Targeting cellular senescence as a therapeutic vulnerability in gastric cancer

AIMS

Cellular senescence (CS) represents an intracellular defense mechanism responding to stress signals and can be leveraged as a "vulnerability" in cancer treatment. This study aims to construct a CS atlas for gastric cancer (GC) and uncover potential therapeutics for GC patients.

MATERIALS AND METHODS

38 senescence-associated regulators with prognostic significance in GC were obtained from the CellAge database to construct Gastric cancer-specific Senescence Score (GSS). Using eXtreme Sum algorism, GSS-based drug repositioning was conducted to identify drugs that could antagonize GSS in CMap database. In vitro experiments were conducted to test the effect of combination of palbociclib and exisulind in eliminating GC cells.

KEY FINDINGS

Patients with high GSS exhibited CS-related features, such as CS markers upregulation, adverse clinical outcomes and hypomethylation status. scRNA-seq data showed malignant cells with high GSS exhibited enhanced senescence state and more immunosuppressive signals such as PVR-CD96 compared with malignant cells with low GSS. In addition, the GSS-High cancer associated fibroblasts might secrete cytokines and chemokines such as IL-6, CXCL1, CXCL12, and CCL2 to from an immunosuppressive microenvironment, and GSS could serve as an indicator for immunotherapy resistance. Exisulind exhibited the greatest potential to reverse GSS. In vitro experiments demonstrated that exisulind could induce apoptosis and suppress the proliferation of palbociclib-induced senescent GC cells.

SIGNIFICANCE

Overall, GSS offers a framework for better understanding of correlation between senescence and GC, which might provide new insights into the development of novel therapeutics in GC.

MRI radiomic features of peritumoral edema may predict the recurrence sites of glioblastoma multiforme

Background and purpose

As one of the most aggressive malignant tumor in the central nervous system, the main cause of poor outcome of glioblastoma (GBM) is recurrence, a non-invasive method which can predict the area of recurrence pre-operation is necessary.To investigate whether there is radiological heterogeneity within peritumoral edema and identify the reproducible radiomic features predictive of the sites of recurrence of glioblastoma(GBM), which may be of value to optimize patients' management.

Materials and methods

The clinical information and MR images (contrast-enhanced T1 weighted and FLAIR sequences) of 22 patients who have been histologically proven glioblastoma, were retrospectively evaluated. Kaplan-Meier methods was used for survival analysis. Oedematous regions were manually segmented by an expert into recurrence region, non-recurrence region. A set of 94 radiomic features were obtained from each region using the function of analyzing MR image of 3D slicer. Paired t test was performed to identify the features existing significant difference. Subsequently, the data of two patients from TCGA database was used to evaluate whether these features have clinical value.

Results

Ten features with significant differences between the recurrence and non-recurrence subregions were identified and verified on two individual patients from the TCGA database with pathologically confirmed diagnosis of GBM.

Conclusions

Our results suggested that heterogeneity does exist in peritumoral edema, indicating that the radiomic features of peritumoral edema from routine MR images can be utilized to predict the sites of GBM recurrence. Our findings may further guide the surgical treatment strategy for GBM.

Norcholic Acid Promotes Tumor Progression and Immune Escape by Regulating Farnesoid X Receptor in Hepatocellular Carcinoma

Accumulating evidence shows a close association between various types of bile acids (BAs) and hepatocellular carcinoma (HCC), and they have been revealed to affect tumor immune response and progression mainly by regulating Farnesoid X receptor (FXR). Nevertheless, the roles of Norcholic acid(NorCA) in HCC progression remain unknown yet. In this study, herein we demonstrate that NorCA can promote HCC cell proliferation, migration and invasion through negatively regulating FXR. Additionally, NorCA can increase PD-L1 level on the surfaces of HCC cells and their exosomes, and NorCA-induced exosomes dramatically dampen the function of CD4⁺T cells, thereby inducing an immunosuppressive microenvironment. Meanwhile, a negative correlation between PD-L1 and FXR expression in human HCC specimens was identified, and HCC patients with FXR^lowPD-L1^high expression exhibit a rather dismal survival outcome. Importantly, FXR agonist (GW4064) can synergize with anti-PD-1 antibody (Ab) to inhibit HCC growth in tumor-bearing models. Taken together, NorCA can promote HCC progression and immune invasion by inhibiting FXR signaling, implying a superiority of the combination of FXR agonist and anti-PD-1 Ab to the monotherapy of immune checkpoint inhibitor in combating HCC. However, more well-designed animal experiments and clinical trials are warranted to further confirm our findings in future due to the limitations in our study.

Visual Analysis of the External Characteristics and Research Hotspots of Literatures in International Forensic Science

Abstract

Objective To analyze the forensic science-related literature included in the Web of Science database in the recent decade through bibliometric methods, to provide reference for relevant research. Methods Literatures were searched in 3 ways： Subject search, Journal search and Institution search. The annual distribution, national （regional） distribution, institution distribution, journal distribution and the research hotspots of the related literatures were analyzed through Thomson Data Analyzer （TDA）, Ucinet, VOSviewer, and so on. Results A total of 49 469 related literatures were included in the recent decade. The number of literatures continued to climb year by year. The top 15 countries （regions） accounted for 78.52% of the total number of published literatures, and China ranked 5th, but ranked 12th in terms of the proportion of high-cited papers; Netherlands, Switzerland, Australia, etc. had high comprehensive influence. The number of countries （regions） that cooperated with China were 129, including the United States, the United Kingdom and Germany. The Institute of Forensic Science of Saint Mary's University, University of Sydney and Netherlands Forensic Institute had high comprehensive influence, and the related literatures were published on 6 357 journals. According to high-frequency co-occurrence network and high-cited papers, brain injury, health policy, assessment scales and models and medical imaging were selected as research hotspots. Conclusion The total number of literatures in forensic science included in international SCI increased significantly, and the influence of China's achievements needs to be greatly enhanced; the research institutions were scattered, and China's research power needs to be continuously condensed; the research hotspots in international fields are extensive, and the international participation of China in top level research needs to be strengthened.

