bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatic silicosis, cirrhosis, and liver tumors in mice and hamsters: Studies of transforming growth factor β expression
Authors: Williams A O , Knapton A D
Published: November 2004

Hepatic silicosis, cirrhosis, liver cell adenoma, and carcinomas developed in nude mice (NCr-Nu) given quartz by the subcutaneous and intraperitoneal routes. Syrian golden hamsters (15:16 EHS:cr) given quartz by both routes developed extensive fibrosis and cirrhosis and had higher morbidity and mortality rates after 3 months. Crystalline silica (quartz) induces fibrosis, adenomas, and carcinomas in the lungs of Fisher 344 rats, but certain strains of mice and hamsters are resistant to quartz-induced pulmonary carcinogenesis. Pulmonary fibrosis, however, is minimal in mice and absent in hamsters who received quartz intratracheally. To determine whether species differences are due to organ-specific rather than species-specific factors, susceptibility of the liver to quartz toxicity was investigated in nude mice and hamsters. The present study shows that the differential manifestations of quartz toxicity by these rodent species are dependent on factors that are organ-specific rather than host-specific. At 3 months, hepatocytes in mice were immunostained with intracellular transforming growth factor (TGF) β1 (LC 1-30) but not with TGF-β1 latency-associated peptide (LAP) protein (266-278); at 12 months, hepatocytes were immunostained with TGF-β1 LAP (266-278) but not with TGF-β1 (LC1-30). The hepatocytes of hamsters at 3 months showed immunoreactivities to TGF-β1 LAP (266-278) and TGF-β1 (LC1-30); immunostaining to TGF-β1 (LC1-30) was detected in nonparenchymal cells. Extracellular TGF-β1 (CC1-30) was detected in the silicotic granulomas and fibrous tissue in livers of both species. Quartz-induced liver carcinoma did not express TGF-β1 LAP (266-278) and LC (1-30) proteins, but these were detected in the cells of the adenoma in the same liver. Control animals showed no hepatic lesions nor immunoreactivity to TGF-β1. The spatial and temporal patterns of expression of TGF-β1, TGF-beta 2, TGF-beta receptor type II messenger RNAs (mRNAs), and TGF-β1 proteins in the different hepatic lesions suggests that TGF-beta isoforms may play a role in the pathogenesis of quartz-induced fibrosis, cirrhosis, liver cell adenoma, and carcinoma.
High Rate of Mutations in the Hepatitis B Core Gene During the Immune Clearance Phase of Chronic Hepatitis B Virus Infection
Authors: Bozkaya H , Ayola B , Lok A S F
Published: November 2004

Cross–sectional studies reported that hepatitis B core gene mutations are associated with active liver disease and responsiveness to interferon therapy. In view of the heterogeneity in published sequences, it is not possible to tell whether the differences in sequences observed were true mutations that developed during the course of infection. We conducted a longitudinal study to determine the rate of hepatitis B core gene mutations and the timing of these mutations in relation to hepatitis B virus replication, activity of liver disease, hepatitis B virus replication, activity of liver disease, hepatitis B e antigen (HBeAg) seroconversion, and interferon therapy. Serial sera from 55 patients with chronic hepatitis B infection were analyzed by direct sequencing of the hepatitis B precore/core gene to identify the nucleotide and amino acid changes that emerged during during follow–up. Patients who remained HBeAg positive and had normal amino transferase levels (Group I) maintained higher serum hepatitis B virus (HBV) DNA levels but significantly lower rates of both nucleotide and amino acid changes during follow–up compared with patients who remained HBeAg positive but had elevated aminotransferase levels (Groups II) and patients who cleard HBeAg (Group III). The rates of nucleotide and amino acid changes in Groups I, II, III patients were: 0.4 +/– 0.1, 1.9 +/– 0.3, and 2.4 +/– 0.4/nucleotide position/year; and 0.04 +/– 0.02, 0.21 +/– 0.05, and 0.38 +/– 0.07/codon/year, respectively. Most of the amino acid changes in Groups II and III patients occured during or shortly after flares in amino transferase levels, before HBeAg seroconversion. Similar rates of nucleotide and amino acid changes were found in interferon treated versus untreated patients, and in responders versus nonresponders. There was no difference in the location or nature of the hepatitis B core gene mutations between patients with and without HBeAg seroconversion, interferon treated versus untreated patients, and interferon responders versus nonresponders. In summary, changes in the hepatitis B core gene sequence was rarely detected in patients who were still in the immune tolerant phase but very high rates of changes were found during the immune clearance of chronic hepatitis B infection. Interferon therapy did not induce a higher rate or specific pattern of mutations in the hepatitis B core gene. Response to interferon therapy in HBeAg positive patients was unrelated to the number or location of hepatitis B core gene mutations.
Systemic Hemodynamics and Serum Nitrate Levels in Patients Undergoing Endoscopic Variceal Ligation
Authors: Yokoyama M , Shijo H , Ota K , Kubara K , Kokawa H , Kim T , Akiyoshi N , Okumura M , Inoue K
Published: November 2004

The effects of endoscopic variceal ligation (EVL) on systemic hemodynamics are unknown. This study was conducted to determine whether the obliteration of portal–systemic collaterals by EVL affects systemic hemodynamics and serum nitrate concentrations in patients with compensated cirrhosis. We measured systemic and hepatic hemodynamics, azygos vein blood flow (AzBF), and serum nitrate concentrations before and immediately following EVL. A prompt decrease in left ventricular end–diastolic volume (LVEDV), stroke volume, cardiac index (CI), and an increase in systemic vascular resistance index (SVRI) were observed following variceal ligation. The reduction in LVEDV was associated with a decline in CI with a rise in SVRI. There was also a prompt reduction in serum nitrate concentration following variceal ligation. AzBF also significantly decreased following variceal ligation. These findings indicate that EVL decreased cardiac output via a reduction in cardiac preload (central venous return). Blood flow through portal–systemic collaterals has an important role in the enhanced cardiac preload of cirrhotic patients. The sudden decrease in serum nitrate concentrations suggests that endogenous nitric oxide may be involved in the regulation of systemic hemodynamics in patients with compensated cirrhosis.
High Insulin–Like Growth Factor Binding Protein 1 Levels in Cirrhosis: Link With Insulin Resistance
Authors: Shmueli E , Miell J P , Stewart M , Alberti K G , Record C O
Published: November 2004

