Values of Different Laboratory Diagnostic Approaches for Tuberculous Peritonitis / 中国医学科学院学报

Objective To evaluate the diagnostic accuracy of different laboratory approaches for tuberculous peritonitis(TP).Methods The clinical data of patients with suspected TP who were mainly manifested as ascites in Peking Union Medical College Hospital from January 2014 to June 2017 were retrospectively analyzed. Ascites samples were tested with different diagnostic approaches,including acid fast stain,culture for mycobacterium,real-time polymerase chain reaction for identifying DNA of mycobacterium tuberculosis,and T-cell spot of tuberculosis test(T-SPOT.TB). Results Totally 163 cases aged 15-84 years [mean±SD:(50±17)years] with complete data were enrolled,among whom 82(50.3%) were males and 81(49.7%) were females. Finally,27 patients were confirmed as TP,which was excluded in the other 136 cases. The sensitivity and specificity of ascites acid fast stain were 0% and 100%,respectively,followed by ascites culture for mycobacterium(21.74% and 100%),real-time polymerase chain reaction for DNA of mycobacterium tuberculosis in ascites(18.52% and 100%),T-SPOT.TB on ascites(95.42% and 61.90%),and T-SPOT.TB on peripheral blood(76.19% and 80.18%). Conclusion The diagnosis of tuberculous peritonitis remains challenging because of the limitations of the currently available diagnostic tests. Diagnosis should also be based on clinical manifestations and auxiliary examinations.

Implementation of literature case study in clinical epidemiology teaching reformation for medical students of the eight-year medical education program / 基础医学与临床

In order to improve the teaching quality of clinical epidemiology for medical students engaged in eight-year curriculum of Peking Union Medical College, and foster the practice of evidence-based medicine and clinical research in Peking Union Medical College Hospital (PUMCH), the Clinical Epidemiology Unit of PUMCH(PUMCH-CEU) utilized successful experience from institutions abroad and conducted a teaching reform. In addition to theory teaching, PUMCH-CEU incorporated literature case study and assignments into the course, so as to improve students' understanding about the design, measurement, and evaluation of clinical research. The execution of a well-designed reformation plan has led to a great success of this course, as well as fruitful achievements.

Systems specificity in responsiveness to intermittent artificial gravity during simulated microgravity in rats / 生理学报

It has been shown that the minimum gravity exposure requirements vary greatly among different physiological systems. A preliminary comparison between two extremes, vessels vs. bones, shows that not only the mechanostat at the tissue level differs greatly, but also the bone loss during weightlessness may also involve calcium deposition-resorption changes. It seems that the surprising efficacy of intermittent artificial gravity (IAG) is due to the vascular tissues possessing a strong resilience or "memory" function toward restoring their original pre-stress and tensegrity state at the 1 G environment. It appears that the bone tissue is related to a more complex tensegrity paradigm involving both osteoblasts and osteoclasts, and a longer half time for calcium deposition-absorption. Cell-level models (CellML) for calcium dynamics is currently available. We hope that the Physiome Project can use this modeling framework to help interpret the resistance of bones to IAG and to evaluate whether the "intermittent" or "continuous" AG scheme should be adopted eventually for future exploration-class spaceflight.

Diagnostic Value of T-cell Interferon-γ Release Assays on Synovial Fluid for Articular Tuberculosis: A Pilot Study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tuberculosis (TB) remains a major global public health challenge. Articular TB is an important form of extrapulmonary tuberculosis, and its diagnosis is difficult because of the low sensitivity of traditional methods. The aim of this study was to analyze the diagnostic value of T-SPOT.TB on synovial fluid for the diagnosis of articular TB.</p><p><b>METHODS</b>Patients with suspected articular TB were enrolled consecutively between August 2011 and December 2015. T-SPOT.TB was performed on both synovial fluid mononuclear cells (SFMCs) and peripheral blood mononuclear cells (PBMCs). The final diagnosis of articular TB was independent of the T-SPOT.TB result. The diagnostic sensitivity, specificity, predictive value, and likelihood ratio of T-SPOT.TB on SFMCs and PBMCs were analyzed.</p><p><b>RESULTS</b>Twenty patients with suspected articular TB were enrolled. Six were diagnosed with articular TB, and 14 patients were diagnosed with other diseases. Sensitivity and specificity were 83% and 86% for T-SPOT.TB on SFMCs, and 67% and 69% for T-SPOT.TB on PBMCs, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of T-SPOT.TB on SFMCs were 71% and 92%, respectively. The PPV and NPV were 50% and 82% for T-SPOT.TB on PBMCs.</p><p><b>CONCLUSION</b>Sensitivity, specificity, and NPV of T-SPOT.TB on SFMCs appeared higher than that on PBMCs, indicating that T-SPOT.TB on SFMCs might be a rapid and accurate diagnostic test for articular TB.</p>