[The roles of two HIV self-testing models in promoting HIV-testing among men who have sex with men]

Objective: To evaluate the roles between two different HIV self-testing models in promoting HIV-testing among men who have sex with men (MSM). Methods: This paper focuses on two HIV self-testing service models. The first; is the online self-testing model (HIV self-testing conventional model) with the sexual health promotion network platform. The other one is an innovative HIV self-testing model (secondary distribution model), based on the previous program. The two different self-testing models, including the number of indexes and alters, the positive rate, and the demographics of indexes and alters, are compared. The influence of volunteers with or without leadership on the number of HIV self-test kits distributed or self-use is analyzed through the leadership survey scale. Results: The return rates of HIV self-testing results in the two models are 94.7%(323/341) and 99.2%(1 141/1 150), respectively, within 30 days. The proportion of alters in the secondary distribution is significantly higher (45.9%,281/612) than the conventional HIV self-testing (6.3%,20/318). In the secondary distribution model, the difference between the number of indexes and alters indicators including age, marital status, residence, sex orientation, anal sex with men in the past six months, and HIV test are statistically significant (χ² test, all P<0.05). The opinion leader of MSM has significantly impacted the promotion of HIV self-testing (P<0.05). Conclusions: Both models can promote HIV self-testing, result return, and HIV positive detection among MSM. In terms of expanding the testing and detection of HIV positive, the secondary distribution mode shows more obvious advantages, which significantly promotes a large number of MSM who have never been tested for HIV to undergo HIV testing. Influential indexes have a significant effect on increasing the HIV testing rate and promoting HIV testing among MSM.

Safety and feasibility of single-incision radical vulvectomy: a novel approach for the treatment of vulvar cancer

Background

In the process of decreasing the morbidity of wound-related complications after vulvectomy and IL for treating vulvar malignancy, we performed a novel surgical procedure—single-incision radical vulvectomy (SIRV). Here, we share our initial experience and report its safety and feasibility.

Methods

Patients with advanced local vulvar tumors were sequentially enrolled in this prospective cohort study to undergo SIRV. While performing SIRV, routine radical vulvectomies were performed first. Subsequently, the flaps of the bridge area between the vulvectomy incisions and femoral triangles were separated and the lymph nodes underneath were removed. Anterior working spaces (AWS) before the femoral triangle were then made. The saphenous vein was carefully identified and retained, while the superficial and deep inguinal lymph nodes were removed from the medial to the lateral sides. After careful hemostasis, the wounds were sutured. Patient demographics, clinical data, pathologic data, operation time, node count, and complications were recorded.

Results

Ten patients underwent SIRV for vulvar cancer. Average hospital stay was 11.70±3.16 (range, 9–13) days. The average number of harvested lymph nodes was 7.59±3.62 (range, 3–15) and 15.14±3.63 (range, 11–20) for per side or both sides of the groin. Blood loss was ≤35 mL. Three patients developed inguinal lymphoceles and underwent needle aspirations. Two patients had impaired wound healing and achieved healing after dressing change. No other postoperative complications were noted during follow-up.

Conclusions

Compared with conventional open inguinal lymphadenectomy (COIL) and video endoscopic inguinal lymphadenectomy (VEIL), SIRV is a more minimally invasive procedure. Our short-term observations showed that SIRV is safe and feasible and has good future application prospects for vulvar cancer. However, definitive conclusions cannot be made. Therefore, long-term oncologic outcomes and large-scale clinical trials are warranted.

Nomograms for Predicting the Overall and Cancer-Specific Survival of Patients with High-Grade Glioma: A Surveillance, Epidemiology, and End Results Study

AIM

To predict the overall survival (OS) and the cancer-specific survival (CSS) of patients with high-grade glioma (HGG) using nomograms and the surveillance, epidemiology, and end results (SEER) database (2000-2013).

MATERIAL AND METHODS

A total of 3706 patients with high-grade glioma were identified by the SEER database (2000-2013). Based on the relevant information of these patients, we divided the primary cohort into a training cohort (n=3336) and a validation cohort (n=370). The nomograms were constructed by the training cohort and corroborated by the validation cohort.

RESULTS

According to the multivariate analysis of the training cohort, the nomograms of OS and CSS indicated that patient age at diagnosis, laterality, radiation, and the extent of resection are significantly correlated with the survival rate. The c-indexes of the nomograms of OS and CSS of the training cohort are 0.682 [95% confidence interval (CI): 0.671-0.693] and 0.678 (95%CI: 0.666- 0.690), respectively. The calibration curve plots of 1- and 3-year OS and CSS showed that the nomogram predictions are consistent with the observed outcomes for both the training and validation cohorts.

CONCLUSION

Based on the data obtained, we established a scoring model to predict the OS and the CSS of patients with HGG. All calibration curves showed high consistency between the predicted and actual survival.

[Cost-effectiveness of HIV self-testing strategy in men who have sex with men]

Objective: To analyze the cost-effectiveness and willingness-to-pay of HIV self-testing (HIVST) strategy and facility-based HIV rapid testing (HIV-RDT) strategy in men who have sex with men (MSM) in Zhuhai, and provide scientific evidence for making health policy. Methods: From the perspective of health service providers, the data of the costs and effectiveness of two HIV testing strategies in MSM in Zhuhai during January-September 2019 were collected, and a decision-tree model of cohort of 10 000 MSM was constructed by using software TreeAge Pro 2019 to measure the cost-effectiveness ratio (CER) and the incremental cost-effectiveness ratio (ICER). One-way and probability sensitivity analysis was performed for the uncertainty of the parameters in the model, and the cost-effectiveness and affordability curve was introduced to estimate the affordability of two strategies. Results: After the mobilization of MSM community-based organization through Internet and social media, 2 303 MSM had HIVST, in whom 33 were HIV positive (1.7%), and 816 MSM received HIV-RDT, in whom 35 were HIV positive (4.3%). The cost for per screening was 60.45 yuan and 240.43 yuan (RMB) respectively, and the cost for per positive screening was 4 218 yuan and 5 606 yuan (RMB) rerspectively. The results of the decision-tree model showed that the mean cost for a MSM using HIVST and using HIV-RDT was 44.67 yuan and 148.42 yuan (RMB) respectively, and the ICER was negative. HIVST strategy was a more cost-effective option when the willing-to-pay was below 6 528 yuan (RMB) for per positive screening, and HIV-RDT strategy was a more cost-effective option when the investment was higher than 6 528 yuan (RMB). Conclusion: HIVST strategy in Zhuhai is a public health project with economic value, and policy makers should strengthen the support to MSM community-based organization to promote the application of HIVST among MSM.

