Disappearing colorectal liver metastases: Strategies for the management of patients achieving a radiographic complete response after systemic chemotherapy

The mainstays of treatment for colorectal liver metastases (CRLMs) are surgery and chemotherapy. Chemotherapeutic benefits of tumor shrinkage and systemic control of micrometastases are in part counterbalanced by chemotoxicity that can modify the liver parenchyma, jeopardizing the detection of CRLM. This review addresses the clinical decision-making process in the context of radiographic and pathologic responses, the preoperative imaging workup, and the approaches to the liver for CRLM, which disappear after systemic chemotherapy.     

Does neoadjuvant therapy for pancreatic head adenocarcinoma increase postoperative morbidity? A systematic review of the literature with meta-analysis

Neoadjuvant treatment (NT) for pancreatic head cancer may allow some patients to undergo curative resection, but its impact on postoperative complications remains unclear. A systematic review and meta-analysis were performed to compare overall postoperative morbidity, pancreatic fistula, and mortality between patients who underwent upfront surgery and those who underwent neoadjuvant therapy first. Forty-five studies with 3359 patients were included. No significant differences in morbidity and mortality rates associated with NT for pancreatic head cancer were detected in this study.     

Population Pharmacokinetic Modeling to Describe the Total Plasma and Free Brain Levels of Fluconazole in Healthy and <Emphasis Type="BoldItalic">Cryptococcus neoformans</Emphasis> Infected Rats: How Does the Infection Impact the Drug’s Levels on Biophase?

Purpose

The present work aimed to evaluate the influence of experimental meningitis caused by C. neoformans on total plasma and free brain concentrations of fluconazole (FLC) in Wistar rats.

Method

The infection was induced by the administration of 100 μL of inoculum (1.10⁵ CFU) through the tail vein. Free drug in the brain was assessed by microdialisys (μD). Blood and μD samples were collected at pre-determined time points up to 12 h after intravenous administration of FLC (20 mg/kg) to healthy and infected rats. The concentration-time profiles were analyzed by non-compartmental and population pharmacokinetics approaches.

Results

A two-compartmental popPK model was able to simultaneously describe plasma and free drug concentrations in the brain for both groups investigated. Analysis of plasma and μD samples showed a better FLC distribution on the brain of infected than healthy animals (1.04?±?0.31 vs 0.69?±?0.14, respectively). The probability of target attainment was calculated by Monte Carlo simulations based on the developed popPK model for 125 mg/kg dose for rats and 400–2000 mg for humans.

Conclusions

FLC showed a limited use in monotherapy to the treatment of criptoccocosis in rats and humans to value of MIC >8 μg/mL.

     

Epidermal growth factor receptor 2 immunoexpression in gastric cells of domestic cats with H. heilmannii infection

The aim of this study was to evaluate the immunoexpression of HER-2 in gastric cells of cats infected with Non H. pylori Helicobacter (NHPH) and to investigate an association with the presence of inflammatory infiltrate. Forty-eight paraffin-embedded gastric samples were retrieved from the archives of the Veterinary Anatomic Pathology Laboratory that had previously been shown to be positive for NHPH with the rapid urease test and cytology. Infection by NHPH was confirmed by histopathology using the Warthin-Starry staining. Hematoxylin-eosin stained sections were reviewed to evaluate inflammatory cell infiltrates. Immunohistochemical analysis was done using anti- H. pylori antibody and anti-HER-2 antibody. Molecular analysis was performed by PCR to confirm the presence of Helicobacter. Statistical analysis was performed to determine whether there was an association between the presence of H. Heilmannii and HER-2 expression in gastric samples. All samples were positive for NHPH, by immunohistochemistry, and confirmed by PCR as H. Heilmannii. On histopathologic analysis, 56,3% of the samples had lymphocytes and plasma cells infiltrates, 52,1% of which were mild and 4,2% moderate. The intensity of the inflammatory infiltrate in the gastric mucosa was significantly greater in the complete plasma membrane of parietal cells of gastric glands that had greater HER-2 immunoexpression (p = 0.0001). A statistically significant association (p = 0.007) between the H. Heilmannii infection score and the expression of HER-2 in the lateral membrane of gastric surface cells was observed. HER-2 expression may be increased in feline gastric cells infected by H. Heilmannii and in parietal cells of gastric glands with an increased inflammatory infiltrate.     

