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Min Wu,* Qi-man Shi,* Sai-Li Duan, Deng-jie Ou-yang, Pei Chen, Biao Tu, Peng Huang Department of General Surgery, Xiangya Hospital Central South University, Changsha, Hunan, 410008, People’s Republic of China*These authors contributed equally to this workCorrespondence: Peng Huang, Email xiangyahp@csu.edu.cnPurpose: Glutamine and serine rich 1 (QSER1), as a DNA methylation modulator, play a crucial role in transforming tumor cells. Previous studies have shown that QSER1 plays a role in regulating the progression of various malignancies and that QSER1 dysfunction is connected with precancerous lesions of hepatocellular carcinoma (HCC) as well as HCC prognosis. However, little is known about the detailed contribution of QSER1 in HCC.Patients and Methods: Various statistical methods such as Kaplan–Meier method, AUC analysis, GSEA, and immune-infiltration analysis were used to evaluate the relationship between QSER1 expression and clinical features, prognostic factors, and potential functional mechanisms of QSER1.Results: QSER1 expression was negatively correlated with clinicopathological features (clinical stage, pathological grade, TP53 mutation, lymph node metastasis) and clinical outcome (overall survival versus recurrence). Functional enrichment analysis further suggested that QSER1 is involved in multiple pathways related to DNA replication and tumor immunity. TIMER analysis indicated that high QSER1 expression was significantly associated with higher macrophage infiltration and poorer macrophage-related outcomes. In particular, QSER1 was significantly more associated with M2 macrophages than M1 macrophages.Conclusion: Overall, elevated QSER1 is a potential prognostic marker for HCC and is associated with immune infiltration in HCC.Keywords: HCC, QSER1, prognosis, immune infiltration

Gui-you Li,1 Hai-long Tan,1 Pei Chen,1 Hui-Yu Hu,1 Mian Liu,1 Deng-jie Ou-yang,1 Rooh-afza Khushbu,1 Deepak Pun,1 Jin-dong Li,1 Zhi-peng Zhang,2 Qiong Yang,1 Peng Huang,1 Shi Chang1 1Department of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China; 2Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of ChinaCorrespondence: Peng Huang; Shi ChangDepartment of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of ChinaTel +86 15273124136; +86 13973192319Email xiangyahp@csu.edu.cn; changshi@csu.edu.cnBackground: Therapeutic lateral neck dissection (LND) is recommended in papillary thyroid carcinoma (PTC) patients with clinically lateral lymph node metastasis (LLNM), whether underwent level V LND remains controversial for lacking of sensitive predicting system. BRAFV600E mutation is associated with aggressive tumor behavior, recurrence, and disease-specific mortality of PTC. However, the relationship between BRAFV600E mutation and level V LNM is unclear.Methods: Univariate and multivariate analyses were retrospectively conducted on the potential predictive factors of 252 PTC patients who underwent initial treatment of neck lymph node dissection from September 2015 to October 2018 in our institute. BRAFV600E mutation and the clinicopathological characteristics of the two groups were compared.Results: LLNM was presented in 208 (82.5%) patients and level II–V LNM was present in 42.8%, 71.2%, 85.1%, 17.8% patients, respectively. BRAFV600E mutation was observed in 188 (74.6%) patients and was significantly associated with patients’ age, lymphocytic thyroiditis, capsule invasion, bilateral central lymph node metastasis (CLNM) and level V LNM in PTC. Univariate analysis revealed that lymphocytic thyroiditis, tumor size, number of CLNM, Level II LNM, Level III LNM, simultaneous Level II+III, simultaneous Level III+IV and simultaneous Level II+III+IV were significantly correlated with Level V LNM. In addition, multivariate analysis revealed that tumor size ≥ 2.5 cm, number of CLNM≥ 3, level II metastases and BRAFV600E mutation were independent Level V LNM predictors (odds ratio 3.910, 3.660, 8.410, 0.439; 95% CI 1.737– 10.135, 1.054– 12.713, 1.233– 57.355, 0.280– 0.827, respectively).Conclusion: In summary, we presented several independent predictive factors for level V LNM in PTC patients. We constructed a risk prediction model consisting of tumor size ≥ 2.5 cm, number of CLNM≥ 3 and level II metastases and BRAFV600E mutation that may guide surgeons to evaluate the nodal status in PTC and perform tailored therapeutic LND.Keywords: papillary thyroid carcinoma, BRAFV600E mutation, level V lymph nodes metastasis, pathological features

Qiong Yang,1 Pei Chen,1 Hui-Yu Hu,1 Hai-long Tan,1 Gui-you Li,1 Mian Liu,1 Deng-jie Ou-yang,1 Rooh-afza Khushbu,1 Deepak Pun,1 Zhi-peng Zhang,2 Peng Huang,1 Shi Chang1 1Department of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China; 2Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of ChinaCorrespondence: Peng Huang; Shi ChangDepartment of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of ChinaTel +86 15273124136Email xiangyahp@csu.edu.cn; changshi@csu.edu.cnBackground: Cervical lymph node metastasis (LNM) is an independent risk factor for poor prognosis of papillary thyroid carcinoma (PTC), but the scope of PTC lateral neck dissection (LND) is controversial. Solitary lateral lymph node metastasis (SLNM) is a special type of PTC with lateral LNM. Currently, study on the preoperative clinical characteristics of SLNM has been seldomly reported. This study evaluated the preoperative characteristics for predicting the SLNM of PTC.Methods: We included 391 patients diagnosed with PTC between May 2011 and July 2017. Among those patients, 44 had SLNM and 347 had multiple lateral neck node metastasis (MLNM). The clinicopathologic characteristics and other central lymph node metastasis risk factors were retrospectively analyzed.Results: Univariate analysis revealed that age and tumor size (≤ 1 cm) were significantly correlated with SLNM. In ROC curve analysis, the optimal cutoff age of preoperative predictors for the prediction of SLNM was 46.5 years (AUC=0.623, 0.536– 0.710). Besides, the frequency and mean number of CLNM was significantly less in the SLNM than MLNM group. The oval and round tumor shape and well-defined margin of the tumor were more common in the SLNM group (p =0.001; p=0.024, respectively). In addition, multivariate analysis revealed that age ≥ 47, capsular invasion, no extrathyroidal extension, with central lymph node metastases and irregular shape were independent SLNM predictors of PTCs (odds ratio 2.386, 0.173, 0.284, 0.239, 0.188; 95% CI 1.07– 5.140, 0.058– 0.840, 0.066– 0.926, 0.091– 0.437, 0.167– 0.864, respectively).Conclusion: This study supported that SLNM is more likely to happen in PTC patients with age ≥ 47 years, capsular invasion, no extrathyroidal extension, with central lymph node metastases and irregular shape. That denotes, selective single level neck dissection can be considered as an alternative to systemic lateral neck dissection in those patients.Keywords: solitary lateral lymph node metastasis, papillary thyroid carcinoma, central lymph node dissection

