[Improved unilateral puncture PVP based on 3D printing technology for the treatment of osteoporotic vertebral compression fracture]

OBJECTIVE

To investigate the clinical effect of unilateral percutaneous vertebroplasty (PVP) combined with 3D printing technology for the treatment of thoracolumbar osteoporotic compression fracture.

METHODS

A total of 77 patients with thoracolumbar osteoporotic compression fractures from October 2020 to April 2022 were included in the study, all of which were vertebral body compression fractures caused by trauma. According to different treatment methods, they were divided into experimental group and control group. Thirty-two patients used 3D printing technology to improve unilateral transpedicle puncture vertebroplasty in the experimental group, there were 5 males and 27 females, aged from 63 to 91 years old with an average of (77.59±8.75) years old. Forty-five patients were treated with traditional bilateral pedicle puncture vertebroplasty, including 7 males and 38 females, aged from 60 to 88 years old with an average of(74.89±7.37) years old. Operation time, intraoperative C-arm X-ray times, anesthetic dosage, bone cement injection amount, bone cement diffusion good and good rate, complications, vertebral height, kyphotic angle (Cobb angle), visual analogue scale(VAS), Oswestry disability index (ODI) and other indicators were recorded before and after surgery, and statistically analyzed.

RESULTS

All patients were followed up for 6 to 23 months, with preoperative imaging studies, confirmed for thoracolumbar osteoporosis compression fractures, two groups of patients with postoperative complications, no special two groups of patients' age, gender, body mass index (BMI), time were injured, the injured vertebral distribution had no statistical difference(P>0.05), comparable data. Two groups of patients with bone cement injection, bone cement dispersion rate, preoperative and postoperative vertebral body height, protruding after spine angle(Cobb angle), VAS, ODI had no statistical difference(P>0.05). The operative time, intraoperative fluoroscopy times and anesthetic dosage were statistically different between the two groups(P<0.05). Compared with the traditional bilateral puncture group, the modified unilateral puncture group combined with 3D printing technology had shorter operation time, fewer intraoperative fluoroscopy times and less anesthetic dosage. The height of anterior vertebral edge, kyphosis angle (Cobb angle), VAS score and ODI of the affected vertebrae were statistically different between two groups at each time point after surgery(P<0.05).

CONCLUSION

In the treatment of thoracolumbar osteoporotic compression fractures, 3D printing technology is used to improve unilateral puncture PVP, which is convenient and simple, less trauma, short operation time, fewer fluoroscopy times, satisfactory distribution of bone cement, vertebral height recovery and kyphotic Angle correction, and good functional improvement.

[Experimental study of individualized 3D printing-guided template combined with thoracolumbar pedicle screw placement for the treatment of ankylosing spondylitis]

OBJECTIVE

To evaluate accuracy and safety of individualized 3D printing guided template for thoracolumbar pedicle screw placement in patients with ankylosing spondylitis.

METHODS

From January 2016 to September 2019, thoracolumbar spine three-dimensional CT data of 8 patients with ankylosing spondylitis were included, Mimics 17.0 and ideaMaker computer software were applied to design thoracolumbar pedicle screw guided template of patients with AS, physical model of all patients (T₁₀-L₂)were printed by 3D printer, 2 parts in each patient, and divided into guide-plate-assisted screw group (experimental group) and free-hand nail group (control group). Thoracolumbar pedicle screws of both groups were placed by the same spinal surgeon. The accuracy of pedicle screw placement between two groups were evaluated according to results of postoperative CT, the accuracy of the fixation of thoracolumbar pedicle screw was divided into 4 grades, grade 0 and 1 screws were acceptable nails, grade 2 and 3 screws were unacceptable nails. The diameter and length of pedicle screws, the distance between entry point and posterior median line designed by preoperative 3D printing were compared with actual use in operation.

