[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.

[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.

[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 β-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.

[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.

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.

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.

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.

Series of new β-cyclodextrin-cored starlike carriers for gene delivery

The development of safe and effective β-cyclodextrin (β-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 β-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.

Short communication: Pheromonicin-SA affects mRNA expression of toll-like receptors, cytokines, and lactoferrin by Staphylococcus aureus-infected bovine mammary epithelial cells

Pheromonicin-SA (Ph-SA) is a newly developed, engineered multidomain peptide that has a bactericidal effect against Staphylococcus aureus. The objective of this study was to characterize innate immune responses by Staph. aureus-stimulated bovine mammary epithelial cells (BMEC) following treatment with Ph-SA. Primary BMEC from one lactating Holstein cow were isolated and exposed to Staph. aureus for 2 h, and then treated with rifampicin or Ph-SA. Total RNA was isolated from BMEC at 0, 2, 6, 12, and 24 h postinfection, and the mRNA expression of selected genes, including toll-like receptor (TLR)2 and TLR4, IL-1β, IL-6, IL-8, tumor necrosis factor α (TNF-α), and lactoferrin, was quantified by real-time PCR. In the rifampicin group, increases in the expression of mRNA for TNF-α, IL-1β, IL-6, IL-8, and lactoferrin were observed at 6 h postinfection and in the expression of mRNA for TLR2 but not for TLR4 at 12 h postinfection. In the Ph-SA group, increases in the mRNA expression of TLR2, TNF-α, IL-1β, IL-6, IL-8, and lactoferrin were observed at 6 h postinfection, and an increase in TLR4 mRNA expression was observed at 24 h postinfection. At 24 h postinfection, the mRNA expression of TLR4, TNF-α, IL-1β, IL-6, IL-8, and lactoferrin was higher in the Ph-SA group than in the rifampicin group. In conclusion, Ph-SA might promote the expression of mRNA for TLR2, TLR4, the pro-inflammatory cytokines IL-1, IL-6, and TNF-α, the chemotactic factor IL-8, and lactoferrin in Staph. aureus-infected BMEC. Moreover, Ph-SA may be of value as an antibiotic in promoting innate immune responses by Staph. aureus-infected bovine mammary epithelial cells.

393 A STUDY OF THE USE OF SEXED SEMEN IN SUPERSTIMULATED HOLSTEIN COWS

A study was designed to investigate the use of sexed semen in superstimulated Holstein cows. Non-lactating Holstein cows (n = 107; those that did not superovulate were excluded) were superstimulated and inseminated with frozen–thawed, sexed semen (at 1 insemination dose) or control semen (at 2 different insemination doses) in 3 groups. Cows received a Cue-Mate (Bioniche Animal Health, Beijing, China) and were injected with 5 mg of estradiol-17β plus 100 mg of progesterone on Day 0. Cows were treated from Days 4 to 7 with decreasing doses of FSH for a total of 300 mg Folltropin-V (Bioniche; 50, 50, 40, 40, 30, 30, 30, and 30 mg) at 12 h intervals. On Day 7, Cue-Mates were removed and cows were injected twice with 0.4 mg cloprostenol (PGF; Institute of Family Planning, Shanghai, China). Bilateral deep uterine horn AI was performed 12 and 24 h after the onset of estrus on Day 9 (Group A: 4 × 106 sexed, frozen–thawed sperm per insemination from 1 of 3 bulls; Group B: 4 × 106 non-sexed, frozen–thawed sperm, or Group C: 10 × 106 non-sexed, frozen–thawed sperm per insemination from 1 of 3 bulls). Cows were assigned to bulls and insemination groups at random. Embryos were collected and evaluated on Day 16. Group A had a significantly lower fertilization and usable embryo (IETS grades 1 and 2) rate than the other 2 groups (Table 1). Although the rate of usable embryos between Groups B and C did not differ, the fertilization rate in Group C was significantly higher, suggesting that 4 million sperm in Group B was an inadequate insemination dose for superstimulated cattle. The significantly lower number of usable embryos in Group A suggests that the use of sexed sperm in superovulation and embryo transfer may not be economically feasible. More research is required to optimize and standardize bovine superstimulation and AI with sexed semen. Table 1. Embryo production following insemination of superstimulated Holstein cows with frozen–thawed sexed (Group A) or unsexed (Groups B and C) semen

[Codon usage of Chinese hamster ovary cells.]

BACKGROUND

To investigate the optimal codons of dihydrofolate reductase (dhfr) minus Chinese hamster ovary cells (CHO dhfr-).

