The role of selective computed tomography in the diagnosis and management of suspected acute appendicitis

The negative appendectomy rate in patients with clinically diagnosed acute appendicitis is 20 to 40 per cent. Recently CT has emerged as a powerful diagnostic tool in the evaluation of suspected appendicitis and its routine use has been advocated. The objective of this study was to evaluate the impact of selective use of abdominal CT on the negative appendectomy rate. Three hundred eight patients were enrolled in this prospective study. Abdominal CT was performed in patients with uncertain clinical signs of appendicitis. CT was not performed in patients with either a very high or a very low index of suspicion. The results were compared with a retrospective analysis of 85 consecutive patients operated by clinical diagnosis alone. One hundred twenty-seven patients had a final diagnosis of acute appendicitis. CT was performed in 198 patients (64%). The sensitivity, specificity, and accuracy of CT scans were 91, 92, and 91 per cent, respectively. Surgical management plans were altered in 54 patients after obtaining the CT results; unnecessary delay in surgical treatment or unnecessary operations were prevented in 28 and 26 patients, respectively. In addition CT detected unrelated pathologies in 23 patients. CT was not performed in patients with low index of suspicion and none were found to suffer from acute appendicitis. The negative appendectomy rate was 17 per cent (7% men and 24% women) in patients selected for surgery on the basis of very high clinical suspicion alone. Overall the negative appendectomy rate with the selective use of CT was 16 per cent, which is significantly lower than the rate achieved by diagnosing patients on clinical grounds alone (24%). CT is highly accurate in diagnosing or ruling out acute appendicitis and may substantially decrease the negative appendectomy rate as well as unnecessary delayed observation. We believe that CT should be performed routinely in women with suspected appendicitis and selectively in men.     

Single-stage medial plateau elevation and metaphyseal osteotomies in advanced-stage Blount’s disease: a new technique

PurposeSurgical treatment in advanced-stage infantile Blount’s disease with medial plateau (MP) depression is challenging. Several osteotomies and fixation methods have been described with no established benchmark. We conducted this study to evaluate the efficacy and safety of a new single-stage technique for acute medial condyle elevation and metaphyseal osteotomies with internal fixation.MethodsA prospective case series of 19 consecutive patients (21 knees) with severe infantile Blount’s disease underwent a single-stage MP elevation and metaphyseal osteotomies, with internal fixation. The mean age was 10.3 years (8.2 to 13.6) and the mean follow-up was 5.1 years (3.2 to 8.3). The outcome measures included clinical and radiological parameters and patient-reported pediatric outcomes data collection instrument (PODCI) score.ResultsThe mean PODCI score improved significantly from 50% to 88%. The mean internal tibial torsion improved from -27° to 11°. All cases maintained full knee extension, no limitation in flexion range of movement and no signs of instability or lateral thrust gait. All the radiographic parameters improved significantly; the mean tibiofemoral angle improved from -29° to 7°, the metaphyseal-diaphyseal angle improved from 33.4° to 4.7° and the angle of depressed MP improved from 38.3° to 2.4° (p < 0.001). At the latest follow-up, no cases of deformity recurrence were identified, the final limb-length discrepancy was < 1 cm in all patients.ConclusionSingle-stage MP elevation and metaphyseal osteotomies with internal fixation significantly improved the clinical and radiographic parameters and PODCI score in advanced infantile Blount’s disease and precluded the use of external immobilization, with no evidence of deformity recurrence.Level of evidenceIV     

SIX2在骨肉瘤组织中表达及其对细胞血管生成与阿霉素耐药逆转的影响

探究SIX2在骨肉瘤组织中表达及其对细胞血管生成与阿霉素耐药逆转的影响。方法 收集2019年3月—2021年12月我院行骨肉瘤手术切除的105例患者的组织标本,免疫组化检测骨肉瘤组织中SIX2表达和微血管密度（MVD）计数;检测骨肉瘤组织中SIX2 mRNA表达水平。将人骨肉瘤细胞系MG-63分为MG-63组、si-NC A组、si-SIX2 A组,将通过阿霉素耐药得到的骨肉瘤阿霉素耐药细胞株MG-63/R分为MG-63/R组、si-NC B组和si-SIX2 B组。分别用MTT法、克隆实验、流式细胞术及Transwell法检测细胞耐药性、细胞增殖、细胞凋亡和细胞侵袭。结果 在骨肉瘤组织中,SIX2阳性表达会随着MVD值升高而增加（P＜0.05）。骨肉瘤组织中SIX2阳性表达与TNM分期、软组织浸润和淋巴结远处转移相关（P＞0.05）。与MG-63组相比,si-SIX A组细胞的血管形成能力明显降低（P＜0.05）;与MG-63/R组相比,si-SIX2 B组细胞IC50、细胞克隆数和细胞侵袭能力均显著降低,细胞凋亡能力明显增加,细胞耐药指数逆转倍数为2.51倍（P＜0.05）。结论 SIX2在骨肉瘤组织中呈高表达,且随着SIX2表达的升高肿瘤血管生成能力也增加;抑制SIX2表达可有效抑制骨肉瘤组织的生成,逆转骨肉瘤细胞阿霉素耐药     

