[Analysis on personal protection in occupational population at high risk for brucellosis and influencing factor in China].

Objective: To understand the current status of personal protection in occupational population at high risk for brucellosis in China and provide evidence for the evaluation of implementation of National Brucellosis Prevention and Control Plan (2016-2020). Methods: Four counties in Shanxi Province and Xinjiang Uygur Autonomous Region were selected to conduct a questionnaire survey in occupational population at high risk for brucellosis from December 2019 to July 2020 by using cross-sectional survey methods. Results: A total of 2 384 persons at high risk for brucellosis were surveyed, and the standardized utilization rate of personal protective equipment (PPE) was 20.13% (480/2 384). The utilization rate of glove, mask, rubber shoe, and work cloth were 38.26% (912/2 384), 31.80% (758/2 384), 32.01% (763/2 384) and 30.87% (736/2 384),respectively. There were significant differences in the utilization rate and standardized utilization rate of the four types of PPE among populations in different age, occupation, educational level and area groups (all P<0.001). The utilization rate and standardized utilization rate of PPE were lower in people over 60 years old, women, farmers, and those with lower educational level. The results of multivariate analysis showed that occupation and area were the influencing factors for the standardized utilization of PPE, the standardized utilization rates of PPE were higher in herdsmen and veterinarians. The standardized utilization rate of PPE in Yanggao County and Huocheng County was significantly higher than that in Zuoyun County and Hunyuan County. Conclusions: The utilization rate of the four types of PPE in occupational population at high risk for brucellosis was not high in China, and the standardized utilization rate was low, lower than the requirement in National Brucellosis Prevention and Control Plan, and there were significant differences among different areas. It is urgent to distribute PPE to occupational population at high risk for brucellosis and carry out health education about PPE utilization. Meanwhile, it is necessary to strengthen information exchange or sharing among different areas.

[Research progress in functional regeneration methods and mechanisms of taste buds].

Gustation is one of the most important human senses. Taste dysfunctions, which may be due to aging, tongue cancer surgery, radiotherapy and chemotherapy, affect life quality. That is why the need for taste bud regeneration has received more attention. At present, research on development and renewal of taste cells provides a basis for taste bud regeneration; molecular mechanisms related to taste bud regeneration are being continuously uncoverd, aiding in the identification of more accurate targets for therapy. New methods such as nerve regeneration, tissue engineering, and cytokine therapy have emerged. The author reviews the mechanism and the latest methods of taste bud regeneration of lingual epithelium, aiming to open new horizions for the prevention and treatment of gustatory diseases, and provide theoretical references for its regeneration.

[Targeting microRNA-125b inhibited the metastasis of Alisertib resistance cells through mediating p53 pathway].

Objective: To clarify the mechanisms involvement in Alisertib-resistant colorectal cells and explore a potential target to overcome Alisertib-resistance. Methods: Drug-resistant colon cancer cell line (named as HCT-8-7T cells) was established and transplanted into immunodeficient mice. The metastasis in vivo were observed. Proliferation and migration of HCT-8-7T cells and their parental cells were assessed by colony formation and Transwell assay, respectively. Glycolytic capacity and glutamine metabolism of cells were analyzed by metabolism assays. The protein and mRNA levels of critical factors which are involved in mediating glycolysis and epithelial-mesenchymal transition (EMT) were examined by western blot and reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR), respectively. Results: In comparison with the mice transplanted with HCT-8 cells, which were survival with limited metastatic tumor cells in organs, aggressive metastases were observed in liver, lung, kidney and ovary of HCT-8-7T transplanted mice (P<0.05). The levels of ATP [(0.10±0.01) mmol/L], glycolysis [(81.77±8.21) mpH/min] and the capacity of glycolysis [(55.50±3.48) mpH/min] in HCT-8-7T cells were higher than those of HCT-8 cells [(0.04±0.01) mmol/L, (27.77±2.55) mpH/min and(14.00±1.19) mpH/min, respectively, P<0.05]. Meanwhile, the levels of p53 protein and mRNA in HCT-8-7T cells were potently decreased as compared to that in HCT-8 cells (P<0.05). However, the level of miRNA-125b (2.21±0.12) in HCT-8-7T cells was significantly elevated as compared to that in HCT-8 cells (1.00±0.00, P<0.001). In HCT-8-7T cells, forced-expression of p53 reduced the colon number (162.00±24.00) and the migration [(18.53±5.67)%] as compared with those in cells transfected with control vector [274.70±40.50 and (100.00±29.06)%, P<0.05, respectively]. Similarly, miR-125b mimic decreased the glycolysis [(25.28±9.51) mpH/min] in HCT-8-7T cells as compared with that [(54.38±12.70)mpH/min, P=0.003] in HCT-8-7T cells transfected with control. Meanwhile, in comparison with control transfected HCT-8-7T cells, miR-125b mimic also significantly led to an increase in the levels of p53 and ß-catenin, in parallel with a decrease in the levels of PFK1 and HK1 in HCT-8-7T cells (P<0.05). Conclusions: Silencing of p53 by miR-125b could be one of the mechanisms that contributes to Alisertib resistance. Targeting miR-125b could be a strategy to overcome Alisertib resistance.

