Characterization of tumoricidal activities mediated by a novel immune cell regimen composing interferon-producing killer dendritic cells and tumor-specific cytotoxic T lymphocytes

BACKGROUND

Although immune cell therapy has long been used for treating solid cancer, its efficacy remains limited. Interferon (IFN)-producing killer dendritic cells (IKDCs) exhibit cytotoxicity and present antigens to relevant cells; thus, they can selectively induce tumor-associated antigen (TAA)-specific CD8 T cells and may be useful in cancer treatment. Various protocols have been used to amplify human IKDCs from peripheral sources, but the complexity of the process has prevented their widespread clinical application. Additionally, the induction of TAA-specific CD8 T cells through the adoptive transfer of IKDCs to immunocompromised patients with cancer may be insufficient. Therefore, we developed a method for generating an immune cell-based regimen, Phyduxon-T, comprising a human IKDC counterpart (Phyduxon) and expanded TAA-specific CD8 T cells.

METHODS

Peripheral blood mononuclear cells from ovarian cancer patients were cultured with human interleukin (hIL)-15, hIL-12, and hIL-18 to generate Phyduxon-T. Then, its phenotype, cytotoxicity, and antigen-presenting function were evaluated through flow cytometry using specific monoclonal antibodies.

RESULTS

Phyduxon exhibited the characteristics of both natural killer and dendritic cells. This regimen also exhibited cytotoxicity against primary ovarian cancer cells and presented TAAs, thereby inducing TAA-specific CD8 T cells, as evidenced by the expression of 4-1BB and IFN-γ. Notably, the Phyduxon-T manufacturing protocol effectively expanded IFN-γ-producing 4-1BB+ TAA-specific CD8 T cells from peripheral sources; these cells exhibited cytotoxic activities against ovarian cancer cells.

CONCLUSIONS

Phyduxon-T, which is a combination of natural killer cells, dendritic cells, and TAA-specific CD8 T cells, may enhance the efficacy of cancer immunotherapy.

May I see what you see? Predicting visual features from neuronal activity

Understanding brain response to audiovisual stimuli is a key challenge in understanding neuronal processes. In this paper, we describe our effort aimed at reconstructing video frames from observed functional MRI images. We also demonstrate that our model can predict visual objects. Our method constructs an autoencoder model for a set of training video segments to code video streams into their corresponding latent representations. Next, we learn a mapping from the observed fMRI response to the corresponding latent video frame representation. Finally, we pass the latent vectors computed using the fMRI response through the decoder to reconstruct the predicted image. We show that the representations of video frames and those constructed from corresponding fMRI images are highly clustered, the latent representations can be used to predict objects in video frames using just the fMRI frames, and fMRI responses can be used to reconstruct the inputs to predict the presence of faces.

[Application of augmented reality navigation combined with indocyanine green fluorescence imaging technology in the accurate guidance of laparoscopic anatomical segment 8 liver resection]

Objective: To investigate the application value of augmented reality navigation combined with indocyanine green(ICG) fluorescence imaging technology in laparoscopic anatomical segment 8 liver resection. Methods: Clinical and pathological data from 8 patients with hepatocellular carcinoma located in segment 8 of the liver admitted to the First Department of Hepatobiliary Surgery,Zhujiang Hospital,Southern Medical University from October 2021 to October 2022 were collected restrospectively. Among them,there were 5 males and 3 females,aged between 40 and 72 years. During the operation,the self-developed laparoscopic augmented reality surgical navigation system was used to integrate the three-dimensional liver model with the laparoscopic scene,and ICG fluorescence imaging technology was used to guide the anatomical liver resection of segment 8. The predicted liver resection volume and actual liver resection volume,related surgical indicators and postoperative complications were analyzed. Results: Among the 8 patients, 4 underwent laparoscopic anatomical segment 8 liver resection,1 underwent laparoscopic anatomical ventral subsegment of segment 8 liver resection,2 underwent laparoscopic anatomical ventral subsegment combined with medial subsegment of segment 8 liver resection, and 1 underwent laparoscopic anatomical dorsal subsegment of segment 8 liver resection. All operations were completed under the guidance of augmented reality navigation combined with ICG fluorescence imaging,without conversion to open surgery. The operation time was (276.3±54.8)minutes(range:200 to 360 minutes). Intraoperative blood loss was (75.0±35.4)ml(range:50 to 150 ml). No blood transfusion was performed during the operation. The length of postoperative hospital stay was (7.6±0.8)days(range:7 to 9 days). There were no deaths or postoperative complications such as bleeding or biliary fistula during the perioperative period. Conclusion: Augmented reality navigation combined with ICG fluorescence imaging technology can guide the implementation of laparoscopic anatomical segment 8 liver resection.

Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4  kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80  MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90  MeV/c^{2} with heavy mediators and m_{χ} larger than 100  MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.

Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46}  cm^{2} (90% C.L.) at DM mass of 10  MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14  MeV/c^{2} for the massless dark photon and bound DM final state, respectively.

Identifying and analyzing sepsis states: A retrospective study on patients with sepsis in ICUs

Sepsis accounts for more than 50% of hospital deaths, and the associated cost ranks the highest among hospital admissions in the US. Improved understanding of disease states, progression, severity, and clinical markers has the potential to significantly improve patient outcomes and reduce cost. We develop a computational framework that identifies disease states in sepsis and models disease progression using clinical variables and samples in the MIMIC-III database. We identify six distinct patient states in sepsis, each associated with different manifestations of organ dysfunction. We find that patients in different sepsis states are statistically significantly composed of distinct populations with disparate demographic and comorbidity profiles. Our progression model accurately characterizes the severity level of each pathological trajectory and identifies significant changes in clinical variables and treatment actions during sepsis state transitions. Collectively, our framework provides a holistic view of sepsis, and our findings provide the basis for future development of clinical trials, prevention, and therapeutic strategies for sepsis.

[Application of augmented reality and mixed reality navigation technology in laparoscopic limited right hepatectomy]

Objective: To investigate the application effect of augmented reality and mixed reality navigation technology in three-dimensional(3D) laparoscopic narrow right hepatectomy(LRH). Methods: A retrospective analysis was performed on the clinical data of 5 patients with hepatic malignancy admitted to the First Department of Hepatobiliary Surgery,Zhujiang Hospital,Southern Medical University from September 2020 to June 2021,all of whom were males,aged from 42 to 74 years.Preoperative evaluation was performed using the self-developed 3D abdominal medical image visualization system; if all the 5 patients were to receive right hemihepatectomy,the remnant liver volume would be insufficient,so LRH were planned.During the operation,the independently developed 3D laparoscopic augmented reality and mixed reality surgical navigation system was used to perform real-time multi-modal image fusion and interaction between the preoperative 3D model and 3D laparoscopic scene.Meanwhile,intraoperative ultrasound assisted indocyanine green fluorescence was used to determine the surgical path.In this way,the LRH under the guidance of augmented reality and mixed reality navigation was completed.The predicted liver resection volume was evaluated before surgery,actual resected liver volume,surgical indicators and postoperative complications were analyzed. Results: All the 5 patients completed LRH under the guidance of augmented reality and mixed reality navigation technology,with no conversion to laparotomy.The median operative time was 300 minutes(range:270 to 360 minutes),no intraoperative blood transfusion was performed,and the median postoperative hospital stay was 8 days(range:7 to 9 days).There were no perioperative deaths,or postoperative complications such as liver failure,bleeding,or biliary fistula. Conclusion: For patients who need to undergo LRH,the use of augmented and mixed reality navigation technology can safely and effectively guide the implementation of surgery,retain more functional liver volume,improve surgical safety,and reduce postoperative complications.

[How to change from traditional surgery to intelligent navigation surgery?]

After more than 20 years of multidisciplinary integration of medical science and technology,as well as research and practice in innovative diagnosis and treatment,digital medicine 4.0 has made a profound and important impact on the development of traditional surgery. To combine traditional surgery with digital medicine 4.0 technology is the direction of surgery development in the future.New technologies represented by digital intelligent navigation surgery have been deeply explored and widely applied in the diagnosis and treatment of many surgical diseases. With the innovative development and application of artificial intelligence,Big Data and mixed reality technology,the surgery will develop in ways similar to aerospace automatic and intelligent navigation,leading to the advent of digital medicine 5.0.

