Analysis of colorectal cancer‐related mutations by liquid biopsy: Utility of circulating cell‐free DNA and circulating tumor cells

We recruited 56 colorectal cancer patients and compared the mutational spectrum of tumor tissue DNA, circulating cell‐free DNA (ccfDNA) and circulating tumor cell (CTC) DNA (ctcDNA) to evaluate the potential of liquid biopsy to detect heterogeneity of cancer. Tumor tissue DNA, ccfDNA, and ctcDNA were extracted from each patient and analyzed using next‐generation sequencing (NGS) and digital PCR. To maximize yields of CTC, three antibodies were used in the capture process. From 34 untreated patients, 53 mutations were detected in tumor tissue DNA using NGS. Forty‐seven mutations were detected in ccfDNA, including 20 not detected in tissues. Sixteen mutations were detected in ctcDNA, including five not detected in tissues. In 12 patients (35.3%), mutations not found in tumor tissues were detected by liquid biopsy: nine (26.5%) in ccfDNA only and three (8.8%) in ctcDNA only. Combination analysis of the two liquid biopsy samples increased the sensitivity to detect heterogeneity. From 22 stage IV patients with RAS mutations in their primary tumors, RAS mutations were detected in 14 (63.6%) ccfDNA and in eight (36.4%) ctcDNA using digital PCR. Mutations not detected in primary tumors can be identified in ccfDNA and in ctcDNA, indicating the potential of liquid biopsy in complementing gene analysis. Combination analysis improves sensitivity. Sensitivity to detect cancer‐specific mutations is higher in ccfDNA compared with ctcDNA.     

The clinical characteristics of Acinetobacter bacteremia differ among genomospecies: A hospital-based retrospective comparative analysis of genotypically identified strains

Background/purposeAcinetobacter is an aerobic, gram-negative coccobacillus, which causes nosocomial infections including bacteremia. Recent development of molecular techniques has made classification of the Acinetobacter genomospecies possible, but there are still only a few studies comparing clinical features of the subspecies. We investigated bacteremia caused by Acinetobacter, isolated subspecies, and compared clinical features for each group.MethodsA retrospective analysis of Acinetobacter bacteremia cases was made in a 900-bed hospital in Japan. In addition to conventional procedures, subspecies identification based on rpoB sequence was made, and comparison of clinical characteristics between each subspecies were analyzed.ResultsWe collected 35 cases (Acinetobacter baumannii 14, A. nosocomialis 12, Acinetobacter ursingii 6, and A. seifertii 3). All of the A. seifertii bacteremia cases were blood stream infection occurring in cerebrovascular disease patients, showing particularly higher incidence of shock (100%) and high Pitt bacteremia score (PBS) (6.33 ± 2.52) in comparison to A. baumannii (43% and 2.86 ± 2.25, respectively). Sequential Organ Failure Assessment (SOFA) score and the PBS were slightly higher in A. nosocomialis in comparison to A. baumannii, and the 7 day mortality rate was higher in A. nosocomialis (25%) than in A. baumannii (7%), though this difference was not found to be significant.ConclusionsA.seifertii, the recently defined novel species, showed distinctive clinical features of bacteremia. And, in contrast to previous studies, the severity of A. nosocomialis infection was not lower than that of A. baumannii, which might suggest the influence of local epidemiology. Further characterization of these subspecies should be continued.     

Application of CT imaging for dental implant simulation

Accurate diagnosis and exact treatment planning are very important for successful implant treatment. Pretreatment examination and simulations using CT can be especially effective information sources, and diagnosis by CT imaging before treatment substantially enhances the security and safety of the treatment plan. New interactive CT software (SIM/Plant) which enables diagnosis of bone morphology and quality, and also implant simulation on a personal computer through multiplanar reformation of CT images, has been developed. Stereolithography models (SLMs) are reproduced anatomical morphological models of an individual patient's bone structure from the information obtained by the CT scan, and is fabricated out of light cure resin. In this article, SLMs and SIM/Plant for simulation of various examinations and diagnosis incorporating CT information are described, and their features are introduced.     

A case of undifferentiated carcinoma arising in the mandible

A case of undifferentiated carcinoma arising in the minor salivary gland is reported. Preoperative chemotherapy, surgery and postoperative immunotherapy were performed and good results were obtained for 15 months after surgery. However, metastasis to the lung occurred 18 months after surgery. The histologic diagnosis, clinical findings and origin of this tumor are discussed.     

Effect of serotonin (5-HT) on trigeminal rhythmic activities generated in in vitro brainstem block preparations

We used rat isolated brainstem block preparations to analyze the functional roles of serotonin receptors in the generation of trigeminal rhythmic activities. We previously reported that trigeminal rhythmic activities could be induced by some pharmacological applications in an isolated brainstem preparation with a rostral boundary at the border between the inferior and superior colliculus, and a caudal border at the level of the rostral facial nucleus. However, the same stimulation did not induce trigeminal rhythmic activities in a whole brainstem block preparation with the same rostral boundary and a caudal border at the obex level. In the present study, both the 5-HT(1A) phthalimido-butyl-piperazine, and the 5-HT(2C) agonist, 1-2,5-dimethoxy-4-iodophenyl-2-aminopropane, combined with N-methyl-D,L-aspartate and bicuculline, elicited trigeminal rhythmic activities in a whole brainstem block preparation. Our results suggest that serotonin has both facilitation and inhibition effects on the generation of trigeminal rhythmic activities in an isolated brainstem block preparation in vitro.     

Depth of cure and hardness of an indirect composite polymerized with three laboratory curing units

This study determined the hardness and curing depth of a light-activated indirect composite polymerized with three laboratory light-polymerizing units for the purpose of comparing the curing performance of the three units. A light-activated composite material for indirect application (Vita Zeta) was polymerized with three light-polymerizing units equipped with the following light sources: 1) one halogen lamp and two fluorescent lamps (alpha-Light II); 2) three halogen lamps (Twinkle HLG); and 3) one metal halide lamp (Twinkle LI). Knoop hardness and curing depth were determined for groups of five specimens using standardized testing methods. The results were compared using analysis of variance (ANOVA) and Scheffé's S intervals (alpha = 0.05). The Knoop hardness number (KHN) generated with the halogen-fluorescent unit (12.5 KHN) was significantly (P < 0.05) lower than those produced by the halogen unit (13.9 KHN) and the metal halide unit (14.2 KHN). Of the three units, the halogen-fluorescent unit exhibited the lowest depth of cure. Both the hardness and curing depth of the composite were influenced by the laboratory polymerizing units employed.