Surgical treatment of recurrent hepatocellular carcinoma based on the mode of recurrence: repeat hepatic resection or ablation are good choices for patients with recurrent multicentric cancer

Hepatocellular carcinomas (HCC) often recur after curvative resection. Recurrence in the remnant liver originates from intrahepatic metastasis (IM) from the primary resected tumor, and/or from multicentric (MC) occurrence. In order to achieve better survival after intrahepatic recurrence in HCC patients, we have surgically treated patients according to the recurrence pattern. In this study, we investigated the advantage of repeat surgery for MC recurrent HCC. The subjects were 176 patients who had undergone primary macroscopically complete tumor removal for HCC at our department from 1984 to 1999. Differential diagnosis of IM and MC recurrence was done by pathological analysis. Twenty-nine of the 149 patients with recurrence (19.5%) underwent a total of 31 second and third operations. Of the 29 patients, 18 had MC (14 received repeat hepatectomy and 4, microwave tissue coagulation [MTC]), 7 had IM (4 had repeat hepatectomy and 3, MTC), and, in 4 patients, pathological investigation failed to determine the mode of recurrence. The 1-, 3-, and 5-year survival rates for MC patients after the repeat operations were 100%, 69.7%, and 58.1%, respectively, and the 1-, 3-, and 5-year survival rates for the IM patients were 57.1%, 14.3%, and 14.3%, respectively. Survival after the repeat operation was significantly better in the MC group than in the IM group (P = 0.0016). Moreover, there was no significant difference between survival in the MC group after a repeat operation and survival in control patients after an initial hepatectomy (P = 0.9282). These results indicated that patients with resectable or ablative recurrent MC HCC have almost the same survival benefit after repeat operations as patients who undergo initial curative resection of HCC.

The role of Kupffer cell oxidant production in early ethanol-induced liver disease

Considerable evidence for a role of Kupffer cells in alcoholic liver disease has accumulated and they have recently been shown to be a predominant source of free radicals. Several approaches including pharmacological agents, knockout mice, and viral gene transfer have been used to fill critical gaps in understanding key mechanisms by which Kupffer cell activation, oxidant formation, and cytokine production lead to liver damage and subsequent pathogenesis. This review highlights new data in support of the hypothesis that Kupffer cells play a pivotal role in hepatotoxicity due to ethanol by producing oxidants via NADPH oxidase.

Thermodynamic database for protein-nucleic acid interactions (ProNIT)

MOTIVATION

Protein-nucleic acid interactions are fundamental to the regulation of gene expression. In order to elucidate the molecular mechanism of protein-nucleic acid recognition and analyze the gene regulation network, not only structural data but also quantitative binding data are necessary. Although there are structural databases for proteins and nucleic acids, there exists no database for their experimental binding data. Thus, we have developed a Thermodynamic Database for Protein-Nucleic Acid Interactions (ProNIT).

RESULTS

We have collected experimentally observed binding data from the literature. ProNIT contains several important thermodynamic data for protein-nucleic acid binding, such as dissociation constant (K(d)), association constant (K(a)), Gibbs free energy change (DeltaG), enthalpy change (DeltaH), heat capacity change (DeltaC(p)), experimental conditions, structural information of proteins, nucleic acids and the complex, and literature information. These data are integrated into a relational database system together with structural and functional information to provide flexible searching facilities by using combinations of various terms and parameters. A www interface allows users to search for data based on various conditions, with different display and sorting options, and to visualize molecular structures and their interactions.

AVAILABILITY

ProNIT is freely accessible at the URL http://www.rtc.riken.go.jp/jouhou/pronit/pronit.html.

How is the liver primed or sensitized for alcoholic liver disease?

