bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementing an energetic life cycle analysis to prove the benefits of lignocellulosic feedstocks with protein separation for the chemical industry from the existing bioethanol industry
Authors: Brehmer Ben , Sanders Johan
Published: August 2008

The biofuel ethanol is currently being produced in large quantities from corn in the US and from wheat in the EU and further capacity expansion is expected. Relying on the so‐called 1st generation technology, only the starch contained in the edible portion of the crops (ears/grains) is subjected to fermentation. Following life cycle calculations reveals minute levels of fossil fuel replacement placing doubt on its renewability and an imbalance on the domestic animal feed markets are immerging due to the by‐product distiller grains. Additional utilization of the lignocellulosic and protein components of the by‐product through new developments has the potential to alleviate both setbacks. A cradle‐to‐factory gate analysis was performed on a variety of bioethanol production layouts incorporating the newest technological developments to determine the maximum fossil fuel reduction potential. Expanding to include lignocellulose pretreatment for ethanol production with protein separation for amine‐based chemical production can increase the fossil fuel mitigation potential by seven‐ to ninefold for US‐corn and five‐ to eightfold for EU‐wheat bioethanol facilities. Biotechnol. Bioeng. 2009; 102: 767–777. © 2008 Wiley Periodicals, Inc.
Genetic analysis of G protein‐coupled receptor expression in Escherichia coli: Inhibitory role of DnaJ on the membrane integration of the human central cannabinoid receptor
Authors: Skretas Georgios , Georgiou George
Published: August 2008

The overexpression of G protein‐coupled receptors (GPCRs) and of many other heterologous membrane proteins in simple microbial hosts, such as the bacterium Escherichia coli, often results in protein mistargeting, aggregation into inclusion bodies or cytoplasmic degradation. Furthermore, membrane protein production is very frequently accompanied by severe cell toxicity. In this work, we have employed a genetic strategy to isolate E. coli mutants that produce markedly increased amounts of the human central cannabinoid receptor (CB1), a pharmacologically significant GPCR that expresses very poorly in wild‐type E. coli. By utilizing a CB1 fusion with the green fluorescent protein (GFP) and fluorescence‐activated cell sorting (FACS), we screened an E. coli transposon library and identified an insertion in dnaJ that resulted in a large increase in CB1‐GFP fluorescence and a dramatic enhancement in bacterial production of membrane‐integrated CB1. Furthermore, the dnaJ::Tn5 inactivation suppressed the severe cytotoxicity associated with CB1 production. This revealed an unexpected inhibitory role of the chaperone/ co‐chaperone DnaJ in the protein folding or membrane insertion of bacterially produced CB1. Our strategy can be easily adapted to identify expression bottlenecks for different GPCRs or any other integral membrane protein, provide useful and unanticipated mechanistic insights, and assist in the construction of genetically engineered E. coli strains for efficient heterologous membrane protein production. Biotechnol. Bioeng. 2009;102: 357–367. © 2008 Wiley Periodicals, Inc.
Effect of Ultrasonic Waves on the Saccharification Processes of Lignocellulose
Authors: Zhang Y. Q. , Fu E. H. , Liang J. H.
Published: August 2008

The pretreatment and saccharification process of lignocellulose were subjected to ultrasonic waves to enhance the saccharification rate. The morphology, structure and crystal performance of the original and treated lignocellulose samples were characterized by SEM and FTIR. Moreover, the effect of different pretreatment methods on the structure of the raw materials and the influence of ultrasonic waves on the saccharification rate, were studied. SEM photographs show that the surface conformation of the granulated raw material is not changed, because the energy of the ultrasonic vibration is too low to cause changes to its structure. A FTIR spectrum shows that the ultrasonically assisted alkali pretreatment effectively destroys the intermolecular hydrogen bonding of lignocellulose and decreases its crystallinity. The catalytic efficiency of cellulase was increased by 70 % under ultrasonic treatment. Therefore, the ultrasonically assisted alkali pretreatment can improves the degradation rate of lignin and the saccharification rate of zymohydrolysis. The mechanism of the effect of ultrasonic waves on the enzymatic catalysis process is also discussed in detail.
Reduction of Energy Consumption and Greenhouse Gas Emissions in a Plant for the Separation of Amines
Authors: Jantes‐Jaramillo D. , Segovia‐Hernández J. G. , Hernández S.
Published: August 2008

The chemical industry comprises of the companies that produce industrial chemicals. It is central to the modern world economy, converting raw materials into more than 70 000 different products. However, environmental regulations and the risk of climate change are putting pressure on the chemical industry to minimize greenhouse gas emissions. In this work, we use the concept of process intensification (using thermally coupled distillation) to reduce energy consumption and CO2 emissions in a plant for the separation of amines. The results show that the use of thermally coupled distillation sequences can be related to a reduction in energy consumption, greenhouse gas emissions, and good theoretical control properties in the re‐designed plant.
Configurationally driven folding of model tetrapeptides containing L‐ or D‐morpholine‐3‐carboxylic acids as β‐turn nucleators
Authors: Trabocchi Andrea , Sladojevich Filippo , Guarna Antonio
Published: August 2008

