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Weipeng Shi,1,2 Yaping Jiang,3 Yingzhen Wang,1 Cailong Zhang,1 Tengbo Yu,1 Tao Li1 1Department of Orthopaedic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China; 2Medical Department of Qingdao University, Qingdao, Shandong, People’s Republic of China; 3Department of Oral Implantology, The Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of ChinaCorrespondence: Tao Li; Tengbo Yu, Department of Orthopaedic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China, Email qdult@qdu.edu.cn; ytb1970@126.comObjective: Previous studies have suggested that the diagnostic biomarkers of periprosthetic joint infection (PJI) are largely influenced by gender. In the present study, we aimed to evaluate the diagnostic value of traditional inflammatory biomarkers, fibrinolytic biomarkers (fibrinogen and D-dimer), and C-reactive protein (CRP)/albumin for PJI in different genders.Methods: A single-center retrospective analysis was performed on revision total hip or knee arthroplasty between June 2013 to June 2021, and the study included 80 patients in the PJI group and 136 patients in the non-PJI group. PJI was diagnosed based on the International Consensus Meeting (ICM) in 2018. The levels of CRP, fibrinogen, erythrocyte sedimentation rate (ESR), D-dimer, and albumin count were determined. Receiver operating characteristic (ROC) curves and Youden’s index were used to evaluate the diagnostic ability of various biomarkers.Results: The levels of CRP, fibrinogen, D-dimer, ESR, and CRP/albumin were significantly higher in the PJI group (P < 0.001). In PJI of females, the predictive value of CRP was the highest among the five biomarkers, with the area under the curve (AUC) of 0.98. The optimal predictive cut-off for CRP was 8.86 mg/L, with a sensitivity and specificity of 90.2% and 95.7%, respectively. When combined with the other four biomarkers, the AUC of CRP was 0.98, 0.99, 0.98, and 0.99, respectively. In PJI of males, the predictive value of ESR was the highest among the five biomarkers, with an AUC of 0.92. The optimal predictive cut-off for ESR was 14.50 mm/h, with a sensitivity and specificity of 84.6% and 86.6%, respectively. When combined with the other four biomarkers, the AUC of ESR was 0.95, 0.94, 0.93, and 0.97, respectively.Conclusion: CRP and ESR were excellent biomarkers for diagnosing PJI in female and male patients, respectively, and their combined use with CPR/albumin could provide higher diagnostic value in different genders.Keywords: gender, biomarkers, periprosthetic joint infection

Cailong Zhang,1 Na Na,2 Li Liu,3 Yingzhu Qiu4 1Department of Arthrology Surgery, The Affiliated Hospital of Qingdao University, Qingdao 266000, People’s Republic of China; 2Department of Obstetrics, Qingdao Eighth People’s Hospital, Qingdao 266000, People’s Republic of China; 3Department of Stereotactic Radiotherapy, Qingdao Central Hospital, Qingdao 266000, People’s Republic of China; 4Department of Spine Surgery, Zibo Central Hospital, Zibo 255000, People’s Republic of ChinaCorrespondence: Yingzhu QiuDepartment of Spine Surgery, Zibo Central Hospital, 56 West Gongqingtuan Road, Zhangdian District, Zibo 255000, People’s Republic of ChinaEmail zhuyinc_1969@163.comObjective: Osteosarcoma (OS) is the most common malignant bone tumor in the pediatric population. The main goal of this study is to investigate the role of hsa_circ_0005909 and the underlying signaling pathway involved in OS.Methods: Cell proliferation was measured using a CCK-8 assay kit and clone formation assay. Change of RNA and protein expression was determined using RNA extract and quantitative real time PCR (RT-qPCR) assay and Western blotting, respectively. CircInteractome was used to predict the target of circRNA and starBase v2.0 was used to predict the target of miRNAs. Luciferase assay was used to confirm the predicted results from CircInteractome, starBase v2.0, and MirTarget2.Results: Expression of circ_0005909 was upregulated in both OS tissues and cell lines. The predicted results from CircInteractome, starBase v2.0, and MirTarget2 demonstrated that circ_0005909 could sponge miR-338-3p and that HGMA1 was the direct target of miR-338-3p. Cell viability and cell clones were inhibited by knockdown of circ_0005909 but increased by dual inhibition of circ_0005909 and miR-338-3p. Phosphorylation of ERK, Akt, and PI3K was inhibited by sh-circ_0005909, while this inhibition was repressed by co-transfection of sh-circ_0005909 and HGMA1.Conclusion: Expression of circ_0005909 was upregulated in both OS tissues and cell lines which upregulated expression of HGMA1 through sponging miR-338-3p, resulting in the activation of MAPK-ERK and PI3K-Akt signaling pathways to promote the development of OS.Keywords: hsa_circ_0005909, osteosarcoma, miR-338-3p, HMGA1

