Search

Background Small-bowel enteroscopies (BEs) are tedious and prolonged, and their efficacy may be affected by the timing of procedures. Objective We aimed to evaluate the differences in diagnostic yield, insertion depth, procedure duration, therapeutic yield, and adverse events (AEs) of enteroscopies performed in the morning versus the afternoon. Design Retrospective cohort study. Setting Tertiary referral center. Patients Patients who underwent BE for suspected small-bowel disease at a single institution between January 2008 and August 2009. Main Outcome Measurement Differences in diagnostic yield, insertion depth, procedure duration, therapeutic yield, and AEs between morning (started before noon) and afternoon (after noon) procedures. Results A total of 250 enteroscopies were performed on 250 patients, of which 125 patients (50%) underwent a procedure in the morning and 125 patients (50%) underwent the procedure in the afternoon. The diagnostic yield with anterograde enteroscopy was the same in both the morning and afternoon (63.7% and 63.7%, respectively; P = .99). The procedure durations were also similar (42.4 ± 21.5 minutes vs 46.2 ± 22.4 minutes, respectively; P = .25). Similarly the diagnostic yield with retrograde enteroscopy was similar in morning and afternoon (44.1% and 35.3%, respectively; P = .46). However, the procedure durations of retrograde BE were significantly shorter in the morning compared with the afternoon (51.3 ± 21.3 minutes vs 66.6 ± 32.9 minutes, respectively; P = .03). Therapeutic yield and AEs were similar. Limitations Retrospective study. Conclusions The timing of procedure, morning versus afternoon, did not affect the diagnostic and therapeutic efficacy of BE in patients with suspected small-bowel disease.

Background— Left atrioesophageal fistula is a rare but devastating complication that may occur after catheter ablation of atrial fibrillation. We used capsule endoscopy to assess esophageal injury after catheter ablation for atrial fibrillation in a population randomized to undergo general anesthesia or conscious sedation. Methods and Results— Fifty patients undergoing atrial fibrillation ablation for paroxysmal symptomatic atrial fibrillation refractory to antiarrhythmic drugs were enrolled and randomized, including those undergoing the procedure under general anesthesia (25 patients, group 1) and those receiving conscious sedation with fentanyl or midazolam (25 patients, group 2). All patients underwent esophageal temperature monitoring during the procedure. The day after ablation, all patients had capsule endoscopy to assess the presence of endoluminal tissue damage of the esophagus. We observed esophageal tissue damage in 12 (48%) patients of group 1 and 1 esophageal tissue damage in a single patient (4%) of group 2 ( P P < 0.003). The time to peak temperature was 9�7 seconds in group 1 and 21�9 seconds in group 2, and this difference was statistically significant ( P Conclusion— The use of general anesthesia increases the risk of esophageal damage detected by capsule endoscopy.

Hepatic stellate cells (HSC) differ in their phenotype depending on the initiation and progression of their activation. Our hypothesis was that different mechanisms govern type I collagen synthesis depending on stage of HSC activation. We investigated the role of α5β1-integrin as a regulator of type I collagen gene COL1A1 expression in primary and passaged HSC cultures using transgenic mouse containing type I collagen gene COL1A1 promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The α5β1protein levels increased during the activation and were highest in day 6 primary cultures but decreased in passaged HSC. CAT activity, reflecting COL1A1 expression, was upregulated by α5β1-integrin. Inhibition of α5β1-integrin by echistatin and blocking antibody resulted in reduced transgene activity only in early primary cultures (compared with the control, 53.3 ± 12% echistatin and 58.8 ± 7% blocking antibody, respectively, P < 0.05). Treatment of passaged HSC with either echistatin or blocking antibody had no effect. Fibronectin, an α5β1-integrin ligand, increased transgene activity in primary (210 ± 33%, P < 0.05) but not in passaged HSC cultures (119 ± 8%). This α5β1-integrin effect appears to be at least in part mediated by CCAAT enhancer binding protein-β (C/EBPβ), because fibronectin increased and α5-gene silencing by small interfering RNA decreased C/EBPβ levels. In addition, C/EBPβ knockout mice showed reduced type I collagen synthesis compared with wild-type littermates. Therefore α5β1-integrin is an important regulator of type I collagen production in early primary HSC cultures but appears to have no direct role once the HSC are fully activated.