The conformational analysis by NMR, IR, and molecular modeling of tetrapeptides containing morpholine‐3‐carboxylic acid (Mor) as a proline surrogate is presented. The relationship between the chirality of the cyclic amino acid at position i+1 and the turn propensity is maintained with respect to the reference proline‐containing peptides, although marked differences in the type of folded structures were observed. The conformational profile of morpholine‐containing turn peptides as a function of the chirality of the cyclic amino acid indicated that the heterochiral tetrapeptide containing the D‐isomer of the cyclic amino acid is more prone to nucleate compact folded structures, although with no resemblance to the β‐turn structures of D‐proline‐containing peptides. Also, the solvation system proved to influence the organization of folded structures, as in the more interactive CD3CN the model peptides showed more compact conformations. The L‐Mor‐containing peptide displayed two rotamers at the Val‐Mor amide bond. The trans isomer did not experience any turn structures, nor any intramolecular hydrogen‐bonds, whereas the cis isomer showed a strong preference for a type VI β‐turn structure, thus providing a different conformational asset with respect to the β‐turn structure as reported for the reference L‐proline model peptide. Chirality, 2008. © 2009 Wiley‐Liss, Inc.
Targeting prostate cancer for focal destruction
Authors: Taneja Samir S. , Tareen Basir
Published: August 2008

With an increasing number of men diagnosed with low‐risk prostate cancer because of prostate‐specific antigen screening, there is growing focus on avoiding overtreatment by radical surgery or radiation. While focal destruction of prostate cancer is an appealing concept, it remains unclear whether current diagnostic tools provide an adequate ability to map cancer for focal destruction. Candidate selection and improvements in diagnostic tools are essential prior to implemention of focal therapy.
Utility of extended pattern prostate biopsies for tumor localization
Authors: Schulte Ryan T. , Wood David P. , Daignault Stephanie , Shah Rajal B. , Wei John T.
Published: August 2008

BACKGROUND.

Focal targeted therapy has been proposed as a potential treatment for localized prostate cancer in an attempt to reduce morbidity. However, these modalities rely heavily on accurate tumor localization to achieve total tumor ablation. In the current study, we sought to examine the ability of contemporary extended pattern prostate biopsy to predict the location of tumors.

METHODS.

A total of 281 men with prostate cancer detected via a standardized extended pattern biopsy template with at least 12 cores and who subsequently underwent radical prostatectomy were evaluated. Tumor location on biopsy, stratified by laterality and by site (apex vs mid‐base prostate), was compared with corresponding locations on the prostatectomy specimen. Generalized estimating equation models were developed to assess the effects of clinical variables on pathologic agreement between biopsy and prostatectomy specimens.

RESULTS.

Of the 281 prostate biopsies, the positive predictive value (PPV) of right and left needle biopsy was high at 97.3% and 96.7%, respectively. However, the negative predictive value (NPV) was low at 24.7% and 31.3%, respectively. When more specific locations were considered, the NPV improved at the apex. However, this came at a cost to the PPV. Tumor focality on prostatectomy specimen was the only clinical feature found to be significantly and consistently related to pathologic agreement.

CONCLUSIONS.

Contemporary extended pattern prostate biopsy, although able to diagnose cancers, fails to provide reliable localization of tumors to specific areas of the prostate. Focal therapy, which relies heavily on localization, should only be performed with this caveat in mind. Cancer 2008. © 2008 American Cancer Society.
Concurrent and longitudinal associations of basal and diurnal cortisol with mental health symptoms in early adolescence
Authors: Shirtcliff Elizabeth A. , Essex Marilyn J.
Published: August 2008

Recent biosocial theories postulate that both biological risk and the social context influence the development of mental health problems [Boyce and Ellis (2005) Development and Psychopathology, 17(2), 271–301]. Guided by this framework, we examined whether basal cortisol and its diurnal rhythm were associated with mental health symptoms in early adolescence. Because cross‐sectional and longitudinal investigations sometimes reveal different cortisol–mental health associations, we examined the association both concurrently and longitudinally when children transition to middle school, a time which entails a major change in social context from single to multiple teachers, classrooms, and sets of classmates. Salivary cortisol was measured three times a day (waking, afternoon, and bedtime) across 3 days when adolescents were 5th graders. Mental health was measured when adolescents were in 5th and 7th grades, just before and after the transition to middle school. To deal with the substantial comorbidity of internalizing and externalizing symptoms at this developmental stage, mental health measures distinguished overall symptom severity from the preponderance of internalizing versus externalizing symptoms (i.e., directionality). A three‐level Hierarchical Linear Model was used to extract basal cortisol and its diurnal rhythm separate from the day‐to‐day and within‐the‐day fluctuations in cortisol in response to daily experiences. Results were specific to symptom severity, suggesting that cortisol is a nonspecific risk factor for mental health symptoms in young adolescents. At 5th grade, low basal cortisol was associated with concurrent symptom severity. However, longitudinally, it was adolescents with high cortisol at 5th grade who were at risk for increasing mental health symptoms by 7th grade. Flat diurnal rhythms in 5th grade were related to levels of symptom severity at both 5th and 7th grades. Considering the change in social context, as defined by the transition to middle school, helped resolve seemingly inconsistent evidence that both hypo‐ and hyper‐arousal were associated with mental health symptoms in early adolescence. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 690‐703, 2008.
Identification of prostaglandin E2 receptors mediating perinatal masculinization of adult sex behavior and neuroanatomical correlates
Authors: Wright Christopher L. , Burks Scott R. , McCarthy Margaret M.
Published: August 2008