Objective: Osteosarcoma (OS) is the most common malignant bone tumor in pediatric population. The main goal of this study is to investigate the role of has_circ_0005909 and the underlying signaling pathway involved in OS.Methods: Cell proliferation was measured using CCK-8 assay kit and clone formation assay. Change of RNA and protein expression was determined using RNA extract and quantitative real time PCR (RT-qPCR) assay and Western blotting, respectively. CircInteractome was used to predict the target of circRNA and starBase v2.0 was used to predict the target of miRNAs. Luciferase assay was used to confirm the predicted results from CircInteractome and starBase v2.0.Results: Expression of circ_0005909 was upregulated in both OS tissues and cell lines. The predicted results from CircInteractome and starBase v2.0 demonstrated that circ_0005909 could sponge miR-338-3p and that HGMA1 was the direct target of miR-338-3p. Cell viability and cell clones was inhibited by knockdown of circ_0005909 but increased by dual inhibition of circ_0005909 and miR-338-3p. Phosphorylation of ERK, Akt, PI3K was inhibited by sh-circ_0005909 while this inhibition was repressed by co-transfection of sh-circ_0005909 and HGMA1.Conclusion: Expression of circ_0005909 was upregulated in both OS tissues and cell lines which upregulated expression of HGMA1 through sponging miR-338-3p, resulting in the activation of MAPK-ERK and PI3K-Akt signaling pathways to promote the development of OS.

The present study investigated the effect of angiotensin II (Ang II) on monocyte chemoattractant protein‑1 (MCP‑1) expression and the underlying mechanism in osteoblasts. MCP‑1 expression levels were analyzed by ELISA and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). Ang II type 1 receptor (AT1R) expression levels was examined by RT‑qPCR, western blotting and immunostaining. In addition, the nuclear factor (NF)‑κB signaling pathway was investigated via western blot analysis. Reactive oxygen species (ROS) were also detected by flow cytometry and fluorescent microscopy. The results of the present study ndicated that Ang II upregulated MCP‑1 expression in osteoblasts, which was mitigated by agonists of the AT1R, including olmesartan, a ROS scavenger N‑acetylcysteine (NAC), ammonium pyrrolidinethiocarbamate (PDTC) and nuclear factor (NF)‑κB, but not by the Ang II type 2 receptor antagonist, PD123319. Furthermore, Ang II increased the generation of ROS and activated the NF‑κB signaling pathway. These effects of Ang II were blocked by olmesartan, NAC and PDTC, but not by PD1123319 in osteoblasts. In conclusion, these data indicated that Ang II enhanced ROS production and activated NF‑κB signaling via AT1R, thus upregulating MCP‑1 expression in osteoblasts.