RESULTS

Twenty three blocks of thoracolumbar 3D printing screw of ankylosing spondylitis guided templates were designed and printed in guide-plate-assisted screw group, 46 screws were inserted and 44 screws were accepted. The time of implanting a screw into thoracolumbar pedicle was (4.20±1.15) min, the frequency of X-ray was (5.00±1.25) times and the average adjustment times of screw and Kirschner needle during screw placement was (1.76±1.32) times. In the control group, 46 nails were placed by traditional surgical method and 30 screws were accepted. The time of implanting a screw into thoracolumbar pedicle was (14.67±2.23) min, the frequency of X-ray fluoroscopy was (14.46±2.21) times and the average times of Kirschner needle adjustment was (4.76±3.39) times. The success rates between experimental group and control group were 95.65%(44 / 46) and 56.22%(30 / 46) respectively, and had statistical difference (χ²=13.538, P<0.05). There was no significant difference in diameter, length of pedicle screws and the distance of posterior median line between virtual designed by 3D printing before operation and actual situation in opertaion (P>0.05). The operation time of inserting a single screw, the times of X-ray fluoroscopy, and the average times of adjustment screw and Kirschner needle in experimental group were significant less than those in control group(P<0.01).

CONCLUSION

The personalized guide template assisted the thoracolumbar fixation designed by 3D printing could significantly improve safety, accuracy and efficiency of surgery, especially suitable for thoracolumbar vertebral bodies requiring posterior pedicle screw fixation for fracture or dislocation with AS.

[Health status and healthcare service utilization among children born to women with maternal syphilis in Shanghai]

Objective: To assess the health status and health service utilization of children born to syphilis infected mothers during pregnancy, in order to prevent mother-to-child transmission of syphilis to the newborns. Methods: Women with maternal syphilis were studied by trained researchers via phone calls, in Shanghai during 2014-2015. Data related to demographics, status of infection and health care, utilization by both mothers and their children were collected through specifically designed questionnaires. Non-parametric tests including chi-square were used to assess the health status and health service utilization of children born to mothers with different demographic and socioeconomic characteristics. Results: A total of 495 children born to mothers with maternal syphilis were recruited from 1 000 syphilis infected parturient women. A total of 61 out of the 495 children were diagnosed as having congenital syphilis (57 children were diagnosed at birth and another 4 were diagnosed during the follow-up period). Children born to women who received syphilis treatment during pregnancy were at lower risk on congenital syphilis (χ(2)=7.214, P=0.027). 37.8% of the children were reported to have had different illnesses in the past three months, mainly involving upper respiratory infections (32.3%) or diarrhea (3.6%). Children diagnosed with congenital syphilis showed a higher prevalence of different kinds of diseases, compared to those without congenital syphilis (47.5% vs. 36.6%). 81.6% of the children had received regular child health care services. Subjects with the following factors as: being immigrant, with lower education, unemployed, unmarried and multipara, were related to the less use of regular child healthcare services. Only 39.7% of the parents would inform the care-takers about the risk of congenital syphilis infection of their own children at the child health care centers. Mothers with residency of Shanghai, having higher education level and employed, were less willing to inform doctors about the risk of congenital syphilis infection of their children. Conclusions: Loss to follow-up among children born to syphilis infected pregnant women remained a serious problem. Few parents would be willing to inform the healthcare takers that their children are at risk of syphilis, when receiving child health care services at the centers. It was necessary to integrate the congenital syphilis follow-up programs into the routine child care services so as to timely diagnose and treat the patients with congenital syphilis.

[3D printing technology assisted the preoperative planning and application value in adult kyphoscoliosis deformity]

OBJECTIVE

To explore the application value of 3D printing technology in preoperative surgery plan and intraoperative auxiliary operation for adult kyphoscoliosis deformity.

METHODS

The clinical data of 12 adult patients with kyphoscoliosis deformity treated from September 2017 to January 2019 were retrospectively analyzed. There were 3 males and 9 females, aged from 21 to 63 years old with an average of (47.67±13.32) years old. Among them, 4 cases were congenital kyphoscoliosis, 2 cases were old tuberculosis thoracolumbar kyphosis ; 2 cases were idiopathic kyphoscoliosis, 4 cases were degenerative kyphoscoliosis. The CT scan data of the patient's spine was imported into Mimics17.0 software to establish the three dimensional model of the spine, and the spine model was produced by 3D printer. Using the spine model simulated operation, preoperative surgery program planning and formulated a precise surgery, and further analysed postoperative imaging parameters improvement. All the patients were followed up for more than 1 year. Before and after operation and at the last follow-up, the scoliosis Cobb angle, maximum kyphosis Cobb angle, and coronal plane balance (distance between C 7 plumbline and center sacral vertical line, C₇PL-CSVL), sagittal plane balance (sagittal vertical axis, SVA), pelvic parameters and other related imaging parameters were measured to further evaluate its orthopedic effect.

