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BackgroundFrom 2004 onwards, the Chinese government has freely offered complimentary Chinese herbal medicine (CHM) to Chinese HIV/AIDS patients, alongside the prescribed first line therapy of highly active antiretroviral therapy (HAART). Thus, we aimed to explore the effectiveness and safety of CHM for patients with HIV/AIDS.MethodsThe data from the Guangxi pilot database and antiviral treatment sites database have been respectively developed into two datasets in this prospective cohort real-world study, the CHM combined HAART group (the integrated group) and the HAART group. A 1:1 propensity score matching (PSM) was performed and the longitudinal data were analyzed using a generalized estimating equation (GEE) model with an autocorrelation matrix and log link function attached to the Gamma distribution.ResultsA final sample of 629 patients, 455 and 174 in the integrated group and HAART group respectively, were obtained from the full dataset. As covariates for PSM, gender, age, baseline CD4+ and CD4+/ CD8+ were assessed based on the results of the logistic regression analyses. Following PSM, 166 pairs from the full dataset were matched successfully, with 98 pairs in the baseline CD4+ > 200 subgroup, and 55 pairs in the baseline CD4+ ≤ 200 subgroup. In the full dataset, HAART group achieved higher CD4+ count (OR = 1.119, 95%CI [1.018, 1.230]) and CD4+/CD8+ ratio (OR = 1.168, 95%CI [1.045, 1.305]) than the integrated group, so did in the CD4+ > 200 subgroup. For the CD4+ ≤ 200 subgroup, the CD4+ (OR = 0.825, 95%CI [0.694, 0.980]) and CD4+/CD8+ (OR = 0.826, 95%CI [0.684, 0.997]) of the integrated group were higher than those of the HAART group. The safety outcomes showed that there were no significant differences in BUN, ALT and AST levels between the groups but Cr showed significantly higher levels in HAART groups of all three datasets.ConclusionsCompared to HAART alone, CHMs combined with HAART had better effects in improving the immune function of HIV/AIDS in patients with baseline CD4+ count ≤ 200. The results of the two subgroups are in opposite directions, and chance does not explain the apparent subgroup effect. A study with larger sample size and longer follow-up period is warranted in order to increase study credibility.

BackgroundChatGPT is a large language model designed to generate responses based on a contextual understanding of user queries and requests. This study utilised the entrance examination for the Master of Clinical Medicine in Traditional Chinese Medicine to assesses the reliability and practicality of ChatGPT within the domain of medical education.MethodsWe selected 330 single and multiple-choice questions from the 2021 and 2022 Chinese Master of Clinical Medicine comprehensive examinations, which did not include any images or tables. To ensure the test's accuracy and authenticity, we preserved the original format of the query and alternative test texts, without any modifications or explanations.ResultsBoth ChatGPT3.5 and GPT-4 attained average scores surpassing the admission threshold. Noteworthy is that ChatGPT achieved the highest score in the Medical Humanities section, boasting a correct rate of 93.75%. However, it is worth noting that ChatGPT3.5 exhibited the lowest accuracy percentage of 37.5% in the Pathology division, while GPT-4 also displayed a relatively lower correctness percentage of 60.23% in the Biochemistry section. An analysis of sub-questions revealed that ChatGPT demonstrates superior performance in handling single-choice questions but performs poorly in multiple-choice questions.ConclusionChatGPT exhibits a degree of medical knowledge and the capacity to aid in diagnosing and treating diseases. Nevertheless, enhancements are warranted to address its accuracy and reliability limitations. Imperatively, rigorous evaluation and oversight must accompany its utilization, accompanied by proactive measures to surmount prevailing constraints.

BackgroundFatigue is a common symptom after viral infection. Chinese herbal medicine (CHM) is thought to be a potential effective intervention in relieving fatigue.PurposeTo assess the effectiveness and safety of CHM for the treatment of post-viral fatigue.Study designSystematic review and meta-analysis of randomized controlled trials (RCTs).MethodsThe protocol of this systematic review was registered on PROSPERO (CRD42022380356). Trials reported changes of fatigue symptom, which compared CHM to no treatment, placebo or drugs, were included. Six electronic databases and three clinical trial registration platforms were searched from inception to November 2023. Literature screening, data extraction, and risk bias assessment were independently carried out by two reviewers. Quality of the included trials was evaluated using Cochrane risk of bias tool, and the certainty of the evidence was evaluated using GRADE. The meta-analysis was performed using Review Manager 5.4, mean difference (MD) and its 95% confidence interval (CI) was used for estimate effect of continuous data. Heterogeneity among trials was assessed through I2 value.ResultsOverall, nineteen studies with 1921 patients were included. Results of individual trial or meta-analysis showed that CHM was better than no treatment (MD = -0.80 scores, 95%CI -1.43 to -0.17 scores, P = 0.01, 60 participants, 1 trial), placebo (MD = -1.90 scores, 95%CI -2.38 to -1.42 scores, PConclusionCurrent systematic review found that the participation of CHM can improve the symptoms of post-viral fatigue and some immune indicators. However, the safety of CHM remains unknown and large sample, high quality multicenter RCTs are still needed in the future.

