Multi-perspective comparison of the immune microenvironment of primary colorectal cancer and liver metastases.

BACKGROUND: Liver metastases are a major contributor to the poor immunotherapy response in colorectal cancer patients. However, the distinctions in the immune microenvironment between primary tumors and liver metastases are poorly characterized. The goal of this study was to compare the expression profile of multiple immune cells to further analyze the similarities and differences between the microenvironments of liver metastases and the primary tumor. METHODS: Tissues from 17 patients with colorectal cancer who underwent resection of primary and liver metastases was analyzed using multispectral immunofluorescence. The expression of multiple immune cells (CD8, Foxp3, CD68, CD163, CD20, CD11c, CD66b, CD56, PD-L1, INF-γ, Ki67 and VEGFR-2) in the tumor center (TC), tumor invasive front (< 150 µm from the tumor center, TF) and peritumoral region (≥ 150 µm from the tumor center, PT) was evaluated via comparison. The expression of CD68 and CD163 in different regions was further analyzed based on the cell colocalization method. In addition, different immune phenotypes were studied and compared according to the degree of CD8 infiltration. RESULTS: The expression trends of 12 markers in the TF and TC regions were basically the same in the primary tumor and liver metastasis lesions. However, in comparison of the TF and PT regions, the expression trends were not identical between primary and liver metastases, especially CD163, which was more highly expressed in the PT region relative to the TF region. In the contrast of different space distribution, the expression of CD163 was higher in liver metastases than in the primary foci. Further analysis of CD68 and CD163 via colocalization revealed that the distribution of macrophages in liver metastases was significantly different from that in the primary foci, with CD68-CD163+ macrophages predominating in liver metastases. In addition, among the three immunophenotypes, CD163 expression was highest in the immune rejection phenotype. CONCLUSIONS: The immune cells found in the primary tumors of colorectal cancer differed from those in liver metastases in terms of their spatial distribution. More immunosuppressive cells were present in the liver metastases, with the most pronounced differential distribution found for macrophages. CD68-CD163+ macrophages may be associated with intrahepatic immunosuppression and weak immunotherapeutic effects.

BOLD signal physiology: Models and applications.

The BOLD contrast mechanism has a complex relationship with functional brain activity, oxygen metabolism, and neurovascular factors. Accurate interpretation of the BOLD signal for neuroscience and clinical applications necessitates a clear understanding of the sources of BOLD contrast and its relationship to underlying physiology. This review describes the physiological components that contribute to the BOLD signal and the steady-state calibrated BOLD models that enable quantification of functional changes with a separate challenge paradigm. The principles derived from these biophysical models are then used to interpret BOLD measurements in different neurological disorders in the presence of confounding vascular factors related to disease.

Results of a Search for Sub-GeV Dark Matter Using 2013 LUX Data.

The scattering of dark matter (DM) particles with sub-GeV masses off nuclei is difficult to detect using liquid xenon-based DM search instruments because the energy transfer during nuclear recoils is smaller than the typical detector threshold. However, the tree-level DM-nucleus scattering diagram can be accompanied by simultaneous emission of a bremsstrahlung photon or a so-called "Migdal" electron. These provide an electron recoil component to the experimental signature at higher energies than the corresponding nuclear recoil. The presence of this signature allows liquid xenon detectors to use both the scintillation and the ionization signals in the analysis where the nuclear recoil signal would not be otherwise visible. We report constraints on spin-independent DM-nucleon scattering for DM particles with masses of 0.4-5 GeV/c^{2} using 1.4×10^{4} kg day of search exposure from the 2013 data from the Large Underground Xenon (LUX) experiment for four different classes of mediators. This analysis extends the reach of liquid xenon-based DM search instruments to lower DM masses than has been achieved previously.

The influence of age, gender and race/ethnicity on the composition of the human axillary microbiome.