We examined the temporal relationship between portacaval anastamosis (PCA), weight gain, changes in skeletal muscle mass and molecular markers of protein synthesis, protein breakdown, and satellite cell proliferation and differentiation. Male Sprague-Dawley rats with end to side PCA ( n = 24) were compared with sham-operated pair-fed rats ( n = 24). Whole body weight, lean body mass, and forelimb grip strength were determined at weekly intervals. The skeletal muscle expression of the ubiquitin proteasome system, myostatin, its receptor (the activin 2B receptor) and its signal, cyclin-dependant kinase inhibitor (CDKI) p21, insulin-like growth factor (IGF)-I and its receptor (IGF-I receptor-α), and markers of satellite cell proliferation and differentiation were quantified. PCA rats did not gain body weight and had lower lean body mass, forelimb grip strength, and gastrocnemius muscle weight. The skeletal muscle expression of the mRNA of ubiquitin proteasome components was higher in PCA rats in the first 2 wk followed by a lower expression in the subsequent 2 wk ( P < 0.01). The mRNA and protein of myostatin, activin 2B receptor, and CDKI p21 were higher, whereas IGF-I and its receptor as well as markers of satellite cell function (proliferating nuclear cell antigen, myoD, myf5, and myogenin) were lower at weeks 3 and 4 following PCA ( P < 0.05). We conclude that PCA resulted in uninhibited proteolysis in the initial 2 wk. This was followed by an adaptive response in the later 2 wk consisting of an increased expression of myostatin that may have contributed to reduced muscle protein synthesis, impaired satellite cell function, and lower skeletal muscle mass.

Proliferation and differentiation of satellite cells are critical in the regeneration of atrophied muscle following immobilization and aging. We hypothesized that impaired satellite cell function is responsible for the atrophy of skeletal muscle also seen in cirrhosis. Myostatin and insulin-like growth factor 1 (IGF1) have been identified to be positive and negative regulators, respectively, of satellite cell function. Using a rat model of cirrhosis [portacaval anastamosis (PCA)] and sham-operated controls, we examined the expression of myostatin, its receptor activinR2b, and its downstream messenger cyclin-dependant kinase inhibitor p21 (CDKI p21) as well as IGF1 and its receptor in the gastrocnemius muscle. Expression of PCNA, a marker of proliferation, and myogenic regulatory factors (myoD, myf5, and myogenin), markers of differentiation of satellite cells, were also measured. Real- time PCR for mRNA and Western blot assay for protein quantification were performed. PCA rats had lower body weight and gastrocnemius weight compared with sham animals ( P < 0.05). PCNA and myogenic regulatory factors were lower in PCA rats ( P < 0.05). Myostatin, activinR2b, and CDKI p21 were higher in the PCA animals ( P < 0.05). The expression of IGF1 and its receptor was lower in liver and skeletal muscle of PCA animals ( P < 0.05). These data suggest that skeletal muscle atrophy seen in the portacaval shunted rats is a consequence of impaired satellite cell proliferation and differentiation mediated, in part, by higher myostatin and lower IGF1 expression.

Objective: Pancreatobiliary malignancies often present as biliary strictures. Biliary brush cytology is an established diagnostic technique in the investigation of such strictures. The main shortcoming of the test, however, is its low sensitivity. The aim of this was to identify factors associated with a positive yield on biliary brush cytology. Methods: Consecutive patients who had brush cytology for investigation of biliary strictures from 2005 to 2007 were included. Association of several factors with a positive result on brush cytology was studied using univariable and multivariable logistic regression analyses. Results: Two hundred eighty patients were evaluated. One hundred nineteen (42.5%) patients had a final diagnosis of malignancy; of whom, 55 had a positive brush cytology (sensitivity, 46%; specificity, 100%). On multivariable analysis, age (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.06-10.4 per 5-year increase), total serum bilirubin levels (OR, 1.3; 95% CI, 1.01-1.6 per 5-unit increase), and presence of a mass on cross-sectional imaging (OR, 11.7; 95% CI 5.1-27.2) were independent predictors of a positive brush cytology result. Conclusions: Increasing age, higher serum bilirubin levels, and presence of a mass on cross-sectional imaging are independent factors associated with a positive result on biliary brush cytology. These findings suggest use of complementary tissue acquisition techniques in selected cases.