Hyperinsulinemic euglycemic clamps were performed on six patients with compensated alcoholic cirrhosis and on six normal comparison subjects. As in previous studies, glucose uptake in the cirrhotic patients was only 21% of the comparison value. The cirrhotic patients had high growth hormone (GH) and low insulin–like growth factor–I (IGF–I) levels, with low insulin–like growth factor–binding protein (IGFBP)–3 levels, but surprisingly high IGFBP–I levels (26.8 ± 8.4 microgH vs. 3.2 ± 0.2 microm/L,

P

< .001). The log IGFBP–1 level was inversely correlated with the log insulin sensitivity (

r

= –.95). The clamps were repeated with a somatostatin infusion to suppress GH secretion. IGFBP–1 increased in both groups, especially in the cirrhotic subjects. Insulin sensitivity increased in the normal subjects but was unchanged in the cirrhotic patients. Following GH treatment (0.13 U/kg/d for 5 days), the clamps were repeated. GH, IGF–1, and IGFBP–3 levels were now similar in the two groups; IGFBP–1 levels decreased in the cirrhotic patients but remained fivefold higher than the comparison value (10.6 ± 3.7 vs. 2.1 ± 0.4,

P

< .05). Glucose uptake in the cirrhotic patients remained only 29% of the comparison value, but the change in their insulin sensitivity was inversely correlated with the change in their IGFB–1 levels (

r

= –.84). These results suggests an important role for IGFBP–1 in modulating insulin sensitivity in cirrhosis.
Glycohydrolases As Markers of Hepatic Ischemia–Reperfusion Injury and Recovery
Authors: Liu W , Schöb O , Pugmire J E , Jackson D , Zucker K A , Fry D E , Glew R H
Published: November 2004

Advances in liver surgery and transplantation have lead to a steady increase in the number of these interventions. Prompt quantitative assessment of hepatic of hepatic function and a patient's subsequent morbidity and mortality following surgery remain difficult despite the currently utilized historic markers of hepatic parenchymal injury (e.g., aspartate transaminase [AST], lactate dehydrogenase [LDH] γ–glutamyl transpeptidase [GGT]). Increases in serum glycohydrolase activities appear to provide sensitive and quantitative markers of hepatic ischemia/reperfusion injury. In 10 male swine (25 to 35 kg body weight) following 30, 45, and 90 minutes of acute hepatic ischemia, the systemic release of eight different glycohydrolases and lipid peroxides into serum were determined and compared with pre– and postischemic serum levels of LDH, GGT, and AST. The rapid release of glycohydrolases into serum was directly proportional to the length of the ischemic period from 30 to 90 minutes; e.g., β–glucosidase, mean 1.9–fold increase at 30 minutes; 8.3–fold at 45 minutes; and 22.8–fold at 90 minutes;

P

< .002 and the activities peaked within the first 3 hours postischemia. In constrast, AST, LDH, and GGT were released slowly and peaked 20 to 30 hours after hepatic blood flow was restored. In swine with fatal outcomes (90 minutes of ischemia), all enzyme levels increased continuously during the final hours of life. However, in swine that survived hepatic ischemia/reperfusion injury (45 minutes of ischemia) the glycohydrolases, but not AST, LDH, and GGT, declined after 2 to 3 hours postischemia and the serum lipid peroxide levels followed the same pattern. Serum β–galactosidase and β–glucosidase levels are sensitive markers that rise as quickly as traditional enzyme markers (AST, LDH, GGT) following hepatic ischemic injury; moreover, the glycohydrolases have the added value of serving as predictors of survival.
Expressions of Basic Fibroblast Growth Factor and Its Receptors and Their Relationship to Proliferation of Human Hepatocellular Carcinoma Cell Lines
Authors: Ogasawara S , Yano H , Iemura A , Hisaka T , Kojiro M
Published: November 2004

On six human hepatocellular carcinoma (HCC) cell lines (KIM–1, KYN–1, KYN–2, KYN–3, HAK–1A, and HAK–1B), we examined expressions and functions of the proteins and messenger RNAs (mRNAs) of basic fibroblast growth factor (bFGF) and its receptor, i.e., fibroblast growth factor receptor–1 (FGFR–1), as well as mRNA expressions of FGFR–2 approximately 4. All six cell lines expressed the proteins and mRNAs of bFGF and FGFR–1, and at least one of FGFR–2 approximately 4 mRNAs. Two of the six cell lines (KYN–1 and KYN–3) presented significant release of bFGF in culture supernatant, while the release in the remaining four cell lines was quite small. Addition of anti–bFGF neutralizing antibody (1, 10, or 20 microg/mL) to culture medium resulted in marked suppression of cell proliferation in all cell lines except HAK–1A. On the other hand, addition of exogenous bFGF (0.1, 1, or 5 ng/mL) to culture medium stimulated cell proliferation except in KIM–1 and KYN–2. When KIM–1 was transplanted to nude mice and anti–bFGF antibody was injected subcutaneously to a space surrounding the developed tumor, tumor proliferation was significantly suppressed in nude mice that received anti–bFGF antibody than in control mice, but there were no histological differences between the groups, including blood space formation in the stroma. In conclusion, hepatocellular carcinoma (HCC) cells may possess a proliferation mechanism regulated by an autocrine mechanism, a paracrine mechanism, or both, which are mediated by bFGF/FGFR.
Experimental Mallory Body Formation Is Accompanied by Modulation of the Expression of Multidrug–Resistance Genes and Their Products
Authors: Preisegger K , Stumptner C , Riegelnegg D , Brown P C , Silverman J A , Thorgeirsson S S , Denk H
Published: November 2004

