Taking the mechanism of glucose catabolism disorder in depression as an example to explore the research ideas and strategies of stable isotope tracer metabolomics / 药学学报

Stable isotope tracer metabolomics tracks and analyzes the whole metabolic process of the body through the tracer atoms, which belongs to the frontier technology in the field of biomedicine. This technology is of great significance and value for explaining the pathogenesis of diseases, finding biomarkers of diseases and drug action targets. Taking the mechanism of glucose catabolism disorder in depression as an example, this paper systematically expounds the stable isotope tracer metabolomics technology and its application. The research idea of stable isotope tracer metabolomics based on unmarked metabolomics was put forward, and the research strategy of biological significance interpretation from four dimensions of metabolite isotope abundance, key metabolic enzymes, metabolic flow direction and metabolite flow was given, which broke through the bottleneck of stable isotope tracer metabolomics research technology based on overall animal experiment, and provided scientific basis for the promotion and application of this technology.

Neurophilic herpesvirus: a powerful tool for neuroscience research / 生物工程学报

Viruses are powerful tools for the study of modern neurosciences. Most of the research on the connection and function of neurons were done by using recombinant viruses, among which neurotropic herpesvirus is one of the most important tools. With the continuous development of genetic engineering and molecular biology techniques, several recombinant neurophilic herpesviruses have been engineered into different viral tools for neuroscience research. This review describes and discusses several common and widely used neurophilic herpesviruses as nerve conduction tracers, viral vectors for neurological diseases, and lytic viruses for neuro-oncology applications, which provides a reference for further exploring the function of neurophilic herpesviruses.

Assessment of availability of tracer drugs and basic diagnostics at public primary health care facilities in Ethiopia during COVID-19 pandemic

BACKGROUND: The emergence of COVID-19 pandemic has disrupted the supply chain and stock of medicines and drugs across the globe. Tracer drugs are essential medicines that address the population's priority health problems. Thus, this study aimed to assess availability of tracer drugs and basic diagnostics at public primary health care facilities in Ethiopia. METHODS: Facility based cross-sectional study was employed in four regions and one city administration. The primary health care units (PHCUs) were purposively selected in consultation with respective regional health bureaus. Finally, 16 hospitals, 92 health centers and 344 health posts were included. This study adopted WHO's tool that was being used to rapidly assess the capacity of health facilities to maintain the provision of essential health services during the COVID-19. Descriptive analysis was done using frequency and percentage, and results were presented. RESULTS: The overall mean availability of tracer drugs in PHCUs was 77.6%. Only 2.8% of PHCUs have all tracer drugs. The mean availability of basic diagnostic at national level was 86.6% in PHUs except health posts where it was less. Health facilities with all basic diagnostic services was 53.7%. Of the total 344 health posts assessed, 71% were providing diagnostic testing for malaria using either laboratory equipment or rapid diagnostic test (RDT) while 43% provide urine test for the pregnancy. Conclusion: This study shows availability of all tracer drugs in PHCUs in Ethiopia was extremely low. There was regional variation in availability of tracer drugs and basic diagnostics. It is very crucial to increase availability of tracer drugs and diagnostics. Drugs and diagnostic materials should be supplied according to the capacity and location of health facilities.

The Quality of Logistics Management Information System and the Availability of Tracer Drugs at Health Posts in Rural Ethiopia: A Mixed-Method Study