AST-to-APOA ratio to predict overall survival in hepatocellular carcinoma receiving TACE

e16637

Background: Current guidelines lack definitive evidences about the predictive capability of clinical parameters for transcatheter arterial chemoembolization (TACE). The aim of this study was to comprehensively investigate the predictive factor among stage I-IV liver hepatocellular carcinoma (LIHC) patients after TACE. Methods: We investigated the clinical features of 211 stage I-IV patients with LIHC in discover group and 341 patients in validation group. Overall survival (OS) was estimated using the Kaplan-Meier method and the log-rank test. Results: Univariate Cox regression revealed that Monocyte count, TNM stage and AST-to-APOA ratio (AAR) were associated with unfavorable OS. AAR was identified as an independent predictor of OS using multivariate analysis. Kaplan-Meier curve demonstrated that patients with AAR < 50 displayed better prognosis. The median follow-up time was 17.1 (95%CI, 14.4 to 19.3) months, 3-year overall survival was 55.9% in the low AAR group versus 28.6% in the high AAR group, and there was significant difference in OS (Hazard ratio [HR] 0.47, 95%CI 0.33 to 0.67, P < 0.001). The AAR showed predictive ability for OS (12-month, AUC = 0.707). These findings were successfully validated in validation group (HR 0.62, 95%CI 0.46 to 0.84, P = 0.002; 12-month AUC = 0.636). Conclusions: AAR was an independent predictor among LIHC patients after TACE. Patients with lower AAR were optimal candidates for TACE.

Risk of Lymphoma in Patients With Inflammatory Bowel Disease Treated With Anti-tumour Necrosis Factor Alpha Agents: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

The association between anti-tumour necrosis factor alpha agents and the risk of lymphoma in patients with inflammatory bowel disease has already been sufficiently reported. However, the results of these studies are inconsistent. Hence, this analysis was conducted to investigate whether anti-tumour necrosis factor alpha agents can increase the risk of lymphoma in inflammatory bowel disease patients.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to identify relevant studies which evaluated the risk of lymphoma in inflammatory bowel disease patients treated with anti-tumour necrosis factor alpha agents. A random-effects meta-analysis was performed to calculate the pooled incidence rate ratios as well as risk ratios.

RESULTS

Twelve studies comprising 285,811 participants were included. The result showed that there was no significantly increased risk of lymphoma between anti-tumour necrosis factor alpha agents exposed and anti-tumour necrosis factor alpha agents unexposed groups (random effects: incidence rate ratio [IRR] = 1.43, 95% CI, 0.91-2.25; P = 0.116; random effects: risk ratio [RR] = 0.83, 95% CI, 0.47-1.48; P = 0.534). However, monotherapy of anti-tumour necrosis factor alpha agents [random effects: IRR = 1.65, 95% CI, 1.16-2.35; P = 0.006; random effects: RR = 1.00, 95% CI, 0.39-2.59; P = 0.996] or combination therapy [random effects: IRR = 3.36, 95% CI, 2.23-5.05; P < 0.001; random effects: RR = 1.90, 95% CI, 0.66-5.44; P = 0.233] can significantly increase the risk of lymphoma.

CONCLUSIONS

Exposition of anti-tumour necrosis factor alpha agents in patients with inflammatory bowel disease is not associated with a higher risk of lymphoma. Combination therapy and anti-tumour necrosis factor alpha agents monotherapy can significantly increase the risk of lymphoma in patients with inflammatory bowel disease.

The prognostic role of pretreatment thrombocytosis in gastric cancer: A systematic review and meta-analysis

BACKGROUND

The association between platelet count and the prognosis of patients with gastric cancer has already been reported by numerous studies. As the reports are inconsistent, we conducted this meta-analysis to evaluate the prognostic significance of platelet count in patients with gastric cancer.

METHODS

A comprehensive search was performed in PubMed, Embase, and the Cochrane Library to identify relevant studies, which evaluated the prognostic impact of pretreatment platelet count in patients with gastric cancer. Data was pooled using a random effect model to calculate hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Around 10 studies were included, comprising 8166 patients in total. The result showed that patients with thrombocytosis had significant worse overall survival (HR 1.57, 95% CI 1.36-1.81, P < .001) than those with normal platelet count, and were associated with advanced clinical stage (OR, 1.57; 95% CI, 1.15-2.13; P = .004), deeper tumor invasion (OR,3.49; 95% CI, 2.48-4.91; P < .001), and higher risk of recurrence (OR, 2.28; 95% CI, 1.55-3.35; P < .001).

CONCLUSION

Pretreatment thrombocytosis is a potential effective predictor of overall survival (OS) for patients with gastric cancer and is correlated with higher risks of recurrence, serosal invasion, and advanced stage.

Decreased CD8+CD28+/CD8+CD28- T cell ratio can sensitively predict poor outcome for patients with complicated Crohn disease

Crohn disease (CD) with complications such as penetrating, stricturing, and perianal disease is called complicated CD. The aim of this study is to test the efficiency with which the CD8CD28/CD8CD28 cell balance can predict a subsequent active stage in patients with newly diagnosed complicated CD.Seventeen patients with complicated CD and 48 CD patients with no complications were enrolled. Blood CD8 T cells were tested from all of the 65 newly diagnosed CD patients upon enrollment. The potential risk factors were compared between the 2 groups. A 30-week follow-up was performed, and the efficiency of the CD8 cell balance at predicting active CD was analyzed using receiver-operating characteristic curves. The cumulative remission lasting rates (CRLRs) were analyzed using the Kaplan-Meier method.Compared with the control CD group, patients with complicated CD were predominantly male and younger in age; they also had lower body mass indices (BMIs), higher Crohn disease activity indices (CDAIs), higher immunosuppressant and steroid prescription rates, and significantly higher surgical rates. The CD8CD28/CD8CD28 balance was associated with BMI, CDAI, steroids, and surgery. The CD8CD28/CD8CD28 ratios were significantly lower at week 0 and on the 6th, 22nd, and 30th week during follow-up with a shorter lasting time of remission for the complicated CD patients. The CD8CD28/CD8CD28 ratio could accurately predict the active stage for the patients with complicated CD, and the highest sensitivity (89.2%) and specificity (85.3%) were found when the ratio was 1.03. Treatment with steroids and surgery, along with a significantly lower CD8CD28/CD8CD28 ratio and lower CRLRs, was closely related to a worse outcome for the patients with complicated CD.Patients requiring steroids and surgery experience more severe disease activity and thus a disequilibrated immunological balance, which could be the main reason for a decreased CD8CD28/CD8CD28 ratio. This ratio can sensitively predict the active stage for patients with complicated CD, and more care should be taken when this ratio is <1.03.

[Association study between candidate genes involved in cell-cell adhesion and non-syndromic cleft lip with or without cleft palate in Chinese population]

OBJECTIVE

To explore the association and gene-environment interaction between single nucleotide polymorphisms (SNPs) involved in cell-cell adhesion and non-syndromic cleft lip with or without cleft palate (NSCL/P) among Chinese population.

