The efficiency of laser application for debonding laminate restorations manufactured of current CAD-CAM materials with different thicknesses.

BACKGROUND: Using lasers for adhesive restoration removal can be practical and atraumatic. AIMS: The purpose of this study was to investigate Er: YAG laser exposure on debonding the adhesive cementation between enamel and feldspar ceramic, lithium disilicate-reinforced and resin nano ceramic composite laminate restorations. MATERIALS AND METHODS: Vita Cerec Blocs, IPS e.max Computer-aided design (CAD). Computer-aided design and manufacturing (CAD-CAM) in full and Lava Ultimate restorative materials were chosen. The 3 × 3 mm2 standardized, 0.5-mm and 1 mm thick specimens were cemented on an enamel surface. After thermocycling, each material group was randomly divided into laser treated and control (non-laser treated) groups. Shear bond strength test was done with a universal testing machine with crosshead speed 0.5 mm/min. Factorial ANOVA Technique and TUKEY HSD multiple comparison test were used for statistical analyses. Moreover, the surface morphology of the debonded samples and the enamel was observed using a scanning electron microscope. RESULTS: The laser application was found to weaken the SBS values significantly (P < 0.05) for all groups; however, the most dramatic SBS decrease was observed for laser treated IPS e.max at both thicknesses. CONCLUSIONS: Laser treatment can serve as a practical and effective method that eliminates the risk the enamel damage and restoration fracture.

Plasma exchange therapy for severe gastrointestinal involvement of Henoch Schönlein purpura in children.

OBJECTIVES: The aim of this report is to evaluate the plasma exchange as a choice for the management of life-threating gastrointestinal system (GIS) involvement in Henoch-Schönlein purpura (HSP) when refractory to conventional therapies. METHODS: We retrospectively reviewed the medical records of HSP patients who had plasma exchange therapy due to massive GIS involvement. We reported age, gender, initial HSP presentation, etiological or triggering factors and disease course. Treatment modalities, side effects and their outcomes were noted. RESULTS: We reported 7 cases of childhood HSP with severe gastrointestinal involvement refractory to common immunosuppression with systemic steroid and cytotoxic therapy. All patients gave inadequate response to pulse methyl prednisolone or oral prednisolone therapy with ongoing GIS bleeding and severe abdominal pain. Therefore, pulse cyclophosphamide was added to the treatment. Two patients received additional intravenous immunoglobulin (IVIG) therapy. Gastrointestinal manifestations continued and plasma exchange was performed. All patients improved after plasma exchange treatment. CONCLUSIONS: Treatment of GI involvement in HSP with plasma exchange has been mainly based on case reports. According to our data, we propose that, plasma exchange may be a safe and efficient management choice in paediatric HSP patients with massive GIS involvement that are refractory to other therapies.

Role of heparin on TNF-alpha and IL-6 levels in liver regeneration after partial hepatic resection.

OBJECTIVES: The aim of this study was to investigate the effect of heparin on TNF-alpha and interleukin (IL)-6 levels and the complement system in liver regeneration in a murine model. MATERIALS AND METHODS: 32 Wistar albino female rats weighing between 180 and 250 g were included in the study. The rats were divided into four groups as follows: group 1, treated with partial (50%) hepatectomy and intravenous heparin 1,000 IU/kg in repeated daily doses; group 2, treated with sham operation and intravenous heparin 1,000 IU/kg in repeated daily doses; group 3, treated with partial (50%) hepatectomy, and group 4 (controls), treated with only sham operation. Before the surgical intervention and after a general anesthetic had been administered to all rats, blood was taken from the left ventricle of each rat, and each sample was assessed to determine total complement hemolytic activity (CH(50)/ml). On the 5th postoperative day, blood was taken to assess CH(50) activity and the levels of TNF-alpha and IL-6 via ELISA. Each rat was then killed by decapitation after which gravimetric analysis and immunohistochemical staining for proliferating cell nuclear antigen (PCNA) were performed. RESULTS: Serum CH(50) activity of group 1 was 4% as compared to 51% in group 3 (p = 0.01). The serum TNF-alpha level of group 1 was 43 pg/ml as compared to 86 pg/ml in group 3 (p = 0.002). The serum IL-6 level of group 1 was 19 pg/ml as compared to 44 pg/ml in group 3 (p = 0.02). The serum IL-6 level of group 2 was 4 pg/ml as compared to 44 pg/ml in group 3 (p = 0.005). According to the results of gravimetric analysis, the mean regeneration rate of group 1 was 4.4% as compared to 22% of group 3 (p = 0.001). The mean PCNA index values of group 2 was the highest of all groups (p = 0.01). However, the mean PCNA index value of group 1 was the lowest of all groups (p = 0.01). CONCLUSION: Because of its anti-inflammatory action via the complement system, heparin produced an unfavorable effect on liver regeneration.

