[Immunogenicity and safety of revaccination of 23-valent pneumococcal polysaccharide vaccine in people aged 60 years and above].

Objective: To evaluate the immunogenicity and safety of revaccination of 23-valent pneumococcal polysaccharide vaccine (PPV23) in elderly people aged ≥60 years. Methods: The elderly aged ≥60 years with 1 dose of PPV23 vaccination were selected as revaccination group and those without history of pneumococcal vaccine immunization were selected as the first vaccination group. One dose of PPV23 was administered to both groups, and the first blood samples were collected before vaccination while the second blood samples were collected on day 28-40 after vaccination. ELISA was used to detect the concentrations of anti-specific serotype Streptococcus pneumoniae podocyte polysaccharide immunoglobulin G, and the safety of the vaccination was evaluated after 30 days. Results: The geometric mean concentration (GMC) of antibody to 23 serotypes before the vaccination (0.73-13.73 µg/ml) was higher in revaccination group than in the first vaccination group (0.39-7.53 µg/ml), the GMC after the vaccination (1.42-31.65 µg/ml) was higher than that before the vaccination (0.73-13.73 µg/ml) in the revaccination group, and the GMC after the vaccination (1.62-43.76 µg/ml) was higher than that before the vaccination (0.39-7.53 µg/ml) in the first vaccination group; the geometric mean growth multiple in revaccination group (2.16-3.60) was lower than that in the first vaccination group (3.86-16.13); The mean 2-fold antibody growth rate was lower in revaccination group (53.68%, 95%CI: 52.30%-55.06%) than in the first vaccination group (93.16%, 95%CI: 92.18%- 94.15%), all differences were significant (P<0.001). After the vaccination, 13 serotypes of GMC were higher in the first vaccination group than in revaccination group (P<0.001), the differences were not significant for 10 serotypes of GMC (P>0.05). The incidence of local adverse reaction was 19.20% and 13.27% in revaccination group and the first vaccination group, respectively (P=0.174). Conclusions: The antibody level in ≥60 years people who received one dose of PPV23 after a 5-year interval was still higher than that in unvaccinated people. The antibody level decreased after 5 years of the first vaccination, and the antibody level could be rapidly increased by one more dose vaccination, but the overall immune response was lower than that of the first vaccination; revaccination with PPV23 has a good safety.

[Whole exome sequencing analysis and prenatal diagnosis in children with neurodevelopmental disorders].

To explore the application value of whole exome sequencing (WES) in the diagnosis of prenatal and postnatal neurodevelopmental disorders (NDDs). A total of 70 patients diagnosed with NDDs who underwent WES at the Medical Genetics Center of the Maternal and Child Health Hospital of Hubei Province between June 2020 and July 2021 were retrospectively analyzed. Genomic DNA was extracted from peripheral blood samples and amniotic fluid. WES-based copy number variant (CNV) analysis was integrated into the routine WES data analysis pipeline. The results showed that a molecular diagnosis rate could be made in 21/70 (30%) cases. Of 21 positive cases, 14 (23%) cases were detected by single-nucleotide variant/small insertion/deletion (SNV/Indel) analysis, of which 12 variants were novel, 6 (9.8%) cases were detected by WES-based CNV analysis, and 1 (1.6%) case was detected by a combination of both. The diagnostic yield of WES combined with CNV analysis was higher than that of SNV/Indel analysis alone (30%, 21/70 vs. 20%, 14/70). Of the 28 prenatally diagnosed cases, 6 cases were found to have inherited parental variation for NDDs, 10 cases were found not to have the same pathogenic variation as the proband, and the remaining 12 cases were found to have no pathogenic or likely pathogenic variation that could explain the NDDs phenotype. Clinical follow-up showed that 5 families opted for abortion and the remaining had no current abnormalities. In conclusion, WES may be an effective method to clarify the genetic etiology and prenatal diagnosis of NDDs, which is helpful in assessing the prognosis to aid clinical management and reproductive guidance.

[Advances in tumor regression patterns and safe distance of distal resection margin after neoadjuvant therapy for rectal cancer].

