Identification of m6A suppressor EIF4A3 as a novel cancer prognostic and immunotherapy biomarker through bladder cancer clinical data validation and pan-cancer analysis.

EIF4A3 represents a novel m6A suppressor that exerts control over the global m6A mRNA modification level, therefore influencing gene destiny. Despite increasing evidence that highlights a pivotal role of EIF4A3 in tumor progression and immunity, a comprehensive pan-cancer analysis of EIF4A3 has yet to be conducted, in order to ascertain whether EIF4A3 could be a viable biomarker for cancer screening, prediction of prognosis, and to facilitate accurate therapy design in various human malignancies. We analyzed the expression levels of EIF4A3 in bladder cancer compared to para-cancer tissue. Subsequently survival analysis was conducted to ascertain the potential association between EIF4A3 expression and patient prognosis. To further corroborate this evidence, we conducted an extensive data mining process of several publicly available databases, including UCSC Xena database, TCGA, and GTEx. Raw data from the UCSC Xena database was processed using online tools to obtain results that could be subjected to further analysis. Our study unveiled a considerable increase in the expression levels of EIF4A3 in bladder cancer compared to para-cancer tissue. Subsequent validation experiments confirmed that bladder cancer patients exhibiting higher levels of EIF4A3 expression have significantly worse prognostic outcomes. Next, our pan-cancer analysis found that the expression level of EIF4A3 is significantly higher in most cancers. Notably, high expression levels of EIF4A3 were negatively associated with patient prognosis across various cancer types. Furthermore, as a novel m6A suppressor, EIF4A3 was found to be correlated with numerous RNA modification genes in multiple cancer types. Meanwhile, analysis of publicly available databases revealed that EIF4A3 expression was significantly related to immune score and immune cell levels in most cancer types. Interestingly, EIF4A3 was also identified as a superior immunotherapy biomarker when compared to several traditional immunotherapy biomarkers. Lastly, genetic alterations analysis revealed that amplification was the most frequently occurring abnormality in the EIF4A3 gene. EIF4A3 emerges as a promising biomarker with the potential to significantly enhance tumor screening, prognostic evaluation, and the design of individualized treatment strategies across a diverse array of malignancies.

An optimized PDMS microfluidic device for ultra-fast and high-throughput imaging flow cytometry.

Imaging flow cytometry (IFC) is a powerful tool for cell detection and analysis due to its high throughput and compatibility in image acquisition. Optical time-stretch (OTS) imaging is considered as one of the most promising imaging techniques for IFC because it can realize cell imaging at a flow speed of around 60 m s-1. However, existing PDMS-based microchannels cannot function at flow velocities higher than 10 m s-1; thus the capability of OTS-based IFC is significantly limited. To overcome the velocity barrier for PDMS-based microchannels, we proposed an optimized design of PDMS-based microchannels with reduced hydraulic resistance and 3D hydrodynamic focusing capability, which can drive fluids at an ultra-high flow velocity (of up to 40 m s-1) by using common syringe pumps. To verify the feasibility of our design, we fabricated and installed the microchannel in an OTS IFC system. The experimental results first proved that the proposed microchannel can support a stable flow velocity of up to 40 m s-1 without any leakage or damage. Then, we demonstrated that the OTS IFC is capable of imaging cells at a velocity of up to 40 m s-1 with good quality. To the best of our knowledge, it is the first time that IFC has achieved such a high flow velocity just by using a PDMS-glass chip. Moreover, high velocity can enhance the focusing of cells on the optical focal plane, increasing the number of detected cells and the throughput. This work provides a promising solution for IFC to fully release its capability of advanced imaging techniques by operating at an extremely high screening throughput.

Optical time-stretch imaging flow cytometry in the compressed domain.

Imaging flow cytometry based on optical time-stretch (OTS) imaging combined with a microfluidic chip attracts much attention in the large-scale single-cell analysis due to its high throughput, high precision, and label-free operation. Compressive sensing has been integrated into OTS imaging to relieve the pressure on the sampling and transmission of massive data. However, image decompression brings an extra overhead of computing power to the system, but does not generate additional information. In this work, we propose and demonstrate OTS imaging flow cytometry in the compressed domain. Specifically, we constructed a machine-learning network to analyze the cells without decompressing the images. The results show that our system enables high-quality imaging and high-accurate cell classification with an accuracy of over 99% at a compression ratio of 10%. This work provides a viable solution to the big data problem in OTS imaging flow cytometry, boosting its application in practice.