Efficacy of erythromycin for psoriasis vulgaris.

Psoriasis is characterised by the presence of neutrophil overactivation and overproduction of interleukin (IL)-6 and IL-8 from keratinocytes. It is now clear that macrolide antibiotics have anti-inflammatory effects, such as inhibition of IL-6, IL-8 and tumour necrosis factor-alpha, perhaps by suppressing the transcription factor nuclear factor-kappaB or activator protein-1, and reduction of neutrophil activity. It is thus possible that macrolides might be a candidate for adjunctive treatment of psoriasis. In this study, we investigated the effectiveness of treatment with the macrolide antibiotic, erythromycin, for skin lesions and pruritus of patients with psoriasis. In total, 60 patients with psoriasis, especially pruritic psoriasis, were included. This was an open-label study and the analysis was on an intention-to-treat basis. Oral macrolide antibiotics and topical corticosteroids were given to the study group of 36 patients. The control group (24 patients) were treated only with topical corticosteroids. After a 4-week treatment period, scores on the Psoriasis Area and Severity Index (PASI) at baseline and at the end of the treatment, and the effectiveness in reducing itching were compared within and between both groups. Although there was no statistically significant difference between the baseline mean PASI of the two groups (P=0.81), there was a statistically significant difference between the mean PASI of the two groups at the end of the treatment (P=0.023, 95% confidence interval: - 3.45 to - 0.27). The comparison of the mean difference in PASI yielded a statistically significant difference (P=0.03, 95% confidence interval 0.73-3.55). Our study suggests that macrolides could be used as one of the adjunctive therapies for psoriasis vulgaris.

Lamivudine therapy in kidney allograft recipients who are seropositive for hepatitis B surface antigen.

BACKGROUND: There are numerous recent reports on the use of lamivudine for hepatitis B virus (HBV) infection after renal transplantation. However, the optimal strategy (prophylactic, preemptive, or salvage approach) for starting lamivudine treatment in this patient group has not been determined. The aim of this study was to assess how the timing of lamivudine therapy affected the HBV serological status and the transaminase levels in renal allograft recipients with chronic HBV infection. METHODS: We investigated outcomes for patients who were seropositive for hepatitis B surface antigen (HBsAg) and underwent transplantation before or after October 2004 (the date our institution implemented a prophylactic lamivudine treatment strategy against HBV). The data included serum liver enzyme levels and polymerase chain reaction (PCR) screening results for HBV-DNA in serum. RESULTS: Fifteen patients (11 before October 2004, four after October 2004) were included in the study. Preoperatively all patients had normal transaminases levels and 2 of 15 patients had detectable HBV-DNA on PCR. Eight of the 15 total HBsAg-positive patients in our series were not placed on lamivudine at the time of renal transplantation. Half of those who were not treated initially showed transaminase elevations in the first year of follow-up requiring lamivudine therapy at that time. In contrast, all seven individuals who received lamivudine at the time of transplantation were negative for HBV-DNA throughout the follow-up. CONCLUSION: To prevent viral replication in HBsAg-positive patients who are scheduled for renal transplantation, it is best to initiate lamivudine therapy before or immediately after transplantation.

Venous complications after orthotopic liver transplantation.