BackgroundLactation mastitis (LM) affects approximately 3% to 33% of postpartum women and the risk factors of LM have been extensively studied. However, some results in the literature reports are still not conclusive due to the complexity of LM etiology and variation in the populations. To provide nationally representative evidence of the well-accepted risk factors for LM in China, this study was aimed to systematically summary the risk factors for LM among Chinese women and to determine the effect size of individual risk factor.Material and methodsSix major Chinses and English electronic literature databases (PubMed, Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wan fang Database and China Science Technology Journal Database) were searched from their inception to December 5st, 2020. Two authors extracted data and assessed the quality of included trials, independently. The strength of the association was summarized using the odds ratio (OR) with 95% confidence intervals (CI). The population attributable risk (PAR) percent was calculated for significant risk factors.ResultsFourteen studies involving 8032 participants were included. A total of 18 potential risk factors were eventually evaluated. Significant risk factors for LM included improper milking method (OR 6.79, 95%CI 3.45-13.34; PAR 59.14%), repeated milk stasis (OR 6.23, 95%CI 4.17-9.30; PAR 49.75%), the first six months postpartum (OR 5.11, 95%CI 2.66-9.82; PAR 65.93%), postpartum rest time less than 3 months (OR 4.71, 95%CI 3.92-5.65; PAR 56.95%), abnormal nipple or crater nipple (OR 3.94, 95%CI 2.34-6.63; PAR 42.05%), breast trauma (OR 3.07, 95%CI 2.17-4.33; PAR 15.98%), improper breastfeeding posture (OR 2.47, 95%CI 2.09-2.92; PAR 26.52%), postpartum prone sleeping position (OR 2.46, 95%CI 1.58-3.84; PAR 17.42%), little or no nipple cleaning (OR 2.05, 95%CI 1.58-2.65; PAR 24.73%), primipara (OR 1.73, 95%CI 1.25-2.41; PAR 32.62%), low education level (OR 1.63, 95%CI 1.09-2.43; PAR 23.29%), cesarean section (OR 1.51, 95%CI 1.26-1.81; PAR 18.61%), breast massage experience of non-medical staff (OR 1.51, 95%CI 1.25-1.82; PAR 15.31%) and postpartum mood disorders (OR 1.47, 95%CI 1.06-2.02; PAR 21.27%).ConclusionsThis review specified several important risk factors for LM in China. In particular, the incidence of LM can be reduced by controlling some of the modifiable risk factors such as improper breastfeeding posture, improper milking method, repeated milk stasis, nipple cleaning, breast massage experience of non-medical staff and postpartum sleeping posture.

ObjectiveTo assess the cardiovascular safety of celecoxib compared to non-selective non-steroid anti-inflammatory drugs or placebo.MethodsWe included randomized controlled trials of oral celecoxib compared with a non-selective NSAID or placebo in rheumatoid arthritis and osteoarthritis patients. We conducted searches in EMBASE, Cochrane CENTRAL, MEDLINE, China National Knowledge Infrastructure, VIP, Wanfang, and Chinese Biomedical Literature Database. Study selection and data extraction were done by two authors independently. The risk of bias was assessed using Cochrane's risk-of-bias Tool for Randomized Trials. The effect size was presented as a risk ratio with their 95% confidence interval.ResultsUntil July 22nd, 2021, our search identified 6279 records from which, after exclusions, 21 trials were included in the meta-analysis. The overall pooled risk ratio for Antiplatelet Trialists Collaboration cardiovascular events for celecoxib compared with any non-selective non-steroid anti-inflammatory drugs was 0.89 (95% confidence interval: 0.80-1.00). The pooled risk ratio for all-cause mortality for celecoxib compared with non-selective non-steroid anti-inflammatory drugs was 0.81 (95% confidence interval: 0.66-0.98). The cardiovascular mortality rate of celecoxib was lower than non-selective non-steroid anti-inflammatory drugs (risk ratio: 0.75, 95% confidence interval: 0.57-0.99). There was no significant difference between celecoxib and non-selective non-steroid anti-inflammatory drugs or placebo in the risk of other cardiovascular events.ConclusionCelecoxib is relatively safe in rheumatoid arthritis and osteoarthritis patients, independent of dose or duration. But it remains uncertain whether this would remain the same in patients treated with aspirin and patients with established cardiovascular diseases.

