bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced oxidative and nitrosative damage in murine experimental colitis in the absence of inducible nitric oxide synthase
Authors: Zingarelli B , Szabó C , Salzman A L
Published: January 2010

BACKGROUND

Oxidative and nitrosative stress have been implicated in the pathogenesis of inflammatory bowel diseases.

AIMS

To study the role of nitric oxide (NO) derived from inducible NO synthase (iNOS) in an experimental model of murine enterocolitis.

METHODS

Trinitrobenzene sulphonic acid (TNBS) was instilled per rectum to induce a lethal colitis in iNOS deficient mice and in wild type controls. The distal colon was evaluated for histological evidence of inflammation, iNOS expression and activity, tyrosine nitration and malondialdehyde formation (as indexes of nitrosative and oxidative stress), myeloperoxidase activity (as index of neutrophil infiltration), and tissue localisation of intercellular adhesion molecule 1 (ICAM-1).

RESULTS

TNBS administration induced a high mortality and weight loss associated with a severe colonic mucosal erosion and ulceration, increased myeloperoxidase activity, increased concentrations of malondialdehyde, and an intense staining for nitrotyrosine and ICAM-1 in wild type mice. Genetic ablation of iNOS gene conferred to mice a significant resistance to TNBS induced lethality and colonic damage, and notably reduced nitrotyrosine formation and concentrations of malondialdehyde; it did not, however, affect neutrophil infiltration and intestinal ICAM-1 expression in the injured tissue.

CONCLUSION

Data show that activation of iNOS is required for nitrosative and oxidative damage in experimental colitis.
Strictures in Crohn’s disease are characterised by an accumulation of mast cells colocalised with laminin but not with fibronectin or vitronectin
Authors: Gelbmann C M , Mestermann S , Gross V , Köllinger M , Schölmerich J , Falk W
Published: January 2010

BACKGROUND/AIMS

Intestinal fibrosis and stricture formation is an unresolved problem in Crohn’s disease. The aim of this study was to investigate whether mast cells accumulate in these tissues and whether their localisation is associated with extracellular matrix components.

METHODS

Mast cells were visualised by immunohistochemical staining of the mast cell specific proteases chymase and tryptase. Their localisation in relation to extracellular matrix components was shown by immunohistochemical double labelling.

RESULTS

In strictures in Crohn’s disease, a striking accumulation of mast cells was seen particularly in the hypertrophied and fibrotic muscularis propria, with a mean (SEM) mast cell number of 81.3 (14.9)v 1.5 (0.9)/mm2 in normal bowel (p<0.0005). All mast cells in the muscularis propria were colocalised with patches of laminin. In contrast, in the submucosa, laminin was exclusively found in the basal lamina of blood vessels where many adherent mast cells were seen. No colocalisation of mast cells was found with fibronectin or vitronectin.

CONCLUSIONS

The large accumulation of mast cells in the muscle layer of strictured bowel suggests a functional role for these cells in the hypertrophic and fibrotic response of the smooth muscle cells. The colocalisation with laminin indicates a mechanism of interaction between smooth muscle cells and mast cells that may be important in the role of mast cells in the process of fibrosis.
Oral contraceptive use and the clinical course of Crohn’s disease: a prospective cohort study
Authors: Cosnes J , Carbonnel F , Carrat F , Beaugerie L , Gendre J-P
Published: January 2010

BACKGROUND

Women with Crohn’s disease are usually advised not to take oral contraceptives, but, unlike smoking, there is no clear association between current oral contraceptive use and more severe disease.

AIM

To assess the effect of oral contraceptive use on the clinical course of Crohn’s disease.

PATIENTS

331 women, aged 16–50 years, with Crohn’s disease and Crohn’s disease activity index <200, were enrolled consecutively during a one year period. Patients were classified at inclusion as oral contraceptive users or non-users and smokers or non-smokers.

METHODS

A prospective 12–18 month cohort study was used. The main outcome measures were flare up rate and time to flare up.

RESULTS

In total, 134 women used oral contraceptives, in most cases low oestrogen formulations. During the study period, 61 oral contraceptive users (46%) developed a flare up, compared with 85 non-users (43%). The hazard ratio for oral contraceptive use was 1.11 (95% confidence interval 0.80 to 1.55). Variables associated with flare up were smoking status, recently active disease, baseline Crohn’s disease activity index, and presence of anoperineal lesions. The same results were obtained when the analysis was restricted to patients eligible for a relapse prevention trial.

CONCLUSION

Unlike smoking, oral contraceptives have no effect on Crohn’s disease activity.
Gut origin of sepsis: a prospective study investigating associations between bacterial translocation, gastric microflora, and septic morbidity
Authors: MacFie J , O’Boyle C , Mitchell C J , Buckley P M , Johnstone D , Sudworth P
Published: January 2010

AIMS

To investigate the “gut origin of sepsis” hypothesis.

METHODS

Prospective controlled study of 279 surgical patients in which cultures of nasogastric aspirates were compared with those obtained from mesenteric lymph nodes taken at laparotomy and the organisms cultured from subsequent septic complications. Bacterial translocation was confirmed if positive cultures were obtained from mesenteric lymph nodes. Postoperative sepsis was defined as any positive culture in the postoperative period. Bacterial species obtained in gastric microflora, mesenteric lymph nodes, and postoperative septic complications were compared.