[Efficacy of three-dimensional visualization technology in the precision diagnosis and treatment for primary liver cancer: a retrospective multicenter study of 1 665 cases in China]

Objective: To evaluate the efficacy of three-dimensional(3D) visualization technology in the precision diagnosis and treatment for primary liver cancer. Methods: A total of 1 665 patients with primary liver cancer who admitted to seven medical centers in China between January 2009 to January 2019, diagnosed and treated by 3D visualization protocol were analyzed, and their clinical data were retrospectively reviewed. There were 1 255 males(75.4%) and 410 females(24.6%), with age of (52.9±11.9) years (range: 18 to 86 years). The acquisition of high-quality CT images with submillimeter spatial resolution were conducted using a quality control system. By means of homogenization methods, 3D reconstruction and 3D visualization analysis were performed. Postoperative observation: pathology reports, microvascular invasion, perioperative complications and follow-up. SPSS 25.0 statistical software was used for statistical description and analysis of clinical data. Kaplan-Meier curve was used to calculate overall survival and disease-free survival rate. Results: (1)In the sample of 1 265 patients, 3D reconstructed models clearly displayed as follows. tumor size: ≤2 cm in 155 cases (9.31%), >2 cm to 5 cm in 551 cases (33.09%), >5 cm to 10 cm in 636 cases (38.20%), >10 cm in 323 cases (19.40%). (2) Classification of hepatic blood vessels. Hepatic artery: type Ⅰ(normal type) in 1 494 cases(89.73%),variant hepatic artery in 171 cases (10.27%), including type Ⅱ in 35 cases, type Ⅲ in 38 cases, and other types in 98 cases. Hepatic vein: type Ⅰ (normal) in 1 195 cases (71.77%),variant hepatic veins in 470 cases(28.23%), including type Ⅱ in 376 cases and type Ⅲ in 94 cases. Portal vein:normal type in 1 315 cases (78.98%), variant portal veins in 350 cases (21.02%), including type Ⅰ in 189 cases, type Ⅱin 103 cases, type Ⅲ in 50 cases, type Ⅳ in 8 cases. Hepatic artery variation coexisting with portal vein variation in 24 cases (1.44%). Hepatic vein variation coexisting with portal vein variation in 113 cases (6.79%). Three types of vascular variation in 4 cases (0.24%), including coexistence of type Ⅱ hepatic artery variation or type Ⅰ portal vein variation with type Ⅲ hepatic vein variation in 2 cases,coexistence of type Ⅲ hepatic artery variation or type Ⅲ portal vein variation with type Ⅱ hepatic vein variation in 2 cases. (3) Preoperative liver volume calculation:1 499.3 (514.4)ml (range:641.7 to 6 637.0 ml) of total liver volume, including 479.1 (460.1) ml (range:10.5 to 2 086.8 ml) for liver resection and 959.9 (460.4)ml (range:306.1 to 5 638.0 ml) for residual function. (4)Operative methods: anatomical hepatectomy in 1 458 cases (87.57%); non-anatomic hepatectomy in 207 cases (12.43%). (5)the median operation time was 285(165)minutes (range: 40 to720 minutes). (6)The median intraoperative blood loss was 200(250)ml (range:10 to 4 200 ml) and 346 cases (20.78%) had intraoperative transfusion. (7)Pathology reports: hepatocellular carcinoma in 1 371 cases (82.34%), cholangiocarcinoma in 260 cases (15.62%) and mixed hepatocellular carcinoma in 34 cases (2.04%). Microvascular invasion: M0 in 199 cases, M1 in 64 cases, and M2 in 27 cases. (8)Postoperative complications in 207 cases (12.43%), including Clavien-Dindo grade Ⅰ or Ⅱ in 57 cases, grade Ⅲ or Ⅳ in 147 cases and grade Ⅴ in 3 cases.There were 13 cases (0.78%) of liver failure and 3 cases (0.18%) of perioperative death. (9) The follow-up time was 3.0 to 96.0 months, with a median time of 21.0(17.8) years. The overall 3-year survival and disease-free survival rates were 80.0% and 56.5%, respectively. The overall 5-year survival and disease-free survival rates were 59.7% and 30.0%, respectively. Conclusion: 3D visualization technology plays an important role in realizing accurate diagnosis of anatomical location and morphology of primary liver cancer, improving the success rate of surgery and reducing the incidence of complications.

AIKYATAN: mapping distal regulatory elements using convolutional learning on GPU

Background

The data deluge can leverage sophisticated ML techniques for functionally annotating the regulatory non-coding genome. The challenge lies in selecting the appropriate classifier for the specific functional annotation problem, within the bounds of the hardware constraints and the model’s complexity. In our system Aikyatan, we annotate distal epigenomic regulatory sites, e.g., enhancers. Specifically, we develop a binary classifier that classifies genome sequences as distal regulatory regions or not, given their histone modifications’ combinatorial signatures. This problem is challenging because the regulatory regions are distal to the genes, with diverse signatures across classes (e.g., enhancers and insulators) and even within each class (e.g., different enhancer sub-classes).

Results

We develop a suite of ML models, under the banner Aikyatan, including SVM models, random forest variants, and deep learning architectures, for distal regulatory element (DRE) detection. We demonstrate, with strong empirical evidence, deep learning approaches have a computational advantage. Plus, convolutional neural networks (CNN) provide the best-in-class accuracy, superior to the vanilla variant. With the human embryonic cell line H1, CNN achieves an accuracy of 97.9% and an order of magnitude lower runtime than the kernel SVM. Running on a GPU, the training time is sped up 21x and 30x (over CPU) for DNN and CNN, respectively. Finally, our CNN model enjoys superior prediction performance vis-‘a-vis the competition. Specifically, Aikyatan-CNN achieved 40% higher validation rate versus CSIANN and the same accuracy as RFECS.

Conclusions

Our exhaustive experiments using an array of ML tools validate the need for a model that is not only expressive but can scale with increasing data volumes and diversity. In addition, a subset of these datasets have image-like properties and benefit from spatial pooling of features. Our Aikyatan suite leverages diverse epigenomic datasets that can then be modeled using CNNs with optimized activation and pooling functions. The goal is to capture the salient features of the integrated epigenomic datasets for deciphering the distal (non-coding) regulatory elements, which have been found to be associated with functional variants. Our source code will be made publicly available at: https://bitbucket.org/cellsandmachines/aikyatan.

Electronic supplementary material

The online version of this article (10.1186/s12859-019-3049-1) contains supplementary material, which is available to authorized users.

[Application of augmented-reality surgical navigation technology combined with ICG molecular fluorescence imaging in laparoscopic hepatectomy]

Objective: To study the application value of augmented-reality (AR) surgical navigation technology combined with indocyanine green (ICG) molecular fluorescence imaging in three-dimensional (3D) laparoscopic hepatectomy. Methods: The clinical data of forty-eight patients who had undergone 3D laparoscopic hepatectomy for hepatocellular carcinoma at First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University from January 2018 to April 2019 were retrospectively analyzed.The patients were divided into two groups: the group of 3D laparoscopic hepatectomy navigated by augment reality technology combined with ICG molecular fluorescence imaging (Group A) , and group of conventional 3D laparoscopic hepatectomy (Group B) . Patients in Group A (n=23) underwent 3D laparoscopic hepatectomy using augmented-reality technology combined with ICG molecular fluorescence imaging. In this group, the self-developed three-dimensional laparoscopic augmented-reality surgical navigation system (No. 2018SR840555) was operated to project the preoperative three-dimensional model to the surgical field, and the use of this system in combination with ICG molecular fluorescence imaging navigated laparoscopic hepatectomy. No surgical navigation technology was applied in Group B (n=25) . All patients signed the informed consent, which were in accordance with the requirements of medical ethics (Ethics No.: 2018-GDYK-003) . The preoperative data, surgical indicators and postoperative complications between the two groups were compared and analyzed. Results: The median amount of intraoperative blood loss of Group A was 250 (200) ml (M (Q(R)) ) , which was significantly lower than that of Group B (300 (150) ml) (Z=-2.307, P=0.021) .The transfusion rate of Group A was 13.0% (3/23) , which was significantly lower than that of Group B (40.0%, 10/25) (χ(2)=4.408, P=0.036) .The median postoperative hospitalization time of Group A was 8 (2) d, which was significantly shorter than that of Group B (11 (6.5) d) (Z=-2.694, P=0.007) . There were no serious complications and perioperative death in both groups.The incidence of postoperative complications in Group A was 17.4% (4/23) , which was not significantly different from that in group B (28%, 7/25) (χ(2)=0.763, P=0.382) . Conclusion: Augmented-reality surgical navigation technology combined with ICG molecular fluorescence imaging has better effect in 3D laparoscopic hepatectomy.