METHODS

A total of 806 NSCL/P trios were drawn by an international consortium, which conducted a genome-wide association study (GWAS) using a case-parent trio design to investigate genes affecting risks to NSCL/P. The transmission disequilibrium test (TDT) was used to explore the association between cell-cell adhesion genes, including CDH1, CTNNB1, PVRL1, PVRL2, PVRL3, ACTN1, VCL, LEF1, and NSCL/P. Conditional Logistic regression models were used to estimate effects on risk of exposed and unexposed children. Four common maternal exposures including maternal smoking, environmental tobacco smoke, alcohol consumption and multivitamin supplementation during pregnancy were included in this study.

RESULTS

A total of 226 SNP markers were tested after quality control in this study. Although 23 SNPs in three genes (CTNNB1, CDH1, ACTN1) showed nominal significant association with NSCL/P in the TDT (P<0.05).There were no significant evidence of linkage and association that remained in the transmission disequilibrium test after Bonferroni correction(P>0.000 2). Tests for gene-environment interaction yielded significant results between rs743127 in ACTN1 and environmental tobacco smoke (P=0.000 1) with an estimated OR (case|G and E)=2.00(95%CI: 1.23-3.26) and OR (case|G no E)=0.59 (95%CI: 0.38-0.90). Among the lower P value results in gene-environment tests, there were no significant results between rs1475034, rs370535, rs2273419 in ACTN1, rs106871 in CTNNB1 and environmental tobacco smoke interaction. There were also no significant results between rs7634000, rs2971366, rs2634553, rs1489032, rs7624812 in PVRL3 and multivitamin supplementation during pregnancy in gene-environment tests(P>0.000 2).

CONCLUSION

There is no association between cell-cell adhesion genes, including CDH1, CTNNB1, PVRL1, PVRL2, PVRL3, ACTN1, VCL, LEF1, and NSCL/P when the genes are considered alone. But our results suggest that SNPs in ACTN1 may influence the risk to NSCL/P through gene-environment interaction.

[Analysis of large deletion of phenylalanine hydroxylase gene in Chinese patients with phenylketonuria]

OBJECTIVE

To analyze the types and distribution of large deletion of phenylalanine hydroxylase (PAH) gene in Chinese patients with phenylketonuria (PKU).

METHODS

On the basis of 953 PKU patients from Peking Union Medical College and Gansu Province Medical Genetics Center, which were detected by directed sequencing of PAH gene between 2006 and 2014. Multiplex ligation-dependent probe amplification (MLPA) of PAH gene was performed in 43 patients with one or two unknown genotypes. And the deletion breakpoints were characterized by Gap PCR-sequencing.

RESULTS

Twenty-four large deletion/duplication alleles were found in 22 patients, accounting for 51.1%(24/47)of the 47 unknown mutations of the 43 patients.There were 6 different large deletions, including Ex1del3758 (n=10), Ex4_5del (n=4), Ex4_7del (n=3), Ex1del5329ins56 (n=3), Ex3del6599ins8 (n=2), and Ex4del (n=1); and 1 duplication was found (Ex12dup, n=1). The most common large deletions in Chinese patients were Ex1del3758 (21.3%), Ex4_5del (8.5%), and Ex4_7del (6.4%).

CONCLUSIONS

Large deletion mutations of PAH gene are present in Chinese PKU patients. It's important to detect the large del/dup mutation, and there are different hotspot mutation genotypes in Chinese patients.

Effect and mechanism of dihydroartemisinin on proliferation, metastasis and apoptosis of human osteosarcoma cells

Osteosarcoma represents an aggressive type of bone malignancy that poses a significant health threat. The objective of the current study was to analyze the effect and mechanism of dihydroartemisinin (DHA) on the proliferation, metastasis and apoptosis of human osteosarcoma cells. A gradient concentration of DHA (15, 25 and 35 μmol.L-1) was used to stimulate the cells, along with control and Dimethyl sulfoxide (DMSO). The phenotypic outcomes were characterized using MTT assay, clone formation assay, Hoechst 33258 staining assay, luciferase reporter plasmid assay, Western blot and wound healing assay. In addition, IBM SPSS Statistics 18.0 software was applied for statistical analysis and all experimental data were expressed as mean ± s.d. Analysis of variance (ANOVA) was applied to compare the differences among multiple groups. Our results demonstrated that DHA inhibited the proliferation and metastasis of osteosarcoma cells and promoted the apoptosis in the cytomorphosis.

Selection of in vitro produced, transgenic embryos by nested PCR for efficient production of transgenic goats

The production of valuable pharmaceutical proteins using transgenic animals as bioreactors has become one of the goals of biotechnology. However, the efficiency of producing transgenic animals by means of pronuclear microinjection is low. This may be attributed in part to the low integration rate of foreign DNA. Therefore, a large number of recipients are required to produce transgenic animals. We recently developed a transgenic procedure that combined the techniques of goat oocyte in vitro maturation (IVM), in vitro fertilization (IVF), microinjection, preimplantation selection of the transgenic embryos with nested PCR and transferring the transgenic embryos into the recipient goat uterus to produce transgenic goats. Thirty-seven transgenic embryos determined by nested PCR were transferred to thirty-two recipient goats. In the end, four live-born kids were produced. As predicted, all the live kids were transgenic as identified by PCR as well as Southern blot hybridization, The integration rate was 100% (4/4) which was completely in accordance with the results of embryo preimplantation detection. The results showed a significant decrease in the number of recipients required as only 8 recipients (32/4) were needed to obtain one live transgenic goat. We suggest that the transgenic system described herein may provide an improved way to efficiently produce transgenic goats on a large scale.

[A study of transgenic IFV cattle integrated with human serum albumin gene]

The mammary gland expression vector (pcDNA 3.1-GCALBm) containing the full-length sequence of human serum albumin (hALB) cDNA and intron 1 as well as the goat beta-casien gene promoter and 5' up-stream regulatory sequence was constructed. The vector was micro-injected into bovine IVF eggs. The embryos were in vitro cultured to the late stage of morulae, and then few embryo cells were aspirated for the implantation detection of target gene integration and SRY DNA sequence using nested-PCR. Afterwards, ten integrated embryos were selected to transfer into eight recipients and three were pregnant. The pregnant rate was 37.5%(3/8). However, two were miscarried in mid-trimester but one was pregnant at term to deliver a male transgenic cattle integrated with hALB mini-gene. The transgenic efficiency was 12.5% (1/8).

