The paper is aimed to study the enzymatic hydrolysis of the activatable cell-penetrating peptide (ACPP) that was designed and synthesized. The ACPP was composed of three parts, polyanionic sequence peptide, peptide sequence that specifically cleaved by matrix metalloproteinase (MMP) and cell penetrating peptide (CPP). The ACPP was hydrolyzed by type IV collagenase (MMP-2/9) under the condition of 37 degrees C and was monitored by reversed-phase high performance liquid chromatography (RP-HPLC). The efflux of peak was collected and detected by matrix assisted laser desorption ionization orthogonal time of flight mass spectrometry (MALDIO-TOF-MS) to speculate the sequences of the peptide fragments. The results indicated that the ACPP could be cleaved by type IV collagenase at target site as predicted, released CPP. The half life of the cleavage was about 4 h. Meanwhile, the peptide fragments may be cleaved again at other sites by type IV collagenase.

Objective To observe the biomechanics of the anterior and posterior interosseous talo-calcaneal ligaments (ITCLs) . Methods Load-displacement characteristics of the subtalar joint were studied in 12 cadaver specimens whose ankle joints were mutilated. The ankle articular surfaces of the talus and the post-calcaneus were exposed. Bone blocks were then embedded in polymethylmethacrylate. The an-terior ITCLs were abscised in 6 of them, and the posterior ITCLs in the other 6. A multi-functional biome-chanical machine was used to perform the biomechanical tests on the specimens. Results When the anterior ITCLs were cut, the tali moved to the anterior-lateral side. When the posterior ITCLs were cut, the tali mostly moved to the anterior-interior side. Conclusions The anterior and posterior ITCLs have dif-ferent roles in maintaining stability of the subtalar joint. Since the posterior ITCLs seem more important than the anterior ones, they should have priority in ITCL reconstruction.

Digital X-ray photography has been applied to clinical medicine in recent 3years.This paper introduces the development situation of the flat detectors for digital X-ray photography.The technical indexes and structure differences of the detectors are presented in this paper.

Objective To design a new X-ray sensor of iono-chamber type to achieve automatic exposure control(AEC) of the X-ray machine. Methods We designed the chamber acording to the ionization theory and the requirements of automatic exposure control. Results (1) The device had double-negative poles, so the distance between positive and negative poles was 1/2 shorter and its test-volume was equal to odd-negative pole. (2)It had good property of electromagnetism-resistance because of the double shielded design by double-negative poles and screen-rings.(3) Iono-chamber was made of low-density material, so it had low absorb-ratio of X-ray and could not form image on film. Conclusion The property of the device was steady and reliable. It had applying and spreading value.

Objective: Introduce Internet and wireless communication technology into radiology image remote diagnosis system, develop a new system combined with PACS. Material and Methods: Used ASP.NET technology under VS. NET2005, and used JAVA to develop the image APPLET, Web server used 11S5.0, database used Microsoft SQL Server. Also need a SMS Modern to send message online. Results: Offer two ways to access medical image remote diagnosis system: Interact and wireless networks. Wherever a doctor he is, as long as has a computer or mobile phones can be connected to Interact or wireless network, can login diagnosis system, browse the patients' images, do some image processing, and also can send reports. Conclusions: The system can be put into practice, lifting the restrictions in time and place of remote diagnosis system, it try in full-development of telemedicine. Although at present reports of this form does not have legal effectiveness, this paper provided a new idea for development of medical image remote diagnosis system.