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Hidekazu Tsukamoto and Yoshiyuki Takei. The presentations were (1) Tribute to Professor Rajendar K. Chawla, by Craig J. McClain; (2) Dysregulated TNF signaling in alcoholic liver disease, by Craig J. McClain, S. Joshi-Barve, D. Hill, J Schmidt, I. Deaciuc, and S. Barve; (3) The role of mitochondria in ethanol-mediated sensitization of the liver, by Anna Colell, Carmen Garcia-Ruiz, Neil Kaplowitz, and Jose C. Fernandez-Checa; (4) A peroxisome proliferator (bezafibrate) can prevent superoxide anion release into hepatic sinusoid after acute ethanol administration, by Hirokazu Yokoyama, Yukishige Okamura, Yuji Nakamura, and Hiromasa Ishii; (5) S-adenosylmethionine affects tumor necrosis factor-alpha gene expression in macrophages, by Rajendar K. Chawla, S. Barve, S. Joshi-Barve, W. Watson, W. Nelson, and C. McClain; (6) Iron, retinoic acid and hepatic macrophage TNFalpha gene expression in ALD, by Hidekazu Tsukamoto, Min Lin, Mitsuru Ohata, and Kenta Motomura; and (7) Role of Kupffer cells and gut-derived endotoxin in alcoholic liver injury, by N. Enomoto, K. Ikejima, T. Kitamura, H. Oide, Y. Takei, M. Hirose, B. U. Bradford, C. A. Rivera, H. Kono, S. Peter, S. Yamashina, A. Konno, M. Ishikawa, H. Shimizu, N. Sato, and R. Thurman.

Development of an animal model of chronic alcohol-induced pancreatitis in the rat

This study was designed to develop an animal model of alcoholic pancreatitis and to test the hypothesis that the dose of ethanol and the type of dietary fat affect free radical formation and pancreatic pathology. Female Wistar rats were fed liquid diets rich in corn oil (unsaturated fat), with or without a standard or high dose of ethanol, and medium-chain triglycerides (saturated fat) with a high dose of ethanol for 8 wk enterally. The dose of ethanol was increased as tolerance developed, which allowed approximately twice as much alcohol to be delivered in the high-dose group. Serum pancreatic enzymes and histology were normal after 4 wk of diets rich in unsaturated fat, with or without the standard dose of ethanol. In contrast, enzyme levels were elevated significantly by the high ethanol dose. Increases were blunted significantly by dietary saturated fat. Fibrosis and collagen alpha1(I) expression in the pancreas were not detectable after 4 wk of enteral ethanol feeding; however, they were enhanced significantly by the high dose after 8 wk. Furthermore, radical adducts detected by electron spin resonance were minimal with the standard dose; however, the high dose increased carbon-centered radical adducts as well as 4-hydroxynonenal, an index of lipid peroxidation, significantly. Radical adducts were also blunted by approximately 70% by dietary saturated fat. The animal model presented here is the first to demonstrate chronic alcohol-induced pancreatitis in a reproducible manner. The key factors responsible for pathology are the amount of ethanol administered and the type of dietary fat.

ICAM-1 is involved in the mechanism of alcohol-induced liver injury: studies with knockout mice

To test the hypothesis that leukocyte infiltration mediated by intercellular adhesion molecule (ICAM)-1 is involved in early alcohol-induced liver injury, male wild-type or ICAM-1 knockout mice were fed a high-fat liquid diet with either ethanol or isocaloric maltose-dextrin for 4 wk. There were no differences in mean urine alcohol concentrations between the groups fed ethanol. Alcohol administration significantly increased liver size and serum alanine aminotransferase levels in wild-type mice over high-fat controls, effects that were blunted significantly in ICAM-1 knockout mice. Dietary ethanol caused severe steatosis, mild inflammation, and focal necrosis in livers from wild-type mice. Furthermore, livers from wild-type mice fed ethanol showed significant increases in the number of infiltrating leukocytes, which were predominantly lymphocytes. These pathological changes were blunted significantly in ICAM-1 knockout mice. Tumor necrosis factor (TNF)-alpha mRNA expression was increased in wild-type mice fed ethanol but not in ICAM-1 knockout mice. These data demonstrate that ICAM-1 and infiltrating leukocytes play important roles in early alcohol-induced liver injury, most likely by mechanisms involving TNF-alpha.