Toothache prevalence and associated factors: a life course study from birth to age 12 yr

This study estimated the lifetime prevalence of toothache at ages 6 and 12 yr, the prevalence of toothache during the last month, and their association with social, behavioural and clinical exposures in the course of life of 339 12-yr-old children from a birth cohort in Pelotas, Brazil. Exploratory variables were collected in the perinatal study and during several follow-up studies. Prevalence ratios were calculated using Poisson regression, following a hierarchical conceptual model. The lifetime prevalence of toothache at ages 6 and 12 yr were 39% [95% confidence interval (CI) = (34;45)] and 63% [95% CI = (58;69)], respectively. Toothache during the last month was reported by 11% [95% CI = (8;15)]. Children who did not live with their biological father at birth, and children with higher dmf-t counts, reported a higher lifetime prevalence of toothache at age 6 yr. Children experiencing poverty between ages 0 and 4 yr, with higher dmf-t and DMF-T indexes presented a greater lifetime prevalence of toothache at 12 yr. Toothache within the last month was more likely to be reported by girls and by children who did not live with their biological father at birth. Preventive strategies should be implemented in early stages of the life cycle, taking into account the socio-economic and family context in which pain mostly occurs.     

Influence of resin composite shade and location of the gingival margin on the microleakage of posterior restorations

OBJECTIVE: The objective of this in vitro study was to evaluate the influence of resin composite shade and location of the gingival margin (enamel or dentin) on the microleakage of proximal restorations on posterior teeth. Methods and MATERIALS: Sixty freshly extracted human third molars were prepared with standardized Class II box-shaped cavities with proportional size and shape, with distal gingival margins located on the enamel and mesial gingival margins on dentin. The teeth were randomly divided into 6 groups according to resin shade (n=10): G1-Incisal; G2-A1; G3-A2; G4-A3; G5-A3.5; G6-A4. The cavities were restored with a total-etch 1-bottle adhesive system and microhybrid resin composites inserted in 4 increments, light cured for 20 seconds through the occlusal surface, then an additional 60 seconds for each surface. After 1 week of immersion in distilled water, the specimens were thermocycled (500 cycles, 5 degrees -55 degrees C, 30 seconds dwell time), sealed with nail polish and immersed in 0.5% basic fuschin solution for 24 hours. The restorations were sectioned longitudinally, and microleakage was evaluated using a 0-3 score scale. RESULTS: Data were subjected to Kruskal-Wallis and Wilcoxon tests at p<0.05. No statistically significant differences between groups were observed regarding the shade of resin composite (p=0.8570). When margins (enamel or dentin) were considered separately, statistically significant differences were observed between groups (p<0.0001), with enamel margins exhibiting lower degrees of microleakage. CONCLUSION: The variation of resin composite shades utilized in this study did not influence the microleakage of Class II restorations. However, the location of the gingival margin influenced the microleakage.     

Shear bond strength of a ceramic to Co-Cr alloys

STATEMENT OF PROBLEM: Different combinations of Co-Cr alloys bonded to ceramic have been used in dentistry; however, the bond strength of ceramic to metal can vary because of different compositions of these alloys. PURPOSE: The purpose of this study was to evaluate the shear bond strength of a dental ceramic to 5 commercially available Co-Cr alloys. MATERIAL AND METHODS: Five Co-Cr alloys (IPS d.SIGN 20, IPS d.SIGN 30, Remanium 2000, Heranium P, and Wirobond C) were tested and compared to a control group of an Au-Pd alloy (Olympia). Specimen disks, 5 mm high and 4 mm in diameter, were fabricated with the lost-wax technique. Sixty specimens were prepared using opaque and dentin ceramics (VITA Omega 900), veneered, 4 mm high and 4 mm in diameter, over the metal specimens (n=10). The shear bond strength test was performed in a universal testing machine with a crosshead speed of 0.5 mm/min. After shear bond testing, fracture surfaces were evaluated in a stereomicroscope under x25 magnification. Ultimate shear bond strength (MPa) data were analyzed with 1-way ANOVA and the Tukey HSD test (alpha =.05). RESULTS: The mean (SD) bond strengths (MPa) were: 61.4 (7.8) for Olympia; 94.0 (18.9) for IPS 20; 96.8 (10.2) for IPS 30; 75.1 (12.4) for Remanium; 71.2 (14.3) for Heranium P; and 63.2 (10.9) for Wirobond C. Mean bond strengths for IPS 20 and IPS 30 were not significantly different, but were significantly (P<.001) higher than mean bond strengths for the other 4 alloys, which were not significantly different from each other. CONCLUSIONS: Bond strength of a dental ceramic to a Co-Cr alloy is dependent on the alloy composition.