BACKGROUND: Proper implementation of the logistics management information system (LMIS) would facilitate access to essential pharmaceutical products. It also prevents wastage at health posts. The aim of this study was to assess the implementation of the LMIS and the availability of tracer drugs at health posts in rural Ethiopia. METHODS: We employed a cross-sectional descriptive design with a mixed-method approach. The data used for this paper was collected from March to May 2019 as part of the National HEP assessment. The study involved 343 health posts randomly selected from nine regions of Ethiopia. Women's Development Army members and household heads participated in the qualitative study (i.e. in FGD and KII). The quantitative data were exported from Open Data Kit (ODK) to Stata 15.1 for statistical analysis, and the qualitative data were entered into NVivo 12 and analyzed using thematic content analysis. RESULTS: Of the health posts, 59.4% had a space for storing drugs; less than half (41.9%; 95% confidence interval (CI) [36%, 48%]) had a functioning refrigerator. The mean percentage of the availability of selected tracer drugs at health posts was 59.6%, with a 95% CI (58.9%, 60.3%). Bin cards were available at 43% (95% CI [40%, 46%]) of health posts, and among these, only 27.5% of the health posts adequately used the bin cards. CONCLUSION: The absence and poor use of LMIS tools was observed at health posts. Proper implementation of the LMIS has the potential to improve the availability of essential drugs that, in turn, improve health post level delivery of health services.

Research progress of molecular imaging technology in the diagnosis and treatment of epilepsy / 中华行为医学与脑科学杂志

Molecular imaging is a developing research field and it has become a research hotspot.It integrates molecular biochemistry, data processing, nanotechnology, image processing and other technologies and has high specificity, high sensitivity, and high image resolution.It can provide qualitative, positioning, and quantitative data for clinical diagnosis.Clinically, 30% of epileptic patients develop into intractable epilepsy, but magnetic resonance imaging(MRI) can not detect structural lesions.These patients need accurate positioning in order to improve the effectiveness of epilepsy surgery.Because the current preoperative positioning methods have certain limitations, some epileptic patients still have recurrent seizures after the operation.Therefore, researchers continue to explore targeted tracers with high specificity and strong sensitivity.Various nanotechnology and functional magnetic resonance imaging methods are used to study the accurate localization methods of epilepsy.This paper summarized and analyzed the latest research of molecular imaging technology in China and abroad, such as the latest research of single photon emission computed tomography(SPECT) and positron emission tomography(PET) molecular imaging, the application of various nanotechnology combined with functional magnetic resonance in the accurate diagnosis and treatment of epilepsy, and various targeted tracers that haven been developed at present.The results suggest that the continuous improvement of quantitative image analysis, the integration of multi-mode imaging, the development of PET radioactive tracers, and the combination of nanotechnology and functional magnetic resonance imaging(fMRI) will facilitate a more comprehensive understanding of the pathophysiological mechanism of epilepsy.It is promising to realize the accurate diagnosis and treatment of intractable epilepsy.

Research progress of metabolic flux analysis technology in glucose metabolism pathway research / 药学学报

With the wide application of stable isotope tracer metabolomics technology, its comprehensive analysis and in-depth mining of data are particularly important, and metabolic flux analysis is one of the main technical means, especially in the study of glucose metabolism. Metabolic flux analysis technology combines isotope tracing with mathematical models to deduce and calculate the metabolic flux between metabolites. The metabolic flux provides more information for research and reflects a dynamic metabolic process more clearly and specifically. This paper reviews the basic process, precautions, and application examples of metabolic flux analysis in glucose metabolism research, and provides a reference for the application of metabolic flux analysis based on stable isotope tracer metabolomics in glucose metabolism research.

Application prospect of common viral tracers in study on brain effect of acupuncture / 中国针灸

The feasibility and prospect of viral tracers and mediating functional components are explored in study on brain effect of acupuncture. In the paper, proceeding with viral tracers, the viral tracers used to analyze the structure of specific neural circuits are introduced, as well as their mediated probes, optical/chemical genetics techniques, Cre-LoxP systems, etc. The viral tracers and their functional components can not only mark specifically nerve cells or neural circuits, but also interfere with the function of specific types of neurons or nuclei. They solve some disadvantage of traditional nerve tracing method that only describes the morphology of neurons of one brain region and the simple projection among brain regions, and the indirect and non-specific absorption. The viral tracers and their functional components play the important approach to decoding the mechanism on brain effect of acupuncture when introduced in experimental acupuncture so as to provide an in vivo, real-time and intuitive novel method for a further analysis of neurobiological mechanism on brain effect of acupuncture.