Cyclic amp receptor protein (CRP) is a global transcriptional factor in many prokaryotes, capable of governing nearly half of the total genes in Escherichia coli. Through the method of error-prone PCR or DNA shuffling, we can first obtain CRP mutant library and then get the expected cell phenotype with enhanced resistance. In this article, we reviewed the following desired phenotype: enhanced tolerance towards oxidative stress, improved osmotolerance, enhanced organic solvent (toluene) tolerance, improved acetate tolerance of E. coli fermentation and improved ethanol tolerance during bio-ethanol production. We then concluded that CRP can also be applied in other host cells to get desired phenotypes. Last, we predicted potential applications of mutant CRP transcriptional factor.
Cyclic AMP Receptor Protein ; biosynthesis ; DNA Shuffling ; Escherichia coli ; metabolism ; Fermentation ; Metabolic Engineering

Objective To explore the clinical value of microsurgery in the treatment of lateral ventricle tumors. Methods Microsurgery was conducted in 14 cases of lateral ventricle trmors in this department from May 1996 to August 2002. According to the location of tumors, we selected the approach close to the focus, protected the surrounding nerve tissue and the deep venous system, and resected the tumor in fractions. Results Among the 14 cases, 13 (92.9%) received total resection and 1 (7.1%) subtotal resection. A total of 11 cases of complications occurred postoperatively, including 3 cases of intracranial infection, 2 cases of hemiparalysis, 1 case of hydrocephalus, 3 cases of frontal lobe mental symptoms, 1 case of intraventricular hematoma and 1 case of nominal aphasia. Except for 1 case of hemiparalysis who were not able to resume the ability to take care of his own basic needs, the remaining 10 cases obtained full recovery. Follow-up in 9 cases for 6～60 months (mean, 29 months) showed 2 cases of recurrence of astrocytoma. Conclusions Microsurgery offers good visualization, minimal invasion and a high total resection rate for tumor.

Digital angiography system is mainly composed of Digital Subtraction Angiography(DSA)equipment and mostly used in angiography and interventional radiology.With the improvement of image quality,modern DSA equipment has a higher radiation output capacity,which increases the potential radiation damage to the operators and patients.Dose optimization studies the relationship between image quality and radiation dose for reasonable reduction of radiation dose and good image quality.

Objective To test and analyse the characteristics of double three field iono chamber developed by ourselves. Methods We tested the time characteristic, dose rate characteristic and X ray quality characteristic by using direct test method, and current characteristic, voltage characteristic and thickness characteristic of double three field iono chamber by using photograph test method with NERO 6000B test meter, RF 500 mA X ray equipment and so on. The results were analysed. Results The time characteristic and dose rate characteristic had satisfied linear scales(the return coefficients of linety scales were R =0.999 61 and R = 0.998 88 respectively). The X ray quality characteristic was steady (the maximum output variation was ? max ≤?5%). The good characteristics of current, voltage and thickness were found(the maximum variations of film density were ?D max ≤?0.01, ?D max ≤?0.15 and ?D max ≤?0.06 respectively). The excellent repeat was showed (repeating error of exposure time and dose were ?T max ≤?0.004 s and ?X max ≤0.01?10 -5 C/kg). Conclusion The performace of the new Iono chamber is excellent and steady, so it has practical value.

In order to construct a recombinant plasmid containing short hairpin RNA (shRNA) targeting survivin and to investigate its effect on survivin expression and cell apoptosis of human retinoblastoma cell line Hxo-rb44 in vitro, RNA interference plasmid pSIRENS that can express shRNA of survivin was designed, constructed, and transfected into human retinoblastoma cell line Hxo-rb44. Survivin and c-Myc expression was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Apoptosis of Hxo-rb44 cells was assayed by Honchest33258 staining and cell growth curve was drawn. The results showed that the oligonucleotide targeting survivin was identified in pSIRENS plasmid. After pSIRENS plasmid transfected, survivin and c-Myc expression in Hxo-rb44 cells was decreased significantly. Apoptotic rate of cells was up-regulated from (3.5+/-1.29) % to (36.1+/-19.66) %. The proliferation ability of Hxo-rb44 cells was inhibited. No significant effects on survivin expression and apoptosis of the cells were found when negative control plasmid was transfected. In conclusion, the plasmid containing shRNA targeting survivin was constructed successfully. It could inhibit efficiently the expression of survivin and c-Myc in human retinoblastoma cell Hxo-rb44 in vitro. The inhibition of the expression of c-Myc might be involved in the apoptosis of Hxo-rb44 cells.