We examined the effect of parathyroid hormone and various signaling molecules on collagen synthesis and chloramphenicol acetyltransferase activity in cultured transgenic mouse calvariae carrying fusion genes of the rat Col1a1 promoter and the chloramphenicol acetyltransferase reporter. After 48 h of culture, parathyroid hormone, forskolin, dibutyryl cAMP, 8-bromo cAMP, and phorbol myristate acetate inhibited transgene activity, while the calcium ionophore ionomycin had no effect. Pretreatment of calvariae with the phosphodiesterase inhibitor isobutylmethylxanthine potentiated the inhibitory effect of 1 nM parathyroid hormone on transgene activity and collagen synthesis. Parathyroid hormone further inhibited transgene activity and collagen synthesis in the presence of phorbol myristate acetate. Parathyroid hormone inhibition of transgene activity and collagen synthesis was not affected by indomethacin or interleukin-6. After 48 h of culture, parathyroid hormone inhibited chloramphenicol acetyltransferase activity by 50-85% in cultured calvariae carrying transgenes having progressive 5' upstream deletions of promoter DNA down to -1683 bp. These data show that the inhibitory effect of parathyroid hormone on Col1a1 expression in mouse calvariae is mediated mainly by the cAMP signaling pathway. Prostaglandins and IL-6 are not local mediators of the parathyroid hormone response in this model. Finally, regions of the Col1a1 promoter downstream of -1683 bp are sufficient for parathyroid hormone inhibition of the Col1a1 promoter.

Exogenously administered zinc compounds have been shown to possess antiulcer activity in the development of gastric lesions. The aim of this study was to investigate the effects of zinc sulphate pretreatment of rats on cysteamine-induced duodenal ulcers and to correlate them with changes in zinc serum and tissue levels. Atomic absorption spectrophotometry was used to determine zinc serum and tissue concentrations in all animal groups. Cysteamine produced marked duodenal ulceration in control animals 24 h after application, with an increase in endogenous zinc tissue concentrations and a marked decrease in serum concentrations. Zinc sulphate (20, 40 or 80 mg kg-1) applied per os one hour prior to cysteamine application inhibited the development of duodenal lesions in a dose-related manner. The application of zinc sulphate in a single intraperitoneal (i.p.) application (80 mg kg-1) did not, however, prevent the formation of duodenal lesions. In order to assess zinc absorption from the gastrointestinal tract, one group of rats received a single oral dose of zinc sulphate (80 mg kg) without cysteamine application. The observations of this study seem to indicate that zinc plays an important cytoprotective role in duodenal ulcer disease.

Our previous studies have shown that the 49-base pair region of promoter DNA between -1719 and -1670 base pairs is necessary for transcription of the rat COL1A1 gene in transgenic mouse calvariae. In this study, we further define this element to the 13-base pair region between -1683 and -1670. This element contains a TAAT motif that binds homeodomain-containing proteins. Site-directed mutagenesis of this element in the context of a COL1A1-chloramphenicol acetyltransferase construct extending to -3518 base pairs decreased the ratio of reporter gene activity in calvariae to tendon from 3:1 to 1:1, suggesting a preferential effect on activity in calvariae. Moreover, chloramphenicol acetyltransferase-specific immunofluorescence microscopy of transgenic calvariae showed that the mutation preferentially reduced levels of chloramphenicol acetyltransferase protein in differentiated osteoblasts. Gel mobility shift assays demonstrate that differentiated osteoblasts contain a nuclear factor that binds to this site. This binding activity is not present in undifferentiated osteoblasts. We show that Msx2, a homeodomain protein, binds to this motif; however, Northern blot analysis revealed that Msx2 mRNA is present in undifferentiated bone cells but not in fully differentiated osteoblasts. In addition, cotransfection studies in ROS 17/2.8 osteosarcoma cells using an Msx2 expression vector showed that Msx2 inhibits a COL1A1 promoter-chloramphenicol acetyltransferase construct. Our results suggest that high COL1A1 expression in bone is mediated by a protein that is induced during osteoblast differentiation. This protein may contain a homeodomain; however, it is distinct from homeodomain proteins reported previously to be present in bone.