Localization of small pulmonary nodules with magnetic beads: An animal experiment / 中国胸心血管外科临床杂志

@#Objective    To investigate the feasibility of using magnetic beads to locate small pulmonary nodules. Methods    Twelve rabbits were randomly divided into two groups, 6 in each group. One group underwent thoracotomy after anesthesia and the other group underwent percutaneous puncture under the guidance of X-ray. One and two cylindrical tracer magnets (magnetic beads) with a diameter of 1 mm and a height of 3 mm were injected adjacent to the imaginary pulmonary nodules in left lung in each group. The magnetic beads beside the imaginary nodules were attracted by a pursuit magnet with a diameter of 9 mm and a height of 19 mm. The effectiveness of localization by magnetic beads were determined by attraction between tracer and pursuit magnets. Results    All processes were uneven in 12 rabbits. There was micro hemorrhage and no hematoma in the lung tissue at the injection site of the magnetic beads. When tracked with the pursuit magnets, there was one bead divorce in cases that one bead was injected, but no migration or divorce of the magnetic beads in cases that two magnetic beads were simultaneously injected to localize the small pulmonary nodules. Conclusion    The feasibility of using magnetic beads to locate small pulmonary nodules has been  preliminarily verified.

Application of tracer methodology combined case-based study model in the pre-job training of medical record writing for residents / 中华医学教育探索杂志

Objective:To observe the value of tracer methodology combined case-based study (CBS) model in the standardized residency training of medical record writing.Methods:A total of 91 residents who were newly recruited from The Sixth Affiliated Hospital of Sun Yat-sen University in July 2019 were selected as the subjects and randomly divided into test group ( n=47) and control group ( n=44). The tracer methodology combined CBS model was used for test group while the traditional model was used for control group to compare the knowledge of medical record writing, performance of medical record writing and feedback to teaching in two groups. SPSS 21.0 was used for t test and chi-square test. Results:The correct response rate in knowledge of medical record writing, the normative scores and integrity scores after training were significantly higher than those before training ( P<0.05). The normative and integrity scores were significantly increased after training, and those in the test group were significantly higher than those in the control group [(90.3±3.5) and (91.3±3.2) vs. (88.6±3.5) and (89.8±3.0), P<0.05, respectively]. The test group was significantly superior to the control group in the autonomous learning ability [97.8% (44/45) vs. 82.9% (34/41)], communication ability [95.6% (43/45) vs. 78.0% (32/41)] and acceptance of teaching form [97.8% (44/45) vs. 82.9% (34/41)] ( P<0.05). Conclusion:The tracer methodology combined CBS model is a good way in the pre-job training of medical record writing for residents, which can mobilize the subjective initiative of the trainees and teachers, complete the teaching tasks and obtain better teaching value.

HSV-1 H129-Derived Anterograde Neural Circuit Tracers: Improvements, Production, and Applications / 神经科学通报·英文版

Anterograde viral tracers are powerful and essential tools for dissecting the output targets of a brain region of interest. They have been developed from herpes simplex virus 1 (HSV-1) strain H129 (H129), and have been successfully applied to map diverse neural circuits. Initially, the anterograde polysynaptic tracer H129-G4 was used by many groups. We then developed the first monosynaptic tracer, H129-dTK-tdT, which was highly successful, yet improvements are needed. Now, by inserting another tdTomato expression cassette into the H129-dTK-tdT genome, we have created H129-dTK-T2, an updated version of H129-dTK-tdT that has improved labeling intensity. To help scientists produce and apply our H129-derived viral tracers, here we provide the protocol describing our detailed and standardized procedures. Commonly-encountered technical problems and their solutions are also discussed in detail. Broadly, the dissemination of this protocol will greatly support scientists to apply these viral tracers on a large scale.