Neoadjuvant therapy has been widely applied in the treatment of rectal cancer, which can shrink tumor size, lower tumor staging and improve the prognosis. It has been the standard preoperative treatment for patients with locally advanced rectal cancer. The efficacy of neoadjuvant therapy for rectal cancer patients varies between individuals, and the results of tumor regression are obviously different. Some patients with good tumor regression even achieve pathological complete response (pCR). Tumor regression is of great significance for the selection of surgical regimes and the determination of distal resection margin. However, few studies focus on tumor regression patterns. Controversies on the safe distance of distal resection margin after neoadjuvant treatment still exist. Therefore, based on the current research progress, this review summarized the main tumor regression patterns after neoadjuvant therapy for rectal cancer, and classified them into three types: tumor shrinkage, tumor fragmentation, and mucin pool formation. And macroscopic regression and microscopic regression of tumors were compared to describe the phenomenon of non-synchronous regression. Then, the safety of non-surgical treatment for patients with clinical complete response (cCR) was analyzed to elaborate the necessity of surgical treatment. Finally, the review studied the safe surgical resection range to explore the safe distance of distal resection margin.

[Considerations for the development of adult vaccination in China].

Adult vaccination is an important component of the life-course immunization for all. Strengthening adult vaccination in China contributes to shrinking immunization gaps between regions and groups, enhancing the overall immunity of our population, and promoting health equity and social prosperity. Chinese adults bear the heavy burden of vaccine preventable diseases such as influenza, pneumococcal diseases and shingles, and have low coverage of vaccines against those diseases, so it is necessary to make efforts to improve adult vaccination development. This article focuses on elaborating the values of adult vaccination, introducing the current status of adult vaccination abroad, and analyzing the challenges and existing foundations for China to provide adult vaccination, and makes suggestions for the building and development of adult vaccination.

[Current status of vaccination services for adults in urban and rural areas of nine provinces in China from 2019 to 2021].

Objective: To understand the current situation of vaccination services for adults in China, explore how to establish a stable and efficient vaccination service system for adults, and provide reference for formulating corresponding policies. Methods: The vaccination information systems of nine provinces in China were used to obtain information on urban and rural vaccination of influenza vaccine, 23-valent pneumococcal polysaccharide vaccine (PPV23), and human papillomavirus vaccine (HPV) from 2019 to 2021. The indicator, vaccination rate/full vaccination rate, was used for statistical description. Results: The vaccination rate/full vaccination rate of the three vaccines in eastern China was generally higher than that in central and western China. The vaccination rate/full vaccination rate in urban areas was generally higher than that in rural areas. From 2019 to 2021, the vaccination rates of influenza vaccine among people aged 60 years and above in urban and rural areas were 2.96%, 6.29%, 6.14% and 1.29%, 2.58%, 2.94%, respectively. The vaccination rates of the PPV23 among people aged 60 years and above in urban and rural areas increased year by year, with rates of 0.38%, 1.05%, 1.15% and 0.14%, 0.49%, 0.59%, respectively. From 2019 to 2021, the HPV coverage of female adults aged 27-45 years in urban and rural areas increased year by year, with rates of 0.46%, 0.93%, 1.88% and 0.17%, 0.40%, 1.08%, respectively. Conclusion: The vaccination rates of influenza vaccine,PPV23 vaccine and HPV vaccine for adults in China are relatively low, with higher rates in the eastern region than in the central and western regions, and higher rates in urban areas than in rural areas. It is recommended to formulate corresponding health and economic policies and explore a suitable vaccination service system for adults in China to improve vaccination rates.

[Efficacy of plasma exchange in severe crescentic IgA nephropathy: A multicentered, cohort study].

OBJECTIVE: To evaluate the efficacy of plasma exchange therapy on crescentic IgA nephropathy (IgAN). METHODS: A retrospective analysis was performed in a cohort of patients with crescentic IgAN from January 2012 to September 2020 at 9 sites across China. Clinical and pathological data, as well as therapeutic regimens, were collected. In order to minimize the effect of potential confounders in baseline characteristics, propensity score matching using a 1 ∶1 ratio nearest neighbor algorithm was performed between the adjunctive plasma exchange therapy group and the intensive immunosuppressive therapy group. The primary outcome was end-stage of kidney disease (ESKD). Kaplan-Meier method was used to compare the difference in renal survival between the two groups. RESULTS: A total of 95 crescentic IgAN patients with acute kidney disease were included in this study, including 37 (38.9%) patients receiving adjunctive plasma exchange therapy, and 58 (61.1%) patients receiving intensive immunosuppressive therapy. In the whole cohort, the baseline eGFR was 12.77 (7.28, 21.29) mL/(min·1.73 m2), 24-hour urinary protein quantification was 5.9 (4.0, 8.9) g, and crescent percentage was 64.71% (54.55%, 73.68%). In the study, 23 patients in each group were matched after propensity score matching The median follow-up time was 7 (1, 26) months. As a whole, 29 patients (63.0%) reached ESKD, including 16 patients (69.6%) in the adjunctive plasma exchange therapy group and 13 (56.5%) patients in the intensive immunosuppressive therapy group.. There were no stastical difference between the two groups in terms of baseline eGFR [14.30 (9.31, 17.58) mL/(min·1.73 m2) vs. 11.45 (5.59, 20.79) mL/(min·1.73 m2)], 24-hour urinary protein (7.4±3.4) g vs. (6.6±3.8) g, crescent percentage 64.49%±13.23% vs. 66.41%±12.65% and the proportion of patients received steroid therapy[23 (100.0%) vs. 21 (91.3%)] (All P>0.05). Kaplan-Meier survival analysis demonstrated that there was no significant difference in renal survival rate between the two groups (Log-rank test, P=0.933). CONCLUSION: The adjunctive plasma exchange therapy in addition to conventional intense immunosuppressive therapy did not additionally improve the prognosis of crescentic IgA nephropathy.