OBJECTIVE: The microbial community plays an important role in the generation of human axillary odour by transforming odourless natural secretions into volatile odorous molecules. A limited number of traditional culturing methods and molecular based research have been performed to characterize the human axillary microbiome in small collection sample sizes. Moreover, only a few have considered the interpersonal variations across age, gender or race/ethnicity, and none have included all three variables within one single study. The aim of this study was to characterize the axillary microbiome of healthy subjects across different age groups, genders and races/ethnicities in a large sample size. METHODS: The underarm skin swab samples were collected from 169 healthy subjects. The axillary microbiome was analysed by IS-pro, a clinically validated high-throughput DNA fingerprinting technique. RESULTS: The results indicate that the senior subjects (55+) tend to have a higher number of total bacterial than younger adults (of a defined age). The diversity of odour causing bacteria, e.g. corynebacteria, increases with age. Among the three races/ethnicities studied, East Asians have a unique microbial composition compared to Caucasians and Hispanics, which may contribute to the different odour profiles observed among the races/ethnicities studied. CONCLUSION: Human axillary microbiome varies by age, gender and race/ethnicity. This study has provided an unprecedented fundamental knowledge about the axillary microbiota as a function of age, gender and race/ethnicity.

OBJECTIF: La population microbienne joue un rôle important dans la génération de l'odeur axillaire par la transformation de sécrétions naturelles inodores en molécules odorantes et volatiles. Un nombre limité d'études par culture traditionnelle et de recherches moléculaires ont été réalisées pour caractériser le microbiome axillaire humain dans des échantillons de prélèvements de petite taille. En outre, seules quelques-unes de ces études ont tenu compte des variations interpersonnelles à travers l'âge, le sexe ou la race/l'origine ethnique, et aucune n'a inclus les trois variables dans une seule et même recherche. Le but de cette étude est de caractériser le microbiome de sujets sains est de réunir différents groupes d'âge, sexes et races/origines ethniques dans un échantillon important. MÉTHODES: Les échantillons de frottis cutanés de l'aisselle ont été recueillis sur 169 sujets sains. Le microbiome axillaire a été analysé par ISpro, une technique cliniquement validée d'empreinte ADN à haut débit. RÉSULTATS: Les résultats indiquent que les sujets séniors (55 ans et plus) ont tendance à présenter un plus grand nombre de bactéries que les adultes plus jeunes (d'un âge défini). La diversité des bactéries odorantes, par exemple, de type corynebacterium, augmente avec l'âge. Parmi les trois races/origines ethniques étudiées, les populations asiatiques présentent une composition microbienne unique par rapport aux populations caucasiennes et hispaniques, ce qui pourrait contribuer aux différents profils d'odeur observés dans les races/origines ethniques prises en compte. CONCLUSION: Le microbiome axillaire varie selon l'âge, le sexe et la race/l'origine ethnique. Cette étude fournit une connaissance fondamentale sans précédent sur la flore axillaire en fonction de l'âge, du sexe et de la race/l'origine ethnique.

Quantitative imaging of bone-cartilage interactions in ACL-injured patients with PET-MRI.

OBJECTIVE: To investigate changes in bone metabolism by positron emission tomography (PET), as well as spatial relationships between bone metabolism and magnetic resonance imaging (MRI) quantitative markers of early cartilage degradation, in anterior cruciate ligament (ACL)-reconstructed knees. DESIGN: Both knees of 15 participants with unilateral reconstructed ACL tears and unaffected contralateral knees were scanned using a simultaneous 3.0T PET-MRI system following injection of 18F-sodium fluoride (18F-NaF). The maximum pixel standardized uptake value (SUVmax) in the subchondral bone and the average T2 relaxation time in cartilage were measured in each knee in eight knee compartments. We tested differences in SUVmax and cartilage T2 relaxation times between the ACL-injured knee and the contralateral control knee as well as spatial relationships between these bone and cartilage changes. RESULTS: Significantly increased subchondral bone 18F-NaF SUVmax and cartilage T2 times were observed in the ACL-reconstructed knees (median [inter-quartile-range (IQR)]: 5.0 [5.8], 36.8 [3.6] ms) compared to the contralateral knees (median [IQR]: 1.9 [1.4], 34.4 [3.8] ms). A spatial relationship between the two markers was also seen. Using the contralateral knee as a control, we observed a significant correlation of r = 0.59 between the difference in subchondral bone SUVmax (between injured and contralateral knees) and the adjacent cartilage T2 (between the two knees) [P < 0.001], with a slope of 0.49 ms/a.u. This correlation and slope were higher in deep layers (r = 0.73, slope = 0.60 ms/a.u.) of cartilage compared to superficial layers (r = 0.40, slope = 0.43 ms/a.u.). CONCLUSIONS: 18F-NaF PET-MR imaging enables detection of increased subchondral bone metabolism in ACL-reconstructed knees and may serve as an important marker of early osteoarthritis (OA) progression. Spatial relationships observed between early OA changes across bone and cartilage support the need to study whole-joint disease mechanisms in OA.