Diphenyleneiodonium sulfate, an NADPH oxidase inhibitor, prevents early alcohol-induced liver injury in the rat

The oxidant source in alcohol-induced liver disease remains unclear. NADPH oxidase (mainly in liver Kupffer cells and infiltrating neutrophils) could be a potential free radical source. We aimed to determine if NADPH oxidase inhibitor diphenyleneiodonium sulfate (DPI) affects nuclear factor-kappaB (NF-kappaB) activation, liver tumor necrosis factor-alpha (TNF-alpha) mRNA expression, and early alcohol-induced liver injury in rats. Male Wistar rats were fed high-fat liquid diets with or without ethanol (10-16 g. kg(-1). day(-1)) continuously for up to 4 wk, using the Tsukamoto-French intragastric enteral feeding protocol. DPI or saline vehicle was administered by subcutaneous injection for 4 wk. Mean urine ethanol concentrations were similar between the ethanol- and ethanol plus DPI-treated groups. Enteral ethanol feeding caused severe fat accumulation, mild inflammation, and necrosis in the liver (pathology score, 4.3 +/- 0.3). In contrast, DPI significantly blunted these changes (pathology score, 0.8 +/- 0.4). Enteral ethanol administration for 4 wk also significantly increased free radical adduct formation, NF-kappaB activity, and TNF-alpha expression in the liver. DPI almost completely blunted these parameters. These results indicate that DPI prevents early alcohol-induced liver injury, most likely by inhibiting free radical formation via NADPH oxidase, thereby preventing NF-kappaB activation and TNF-alpha mRNA expression in the liver.

Transgenic and gene "knockout" models in alcohol research

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Paula L. Hoffman and Takeshi Yagi. The presentations were (1) cAMP signaling in ethanol sensitivity and tolerance, by Boris Tabakoff; (2) Synaptic signaling pathways of Fyn-tyrosine kinase, by Takeshi Yagi; (3) Ethanol drinking and sensitization in dopaminergic and serotonergic receptor knockouts, by Tamara J. Phillips; (4) ICAM-1 is involved in early alcohol-induced liver injury in the mouse given enteral alcohol, by Hiroshi Kono; and (5) Strategies for targeted and regulated knockouts, by Robert O. Messing and Doo-Sup Choi.

How is the liver primed or sensitized for alcoholic liver disease?

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Hidekazu Tsukamoto and Yoshiyuki Takei. The presentations were (1) Tribute to Professor Rajendar K. Chawla, by Craig J. McClain; (2) Dysregulated TNF signaling in alcoholic liver disease, by Craig J. McClain, S. Joshi-Barve, D. Hill, J Schmidt, I. Deaciuc, and S. Barve; (3) The role of mitochondria in ethanol-mediated sensitization of the liver, by Anna Colell, Carmen Garcia-Ruiz, Neil Kaplowitz, and Jose C. Fernandez-Checa; (4) A peroxisome proliferator (bezafibrate) can prevent superoxide anion release into hepatic sinusoid after acute ethanol administration, by Hirokazu Yokoyama, Yukishige Okamura, Yuji Nakamura, and Hiromasa Ishii; (5) S-adenosylmethionine affects tumor necrosis factor-alpha gene expression in macrophages, by Rajendar K. Chawla, S. Barve, S. Joshi-Barve, W. Watson, W. Nelson, and C. McClain; (6) Iron, retinoic acid and hepatic macrophage TNFalpha gene expression in ALD, by Hidekazu Tsukamoto, Min Lin, Mitsuru Ohata, and Kenta Motomura; and (7) Role of Kupffer cells and gut-derived endotoxin in alcoholic liver injury, by N. Enomoto, K. Ikejima, T. Kitamura, H. Oide, Y. Takei, M. Hirose, B. U. Bradford, C. A. Rivera, H. Kono, S. Peter, S. Yamashina, A. Konno, M. Ishikawa, H. Shimizu, N. Sato, and R. Thurman.

Development of an intragastric enteral model in the mouse: studies of alcohol-induced liver disease using knockout technology

The establishment of a continuous intragastric enteral feeding protocol in the rat by Tsukamoto and French was a major development in research of alcohol-induced liver disease. Unlike other models which only produce fat, with this model, inflammation, necrosis, and fibrosis can now be studied. However, much of what has been learned to date involves inhibitors or nutritional manipulation which may not be specific. Knockout technology could avoid these potential problems. Therefore, we have adapted a rat long-term intragastric protocol to the mouse so that the knockout technology can be used to study the mechanism of alcohol-induced liver injury. Reactive free radicals are involved in the mechanisms of early alcohol-induced liver injury; however, the key source of these species remains unclear. Cytochrome P450 (CYP) 2E1 is induced predominantly in hepatocytes by ethanol and could be one source of reactive oxygen species leading to liver injury. On the other hand, NADPH oxidase or xanthine oxidase is also a potent source of free radicals. In studies using CYP2E1 and p47phox (NADPH oxidase-deficient) knockout mice with this enteral model, it was reported that oxidants from CYP2E1 play only a small role in the mechanisms of early alcohol-induced liver injury in the mouse. Further, free radicals from NADPH oxidase in Kupffer cells play an important role in early alcohol-induced liver injury. Thus, this new enteral mouse model using knockout technology will provide a powerful tool in alcohol research.

