Aggregatibacter actinomycetemcomitans has emerged as one of the aetiological agents in periodontal disease. Although Type IV secretion systems (T4SSs) are widely distributed in many bacteria, the ...genetic features and distribution of T4SSs in A. actinomycetemcomitans remain unclear. In this study, we investigated the prevalence of A. actinomycetemcomitans serotypes and their T4SSs in a Taiwanese population.
A comparative analysis of 20 A. actinomycetemcomitans genomes and their T4SSs deposited in GenBank was performed. One hundred subjects, including 20 periodontitis and 80 normal subjects, were enrolled and PCR identification of A. actinomycetemcomitans serotypes and T4SS genes were performed.
Of 100 subjects, serotypes C (22%) and E (11%) were most common. In addition, T4SSs were distributed in all of the serotypes. The prevalence of T4SSs and their location in plasmids in periodontitis subjects were 1.28–2 fold higher but not significantly different compared to normal subjects. Of 20 A. actinomycetemcomitans genomes, only ten with complete T4SS modules could be detected, which was highly correlated with localized aggressive periodontitis (p < 0.1). Nine of ten T4SS modules were from periodontitis subjects. Phylogenetic analysis of 10 T4SSs in A. actinomycetemcomitans showed that they were clustered into two groups, T4SSAaI and T4SSAaII, with only T4SSAaI appearing in the Taiwanese subjects.
A. actinomycetemcomitans strains with different serotypes carrying T4SSAaI are widely distributed in a Taiwanese population. This is the first report to show the distribution and detailed comparative genomics of T4SSs in A. actinomycetemcomitans.
Mandibular defects involving the central segment are challenging. This study analyzes the impact of defect extent and reconstruction method on quality of life (QOL) and obstructive sleep apnea (OSA).
...Twenty-nine ameloblastoma patients received segmental mandibulectomy involving the C-segment and immediate fibula free flap reconstruction were recruited. Defects: (C: 2, LC: 11, LCL: 19). Mean defect length: 8.79 cm (± 2.34). Inset: Low-single-barrel (n: 19), with secondary distraction osteogenesis (n: 8/19), high-single-barrel (n: 7), double barrel (n: 3). Patients were surveyed using University of Washington Quality of Life (UW-QOL) and Berlin risk of postoperative sleep apnea questionnaires.
Flap failure: None. Mean follow-up: 109.6 ± 92.8 months. UW-QOL: Physical function 91.83 (± 14.92); social function 90.17 (± 17.19). No statistical difference between C, LC, and LCL was found, but C group which received low-single-barrel had the lowest score in appearance and chewing domains. In health-related QOL (HR-QOL) compared with 1 month before cancer, 69% reported best results. “Appearance” was the most important issue for the past 7 days, followed by “Chewing,” prevailing in LC and C groups that predominately reconstructed by low-single-barrel. Berlin score: 7 patients (4 LCL, 3 LC≥8 cm) were at high risk for postoperative OSA.
“Like-with-like” reconstruction with immediate endosteal dental implants yields the best results. Inset of fibula bone could affect outcomes, favoring double-barrel or single-high-barrel inset. Appearance and chewing remain the main concerns, largely, in those with low-single-barrel inset and no dental restoration. After long/extensive LCL and LC mandibulectomies, postoperative OSA warrants further investigation, and modification of resection/reconstruction techniques.
Even with multidisciplinary treatment, the prognosis and quality of life of patients diagnosed with head and neck squamous cell carcinoma (HNSCC) are still not satisfactory. Previously, ...19-Nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3 (MART-10), the new brand 1α,25(OH)2D3 analog, has been demonstrated to be an effective drug to inhibit HNSCC growth in vitro. Since most cancer patients die of metastasis, in this study, the antimetastatic effect of MART-10 on HNSCC was investigated. Our results reveal that both 1α,25(OH)2D3 and MART-10 effectively repressed the migration and invasion of HNSCC cells, with MART-10 being much more potent than 1α,25(OH)2D3. The antimetastatic effect of 1α,25(OH)2D3 and MART-10 was mediated by attenuation of epithelial-mesenchymal transition (EMT), which was supported by the finding that the expression of EMT-inducing transcriptional factors, Sail and Twist, was inhibited by 1α,25(OH)2D3 and MART-10. The upregulation of E-cadherin and downregulation of N-cadherin in FaDu cells induced by both drugs further confirmed the repression of EMT. In addition, 1α,25(OH)2D3 and MART-10 treatment inhibited intracellular MMP-9 expression and extracellular MMP activity in FaDu cells. Collectively, our results suggest that the less-calcemia 1α,25(OH)2D3 analog, MART-10, is a promising drug for HNSCC treatment. Further clinical studies are warranted.