INTRODUCTION:Little is known of acupuncture patients' experiences and opinions of clinical trials, and what may influence their compliance when participating in an acupuncture trial. OBJECTIVES:To explore the potential factors that influence patients' choice and determinants to participate in acupuncture clinical trials. METHODS:Ten qualitative, in-depth interviews were conducted with patients from acupuncture clinics in Beijing, who had previously participated in acupuncture clinical trials. RESULTS:Four main themes emerged from the interview data: effectiveness of the treatment, convenience of participating in a trial, doctor-participant communication, and participant acceptance of the treatment (or the trial). Effectiveness of acupuncture in treating the health condition was the most important factor for participant adherence. Pragmatics of treatment schedules, travel and attendance burden, together with confidence in the doctor's ability additionally influenced trial and treatment compliance. CONCLUSIONS:In-depth interviews suggest that treatment effectiveness, the pragmatics of attending treatment sessions, and the expertise and attitudes of acupuncturists are determining factors of participation and compliance in acupuncture clinical trials. Participants' confidence in, and expectation of, acupuncture may facilitate compliance, while their fear of acupuncture and negative perceptions of the trial's purpose may reduce treatment compliance. Compliance may be facilitated by enhanced doctor-patient communication, personalized treatment programs, and feedback on treatment outcomes.

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INTRODUCTION:Antimicrobial resistance (AMR) is a substantial threat to public health. Safe and effective alternatives are required to reduce unnecessary antibiotic prescribing. Andrographis Paniculata (A. Paniculata, Chuān Xīn Lián) has traditionally been used in Indian and Chinese herbal medicine for cough, cold and influenza, suggesting a role in respiratory tract infections (RTIs). This systematic review aimed to evaluate the clinical effectiveness and safety of A. Paniculata for symptoms of acute RTIs (ARTIs). MATERIALS AND METHODS:English and Chinese databases were searched from their inception to March 2016 for randomised controlled trials (RCTs) evaluating oral A. Paniculata without language barriers (Protocol ID: CRD42016035679). The primary outcomes were improvement in ARTI symptoms and adverse events (AEs). A random effects model was used to pool the mean differences and risk ratio with 95% CI reported. Methodological quality was evaluated using the Cochrane risk of bias tool; two reviewers independently screened eligibility and extracted data. RESULTS:Thirty-three RCTs (7175 patients) were included. Most trials evaluated A. Paniculata (as a monotherapy and as a herbal mixture) provided commercially but seldom reported manufacturing or quality control details. A. Paniculata improved cough (n = 596, standardised mean difference SMD: -0.39, 95% confidence interval CI [-0.67, -0.10]) and sore throat (n = 314, SMD: -1.13, 95% CI [-1.37, -0.89]) when compared with placebo. A. Paniculata (alone or plus usual care) has a statistically significant effect in improving overall symptoms of ARTIs when compared to placebo, usual care, and other herbal therapies. Evidence also suggested that A. Paniculata (alone or plus usual care) shortened the duration of cough, sore throat and sick leave/time to resolution when compared versus usual care. No major AEs were reported and minor AEs were mainly gastrointestinal. The methodological quality of included trials was overall poor. CONCLUSIONS:A. Paniculata appears beneficial and safe for relieving ARTI symptoms and shortening time to symptom resolution. However, these findings should be interpreted cautiously owing to poor study quality and heterogeneity. Well-designed trials evaluating the effectiveness and potential to reduce antibiotic use of A. Paniculata are warranted.