[Epidemiological characteristics of hand, foot and mouth disease among people aged 6 and over in Beijing, 2011-2020].

Objective: To analyze the epidemiological characteristics of hand, foot and mouth disease (HFMD) among people ≥6 years old in Beijing from 2011 to 2020. Methods: The incidence data of HFMD cases from 2011 to 2020 were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and the etiological surveillance of HFMD in 29 sentinel hospitals from 16 districts of Beijing. Descriptive epidemiological methods were used to analyze the distributions, pathogen constituents, and changes of HFMD cases in Beijing people ≥6 years old. Results: From 2011 to 2020, a total of 38 183 cases of HFMD were reported among people ≥6 years old in Beijing, of which 46 (0.12%) cases were severe. The average annual reported incidence was 19.04/100 000. The ratio of males to females were 1.37∶1(22 064∶16 119). The proportion of HFMD in people ≥6 years old increased from 7.56%(2 606/34 488) in 2011 to 24.54% (546/2 225) in 2020. The average incidence of HFMD was higher in Shunyi district, Yanqing district, and Tongzhou district than in other districts in Beijing. The positive rate of enterovirus in sentinel surveillance was 66.78% (1 976/2 959), the proportion of enterovirus group A 71 (EV-A71) was 45.29% (101/223) in 2014, no EV-A71 positive was detected in 2020, and the proportion of Coxsackievirus A 6 (CV-A6) increased from 15.11% (34/225) in 2016 to 81.08% (60/74) in 2020. Conclusions: From 2011 to 2020, the proportion of cases with HFMD in people ≥6 years old in Beijing increased yearly, and the proportion of EV-A71 positive patients decreased basically. Since 2016, CV-A6 has gradually become the dominant pathogen. More attention should be paid to the epidemic situation and dynamic pathogen changes of hand foot mouth disease in people ≥6 years old.

PM2.5-induced inflammation and myocardial cell injury in rats.