[Thoughts and suggestions on co-administration of seasonal influenza vaccine and COVID-19 vaccine].

In the context of the global pandemic of COVID-19, the epidemic intensity, epidemic characteristics and infection risk of influenza have presented new features. COVID-19 and influenza have simultaneously emerged in many regions of the world. COVID-19 and influenza are similar in terms of transmission mode, clinical symptoms and other aspects. There are also similarities in the mechanism of influenza virus and novel coronavirus on cells. At the same time, it is feasible and significant to do a good job in the prevention and control of COVID-19 and influenza. This paper discusses the relevant strategies and measures for the joint prevention and control of influenza and novel coronavirus from the aspects of influenza vaccination to prevent co-infection, simultaneous vaccination of influenza vaccine and novel coronavirus vaccine, etc., and puts forward corresponding thoughts and suggestions, in order to provide scientific support for the formulation of strategies on seasonal influenza vaccine and novel coronavirus vaccination.

Retraction Note: Circular RNA circ_0079593 promotes glioma development through regulating KPNA2 expression by sponging miR-499a-5p.

The article "Circular RNA circ_0079593 promotes glioma development through regulating KPNA2 expression by sponging miR-499a-5p, by Z. Yang, C. Li, X.-Y. Fan, L.-J. Liu, published in Eur Rev Med Pharmacol Sci 2020; 24 (3): 1288-1301-DOI: 10.26355/eurrev_202001_20186-PMID: 32096160" has been retracted by the authors as they cannot ensure the reliability of the results (Figure 6C could not be repeatedly verified). The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/20186.

Effects of early post-hatch feeding on the growth performance, hormone secretion, intestinal morphology, and intestinal microbiota structure in broilers.

This study aimed to investigate the effects of time access to post-hatch feeding on the growth performance, hormone secretion, intestinal morphology, and intestinal microbiota structure of broilers. A total of 900 broilers were randomly allocated to 3 treatment groups, with 6 replicates of 50 broilers each. The 3 treatments were: immediate feeding (Group 2 h), delayed access to feed for 24 h (Group 24 h), and delayed access to feed for 48 h (Group 48 h). The experiment lasted for 50 d. Results revealed that Group 2 h had a higher average daily gain (ADG) and average daily feed intake (ADFI) as well as a lower feed-to-gain ratio (F/G) than Group 48 h during the starter period (P < 0.05). Compared with Group 48 h, broilers in Group 2 h exhibited significantly elevated villus height (VH) and villus height to crypt depth ratio (VH: CD) in the duodenum, increased Occludin, and Claudin-1 mRNA expression in the jejunum but decreased crypt depth (CD) in the duodenum at 50 d (P < 0.05). Meanwhile, broilers in Groups 2 h and 24 h had increased glycogen (Gn) and protein (Pro) levels in breast muscle and TG levels in the liver, as well as a higher concentration of serum T3, T4, and IGF-1 compared with Group 48 h at 21 d (P < 0.05). Besides, intestinal microbiota consisted primarily of Firmicutes, Bacteroidetes, and Proteobacteria at the phylum level at 21 d and 50 d; at the genus level, broilers in Group 2 h displayed significantly reduced abundance of Escherichia at 21 d and Bacteroides at 50 d compared with Group 48 h (P < 0.05). Collectively, these findings signal that early post-hatch feeding measures, especially at 21 d, improve hormone secretion, intestinal morphology, and the growth performance of broilers by enhancing intestinal health and modulating the intestinal microbiota.

