obtained for screening. Additionally, effluent collected from a clinical bioreactor was analyzed. The presence of viral particles was estimated by reverse transcriptase-polymerase chain reaction (RT-PCR) and RT assays. For the detection of pig genomic and mitochondrial DNA, sequence-specific PCR (SS-PCR) was used. Finally, the presence of infectious viral particles in the samples was ascertained by exposure to the PERV-susceptible human cell line HEK-293.

RESULTS

PERV transcripts, RT activity, and infectious PERV particles were not detected in the luminal effluent of a bioreactor. Culture supernatant from untreated control or mitogen-treated porcine hepatocytes (cleared of cellular debris) also failed to infect HEK-293 cell lines. Finally, RT-PCR, SS-PCR, and PERV-specific RT assay detected no PERV infection in the blood samples obtained from five study patients both before and at various times post-hemoperfusion.

CONCLUSION

Although longer patient follow-up is required and mandated to unequivocally establish the biosafety of this device and related bioartificial organ systems, these analyses support the conclusion that when used under standard operational conditions, the BLSS is safe.

Safety observations in phase I clinical evaluation of the Excorp Medical Bioartificial Liver Support System after the first four patients

A Phase I clinical safety evaluation of the Excorp Medical, Inc, Bioartificial Liver Support System (BLSS) is in progress. Inclusion criteria are patients with acute liver failure of any etiology, presenting with encephalopathy deteriorating beyond Parson's Grade 2. The BLSS consists of a blood pump, heat exchanger to control blood temperature, oxygenator to control oxygenation and pH, bioreactor, and associated pressure and flow alarm systems. Patient liver support is provided by 70-100 g of porcine liver cells housed in the hollow fiber bioreactor. A single support period evaluation consists of 12 hour extracorporeal perfusion with the BLSS sandwiched between 12 hours of pre (baseline) and 12 hours of post support monitoring. Blood chemistries and hematologies are obtained every 6 hours during monitoring periods and every 4 hours during perfusion. Physiologic parameters are monitored continuously. The patient may receive a second treatment at the discretion of the clinical physician. Preliminary evaluation of safety considerations after enrollment of the first four patients (F, 41, acetaminophen induced, two support periods; M, 50, Wilson's disease, one support period; F, 53, acute alcoholic hepatitis, two support periods; F, 24, chemotherapy induced, one support period) is presented. All patients tolerated the extracorporeal perfusion well. All patients presented with hypoglycemia at the start of perfusion, treatable by IV dextrose. Transient hypotension at the start of perfusion responded to an IV fluid bolus. Only the second patient required heparin anticoagulation. No serious or unexpected adverse events were noted. Moderate biochemical response to support was noted in all patients. Completion of the Phase I safety evaluation is required to fully characterize the safety of the BLSS.

Comparison of fever treatments in the critically ill: a pilot study

BACKGROUND: Fever in critically ill patients is often treated with antipyretics or physical cooling methods. Although fever is a host defense response that may benefit some critically ill patients, others may not tolerate the cardiovascular demands associated with fever. OBJECTIVES: To compare antipyretics and physical cooling for their effects on core body temperature and cardiovascular responses in critically ill patients. METHODS: The antipyretic administered was 650 mg of acetaminophen. Physical cooling was accomplished by anterior placement of a cooling blanket at 18 degrees C. Core temperature and cardiovascular responses were measured in 14 febrile (body temperature, 38.8 degrees C) critically ill patients at baseline before treatment and up to 3 hours after treatment. Patients able to receive acetaminophen were randomly assigned to receive either acetaminophen only (n = 5) or acetaminophen in combination with a cooling blanket (n = 3). Patients not able to receive acetaminophen were treated with physical cooling only (n = 6). RESULTS: Mean body temperature decreased minimally from baseline to 3 hours after treatment in the physical-cooling-only group (from 39.1 degrees C to 39.0 degrees C) and in the physical cooling and acetaminophen group (from 39.1 degrees C to 38.6 degrees C), but the mean body temperature increased in the acetaminophen-only group (from 39.2 degrees C to 39.4 degrees C). Other notable findings included a slight increase in systemic vascular resistance index in the physical-cooling-only group and in the physical-cooling-plus-acetaminophen group. CONCLUSIONS: Although the study included only 14 subjects, the findings will provide information for future studies in febrile critically ill patients.

