The effects of up to 240 days of tacrolimus therapy on the gingival tissues of rats – a morphological evaluation

Background:  Tacrolimus, an immunosuppressive drug used in organ transplantation, has been reported not to induce gingival overgrowth. However, prevalence studies are limited, and the methods used for assessing gingival overgrowth varies among studies.
Objective:  The purpose of this study was to evaluate the effects of up to 240 days of tacrolimus therapy on gingival tissues of rats.
Materials and methods:  Rats were treated for 60, 120, 180 and 240 days with daily subcutaneous injections of 1 mg/kg body weight of tacrolimus. After histological processing, the oral and connective tissue, volume densities of fibroblasts ( V _f), collagen fibers ( V _cf) and other structures ( V _o) were assessed in the region of the lower first molar.
Results:  After 60 and 120 days of treatment with tacrolimus, gingival overgrowth was not observed. The gingival epithelium, connective tissue, as well as the values for V _f, V _cf, and V _o were similar to those of the control rats ( P  > 0.05). After 180 and 240 days of the treatment, gingival overgrowth was associated with a significant increase in the gingival epithelium and connective tissue as well as an increase in the V _f and V _cf ( P  < 0.05).
Conclusions:  Within the limits of the experimental study, it may be concluded that the deleterious side effects of tacrolimus on the gingival tissues of rats may be time-related.     

Retention of cast crown copings cemented to implant abutments

Background: The cementation of crowns to dental implant abutments is an accepted form of crown retention that requires consideration of the properties of available cements within the applied clinical context. Dental luting agents are exposed to a number of stressors that may reduce crown retention in vivo, not the least of which is occlusal loading. This study investigated the influence of compressive cyclic loading on the physical retention of cast crown copings cemented to implant abutments. Methods: Cast crown copings were cemented to Straumann synOcta titanium implant abutments with three different readily used and available cements. Specimens were placed in a humidifier, thermocycled and subjected to one of four quantities of compressive cyclic loading. The uniaxial tensile force required to remove the cast crown copings was then recorded. Results: The mean retention values for crown copings cemented with Panavia‐F cement were statistically significantly greater than both KetacCem and TempBond non‐eugenol cements at each compressive cyclic loading quantity. KetacCem and TempBond non‐eugenol cements produced relatively low mean retention values that were not statistically significantly different at each quantity of compressive cyclic loading. Compressive cyclic loading had a statistically significant effect on Panavia‐F specimens alone, but increased loading quantities produced no further statistically significant difference in mean retention. Conclusions: Within the limitations of the current in vitro conditions employed in this study, the retention of cast crown copings cemented to Straumann synOcta implant abutments with a resin, glass ionomer and temporary cement was significantly affected by cement type but not compressive cyclic loading. Resin cement is the cement of choice for the definitive non‐retrievable cementation of cast crown copings to Straumann synOcta implant abutments out of the three cements tested.     

Five-day storage of platelets in a non-diethylhexyl phthalate- plasticized container

A non-diethylhexyl phthalate (DEHP)-plasticized blood bag for 5-day storage of random-donor platelet concentrates has been developed. The plastic bag is composed of polyvinylchloride plastic with a butyryl trihexyl citrate plasticizer. The suitability of this plastic for the storage of platelet concentrates for use in clinical transfusion practice was evaluated. In vitro storage studies showed no significant differences at Day 5 for a series of in vitro assays (test plastic vs. control plastic) including pH (7.31 vs. 7.44), lactate dehydrogenase discharge (21.8 vs. 17.1%), pO2 (103 vs. 120 torr), osmotic recovery (52 vs. 57%), and morphology score (527 vs. 516). For paired radiolabeled recovery and survival data from autologous blood donors, results showed equivalence between the test plastic and two control plastics. A small but significant difference between test and control plastics in regard to survival was found by using a linear computer model, but not with a gamma function (multiple-hit) model. For paired transfusions to thrombocytopenic patients, the corrected count increments at 1 to 4 hours (test vs. control) were 13,534 versus 15,494 (p > 0.05, NS). Similar results were seen for corrected count increments determined at 12 to 24 hours. It can be concluded that platelets stored in the test plastic are acceptable for use in clinical practice.     

Quality of measurements of acute surgical and traumatic wounds using a digital wound‐analysing tool

The aim of this study was to assess the reliability of measurements using a wound‐analysing tool and their interpretability. Wound surface areas and tissue types, such as granulation, slough and necrosis, in twenty digital photographs were measured using a specific software program. The ratio of these tissue types in a wound was calculated using a wound profile. We calculated the intraclass coefficient or κ for reliability, standard error of measurement (SEM) and smallest detectable change (SDC). The inter‐rater reliability intraclass correlation coefficient (ICC) was 0·99 for surface area, 0·76 for granulation, 0·67 for slough and 0·22 for necrosis. The profiles gave an overall κ of 0·16. For test–retest reliability, the ICC was 0·99 for surface area, 0·81 for granulation, 0·80 for slough and 0·97 for necrosis. The agreement of the applied profiles in the test–retest was 66% (40–100). SEM and SDC for surface area were 0·10/0·27; for granulation, 6·88/19·08; for slough, 7·17/19·87; and for necrosis, 0·35/0·98, respectively. Measuring wound surface area and tissue types by means of digital photo analysis is a reliable and applicable method for monitoring wound healing in acute wounds in daily practice as well as in research.     