OBJECTIVE: Numerous studies show association of particular matter (PM) in air pollution with cardiovascular dysfunction, and increased morbidity and mortality. The main mechanisms of this adverse effect involve increasing oxidative stress, inflammatory responses, and genotoxicity. Several recent studies investigated the ability of PM2.5 to cause myocardial injury in animal models using various methods, such as intratracheal instillation, intraperitoneal injection or tail vein injection. The purpose of this study is to explore the PM2.5-induced myocardial inflammatory reaction in rats through the new technology of multi-functional aerosol concentration and enrichment system. MATERIALS AND METHODS: Thirty Wistar rats were divided into two groups, 15 in each group. In the exposure group, PM2.5 multi-functional aerosol concentration and enrichment system was used for PM2.5 online oral and nasal exposure (5 times a week, 4 hours exposure, for the duration of 3 months). Histopathological examination of the left ventricular myocardial tissue of both groups was done using hematoxylin and eosin (H&E) staining. Ultrastructural changes of the heart specimens were assessed using electron microscopy. The levels of CRP and ICAM-1 were detected by immunohistochemistry. RESULTS: Compared with the control group, myocardial tissue of the exposure group exhibited edema, widened myocardial space and infiltration of inflammatory cells. There was nuclear pyknosis, mitochondrial membrane and spinal fusion, rough endoplasmic reticulum expansion, degranulation and cell swelling in the exposed group. The area of CRP positive staining in the exposed group was 3.7-fold higher than that in the control group (p < 0.05), and the ICAM-1 positive staining area of the exposed group was 12-fold higher than that of the control group (p < 0.05). CONCLUSIONS: Prolonged exposure to PM2.5 inhalation promotes significant upregulation of ICAM-1 and CRP expression in myocardial tissues, ultrastructural alterations in myocardial cells, and influx of inflammatory cells.

[Surveillance of immunization effectiveness and titer of type â and type â ¢ polio vaccine in Beijing before and after the adjustment of immunization strategy in 2012-2018].

Objective: To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy. Methods: According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method. Results: The [M（P25，P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 (P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID50 per 100 µl in 2016 and 2018 (P<0.001). Conclusion: Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.

[A multicenter survey of the accessibility of essential medicines for children in China].

Objective: To investigate the availability, prices and affordability of essential medicines in pediatric population across China, in the hope of improving rational use of medicines. Methods: A multicenter cross-sectional survey of medicine prices, availability and affordability was conducted in 17 provinces, municipalities and autonomous region across east, south-central part, west and north of China. Data on 42 medicines used in pediatric population, both original and generic, were collected in 55 public hospitals from May 26 to June 2, 2017. Availability was expressed as the percentage of hospitals with stock of the target medicine on the day of data collection,and median price ratio (MPR) was the ratio of price upon investigation to international reference. Based on national minimum daily wage, affordability represents the number of working days needed to earn the expense which covers a standard course using the target medicine. Statistical software SPSS 13.0 was applied for descriptive analysis of availability, MPR and affordability. Results: Mean Availability of original and generic medicine was 33% and 32%, with median MPR being 5.43 and 1.55. Among the 19 medicines with price information for both original and generic product, the median MPR was 7.73 and 2.04 respectively. Regarding the five medicines used to treat four common pediatric diseases (pneumonia,peptic ulcer, congenital hypothyroidism, refractory nephrotic syndrome), the affordability was 0.63 (0.16-6.17) d for generic medicine, and 1.03 (0.16-11.53) d for its original counterpart. Conclusions: The availability to both original and generic products of the 42 medicines used in pediatric population was low in China. The prices of generic medicines seem to be lower and affordability higher than those of original medicines. There is an urgent need to improve the availability and affordability of pediatric medicines.

Association of tumor necrosis factor-α gene polymorphism with osteoarticular tuberculosis prognosis in a Hebei population.

This study investigated the association of tumor necrosis factor-α (TNF-α)-308, -238, and -863 polymorphisms with osteoarticular tuberculosis (OA-TB) prognosis in a Hebei population. Genomic DNA was extracted from venous blood samples of 120 OA-TB patients and 100 healthy volunteers. TNF-α-308, -238, and -863 were analyzed by PCR-restriction fragment length polymorphism; genotype and allele frequencies were calculated. Serum TNF-α level was significantly higher in OA-TB patients (283.16 ± 51.68 ng/L) than in control (122.54 ± 54.65 ng/L; P < 0.05). Higher frequency of TNF-α-308 GG genotype in healthy volunteers (91.0%) than in OA-TB patients (79.2%) indicated that it was a protective factor against OA-TB (OR = 0.405, 95%CI = 0.147-0.657, P = 0.007). Higher frequencies of TNF-α-308 GA genotype and TNF-α-308 allele (A) in OA-TB patients (20.8 and 10.4%, respectively) than in healthy volunteers (8.0 and 5.0%, respectively) indicated an association with increased risk of OA-TB (OR = 3.112, 95%CI = 1.520-6.343, P = 0.003; OR = 3.109, 95%CI = 1.676-6.538, P = 0.006; respectively). Haplotype association analysis of TNF-α polymorphisms (-308/-238/-863) showed a higher frequency of TNF-α AGA in OA-TB patients (12.1%) than in healthy volunteers (3.5%), indicating that it was a risk factor for OA-TB (OR = 4.201, 95%CI = 1.80-9.91, P = 0.010). TNF-α-308 G/A and TNF-α AGA (-308/-238/-863) were associated with a predisposition to OA-TB, which could aid clinical detection, prevention, and prognosis of OA-TB.