Prostaglandin E2 (PGE2) mediates the organization of male rat sexual behavior and medial preoptic area (MPOA) neuroanatomy during a sensitive perinatal window. PGE2 is up‐regulated in response to estradiol, and initiates a two‐fold increase in dendritic spines densities on neurons. All the four receptors for PGE2 and EP1‐4 are present in developing POA, a critical region controlling male sexual behavior. Previous studies explored that EP receptors are involved in PGE2‐induction of neonatal levels of spinophilin protein, a surrogate marker for dendritic spine formation, but did not assess behavioral masculinization. Here, we used two approaches, suppression of EP receptor expression with antisense oligonucleotides and activation of EP receptors with selective agonists, to test which receptors are necessary and sufficient, respectively, for the effects of PGE2 on behavior and neuronal morphology. In female rats, neonatal treatment with antisense oligonucleotides against EP2 or EP4 but not EP1 or EP3 completely prevented the expression of adult behavior organized by PGE2 exposure. The effects of ONO‐DI‐004, ONO‐AE‐259‐01, ONO‐AE‐248, and ONO‐AE1‐329 (EP1‐4 agonists respectively) were equivalent to PGE2 treatment, which suggests activating any EP receptor neonatally suffices in masculinizing sex behavior. When given alone, not all EP agonists increased neonatal POA spinophilin levels; yet giving each agonist neonatally increased adult levels. Moreover, adult spinophilin levels significantly correlated with two measures of male sexual behavior. The body of evidence suggests that EP2 and EP4 are both necessary and sufficient for PGE2‐induced masculinization of sex behavior, whereas EP1 and EP3 provide redundant roles. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
The atRA‐responsive gene neuron navigator 2 functions in neurite outgrowth and axonal elongation
Authors: Muley P.D. , McNeill E.M. , Marzinke M.A. , Knobel K.M. , Barr M.M. , Clagett‐Dame M.
Published: August 2008

Neuron navigator 2 (Nav2) was first identified as an all‐trans retinoic acid (atRA)‐responsive gene in human neuroblastoma cells (retinoic acid‐induced in neuroblastoma 1, RAINB1) that extend neurites after exposure to atRA. It is structurally related to the Caenorhabditis elegans unc‐53 gene that is required for cell migration and axonal outgrowth. To gain insight into NAV2 function, the full‐length human protein was expressed in C. elegans unc‐53 mutants under the control of a mechanosensory neuron promoter. Transgene expression of NAV2 rescued the defects in unc‐53 mutant mechanosensory neuron elongation, indicating that Nav2 is an ortholog of unc‐53. Using a loss‐of‐function approach, we also show that Nav2 induction is essential for atRA to induce neurite outgrowth in SH‐SY5Y cells. The NAV2 protein is located both in the cell body and along the length of the growing neurites of SH‐SY5Y cells in a pattern that closely mimics that of neurofilament and microtubule proteins. Transfection of Nav2 deletion constructs in Cos‐1 cells reveals a region of the protein (aa 837–1065) that directs localization with the microtubule cytoskeleton. Collectively, this work supports a role for NAV2 in neurite outgrowth and axonal elongation and suggests this protein may act by facilitating interactions between microtubules and other proteins such as neurofilaments that are key players in the formation and stability of growing neurites. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
Electrocommunication signals alone are sufficient to increase neurogenesis in the brain of adult electric fish, Apteronotus leptorhynchus
Authors: Dunlap Kent D. , McCarthy Elizabeth A. , Jashari Denisa
Published: August 2008

Social interaction can have profound influences on the structure of the adult brain, but little is known about the precise stimulus feature found within social interaction that induces such brain plasticity. We examined the effects of social stimuli on cell addition and radial glial fiber formation in the brains of adult electric fish. These fish communicate primarily through weak, quasi‐sinusoidal electric signals. Fish were housed in isolation, paired with another fish or exposed to only the electrocommunication signals of another fish for 7 days. After 3 days of exposure to these stimulus conditions, fish were injected with bromodeoxyuridine (BrdU) to mark newborn cells. We sacrificed the fish 4 days after BrdU injection and used immunohistochemistry to measure cell addition (BrdU+), the fraction of added cells that differentiated into neurons (BrdU+/NeuroTrace®+) and the density of radial glia fibers (vimentin+) in the periventricular zone of the diencephalon. Fish that were exposed only to the electrocommunication signals of another fish and no other social stimuli had equivalent levels of cell addition and radial glial fiber density to fish that were housed with full social interaction and higher levels than fish housed in isolation. About 60% of the added cells differentiated into neurons; this fraction did not differ among treatment groups. Artificial sine wave electrical stimuli that mimicked electrocommunication signals were ineffective in increasing cell addition and glia fiber formation above those found in isolated fish. Thus, stimuli through a single modality are sufficient for inducing this brain plasticity, but the waveform or dynamic features of communication signals are crucial for the effect. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
Stabilization of Long Cationic EMACs by Reduction or Loss of One Metal Ion
Authors: Ismayilov Rayyat H. , Wang Wen‐Zhen , Wang Rui‐Ren , Huang Yi‐Lin , Yeh Chen‐Yu , Lee Gene‐Hsiang , Peng Shie‐Ming
Published: August 2008

