[The 506th case: fever of unknown origin, negative PET-CT and hemoperitoneum].

A 48-year-old male was admitted to Peking Union Medical College Hospital presented with intermittent fever for two years. The maximum body temperature was 39 ℃, and could spontaneously relieve. The efficacy of antibacterial treatment was poor. He had no other symptoms and positive signs. He had a significant weight loss, and the serum lactate dehydrogenase increased significantly. It was highly alert to be lymphoma, but bone marrow smear and pathology, and PET-CT had not shown obvious abnormalities. Considering high inflammatory indicators, increased ferritin and large spleen, the patient had high inflammatory status, and was treated with methylprednisolone. Then the patient's body temperature was normal, but the platelet decreased to 33×109/L. During hospitalization, he had suddenly hemoperitoneum and hemorrhagic shock. He was found spontaneous spleen rupture without obvious triggers, and underwent emergency splenectomy. The pathological diagnosis of spleen was diffuse large B-cell lymphoma.

Threshold of 25(OH)D and consequently adjusted parathyroid hormone reference intervals: data mining for relationship between vitamin D and parathyroid hormone.

PURPOSE: By recruiting reference population, we aimed to (1): estimate the 25(OH)D threshold that maximally inhibits the PTH, which can be defined as the cutoff value for vitamin D sufficiency; (2) establish the PTH reference interval (RI) in population with sufficient vitamin D. METHODS: Study data were retrieved from LIS (Laboratory Information Management System) under literature suggested criteria, and outliers were excluded using Tukey fence method. Locally weighted regression (LOESS) and segmented regression (SR) were conducted to estimate the threshold of 25(OH)D. Multivariate linear regression was performed to evaluate the associations between PTH concentration and variables including 25(OH)D, gender, age, estimated glomerular filtration rate (EGFR), body mass index (BMI), albumin-adjusted serum calcium (aCa), serum phosphate(P), serum magnesium(Mg), and blood collection season. Z test was adopted to evaluate whether the reference interval should be stratified by determinants such as age and gender. RESULTS: A total of 64,979 apparently healthy subjects were recruited in this study, with median (Q1, Q3) 25(OH)D of 45.33 (36.15, 57.50) nmol/L and median (Q1, Q3) PTH of 42.19 (34.24, 52.20) ng/L. The segmented regression determined the 25(OH)D threshold of 55 nmol/L above which PTH would somewhat plateau and of 22 nmol/L below which PTH would rise steeply. Multivariate linear regression suggested that gender, EGFR, and BMI were independently associated with PTH concentrations. The PTH RI was calculated as 22.17-72.72 ng/L for subjects with 25(OH)D ≥ 55 nmol/L with no necessity of stratification according to gender, age, menopausal status nor season. CONCLUSION: This study reported 25(OH)D thresholds of vitamin D sufficiency at 55 nmol/L and vitamin D deficiency at 22 nmol/L, and consequently established PTH RIs in subjects with sufficient vitamin D for northern China population for the first time.

[Palliative care in China: a way out of the dilemma].

It is still common for terminally ill patients to suffer from pain, and the development of palliative care faces many obstacles. The value of death to human society is ignored, and the intrinsic relationship between the meaning of life and the value of death has not been fully explored. This article discusses the current status of palliative care in China, how clinicians reflect and respond, the change of the whole society's concept of palliative care, and suggestions for action, and tries to provide a medical humanistic perspective for walking out of the dilemma of palliative care.

Comparison of Telomere Length between Buccal Cells and Blood Cells.

Telomere length (TL) in blood cells is commonly used as a proxy for TL in other tissue types. The source of DNA of adequate quality and quantity is important for TL analysis. Compared to blood cells, buccal cells easy for genomic DNA preparation would facilitate the rapid and reliable TL analysis. However, the feasibility of buccal cells for TL analysis remains yet unestablished. We characterized TL of buccal cells and blood cells collected from 52 individuals using buccal cell swabs and fingertip sticks. Relative TL (RTL) determined by quantitative PCR showed that there is a strong correlation between buccal RTL and blood RTL (r=0.877, p<0.001), suggesting that buccal cells are adequate sources of DNA for TL analysis. The validity of sampling using buccal cell swabs provides simple operation and good reproducibility for TL analysis, that overcomes the discomfort and risk of infection caused by blood sampling.