Delivery of the Cu/Zn-superoxide dismutase gene with adenovirus reduces early alcohol-induced liver injury in rats

BACKGROUND AND AIMS

Alcohol-induced liver injury is associated with an increase in oxidants from a variety of possible sources. Therefore, it was hypothesized that increased and stable expression of the antioxidant enzyme Cu/Zn-superoxide dismutase (SOD1) would diminish oxygen free radicals and reduce alcohol-induced liver injury.

METHODS

To test this hypothesis, rats were given recombinant adenovirus containing Cu/Zn-superoxide dismutase (Ad.SOD1) or beta-galactosidase (Ad.lacZ) and fed ethanol enterally for 3 weeks.

RESULTS

SOD was increased significantly 3-5-fold over endogenous levels in both hepatocytes as well as Kupffer cells 3 weeks after infection. Serum transaminase levels and pathology were elevated significantly in Ad.lacZ-treated animals by using an intragastric feeding model. This effect was blunted significantly in Ad.SOD1-infected animals. Importantly, electron spin resonance-detectable free-radical adducts caused by ethanol were also decreased by SOD1 overexpression. Moreover, the increase in nuclear factor kappaB (NFkappaB), tumor necrosis factor alpha (TNF-alpha), and interleukin 1 messenger RNA (mRNA) caused by ethanol was blunted in animals treated with Ad.SOD1.

CONCLUSIONS

These data support the hypothesis that oxidant production is critical in early alcohol-induced liver injury and that gene delivery of antioxidant enzymes may be useful in prevention and treatment.

Phthalates rapidly increase production of reactive oxygen species in vivo: role of Kupffer cells

The role of oxidants in the mechanism of tumor promotion by peroxisome proliferators remains controversial. The idea that induction of acyl-coenzyme A oxidase leads to increased production of H(2)O(2), which damages DNA, seems unlikely; still, free radicals might be important in signaling in specialized cell types such as Kupffer cells, which produce mitogens. Because hard evidence for increased oxidant production in vivo after treatment with peroxisome proliferators is lacking, the spin-trapping technique and electron spin resonance spectroscopy were used. Rats were given di(2-ethylhexyl) phthalate (DEHP) acutely. The spin trapping agent alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone was also given and bile samples were collected for 4 h. Under these conditions, the intensity of the six-line radical adduct signal increased to a maximum value of 2.5-fold 2 h after administration of DEHP, before peroxisomal oxidases were induced. Furthermore, DEHP given with [(13)C(2)]dimethyl sulfoxide produced a 12-line electron spin resonance spectrum, providing evidence that DEHP stimulates (*)OH radical formation in vivo. Furthermore, when rats were pretreated with dietary glycine, which inactivates Kupffer cells, DEHP did not increase radical signals. Moreover, similar treatments were performed in knockout mice deficient in NADPH oxidase (p47(phox) subunit). Importantly, DEHP increased oxidant production in wild-type but not in NADPH oxidase-deficient mice. These data provide evidence for the hypothesis that the molecular source of free radicals induced by peroxisome proliferators is NADPH oxidase in Kupffer cells. On the contrary, radical adduct formation was not affected in peroxisome proliferator-activated receptor alpha knockout mice. These observations represent the first direct, in vivo evidence that phthalates increase free radicals in liver before peroxisomal oxidases are induced.