The new pyrimidyl‐ and naphthyridyl‐modulated pentapyridyltetramine ligand (H3N9‐2pm) and its linear nona‐ and octanickel chain complexes were successfully synthesized. The nonanickel complex [Ni9(μ9‐N9‐2pm)4Cl2](PF6)2 (1) contains two fully delocalized, mixed‐valence [Ni2(napy)4]3+ units. Magnetic measurements performed on the defective octanuclear complex [Ni8(μ8‐N9‐2pm)4Cl2](PF6)2 (2) demonstrate that the metal chain provides a pathway of magnetic superexchange coupling over the extended metal atom chain (EMAC). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A parylene‐based dual channel micro‐electrophoresis system for rapid mutation detection via heteroduplex analysis
Authors: Sukas Sertan , Elif Erson Ayse , Sert Cuneyt , Kulah Haluk
Published: August 2008

A new dual channel micro‐electrophoresis system for rapid mutation detection based on heteroduplex analysis was designed and implemented. Mutation detection was successfully achieved in a total separation length of 250 μm in less than 3 min for a 590 bp DNA sample harboring a 3 bp mutation causing an amino acid change. Parylene‐C was used as the structural material for fabricating the micro‐channels as it provides conformal deposition, transparency, biocompatibility, and low background fluorescence without any surface treatment. A new dual channel architecture was derived from the traditional cross‐channel layout by forming two identical channels with independent sample loading and waste reservoirs. The control of injected sample volume was accomplished by a new u‐turn injection technique with pull‐back method. The use of heteroduplex analysis as a mutation detection method on a cross‐linked polyacrylamide medium provided accurate mutation detection in an extremely short length and time. The presence of two channels on the microchip offers the opportunity of comparing the sample to be tested with a desired control sample rapidly, which is very critical for the accuracy and reliability of the mutation analyses, especially for clinical and research purposes.
Gas utilities: Environmental bad guys?
Authors: Smith William H.
Published: August 2008

Today we are confronted with external costs, imposed by decisions made in the past, when the consequences of those decisions could not be foreseen. Utilities were behaving reasonably in light of industry practices at the time. Recovery of these costs should not be treated under nationsof fault or prudence; there is no blame to assess. The costs are simply a result of transitions in the industry and it is fair for all elements of the industry to shoulder a share of these costs
Immigrants and the use of preventive care in the United States
Authors: Pylypchuk Yuriy , Hudson Julie
Published: August 2008

Using data from the Medical Expenditure Panel Survey, we compare immigrants' use of preventive care with that of natives. We employ a multinomial switching regression framework that accounts for non‐random selection into continuous private insurance, temporary private insurance, public insurance, and no insurance. Our results indicate that among the populations with continuous private coverage and without coverage (uninsured), immigrants, especially non‐citizens, are less likely to use preventive care than natives. We find that the longer immigrants stay in the US the more their use of care approximates to that of natives. However, for most types of care, immigrants' use of care never fully converges to that of natives. Among the publicly insured population, immigrants' use of care is similar to natives, but non‐citizen immigrants are significantly less likely to use preventive measures. We find that the ability to speak English does not have a significant effect on the use of preventive care among publicly insured persons. Published in 2008 by John Wiley & Sons, Ltd.
Changes in Glutamate Receptors on Synaptic Membranes Associated with Hepatic Encephalopathy or Hyperammonemia in the Rabbit
Authors: Ferenci Peter , Pappas Chris S. , Munson Peter J. , Jones Anthony E.
Published: August 2008

The status of the excitatory glutamatergic neurotransmitter system in hepatic encephalopathy has been studied. Synaptic membranes (SM) were prepared from the brains of normal rabbits, hyperammonemic normal rabbits, and rabbits with fulminant hepatic failure. Data on the specific binding of glutamate to SM indicated that fulminant hepatic failure was associated with a decrease in the number of glutamate receptors on SM from cerebral cortex, cerebellum, and particularly the hippocampus, without any associated change in the affinity of these receptors. In contrast, hyperammonemia was associated with an increase in the affinity and no decrease in the number of glutamate receptors on SM from the hippocampus. These findings indicate that the effects of hyperammonemia and fulminant hepatic failure on cerebral glutamate receptors are fundamentally different. The decreased number of glutamate receptors in hepatic encephalopathy might reflect a decreased sensitivity of glutamatergic neurons to glutamate-mediated neural excitation, a phenomenon that could contribute to the neural inhibition of hepatic encephalopathy.
Cholestasis Induced by Estradiol-17β-D-Glucuronide: Mechanisms and Prevention by Sodium Taurocholate†
Authors: Adinolfi Luigi E. , Utili Riccardo , Gaeta Giovanni B. , Abernathy Charles O. , Zimmerman Hyman J.
Published: August 2008