Study of Bayesian variable selection method on mixed linear regression models.

Variable selection has always been an important issue in statistics. When a linear regression model is used to fit data, selecting appropriate explanatory variables that strongly impact the response variables has a significant effect on the model prediction accuracy and interpretation effect. redThis study introduces the Bayesian adaptive group Lasso method to solve the variable selection problem under a mixed linear regression model with a hidden state and explanatory variables with a grouping structure. First, the definition of the implicit state mixed linear regression model is presented. Thereafter, the Bayesian adaptive group Lasso method is used to determine the penalty function and parameters, after which each parameter's specific form of the fully conditional posterior distribution is calculated. Moreover, the Gibbs algorithm design is outlined. Simulation experiments are conducted to compare the variable selection and parameter estimation effects in different states. Finally, a dataset of Alzheimer's Disease is used for application analysis. The results demonstrate that the proposed method can identify the observation from different hidden states, but the results of the variable selection in different states are obviously different.

Cell damage evaluation by intelligent imaging flow cytometry.

Essential thrombocythemia (ET) is an uncommon situation in which the body produces too many platelets. This can cause blood clots anywhere in the body and results in various symptoms and even strokes or heart attacks. Removing excessive platelets using acoustofluidic methods receives extensive attention due to their high efficiency and high yield. While the damage to the remaining cells, such as erythrocytes and leukocytes is yet evaluated. Existing cell damage evaluation methods usually require cell staining, which are time-consuming and labor-intensive. In this paper, we investigate cell damage by optical time-stretch (OTS) imaging flow cytometry with high throughput and in a label-free manner. Specifically, we first image the erythrocytes and leukocytes sorted by acoustofluidic sorting chip with different acoustic wave powers and flowing speed using OTS imaging flow cytometry at a flowing speed up to 1 m/s. Then, we employ machine learning algorithms to extract biophysical phenotypic features from the cellular images, as well as to cluster and identify images. The results show that both the errors of the biophysical phenotypic features and the proportion of abnormal cells are within 10% in the undamaged cell groups, while the errors are much greater than 10% in the damaged cell groups, indicating that acoustofluidic sorting causes little damage to the cells within the appropriate acoustic power, agreeing well with clinical assays. Our method provides a novel approach for high-throughput and label-free cell damage evaluation in scientific research and clinical settings.

Typing of acute leukemia by intelligent optical time-stretch imaging flow cytometry on a chip.

Acute leukemia (AL) is one of the top life-threatening diseases. Accurate typing of AL can significantly improve its prognosis. However, conventional methods for AL typing often require cell staining, which is time-consuming and labor-intensive. Furthermore, their performance is highly limited by the specificity and availability of fluorescent labels, which can hardly meet the requirements of AL typing in clinical settings. Here, we demonstrate AL typing by intelligent optical time-stretch (OTS) imaging flow cytometry on a microfluidic chip. Specifically, we employ OTS microscopy to capture the images of cells in clinical bone marrow samples with a spatial resolution of 780 nm at a high flowing speed of 1 m s-1 in a label-free manner. Then, to show the clinical utility of our method for which the features of clinical samples are diverse, we design and construct a deep convolutional neural network (CNN) to analyze the cellular images and determine the AL type of each sample. We measure 30 clinical samples composed of 7 acute lymphoblastic leukemia (ALL) samples, 17 acute myelogenous leukemia (AML) samples, and 6 samples from healthy donors, resulting in a total of 227 620 images acquired. Results show that our method can distinguish ALL and AML with an accuracy of 95.03%, which, to the best of our knowledge, is a record in label-free AL typing. In addition to AL typing, we believe that the high throughput, high accuracy, and label-free operation of our method make it a potential solution for cell analysis in scientific research and clinical settings.

From Cognitive MR-Targeted Fusion Prostate Biopsy to Radical Prostatectomy: Incidence and Predictors of Gleason Grade Group Upgrading in a Chinese Cohort.