Quantitative determination of endogenous cardiolipin in rat cerebral tissues by high-performance liquid chromatography using standard addition method.

Cardiolipin is an important cellular component, and its normal level is a key prerequisite for maintaining the structure and function of mitochondria. To accurately quantify endogenous cardiolipin content in mitochondria, a standard addition method (SAM) was developed to establish a high-performance liquid chromatographic (HPLC) technique that is both reliable and accurate. Increasing amounts of cardiolipin standards were added to a constant amount of isolated mitochondria prior to the extraction procedure, and the two were extracted together. By limiting the interference effects that occur to within an acceptable range in an analytical system examined, this procedure ensures an ideal match of the sample composition in the standards, even if the composition is extremely complex or completely unknown. Then, the desired results can be obtained by extrapolation. As such, the authentic content of the endogenous cardiolipin can be obtained with greater accuracy than with classical detection methods, e.g. external standard calibration (ESC) and internal standard calibration (ISC). This method provides an excellent means of quantifying endogenous substances in living cells. The authors expect this method to be useful for researchers working on mitochondria-related mechanisms, cell survival-related mechanisms and similar topics.

Hypoxia inducible factor-1α-induced interleukin-33 expression in intestinal epithelia contributes to mucosal homeostasis in inflammatory bowel disease.

Intestinal epithelial cells (IECs), an important barrier to gut microbiota, are subject to low oxygen tension, particularly during intestinal inflammation. Hypoxia inducible factor-1α (HIF-1α) is expressed highly in the inflamed mucosa of inflammatory bowel disease (IBD) and functions as a key regulator in maintenance of intestinal homeostasis. However, how IEC-derived HIF-1α regulates intestinal immune responses in IBD is still not understood completely. We report here that the expression of HIF-1α and IL-33 was increased significantly in the inflamed mucosa of IBD patients as well as mice with colitis induced by dextran sulphate sodium (DSS). The levels of interleukin (IL)-33 were correlated positively with that of HIF-1α. A HIF-1α-interacting element was identified in the promoter region of IL-33, indicating that HIF-1α activity regulates IL-33 expression. Furthermore, tumour necrosis factor (TNF) facilitated the HIF-1α-dependent IL-33 expression in IEC. Our data thus demonstrate that HIF-1α-dependent IL-33 in IEC functions as a regulatory cytokine in inflamed mucosa of IBD, thereby regulating the intestinal inflammation and maintaining mucosal homeostasis.

Diversity of platelet function and genetic polymorphism in clopidogrel-treated Chinese patients.

We investigated the correlation between genetic polymorphisms of cytochrome P450 enzyme genes and the outcome of clopidogrel treatment in 118 coronary disease patients after percutaneous coronary intervention at the Chinese PLA General Hospital. Patients were divided into an ischemia event relapse group (IERG) and a non-IERG group (NIERG) based on relapse of ischemia events within 6 months after percutaneous coronary intervention. Ischemia occurred in 26.27% of patients. Thromboelastogram platelet mapping results showed that compared with the NIERG, the ADP-induced platelet inhibition ratio in the IERG was significantly lower (31.33 ± 24.91% vs 54.68 ± 26.63%, P < 0.05). The platelet inhibition ratio of patients carrying mutant alleles CYP3A5*3 (41.98 ± 29.33% vs 52.89 ± 26.49%), CYP2C19*2 (43.15 ± 27.97% vs 55.89 ± 26.71%), and P2Y12*1 (38.74 ± 24.36% vs 52.19 ± 28.58%) was lower than patients with the wild-type alleles. The frequency of ischemia event relapse in patients with the mutant alleles CYP3A5*3 and CYP2C19*2 was significantly higher than patients carrying the G/G genotype; however, there was no significant difference between patients carrying the T/T genotype and C allele of P2Y12*1. Thus, coexisting polymorphisms of CYP3A5*3 and 2C19*2, but not P2Y12*1, play an important role in the variability of clopidogrel's curative effect.

Association of sedentary behaviour with colon and rectal cancer: a meta-analysis of observational studies.