Estradiol-17β-D-glucuronide (E-17G), a metabolite of natural estrogen, is a potent cholestatic agentin vivo.We, therefore, studied the mechanisms of E-17G cholestasis usingin vitroperfused rat liver system. Furthermore, since it has been postulated that sodium taurocholate (TC) may interfere with either uptake or biliary excretion of other steroid agents, we tested whether E-17G cholestasis could be modified by TC administration. During a constant infusion of TC at a physiological rate (0.50 μ mole per min), a dose-dependent decrease of bile flow was observed after E-17G addition from 1.5 to 5 x 10−5M. E-17G decreased bile acid excretory rate but not bile acid concentration in bile. In separate experiments, TC was infused at different rates (0, 0.25, 0.50, and 0.75 μ mole per min) into the perfusate over the entire experimental period, and E-17G was added at 1.75 x 10−5M. In this setting, E-17G cholestasis was diminished by increasing TC infusion rate and was prevented by TC at 0.75 μ mole per min. Infusion of sodium dehydrocholate (0.75 μ mole per min), a nonmicelle-forming bile acid, did not prevent E-17G cholestasis. During E-17G cholestasis, an increased biliary permeability to14C-sucrose was observed. This effect was also prevented by TC, but not by sodium dehydrocholate which was infused at 0.75 μ mole per min. The perfusate disappearance curves of3H-E-17G at the different TC infusion rates showed no changes in the initial uptake phase, but a profound dose-dependent difference in the excretory phase. The amount of E-17G left in perfusate at the end of experiments was 34% when no TC was infused and decreased to 28%; 22 and 7% at 0.25; 0.50 and 0.75 nmole per min TC rate, respectively. Measurement of3H-E-17G excreted in bile as well as its biliary concentration in the four TC groups showed that TC significantly increased E-17G excretion. Small amounts of E-17G were recovered in liver plasma membranes. However, these amounts were directly proportional to changes of bile flow induced by estrogen at different TC infusion rates. In these same liver membrane preparations, neither Na+,K+− nor Mg++−ATPases were altered. The data suggest that alterations of canalicular membrane permeability may be critical in the development of E-17G cholestasis. Prevention of E-17G cholestasis by TC infusion may occur through increased micellar solubilization and facilitated biliary excretion of the estrogen thus avoiding its membrane-altering action.
Hepatic Injury in the Toxic Epidemic Syndrome Caused by Ingestion of Adulterated Cooking Oil (Spain, 1981)
Authors: Solis-Herruzo JosÉ A. , Castellano Gregorio , Colina Francisco , Morillas Juan Diego , Teresamuñoz-Yagüe Maria , Del Carmen Coca Maria , Jelavic Dusko
Published: August 2008

We describe the clinico-pathological characteristics of hepatic injury associated with the toxic-epidemic syndrome caused by the consumption of adulterated rapeseed oil. Of 842 toxic-epidemic syndrome patients admitted to our hospital between May, 1981, and January, 1982, 24.1% showed signs of liver involvement which was more frequent in women and in the fourth decade of life. No statistical significance was found in relation to alcohol consumption, treatment with potentially hepatotoxic antibiotics, or adult respiratory distress syndrome. Most (91.6%) patients with hepatic injury were asymptomatic; jaundice or abdominal pain was rarely noted. One patient died of acute liver failure following Budd-Chiari syndrome. Serum 7-glutamyl transpeptidase activity was raised in all cases, alkaline phosphatase in 94.6%, and less frequently lactate dehydrogenase (80%), SGPT (84.7%), and SGOT (76%). Serum total bilirubin was usually normal (89.2%). The histologic lesion was similar to drug-induced cholestatic hepatitis. Lamellar inclusions, canalicular injury, giant mitochondria, and hyperplasia of the smooth endoplasmic reticulum were seen by electron microscopy. Ultrastructural signs of cholestasis were common (78.9%). The pathogenesis of this lesion is unknown; however, because of similarities with chlorpromazine-induced cholestatic hepatitis, we suggest that a combination of hypersensitivity and intrinsic hepatotoxicity is a possible mechanism.
Black and Brown Pigment Gallstones Differ in Microstructure and Microcomposition
Authors: Malet Peter F. , Takabayashi Arimichi , Trotman Bruce W. , Soloway Roger D. , Weston Norman E.
Published: August 2008

The two subtypes of pigment gallstones, black and brown stones, differ in chemical composition and pathogenesis. We examined a black bilirubinate stone and a black phosphate stone (which represented opposite ends of the compositional spectrum of black noncarbonate stones), a black carbonate stone, and a brown pigment stone using scanning electron microscopy and microchemical techniques to determine if stone microstructure and microcomposition reflected different patterns of formation. The cross-sectional surfaces of the black bilirubinate and black phosphate stones were smooth and homogenous. Electron probe microanalysis demonstrated high concentrations of sulfur and copper in the center of the black bilirubinate stone; sulfur was in a low valence state consistent with disulfide linkages in proteins. The brown stone was rough-surfaced with lamellated bands on cross-section. The lighter-colored bands in this stone contained virtually all of the detected calcium palmitate, while the darker sections contained much more calcium bilirubinate. Plasma oxygen etching demonstrated a network of protein interdigitating with calcium bilirubinate salts in the black bilirubinate and black phosphate stones but not in the black carbonate or brown stones. Argon ion etching demonstrated that calcium bilirubinate was in a closely packed rod-shaped arrangement in all three black stones but not in the brown stone. We conclude that the marked differences in structure and composition between the black noncarbonate and brown pigment gallstones support the hypothesis that the two major pigment gallstone types form by different mechanisms. In addition, the layered structures of the black carbonate and brown stones suggest that stone growth is affected by cyclic changes in biliary composition.
Glomerular Tubular Reflux-A Morphologic Renal Lesion Associated with the Hepatorenal Syndrome
Authors: Kanel Gary C. , Peters Robert L.
Published: August 2008