Clinical and Laboratory Diagnosis of Intestinal Tuberculosis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tuberculosis (TB) remains a worldwide problem. Intestinal TB (ITB) constitutes a major public health problem in developing countries and has been associated with significant morbidity and mortality. The aim of this study was to characterize the clinical, radiological, endoscopic, and pathological features of ITB and to define the strategy for establishing the diagnosis.</p><p><b>METHODS</b>A retrospective study (from January 2000 to June 2015) was carried out in Peking Union Medical College Hospital and all hospitalized cases were diagnosed as ITB during the study period were included. The relevant clinical information, laboratory results, microbiological, and radiological investigations were recorded.</p><p><b>RESULTS</b>Of the 85 cases, 61 cases (71.8%) were ranged from 20 to 50 years. The ileocecal region was involved in about 83.5% (71/85) of patients. About 41.2% (35/85) of patients had co-existing extra ITB, especially active pulmonary TB. Abdominal pain (82.4%) was the most common presenting symptom followed by weight loss (72.9%) and fever (64.7%). Both T-cell spot of TB test (T-SPOT.TB) and purified protein derivatives (PPD) tests were performed in 26 patients: 20 (76.9%) positive T-SPOT.TB and 13 (50.0%) positive PPD were detected, with a statistical significant difference (P = 0.046). Twenty cases (23.5%) were histopathology and/or pathogen confirmed TB; 27 cases (31.8%) were diagnosed by clinical manifestation consistent with ITB and evidence of active extra ITB; 38 cases (44.7%) were diagnosed by good response to diagnostic anti-TB therapy.</p><p><b>CONCLUSIONS</b>ITB is difficult to diagnose even with modern medical techniques due to its nonspecific clinical and laboratory features. At present, combination of clinical, endoscopic, radiological, and pathological features continues to be the key to the diagnosis of ITB.</p>

Clinical and Laboratory Characteristics of Patients with Nontuberculous Mycobacterium Bloodstream Infection in a Tertiary Referral Hospital in Beijing, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nontuberculous Mycobacterium (NTM) bloodstream infection (BSI) is relatively rare. We aimed in this study to evaluate the clinical characteristics, laboratory evaluation, and outcomes of patients with NTM BSI.</p><p><b>METHODS</b>We retrospectively reviewed the clinical records of inpatients with NTM BSI at our institution between January 2008 and January 2015 and recorded clinical parameters including age, gender, underlying disease, clinical manifestation, organs involved with NTM disease, species of NTM, laboratory data, treatment and outcome of these patients. We also reviewed the reported cases and case series of NTM BSI by searching PubMed, EMBASE, and Wanfang databases. Data of normal distribution were expressed by mean ± standard deviation (SD). Data of nonnormal distribution were expressed by median and interquartile range (IQR).</p><p><b>RESULTS</b>Among the ten patients with NTM BSI, the median age was 51 years (IQR 29-57 years) and three patients were males. Eight patients were immunocompromised, with underlying diseases including human immunodeficiency virus (HIV) infection (one patient), rheumatic diseases (two patients), breast cancer (one patient), myelodysplastic syndrome (two patients), and aplastic anemia (two patients). Other organ(s) involved were lung (two patients), endocardium (two patients), brain, spinal cord, and soft tissue (one each patient). The median lymphocyte was 0.66 × 109/L (IQR 0.24-1.93 × 109/L). The median cluster of differentiation 4 (CD4) cell count was 179/mm3 (IQR 82-619/mm3). Five patients died (three with hematological diseases, one with breast cancer, and one with rheumatic disease), three recovered, and two were lost to follow-up.</p><p><b>CONCLUSIONS</b>We reported all cases in our hospital diagnosed with bloodstream NTM infection that was rarely reported. In this group of patients, patients usually had a high fever and could have multiple organ involvements. All patients with poor prognosis had underlying diseases.</p>