The optimal management after the resection of mandibular ameloblastoma has been very challenging to surgeons. The aim of this study is to evaluate the functional, aesthetic, and quality of life ...outcomes of patients who had a segmental mandibular resection and immediate reconstruction with or without osseointegrated implants.
Patients' demographics, tumor characteristics, treatment, and complications were retrieved. Patients were divided into two groups: dental rehabilitated vs. nondental rehabilitated depending on the placement of osseointegrated implants followed by an implanted-retained prosthesis. Functional outcomes and quality of life were assessed using the Performance Status Scale, the University of Washington Quality of Life (UW-QOL) scale, and the 14-item Oral Health Impact Profile (OHIP-14). Aesthetic outcome was evaluated by patients using a Visual Analog Scale.
Thirty-four patients were reviewed. Twenty-two patients were included in the dental rehabilitated group and 12 in the nondental rehabilitated group. No recurrence of the tumor was found during the average follow-up period of 7.4 years. Although both groups reported a similar satisfaction in appearance, patients in the dental rehabilitated group scored significantly higher in masticatory function and “eating in public” (p < 0.01). There were significant differences (p < 0.05) regarding “chewing,” “activity,” and “anxiety” when assessed using the UW-QOL scale. Indeed, patients in the dental rehabilitated group showed a definitively better outcome in “physical disability” and “psychological discomfort” dimensions when assessed using the OHIP-14.
Vascularized bone graft reconstruction followed by immediate or delayed placement of osseointegrated implants showed as an ideal and predictable treatment modality for patients with ameloblastoma. The results suggested that patients with osseointegrated implants had a significantly better masticatory function, improved quality of life, and less psychological consequences.
In this work the hydrodynamic characteristics and distribution of flow in two cross-corrugated channels of plate heat exchangers have been investigated. A three-dimensional model with the real-size ...geometry of the two cross-corrugated channels provided by chevron plates and taking into account the inlet and outlet ports has been conducted for the numerical study. The numerical results have been validated with the measurements taken by laboratory experiments. The local flow characteristics around the contact points have been discussed. The velocity, pressure and flow distribution of the fluid among the two channels of the plate heat exchanger have also been presented.
The free fibula osteoseptocutaneous flap remains the first choice for segmental mandible and contiguous soft-tissue defect reconstructions in most situations.
Several important principles are ...described that should be respected during skin paddle design: fibula contouring, insetting, and fixation, and dental implant osseointegration. Recent advancements that address difficulties in height contouring, particularly at the anterior segment, are highlighted.
The presented methods can help provide an optimal mandibular reconstruction that restores mechanical functions, facial aesthetics, and complete dental competence.
Efficient interdisciplinary communication and teamwork are necessary throughout the longitudinal care of the patient if optimal results are to be achieved.
•NCCN maintains that END should be considered for cT1-2N0M0 OCSCC with a DOI > 3 mm.•DOI > 2.5 mm and poor differentiation predict adverse outcomes in cT1N0M0 OCSCC.•The decision to perform END ...should be guided by DOI and tumor differentiation.•This strategy allows avoiding END in 48.6% of patients, without compromising outcomes.
According to the NCCN guidelines, there is weak evidence to support the use of elective neck dissection (END) in early-stage oral cavity squamous cell carcinoma (OCSCC). We sought to examine the indications for END in patients with cT1N0M0 OCSCC defined according to the AJCC Staging Manual, Eight Edition.
Of the 3886 patients diagnosed with cT1N0M0 included in the study, 2065 underwent END and 1821 neck observation.
The 5-year outcomes for patients who received END versus neck observation before and after propensity score matching (n = 1406 each) were as follows: neck control, 96 %/90 % (before matching), p < 0.0001; 96 %/90 % (after matching), p < 0.0001; disease-specific survival (DSS), 93 %/92 % (before matching), p = 0.0227; 93 %/92 % (after matching), p = 0.1436. Multivariable analyses revealed that neck observation, depth of invasion (DOI) > 2.5 mm, and poor differentiation were independent risk factors for 5-year outcomes. Upon the application of a scoring system ranging from 0 (no risk factor) to 3 (presence of the three risk factors), the following 5-year rates were observed: neck control, 98 %/95 %/84 %/85 %; DSS, 96 %/93 %/88 %/85 %; and overall survival, 90 %/86 %/79 %/59 %, respectively (all p < 0.0001). The survival outcomes of patients with scores of 0 and 1 were similar. The occult metastasis rates in the entire study cohort, DOI > 2.5 mm, and poor differentiation were 6.8 %/9.2 %/17.1 %, respectively.