Reversal of aberrant splicing of beta-thalassaemia allele (IVS-2-654 C-->T) by antisense RNA expression vector in cultured human erythroid cells

The antisense fragment targeting the aberrant splice sites of the beta-thalassaemia allele, IVS-2-654 C-->T (beta654), pretranscript was cloned into the mammalian expression vector, pcDNA3. The recombinant construct, pCMVA, was then used to repair the defective splicing of the beta654 mutant pretranscript in cultured beta654 erythroid cells by the lipofectin-mediated DNA transfection method. The total RNA was extracted at given time points after transfection and the effect of antisense RNA was studied by reverse transcription polymerase chain reaction (RT-PCR)-mediated mRNA quantitative assay, as well as globin chain microbiosynthesis. The antisense fragment transcribed from pCMVA effectively improved the beta654 splicing pattern in cultured erythroid cells. The level of correctly spliced transcript increased from 0.19 (day 0 after transfection) to 0.58 (day 8) in beta654/beta654 homozygous erythroid cells, and from 0.45 (day 0) to 0.83 (day 8) in beta654/betaA heterozygous erythroid cells, as determined by the ratio of normally spliced beta-globin transcript over total beta-globin transcript. Correspondingly, the ratios of globin chain biosynthesis (beta/alpha) increased from 0.16 (day 0) to 0.52 (day 8) in beta654/beta654 erythroid cells, and from 0.39 (day 0) to 0.84 (day 8) in beta654/betaA erythroid cells. Antisense RNA had no significant effect on the splicing pattern in betaA/betaA erythroid cells. The splicing pattern in transfected cells with pCMVA showed significant changes compared with that in untransfected cells and that in transfected cells with the control antisense fragment (human SRY gene sequence). In addition, we did not observe side-effects on cytological features after the introduction of pCMVA. All these results indicated that the antisense RNA transcribed from the mammalian expression vector pCMVA could efficiently and specifically suppress the aberrant splicing pattern of beta654 mutant pretranscript and restore the correct splicing pathway in vivo, leading to the improvement of globin chain biosynthesis in thalassaemic cells.

[The gene expression of some cytokines and collagen proteins in rat bone tissue is related to estradiol (E2) and age]

30 female SD rats (3 months old) are equally divided into three groups: ovariectomy (OVX) rats, sham-operated (SHO) rats and 17 beta estradiol (E2) treated OVX rats. For each group, mRNA was isolated from long bone at one month and three months after surgery, respectively. mRNA was reverse transcribed into single strand cDNA and then used as a probe hybridizing to the DNA fragments of col I alpha(1), col I alpha(2), col III, col V, fibronectin, IL-1, IL-6, TGF-beta, LIF, TNF-alpha, TNF-beta by reverse northern and dot blot hybrization. The housekeeping gene, gapdh, was used as an internal control. The results show that in bone of rat, the stable expression of col I alpha (1), col I alpha(2) and col III are related to age not ovariectomy, while supplement with E2 can inhibit the expression of col III and col I alpha(2) completely. The expression of col V, IL-1, IL-6 can be inhibited by estrogen and recovered by removal of estrogen by OVX, then addition of E2 decreased it to the normal level. The expression of TGF-beta is also inhibited by estrogen. It increased during one month after overiectomy, and partially decreased in E2 complemented rat. Three months after surgery, the level of increasing and decreasing is less evident as two months ago. It seems that in young SD rat, the expression of TGF-beta is related to both estrogen and age.

The delta-globin RNA transcript level in beta-thalassemia carriers

Increased levels of hemoglobin A(2) (HbA(2)) are present in most beta-thalassemia carriers. The mechanism of this effect is not understood, although the increase may result from transcriptional and posttranscriptional changes. In the present study, we quantitate delta-globin mRNA levels in peripheral-blood-enriched reticulocytes and characterize the variation of delta-mRNA levels in 30 beta-thalassemia heterozygotes who individually carry one of the four common Chinese beta-thalassemia alleles [codons 41/42 (-TTCT); codon 17 (A-->T); IVS-II-654 (C-->T); -28 (A-->G)]. A sensitive and quantitative competitive reverse-transcriptase polymerase chain reaction method was developed and used to assess the absolute amounts of delta-mRNA transcripts in these peripheral erythroid cells. The results showed a large increase in delta-mRNA amounts in all the carriers examined (72.3 +/- 9.0 amol/microg RNA) as compared with those in 12 controls (1.2 +/- 0.2 amol/ microg RNA). There was a direct correlation between the delta-mRNA levels and types of beta-thalassemia alleles; generally, the delta-mRNA levels are higher in heterozygotes for beta(0)-thalassemia mutations than beta(+)-thalassemia mutations. The delta-mRNA levels correlated inversely with hemoglobin and red cell indices but directly with HbA(2) levels in heterozygotes of each of the group of beta-thalassemia mutations. These results suggest that a greater impairment in beta-globin gene expression results in increased transcription of delta-globin gene and in a higher level of HbA(2).

Hydroxyurea therapy in beta-thalassaemia intermedia: improvement in haematological parameters due to enhanced beta-globin synthesis

The beta-thalassaemias represent a heterogenous group of diseases resulting from decreased erythroid beta-globin mRNA expression and imbalanced alpha/beta-globin chain synthesis which are manifest clinically by ineffective erythropoiesis and excessive haemolysis. Increasing levels of haemoglobin F (HbF) by pharmacological agents has been proposed to ameliorate the severity of the disease by improving the balance in globin chain synthesis. Hydroxyurea (HU), as an effective agent with low toxicity for activating gamma-globin gene, has been shown to enhance HbF synthesis in experimental animals and in patients with sickle cell anaemia. However, previous trials of HU in beta-thalassaemia patients are ambiguous, with a small number having increased HbF synthesis. In a recent study of HU effects in Chinese beta-thalassaemia patients we unexpectedly found that two unrelated patients with beta-thalassaemia intermedia demonstrated an improvement in the effectiveness of erythropoiesis reflected by an increase in haemoglobin concentration (from 4.1 to 6.3 g/dl, patient 1; from 6.5 to 9.7 g/dl, patient 2) and in red cell volume (from 68 to 104 fl, patient 1; from 68 to 85 fl, patient 2) after a period of excess of 300d of low-dosage HU treatment. These effects, however, appear to be due to increased beta-globin biosynthesis, because the percentage of HbF decreased in each patient as total Hb increased. This was reflected by changes in the beta/alpha ratio (from 0.301 to 0.581, patient 1; from 0.348 to 0.487, patient 2) with minimal changes in gamma-globin biosynthesis. We conclude that in addition to its known effects in stimulating gamma-globin production, hydroxyurea may have a more general role in augmenting globin synthesis, including beta-globin in some thalassaemia intermedia patients who maintain the capacity to express normal beta-globin chains.