Shu-Wei Chen,1–3,* Quan Zhang,1–3,* Zhu-Ming Guo,1–3 Wen-Kuan Chen,1–3 Wei-Wei Liu,1–3 Yan-Feng Chen,1–3 Qiu-Li Li,1–3 Xue-Kui Liu,1–3 Hao Li,1–3 Dian Ou-Yang,1–3 Wei-Chao Chen,1–3 Xiao-Yan Fu,1–3 Xi-Di Wang,1–3 An-Kui Yang,1–3 Jin-Xin Bei,2–4 Ming Song1–3 1Department of Head and Neck Surgery, Sun Yat-sen University Cancer Center, 2State Key Laboratory of Oncology in South China, 3Collaborative Innovation Center of Cancer Medicine, 4Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China *These authors contributed equally to this work Background: Global data demonstrate minimal improvement in the survival rate for oral cavity cancer (OCC) patients. We wished to know whether or not clinical features and survival rate have changed over time for OCC patients receiving initial treatment and follow-up at a large cancer center in China. Methods: Clinical features and survival data were collected on patients diagnosed during the successive decades of 1960–1969 (n=253), 1970–1979 (n=497), 1980–1989 (n= 659), 1990–1999 (n=793), and 2000–2009 (n=1,160) at the Sun Yat-sen University Cancer Center. Results: Over time, the overall 5-year survival rate for OCC patients was 52.0%. According to tumor localization, this rate was 71.4% for lip cancer, 56.3% for oral tongue cancer, and 42.7% for other parts of the oral cavity. From the 1960s to the 2000s, the 5-year survival rate steadily improved from 47.8% to 55.6% (P

» We aimed to determine the cost-effectiveness of different protocols of extended postoperative antibiotic prophylaxis (E-PAP) following adult spinal surgery., » Both stratified (randomized controlled trials only) and nonstratified (all studies) analyses demonstrated that E-PAP has no significant value in reducing the rate of surgical site infection (SSI), deep SSI, or superficial SSI., » Notably, the E-PAP protocols were associated with a significant increase in the length of hospital stay, resulting in an additional expenditure of $244.4 per episode for the E-PAP 72 hours protocol compared with PAP 24 hours and $309.8 per episode for the E-PAP >48 hours protocol compared with PAP <48 hours., » E-PAP does not demonstrate any significant reduction in the rate of SSIs following spine surgery. However, these extended protocols were significantly associated with an increase in the length of hospital stay and higher overall projected costs., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSREV/B136)., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: For patients with complete breast resection, conventional contrast-enhanced T1-weighted imaging (CE-T1WI) with frequency-selective spectral attenuated inversion recovery (SPAIR) provides limited fat suppression on the postoperative side due to the uneven skin surface, inhomogeneous tissue environment, and frequency-selective feature of the SPAIR scheme, leading to difficulties in precise diagnosis. This study aimed to investigate the image quality and performance of the Dixon method compared with SPAIR in breast high-resolution CE-T1WI for mastectomy patients., Materials and Methods: Sixty female patients who had not performed any breast surgeries were randomly selected retrospectively as the control group. Postmastectomy female patients were enrolled to undergone high-resolution CE-T1WI with SPAIR and Dixon breast scans. Subjective scores were rated using a 5-point scale. Objective parameters, including contrast-to-noise ratio (CNR), edge sharpness, and signal uniformity were measured and calculated. The Wilcoxon rank-sum test and Kappa statistic were used., Results: A total of 114 consecutive postmastectomy patients were included. Subjective scores of T1WI-SPAIR in the control group were all significantly better than those with SPAIR on the postoperative side of mastectomy patients (P < 0.01). Dixon outperformed SPAIR with significantly better subjective scores in regards to uniformity and degree of fat-suppression, anatomical structures depiction, lesion conspicuity, and axillary visibility (p < 0.05) in both post- and non-operative sides and bilateral axillary areas through the paired comparison. The objective parameters of Dixon were significantly better than those of SPAIR., Conclusion: The Dixon method provided better image uniformity and higher fat suppression efficiency, and showed significant advantages in delineating the anatomical structures, with better axillary and lesion visibilities, especially on the completely removed breast side., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. All authors have completed the ICMJE uniform disclosure form. Peng Sun, Jia-zheng Wang are employees of Philips Healthcare. The other authors have no conflicts of interest to declare., (Copyright © 2023. Published by Elsevier Inc.)

The treatment of spinal infections is not well defined, and a cursory review of the literature can lead to conflicting treatment strategies. To add to the complexity, infections can include primary infection of the spine, infection secondary to another primary source, and postoperative infections including epidural abscesses, discitis, osteomyelitis, paraspinal soft-tissue infections, or any combination. Furthermore, differing opinions often exist within the medical and surgical communities regarding the outcomes and effectiveness of varying treatment strategies. Given the paucity of defined treatment protocols and long-term follow-up, it is important to develop multidisciplinary treatment teams and treatment strategies. This, along with defined protocols for the treatment of varying infections, can provide the data needed for improved treatment of spinal infections.

Circular RNAs have been extensively studied in eukaryotes, but their presence and/or biological functionality in bacteria are unclear. Here, we show that a regulatory noncoding RNA (DucS) exists in both linear and circular conformation in Bacillus altitudinis. The linear forms promote B. altitudinis tolerance to H 2 O 2 stress, partly through increased translation of a stress-responsive gene, htrA. The 3' end sequences of the linear forms are crucial for RNA circularization, and formation of circular forms can decrease the levels of the regulatory linear cognates. Bioinformatic analysis of available RNA-seq datasets from 30 bacterial species revealed multiple circular RNA candidates, distinct from DucS, for all the examined species. Experiments testing for the presence of selected circular RNA candidates in four species successfully validated 7 out of 9 candidates from B. altitudinis and 4 out of 5 candidates from Bacillus paralicheniformis; However, none of the candidates tested for Bacillus subtilis and Escherichia coli were detected. Our work identifies a dual-conformation regulatory RNA in B. altitutidinis, and indicates that circular RNAs exist in diverse bacteria. However, circularization of specific RNAs does not seem to be conserved across species, and the circularization mechanisms and biological functionality of the circular forms remain unclear., (© 2023. Springer Nature Limited.)

The treatment of waste-gas containing chlorinated volatile organic compounds (CVOCs) has become a difficult issue in current air pollution control. Biotrickling filters (BTFs) have been recognized to be applicable for the treatment of CVOCs, but research on the biodegradation of binary gaseous CVOCs is rare. Herein, a BTF inoculated with Methylobacterium (M.) rhodesianum H13, Starkeya sp. T-2 and activated sludge was established to investigate the biodegradation of the gaseous dichloromethane (DCM) and 1,2-dichloroethane (1,2-DCE) and their interactions implicated. The bioaugmented BTF showed a faster startup (13 days), better removal efficiencies of DCM (80%) and 1,2-DCE (72%), and superior mineralization (65.9%) than that inoculated with activated sludge alone. The ECs of DCM and 1,2-DCE were positively related with the inlet load when the total inlet load was <50 g m -3  h -1 . However, inlet loads higher than 50 g m -3  h -1 led to dramatic drop of the RE of DCM and 1,2-DCE due to the limitation of the degradation capacity of microorganisms and the toxic effect of high-concentration substrates. Besides, BTF could stand a lower shock load of 400 mg m -3 , while higher shock loads would deteriorate the RE of DCM and 1,2-DCE. And BTF showed better impact resistance toward DCM than 1,2-DCE, probably because the 1,2-DCE biodegrading bacteria was more sensitive to the concentration change. For the same reason, the removal recovery of DCM after starvation was quicker than 1,2-DCE. Kinetic interactions were quantified by the EC-SKIP model, results of which revealed that DCM cast negative effect on 1,2-DCE biodegradation, while 1,2-DCE could promote DCM biodegradation. Moreover, both the results of real-time PCR and high-throughput sequencing showed M. rhodesianum H13 had stronger competitiveness and adaptability than Starkeya sp. T-2. The survived M. rhodesianum H13 and Starkeya sp. T-2 after starvation robustly demonstrated the success of bioaugmentation as well as its great potential of engineering application., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