About 85.3% of hemolytic disease of the newborn (HDN) is caused by maternal-fetal ABO blood group incompatibility. However, there is currently no recommended "best" therapy for ABO incompatibility during pregnancy.To systematically assess the safety and effectiveness of oral Chinese herbal medicine (CHM) for preventing HDN due to ABO incompatibility.The protocol of this review was registered on the PROSPERO website (No. CRD42016038637).Six databases were searched from inception to April 2016. Randomized controlled trials (RCTs) of CHM for maternal-fetal ABO incompatibility were included. The primary outcome was incidence of HDN. The Cochrane risk of bias tool was used to assess the methodological quality of included trials. Risk ratios (RR) and mean differences with 95% confidence interval were used as effect measures. Meta-analyses using Revman 5.3 software were conducted if there were sufficient trials without obvious clinical or statistical heterogeneity available.Totally 28 RCTs involving3413 women were included in the review. The majority of the trials had unclear or high risk of bias. Our study found that the rate of HDN and the incidence of neonatal jaundice might be 70% lower in the herbal medicine group compared with the usual care group (RR from 0.25 to 0.30).After treatment with herbal medicine, women were twice as likely to have antibody titers lower than 1:64 compared with women who received usual care(RR from 2.15 to 3.14) and the umbilical cord blood bilirubin level in the herbal medicine group was 4umol/L lower than in those receiving usual care. There was no difference in Apgar scores or birthweights between the two groups.This review found very low-quality evidence that CHM prevented HDN caused by maternal-fetal ABO incompatibility. No firm conclusions can be drawn regarding the effectiveness or safety of CHM for this condition.

Prostate cancer is the most common malignant tumor associated with male reproductive system.The existing eligible randomized controlled trials (RCTs) were critically appraised for the safety and effectiveness of CHM for prostate cancer.A literature search was conducted by using PubMed, CENTRAL, CNKI, CBM, VIP and Wanfang databases until August 2015. RCTs of CHM or CHM plus conventional medicine for prostate cancer patients were included. The primary outcomes appraised were survival time, time to progression and quality of life. The risk of bias assessment according to the Cochrane Handbook was used to evaluate the methodological quality of the included trials. Revman 5.3 software was used for data analyses. Risk ratio and mean difference (MD) with a 95% confidence interval (CI) were used as effect measures. Meta-analysis was to be used if sufficient trials without obvious clinical or statistical heterogeneity were available.A total of 17 RCTs involving 1224 participants were analyzed. One trial was about CHM comparing to no treatment. The remaining 16 trials used CHMs as adjunctive treatment for endocrine therapy. Due to the poor quality of methodologies of most trials, only limited evidence showed that a combination of CHM and endocrine therapy might be more effective in restraining the development of the disease (MD 10.37 months, 95%CI 9.10 to 11.63 months), increasing patients' survival time (7-15 months) or improving patients' performance status, when compared to endocrine therapy alone (Karnofsky performance scale average changed 15 scores between groups). No severe adverse event was reported related to CHM.Due to the insufficient quality of trials that were analyzed, it is not appropriate to recommend any kind of CHMs in treating prostate cancer at the present time. Well-designed trials with high methodological quality are needed to validate the effect of CHMs for patients with prostate cancer.

BACKGROUND: The safety and health benefits of Tai Chi mind-body exercise has been documented in a large number of clinical studies focused on specific diseases and health conditions. The objective of this systematic review is to more comprehensively summarize the evidence base of clinical studies of Tai Chi for healthcare. METHODS AND FINDINGS: We searched for all types of clinical studies on Tai chi in PubMed, the Cochrane Library and four major Chinese electronic databases from their inception to July 2013. Data were analyzed using SPSS17.0 software. A total of 507 studies published between 1958 and 2013 were identified, including 43 (8.3%) systematic reviews of clinical studies, 255 (50.3%) randomized clinical trials, 90 (17.8%) non-randomized controlled clinical studies, 115 (22.7%) case series and 4 (0.8%) case reports. The top 10 diseases/conditions was hypertension, diabetes, osteoarthritis, osteoporosis or osteopenia, breast cancer, heart failure, chronic obstructive pulmonary disease, coronary heart disease, schizophrenia, and depression. Many healthy participants practiced Tai Chi for the purpose of health promotion or preservation. Yang style Tai Chi was the most popular, and Tai Chi was frequently practiced two to three 1-hour sessions per week for 12 weeks. Tai Chi was used alone in more than half of the studies (58.6%), while in other studies Tai Chi was applied in combination with other therapies including medications, health education and other physical therapies. The majority of studies (94.1%) reported positive effects of Tai Chi, 5.1% studies reported uncertain effects and 0.8% studies reported negative effects. No serious adverse events related to Tai Chi were reported. CONCLUSIONS: The quantity and evidence base of clinical studies on Tai Chi is substantial. However, there is a wide variation in Tai Chi intervention studied and the reporting of Tai Chi intervention needs to be improved. Further well-designed and reported studies are recommended to confirm the effects of Tai Chi for the frequently reported diseases/conditions.

