Keratin variants associate with progression of fibrosis during chronic hepatitis C infection

Keratins 8 and 18 (K8/K18) protect the liver from various forms of injury. Studies of liver explants from a large cohort of U.S. patients showed that K8/K18 mutations confer a risk to developing end-stage liver diseases, though which diseases are preferentially involved is unknown. We tested the hypothesis that K8/K18 variants are associated with chronic hepatitis C (CHC) and that their presence correlates with progression of fibrosis. Genomic DNA was isolated from peripheral blood of a well-characterized German cohort of 329 patients with CHC infection. Exonic regions were PCR-amplified and analyzed using denaturing high-performance liquid chromatography and DNA sequencing. Our findings showed: (1) amino acid altering keratin heterozygous variants in 24 of 329 CHC patients (7.3%) and non-coding heterozygous variants in 26 patients (7.8%), and (2) 3 new exonic K8 variants (T26R/G55A/A359T); 6 novel non-coding variants and one K18 coding variant (K18 S230T; 2 patients). The most common variants were K8 R341H (10 patients), K8 G62C (6 patients) and K8 I63V (4 patients). A novel and exclusive association of an intronic KRT8 IVS7+10delC deletion in all 10 patients with K8 R341H was observed. Notably, there was a significant association of exonic, but not of intronic K8 variants with increased fibrosis. In conclusion, previously described and novel K8 variants are present in a German population and collectively associate with progression of fibrosis in CHC infection. The unique 100% segregation of the most common K8 variant, R341H, with an intronic deletion suggests that one of these two genetic changes might lead to the other.

Role of the different isoforms of cyclooxygenase and nitric oxide synthase during gastric ulcer healing in cyclooxygenase-1 and -2 knockout mice

Traditional NSAIDs, selective cyclooxygenase (COX)-2 inhibitors, and inhibitors of nitric oxide synthase (NOS) impair the healing of preexisting gastric ulcers. However, the role of COX-1 (with or without impairment of COX-2) and the interaction between COX and NOS isoforms during healing are less clear. Thus we investigated healing and regulation of COX and NOS isoforms during ulcer healing in COX-1 and COX-2 deficiency and inhibition mouse models. In this study, female wild-type COX-1(-/-) and COX-2(-/-) mice with gastric ulcers induced by cryoprobe were treated intragastrically with vehicle, selective COX-1 (SC-560), COX-2 (celecoxib, rofecoxib, and valdedoxib), and unselective COX (piroxicam) inhibitors. Ulcer healing parameters, mRNA expression, and activity of COX and NOS were quantified. Gene disruption or inhibition of COX-1 did not impair ulcer healing. In contrast, COX-2 gene disruption and COX-2 inhibitors moderately impaired wound healing. More severe healing impairment was found in dual (SC-560 + rofecoxib) and unselective (piroxicam) COX inhibition and combined COX impairment (in COX-1(-/-) mice with COX-2 inhibition and COX-2(-/-) mice with COX-1 inhibition). In the ulcerated repair tissue, COX-2 mRNA in COX-1(-/-) mice, COX-1 mRNA in COX-2(-/-) mice, and, remarkably, NOS-2 and NOS-3 mRNA in COX-impaired mice were more upregulated than in wild-type mice. This study demonstrates that COX-2 is a key mediator in gastric wound healing. In contrast, COX-1 has no significant role in healing when COX-2 is unimpaired but becomes important when COX-2 is impaired. As counterregulatory mechanisms, mRNA of COX and NOS isoforms were increased during healing in COX-impaired mice.