RESULTS

Only 85/279 patients (31%) had a sterile nasogastric aspirate; the most frequently identified organism was Candida spp. (54%) and the most common enteric organism cultured was E coli (20%). Multiple organisms were isolated in 39% and occurred more frequently in patients aged over 70 years, those undergoing non-elective surgery, and in those requiring proximal gastrointestinal surgery. Postoperative sepsis was more common in these patients. Bacterial translocation occurred in 21% and was significantly more frequent in those with multiple organisms in their nasogastric aspirates. E coli was the commonest organism isolated from the lymph node specimens (48%) and septic foci (53%). Fungal translocation did not occur. An identical genus was identified in the nasogastric aspirate and the septic focus in 30% of patients, in the nasogastric aspirate and the lymph node in 31%, and in the lymph node and a postoperative septic focus in 45%.

CONCLUSIONS

Proximal gut colonisation is associated with both increased bacterial translocation and septic morbidity. The commonality of organisms identified supports the gut origin of sepsis hypothesis.
Intestinal crypt cell apoptosis in murine acute graft versus host disease is mediated by tumour necrosis factor α and not by the FasL-Fas interaction: effect of pentoxifylline on the development of mucosal atrophy
Authors: Stüber E , Büschenfeld A , von Freier A , Arendt T , Fölsch U R
Published: January 2010

BACKGROUND

Murine T cell mediated acute semiallogeneic graft versus host disease (GVHD) is characterised by lymphocytic infiltrates, crypt hyperplasia, and villous atrophy. It has been shown that programmed cell death (apoptosis) of the crypt epithelium takes place during the intestinal manifestation of acute GVHD.

AIMS

To investigate which of the two most investigated inductors of apoptosis (Fas ligand (FasL) and tumour necrosis factor α (TNF-α)) is responsible for the induction of apoptosis in this animal model.

METHODS

Animals undergoing acute semiallogeneic GvH reaction were treated with neutralising anti-TNF-α, two different anti-FasL antibodies, or pentoxifylline.

RESULTS

Anti-TNF-α application inhibited the appearance of apoptotic cells in the intestinal mucosa, whereas anti-FasL antibodies had no influence on mucosal apoptosis. In addition, the transfer of FasL deficient (gld) donor lymphocytes still induced crypt cell apoptosis, villous atrophy, and crypt hyperplasia. Furthermore, when the animals were treated with pentoxifylline, a known inhibitor of TNF-α secretion in vitro and in vivo, there was significant normalisation of the intestinal morphology accompanied by inhibition of epithelial apoptosis.

CONCLUSIONS

The FasL-Fas interaction is not involved in the induction of apoptosis during acute GVHD. However, neutralisation of TNF-α by an antibody or by pentoxifylline inhibits the occurrence of apoptosis and of mucosal atrophy in this animal model. These results have implications for the treatment of immunologically mediated human atrophic gut diseases—for example, diet refractory cases of coeliac disease.
Structural, neuronal, and functional adaptive changes in atrophic rat ileum
Authors: Ekelund K M , Ekblad E
Published: January 2010

BACKGROUND

Inactivity of the gut leads to atrophic changes of which little is known.

AIMS

To investigate structural, neuronal, and functional changes occurring in bypassed rat ileum.

METHODS

Morphometry was used to characterise the atrophic changes. The numbers of enteric neurones, their expression of neurotransmitters, and the presence of interstitial cells of Cajal were studied using immunocytochemistry and in situ hybridisation. Motor activity was studied in vitro.

RESULTS

Adaptive changes in bypassed ileum include atrophy and remodelling of the gut wall. The total numbers of submucous and myenteric neurones per unit length increased one and four weeks after bypass but were identical to sham operated intestine 10 weeks after bypass. Neurones expressing vasoactive intestinal peptide, neuropeptide Y, or pituitary adenylate cyclase activating peptide decreased gradually in number in bypassed ileum. Nitric oxide synthase expressing neurones were increased, particularly in the myenteric ganglia. No change in the frequency and distribution of interstitial cells of Cajal was noted. The contractile response elicited by electrical stimulation of sham operated ileum consisted of a fast cholinergic twitch followed by a slower non-adrenergic, non-cholinergic contraction. In the bypassed ileum an identical biphasic contraction was elicited; however, the entire response was non-adrenergic, non-cholinergic. The relaxatory response to electrical stimulation in sham operated ileum was nitric oxide mediated; after bypass it was non-nitrergic.

CONCLUSIONS

Notable atrophic changes were seen in the rat ileum after bypass. The enteric nervous system reacted with neuronal cell death and plasticity in terms of release and expression of neurotransmitters.
Interleukin 1 and interleukin 1β converting enzyme (caspase 1) expression in the human colonic epithelial barrier. Caspase 1 downregulation in colon cancer
Authors: Jarry A , Vallette G , Cassagnau E , Moreau A , Bou-Hanna C , Lemarre P , Letessier E , Le Neel J-C , Galmiche J-P , Laboisse C L
Published: January 2010

BACKGROUND

Interleukin (IL) 1β converting enzyme (now known as caspase 1) is able to process pro-IL-1β into its active form and is involved in proapoptotic signalling.

AIMS

To characterise IL-1 and caspase 1 expression in human colonic epithelial cells.

METHODS

Intracellular IL-1 content (IL-1α and IL-1β) was measured by ELISA in freshly isolated human normal colonocytes. Caspase 1 expression was determined both at the mRNA level using in situ hybridisation and reverse transcription polymerase chain reaction, and at the protein level by immunoblotting experiments using antibodies specific for the proform of caspase 1 and for its cleavage forms.

RESULTS

Low amounts of IL-1β were found in nearly all preparations (92%), and IL-1α was detected in only 45% of human colonocyte preparations. The normal colonic epithelium strongly expressed caspase 1, both at the mRNA level and at the protein level in its latent form. In contrast, caspase 1 was not expressed in colon cancer (primary colonic adenocarcinomas and cancer cell lines).