Background MiroCam, a capsule endoscope, uses a novel transmission technology, electric-field propagation, which uses the human body as a conduction medium for data transmission. Objective To compare the ability of the MiroCam (MC) and PillCam (PC) to identify sources of obscure GI bleeding (OGIB). Design Prospective, multicenter, comparative study. Setting Six academic hospitals. Patients A total of 105 patients with OGIB. Intervention Patients ingested both the MC and PC capsules sequentially in a randomized fashion. Main Outcome Measurements Concordance of rates in identifying a source of OGIB, operational times, and rates of complete small-bowel examination. Results Data analysis resulted in 43 (48%) "abnormal" cases identifying a source of OGIB by either capsule. Twenty-four cases (55.8%) were positive by both capsules. There was negative agreement in 46 of 58 cases (79.3%). The κ index was 0.547 (χ 2 = 1.32; P = .36). In 12 cases, MC positively identified a source that was not seen on PC, whereas in 7 cases, PC positively identified a source that was not seen on MC. MC had a 5.6% higher rate of detecting small-bowel lesions ( P = .54). MC captured images at 3 frames per second for 11.1 hours, and PC captured images at 2 frames per second for 7.8 hours ( P P = .10). Limitations Readers were not blinded to the particular capsule they were reading. Conclusion A positive diagnostic finding for OGIB was identified by either capsule in 48% of cases. The concordance rate between the 2 capsules was comparable to that of prior studies in identifying sources of small-bowel bleeding. The longer operational time of the MC may result in higher rates of complete small-bowel examination, which may, in turn, translate into a higher rate of detecting small-bowel lesions. (Clinical trial registration number: NCT00878982.)

To establish pentagastrin cytoprotection, the effectiveness of various doses of pentagastrin on ethanol induced gastric mucosal lesions was investigated in Wistar rats. Significant protection was obtained only after parenteral pretreatment with the exception of the lowest dose (1 microgram/kg b.w.). Pentagastrin cytoprotection is not mediated either by a dopamine, muscarinic or gastrin/CCK receptor or by prostaglandin synthesis. However, the protective effect of pentagastrin is abolished by prior vagotomy, although this procedure alone or sham operation is ineffective to influencing control-ethanol lesions. In secretory studies pentagastrin increased both the volume of gastric juice and total acid output. Unlike cytoprotection, these were reversed by vagotomy, but also with atropine and problumide, whereas domperidone and indomethacin were ineffective.

OBJECTIVES In secretin-stimulated pancreatic function testing, the standard technique for bicarbonate measurement is back titration (BT). Chemistry autoanalyzers (AAs) automate bicarbonate measurement and are universally available; however, this method has not been validated in pancreatic fluid. The aims of the study were (1) to compare the AA and BT for measurement of bicarbonate in pancreatic fluid and (2) to determine the effects of variable conditions on bicarbonate concentration. METHODS Pancreatic fluid samples were analyzed for bicarbonate concentration using both BT and AA. Additional experiments were conducted to determine the effect of different sample conditions. RESULTS The results obtained by BT and AA were highly concordant (Lin concordance coefficient, 0.96). An AA cutpoint of 84 mM optimized sensitivity (91.1%) and specificity (94.1%) compared with the BT reference standard. Blood contamination spuriously increased the bicarbonate, an effect that was eliminated by centrifugation. The bicarbonate levels were not significantly affected by delayed analysis, storage condition, nitrogen gas treatment, or the addition of mineral oil or protease inhibitors. CONCLUSIONS The bicarbonate concentrations obtained by AA are highly concordant with those obtained by BT. Secretin pancreatic function testing fluid analysis may now be performed in any hospital.

The distinct role of portosystemic shunting (PSS) in the pathogenesis of sarcopenia (skeletal muscle loss) that occurs commonly in cirrhosis is unclear. We have previously shown increased expression of myostatin (inhibitor of skeletal muscle mass) in the portacaval anastamosis (PCA) rat model of sarcopenia of PSS. The present study was performed to examine the mechanisms of sarcopenia following PCA.In PCA and sham operated pair fed control rats, the phenylalanine flooding dose method was used to quantify the fractional and absolute protein synthesis rates in the skeletal muscle over time and in response to follistatin, a myostatin antagonist. The expression of myostatin and markers of satellite cell (myocyte precursors) proliferation and differentiation were quantified by real-time PCR and Western blot analyses.The absolute synthesis rate (ASR) was lower at 2, 4, and 6 weeks (p0.05) and the fractional synthesis rate (FSR) of skeletal muscle protein was significantly lower (p0.05) at week 2 in the PCA rats compared to control rats. Expression of myostatin was elevated while markers of satellite cell proliferation and differentiation were lower at 4 and 6 weeks after PCA. Follistatin increased skeletal muscle mass, muscle FSR and ASR, decreased expression of myostatin protein, and increased expression of markers of satellite cell function.Sarcopenia associated with PSS is caused by impaired protein synthesis and reduced satellite cell function due to increased myostatin expression. Confirming these alterations in human patients with cirrhosis will provide novel therapeutic targets for sarcopenia of liver disease.