Progression of pulmonary hyperinflation and trapped gas associated with genetic and environmental factors in children with cystic fibrosis

BACKGROUND: Functional deterioration in cystic fibrosis (CF) may be reflected by increasing bronchial obstruction and, as recently shown, by ventilation inhomogeneities. This study investigated which physiological factors (airway obstruction, ventilation inhomogeneities, pulmonary hyperinflation, development of trapped gas) best express the decline in lung function, and what role specific CFTR genotypes and different types of bronchial infection may have upon this process. METHODS: Serial annual lung function tests, performed in 152 children (77 males; 75 females) with CF (age range: 6-18 y) provided data pertaining to functional residual capacity (FRCpleth, FRCMBNW), volume of trapped gas (VTG), effective specific airway resistance (sReff), lung clearance index (LCI), and forced expiratory indices (FVC, FEV1, FEF50). RESULTS: All lung function parameters showed progression with age. Pulmonary hyperinflation (FRCpleth > 2SDS) was already present in 39% of patients at age 6-8 yrs, increasing to 67% at age 18 yrs. The proportion of patients with VTG > 2SDS increased from 15% to 54% during this period. Children with severe pulmonary hyperinflation and trapped gas at age 6-8 yrs showed the most pronounced disease progression over time. Age related tracking of lung function parameters commences early in life, and is significantly influenced by specific CFTR genotypes. The group with chronic P. aeruginosa infection demonstrated most rapid progression in all lung function parameters, whilst those with chronic S. aureus infection had the slowest rate of progression. LCI, measured as an index of ventilation inhomogeneities was the most sensitive discriminator between the 3 types of infection examined (p < 0.0001). CONCLUSION: The relationships between lung function indices, CFTR genotypes and infective organisms observed in this study suggest that measurement of other lung function parameters, in addition to spirometry alone, may provide important information about disease progression in CF.

Bone healing and graft resorption of autograft, anorganic bovine bone and beta-tricalcium phosphate. A histologic and histomorphometric study in the mandibles of minipigs

OBJECTIVE: The purpose was to qualitatively and quantitatively compare the bone formation and graft resorption of two different bone substitutes used in both orthopedic and oral surgery, with autogenous bone as a positive control. MATERIALS AND METHODS: Three standardized bone defects were prepared in both mandibular angles of 12 adult minipigs. The defects were grafted with either autograft, anorganic bovine bone (ABB), or synthetic beta-tricalcium phosphate (beta-TCP). Sacrifice was performed after 1, 2, 4, and 8 weeks for histologic and histomorphometric analysis. RESULTS: At 2 weeks, more new bone formation was seen in defects filled with autograft than with ABB (P approximately 0.0005) and beta-TCP (P approximately 0.002). After 4 weeks, there was no significant difference between beta-TCP and the two other materials. Defects grafted with ABB still exhibited less bone formation as compared with autograft (P approximately 0.004). At 8 weeks, more bone formation was observed in defects grafted with autograft (P approximately 0.003) and beta-TCP (P approximately 0.00004) than with ABB. No difference could be demonstrated between beta-TCP and autograft. beta-TCP resorbed almost completely over 8 weeks, whereas ABB remained stable. CONCLUSION: Both bone substitutes seemed to decelerate bone regeneration in the early healing phase as compared with autograft. All defects ultimately regenerated with newly formed bone and a developing bone marrow. The grafting materials showed complete osseous integration. Both bone substitutes may have a place in reconstructive surgery where different clinical indications require differences in biodegradability.

Rates of disease progression according to initial highly active antiretroviral therapy regimen: a collaborative analysis of 12 prospective cohort studies

BACKGROUND: No large clinical end-point trials have been conducted comparing regimens among human immunodeficiency virus type 1-positive persons starting antiretroviral therapy. We examined clinical progression according to initial regimen in the Antiretroviral Therapy Cohort Collaboration, which is based on 12 European and North American cohort studies. METHODS: We analyzed progression to death from any cause and to AIDS or death (AIDS/death), comparing efavirenz (EFV), nevirapine (NVP), nelfinavir, idinavir, ritonavir (RTV), RTV-boosted protease inhibitors (PIs), saquinavir, and abacavir. We also compared nucleoside reverse-transcriptase inhibitor pairs: zidovudine/lamivudine (AZT/3TC), stavudine (D4T)/3TC, D4T/didanosine (DDI), and others. RESULTS: A total of 17,666 treatment-naive patients, 55,622 person-years at risk, 1,617 new AIDS events, and 895 deaths were analyzed. Compared with EFV, the adjusted hazard ratio (HR) for AIDS/death was 1.28 (95% confidence interval [CI], 1.03-1.60) for NVP, 1.31 (95% CI, 1.01-1.71) for RTV, and 1.45 (95% CI, 1.15-1.81) for RTV-boosted PIs. For death, the adjusted HR for NVP was 1.65 (95% CI, 1.16-2.36). The adjusted HR for death for D4T/3TC was 1.35 (95% CI, 1.14-1.59), compared with AZT/3TC. CONCLUSIONS: Outcomes may vary across initial regimens. Results are observational and may have been affected by bias due to unmeasured or residual confounding. There is a need for large, randomized, clinical end-point trials.