Objective: To analyze the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with irradiated bone-patellar tendon-bone (BPTB) allograft compared with non-irradiated allograft and autograft. Methods: All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 mrad of irradiation prior to distribution. A total of 68 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into one of the two groups (autograft and irradiated allograft groups). The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months of follow-up (ranging from 24 to 47 months), patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results: Of these patients, 65 (autograft 33, irradiated allograft 32) were available for full evaluation. When the irradiated allograft group was compared to the autograft group at the 31-month follow-up by the Lachman test, the anterior drawer test (ADT), the pivot shift test, and KT-2000 arthrometer test, statistically significant differences were found. Most importantly, 87.8% of patients in the autograft group and just only 31.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee (IKDC), functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups. Besides, patients in the irradiated allograft group had a shorter operation time and a longer duration of postoperative fever. When the patients had a fever, the laboratory examinations of all patients were almost normal. Blood routine was normal, the values of erythrocyte sedimentation rate (ESR) were 5~16 mm/h and the contents of C reactive protein (CRP) were 3~10 mg/L. Conclusion: We conclude that the short term clinical outcomes of the ACL reconstruction with irradiated BPTB allograft were adversely affected. The less than satisfactory results led the senior authors to discontinue the use of irradiated BPTB allograft in ACL surgery and not to advocate using the gamma irradiation as a secondary sterilizing method.

The effect of using gamma irradiation to sterilize bone-patellar tendon-bone (BPTB) allograft on the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with irradiated allograft remains controversial. Our study was aimed to analyze the clinical outcomes of arthroscopic ACL reconstruction with irradiated BPTB allograft compared with non-irradiated allograft and autograft. All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 Mrad of irradiation prior to distribution. A total of 102 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into three groups. The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months follow-up (range 24-47 months) patients were evaluated by the same observer according to objective and subjective clinical evaluations. Of these patients, 99 (autograft 33, non-irradiated allograft 34, irradiated allograft 32) were available for full evaluation. When compared the irradiated allograft group to non-irradiated allograft group or autograft group at 31 months follow-up by the Lachman test, ADT, pivot shift test and KT-2000 arthrometer testing, statistically significant differences were found. Most importantly, 87.8% of patients in the Auto group, 85.3% in the Non-Ir-Auto group and just only 31.3% in the Ir-Allo group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%) and non-irradiated allograft (8.8%). The anterior and rotational stability decreased significantly in the irradiated allograft group. According to the overall IKDC, functional, subjective evaluations and activity level testing, no statistically significant differences were found between the three groups. However, there was a trend that the functional and activity level decreased and the patients felt uncomfortable more often in the irradiated allograft group. The statistical analysis showed no significant difference between the non-irradiated allograft group and the autograft group according to the aforementioned evaluations, except that patients in the allograft group had a shorter operation time and a longer duration of postoperative fever. When comparing the postoperative duration of fever of the two allograft groups, there was also a trend that the irradiated allograft group was longer than the non-irradiated allograft group, but no significant difference was found. When the patients had a fever, the laboratory examinations of all patients were almost normal (Blood routine was normal, the values of ESR were 5 - 16 mm/h, CRP were 3 - 10 mg/l). On the basis of our study, we concluded that patients undergoing ACL reconstruction with BPTB non-irradiated allograft or autograft had similar clinical outcomes. Non-irradiated BPTB allograft is a reasonable alternative to autograft for ACL reconstruction. While the short term clinical outcomes of the ACL reconstruction with irradiated BPTB allograft were adversely affected with an increased failure rate. The less than satisfactory results led the senior authors to discontinue the use of irradiated BPTB allograft in ACL surgery and not to advocate that gamma irradiation be used as a secondary sterilizing method. Further research into alternatives to gamma irradiation is needed.