CONCLUSIONS

The demonstration that the human colonic epithelial barrier is able to express caspase 1 and its substrate IL-1β reinforces the concept that, under certain conditions, the epithelium could trigger an inflammatory reaction. In addition, the finding that caspase 1 was downregulated in colonic adenocarcinomas supports the concept that disrupted apoptosis pathways may be involved in tumour formation and/or may confer resistance to treatment.
Contribution of matrilysin (MMP-7) to the metastatic pathway of human colorectal cancers
Authors: Adachi Y , Yamamoto H , Itoh F , Hinoda Y , Okada Y , Imai K
Published: January 2010

BACKGROUND/AIM

Matrilysin is one of the matrix metalloproteinases that has a critical role in tumour invasion, and is often expressed in gastrointestinal cancers. The aim of this study was to examine the role of matrilysin in metastasis of human colorectal cancers.

PATIENTS (SUBJECTS)/METHODS

The relation between matrilysin expression and Dukes’s type was investigated immunohistochemically in 83 surgically resected colorectal cancers, including five with liver metastasis. Moreover, the effects of matrilysin on the in vivo invasive and metastatic potential of colon cancer cells transfected with matrilysin cDNA were examined after subcutaneous injection into SCID mice.

RESULTS

In 46% of primary and all of metastatic liver tumours, over 10% of cancer cells were stained positively for matrilysin. The expression of matrilysin correlated significantly with the presence of nodal or distant metastases (p<0.05). In addition, matrilysin transfectants formed invasive tumours and multiple liver metastases in SCID mice, without producing any significant difference in the subcutaneous tumour growth from mock transfectants. Casein zymography showed that the invading and metastasised tumours showed conspicuous matrilysin activity, which correlated with the number of metastatic lesions (p<0.001).

CONCLUSIONS

Matrilysin showed a correlation with metastasis in a cohort of 83 colorectal cancer patients and marked metastatic potentiation in human colorectal cancer xenografts, indicating that it may play a critical role in the metastatic pathway of colorectal cancers.
Gall bladder emptying in severe idiopathic constipation
Authors: Penning C , Gielkens H A J , Delemarre J B V M , Lamers C B H W , Masclee A A M
Published: January 2010

BACKGROUND

It has been suggested that slow transit constipation (STC) may be part of a panenteric motor disorder.

AIM

To evaluate motility of an upper gastrointestinal organ, the gall bladder, in 16 patients with STC and 20 healthy controls.

METHODS

Gall bladder emptying (ultrasonography) was studied in response to neural, cephalic-vagal stimulation with modified sham feeding (MSF) for 90 minutes and in response to hormonal stimulation with cholecystokinin (CCK, 0.5 IDU/kg/h) for 60 minutes.

RESULTS

Fasting gall bladder volume in patients with STC (17 (2) cm3) was significantly (p<0.01) reduced compared with that in controls (24 (2) cm3). Gall bladder emptying in response to MSF was significantly reduced in patients with STC expressed both as percentage emptying (11 (5)% versus 22 (3)%; p<0.05) and as absolute emptying (2.1 (0.7) cm3 versus 4.9 (0.7) cm3; p<0.02). However, percentage gall bladder emptying in response to CCK was not different between patients and controls (73 (4)% versus 67 (4)%) although the absolute reduction in gall bladder volume was significantly (p<0.05) smaller in patients (10.7 (1.1) cm3versus 15.3 (1.4) cm3).

CONCLUSIONS

Patients with slow transit constipation have smaller fasting gall bladder volumes, impaired gall bladder responses to vagal cholinergic stimulation, but normal gall bladder responses to hormonal stimulation with CCK. These results point to abnormalities in gastrointestinal motility proximal from the colon in slow transit constipation and more specifically, impaired neural responsiveness.
Myofibroblast proliferation, fibrosis, and defective pancreatic repair induced by cyclosporin in rats
Authors: Vaquero E , Molero X , Tian X , Salas A , Malagelada J-R
Published: January 2010

BACKGROUND

Full recovery is always achieved after caerulein induced pancreatitis. Cyclosporin stimulates transforming growth factor β (TGF-β) and may interfere with pancreatic regeneration.

AIM

To investigate the effects of cyclosporin after caerulein induced pancreatitis or after caerulein injury.

METHODS

Protocol A: rats received cyclosporin daily (20 mg/kg) and caerulein pancreatitis was induced on days 2 and 8. Protocol B: six courses of caerulein pancreatitis were induced at weekly intervals. Cyclosporin was administered on induction and the day before. Rats recovered for two weeks before being killed. Control groups received saline, cyclosporin, or caerulein alone.

RESULTS

Protocol A: plasma TGF-β1 and tissue collagenase rose after pancreatitis but decreased towards baseline values on day 15, matching a low collagen content. Morphology disclosed minimal inflammatory infiltration and some interstitial cells immunoreactive for smooth muscle α-actin (SMA). TGF-β1 increased, and remained high in cyclosporin treated groups (cyclosporin alone and cyclosporin plus caerulein). Rats treated with cyclosporin and caerulein showed severe pancreatic weight reduction, abundant inflammatory infiltrates, increased SMA immunoreactive interstitial cells, high collagen content, and delayed collagenase response. No SMA immunoreactive cells were detected in normal rats. Cyclosporin alone also increased SMA immunoreactive cells, despite the absence of inflammatory infiltration and fairly conserved pancreatic structure. Protocol B: the combined pulse treatment induced appreciable collagen deposition and resulted in a smaller pancreas than controls. Morphological examination showed atrophy, fibrosis, fibroblast proliferation, and mononuclear infiltrates.