The effect of tocopheryl phosphates on atherosclerosis progression in rabbits fed with a high cholesterol diet

The effect of tocopheryl phosphate on atherosclerosis progression has been studied in rabbits, fed with a 2% cholesterol diet and compared with an equivalent amount of alpha-tocopheryl acetate. The results show that the atherosclerotic-preventing effect of the phosphate derivative was more pronounced than that of the acetate derivative. alpha-Tocopheryl phosphate was also more potent in diminishing the expression of CD36 than the acetate derivative.

Correlation between the area of increased autofluorescence surrounding geographic atrophy and disease progression in patients with AMD

PURPOSE: To test the hypothesis that the extension of areas with increased fundus autofluorescence (FAF) outside atrophic patches correlates with the rate of spread of geographic atrophy (GA) over time in eyes with age-related macular degeneration (AMD). METHODS: The database of the multicenter longitudinal natural history Fundus Autofluorescence in AMD (FAM) Study was reviewed for patients with GA recruited through the end of August 2003, with follow-up examinations within at least 1 year. Only eyes with sufficient image quality and with diffuse patterns of increased FAF surrounding atrophy were chosen. In standardized digital FAF images (excitation, 488 nm; emission, >500 nm), total size and spread of GA was measured. The convex hull (CH) of increased FAF as the minimum polygon encompassing the entire area of increased FAF surrounding the central atrophic patches was quantified at baseline. Statistical analysis was performed with the Spearman's rank correlation coefficient (rho). RESULTS: Thirty-nine eyes of 32 patients were included (median age, 75.0 years; interquartile range [IQR], 67.8-78.9); median follow-up, 1.87 years; IQR, 1.43-3.37). At baseline, the median total size of atrophy was 7.04 mm2 (IQR, 4.20-9.88). The median size of the CH was 21.47 mm2 (IQR, 15.19-28.26). The median rate of GA progression was 1.72 mm2 per year (IQR, 1.10-2.83). The area of increased FAF around the atrophy (difference between the CH and the total GA size at baseline) showed a positive correlation with GA enlargement over time (rho=0.60; P=0.0002). CONCLUSIONS: FAF characteristics that are not identified by fundus photography or fluorescein angiography may serve as a prognostic determinant in advanced atrophic AMD. As the FAF signal originates from lipofuscin (LF) in postmitotic RPE cells and since increased FAF indicates excessive LF accumulation, these findings would underscore the pathophysiological role of RPE-LF in AMD pathogenesis.

Resonance frequency analysis in relation to jawbone characteristics and during early healing of implant installation

OBJECTIVES: To monitor resonance frequency analysis (RFA) in relation to the jawbone characteristics and during the early phases of healing and incorporation of Straumann dental implants with an SLA surface. MATERIAL AND METHODS: 17 Straumann 4.1 mm implants (10 mm) and 7 Straumann 4.8 mm implants (10 mm) were installed and ISQ determined at baseline and after 1, 2, 3, 4, 5, 6, 8 and 12 weeks. Central bone cores were analyzed from the 4.1 mm implants using micro CT for bone volume density (BVD) and bone trabecular connectivity (BTC). RESULTS: Pocket probing depths ranged from 2-4 mm and bleeding on probing from 5-20%. At baseline, BVD varied between 24% and 65% and BTC between 4.9 and 25.4 for the 4.1 mm implants. Baseline ISQ varied between 55 and 74 with a mean of 61.4. No significant correlations were found between BVD or BTC and ISQ Values. For the 4.8 mm diameter implants baseline ISQ values ranged from 57-70 with a mean of 63.3. Over the healing period ISQ values increased at 1 week and decreased after 2-3 weeks. After 4 weeks ISQ values, again increased slightly, no significant differences were noted over time. One implant (4.1 mm) lost stability at 3 weeks. Its ISQ value had dropped from 68 to 45. However the latter value was determined after the clinical diagnosis of instability. CONCLUSION: ISQ values of 57-70 represented homeostasis and implant stability. However no predictive value for loosing implant stability can be attributed to RFA since the decrease occurred after the fact.