Identification of lung cancer oncogenes based on the mRNA expression and single nucleotide polymorphism profile data.

This study aimed to identify the oncogenes associated with lung cancer based on the mRNA and single nucleotide polymorphism (SNP) profile data. The mRNA expression profile data of GSE43458 (80 cancer and 30 normal samples) and SNP profile data of GSE33355 (61 pairs of lung cancer samples and control samples) were downloaded from Gene Expression Omnibus database. Common genes between the mRNA profile and SNP profile were identified as the lung cancer oncogenes. Risk subpathways of the selected oncogenes with the SNP locus were analyzed using the iSubpathwayMiner package in R. Moreover, protein-protein interaction (PPI) network of the oncogenes was constructed using the HPRD database and then visualized using the Cytoscape. Totally, 3004 DEGs (1105 up-regulated and 1899 down-regulated) and 125 significant SNPs closely related to 174 genes in the lung cancer samples were identified. Also, 39 common genes, like PFKP (phosphofructokinase, platelet) and DGKH-rs11616202 (diacylglycerol kinase, eta) that enriched in sub-pathways such as galactose metabolism, fructose and mannose metabolism, and pentose phosphate pathway, were identified as the lung cancer oncogenes. Besides, PIK3R1 (phosphoinositide-3-kinase, regulatory subunit 1), RORA (RAR-related orphan receptor A), MAGI3 (membrane associated guanylate kinase, WW and PDZ domain containing 3), PTPRM (protein tyrosine phosphatase, receptor type, M), and BMP6 (bone morphogenetic protein 6) were the hub genes in PPI network. Our study suggested that PFKP and DGKH that enriched in galactose metabolism, fructose and mannose metabolism pathway, as well as PIK3R1, RORA, and MAGI3, may be the lung cancer oncogenes.

Effects of docetaxel plus three-dimensional conformal radiation therapy on microvessel density and apoptosis expression in local advanced squamous non-small-cell lung cancer.

We examined the effects of weekly single-agent docetaxel plus three-dimensional conformal radiation therapy (3D-CRT) on apoptotic index (AI) and microvessel density (MVD) in local advanced non-small-cell lung squamous cancer patients and analyzed the correlation of MVD, AI, and 50% tumor shrinkage time (T0.5) The molecular mechanism of docetaxel radiosensitization was investigated. Sixty untreated patients with stage IIIA or IIIB lung squamous cancer were enrolled and randomly divided into two groups: observation (N = 30; 3D-CRT + docetaxel + adjuvant chemotherapy) and control (N = 30; 3D-CRT + adjuvant chemotherapy). From day 1 radiotherapy, the observation group received intravenous docetaxel (36 mg/m(2)) once weekly for 6 weeks. Post-radiotherapy, chemotherapy of docetaxel combined with cisplatin lasted 4-6 cycles in both groups. Before radiotherapy and within 24 h after radiotherapy (20 Gy), bronchoscopic biopsy was performed twice at the same site. To analyze the MVD of tumor specimens with immunohistochemical staining . The AI of lung cancer cells was assessed with TUNEL assay, T0.5 values were calculated. The observation group had significantly lower MVD than the control group (P < 0.05). AI significantly increased before and after treatment in the observation group compared with the control group (P < 0.05). The decreased MVD values negatively correlated with T0.5 values (r = -0.624, P < 0.05), whereas the increased AI values did not correlate with the T0.5 values. Docetaxel radiosensitization may occur by decrease in MVD and increase in AI values. Weekly single-agent docetaxel plus 3D-CRT can improve prognosis and quality of life in local advanced non-small-cell lung squamous cancer patients.

