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Abstract Advanced nasopharyngeal carcinoma (NPC) has a poor prognosis, with an unfavorable response to palliative chemotherapy. Unfortunately, there are few effective therapeutic regimens. Therefore, we require novel treatment strategies with enhanced efficacy. The present study aimed to investigate the antitumor efficacy of APG-1252-M1, a dual inhibitor of BCL-2/BCL-XL, as a single agent and combined with gemcitabine. We applied various apoptotic assays and used subcutaneous transplanted NPC model to assess the in vitro and in vivo antitumor activity. Moreover, phospho-tyrosine kinase array was used to investigate the combined therapy’s potential synergistic mechanism. In addition, further validation was performed using immunohistochemistry and western blotting. In vitro, we observed that APG-1252-M1 had moderate antitumor activity toward NPC cells; however, it markedly improved gemcitabine’s ability to promote NPC cell apoptosis and suppress invasion, migration, and proliferation. Specifically, APG-1252 plus gemcitabine exhibited even remarkable antitumor activity in vivo. Mechanistically, the drug combination synergistically suppressed NPC by activating caspase-dependent pathways, blocking the phospho (p)-JAK-2/STAT3/MCL-1 signaling pathway, and inhibiting epithelial-mesenchymal transition. In conclusion, the results indicated that the combination of APG-1252 and gemcitabine has synergistic anticancer activities against NPC, providing a promising treatment modality for patients with NPC.

Abstract. Background:. Delivery room resuscitation assists preterm infants, especially extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI), in breathing support, while it potentially exerts a negative impact on the lungs and outcomes of preterm infants. This study aimed to assess delivery room resuscitation and discharge outcomes of EPI and ELBWI in China. Methods:. The clinical data of EPI (gestational age [GA]

BackgroundImmune checkpoint inhibitor (ICI)-combined chemotherapy in advanced intrahepatic cholangiocarcinoma has been proved to have more efficacy in a series of clinical trials. However, whether the tumor microenvironment (TME) plays a vital role in immune-combined therapy has not been rigorously evaluated.MethodsFirstly, we assayed the immunogenic properties of GEM-based chemotherapy. Then, 12 ICC patients treated with PD-1 inhibitor (sintilimab) combined with gemcitabine and cisplatin (GemCis) from a phase 2 clinical trial (ChiCTR2000036652) were included and their immune-related gene expression profiles were analyzed using RNA from baseline tumor samples. Immune-related signature correlating with clinical outcome was identified according to the 12 ICC patients, and its predictive value was validated in an ICC cohort with 26 patients. Multiplexed immunofluorescence (mIF) and flow cytometry (FCM) analysis were performed to evaluate the immune-related molecules with therapeutic outcomes.ResultsGEM-based chemotherapy induced immunogenic cell death of cholangiocarcinoma cells, together with increased CD274 expression. In an ICC cohort, we found that upregulation of immune-checkpoint molecules and immune response-related pathways were significantly related to better clinical outcome. On the contrary, baseline immune-cell proportions in tumor tissues did not show any correlation with clinical benefit between responders and non-responders. Immune-related signature (including six genes) correlating with clinical outcome was identified according to the 12 ICC patients, and its predictive value was validated in a small ICC cohort with 26 patients.ConclusionImmune-related RNA signature predicts the outcome of PD-1 inhibitor-combined GEMCIS therapy in advanced intrahepatic cholangiocarcinoma, which could be tested as a biomarker for immune-chemotherapy in the future.

Abstract A 60‐year‐old man was hospitalized because of numbness and weakness in the right upper limb. Magnetic resonance imaging revealed a large mass in the right upper lobe invading the right eighth cervical and first thoracic nerve root. Biopsy pathology confirmed primary lung adenocarcinoma with a clinical stage of cT4N0M0 IIIA, negative for anaplastic lymphoma kinase fusion gene and epidermal growth factor receptor mutations but positive for programmed death ligand 1 (3%). Neoadjuvant tislelizumab and chemotherapy were offered to this patient with Pancoast tumor, and tumor shrinkage of 71% was achieved. After the operation, surgical pathology indicated pathologic complete response (pCR). Circulating tumor cells testing was negative after the first adjuvant treatment. In this case, we provide real‐world evidence of encouraging pCR with neoadjuvant tislelizumab and chemotherapy for a patient with Pancoast tumor.

Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease. However, it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease. In this review, we evaluated the ways in which modern imaging techniques such as positron emission computed tomography, single photon emission tomography, magnetic resonance spectrum imaging, structural magnetic resonance imaging, magnetic resonance diffusion tensor imaging, magnetic resonance perfusion weighted imaging, magnetic resonance sensitive weighted imaging, and functional magnetic resonance imaging have revealed specific changes not only in brain structure, but also in brain function in Alzheimer’s disease patients. The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer’s disease patients is frequently observed via positron emission computed tomography. Furthermore, patients with Alzheimer’s disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging. Atrophy of the entorhinal cortex, hippocampus, and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging. Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism. Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation. Resting functional magnetic resonance imaging can display the functional connection between brain neural networks. These are helpful for the differential diagnosis and experimental study of Alzheimer’s disease, and are valuable for exploring the pathogenesis of Alzheimer’s disease.

Background: Acupuncture can effectively alleviate the nasal symptoms of allergic rhinitis (AR); however, the mechanism is unclear. Previous studies suggested it may be related to improve hypothalamus-pituitary-adrenal (HPA) axis dysfunction. Materials and Methods: The study was a randomised controlled trial including ninety patients with moderate to severe persistent AR. Subjects were randomised 1:1:1 to the 8-weeks treatment with mind-regulating acupuncture combined with intranasal glucocorticosteroids (INGC), conventional acupuncture combined with INGC and INGC alone (MA, CA, GC respectively). The primary outcome was the change from baseline in the Visual Analogue Scale (VAS) score of nasal symptoms. Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score was a key secondary outcome. The levels of corticotrophin releasing hormone (CRH), cortisol (COR) and adrenocorticotropic hormone (ACTH) were also analysed. Results: MA, CA and GC reduced VAS score and total RQLQ by a similar degree, but the sleep domain of RQLQ significantly improved in MA and CA compared to GC. Meanwhile, the COR and ACTH level increased, and CRH level decreased after treatment in MA and CA, but the changes showed no difference among the three groups after Bonferroni correction. Conclusions: Although acupuncture combined with INGC may have potential effect on sleep quality, the combination therapy cannot further improve nasal symptoms or RQLQ compared to INGC alone in AR patients. The influence of acupuncture on HPA axis needs to be further explored.

MazF endoribonucleases are thought to arrest growth of Mycobacterium tuberculosis by global translation inhibition. Here, Barth et al. show that MazF-mt9 cleaves a specific tRNA, leading to ribosome stalling at AAA codons and thus selective mRNA degradation and changes in transcriptome and proteome.

Abstract Background Patients with moderate and severe persistent allergic rhinitis (AR) have long-term physical and mental stress, leading to dysfunction of the hypothalamus-pituitary-adrenal (HPA) axis, which results in recurrence of AR. Previous research has proved acupuncture can regulate the function of the neuron-endocrine-immune system and contribute to improving the quality of life of patients with AR. This research aims to investigate the mechanism of acupuncture on the HPA axis in patients with moderate or severe persistent AR. Methods/design This randomized controlled trial aims to study the impact of acupuncture on the HPA axis of patients with moderate and severe AR. This research also aims to compare the curative effects of different treatments in three groups of patients: those receiving western medicine, western medicine and conventional acupuncture, or western medicine and mind-regulating acupuncture. We will study the therapeutic effect of acupuncture and the correlation between the changes of therapeutic indexes and experimental indexes after the treatments. Therapeutic indexes include the Visual Analog Scale (VAS) of nasal symptoms and the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) for AR patients; experimental indexes include corticotropin releasing hormone (CRH), adreno-corticotropic hormone (ACTH), cortisol (CORT), interleukin 4 (IL-4), and interferon-γ (IFN-γ). Discussion The results of this trial will provide evidence for the influence of chronic, long-term, repeated stimulation in patients with moderate and severe persistent AR and the impact of acupuncture on the HPA axis of these patients. Trial registration Acupuncture-Moxibustion Clinical Trial Registry, AMCTR-IOR-16000009. Registered on 22 August 2016.