RESULTS

Twelve patients with spine deformity were treated with different osteotomy and internal fixation fusion methods under the guidance of a 1∶1 spine model (pedicle screw placement of 4 patients with severe deformity were assisted by pedicle screw guide plates), nail placement and osteotomy have good effects, no major tissue damage such as blood vessels, nerves and spinal cord during and after surgery, no complications such as cerebrospinal fluid leakage and infection. Preoperative Cobb angle of scoliosis was (56.5±22.5) °, Cobb angle of kyphosis was (65.2±19.5) °, C₇ PL-CSVL was (45.8±16.9) mm, SVA was (48.7±25.4) mm. Postoperative at 4 weeks, Cobb angle of scoliosis was (20.8±11.5) °, and Cobb angle of kyphosis was (22.0±6.6) °, with correction rates of (65.1±9.7)% and (64.6± 10.6)%, respectively ; C₇ PL-CSVL was (22.3±8.9) mm, and SVA was (23.3±13.1) mm, all of which were significantly improved compared with preoperative results. The mean follow-up time was (18.5±7.9) months in 12 patients. At the last follow-up, the Cobb angles of scoliosis and kyphosis were (22.2±10.8) ° and (23.6±7.7) °, respectively, C₇ PL-CSVL was (23.5±10.8) mm, and SVA was (24.7±12.5) mm. The results were statistically significant compared preoperative (P<0.05). There was no significant difference at the postoperative at 4 weeks and the last follow-up (P>0.05).

CONCLUSION

The 3D print model can visually and clearly show the vertebral morphology and structure of adult kyphoscolisis and its spatial relationship with the adjacent vertebrae, blood vessels, and nerves, which provides a good and intuitive stereoscopic anatomical structure observation for the individualization of the surgical plan. Pre-simulation of operations to determine the internal fixation, fusion segment and osteotomy orthopedic way, may to provide a reference for actual clinical surgery, and can improve the accuracy and safety of surgery.

Organic degradation and extracellular products of pure oxygen aerated activated sludge under different F/M conditions

This study aimed to investigate the effect of food to microorganisms rate (F/M) on organic removal, extracellular polymeric substances (EPS) and soluble microbial products (SMP) of the pure oxygen aerated activated sludge running in batch mode. The F/M rates were controlled by adjusting the MLSS concentrations (2000, 5000, 8000 mg/L) and/or the initial TOC concentrations (100, 500 mg/L). Results showed that at high F/M rate (0.25 kg TOC/kg MLSS), the substrate degradation rate in the oxygen aerated reactor could reach 1.347 mg TOC/(L·min)), much higher than that in the air aerated reactor (0.640 mg TOC/(L·min)). The SMP concentrations with oxygen aeration were also higher than those with air aeration under high F/M conditions. The total EPS contents in the pure oxygen aerated sludge were significantly lower regardless of the different F/M rates. High F/M condition would lead to more amount of polysaccharides synthesis rather than proteins synthesis in EPS.

Dynamic changes of bacterial community in activated sludge with pressurized aeration in a sequencing batch reactor

This study aimed to investigate the organic removal efficiency and microbial population dynamics in activated sludge with pressurized aeration. The activated sludge was fed with synthetic wastewater composed of simple carbon source to avoid the effect of complex components on microbial communities. The pressurized acclimation process was conducted in a bench-scale sequencing batch reactor (SBR) under 0.3 MPa gage pressure. Another SBR was running in atmospheric environment as a control reactor, with the same operation parameters except for the pressure. Bacterial diversity was investigated by Illumina sequencing technology. The results showed that the total organic carbon removal efficiency of the pressurized reactor was significantly higher, while the mixed liquor suspended solids concentrations were much lower than those of the control reactor. Moderate pressure of 0.3 MPa had little effect on Alpha-diversity of bacterial communities due to the similar running conditions, e.g., feed water, solids retention time (SRT) and the cyclic change of dissolved oxygen (DO) concentrations. Although the relative percentage of the bacterial community changed among samples, there was no major change of predominant bacterial populations between the pressurized group and the control group. Pressurized aeration would have a far-reaching impact on microbial community in activated sludge when treating wastewaters being unfavorable to the dissolution of oxygen.