[Antagonistic effect of quercetin on PM2.5 toxicity in the rat's embryonic development in vitro].

OBJECTIVE: To explore the antagonistic effect of quercetin on fine particulate matter (PM2.5)-induced embryonic developmental toxicity in vitro. METHODS: PM2.5 was collected on glass fiber filters by PM2.5 samplers during the heating period of Dec. 2015 to Mar. 2016 in an area of Haidian District, Beijing City. The sampled filters were cut into 1 cm×3 cm pieces followed by sonication. The PM2.5 suspension was filtered into a 10 cm glass dish through 8 layers of sterile carbasus and stored at -80 °C until freeze drying. Frozen PM2.5 suspension was dried by vacuum freeze-drying. In vitro post-implantation whole embryo culture was used in this study. Pregnant rats with 9.5 gestation days (GD) were killed by cervical dislocation and the uteri were removed into sterile Hank's solution. The embryos with intact yolk sacs and ecto placental cones were induced by PM2.5, and then subjected to intervention of quercetin at the doses of 0.1 µmol/L, 0.5 µmol/L, 1.0 µmol/L and 5.0 µmol/L, respectively. At the end of the 48 h culture period, the cultures were terminated, and all embryos were removed from the culture bottles and placed in prewarmed Hank's solution for evaluation. Morphological evaluation of the embryos was conducted under a stereomicroscope using the morphologic scoring system by Brown and Fabro. The mitochondrial reactive oxygen species (ROS) level was detected by FACSCalibur flow cyto-metry using MitoSOXTM Red staining. RESULTS: An obvious antagonistic effect was achieved through quercetin at the dose of 1.0 µmol/L, which could result in an increase of visceral yolk sac (VYS) diameter, crown-rump length and head length, somite number, and the differentiation of visceral yolk sac vascular vessels. The scores of allantois, flexion, heart, hind brain, midbrain, forebrain, auditory system, visual system, olfactory system, branchialarch, maxillary process, forelimb bud and hindlimb bud also revealed a significant increase and the relative mitochondrial ROS level of embryonic cells was significantly decreased when compared with PM2.5 group. Although quercetin at the doses of 0.1 µmol/L, 0.5 µmol/L, 5.0 µmol/L also exhibited protective effects against PM2.5-induced embryonic developmental toxicity, the protective effect was weaker when compared with the dose of 1.0 µmol/L. CONCLUSION: Quercetin at proper dose may be of great benefit for the development of embryos exposed to PM2.5 in the uterus of the rats. Quercetin provides an effective strategy for the prevention of PM2.5-induced embryonic developmental toxicity. Clearance of mitochondrial ROS may be one of its mechanisms.

[The composition of gut microbiota in infant and its influencing factors].

Gut microbiota provide enzymes and additional biochemical metabolic pathways for the host, which together with the host genome and the external environment, influence the body function. The composition of gut microbiota in infant is closely related to health in later life. However, it is influenced by many factors, including delivery mode, feeding pattern, prenatal diet, pregnancy psychology and antepartum antibiotic treatment. Vaginal delivery and breastfeeding is beneficial for shaping gut microbiota, while cesarean section and formula feeding would reduce the amount of gut dominant bacteria. In addition, inappropriate diet during pregnancy, prenatal stress and antepartum antibiotic treatment alters bacterial colonization of the gut in infant.