Objective To investigate the relationship between peroxisome proliferator-activated receptor gamma (PPARγ) mRNA, serum adiponectin (ADP) and lipids in paediatric patients with Kawasaki disease (KD). Methods This prospective study enrolled paediatric patients with KD and grouped them according to the presence or absence of coronary artery lesions (CAL). A group of healthy age-matched children were recruited as the control group. The levels of PPARγ mRNA, serum ADP and lipids were compared between the groups. Receiver operating characteristic (ROC) curve analysis was undertaken to determine if the PPARγ mRNA level could be used as a predictive biomarker of CAL prognosis. Results The study enrolled 42 patients with KD (18 with CAL [CAL group] and 24 without CAL [NCAL group]) and 20 age-matched controls. PPARγ mRNA levels in patients with KD were significantly higher than those in the controls; but significantly lower in the CAL group than the NCAL group. ROC curve analysis demonstrated that the PPARγ mRNA level provided good predictive accuracy for the prognosis of CAL. There was no association between PPARγ, ADP and lipid levels. Conclusion There was dyslipidaemia in children with KD, but there was no correlation with PPARγ and ADP. PPARγ may be a predictor of CAL in patients with KD with good predictive accuracy.

While Baccillus Calmette-Guerin (BCG) is used worldwide, tuberculosis (TB) is still a global concern due to the poor efficacy of BCG. Novel vaccine candidates are therefore urgently required. In this study, two attenuated recombinant Listeria strains, LMΔ-msv and LIΔ-msv were constructed by deletion of actA and plcB and expression of a fusion protein consisting of T cell epitopes from four Mycobacterium tuberculosis (Mtb) antigens (Rv2460c, Rv2660c, Rv3875, and Rv3804c). The safety and immunogenicity of the two recombinant strains were evaluated in C57BL/6J mice. After intravenous immunization individually, both recombinant strains entered liver and spleen but eventually were eliminated from these organs after several days. Simultaneously, they induced antigen-specific cell-mediated immunity, indicating that the recombinant Listeria strains were immunogenic and safe in vivo. LMΔ-msv immunization induced stronger cellular immune responses than LIΔ-msv immunization, and when boosted with LIΔ-msv, antigen-specific IFN-γ CD8+ T cell responses were notably magnified. Furthermore, we evaluated the protection conferred by the vaccine candidates against mycobacterial infection via challenging the mice with 1 × 107 CFU of BCG. Especially, we tested the feasibility of application of them as heterologous BCG supplement vaccine by immunization of mice with BCG firstly, and boosted with LMΔ-msv and LIΔ-msv sequentially before challenging. Combination immune strategy (LMΔ-msv prime-LIΔ-msv boost) conferred comparable protection efficacy as BCG alone. More importantly, BCG-vaccinated mice acquired stronger resistance to Mycobacterial challenge when boosted with LMΔ-msv and LIΔ-msv sequentially. Our results inferred that heterologous immunization with Listeria-based recombinant strains boosted BCG-primed protection against pulmonary mycobacterial infection.

We first described the 2019 novel coronavirus infection in 10 children occurring in areas other than Wuhan. The coronavirus diseases in children are usually mild and epidemiological exposure is a key clue to recognize pediatric case. Prolonged virus shedding is observed in respiratory tract and feces at the convalescent stage. [ABSTRACT FROM AUTHOR]

Chuanbai Rex Rabbit (Oryctolagus cuniculus domesticus) is a hybrid breed in Sichuan, China. In this study, we reveal the mitochondrial genome sequence of the Chuanbai Rex Rabbit for the first time. The length of the mitochondrial genome is 17,179 bp and contains 2 ribosomal RNA genes, 14 protein-coding genes, 22 transfer RNA genes, and 1 D-loop sequence. We further provide a phylogenetic tree showing relationships among Chuanbai Rex Rabbit and other Leporidae species.