CONCLUSION

Cyclosporin greatly distorts pancreatic repair, transforming caerulein induced pancreatitis into a fibrotic chronic-like disease. The mechanism involves TGF-β, myofibroblasts, and defective collagenase activation.
Iron overload in urban Africans in the 1990s
Authors: Gangaidzo I T , Moyo V M , Saungweme T , Khumalo H , Charakupa R M , Gomo Z A R , Loyevsky M , Stearman R , Vaute T La , Enquist E G , Rouault T A , Gordeuk V R
Published: January 2010

BACKGROUND

In a previously described model, heterozygotes for an African iron loading locus develop iron overload only when dietary iron is high, but homozygotes may do so with normal dietary iron. If an iron loading gene is common, then homozygotes with iron overload will be found even in an urban population where traditional beer, the source of iron, is uncommon.

AIMS

To determine whether iron overload and the C282Y mutation characteristic of hereditary haemochromatosis are readily identifiable in an urban African population.

METHODS

Histological assessment, hepatocellular iron grading, and dry weight non-haem iron concentration were determined in post mortem tissue from liver, spleen, heart, lungs, and skin. DNA of subjects with elevated hepatic iron indexes was analysed for the C282Y mutation. Iron concentrations in other tissues were compared.

RESULTS

A moderate increase (>30 μmol/g) in hepatic iron concentrations was found in 31 subjects (23%; 95% confidence interval 15.9 to 30.1%), and they were considerably elevated (>180 μmol/g) in seven subjects (5.2%; 95% confidence interval 1.5 to 8.9%). Appreciably elevated hepatic iron concentrations were associated with heavy iron deposition in both hepatocytes and macrophages, and either portal fibrosis or cirrhosis. All were negative for the C282Y mutation. Very high concentrations were uncommon in subjects dying in hospital. Concentrations of iron in spleen, heart, lung, and skin were significantly higher in subjects with elevated hepatic iron.

CONCLUSIONS

Iron overload is readily identified among urban Africans and is associated with hepatic damage and iron loading of several tissues. The condition is unrelated to the genetic mutation found in hereditary haemochromatosis.
High prevalence of anti-hepatitis B virus serological markers in patients with hepatitis C virus related chronic liver disease in Japan
Authors: Marusawa H , Osaki Y , Kimura T , Ito K , Yamashita Y , Eguchi T , Kudo M , Yamamoto Y , Kojima H , Seno H , Moriyasu F , Chiba T
Published: January 2010

BACKGROUND/AIMS

Evidence is accumulating that hepatitis B virus (HBV) is present in patients who are hepatitis B surface antigen negative but have antibody to hepatitis B core antigen (anti-HBc). Furthermore, recent studies have shown that patients with hepatocellular carcinoma who have antibody to hepatitis C virus (HCV) often possess HBV related serological markers. Data on the seroprevalence of HBV infection in patients with HCV related chronic liver disease were collected to evaluate the significance of the presence of antibodies to HBV.

METHODS

The prevalence of HBV related serological markers was analysed in a total of 2014 Japanese patients with HCV infection. The control group comprised 352 subjects without liver disorder.

RESULTS

A large number of patients (49.9%) with HCV related chronic liver disease including hepatocellular carcinoma were positive for anti-HBc. In addition, the prevalence of anti-HBc closely correlated with the clinical stage of the liver disease. There was no relation between a past history of blood transfusion and the prevalence of anti-HBc. Notably, anti-HBc was the only serological marker for HBV infection in a significant number of patients with HCV related chronic liver disease (24.1%).

CONCLUSIONS

Our data provide further evidence for the high prevalence of anti-HBc in patients with HCV related chronic liver disease, particularly those with hepatocellular carcinoma, suggesting that HBV infection, probably including latent infection, may play an important role in carcinogenesis in these patients.
Familial occurrence of nodular regenerative hyperplasia of the liver: a report on three families
Authors: Dumortier J , Boillot O , Chevallier M , Berger F , Potier P , Valette P-J , Paliard P , Scoazec J-Y
Published: January 2010

BACKGROUND/AIMS

Nodular regenerative hyperplasia of the liver is a histological lesion usually associated with systemic diseases, haematological malignancies, or drugs. Its prognosis depends on portal hypertension, which usually is well tolerated and requires medical management only.

PATIENTS

Three unrelated families, in which two sibling adult male patients presented with nodular regenerative hyperplasia of the liver, were studied.

METHODS

Complete clinical charts and liver biopsy specimens were available for all patients. In addition, explanted livers were available for examination for the two transplanted patients.

RESULTS

There was no evidence of any of the various clinical situations known to be associated with nodular regenerative hyperplasia of the liver. Portal hypertension was severe, requiring surgical treatment in two cases. Renal lesions were present in three patients. In two patients, progressive evolution to liver atrophy and hepatic failure, associated with renal failure, led to combined liver and renal transplantation.

CONCLUSIONS

This report describes the existence of familial cases of nodular regenerative hyperplasia of the liver, occurring without underlying or associated systemic disease, characterised by a poor clinical course and often associated with progressive renal failure.
Development of a disease specific questionnaire to measure health related quality of life in patients with chronic liver disease
Authors: Younossi Z M , Guyatt G , Kiwi M , Boparai N , King D
Published: January 2010

BACKGROUND AND AIMS

To develop and assess a disease specific instrument for measuring health related quality of life (HRQL) in patients with chronic liver disease (CLD).

METHODS

Based on responses from 60 patients with chronic liver disease, from 20 liver experts, and from a Medline search of the literature, items potentially affecting the HRQL of these patients were identified. A separate sample of 75 patients identified which items they found problematic and rated their importance. Results were explored using factor analysis; domains were chosen and items placed within domains. Redundant questions were eliminated and the final questionnaire was pretested in 10 patients. Using this instrument, HRQL was assessed in a further 133 patients with various types and stages of liver disease.