Comparison of fever treatments in the critically ill: a pilot study

BACKGROUND

Fever in critically ill patients is often treated with antipyretics or physical cooling methods. Although fever is a host defense response that may benefit some critically ill patients, others may not tolerate the cardiovascular demands associated with fever.

OBJECTIVES

To compare antipyretics and physical cooling for their effects on core body temperature and cardiovascular responses in critically ill patients.

METHODS

The antipyretic administered was 650 mg of acetaminophen. Physical cooling was accomplished by anterior placement of a cooling blanket at 18 degrees C. Core temperature and cardiovascular responses were measured in 14 febrile (body temperature, 38.8 degrees C) critically ill patients at baseline before treatment and up to 3 hours after treatment. Patients able to receive acetaminophen were randomly assigned to receive either acetaminophen only (n = 5) or acetaminophen in combination with a cooling blanket (n = 3). Patients not able to receive acetaminophen were treated with physical cooling only (n = 6).

RESULTS

Mean body temperature decreased minimally from baseline to 3 hours after treatment in the physical-cooling-only group (from 39.1 degrees C to 39.0 degrees C) and in the physical cooling and acetaminophen group (from 39.1 degrees C to 38.6 degrees C), but the mean body temperature increased in the acetaminophen-only group (from 39.2 degrees C to 39.4 degrees C). Other notable findings included a slight increase in systemic vascular resistance index in the physical-cooling-only group and in the physical-cooling-plus-acetaminophen group.

CONCLUSIONS

Although the study included only 14 subjects, the findings will provide information for future studies in febrile critically ill patients.

High detection rate of breast ductal carcinoma in situ calcifications on mammographically directed high-resolution sonography

OBJECTIVE

To assess the high-frequency sonographic characteristics of ductal carcinoma in situ of the breast.

METHODS

In a retrospective review, we identified 18 patients with biopsy-proven pure ductal carcinoma in situ who had received mammographic and high-frequency sonographic examinations at transducer frequencies of 8-15 MHz, 8-5 MHz and 5 to 13 MHz [corrected].

RESULTS

All 18 patients had mammographically identified calcifications. Four (22%) of the 18 had either asymmetric focal mammographically identified densities or masses with the calcifications. These calcifications were identified sonographically in 17 (94%) of the 18 patients. In 9 (50%) of 18 patients, the calcifications were associated with sonographically detected malignant masses, and in 3 (17%) of 18 patients the calcifications were within focally dilated ducts. Lesions that had masses or dilated ducts visible on sonography represented 9 (82%) of 11 of the grade 3 neoplasms and only 2 (28%) of 7 of the grade 1 and 2 tumors. This difference was statistically significant (P < .039).

CONCLUSIONS

Our study showed that ductal carcinoma in situ may appear on sonography as calcifications, masses, or focally dilated ducts. Those lesions that were associated with masses or dilated ducts on sonography were more likely high-grade histologic specimens.

Short-term and long-term outcome prediction with the Acute Physiology and Chronic Health Evaluation II system after orthotopic liver transplantation

OBJECTIVE

To evaluate the relationship between the postoperative Acute Physiology and Chronic Health Evaluation (APACHE) II score and mortality at hospital discharge and at 1 yr in liver transplant recipients.

POPULATION

Adult orthotopic liver transplant (OLTX) recipients (n = 599) admitted to the intensive care unit postoperatively at a university hospital.

METHODS

The cohort was split randomly into development and validation sets. Three models were compared for each end point: a) the original APACHE II slope with the original APACHE II postgastrointestinal surgery intercept; b) the original APACHE II slope with an OLTX-specific intercept generated from the development set; and c) an OLTX-specific slope and intercept generated from the development set. Goodness-of-fit and calibration were assessed by the Hosmer-Lemeshow C statistic (where p>.05 suggests good fit) and standardized mortality ratios. Discrimination was assessed by receiver operator characteristic area under the curve analysis.

MEASUREMENTS AND MAIN RESULTS

Hospital and 1-yr mortality rates were 9.9% and 15.9%, respectively. The APACHE II score was strongly associated with mortality (chi-square, p<.0001), but when used with the original equation, it significantly overestimated hospital mortality (standardized mortality ratio, 0.73 [confidence interval, 0.58-0.99]). Using the OLTX-specific approaches, goodness-of-fit for both hospital and 1-yr mortality was good (p = .2-.57) but discrimination was only moderate (receiver operator characteristic area under the curve, 0.675-0.723).