RNA transcripts of the beta-thalassaemia allele IVS-2-654 C-->T: a small amount of normally processed beta-globin mRNA is still produced from the mutant gene

IVS-2-654 C-->T is a common Chinese beta-thalassaemia mutation. Previous studies report that this mutation resulted in the formation of an abnormally spliced mRNA and the absence of detectable normal beta-globin mRNA, hence the mutation was considered to cause beta o-thalassaemia. We recently used the method of PCR amplified cDNA copies of circulating erythroid cell mRNA to analyse the mutant gene transcripts and found that this IVS-2-654 mutation does not abolish normal RNA processing entirely, but that a significant amount (over 15%) of normally processed beta-globin mRNA is produced. Microglobin chain biosynthetic analysis using the HPLC method showed that beta-globin chain was also present in the blood of patients with IVS-2-654 C-->T mutation. Accordingly, this mutant allele leads to a beta (+)-thalassaemia. Further, the methodology described in this paper provides a new approach towards the detection of RNA transcripts of beta-thalassaemia alleles as well as the study of gene expression in beta-thalassaemia and other genetic diseases.

[The relation between prognosis and amplification of the c-erB-2 (HER-2/neu) proto-oncogene in ovarian carcinomas]

C-erbB-2 (HER-2/neu) proto-oncogene is mainly expressed in epithelial tissue and activated due to its amplification. Amplification of the C-erbB-2 proto-oncogene is associated with poor prognosis in human ovarian cancer. We examined whether amplification of C-erbB-2 is common in ovarian carcinoma or is associated with poor prognosis. The DNA of ovarian carcinoma was extracted and consequently digested with restriction endonuclease EcoRI, electrophoresed in 0.8% agarose gels and blotted onto nitrocellulose filter with Southern transfering method. It was hybridized with a 32p-labelled C-erbB-2 probe and subsequently underwent autoradiography. It was shown that the C-erbB-2 (HER-2/neu) gene was amplified in 8 of 26 human ovarian carcinomas (30.8%). Clinically the 8 patients with the amplified C-erbB-2 were in their advanced stage (III-IV). Five of the patients died from 2 to 4 months after operation. These findings suggest that amplification of the C-erbB-2 gene may play a role in the pathogenesis of ovarian carcinoma, it is frequently observed in advanced ovarian carcinoma and associated with poor prognosis for these patients.

Treatment of beta-thalassemia with hydroxyurea (HU)--effects of HU on globin gene expression

A newly developed method of RT-PCR/competitive PCR for measuring the relative and absolute content of globin mRNAs as well as micro-globin chain biosynthetic assay have been used to study the alterations of globin gene expressions in the patients with beta-thalassemia pre- and post-hydroxyurea (HU) treatment. It was found for the first time that HU had the effect of enhancing beta-globin gene expression in some patients. Two cases with beta-thalassemia who were subjected to HU treatment for over two years showed a marked increase in beta-globin mRNA level and beta-globin chain synthesis, resulting in more effective erythropoiesis and the alleviation of clinical symptoms.

Experimental studies on immune-complex in situ type glomerulonephritis in rabbits treated with mai-luo-tong and natural indigo

By injection of C-BSA, immune-complex in situ type glomerulonephritis was duplicated in rabbits and treated with Mai-Luo-Tong and natural Indigo. The results showed that proteinuria in the treated groups M and Q was decreased. The difference between group M and control group is statistically significant (P < 0.05). Under light and electron microscope, although glomerular basement membrane was irregularly thickened and subepithelial dense electron deposited in the treated group, but microthrombus, erythrocytes and platelets aggregation and leukocytes impaction were not seen within glomerular capillaries. Also in groups C, Q, M, mesenteric cell count was 99.40 +/- 18.53, 92.87 +/- 17.89, 66.55 +/- 7.75 respectively, the M. Q groups are compared with group C, the result is of statistical significance (P < 0.05) and there is no apparent glomerular fibrosis in the treated groups.

Amplification of the C-erbB-2(HER-2/neu) proto-oncogene in ovarian carcinomas

C-erbB-2(HER-2/neu) proto-oncogene is mainly expressed in epithelial tissue and activated due to its amplification. Amplification of the C-erbB-2 proto-oncogene has been associated with poor prognosis in human ovarian cancer. Our study was to examine whether amplification is more frequently observed in ovarian cancer, or it is associated with poor prognosis of human ovarian cancer in China. The DNA of ovarian cancers was extracted and consequently digested with restriction endonuclease EcoRI, electrophoresed in 0.8% agarose gels and blotted onto nitrocellulose filter with Southern transferring method. It was then hybridized with a 32P-labelled C-erbB-2 probe and subsequently underwent autoradiography. The result has shown that the C-erbB-2(HER-2/neu) gene was amplified in 8 of 26 human ovarian cancers (30.8%). The clinical data showed that all of the 8 cases with the amplified C-erbB-2 were in their advanced stage (III-IV). Five of the patients died from 2 to 4 months after operation. These data suggest that amplification of the C-erbB-2 gene may play a role in the pathogenesis of ovarian carcinoma; it is frequently observed in advanced ovarian cancer and is associated with poor prognosis for these patients.

Sexing bovine embryos using PCR amplification of bovine SRY sequence

This study analyses the bovine SRY DNA sequence by direct sequencing procedure, followed by the designation of the PCR primers specific for bovine SRY. Using PCR amplification of bovine SRY gene, the embryo sex was determined. The results of the embryo sex identification were confirmed after the embryo transfer and pregnancies.

A new de novo mutation (A113T) in HMG box of the SRY gene leads to XY gonadal dysgenesis

We describe a new point mutation in the SRY gene of a Chinese XY female with gonadal dysgenesis (Swyer syndrome). Using the double stranded DNA cycle sequencing method, a single nucleotide substitution of G-->A was identified at codon 113 of the patient's SRY gene, resulting in a conservative amino acid change from alanine (A) to threonine (T) at a residue that lies within the putative DNA binding motif. With this mutation, one MnlI recognition site is abolished and a new BsmAI site is present in the DNA sequence of the SRY gene; therefore, it is easily detected by analysis of the digestion of the amplified SRY DNA fragment on an electrophoretic agarose gel. In situ hybridisation to the XY female's chromosomes showed that her mutant SRY gene was indeed located on the short arm of her Y chromosome. The SRY mutation in the XY female reported here occurred de novo, as sequence analysis showed that it was not present in her father or other family members.