Serum HBV DNA level at week 12 is superior to viral response at week 24 in predicting long-term treatment outcome of telbivudine for chronic hepatitis B patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Telbivudine, one of the five nucleos(t)ide antiviral drugs, was reported to be superior to lamivudine in a better biochemical, virological, and histological response for treatment-naive patients in the GLOBE trial. The aim of this study was to determine the antiviral potency, viral resistance, and the signifcance of early response for long-term telbivudine treatment.</p><p><b>METHODS</b>We recruited 161 patients of chronic hepatitis B (CHB) on telbivudine between January 2009 and September 2011 in Macau, China. The serum hepatitis B virus DNA levels, hepatitis B e antigen (HBeAg) seroconversion, alanine aminotransferase (ALT) normalization, and viral resistance were analyzed.</p><p><b>RESULTS</b>The median age and follow-up duration were 48 years and 16.9 months. All patients were followed up for at least 6 months, while data were collected for 132, 120, 95, and 53 patients at 12, 24, 48, and 96 weeks respectively. The cumulative HBeAg seroconversion rate was 20.8% and only three patients (1.9%) presented with telbivudine low level resistance. The ALT normalization rates were 76.9% at 48 weeks and 77.6% at 96 weeks. Undetectable HBV DNA was achieved by 1.8%, 31.6%, 60%, and 74.1% in HBeAg positive patients and 29.3%, 60.3%, 84%, and 84.6% in HBeAg negative patients at each time point. Week 12 HBV DNA level < 1000 copies/ml (< 200 IU/ml) was a better predictor of viral suppression at 2-year follow-up (P = 0.001, OR = 27.00) than undetectable HBV DNA level at week 24 (P = 0.120, OR = 4.81).</p><p><b>CONCLUSIONS</b>Two-year telbivudine treatment yielded high rates of viral suppression and ALT normalization. Serum HBV DNA level at week 12 is a superior predictor for long-term viral suppression.</p>

Major causes of fever of unknown origin at Peking Union Medical College Hospital in the past 26 years / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Despite the recent advances in medicine, fever of unknown origin (FUO) remains a diagnostic and therapeutic challenge even to expert physicians. To increase the knowledge of FUO, we conducted a retrospective study to investigate the causes of FUO and the change of major causes of FUO during the past 26 years.</p><p><b>METHODS</b>The clinical data were retrospectively analyzed from 997 patients with FUO hospitalized at the Peking Union Medical College Hospital (PUMCH) between January 2004 and October 2010. Furthermore, the results were compared to that reported in previous studies of FUO in PUMCH since 1985.</p><p><b>RESULTS</b>Of the 997 FUO cases, definite diagnosis was eventually achieved in 797 (79.9%) patients. The most common cause of FUO was infectious diseases (479 cases, 48.0%), with tuberculosis accounting for 45.3% (217/479) of the cases of infections. One hundred and sixty-eight (16.9%) patients were diagnosed with connective tissue diseases, with Still's disease and vasculitis accounted for 31.5% (53/168) and 24.4% (41/168) of this category, respectively. Neoplasms and miscellaneous causes were found in 7.9% (79/997) and 7.1% (71/997), respectively. However, no definite diagnosis had been made in the remaining 200 (20.1%) cases until they were discharged from the hospital.</p><p><b>CONCLUSIONS</b>During different periods, infectious diseases, especially tuberculosis, were the leading etiology of FUO and the proportion of tuberculosis had no significant difference. While the frequency of neoplasms was descending, the proportion of lymphoma in neoplasm was ascending; the frequency of undiagnosed cases was increasing, but in most FUO cases the causes can be diagnosed eventually after careful analysis of clinical data.</p>