Background/Aims: Glucagon-like peptide-1 (GLP-1), which counteracts insulin resistance in humans with type 2 diabetes, has been shown to ameliorate diabetic nephropathy in experimental models. However, the mechanisms through which GLP-1 modulates renal function remained illdefined. The present study investigated the putative mechanisms underlying effects of exendin-4, a GLP-1 analog, on mesangial cell proliferation and fibronectin. Methods: Rat mesangial cells (MCs) were treated with exendin-4 under high glucose conditions. AMP-activated protein kinase (AMPK) inhibitors (compound C) and agonists (AICAR) were used to analyze the role of this kinase. Cell proliferation was measured using a MTT assay. Fibronectin expression and AMPK-signaling pathway activity were assessed using ELISA and Western blotting, respectively. The production of matrix metalloproteinase (MMP)-2 and tissue inhibitors of metalloproteinases (TIMP)-2 was evaluated using quantitative real-time RT-PCR. Results: Exendin-4 inhibited cell proliferation and fibronectin secretion in high glucose-induced MCs. It also caused phosphorylation of AMPK and subsequently increased the ratio of MMP-2 to TIMP-2, which resulted in the degradation of fibronectin. Exendin-4 reversed extracellular signal-regulated kinase (ERK) phosphorylation and enhanced expression of mammalian target of rapamycin (mTOR) in MCs. Moreover, the activation of the AMPK pathway by exendin-4 was induced by AICAR, which was inhibited by compound C. Conclusion: Exendin-4 exerts an inhibitory effect on cell proliferation and fibronectin secretion in rat MCs, partly through AMPK activation. These results may explain some of the beneficial effects of exendin-4 on the kidney.

Piwi proteins are required for germ cell proliferation, differentiation, and germ line stem cell maintenance. In normal tissues, human and mouse Piwil2 are primarily expressed in testis but widely expressed in tumors. However, the underlying mechanism remains largely unknown. In vertebrates, transforming growth factor (TGF)-β signaling plays an important role in patterning embryo and control of cell growth and differentiation. A previous study has shown a role for Zili, a Piwil2 gene in zebrafish, in germ cells in zebrafish. Here we report that zili functions in patterning the early embryo and inhibits TGF-β signaling. Whole mount expression analysis shows that zili expresses not only in PGCs but also in axis. Ectopic expression of zili causes fusion of the eyes and reduction of mesodermal marker genes expression, suggesting that zili functions to inhibit Nodal signaling and mesoderm formation. Genetic interaction shows that zili inhibits Nodal and bone morphogenetic protein signaling. The results of protein interaction assays identify that Zili binds to Smad4 via its N-terminal domain and prevents the formation of Smad21314 and Smadl/5/9/4 complexes to antagonize TGF-β signaling. This work shows that zili plays a role in early embryogenesis beyond germ line as a novel negative regulator of TGF-β signaling, extending the function of Piwi proteins in vertebrates. [ABSTRACT FROM AUTHOR]

Canopy exchanges of H+ and N (NH4+-N, NO3−-N) and other major ions were evaluated and quantified in two-layer canopies based on throughfall measurements in Shaoshan Forest during the period 2000–2002, central-south China. The collected annual rainfall, throughfall, and sub-throughfall were 1401,1191, and 1 084 mm/year, respectively. Fifteen percent and 8% of rainfall (or 9% of throughfall) were intercepted by the top canopy and sub-canopy layers, respectively. The foliar leaching of base cations from the top canopy was significantly higher than that from the sub-canopy, and the latter accounted for 25% of the former. The uptake of H+ and NH4+ was significantly higher in the top canopy than in the sub-canopy, indicating that the canopy buffering capacity in the top canopy was stronger than the sub-canopy; Mg2+ can be absorbed from water flux on the sub-canopy foliar surfaces to compensate for the Mg deficit in the forest soil during the growing season. (Managing editor: Ya-Qin Han) [ABSTRACT FROM AUTHOR]

The title compound, C20H32O5.H2O, crystallizes in the non-centrosymmetric space group C2. The molecular skeleton consists of an irregular 14-membered ring and a nearly twist–boat seven-membered γ-lactone ring with a trans connection. In the solid-state structure, cembradienolide and water mol­ecules form an R22(7) motif through O—H⋯O W and O W—H⋯O hydrogen bonds, while adjacent mol­ecules form an infinite chain, described by graph-set motif C22(12), along the c axis via O—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title compound, C15H20O3, molecules are linked in an infinite chain along the a axis, with graph-set motifs (12) or (14), through O—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