[Research on immune complex in situ type glomerulonephritis treated with mai-luo-tong in rabbits]

Applying c-BSA to duplicate immune complex in situ type glomerulonephritis in rabbits and treating it with Blood Circulation Promoting and Stasis-Removing Drugs Mai-Luo-Tong, the results showed that proteinuria in the treated group was decreased significantly, as compared to the control group (P < 0.01). Under light and electron microscope, although glomerular basement membrane was irregularly thickened and subepithelial dense electron deposits were found in both groups, but histopathologic damage in the treated group less than that of control one. In the treated group micro-thrombus, erythrocytes and platelets aggregation, leukocytes impaction were not seen within glomerular capillary. Also in the treated group mesangial cell proliferation and granulocyte infiltration were decreased significantly (P < 0.01) and there was no apparent glomerular fibrosis in former group.

Study of the RNA splicing defect in the common Chinese beta-thalassemia gene, IVS-II nt. 654 C-->T by using mRNA/PCR

With direct sequencing of the amplified cDNA, we analysed the transcript and mRNA splicing defect in a common Chinese beta-thalassemia mutant (IVS-II nt. 654 C-->T). The result shows that this mutant gene would not only produce abnormally processed beta-globin mRNA, but also transcribes a small amount of normally spliced mRNA, hence leading to beta+ thalassemia. The method described herein provides a simple and sensitive approach to the studies of gene expression and molecular defects in genetic diseases at transcriptional level.

Identification of three novel missense PKU mutations among Chinese

Three novel missense mutations have been identified in the phenylalanine hydroxylase (PAH) genes of Chinese individuals afflicted with various degrees of phenylketonuria (PKU). A T-to-C transition was observed in exon 5 of the gene, resulting in the substitution of Phe161 by Ser161. Two substitutions, G-to-T and T-to-G, were observed in exon 7, resulting in the substitution of Gly247 by Val247 and Leu255 by Val255, respectively. Expression analysis demonstrated that these mutant proteins produced between 0 and 15% of normal PAH enzyme activity. Population screening of a Chinese sample population indicates that these mutations are quite rare, together accounting for only about 4% of all PKU alleles among the Chinese. The P161S and G247V mutations were each present on a single PAH RFLP haplotype 4 chromosome in patients form Northern China, while the L255V mutation was present on chromosomes of both haplotypes 18 and 21 in patients from Southern China. These results suggest that the remaining 30% of uncharacterized PKU alleles in the Chinese population may bear a large number of relatively rare PAH mutations.

Identification of three novel PKU mutations among Chinese: Evidence for recombination or recurrent mutation at the PAH locus

Three novel mutations have been identified in the phenylalanine hydroxylase (PAH) genes of Chinese classical phenylketonuria (PKU) patients. Two of these substitutions (W326X and Y356X) result in the generation of a premature stop codon, while the third (IVS-7nt2) alters an invariant dinucleotide splicing signal. These mutations together account for about 10% of all PKU alleles in the Chinese population. The W326X mutation is associated with PAH RFLP haplotype 4, the most common haplotype in Orientals, while the IVS-7nt2 mutation occurs once on a haplotype 7 chromosome. The Y356X mutation is associated with multiple haplotypes, possibly due to crossover, gene conversion, or recurrent mutation.

Detection of molecular deletions in the Chinese DMD patients using two amplified dystrophin sequences

This Brief Communication reports the detection of molecular deletions in Chinese DMD patients using two new amplified dystrophin DNAs involving the regions of exon 49 and 50. The results show that over 50% of the DMD deletions can be rapidly detected by PCR amplification of these two dystrophin sequences.

Clinical observations and methods for identifying the existence of cultured epidermal allografts

Thirty-two burned or plastic surgery patients were grafted with allogeneic cultured epidermis on autograft donor sites. Two techniques, the indirect enzyme conjugated Staphylococcus Protein A assay with monoclonal antibodies against A or B blood group antigens and the polymerase chain reaction to detect a Y chromosome-specific DNA sequence, were employed to identify the presence of cultured epidermal allograft based on different ABO blood grouping or sex between donor and recipient. The methods have the advantage of high sensitivity and specificity in identifying the existence of allogeneic skin cells in grafts. The results indicated that the survival time of cultured epidermal allograft was prolonged up to 35 days. In addition, the intact coverage on some grafting sites may be composed of both host and donor origin cells, after about 3 weeks postgrafting.

Hb Q-Thailand [alpha 74(EF3)Asp-->His]: gene organization, molecular structure, and DNA diagnosis

Hb Q-Thailand [alpha 74(EF3)Asp-->His] is often found in Thailand, China, and other Southeast Asian countries. The alpha-Q-Thailand gene is strongly linked to an alpha gene deletion and has important implications in the identification and diagnosis of hemoglobinopathies and thalassemias. The alpha-Q-Thailand mutation was previously mapped to the alpha 1 gene in a study of Chinese patients. In this paper, a Thai patient with Hb Q-Thailand/Hb H disease and his mother were studied at the DNA level, and the gene organization of Hb Q-Thailand in the Thai patient was found to be the same as that of Chinese patients (i.e. the Hb Q-Thailand gene is located on the alpha 1 gene of chromosome #16, while the -4.2 kb or leftward deletion involves the alpha 2 gene). Also, the GAC-->CAC mutation proposed at codon 74, has been confirmed by DNA sequencing and a simple and accurate method for diagnosis of the Hb Q-Thailand variant has been developed based on restriction enzyme analysis. Since the GAC-->CAC mutation generates new cutting sites for both restriction enzymes Apa LI and Hgi AI, polymerase chain reaction amplification of a specific region around codon 74, followed by digestion with these enzymes and agarose gel electrophoresis of the digested products, permits rapid and accurate identification of Hb Q-Thailand.

Diagnosis of thalassemia using cDNA amplification of circulating erythroid cell mRNA with the polymerase chain reaction

We have developed a technique to diagnose the alpha- and beta-thalassemia (thal) syndromes using the polymerase chain reaction to amplify cDNA copies of circulating erythroid cell messenger RNA (mRNA) so as to quantitate the relative amounts of alpha-, beta-, and gamma-globin mRNA contained therein. Quantitation, performed by scintillation counting of 32P-dCTP incorporated into specific globin cDNA bands, showed ratios of alpha/beta-globin mRNA greater than 10-fold and greater than fivefold increased in patients with beta 0- and beta (+)-thal, respectively, as well as a relative increase in gamma-globin mRNA levels. Conversely, patients with alpha-thalassemia showed a decreased ratio of alpha/beta-globin mRNA proportional to the number of alpha-globin genes deleted. This methodology of ascertaining ratios of globin mRNA species provides a new, simplified approach toward the diagnosis of thalassemia syndromes, and may be of value in other studies of globin gene expression at the transcription level.