CONCLUSIONS

APACHE II is a good predictor of short- and long-term mortality after liver transplantation, especially when using OLTX-specific coefficients. Because fit and calibration were better than discrimination, APACHE II will be most useful in the prediction of risk for groups of patients (e.g., in clinical trials or institutional comparisons) rather than for individuals. This study raises the possibility that APACHE II may be useful for long-term mortality prediction in other critically ill populations. The overestimation of mortality using the original equation suggests that orthotopic liver transplantation, by reversing the underlying pathophysiology, may modify risk.

Applications of musculoskeletal sonography

To successfully examine the musculoskeletal system sonographically, one must understand the normal musculoskeletal anatomy and function and be aware of the abnormal processes that affect the musculoskeletal structures. The goal of this review article is to provide a systematic approach to sonographic examination of the musculoskeletal system. The general sonographic appearances of normal and abnormal muscles, tendons, ligaments, bursae, and nerves are reviewed. The article then applies this general information to specific clinical applications by reviewing the normal anatomy of and specific pathologic conditions that affect the shoulder, elbow, hand, wrist, hip, knee, ankle, and foot.

Novel bioartificial liver support system: preclinical evaluation

Preclinical safety and efficacy evaluation of a novel bioartificial liver support system (BLSS) was conducted using a D-galactosamine canine liver failure model. The BLSS houses a suspension of porcine hepatocytes in a hollow fiber cartridge with the hepatocytes on one side of the membrane and whole blood flowing on the other. Porcine hepatocytes harvested by a collagenase digestion technique were infused into the hollow fiber cartridge and incubated for 16 to 24 hours prior to use. Fifteen purpose-bred male hounds, 1-3 years old, 25-30 kg, were administered a lethal dose, 1.5 g/kg, of D-galactosamine. The animals were divided into three treatment groups: (1b) no BLSS treatment (n = 6); (2b) BLSS treatment starting at 24-26 h post D-galactosamine (n = 5); and (2c) BLSS treatment starting at 16-18 h post D-galactosamine (n = 4). While maintained under isoflurane anesthesia, canine supportive care was guided by electrolyte and invasive physiologic monitoring consisting of arterial pressure, central venous pressure, extradural intracranial pressure (ICP), pulmonary artery pressure, urinary catheter, and end-tidal CO2. All animals were treated until death or death-equivalent (inability to sustain systolic blood pressure > 80 mmHg for 20 minutes despite massive fluid resuscitation and/or dopamine administration), or euthanized at 60 hours. All animals developed evidence of liver failure at 12-24 hours as evidenced by blood pressure lability, elevated ICP, marked hepatocellular enzyme elevation with microscopic massive hepatocyte necrosis and cerebral edema, elevated prothrombin time, and metabolic acidosis. Groups 2b and 2c marginally prolong survival compared with Group 1b (pairwise log rank censored survival time analysis, p = 0.096 and p = 0.064, respectively). Since survival times for Groups 2b and 2c are not significantly different (p = 0.694), the groups were combined for further statistical analysis. Survival times for the combined active treatment Groups 2b and 2c are significantly prolonged versus Group 1b (p = 0.047). These results suggest the novel BLSS reported here can have a significant impact on the course of liver failure in the D-galactosamine canine liver failure model. The BLSS is ready for Phase I safety evaluation in a clinical setting.

Early complications after orthotopic liver transplantation

The cost and impact of early post-transplant complications continue to be high. Diagnosis and management involves a high index of suspicion, rapid diagnostic and therapeutic interventions, and elimination of technical problems. Preoperative assessment of the donor and recipient medical condition and meticulous attention to detail during the technical performance of OLTx are the mainstays in achieving a good outcome.

Fulminant hepatic failure

Fulminant hepatic failure is a disease of varied causes and a high mortality rate. A sudden onset, jaundice, hepatic encephalopathy, and multiorgan failure are the hallmarks of this syndrome. The management of patients with FHF requires a multidisciplinary approach and intense monitoring. The availability of liver transplantation has provided the means to rescue such patients from near-certain death. Early prognostication and timely availability of donor livers are requirements for a successful outcome. The development of effective artificial liver support devices may greatly prolong the window of opportunity to provide a donor liver, or alternatively, to allow the native liver to regenerate.