A prospective longitudinal study evaluating a T-cell-based assay for latent tuberculosis infection in health-care workers in a general hospital in Beijing / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The health-care workers (HCWs) are at high risk of acquiring infection with Mycobacterium tuberculosis. The objectives of this study were to compare the performance of the T-SPOT.TB and tuberculin skin test (TST) for latent tuberculosis infection (LTBI), evaluate diagnostic concordance and risk factors for LTBI, and observe the progression to active tuberculosis (TB) disease among HCWs in a general hospital in Beijing.</p><p><b>METHODS</b>The prospective cohort study enrolled HCWs in a tertiary general hospital in Beijing, China, to evaluate LTBI with T-SPOT.TB and TST. The subjects were evaluated every 12 months during the 60-month follow-up.</p><p><b>RESULTS</b>Of 101 participating HCWs, 96 and 101 had valid TST and T-SPOT.TB results, respectively. Twenty-nine (28.7%, 95% confidence interval (CI), 19.9% - 37.5%) were defined as positive by T-SPOT.TB and 53 (55.2%, 95%CI, 45.2% - 64.9%) were defined as positive by TST (using a ≥ 10 mm cutoff). An agreement between the two tests was poor (57.3%, κ = 0.18, 95%CI, 0.01% - 0.52%). In multivariate analysis, direct exposure to sputum smear-positive TB patients was a significant risk factor for a positive T-SPOT.TB (OR 5.76; 95%CI 1.38 - 24.00). Pooled frequency of antigen-specific IFN-γ secreting T-cells for subjects who reported direct contact with sputum smear-positive TB patients was significantly higher than that for participants without direct contact (P = 0.045). One of 20 participants with positive result of T-SPOT.TB and TST developed active TB at 24-month follow-up.</p><p><b>CONCLUSION</b>T-SPOT.TB is a more accurate, targeted method of diagnosing LTBI than TST.</p>

In-vivo and ex-vivo studies on region-specific remodeling of large elastic arteries due to simulated weightlessness and its prevention by gravity-based countermeasure / 生理学报

The present study was designed to test the hypothesis that a medium-term simulated microgravity can induce region-specific remodeling in large elastic arteries with their innermost smooth muscle (SM) layers being most profoundly affected. The second purpose was to examine whether these changes can be prevented by a simulated intermittent artificial gravity (IAG). The third purpose was to elucidate whether vascular local renin-angiotensin system (L-RAS) plays an important role in the regional vascular remodeling and its prevention by the gravity-based countermeasure. This study consisted of two interconnected series of in-vivo and ex-vivo experiments. In the in-vivo experiments, the tail-suspended, hindlimb unloaded rat model was used to simulate microgravity-induced cardiovascular deconditioning for 28 days (SUS group); and during the simulation period, another group was subjected to daily 1-hour dorso-ventral (-G(x)) gravitation provided by restoring to normal standing posture (S + D group). The activity of vascular L-RAS was evaluated by examining the gene and protein expression of angiotensinogen (Ao) and angiotensin II receptor type 1 (AT1R) in the arterial wall tissue. The results showed that SUS induced an increase in the media thickness of the common carotid artery due to hypertrophy of the four SM layers and a decrease in the total cross-sectional area of the nine SM layers of the abdominal aorta without significant change in its media thickness. And for both arteries, the most prominent changes were in the innermost SM layers. Immunohistochemistry and in situ hybridization revealed that SUS induced an up- and down-regulation of Ao and AT1R expression in the vessel wall of common carotid artery and abdominal aorta, respectively, which was further confirmed by Western blot analysis and real time PCR analysis. Daily 1-hour restoring to normal standing posture over 28 days fully prevented these remodeling and L-RAS changes in the large elastic arteries that might occur due to SUS alone. In the ex-vivo experiments, to elucidate the important role of transmural pressure in vascular regional remodeling and differential regulation of L-RAS activity, we established an organ culture system in which rat common carotid artery, held at in-vivo length, can be perfused and pressurized at varied flow and pressure for 7 days. In arteries perfused at a flow rate of 7.9 mL/min and pressurized at 150 mmHg, but not at 0 or 80 mmHg, for 3 days led to an augmentation of c-fibronectin (c-FN) expression, which was also more markedly expressed in the innermost SM layers, and an increase in Ang II production detected in the perfusion fluid. However, the enhanced c-FN expression and increased Ang II production that might occur due to a sustained high perfusion pressure alone were fully prevented by daily restoration to 0 or 80 mmHg for a short duration. These findings from in-vivo and ex-vivo experiments have provided evidence supporting our hypothesis that redistribution of transmural pressures might be the primary factor that initiates region-specific remodeling of arteries during microgravity and the mechanism of IAG is associated with an intermittent restoration of the transmural pressures to their normal distribution. And they also provide support to the hypothesis that L-RAS plays an important role in vascular adaptation to microgravity and its prevention by the IAG countermeasure.