The hepatorenal syndrome, a primary cause of death from acute and chronic liver disease, consists of a functional renal failure whereby examination of the kidney has previously shown no distinct or specific morphologic change. We describe an unusual renal lesion consisting of the reflux of proximal convoluted tubular epithelium into Bowman's space. An autopsy series shows this glomerular change to be present in 71.4% of cases with the hepatorenal syndrome, while only present in 0 to 27.3% in other autopsy categories (p < 0.001). Since this lesion has been previously described with experimental renal ischemic change and terminal hypotension, it is possible that it is caused in part by the decreased or altered renal blood flow known to be associated with the hepatorenal syndrome.
Comparison of Dietary Protein with an Oral, Branched Chain-Enriched Amino Acid Supplement in Chronic Portal-Systemic Encephalopathy: A Randomized Controlled Trial
Authors: Horst Douglas , Grace Norman D. , Conn Harold O. , Schiff Eugene , Schenker Steven , Viteri Alfredo , Law David , Atterbury Colin E.
Published: August 2008

A randomized study was conducted in 37 hospitalized patients at six cooperating hospitals in which protein-intolerant cirrhotic patients were fed increasing amounts of either dietary protein or a branched-chain enriched amino acid solution (BCAA) until they attained an intake of 80 gm protein per day or equivalent or until they developed stage 2 encephalopathy. All patients initially received 20 gm of dietary protein for 1 week, after which 20 gm of protein or BCAA were added weekly. Nitrogen balance improved from negative to positive in all patients in whom it was measured and increased equally in both groups. Seven of the 20 patients in the protein group and 1 of 17 in the BCAA group developed encephalopathy of stage 2 or greater (p < 0.05). Changes in each component of the portal-systemic encephalopathy syndrome were compared, and differences were statistically significant for mental status grade (p < 0.01), asterixis (p < 0.05), Portal-systemic encephalopathy index (p < 0.01), but insignificant for Number Connection Test, EEG or ammonia. Plasma amino acid profiles showed an increase in BCAA in the study group. Thus, oral BCAA supplements appear to induce positive nitrogen balance to approximately the same degree as an equivalent amount of dietary protein without inducing encephalopathy as frequently.
Frequency of Hyperprolinemia in Alcoholic Liver Cirrhosis: Relationship to Blood Lactate
Authors: Shaw Spencer , Worner Theresa M. , Lieber Charles S.
Published: August 2008

In alcohol-induced liver injury, hyperprolinemia has been proposed as a marker of fibrogenesis probably secondary to hyperlactacidemia. However, some studies of plasma proline in alcoholics with cirrhosis have reported normal rather than increased levels. In order to evaluate the frequency of hyperprolinemia in alcoholic liver disease and its relationship to blood lactate, we measured plasma proline levels in 145 subjects including 91 alcoholics with a spectrum of liver disease as well as 22 nonalcoholics with liver injury unrelated to alcohol. We also studied baboons fed alcohol as 50% of total calories for 1 to 4 years. Among alcoholics only 21/91 had elevated proline values. Elevations were most frequent among patients with severe hepatic decompensation (3/8), in patients with alcoholic hepatitis on liver biopsy (5/17), and in those with acute alcohol-related withdrawal, with alcohol still present in the blood (4/9). Patients with liver disease unrelated to alcohol but severe in nature also has elevations in proline (3/3). Only 4/28 patients with cirrhosis due to alcohol had elevated values, and none of the baboons fed alcohol had hyperprolinemia whether withdrawn from alcohol or not. Hyperlactacidemia was associated with hyperprolinemia, but so were depressed serum albumin values and prolongations of the prothrombin time, suggesting a general association with severe liver disease. These results reveal that hyperprolinemia occurs infrequently in patients with alcohol-induced cirrhosis and therefore does not appear to be a sensitive marker of hepatic fibrosis in these patients.
Ticrynafen-Associated Hepatic Injury: Analysis of 340 Cases
Authors: Zimmerman Hyman J. , Lewis James H. , Ishak Kamal G. , Maddrey Willis C.
Published: August 2008

Ticrynafen, a uricosuric diuretic, was withdrawn from clinical use in the United States in 1980 after having been implicated as the cause of a number of instances of serious hepatic injury. In this report, we analyze 340 cases of ticrynafen-associated hepatic disease reported to the manufacturer from the time of initial marketing until shortly after the drug had been recalled. Jaundice was recorded in 246 of 287 patients with sufficient clinical information, and 25 (10.2%) of these icteric patients died. The high levels of serum aminotransferase and the case fatality rate are consistent with the hepatocellular injury that was evident in all of the histologic material. In three-fourths of the cases available to us for histologic study, the lesion was that of acute hepatocellular injury. In the remaining cases there was evidence of chronic active hepatitis and/or cirrhosis. Comparison of demographic characteristics of the total population exposed to ticrynafen with the subset developing hepatic injury suggests a proportionately higher risk of injury for females over the age of 60 years. The variable and unusually prolonged latent period and lack of reported eosinophilia or rash generally suggest a mechanism other than hypersensitivity. However, the recurrence of hepatic injury in 15 of the 16 patients challenged with the drug and the prominence of eosinophils in hepatic tissue in some of the cases suggests that hypersensitivity may also play a pathogenetic role. Accordingly, there is reason to incriminate both metabolic idiosyncrasy and hypersensitivity in the mechanism of injury.
Prognostic Value of Total Serum Bilirubin/γ-Glutamyl Transpeptidase Ratio in Cirrhotic Patients
Authors: Poynard Thierry , Zourabichvili Othar , Hilpert Gerard , Naveau Sylvie , Poitrine Alain , Benatar Clarisse , Chaput Jean-Claude
Published: August 2008