Impact of acute renal failure on mortality in end-stage liver disease with or without transplantation

BACKGROUND

Acute renal failure (ARF) is traditionally considered a poor prognostic factor in end-stage liver disease and is associated with a mortality approaching 90%. While the increased use of orthotopic liver transplantation (OLTX) has changed the outcome for patients with end-stage liver disease (ESLD), it is not clear whether this has affected the outcome of patients with ESLD and ARF.

METHODS

We prospectively followed the course of ARF in 177 patients with ESLD being evaluated for OLTX. Of these patients 111 received OLTX. In-hospital mortality was compared to that of 316 ESLD patients without ARF, of these 196 received OLTX. Variables include severity of illness as assessed by APACHE II, co-morbid conditions, oliguria, need for renal replacement therapy, and etiologies of ESLD and ARF. These variables were evaluated with respect to the outcome in-hospital mortality by multiple regression analysis for patients with ARF.

RESULTS

Mortality was significantly higher in oliguric versus non-oliguric patients and in patients who required renal replacement therapy. Mortality correlated strongly with the number of co-morbid conditions, especially sepsis, encephalopathy, respiratory failure, and DIC. For OLTX recipients who developed ARF, no significant difference in survival occurred whether the ARF was pre-OLTX or post-OLTX.

CONCLUSION

ARF was associated with an increased mortality consistent with the known adverse prognostic effect of ARF in ESLD. However, the effect of ARF on mortality was remarkably reduced in patients who received a functioning OLTX. Since expected mortality generated from APACHE II scores was higher in the ARF groups, it is not clear that there is an additional effect of ARF beyond the physiologic derangements captured by APACHE II. ARF per se should not necessarily be a contraindication to liver transplant.

Mononeuropathies associated with liver transplantation

Mononeuropathies associated with orthotopic liver transplantation were evaluated in a prospective manner. Ten percent of liver transplant recipients were noted to have focal peripheral nerve lesions in the postoperative period. The ulnar nerve was most commonly involved, with intraoperative compression or postoperative trauma as possible mechanisms of injury. Other upper extremity mononeuropathies were likely a result of vascular cannulations. No brachial plexus injuries occurred. Diabetes and alcoholism were not risk factors for the development of a mononeuropathy.

Quantitative analysis of respiratory, motor, and sensory function after supraclavicular block

The incidence and clinical significance of hemidiaphragmatic paresis after supraclavicular block of the brachial plexus is unknown. Eight healthy volunteers received a supraclavicular block with a standard technique using 30 mL of 1.5% lidocaine. Respiratory function was assessed with ultrasound of the diaphragm, respiratory inductive plethysmography (RIP), and pulmonary function tests (PFT) every 20 min. Sensory block was assessed with pinprick and motor block with isometric force dynamometry every 20 min. Four of eight subjects demonstrated hemidiaphragmatic paresis on both ultrasound and RIP. No subject experienced changes in PFT values or subjective symptoms of respiratory difficulty. Motor and sensory blockade outlasted hemidiaphragmatic paresis. These results are contrasted to the often symptomatic, 100% incidence of hemidiaphragmatic paresis seen after interscalene block. In this study of healthy volunteers, supraclavicular block was associated with a 50% incidence (95% confidence interval 14-86) of hemidiaphragmatic paresis that was not accompanied by clinical evidence of respiratory compromise.

IMPLICATIONS

Interscalene block is always associated with diaphragmatic paralysis and respiratory compromise. The significance of these side effects after supraclavicular block is unknown. Using sensitive measures of respiratory function, we determined that diaphragmatic paralysis occurs less often with the supraclavicular approach and is not associated with respiratory difficulties in healthy subjects.

Etiology of metabolic acidosis during saline resuscitation in endotoxemia

We sought to understand the mechanism of metabolic acidosis that results in acute resuscitated endotoxic shock. In six pentobarbital-anesthetized dogs, shock was induced by Escherichia coli endotoxin infusion (1 mg/kg) and was treated with saline infusion to maintain mean arterial pressure > 80 mmHg. Blood gases and strong ions were measured during control conditions and at 15, 45, 90, and 180 min after endotoxin infusion. The mean saline requirement was 1833+/-523 mL over a 3 h period. The total acid load from each source was calculated using the standard base deficit. The mean arterial pH decreased from 7.32 to 7.11 (p < .01); pCO2 and lactate were unchanged. Saline accounted for 42% of the total acid load. However, 52% of the total acid load was unexplained. Although serum Na+ did not change, serum Cl-increased (127.7+/-5.1 mmol/L vs. 137.0+/-6.1 mmol/L; p=.016). We conclude that saline resuscitation alone accounts for more than one-third of the acidosis seen in this canine model of acute endotoxemia, whereas lactate accounts for less than 10%. A large amount of the acid load can be attributed to differential Na+ and Cl- shifts from extravascular to vascular spaces.