ObjectivesThe aims of this study were to investigate whether there is a gap between evidence of traditional medicine (TM) interventions in East-Asian countries from the current Clinical Practice Guidelines (CPGs) and evidence from current systematic reviews and meta-analyses (SR-MAs) and to analyze the impact of this gap on present CPGs.MethodsWe examined 5 representative TM interventions in the health care systems of East-Asian countries. We searched seven relevant databases for CPGs to identify whether core CPGs included evidence of TM interventions, and we searched 11 databases for SR-MAs to re-evaluate current evidence on TM interventions. We then compared the gap between the evidence from CPGs and SR-MAs.ResultsThirteen CPGs and 22 SR-MAs met our inclusion criteria. Of the 13 CPGs, 7 CPGs (54%) mentioned TM interventions, and all were for acupuncture (only one was for both acupuncture and acupressure). However, the CPGs did not recommend acupuncture (or acupressure). Of 22 SR-MAs, 16 were for acupuncture, 5 for manual therapy, 1 for cupping, and none for moxibustion and herbal medicine. Comparing the evidence from CPGs and SR-MAs, an underestimation or omission of evidence for acupuncture, cupping, and manual therapy in current CPGs was detected. Thus, applying the results from the SR-MAs, we moderately recommend acupuncture for chronic LBP, but we inconclusively recommend acupuncture for (sub)acute LBP due to the limited current evidence. Furthermore, we weakly recommend cupping and manual therapy for both (sub)acute and chronic LBP. We cannot provide recommendations for moxibustion and herbal medicine due to a lack of evidence.ConclusionsThe current CPGs did not fully reflect the evidence for TM interventions. As relevant studies such as SR-MAs are conducted and evidence increases, the current evidence on acupuncture, cupping, and manual therapy should be rigorously considered in the process of developing or updating the CPG system.

ObjectiveChinese proprietary herbal medicines (CPHMs) have long history in China for the treatment of common cold, and lots of them have been listed in the 'China national essential drug list' by the Chinese Ministry of Health. The aim of this review is to provide a well-round clinical evidence assessment on the potential benefits and harms of CPHMs for common cold based on a systematic literature search to justify their clinical use and recommendation.MethodsWe searched CENTRAL, MEDLINE, EMBASE, SinoMed, CNKI, VIP, China Important Conference Papers Database, China Dissertation Database, and online clinical trial registry websites from their inception to 31 March 2013 for clinical studies of CPHMs listed in the 'China national essential drug list' for common cold. There was no restriction on study design.ResultsA total of 33 CPHMs were listed in 'China national essential drug list 2012' for the treatment of common cold but only 7 had supportive clinical evidences. A total of 6 randomised controlled trials (RCTs) and 7 case series (CSs) were included; no other study design was identified. All studies were conducted in China and published in Chinese between 1995 and 2012. All included studies had poor study design and methodological quality, and were graded as very low quality.ConclusionsThe use of CPHMs for common cold is not supported by robust evidence. Further rigorous well designed placebo-controlled, randomized trials are needed to substantiate the clinical claims made for CPHMs.

BackgroundHuperzine A is a Chinese herb extract used for Alzheimer's disease. We conducted this review to evaluate the beneficial and harmful effect of Huperzine A for treatment of Alzheimer's disease.MethodsWe searched for randomized clinical trials (RCTs) of Huperzine A for Alzheimer's disease in PubMed, Cochrane Library, and four major Chinese electronic databases from their inception to June 2013. We performed meta-analyses using RevMan 5.1 software. (Protocol ID: CRD42012003249).Results20 RCTs including 1823 participants were included. The methodological quality of most included trials had a high risk of bias. Compared with placebo, Huperzine A showed a significant beneficial effect on the improvement of cognitive function as measured by Mini-Mental State Examination (MMSE) at 8 weeks, 12 weeks and 16 weeks, and by Hastgawa Dementia Scale (HDS) and Wechsler Memory Scale (WMS) at 8 weeks and 12 weeks. Activities of daily living favored Huperzine A as measured by Activities of Daily Living Scale (ADL) at 6 weeks, 12 weeks and 16 weeks. One trial found Huperzine A improved global clinical assessment as measured by Clinical Dementia Rating Scale (CDR). One trial demonstrated no significant change in cognitive function as measured by Alzheimer's disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and activity of daily living as measured by Alzheimer's disease Cooperative Study Activities of Daily Living Inventory (ADCS-ADL) in Huperzine A group. Trials comparing Huperzine A with no treatment, psychotherapy and conventional medicine demonstrated similar findings. No trial evaluated quality of life. No trial reported severe adverse events of Huperzine A.ConclusionsHuperzine A appears to have beneficial effects on improvement of cognitive function, daily living activity, and global clinical assessment in participants with Alzheimer's disease. However, the findings should be interpreted with caution due to the poor methodological quality of the included trials.