Marcaje de arena sílice con 99mTc para la obtención de un radiotrazador sólido / Labeling of silica sand with 99mTc for obtaining a solid radiotracer

Resumen Para la obtención de radiotrazadores sólidos de 99mTc actualmente se necesitan nuevos soportes porosos. Estudios anteriores realizados por otros autores mostraron la posibilidad del marcaje con 99mTc de sedimentos de ríos con alto contenido de aluminosilicatos. En el presente trabajo se desarrolló una metodología para el marcaje de arena sílice con el 99mTcO4- para su uso como radiotrazador sólido. Se realizó el marcaje de la arena sílice previamente tratada y sin tratar empleando concentraciones variables de cloruro y fluoruro estañoso como agentes reductores y diferentes tiempos de marcaje. Se evaluó la influencia de la etapa de tratamiento previo de la arena en los rendimientos de retención del Tc obtenidos. Los cambios en la composición de la arena sílice luego de su tratamiento previo se pudieron constatar a partir de la Microscopía Electrónica de Barrido (SEM-EDS). Los resultados sugirieren el empleo de la arena sílice previamente tratada y de fluoruro estañoso como agente reductor, adicionalmente se propusieron modificaciones a la metodología inicial de tratamiento previo de la arena. Se pudo constatar a partir de la técnica SEM-EDS que el aumento del porciento de retención del Tc en la arena luego de su tratamiento, se debe fundamentalmente a los cambios observados en su composición química y en su estructura. Se logró la obtención de un radiotrazador sólido marcado con 99mTc en soporte de arena sílice con un tiempo de preparación estimado de 4 horas y un rendimiento de retención de 74%.

Abstract To obtain 99mTc solid radiotracers, new porous supports are currently needed. Previous studies carried out by other authors showed the possibility of 99mTc labeling of sediments from rivers with a high content of aluminosilicates. In the present work a methodology for labeling of silica sand with 99mTcO4- as a prospective solid radiotracer was developed. Labeling of the previously treated and untreated silica sand was carried out using variable concentrations of chloride and stannous fluoride as reducing agents and different labeling times. The influence of the pre-treatment stage of the sand on the obtained Tc retention yields was evaluated. The changes in the composition of the silica sand after its previous treatment could be verified from the Scanning Electron Microscopy (SEM-EDS). The results suggested the use of previously treated silica sand and stannous fluoride as a reducing agent, modifications were proposed to the initial methodology of previous treatment of the sand. It was possible to confirm from the SEM-EDS technique that the increase in the percentage of retention of Tc in the sand after its treatment is mainly due to the observed changes in its chemical composition and structure. It was possible to obtain a 99mTc solid radiotracer on support of silica sand with an estimated preparation time of 4 hours and a retention yield of 74%.

Para-aortic lymph node tracing and dissection in advanced gastric cancer: Effectiveness of carbon nanoparticles injection through the no. 12b lymph node

Background and Objectives: The relative effectiveness of tracers in guiding para-aortic lymph node dissection (PAND) in advanced gastric cancer is undefined. In this single-center, prospective study, we aimed to discuss the effectiveness of such tracers. Materials and Methods: Between January 2015 and January 2016, 90 consecutive patients with stage T4a gastric cancer were evenly assigned to receive 0.2 mL of carbon nanoparticles (a), methylene blue (b), or no tracer (c) injection through no. 12b lymph nodes before PAND. Results: There was no difference in the baseline characteristics between the three groups. Group A vs. B or C had a higher number of dissected lymph nodes (34.1 ± 9.8, 25.5 ± 5.5, and 22.6 ± 3.7; P < 0.001; B vs. C: P =0.321) and no. 16a2/b1 para-aortic lymph nodes (PANs; 11.8 ± 4.8, 7.0 ± 1.2, and 5.5 ± 1.2; P < 0.001; B vs. C: P =0.178) and similar rates of lymph node metastasis (20.9 ± 17.5%, 19.1 ± 15.1%, and 23.6 ± 19.7%; P = 0.511), positive dissected PAN (23.3% [7/30], 16.7% [5/30], and 16.7% [5/30]), surgery duration (252.9 + 35.4, 244.4 ± 29.0, and 250.3 + 29.9 min; P = 0.421), and blood loss (266.7 ± 115.5, 270.0 ± 82.6, and 260.0 ± 116.3 mL, P = 0.933). There was no common bile duct damage by tracer injection, and one case of duodenal stump fistula, one abdominal infection, and two anastomotic leakages in Groups A–C, respectively, were treated successfully. Conclusions: In advanced gastric cancer treatment, carbon nanoparticle injection into no. 12b nodes appears to better trace no. 16a2/b1 PAN