BACKGROUND: Sedentary behaviour is ubiquitous in modern society. Emerging studies have focused on the health consequences of sedentary behaviour, including colorectal cancer, but whether sedentary behaviour is associated with the risks of colon and rectal cancer remains unclear. No systematic reviews have applied quantitative techniques to independently compute summary risk estimates. We aimed to conduct a meta-analysis to investigate this issue. METHODS: We searched PubMed, Embase, and Google Scholar databases up to May 2013 to identify cohort and case-control studies that evaluated the association between sedentary behaviour and colon or rectal cancer. A random-effect model was used to pool the results of included studies. Publication bias was assessed by using Begg's funnel plot. RESULTS: Twenty-three studies with 63 reports were included in our meta-analysis. These groups included 4,324,462 participants (27,231 colon cancer cases and 13,813 rectal cancer cases). Sedentary behaviour was significantly associated with colon cancer (relative risk (RR): 1.30, 95% confidence interval (CI): 1.22-1.39) but did not have a statistically significant association with rectal cancer (RR 1.05, 95% CI, 0.98-1.13). Subgroup analyses suggested that the odds ratio (OR) of colon cancer was 1.46 (95% CI: 1.22-1.68) in the case-control studies, and the RR was 1.27 (95% CI: 1.18-1.36) in the cohort studies, the OR of rectal cancer was 1.06 (95% CI: 0.85-1.33) in the case-control studies, and the RR was 1.06 (95% CI, 1.01-1.12) in the cohort studies. CONCLUSION: Sedentary behaviour is associated with an increased risk of colon cancer. Subgroup analyses suggest a positive association between sedentary behaviour and risk of rectal cancer in cohort studies. Reducing sedentary behaviour is potentially important for the prevention of colorectal cancer.

Diagonally implicit symplectic Runge-Kutta methods with high algebraic and dispersion order.

The numerical integration of Hamiltonian systems with oscillating solutions is considered in this paper. A diagonally implicit symplectic nine-stages Runge-Kutta method with algebraic order 6 and dispersion order 8 is presented. Numerical experiments with some Hamiltonian oscillatory problems are presented to show the proposed method is as competitive as the existing same type Runge-Kutta methods.

Human body numerical simulation: An accurate model for a thigh subjected to a cold treatment.

This article presents the development of a digital twin model of a thigh portion subjected to various thermal treatments. Two scenarios are investigated: cold water immersion (CWI) and whole body cryotherapy (WBC), for which the comparison of numerical results with experimental measurements validates the consistency of the developed model. The use of real geometry on a first subject demonstrates the high heterogeneity of the temperature field and the need for accurate geometry. A second subject with thicker adipose tissue highlights the impact of the subject's actual morphology on the validity of the treatment and the necessity to work with real geometry in order to optimize cold modalities and develop personalized treatments.

Anti-tumour necrosis factor therapy enhances mucosal healing through down-regulation of interleukin-21 expression and T helper type 17 cell infiltration in Crohn's disease.

Anti-tumour necrosis factor (TNF) monoclonal antibody (mAb) (infliximab, IFX) has been shown to be highly effective in the management of Crohn's disease (CD). Herein we investigated the potential role of IFX in inducing clinical remission and regulating interleukin (IL)-21 expression and T helper type 17 (Th17) cell infiltration in the intestinal mucosa of CD patients. Twenty-six CD patients were treated with IFX at weeks 0, 2 and 6. Clinical response, mucosal healing, serum C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were evaluated at week 10 after IFX administration. Expression of IL-21, IL-17A and retinoic acid-related orphan receptor C (RORC) in intestinal mucosa were analysed by quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry. Peripheral blood and lamina propria CD4(+) T cells were stimulated with anti-CD3 and anti-CD28 mAbs in the presence of IFX. Cytokine profiles and RORC were determined with enzyme-linked immunosorbent assay (ELISA) and real-time PCR. IL-21 and Th17 cells were found to be expressed highly in inflamed mucosa of active CD patients compared with healthy controls. Ten weeks after IFX infusion, CD activity index, ESR, CRP and intestinal mucosal healing were improved markedly in CD patients, and IL-21 expression and Th17 cell infiltration were decreased significantly compared with those before IFX therapy. In-vitro study demonstrated that IFX treatment could suppress IL-21, IL-17A and RORC expression in cultured CD biopsies. Moreover, IFX was also observed to down-regulate markedly IL-17A, IL-21 and RORC expression by CD CD4(+) T cells. IFX is highly effective in inducing clinical remission and promoting intestinal mucosal healing in CD patients through down-regulation of IL-21 expression and Th17 cell infiltration in intestinal mucosa.