We report venous complications, including portal vein and hepatic vein stenoses, that required interventional radiological treatment in three pediatric and two adult living related liver transplant recipients. Between April 2001 and April 2005, 81 liver transplantations were performed at our hospital. Sixty-two grafts were from living donors. During follow-up, three portal vein stenoses were identified in three pediatric recipients, and two hepatic vein stenoses in two adult patients. In the children, two had received left lateral segment grafts, and one had received a right lobe graft from two mothers and one father, respectively. The etiologies of liver failure were Alagille syndrome, biliary atresia, and fulminant Wilson's disease. Portal vein stenoses were identified at 8, 11, and 12 months after transplantation; all three patients underwent percutaneous transhepatic portal venous angioplasty with a success rate of 100%. The mean follow-up was 102 days; no recurrence has occurred. In contrast, hepatic venous stenoses were diagnosed in two adult recipients. One of them was a 24-year-old woman with autoimmune hepatitis and the other a 43-year-old man with cryptogenic cirrhosis. Hepatic vein stenoses were diagnosed at 3 and 4 months after transplantation. Both hepatic vein stenoses were dilated with balloon angioplasties via the transjugular route. Venous complications identified by Doppler ultrasonography were confirmed by computerized tomographic angiography. Angioplasty represents an effective and safe alternative to reconstructive surgery in the treatment of venous complications after liver transplantation.

The role of early colonoscopy in CMV colitis of transplant recipients.

Cytomegalovirus (CMV)-associated diseases remain a major problem in transplant recipients. Early diagnosis is critical. Presentation of early CMV colitis can be mild and nonspecific in transplant recipients. Although serology is helpful in the diagnosis, sometimes it is inadequate. Because the endoscopic features of CMV colitis are specific, colonoscopy facilitates the histopathologic examination. We present the clinical properties and advantages of early colonoscopy in transplant recipients with CMV colitis. The study group included seven patients (six men, one woman of mean age, 36.7 years (range, 22 to 64 years) whose mean transplant duration was 12.3 months (range, 1 to 72 months). Six of the seven patients experienced an acute graft rejection treated with high doses of steroids; one patient had a herpes simplex virus infection. All patients were on steroid treatment with a various combinations of immunosuppressive agents, including cyclosporine, mycophenolate mofetil, and tacrolimus. All patients presented with mild diarrhea without any blood or mucous discharge. Four patients had fever exceeding 38 degrees C; two had abdominal pain. Stool examinations revealed normal findings in six patients, while one patient had white blood cells and amoebic cysts. Serum CMV IgM and CMV pp65 antigenemia were negative in five of seven patients and two had positive results. All patients showed typical colonoscopic and histopathologic findings compatible with CMV colitis. Standard ganciclovir treatment was successful in all patients. Early and rapid colonoscopy is beneficial for the early diagnosis and management of CMV colitis in transplant recipients.

Acute pancreatitis due to ramipril therapy.

Few data exist about the incidence of drug induced acute pancreatitis in the general population. Drugs are related to the aetiology of pancreatitis in about 1.4%-2% of cases. Although angiotensin converting enzymes are generally well tolerated, acute pancreatitis has been reported in a few subjects treated with captopril, enalapril, and lisinopril. A 85 year old man with a long standing history of hypertension, who was treated with ramipril 5 mg once daily, presented with acute pancreatitis. Other causes of the disease were ruled out. After cessation of ramipril his condition improved and amylase level decreased. This was his third episode of acute pancreatitis since ramipril was started in 2000. To the authors' knowledge ramipril induced pancreatitis has not previously been reported.

Investigation of possible clinical and laboratory predictors of liver fibrosis in hemodialysis patients infected with hepatitis C virus.

Hepatitis C virus (HCV) infection is common in patients with end-stage renal disease. The severity of liver damage, including fibrosis, in these cases varies widely. Although many investigators have searched for noninvasive alternatives to liver biopsy for evaluating the extent of liver fibrosis, no useful noninvasive predictors have been found. Currently, liver biopsy is essential to assess the degree of fibrosis. The aim of this retrospective study was to investigate a range of clinical and laboratory parameters in HCV-infected hemodialysis (HD) patients and identify possible predictors of fibrosis. Ninety-five consecutive HD patients with HCV infection underwent liver biopsy. Each specimen was evaluated for fibrosis stage. Correlations were sought between the degree of fibrosis and the age, HD duration, time since first possible HCV exposure, body mass index, HCV RNA titer, serum ferritin level, and serum alanine aminotransferase (ALT) level. The analysis revealed no significant correlations between fibrosis stage and the parameters investigated (mean age: r =.017, P =.89; mean HD duration: r =.066, P =.576; body mass index r =.231, P =.152; HCV RNA titer: r =.015, P =.091; serum ferritin: r =.134, P =.32; serum ALT r =.108, P =.927). Links with serum ALT were reevaluated with upper normal levels arbitrarily set at 30 IU/L and 20 IU/L, but these analyses also revealed no correlations between fibrosis stage and ALT level (P =.98 and P =.449, respectively). Therefore liver biopsy is still essential for accurate assessment of liver pathology in HD patients with HCV.