Evaluation of Erythrocyte Iron Incorporation in Beijing Prepubertal Children Using a Single Stable Isotope Tracer Method / 生物医学与环境科学（英文）

Objective@#To analyze the rate of erythrocyte iron incorporation and provided guidance for the iron nutrition for prepubertal children.@*Methods@#Fifty-seven prepubertal children of Beijing were involved in this study and each subject was orally administered 3 mg of Fe twice daily to obtain a total of 30 mg Fe after a 5-d period. The stable isotope ratios in RBCs were determined in 14th day, 28th day, 60th day, and 90th day. The erythrocyte incorporation rate in children was calculated using the stable isotope ratios, blood volume and body iron mass.@*Results@#The percentage of erythrocyte Fe incorporation increased starting 14 th day, reached a peak at 60 d (boys: 19.67% ± 0.56%, girls: 21.33% ± 0.59%) and then decreased. The erythrocyte incorporation rates of Fe obtained for girls in 60th day was significantly higher than those obtained for boys ( < 0.0001).@*Conclusions@#The oral administration of Fe to children can be used to obtain erythrocyte iron incorporation within 90 d. Prepubertal girls should begin to increase the intake of iron and further studies should pay more attention to the iron status in prepubertal children.

Tracing effect of new nano-carbon on pelvic lymph nodes of patients during laparoscopic radical cystectomy and its safety evaluation / 吉林大学学报(医学版)

Objective: To investigate the tracing fect of new nano-carbon (Kanalin) on the pelvic lymph nodes of the patents with bladder cancer during the laparoscopic radcal cystectomy (RC), and to explain the signcance of its applicaton in the precision surgical treatment. Methods: A total of 44 patents with bladder cancer who underwent RC were divded into tracer group (n=22) and control group (n=22) according to whether Kanalin was used before operaton or not. The laparoscopic RC combined with standard pelvc lymph node dissecon (LND) was performed in the patents in two groups. The effectiveness evaluaton indexes and safety evaluaton indexes of the patents in two groups were collected and compared. The efectiveness evaluaton indexes included black staining situaton of lymph nodes during operaon, the number of detected lymph nodes, the black staining rate of lymph nodes, the number of positive lymph nodes, and operaton time. The safety evaluaton indexes included the blood loss and the indences of perioperative complicatons. Results: The black sainng fect of lymph nodes of the patents in tracer group was definite and there were no tracer-related sde effects and complicatons during the perioperative period. Compared with control group, the clearance rate and detecon rate of lymph nodes of the patents in tracer group were increased (P 0. 05). Conclusion: During the laparoscopic RC, the applicaton of Kanalin for pelvic lymph node tracng is safe, without toxic and side effects; Kanalin is helpful for ncreasing the intraoperative clearance rates and postoperative pathological detecon rates of lymph nodes.

Trans-synaptic Neural Circuit-Tracing with Neurotropic Viruses / 神经科学通报·英文版

A central objective in deciphering the nervous system in health and disease is to define the connections of neurons. The propensity of neurotropic viruses to spread among synaptically-linked neurons makes them ideal for mapping neural circuits. So far, several classes of viral neuronal tracers have become available and provide a powerful toolbox for delineating neural networks. In this paper, we review the recent developments of neurotropic viral tracers and highlight their unique properties in revealing patterns of neuronal connections.