Thymus and mediastinal node involvement in childhood langerhans cell histiocytosis: Long‐term follow‐up from the French national cohort

Background

Mediastinal involvement (MI) in Langerhans cell histiocytosis (LCH) has been rarely reported. Here, we describe the clinical, radiological, and biological presentation, and the outcome of childhood LCH with MI.

Method

From the French LCH register, which includes 1,423 patients aged less than 18 years, we retrieved the medical charts of patients with mediastinal enlargement detected on chest X‐rays.

Results

Thirty‐seven patients were retrieved, including 18 males; median age of diagnosis was 0.7 years, and median follow‐up time was 6.2 years. The prevalence of MI varied with the age at diagnosis, ranging from 7% below 1 year old to less than 1% at >5 years. Thirteen cases (35%) were diagnosed because of MI‐related symptoms, including respiratory distress (N = 4), superior venous cava syndrome (N = 2), and/or cough and polypnea (N = 10). CT scans performed in 32 cases at diagnosis showed tracheal compression (N = 5), cava thrombosis (N = 2), and/or calcification (N = 16). All patients presented multi‐system disease at LCH diagnosis, and 35/37 were initially treated with vinblastine and corticosteroids. Death occurred in five cases, due to MI (N = 1) or hematological refractory involvement (N = 4). The overall 5‐year survival was 87.1%, and immunodeficiency was not detected as a sequel.

Conclusions

MI in LCH mainly occurs in young children, and diagnosis was based on CT showing thymus enlargement and calcifications. Pediatr Blood Cancer 2013;60:1759–1765. © 2013 Wiley Periodicals, Inc.     

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large‐sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)‐positive chronic HBV infection (n = 588), HBeAg‐positive chronic hepatitis B (n = 596), and HBeAg‐negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%‐90% confidence interval: 3.52 log10 IU/mL‐4.99 log10 IU/mL]) in patients with HBeAg‐positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg‐positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg‐negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg‐positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg‐negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.     

Dosimetric implications of the addition of 18 fluorodeoxyglucose-positron emission tomography in CT-based radiotherapy planning for non-small-cell lung cancer

The aim of this study was to assess the impact of F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) CT on radiotherapy planning parameters for patients treated curatively with radiotherapy for non-small-cell lung cancer (NSCLC). Five patients with stages I–III NSCLC underwent a diagnostic FDG-PET CT (dPET CT), planning FDG-PET CT (pPET CT) and a simulation CT (RTP CT). For each patient, three radiation oncologists delineated a gross tumour volume based on RTP CT alone, and fused with dPET CT and pPET CT. Standard expansions were used to generate PTVs, and a 3D conformal plan was created. Normal tissue doses were compared between plans. Coverage of pPET CT PTV by the plans based on RTP CT and dPET CT was assessed, and tumour control probabilities were calculated. Mean PTV was similar between RTP CT, dPET CT and pPET CT, although there were significant inter-observer differences in four patients. The plans, however, showed no significant differences in doses to lung, oesophagus, heart or spinal cord. The RTP CT plan and dPET CT plan significantly underdosed the pPET PTV in two patients with minimum doses ranging from 12 to 63% of prescribed dose. Coverage by the 95% isodose was suboptimal in these patients, but this did not translate into poorer tumour control probability. The effect of fused FDG-PET varied between observers. The addition of dPET and pPET did not significantly change the radiotherapy planning parameters. Although FDG-PET is of benefit in tumour delineation, its effect on normal tissue complication probability and tumour control probability cannot be predicted.     

The effect of casein phosphopeptide-amorphous calcium phosphate on erosive dentine wear

Background:  Erosive tooth wear is a growing concern in clinical dentistry. Our aims were to assess the effect of Tooth Mousse (TM) in managing erosive dentine wear in vitro .
Methods:  Opposing enamel and dentine specimens from 36 third molar teeth were worn under a load of 100 N for 75 000 cycles in electromechanical tooth wear machines. In experiment 1, TM was applied continuously at the wear interface and the mean dentine wear rate was compared with those of specimens subjected to continuous application of hydrochloric acid (HCl, pH 3.0) and deionized water (DW, pH 6.1) as lubricants. In experiment 2, specimens were subjected to TM application every 1600 cycles at both pH 3.0 and 6.1, and the mean dentine wear rates were compared with those of specimens worn with continuous application of HCl and DW lubricants.
Results:  Dentine wear was reduced significantly with continuous application of TM compared with HCl and DW lubricants. Specimens prepared with continuous TM application displayed smooth wear facets, whereas more pronounced microwear details were observed with HCl and DW lubricants.
Conclusions:  Both remineralization and lubrication seem to contribute to reduction in dentine wear associated with TM application, although lubrication appears to have a more pronounced effect.