Gadolinium chloride prevents mortality in hepatectomized rats given endotoxin

The purpose of this study was to determine if inhibition of Kupffer cells by gadolinium chloride (GdCl(3)) affects the arterial ketone body ratio (AKBR), liver injury, and mortality in hepatectomized rats administered lipopolysaccharide (LPS). Rats treated with or without GdCl(3) received a 70% hepatectomy. Either LPS (5 mg/kg) or vehicle (saline) was administered 48 h after hepatectomy. Further, hepatectomized rats were administered superoxide dismutase (CuZnSOD, 9 x 10(4) U/kg) before and every 3 h after LPS injection up to 9 h to assess involvement of superoxide in liver injury in this model. All hepatectomized rats with saline died within 24 h after LPS administration. In contrast, GdCl(3) prevented this mortality completely. Serum AST levels were about 160 IU/L in hepatectomized rats with vehicle; however, values were increased approximately 25-fold by LPS administration. In contrast, these increases were blunted significantly by about 90% by GdCl(3). Further, GdCl(3) also prevented decreases in AKBR caused by LPS. LPS caused severe liver injury, which was stopped almost completely by GdCl(3). LPS-induced increases in superoxide production by isolated Kupffer cells were stopped by about 90% by GdCl(3). Importantly, SOD administration prevented decreases in AKBR, liver injury, and mortality significantly as well as GdCl(3). These results indicated that GdCl(3) prevented liver injury and mortality caused by LPS most likely by inhibiting superoxide production by Kupffer cells. Thus, inhibition of activation of Kupffer cells could be useful for preventing liver dysfunction in postoperative endotoxemia.

Laparoscopic findings in primary sclerosing cholangitis

BACKGROUND AND STUDY AIMS

Primary sclerosing cholangitis (PSC) is a cholestatic disease characterized by segmental narrowing and dilatation of bile ducts. Few studies have been performed on the laparoscopic findings associated with this disease, and the present study was intended to assess the usefulness of laparoscopy for the diagnosis and staging of PSC.

PATIENTS AND METHODS

Six patients were examined by laparoscopy with liver biopsy. Repeated laparoscopy was performed in three patients.

RESULTS

Laparoscopy revealed coarse surface irregularity and discoloration. Surface irregularity was classified into four grades: smooth, shallowly depressed, undulated, and nodular. The affected area showed whitish yellow discoloration. The discolored area was demonstrated as a poorly stained area by intravenous injection of indocyanine green (ICG). Lobular markings became apparent because of the yellow color change in the portal tract, resulting in a leopardskin-like appearance. Lymph-vessel dilatation was seen in advanced stages. Repeated laparoscopy of a patient without treatment demonstrated a progression from a smooth surface to a shallow depression with leopardskin-like markings. On the other hand, the two patients treated with immunosuppressive agents showed improvement of liver swelling and disappearance of the leopardskin-like markings and lymph-vessel dilatation.

CONCLUSIONS

Laparoscopy may provide useful information for the diagnosis and staging of PSC.

Statistical theory for protein combinatorial libraries. Packing interactions, backbone flexibility, and the sequence variability of a main-chain structure

Combinatorial experiments provide new ways to probe the determinants of protein folding and to identify novel folding amino acid sequences. These types of experiments, however, are complicated both by enormous conformational complexity and by large numbers of possible sequences. Therefore, a quantitative computational theory would be helpful in designing and interpreting these types of experiment. Here, we present and apply a statistically based, computational approach for identifying the properties of sequences compatible with a given main-chain structure. Protein side-chain conformations are included in an atom-based fashion. Calculations are performed for a variety of similar backbone structures to identify sequence properties that are robust with respect to minor changes in main-chain structure. Rather than specific sequences, the method yields the likelihood of each of the amino acids at preselected positions in a given protein structure. The theory may be used to quantify the characteristics of sequence space for a chosen structure without explicitly tabulating sequences. To account for hydrophobic effects, we introduce an environmental energy that it is consistent with other simple hydrophobicity scales and show that it is effective for side-chain modeling. We apply the method to calculate the identity probabilities of selected positions of the immunoglobulin light chain-binding domain of protein L, for which many variant folding sequences are available. The calculations compare favorably with the experimentally observed identity probabilities.