Research progress of MR nanoprobers in targeting oral squamous cell carcinoma / 中国介入影像与治疗学

For analyzing the migration ability of oral squamous cell carcinoma (OSCC) cells in vivo, invasive methods were often used in the past. The experimental animals would be executed within a certain period of time after cell transplantation, and the oral and maxillofacial tissues should be analyzed with pathological section. These method can not be used to observe the migration and proliferation of OSCC cells dynamically in the same experimental animal in vivo. With the development of non-invasive methods in recent years, the highly specific protein expressed in OSCC cells can be labeled with MR technology using nanoparticles as contrast agent, thus to target and trace the metastasis in vivo, and to speculate the specific stages of OSCC. The advancements of targeting and tracing OSCC with MR nanomolecular probes were reviewed in this article.

Efficacy comparison between minimally invasive fixation and routine fixation of tracer in robot-assisted pedicle screw placement / 中华创伤杂志

Objective@#To investigate the clinical efficacy of modified tracer minimally invasive fixation in robot-assisted pedicle screw placement.@*Methods@#A prospective randomized controlled study was conducted to analyze the clinical data of 41 patients with thoracolumbar fresh fracture at the orthopaedics department of Karamay Central Hospital from July 2017 to December 2017. There were 20 males and 21 females, aged 25-55 years, with an average of 40.6 years. According to AO fracture typing, there were 28 patients with type A and 13 patients with type B. The patients underwent robot-assisted pedicle screw placement. Random number table method was used to divide the patients into the conventional group (20 patients) and modified group (21 patients). The conventional group was treated with conventional tracer fixation, and the modified group modified tracer minimally invasive fixation. A total of 92 pedicle screws were implanted in the conventional group and 96 pedicle screws were implanted in the modified group. The size of wound, wound bleeding, time of fixing the tracer, complications (spinal cord injury and nerve root injury when fixing the tracer), development of the tracer fixator and artifacts were recorded. The accuracy of nail placement was evaluated by 320-slice CT scan and Gertzbein-Robbins criteria.@*Results@#There was no significant difference in age, sex, diagnosis, transverse diameter of pedicle and e angle between the two groups (P>0.05). The wound size, wound bleeding, and time of fixing the tracer in the modified group were (6.00±1.26)mm, (1.38±0.22)ml and (1.42±0.17)minutes, respectively, while those of the conventional group were (40.16±5.71)mm, (11.61±1.15)ml, and (5.12±0.64)minutes respectively (P<0.05). No spinal cord or nerve root injury occurred in either group when the tracer was fixed. In the process of three-dimensional image acquisition and automatic registration, the tracer fixator in the modified group developed with Kirschner needle without artifacts, and the tracer in minimally invasive fixator had good fluoroscopy effect. The modified group included 94 pedicle screws of type A and two of type B according to Gertzbein-Robbins criteria. The conventional group included 89 pedicle screws of type A and three of type B according to Gertzbein-Robbins criteria. There was no significant difference in the screw placement accuracy between the two groups (P>0.05).@*Conclusion@#In the robot-assisted pedicle screw placement, the modified tracer minimally invasive fixation method is safe and less traumatic, with no side effect on the accuracy of pedicle screw placement.

Application progress of indocyanine green angiography in lymphedema / 中国修复重建外科杂志

Objective: To summarize the application progress of indocyanine green (ICG) angiography in diagnosis and treatment of lymphedema. Methods: The literature related to dynamic imaging tracing of lymphedema at home and abroad was reviewed extensively. And the research status and progress of ICG angiography in diagnosis and treatment of lymphedema were retrospectively analyzed. Results: ICG angiography can be used as the gold standard for the diagnosis of lymphedema at present and the classification of lymphedema severity, selection of surgical incisions and methods, and intraoperative operation. It can also be used to observe lymphatic drainage and regeneration within 1.5 cm of subcutaneous and determine the prognosis. Conclusion: Compared with traditional methods, ICG angiography has more obvious advantages and value in diagnosis and treatment of lymphedema. However, it also has problems such as slow development speed and difficulty in developing deep lymphatic vessels (nodes).