The aim of this study was to assess the prognostic value of total serum bilirubin (TSB), γ-glutamyl transpeptidase (GGT) and the TSB/GGT ratio in 129 consecutive cirrhotic patients, and to determine how seven other clinical and biochemical variables affect the prognostic value of these measurements. The Cox model and log rank test were used to compare survival rates at 1 year. Considered alone, encephalopathy, ascites, TSB, prothrombin time, serum albumin, GGT and the TSB/GGT ratio (TSB expressed in /imoles per liter and GGT in IU per liter were associated to the 1-year survival (p < 0.10). The estimated per cent surviving at the end of 1 year was 20% for those with encephalopathy and 59% for those without, 46% and 62% for those with and without ascites, 28% for those with TSB ± 3.0 mg per dl, 68% for those with TSB ± 3.0 mg per dl, 44% for those with GGT ± 100 IU per liter, 60% for those with GGT ± 100 IU per liter, and 12% for those with TSB/GGT ± 1, 66% for those with TSB/GGT ± 1. With the Cox model, which was used to assess the combined effect of several prognostic variables, GGT was the only biochemical variable which added significant prognostic value to TSB. The combination of TSB and GGT added significant prognostic value to encephalopathy and ascites.
Differential Effects of Hypoxia on the Disposition of Propranolol and Sodium Taurocholate by the Isolated Perfused Rat Liver
Authors: Jones Brian D. , Mihaly George W. , Smallwood Richard A. , Webster Lorraine K. , Morgan Denis J. , Madsen Norman P.
Published: August 2008

Although the adverse effect of hypoxia on drug metabolism is well documented in subcellular systems, its effect on drug clearance by the intact liver has not been defined. This study was undertaken in the isolated perfused rat liver to examine the effects of acute hypoxia on the hepatic elimination of two highly cleared substances-propranolol and sodium taurocholate. Hypoxia was established by equilibrating the perfusate with 100% nitrogen rather than 100% oxygen. This led to a fall in portal vein PO2from 300 to 30 mm Hg, and a 10-fold rise in hepatic venous lactate:pyruvate ratio, indicating a profound alteration in hepatic cellular redox state. In bolus dose studies, propranolol uptake was unimpaired by hypoxia, with a monoexponential decline in perfusate concentrations from 2,000 to 30 ng per ml, (t½ uptake = 2.5 min). After 20 min of hypoxia, perfusate propranolol concentrations rose from 30 to 80 ng per ml, indicating release of propranolol from the liver back into the perfusate. Reoxygenation of perfusate restored hepatic extraction of propranolol to normal (t½ uptake = 2.37 ± 0.19 min vs. 2.55 ± 0.60 min p ± 0.1) such that perfusate concentrations were undetectable by 30 min. In steady-state studies, perfusate propranolol concentrations rose from 1.55 ± 0.50 to 4.08 ± 1.47μg per ml (p < 0.005), after 1 hr of hypoxia indicating a change in propranolol clearance from 15 ml per min to less than 6 ml per min. Reoxygenation resulted in a fall in perfusate propranolol concentrations towards control values (2.78 ± 1.13 vs. 1.80 ± 0.41 /xg per ml, p ± 0.1). By contrast, steady-state sodium taurocholate concentrations were unaffected by hypoxia [control (76.6 ± 41.0) vs. hypoxia (50.4 ± 13.6 nmoles per ml), p ± 0.1]. These studies demonstrate that although propranolol uptake is unchanged by hypoxia, overall elimination is greatly reduced, consistent with reduced activity of hepatic mixed function oxidases. By contrast, sodium taurocholate uptake remains unimpaired, affirming the low oxygen dependence of this transport process.
Resistance of the Suckling Guinea Pig to Lithocholic Acid-Induced Cholestasis†
Authors: Lewittes Malka , Tuchweber Beatrix , Weber Andree , Roy Claude C. , Yousef Ibrahim M.
Published: August 2008

Although immaturity of the liver and synthesis of monohydroxy bile acids have been implicated as pathogenic factors in neonatal cholestasis, there is no direct evidence to show that these bile acids induce cholestasis in the newborn. In the present investigation, we compared the effects of lithocholic acid (LCA) injection on bile flow in suckling (2-week-old) and adult (12-week-old) guinea pigs. Bile flow was not modified by LCA in 2-week-old animals, but it was reduced by 50 to 80% in the adults, the decrease being dose-dependent. In the newborn, the injected LCA was mainly secreted in bile (>90%), while in the adults it was distributed between the liver and bile. The percentage of biliary bile acids (as determined by gas-liquid chromatography) in the two groups was similar before and after LCA injection. Morphologic lesions characteristic of LCA-induced cholestasis were observed only in the adult guinea pigs. This study demonstrates that the newborn guinea pig is less susceptible to cholestasis induced by 90 to 180 /imoles per kg body weight of lithocholate and that, in the neonatal liver, there is no defect in the transport of this bile acid from blood to bile.
Enhancement by Secretin of the Apparently Maximal Hepatic Transport of Bilirubin in the Rat
Authors: Ricci Giovanni L. , Michiels Roger , Fevery Johan , Groote Jan De
Published: August 2008

The effect of secretin (0.4 C.U. per hr per 100 gm body weight) on bile flow and the apparent maximal hepatic transport of bilirubin (Tm) was investigated in the rat. When secretin was administered during an already established bilirubin-Tm condition, it increased bile flow and bilirubin-Tm by 15 to 20% over a 30- to 50-min period. Enhancement of bilirubin output correlated with augmented flow and was sustained by an increased rate of excretion of monoglucuronides.