Objective: To establish a quantitative estimate model for diagnosing traditional Chinese medicine (TCM) syndromes of patients with osteoporosis., Methods: Symptoms and signs of osteoporosis and methodology related to syndrome research were collected by reviewing medical literature. The symptoms and sighs were quantitatively classified into three, two or one category according to a 100-mm visual analog scale. Fuzzy comprehensive evaluation model of TCM qualitative syndromes was performed based on analytic hierarchy process. Then "Hall for Workshop of Metasynthetic Engineering" expert symposium was held on subjects of syndrome quantification method and weight of evaluation indices in different levels for developing the analysis model of common syndromes. For clinical verification, the created models were applied to patients with osteoporosis for discriminating syndromes. Syndrome of each patient was also identified by 8 experts major in integrative medicine treating osteoporosis for comparing the coincidence rate using a self-made clinical questionnaire., Results: Through literature reviewing, symptoms and signs quantification and expert discussing, the authors formed estimate models of essence deficit, qi deficiency, yin deficiency, yang deficiency, and blood stasis. A total of 220 patients with osteoporosis were enrolled and filled the clinical questionnaire. All 8 experts completed and returned the questionnaire (1 760 cases), and 1 545 of them were filled in completely. Experts' opinion on syndrome differentiation was exactly coincidence to estimate model in 611 cases and almost coincidence in 639 cases. The total coincidence rate reached to 94.05%., Conclusion: The estimate model for syndrome differentiation of osteoporosis has a high-coincidence rate with the fuzzy evaluation from experts, with good rationality and feasibility, and is worthy of promotion in the clinical study.

Objective: To establish diagnostic criteria for common traditional Chinese medicine (TCM) syndromes in osteoporosis., Methods: Based on the collection and analysis of related medical literature, clinical investigation, and expert discussion, a draft of preliminary diagnostic criteria for the basic syndromes of TCM in patients with osteoporosis was formulated. Then it was used in clinic for verification and revised repeatedly until a formal version of diagnostic criteria was satisfactorily achieved., Results: The basic syndromes listed in the diagnostic criteria for patients with osteoporosis consisted of two parts: qualitative diagnosis and localization diagnosis. Results of qualitative diagnosis showed that the qualitative syndromes included damage of essence, deficiency of vital energy, deficiency of yin, deficiency of yang and blood stasis. The localization diagnosis showed that location of osteoporosis is bone and corresponds to the kidney, and also involves liver, lung, spleen (stomach) and heart. The diagnostic content has established the specific symptoms and the non-specific symptoms during various stages. Each of the above syndromes could be diagnosed according to a specific combination of its corresponding symptoms or signs. The clinical verification results showed that the total matching ratio of qualitative diagnosis was 80.56% between the diagnoses made according to the criteria and the diagnoses acquired from the experts' experience, and the total matching ratio of localization diagnosis was 85.56%., Conclusion: The TCM syndrome diagnostic criteria for osteoporosis is generally consistent with TCM clinical practice, worthy of further popularization and application in clinical practice.

Objective: To establish a quantitative model for evaluating the degree of traditional Chinese medicine (TCM) syndromes often seen in patients with coronary heart disease (CHD)., Methods: Medical literature concerning clinical investigation of TCM syndromes of CHD was collected and organized, and the "Hall for Workshop of Metasynthetic Engineering" expert symposium method was applied. First, the 100 millimeter scaling was used for combining with scoring on degree of symptoms to establish a quantitative criterion for classification of symptom degree in CHD patients, and the model was established by using comprehensive analytic hierarchy process as the mathematical tool to estimate the weight of the criterion for evaluating qualitative syndromes in various layers by specialists. Then the model was verified in clinical practice and the outcomes were compared with fuzzy evaluation from the specialists., Results: A total of 287 clinical observation forms on CHD cases were collected, and 167 forms were available after excluding any irregular forms. The results showed that basic coincidence rate between the outcomes derived from specialists and those from the model was 68.26% (114/167), and part coincidence rate was 88.62%(148/167)., Conclusion: This model, with good rationality and feasibility, has a high coincidence rate with fuzzy evaluation from specialists, and can be promoted in clinical practice. It is a good quantitative model for evaluating the degree of TCM syndromes of CHD.