The Spodoptera exigua (Lepidoptera: Noctuidae) ABCC2 Mediates Cry1Ac Cytotoxicity and, in Conjunction with Cadherin, Contributes to Enhance Cry1Ca Toxicity in Sf9 Cells

In insects, the mode of Cry1A toxins action has been studied in detail and many receptors that participate in the process are known. Recent evidence has revealed that an ABC transporter (ABCC2) is involved in conferring resistance to Cry1A toxins and that ABCC2 could be a receptor of Cry1A. However, it is not known whether Cry1Ca interacts with the same receptor proteins as Cry1A. In this study, we report the cloning of an ABC transporter gene, SeABCC2b, from the midgut of Spodoptera exigua (Hübner) larvae, and its expression in Sf9 cells for a functional analysis. The addition of Cry1Ca and Cry1Ac to Sf9 cell culture caused swelling in 28.5% and 93.9% of the SeABCC2-expressing cells, respectively. In contrast, only 7.4% and 1.3% of the controls cells swelled in the presence of Cry1Ca and Cry1Ac. Thus, SeABCC2b-expressing Sf9 cells had increased susceptibility to Cry1Ca and Cry1Ac. Similarly, S. exigua cadherin (SeCad1b) expressed in Sf9 cells caused 47.1% and 1.8% of the SeCad1b-expressing cells to swell to Cry1Ca and Cry1Ac exposure. Therefore, Sf9 cells expressing SeCad1b were more sensitive to Cry1Ca than Cry1Ac. Together, our data suggest that SeABCC2b from S. exigua mediates Cry1Ac cytotoxicity and, in conjunction with SeCad1b, contributes to enhance Cry1Ca toxicity in Sf9 cells.

Protective roles of pulmonary rehabilitation mixture in experimental pulmonary fibrosis in vitro and in vivo

Abnormal high mobility group protein B1 (HMGB1) activation is involved in the pathogenesis of pulmonary fibrosis. Pulmonary rehabilitation mixture (PRM), which combines extracts from eight traditional Chinese medicines, has very good lung protection in clinical use. However, it is not known if PRM has anti-fibrotic activity. In this study, we investigated the effects of PRM on transforming growth factor-β1 (TGF-β1)-mediated and bleomycin (BLM)-induced pulmonary fibrosis in vitro and in vivo. The effects of PRM on TGF-β1-mediated epithelial-mesenchymal transition (EMT) in A549 cells, on the proliferation of human lung fibroblasts (HLF-1) in vitro, and on BLM-induced pulmonary fibrosis in vivo were investigated. PRM treatment resulted in a reduction of EMT in A549 cells that was associated with attenuating an increase of vimentin and a decrease of E-cadherin. PRM inhibited the proliferation of HLF-1 at an IC₅₀ of 0.51 µg/mL. PRM ameliorated BLM-induced pulmonary fibrosis in rats, with reduction of histopathological scores and collagen deposition, and a decrease in α-smooth muscle actin (α-SMA) and HMGB1 expression. An increase in receptor for advanced glycation end-product (RAGE) expression was found in BLM-instilled lungs. PRM significantly decreased EMT and prevented pulmonary fibrosis through decreasing HMGB1 and regulating RAGE in vitro and in vivo. PRM inhibited TGF-β1-induced EMT via decreased HMGB1 and vimentin and increased RAGE and E-cadherin levels. In summary, PRM prevented experimental pulmonary fibrosis by modulating the HMGB1/RAGE pathway.

Deaths of tuberculosis patients in urban China: a retrospective cohort study

BACKGROUND

The case-fatality rate for tuberculosis (TB) remains high in China, whereas risk factors for deaths among TB cases are still unclear.

DESIGN

This was a retrospective cohort study of all pulmonary TB patients registered in four districts of Shanghai from 2004 to 2008. Data were derived from the China National TB Surveillance System. A total of 4271 patients were followed up in communities. Data were analysed using Cox regression.