Purpose: To access the incidence and predictors of Gleason grade group upgrading from cognitive MR-targeted fusion prostate biopsy to radical prostatectomy in a Chinese cohort. Materials and Methods: We included 199 patients in our institution between January 2016 and June 2021. Multivariable logistic regression model and nomograms were utilized to analyze the collected data. Results: The concordance rate of biopsy Gleason grade group and radical prostatectomy was 50.3% (100 in 199). Upgrading occurred in 80 (40.2%) patients and 37 (68.5%) patients have an upgrading Gleason grade group when the biopsy Gleason grade group was 1. Multivariable logistic regression models were established to analyze the incidence and predictors of Gleason grade group upgrading from cognitive MR-targeted fusion prostate biopsy to radical prostatectomy. Biopsy Gleason grade group, prostate volume, and patient year were confirmed to be individual predictors of upgrading. Based on the logistic regression models, nomograms for predicting probability of prostate Gleason grade group upgrading were generated. Conclusions: We established a logistic regression model to predict the accuracy of prostate biopsy GG and provide the probability of upgrading. Clinicians should be more cautious when deciding the treatment strategy especially for prostate cancer biopsy GG1 patients. Future studies should expand the sample size and include more variables to improve the accuracy of predicting upgrading and prostate cancer early screening program is urgently needed in our city in China.

Roles and mechanisms of the m6A reader YTHDC1 in biological processes and diseases.

N6-methyladenosine (m6A) is a key area in Epigenetics and has been increasingly focused these years. In the m6A process, readers recognize the m6A modification on mRNAs or noncoding RNAs and mediate different downstream events. Emerging studies have shown that YTHDC1, an important m6A reader, plays a key role in many biological functions and disease progression, especially cancers. Here we summarized the current mechanisms of YTHDC1 in biological functions and diseases and offered guidance for future researches to provide potential strategy for clinical diagnose and therapy.

Fruit and Vegetable Consumption and the Risk of Prostate Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Emerging researches has evaluated whether fruit and vegetable consumption reduce the risk of prostate cancer. However, the conclusions of published articles remained confusing. Thus, we conducted an updated systematic review and meta-analysis to confirm the relationship of fruit and vegetable consumption and the risk of prostate cancer. METHOD: We searched PubMed, EMBASE, Web of Science and Chinese National Knowledge Infrastructure (CNKI) up to September 1, 2020. We finally included 17 cohort studies related to fruit or vegetable intake after rigid quality assessment and checking references of the retrieved articles and relevant reviews. Newcastle-Ottawa scale was adopted to assess the quality of studies and random effect model with RR and 95% CI were used to assess the risk. RESULTS: No significant relationship was found between fruit consumption (RR = 1.00, 95% CI = 0.94-1.05) and vegetable consumption (RR = 0.98, 95% CI = 0.94-1.02) and the risk of prostate cancer. No significant heterogeneity or publication bias was identified. CONCLUSION: Our updated meta-analysis demonstrated that fruit and vegetable consumption can barely reduce the risk of prostate cancer with several limitations. Further clinical and basic researches are eagerly awaited to confirm our results and clarify the potential biological mechanisms.

LncRNA FGF14-AS2 represses growth of prostate carcinoma cells via modulating miR-96-5p/AJAP1 axis.

OBJECTIVE: This investigation devoted to lncRNA FGF14 antisense RNA 2 (FGF14-AS2) in prostate carcinoma progression. METHODS: The levels of lncRNA FGF14-AS2, miR-96-5p, and Adherens junction-associated protein-1 (AJAP1) in prostate carcinoma were tested by Western blot and qRT-PCR. How these two genes interacted was confirmed by RNA immunoprecipitation and dualluciferase gene methods. The effect of FGF14-AS2/miR-96-5p/AJAP1 axis in prostate carcinoma progression was determined by MTT, Transwell, and nude mice tumor model. RESULTS: FGF14-AS2 was a downregulated lncRNA in prostate carcinoma tissue and cells. FGF14-AS2 could restrain miR-96-5p expression while miR-96-5p hampered AJAP1. FGF14-AS2 could effectively decrease the biological behaviors of prostate carcinoma cells, while knock-down of FGF14-AS2 triggered opposite results. Moreover, miR-96-5p mimic presented a cancer promoter role in prostate carcinoma cells. AJAP1 expression level could affect levels of proteins related to epithelial-mesenchymal transition. In vivo experiment suggested that overexpressing FGF14-AS2 could reverse the promotion of silenced AJAP1 on prostate carcinoma cell metastasis, thus to inhibit tumor growth. CONCLUSION: lncRNA FGF14-AS2 was a downregulated lncRNA in prostate carcinoma and influenced cell proliferation and metastasis. The influence relied on modulating miR-96-5p and its target gene AJAP1.

Orientation Identification of the Black Phosphorus with Different Thickness Based on B2g Mode Using a Micro-Raman Spectroscope under a Nonanalyzer Configuration.