Ebselen prevents early alcohol-induced liver injury in rats

Oxidants have been shown to be involved in alcohol-induced liver injury. Moreover, 2-phenyl-1,2-benzisoselenazole-3(2H)-one (ebselen), an organoselenium compound and glutathione peroxidase mimic, decreases oxidative stress and protects against stroke clinically. This study was designed to test the hypothesis that ebselen protects against early alcohol-induced liver injury in rats. Male Wistar rats were fed high-fat liquid diets with or without ethanol (10-16 g/kg/d) continuously for up to 4 weeks using the intragastric enteral feeding protocol developed by Tsukamoto and French. Ebselen (50 mg/kg twice daily, intragastrically) or vehicle (1% tylose) was administered throughout the experiment. Mean urine ethanol concentrations were not significantly different between treatment groups, and ebselen did not affect body weight gains or cyclic patterns of ethanol concentrations in urine. After 4 weeks, serum ALT levels were increased significantly about 4-fold over control values (37 +/- 5 IU/l) by enteral ethanol (112 +/- 7 IU/l); ebselen blunted this increase significantly (61 +/- 8 IU/l). Enteral ethanol also caused severe fatty accumulation, mild inflammation, and necrosis in the liver (pathology score: 4.3 +/- 0.3). In contrast, these pathological changes were blunted significantly by ebselen (pathology score: 2.5 +/- 0.4). While there were no significant effects of either ethanol or ebselen on glutathione peroxidase activity in serum or liver tissue, ebselen blocked the increase in serum nitrate/nitrite caused by ethanol. Furthermore, ethanol increased the activity of NF-kappaB over 5-fold, the number of infiltrating neutrophils 4-fold, and the accumulation of 4-hydroxynonenal over 5-fold. Ebselen blunted all of these effects significantly. These results indicate that ebselen prevents early alcohol-induced liver injury, most likely by preventing oxidative stress, which decreases inflammation.

Chronic ethanol increases adeno-associated viral transgene expression in rat liver via oxidant and NFkappaB-dependent mechanisms

Recombinant adeno-associated virus (rAAV) transduction is limited in vivo, yet can be enhanced by hydroxyurea, ultraviolet-irradiation, or adenovirus coinfection, possibly via mechanisms involving stress in the host cell. Because chronic ethanol induces oxidative stress, it was hypothesized that chronic ethanol would increase rAAV transduction in vivo. To test this hypothesis, rAAV encoding beta-galactosidase was given to Wistar rats that later received either ethanol diet or high-fat control diet via an enteral-feeding protocol for 3 weeks. Expression and activity of beta-galactosidase in the liver were increased nearly 5-fold by ethanol. The increase in transgene expression was inhibited by antioxidant diphenylene iodonium (DPI), which is consistent with the hypothesis that ethanol causes an increase in rAAV transduction via oxidative stress. Ethanol increased DNA synthesis only slightly; however, it increased the nuclear transcription factor kappaB (NFkappaB) 4-fold, a phenomenon also sensitive to DPI. Moreover, a 6-fold increase in rAAV transgene expression was observed in an acute ischemia-reperfusion model of oxidative stress. Transgene expression was transiently increased 24 hours after ischemia-reperfusion 3 days and 3 weeks after rAAV infection. Further, adenoviral expression of superoxide dismutase or IkappaBalpha superrepressor inhibited rAAV transgene expression caused by ischemia-reperfusion. Therefore, it is concluded that ethanol increases rAAV transgene expression via mechanisms dependent on oxidative stress, and NFkappaB likely through enhancement of cytomegaloviral (CMV) promoter elements. Alcoholic liver disease is an attractive target for gene therapy because consumption of ethanol could theoretically increase expression of therapeutic genes (e.g., superoxide dismutase). Moreover, this study has important implications for rAAV gene therapy and potential enhancement and regulation of transgene expression in liver.

Importance of surrounding residues for protein stability of partially buried mutations

For understanding the factors influencing protein stability, we have analyzed the relationship between changes in protein stability caused by partially buried mutations and changes in 48 physico-chemical, energetic and conformational properties of amino acid residues. Multiple regression equations were derived to predict the stability of protein mutants and the efficiency of the method has been verified with both back-check and jack-knife tests. We observed a good agreement between experimental and computed stabilities. Further, we have analyzed the effect of sequence window length from 1 to 12 residues on each side of the mutated residue to include the sequence information for predicting protein stability and we found that the preferred window length for obtaining the highest correlation is different for each secondary structure; the preferred window length for helical, strand and coil mutations are, respectively, 0, 9 and 4 residues on both sides of the mutant residues. However, all the secondary structures have significant correlation for a window length of one residue on each side of the mutant position, implying the role of short-range interactions. Extraction of surrounding residue information for various distances (3 to 20A) around the mutant position showed the highest correlation at 8A, 6A and 7A, respectively, for mutations in helical, strand and coil segments. Overall, the information about the surrounding residues within the sphere of 7 to 8A, may explain better the stability in all subsets of partially buried mutations implying that this distance is sufficient to accommodate the residues influenced by major intramolecular interactions for the stability of protein structures.