LC-ESI-MS/MS reveals the formation of reactive intermediates in brigatinib metabolism: elucidation of bioactivation pathways

Brigatinib (BGB) is a newly approved anaplastic lymphoma kinase (ALK) inhibitor. On April 28, 2017, BGB was approved by the U.S. FDA for the treatment of metastatic anaplastic lymphoma kinase-positive non-small cell lung cancer. The toxicity profile of BGB includes nausea, fatigue, diarrhea, elevated lipase, dyspnoea, hypertension, hypoxia, pneumonia, elevated amylase, pulmonary embolism, elevated ALT, hyponatraemia and hypophosphatemia. Using LC-MS/MS, we investigated the in vitro phase I metabolism of for BGB in rat liver microsomes (RLMs). In the in vitro metabolism of BGB, iminium reactive intermediates were trapped by potassium cyanide forming a stable complex that can be characterized by LC-MS/MS. Four BGB in vitro phase I metabolites were identified. In vitro phase I metabolic pathways were N-dealkylation, α hydroxylation and α oxidation. Additionally, three iminium reactive metabolites were found and the bioactivation mechanisms were proposed. A piperidine ring was found to be responsible for BGB bioactivation. The presence of these three reactive metabolites may be the main reason for BGB side effects. A literature review showed no previous article reported the in vitro phase I metabolism study of BGB or structural identification of the formed reactive metabolites.

Four phase I BGB metabolites and three cyano adducts for BGB were detected using LC-MS/MS. The piperidine ring was found to be responsible for BGB bioactivation and the bioactivation pathways are proposed.     

Respiratory oxygen uptake is associated with survival in a cohort of ventilated trauma and burn patients

Background

Little data is available in the literature about the role of end tidal oxygen in critically ill patients. We sought to identify the association between the level of respiratory oxygen and clinical outcomes in critically-ill ventilated trauma and burn patients.

Evaluation of Ozone Application in Dental Unit Water Lines Contaminated with Pathogenic Acanthamoeba

Background: In this study morphological and molecular characterization of Acanthamoeba strains, isolated from dental unit waterlines (DUWLs) were surveyed and the levels of disinfection achievable in vitro by the application of ozone disinfectant to DUWLs were evaluate. Methods: Water samples were collected from air-water syringes, cup fillers and tap water before and at the end of the working day. They were cultured on non-nutrient agar (NNA) plates. Species identification was carried out with a PCR assay based on sequence analysis of the 18S rRNA gene. The cellular response to ozone was tested on Acanthamoeba cyst with different doses at different contact time in vitro twice. Results: Prevalence rates for Acanthamoeba contamination were 100, 100 and 72% for air-water syringes, cup fillers and tap water, respectively. The morphological analysis revealed the presence of A. castellanii, A. griffin, A. hatchitti and A. lenticulata. Phylogenetic analysis of the sequences showed the four strains to be closely related to a sequence type (T3, T4, T5 and T11). Acanthamoeba cells were stained with trypan blue, which revealed killed of Acanthamoeba instantaneously after 10 minutes in ozonized water. There was no growth of Acanthamoeba occurred after ozone treatment in water bottles for 5 minutes with a flow rate of 500 mg/hour. Conclusion : Ozone can play an important role in controlling the problem of contamination of DUWLs as a potent disinfectant.Key Words: Acanthamoeba spp., Dental units water lines, PCR, Ozone     

Optical characteristics of contemporary dental composite resin materials

Objectives

Optical and physical properties of dental restorative composite materials are affected by composition. Basic optical absorption and scattering properties have been derived through the use of a corrected reflectance model, but practical and important optical properties are not easily derived from these basic spectral characteristics. The purposes of this study are to derive and compare colour and translucency characteristics of two cured contemporary nanohybrid composites being marketed as universal composites, and to evaluate colour difference between each composite material and published shade guide data.

Methods

Previously derived optical scattering and absorption coefficients for five diverse shades of these composite materials were used to calculate the CIE colour parameters of L*, a* and b* at infinite thickness under various illuminants and to derive ideal translucency parameters at various thicknesses using two colour difference formulae.

Results

Differences were found in the inherent colour parameters and in the translucency parameters between the brands for some of the shades studied. The colour differences of the inherent colours from published shade guide data were always higher than the perceptibility limit, and often higher than the acceptability limit.

Conclusions

Inherent colours and ideal translucency parameters may be calculated from optical coefficients for a variety of illuminants. Different inherent colour parameters of composite materials marked for the same shade indicate the influence of compositional differences between these materials.

Clinical significance

Since patients are seen under various illuminations, the ability to assess appearance matching characteristics under diverse illuminants will help assure an optimum match for the patient.