Capsule Endoscopy in Examination of Esophagus. Background: Esophageal injury can result from left atrial radiofrequency ablation (RFA) therapy, with added concern because of its possible relationship to the development of atrial-esophageal (A-E) fistulas. Objective: Evaluate utility of esophageal capsule endoscopy to detect esophageal lesions as a complication of RFA therapy in the treatment of atrial fibrillation (AF). Methods: Consecutive patients with AF who underwent left atrial RFA therapy and received capsule endoscopy within 48 hours postablation. Video was reviewed by a single gastroenterologist. The medical records were also reviewed for symptoms immediately postablation and at the 3-month follow-up. Results: A total of 93 consecutive patients were included and 88 completed the study and were analyzed. The prevalence of esophageal lesions was 17% (15/88 patients). Nine percent (8/88) of these patients had lesions anatomically consistent with the location of the ablation catheter. Six patients with positive capsule findings had symptoms of chest pain (3/6, 50%), throat pain (2/6, 33%), nausea (1/6, 17%), and abdominal pain (1/6, 17%). An additional 24 patients were symptomatic postablation, but with normal capsule findings. All patients with identified lesions by capsule endoscopy received oral proton pump inhibitor therapy, and were instructed to contact the Cleveland Clinic in the event of worsening symptoms. No delayed complications were reported at the 3-month follow-up. Conclusion: This study supports the use of capsule endoscopy as a tool for the detection of esophageal injury post-RFA therapy. PillCam ESO is well tolerated and provides satisfactory images of the areas of interest in the esophagus without potential risk related to insufflation with regular esophagogastroduodenoscopy. (J Cardiovasc Electrophysiol, Vol. 21, pp. 839-844, August 2010)

The present study investigated both the healing rate (after four weeks) and the relapse rate (during six months) following treatment with the dopamine-like drugs bromocriptine (2.5 mg twice daily), amantadine (100 mg nocte), or with the H2 blockers cimetidine (800 mg nocte), and famotidine (40 mg nocte) in 124 patients with endoscopically proven duodenal ulcer (DU). The ulcer was completely healed in 27 (amantadine), 26 (bromocriptine), 23 (cimetidine), and in 24 (famotidine) patients. Relapse was noted in 34.7% (cimetidine) and 25% (famotidine) versus 11.7% (amantadine) and 7.7% (bromocriptine) DU patients. No significant difference was found in initial healing rates. However, the relapse rate in the cimetidine-treated group was significantly higher than in all the other test groups. Additional comparisons between all the treatment categories showed a significantly lower relapse rate with the dopamine-like agents. These important new results indicate that dopamine-like compounds are equally effective as H2 blockers in inducing DU healing and may offer a promising advantage over H2 blockers concerning their efficacy in preventing ulcer relapse in DU patients.

Background/Aims The portacaval anastamosis (PCA) rat is a model of the nutritional and endocrine consequences of liver cirrhosis. We hypothesized that failure to gain body weight in the PCA rat was the consequence of low testosterone levels and will be reversed by 4-hydroxyandrostenedione, a specific aromatase inhibitor. Methods Male Sprague–Dawley rats subjected to an end-to-side PCA or sham surgery were administered either 4-hydroxyandrostenedione or vehicle. Food intake, food efficiency, and body weight were measured, animals sacrificed 3 weeks after surgery, visceral organs harvested and plasma sex steroids measured. Hepatic RNA was extracted and dot blots done to quantify the expression of sex hormone dependent enzymes 16α hydroxylase and 15β hydroxylase. Results Growth, food intake, food efficiency and plasma testosterone were lower and plasma estradiol higher in PCA than sham rats. Hepatic expression of testosterone driven 16α hydroxylase was lower and estradiol driven 15β hydroxylase higher in PCA rats. These alterations were reversed by 4-hydroxyandrostenedione. Conclusions These observations demonstrate that use of aromatase inhibitor reverses the nutritional and endocrine abnormalities in the PCA rat and suggest that this approach may be useful in cirrhotic patients.