Mechanical properties and composition of mesenteric small arteries of simulated microgravity rats with and without daily -G(x) gravitation / 生理学报

The aim of the present study was to evaluate the active and passive mechanical properties and wall collagen and elastin contents of mesenteric small arteries (MSAs) isolated from rats of 28-day simulated microgravity (SUS), countermeasure [S + D: SUS plus 1 h/d -G(x) to simulate intermittent artificial gravity (IAG)] and control (CON) groups. Three mechanical parameters were calculated: the overall stiffness (β), circumferential stress (σ(θ))-strain (ε(θ)) relationship and pressure-dependent incremental elastic modulus (E(inc,p)). Vessel wall collagen and elastin percentage were quantified by electron microscopy. The results demonstrate that the active mechanical behavior of MSAs differs noticeably among the three groups: the active stress-strain curve of SUS vessels is very close to the passive curve, whereas the active σ(θ)-ε(θ) curves of CON and S + D vessels are shifted leftward and display a parabolic shape, indicating that for MSAs isolated from S + D, but not those from SUS rats, the pressure-induced myogenic constriction can effectively stiffen the vessel wall as the CON vessels. The passive mechanical behavior of MSAs does not show significant differences among the three groups. However, the percentage of collagen is decreased in the wall of SUS and S + D compared with CON vessels in the following order: SUS < S + D < CON. Thus, the relationship between passive mechanical behavior and compositional changes may be complex and yet depends on factors other than the quantity of collagen and elastin. These findings have provided biomechanical data for the understanding of the mechanism of postflight orthostatic intolerance and its gravity-based countermeasure.

Comparison on heat sensation degree of ginger-partition moxibustion and suspended moxibustion at different acupoints for different time / 中国针灸

<p><b>OBJECTIVE</b>To measure the threshold of feeling temperature, comfortable temperature and tolerant temperature to ginger-partition moxibustion and suspended moxibustion at different acupoints of healthy persons, and to instruct the clinical practice of moxibustion better.</p><p><b>METHODS</b>Forty-three healthy students were divided into a ginger-partition moxibustion group (22 cases) and a suspended moxibustion group (21 cases) randomly. Shenshu (BL 23), Zhongwan (CV 12), Zusanli (ST 36) and Waiguan (TE 5) were used in both groups. The feeling temperature, comfortable temperature and tolerant temperature in each group were measured by thermometer. SPSS 18.0 was used to analyze the data.</p><p><b>RESULTS</b>The feeling temperature, comfortable temperature and tolerant temperature rose in proper order and the difference was significant (all P < 0.05). The tolerant temperature of suspended moxibustion group ((40.69 +/- 1.85) degrees C) was lower than that of ginger-partition moxibustion group ((42.44 +/- 3.90) degrees C) (P < 0.05). The feeling temperature of ginger-partition moxibustion at Shengshu (BL 23) was 4-5 degrees C lower than that at other acupoints.</p><p><b>CONCLUSION</b>The heat sensations of different acupoints to ginger partition moxibustion and suspended moxibustion are different at different stages. The threshold of heat sensation of ginger-partition moxibustion is higher than that of suspended moxibustion. There is a best temperature zone for moxibustion which is a little higher than normal temperature between comfortable temperature and tolerant temperature. To improve effect, doctors should try to prolong the effective time of this zone in clinic. As the limiting temperature of patients, tolerant temperature can provide reference for the use of moxibustion safely in clinic.</p>