Colonoscopy is a useful diagnostic tool for transplant recipients with lower abdominal symptoms.

Transplant recipients are at higher risk for infection and malignancy due to therapies aimed at preventing rejection. Early detection and successful treatment of such complications is of pivotal importance for both patient and graft survival. In this study, we evaluated findings of 91 colonoscopies and colonic histopathologic findings in recipients who presented with lower gastrointestinal system complaints between January 1996 and January 2003. The study group included 79 renal and liver transplant patients. The indications for colonoscopy were diarrhea (n = 58), abdominal pain (n = 5), hematochezia (n = 19), unexplained anemia (n = 5), thickening of a colonic segment detected on computerized tomography (n = 2), screening for lymphoma (n = 1), and Kaposi's sarcoma (n = 1). During the procedures, all suspicious lesions were biopsied and specimens of normal-appearing mucosa collected when deemed necessary in relation to the clinical complaints. The endoscopic findings were classified as follows: 0 = "normal," with clear visualization of the vascular network and normal-appearing mucosa; 1 = "erythema", with tissues showing erythema, edema, hyperemia, and loss of normal vascular network; 2 = "ulcerative," with tissues exhibiting ulceration and fragility; and 3 = "coincidental findings," such as polyp or angiodysplasia. Colonoscopic and/or histopathologic abnormalities were detected in 44.5% of the 91 colonoscopy procedures. The results indicate that colonoscopy is a valuable diagnostic tool for evaluation of transplant recipients with lower gastrointestinal complaints. After an initial workup colonoscopy is important to establish an accurate diagnosis.

GnRH signaling pathways regulate differentially the tilapia gonadotropin subunit genes.

Exposure of tilapia pituitary cells in culture to salmon gonadotropin-releasing hormone (sGnRH; 0.01-100 nM) elevated the phosphorylated extracellular signal-regulated kinase (pERK) levels. sGnRH also elevated the alpha, FSHbeta and LHbeta subunit mRNA levels. The phorbol ester, 1-O-tetradecanoyl phorbol-13-acetate (TPA; 12.5 nM) increased pERK levels, whereas protein kinase C (PKC) depletion or inhibition by GF109203X (GF; 0.01-10 microM) suppressed GnRH-activated ERKs. GF too abated the GnRH-induced alpha and LHbeta mRNA levels, but had no effect on those of FSHbeta. Forskolin (0.001-100 microM) activated ERK, while inhibition of protein kinase A (PKA) by H89 (0.01-10 microM) suppressed pERK levels and all GnRH-stimulated gonadotropin subunit transcripts. Exposure of cells to the mitogen-activated protein kinase kinase (MAPK kinase; MEK) inhibitor (PD98059; PD 10, 25 and 50 microM) completely blocked GnRH-induced increase in ERKs activation. Furthermore, PD suppressed the alpha and LHbeta mRNA responses to GnRH, but had no effect on FSHbeta mRNA levels. It is suggested that in tilapia the differential regulation of gonadotropin subunit gene expression by GnRH results from a divergent recruitment of signal transduction pathways, activated upon GnRH binding; PKC-ERK cascade is involved in elevating alpha and LHbeta mRNAs, whereas induction of FSHbeta transcript is ERK-independent and is under direct cAMP-PKA regulation or through other MAPK cascades.

Gonadotropin response to GnRH during sexual ontogeny in the common carp, Cyprinus carpio.