Mallory bodies (MBs) are characteristic morphological features of alcoholic hepatitis and are also found in other chronic liver disorders and hepatocellular neoplasms. MBs can be produced in mouse liver by chronic administration of the porphyrinogenic drugs griseofulvin (GF) and 3,5–diethoxy–carbonyl–1,4–dihydrocollidine (DDC). The mechanisms causing the formation of MBs are poorly understood, and the significance of MB formation during the course of liver disease remains unclear. We investigated the relationship between the mechanisms underlying the formation of MBs and the regulation of multidrug resistance (

mdr

) genes and their products, the P–glycoproteins (Pgp). Immunofluorescence microscopy using the monoclonal antibody C219 revealed an increase of Pgp expression in almost all hepatocytes after 3 to 8 days of feeding mice DDC– and GF–containing diets. However, after approximately 4 weeks of DDC and approximately 8 weeks of GF feeding, when the first small MBs appeared and loosening and diminution of keratin intermediate filament (KIF) cytoskeleton occurred in some hepatocytes, a decrease or loss of Pgp staining in affected hepatocytes was observed. After feeding mice DDC for 6 weeks and GF for 12 weeks, many hepatocytes contained MBs and displayed a disruption of the immunohistochemically demonstrable KIF meshwork. Double immunofluorescence microscopy with the keratin polyclonal antibody and the mab C219 at this time point revealed a complete loss of Pgp staining in affected cells, although remaining hepatocytes with unaltered KIF meshwork showed a strong reaction with the C219 antibody. Northern blot analyses revealed a significant increase of

mdr

2 mRNA and, to a lesser extent, of

mdr1a

mRNA in the livers of DDC– and GF–fed animals.
Postmenopausal levels of sex hormones and risk of breast carcinoma in situ: Results of a prospective study
Authors: Zeleniuch‐Jacquotte Anne , Gu Yian , Shore Roy E. , Koenig Karen L. , Arslan Alan A. , Kato Ikuko , Rinaldi Sabina , Kaaks Rudolf , Toniolo Paolo
Published: November 2004

We report on a prospective study to assess the association of postmenopausal serum levels of sex hormones with subsequent risk of breast carcinoma in situ. We conducted a case‐control study nested within the cohort of the New York University Women's Health Study, a large prospective study documenting a positive association of circulating levels of estrogens and androgens with invasive breast cancer. The study included 69 cases of incident in situ carcinoma and 134 individually matched controls. No statistically significant trend of increasing risk with increasing level of any of the hormones was observed. Odds ratios (95% CIs) for the highest tertile relative to the lowest were 1.10 (0.51–2.39) for estradiol, 0.95 (0.41–2.19) for estrone, 1.63 (0.69–3.88) for testosterone, 0.99 (0.44–2.24) for androstenedione, 0.99 (0.45–2.20) for dehydroepiandrosterone sulfate and 0.81 (0.38–1.74) for sex hormone–binding globulin. Adjusting for potential confounders did not materially affect the results, nor did limiting the analysis to the 59 cases of ductal carcinoma in situ, the lesion thought to be the direct precursor of most invasive breast cancers. Our results are at variance with the positive associations observed in this same cohort with risk of invasive breast cancer. Possible explanations for our results include lack of power, an effect of sex hormones limited to the progression from in situ to invasive tumors, overrepresentation of indolent tumors or an effect of sex hormones on the induction of only a subset of in situ tumors, those that would develop into invasive tumors. © 2004 Wiley‐Liss, Inc.
Active and passive smoking and breast cancer risk in middle‐aged Japanese women
Authors: Hanaoka Tomoyuki , Yamamoto Seiichiro , Sobue Tomotaka , Sasaki Satoshi , Tsugane Shoichiro
Published: November 2004

To examine the hypothesis that tobacco smoke is associated with the risk of female breast cancer, we estimated the relative risks of active and passive smoke in middle‐aged Japanese women in a population‐based prospective study. The cohort consisted of residents in 4 public health center areas, aged 40 to 59 years. A self‐administered questionnaire survey was conducted in 1990. This analysis included 21,805 subjects, 180 of whom had developed breast cancer by December 31, 1999. When the reference was defined as never‐active smokers without passive smoking, adjusted relative risks (RRs) were 1.9 (95% confidence interval [CI] = 1.0–3.6) in current active smokers, 1.2 (95% CI = 0.4–4.0) in ex‐active smokers and 1.2 (95% CI = 0.8–1.6) in never‐active smokers with passive smoking. The elevated risk for ever‐smokers was clearly observed in premenopausal women at baseline (RR = 3.9, 95% CI = 1.5–9.9) but not in postmenopausal women (RR = 1.1, 95% CI = 0.5–2.5). In never‐active smokers, the adjusted RR for passive smoking, residential or occupational/public tobacco smoke exposure was 1.1 (95% CI = 0.8–1.6). In premenopausal women, passive smoking increased the risk (RR = 2.6; 95% CI = 1.3–5.2) but not in postmenopausal women (RR = 0.7; 95% CI = 0.4–1.0). We conclude that tobacco smoking increases the risk of female breast cancer in premenopausal women. © 2004 Wiley‐Liss, Inc.
CXCR4 expression reflects tumor progression and regulates motility of bladder cancer cells
Authors: Retz Margitta M. , Sidhu Sukhvinder S. , Blaveri Ekaterina , Kerr Sheena C. , Dolganov Gregory M. , Lehmann Jan , Carroll Peter , Simko Jeff , Waldman Frederic M. , Basbaum Carol
Published: November 2004