A growing number of works have proved that microRNAs (miRNAs) are a crucial biomarker in diverse bioprocesses affecting various diseases. As a good complement to high-cost wet experiment-based methods, numerous computational prediction methods have sprung up. However, there are still challenges that exist in making effective use of high false-negative associations and multi-source information for finding the potential associations. In this work, we develop an end-to-end computational framework, called MHDMF, which integrates the multi-source information on a heterogeneous network to discover latent disease-miRNA associations. Since high false-negative exist in the miRNA-disease associations, MHDMF utilizes the multi-source Graph Convolutional Network (GCN) to correct the false-negative association by reformulating the miRNA-disease association score matrix. The score matrix reformulation is based on different similarity profiles and known associations between miRNAs, genes, and diseases. Then, MHDMF employs Deep Matrix Factorization (DMF) to predict the miRNA-disease associations based on reformulated miRNA-disease association score matrix. The experimental results show that the proposed framework outperforms highly related comparison methods by a large margin on tasks of miRNA-disease association prediction. Furthermore, case studies suggest that MHDMF could be a convenient and efficient tool and may supply a new way to think about miRNA-disease association prediction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Objective: There are few prior reports of acute pelvic instrumentation failure in spinal deformity surgery. The objective of this study was to determine if a previously identified mechanism and rate of pelvic fixation failure were present across multiple institutions, and to determine risk factors for these types of failures., Methods: Thirteen academic medical centers performed a retrospective review of 18 months of consecutive adult spinal fusions extending 3 or more levels, which included new pelvic screws at the time of surgery. Acute pelvic fixation failure was defined as occurring within 6 months of the index surgery and requiring surgical revision., Results: Failure occurred in 37 (5%) of 779 cases and consisted of either slippage of the rods or displacement of the set screws from the screw tulip head (17 cases), screw shaft fracture (9 cases), screw loosening (9 cases), and/or resultant kyphotic fracture of the sacrum (6 cases). Revision strategies involved new pelvic fixation and/or multiple rod constructs. Six patients (16%) who underwent revision with fewer than 4 rods to the pelvis sustained a second acute failure, but no secondary failures occurred when at least 4 rods were used. In the univariate analysis, the magnitude of surgical correction was higher in the failure cohort (higher preoperative T1-pelvic angle [T1PA], presence of a 3-column osteotomy; p < 0.05). Uncorrected postoperative deformity increased failure risk (pelvic incidence-lumbar lordosis mismatch > 10°, higher postoperative T1PA; p < 0.05). Use of pelvic screws less than 8.5 mm in diameter also increased the likelihood of failure (p < 0.05). In the multivariate analysis, a larger preoperative global deformity as measured by T1PA was associated with failure, male patients were more likely to experience failure than female patients, and there was a strong association with implant manufacturer (p < 0.05). Anterior column support with an L5-S1 interbody fusion was protective against failure (p < 0.05)., Conclusions: Acute catastrophic failures involved large-magnitude surgical corrections and likely resulted from high mechanical strain on the pelvic instrumentation. Patients with large corrections may benefit from anterior structural support placed at the most caudal motion segment and multiple rods connecting to more than 2 pelvic fixation points. If failure occurs, salvage with a minimum of 4 rods and 4 pelvic fixation points can be successful.

Study Design: Review of current literature and authors experience., Objective: Pre-operative planning is an integral part of complex spine surgery. With the advent of computer-assisted planning, multiple surgical plans can be evaluated utilizing alignment parameters, and the best plan for individual patients selected. However, the ability to evaluate and measure surgical correction goals intraoperatively are still limited. The use of patient-specific UNiD rods, created based on pre-operative plans, provided an initial tool for implementation of pre-operative plans in the operative setting., Methods: A literature review for the use of patient-specific UNiD rods in thoracolumbar spine complex surgery was performed. The articles were selected and reviewed for the initial experience/outcomes of these techniques. Further, the initial experience of the authors at The University of Colorado is described., Results: The use of UNiD patient-specific rods, in combination with pre-operative planning has been shown to provide a higher rate of patients with spinopelvic alignment parameters within currently accepted ranges. This includes improvement of sagittal vertical axis (SVA) < 50 mm and pelvic incidence (PI)-lumbar lordosis (LL) = ± 10°. Multiple authors have shown improvement in pelvic tilt to age adjusted values but note continued difficulties in obtaining correction goals., Conclusions: The use of pre-operative planning software and UNiD patient-specific rods has been shown to improve surgeon's ability to achieve spinopelvic alignment parameters, specifically SVA and PI-LL, along with other possible benefits. Further research is needed regarding long-term value of the technology.

Introduction: What is overlooked in clinical studies are the possibilities of manufacturing and design aspects of the instrumentation that could initiate rod fracture. Although revision because of hardware fracture is a small fraction of the overall revision rates (12.1% to 13.7%), there are sufficient numbers of revision cases where hardware removed can undergo a thorough metallurgic analysis. This study is unique in that rod characteristics, such as alloy, surface markings, and fracture type, seen at fracture surfaces are considered in the analysis., Methods: This work was conducted under both a retrospective and prospective IRB. Patients considered for this study were between the ages of 18 and 85 years who underwent or were undergoing revision spine surgery with previous instrumentation in the cervical, thoracic, or lumbar region and evidence of at least one of the following: catastrophic hardware failure, pseudarthrosis, implant loosening, or nonfusion. Inclusion criteria were determined through radiographic and medical records review., Results: Fifty-six patients who had revision procedures because of different indications were included; 101 rods were removed, tested for fracture, and included in the analysis. Laser marking is significantly (P < 0.0001) associated with rod fracture. Detailed analysis showed notable surface and subsurface changes as the result of the marking, such as surface melting, cracking, and notching, creating locations to initiate a fracture. The three most informative variables to clinical rod fracture using multiple regression modeling were body mass index, presence or absence of laser mark (yes/no), and length of posterior fusion (≤2 spinal levels/>2 spinal levels). It was found that the relative risk of rod fracture is 23 times higher during 20 postoperative years than in cases with this index <0.4., Discussion: For a patient with a given body mass index, if they require a multilevel fixation greater than two levels and rods with laser marks are used, the risk of early rod fracture increases by 40%., (Copyright © 2021 by the American Academy of Orthopaedic Surgeons.)

As coronavirus disease 2019 (COVID-19) reached pandemic status, in-person orthopedic clinics across the United States were forced to close as many states adopted stay-at-home orders. Previously, the use of telemedicine in orthopedic practices was minimal for a variety of reasons, one being the inability to perform a physical examination in a specialty reliant on direct patient contact for diagnosis and treatment. A prospective cohort of 52 patients consented to participate in a novel virtual physical examination protocol during routine telemedicine visits at a large, tertiary orthopedic spine practice. Participants were asked to perform a series of carefully designed physical maneuvers using readily available household objects to allow their provider to better assess sensory and motor function in the tele-medicine setting. Patients were then asked to complete a short satisfaction survey. In total, 52 patients completed the physical examination and survey. Males and females were distributed evenly among the cohort at 50%. The mean age was 52.1±15.5 years. The average score for ease of understanding the examination (1=easiest, 5=hardest) was 1.1, while the average score for ease of performance was 1.5. Most participants (97.56%) felt their provider was better able to understand their condition using the virtual examination findings. This study highlights the utility of a virtual physical examination for assessment of spine patients in the telemedicine setting. Furthermore, this study illustrates the ease with which such an examination can be implemented and performed to improve patient evaluation and satisfaction. [ Orthopedics . 2022;45(1):e7-e10.].