Efficacy of oral moxifloxacin for aerobic vaginitis.

The purpose of this study was to investigate the therapeutic efficacy of oral moxifloxacin for aerobic vaginitis (AV). We also identified factors that are associated with therapeutic efficacy. This prospective study enrolled general gynecological outpatients at Tianjin Medical University General Hospital between September 2012 and May 2014. Women diagnosed with AV (n = 102) were recruited. All enrolled women were treated with oral moxifloxacin, 400 mg once daily for 6 days (one course). Therapeutic efficacy was evaluated based on microscopic criteria, and cure rates were calculated. Women who were microscopically improved (but not cured) received a second course of therapy. Women classified with microscopic failure were treated using other strategies. Univariate and multivariate logistic regression analysis was used to identify factors that may be associated with a cure after one course of therapy. After one course of therapy, 65.7 % (67/102) of women were cured, 29.4 % (30/102) of women were improved (but not cured), 4.9 % (5/102) of women failed to respond to the therapy. After two courses of therapy, 85.3 % (87/102) of women were cured, 9.8 % (10/102) of women were improved, 4.9 % (5/102) of women failed to respond to the therapy, and clinical improvement was achieved in additional women. In the multivariate logistic regression analysis, women with a baseline vaginal pH value of <5.0 had a 3.5-times higher chance of being cured, compared with those with a baseline vaginal pH value of ≥5.0 (OR, 3.503; 95 % CI, 1.278-9.601). Moxifloxacin is an effective therapeutic option for patients with AV. Most women with AV were cured with one course of moxifloxacin. For those with a higher vaginal pH value of ≥5.0 before treatment, two courses of therapy should be considered.

Haptic characterization of human skin in vivo in response to shower gels using a magnetic levitation device.

BACKGROUND/PURPOSE: Skin products such as shower gels have a direct impact on skin health and wellness. Although qualitative haptic characterization through explicit, verbal measures in consumer studies are often sufficient for general comparison on consumer perceived skin feel, a quantitative approach is desired to characterize minute changes in skin condition in response to various skin products. Prior research has sought to characterize the haptic properties of human skin in vitro and in vivo, but very few studies have compared the haptic effects of commercial skin products having relatively similar formulations. In addition, related studies have typically utilized simple, low-precision devices and fixtures. The purpose of this study was to use a precision magnetic levitation haptic device to characterize the frictional properties of human skin in vivo before, during, and after treatment with commercially available shower gels, to capture the entire cycle of consumer experience on skin feel. METHODS: A hybrid force-position control algorithm was used to control a precision magnetic levitation haptic device with silicone tactor to stroke the human skin (on the volar forearm) in vivo. Position and force data were collected from 32 human subjects using eight different commercially available shower gels, while stroking the skin before, during, and after treatment. The data were analyzed to produce coefficients of friction and viscous damping constant, which were used as metrics for comparing the effects of each shower gel type. Other factors investigated include skin test location, order, and subject age and gender. RESULTS: Results showed significant differences between the effects of eight various shower gels, especially after accounting for variance between subjects. Most notably, Shower Gel four with high level of petrolatum, along with Shower Gels five and six with low levels of castoryl maleate (a skin lipid analog), as well as Shower Gel two with high levels of vegetable oils yielded higher skin coefficients of friction 20 min after treatment, indicating higher levels of skin hydration than other shower gels without either high levels of skin beneficial agents or low levels of castoryl maleate. Conversely, Shower Gel eight treatment yielded the lowest skin coefficient of friction both immediately after rinsing and 20 min after treatment. In addition, when applied to the skin as un-lathered gels, Shower Gels six and seven with acrylate polymers yielded viscous damping constants twice that of other gels, while Shower Gel three yielded the lowest. When lathered into foam on skin, Shower Gel eight yielded the highest viscous damping constant, while Shower Gel three, along with Shower Gels one and five yielded lower values than others. CONCLUSION: The results of this study show that different shower gels do have significant measurable differences in their effects on skin properties, and that using a high-precision haptic device can be a useful tool for quantifying the haptic properties of skin in vivo.