Effects of intravenous analgesia with combined dezocine and butorphanol on postoperative cognitive function in elderly patients.

The aim of this study was to observe the analgesic effects of the combination of dezocine and butorphanol on postoperative cognitive function in elderly patients. Forty elderly patients undergoing upper abdominal surgeries or thoracotomies with general anesthesia were randomly divided into the dezocine and butorphanol group or the butorphanol group (20 patients per group). A visual analog scale was used to evaluate analgesia and the degree of malignant vomiting. The Ramsay scoring method was used to evaluate sedation. The Mini-Mental State Examination (MMSE) was used to evaluate cognitive function. Forty-eight hours after the operation, the pain score of the dezocine and butorphanol group (means ± SD, 1.75 ± 0.44) was lower than that of the butorphanol group (2.25 ± 0.79; P < 0.05), and the nausea and vomiting score of the dezocine and butorphanol group (0) was lower than that of the butorphanol group (0.70 ± 1.30; P < 0.05). Six hours after the operation, the sedative score of the butorphanol group (3.75 ± 0.79) was higher than that of the dezocine and butorphanol group (2.15 ± 0.75; P < 0.05). Compared to 1 day before the operation, the MMSE scores of both groups decreased 6 h after the operation, and the MMSE score of the butorphanol group (15.00 ± 2.00) was lower than that of the dezocine and butorphanol group (20.95 ± 1.54; P < 0.05). Dezocine and butorphanol analgesia had transient effects on postoperative cognitive function in elderly patients, and the effect of the combination was superior than butorphanol only.

Exon 19 deletion was associated with better survival outcomes in advanced lung adenocarcinoma with mutant EGFR treated with EGFR-TKIs as second-line therapy after first-line chemotherapy: a retrospective analysis of 128 patients.

OBJECTIVE: To determine whether the specific genotype of exon 19 deletion has a better survival outcome than that of exon 21 substitution in advanced lung adenocarcinoma with EGFR mutant patients that were treated with EGFR-TKIs as second-line therapy after first-line chemotherapy. METHODS: Between April 1, 2010 and December 31, 2012, the detailed clinical information of 128 patients was screened from the hospital information database of the First Affiliated Hospital and the Third Affiliated Hospital of Kunming Medical University by inclusion/exclusion criteria. Then, a telephone follow-up and a review of all patients' image data were done to obtain the survival information of all patients. After that, all patients' data were processed by IBM(®) SPSS(®) version 19.0. RESULTS: There were correlations between EGFR mutation status, gross tumor type and PFS or OS according to the Kaplan-Meier survival analyses and log-rank tests. The exon 19 deletions had significantly better survival outcomes in comparison to exon 21 substitutions (median PFS: 8.1 vs. 6.8 months, P = 0.002; median OS: 17.6 vs. 12.5 months, P = 0.000). Stratification analyses of PFS and OS revealed that exon 19 deletions had a survival superior to exon 21 substitutions. CONCLUSION: Compared with L858R mutation, the genotype of exon 19 deletion had a better survival outcome in terms of PFS and OS in patients with advanced lung adenocarcinoma treated with EGFR-TKIs as second-line therapy after first-line chemotherapy.

Series of new ß-cyclodextrin-cored starlike carriers for gene delivery.