RESULTS

The percentage of all-cause deaths in the study population was 15% 2-6 years after the most recent TB diagnosis. TB was responsible for only 17% of all deaths; male sex was significantly associated with all-cause deaths. After adjustment for sex, age and treatment history, four factors were significantly and independently associated with increased risk of death: psychopathy, chronic bronchitis, cancer and the presence of multiple diseases. TB was responsible for 7.2 potential years of life lost (PYLL); PYLL was higher in females (8.2) than males (5.3).

CONCLUSIONS

TB remains a significant problem in urban China. Implementation of improved clinical management, prevention strategies and other public health programmes should target TB patients with chronic conditions, particularly those with multiple diseases.

[A-cohort study on the standard short-course chemotherapy program for drug resistant tuberculosis in the rural counties in Eastern China]

OBJECTIVE

To investigate the therapeutic efficacy of short course chemotherapy (SCC) on drug resistant tuberculosis (DR-TB) cases and related influencing socioeconomic factors. TB patients registered in local county TB dispensaries of two rural counties were followed up in Deqing and Guanyun of Eastern China, during 2004/2005.

METHODS

Culture-positive patients (Deqing: 182, Guanyun: 217) were selected as subjects of this study. A cohort of TB patients was established at the beginning of their treatment and each patient was followed-up three times by questionnaires. Proportional method of drug susceptibility test was used to define the resistance to the 1st-line anti-TB drugs. chi2 test Kaplan-Meier method and Cox analysis were applied in multivariate analysis to investigate the negative conversion of smear positive sputum, treatment result of SCC and its socioeconomic influencing factors.

RESULTS

The cure rates of multi-drug resistant TB (MDR-TB), other drug resistant TB (ODR-TB) and pan-drug susceptible TB, were 58.3%, 91.0%, 98.7% and 51.3%, 89.5%, 93.5% respectively in Deqing and Guanyun. The liver dysfunction (RR = 0.18, 95% CI: 0.04-0.69) and previous treatment history (RR = 0.26, 95% CI: 0.07-0.93) were associated with treatment result among MDR-TB. Result on treatment in ODR-TB was influenced by previous treatment history (RR = 0.66, 95% CI: 0.44-0.98) and Patient delay (> 2 weeks) (RR = 0.67, 95% CI: 0.46- 0.97).

CONCLUSION

The priority in treating MDR-TB would include: managing side effect, developing the fast sensitive drug susceptibility test and modifying the treatment regimen corresponding to drug resistance.

[Analysis of simple sequence repeats in genomes of Sclerotinia sclerotiorum and Botrytis cinerea]

Simple sequence repeats or microsatellites have been used as genetic markers in population genetics because of their abundance and length variation between different individuals. This study examined the SSRs in the completely sequenced Sclerotinia sclerotiorum and Botrytis cinerea genomes. The occurrences, relative abundance, relative density, most common motifs, and the longest SSRs in the two species were analyzed, and compared with other plant pathogenic fungal species, such as Fusarium graminearum, Magnaporthe grisea and Ustilago maydis. The results demonstrated that the SSRs are abundant in S. sclerotiorum and B. cinerea genomes, and 6 539 and 8 627 SSRs were obtained from these species. The types and distributions of SSRs have similarities between the two species. In the genomes of S. sclerotiorum and B. cinerea, tetra-, penta- and hexa-nucleotide repeats were more abundant than other species, indicating high mutation rates in these species. Furthermore, the abundance and relative density of SSRs were not influenced by the genome sizes and GC content. The analysis in this study provided useful information on applications of microsatellites in population genetics of S. sclerotiorum and B. cinerea.