Efficacy comparison between minimally invasive fixation and routine fixation of tracer in robot-assisted pedicle screw placement / 中华创伤杂志

Objective To investigate the clinical efficacy of modified tracer minimally invasive fixation in robot-assisted pedicle screw placement. Methods A prospective randomized controlled study was conducted to analyze the clinical data of 41 patients with thoracolumbar fresh fracture at the orthopaedics department of Karamay Central Hospital from July 2017 to December 2017. There were 20 males and 21 females, aged 25-55 years, with an average of 40. 6 years. According to AO fracture typing, there were 28 patients with type A and 13 patients with type B. The patients underwent robot-assisted pedicle screw placement. Random number table method was used to divide the patients into the conventional group (20 patients) and modified group (21 patients). The conventional group was treated with conventional tracer fixation, and the modified group modified tracer minimally invasive fixation. A total of 92 pedicle screws were implanted in the conventional group and 96 pedicle screws were implanted in the modified group. The size of wound, wound bleeding, time of fixing the tracer, complications (spinal cord injury and nerve root injury when fixing the tracer), development of the tracer fixator and artifacts were recorded. The accuracy of nail placement was evaluated by 320-slice CT scan and Gertzbein-Robbins criteria. Results There was no significant difference in age, sex, diagnosis, transverse diameter of pedicle and e angle between the two groups (P>0. 05). The wound size, wound bleeding, and time of fixing the tracer in the modified group were (6. 00 ± 1. 26)mm,(1. 38 ± 0. 22)ml and (1.42 ±0.17)minutes, respectively, while those of the conventional group were (40. 16 ± 5. 71)mm, (11.61 ±1.15)ml, and (5.12 ±0.64)minutes respectively (P<0.05). No spinal cord or nerve root injury occurred in either group when the tracer was fixed. In the process of three-dimensional image acquisition and automatic registration, the tracer fixator in the modified group developed with Kirschner needle without artifacts, and the tracer in minimally invasive fixator had good fluoroscopy effect. The modified group included 94 pedicle screws of type A and two of type B according to Gertzbein-Robbins criteria. The conventional group included 89 pedicle screws of type A and three of type B according to Gertzbein-Robbins criteria. There was no significant difference in the screw placement accuracy between the two groups (P>0. 05). Conclusion In the robot-assisted pedicle screw placement, the modified tracer minimally invasive fixation method is safe and less traumatic, with no side effect on the accuracy of pedicle screw placement.

Protein quality & amino acid requirements in relation to needs in India

The relevance of protein and its constituent amino acids (AAs) in the structure and function of the human body is well known. Accumulating evidence has conferred specific functional and regulatory roles for individual AAs, adding relevance to their requirements across different age groups. The methods for measuring AA requirements have progressed from the classical nitrogen balance to the current stable isotope-based AA balance methods. Requirements of most of the indispensable AA (IAA) have been estimated in healthy Indian population by the best available balance method and has shown to be higher than earlier 1985 WHO/FAO/UNU (World Health Organization/Food and Agriculture Organization/United Nations University) recommendations. In addition, potential changes in the requirement, through adaptation to chronic undernutrition or to infection, have also been evaluated. In 2007, the WHO/FAO/UNU released a recommendation that increased the daily IAA requirement, based on primary evidence from Indian balance studies. This meant that to ensure that the new IAA requirements were met, individual foods or mixed diets needed to be assessed for their protein quality, or their ability to deliver the required amount of IAA. The recent FAO report on protein quality evaluation recommends the use of a new chemical AA score, the digestible IAA score (DIAAS), to replace the earlier protein digestibility corrected AA score. The DIAAS requires the determination of individual AA digestibility at the ileal level. A minimally invasive dual stable isotope tracer-based approach has been developed in India and has been used to determine digestibility of various foods in Indian adults and children. The increase in IAA requirements and subsequent protein quality requirements have implications for national regulatory frameworks, growth and development, and in turn, for economic and agricultural policy.