Because all patients who received neck observation had a score of 1 or higher, END should be performed when a DOI > 2.5 mm or poorly differentiated tumors are present. Under these circumstances, 48.6 % (1888/3886) of cT1N0M0 patients may avoid END without compromising oncological outcomes.
Molecular methods for predicting prognosis in patients with oral cavity squamous cell carcinoma (OSCC) are urgently needed, considering its high recurrence rate and tendency for metastasis. The ...present study investigated the genetic basis of variations in gene expression associated with poor prognosis in OSCC using Affymetrix SNP 6.0 and Affymetrix GeneChip Human Gene 1.0 ST arrays. We identified recurrent DNA amplifications scattered from 8q22.2 to 8q24.3 in 112 OSCC specimens. These amplicons demonstrated significant associations with increased incidence of extracapsular spread, development of second primary malignancies, and poor survival. Fluorescence in situ hybridization, in a validation panel consisting of 295 cases, confirmed these associations. Assessment of the effects of copy number variations (CNVs) on genome-wide variations in gene expression identified a total of 85 CNV-associated transcripts enriched in the MYC-centered regulatory network. Twenty-four transcripts associated with increased risk of second primary malignancies, tumor relapse, and poor survival. Besides MYC itself, a novel dysregulated MYC module plays a key role in OSCC carcinogenesis. This study identified a candidate molecular signature associated with poor prognosis in OSCC patients, which may ultimately facilitate patient-tailored selection of therapeutic strategies.
► Numerical and experimental study of the fuel cell with spiral channels is performed. ► Secondary vortices in cross section of the spiral channels are found. ► Enhancement in the performance of the ...fuel cell by the secondary vortices is discussed. ► The spiral channels also lead to a reduction in the pressure drop of the gas flow.
Numerical simulation of the performance of a proton exchange membrane fuel cell (PEMFC) with spiral channels is performed in this study. Experiments are also conducted to verify the numerical predictions. The spiral channel pattern produces secondary vortices which lead to enhancement in heat and mass transfer in the curved channels and appreciably improves the performance of the fuel cell. In addition, the spiral channels may also lead to a reduction in the pressure drop of the gas flow through the fuel cell. When the sizes of the outlet channels are designed to be smaller than those of the inlet channels, water flooding in the catalyst layers can be further improved. In the present study, the spiral channel pattern consists of five inlet channels and five outlet channels. Radius and area of the active zone are 28.2mm and 2500mm2, respectively. A comparison between the spiral and the serpentine channels shows that the average current density with the former is higher than that with the latter by 11.9%. It is found that numerical predictions are in close agreement with the experimental results.
•Several studies indicated that margins < 1 mm should be classified as positive margins in OCSCC.•Margin < 1 mm exhibited distinct clinicopathological characteristics and a more favorable ...prognosis.•Positive margins should remain a high risk factor, whereas margins < 1 mm could be considered an intermediate risk factor.
While several studies have indicated that a margin status of < 1 mm should be classified as a positive margin in oral cavity squamous cell carcinoma (OCSCC), there is a lack of extensive cohort studies comparing the clinical outcomes between patients with positive margins and margins < 1 mm.
Between 2011 and 2020, we identified 18,416 Taiwanese OCSCC patients who underwent tumor resection and neck dissection. Of these, 311 had margins < 1 mm and 1013 had positive margins. To compare patients with margins < 1 mm and those with positive margins, a propensity score (PS)-matched analysis (n = 253 in each group) was conducted.
The group with margins < 1 mm displayed a notably higher prevalence of several variables: 1) tongue subsite, 2) younger age, 3) smaller depth of invasion), 4) early tumor stage, and 5) treatment with surgery alone. Patients with margins < 1 mm demonstrated significantly better disease-specific survival (DSS) and overall survival (OS) rates compared to those with positive margins (74 % versus 53 %, 65 % versus 43 %, both p < 0.0001). Multivariable analysis further confirmed that positive margins were an independent predictor of worse 5-year DSS (hazard ratio HR = 1.38, p = 0.0103) and OS (HR = 1.28, p = 0.0222). In the PS-matched cohort, the 5-year outcomes for patients with margins < 1 mm compared to positive margins were as follows: DSS, 71 % versus 59 %, respectively (p = 0.0127) and OS, 60 % versus 48 %, respectively (p = 0.0398).
OCSCC patients with a margin status < 1 mm exhibited distinct clinicopathological characteristics and a more favorable prognosis compared to those with positive resection margins.
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