Probing

The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

[Clinical analysis of 15 cases with myeloperoxidase antineutrophil cytoplasmic antibody associated hypertrophic pachymeningitis].

To study the clinical features of myeloperoxidase(MPO) antineutrophil cytoplasmic antibody (ANCA) associated hypertrophic pachymeningitis (HP). Clinical data of 15 cases diagnosed with MPO-ANCA vasculitis complicated with HP were retrospectively analyzed. Nine cases were males and the other 6 were females, with an average age of (58±8) years. All cases presented with chronic headache. Contrast-enhanced magnetic resonance imaging (MRI) scan showed local or diffused thickening of cerebral and/or spinal dura matter while brain parenchyma were normal. Nine cases developed multiple cranial nerve paralysis, with trigeminal nerve and auditory nerve involved most commonly. The main clinical manifestations were facial pain, hearing loss and tinnitus. Two cases were complicated with hypertrophic spinal pachymeningitis (HSP) and 4 cases were complicated with pulmonary diseases. Positive serum perinuclear pattern ANCA (pANCA) and MPO could be found in all cases, positive serum IgG4 was seen in two patients. erythrocyte sedimentation rate(ESR;25-116 mm/1h) and C-reactive protein (CRP;29.02-146.00 mg/L) were both elevated in 14 cases. Nine cases had elevated intracranial pressure[180-235 mmH2O (1 mmH2O=0.009 8 kPa)] and abnormal protein level (457.6-3710.0 mg/L) in cerebrospinal fluid. Six cases were treated with glucocorticoids (prednisone 20-60 mg/d) and 9 cased with glucocorticoids and immunosuppressants (methotrexate 15 mg/week or cyclophosphamide 100 mg/d po). All patients achieved remission. MPO-ANCA associated HP is a special type of central nervous system involvement in ANCA associated vasculitis (AAV). It rarely involves the lung or kidney. Steroids and immunosuppressive agents are effective. In HP with unknown underlying diseases, it is suggested to screen ANCA and IgG4 tests for AAV or IgG4-related disease.

[Establishment of morphological reference values for the differential count of white blood cells in peripheral blood smear, as well as nucleated cells and megakaryocytes in bone marrow smear].

Objective: To establish the morphological reference values for the differential count of white blood cells in peripheral blood smear as well as nucleated cells and megakaryocytes in bone marrow smear. Methods: From April 2012 to June 2020, 4 221 healthy donors for hematopoietic stem cell transplantation in Hebei Yanda Lu Daopei Hospital were selected. The median age was 36 (3-72) years old, including 2 520 males and 1 701 females. They were divided into four groups according to age: children group, with age≤14 years old [n=334, 11 (3-14) years old], youth group, with age >14 years old and <45 years old [n=2 855, 33 (15-44) years old], middle-aged adult group, with age ≥45 years old and < 60 years old [n=929, 49 (45-59) years old], and older adult group, with age ≥60 years old [n=103, 62 (60-72) years old]. Gender subgroups were established in each age group. According to different hematopoietic characteristics, the children group were divided into two subgroups: children group 1 [n=48, 6 (3-7) years old] and children group 2 [n=286, 11 (8-14) years old]. According to the clinical routine, 100 white blood cells in peripheral blood, 200 nucleated cells in bone marrow, and cell numbers/4.5 cm2 for megakaryocytes were classified and counted. The results of cell count in different age and gender groups were compared, and the reference values of morphological classification were established for different groups with statistical or clinical significance. Results: Due to the existence of statistically significant differences between children and adult groups and different gender subgroups in adults (all P<0.05), the reference values were established for children group and adult gender subgroups. The counts of segmented neutrophils and lymphocytes in peripheral blood were 46.65(43.97-49.32)% and 44.00(10.60-65.10)% in children group 1, 50.73(49.50-51.96)% and 39.55 (38.36-40.74)% in children group 2, and 57.00 (39.00-75.23) % and 33.00 (17.00-52.00) % in adult group, respectively. Bone marrow segmented neutrophils, orthochromatic erythroblasts, and mature lymphocytes were 11.54 (10.68-12.41)%, 14.20 (13.19-15.21)%, and 23.99 (22.06-25.92)% in children group 1, 12.50 (7.00-21.50)%, 15.00(9.50-25.50)%, and 21.02 (20.24-21.81)% in children group 2, 13.50 (7.50-21.00)%, 16.50 (10.50-26.00)%, and 15.50 (7.50-26.00)% in adult male group, and 14.50 (8.00-24.50)%, 14.50 (9.00-23.00)%, and 17.50 (8.50-29.00)% in adult female group, respectively. The myelopoiesis/erythropoiesis ratio in children group, adult male group and adult female group was 1.86∶1 (1.14∶1-3.23∶1), 1.96∶1 (1.12∶1-3.19∶1), 2.22∶1 (1.30∶1-3.69∶1), respectively. The numbers of granular megakaryocytes and thromocytogenic megakaryocytes were 138 (25-567) cells/4.5cm2 and 86 (13-328) cells/4.5 cm2 in children group, and 92 (13-338) cells/4.5 cm2 and 38 (3-162) cells/4.5 cm2 in adult group, respectively. Conclusion: The morphological reference values for the differential count of white blood cells in peripheral blood smear as well as nucleated cells and megakaryocytes in bone marrow smear are successfully established, which is helpful to improve the application of morphological examination in disease screening, diagnosis and monitoring.