METHODS

A cDNA library of CHO dhfr- containing high abundence mRNA was constructed and protein-coding sequences were obtained after identification and analysis. Codon frequence of CHO dhf- was compared with that of Chinese hamster in CUTG database. Then codon usage variation among cDNA was investigated using correspondence analysis (COA).

RESULTS

Fifty qualified cDNAs from CHO dhfr- were selected, which encodes proteins of high abundence. Comparing with the codon frequence of Chinese hamster, the highest frequence of synonymous codons for amino acids in CHO dhfr- cells were the same as Chinese hamster except that of Arg and Pro. This method of COA identifies the first main factor which can account for the largest fractions (14.7%) of variation among cDNAs. Twenty-two synonymous codons were identified as the optimal codons of CHO cell.

CONCLUSION

CHO dhfr- cell has its own optimal codons, it is suggested that codon bias is one of reasons for functional diversity of different mammal cells and it is an effective stratagy to modification of the codon usage of the foreign gene according to the optimal codons of CHO dhfr- to increase the production of foreign gene.

Defective T cell activation and autoimmune disorder in Stra13-deficient mice

Stra13, a basic helix-loop-helix transcription factor, is up-regulated upon activation of CD4+ T cells. Here we show that Stra13-deficient mice exhibit defects in several phases of CD4+ T cell activation. In vivo, Stra13 deficiency results in ineffective elimination of activated T and B cells, which accumulate progressively, leading to lymphoid organ hyperplasia. Consequently, aging Stra13-/- mice develop autoimmune disease characterized by accumulation of spontaneously activated T and B cells, circulating autoantibodies, infiltration of T and B lymphocytes in several organs and immune complex deposition in glomeruli. Our studies identify Stra13 as a key regulator of lymphocyte activation that is vital for maintenance of self-tolerance and for constraint of autoimmunity.

[The study of the peritoneal dialyzer with multipriority and its auxiliary spring brush]

This paper introduces the design, principle and clinical applications of the peritoneal dialyzer with multipriority and its auxiliary spring-brush.

Delta-aminolevulinate dehydratase polymorphism and blood lead levels in Chinese children

This study investigated the relationship between the delta-aminolevulinate dehydratase (ALAD) isozymes and the blood lead levels of Chinese children. The purpose of this study was to determine the precise ALAD genotyping in Chinese children and identify the contribution of the ALAD genotype to the body lead burden. Blood samples were obtained from 109 boys and 120 girls. These children were 6-10 years old and from a single primary school. Both the school and their homes were within a community in which a large smelter was located. An environmental questionnaire was obtained for each subject, and blood lead levels and ALAD isozyme phenotype were analyzed in a double-blinded fashion. The blood lead levels of 229 children ranged from 4.5 to 26.4 microg/dl; the mean was 10.3 microg/dl and the standard deviation was 3.3 microg/dl. The gene distribution of the ALAD isozyme phenotypes in these environmentally exposed children was ALAD 1-1 (92%), ALAD 1-2, (8%), and ALAD 2-2 (0%). The mean blood level of the environmentally exposed children, who were homozygous for the ALAD1 allele, was 9.7 microg/dl; the mean for those who were heterozygous for the ALAD2 allele was 11.7 microg/dl. Using the t test, the means of the groups were different at the level of t=2.2058, P<0.05. Step-wise regression and multiple analyses of covariance were employed to control the confounders to measuring the independent contribution of the ALAD genotype on blood lead levels. After controlling the confounders, the contribution of the ALAD genotype to the blood lead level was greater and still statistically significant (F=7.3201, P<0.01). These results indicate that individuals carrying the ALAD2 allele are more likely to have sustained increases in blood lead levels when exposed to a lead-contaminated environment.

Low-level prenatal lead exposure and neurobehavioral development of children in the first year of life: a prospective study in Shanghai