Background: Recent studies support the need for sagittal alignment restoration when performing lumbar degenerative spinal fusions. The development of patient-specific spine rods (PSSRs) may help maintain or improve sagittal alignment in these surgeries., Methods: A retrospective review was conducted for patients who underwent posterior spinal surgeries involving 4 or less levels. The preplanned PSSR radii of curvature (ROC) was compared with standard prebent rods with a ROC of 125 mm. All surgeries were performed at a single institution by 3 surgeons from September 2016 through October 2018. Data were then compared using a 2-tailed paired t test. PSSR had either 1 or 2 definitive ROCs., Results: For rods with 2 ROCs, the "cranial" curve was measured between the upper instrumented level and L4 or L5. The "caudal" curve was measured between L4 or L5 and the lower instrumented level. The PSSR with 1 ROC and the caudal portion of the rods with 2 ROCs were significantly smaller than the industry standard ROC., Conclusions: PSSR demonstrate more acute ROC than industry standard rods. In PSRs, the most lordosis occurs between L4-S1 and flattens out at the thoracolumbar junction, mimicking the normal distribution of lumbar lordosis. PSSRs could help achieve or maintain sagittal alignment and prevent the sequela of flat back syndrome., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2020 ISASS.)

Background: Adult spinal deformity surgery requires use of long thoracolumbar instrumentation, which is associated with risk of postoperative proximal junctional kyphosis (PJK). Tethering has been used in spinal surgery but not around the spinous process (SP) in the context of preventing PJK., Methods: Researchers applied a nondestructive hybrid loading protocol to 7 T8-L2 cadaveric specimens in flexion-extension, lateral bending, and axial rotation (AR). A rigid construct (pedicle screws and rods) and 1- and 2-level SP constructs were tested, as was a hand-tie technique. SP tethering (SPT) constructs use clamps on both sides of the SP; SPT helix constructs use 1 clamp and wrap around the SP., Results: All tether constructs showed greater motion at the instrumented level and less motion at adjacent levels compared to rigid constructs. In AR, 1- and 2-level SPT constructs restricted first instrumented level motion to a greater extent when compared with other tether constructs ( P ≤ .05). Passing the band through the T10 SP did not produce significant biomechanical differences compared to passing it through the T9-T10 interspinous ligament ( P > .05). Hand-tied constructs demonstrated more motion compared to tensioned constructs ( P > .05). Intradiscal pressure results corroborated motion data., Conclusions: SPT at the proximal end of a rigid construct produced more favorable biomechanical outcomes at instrumented and adjacent levels than were seen with a completely rigid construct. Clinical research is needed to determine whether these methods reduce the risk of PJK among patients., Level of Evidence: 3., Clinical Relevance: This work sheds light on the biomechanical stability of proximal tethering constructs in an effort to enhance the surgeon's ability to reduce rates of proximal junctional kyphosis and failure in thoracolumbar spinal fusion surgery., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2020 ISASS.)

Study Design: This is a retrospective, single-institution, cohort study., Objectives: To evaluate the association of Mersilene tape use and risk of proximal junctional kyphosis (PJK), after surgical correction of adult spinal deformity (ASD) by posterior instrumented fusion (PIF). PJK, following long spinal PIF, is a complication which often requires reoperation. Mersilene tape, strap stabilization of the supra-adjacent level to upper instrumented vertebra (UIV) seems a preventive measure., Methods: Patients who underwent PIF for ASD with Mersilene tape stabilization (case group) or without (control group) between 2006 and 2016 were analyzed preoperatively to 2-year follow-up. Matching of potential controls to each case was performed. Radiographic sagittal Cobb angle (SCA), lumbar lordosis, pelvic tilt, sacral slope, and pelvic incidence were measured pre- and postoperatively, using a deformity measuring software program. PJK was defined as progression of postoperative junctional SCA at UIV ≥ 10°., Results: Eighty patients were included: 20 cases and 60 controls. The cumulative rate of PJK ≥ 10° at 2-year follow-up was 15% in cases versus 38% of controls (OR = 0.28; P = 0.04) with higher latent period in cases, (20 vs. 7.5 months), P = 0.018. Mersilene tape decreased risk of PJK linked with the impact of the following confounders: age, ≥ 55 years old (OR = 0.19; 0.02 ≥ P ≤ 0.03); number of spinal levels fused 7-15 (OR = 0.13; 0.02 ≥ P ≤ 0.06); thoracic UIV (T12-T1) (OR = 0.13; 0.02 ≥ P ≤ 0.06); BMI ≥ 27 kg/m 2 (OR = 0.22; 0.03 ≥ P ≤ 0.08); and osteoporosis (OR = 0.13; 0.02 ≥ P ≤ 0.08)., Conclusions: Mersilene tape at UIV + 1 level decreases the risk of PJK following PIF for ASD. These slides can be retrieved under Electronic Supplementary Material.

Current explanations of biomedical alloy degradation are focused on the physicochemical mechanisms of galvanic, pitting, crevice, and fretting corrosion. Ultimately, these studies dismiss the corrosion mechanism as a function of the local microbiome. Sixty spine hardware constructs were examined immediately after explantation for biofilm formation. Marked rod sections were imaged using scanning electron microscopy with energy dispersive x-ray spectroscopy. Backscatter mode was employed to better image the topology of the surface. There is clear differentiation between discoloration due to corrosion vs mechanical damage. Under scanning electron microscopy backscatter electron shadow examination, the authors noted that not all biofilm was removed using the surgical wipes. Corrosion pits were noticeably larger and numerous in areas of biofilm. In areas not associated with biofilms, there were few pits even if mechanical wear was evident. There is no evidence that the surface corrosion is modified between clinically diagnosed infected and noninfected patients. The surface damage present on explanted Ti6Al4V spine rods is uniquely similar to damage found in other industries where microbial-influenced corrosion is prevalent. Given that similar anaerobic, sulfur-reducing bacteria reside in and on human tissues, it is most likely that corrosion observed on explanted hardware is the result of microbial-influenced corrosion and not from inflammatory or other processes. Using analysis methods from other industries to characterize the microbiome present on explanted hardware is necessary. In so doing, a new definition of hardware-induced infection will be forthcoming. [Orthopedics. 2020;43(1):62-67.]., (Copyright 2020, SLACK Incorporated.)