Spectral characteristics of electroretinogram in X-linked dichromats--a preliminary study

Spectral characteristics of X-linked Dichromats (13 protanopes, 20 deuteranopes) were studied with spectral ERG. The results are as follows: The maximal spectral response of the b-wave in protanopes tended to shift toward the short wavelength side and the sensitivity to long wavelengths decreased obviously. The ratio value of the amplitude in 500 nm and in 620 nm (500/620) was greater in the protanope than that in the normal subject. Like the normals, the maximal response of the b-wave in deuteranopes appeared at 550-570 nm. Though the differences between the normals and deuteranopes in the ratio values (600/620 and b/a at 520 nm) were found by means of analysing a, b wave responses at each wavelength, most of the ratio values (600/620 or b/a at 520 nm) overlapped between the normals and deuteranopes. We established the discriminant function or score made up by the combination of two ratios basing on Fisher's rule, which can raise the diagnostic rate for deuteranopes.

Missense mutations prevalent in Orientals with phenylketonuria: molecular characterization and clinical implications

Two missense mutations in the phenylalanine hydroxylase (PAH) genes of Orientals with phenylketonuria (PKU) have been identified. A G-to-A transition in exon 7 of the gene results in the substitution of Gln243 for Arg243 (R243Q) and accounts for 18% of all PKU chromosomes among Chinese. An A-to-G transition in exon 6 of the gene results in the substitution of Cys204 for Tyr204 (Y204C) and identifies about 13 and 5% of all PKU chromosomes in the Chinese and Japanese populations, respectively. The R243Q construct produced less than 10% of normal PAH activity in in vitro expression analysis in a eukaryotic cell system, and patients homozygous for this substitution exhibit a severe clinical phenotype. These results are consistent with previous findings in this expression system. The Y204C construct, however, produced near normal levels of PAH enzyme activity and immunoreactivity in this in vitro expression system. Because this substitution is present only on PKU chromosomes, it is a valuable marker for identifying the corresponding mutant allele for carrier screening of PKU. With the characterization of these two substitutions, about 60% of PKU alleles in China can now be identified. The continuing search for additional PKU mutations will permit effective carrier screening and prenatal gene diagnosis of PKU in East Asia.

A new silent mutation found in the Chinese PAH locus and its role in the prenatal diagnosis of phenylketonuria

A silent mutation or sequence polymorphism. A to T substitution at codon 399 in exon 11 of the PAH gene from a Chinese PKU patient, was found by sequence analysis. The frequencies of this new mutation in normal and abnormal (PKU) genes were 0.005 and 0.09, respectively, based on the analyses of 100 normal individuals and 39 PKU patients using DNA amplification with polymerase chain reaction (PCR) and oligonucleotide hybridization methods. This silent mutation can be used as a "genetic marker" for PKU prenatal diagnosis. Recently, a fetus at risk for PKU, who could not be completely predicted by RFLPs linkage analysis, was prenatally diagnosed with this genetic marker.

Founder effect of a prevalent phenylketonuria mutation in the Oriental population

A missense mutation has been identified in the human phenylalanine hydroxylase [PAH; phenylalanine 4-monooxygenase; L-phenylalanine, tetrahydrobiopterin:oxygen oxidoreductase (4-hydroxylating), EC 1.14.16.1] gene in a Chinese patient with classic phenylketonuria (PKU). A G-to-C transition at the second base of codon 413 in exon 12 of the gene results in the substitution of Pro413 for Arg413 in the mutant protein. This mutation (R413P) results in negligible enzymatic activity when expressed in heterologous mammalian cells and is compatible with a classic PKU phenotype in the patient. Population genetic studies reveal that this mutation is tightly linked to restriction fragment length polymorphism haplotype 4, which is the predominant haplotype of the PAH locus in the Oriental population. It accounts for 13.8% of northern Chinese and 27% of Japanese PKU alleles, but it is rare in southern Chinese (2.2%) and is absent in the Caucasian population. The data demonstrate unambiguously that the mutation occurred after racial divergence of Orientals and Caucasians and suggest that the allele has spread throughout the Orient by a founder effect. Previous protein polymorphism studies in eastern Asia have led to the hypothesis that "northern Mongoloids" represented a founding population in Asia. Our results are compatible with this hypothesis in that the PKU mutation might have occurred in northern Mongoloids and subsequently spread to the Chinese and Japanese populations.

Analysis of RFLPs and DNA deletions in the Chinese Duchenne muscular dystrophy gene

Sixty-nine unrelated Chinese DMD patients were studied with a series of genomic and cDNA probes. Analysis of 13 polymorphic sites showed that pERT87-1, 87-8, 87-15, and XJ probes gave favourable allele frequencies in the Chinese population, and nearly 90% of the DMD families in this study were informative for prenatal diagnosis and carrier detection using these four polymorphic markers. Nine out of 69 (13%) were also found to have gene deletions using a panel of genomic probes. However, when using cDNA probes, deletions were found in 56.5% of the patients. The deletions were concentrated in the areas of probes 7 and 8, giving a proportion of about 80% of all deleted patients in this study. All these results provide valuable information for planning prenatal diagnosis programmes for DMD in China.

Identification of a novel phenylketonuria (PKU) mutation in the Chinese: further evidence for multiple origins of PKU in Asia

A novel mutation has been identified in the human phenylalanine hydroxylase (PAH) gene of a Chinese patient with classical phenylketonuria (PKU). It is a single base transition of G to A at the last base in intron 4 of the gene, which abolishes the 3'-acceptor site of the intron. Population screening indicates that this mutation constitutes about 8% of all PKU chromosomes in Chinese but is absent in Japanese and Caucasian PKU patients. It is prevalent in southern China but rare in northern China, providing additional evidence that there were multiple founding populations of PKU in east Asia.

Prenatal detection of an Arg----Ter mutation at codon 111 of the PAH gene using DNA amplification

A CGA----TGA mutation at codon 111 in exon 3 of the phenylalanine hydroxylase (PAH) gene was recently identified in a Chinese phenylketonuria (PKU) patient. This paper reports the prenatal diagnosis of a Chinese fetus at risk for PKU using DNA amplification with PCR and oligonucleotide hybridization. RFLP analysis revealed that the fetus had inherited a PKU gene from his mother, but his paternal PAH gene was uninformative. PCR amplification of 300 bp which included exon 3 plus the flanking intronic sequences of the PAH gene was performed. The amplified DNA was hybridized with a pair of allele-specific oligonucleotide probes. The results indicated that the fetal DNA carried a PAH 111 Arg----Ter mutant gene inherited from his father. Thus, the fetus was predicted to be affected with PKU.