Transitional cell carcinoma of the urinary bladder remains life threatening due to the high occurrence of metastases. Emerging evidence suggests that chemokines and their receptors play a critical role in tumor metastases. In our study, we performed a systematic analysis of the mRNA and protein expression levels of all 18 chemokine receptors in normal urothelium and bladder cancer. CXCR4 was the only chemokine receptor whose mRNA expression level was upregulated in bladder cancer cell lines as well as in invasive and locally advanced bladder cancer tissue samples (pT2–pT4). In contrast, superficial bladder tumors (pTa and pT1) displayed low CXCR4 expression levels and normal urothelial cells were negative for CXCR4. Immunohistochemistry of a bladder cancer tissue microarray (TMA) confirmed that a subgroup of invasive bladder cancers revealed a high CXCR4 protein expression, while superficial bladder tumors showed low immunoreactivity. To investigate the functional significance of CXCR4 expression, we performed migration and invasion assays. Exposure of CXCR4‐positive bladder cancer cells to CXCL12 in a Boyden chamber type assay provoked a significant increase in migration as well as invasion across a Matrigel barrier. Enhanced migration and invasion were inhibited by a CXCR4‐specific blocking antibody. In contrast, normal urothelial cells did not respond to CXCL12 and lacked chemotactic migration. In conclusion, bladder cancer cells express CXCR4 progressively with advanced tumorigenesis and this receptor interacts with CXCL12 to mediate tumor chemotaxis and invasion through connective tissue. These properties identify CXCR4 as a potential target for the attenuation of bladder cancer metastases. © 2004 Wiley‐Liss, Inc.
Osteosarcoma cell lines display variable individual reactions on wildtype p53 and Rb tumour‐suppressor transgenes
Authors: Hellwinkel Olaf J. C. , Müller Jürgen , Pollmann Annika , Kabisch Hartmut
Published: November 2004

Background

One of the most widely studied gene therapeutic strategies for cancer is the introduction of tumour‐suppressor genes—generally p53—into the target cells. As the genes of p53 and/or retinoblastoma (Rb) are mutated in the major part of osteosarcomas (OS), we aimed to study the effect of p53 and Rb transgenes on a panel of five different osteosarcoma cell lines.

Methods

OS cell lines were transduced by adenoviral vectors delivering the transcription units of the wildtype p53 and the Rb gene. Effects of the transgenes alone and at additional cytostatic stress were studied by proliferation, alive/dead and cell cycle assays.

Results

The individual cells lines displayed divergent reactions to p53‐ or Rb‐transgene delivery reaching from cell death (SaOs‐2, U2OS at p53 transduction) over stopped or lowered cell division (MG‐63, K‐HOS, SJSA‐1 at p53 and Rb transduction) to nearly unhindered cell growth (U2OS at Rb transduction). In those OS cell lines reacting with lowered cell division to p53 or Rb delivery, cytostatics only moderately intensified the transgene effects. Surprisingly, these reactions were apparently not dependent on the functional status of the cellular p53 and/or Rb genes or on differences in the infectability of the cell lines by the adenoviral vectors. Most interestingly, the respective effects of the p53 or Rb transgenes were not multiplied by simultaneous transduction of both tumour‐suppressor genes.

Conclusions

The application of wildtype tumour‐suppressor gene therapy on genetically variable osteosarcomas may be efficient only in yet not identified genetic subgroups of this tumour entity. Hyperactive tumour‐suppressor transgenes could be an alternative. Copyright © 2004 John Wiley & Sons, Ltd.
Polystyrene/Montmorillonite Nanocomposites Prepared by In Situ Intercalative Polymerization: Influence of the Surfactant Type
Authors: Essawy Hisham A. , Badran Ahmed S. , Youssef Ahmed M. , Abd El‐Hakim Abou El‐Fettouh A.
Published: November 2004

Summary: Na‐montmorillonite (MMT) with a cation exchange capacity (CEC) of 90 meq/100 g was converted to MMT‐CTAB and MMT‐CPC by the intercalation of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC), respectively. The intercalation of CPC onto the basal space of the montmorillonite expanded the basal space from 12.19 to 21.47 Å, whereas in the case of CTAB, the spacing was only expanded to 19.35 Å. The MMT‐CPC and MMT‐CTAB forms were subsequently used as hosts for the preparation of polystyrene nanocomposites via intercalative free‐radical polymerization of styrene. Different structures were obtained by varying the preparation conditions; the exfoliated and intercalated nanocomposites were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and differential scanning calorimeter (DSC). The produced nanocomposites exhibited improved thermal stability in comparison with that of pure polystyrene above 400 °C especially in the case of the nanocomposites based on the MMT‐CPC, in which intercalation exists. A glass transition temperature (Tg) could not be detected for the prepared nanocomposites using DSC; this was assumed to result from the restricted molecular motion of the polymer chains.

XRD pattern of PS nanocomposites prepared by intercalative polymerization.

magnified image

XRD pattern of PS nanocomposites prepared by intercalative polymerization.
Systematic survey on the prevalence of genes coding for staphylococcal enterotoxins SElM, SElO, and SElN
Authors: Becker Karsten , Friedrich Alexander W. , Peters Georg , von Eiff Christof
Published: November 2004