Study Design: Retrospective single-center., Objectives: To investigate changes in pelvic incidence from flexion to extension. To assess interobserver error in the measurement of pelvic incidence., Background: Pelvic incidence (PI) has been considered a static parameter since it was originally described. But recent studies have shown that PI can change with age and after spinal procedures. Changes in PI based on position have not been investigated., Methods: Seventy-two patients who had obtained flexion and extension radiographs of the lumbar spine were identified using strict inclusion and exclusion criteria. PI along with pelvic tilt (PT), sacral slope (SS), and lumbar lordosis were measured in both flexion and extension by two independent measurers. Variations in all parameters and interobserver measurement reliability were analyzed for the entire group., Results: PI changed significantly from flexion to extension with a general tendency to decrease: mean (-0.94°), p <.044. However, these changes might have had opposite vectors, and exceeded | 6°| (measurement error) in 20% of cases, with a maximum of 12°. Inconsistencies in changes of SS, as opposed to PT from flexion to extension, were found to be the major factor determining changes in PI (p >.001). Obesity significantly contributed to differences in PI between flexion and extension (p = .003)., Conclusions: PI is a dynamic parameter that changes between flexion and extension. Changes in SS are the main factor involved in these changes, implicating movement through the sacroiliac joints as the cause. Obese patients have greater changes in PI from flexion to extension., Level of Evidence: Level II., (Copyright © 2018 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Pinato prognostic nutritional index (PNI) adequately predicts long-term outcomes of various malignancies. However, its value in predicting outcomes in laryngeal squamous cell carcinoma (LSCC) is unknown. All patients newly diagnosed with LSCC presenting to the Department of Head and Neck Oncology at Sun Yat-sen University Cancer Center between January 1, 1990 and July 31, 2010 were eligible. The PNI was calculated as serum albumin (g/L) + 5 × total lymphocyte count/L. The Cutoff Finder software program was used to classify the patients into 3 groups for which the PNI score was at least 70% sensitive, at least 70% specific, or equivocal. Cancer-specific survival was estimated using the Kaplan-Meier method, and predictors were assessed with Cox regression analysis. Median time between surgery and PNI administration for the 975 eligible patients was 83 months. Index score groups were significantly associated with age, T stage, TNM stage, and type of surgery. Five-year CSS and OS were 57.3% and 56.6% in patients with PNI scores below 48.65 (low-probability of survival), 72.8% and 71.3% with scores between 48.65 and 56.93 (moderate-probability of survival), and 77.6% and 75.3% with scores above 56.93 (high-probability of survival); 10-year CSS and OS were 44.2% and 42.7%, 61.6% and 55.6%, 68.3% and 63.5%, respectively. The PNI score groups significantly predicted CSS and OS (P < 0.001). The PNI is an inexpensive and readily available score that predicted survival in patients with LSCC after curative laryngectomy.

The design of nanoparticle (NP) size, shape and surface chemistry has a significant impact on their performance. While the influences of the particle size and surface chemistry on drug delivery have been studied extensively, little is known about the effect of particle shapes on nanomedicine. In this perspective article, we discuss recent progress on the design and fabrication of NPs of various shapes and their unique delivery properties. The shapes of these drug carriers play an important role in therapeutic delivery processes, such as particle adhesion, distribution and cell internalization. We envision that stimuli-responsive NPs, which actively change their shapes and other properties, might pave way to the next generation of nanomedicine.

Inflammatory myofibroblastic tumor (IMT) is a rare benign neoplasm. The aim of this study was to enhance the understanding of head and neck IMT and to improve its diagnosis and management. Clinical features and related treatment of 10 IMT cases were retrospectively analyzed and the literature was reviewed. Tumor sites identified included four in the maxillary space, two in the buccal space, two in the parotid gland, one in the post aurem, and one in the neck. Nine of ten patients received local resection, and one of ten patients received a total maxillectomy. One patient had a local recurrence and died, while the other nine patients had no distant metastases and survived. A computed tomography (CT) exam performed on nine of the ten patients showed that six of these nine cases were heterogeneous in density, while the other three cases were homogeneous. Four cases showed marked heterogeneous enhancement, two cases showed mild heterogeneous enhancement, and three cases showed moderate homogeneous enhancement on contrast-enhanced CT images. The incidence of IMT in the head and neck is low, and local resection is currently the best treatment. A prolonged postoperative follow-up period is necessary for patients with IMT.

Immunofluorescence imaging on polymeric biomaterials is often inhibited by autofluorescence and other optical phenomena. This often limits the analysis that can be performed on cells that are in contact with these materials. This study outlines a method that will quench these inhibitive optical phenomena on a variety of polymeric materials, including poly(glycerol sebacate), poly(urethane), poly(L-lactide-co-ε-caprolactone), and poly(lactic acid-co-glycolic acid). The method uses a simple material treatment method utilizing Sudan Black B (SB), which is commonly used as an autofluorescence quenching molecule in tissue histology, but has not yet been used in biomaterials analysis. The quenching mechanism in the selected polymers is investigated using attenuated total reflectance Fourier transform infrared spectroscoy, ultraviolet-visible light absorbance and fluorescence analysis, and scanning electron microscopyobservation of the material morphology prior to and after SB treatment. The results point to SB eliminating the inhibitive light phenomena of these materials by two methods: (i) chemical interaction between SB and the polymer molecules and (ii) physical interaction whereby SB forms a physical barrier that can absorb scattered light and quench autofluorescence interference during fluorescence microscopy. The studies show that the treatment of polymers with SB is robust across the polymers tested, in both porous and non-porous formats. The method does not interfere with immunofluorescent imaging of fluorescently labeled biological cells cultured on these polymers. This quick, simple, and affordable method enables a variety of analyses to be conducted that may otherwise have been impractical or impossible., (Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Objective: The current study was designed to examine the expression of Skp2 gene in laryngeal squamous cell carcinoma (LSCC) and to investigate the role of Skp2 gene in tumorigenesis and progression of LSCC., Method: FQ-PCR method was used to examined the expression of Skp2 gene in 40 LSCC and 10 normal laryngeal mucosa tissues, and relationship between its expression and clinical biological factors of patients with LSCC was analyzed., Result: The median copy number of Skp2 mRNA expression in LSCC was 6622.54 copy/microg RNA, the median copy number of Skp2 mRNA expression in normal laryngeal mucosa tissues was 0 copy/microg RNA, there was a very significant difference between them (P < 0.01); The positive rate of Skp2 mRNA expression in LSCC and adjacent normal laryngeal tissue were 50%, 0, respectively (P < 0.01). The median copy number of Skp2 RNA expression in LSCC with cervical lymph node metastasis was 617138.4 copy/microg RNA, the median copy number of Skp2 mRNA expression in LSCC without cervical lymph node metastasis was 0 copy/microg RNA, there was a very significant difference between them (P < 0.05); The positive rate of Skp2 mRNA expression in LSCC with and without cervical lymph node metastasis were 100.00%, 35.48%, respectively (P < 0.01)., Conclusion: Skp2 gene might have relation with the cervical lymph node metastasis of LSCC. FQ-PCR is an accurate assay to detecting expression of Skp2 mRNA in patient with LSCC. The level of Skp2 mRNA expression might be a new and more accurate marker, and it can be used to predict cervical lymph node metastasis of LSCC.