RESULTS

Patients, experts, and the literature search identified 156 items of potential importance. Of these, 35 proved important to over 50% of 75 respondents in the item reduction sample. The factor analysis suggested six domains. After eliminating redundancies, the Chronic Liver Disease Questionnaire (CLDQ) included 29 items in the following domains: fatigue, activity, emotional function, abdominal symptoms, systemic symptoms, and worry. In pretesting, patients found the CLDQ clear and easy to complete in 10 minutes. In another 133 patients, the CLDQ showed a gradient between patients without cirrhosis, Child’s A cirrhosis, and those with Child’s B or C cirrhosis. CLDQ has evidence for moderate reliability at six months and seems to be responsive.

CONCLUSION

The CLDQ is short, easy to administer, produces both a summary score and domain scores, and correlates with the severity of liver disease.
Spur cell anaemia and hepatic iron stores in patients with alcoholic liver disease undergoing orthotopic liver transplantation
Authors: Pascoe A , Kerlin P , Steadman C , Clouston A , Jones D , Powell L , Jazwinska E , Lynch S , Strong R
Published: January 2010

BACKGROUND

Following orthotopic liver transplantation (OLT) histological examination of explant livers from patients with alcoholic liver disease (ALD) sometimes shows extensive iron deposits in a distribution suggestive of homozygous haemochromatosis.

AIMS

To use haemochromatosis gene (HFE) assays to distinguish between ALD with notable siderosis and hereditary haemochromatosis. To evaluate the possible influence of spur cell haemolytic anaemia on hepatic iron loading.

PATIENTS

Thirty seven patients with ALD were abstinent for at least six months prior to OLT. Twenty three patients had transferrin saturations greater than 55%, 16 also had increased serum ferritin (>350 μg/l). Eight of 37 (22%) explant livers had grade 3 or 4 hepatic iron deposition, predominantly in hepatocytes. Of these, four had a hepatic iron index greater than 1.9 and most seemed to have spur cell haemolytic anaemia.

METHODS

Mutation analysis for C282Y and H63D mutations was performed on DNA extracts from peripheral blood or explant liver. Spur cell haemolytic anaemia was diagnosed when the haemoglobin was 105 g/l in the presence of notable acanthocytosis.

RESULTS

None of the eight patients with grade 3 or 4 hepatic iron had evidence of the C282Y mutation. Two of the eight were heterozygous for H63D. None of the remaining 28 patients tested showed homozygous HFE mutations. Spur cell anaemia was present in six of the eight patients with heavy iron deposition and only one of the remaining patients.

CONCLUSIONS

The HFE mutation was not present in these patients with advanced ALD and heavy iron loading. Spur cell haemolytic anaemia provides an alternative potential mechanism for the heavy iron loading.
Selection of hepatitis B surface “escape” mutants during passive immune prophylaxis following liver transplantation: potential impact of genetic changes on polymerase protein function
Authors: Shields P L , Owsianka A , Carman W F , Boxall E , Hubscher S G , Shaw J , O’Donnell K , Elias E , Mutimer D J
Published: January 2010

CASE REPORT

A patient is described who developed hepatitis B virus (HBV) reinfection five months following liver transplantation. Failure of hepatitis B immunoglobulin prophylaxis was associated with the emergence of mutations. HBV gene sequencing identified nucleotide substitutions associated with amino acid changes, one within the major hydrophilic region (MHR) of the HBV surface antigen at amino acid position 144 and one outside the MHR. Because of the overlapping reading frames of surface and polymerase genes, the latter surface antigen change was associated with an amino acid change in the polymerase protein. The patient developed significant allograft hepatitis and was treated with lamivudine (3TC) 100 mg daily. Rapid decline of serum HBV DNA was observed with loss of HBV e antigen and HBV surface antigen from serum. There was normalisation of liver biochemistry, and liver immunohistochemistry showed a reduction in HBV core and disappearance of HBs antigen staining.

CONCLUSION

Surface antigen encoding gene mutations associated with HBIg escape may be associated with alteration of the polymerase protein. The polymerase changes may affect sensitivity to antiviral treatment. Selection pressure on one HBV reading frame (for example, HBIg pressure on HBsAg, or nucleoside analogue pressure on polymerase protein) may alter the gene product of the overlapping frame. Such interactions are relevant to strategies employing passive immune prophylaxis and antiviral treatment.
Evaluation of a policy to reduce youth tractor crashes on public roads
Authors: Marlenga B , Doty B C , Berg R L , Linneman J G
Published: January 2010

Objective:Evaluate the effectiveness of a United States state law, Wisconsin Act 455, in reducing highway tractor crashes involving youth operators.

Design:Policy outcome evaluation involving review of a retrospective case series.

Setting:Youth highway tractor crashes from Wisconsin for the years 1994–2003 that resulted in a fatality, injury, and/or property damage.

Subjects:One hundred and forty six tractor crash cases involving operators younger than 16 years.

Methods:Describe and model the tractor crash patterns before and after enactment of the law, and examine the relation between the contributing circumstances identified in the crash reports and the content covered in the mandated tractor certification course.

Results:There was neither a significant change in the number of youth tractor crashes after the law was passed, nor any reduction in the proportion of crashes where the youth operator was designated at fault. The tractor certification course did not cover the major factors contributing to youth tractor crashes on public roads.