[Effects of eye exercises on axial eye elongation in junior students].

Objective: To evaluate the association between the eye exercises and one-year axial eye elongation in grade 7 students in Beijing. Methods: Sampling was performed using a multistage random cluster approach, and 1 443 students of grade 7 were selected from 9 middle schools in 6 districts for the baseline survey. Data were collected by questionnaires and axial length measurement. Multiple linear regression analysis was used to evaluate the association between eye exercises and excessive axial eye elongation. Results: Among 1 197 (82.95%) students with complete information, the median (QR) age was 12.00 (1.00) years old, girls accounted for 44.28%, and the median (QR) axial eye elongation was 0.22 (0.18) mm. In the multiple linear regression analysis, the frequency of eye exercises was significantly correlated with excessive axial eye elongation in boys (ß=-0.135, 95%CI:-0.253--0.018) but not in girls (ß=-0.075, 95%CI:-0.207- 0.058) after adjusting for sex, age, body height, the number of myopic parents, time spent outdoors and time spent on reading and writing outside class; while the seriousness of eye exercises was not significantly associated with axial eye elongation in boys (ß=-0.028, 95%CI: -0.114-0.058) and girls (ß=-0.035, 95%CI: -0.134-0.064). Conclusion: The increased frequency of eye exercises is beneficial to control the axial eye elongation in boys in Beijing.

Cryogenic spectrometer for measuring the far-IR to millimeter-wave absorptivity of cosmic analog dusts.

We report on the design, construction, and performance of a custom apparatus built to measure the frequency- and temperature-dependent absorptivity of millimeter-wave light by cosmic analog dusts. We highlight the unique challenges faced as well as a few key innovations that are part of the instrument. Among those is an ultra-compact Fourier transform spectrometer. We have measured its effective frequency range and FWHM resolution to be 150-2100 GHz and ∼45GHz, respectively. Another innovation is a cold sample positioner whose temperature can be controlled within the range of 3.7-50 K. The use of a pulse-tube cryocooler results in a pulse-synchronous signal that dominates the detector (bolometer) signal. Methods used to address that challenge are also presented.

[Efficacy and safety of ticagrelor versus clopidogrel in Chinese patients with acute coronary syndrome treated with glycoprotein â ¡b/â ¢a receptor antagonist].

Objective: To explore the efficacy and safety of ticagrelor versus clopidogrel in acute coronary syndrome (ACS) Chinese patients using glycoprotein Ⅱb/Ⅲa inhibitor (GPI). Methods: The data from CCC-ACS (Improving Care for Cardiovascular Disease in China-ACS) project were systematically reviewed in ACS patients with GPI. The patients were divided into ticagrelor and clopidogrel groups. A logistic analysis and propensity score matching (PSM) were performed to compare occurrences of major cardiovascular events (MACE) and bleeding events between the two groups during hospitalization. Results: A total of 63 641 ACS patients were collected from 150 hospitals. Logistic regression analyses showed that there was no statistically significant difference in the reduction of MACE between ticagrelor and clopidogrel when using GPI (OR=0.881, 95%CI 0.599-1.296; P=0.521). However, major bleeding rate was higher in the ticagrelor group than that in the clopidogrel group (OR=1.401, 95%CI 1.075-1.852; P=0.013). Similar results were observed after PSM. No statistic difference in MACE between the ticagrelor and clopidogrel group (OR=0.919, 95%CI 0.613-1.376; P=0.681). Major bleeding rate was higher in the ticagrelor group (OR=1.559, 95%CI 1.130-2.150; P=0.007). Conclusion: In ACS patients with GPI, ticagrelor did not reduce MACE, but increased the major bleeding risk compared with clopidogrel.