Resonance Frequency Analysis (RFA) during early healing

Objectives: - to monitor resonance frequency analysis (RFA) in relation to the jawbone characteristics during the early phases of healing and incorporation of Straumann® dental implants with an SLA surface. Material and methods: 17 Straumann 4.1mm implants (10mm) and 7 Straumann 4.8mm implants (10mm) were installed and ISQ determined at baseline and after 1, 2, 3, 4, 5, 6, 8 and 12 weeks. Central bone cores were analyzed from the 4.1mm implants using micro CT for bone volume density (BVD) and bone trabecular connectivity (BTC). Results: Pocket probing depths ranged between 2-4mm and bleeding on probing between 5-20%. At baseline, BVD varied between 24 and 65% and BTC between 4.9 and 25.4 for the 4.1mm implants. Baseline ISQ varied between 55 and 74 with a mean of 61.4. No significant correlations were found between BVD or BTC and ISQ Values. For the 4.8mm diameter implants baseline ISQ values ranged from 57 – 70 with a mean of 63.3. Over the healing period ISQ values increased at 1 week and decreased after 2-3 weeks. After 4 weeks ISQ values, again increased slightly, no significant differences were noted over time. One implant (4.1mm) lost stability at 3 weeks. Its ISQ value had dropped from 68 to 45. However the latter value was determined after the clinical diagnosis of instability. Conclusion: ISQ values of 57 – 70 represented homeostasis and implant stability. However no predictive value for loosing implant stability can be attributed to RFA since decease occurred after the fact.

MRI follow-up of TNF-dependent differential progression of atherosclerotic wall-thickening in mouse aortic arch from early to advanced stages

OBJECTIVES: An optimized, longitudinal in vivo magnetic resonance vessel wall-imaging protocol was evaluated regarding its capability of detecting differences in the time-dependent atherosclerotic lesion progression in the aortic arch between ApoE(-/-) and double-deficient ApoE(-/-)/TNF(-/-) mice at comparatively early plaque development stages. MATERIALS AND METHODS: Seven ApoE(-/-) and seven ApoE(-/-)/TNF(-/-) female mice underwent MRI at 11.75 teslas at four stages up to 26 weeks of age. A double-gated spin-echo MRI sequence was used with careful perpendicular slice positioning to visualize the vessel wall of the ascending aortic arch. RESULTS: Wall-thickness progression measured with MRI was significant at 11 weeks of age in ApoE(-/-) mice, but only at 26 weeks in ApoE(-/-)/TNF(-/-) mice. A significant correlation was found between MRI wall-thickness and lesion area determined on histology. CONCLUSION: MRI was shown to be sensitive enough to reveal subtle genetically-induced differences in lesion progression at ages earlier than 25 weeks.

Correlation of bone defect dimensions with healing outcome one year after apical surgery

This clinical study prospectively evaluated the healing outcome 1 year after apical surgery in relation to bony crypt dimensions measured intraoperatively. The study cohort included 183 teeth in an equal number of patients. For statistical analysis, results were dichotomized (healed versus non-healed cases). The overall success rate was 83% (healed cases). Healing outcome was not significantly related to the level and height of the facial bone plate. In contrast, a significant difference was found for the mean size of the bony crypt when healed cases (395 mm(3)) were compared with non-healed cases (554 mm(3)). In addition, healed cases had a significantly shorter mean distance (4.30 mm) from the facial bone surface to the root canal (horizontal access) compared with non-healed cases (5.13 mm). With logistic regression, however, the only parameter found to be significantly related to healing outcome was the length of the access window to the bony crypt.