[Immunomodulatory effect of oyster peptide on immunosuppressed mice].

OBJECTIVE: To evaluate the immunomodulating effect of oyster peptide on immunosuppressed mice. METHODS: ICR mice injected with cyclophosphamide (CTX) were adopted as the module group, with mice without treatment as the control group, and different dosages of oyster peptide (0.5 g/kg, 1.0 g/kg, and 2.0 g/kg) were given to the low, middle, and high groups for 15 days. The body weight, spleen, and thymus weight of the mice, structures under the microscope of the immune organs, numbers of white blood cells, ratios of T lymphocyte subsets, immune cytokines and numbers of nuclear cells, and DNA content in bone marrow were all assessed. RESULTS: Compared with the control group, the structures of thymus and spleen of the mice in the CTX group appeared obscure and shrunk when observed under microscope, the number of their white blood cells declined (P=0.04), the proportion of their CD3(+) T cells in peripheral blood declined (P=0.003), the proportion of their CD8(+) T cells in peripheral blood declined (P=0.002), the concentration of their IL-5 in peripheral blood significantly increased (P<0.01), the concentration of their nucleated cells and DNA density in bone marrow decreased (P=0.04, P<0.01). Oyster could improve the structures of thymus and spleen of the immunosuppressed mice. Compared with the CTX group, the number of white blood cells in 2.0 g/kg group increased (P=0.003), the proportion of CD3(+) T cells in peripheral blood in 1.0 g/kg group (P=0.04) and 2.0 g/kg group (P=0.02) increased, the proportion of CD8(+) T cells in peripheral blood in 2.0 g/kg group increased (P=0.002), the concentration of IL-5 in peripheral blood in all the oyster treated groups increased (P<0.01 in 0.5 g/kg, 1.0 g/kg, and 2.0 g/kg groups), the concentration of IL-17 in peripheral blood in 2.0 g/kg group decreased (P=0.03), the concentration of nucleated cells in bone marrow of all the oyster treated groups increased (0.5 g/kg vs. CTX, P=0.04; 1.0 g/kg vs. CTX, P=0.02; 2.0 g/kg vs. CTX P=0.01), the DNA content in bone marrow of all the oyster treated groups increased (P<0.01 in the 0.5 g/kg, 1.0 g/kg, and 2.0 g/kg groups). CONCLUSION: Oyster peptide could improve the structures of immune organs of the CTX-induced immunosuppressed mice, recover the imbalances of T lymphocyte subsets, improve the immune cytokines and increase numbers of nucleated cells and DNA content in bone marrow, thus improving the immunologic function.

The construction of cloned Sika deer embryos (Cervus nippon hortulorum) by demecolcine auxiliary enucleation.

The objective of our study was to establish the feasibility of experimental protocols for cloning sika deer. We performed auxiliary enucleation to improve the efficiency of nuclear transfer operation by optimizing the demecolcine concentration to induce cytoplasmic protrusions in the sika deer oocytes. In the present study,we had studied the impact of different demecolcine concentrations on cytoplasmic protrusions and enucleation rates. We determined that 95.9% of the sika deer oocytes formed cytoplasmic protrusions when treated for 1 h with 0.8 µg/ml demecolcine. The lowest observed rate of protrusion was 19.3% after overnight treatment with demecolcine. When the oocytes aged or had a poor cumulus expansion, they exhibited a significant decrease in the ability to form cytoplasmic protrusions. The rates of enucleation (94.9% vs 85.8%, p < 0.05), cell fusion (84.6% vs 70.1%, p < 0.05) and blastocyst formation (15.4% vs 10.9%, p < 0.05) using demecolcine auxiliary enucleation were significantly higher than those after blind enucleation. These results demonstrated that sika deer oocytes could be enucleated quickly and effectively using demecolcine auxiliary enucleation, which could enhance the enucleation rate, cell fusion rate and blastocyst rate of cloned embryos in vitro.