Conclusions:No significant effect of the law was detected and crash rates at the end of the study period were similar to those before Wisconsin Act 455. The authors’ findings should not be construed to suggest that public policy, in general, is an ineffective strategy for the prevention of pediatric agricultural injuries. Negotiating a balance in public policy debates will be a challenge, but it is clear that future policy initiatives need to identify and implement the right policy for the right problem.
Absence of Klein’s paradox for massive bosons coupled by nonminimal vector interactions
Authors: Cardoso T. R. , Castro L. B. , de Castro A. S.
Published: January 2010

A few properties of the nonminimal vector interactions in the Duffin–Kemmer–Petiau theory are revised. In particular, it is shown that the space component of the nonminimal vector interaction plays a peremptory role for confining bosons, whereas its time component contributes to the leakage. Scattering in a square step potential with proper boundary conditions is used to show that Klein’s paradox is not manifested in the case of a nonminimal vector coupling.
NONLINEAR FREE VIBRATION OF A MODERATELY THICK DOUBLY CURVED SHALLOW SHELL OF ELLIPTICAL PLAN-FORM
Authors: CHORFI S. M. , HOUMAT A.
Published: January 2010

The p-version of the finite element method is used in conjunction with the blending function method to investigate the nonlinear free vibration of a doubly curved shallow shell of elliptical plan-form. The effects of transverse shear deformations, rotary inertia, and geometrical nonlinearity are taken into account. The harmonic balance method is used to derive the equations of free motion. The resultant nonlinear equations are solved iteratively using the linearized updated mode method. The efficiency of the method is demonstrated through convergence study and comparison with published results. The effects of geometric parameters such as thickness, ellipse aspects, and curvatures on the backbone curves of a clamped doubly curved shallow shell of elliptical plan-form are studied. It is shown that the increase or decrease of the hardening behavior is dependent upon these parameters.
EISENSTEIN AND POINCARÉ SERIES ON SL(3,R)
Authors: EHRENPREIS LEON
Published: January 2010

This work continues the ideas presented in the author's book, The Universality of the Radon Transform (Oxford, 2003), which deals with the group SL(2,R). The complication that arises for G = SL(3,R) comes from the fact that there are now two fundamental representations. This has the consequence that the wave operator, which plays a central role in our work on SL(2,R) is replaced by an overdetermined system of partial differential equations. The analog of the wave operator is defined using an MN invariant orbit of G acting on the direct sum of the symmetric squares of the fundamental representations. The relation of orbits, or, in general, of any algebraic variety, to a system of partial differential equations comes via the Fundamental Principle, which shows how Fourier transforms of functions or measures on an algebraic variety correspond to solutions of the system of partial differential equations defined by the equations of the variety. In particular, we can start with the sum T of the delta functions of the orbit of the group Γ = SL(2,Z) on the light cone. We then take its Fourier transform, using a suitable quadratic form. We then decompose the Fourier transform under the commuting group of G. In this way, we obtain a Γ invariant distribution which has a natural restriction to the orbit G/K, which is the symmetric space of G. This restriction is (essentially) the nonanalytic Eisenstein series. We can compute the periods of the Eisenstein series over various orbits of subgroups of G by means of the Euclidean Planchere formula. A more complicated form of these ideas is needed to define Poincaré series.
ON BINARY QUADRATIC FORMS AND THE HECKE GROUPS
Authors: RESSLER WENDELL
Published: January 2010

We present a reduction theory for certain binary quadratic forms with coefficients in ℤ[λ], where λ is the minimal translation in a Hecke group. We generalize from the modular group Γ(1) = PSL(2,ℤ) to the Hecke groups and make extensive use of modified negative continued fractions. We also define and characterize "reduced" and "simple" hyperbolic fixed points of the Hecke groups.
Antioxidant treatment attenuates pulmonary arterial hypertension-induced heart failure
Authors: Redout Everaldo M. , van der Toorn Annette , Zuidwijk Marian J. , van de Kolk Cees W. A. , van Echteld Cees J. A. , Musters René J. P. , van Hardeveld Cornelis , Paulus Walter J. , Simonides Warner S.
Published: January 2010

ROS have been implicated in the development of pathological ventricular hypertrophy and the ensuing contractile dysfunction. Using the rat monocrotaline (MCT) model of pulmonary arterial hypertension (PAH), we recently reported oxidative stress in the failing right ventricle (RV) with no such stress in the left ventricle of the same hearts. We used the antioxidant EUK-134 to assess the role of ROS in the pathological remodeling and dysfunction of the RV. PAH was induced by an injection of MCT (80 mg/kg, day 0), treatment with EUK-134 (25 mg/kg, once every 2 days) of control and MCT-injected animals [congestive heart failure (CHF) group] was started on day 10, and animals were analyzed on day 22. EUK-134 treatment of the CHF group attenuated cardiomyocyte hypertrophy and associated changes in mRNA expression (myosin heavy chain-β and deiodinase type 3). It also reduced RV oxidative stress and proapoptotic signaling and prevented interstitial fibrosis. Cardiac MRI showed that ROS scavenging did not affect the 37% increase in end-diastolic volume of the RV in the CHF relative to the control group, but the threefold increase in end-systolic volume was reduced by 42% in the EUK-134-treated CHF group. The improved systolic function was confirmed using echocardiography by an assessment of tricuspid annular plane systolic excursion. These data indicate an important role of ROS in RV cardiomyocyte hypertrophy and contractile dysfunction due to PAH and show the potential of EUK-class antioxidants as complementary therapeutics in the treatment of RV dysfunction in PAH.
Year-long upregulation of connexin43 in rabbit hearts by heavy ion irradiation
Authors: Amino Mari , Yoshioka Koichiro , Fujibayashi Daisuke , Hashida Tadashi , Furusawa Yoshiya , Zareba Wojciech , Ikari Yuji , Tanaka Etsuro , Mori Hidezo , Inokuchi Sadaki , Kodama Itsuo , Tanabe Teruhisa
Published: January 2010