Proteome alterations in human hepatoma cells transfected with antisense epidermal growth factor receptor sequence

The epidermal growth factor (EGF) is a member of the growth factor superfamily that can stimulate the proliferation of many types of cells. Overexpression of EGF receptor (EGFR) was observed in many types of cancer cells. Anti-EGFR antibodies or antisense nucleic acid sequences of EGFR can suppress the growth of hepatoma cells. In order to further investigate the proteome alterations associated with malignant growth of the human hepatoma cells and the influence of EGFR signal pathway on the cellular proteome, we have comparatively analyzed the proteomes of human hepatoma cells transfected with antisense EGFR sequence (cell strain JX-1) and its control cells (cell strain JX-0) by two-dimensional (2-D) gel electrophoresis and mass spectrometry. Image analysis of silver-stained 2-D gels revealed that 40 protein spots showed significant expression changes in JX-1 cells compared to JX-0 cells. Three of them, including the tumor suppressor protein maspin, changed with tendency to the normal levels. Two protein spots were identified as HSP27 in the same gel, and one of them had a reduced level in JX-1 cells. The apparent alterations of HSP27 in expression level might be the results from their differential chemical modifications, suggesting the effect of dynamic post-translational modifications of proteins on the growth of hepatoma cells. Other proteins such as glutathione peroxidase (GPX-1) and 14-3-3-sigma also exhibited altered expression in JX-1 cells, and their functional implications are discussed.

Inhibitory effect of recombinant TGFalpha-PE40 on neointimal proliferation after arterial balloon injury

AIM

To investigate inhibitory effects of recombinant transforming growth factor alpha-Pseudomonas exotoxin 40 fusion protein (TGFalpha-PE40; TP40) on neointimal proliferation after arterial balloon injury.

METHODS

Forty male rabbits fed a cholesterol rich diet were randomly divided into TP40 15 microg, 30 microg, 60 microg, physiologic saline control, and normal artery groups (n=8). Rabbits in the treatment groups were treated by local administration of TP40 (15 microg, 30 microg, and 60 microg per rabbit) 24 h postinjury, and those in the control group were treated by physiologic saline 24 h postinjury. Remained 8 rabbits in normal artery group were treated by TP40 (60 microg). Optical microscope, electron microscope, and computer image analysis were used to study arterial segments 2 weeks after treatment.

RESULTS

Irregular thickening of the arterial intima, large amounts of smooth muscle cells (SMC) within the neointima, and stenosis of the arterial cavity were observed in the physiologic saline control group. Great inhibition of intimal proliferation and prevention of stenosis of the arterial cavity were observed in the TP40 treated groups that were examined 2 weeks postinjury by optical microscope. The uninjured carotids were histologically normal. Lots of destructural and necrotic SMC were observed in media in TP40 60 microg group by electron microscope. Computer image analysis showed that the neointimal area of the TP40-treated groups was markedly smaller than that of the saline control group (P < 0.01).

CONCLUSION

Recombinant TP40 greatly inhibited neointimal proliferation after arterial balloon injury.

[Determination of sotalol hydrochloride by reversed-phase high performance liquid chromatography]

An RP-HPLC method for determination and detection of sotalol hydrochloride is described. The baseline separation was achieved on ODS column within 15 minutes by using 0.1% HAc-acetonitrile (80:20, V/V) as mobile phase at a flow rate 1.5 mL/min, and the wavelength was set at 227 nm. The linear range was 5-45 mg/L (r = 0.9991) and the limit of detection was 1 mg/L(S/N > 3). The intra-day and inter-day RSDs were 0.20% and 0.93% respectively.

Inhibitory effect of recombinant TGF alpha-PE40 on vascular smooth muscle cell proliferation

AIM

To study inhibitory effect of recombinant transforming growth factor alpha-Pseudomonas exotoxin fusion protein (TP40) on proliferation of the cultured vascular smooth muscle cells (SMC).

METHODS

Expression of epidermal growth factor receptor (EGFR) mRNA and EGFR in cultured proliferating and quiescent SMC was analyzed with Northern blot and immunohistochemistry. Inhibitory effects of TP40 on SMC proliferation and protein synthesis were analyzed with crystal violet staining and [3H]leucine incorporation. Competition assays were performed by the addition of 100-fold excess of EGF.

RESULTS

Expression of EGFR mRNA and EGFR in rapidly proliferating SMC increased than that in quiescent SMC. When the concentration of TP40 was 10 or 100 micrograms.L-1, inhibitory effects of TP40 on rapidly proliferating SMC proliferation and protein synthesis were much higher than that on quiescent SMC (P < 0.01), and the IC50 of [3H]leucine incorporation against rapidly proliferating and quiescent SMC were 8.01 (5.05-12.69) and 121.95 (90.98-163.47) micrograms.L-1. Excess EGF completely blocked inhibitory effects of TP40.

