Mesenchymal stem cells(MSC) have the ability to self-renew and differentiate into tissues of mesodermal origin (osteocytes, adipocytes, chondrocytes), and the cellular constituents of the microenvironment, largely derive from a common progenitor of mesenchymal origin. MSC themselves and their large numbers of progeny form three kinds of niches(osteoblastic niche, stromal niche and adipocyte niche)which have a fully competent microenvironment to provide appropriate signals via production of soluble factors and cell contact interactions of adhesion molecules, by which they play the role in supporting haemopoiesis and differentiation. Many of the discoveries described herein may contribute to future clinical treatments for hematopoietic, including cancer.

Objective To study the clinical features and differential diagnosis of Langerhans cell histiocytosis (LCH).Methods A case of LCH was reported and the literatures were reviewed.Results The of multisystem LCH patient,presented with a diabetes insipidus (DI) and panhypopituitarism,was 44 years old,and developed costal,tibial and femoral multiple lesions.The final diagnosis as LCH was made based on biopsy of tibia and lymph nodes.The biopsy specimen showed that the cells were infiltrated exhibiting the characteristic morphologic features of Langerhans cell (LC) with a convoluted shape,elongated nuclei exhibiting longitudinal grooves,and immunohistochemistry results revealed positive LC for the S-100,CD1a and Langerin immunostaining.Conclusions LCH may range from a solitary lytic bone lesion (for example eosinophilic granuloma) with a favorable course to a fatal disseminated leukaemia-like form.LCH typically involves the bone,lesions almost can be found in all organs.DI and CNS involvement often present as a puzzling syndrome,which renders the diagnosis problematicly,and often delays the diagnosis of LCH.The damage to the pituitary/hypothalamus axis results in life-long hormonal replacement therapy.

20?10~9/L. This regimen was given for one course for induction, and was followed by conventional chemotherapy as maintenance or consolidation when complete remission(CR) achieved, or succeeding with other treatment when no response could be observed. Results Six patients achieved CR (54.5%) and one achieved partial remission (PR)(9.1%) with one course of treatment. Among 6 of 11 patients with CR, 5 relapsed at 2,3,6,8 and 16 months respectively. Three relapsed patients were retreated with the same protocol but achieved only one partial responses. Nine of the 11 patients had been died and their mean survival (since induction chemotherapy) was 9.2 months. Infectious complications during cytopenia were less serious than conventional chemotherapy withno treatment-related.Conclusion This moderate intensity protocol with G-CSF priming is effective and safe but remissions are of short duration.

ObjectiveTo explore the impact of the interaction between occupational and non-occupational noise exposure on the risk of high-frequency hearing loss (HFHL) in noise-exposed workers. Methods A total of 602 male workers with normal hearing, engaged in an automobile manufacturing company between 2016 and 2018, were selected as the study subjects using the retrospective cohort study method. Pure-tone audiometry and questionnaire surveys were conducted on the workers. The Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression model were used to analyze the interaction between occupational and non-occupational noise exposure and the risk of HFHL in these workers. Results The prevalence of HFHL of the workers was 34.1% in 2020, without any cases of speech frequency hearing loss. Kaplan-Meier survival analysis result showed that the risk of HFHL increased in workers with excessive national occupational noise exposure intensity, self-reported noisy living environments, and both excessive national occupational noise exposure intensity and self-reported noisy living environments (all P<0.01). The results of the Cox proportional hazards model showed that the combined effect of excessive national occupational noise exposure intensity and self-reported noisy living environments [relative risk (RR)=2.40, P<0.01] was higher than the individual effects of excessive national occupational noise exposure intensity (RR=2.09, P<0.01) and self-reported noisy living environments (RR=2.39, P<0.01). There was an antagonistic effect between excessive national occupational noise exposure intensity and self-reported noisy living environments (interaction index <1.00). Conclusion Both occupational and non-occupational noise exposure can increase the risk of HFHL in noise-exposed workers, and there is an interaction between them.