As an anisotropic material, the unique optoelectronic properties of black phosphorus are obviously anisotropic. Therefore, non-destructive and fast identification of its crystalline orientation is an important condition for its application in optoelectronics research field. Identifying the crystalline orientation of black phosphorus through Ag1 and Ag2 modes under the parallel polarization has high requirements on the Raman system, while in the nonanalyzer configuration, the crystalline orientation of the thick black phosphorus may not be identified through Ag1 and Ag2 modes. This work proposes a new method to identify the crystalline orientation of black phosphorus of different thicknesses. This method is conducted under the nonanalyzer configuration by B2g mode. The results show that B2g mode has a good consistency in the identification of crystalline orientations. In this paper, a theoretical model is established to study the angle-resolved Raman results of B2g mode. The new method can accurately identify the crystalline orientation with different layers of black phosphorus without misidentification.

Experimental study on the control form of fin stabilizer at zero speed.

The zero-speed fin stabilizer is used to stabilize the roll motion of the ship at full speed. It has two working modes, that is the lift-based normal anti-rolling mode and the drag-based zero-speed anti-rolling mode. Different force generation mechanisms cause different control methods, especially in the form of control. The zero-speed fin stabilizer works in a sinusoidal fashion in normal mode, the same as the conventional fin stabilizer. However, its control form at zero speed is not particularly clear. This paper aims to investigate the control form of fin stabilizer at zero speed through a composite method of theoretical analysis and experimental research. Based on the established reaction force model, the forces generated on the fin flapped in sinusoidal and trapezoidal forms are compared and analyzed. It is found that the trapezoidal form flapping with a small half-cycle ratio generates larger force than the sinusoidal flapping form when the flapping amplitude is the same. The forced rolling tank tests with the fins flapping in sinusoidal and trapezoidal forms were conducted. The test results are consistent with the theoretical analysis results, and the trapezoidal flapping form with a proper small half-cycle ratio is recommended for fin stabilizers at zero speed. The control strategy of fin stabilizer at zero speed is obtained based on the further analysis of the force characteristics of the trapezoidal flapping form and the limitations of the actual fin stabilizer actuation system. The model and full scale roll reduction tests at zero speed were conducted, achieving more than 70% and 60% of the anti-rolling effect respectively. The test results further verify the effectiveness, applicability and practicability of the obtained control form and strategy for fin stabilizers in at-anchor conditions, and can be a reference for engineering practice and other similar studies.

Isoniazid-loaded chitosan/carbon nanotubes microspheres promote secondary wound healing of bone tuberculosis.

Poor blood circulation makes it difficult for antitubercular drugs to achieve effective bactericidal concentration at tuberculose focus. The residual Mycobacterium tuberculosis around surgical wound would multiply, resulting in nonunion or sinus formation. Carbon nanotubes have strong tissue penetration and can cross many kinds of physiological barriers. Here, we constructed a chitosan/carbon nanotubes nanoparticles to control slow release of isoniazid. Transmission electron microscopy and nanoparticle tracking and analysis results showed that the diameter of chitosan/carbon nanotubes nanoparticles was between 150 and 250 nm. Chitosan/carbon nanotubes nanoparticles significantly prolonged the release time of isoniazid, and the release rate was more uniform, no sudden release was observed. In vitro experiments showed that chitosan/carbon nanotubes nanoparticles did not destroy biological function of isoniazid, but could reduce its cytotoxicity and inflammation. We further constructed animal model of tuberculous ulcer. The results showed that isoniazid/chitosan/carbon nanotubes nanoparticles promoted the healing of tuberculosis ulcer. Compared with isoniazid group and isoniazid/carbon nanotubes group, the area of wounds decreased by 94.6% and 89.8%, respectively. Immunohistochemistry showed that CD3+ and CD4+ T cell number decreased significantly in isoniazid/chitosan/carbon nanotubes group. In conclusion, we constructed a kind of isoniazid/chitosan/carbon nanotubes nanoparticles, which can significantly promote the healing of tuberculosis ulcer. Our study provided an effective way for the treatment of secondary wound healing of bone tuberculosis.

Prevention of intra-abdominal adhesion using electrospun PEG/PLGA nanofibrous membranes.