CONCLUSION

The rapidly proliferating SMC express EGFR at a high level. TP40 selectively inhibited the proliferation of rapidly proliferating SMC. The cytotoxic effects of TP40 were specifically mediated by EGFR.

[Gene cloning, expression of fusion protein TGF alpha-PE 40 and its inhibition activity on cancer cell growth]

Recombinant plasmid pYX382 and pYX3825 were constructed by fusing the cDNA encoding transforming growth factor type alpha (TGF alpha) to Pseudomonas exotoxin gene (PE) in which the cell recognition domain was deleted. The chimeric proteins produced by host E. Coli cells BL21 transformed by plasmid pYX382 and pYX3825 are termed TGF alpha-PE 40 which reacts with antibody against TGF alpha or antibody against PE in immunoblotting to show a 46 kd protein band reflecting the fusion of 56 kD TGF alpha peptide and 40 kD truncated Pseudomonas exotoxin molecule. An additional signal sequence OmpA was inserted into upstream region of TGF alpha cDNA in plasmid pYX3825 resulting in the partly secreting of expression product into medium and periplasm of the cells. TGF alpha-PE 40 was purified from medium by MONO Q ion exchange column and TSK 250 gel filtration column attached to Pharmacia EPLC system. The TGF alpha-PE 40 molecules showed a very strong activities inhibiting the protein synthesis and killing the cancer cells overexpressing EGF receptor on the cell surface.

[EGFR expression and EGF stimulation of proliferation in human liver carcinoma cells]

Epidermal growth factor receptor (EGFR) gene expression and growth stimulation of EGF on human hepatoma cells of cell lines BEL-7404 and SMMC-7721 were studied. 125I-EGF binding assay was used to measure the binding characteristics and the amounts of EGFR on these cells. The binding time course and the binding competition assay showed that the binding of 125I-EGF to 7404 cells was saturable and specific. Scatchard analysis of EGF binding curve indicated that 7404 and 7721 cells expressed approximately 1.1 x 10(5) and 0.7 x 10(5) EGFRs per cell with binding affinity (Kd) 2.1 nM and 1.8 nM respectively. Northern hybridization and immunoblotting analysis showed the EGFR gene expression products in 7404 and 7721 cells were 5.6 Kb mRNA and 170 Kilo-dalton glycoprotein. Anchorage-dependent growth of 7404 and 7721 cells was stimulated in the presence of nanogram quantities of EGF in medium containing 10% calf serum or 0.5% calf serum. The factors in serum appeared to act synergitically in stimulating of cell proliferation. EGF also stimulated the anchorage-independent growth of 7404 and 7721 cells in soft agar. The results suggest that EGFR is actively expressed in human hepatoma 7404 and 7721 cells and EGF may be one of the mitogens needed for the growth of hepatoma cells.

State of hepatitis B virus DNA in leucocytes of hepatitis B patients

Hepatitis B virus (HBV) DNA in leucocytes from 50 hepatitis patients with various patterns of HBV serological markers and serum HBV DNA and 13 normal controls were examined by Southern blot hybridization with 32P-labeled 3.2 Kb HBV DNA. A free form of HBV DNA was observed in leucocytes of 8 patients, 7 of whom were positive for serum HBeAg, and in 6 patients an integrated form of HBV DNA was identified. HBV DNA was not identified in leucocytes from 13 normal controls. The free form of HBV DNA in leucocytes existed as a heterogeneous smear from 2.0 to 3.2 Kb, similar to the pattern in liver and hepatocellular carcinoma cells but different from serum HBV DNA in which the 3.2 Kb band was absent. The banding pattern of the integrated form of HBV DNA in leucocytes varied among different patients. During preparation of white blood cells and purification of HBV DNA probes, it was important to remove plasma contamination and traces of pBR322, respectively. The presence of extrachromosomal DNA sequences partially homologous to pBR322 could cause false results. The presence of a free and integrated form of HBV DNA in leucocytes is important for explaining the biology of HBV, the harbouring and replication sites of extrahepatic origin, the mechanism of recurrent infection, and the rationale of the treatment of hepatitis B.