Staphylococcus aureus remains a leading cause of food‐poisoning with substantial impact on public health. Using a multiplex polymerase chain reaction‐DNA enzyme immunoassay (PCR‐DEIA), we studied the presence of genes encoding staphylococcal enterotoxin‐like (SEl) superantigens sem, sen, and seo, associated with the enterotoxin gene cluster (egc), in 429 clinical Staphylococcus aureus isolates. 294 (68.5%) isolates tested positive for at least one of the three SEl genes. In contrast to the fixed gene combination seg/sei also located on egc, a substantial number of isolates (n = 108) were found to bear only one or two of the genes encoding SElM, SElN, and SElO. Regarding the origin of the S. aureus isolates, a significant difference (P = 0.022) was found for the possession of seo (61.2% of blood isolates versus 42.9% of nasal strains). Also sem (not significantly) was found more common in blood isolates (52.1% versus 40.5%). The survey of the newly described SEl genes sem‐seo supports the concept that most clinical S. aureus isolates harbor subsets of pyrogenic toxin superantigens. The potential contribution of seo and sem to the pathogenic potential of S. aureus has to be further evaluated.
Thermal behavior and intermolecular interactions in blends of poly(3‐hydroxybutyrate) and maleated poly(3‐hydroxybutyrate) with chitosan
Authors: Chen Cheng , Zhou Xuesong , Zhuang Yugang , Dong Lisong
Published: November 2004

The thermal behavior and intermolecular interactions of blends of poly(3‐hydroxybutyrate) (PHB) and maleated PHB with chitosan were studied with differential scanning calorimetry, Fourier transform infrared (FTIR), wide‐angle X‐ray diffraction (WAXD), and X‐ray photoelectron spectroscopy (XPS). The differences in the two blend systems with respect to their thermal behavior and intermolecular interactions were investigated. The melting temperatures, melting enthalpies, and crystallinities of the two blend systems gradually decreased as the chitosan content in the blends increased. Compared with that of the PHB component with the same composition, the crystallization of the maleated PHB component was more intensively suppressed by the chitosan component in the blends because of the rigid chitosan molecular chains and the intermolecular hydrogen bonds between the components. FTIR, WAXD, and XPS showed that the intermolecular hydrogen bonds in the blends were caused by the carbonyls of PHB or maleated PHB and chitosan aminos, and their existence depended on the compositions of the blends. The introduction of maleic anhydride groups onto PHB chains promoted intermolecular interactions between the maleated PHB and chitosan components. In addition, the intermolecular interactions disturbed the original crystal structures of the PHB, maleated PHB, and chitosan components; this was further proven by WAXD results. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 35–47, 2005
Truncated E‐cadherin potentiates cell death in prostate epithelial cells
Authors: Rios‐Doria Jonathan , Day Mark L.
Published: November 2004

BACKGROUND

E‐cadherin, a fundamental component of the adherens junction, is known to mediate aggregation‐dependent cell survival. We have previously identified a novel, calpain‐dependent proteolytic cleavage of E‐cadherin that resulted in the generation of a stable 100‐kDa E‐cadherin fragment (E‐cad100) in prostate epithelial cells in response to cell death stimuli. We postulated that the E‐cad100 fragment may play a role in abrogating survival of LNCaP cells following induction of apoptosis.

METHODS

Wild‐type E‐cadherin and E‐cad100 were engineered, tagged with GFP, and stably expressed in LNCaP cells. These cell lines were characterized for E‐cadherin‐GFP/β‐catenin interactions, endogenous E‐cadherin and β‐catenin expression, and sensitivity to apoptosis induced by PKC activation.

RESULTS

E‐cad100‐GFP demonstrated a punctuate expression pattern, in contrast to E‐cad120‐GFP, which was membrane‐localized. E‐cad100‐GFP, unlike E‐cad120‐GFP, failed to bind to and co‐localize with β‐catenin. Transient or stable overexpression of E‐cad100 resulted in the downregulation of endogenous E‐cadherin expression at the cell membrane. Activation of PKC in LNCaP cells which overexpressed E‐cad100 potentiated cell death.

CONCLUSIONS

Truncated E‐cadherin may play a role in the regulation of endogenous E‐cadherin expression and epithelial cell survival. © 2004 Wiley‐Liss, Inc.
Fragmentation of N‐linked glycans with a matrix‐assisted laser desorption/ionization ion trap time‐of‐flight mass spectrometer
Authors: Harvey David J. , Martin Rachel L. , Jackson Kathryn A. , Sutton Chris W.
Published: November 2004

N‐Linked glycans were ionized from several matrices with a Shimadzu‐Biotech AXIMA‐QIT matrix‐assisted laser desorption/ionization quadrupole ion trap time‐of‐flight mass spectrometer. [M+Na]+ ions were produced from all matrices and were accompanied by varying amounts of in‐source fragmentation products. The least fragmentation was produced by 2,5‐dihydroxybenzoic acid and the most by α‐cyano‐4‐hydroxycinnamic acid and 6‐aza‐2‐thiothymine. Sialic acid loss was extensive but could be prevented by formation of methyl esters. Fragmentation produced typical low‐energy‐type spectra dominated by ions formed by glycosidic cleavages. MSn spectra (n = 3 and 4) were used to probe the pathways leading to the major diagnostic ions. Thus, for example, an ion that was formed by loss of the core GlcNAc residues and the 3‐antenna was confirmed as being formed by a B/Y rather than a C/Z mechanism. The proposed structures of several cross‐ring cleavage ions were confirmed and it was shown that MS3 spectra could be obtained from as little as 10 fmol of glycan. Copyright © 2004 John Wiley & Sons, Ltd.
Acetylcholinesterase activity as a marker of maturation of the basolateral complex of the amygdaloid body in the rat
Authors: Berdel Bożena , Moryś Janusz , Maciejewska Beata , Narkiewicz Olgierd
Published: November 2004

Development and maturation of the basolateral complex of the amygdaloid body were studied in fetal and postnatal rat brains. In cresyl violet‐stained sections the basolateral complex was distinguishable at the 17th prenatal day. On about the 14th postnatal day, it showed all the features of the adult structure. The acetylcholinesterase activity appeared in neuropil of the basolateral complex on the seventh postnatal day; it increased slowly up to the 60th day. After that age, the acetylcholinesterase activity was stable in all parts of the basolateral complex and corresponded to its cytoarchitectonic differentiation. Our results suggest that the process of maturation of the amygdaloid basolateral complex, being related to the ingrowing of the cholinergic fibers from the basal forebrain, lasts at least up to the end of the second month of postnatal life.
Soil-associated lichens in rangelands of north-eastern Patagonia. Lichen groups and species with potential as bioindicators of grazing disturbance
Authors: SCUTARI Nora C. , BERTILLER Mónica B. , CARRERA Analía L.
Published: November 2004