A previous study from our laboratory has shown that a single targeted heavy ion irradiation (THIR; 15 Gy) to rabbit hearts increases connexin43 (Cx43) expression for 2 wk in association with an improvement of conduction, a decrease of the spatial inhomogeneity of repolarization, and a reduction of vulnerability to ventricular arrhythmias after myocardial infarction. This study investigated the time- and dose-dependent effects of THIR (5–15 Gy) on Cx43 expression in normal rabbit hearts ( n = 45). Five rabbits without THIR were used as controls. A significant upregulation of Cx43 protein and mRNA in the ventricular myocardium was recognized by immunohistochemistry, Western blotting, and real-time PCR from 2 wk up to 1 yr after a single THIR at 15 Gy. THIR ≥10 Gy caused a significant dose-dependent increase of Cx43 protein and mRNA 2 wk after THIR. Anterior, lateral, and posterior free wall of the left ventricle, interventricular septum, and right ventricular free wall were affected similarly by THIR in terms of Cx43 upregulation. The radiation-induced increase of immunolabeled Cx43 was observed not only at the intercalated disk region but also at the lateral surface of ventricular myocytes. The increase of immunoreactive Cx43 protein was predominant in the membrane fraction insoluble in Triton X-100, that is the Cx43 in the sarcolemma. In vivo examinations of the rabbits 1 yr after THIR (15 Gy) revealed no significant changes in ECGs and echocardiograms (left ventricular dimensions, contractility, and diastolic function), indicating no apparent late radiation injury. A single application of THIR causes upregulation and altered cellular distribution of Cx43 in the ventricles lasting for at least 1 yr. This long-lasting remodeling effect on gap junctions may open the pathway to novel therapy against life threatening ventricular arrhythmias in structural heart disease.
Innate immunity mediates myocardial preconditioning through Toll-like receptor 2 and TIRAP-dependent signaling pathways
Authors: Dong Jian-Wen , Vallejo Jesus G. , Tzeng Huei-Ping , Thomas James A , Mann Douglas L.
Published: January 2010

Recent studies have implicated Toll-like receptor 2 (TLR2) and TLR4 signaling in delimiting liver and brain injury following ischemia-reperfusion (I/R). To determine whether TLR2 and TLR4 conferred cytoprotection in the heart, we subjected hearts of wild-type (WT) mice and mice deficient in TLR2 (TLR2D), TLR4 (TLR4D), and TIR domain-containing adapter protein (TIRAP-D) to ischemic preconditioning (IPC). Langendorff-perfused hearts were subjected to 30 min ischemia and 60 min reperfusion with or without IPC. IPC resulted in a significant increase ( P < 0.05) in the percent recovery of left ventricular developed pressure (%LVDP) in WT mouse hearts (54.4 ± 2.7% of baseline), whereas there was no significant increase in %LVDP ( P > 0.05) in TIRAP-D mouse hearts (43.8 ± 1.9%) after I/R injury. IPC also resulted in a significant ( P < 0.05) decrease in I/R-induced creatine kinase release and Evans blue dye uptake in WT but not TIRAP-D hearts. Interestingly, IPC resulted in a significant ( P < 0.05) increase in %LVDP in TLR4-deficient hearts (52.7 ± 3%) but not in TLR2D hearts (39.3 ± 1.5%). Pretreatment with a specific TLR2 ligand (Pam3CSK) protected WT hearts against I/R-induced left ventricular dysfunction. The loss of IPC-induced cardioprotection in TIRAP-D mouse hearts was accompanied by a decreased translocation of protein kinase C-ε and decreased phosphorylation of GSK-3β. Taken together, these data suggest that the cardioprotective effect of IPC is mediated, at least in part, through a TLR2-TIRAP-dependent pathway, suggesting that the modulation of this pathway represents a viable target for reducing I/R injury.
Increased expression and secretion of resistin in epicardial adipose tissue of patients with acute coronary syndrome
Authors: Langheim Silvia , Dreas Lorella , Veschini Lorenzo , Maisano Francesco , Foglieni Chiara , Ferrarello Santo , Sinagra Gianfranco , Zingone Bartolo , Alfieri Ottavio , Ferrero Elisabetta , Maseri Attilio , Ruotolo Giacomo
Published: January 2010

The purpose of this study was to test the hypothesis that specific epicardial adipose tissue (EAT) proinflammatory adipokines might be implicated in acute coronary syndrome (ACS). We compared expression and protein secretion of several EAT adipokines of male ACS with those of matched stable coronary artery disease (CAD) patients and controls with angiographically normal coronary arteries. The effect of supernatant of cultured EAT on endothelial cell permeability in vitro was also evaluated in the three study groups. EAT of ACS patients showed significantly higher gene expression and protein secretion of resistin than patients with stable CAD. Interleukin-6, plasminogen activator inhibitor-1, and monocyte chemoattractant protein-1 genes were also significantly overexpressed in ACS compared with the control group but not when compared with stable CAD. Immunofluorescence of EAT sections revealed a significantly greater number of CD68+cells in ACS patients than stable CAD and control groups. The permeability of endothelial cells in vitro was significantly increased after exposure to supernatant of cultured EAT from ACS, but not control or stable CAD groups, and this effect was normalized by anti-resistin antiserum. We found that EAT of patients with ACS is characterized by increased expression and secretion of resistin and associated with increased in vitro endothelial cell permeability.
Endothelium-dependent relaxation by G protein-coupled receptor 30 agonists in rat carotid arteries
Authors: Broughton Brad R. S. , Miller Alyson A. , Sobey Christopher G.
Published: January 2010