[Application of liver three-dimensional visualization technologies in the treatment planning of hepatic malignant tumor]

Objective: To discuss the application of three dimentional(3D)visualization technologies in treatment plan of hepatic malignant tumor. Methods: The clinical data of 300 patients with liver malignant tumor who received treatment from January 2016 to January 2017 in the Third Department of Hepatic Surgery of Eastern Hepatobiliary Surgery Hospital was retrospectively analyzed in this study, including 221 male and 79 female patients aged from 7 to 76 years with median age of 54 years. The median height was 168 cm (115-183 cm), the median weight was 65 kg (20-105 kg) and the median tumor volume was 142 ml (23-2 493 ml). Three-dimensional visualization technology was used in all patients to reconstruct liver three-dimensional graphics. Also, two and three-dimensional methods were taken respectively to evaluate patients and develop treatment strategy. The change of treatment strategy caused by 3D evaluation, actual surgical plan, operation time, time of hepatic vascular occlusion, intraoperative blood loss, volumes of blood transfusion and postoperative complications was observed. Results: After three-dimensional visualization technology was applied, 75(25%) of 300 patients' treatment strategies had been changed. The range of hepatectomy was extended in 25 patients. And 7 of them were due to hepatic venous variation, which resulted in increasing drainage area. In other 4 patients, liver resections were extended due to lack of perfusion of the liver parenchyma after the removal of portal vein. And hepatectomy was expanded in 14 patients in order to increase the surgical margin. The range of hepatectomy was reduced in 8 patients, 4 of which were due to hepatic venous variation, such as hepatic vein of segment 4 or lower right posterior hepatic vein. The remaining 4 cases were because of insufficient residual liver volume.The surgical resection was performed in 278 cases, 257 of which received operation directly. Left hepatectomy was performed in 24 patients and right hepatectomy was performed in 33 patients. Left trisectionectomy was carried out in 12 patients and right trisectionectomy was carried out in 11 patients. Caudate lobectomy was applied in 10 patients. There were 18 cases of left lateral sectionectomy, 7 cases of right anterior sectionectomy, 25 cases of right posterior sectionectomy and 18 cases of mesohepatectomy. Single or multi segment resection was performed in 99 patients. The treatment strategy of thirty-six patients was converted to staged hepatectomy (ALPPS 11 cases and portal vein embolization 25 cases). The median operation time was 130 minutes (90-360 minutes) and the median inflow blood occlusion time was 20 minutes (0-75 minutes). Median blood loss volume was 200 ml (20-1 600 ml). Thirty-seven of 278 patients received transfusions, and the average red blood transfusion volume was (4.4±1.7)units (0-8 units). Median hepatic resection volume was 530 ml(30-2 600 ml). There were 117 cases of pleural effusion after operation, including 3 patients needing invasive therapy. Ascites occurred in 23 patients, 6 of whom needed invasive therapy. Biliary leakage was observed in 30 patients. Eight patients occurred hepatic cutting surface hemorrhage, 6 of whom received blood transfusion, and 4 of whom underwent laparotomy to stop bleeding. Three patients had pulmonary infection after surgery and 3 patients appeared biliary obstruction. Deep vein thrombosis took place in 2 patients and portal vein thrombosis was observed in 4 patients. No postoperative liver failure and death ever happened in our study group. Conclusion: Three-dimensional visualization technique can optimize the treatment strategy of patients with liver malignant tumor, improve surgical safety.

[Selective preimplantation pathological evaluation in renal transplantation: a single center's experience]

Objective: To summarize the clinical data of pre-implantation biopsy donors in our hospital and explore the clinical characteristics of those donors in pathological high-risk, and to provide references for the selective histological evaluation of extended criteria donor kidneys. Methods: We retrospectively reviewed the clinical data and pre-implantation renal pathologic score of donors from January 1, 2015 to May 1, 2017.During this period, 247 cases of donation after citizen's death (DCD) occurred.After clinical evaluation and selective machine perfusion( Lifeport) evaluation, 30 cases of pre-implantation pathological evaluation were performed.According to Remuzzi scores, donors were divided into low-risk and high-risk group.Nine cases of low-risk group (bilateral kidney's Remuzzi score ≤3) and 16 cases of high-risk group (bilateral or unilateral kidney's Remuzzi score ≥4, severe glomerular micro-thrombi or severe tubular necrosis) were included.Five cases of donors were excluded due to only unilateral renal pathological result available.Both high-risk and low-risk groups' clinical data, including sex, age, height, body weight, body mass index, proteinuria, hematuria, urinary glucose, baseline or admission serum creatinine, serum creatinine before procurement, history of hypertension and/or diabetes mellitus, cardiopulmonary resuscitation or not, with or without the history of shock, urine output prior to acquisition, macroscopical manifestations of donor kidney, cause of death were statistically analyzed. Results: The donors' baseline serum creatinine/upper limit of normal serum creatinine range in high-risk group were significantly higher than that in low-risk group [(129.8±42.2)% vs(92.4±30.5)%, P=0.029]. The poor macroscopical manifestations of donor kidneys were significantly more frequent in high-risk group than that in low-risk group (12/16 vs 0/9, P= 0). No significant differences between two groups were found regarding their age, height, weight, BMI, proteinuria, hematuria, urine glucose, pre-procure creatinine level, history of hypertension and/or diabetes mellitus, cause of death and so on (P>0.05). Conclusions: After clinical evaluation and selective Lifeport evaluation, donor grafts of whose baseline serum creatinine levels increased beyond normal range and of whose grafts' macroscopical manifestations were poor, should undergo pre-implantation pathological evaluation further.Also, it is reasonable to perform pre-implantation biopsy in cases of equivocal results after Lifeport evaluation.This will be beneficial to identify histological high-risk donors and also be predictive to allocate the grafts.

[The construction of three-dimensional visualization platform and its application in diagnosis and treatment for hilar cholangiocarcinoma]

OBJECTIVE

To explore the construction and clinical efficacy of three-dimensional(3D) visualization platform about diagnosis and treatment of hilar cholangiocarcinoma.

METHODS

From January 2009 to December 2015, a total of 32 patients with hilarcholangiocarcinoma treated in Zhujiang Hospital of Southern Medical University were analyzed.There were 20 male and 12 female patients aged from 40 to 85 years. Bismuth-Corlette 3D visualization type: 2 cases with type Ⅰ, 5 cases with type Ⅱ, 10 cases with type Ⅲa, 11 cases with type Ⅲb, 4 cases with type Ⅳ.Among 32 cases, there were 5 cases who were established liver 3D printing models to guide intraoperative real-time navigation.The clinical effect of this platform was evaluated by the operation time, intraoperative blood loss, laboratory test and postoperative complications.The 3D visualization platform consists of the preoperative surgical planning with the aid of virtual 3D reconstruction technology and intraoperative real-time navigation with 3D printing models.

RESULTS

The liver 3D models for all patients were constructed successfully, they could clearly show intrahepatic pipeline, size and location of tumors, relationship between tumor and intrahepatic pipeline.The 3D printing models could accomplish real-time intraoperative navigation surgery with strong stereoscopic sense.According to Bismuth classification 3D visualization type, 2 patients with type Ⅰ received local excision of tumor and choledochojejunostomy; 5 patients with type Ⅱ received resection of segment Ⅰ, Ⅳb and partial Ⅴ combined with choledochojejunostomy; 10 patients with type Ⅲa received right semi-hepatectomy combined with resection of segment Ⅰ and choledochojejunostomy; 11 cases with type Ⅲb received left semi-hepatectomy combined with resection of segment Ⅰ and choledochojejunostomy; 4 cases with type Ⅳ received resection of segment Ⅳb and Ⅴ combined with choledochojejunostomy.The operation time was 270-660 minutes; the mean intraoperative blood loss was 588 ml; the mean postoperative hospital stay was 25 days.The bilirubin level three day after operation was 233 μmol/L.There was 1 case presented biliary fistula and cured by conservative treatment; there was no incision infection, no liver failure and no perioperative deaths occurred.

CONCLUSION

The 3D visualization is valuable for optimizing the operation scheme preoperatively and navigating surgery accurately intraoperatively in real-time which may improve the precision of the operation and achieve better the recovery.