Tobacco control in Vietnam.

OBJECTIVES: To investigate the use of tobacco in Vietnam. STUDY DESIGN: Review study. METHODS: Data were collected through a review of tobacco-related literature in Vietnam. Grey literature and web content from agencies such as the World Health Organization and the US Centers for Disease Control and Prevention were consulted. RESULTS: Tobacco smoking is still common in Vietnam, although numerous policies have been issued and implemented over the last two decades. Based on the most recent data (2010), the prevalence of smoking among adults aged >15 years was 23.8%, with a higher percentage among males (47.4%) than females (1.4%). The prevalence of smoking among students aged 13-15 was 3.8% (2007), with a similar gender pattern. The prevalence of exposure to secondhand smoke is of concern, with 73.1% and 55.9% of adults reporting exposure to secondhand smoke at home and at work or other places, respectively. Of the adult respondents, 55.5% believed that smoking may cause lung cancer, stroke and heart disease. Most students (93.4%) and adults (91.6%) had seen anti-smoking media messages. Of the students, 56.4% had seen pro-cigarette advertisements on billboards, 36.9% had seen pro-cigarette advertisements in newspapers or magazines, and 8.2% had been offered free cigarettes by tobacco company representatives. The price of cigarettes decreased by approximately 5% between 1995 and 2006, whereas gross domestic product per capita increased by more than 150%. On average, smokers smoked 13.5 cigarettes per day, and spent US$86 on cigarettes per year. Despite such high levels of tobacco exposure in Vietnam, the total tax on cigarettes remains at 45% of the retail price. Furthermore, only 29.7% of smokers had been advised to quit by a healthcare provider in the past 12 months. CONCLUSION: Strong enforcement and evidence-based regulations which rounded on MPOWER are needed to help protect current smokers and non-smokers from the devastating effects of tobacco.

eEF1A1 promotes colorectal cancer progression and predicts poor prognosis of patients.

Colorectal cancer (CRC) is a major leading cause of cancer mortality worldwide in which dysregulated protein synthesis plays an etiologic role. The eukaryotic elongation factor 1 A1 (eEF1A1) exerts significant effects on protein synthesis by contributing to peptide chain extension. Whereas its role in CRC remains to be investigated. In this study, we found that the mRNA and protein levels of eEF1A1 were significantly upregulated in CRC cell lines and tissues. Elevated expression of eEF1A1 was correlated with shorter overall survival in 94 CRC patients. The inhibition of proliferation and cell cycle block were observed in CRC cells after eEF1A1 downregulation. Mechanistically, weighted gene correlation network analysis and further Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that mitogen-activated protein kinases (MAPKs) signaling pathways were significantly enriched in high-eEF1A1 expression group, and the levels of phosphorylated p38/JNK/ERK MAPK were dramatically decreased after eEF1A1 downregulation. Overexpression of eEF1A1 in CRC correlated with a poor prognosis. Collectively, this study determined the oncogenic role of eEF1A1 in CRC proliferation and tumorigenesis. eEF1A1 might be a promising therapeutic target and prognostic biomarker in CRC.

Medical education in Vietnam.

BACKGROUND: Vietnam is one of the most populous countries in Southeast Asia, yet it displays an unsettling lack of doctors. AIMS: Medical education is an important factor contributing to this issue, yet little is known about the system currently in place in Vietnam. METHODS: Through an extensive literary search of medical schools' and Ministry of Health's data, we have examined the current medical education system in Vietnam. RESULTS: At present, there are 12 medical universities, and the general curriculum at each university follows a national framework but tends to vary from university to university. Medical training lasts either 4 or 6 years, with competitive graduates attending residency programs following graduation. While examinations are required to graduate, the lack of a national licensing exam makes it difficult to ensure that a nation-wide standard of quality exists, both at the medical universities themselves as well as amongst the doctors graduating from them. CONCLUSIONS: The development and institution of a national exam would introduce a standard of training throughout Vietnam's medical education system. Further, a substantial portion of a doctor's education is in subjects that are loosely related to medicine. When looking forward it will be important to evaluate whether or not these non-medical subjects detract from the quality of medical training.