Objective: To identify clinical and molecular signatures for predicting response to decitabine (DAC) in patients with myelodysplastic syndrome (MDS) and related neoplasms. Methods: The clinical characteristics of 109 patients with MDS and related neoplasms who were treated with DAC were analyzed retrospectively and the next target sequencing was performed to define recurrently mutated genes in these disease samples, to examine the association of the clinical and molecular signatures with response to DAC treatment. Results: Of 109 MDS and related neoplasms patients, there were 70 males and 39 females, the median age was 61 years old (ranges: 17-85 years old) . According to the international prognostic scoring system (IPSS) , 46 cases were included in the relatively low risk group (low risk and intermediate-1 risk) , 63 in the relative high risk group (intermediate-2 and high risk) . There were 21 cases with complex karyotype, 17 chromosome 7 abnormality and 17 monosomal karyotype. The median courses of DAC treatment was 4 (2-11) . A total of 74 patients achieved response (67.9%) and 30 (27.5%) achieved complete response (CR) . Univariate analysis found that CR was higher in patients with high risk of IPSS, complex karyotypes, monosomal karyotypes, chromosome 7 abnormality, and platelet doubling after one cycle of DAC treatment. Patients with TP53 gene mutation were more likely to receive CR, 10 of 15 patients with TP53 mutations achieved CR. (66.7%) , which was significantly higher than that of the patients without TP53 gene mutation (21.3%) (P=0.001) . Multivariate analysis showed that TP53 gene mutation, platelet doubling after one cycle of DAC treatment and the complex karyotype were independent prognostic factors for CR. Of them, TP53 gene mutation is the strongest predictor (OR=4.39, 95%CI, 1.20-16.06, P=0.026) . Conclusion TP53 mutation, platelet doubling after one cycle of DAC treatment and complex karyotypes could predict CR to DAC.

ObjectiveTo analyze the research status and trends in low-level occupational benzene exposure. Methods Articles on low-level occupational benzene exposure from Chinese and English journals from January 1st, 2000, to December 31th, 2022 were retrieved using the Web of Science and the China National Knowledge Infrastructure, and a bibliometric analysis was conducted. Results A total of 327 articles were included in the analysis, comprising 216 English articles and 111 Chinese articles. i) The number of articles published in English fluctuates greatly over the years, without a trend of continuous growth or decline. Authors from 359 research institutions in 45 countries and regions have published relevant English articles in 97 kinds of journals, involving 281 grants from 226 foundations. The top three countries in terms of articles amount were the United States, Italy, and China, with 81, 46, and 43 papers, respectively. The English articles mainly focused on mechanistic research at the genetic level, such as hematotoxicity, oxidative stress, and DNA damage. ii) The number of Chinese articles increased gradually after 2012, with the growth peak in 2017. Authors from 127 research institutions in 26 provinces, autonomous regions, and municipalities published Chinese articles in 51 kinds of journals, involving 154 grants from 78 foundations. Chinese articles tended to focus on benzene-induced hematotoxicity and occupational health damage. Conclusion Most studies on low-level occupational benzene exposure were conducted in China, the United States and Italy, focused on hematotoxicity. Monitoring international research topics and hotspots of the field has certain reference value for related research in China.

OBJECTIVETo determine the incidence and risk factors of HCV infection among heroin addicts who were receiving methadone maintenance treatment(MMT)in Dehong prefecture, Yunnan province.

METHODSAll heroin addicts who were HCV negative at the initiation of MMT in June 2005 through March 2012, in Dehong prefecture, were included in this cohort analysis. HCV incidence was calculated and related risk factors determined by using Cox proportional hazard regression model.

RESULTSA total of 2390 MMT clinic attendants were qualified for this cohort study by March 2012. 731(30.6%) of them had never received any follow-up HCV testing so were recognized as loss to follow-up. The other 1659 (69.4%) participants had received at least one follow-up HCV testing and were observed for a total of 3509.12 person-years(py). During this period 99 new HCV infections or HCV sero-converters were identified. The overall HCV incidence was 2.82/100 py and was 3.62/100 py for 2006, 5.36/100 py for 2007, 6.71/100 py for 2008, 2.56/100 py for 2009, 1.90/100 py for 2010, and 0.44/100 py for 2011, respectively. Results from multiple regression analysis, using Cox proportional hazard model, indicated that after controlling for confounding variables, those who were unemployed, being injecting drug users(IDUs)or HIV positive at entry into the MMT program were more likely to be newly infected with HCV or HCV sero-converted during the follow-up period than those who were peasants, non-IDUs or HIV negative at entry into the MMT program(HR = 2.02, 95% CI:1.18-3.48; HR = 9.05, 95% CI:5.49-14.93; HR = 2.12, 95% CI: 1.37-3.56), respectively.

CONCLUSIONThe incidence of HCV infection among MMT clinic attendants was decreasing since 2009 in Dehong prefecture. Those who were unemployed, injecting drug users and HIV positive were at higher risk of HCV infection.