Soil-associated lichen species characteristic of north-eastern Patagonia are classified by cluster analysis into six groups using ecological and morphological characters. The constancy of species, the total number of species, the number of species per crust and the relative frequency of species are analysed at sites with different grazing levels: three non-grazed, three regulary grazed, and three heavily grazed. Using the results, the potential use of lichen groups as bioindicators of rangeland conservation and degradation are explored. Species of three lichen groups (group A: lichens growing on calcareous gravels; group C: terricolous lichens with pale, crustose non-areolate thalli; group F: terricolous lichens with pale, areolate thalli) are identified as sensitive to grazing, and most of the species forming these groups are suggested as potential bioindicators of grazing disturbance. Thus, Rinodina bischoffii, Caloplaca holocarpa, Catillaria lenticularis, Acarospora heppii (group A); Lecanora dispersa and Rinodina mucronatula (group C); and Psora decipiens (group F) are the species most sensitive to grazing disturbance. Conversely, species of group D (terricolous lichens with dark, foliose thallus: Collema coccophorum), and group B (lichens growing on siliceous gravels: Aspicilia contorta) may be indicated as the most resistant to grazing disturbance.
Studies of embryonic development and the reproductive cycle in ovoviviparous Australian Onychophora (Peripatopsidae)
Authors: Walker Muriel H. , Tait Noel N.
Published: November 2004

Embryos of four ovoviviparous species of Australian onychophorans were examined to establish the process of their development, their reproductive cycle and to estimate the gestation period. The process of development is the same in all four species with, in the early embryo, segment halves separated by broad bands of extra‐embryonic ectoderm and the embryos growing by the posterior addition of segments. Seven developmental stages (I–VII) can be clearly identified from external morphology. Analysis of the developmental stages of the embryos present in females collected throughout a calendar year has allowed estimation of the time taken for each developmental stage and demonstrated that there is an annual reproductive cycle with a total gestation period of c. 12 months. Stages I and VII are prolonged, the latter related to the late completion of midgut development. The simultaneous presence of stage I and stage VII embryos at certain times of year indicates an overlap of generations within the uteri, which is more extensive for some species than others. As the stage VII embryos of one cohort complete their development, enlarged oocytes are released from the ovaries to become fertilized as they pass the seminal receptacles and enter the uteri to start their embryonic development to form the next cohort. Cephalofovea clandestina, Phallocephale tallagandensis and Ruhbergia bifalcata have head structures in males, Euperipatoides rowelli does not. The presence of embryos at all times of year in the uteri of mature females has implications for mating and sperm storage that are discussed.
The biology and functional morphology of Nipponoclava gigantea: clues to the evolution of tube dwelling in the Penicillidae (Bivalvia: Anomalodesmata: Clavagelloidea)
Authors: Morton Brian
Published: November 2004

Nipponoclava gigantea is restricted to the tropical Western Pacific waters of southern Japan at depths of between 5 and 70 m and lives in coarse sand and gravel. In many respects, N. gigantea appears to be similar to other endobenthic penicillids in that there is a true shell, the margins of which, via the intermediary of a narrow ‘saddle’, are united with an adventitious tube. This has a large watering pot anteriorly and pleated ruffles, representing either growth or repair events, posteriorly. Nipponoclava gigantea differs from other penicillids, however, in that its true shell is large, i.e. ˜20 mm high as compared to 2–3 mm, and the angle of valve splay is ˜80° as opposed to 180°. Internally the shell has a wide pallial line and shallow pallial sinus and there are anterior adductor muscle scars. There are possibly posterior adductor muscle scars also. These are not present in the adult animal, however, although the anterior adductor is. Also present are paired anterior and (possibly) posterior pedal retractor muscles, the latter having a nervous union with the visceral ganglia to create simple stretch or tonus proprioreceptors. It is argued that N. gigantea provides clues about how the tube‐dwelling lifestyle has evolved in the various taxa of the Penicillidae. It is suggested that through a process of heterochrony, in which the animal produces its adventitious tube at progressively earlier and earlier developmental stages, the true shell has become actually and relatively smaller and smaller and, hence, more splayed in more derived penicillids. Nipponoclava gigantea is thus an important link between an hypothetical lyonsiid ancestor and the more specialized penicillids and helps us to understand the adaptive radiation of this group of tube‐dwelling bivalves.
Structure of interplanetary magnetic cloud on April 16, 1999 and its origin estimated by fitting the torus‐shaped flux rope model
Authors: Ishibashi Hiromitsu , Marubashi Katsuhide
Published: November 2004

We examined the relationship between interplanetary magnetic cloud observed by the ACE satellite on April 16, 1999 and its solar origin. The solar and interplanetary background was relatively quiet for 10 clear days before April 16, enabling us to unambiguously assume the solar origin of the magnetic cloud. However, the results of fitting a constant‐alpha force‐free cylindrical flux rope model is inconsistent with findings from previous studies about magnetic clouds and their solar origins, although corresponding solar surface phenomena occurred near the central meridian. We therefore attempted to fit another model with the torus‐shaped magnetic field structure, which is a simple extension of the conventional cylindrical model with more geometrical flexibility. Using the estimated planar structure of the flux rope, we were able to interpret reasonably the observed magnetic cloud as an expansion into interplanetary space of a filament eruption or halo CME (coronal mass ejection) on April 13, 1999.
Transport and chemical transformation of anthropogenic and mineral aerosol in the marine boundary layer over the western North Pacific Ocean
Authors: Matsumoto Kiyoshi , Uyama Yukiko , Hayano Teruaki , Uematsu Mitsuo
Published: November 2004