Background & Aims: Hepatic stellate cells play an important role in liver fibrogenesis, and hepatic stellate cell death may be involved in the termination of this response. Methods: Molecular mechanisms of hepatic stellate cell killing were studied in hepatic stellate cell/Kupffer cell cocultures. Results: Lipopolysaccharide stimulation of hepatic stellate cell/Kupffer cell cocultures, but not of hepatic stellate cell monocultures, induced profound alterations of hepatic stellate cell morphology and hepatic stellate cell death. Kupffer cell-induced hepatic stellate cell killing required hepatic stellate cell/Kupffer cell contacts and was prevented by dexamethasone, prostaglandin E(2), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 2 antagonists, and down-regulation of receptor-interacting protein, but not by antioxidants, tumor necrosis factor receptor, or CD95 antagonists. Hepatic stellate cell death was characterized by activation of caspases 3, 8, and 9, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling negativity, lack of gross calcium overload, and TRAIL trafficking to the plasma membrane. Inhibition of caspase 9, but not of caspases 3, 8, or 10, prevented hepatic stellate cell death. Lipopolysaccharide induced a dexamethasone- and prostaglandin E(2)-sensitive expression of TRAIL in Kupffer cells. TRAIL receptors 1 and 2, FLIP (caspase 8-inhibitory protein), and receptor-interacting protein were up-regulated during hepatic stellate cell transformation ; however, TRAIL addition did not induce hepatic stellate cell death. Hepatic stellate cell susceptibility toward Kupffer cell-induced death paralleled receptor-interacting protein and TRAIL-receptor expression levels. Conclusions: Activated Kupffer cell can effectively kill hepatic stellate cell by a caspase 9- and receptor-interacting protein-dependent mechanism, possibly involving TRAIL. The data may suggest a novel form of hepatic stellate cell death.

Our laboratory and others have shown that a homeodomain protein binding site plays an important role in transcription of the Col1a1 gene in osteoblasts. This suggests that homeodomain proteins have an important role in osteoblast differentiation. We have investigated the role of Dlx5 in osteoblastic differentiation. In situ hybridization studies indicated that Dlx5 is expressed in chick calvarial osteoblasts (cCOB) in vivo. Northern blot analysis indicated that Dlx5 expression in cultured cCOBs is induced concurrently with osteoblastic markers. To study the effect of overexpression of Dlx5 on osteoblast differentiation, we infected primary osteoblast cultures from 15-day-old embryonal chicken calvaria with replication competent retroviral vectors [RCASBP(A)] expressing Dlx5 or control replication competent avian splice acceptor brianhightiter polymerase subtype A [RCASBP(A)]. Expression of Col1a1, osteopontin, alkaline phosphatase, and osteocalcin messenger RNA (mRNA) occurred sooner and at higher levels in cultures infected with RCASBP(A)DLX5 than in RCASBP(A)-infected cultures. Mineralization of Dlx5-expressing cultures was evident by days 12-14, and RCAS-infected control osteoblasts did not begin to mineralize until day 17. Dlx5 also stimulated osteoblastic differentiation of calvarial cells that do not normally undergo osteoblastic differentiation in vitro. Our results suggest that Dlx5 plays an important role in inducing calvarial osteoblast differentiation.

Hepatitis C virus (HCV) has become a major contributor to morbidity and mortality in patients with human immunodeficiency virus (HIV). It is estimated that 30% to 50% of patients with HIV are coinfected with HCV. Advances in antiretroviral therapy and improved life expectancy of HIV patients have resulted in an emergence of HCV-induced liver disease as a leading cause of significant morbidity and death in this population. Clinically, hepatitis C is a more severe disease in HIV-infected individuals, characterized by rapid progression toward end-stage liver disease. Highly active antiretroviral therapy is the mainstay of current acquired immunodeficiency syndrome management. One of the limiting side effects of combination therapy for HIV is hepatotoxicity, which is more common and often more serious in patients with underlying liver disease. Management of coinfected patients has no strict guidelines, but it is generally accepted that HIV infection needs to be treated before HCV. Hepatitis C in coinfected individuals is probably best treated using combination therapy (interferon alpha and ribavirin). It appears that combination therapy can safely be administered to this population and that previous concerns about ribavirin/zidovudine antagonism are unsubstantiated in clinical practice. Although initial results using only interferon alpha showed poor results in HIV coinfected patients, combination therapy seems to be as effective as in the general population. All HIV-HCV coinfected patients should be vaccinated against hepatitis B and hepatitis A; vaccines are safe and effective.