The development of safe and effective ß-cyclodextrin (ß-CD)-cored cationic star gene carriers has attracted considerable attention. In this work, a series of star-shaped hemocompatible CD-PGPP, CD-PGAEPP, and CD-PGAPP vectors composed of ß-CD cores and piperazine (PP)-, N-(aminoethyl)piperazine (AEPP)-, or N-(3-aminopropyl)-2-pyrrolidinone (APP)-functionalized poly(glycidyl methacrylate) arms were successfully proposed and compared for highly efficient gene delivery. Such star carriers possess plentiful secondary amine, tertiary amine, and nonionic hydroxyl groups. CD-PGPP, CD-PGAEPP, and CD-PGAPP were effective in condensing plasmid DNA into nanoparticles, whose sizes were 100-200 nm and positive ζ potentials were 25-40 mV at nitrogen/phosphate (N/P) ratios of 10 and above. CD-PGPP, CD-PGAEPP, and CD-PGAPP showed significantly lower cytotoxicity than control poly(ethylenimine) (PEI; ∼25 kDa). At most N/P ratios, CD-PGAPP exhibited better gene transfection performance than CD-PGPP and CD-PGAEPP particularly in HepG2 cells. More importantly, in comparison with PEI, all of the CD-PGPP, CD-PGAEPP, and CD-PGAPP vectors did not cause undesirable hemolysis.

Bioreducible comb-shaped conjugates composed of secondary amine and hydroxyl group-containing backbones and disulfide-linked side chains with tertiary amine groups for facilitating gene delivery.

Comb-shaped polymeric vectors (SS-PGEADMs) consisting of ethanolamine/cystamine-functionalized poly(glycidyl methacrylate) (SS-PGEA-NH2) backbones and bioreducible poly((2-dimethyl amino)ethyl methacrylate) (PDMEAMA) side chains were prepared by a combination of the ring-opening reaction and atom transfer radical polymerization (ATRP). The SS-PGEA-NH2 backbones, which were prepared via the ring-opening reaction of the pendant epoxide groups of poly(glycidyl methacrylate) with the amine moieties of ethanolamine/cystamine, possess plentiful flanking secondary amine and hydroxyl groups and some flanking disulfide bond-containing cystamine derivatives. The primary amine groups of the cystamine derivatives were activated to produce bromoisobutylryl-terminated SS-PGEA (SS-PGEA-Br) as multifunctional initiators for subsequent ATRP of DMAEMA. The resultant disulfide-linked short PDMEAMA side chains possess pendant tertiary amine groups and are biocleavable. Such SS-PGEADMs can effectively condense pDNA. The cytotoxicity of SS-PGEADMs could be controlled by adjusting the grafting amount of PDMEAMA side chains. In comparison with the pristine SS-PGEA-NH2, the moderate introduction of PDMEAMA side chains can further enhance the gene transfection efficiency in different cell lines. The present approach to well-defined comb-shaped vectors with multifunctional groups could provide a versatile means for tailoring the functional structures of advanced gene/drug vectors.

Functional expression of mouse insulin-like growth factor-I with food-grade vector in Lactococcus lactis NZ9000.

AIMS: To functionally express the recombinant mouse insulin-like growth factor-I (rtmIGF-I) in Lactococcus lactis NZ9000 with a food-grade vector. METHODS AND RESULTS: The rtmIGF-I encoding sequence was inserted into secreted food-grade vector pLEB688 and transformed into L. lactis NZ9000. The expression of the recombinant protein rtmIGF-I was confirmed by tricine-SDS-PAGE analysis and Western blot. The concentration of this recombinant protein was 3 mg l(-1) in the medium fraction. Further experiment demonstrated that the recombinant protein was biologically active and promoted NIH3T3 cell proliferation in a concentration-dependent manner. CONCLUSIONS: The rtmIGF-I was expressed in L. lactis and located into the medium fraction. The optimal final concentration which could promote NIH3T3 cell proliferation after incubation was 100 ng ml(-1) . SIGNIFICANCE AND IMPACT OF THE STUDY: The rtmIGF-I was functionally expressed in L. lactis NZ9000 with a food-grade vector. Thus, the recombinant L. lactis NZ9000 could act as a host for the production of rtmIGF-I for further study. The recombinant strain could serve as an IGF-I delivery system.