To characterize the transport and chemical transformation of anthropogenic and mineral aerosols in the marine boundary layer over the western North Pacific, intensive observations of aerosol chemistry were conducted in the period from March to May of 2001 simultaneously on two remote islands, Hachijo and Chichi‐jima, located about 300 km and 1000 km south of Japan's main island, respectively. Mean concentrations of nss‐SO42−, NO3−, NH4+, and nss‐Ca2+ in aerosols during this period were 3.61, 1.35, 0.83, and 0.36 μg m−3, respectively, at Hachijo and 2.18, 0.52, 0.50, and 0.08 μg m−3, respectively, at Chichi‐jima. Most of the nss‐SO42 was associated with NH4+ in fine particles at both sites. In the coastal oceanic region, NO3− was adsorbed mainly on coarse mineral particles, indicating that mineral particles act as important carriers and sinks for NO3−. On the other hand, in the remote marine environment, NO3− was mainly associated with sea‐salt particles. Thus sea‐salt particles act as important sinks for NO3− over the remote ocean. Elemental carbon (EC) in fine particles exhibited mean concentrations of 0.27 and 0.18 μg m−3 at Hachijo and Chichi‐jima, respectively, with higher concentrations at Hachijo due to the influence of anthropogenic sources. On the other hand, mean concentrations of organic carbon (OC) in fine particles were estimated to be 0.35 and 0.41 μg m−3 at Hachijo and Chichi‐jima, respectively. The higher concentration of OC in the remote marine atmosphere of Chichi‐jima was attributed to carbonaceous substances evolved at lower temperatures (<200°C), which are probably derived from en route production and/or oceanic emissions.
Nucleation rate and vapor concentration estimations using a least squares aerosol dynamics method
Authors: Lehtinen K. E. J. , Rannik Ü. , Petäjä T. , Kulmala M. , Hari P.
Published: November 2004

A novel method for the determination of particle formation rates and condensable vapor concentrations for atmospheric nucleation events is presented that is based on combining least squares optimization with aerosol dynamics. Tests of the method with simulated events show that the method is able to capture the temporal behavior of formation and growth with reasonable accuracy. Example analyses have been performed for observed particle formation bursts in Hyytiälä, Finland. The results agree with previous analyses that are, in principle, based on analyzing size distribution contour plots by eye. However, the presented method also reveals detailed temporal behavior of the important processes, which is an important improvement compared to the previous methods.
A novel Na+ channel agonist, dimethyl lithospermate B, slows Na+ current inactivation and increases action potential duration in isolated rat ventricular myocytes
Authors: Yoon Jin‐Young , Ahn Sung‐Hun , Oh Hyuncheol , Kim Young‐Sup , Ryu Shi Yong , Ho Won‐Kyung , Lee Suk‐Ho
Published: November 2004

Voltage‐gated Na+ channel blockers have been widely used as local anaesthetics and antiarrhythmic agents. It has recently been proposed that Na+ channel agonists can be used as inotropic agents. Here, we report the identification of a natural substance that acts as a Na+ channel agonist.

Using the patch‐clamp technique in isolated rat ventricular myocytes, we investigated the electrophysiological effects of the substances isolated from the root extract of Salvia miltiorrhiza, which is known as ‘Danshen’ in Asian traditional medicine. By the intensive activity‐guided fractionation, we identified dimethyl lithospermate B (dmLSB) as the most active component, while LSB, which is the major component of the extract, showed negligible electrophysiological effect. Action potential duration (APD90) was increased by 20 μM dmLSB from 58.8±12.1 to 202.3±9.5 ms. In spite of the prolonged APD, no early after‐depolarization (EAD) was observed.

dmLSB had no noticeable effect on K+ or Ca2+ currents, but selectively affected Na+ currents (INa). dmLSB slowed the inactivation kinetics of INa by increasing the proportion of slowly inactivating component without inducing any persistent INa. The relative amplitude of slow component compared to the peak fast INa was increased dose dependently by dmLSB (EC50=20 μM). Voltage dependence of inactivation was not affected by dmLSB, while voltage dependence of activation shifted by 5 mV to the depolarised direction.

Since the APD prolongation by dmLSB did not provoke EAD, which is thought as a possible mechanism for the proarrhythmia seen in other Na+ channel agonists, dmLSB might be an excellent candidate for a Na+ channel agonist.

British Journal of Pharmacology (2004) 143, 765–773. doi:10.1038/sj.bjp.0705969
Electrophysiological characterization of the SK channel blockers methyl‐laudanosine and methyl‐noscapine in cell lines and rat brain slices
Authors: Scuvée‐Moreau Jacqueline , Boland Andre , Graulich Amaury , Overmeire Lionel Van , D'hoedt Dieter , Graulich‐Lorge Fabienne , Thomas Elizabeth , Abras Aude , Stocker Martin , Liégeois Jean‐Francois , Seutin Vincent
Published: November 2004

We have recently shown that the alkaloid methyl‐laudanosine blocks SK channel‐mediated afterhyperpolarizations (AHPs) in midbrain dopaminergic neurones. However, the relative potency of the compound on the SK channel subtypes and its ability to block AHPs of other neurones were unknown.

Using whole‐cell patch‐clamp experiments in transfected cell lines, we found that the compound blocks SK1, SK2 and SK3 currents with equal potency: its mean IC50s were 1.2, 0.8 and 1.8 μM, respectively. IK currents were unaffected. In rat brain slices, methyl‐laudanosine blocked apamin‐sensitive AHPs in serotonergic neurones of the dorsal raphe and noradrenergic neurones of the locus coeruleus with IC50s of 21 and 19 μM, as compared to 15 μM in dopaminergic neurones. However, at 100 μM, methyl‐laudanosine elicited a constant hyperpolarization of serotonergic neurones of about 9 mV, which was inconsistently (i.e. not in a reproducible manner) antagonized by atropine and hence partly due to the activation of muscarinic receptors.