Acute myopathy after liver transplantation

Acute myopathy is a cause of weakness and additional morbidity in a variety of critically ill patients, including transplant recipients. We report the incidence of and risk factors associated with acute myopathy after orthotopic liver transplantation (OLTx). One hundred consecutive adult patients were prospectively assessed for muscle weakness after OLTx. Electrodiagnostic studies and muscle biopsies were performed on consenting affected patients. Potential risk factors for myopathy were evaluated in patients with myopathy versus control subjects. Seven patients developed acute persistent weakness after OLTx. Electrodiagnostic studies were consistent with a necrotizing myopathy. Histopathologic evaluation in five revealed a necrotizing myopathy with loss of myosin thick filaments. A higher initial index of illness severity, dialysis requirement, and higher doses of glucocorticoids were associated with development of myopathy. Patients with myopathy subsequently remained in the intensive care unit (ICU) longer than unaffected patients. In conclusion, acute substantial weakness was a source of additional morbidity in 7% of patients after OLTx. Most had myopathy with loss of myosin thick filaments. Patients with greater severity of illnesses and renal failure requiring dialysis were more likely to be affected. The effect of reducing exposure to corticosteroids in high-risk patients warrants further investigation.

Effect of quinupristin/dalfopristin on the outcome of vancomycin-resistant Enterococcus faecium bacteraemia: comparison with a control cohort

Serious infection with vancomycin-resistant Enterococcus faecium (VREF) strains has no proven effective antimicrobial therapy. We compared the clinical and bacteriological outcomes of 20 patients with VREF bacteraemia treated with quinupristin/dalfopristin (RP 59500), an investigational streptogramin, with a historical cohort of 42 patients with VREF bacteraemia treated with other agents. Quinupristin/dalfopristin demonstrated in-vitro bacteriostatic activity against all 20 initial VREF blood isolates (MIC range 0.03-0.50 mg/L) by macrobroth dilution. The clinical characteristics of both groups were comparable for major outcome-dependent variables. There were five cases of recurrent VREF bacteraemia in the quinupristin/dalfopristin-treated cohort and 21 in the controls (P = 0.11); persistence of VREF at the primary site was found in six and 18 of the evaluable patients with follow-up cultures in these two cohorts (P = 0.06). In-hospital mortality was high in both groups: 65% in the quinupristin/dalfopristin group and 52% in the control group; however, VREF-associated mortality was significantly lower in the quinupristin/dalfopristin group (five and 17 respectively; P = 0.05). Follow-up susceptibility testing of five VREF isolates in the quinupristin/ dalfopristin group did not demonstrate resistance to quinupristin/dalfopristin. Quinupristin/ dalfopristin may be a useful agent for the therapy of serious VREF infection. Further clinical investigations are warranted to confirm or refute its clinical efficacy.

Release of lactate by the lung in acute lung injury

The pathogenesis of hyperlactatemia during sepsis is poorly understood. We have previously described an increase in lactate concentration across the lung in the dog during early endotoxemia. Accordingly, we sought to determine if the lung releases lactate in humans and what relation this has with lung injury.

METHODS

We measured lactate concentrations across the lung and lung injury scores (LIS) in two groups of patients. Group 1 consisted of nine patients with acute lung injury (LIS > or = 2.0) and elevated lactate concentrations (> 2.0 mmol/L). Group 2 contained 12 patients with no acute lung injury (LIS scores < or = 1.5), with or without increased lactate concentrations. Simultaneous measurements of plasma lactate and blood gases were obtained from indwelling arterial and pulmonary artery catheters. Measurements of cardiac output were also obtained. Lactate measurements were done using a lactate analyzer (YSI; Yellow Springs, Ohio).

RESULTS

For each patient with acute lung injury and hyperlactatemia, an arterial-venous lactate gradient existed demonstrating release of lactate by the lung. This gradient persisted after correction for changes in hemoconcentration across the lung. The lactate gradient across the lung was 0.4 +/- 0.2 mmol/L for group 1 vs 0.05 +/- 0.1 mmol/L for group 2 (p = 0.001). This corresponded to a mean pulmonary lactate flux of 231.3 +/- 211.3 vs 5.0 +/- 37.2 mmol/h (p = 0.001). The lactate flux and the arterial-venous lactate difference correlated with LIS both for the entire sample and for the subgroup with hyperlactatemia (r = 0.69, p < 0.01). Pulmonary lactate flux was not related to arterial lactate levels (r = 0.25).