To study the effect of platelet lysate (PL) on chondrogenic differentiation of human umbilical cord derived mesenchymal stem cells (hUCMSCs) in vitro.Umbilical cords were voluntarily donated by healthy mothers. The hUCMSCs were isolated by collagenase digestion and cultured in vitro. The surface markers of the cells were detected by flow cytometer. According to different components of inductive medium, the cultured hUCMSCs were divided into 3 groups: group A [H-DMEM medium, 10% fetal bovine serum (FBS), and 10%PL]; group B [H-DMEM medium, 10%FBS, 10 ng/mL transforming growth factor beta1 (TGF-beta1), 1 x 10(-7) mol/L dexamethasone, 50 microg/mL Vitamin C, and 1% insulin-transferrin-selenium (ITS)]; and group C (H-DMEM medium, 10%FBS, 10 ng/mL TGF-beta1, 1 x 10(-7) mol/L dexamethasone, 50 microg/mL vitamin C, 1%ITS, and 10%PL). The hUCMSCs were induced in the mediums for 2 weeks. Toluidine blue staining was used to detect the secretion of chondrocyte matrix. Immunofluorescence method was used to identify the existence of collagen type II. The expressions of Aggrecan and collagen type II were detected by semiquantitative RT-PCR.Flow cytometer results showed that the hUCMSCs did not express the surface markers of hematopoietic cell CD34, CD45, and human leukocyte antigen DR, but expressed the surface markers of adhesion molecule and mesenchymal stem cells CD44, CD105, and CD146. Toluidine blue staining and immunofluorescence showed positive results in group C, weak positive results in group B, and negative results in group A. Semiquantitative RT-PCR showed the expressions of Aggrecan and collagen type II at mRNA level in groups B and C, but no expression in group A. The mRNA expressions of Aggrecan and collagen type II were higher in group C than in group B (P0.05).Only 10%PL can not induce differentiation of hUCMSCs into chondrocytes, but it can be a supplement to the induced mediums. PL can improve hUCMSCs differentiating into chondrocytes obviously in vitro. This study provides new available conditions for constructing tissue engineered cartilage.

An increasing number of tissue banks have begun to focus on gamma irradiation and freeze-thaw in the reconstruction of anterior cruciate ligaments using allografts. The purpose of this study was to evaluate the biomechanical properties of human tendons after exposure to gamma radiation and repeated freeze-thaw cycles and to compare them with fresh specimens. Forty flexor digitorum superficialis tendons were surgically procured from five fresh cadavers and divided into four groups: fresh tendon, gamma irradiation, freeze-thaw and gamma irradiation+freeze-thaw. The dose of gamma irradiation was 25 kGy. Each freeze-thaw cycle consisted of freezing at -80 °C for 7 day and thawing at 25 °C for 6 h. These tendons underwent 4 freeze-thaw cycles. Biomechanical properties were analyzed during load-to-failure testing. The fresh tendons were found to be significantly different in ultimate load, stiffness and ultimate stress relative to the other three groups. The tendons of the gamma+freeze-thaw group showed a significant decrease in ultimate load, ultimate stress and stiffness compared with the other three groups. Gamma irradiation and repeated freezing-thawing (4 cycles) can change the biomechanical properties. However, no significant difference was found between these two processes on the effect of biomechanical properties. It is recommended that gamma irradiation (25 kGy) and repetitive freeze-thaw cycles (4 cycles) should not be adopted in the processing of the allograft tendons.

Background: Most studies of allograft versus autograft for anterior cruciate ligament reconstruction have been of bone–patellar tendon–bone; outcome reports evaluating anterior cruciate ligament reconstruction with hamstring tendon autograft versus allograft are rare. Purpose: This study was undertaken to compare the clinical outcome of arthroscopic anterior cruciate ligament reconstruction with hamstring tendon autograft versus allograft. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Between 2000 and 2004, 208 patients who met the inclusion and exclusion criteria of the study were prospectively randomized into autograft (n = 104) or allograft (n = 104) groups. All hamstring tendon allografts were fresh-frozen and obtained from a single certified tissue bank. All the operations were done by the same surgeon with the same surgical technique. Femoral and tibial fixation was by means of an EndoButton and a bioabsorbable interference screw augmented with a staple, respectively. Patients were evaluated preoperatively and postoperatively. Evaluations included detailed history, physical examination, functional knee ligament testing, KT-2000 arthrometer testing, Harner vertical jump and Daniel 1-legged hop tests, Lysholm score, Tegner score, the International Knee Documentation Committee (IKDC) standard evaluation form, Cincinnati knee score, and radiographs. Results: Of these patients, 186 (autograft, n = 91; allograft, n = 95) were available for full evaluation. Demographic data were comparable between groups. The mean follow-up was 7.8 years for both groups. There were no statistically significant differences according to the evaluations of the outcome aforementioned between the 2 groups except that patients in the allograft group had a shorter operation time than the autograft group. Seven patients (7.7%) in the autograft group and 8 (8.4%) in the allograft group had a side-to-side difference >5 mm. Eighty-five patients (93.4%) in the autograft group and 86 (90.5%) in the allograft group were normal or nearly normal according to the overall IKDC. According to the subjective IKDC, the average scores were 89 and 90 points, respectively, for the autograft and allograft groups. The mean Lysholm and Tegner scores were 89 points and 7.7 points, respectively, for the autograft group and 90 points and 7.6 points, respectively, for the allograft group. For the Cincinnati knee score, the average scores were 90 and 91 points, respectively, for the autograft and allograft groups. Conclusion: Both groups of patients achieved almost the same satisfactory outcome at an average of 7.8 years of follow-up. Fresh-frozen hamstring tendon allograft is a reasonable alternative choice to autograft for anterior cruciate ligament reconstruction.