[A multi-center analysis of thyroid-stimulating hormone level in apparently healthy elderly population in China].

OBJECTIVE: To investigate serum thyroid stimulating hormone (TSH) level and its changes with age in apparently healthy Chinese elderly population and analyze the differences between TSH levels detected using Roche and Snibe electrochemiluminescence immunoassay analyzers. METHODS: General clinical data and frozen fasting serum samples were collected from 5451 apparently healthy Chinese elderly individuals (> 60 years) from 10 centers in different geographic regions in China. Thyroid function indexes including TSH level were detected using Roche and Snibe electrochemiluminescence immunoassay analyzer, and the median (2.5% and 97.5% quantiles) TSH level was calculated. The variations of TSH level among the participants with geographic regions, gender, and age (with an interval of 5 years) were analyzed to determine the influence of these factors on TSH level. RESULTS: The reference ranges of serum TSH level established using Roche and Snibe electrochemiluminescence immunoassay analyzers were 0.42-9.47 mU/L and 0.36-7.98 mU/L, respectively, showing significant differences between the two methods (P < 0.001). The TSH levels measured at two centers in Western China were significantly higher than those at the other centers (P < 0.05). In elderly male population, serum TSH level tended to increase with age, which was not observed in elderly female population. At the age of 60-75 years, women generally had higher serum TSH level than men, but this difference was not observed in the population beyond 75 years. CONCLUSION: In elderly population, serum TSH level can vary with geographic region, gender, and age, but there was no need for establishing specific reference ranges for these factors. The differences between different detection methods should be evaluated when interpreting the detection results of TSH level.

Identification of the critical amino acid residues of immunoglobulin E and immunoglobulin G epitopes in ß-lactoglobulin by alanine scanning analysis.

ß-Lactoglobulin represents one of the major allergens causing cow milk allergy. Few studies have clearly evaluated immunological relationships between IgE- and IgG-binding epitopes of ß-lactoglobulin. For characterization of immunological epitopes, peptides of 15 amino acids (AA) in length were synthesized. Immunoglobulin E- and IgG-binding epitopes were immunolabeled with individual sera from cow milk-allergic patients. Alanine scanning of immunodominant epitopes was used to identify the critical AA of IgE- and IgG-binding epitopes. The results showed that 4 IgE-binding epitopes were identified. Our initial data revealed IgE-binding epitopes at AA 17 to 31, AA 72 to 86, AA 92 to 106, and AA 152 to 166. Threonine 20, Met23, and Asp27 are the critical AA of IgE-binding epitopes. Two IgG epitopes were identified, which were located at AA 22 to 36 and AA 127 to 141. The critical AA of IgG-binding epitopes were Leu26 and Val31. Results obtained from this study will provide necessary information to alter the cDNA to encode a protein capable of activating milk-specific T cells, but with reduced IgE- or IgG-binding capacity.

Inactivation of HIV-1 chemokine co-receptor CXCR-4 by a novel intrakine strategy.

CXC-chemokine receptor (CXCR)-4/fusin, a newly discovered co-receptor for T-cell line (T)-tropic HIV-1 virus, plays a critical role in T-tropic virus fusion and entry into permissive cells. The occurrence of T-tropic HIV viruses is associated with CD4-positive cell decline and progression to AIDS, suggesting that the T-tropic HIV-1 contributes to AIDS pathogenesis. In this study, we used a novel strategy to inactivate CXCR-4 by targeting a modified CXC-chemokine to the endoplasmic reticulum (ER) to block the surface expression of newly synthesized CXCR-4. The genetically modified lymphocytes expressing this intracellular chemokine, termed "intrakine", are immune to T-tropic virus infection and appear to retain normal biological features. Thus, this genetic intrakine strategy is uniquely targeted at the conserved cellular receptor for the prevention of HIV-1 entry and may be developed into an effective treatment for HIV-1 infection and AIDS.