While exploring the pharmacology of related compounds, we found that methyl‐noscapine also blocked SK channels. In cell lines, methyl‐noscapine blocked SK1, SK2 and SK3 currents with mean IC50s of 5.9, 5.6 and 3.9 μM, respectively. It also did not block IK currents. Methyl‐noscapine was slightly less potent than methyl‐laudanosine in blocking AHPs in brain slices, its IC50s being 42, 37 and 29 μM in dopaminergic, serotonergic and noradrenergic neurones, respectively. Interestingly, no significant non‐SK effects were observed with methyl‐noscapine in slices. At a concentration of 300 μM, methyl‐noscapine elicited the same changes in excitability in the three neuronal types than did a supramaximal concentration of apamin (300 nM).

Methyl‐laudanosine and methyl‐noscapine produced a rapidly reversible blockade of SK channels as compared with apamin. The difference between the IC50s of apamin (0.45 nM) and methyl‐laudanosine (1.8 μM) in SK3 cells was essentially due to a major difference in their k−1 (0.028 s−1 for apamin and 20 s−1 for methyl‐laudanosine).

These experiments demonstrate that both methyl‐laudanosine and methyl‐noscapine are medium potency, quickly dissociating, SK channel blockers with a similar potency on the three SK subtypes. Methyl‐noscapine may be superior in terms of specificity for the SK channels.

British Journal of Pharmacology (2004) 143, 753–764. doi:10.1038/sj.bjp.0705979
Evidence for an apamin‐sensitive, but not purinergic, component in the nonadrenergic noncholinergic relaxation of the rat gastric fundus
Authors: Currò Diego , Marco Teresina De , Preziosi Paolo
Published: November 2004

The involvement of adenosine triphosphate (ATP) and carbon monoxide (CO) in the non‐nitrergic nonpeptidergic component of high‐frequency electrical field stimulation (EFS)‐induced nonadrenergic noncholinergic (NANC) relaxation of longitudinal muscle strips from the rat gastric fundus was investigated.

Under NANC conditions (1 μM atropine+5 μM guanethidine), NG‐nitro‐L‐arginine methyl ester (L‐NAME, 1 mM) slightly reduced the amplitude, but did not affect the area under the curve (AUC) of EFS (13 Hz, 2 min)‐induced relaxation of 9,11‐dideoxy‐9α,11α‐methanoepoxy prostaglandin F2α (U46619, 0.1 μM)‐precontracted strips. With L‐NAME (1 mM) plus α‐chymotrypsin (1 U ml−1), the amplitude and the AUC of relaxation were reduced to approximately two‐third and one‐third of controls, respectively.

Pyridoxal‐phosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (100 μM), apamin (0.3 μM), desensitization to ATP, suramin (100 μM), zinc protoporphirin IX (300 μM) or ferrous haemoglobin (100 μM) did not inhibit the component of relaxation resistant to L‐NAME plus α‐chymotrypsin.

L‐NAME (1 mM) plus anti‐vasoactive intestinal peptide (VIP) serum (1 : 100) reduced the amplitude and the AUC of relaxation to a similar extent as L‐NAME (1 mM) plus α‐chymotrypsin (1 U ml−1). Adding apamin (0.1 μM) to L‐NAME (1 mM) plus anti‐VIP serum (1 : 100) further reduced the amplitude and the AUC of relaxation.

These findings suggest that the non‐nitrergic nonpeptidergic component of NANC relaxation of the rat gastric fundus induced by high‐frequency stimulation is mediated by a neurotransmitter thatacts through apamin‐sensitive mechanisms, that is neither ATP nor CO.

British Journal of Pharmacology (2004) 143, 785–793. doi:10.1038/sj.bjp.0705993
Protein kinase C activation inhibits eosinophil degranulation through stimulation of intracellular cAMP production
Authors: Ezeamuzie Charles I , Taslim Najla
Published: November 2004

The mechanism of inhibition of eosinophil degranulation by protein kinase C (PKC) was investigated in complement C5a (C5a)‐stimulated degranulation of highly purified human eosinophils using the specific PKC activator – phorbol 12‐myristate 13‐acetate (PMA).

C5a‐induced release of eosinophil peroxidase and eosinophil cationic protein was potently inhibited in a concentration‐dependent manner by PMA (IC50: 3 and 5 nM, respectively). The inhibition by PMA, but not histamine, was significantly reversed by the specific, but isoform nonselective, PKC inhibitor Ro 31‐8220 (1 μM).

In the presence of phosphodiesterase inhibitor rolipram (5 μM), PMA stimulated a pronounced concentration‐dependent increase in intracellular cAMP, with a potency 400 times that of histamine (EC50: 55 nM vs 22.5 μM). The inactive PMA analogue, 4α‐PMA, had no such effect.

The cAMP production by PMA, but not histamine, was significantly reversed by Ro 31‐8220 (1 μM) and the selective inhibitor of the novel PKCδ, rottlerin (1–3 μM), but not the selective inhibitor of the classical PKC isoforms, Gö 6976 (0.01–0.1 μM).

Western blot analysis revealed the presence of six PKC isoforms (α, βI, βII, δ, ι and ζ) in isolated eosinophils.

Chelation of internal or external calcium had no effect on PMA‐induced cAMP response, but abolished that induced by histamine.

There was a good correlation between increase in intracellular cAMP and inhibition of degranulation.

These results show, for the first time, that in human eosinophils, PMA, via activation of PKCδ isoform, can stimulate cAMP production, and that this may be the basis for its potent anti‐degranulatory effect.

British Journal of Pharmacology (2004) 143, 725–732. doi:10.1038/sj.bjp.0706028