Recent studies have identified that the novel membrane estrogen receptor, G protein-coupled receptor 30 (GPR30), is present in blood vessels. However, the signaling mechanisms associated with GPR30 in the vasculature remain unclear. We examined whether putative agonists of GPR30 exert vasorelaxant and/or antioxidant effects similar to those reported for estrogen. Using wire myography, we assessed the role of the endothelium in relaxation responses to the GPR30 agonists, G-1 and 5408-0877 (1 nM-10 μM), in U-46619-precontracted common carotid arteries from Sprague-Dawley rats. Furthermore, using lucigenin (5 μM)-enhanced chemiluminescence, we tested the effect of G-1 (10 μM) on superoxide levels. Specific immunofluorescence was also used to confirm GPR30 expression in the arterial wall. We found that G-1 and 5408-0877 induced a concentration-dependent relaxation in carotid arteries from both male and female rats. Interestingly, G-1- and 5408-0877-induced relaxation was abolished by endothelium removal and abrogated in the presence of the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (100 μM). In addition, G-1 significantly decreased NADPH (100 μM)-stimulated superoxide production by carotid and intracranial (pooled basilar and middle cerebral) arteries but also attenuated the superoxide signal detected in a cell-free xanthine/xanthine oxidase assay. Furthermore, GPR30 immunoreactivity was observed in endothelial and vascular smooth muscle cells of carotid arteries from both genders. These findings indicate that GPR30 is expressed throughout the arterial wall and that GPR30 agonists elicit endothelial-derived nitric oxide-dependent relaxation of the carotid artery in male and female rats. Additionally, G-1 appears to directly scavenge superoxide anion.
High-density lipoprotein determines adult mouse cardiomyocyte fate after hypoxia-reoxygenation through lipoprotein-associated sphingosine 1-phosphate
Authors: Tao Rong , Hoover Holly E. , Honbo Norman , Kalinowski Mikaila , Alano Conrad C. , Karliner Joel S. , Raffai Robert
Published: January 2010

The lipid mediator sphingosine 1-phosphate (S1P) confers survival benefits in cardiomyocytes and isolated hearts subjected to oxidative stress. High-density lipoprotein (HDL) is a major carrier of S1P in the serum, but whether HDL-associated S1P directly mediates survival in a preparation composed exclusively of cardiomyocytes has not been demonstrated. Accordingly, we tested the hypothesis that signal activation and survival during simulated ischemia-reperfusion injury in response to HDL require lipoprotein-associated S1P. As a model, we used adult mouse cardiomyocytes subjected to hypoxia-reoxygenation. Cells were treated or not with autologous mouse HDL, which significantly increased myocyte viability as measured by trypan blue exclusion. This survival effect was abrogated by the S1P1 and SIP3 receptor antagonist VPC 23019. The selective S1P3 antagonist CAY10444, the Gi antagonist pertussis toxin, the MEK (MAPK/ERK) kinase inhibitor PD-98059, and the phosphoinositide-3 kinase inhibitor wortmannin also inhibited the prosurvival effect of HDL. We observed that HDL activated both Akt (protein kinase B) and the MEK1/2-ERK1/2 pathway and also stimulated phosphorylation of glycogen synthase kinase-3β. ERK1/2 activation was through an S1P1 subtype receptor-Gi protein-dependent pathway, whereas the activation of Akt was inhibited by CAY10444, indicating mediation by S1P3 subtype receptors. We conclude that HDL, via its cargo of S1P, can directly protect cardiomyocytes against simulated oxidative injury in the absence of vascular effects and that prosurvival signal activation is dependent on both S1P1 and S1P3 subtype receptors.
Triggering role of acid sphingomyelinase in endothelial lysosome-membrane fusion and dysfunction in coronary arteries
Authors: Bao Jun-Xiang , Xia Min , Poklis Justin L. , Han Wei-Qing , Brimson Christopher , Li Pin-Lan
Published: January 2010

The present study determined whether activation of acid sphingomyelinase (ASM) drives membrane proximal lysosomes to fuse to the cell surface, facilitating membrane lipid rafts (LRs) clustering in coronary arterial endothelial cells (CAECs) and leading to endothelial dysfunction. By confocal microscopy, the activators of ASM, phosphatidylinositol (PI), and bis (monoacylglyceryl) phosphate (Bis), and an inducer of ASM, butyrate, were found to increase LRs clustering in bovine CAECs, which was blocked by lysosome fusion inhibitor vacuolin-1. However, arsenic trioxide (Ars), an inducer of de novo synthesis of ceramide, had no such effect. Similarly, vacuolin-1-blockable effects were observed using fluorescence resonance energy transfer detection. Liquid chromatography-electrospray ionization-tandem mass spectrometry analysis demonstrated that all of these treatments, even Ars, increased ceramide production in CAECs. When ASM gene was silenced, all treatments except Ars no longer increased ceramide levels. Furthermore, dynamic fluorescence monitoring in live cells showed that PI and Bis stimulated lysosome-membrane fusion in CAECs. Functionally, PI and Bis impaired endothelium-dependent vasodilation in perfused coronary arteries, which was blocked by vacuolin-1 and a lysosome function inhibitor, bafilomycine. FasL (Fas ligand), a previously confirmed lysosome fusion stimulator as a comparison, also produced a similar effect. It is concluded that ASM activation serves as a triggering mechanism and driving force, leading to fusion of membrane proximal lysosomes into LR clusters on the cell membrane of CAECs, which represents a novel mechanism mediating endothelial dysfunction during death receptor activation or other pathological situation.