We used a prospective study design to assess the effects of prenatal low-level lead exposure on the development of urban, inner-city children in Shanghai. Umbilical cord blood samples wee consecutively collected from 605 live newborns. Two hundred and fifty-seven samples were excluded from the study due to clotting. Lead levels were determined on 348 cord blood samples. The geometric mean was 9.2 micrograms/dl. Based on their cord blood lead levels, infants were classified into two exposure groups: 104 in a relatively low lead group (lead levels < or = 30 percentile), and 104 in a relatively high lead group (lead levels > or = 70 percentile). Seventy-five subjects failed to complete the study, and 133 babies were included in the final cohort: 69 babies in the high lead group and 64 in the low lead group. At 3, 6, and 12 months, the Bayley Scales of Infant Development were administered and capillary blood lead levels were measured. Detailed information was obtained on a wide range of variables relevant to infant development. At all three ages, the Mental Development index (MDI) scores, adjusted for confounders, were inversely related to the infants' cord blood lead levels. The difference of the mean adjusted MDI scores between low and high lead groups was 3.4 at 3 months, 6.3 at 6 months, and 5.2 at 12 months of age. These differences were statistically significant at all time points. No significant association between cord blood lead levels and the Psychomotor Development Index (PDI) scores was detected at all three visits after adjustment for confounders. Postnatal lead levels were unrelated to concurrent developmental status. We conclude that prenatal low-level lead exposure, which is relatively common in Shanghai, is associated with an adverse developmental impact on children through the first year of life.

Umbilical cord blood lead levels in Shanghai, China

This study was designed to determine the cord blood lead (BPb) levels of babies born in one urban area of Shanghai, and to preliminarily identify the demographic, social environment and prenatal factors which have an effect on the cord BPb concentrations. From August to November 1993, umbilical cord blood samples were obtained from 605 live newborns in the Yangpu Maternal and Child Hospital. 257 samples were excluded from measurement because of clotting. In 348 cord samples, the geometric mean of cord BPb levels was 9.2 micrograms/dl, with a 95% confidence interval of the mean 8.86-9.54 (micrograms/dl). 142 babies (40.8%) had cord BPb levels of 10 micrograms/dl or greater. As a result of this high percentage of newborns with BPb levels equal to or greater than 10 micrograms/dl, we estimate that each year in the Shanghai City about 60,000 newborns are at risk for developing neuropsychological deficiencies caused by maternal lead exposure during pregnancy. To investigate the factors affecting cord blood levels, the subjects with levels greater than the 70th percentile (10.7 micrograms/dl) (n = 104) and less than the 30th percentile (7.4 micrograms/dl) (n = 104) were selected to compare the demographic, environment and prenatal medical history. Increased BPb levels at birth were associated with maternal passive smoking, a family member being occupationally exposed to lead, proximity to major traffic way, household coal combustion, neighborhood coal combustion, low level of maternal occupations, and the increasing occurrence of having the high lead foodstuff pidan (preserved duck egg) during pregnancy. We conclude that prenatal lead exposure has become an important health issue for young children in Shanghai.

Phylogeny analysis of 25 apple rootstocks using RAPD markers and tactical gene tagging

RAPD (random amplified polymorphic DNA) markers were used to fingerprint eight commercially available apple rootstocks (Nertchinsk, Northern Spy, Osman, Heyer 12, M.1, M.9, M.26 and MM.106), 10 winter hardy offsprings derived from the cross of Nertchinsk x M.9, six winter hardy offsprings derived from the cross of Nertchinsk x M.26 and one winter hardy offspring derived from each of the two crosses between Osman x Heyer 12 and Northern Spy x M.1. Phylogeny analysis using parsimony allowed us to draw the genetic relationship between these lines using only RAPD markers data. The resulting cladogram was compared to the true genetic relationship between these lines in order to assess the efficiency of RAPD markers in determining accurately the phylogenetic relationship. We also developed a DNA fingerprinting system based on 13 informative RAPD loci amplified by five RAPD primers that allowed the rapid identification of apple rootstocks.

[Gastrointestinal transit time (GITT) in normal Chinese and patients]

Two kinds of radiopaque pellets were ingested as markers to determine GITT in 60 normal subjects, 7 patients with ulcerative colitis (UC), 10 patients with idiopathic constipation (IC) and 8 patients with other diseases. The food contained 10-20g dietary fiber per day. Besides, GITT was determined in 14 normal subjects whose dietary content was 40-50g or 10g MO YU and 10-20g dietary fiber per day. Results are expressed in hours as 50% transit time (mean +/- s) and the values or normal subjects are as the follows: total GITT 25.0 +/- 7.3h, mouth iteum TT 9.0 +/- 3.3h, colonic TT 15.9 +/- 7.5h. There was no difference in age or sex groups. However, in high dietary fiber or MO YU group, GITT shortened significantly. Abnormal GITT was shown in patients with UC, IC, other gut and systemic diseases. In conclusion, the method employed in the present study is simple, safe and useful in the clinical study of gastrointestinal motility; and may provide important information to elucidate the pathophysiology of the diseases related to disorders in motility of the digestive tract.