Objective: To analyze the reasons for re-operation and living condition of thyroid carcinoma patients who received second operation, and to formulate indications for selecting re-operation candidates and operation types., Methods: One hundred and eleven thyroid carcinoma patients were retrospectively summarized. All patients received re-operation after thyroidectomy from 1986 to 1997. The post operative follow-up data were analyzed statistically., Results: Pathological results confirmed there were 67.6% (75/111) cases with residual tumor. The incidence rate of post-operative complications was 2.7%, including 0.9% (1/111) recurrent laryngeal nerve injury. The sensitivity of residual carcinoma detection by CT scan before operations was 80.0% (28/35), with the positive predictive value of 87.5% (28/32). The recurrence rate within 3 years was 11.7% (13/111), with a local control rate of 88.3% (98/111). The recurrence rate within 5 years was 14.4% (16/111), with a local control rate of 85.6% (95/111). Life table was adopted to calculate living rates. The accumulated 5-year and 10-year living rates of re-operated thyroid carcinoma patients were 95.0% and 93.2% respectively. Analysis of Cox Regression showed that carcinoma recurrence influenced survival conditions significantly., Conclusions: The residual rate of re-operated patients with thyroid carcinoma was relatively higher, so a cautious re-operation was necessary. CT scan has a relatively higher positive predictive rate in detecting residual carcinoma, so it is necessary for screening right candidates for re-operation. Recurrence was the main factor that influenced patients' survival. So making proper indications, according to which to select patients who need re-operations will decrease the incidence of unnecessary operations.

Objectives: Our goal was to establish and validate a modified cocktail approach including probe drugs caffeine, chlorzoxazone, mephenytoin, metoprolol, and midazolam for simultaneous phenotyping of CYP1A2, CYP2E1, CYP2C19, CYP2D6, and CYP3A., Methods: The study was conducted in 14 healthy, nonsmoking male volunteers with a cocktail of 5 drugs consisting of 100 mg caffeine, 200 mg chlorzoxazone, 100 mg mephenytoin, 100 mg metoprolol, and 7.5 mg midazolam in a randomized manner with a 7 x 7 Latin square design. Plasma was obtained at 1, 4, and 6 hours, and urine was collected from 0 to 8 hours after oral drug administration., Results: The phenotypic indexes determined for caffeine, chlorzoxazone, mephenytoin, metoprolol, and midazolam were not significantly different when the drugs were given in different combinations. There were no metabolic interactions or analytic interference of these probe drugs., Conclusions: This cocktail approach can simultaneously provide independent in vivo phenotypic measures for the cytochrome P450 (CYP) enzymes CYP1A2, CYP2E1, CYP2C19, CYP2D6, and CYP3A.

Aims: The study was designed to investigate whether genetically determined CYP2C19 activity affects the metabolism of fluoxetine in healthy subjects., Methods: A single oral dose of fluoxetine (40 mg) was administrated successively to 14 healthy young men with high (extensive metabolizers, n=8) and low (poor metabolizers, n = 6) CYP2C19 activity. Blood samples were collected for 5-7 half-lives and fluoxetine, and norfluoxetine were determined by reversed-phase high performance liquid chromatography., Results: Poor metabolizers (PMs) showed a mean 46% increase in fluoxetine peak plasma concentrations (Cmax, P < 0.001), 128% increase in area under the concentration vs time curve (AUC(0, infinity), P < 0.001), 113% increase in terminal elimination half-life (t(1/2)) (P < 0.001), and 55% decrease in CLo (P < 0.001) compared with extensive metabolizers (EMs). Mean +/- (s.d) norfluoxetine AUC(0, 192 h) was significantly lower in PMs than that in EMs (1343 +/- 277 vs 2935 +/- 311, P < 0.001). Mean fluoxetine Cmax and AUC(0, infinity) in wild-type homozygotes (CYP2C19*1/CYP2C19*1) were significantly lower than that in PMs (22.4 +/- 3.9 vs 36.7 +/- 8.9, P < 0.001; 732 +/- 42 vs 2152 +/- 492, P < 0.001, respectively). Mean oral clearance in individuals with the wild type homozygous genotype was significantly higher than that in heterozygotes and that in PMs (54.7 +/- 3.4 vs 36.0 +/- 8.7, P < 0.01; 54.7 +/- 3.4 vs 20.6 +/- 6.2, P < 0.001, respectively). Mean norfluoxetine AUC(0, 192 h) in PMs was significantly lower than that in wild type homozygotes (1343 +/- 277 vs 3163 +/- 121, P < 0.05) and that in heterozygotes (1343 +/- 277 vs 2706 +/- 273, P < 0.001), respectively., Conclusions: The results indicated that CYP2C19 appears to play a major role in the metabolism of fluoxetine, and in particular its N-demethylation among Chinese healthy subjects.

Either G-2964 or A734 in the human CYP1A2 gene was confirmed to be associated with high inducible enzyme activity in smokers, but not in nonsmokers. In this study, for the first time, we observed an association between phenotypes and genotypes of CYP1A2 with respect to the two genetic polymorphisms in 163 healthy Chinese volunteers living in Qidong. The ratio of plasma 17X/137X at 6 h after oral administration of 300 mg caffeine was employed in CYP1A2 phenotyping analysis, while genotyping analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism. The allele frequencies of A at -2964 and A at 734 in 139 non-smoking subjects were 0.25 and 0.67, respectively. The A/A-2964C/C734, G/A-2964C/C734 or A/A-2964C/A734 genotype that was thought to have lower inducibility/activity of CYP1A2 than the other genotypes did not exist in the tested Chinese subjects. The ratio of 17X/137X was 0.46 +/- 0.26 in G/G-2964A/A734 genotypes (n = 22) and 0.36 +/- 0.19 in non-G/G-2964A/A734 (n = 117). In addition, there was significant difference between them (P = 0.036). A similar result was also achieved in 24 smokers. Since Qidong is a special region with particularly high incidence of hepatocellular carcinoma in China, the association of phenotypes with genotypes of CYP1A2 in the Qidong population might result from some inducible environmental factors such as those of cigarettes in smokers.

Aim: To find out a single plasma sampling to estimate oral clearance of midazolam (MDZ) and CYP3A activity, and explore the pharmacokinetics of midazolam hydroxylation in Chinese subjects., Methods: The pharmacokinetics of midazolam was assessed in ten healthy male individuals after an oral dose of 7.5 mg midazolam., Results: A significant correlation (r = 0.7, P < 0.05, n = 10) was found between plasma MDZ clearance and the plasma ratio of 1'-hydroxymidazolam to midazolam, which was assessed at 1 h after MDZ intake in the volunteers. Pharmacokinetics parameters of midazolam were as follows: Cmax (191 +/- 17) nmol/L, tmax (1.01 +/- 0.14) h, t(1/2) (3.2 +/- 0.4) h, AUC(0-infinity) (681 +/- 43) nmol.h.L-1), Cl(oral) (0.54 +/- 0.04) L.h-1.kg-1, Ke (0.2415 +/- 0.0021) h-1, Kalpha (0.82 +/- 0.18) h-1., Conclusion: Single plasma sampling of 1 h after 7.5 mg oral MDZ intake can be used to predict the oral clearance of midazolam.

Aim: To compare the level and/or activity of several important cytochrome P-450 (CYP) enzymes in liver microsomes prepared from different Chinese subjects., Methods: Individual CYP contents, including CYP1A2, CYP2C9, and CYP3A4, in liver microsomes of 17 Han, 17 Zhuang, and 8 Miao subjects were determined by using Western blot analysis and densitometric scanning. The substrates for measuring the activity of individual CYP in vitro included phenacetin, tolbutamide, debrisoquine, and omeprazole., Results: There was a large interindividual variability in the content and activity of CYP1A2, 2C9 and 3A4. And the activity of CYP2D6 also varied greatly between individual samples. CYP3A4 (32 %) is the most abundant CYP in Chinese liver microsomes, and the levels of CYP2C9 (19 %) and CYP1A2 (16 %) were also considerable. No clear ethnic, sex- and age-related differences in individual CYP content and catalytic activity were detected in 42 Chinese liver samples, except that there were somewhat ethnic and sex-related differences in the content and activity of CYP1A2. Good correlation between enzyme protein content and activity was found for CYP1A2, 2C9 and 3A4., Conclusion: Our results may provide useful information for the study of drug metabolism by liver microsomes in Chinese.