[The present status and future prospects of application of digital medical technology in general surgery in China]

It has been almost 10 years since digital medical technology has started to becommonly used in general surgery in China.Led by advances in three dimensional(3D) visualization technology, virtual reality, simulation surgery, and 3D printing, digital medical technology have played important roles in changing the current practice of general surgery in China to become more effective by improving diagnostic accuracy and a better choice of therapeutic procedure with a resultant increased surgical success rate and a decreased surgical risks.Furthermore, education of medical students and young doctors become better and easier.

[Application of indocyanine green-fluorescent imaging technique in planning resection line and real-time surgical navigation in small hepatocellular carcinoma]

Objective: To explore the value of near-infrared technology guided by indolecyanine green(ICG) in planning resection line and real-time surgical navigation in small liver cancer. Methods: From March to September 2015, 11 patients with hepatic tumors received hepatectomy were treated in First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University.There were 5 male and 6 female patients with average age of (55±10)years (range 39-70 years). Among whom, there were 9 cases with hepatocellular carcinoma and 2 cases with colorectal cancer. A near-infrared light camera system was used to detect the liver surfaces before resection, and to plan resection line and surgical specimens. A student's t test was used to compare continuous parametric variables. Results: The ICG-fluorescent imaging and histological examination had been used in the 15 lesions of the 11 patients. Among the 15 lesions, 7 lesions were detected by visual inspections, palpation and ICG-fluorescent imaging, 6 lesions were identified only by ICG-fluorescent imaging, 2 lesions were detected only by ICG-fluorescent imaging after resection.Results of pathologic examination indicated that the total fluorescent type include 5 well differentiated hepatocellular carcinoma and 2 cirrhotic nodule; the partial fluorescent type include 3 moderately differentiated hepatocellular carcinomas and 1 well differentiated hepatocellular carcinomas; the rim fluorescent type included 2 liver metastatic carcinoma and 2 poorly differentiated hepatocellular carcinomas. The average diameter of the tumor size measured by CT was (1.7±0.2)cm, while the average diameter measured by ICG-fluorescent imaging was (1.7±0.3)cm(t=-0.188, P>0.05). Conclusion: Near-infrared technology guided by ICG has important value in planning resection line and real-time surgical navigation in small liver cancer.

[The application value of two-dimensional image technology and three-dimensional visualization technology in hepatocellular carcinoma treated by associating liver partition and portal vein ligation for staged hepatectomy: a preliminary study]

OBJECTIVE

To preliminarily explore the application value of two-dimensional image technology and three-dimensional visualization technology in hepatocellular carcinoma(HCC) treated by associating liver partition and portal vein ligation for staged hepatectomy(ALPPS).

METHODS

Clinical data of nineteen HCC patients treated by ALPPS were retrospectively analyzed in Sun-Yat-Sen Memorial Hospital of Sun Yat-Sen University from August 2013 to May 2015.Preoperative assessment, surgical planning and intraoperative guidance were assisted by traditional two-dimensional imaging technology(group 2D) in 15 cases, and the rest 4 cases were assisted by three-dimensional visualization technology(group 3D).

RESULTS

Three-dimensional visualization technology offered precise, visual, and distinct images, calculated the liver volume precisely, achieved virtual simulation operations, and assisted the formulation of intraoperative decisions.The mean operation time of the first stage were(331.3±61.7)minutes and (261.3±21.4)minutes in group 2D and group 3D, and the mean volume of intraoperative bleedings were (360.7±51.9)ml and (300.0±40.8)ml, respectively.The mean operation time of the second stage were (199.3±41.0)minutes and (170.0±29.4)minutes in group 2D and group 3D, and the mean volume of intraoperative bleedings were (285.3±132.6)ml and (257.5±99.5)ml, respectively.The mean interval time between two stages of operations were (15.3±6.5)d and (13.8±5.1)d in group 2D and group 3D, and the mean hospital stays were (39.3±5.8)d and (31.5±7.5)d, respectively.There were 4 cases and 12 cases who accepted the second stage operation in group 2D and group 3D respectively.There were 7 cases(4 with grade A, 2 with grade B, 1 with grade C) and 2 cases(1 with grade A, 1 with grade B) with post-hepatectomy liver failure and 9 cases(4 with grade Ⅰ, 2 with grade Ⅱ, 1 with grade Ⅲ, 2 with grade Ⅳ) and 3 cases (1 with grade Ⅰ, 1 with grade Ⅱ, 1 with grade Ⅲ)with postoperative complications in group 2D and group 3D respectively.There were 2 cases and 0 case died after operation in group 2D and group 3D respectively.There were 3 cases and 1 case who were recurrent and 4 cases and 1 case died 6 months after surgery in group 2D and group 3D respectively.

CONCLUSION

Three-dimensional visualization technology assisted the formulation of preoperative assessments and surgical planning individually and precisely, which displayed potential application value in HCC treated by ALPPS.

[The clinical application of three dimention printing technology]

In recent years, the three-dimentional(3D)printing technology is gradually applied in medicine.Now, the 3D printing has already play an important role in medical education, surgical device development, prosthesis implantation and so on.There are still many challenges and difficulties in the clinical overall application of 3D printing for some time, but it also contains a huge application prospect.Once with appropriate applications of this technology, it will be a major breakthrough in iatrical history once more.

Opening up the blackbox: an interpretable deep neural network-based classifier for cell-type specific enhancer predictions

Background

Gene expression is mediated by specialized cis-regulatory modules (CRMs), the most prominent of which are called enhancers. Early experiments indicated that enhancers located far from the gene promoters are often responsible for mediating gene transcription. Knowing their properties, regulatory activity, and genomic targets is crucial to the functional understanding of cellular events, ranging from cellular homeostasis to differentiation. Recent genome-wide investigation of epigenomic marks has indicated that enhancer elements could be enriched for certain epigenomic marks, such as, combinatorial patterns of histone modifications.

Methods

Our efforts in this paper are motivated by these recent advances in epigenomic profiling methods, which have uncovered enhancer-associated chromatin features in different cell types and organisms. Specifically, in this paper, we use recent state-of-the-art Deep Learning methods and develop a deep neural network (DNN)-based architecture, called EP-DNN, to predict the presence and types of enhancers in the human genome. It uses as features, the expression levels of the histone modifications at the peaks of the functional sites as well as in its adjacent regions. We apply EP-DNN to four different cell types: H1, IMR90, HepG2, and HeLa S3. We train EP-DNN using p300 binding sites as enhancers, and TSS and random non-DHS sites as non-enhancers. We perform EP-DNN predictions to quantify the validation rate for different levels of confidence in the predictions and also perform comparisons against two state-of-the-art computational models for enhancer predictions, DEEP-ENCODE and RFECS.

Results

We find that EP-DNN has superior accuracy and takes less time to make predictions. Next, we develop methods to make EP-DNN interpretable by computing the importance of each input feature in the classification task. This analysis indicates that the important histone modifications were distinct for different cell types, with some overlaps, e.g., H3K27ac was important in cell type H1 but less so in HeLa S3, while H3K4me1 was relatively important in all four cell types. We finally use the feature importance analysis to reduce the number of input features needed to train the DNN, thus reducing training time, which is often the computational bottleneck in the use of a DNN.

Conclusions

In this paper, we developed EP-DNN, which has high accuracy of prediction, with validation rates above 90 % for the operational region of enhancer prediction for all four cell lines that we studied, outperforming DEEP-ENCODE and RFECS. Then, we developed a method to analyze a trained DNN and determine which histone modifications are important, and within that, which features proximal or distal to the enhancer site, are important.

Subset selection of high-depth next generation sequencing reads for de novo genome assembly using MapReduce framework

BACKGROUND

Recent progress in next-generation sequencing technology has afforded several improvements such as ultra-high throughput at low cost, very high read quality, and substantially increased sequencing depth. State-of-the-art high-throughput sequencers, such as the Illumina MiSeq system, can generate ~15 Gbp sequencing data per run, with >80% bases above Q30 and a sequencing depth of up to several 1000x for small genomes. Illumina HiSeq 2500 is capable of generating up to 1 Tbp per run, with >80% bases above Q30 and often >100x sequencing depth for large genomes. To speed up otherwise time-consuming genome assembly and/or to obtain a skeleton of the assembly quickly for scaffolding or progressive assembly, methods for noise removal and reduction of redundancy in the original data, with almost equal or better assembly results, are worth studying.