We studied the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on organ cultures of transgenic mouse calvariae containing segments of the Col1a1 promoter extending to -3518, -2297, -1997, -1794, -1763, and -1719 bp upstream of the transcription start site fused to the chloramphenicol acetyltransferase (CAT) reporter gene. 1,25(OH)2D3 had a dose-dependent inhibitory effect on the expression of the -3518 bp promoter construct (ColCAT3.6), with maximal inhibition of about 50% at 10 nM. This level of inhibition was consistent with the previously observed effect on the endogenous Col1a1 gene in bone cell models. All of the shorter constructs were also inhibited by 10 nM 1,25(OH)2D3, suggesting that the sequences required for 1, 25(OH)2D3 inhibition are downstream of -1719 bp. The inhibitory effect of 1,25(OH)2D3 on transgene mRNA was maintained in the presence of the protein synthesis inhibitor cycloheximide, suggesting that the inhibitory effect on Col1a1 gene transcription does not require de novo protein synthesis. We also examined the in vivo effect of 1,25(OH)2D3 treatment of transgenic mice on ColCAT activity, and found that 48 h treatment caused a dose-dependent inhibition of CAT activity in calvariae comparable to that observed in organ cultures. In conclusion, we demonstrated that 1,25(OH)2D3 inhibits Col1A1 promoter activity in transgenic mouse calvariae, both in vivo and in vitro. The results indicate that there is a 1, 25(OH)2D3 responsive element downstream of -1719 bp. The inhibitory effect does not require new protein synthesis.

Since zinc is an important requirement for the growth and repair of epithelial tissue, the aim of this study was to focus on the healing influence of ZnSO4 on cysteamine-induced duodenal ulcer in the rat. Prior to the healing study, a separate study was carried out to determine the rate of spontaneous healing. Animals were sacrificed 7, 14, 21 and 28 days following cysteamine application and zinc concentrations in serum and tissue samples were determined using atomic absorption spectro-photometry. Animals used in the healing study received daily treatment with ZnSO4 at a dose of 80 mg/kg body weight given orally starting 24 h after cysteamine application and were sacrificed 7, 14 and 21 days following cysteamine application. The serum and tissue levels of zinc as well as its antiulcerogenic effect were determined. To assess the absorption of ZnSO4 a single dose of the substance (80 mg/kg body weight) was administered intragastrically to ten animals that did not receive cysteamine. The results of our study indicate that duodenal lesions induced with cysteamine spontaneously heal four weeks following its application. Spontaneous healing of the ulcer lesion was associated with positive shifts in zinc metabolism which returned to normal values upon ulcer healing. Daily treatment with ZnSO4 progressively accelerated ulcer healing, and ulcers completely healed within one week of treatment. Shifts in zinc serum and tissue in this group were similar to shifts in the spontaneously healed group. A single intragastric treatment of zinc sulphate did not modify the normal aspect of the duodenal mucosa or serum and tissue concentrations.

Exogenously administered zinc compounds have been shown to possess anti-ulcer activity against a wide variety of ulcerogenic agents, both in laboratory animal models and in human peptic ulcer disease. However, a strong possibility exists that endogenous zinc may also play an important role during noxious events by various mechanisms. Therefore, the aim of this study was to focus on the changes of endogenous zinc serum and tissue concentrations in cysteamine-induced duodenal lesions. We used atomic absorption spectropho- tometry to determine the tissue and serum concentrations of zinc in normal (control) rats and those with cysteamine-induced duodenal ulcers. The results obtained in this study indicated that the onset, development and spontaneous healing of ulcer lesions were associated with certain shifts in zinc serum and tissue concentrations. Prior to ulcer formation, a significant increase was noted in serum zinc values. With the onset of duodenal lesions, zinc serum concentrations significantly decreased, while there was a significant increase in duodenal tissue concentrations when compared to healthy control animals. Zinc tissue concentrations decreased and returned to starting values by the end of the first week of spontaneous healing. This decrease in zinc tissue concentration corresponded to the healing rate of the duodenal ulcers. Serum zinc concentrations also returned to starting values within the first week period. These observations indicate and confirm that zinc could play an important role in duodenal ulcer disease and represent a natural defense system in the body.