To analyze the outcome of arthroscopic anterior cruciate ligament reconstruction with irradiated versus non-irradiated hamstring tendon allograft. All hamstring tendon allografts were obtained from a single certified tissue bank, and the irradiated allografts were sterilized with 2.5 Mrad of irradiation prior to distribution. A total of 78 patients who met the inclusion and exclusion criteria of the study were prospectively randomized consecutively into two groups (Non-ir-Allo vs. Ir-Allo). All the operations were done by the same senior surgeon. Before surgery and at follow-up, patients were evaluated by the same observer according to clinical evaluations including the Lachman test, ADT, pivot shift test, varus/valgus stress test, the instrumented KT-2000 arthrometer testing, vertical jump test, one-leg hop test, ROM of knee, Cincinnati knee score, IKDC Subjective Knee Form, Tegner activity score, modified Lysholm knee scoring scale, and the standard knee ligament evaluation form of the IKDC. Of these patients, 69 (Non-ir-Allo 38, Ir-Allo 31) were available for full evaluation. When compared the Ir-Allo group with Non-ir-Allo group at the final follow-up by Lachman test, ADT, pivot shift test, and KT-2000 arthrometer testing, statistically significant differences were found (P

Purpose To compare the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with hamstring tendon autograft versus irradiated allograft. Methods All irradiated hamstring tendon allografts (gracilis and semitendinosus), which were sterilized with 2.5 Mrad of irradiation before distribution, were obtained from a single certified tissue bank. A total of 78 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into 1 of 2 groups: autograft and irradiated allograft. The same surgical technique was used in all operations, which were performed by the same senior surgeon. Before surgery and at a mean of 42.2 months of follow-up, patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results Of the patients, 67 (36 in autograft group and 31 in irradiated allograft group) were available for full evaluation. When the irradiated allograft group was compared with the autograft group at the final follow-up by the Lachman test, anterior drawer test, pivot-shift test, and KT-2000 arthrometer (MEDmetric, San Diego, CA) assessment, statistically significant differences were found ( P = .00011, P = .00016, P = .008, and P = .00021, respectively). Most importantly, 86.1% of patients in the autograft group and only 32.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000 assessment. The rate of laxity (side-to-side difference >5 mm) with irradiated allograft (32.3%) was higher than that with autograft (8.3%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee rating, functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the 2 groups. However, patients in the irradiated allograft group had a shorter operative time and a longer duration of postoperative fever. When the patients had a fever, the laboratory examination findings of all patients were almost normal (white blood cell count, normal; erythrocyte sedimentation rate, 8 to 20 mm/h; and C-reactive protein level, 4 to 11 mg/L). Conclusions The clinical outcome of ACL reconstruction with hamstring tendon autograft was satisfactory, whereas the difference in instrumented laxity between the 2 groups was significant and the difference in functional test results was not significant. Level of Evidence Level II, prospective comparative study.