RESULTS

We developed two subset selection methods for single-end reads and a method for paired-end reads based on base quality scores and other read analytic tools using the MapReduce framework. We proposed two strategies to select reads: MinimalQ and ProductQ. MinimalQ selects reads with minimal base-quality above a threshold. ProductQ selects reads with probability of no incorrect base above a threshold. In the single-end experiments, we used Escherichia coli and Bacillus cereus datasets of MiSeq, Velvet assembler for genome assembly, and GAGE benchmark tools for result evaluation. In the paired-end experiments, we used the giant grouper (Epinephelus lanceolatus) dataset of HiSeq, ALLPATHS-LG genome assembler, and QUAST quality assessment tool for comparing genome assemblies of the original set and the subset. The results show that subset selection not only can speed up the genome assembly but also can produce substantially longer scaffolds.

AVAILABILITY

The software is freely available at https://github.com/moneycat/QReadSelector.

Feasibility study on identification of green, black and Oolong teas using near-infrared reflectance spectroscopy based on support vector machine (SVM)

Near-infrared (NIR) spectroscopy has been successfully utilized for the rapid identification of green, black and Oolong teas. The spectral features of each category are reasonably differentiated in the NIR region, and the spectral differences provided enough qualitative spectral information for identification. Support vector machine as a pattern recognition was applied to attain the differentiation of the three tea categories in this study. The top five latent variables are extracted by principal component analysis as the input of SVM classifiers. The identification results of the three tea categories were achieved by the RBF SVM classifiers and the polynomial SVM classifiers in different parameters. The best identification accuracies were up to 90%, 100% and 93.33%, respectively, when training, while, 90%, 100% and 95% when test. It was obtained using the RBF SVM classifier with sigma=0.5. The overall results ensure that NIR spectroscopy combined with SVM discrimination method can be efficiently utilized for rapid and simple identification of the different tea categories.

Three dimensional reconstruction of the pancreas based on the virtual Chinese human--female number 1

OBJECTIVE

To study the three dimensional (3D) reconstruction and 3D visualisation of the pancreas and create anatomy of the digitalised visual pancreas so as to construct a concrete basis for virtual operation and surgical operation on pancreas.

METHODS

The digital imaging data of pancreas, duodenum, common bile duct, arteries, and veins were obtained from the virtual Chinese human--female 1 (VCH-F1). The image data were investigated and 380 images ascertained of pancreas picked up from images numbers 2617 to 2996. Finally, the images from number 2574 to 3017 were adopted to segment and processed using ACDSee and Photoshop so as to reconstruct 3D pancreas digitally. The data of pancreatic surfaces were transformed into Visualization Toolkit (VTK). The GUI program written with VC+ was used to display this VTK file and realise 3D visualisation of the pancreas.

RESULTS

3D reconstruction and visualisation of the pancreas and the peri-pancreatic structures (the duodenum, the common bile duct,the inferior vena cava, the portal vein vessels, the aorta, the coeliac trunk vessels) was successful. The 3D and visualised pancreas manifested itself with its complete structure as well as its adjacency to other tissues.

CONCLUSION

The 3D reconstruction and 3D visualisation of the pancreas based on the digital data of VCH-F1 produces a digitally visualised pancreas, which promises a novel method for virtual operation on the pancreas, clinical operation on the pancreas, and anatomy of 3D visualised pancreas.

Qualitative identification of tea categories by near infrared spectroscopy and support vector machine

Near-infrared (NIR) spectroscopy has been successfully utilized for the rapid identification of green, black and Oolong tea. The spectral features of each tea category are reasonably differentiated in the NIR region, and the spectral differences provided enough qualitative spectral information for the identification of tea. Support vector machine (SVM) as the pattern recognition was applied to identify three tea categories in this study. The top five principal components (PCs) were extracted as the input of SVM classifiers by principal component analysis (PCA). The RBF SVM classifiers and the polynomial SVM classifiers were studied comparatively in this experiment. The best experimental results were obtained using the radial basis function (RBF) SVM classifier with sigma=0.5. The accuracies of identification were all more than 90% for three tea categories. Finally, compared with the back propagation artificial neural network (BP-ANN) approach, SVM algorithm showed its excellent generalization for identification results. The overall results show that NIR spectroscopy combined with SVM can be efficiently utilized for rapid and simple identification of the tea categories.

Qualitative identification of tea categories by near infrared spectroscopy and support vector machine

Near-infrared (NIR) spectroscopy has been successfully utilized for the rapid identification of green, black and Oolong tea. The spectral features of each tea category are reasonably differentiated in the NIR region, and the spectral differences provided enough qualitative spectral information for the identification of tea. Support vector machine (SVM) as the pattern recognition was applied to identify three tea categories in this study. The top five principal components (PCs) were extracted as the input of SVM classifiers by principal component analysis (PCA). The RBF SVM classifiers and the polynomial SVM classifiers were studied comparatively in this experiment. The best experimental results were obtained using the radial basis function (RBF) SVM classifier with sigma=0.5. The accuracies of identification were all more than 90% for three tea categories. Finally, compared with the back propagation artificial neural network (BP-ANN) approach, SVM algorithm showed its excellent generalization for identification results. The overall results show that NIR spectroscopy combined with SVM can be efficiently utilized for rapid and simple identification of the tea categories.

Intestinal permeability is reduced and IL-10 levels are increased in septic IL-6 knockout mice

Sepsis is associated with increased intestinal permeability, but mediators and mechanisms are not fully understood. We examined the role of interleukin (IL)-6 and IL-10 in sepsis-induced increase in intestinal permeability. Intestinal permeability was measured in IL-6 knockout (IL-6 -/-) and wild-type (IL-6 +/+) mice 16 h after induction of sepsis by cecal ligation and puncture or sham operation. In other experiments, mice or intestinal segments incubated in Ussing chambers were treated with IL-6 or IL-10. Intestinal permeability was assessed by determining the transmucosal transport of the 4.4-kDa marker fluorescein isothiocyanate conjugated dextran and the 40-kDa horseradish peroxidase. Intestinal permeability for both markers was increased in septic IL-6 +/+ mice but not in septic IL-6 -/- mice. Treatment of nonseptic mice or of intestinal segments in Ussing chambers with IL-6 did not influence intestinal permeability. Plasma IL-10 levels were increased in septic IL-6 -/- mice, and treatment of septic mice with IL-10 resulted in reduced intestinal permeability. Increased intestinal permeability during sepsis may be regulated by an interaction between IL-6 and IL-10. Treatment with IL-10 may prevent the increase in mucosal permeability during sepsis.

Burn injuries in rats upregulate the gene expression of the ubiquitin-conjugating enzyme E2(14k) in skeletal muscle

Burn injuries are associated with muscle cachexia, which mainly reflects protein breakdown in the ubiquitin-proteasome pathway. Ubiquitination of proteins degraded by this mechanism is regulated by multiple enzymes, including the 14-kd ubiquitin-conjugating enzyme, E2(14k). In this study, burn injuries in rats resulted in increased levels of the 1.2 kilobase E2(14k) transcript in the white, fast-twitch extensor digitorum longus muscle with no changes or only minor changes in the red, slow-twitch soleus muscle, liver, and kidney. The results provide the first evidence that burn injuries upregulate the gene expression of E2(14k) in skeletal muscle and suggest that ubiquitin-proteasome-dependent muscle protein breakdown after thermal injuries may, at least in part, be regulated by E2(14k).

Burn injury upregulates the activity and gene expression of the 20 S proteasome in rat skeletal muscle

There is evidence that burn injury stimulates ubiquitin-proteasome-dependent protein breakdown in skeletal muscle. In this proteolytic pathway, protein substrates are conjugated to multiple molecules of ubiquitin, whereafter they are recognized, unfolded and degraded by the multicatalytic 26 S protease complex. The 20 S proteasome is the catalytic core of the 26 S protease complex. The influence of burn injury on the expression and activity of the 20 S proteasome has not been reported. We tested the hypothesis that burn injury increases 20 S proteasome activity and the expression of mRNA for the 20 S proteasome subunits RC3 and RC7. Proteolytic activity of isolated 20 S proteasomes, assessed as activity against fluorogenic peptide substrates, was increased in extensor digitorum longus muscles from burned rats. Northern-blot analysis revealed that the expression of mRNA for RC3 and RC7 was increased by 100% and 80% respectively following burn injury. Increased activity and expression of the 20 S proteasome in muscles from burned rats support the concept that burn-induced muscle cachexia is at least, in part, regulated by the ubiquitin-proteasome proteolytic pathway.