Risk factors for the development of hepatocellular carcinoma in Chengdu: a prospective cohort study.

OBJECTIVE: To investigate the incidence of hepatocellular carcinoma (HCC) in Chengdu, identify the risk factors for the development of HCC in Chengdu and provide a reference for the prevention of HCC. PATIENTS AND METHODS: The study population was recruited from Chengdu, Sichuan Province, China. The study group recruited volunteers in Chengdu from 2007 to 2012, conducted a baseline survey, and subsequently conducted long-term follow-up until December 31, 2019. A total of 22,525 study subjects were enrolled, excluding those who reported a previous history of liver disease, malignancy, and HCC within three months of enrollment. Cox proportional risk regression models were used to screen and determine the various risk factors and their hazard ratios (HR) for HCC in Chengdu, as well as to determine whether the association between other risk factors and HCC was modified by gender. RESULTS: The study population had a median follow-up of 5.35 years, and a total of 142 people developed HCC, with an incidence rate of 0.71%. Analysis of the multifactorial Cox proportional risk regression model showed that age (age 10 years for 1 group, HR= 1.98, 95% CI: 1.86-2.11, p<0.001), current smoking (HR= 1.25, 95% CI: 1.07-1.31, p=0.031), weekly consumption of pickled vegetables (HR= 1.70, 95% CI: 1.49-1.81, p=0.003) and consumption of pickled vegetables daily (HR= 1.36, 95% CI: 1.21-1.42, p=0.021) were risk factors for HCC, and women (HR= 0.39, 95% CI: 0.28-0.55, p=0.002) and the use of air conditioning (10 years for 1 group, HR= 0.79, 95% CI: 0.68-0.83, p=0.002) were protective factors against HCC. Further analysis revealed that the association between length of time using air conditioning and HCC was heterogeneous among men and women (p=0.007) and that there was an interaction between sex and use of air conditioning in the association with HCC development (p<0.001). CONCLUSIONS: The Chengdu population has a high incidence of HCC and numerous risk factors for HCC. There is a synergistic interaction between sex and length of time using air conditioning in their role in the development of HCC.

Diversity of killer cell immunoglobulin-like receptor genes in the Bai ethnic minority of Yunnan, China.

Killer cell immunoglobulin-like receptors (KIRs), expressed in both natural killer (NK) cells and a subset of T cells, represent a family of both inhibitory and activating receptors that can regulate NK and T cells upon interacting with human leucocyte antigen (HLA) class I molecules on target cells. The number and distribution of KIR genes vary between individuals and populations from different geographical regions and ethnic origins. In this study, we investigated KIR gene frequencies and genotype diversities of 13 KIR genes, 2 pseudogenes, expressed and non-expressed forms of KIR2DL5 and the two subtypes, full-length and deleted forms, of KIR2DS4 in 100 unrelated healthy individuals of the Bai population, living in the Dali Bai autonomous prefecture in the Yunnan province. All individuals were typed positive for the three framework loci KIR3DL3, 2DL4 and 3DL2, as well as for three non-framework genes KIR2DL1, 2DL3 and the pseudogene KIR2DP1. The gene frequencies of the other KIR genes ranged from 7%-95%. The results of tested linkage disequilibrium (LD) among KIR genes demonstrated that they display a wide range of LD. χ² analysis among non-ubiquitous genes, using the KIR gene frequency data from our study population, as well as from previously published population data, was conducted and revealed significant differences in the KIR2DL1, 2DL2, 3DL1 and KIR2DS1 genes. The results of the present study can be valuable for enriching the Chinese ethnic gene information resources of the KIR gene pool, for anthropological studies, as well as for KIR-related disease research.