An alcohol-free tissue conditioner--a laboratory evaluation

OBJECTIVES: An alcohol-free tissue conditioner based on a n-butyl methacrylate/i-butyl methacrylate copolymer has recently been developed. The purpose of the present study was to compare some key properties of the new tissue conditioner with those of poly(ethyl methacrylate)-based conventional materials containing ethyl alcohol. The effect of a coating, which consisted of poly(ethyl methacrylate) and methyl methacrylate, was also evaluated. METHODS: The new alcohol-free tissue conditioner (Fictioner) and three tissue conditioners containing ethyl alcohol (FITT, Hydro-Cast, SR-Ivoseal) were evaluated. The coated alcohol-free material was also used. Gelation characteristics, dynamic viscoelastic properties and compatibility with dental stones were measured using a displacement rheometer, dynamic viscoelastometer and profilometer, respectively. In addition, weight changes during immersion in water were determined. RESULTS: The working time and gelation time of the alcohol-free tissue conditioner were similar to those of the conventional materials. This alcohol-free material had significantly lower shear storage modulus and shear loss modulus, and higher loss tangent (P<0.05) than FITT and SR-Ivoseal at 0.01 and 1 Hz. The alcohol-free material maintained its inherent viscoelastic properties and exhibited only a slight change in weight during 14 days of water immersion when compared to the conventional materials. The application of the coating significantly reduced the loss of the initial viscoelastic properties and surface quality during the test periods. CONCLUSIONS: The coated alcohol-free tissue conditioner would be superior to the conventional materials containing ethyl alcohol in view of viscoelastic properties after gelation, compatibility with dental stones and durability.     

Serum reactivity against bacterial pyruvate dehydrogenase: increasing the specificity of anti-mitochondrial antibodies for the diagnosis of primary biliary cirrhosis

Antimitochondrial antibodies (AMA) are the serum hallmark of primary biliary cirrhosis (PBC). However, AMA-positivity can be found in non-PBC sera when lower dilutions are used, thus raising issues about the specificity and sensitivity of the test. AMA reacts primarily with the lipoylated domains of pyruvate dehydrogenase-E2 (PDC-E2) which is highly conserved across species, including bacteria. We studied 77 serum samples, including 24 from patients with anti-PDC-E2-positive PBC and 53 controls (16 with autoimmune hepatitis (AIH), 10 with primary sclerosing cholangitis (PSC), and 27 healthy individuals) for their reactivities at serial dilutions (1:10, 1:20 and 1:40) against Escherichia coli DH5 alpha lysate overexpressing human PDC-E2 using immunoblotting (IB). A murine anti-human PDC-E2 monoclonal antibody (mAB) was used as control. We further studied positive sera using adsorption with a synthetic E. coli peptide sharing similarity with human PDC-E2. Finally, we verified whether a unique buffer for E. coli preparation could reduce non-specific serum reactivity. Results demonstrated that 100% of anti-PDC-E2-positive PBC and up to 38% of control sera at 1:10 dilution recognized E. coli PDC-E2 at IB while dilution tests indicated that the overall potency of PBC reactivity was 100-fold higher compared to controls. In fact, a subgroup (20-38%) of non-PBC sera were positive at low titers but lost the reactivity when absorbed with the synthetic E. coli peptide. Finally, our unique buffer reduced the reactivity of non-PBC sera as measured by ELISA. In conclusion, we demonstrated that weak cross-reactivity with E. coli PDC-E2 occurs in non-PBC sera at lower dilutions and that such reactivity is not due to AMA-positivity. The use of a specific buffer might avoid the risk of false positive AMA determinations when E. coli-expressed recombinant antigens are used.     

Sodium orthovanadate enhances proliferation of progenitor cells in the adult rat subventricular zone after focal cerebral ischemia

Neuronal progenitor cells able to produce new neuron and glia persist in the adult central nervous system (CNS). Their proliferation is up-regulated by growth factors or cytokines under some pathological conditions, including ischemia. Because sodium orthovanadate (SOV), a protein tyrosine phosphatase inhibitor, can up-regulate tyrosine kinase-linked growth factor receptor signaling via the inhibition of tyrosine residue dephosphorylation, it may be capable of enhancing progenitor cells. To investigate the effect of SOV on progenitor cells in the subventricular zone (SVZ), we injected rats intraperitoneally with 50 mg/kg bromodeoxyuridine (BrdU) and 12.5 or 25 mM SOV or BrdU and saline (control) on days 1 to 7 after middle cerebral artery occlusion. The density of BrdU-positive cells in the ipsilateral SVZ showed a significant SOV dose-dependent increase. This effect was found only in the ipsilateral and not contralateral SVZ, and it was not found in nonischemic rats. Double immunolabeling with BrdU and double cortin, a marker of migrating neuroblast, revealed that the density of double-positive cells increased significantly in an SOV dose-dependent manner. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining suggested that the SOV-induced increase was not due to antiapoptotic effects. Treatment with SOV also significantly increased the density of cells positive for BrdU and phosphorylated Akt and BrdU and phosphorylated extracellular signal-regulated kinase (ERK). We postulate that ischemia triggers off the proliferation of SVZ cells by bioactive factors such as growth factors and that SOV enhances the proliferation of only triggered-off SVZ cells with Akt and ERK activation. Our findings suggest that SOV may aid in the self-repair of the postischemic CNS.     