NADPH oxidase-derived free radicals are key oxidants in alcohol-induced liver disease

In North America, liver disease due to alcohol consumption is an important cause of death in adults, although its pathogenesis remains obscure. Despite the fact that resident hepatic macrophages are known to contribute to early alcohol-induced liver injury via oxidative stress, the exact source of free radicals has remained a mystery. To test the hypothesis that NADPH oxidase is the major source of oxidants due to ethanol, we used p47(phox) knockout mice, which lack a critical subunit of this major source of reactive oxygen species in activated phagocytes. Mice were treated with ethanol chronically, using a Tsukamoto-French protocol, for 4 weeks. In wild-type mice, ethanol caused severe liver injury via a mechanism involving gut-derived endotoxin, CD14 receptor, production of electron spin resonance-detectable free radicals, activation of the transcription factor NF-kappaB, and release of cytotoxic TNF-alpha from activated Kupffer cells. In NADPH oxidase-deficient mice, neither an increase in free radical production, activation of NF-kappaB, an increase in TNF-alpha mRNA, nor liver pathology was observed. These data strongly support the hypothesis that free radicals from NADPH oxidase in hepatic Kupffer cells play a predominant role in the pathogenesis of early alcohol-induced hepatitis by activating NF-kappaB, which activates production of cytotoxic TNF-alpha.

Solvent density and long-range dipole field around a DNA-binding protein studied by molecular dynamics

The distribution and orientation of solvent around a DNA-binding protein, 434 Cro, were investigated by molecular dynamics simulations with a periodic-boundary condition. The protein was treated in two states: charged and neutral. The computed high-density sites of the solvent around the protein correlated well with the experimentally determined crystal-water sites, in both the charged and neutral states. A local density map, introduced to investigate the solvent density around the highly mobile regions of the protein, showed a hydration shell around hydrophobic sidechains and hydrogen-bondable sites around hydrophilic sidechains, and also showed that the solvent density is sensitive to the slight concaves of the sidechain surface. The long-range solvent-dipole field was observed around the protein, where the pattern of the dipole ordering was considerably different between the charged and neutral states. A local solvent-dipole field was introduced, and the pattern of the dipole ordering was different between the hydrophobic and hydrophilic sidechains. The dipole field from the charged state provided a higher correlation to the electrostatic field obtained from the Poisson-Boltzmann's equation than that from the neutral state, although the correlation become weak quickly for the both states with increasing the protein-solvent distance.

Differential involvement of Src family kinases in Fc gamma receptor-mediated phagocytosis

The tyrosine phosphorylation cascade originated from Fc gamma receptors (Fc gamma Rs) is essential for macrophage functions including phagocytosis. Although the initial step is ascribed to Src family tyrosine kinases, the role of individual kinases in phagocytosis signaling is still to be determined. In reconstitution experiments, we first showed that expression in the RAW 264.7 cell line of C-terminal Src kinase (Csk) inhibited and that of a membrane-anchored, gain-of-function Csk abolished the Fc gamma R-mediated signaling that leads to phagocytosis in a kinase-dependent manner. We next tested reconstruction of the signaling in the membrane-anchored, gain-of-function Csk-expressing cells by introducing Src family kinases the C-terminal negative regulatory sequence of which was replaced with a c-myc epitope. Those constructs derived from Lyn and Hck (a-Lyn and a-Hck) that associated with detergent-resistant membranes successfully reconstructed Fc gamma R-mediated Syk activation, filamentous actin rearrangement, and phagocytosis. In contrast, c-Src-derived construct (a-Src), that was excluded from detergent-resistant membranes, could not restore the series of phagocytosis signaling. Tyrosine phosphorylation of Vav and c-Cbl was restored in common by a-Lyn, a-Hck, and a-Src, but Fc gamma RIIB tyrosine phosphorylation, which is implicated in negative signaling, was reconstituted solely by a-Lyn and a-Hck. These findings suggest that Src family kinases are differentially involved in Fc gamma R-signaling and that selective kinases including Lyn and Hck are able to fully transduce phagocytotic signaling.