LncRNA NORAD promotes thyroid carcinoma progression by targeting miR-451.

OBJECTIVE: Long non-coding RNA (lncRNA) NORAD plays an essential role in the development and progress of papillary thyroid carcinoma (PTC). MicroRNA-451 (MiR-451) has been identified as playing an inhibitory role in some types of cancer. However, the molecular mechanism of lncRNA NORAD regulating metastasis of PTC cells by miR-451 has not been fully elucidated. MATERIALS AND METHODS: Real-Time quantitative Polymerase Chain Reaction (RT-qPCR) or Western blot analysis of the expression of NORAD, miR-451, and interleukin-6 receptor (IL-6R) in PTC cell lines were carried out. The detection of Luciferase reporter gene showed the relationship between lncRNA NORAD, miR-451 and IL-6R. Cell Counting Kit-8 (CCK-8) assay and transwell assay were performed to detect the influence of lncRNA NORAD, miR-451 on the proliferation, migration, and invasion of PTC cells. RESULTS: The results of RT-qPCR and Western blotting suggested that the expression of lncRNA NORAD and IL-6R were higher than that of the control group, while the expression of miR-451 was lower. Transwell assay indicated that the knockdown of lncRNA NORAD or overexpression of miR-451 significantly inhibited cell proliferation, migration and invasion in PTC cell lines. In addition, lncRNA NORAD negatively controls the expression of miR-451, resulting in the upregulation of IL-6R. IL-6R overexpression can reverse the inhibitory effect of lncRNA NORAD knockdown or miR-451 on PTC cell proliferation and metastasis. CONCLUSIONS: Our results indicated that the cell migration and invasion were inhibited by knockdown of lncRNA NORAD or overexpression of miR-451, suggesting that the axis of lncRNA NORAD -miR-451- IL-6R was involved in the development of PTC.

[Surveillance and genetic characteristics of imported cases of measles virus of D8 genotype in Hebei province].

Objective: To understand the epidemiological and genotypic characteristics of imported cases of measles virus of D8 genotype in Hebei province. Methods: Epidemiological investigation of measles cases in surveillance was carried out. The throat swabs of the measles cases in acute phase were collected for real time RT-PCR identification, measles virus culture and genotype identification. Results: A total of 36 imported measles cases of genotype D8 were detected. The cases were mainly distributed in 8 counties of Handan city. Number of confirmed measles cases in Cheng'an county was the highest, accounting for 58.33% (21/36) of all the reported cases. All patients had fever and rash, and 55.55% (20/36) of the cases were under 2 years old and 86.11% (31/36) of the cases had no immunization history. The children with pneumonia accounted for 44.12% (15/34) of the total children with D8 genotype measles virus infection. The nucleotide and amino acid homologies between the imported measles virus genotype D8 and the WHO reference strain of D8 genotype (D8-Manchester.UNK/30.94) were 98.4%-98.6% and 97.3%, respectively. Compared with the strains of H1 genotype in China, the nucleotide and amino acid homologies were 92.8%-93.1% and 93.3%, respectively. Conclusions: The imported cases of measles virus of D8 genotype might have caused local transmission in Hebei province. Molecular epidemiological surveillance for measles virus needs to be further strengthened. It is necessary to detect and control the epidemic early and improve the coverage rate and timely rate of measles vaccination. It is also important to prevent cross infection in hospitals.

Preclinical Immune Response and Safety Evaluation of the Protein Subunit Vaccine Nanocovax for COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health concern. The development of vaccines with high immunogenicity and safety is crucial for controlling the global COVID-19 pandemic and preventing further illness and fatalities. Here, we report the development of a SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the spike (S) protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG and neutralizing antibodies in three animal models: BALB/c mouse, Syrian hamster, and a non-human primate (Macaca leonina). In addition, a viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. Nanocovax did not induce any adverse effects in mice (Mus musculus var. albino) and rats (Rattus norvegicus). These preclinical results indicate that Nanocovax is safe and effective.