When secretin was given for 90 min before bilirubin loading, it enhanced biliary bilirubin concentration and output, largely as diglucuronides. Bilirubin-Tm correlated positively with glururonyltransferase activity in liver homogemates.

In the isolated perfused rat liver, injection of secretin in the portal cannula failed to produce choleresis. Bilirubin uridine diphosphate-glucuronyltransferase activity was lower than in intact rats and higher after treatment than in controls.

The effect of secretin had an early effect on hepatocytic bile flow and a later effect on conjugation. Maximal hepatic bilirubin output was modulated both by flow and conjugation rate; the two mechanism may act independently.
Noncirrhotic Portal Hypertension in Congenital Cytomegalovirus Infection
Authors: Ghishan Fayez K. , Greene Harry L. , Halter Susan , Barnard John A. , Moran Roberto J.
Published: August 2008

The majority of infants with cytomegalovirus hepatitis have resolution of the disease with little evidence of fibrosis; there are only rare instances of cirrhosis. We report an infant with cytomegalovirus hepatitis who developed portal hypertension and hematemesis at 3 months of age. Liver biopsy showed resolution of the hepatitis but the presence of noncirrhotic sinusoidal fibrosis. Because of recurrent hematemesis in spite of sclerosing therapy on two occasions, the beta antagonist propranolol was begun. Hepatic wedge pressures before and after treatment with propranolol were 13 and 7 mm Hg, respectively. The findings emphasize: (i) that cytomegalovirus hepatitis may result in noncirrhotic sinusoidal fibrosis and (ii) that propranolol may be beneficial in the management of portal hypertension secondary to noncirrhotic sinusoidal fibrosis.
Portacaval Transposition in the Rat: Definition of a Valuable Model for Hepatic Research
Authors: Benjamin Irving S. , Ryan Calvin J. , Engelbrecht Gert H. C. , Campbell John A. H. , Hoorn-Hickman Rosemaryvan , Blumgart Leslie H.
Published: August 2008

Portacaval transposition (PCT) in rats results in a smaller loss of body mass and liver mass than end-to-side portacaval shunt (PCS). Detailed studies of liver function, mass and histology were not previously available and have been undertaken in two different strains of growing rat in order to define the value of this model. PCT rats gained weight normally, while only 50% of PCS rats regained their preoperative weight by the tenth week. Wet and dry weights of liver fell relative to control values after both operations, but the fall was significantly greater after PCS than after PCT: there were parallel changes in hepatocyte size. There was a marked rise in liver-associated enzymes in the first 2 days after PCS only, and minimal enzyme elevations persisted in this group. The extent of cellular damage seen histologically closely parallelled the rise in SGOT in individual rats. At 72 hr, PCS rats showed focal necrotic changes, and by 10 weeks there was marked fatty infiltration: PCT rats had normal histology or showed minimal changes.

PCT therefore provides a model in which there is total portal diversion without the more severe effects of the conventional PCS on hepatic structure and function. This has particular value in studies of experimental hepatic encephalopathy, of hormonal and amino acid changes after portal diversion, and of factors initiating or controlling liver regeneration.
In Vitro Response to HBsAg of Peripheral Blood Lymphocytes from Recipients of Hepatitis B Vaccine
Authors: Chang Tse Wen , Celis Esteban , Miller Richard W. , Zurawski Vincent R. , Kung Patrick C.
Published: August 2008

Lymphocytes isolated from recipients of hepatitis B vaccine were studied for their immune response to HBsAg in vitro. Peripheral blood mononuclear cells (PBMs) from 70 to 80% of 40 vaccinees yielded proliferative indices larger than 2 after 5 to 7 days incubation with HBsAg. This in vitro proliferative response could be augmented by incubating the cells with HBsAg and supernatants of activated T cells for 2 weeks or longer. After 7 to 10 days, in vitro stimulation with antigen, PBMs (1 ± 106) could yield 5 to 15 HBsAg-specific antibody-secreting plaque-forming cells. The antibody to HBsAg produced in vitro was greatly increased in cultures that contained antigen-specific B cells enriched by panning with HBsAg-coated plates and a T cell growth factor-dependent, HBsAg-specific autologous T cell line. The results indicate that HBsAg-specific B and T cells are present, although at low frequencies, in the circulation of hepatitis B vaccinees.
Prolonged Maintenance of Active Cytochrome P-450 in Adult Rat Hepatocytes Co-Cultured with Another Liver Cell Type
Authors: Begue Jean-Marc , Guguen-Guillouzo Christiane , Pasdeloup Nicole , Guillouzo Andre
Published: August 2008

The cytochrome P-450 content promptly fell in adult rat hepatocytes cultured in conventional conditions whereas no obvious change was detected over a 10-day period when these cells were co-cultured with another rat liver epithelial cell type. A concomitant maintenance of the amino-pyrineN-demethylase activity and a high aflatoxin B1-induced cytotoxicity was observed, and addition of phenobarbital to the culture medium produced about a 2-fold increase in cytochrome P-450 level. These results indicate that when placed in co-culture, adult hepatocytes remain differentiated for several days and suggest that such a co-culture system is an appropriate model for pharmacotoxicological studies.