Insulin-like growth factor I reduces ubiquitin and ubiquitin-conjugating enzyme gene expression but does not inhibit muscle proteolysis in septic rats

We examined the effect of insulin-like growth factor I (IGF-I), administered in vivo, on protein turnover rates and gene expression of the ubiquitin-proteasome proteolytic pathway in skeletal muscle of septic rats. Sepsis was induced by cecal ligation and puncture. Other rats were sham-operated. Miniosmotic pumps were implanted sc, and groups of rats received IGF-I (7 mg/kg x 24 h) or saline. Protein synthesis and breakdown rates were determined in incubated extensor digitorum longus muscles. Messenger RNA levels for ubiquitin and the ubiquitin-conjugating enzyme E2(14k) were determined by Northern blot analysis. Sepsis resulted in an approximately 30% reduction of muscle protein synthesis, and this effect of sepsis was blunted in rats treated with IGF-I. In contrast, IGF-I did not prevent the sepsis-induced increase in total and myofibrillar muscle protein breakdown. Ubiquitin and E2(14k) messenger RNA levels were increased several fold in muscle from septic rats, and this effect of sepsis was abolished in IGF-I treated rats. The results suggest that administration of IGF-I may improve sepsis-induced muscle cachexia by stimulating protein synthesis. However, because muscles were resistant to IGF-I, with regard to regulation of protein breakdown, the use of IGF-I to treat muscle cachexia during sepsis remains unclear. An additional important implication of the present study is that changes in messenger RNA levels for ubiquitin and the ubiquitin-conjugating enzyme E2(14k) do not always reflect changes in muscle protein breakdown rates.

Degradation of methoxysuccinyl-phe-leu-phe-7-amido-4-trifluoromethyl coumarin (FLF) in cultured myotubes and HepG2 cells is proteasome- and calpain/calcium-dependent

During recent years, it has become increasingly clear that the ubiquitin-proteasome proteolytic pathway regulates intracellular protein degradation in various physiological and pathophysiological conditions. Substrates specifically degraded by the proteasome are important tools to assess the involvement of the proteasome in cellular proteolysis. It was recently proposed that the membrane permeable substrate methoxysuccinyl-phenylalanine-leucine-phenylalanine-7-amido-4- trifluoromethyl coumarin (FLF) is degraded specifically by the proteasome. The role of other proteolytic pathways in the degradation of FLF, however, is not fully understood. In the present study, we tested the role of different proteolytic pathways in the degradation of FLF in cultured myotubes and HepG2 cells by treating the cells with inhibitors of lysosomal, calpain and proteasome activity. In addition, we tested the hypothesis that insulin blocks proteasome-dependent degradation of FLF in myotubes and HepG2 cells. Results suggest that degradation of FLF in both myotubes and HepG2 cells is regulated by proteasome and calpain activity but not by lysosomal activity. Insulin inhibited proteasome-dependent but not calpain-dependent degradation of FLF in both myotubes and HepG2 cells. The results are important because they suggest that FLF degradation does not specifically reflect proteasome activity.

Treatment of burned rats with insulin-like growth factor I inhibits the catabolic response in skeletal muscle

Thermal injury is associated with a pronounced catabolic response in skeletal muscle, reflecting inhibited protein synthesis and increased protein breakdown, in particular myofibrillar protein breakdown. Administration of insulin-like growth factor I (IGF-I) has a nitrogen-sparing effect after burn injury, but the influence of this treatment on protein turnover rates in skeletal muscle is not known. In the present study, we examined the effect of IGF-I on muscle protein synthesis and breakdown rates following burn injury in rats. After a 30% total body surface area burn injury or sham procedure, rats were treated with a continuous infusion of IGF-I (3. 5 or 7 mg . kg-1 . 24 h-1) for 24 h. Protein synthesis and breakdown rates were determined in incubated extensor digitorum longus muscles. Burn injury resulted in increased total and myofibrillar protein breakdown rates and reduced protein synthesis in muscle. The increase in protein breakdown rates was blocked by both doses of IGF-I and the burn-induced inhibition of muscle protein synthesis was partially reversed by the higher dose of the hormone. IGF-I did not influence muscle protein turnover rates in nonburned rats. The results suggest that the catabolic response to burn injury in skeletal muscle can be inhibited by IGF-I.

Proteasome blockers inhibit protein breakdown in skeletal muscle after burn injury in rats

1. Burn injury stimulates ubiquitin-dependent protein breakdown in skeletal muscle. The 20S proteasome is the proteolytic core of the 26S proteasome that degrades ubiquitin conjugates. We examined the effects of the proteasome inhibitors N-acetyl-L-leucinyl-L-leucinal-L-norleucinal (LLnL), lactacystin and beta-lactone on protein breakdown in muscles from burned rats. 2. A full-thickness burn of 30% total body surface area was inflicted on the back of rats. Control rats underwent a sham procedure. After 24 h, extensor digitorum longus muscles were incubated in the absence or presence of 20S proteasome blocker and protein turnover rates and ubiquitin mRNA levels were determined. 3. LLnL resulted in a dose- and time-dependent inhibition of total protein breakdown in incubated muscles from burned rats. Lactacystin and beta-lactone blocked both total and myofibrillar muscle protein breakdown. In addition to inhibiting protein breakdown, LLnL increased ubiquitin mRNA levels, possibly reflecting inhibited proteasome-associated RNase activity. 4. Inhibited muscle protein breakdown caused by LLnL, lactacystin and beta-lactone supports the concept that the ubiquitin-proteasome pathway plays a central role in burn-induced muscle proteolysis. Because the proteasome has multiple important functions in the cell, in addition to regulating general protein breakdown, further studies are needed to test the role of proteasome blockers in the treatment or prevention of muscle catabolism.

The anabolic effects of IGF-1 in skeletal muscle after burn injury are not caused by increased cell volume

BACKGROUND

In a recent report, insulin-like growth factor 1 (IGF-1) stimulated protein synthesis and inhibited protein breakdown in skeletal muscle after bum injury. The mechanism of the anabolic effects of IGF-1 in skeletal muscle is not known. We tested the hypotheses that IGF-1 stimulates protein synthesis and inhibits protein breakdown in skeletal muscle secondary to cell swelling and that cell swelling in itself induces an anabolic response in muscle tissue.

METHODS

Extensor digitorum longus muscles from control and burned rats were incubated in the absence or presence of 1 microg/mL of IGF-1. Protein synthesis and breakdown rates were determined by measuring incorporation of 14C-phenylalanine into protein and net release of tyrosine, respectively. Cell volume was measured by determining wet and dry weight and by using 3H-mannitol as an extracellular marker.

RESULTS

IGF-1 stimulated protein synthesis and inhibited protein breakdown in muscles from nonburned and burned rats without influencing cell volume. Incubating muscles in hypo-osmotic medium increased cell volume by 17% and inhibited protein breakdown by 14% but did not influence protein synthesis.

CONCLUSIONS

The anabolic effects of IGF-1 in skeletal muscle are not caused by increased cell volume. The results differ from those reported previously in liver cells in which the anabolic effects of IGF-1 were associated with cell swelling. The role of changes in cell volume in the regulation of protein metabolism may be different in skeletal muscle than in other tissues.

The molecular regulation of protein breakdown following burn injury is different in fast- and slow-twitch skeletal muscle

We compared the effect of burn injury on the energy-ubiquitin-dependent proteolytic pathway in the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus muscle in rats. Rats were subjected to a 30% total body surface area full-thickness burn or sham procedure. At various time points after injury, total and myofibrillar protein breakdown rates were determined in incubated EDL and soleus muscles. The energy-dependent component of protein break-down was determined by incubating muscles in energy-depleting medium. Messenger RNA levels for ubiquitin and RC3, a 20S proteasome subunit, were measured by Northern blot analysis. Burn injury resulted in an approximately 50% increase in total protein breakdown and a 3-4 fold increase in myofibrillar protein breakdown in EDL muscles, and this response reflected increased energy-dependent protein breakdown. In contrast, protein breakdown rates were not significantly influenced by the burn injury in soleus muscles. Ubiquitin mRNA levels were increased almost 10-fold in EDL and approximately 4.5-fold in soleus muscles following burn injury. Burn injury resulted in a 2-fold increase in RC3 mRNA in EDL with no significant changes noted in soleus muscles. The results suggest that the more pronounced effect of burn injury on protein breakdown in fast-twitch than in slow-twitch muscle may reflect different regulation of proteolysis at the molecular level.