Aim: Catechol estrogens and 16alpha-hydroxy estrogen are important metabolites that cause carcinogenesis. This study was aimed to stud y the role of cytochrome P450 in estradiol metabolism., Methods: The estradiol metabolites were determined with HPLC-ECD. Correlation of estradiol metabolites production between cytochrome P450 activity, the inhibitory effect of specific inhibitors and enzyme catalyzing kinetics were studied in cDNA-expressed P450 or human liver microsomes., Result: CYP1A2, CYP3A4, and CYP2C9 catalyze the estradiol 2-hydroxylation. CYP2C9, CYP2C19, and CYP2C8 have high activity in catalyzing 17beta-hydroxy dehydrogenation in cDNA expressed P450, but CYP1A2 is the most important enzyme in catalyzing estradiol 2-hydroxylation. Using furafyllin and troleandomycin to inhibit CYP1A2 and CYP3A4 in liver microsomes, it was found that the 2-hydroxylation had been inhibited about the same amount. This result suggests that in human liver microsomes CYP1A2 and CYP3A4 play an important role in 2-hydroxy estradiol formation. At low substrate concentration, 17beta -hydroxy dehydrogenation dominated the estradiol metabolism, but at high substrate concentration, 2-hydroxylation exceeded 17beta-hydroxy dehydrogenation to become the important mechanism., Conclusion: CYP1A2 and CYP3A4 are two important enzymes catalyzing the main estradiol 2-hydroxylation metabolism pathway at high substrate concentrations. 17beta-hydroxy dehydrogenation is the main metabolism pathway at low concentrations, and CYP2C9, CYP2C19, and CYP2C8 may have high catalyzing activity.

Aim: A high-performance liquid chromatography (HPLC) method was developed for the determination of fluoxetine (FLU) and its metabolite norfluoxetine (N-FLU) in human liver microsomes in vitro., Methods: An incubation buffer containing human liver microsomes, NADPH-generating system, and FLU, after termination of enzyme reaction and addition of nortriptyline (NOR) as internal standard (IS), was extracted with n-hexane/acetonitrile, and separated on a reversed-phase ODS column. Detection was achieved at 226 nm by ultraviolet detector (UV)., Results: The limit of detection was 5 micrograms/L for both FLU and N-FLU. No potential interference was found. The method provides recoveries of up to 94%-104% and acceptable coefficients of variation were found for both within-run (< 7.8%) and day to day (< 9.1%) assays., Conclusion: This method is rapid, sensitive, and simple for studying the metabolism of FLU and N-FLU.

Aim: To identify the cytochrome P450 isoforms involved in proguanil (PG) activation to cycloguanil (CG) in Chinese liver microsomes., Methods: The kinetics of the CG formation from PG was determined in the liver microsomes of 6 Chinese subjects. Selective chemical inhibitors to various cytochrome P450 isoforms were employed to conduct inhibition experiments. The relationship between the CG formation and S-mephenytoin 4'-hydroxylation was analyzed., Results: The kinetic behaviors of CG formation were described well by a single-enzyme Michaelis-Menten equation in five livers. The apparent Km and Vmax were (82 +/- 47) mumol.L-1 and (8 +/- 6) pmol.min-1.mg-1 protein, respectively. However, the remaining one displayed a two-enzyme kinetic behavior. Inhibition experiments showed that troleandomycin (100 mumol.L-1) and diethyldithiocarbamate (100 mumol.L-1), as potent CYP3A4 and CYP2E1 inhibitors, respectively, reduced the formation rate of CG by 81.1% and 47.23%, while quinidine (10 mumol.L-1), furafylline (20 mumol.L-1), and sulfaphenazole (10 mumol.L-1), which were inhibitors towards CYP2D6, 1A2 and 2C9/10, respectively, did not display significant inhibition. At a low PG concentration of 5 mumol.L-1, the CG formation correlated well with S-mephenytoin 4'-hydroxylation (r = 0.805, P < 0.05). Nevertheless, when a high substrate concentration (500 mumol.L-1) was used, the correlation coefficient decreased (r = 0.581, P < 0.05)., Conclusion: The present study indicates that CYP3A4 and CYP2C19 are involved in PG activation to CG in adult Chinese liver microsomes. CYP2C19 played an important role in the clearance of PG at a substrate concentration close to in vivo therapeutic concentrations, while CYP3A4 gradually made a dominant contribution with the increase of PG concentration.

Aim: To improve a gas chromatography/electron impact ionization mass spectrometry (GC/MS) method for determining the concentration of procaterol in human plasma., Methods: GC/MS was developed with capillary column. Samples were extracted by liquid phase before derivated. Imipramine was used as an internal standard. The injector and GC/MS interface temperatures were set at 280 degrees C and 250 degrees C, respectively. The carrier gas (helium) was 0.8 mL.min-1, and injections were made in the pulse-splitless mode. The MS source and MS Quad temperature were 230 degrees C and 150 degrees C, respectively., Results: The detection limit of plasma procaterol was 5 ng.L-1. The assay was linear over the range of 10-10,000 ng.L-1 with correlation coefficient of 0.9987. The coefficients of variation were less than 10% for procaterol detection at high, medium and low concentration levels (n = 5). The average recovery of the assay was 99.1% +/- 1.3%., Conclusion: This assay was sensitive, precise, and accurate for evaluating the clinical pharmacokinetics of procaterol.

Aims: To investigate the distribution characteristics of CYP1A2 in a Chinese population, and to examine gender-related differences in CYP1A2 activity., Methods: Two hundred and twenty-nine healthy subjects, 120 men and 109 women, were enrolled in this study. CYP1A2 activity was measured by plasma paraxanthine/caffeine (1,7X/1,3,7X) ratio 6 h after administration of 300 mg caffeine. The concentrations of paraxanthine and caffeine in plasma were detected by h.p.l.c., Results: A 16-fold variation of CYP1A2 activity (range 0. 09 to 1.46) was shown in this study. The coefficient of variation (CV %) of CYP1A2 activity was 62.9%. Non-normal distribution of CYP1A2 activity was indicated by the Shapiro-Wilk test (P<0.001). Probit plots of CYP1A2 activity revealed a bimodal distribution with breakpoint of 1,7X/1,3,7X ratio of 0.12. The percentage of poor metabolizers (PMs) was 5.24% (95% CI: 2.35% approximately 8.13%) in this Chinese population. Residual analysis of the data also supported bimodality (P<0.01). The CYP1A2 activity of men was higher than that of women (median: 0.33 vs 0.23, P<0.001). A probit plot of CYP1A2 activity in men was shifted to the left compared with that in women. Based on phenotype, the gender-related difference was observed in extensive metabolizers (EMs) (P<0.001), but not in PMs (P >0.1). In addition, there was no sex-related difference in the incidence of PMs (P >0.1)., Conclusions: There is a phenotypic polymorphism in CYP1A2 activity in this Chinese population, and CYP1A2 activity is higher in men than that in women.