CONCLUSION

In patients with acute lung injury and hyperlactatemia, the lung is a major source of lactate and lactate flux correlates with LIS. This lactate flux could explain some of the hyperlactatemia seen in sepsis.

Splanchnic buffering of metabolic acid during early endotoxemia

PURPOSE

We sought to determine the sites of metabolic acid production and clearance during acute endotoxemia.

MATERIALS AND METHODS

In 10 pentobarbital-anesthetized dogs, flow was measured (ultrasonic probes) for the protal vein, hepatic artery, and renal artery. Catheters were inserted into the hepatic vein, pulmonary artery, renal vein and portal vein. Measurements of blood gases and strong ions were obtained from each site during control conditions and after 30 minutes of intravenous infusion of 1 mg/kg of Escherichia coli endotoxin. The total metabolic acid flux across each organ was calculated using the standard base excess formula and the effective strong ion difference method. PaCO2 was maintained by controlled ventilation.

RESULTS

Mean arterial pH decreased from 7.34 to 7.22 with acute endotoxemia. Although transvisceral pH gradients revealed net acid release, the source of this was purely respiratory (carbon dioxide). During early endotoxemia, the gut significantly increased metabolic acid uptake (36.60 +/- 6.60 mmol/h, P < .05).

CONCLUSIONS

We conclude that during early endotoxemia in the dog, the gut is a major site of metabolic acid removal.

Acute myopathy of intensive care: clinical, electromyographic, and pathological aspects

An acute myopathy of intensive care occurs in critically ill patients treated with intravenous corticosteroids and neuromuscular junction-blocking agents. The full clinicopathological spectrum is uncertain. We evaluated the clinical, electrodiagnostic, and histopathological features of 14 patients who developed acute myopathy of intensive care after organ transplantation or during treatment of severe pulmonary disorders and sepsis. Patients received high-dose intravenous corticosteroids, usually in conjunction with relatively low to moderate doses of neuromuscular junction-blocking agents. After discontinuation of the latter drugs, most had diffuse, flaccid weakness with failure to wean from mechanical ventilation. Electrodiagnostic findings were consistent with a necrotizing myopathy. Muscle histopathology revealed myopathy with loss of thick filaments in 79%, mild myopathic changes in 14%, and atrophy of type 1 and type 2 fibers in 7%. Loss of thick filaments was identified in muscle biopsy specimens obtained 30 +/- 11 days (mean +/- standard deviation) after intravenous corticosteroid treatment but not in those obtained earlier (12 +/- 2 days). Critically ill patients, including those receiving organ transplants, may develop acute myopathy of intensive care after exposure to intravenous corticosteroids and neuromuscular junction-blocking agents, although the exposure to the latter drugs may be minimal. Selective loss of thick filaments is common in acute myopathy of intensive care, especially if the muscle biopsy specimen is obtained 2 weeks or more after intravenous corticosteroid exposure.

Differences in outcomes for patients with bacteremia due to vancomycin-resistant Enterococcus faecium or vancomycin-susceptible E. faecium

To determine the differences in outcome in cases of enterococcal bacteremia due to vancomycin-resistant organisms, we compared consecutive patients on a liver transplant service who had clinically significant bacteremia due to vancomycin-resistant Enterococcus faecium (VREF) (n = 54) with a contemporaneous cohort of patients who had vancomycin-susceptible E. faecium (VSEF) bacteremia (n = 48). VREF bacteremia occurred significantly later in the hospitalization than did VSEF bacteremia (43 days vs. 24 days, respectively; P < .01); in addition, VREF was more frequently the sole blood pathogen isolated (91% of patients) than was VSEF (56% of patients) (P = .0002). Invasive interventions for intraabdominal and intrathoracic infection were required more often in the VREF cohort than in the VSEF cohort (34 of 45 patients vs. 20 of 41 patients, respectively; P = .01). Vancomycin resistance more frequently resulted in recurrent bacteremia (22 of 54 patients infected with VREF vs. 7 of 48 patients infected with VSEF; P = .006), persistent isolation of Enterococcus species at the primary site (27 of 33 patients infected with VREF vs. 7 of 18 patients infected with VSEF; P = .005), and endovascular infection (4 patients infected with VREF vs. none infected with VSEF). The decrement in patient survival, as measured from the last bacteremic episode, was greater in the VREF cohort (P = .02). Vancomycin resistance, shock, and liver failure were independent risk factors for Enterococcus-associated mortality. Higher rates of refractory infection, serious morbidity, and attributable death occurred in the VREF cohort and were partially mediated by the lack of effective antimicrobial therapy.