Cytokines block the effects of insulin-like growth factor-I (IGF-I) on glucose uptake and lactate production in skeletal muscle but do not influence IGF-I-induced changes in protein turnover

There is evidence that proinflammatory cytokines are involved in the regulation of muscle protein breakdown in various catabolic conditions but the mechanisms are not fully understood. Previous studies suggest that cytokines reduce circulating and tissue levels of insulin-like growth factor-I (IGF-I) and may block the anabolic effects of the hormone in certain cell types and tissues. We tested the hypothesis that a mixture of tumor necrosis factor alpha, interleukin-1 alpha, and interferon-gamma block the anabolic effects of IGF-I in skeletal muscle. Muscles from burned or unburned rats were incubated in the absence or presence of 1 microgram/mL of IGF-I with or without the addition of the cytokines. As expected, IGF-I stimulated protein synthesis and inhibited protein breakdown in incubated muscles. The cytokines did not influence protein turnover rates in muscles incubated with or without IGF-I. In additional experiments, the effects of IGF-I on glucose uptake and lactate production were tested. IGF-I increased glucose uptake approximately 2.5-fold and stimulated lactate production approximately 5-fold. These effects of the hormone were significantly inhibited by the cytokine mixture. The results suggest that cytokines do not induce protein catabolism by directly inhibiting the anabolic effects of IGF-I in muscle tissue. The inhibitory effects of the cytokines on IGF-I-stimulated glucose transport and lactate production suggest that the lack of effect of cytokines on protein metabolism was not due to a metabolic unresponsiveness of the incubated muscles to the cytokines.

Insulin-like growth factor 1 stimulates protein synthesis and inhibits protein breakdown in muscle from burned rats

BACKGROUND

Burn injury is associated with substantial whole-body protein loss, reflecting mainly a catabolic response in skeletal muscle. Recent studies suggest that treatment with insulin-like growth factor 1 (IGF-1) may reverse the catabolic response to burn injury, but the effects of IGF-1 on muscle protein synthesis and breakdown rates after burn injury are not known. We tested the hypothesis that IGF-1 blunts the catabolic response in skeletal muscle after burn injury by stimulating protein synthesis and inhibiting protein breakdown and that this effect of IGF-1 is caused by a direct effect on muscle tissue.

METHODS

Intact extensor digitorum longus muscles from burned, sham-burned, and untreated rats were incubated in the absence or presence of different concentrations of IGF-1. Total and myofibrillar protein breakdown rates were measured as net release of tyrosine and 3-methylhistidine, respectively. Protein synthesis rates were determined by measuring the incorporation of (U-14C)-phenylalanine into protein.

RESULTS

IGF-1 stimulated protein synthesis and inhibited protein breakdown in a dose-dependent fashion in muscles from burned and unburned rats. The maximal effect of IGF-1 on protein synthesis was seen at a hormone concentration of 100 ng/mL, whereas protein breakdown was further inhibited when the hormone concentration was increased to 1 microgram/mL. Ubiquitin messenger RNA (mRNA) levels were reduced by IGF-1 in incubated muscles, suggesting that IGF-1 may inhibit ubiquitin-dependent protein breakdown.

CONCLUSIONS

These results suggest that the anabolic effects of IGF-1 after burn may reflect inhibited protein breakdown and stimulated protein synthesis in skeletal muscle and that this response may be caused by a direct effect of IGF-1 on muscle tissue.

Linkage of aerobic glycolysis to sodium-potassium transport in rat skeletal muscle. Implications for increased muscle lactate production in sepsis

Although a linkage between aerobic glycolysis and sodium-potassium transport has been demonstrated in diaphragm, vascular smooth muscle, and other cells, it is not known whether this linkage occurs in skeletal muscle generally. Metabolism of intact hind-leg muscles from young rats was studied in vitro under aerobic incubation conditions. When sodium influx into rat extensor digitorum longus (EDL) and soleus muscles was facilitated by the sodium ionophore monensin, muscle weight gain and production of lactate and alanine were markedly stimulated in a dose-dependent manner. Although lactate production rose in both muscles, it was more pronounced in EDL than in soleus. Monensin-induced lactate production was inhibited by ouabain or by incubation in sodium-free medium. Preincubation in potassium-free medium followed by potassium re-addition also stimulated ouabain-inhibitable lactate release. Replacement of glucose in the incubation medium with pyruvate abolished monensin-induced lactate production but exacerbated monensin-induced weight gain. Muscles from septic or endotoxin-treated rats exhibited an increased rate of lactate production in vitro that was partially inhibited by ouabain. Increases muscle lactate production in sepsis may reflect linked increases in activity of the Na+, K+-ATPase, consumption of ATP and stimulation of aerobic glycolysis.

Activation of factor X by factor VIIa complexed with human-mouse tissue factor chimeras requires human exon 3

In an attempt to define sequence elements in human and mouse tissue factor (TF) that are responsible for the species specificity observed in their interaction with human factor VIIa (HVIIa), we constructed human-mouse chimeric TF cDNAs, inserted them into plasmid vectors, and induced their expression in E. coli. Assays for procoagulant activity were carried out with the resulting E. coli lysates using (HVIIa) human and mouse (MVIIa). The ratio of the procoagulant activities, HVIIa/MVIIa, revealed that human TF exon 3 was essential for activity when the TF:VIIa complex was formed with HVIIa. By ligating the maltose binding protein (MBP) gene to TF cDNAs it was possible to construct, express and purify MBP-TF chimeras as well as to estimate their specific activities. With selected MBP-TF chimeras and HVIIa we determined kinetic parameters for the activation of human factor X. Replacement of exon 3 in human TF cDNA with the corresponding exon from mouse TF cDNA resulted in both lower affinity for HVIIa and failure to convert bound HVIIa into a potent protease.

Ciliary neurotrophic factor is catabolic and shares with IL-6 the capacity to induce an acute phase response

Ciliary neurotrophic factor (CNTF), a member of the interleukin-6 (IL-6) superfamily, has recently been shown to induce several inflammatory responses when administered to healthy animals, including induction of fever and a hepatic acute phase protein response. In the present report, 250 micrograms.kg body wt-1.day-1 of recombinant rat CNTF or murine IL-6 were repeatedly administered to healthy mice over a 7-day period in an effort to compare biological responses. In addition to its in vivo capacity to elicit a hepatic acute phase response, administration of CNTF, but not IL-6, produced profound anorexia and lean tissue wasting in mice. In C57B1/6 mice, 7 days of CNTF administration led to a 21% loss in carcass protein content, resulting from carcass protein breakdown rates being increased 218% over freely fed controls (both P < 0.01). Protein synthesis rates in carcass protein were also increased in CNTF-treated mice compared with both freely fed animals and mice pair-fed equivalent quantities of food. In contrast, administration of equivalent quantities of murine IL-6 had no effect on food intake or body weight in mice, although IL-6 produced a similar hepatic acute phase response, as determined by increases in serum amyloid P and seromucoid fraction and increases in total hepatic protein synthesis. However, when CNTF was coincubated with extensor digitorum longus muscles from juvenile rats in vitro, rates of total muscle and myofibrillar protein degradation and muscle protein synthesis were unchanged. We conclude that CNTF can regulate in vivo both skeletal muscle remodeling as well as the distant anorexia and hepatic acute phase protein responses. In the case of skeletal muscle, these actions are both indirect and independent of the associated anorexia. These properties of CNTF are distinct from IL-6, which when administered to the mouse at these doses is neither anorexigenic nor cachexia producing.

Is muscle protein turnover regulated by intracellular glutamine during sepsis?

BACKGROUND

Low muscle glutamine levels during sepsis are associated with reduced protein synthesis and elevated protein breakdown, in particular myofibrillar protein breakdown. It is not known if this is a causal or coincidental relationship. We tested the hypothesis that muscle protein turnover rates are directly regulated by glutamine.

METHODS

Paired extensor digitorum longus muscles from nonseptic (sham-operated) and septic rats (16 hours after cecal ligation and puncture) were incubated in the absence or presence of 15 mmol glutamine/L. The effect of glutamine was tested in unsupplemented medium or in medium containing 1 mU/mL of insulin or a mixture of amino acids at normal plasma concentrations. Protein synthesis was measured as incorporation of 14C-phenylalanine into protein; total and myofibrillar protein breakdown was determined by measuring tyrosine and 3-methylhistidine, respectively.