Adolescent ; Adult ; Aged ; China ; epidemiology ; Cohort Studies ; Drug Users ; Female ; Hepatitis C ; epidemiology ; Humans ; Incidence ; Male ; Methadone ; therapeutic use ; Risk Factors ; Substance-Related Disorders ; drug therapy ; epidemiology ; virology

OBJECTIVETo study the HIV incidence and risk factors among sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province.

METHODSA cohort of sero-negative spouses of the HIV patients had been developed and followed up since November, 2005. HIV new infections and related behaviors had been investigated every six months.

RESULTSBy the end of June, 2008, 790 sero-negative spouses of HIV patients had been recruited, of whom 702 were followed-up for at least one time. During the total 1202.35 person-years, 31 new HIV infections were identified, with an overall incidence of 2.58/100 person-years. The HIV incidence rates were 2.22/100 person-years in 2006, 2.95/100 person-years in 2007 and 2.74/100 person-years in 2008. Data from the Cox proportional hazard regression model indicated that those who resided in Yingjiang county [hazard ratio (HR) = 4.37, 95%CI: 1.48 - 12.90, P = 0.008], ever using drugs (HR = 3.49, 95%CI: 1.09 - 11.18, P = 0.035), or having an HIV-infected spouse who never exposed to antiretroviral treatment (HR = 3.60, 95%CI: 1.41 - 9.16, P = 0.007) were at higher risk for HIV infection.

CONCLUSIONSero-negative spouses of HIV patients in Dehong prefecture of Yunnan province had a relatively high incidence of HIV new infection during 2006-2008. More efforts should put on those people living in these areas, having a history of drug use or having an HIV-infected spouse who had never been exposed to antiretroviral treatment.

Adolescent ; Adult ; China ; epidemiology ; Female ; HIV Infections ; epidemiology ; HIV Seronegativity ; Humans ; Incidence ; Male ; Middle Aged ; Prospective Studies ; Risk Factors ; Sexual Behavior ; Spouses ; Young Adult

OBJECTIVECompare the characteristics of magnetic resonance imaging（MRI）liver T2*, cardiac T2* and serum ferritin on the assessment of iron overload.

METHODSA total of sixty-nine patients from November 2011 to June 2014 were enrolled in this study. Their cardiac and liver iron concentration levels were measured through MRI examination, with other clinical data were collected to perform statistical analysis.

RESULTSThe correlation between liver T2* and adjusted serum ferritin（ASF） was statistically significant（P=0.003）. However, no significant correlation was found between cardiac T2* and liver T2*, ASF, respectively. According to the statistical analysis of the 69 cases, it is found that the number of iron overload cases diagnosed by liver T2* was 62 and 20 cases were severe iron overload （32.26%）; the number of iron overload cases diagnosed by ASF was 47 and 14 cases were severe iron overload（29.79%）, while the number of iron overload cases diagnosed by cardiac T2* was only 25 and no severe iron overload cases.

CONCLUSIONSince SF was affected by other factors, it cannot reflect the level of iron overload in human body objectively. Now, liver T2* has become the gold standard for assessment of iron overload because of its good reliability and repeatability. However, cardiac T2* cannot correctly be used as assessment for iron overload, and it is only a method of evaluating the level of cardiac iron deposition.

Ferritins ; blood ; Hematologic Diseases ; diagnosis ; Humans ; Iron Overload ; diagnosis ; Liver ; Magnetic Resonance Imaging ; Myocardium ; Reproducibility of Results

To evaluate the application of midpalatal cortex osteotomy assisted rapid maxillary expansion for correction of maxillary transverse deficiency in young adults.Fourteen young adult patients with maxillary transverse deficiency were treated with midpalatal cortex osteotomy assisted rapid maxillary expansion. Lateral cephalogram and cone beam CT (CBCT) were taken before and 3 months after treatment. The width of basal bone, arch of maxilla and the torque of anchorage teeth were compared before and after treatment.The width of dental arch of maxilla was increased from 40.54±5.26 mm before treatment to 46.83±5.83 mm after treatment (<0.05) and the width of basal bone was increased from 64.86±4.16 mm to 67.60±4.66 mm (<0.05) at the plane of the maxillary first molars. Accordingly, the width of dental arch of maxilla was increased from 31.92±2.55 mm to 38.65±3.14 mm (<0.05) and the width of basal bone was increased from 43.33±3.70 mm to 45.78±4.57 mm (<0.05) at the plane of first premolar. And the torque of maxillary anchorage teeth were increased (<0.05).Midpalatal cortex osteotomy assisted rapid maxillary expansion is an effective micro-invasive method in expansion of basal bone and arch of maxilla for young adult patients with maxillary transverse deficiency.