The use of physical barriers, such as nanofiber membranes, is a potential method to prevent adhesion formation after surgery. In this study, we fabricated electrospun composite poly(ethylene glycol) (PEG)/poly(lactic-co-glycolic) (PLGA) nanofibrous membrane to prevent abdomen adhesion; this composite acts as a barrier between cecum and the surrounding tissues without interrupting mass transfer and cecum healing. PEG/PLGA nanofibrous membranes consisting of 0% (P0), 5% (P1), 10% (P2), 15% (P3), 20% (P4), and 25% (P5) PEG were prepared, and their physicochemical properties were characterized. The P0 shows the highest thermostability, whereas P1 exhibited the most homogenous morphology, the narrowest diameter distribution, and the largest ultimate stress and strain. In vitro cell adhesion and proliferation tests using fibroblasts indicate that all nanofibrous membranes inhibited cell proliferation, with P1 showing the lowest degree of cell attachment. In vivo application of nanofibrous membranes on the repaired site of rat cecum model demonstrated that all of the membranes prevent adhesion formation to a certain extent. We concluded based on gross observation, histological analysis, and functional assays that P1 served as an effective anti-adhesion membrane after cecum surgery in a clinical setting.

Recycling of indium from waste LCD: A promising non-crushing leaching with the aid of ultrasonic wave.

The tremendous amount of end-of-life liquid crystal displays (LCDs) has become one of the prominent sources of waste electrical and electronic equipment (WEEE) in recent years. Despite the necessity of safe treatment, recycling indium is also a focus of waste LCD treatment because of the scarcity of indium. Based on the analyses of the structure of Indium Tin Oxide (ITO) glass, crushing is demonstrated to be not required. In the present research, a complete non-crushing leaching method was firstly adopted to recycle indium from waste LCDs, and the ultrasonic waves was applied in the leaching process. The results demonstrated that indium can be leached efficiently with even a low concentration of chloride acid (HCl) without extra heating. About 96.80% can be recovered in 60mins, when the ITO glass was leached by 0.8MHCl with an enhancement of 300W ultrasonic waves. The indium leaching process is abridged free from crushing, and proves to be of higher efficiency. In addition, the ultrasonic wave influence on leaching process was also explained combing with micron-scale structure of ITO glass.

[Study on the prevention of postoperative intraperitoneal adhesion of rat with PLGA/PEG electrospun polymer membrane].

Objective: Adopting poly- L-lactic/glycolic acid (PLGA) and polyethylene glycol (PEG) as the material to fabricate PLGA/PEG electrospun polymer membrane by electrospinning technology. And to study its preventive effect on postoperative intraperitoneal adhesion of rat. Methods: PLGA and PEG were mixed at the ratio of 19∶1( M/M), then dissolved in organic solvent. The PLGA/PEG electrospun polymer membrane was prepared by electrospinning technology, and then the gross observation and scanning electron microscope observation were taken. Fifty-four Sprague Dawley rats (weighing, 180-200 g), were randomly divided into 3 groups. The rats in control group ( n=6) were left intact. The rats in model group ( n=24) and PLGA/PEG group ( n=24) were treated with the method of mechanical injury of the cecal serosa in order to establish the intraperitoneal adhesion models; then the PLGA/PEG electrospun polymer membrane was used to cover the wound in PLGA/PEG group, but was not in the model group. The intraperitoneal adhesion in PLGA/PEG group and model group were observed at 3 days, 1 week, 2 weeks, and 8 weeks after operation, and the adhesion degree was assessed according to the self-generated standard. The degradation of PLGA/PEG electrospun polymer membrane was also observed in PLGA/PEG group. At each time point, the rats were harvested for histological observation. All the above indexes were compared with the control group. Results: Using the electrospinning technology, PLGA/PEG electrospun polymer membrane was prepared successfully. PLGA/PEG electrospun polymer membrane was white and opaque, with soft texture. Scanning electron microscopy observation showed that PLGA/PEG electrospun polymer membrane was mainly composed of disorderly staggered fibers, with microporous structure. All rats survived to the end of the experiment. Gross observation showed that PLGA/PEG electrospun polymer membrane gradually degraded after implantation in vivo, and the adhesion degree in PLGA/PEG group was significantly lower than that in model group ( P<0.05), but it had not yet reached to the level of the control group ( P<0.05). Histological observation showed that the proliferation of cecal fibrous connective tissue was slower in PLGA/PEG group than in model group, and adhesion severity significantly decreased, only with a small amount of inflammatory cell infiltration. Nevertheless, it was not up to the level of the control group. Conclusion: PLGA/PEG electrospun polymer membrane can effectively prevent postoperative intraperitoneal adhesion of rat, and has good biodegradability.

Determination of piperphentonamine and metabolites M1 and M6 in human plasma and urine by LC/MS/MS and its application in a pharmacokinetics study in Chinese healthy volunteers.