Objective: To explore the change of brain cognition function in severe head injury and the correlation between P300 in event-related potential (ERP) and intelligence quotient (IQ)., Methods: Auditory P300 was measured and intelligence quotient was tested by Wechsler Adult Intelligence Scale Revised in China (WAIS-RC) in 40 severe head injury patients. Auditory P300 was measured in 40 normal healthy people as control group., Results: The latencies of P300 in severe head injury patients group were longer than in control group. There was a significant difference between the two groups (P< 0.01). There were significant negative correlations between P300 latency and VIQ and FIQ respectively (r=-0.335,-0.344, P<0.05)., Conclusion: ERP might be taken as an objective index for measuring the change of the brain cognition function in patients with severe head injury.

Aim: To compare the sequencing of PCR products, pyrosequencing, and real-time PCR for detection of Tyrosine-methionine-aspartate-aspartate (YMDD) mutants in patients with chronic hepatitis B., Methods: Mixtures of plasmids and serum samples from 69 chronic hepatitis B patients treated with lamivudine were tested for YMDD mutations by sequencing of PCR products, pyrosequencing, and real-time PCR, respectively. Time required and reagent costs of the three assays were evaluated., Results: Real-time PCR detected 100%, 50%, 10%, 1% and 0.1% of YVDD plasmid in mixtures with 10(6) copies/mL of YMDD plasmid, whereas sequencing and pyrosequencing only detected 100% and 50% of YVDD plasmid in aliquots of the corresponding mixtures. Completely concordant results were obtained from 60 (87%) out of the 69 clinical serum samples by the three assays. Mutants were detected by real-time PCR in less than 20% of the total virus population, but no mutant was detected by sequencing and pyrosequencing. In addition, real-time PCR required less time and was more cost-effective than the other two assays. However, throughput of pyrosequencing was the highest., Conclusion: Among the three assays compared, real-time PCR is the most sensitive, cost-effective, and time saving for monitoring YMDD mutants in patients with chronic hepatitis B on lamivudine therapy.

Objective: This case-control study was carried out to assess the alteration of endothelium-dependent arterial dilation before and after subtotal thyroidectomy in subjects with hyperthyroidism., Patients and Methods: The study subjects included 12 patients with hyperthyroidism and 39 apparently healthy individuals. We performed a subtotal thyroidectomy on the hyperthyroid patients. The endothelium-dependent arterial dilation was determined with a high-resolution ultrasound method in each patient at the hyperthyroid stage before treatment (stage H), the euthyroid stage induced immediately before surgery (stage E), and the transient hypothyroid stage 1 or 2 months after surgery (stage L)., Results: The flow-mediated arterial dilation decreased significantly from H to E and from E to L (P < 0.001). As compared with H, baseline blood flow decreased markedly at stages E and L (P < 0.001). The flow-mediated arterial dilation and baseline blood flow in the control subjects were very close to those at stage E of the hyperthyroid patients. The absolute change in the flow-mediated arterial dilation showed significant negative correlation with the changes in TSH (r =-0.86, P < 0.001), lipoprotein (a) [Lp(a)] (r =-0.77, P < 0.001) and low density lipoprotein (LDL) (r =-0.79, P < 0.001), and significant positive correlation with changes in fT3 (r =+0.88, P < 0.001). The absolute change in the baseline blood flow showed significant positive correlation with the change in fT3 (r =+0.85, P < 0.001) and significant negative correlation with the change in TSH (r =-0.63, P < 0.01)., Conclusion: The endothelium-dependent arterial dilation increases significantly in untreated hyperthyroid patients, and decreases markedly after a subtotal thyroidectomy. Therefore, we conclude that the endothelium is more responsive to reactive hyperaemia in the hyperthyroid than the euthyroid state.

ZnO thin film is a promising material for short-wave laser and LED etc, due to its high excition binding energy, intense stimulated emission, low lasing threshold, and high working temperature. ZnO thin films were prepared by laser molecular beam epitaxy (L-MBE) in our work. At room-temperature we reported the measurements of absorption spectra and emission spectra of ZnO thin films excited by various optical pumping intensities. High structural perfection of our sample was shown in these figures. We studied the properties and mechanism of stimulated emission in ZnO thin films. The relation between emission intensity and pumping intensity was obtained. Time behaviors of the stimulated emission under relatively high pumping intensity, spontaneous emission, and laser pulses were compared, and hence the stimulated emission of ZnO thin films was proved.