The purpose of this study was to analyze the clinical outcome of arthroscopic anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone autograft versus allograft.Between May 2000 and June 2004, 172 patients undergoing arthroscopic bone-patellar tendon-bone ACL reconstruction were prospectively randomized into autograft (n = 86) or allograft (n = 86) groups. The senior surgeon performed all operations using the same surgical technique. Each fixation was performed by means of an interference screw. Patients were evaluated preoperatively and postoperatively at follow-up. Of the patients, 156 (76 in the autograft group and 80 in the allograft group) were available for full evaluation. Evaluations included a detailed history, physical examination, functional knee ligament testing, KT-2000 arthrometer testing (MEDmetric, San Diego, CA), Harner's vertical jump and Daniel's 1-leg hop tests, Lysholm score, Tegner score, International Knee Documentation Committee standard evaluation form, Cincinnati knee score, and radiograph.Demographic data were comparable between groups. The mean follow-up was 5.6 years for both groups. There were no statistically significant differences according to evaluations of outcome between the 2 groups except that patients in the allograft group had a shorter operation time and longer fever time postoperatively compared with the autograft group. The postoperative infection rates were 0% and 1.25% for the autograft group and allograft group, respectively. There was a significant difference (P.05) in the development of osteoarthritis between the operated knee in comparison to the contralateral knee according to radiographs. However, no significant difference was found between the 2 groups at the final follow-up examination (P.05).Both groups of patients achieved almost the same satisfactory outcomes after a mean of 5.6 years of follow-up. Allograft is a reasonable alternative to autograft for ACL reconstruction.Level II, prospective comparative study.

To research the gene expression of transforming growth factor beta1 (TGF-beta1) in zone II flexor tendon wound healing of rabbit.Sixty New Zealand white rabbits forepaws (left side) underwent complete transection and the middle digit flexor digitorum profundus tendon in zone II were repaired by Kessler methods as the experimental group. The normal right forepaws served as the control group. The tendons and tendon sheaths were harvested at 1, 7, 14, 21, 28 and 56 days after repair (n = 10). The expression patterns of TGF-beta1 were analyzed by in situ hybridization and immunohistochemistry staining methods.The in situ hybridization examination revealed that TGF-beta1 mRNA expression up-regulated at 1 day, reached the peak levels at 14-21 days and remained high levels up to 56 days in the experimental group. The expression of TGF-beta1 mRNA in control group was lower than that in the experimental group, showing statistically significant difference (P0.05). The results of immunohistochemical staining was similar to that of in situ hybridization.The normal tendon and tendon sheath cells are capable of TGF-beta1 production. The cytokine is activated in tendon wound condition. The up-regulation of this cytokine in both tendon and tendon sheath cells are coincidence with both extrinsic and intrinsic mechanisms for tendon repair.

It has become increasingly important to get high quality prints from TV or other video signals in the desktop publishing and multi-media environment. Normally, a video signal has very low spatial resolution compared with the spatial resolution of printing devices. Hard copy from direct printing of a video signal is usually very poor in quality. To improve the video signal spatial resolution for printing, the algorithm presented in this paper applies an adaptive spatial interpolation technique to the video signal. The algorithm is based on a computer graphics curve-fitting algorithm with the addition of edge-restricted interpolation to sharpen edges and to enhance image details. Therefore, the new interpolation algorithm will not only improve the spatial resolution but also improve the sharpness of the printed image. In this paper, the aspects of theoretical development of the new algorithm will be discussed and some simulation results will be shown and evaluated to present the effect of the algorithm.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper, a technique to convert page description language (PDL) code to a bitmap color image using an optical image memory is discussed. The technique is useful in developing a low cost PDL compatible high resolution graphic printing device for desktop publishing applications. The optical image memory in this discussion is a raster scan addressable device which is write-only in the sense of electrical digital access, and its content is continually accessible by an analog optical mean. Utilizing the low cost optical image memory, the algorithm can rasterize PDL code without large amounts of expensive digital image frame memory. Since the optical image memory is a raster scan addressable device, the rasterization ofeach pixel ofthe color image must be done within the access time of each pixel writing. Some novel techniques are introduced in this algorithm. System development, performance analysis, and the application of the algorithm will be presented.