Piperphentonamine hydrochloride (PPTA) is a new calcium sensitizer. A liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for determination of piperphentonamine and its metabolites M1 and M6 was developed for the first time and applied to a pharmacokinetics study. Protein precipitation was used for pre-treatment of plasma samples, and solid phase extraction method was used for pre-treatment of urine samples. The chromatographic separation was achieved on a C(18) column using gradient elution in this study: A: 1% acetic acid aqueous solution, and B: acetonitrile. The whole analysis lasted for 10.5min and the gradient flow rate was 0.25mL/min constantly. The detection was performed of a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via a positive electrospray ionization source. The results were that the m/z ratios of monitored precursor ions and product ions of PPTA, M1 and M6 were 354.0→191.8, 356.0→148.7 and 358.0→148.7, respectively. From the standard curve, the concentration ranges of both PPTA and M1 in blood and urine samples were 0.1-500ng/mL and 0.1-200ng/mL, respectively; the concentration ranges of M6 in blood sample and urine sample were 0.2-500ng/mL and 0.2-200ng/mL, respectively; and the correlation coefficient of standard curve was r>0.99. A total of 31 healthy Chinese subjects participated in the pharmacokinetic study of single bolus intravenous injection of piperphentonamine hydrochloride. They were divided into three dosage groups and given 0.2, 0.4 and 0.6mg/kg of PPTA. After drug administration, concentrations of PPTA, M1 and M6 in human plasma and urine samples were determined to evaluation the pharmacokinetic characteristics of PPTA and its metabolites M1 and M6.

[Technique of running urethrovesical anastomosis during radical laparoscopic prostatectomy: separate application of two needles].

OBJECTIVE: To study the value and feasibility of a novel method of urethrovesical anastomosis during radical laparoscopic prostatectomy. METHODS: From 2008 to 2009, 10 patients with local prostate cancer (LPC) underwent radical laparoscopic prostatectomy through the placement of two separate needles for running urethrovesical anastomosis. The first step comprised the first stitch placed in the posterior wall of anastomosis (at 4 o'clock) and then clockwise running suture from 4 to 12 o'clock position. The next steps entailed another needle, stitching at 3 o'clock position and counterclockwise running suture. Two sutures would meet at 12 o'clock position for the third and final knot. When the position of urinary leak was observed, an additional suture would be performed. RESULTS: This technique was performed in 10 patients with a mean anastomosis duration of 30 minutes (range: 25 - 45) and a mean operative duration of 220 minutes (range: 200 - 300). The Foley catheter was implanted for 14 days. Neither bladder neck stricture nor urinary leak was observed with a follow-up period of 3 - 24 months. CONCLUSIONS: The described technique is a feasible and safe method for urethrovesical anastomosis with a low rate of complications. And it may be quickly mastered so as to lower the learning curve of a novice.

Pharmacokinetics and pharmacodynamics of subcutaneous injection and intravenous infusion of recombinant human interleukin-12 and recombinant human interleukin-12 combined with hepatitis B surface antigen in cynomolgus monkeys.

BACKGROUND/AIMS: Interleukin-12 (IL-12) is a cytokine that plays an important role in cell-mediated immunity and shows great potential as a therapeutic agent for the treatment of tumors and infectious diseases. METHODS: We investigated the pharmacokinetics (PK) and pharmacodynamics of recombinant human IL-12 (rhIL-12) and rhIL-12 combined with hepatitis B surface antigen (HB(s)Ag) after administration by subcutaneous (s.c.) injection or intravenous infusion in cynomolgus monkeys. RESULTS: After s.c. injection of rhIL-12 at doses of 0.15-1.5 microg/kg, the monkey's metabolism showed linear kinetic characteristics. The intramuscular injection of HB(s)Ag vaccine did not affect the pharmacokinetic profile of rhIL-12. In monkeys administered rhIL-12 in a continuous dosing fashion, serum rhIL-12 was undetectable, probably due to the neutralizing effect of anti-rhIL-12 antibodies. In monkeys receiving high-dose s.c. injection of rhIL-12, the T(max) for serum rhIL-12 concentration was 4-8 h, and the T(max) for serum interferon-gamma (IFN-gamma) concentration was 24-72 h. However, in monkeys receiving continuous dosing of rhIL-12, serum IFN-gamma concentration was very low or even undetectable. CONCLUSION: We found that the PK of rhIL-12 was dose-dependent and its pharmacological effects appeared after T(max) and lasted much longer than mean retention time.