[Analysis of bleeding risk in percutaneous renal biopsy in Tibet].

OBJECTIVE: To observe the postoperative bleeding after percutaneous renal biopsy (PRB) in Tibet, To analyze and summarize the risk factors associated with bleeding in high altitude patients to improve the safety of surgery. METHODS: A retrospective analysis of 150 cases of PRB in the Department of Nephrology, People's Hospital of Tibet Autonomous Region from May 2016 to May 2018 were carried out, and the correlations between the potential risk factors (gender, age, blood pressure, hemoglobin, platelet, serum creatinine) and postoperative bleeding events were analyzed. RESULTS: During the study period, the 150 patients receiving procedure of PRB were enrolled in our hospital, with an average age of (41.2±15.6) years, of whom 58.7% (88/150) were male, 41.3% (62/150) were female, and major bleeding complications occurred in 12 biopsies (8.0%, 12/150). Six cases for men and women, respectively. The mean age in the bleeding group seemed to be higher than that in the non-bleeding group [(48.3±20.0) years vs. (40.6±15.1) years, P=0.099]. There was no significant difference in the incidence of hypertension, hemoglobinemia, urea nitrogen and prothrombin time between the two groups. The level of serum creatinine in the hemorrhage group seemed to be higher than that in the non-bleeding group (P=0.090), and the time of the hemorrhagic group was longer than that in the non-bleeding group (P=0.069). The platelet count in the bleeding group was significantly lower than that in the non-bleeding group (P < 0.05). Multivariate Logistic regression analysis showed that the prolonged activation of partial prothrombin time and lower platelet count had a relatively high risk of bleeding, which was statistically significant (P=0.079, P=0.082). CONCLUSION: PRB is safe and reliable on the whole in plateau areas; Old age, low platelet count, decreased renal function and prolonged activated partial coagulation time are related to postoperative bleeding of PRB, and hyperhemoglobin is not a risk factor for bleeding. High hemoglobin is not a risk factor for postoperative bleeding of PRB at high altitude.

[The value of MRI plain scan and DWI in the diagnosis of brain metastases].

Objective: To investigate the clinical value of magnetic resonance imaging (MRI) plain scan and diffusion weighted imaging (DWI) in the diagnosis of brain metastases. Methods: The MRI plain imaging findings of 105 cases with brain metastases and 103 cases without brain metastases confirmed by enhanced MRI examination and clinical diagnosis were retrospectively analyzed. The comparisons of plain MRI findings including T1 weighted image (T1WI), T2WI, T2/fluid attenuated inversion recovery (T2/FLAIR), DWI and apparent diffusion coefficient (ADC) values were made between brain metastases and non-brain metastases. Results: The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T1WI in the brain metastatic group were 54, 23, 9 and 19, respectively, while the numbers of hypo-intensity and iso-intensity in the non-brain metastatic group were 52 and 51, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI in the brain metastatic group were 1, 9, 72 and 23, respectively, while the numbers of iso-intensity and hyper-intensity in the non-brain metastatic group were 11 and 92, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, hyper-intensity and heterogeneous signal intensity of DWI in the brain metastatic group were 4, 31 and 65, respectively, while the number of hyper-intensity in the non-brain metastatic group was 4 and others were iso-intensity, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI/FLAIR in the brain metastatic group were 4, 5, 60 and 36, respectively, while all cases in the non-brain metastatic group were hyper-intensity, with statistically significant difference (P<0.001). The number of lesion accompanied with peripheral edema in the brain metastatic group were 69 cases, significantly higher than 0 cases in the non-brain metastatic group (P<0.001). The mean ADC value in the brain metastatic group were (0.919±0.019)×10(-3) mm(2)/s, significantly lower than (1.098±0.012)×10(-3) mm(2)/s of non-brain metastatic group (P<0.05). Conclusions: For patients with a history of primary malignancy, the MRI plain scan signals of T1WI, T2WI, T2WI/FLAIR and DWI are significantly different between brain metastatic tumor and non-metastatic tumor. The mixed signal, peripheral edema and the restriction of DWI diffusion indicate brain metastases. The combined application of the above parameters can improve the diagnostic efficacy of predicting brain metastases, and contrast enhancement MRI examination should be performed for the confirmation of diagnosis.