Pachymeningitis in microscopic polyangiitis (MPA): a case report and a review of central nervous system involvement in MPA

A case of microscopic polyangiitis (MPA) with pachymeningitis is described. The patient had renal, skin, gallbladder and peripheral nervous system involvement, simultaneously with pachymeningitis. Necrotizing glomerulonephritis with crescent formation, and necrotizing small vessel vasculitis in the kidney and skin were confirmed by biopsy. A highly elevated titer of antineutrophil cytoplasmic antibody for myeloperoxidase (MPO-ANCA) was observed. All of the clinical and laboratory abnormalities improved with high-dose pulse and conventional steroid therapy. The literature on central nervous system involvement in MPA and perinuclear-ANCA (p-ANCA)-related vasculitis is reviewed. This case serves to emphasize that pachymeningitis can occur as one of the features of MPA.

Pneumomediastinum in dermatomyositis: association with cutaneous vasculopathy

OBJECTIVES

To study the pathogenesis of pneumomediastinum in polymyositis/dermatomyositis (PM/DM).

PATIENTS AND METHODS

The clinical records of 48 patients with PM/DM were reviewed, focusing mainly on the presence of pneumomediastinum and cutaneous vasculopathy, and the chest radiographic changes. A patient with pneumomediastinum with a characteristic change in his bronchus is described in detail. Case reports of pneumomediastinum in PM/DM in English publications are reviewed.

RESULTS

Among the 48 patients with PM/DM, pneumomediastinum was observed as a complication in four patients with DM and none of the patients with PM. Three of the four patients with pneumomediastinum, but only six of the 44 patients without this complication, had associated cutaneous vasculopathy. There was a significant association of pneumomediastinum with cutaneous vasculopathy (p = 0.02) and younger age (p = 0.04), but not with the prevalence of lung disease. A 30 year old man (patient 1) with DM, who had interstitial pneumonitis and skin ulceration due to vasculopathy, developed pneumomediastinum. Fibreoptic bronchoscopy showed white plaques on the bronchial mucosa, which were confirmed by microscopic examination as representing subepithelial necrosis. A literature review showed 13 cases of DM but no patient with PM with pneumomediastinum.

CONCLUSIONS

In patient 1, bronchial necrosis due to vasculopathy was strongly suspected as being responsible for the pneumomediastinum. The results suggest that pneumomediastinum was associated not with interstitial pneumonitis but with the complication of vasculopathy appearing as skin lesions in DM.

Gender differences in early alcohol-induced liver injury: role of CD14, NF-kappaB, and TNF-alpha

The purpose of this study was to determine whether early alcohol-induced liver injury (ALI) in females is associated with changes in CD14 on Kupffer cells, activation of hepatic nuclear factor (NF)-kappaB, and expression of tumor necrosis factor (TNF)-alpha mRNA. Male and female rats were given high-fat control or ethanol-containing diets for 4 wk using the intragastric enteral protocol. Physiological parameters were similar in both genders. Ethanol was increased as tolerance developed with higher blood levels than previously observed, resulting in a fourfold increase in aspartate aminotransferase (males 389 +/- 47 IU/l vs. females 727 +/- 66 IU/l). Hepatic pathology developed more rapidly and was nearly twofold greater and endotoxin levels were significantly higher in females after ethanol. Also, expression of CD14 on Kupffer cells was 1.5-fold greater and binding of transcription factor NF-kappaB in hepatic nuclear extracts and TNF-alpha mRNA expression were threefold greater in females. These data are consistent with the hypothesis that elevated endotoxin after ethanol triggers more activation of Kupffer cells via enhanced CD14 expression in females. NF-kappaB is activated in this process, leading to increases in TNF-alpha mRNA expression in the liver and more severe liver injury in females. It is concluded that gender differences in ALI are dependent on endotoxin and a signaling cascade leading to TNF-alpha.