Quantification of thrombelastographic changes after blood component transfusion in patients with liver disease in the intensive care unit

Thrombelastography (TEG) can be used to monitor hemostasis and guide transfusion therapy during orthotopic liver transplantation. However, data are limited regarding the type and quantity of blood components necessary for TEG-guided blood component transfusion in coagulopathic critically ill patients with liver disease. We evaluated changes in four thrombelastogram variables (reaction time, thrombin constant time, alpha angle, and maximum amplitude) in whole blood samples after 74 separate blood component transfusions in 60 critically ill patients with a coagulopathy and liver disease. Only platelets significantly improved TEG variables in patients who received a single type of blood component. Each unit of platelets decreased the reaction and thrombin constant time by 0.43 (P < 0.05) and 0.82 (P < 0.005) min, respectively, increased the alpha angle by 1.5 degrees (P < 0.005), and the maximum amplitude by 1.4 mm (P < 0.005). In patients who received multiple blood components, cryoprecipitate decreased the thrombin constant time by 0.56 min/U (P < 0.05), and each unit of platelets decreased the thrombin constant time by 0.39 min (P < 0.005), and increased the alpha angle and maximum amplitude by 0.63 degrees (P < 0.05) and 0.99 mm (P < 0.005), respectively. We conclude that platelet transfusions, alone or in combination with other blood components, are most effective for improving abnormal TEG variables in coagulopathic critically ill patients with liver disease.

Fetal cleft lip with and without cleft palate: US classification and correlation with outcome

PURPOSE

To develop a prenatal ultrasonographic (US) classification of cleft lip with or without cleft palate (CL-P) and correlate the classification with fetal outcome.

MATERIALS AND METHODS

During a 5-year period (1988 to 1993), 65 fetuses with CL-P were identified with prenatal US at one of two referral centers for high-risk obstetric cases. Sonograms from each case were prospectively and retrospectively evaluated. Clefts were classified into one of five categories: type 1, cleft lip alone (n = 5); type 2, unilateral cleft lip and palate (n = 15); type 3, bilateral cleft lip and palate (n = 20); type 4, midline cleft lip and palate (n = 21); and type 5, facial defects associated with amniotic bands or limb-body-wall complex (n = 4).

RESULTS

The US classification correlated with severity of defect and fetal outcome. Type 4 and 5 clefts were universally associated with concurrent anomalies and a fetal outcome, type 1 clefts with a lower rate of anomalies (20%), and type 2 and 3 clefts with intermediate prognosis. Chromosome abnormalities also varied with the type of cleft as follows: type 1, 0%; type 2, 20%; type 3, 30%; type 4, 52%; and type 5, 0%.

CONCLUSION

Prenatal classification of fetal CL-P correlates with fetal outcome. This classification should help counseling and management.

Hepatic anion flux during acute endotoxemia

We sought to determine the role the liver might play in the regulation of anion-cation balance during both stable baseline conditions and acute endotoxemia. Ten pentobarbital sodium-anesthetized dogs were instrumented at laparotomy with ultrasonic flow probes around the left renal artery, portal vein, and hepatic artery, and catheters were inserted into the hepatic vein, portal vein, pulmonary artery, left renal vein, and abdominal aorta. Measurements were obtained from each site at baseline and 30-45 min after the intravenous infusion of endotoxin. The total anion flux across the liver was calculated from the strong-ion difference. At baseline, the liver removed anions from the circulation (-0.34 meq/min). With early endotoxemia, however, the liver switched to the release of anions (0.12 meq/min; P = 0.0046). After endotoxin administration, the gut, which was neutral at baseline, began to take up anions (-0.47 meq/min; P = 0.008). Anion flux across the lung and kidney was unchanged. We conclude that in the dog the liver, which removes anions at baseline, switches to release anions during early endotoxemia and may be a major site of acid production in early sepsis.