Assessment of rectal aberrant crypt foci by standard chromoscopy and its predictive value for colonic advanced neoplasms

BACKGROUND AND AIMS: Aberrant crypt foci (ACF) are thought to be preneoplastic lesions and are assessed by magnifying chromoscopy with methylene blue staining. The aim of this study was to evaluate the predictive value of rectal ACF recognized by conventional chromoscopy for colonic advanced neoplasms. METHODS: Total colonoscopy, involving rectal chromoscopy using indigo carmine with standard colonoscopies, was performed on 386 patients. Patients who showed no ACF were classified as Grade 0, and those who had 1-4, 5-9, and 10+ ACF were classified as Grades 1, 2, or 3, respectively. The correlation between ACF grading and the prevalence of colonic advanced neoplasm, any adenoma>or=1 cm in size and/or with villous or tubulovillous morphology, and/or with high-grade dysplasia or invasive cancer, was assessed. RESULTS: Sixty-three patients were classified as ACF Grade 0, 119 as Grade 1, 116 as Grade 2, and 88 as Grade 3. Colonic advanced neoplasm was observed in 4 patients (6.3%) for Grade 0, 43 (36.1%) for Grade 1, 61 (52.6%) for Grade 2, and 57 (64.8%) for Grade 3. As the ACF grade increased, the chance of a patient having a colonic advanced neoplasm increased. For multivariate analyses, compared with patients with Grade 0, those with Grades 1, 2, or 3 had a greater risk of colonic advanced neoplasm (odds ratio [OR] 9.18, 95% CI 3.08-27.33, OR 20.44, 95% CI 6.81-61.42, and OR 32.94, 95% CI 10.49-103.41, respectively). CONCLUSIONS: Chromoscopic assessment of rectal ACF by conventional techniques is useful for predicting colonic advanced neoplasms.     

Elimination of late potentials by quinidine in a patient with Brugada syndrome

The beneficial effects of quinidine on ST-segment elevation, inducible ventricular tachyarrhythmias, and episodes of ventricular tachyarrhythmia have been reported in Brugada syndrome. This is the first report describing quinidine-induced elimination of the late potential, which is considered one of the parameters for an arrhythmic event, in a patient with Brugada syndrome.     

Comparison between compliance of fluticasone propionate diskhaler and of fluticasone propionate diskus in adult bronchial asthma patients

BACKGROUND AND OBJECTIVES: Because inhaled corticosteroids (ICS) play a central role in the management of asthma, new drug delivery systems for fluticasone propionate, Diskhaler (FPdh) and Diskus (FPdk), were developed. However, few studies have focused on compliance with these drug delivery systems, which can influence drug efficacy. Hence, we compared compliance with FPdk versus that with FPdh. METHODS: Data were obtained from a survey of pharmacists dispensing anti-asthmatic drugs to adult asthma patients who visited participating pharmacies between October 2002 and November 2003. Patients were limited to regular users of FPdh or FPdk whose medication had not been changed for >6 months before the survey. Compliance and daily administration frequency of ICS were evaluated on the basis of pharmaceutical records. Data on asthma status and various other factors affecting ICS compliance were obtained by questionnaire. RESULTS: Data were acquired on 337 patients. There were no significant differences in gender, age, and duration between the FPdk and FPdh groups. Although FPdk compliance was significantly higher than that of FPdh, conversely there was no significant difference in daily dose and administration frequency between the 2 groups. Furthermore, there was no significant difference in the rate of concomitant drug and in various influencing factors associated with drug compliance. Regarding compliance of concomitant drug, that of oral sustained-released theophylline was significantly lower in FPdk versus FPdh users. CONCLUSION: In the area of drug compliance, FPdk is superior to FPdh. Although the reason for this is unclear, it is probably due to the characteristics of FPdk itself.