Objective: To determine whether the gene dosage of CYP2C19 affects the metabolism of diazepam and desmethyldiazepam in healthy Chinese subjects., Subjects and Methods: Eighteen unrelated adult men were recruited for the study from a total of 101 healthy Chinese volunteers who had been screened for CYP2C19 phenotype and genotype. All subjects received a single oral dose (5 mg) of diazepam, and the pharmacokinetics of diazepam and desmethyldiazepam were compared in six ml homozygotes (ml/ml), six ml heterozygotes (wt/ml), and six wild-type homozygotes (wt/wt)., Results: The plasma elimination half-life values of diazepam (84.0 +/- 13.7 hours) and desmethyldiazepam (176.0 +/- 28.9 hours) in subjects of ml/ml were significantly longer than those (62.9 +/- 9.8 hours for diazepam; 132.1 +/- 24.9 hours for desmethyldiazepam; both P < .01) in subjects of wt/ml or those (20.0 +/- 10.8 hours for diazepam; 99.2.+/- 21.7 hours for desmethyldiazepam; both P < .01) in subjects of wt/wt. A significant difference in the corresponding half-life values existed between the wt/ml and wt/wt subjects (P < .01). As expected, the slowest mean clearance of diazepam was observed in the ml/ml subjects (2.8 +/- 0.9 mL/min) and the fastest in the wt/wt subjects (19.5 +/- 9.8 mL/min), with the wt/ml heterozygotes having an intermediate value (7.2 +/- 2.6 mL/min)., Conclusion: The presence of a single-nucleotide polymorphism (G681A) of the CYP2C19 gene cosegregates with the impaired metabolism of diazepam and desmethyldiazepam among Chinese subjects in a gene-dosage effect manner.

Aim: To study the effect of cytochrome P-450 (CYP450) inhibitors on clomipramine (Clo) N-demethylation in vitro., Methods: The kinetic parameters of Clo N-demethylation in human liver microsomes were obtained by the Michaelis-Menten equation. The parameters after pretreatment with putative inhibitors of various CYP450 isoforms were compared with controls., Results: K(m1), K(m2), Vmax1, Vmax2, Vmax1/K(m1), and Vmax2/K(m2) were (0.11 +/- 0.06), (24 +/- 14) mumol.L-1, (114 +/- 47), (428 +/- 188) nmol.g-1.min-1, (1.8 +/- 1.6), and (0.019 +/- 0.005) L.g-1.min-1, respectively. The interindividual variations for the last 4 parameters reached up to 2.5-, 7.3-, 3.4-, and 1.8-fold. At 5 mumol.L-1 of Clo, troleandomycin (Tro), furafylline (Fur), ditiocarb sodium (Dit), and S-mephenytoin (Mep) produced a marked inhibition on Clo N-demethylation while sulfaphenazole (Sul) and quinidine (Qui) had only slight effects. The inhibitory rates by Dit 30, Mep 500, Fur 10, Tro 10, Fur 80, Tro 200 and Fur 80 + Tro 200 mumol.L-1 were 27.0%, 32.9%, 42.8%, 40.5%, 63.9%, 66.4%, and 78.3%, respectively. The IC50 (95% confidence limits) for Fur and Tro were 27.7 (19.1-36.3) and 42.1 (20.9-63.3) mumol.L-1, respectively., Conclusions: The N-demethylation of Clo exhibited a biphasic behavior. This reaction was mediated mainly by both CYP1A2 and CYP3A4, to a minor extent by CYP2C19 at the low concentration of Clo in vitro.

Aim: To develop a rapid HPLC method for the determination of cytochrome P-450 CYP1A2 activity., Methods: A 300-microL plasma was prepared by extraction with 5-mL chloroform/isopropanol (9:1), and beta-hydroxyletheophylline was added as internal standard (IS). Samples were separated on an ODS column by a gradient elution system, of which mobile phase consisted of 0.05% acetic acid, acetonitrile, and methanol. The compounds of interest were monitored at 282 nm by UV detector., Results: No potential interfering peaks were found. Paraxanthine (17X), IS and caffeine (137X) were rapidly eluted with baseline resolution, and their retention time was less than 13 min. The detection limits of both 17X and 137X were 0.1 mumol.L-1. Linear relations ranged over 1-100 mumol.L-1 and 1-200 mumol.L-1 with correlation coefficient of 0.9999 and 0.9987, respectively, for 17X and 137X. The coefficients of variation were within 6% for 17X, and 10% for 137X. The average recoveries for both compounds were ranged from 96% to 108%., Conclusion: This method is sensitive and rapid, and can be used for population studies of CYP1A2.

Data on both the incidence of slow acetylator phenotype of probe drugs isoniazid, sulfadimidine or sulfamethazine, caffeine and dapsone in mainland or overseas Chinese, and the distribution of NAT2 genotypes and the frequency of NAT2 alleles in the Chinese populations were summarized and reanalysed using a meta-analysis method. Frequency of the slow acetylator phenotype in 3516 healthy Han Chinese gave an overall mean of approximately 19.9 +/- 4.0%, with the range of the combined data being between 15.8% and 25.5%. In addition, frequencies of the slow acetylator phenotype differ between the different minorities in Chinese populations and the range was between 3.2% and 50.6%, with a mean value of 20.6 +/- 12.9% in a total of 1842 individuals from 17 Chinese minorities. In addition, there was no significant heterogeneity in overseas Chinese between the probe drugs isoniazid and sulfadimidine or sulfamethazine (chi 2 = 5.97, df = 4; p > 0.05), and the mean value of slow acetylator phenotype incidence was 24.5% (119/485; 95% CI: 20.7-28.3%), consistent with that of the native Chinese. As expected, frequency of the slow acetylator genotypes in Chinese populations was 25.4% (112/441; 95% CI: 21.3-29.5%), which was in accordance with that of the slow acetylator phenotype in native or overseas Chinese. For all genotypes, *4/*4 (29.9%, 132/441), *4/*6A (27.4%, 121/441), *4/*7A (12%, 53/441) and *6A/*6A (11.3%, 50/441) occupied 80.6%, but *5A/*7A (0.2%, 1/441), *5A/*5A (1.1%, 5/441) and *7A/*7A (1.8%, 8/441) were not frequently found. From this report, the genotype frequencies of homozygous rapid acetylator, heterozygous rapid acetylator, and homozygous slow acetylator were found to be 0.299 (132/441), 0.447 (197/441) and 0.254 (112/441), respectively. Furthermore, both *4 (52.3%; 95% CI: 49-56%) and *6A (30.5%; 95% CI: 28-34%) were major NAT2 alleles, while *7A (11.2%; 95% CI: 9-13%) and *5A (6%; 95% CI: 4-8%) were uncommonly present. Frequency of the mutant alleles was observed at 0.477 (421/882 alleles). The *7A constituted 23.5% t(99/421) of slow acetylator alleles in Chinese populations, showing that this point mutation exists not only in Oriental or Asiatic, but also in Chinese populations. According to the Hardy-Weinberg equilibrium, in the phenotyped Chinese populations, the mean estimate of predicted allelic frequencies of the genotypes RR, Rr, and rr was 0.294, 0.496, and 0.210 for the Chinese, and the expected frequency of the deficient gene r was 0.458. By comparison, the predicted values are in complete agreement with the observed ones. In conclusion, this meta-analysis determined the accurate population frequencies of phenotype and genotype of the NAT2 genetic deficiency in healthy Chinese subjects.