RESULTS

Muscles accumulated intracellular glutamine well above normal concentrations in the presence of 15 mmol glutamine/L. In spite of this, protein synthesis was not affected by glutamine, neither when muscles were incubated in unsupplemented medium nor in medium containing insulin or amino acid mixture. Total protein breakdown was not influenced by glutamine when muscles were incubated in unsupplemented medium or with insulin but was reduced by glutamine in the presence of an amino acid mixture. Myofibrillar protein breakdown was unaffected by glutamine in unsupplemented medium and in medium containing insulin but was increased by glutamine in the presence of amino acid mixture.

CONCLUSION

Reduced muscle protein synthesis and increased myofibrillar protein breakdown during sepsis are probably not caused by the low intracellular glutamine levels noticed in this condition.

Burn injury stimulates multiple proteolytic pathways in skeletal muscle, including the ubiquitin-energy-dependent pathway

BACKGROUND

Burn injury is associated with increased muscle protein breakdown. However, the role of different intracellular proteolytic pathways in burn-induced muscle proteolysis is not known.

STUDY DESIGN

A 30 percent total body surface area burn injury was inflicted on rats. Total and myofibrillar proteolysis was determined in incubated extensor digitorum longus muscles as release of tyrosine and 3-methylhistidine, respectively. Lysosomal proteolysis was assessed by using the lysosomotropic agents leupeptin and methylamine. Calcium-dependent proteolysis was determined by incubating muscles in the absence or presence of calcium or by blocking the calcium-dependent proteases calpain I and II. Energy-dependent proteolysis was determined in muscles depleted of adenosine triphosphate (ATP) by 2-deoxyglucose and 2,4-dinitrophenol. Muscle ubiquitin messenger RNA (mRNA) was determined by Northern blot analysis to assess ATP-ubiquitin-dependent proteolysis.

RESULTS

Calcium-dependent total protein breakdown was stimulated in muscles from burned rats. However, the sensitivity to calcium in vitro was not increased after burn. The lysosomal and energy-dependent components of total protein breakdown were doubled in muscles from burned rats and the energy-dependent myofibrillar protein breakdown was increased almost seven-fold. Ubiquitin mRNA was increased in muscles from burned rats.

CONCLUSIONS

Burn injury stimulates multiple proteolytic pathways in skeletal muscle. The ubiquitin-energy-dependent pathway may be particularly important for the breakdown of myofibrillar proteins.

Influence of burn injury on protein metabolism in different types of skeletal muscle and the role of glucocorticoids

BACKGROUND

Negative nitrogen balance after burn injury mainly indicates muscle catabolism, but the exact influence of burn on protein synthesis and breakdown in different types of skeletal muscle and the role of glucocorticoids in this metabolic response are unknown.

STUDY DESIGN

A 30 percent body surface area flame burn was inflicted on rats. Protein turnover rates were measured in vitro in the white fast-twitch extensor digitorum longus (EDL) muscle and the red slow-twitch soleus muscle. To test the role of glucocorticoids, groups of rats were treated with the glucocorticoid receptor antagonist RU 38486 or vehicle.

RESULTS

Burns resulted in reduced protein synthesis and stimulated protein breakdown, in particular myofibrillar protein breakdown, and the changes were substantially more pronounced in the EDL than in the soleus muscle. A burn-induced increase in muscle proteolysis was abolished by treatment with RU 38486, whereas the reduced protein synthesis was not affected by the glucocorticoid receptor antagonist.

CONCLUSIONS

The results suggest that the white fast-twitch muscle is more sensitive to the effects of burn injury than the red slow-twitch muscle. Burn-induced muscle proteolysis may be mediated, at least in part, by glucocorticoids, whereas protein synthesis is probably regulated by other mechanisms.

[The effects of bFGF on the contraction of composite skin grafts]

The authors previously reported that a composite skin graft (CSG) consisting of allodermis graft overlaid with an isogenic epidermis accomplished permanent coverage of a full-thickness skin defect in one operation setting in a rat model. However, the CSG contracted more than the isogenic epidermis alone, presumably due to patchy necrosis of the CSG caused by inadequate blood supply to the isografts. The present study was designed to determine the effects of bFGF on CSG take and its contraction. Rats were divided into two groups. In the tested group the allodermis of CSG was treated with bFGF prior to grafting, while in the control group no treatment was administered. The results showed that the incidence of ischemic necrosis of the isograft was lowered and the area of necrotic patches was lessened in the bFGF group than the control (P < 0.05), and that the contraction of the CSG in the treated group was much less severe than the control as well (P < 0.001). It was found that the extent of necrosis of the CSG was negatively correlated with the resultant area of contraction (r = -0.450, P < 0.05). The study suggests that the ideal results may be obtained when the CSG contracts less than the simple isogenic epidermis graft, provided an optimum treatment modality of CSG by bFGF should be found.

[Clinical experience of the treatment of ipsilateral femoral shaft fractures after hip arthroplasty]

Femoral shaft fracture after hip arthroplasty is a rate problem. Between January 1983 and January 1989, twelve cases were admitted to Taichung Veteran General Hospital. The causes of the fractures were due to (1) a weakening of the bone stock secondary to stress risers from prior surgery, (2) prefracture evidence of loosening, and (3) high velocity trauma. The twelve cases were treated with different methods and were followed up within an average time of 21.6 months (ranging from 12 to 66 months). After the treatment, it was showed that 83.3% of the patients had satisfactory results (33.3% of the patients has good results and 50% of the patients had fair results.) A comparison of the superiority of different treatment methods and the short term results of this study was presented.

Observations on stability and contraction of composite skin grafts: xenodermis or allodermis with an isograft overlay

Composite skin grafts of xenodermis or allodermis with a thin split-thickness isograft overlay were evaluated for stability and contraction. Male inbred Lewis rats were used as recipients, with Buffalo rats serving as allogeneic dermis donors. Cryopreserved human skin was used for xenodermis grafts. The two components of the composite graft, the xenodermis or allodermis and the isograft overlay, were grafted in one operation to a surgically created wound. Wounds were observed for 1 year. The composite skin grafts took fairly well, although spotty loss of the overlaid isograft was noted. The xenodermis and allodermis remained grossly intact even at 1 year after grafting. However, composite skin grafts in this animal model contracted more than did sheet isografts alone.

[Clinical experience of hemiarthroplasty with Bateman bipolar endoprosthesis]

Between April 1985 and August 1986, 97 patients (101 hips) were treated with Bateman bipolar hemiarthroplasty after diagnosis of femoral neck fracture and ischemic necrosis of the femoral head at Veterans' General Hospital, Taichung. Seventy hips were followed up for an average of 44 months (range from 36 to 53 months). 58.6% of the patients had excellent or good results, 21.4% had fair results and 20% poor results. Twelve cases (17.1%) with thigh pain were diagnosed as have loosening of the stem and this was verified by X-ray and 99m Tc-MDP bone scan examination. 2 of these twelve cases received revisional total hip replacement. Wearing of the acetabulum was noted in only 2 patients (2.9%). From the short-term follow-up study, we would suggest that good results can be obtained with improved cementing technique or a special stem design to fit the different indications.

Wound contraction following transplantation of microskin autografts with overlaid skin allograft in experimental animals

The wound contraction associated with a new grafting technique, transplantation of microskin autografts with overlaid skin allograft, was evaluated in a rat model. Male inbred Lewis rats were used as microskin autograft recipients while Buffalo rats were used as allogeneic skin graft donors providing a sheet allograft for overlay. This technique was compared with the use of sheet isografts. Wound contraction was observed for 4 months. The results showed that the application of autologous microskin grafting with allograft overlay was associated with more scar contraction than was the use of a sheet isograft. Maximum contraction to 43 per cent of the original size appeared at 7 weeks postgrafting in the microskin grafting group, while in the sheet isografting group the greatest contraction occurred at 4 weeks postgrafting when it retained 72 per cent of the original size.

Comparison of scar contracture with the use of microskin and Chinese-type intermingled skin grafts on rats

Wounds that were measured precisely 4 x 5 cm in size were created over the dorsal surfaces of rats. The defects were grafted with the use of either the microskin or Chinese technique of intermingled auto/allograft with an expansion ratio of 10:1. The size of the grafted wound of each rat was recorded on the fifth graft day after grafting and then weekly for 11 weeks. The extent of scar contracture on each rat was calculated weekly as a percentage of the original size. The results showed that the scar contracture associated with the Chinese type of intermingled auto/allograft transplantation was less than that associated with the microskin technique. The healing process in both forms of grafting was uneventful.