This study was designed to reveal whether gonadotropic response to GnRH in the common carp (Cyprinus carpio) changes during sexual ontogeny and whether the response of FSHbeta and LHbeta subunits is uniform or differential. The study comprised fish at the following stages: juveniles (4-month-old females with primary oocytes and early spermatogenic males); maturing (9-month-old previtellogenic females and advanced spermatogenic males); and mature (16-month-old postvitellogenic females and spermiating males). Fish were injected with superactive salmon GnRH analogue (sGnRHa; 25 microg/kg) and blood was sampled 6, 12 and 24 h later for cGtH (LH) and sex steroid levels. Pituitaries were taken for determination of FSHbeta and LHbeta mRNA levels by slot-blot hybridization and for cGTH content in the same glands by radioimmunoassay (RIA). Values were compared with the levels prior to sGnRHa administration and with control fish sampled at the same intervals. Juvenile fish did not respond at all to sGnRHa. In maturing females, FSHbeta mRNA increased by >300%, while that of LHbeta increased by 200%. In maturing males, FSHbeta mRNA did not change and only a slight increase occurred in that of LHbeta. In 16-month-old postvitellogenic females, there was no response of FSHbeta mRNA, while that of LHbeta dramatically increased. In spermiating males of the same age, mRNA of both FSHbeta and LHbeta increased following sGnRHa injection. Immunoreactive cGtH was present in the pituitary and plasma of all fish examined, but in juveniles it did not change following sGnRHa injection. In maturing and mature fish of both genders, sGnRHa administration was followed by a marked increase in circulating cGtH, concomitant with a decrease in its pituitary content, indicating the limited amount of the hormone stored in the gland. In conclusion, the response of the gonadotropin subunit mRNAs in the common carp was found to be differential and dependent on the gender and the phase of sexual ontogeny.

Tilapia glycoprotein hormone alpha subunit: cDNA cloning and hypothalamic regulation.

The cDNA encoding the glycoprotein alpha (GPalpha) subunit of tilapia (Oreochromis mossambicus) was partially cloned using RACE-polymerase chain reaction (PCR) technique. The amplified cDNA was found to be 583 bases long, and to consist of a portion of the signal peptide, the full sequence encoding the mature peptide (94 amino acids) and the 3' untranslated region. Northern blot analysis revealed a single band of approximately 600 bp. Alignment of the deduced amino acids of the mature protein showed that the tilapia GPalpha subunit shares more than 80% identity with that of other perciform fish (i.e. striped bass, sea bream and yellowfin porgy) and less than 70% with that of more taxonomically remote fish and other vertebrates. Exposure of dispersed tilapia pituitary cells to salmon gonadotropin-releasing hormone (sGnRH) elevated GPalpha mRNA levels via both PKC and cAMP-protein kinase A (PKA) pathways. The transcript levels were also regulated by pituitary adenylate cyclase activating polypeptide (PACAP) and neuropeptide Y (NPY), both acting through PKC and PKA pathways. Moreover, a combined treatment of PACAP or NPY with GnRH seems to have an additive effect on the GPalpha subunit gene transcription. These results suggest that in tilapia the expression of GPalpha subunit is regulated by GnRH mainly via PKC and PKA pathways. Furthermore, PACAP and NPY can elevate the GnRH-stimulated GPalpha subunit transcription and can directly affect the subunit mRNA levels, via the same transduction pathways.

Characterization of tilapia FSHbeta gene and analysis of its 5' flanking region.

The objective of the current study was to unveil molecular mechanisms underlying transcriptional regulation of the FSHbeta gene expression in the pituitary of tilapia (Oreochromis mossambicus). The full-length sequence of tilapia FSHbeta (tFSHbeta) gene was determined. Its transcriptional unit (2.7 kb) exhibits the conserved genomic organization, i.e. three exons and two introns. Primer extension and RT-PCR analysis revealed heterogeneity of the tFSHbeta transcripts, due to alternate mRNA splicing and multiple initiation sites for transcription. Examination of the 5' flanking region (5'FR) of the tFSHbeta gene identified potential CAAT and TATA promoter proximal elements as well as several sequences of cis-acting motifs known to dictate inducible and tissue-specific transcriptional regulation in other gonadotropin genes. Chimeric constructs containing 1.7 kb of the tFSHbeta 5'FR fused to a luciferase (LUC) reporter gene were transiently transfected into primary culture of tilapia pituitary cells. The tFSHbeta-LUC construct was efficiently expressed under basal conditions and was rapidly induced by GnRH stimulation. Our data indicate that the 5'FR contains a functional promoter, which is responsive to GnRH treatment. In addition, 5' deletion analysis showed that the 1.7 kb, DNA sequence of the FSHbeta 5'FR encompasses both positive and negative regulatory elements.