Previous deletion studies using a series of COL1A1-CAT fusion genes have indicated that the 625 bp region of the COL1A1 upstream promoter between -2295 and -1670 bp is required for high levels of expression in bone, tendon, and skin of transgenic mice. To further define the important sequences within this region, a new series of deletion constructs extending to -1997, -1794, -1763, and -1719 bp has been analyzed in transgenic mice. Transgene activity, determined by measuring CAT activity in tissue extracts of 6- to 8-day-old transgenic mouse calvariae, remains high for all the new deletion constructs and drops to undetectable levels in calvariae containing the -1670 bp construct. These results indicate that the 49 bp region of the COL1A1 promoter between -1719 and -1670 bp is required for high COL1A1 expression in bone. Although deletion of the same region caused a substantial reduction of promoter activity in tail tendon, the construct extending to -1670 bp is still expressed in this tissue. However, further deletion of the promoter to -944 bp abolished activity in tendon. Gel mobility shift studies identified a protein in calvarial nuclear extracts that is not found in tendon nuclear extracts, which binds within this 49 bp region. Our study has delineated sequences in the COL1A1 promoter required for expression of the COL1A1 gene in high type I collagen-producing tissues, and suggests that different cis elements control expression of the COL1A1 gene in bone and tendon.

The hepatoprotective effects of a newly synthesized 15 amino acid fragment code named BPC 157 was evaluated in comparison with the reference standards (bromocriptine, amantadine and somatostatin) in various experimental models of liver injury in rats: 24 h-bile duct + hepatic artery ligation 48 h-restraint stress and CCl4 administration. BPC 157 administered either intragastrically or intraperitoneally, significantly prevented the development of liver necrosis or fatty changes in rats subjected to 24 h bile duct + hepatic artery ligation, 48 h- restraint stress, CCl4 treatment (1 ml/kg i.p., sacrifice 48 h thereafter). The other reference drugs had either little or no protective actions in these models. Noteworthy, the laboratory test results for bilirubin, SGOT, SGPT fully correlated with the macro/microscopical findings. Thus, on the basis of consistent protective eefect of BPC 157, possible clinical application in liver diseases is now warranted.

The possibility that the stomach, affected by general stress, might initiate a counter-response has not until recently been considered in theories of stress. We suggest that the stomach, as the most sensitive part of the gastrointestinal tract and the largest neuroendocrine organ in the body, is crucial for the initiation of a full stress response against all noxious stress pathology. The end result would be a strong protection of all organs invaded by 'stress'. Consistent with this assumption, this coping response is best explained in terms of 'organoprotection'. Endogenous organoprotectors (eg prostaglandins, somatostatin, dopamine) are proposed as mediators. Such an endogenous counteraction could even be afforded by their suitable application. A new gastric juice peptide, M(r) 40,000, named BPC, was recently isolated. Herein, a 15 amino acid fragment (BPC 157), thought to be essential for its activity, has been fully characterized and investigated. As has been demonstrated for many organoprotective agents using different models of various tissue lesions, despite the poorly understood final mechanism, practically all organ systems appear to benefit from BPC activity. These effects have been achieved in many species using very low dosages (mostly microgram and ng/kg range) after ip, ig, and intramucosal (local) application. The effect was apparent already after one application. Long lasting activity was also demonstrated. BPC was highly effective when applied simultaneously with noxious agents or in already pathological, as well as chronical, conditions. Therefore, it seems that BPC treatment does not share any of the so far known limitations for 'conventional organoprotectors'. No influence on different basal parameters and no toxicity were observed. These findings provide a breakthrough in stress theory. BPC, as a possible endogenous free radical scavenger and organoprotection mediator, could be a useful prototype of a new class of drugs, organoprotective agents.

Msx2 is believed to play a role in regulating bone development, particularly in sutures of cranial bone. In this study we investigated the effects of retroviral-mediated overexpression of Msx2 mRNA, in both sense and antisense orientations, on primary cultured chick calvarial osteoblasts. Unregulated overexpression of sense mRNA produced high levels of Msx2 protein throughout the culture period, preventing the expected fall as the cells differentiate. The continued high expression of Msx2 prevented osteoblastic differentiation and mineralization of the extracellular matrix. In contrast, expression of antisense Msx2 RNA decreased proliferation and accelerated differentiation. In other studies, we showed that the Msx2 promoter was widely expressed during the proliferative phase of mouse calvarial osteoblast cultures but was preferentially downregulated in osteoblastic nodules. These results support a model in which Msx2 prevents differentiation and stimulates proliferation of cells at the extreme ends of the osteogenic fronts of the calvariae, facilitating expansion of the skull and closure of the suture.