BACKGROUND: A large number of infertile couples are choosing Chinese herbal medicine (CHM) as an adjuvant therapy to improve their success when undergoing in vitro fertilization (IVF). There is no systematic review to evaluate the impact of CHM on the IVF outcomes. OBJECTIVE: To evaluate the effectiveness of CHM with concurrent IVF versus IVF alone on the outcomes of IVF and its safety. METHODS: The protocol of this study is registered at PROSPERO. Eligible RCTs searched from 8 databases which compared a combination of CHM and IVF with IVF alone were included. Two authors independently selected studies, extracted data and assessed methodological quality. Meta-analysis of RCTs was conducted if there was non-significant heterogeneity (evaluated by I(2) test) among trials. All statistical analysis was performed using RevMan 5.1 software. RESULTS: Twenty trials involving 1721 women were included in the meta-analysis. Three trials were evaluated as having an unclear risk of bias. The remaining trials were evaluated as having a high risk of bias. Combination of CHM and IVF significantly increases clinical pregnancy rates (OR 2.04, 95%CI 1.67 to 2.49, p

Manual acupuncture has commonly been used in China, either alone or in combination with conventional medicine, to treat diabetic peripheral neuropathy (DPN). The objective of this study was to perform a systematic review to evaluate the potential benefits and harms of manual acupuncture for DPN to justify its clinical use.We searched for published and unpublished randomized controlled trials of manual acupuncture for DPN till 31 March 2013. Revman 5.2 software was used for data analysis with effect estimate presented as relative risk (RR) and mean difference (MD) with a 95% confidence interval (CI).A total of 25 trials involving 1649 participants were included. The methodological quality of included trials was generally poor. Meta-analysis showed that manual acupuncture had better effect on global symptom improvement compared with mecobalamin (RR 1.31, 95%CI 1.21 to 1.42), vitamin B1 and B12 (RR 1.55, 95%CI 1.33 to 1.80), and no treatment (RR 1.56, 95%CI 1.31 to 1.85), and that the combination of manual acupuncture and mecobalamin had better effect compared with mecobalamin alone on global symptom improvement (RR 1.56, 95%CI 1.28 to 1.90). Adverse events were not reported in any trials. The asymmetric funnel plot suggested publication bias.Despite the number of trials of manual acupuncture for DPN and their uniformly positive results, no clinically relevant conclusions can be drawn from this review due to the trials' high risks of bias and the possibility of publication bias. Clearly defined and internationally acknowledged outcome measures are required for future study. There remains an urgent need for training Chinese researchers in conducting unbiased trials as well as prospectively registering all initiated Chinese trials to avoid publication bias.

The whole-genome duplication (WGD) may provide a basis for the emergence of the very characteristic life style of Saccharomyces cerevisiae-its fermentation-oriented physiology and its capacity of growing in anaerobiosis. Indeed, we found an over-representation of oxygen-responding genes in the ohnologs of S. cerevisiae. Many of these duplicated genes are present as aerobic/hypoxic(anaerobic) pairs and form a specialized system responding to changing oxygen availability. HYP2/ANB1 and COX5A/COX5B are such gene pairs, and their unique orthologs in the 'non-WGD' Kluyveromyces lactis genome behaved like the aerobic versions of S. cerevisiae. ROX1 encodes a major oxygen-responding regulator in S. cerevisiae. The synteny, structural features and molecular function of putative KlROX1 were shown to be different from that of ROX1. The transition from the K. lactis-type ROX1 to the S. cerevisiae-type ROX1 could link up with the development of anaerobes in the yeast evolution. Bioinformatics and stochastic analyses of the Rox1p-binding site (YYYATTGTTCTC) in the upstream sequences of the S. cerevisiae Rox1p-mediated genes and of the K. lactis orthologs also indicated that K. lactis lacks the specific gene system responding to oxygen limiting environment, which is present in the 'post-WGD' genome of S. cerevisiae. These data suggested that the oxygen-responding system was born for the specialized physiology of S. cerevisiae.