Regulation of gonadotropin subunit genes in tilapia.

A steroidogenic tilapia gonadotropin (taGtH=LH) was purified from pituitaries of hybrid tilapia (Oreochromis niloticus x O. aureus) and a homologous RIA was established. This RIA enabled the study of the endocrine regulation of GtH release, the transduction pathways involved in its secretion and its profile during the spawning cycle. Discrepancies between steroid and taGtH peaks during the cycle led to the conclusion that an additional gonadotropin similar to salmonid FSH operates early in the cycle. In order to identify this hormone and to study the endocrine control of synthesis of all gonadotropin (GtH) subunits, a molecular approach was taken. The cDNA sequences and the entire gene sequences encoding the FSHbeta and LHbeta subunits, as well as an incomplete sequence of the glycoprotein hormone alpha subunit (GPalpha), were cloned. Salmon gonadotropin-releasing hormone (sGnRH) elevated mRNA steady-state levels of all three GtH subunits in cultured pituitary cells. Pituitary adenylate cyclase-activating polypeptide (PACAP) and neuropeptide Y (NPY) also stimulated the expression of these subunits and potentiated the effect of GnRH, except that NPY did not affect FSHbeta. The GnRH and NPY effects were found to be mediated mainly through protein kinase C (PKC), while protein kinase A (PKA) cascade was involved to a lesser extent. Mitogen-activated protein kinase (MAPK) cascade takes part in mediating GnRH effects, possibly via PKC. Testosterone (T) and estradiol (E2), but not 11-ketotestosterone (KT), are able to elevate GPalpha and LHbeta mRNAs in pituitary cells of early maturing or regressing males. Low levels of T exposure are associated with elevated FSHbeta mRNA in cells of mature fish, while higher levels suppress it, but elevate LHbeta mRNA. In vivo observations also showed the association of low T levels with increased FSHbeta mRNA and high T levels with elevated LHbeta mRNA. In accordance with these findings, analysis of LHbeta and FSHbeta 5' gene-flanking regions revealed on both gene promoters a GtH-specific element (GSE), half site estrogen response elements (ERE), cAMP response element (CRE) and AP1. In vitro experiments showed that recombinant human activin-A leads to higher levels of GPalpha, FSHbeta and LHbeta mRNAs in pituitary cell culture. Porcine inhibin marginally decreased the mRNA levels of GPalpha and FSHbeta, but at a low level (1 ng/ml) it stimulated that of LHbeta. These results shed some light on certain hypothalamic and gonadal hormones regulating the expression of GtH subunit genes in tilapia. In addition, they provide evidence for their differential regulation, and insight into their mode of action.

GnRH receptor signaling in tilapia pituitary cells: role of mitogen-activated protein kinase (MAPK).

The role of mitogen-activated protein kinase (MAPK, also known as extracellular signal regulated kinase; ERK) stimulation in gonadotropin-releasing hormone (GnRH) signaling was investigated in cultured pituitary cells of tilapia hybrids (Oreochromis niloticus x O. aureus). Exposure of the cells to salmon GnRH (sGnRH) resulted in a dose- and time-dependent elevation in ERK levels. The PKC activator, 1-O-tetradecanoyl phorbol-13-acetate (TPA) increased kinase levels, while addition of GnRH had no further effect. However, chronic exposure to TPA resulted in reduction of basal and GnRH-induced ERK elevation. When PKC was inhibited by GF109203X, the GnRH-elevated ERK levels were totally abolished. The role of MAPK activation on GPalpha, FSHbeta and LHbeta gene expression was determined by administration of MAPK-kinase (MEK) inhibitor (PD98059; PD). This inhibitor completely blocked GnRH-induced increases in ERK activity. Furthermore, it suppressed GPalpha and LHbeta mRNA responses to GnRH, but had no effect on FSHbeta transcript levels. PD also decreased basal LHbeta mRNA levels. These results indicate that in tilapia pituitary cells, GnRH activates MAPK cascade in a PKC-dependent manner. ERK is involved in GnRH elevation of GPalpha and LHbeta, but not in FSHbeta genes transcription.