Longitudinal observation of an interferon gamma-released assay (T-SPOT.TB) for Mycobacterium tuberculosis infection in AIDS patients on highly active antiretroviral therapy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>T-SPOT.TB is a novel test for tuberculosis infection with higher sensitivity and specificity than the traditional tuberculin skin test (TST). However, there are no longitudinal data in the literature evaluating T-SPOT.TB for Mycobacterium tuberculosis in patients with acquired immune deficiency syndrome (AIDS) on highly active antiretroviral therapy (HAART). The objective of this study was to assess the value of T-SPOT.TB longitudinally in AIDS patients on HAART without prophylaxis for tuberculosis.</p><p><b>METHODS</b>A prospective observational study was conducted in 50 AIDS patients on HAART. None of the subjects had evidence of active tuberculosis. T-SPOT.TB, a T-cell-based interferon gamma released assay, was performed at the onset of the study and repeated 24 months thereafter. Subjects were evaluated every 6 months during the 36-month follow-up.</p><p><b>RESULTS</b>Twenty-one (42%) AIDS patients on HAART tested positive by T-SPOT.TB (95%CI 28.3% - 55.7%). The pooled spot-forming cells of early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) peptides were 68/million peripheral blood mononuclear cell (PBMC) (interquartile range 44 - 220). The average number of CD4 cells in subjects was (305 +/- 152) cells/microl, and there was no significant difference in T-SPOT.TB response rates between subjects with CD4 cell counts < 200 cells/microl (7/15 (46.7%), 95%CI 21.5% - 71.9%) and those with CD4 cell counts >/= 200 cells/microl (14/35 (40.0%), 95%CI 23.8% - 56.2%, P = 0.662). In the 32 subjects who completed the 24-month follow-up, 10 underwent T-SPOT.TB reversion, one had T-SPOT.TB conversion, six remained positive and 15 remained negative. None of them advanced to active tuberculosis during the 36-month follow-up.</p><p><b>CONCLUSION</b>The inactive status of tuberculosis infection may be maintained for a long period in AIDS patients on HAART.</p>

Differential effect of simulated microgravity on myogenic tone of middle cerebral and mesenteric small arteries in rats / 生理学报

The aim of the present study was to investigate the effect of a short-term (3-day) simulated microgravity with and without daily dorsoventral gravitation (-G(x)) for 1 h on myogenic tone and vasoconstrictor responsiveness of the middle cerebral artery and mesenteric third-order small artery in rats. The tail-suspension (SUS) model was used to simulate cardiovascular deconditioning due to microgravity. Daily restoring to normal standing (STD) posture for 1 h was adopted to provide -G(x) as the countermeasure. Segments of middle cerebral artery and mesenteric third-order small artery were isolated and cannulated. Vascular diameters in response to increased intraluminal pressure (from 20 mmHg to 120 mmHg, by 20 mmHg steps) of isolated arteries under no-flow conditions were recorded by a Pressure Myograph System in both physiologic salt solution (PSS) (active diameter, Da) and calcium-free PSS (passive diameter, Dp). The myogenic tone was calculated by (Dp-Da)/Dpx100%. Vasoconstrictor responsiveness of the isolated middle cerebral artery to serotonin and that of small mesenteric artery to phenylephrine were assessed in the PSS under an intraluminal pressure of 40 mmHg. The results showed that SUS induced an enhancement of the myogenic tone and vasoconstrictor responsiveness in the isolated middle cerebral artery but a depression of those in the small mesenteric artery. Daily STD for 1 h prevented the depression of myogenic tone and vasoconstrictor responsiveness in the small mesenteric artery, but did not prevent the functional enhancement in the middle cerebral artery. These data suggest that a short-term simulated microgravity may result in different alterations in the function of the cerebral artery and the resistance vessel in the hind-body. Moreover, only the decrease of function in these resistance vessels, not in the cerebral arteries, can be prevented by such a countermeasure of daily STD for 1 h.

Comparison of biomechanical behavior of cerebral and mesenteric small arteries of simulated microgravity rats / 生理学报

The aim of the present study was to further elucidate the mechanisms of vascular adaptation to microgravity and its gravity-based countermeasure by a biomechanical approach. Active (the dissected vessel segment was superfused with PPS) and passive (while it was superfused with Ca(2+)-free PPS) biomechanical properties of mesenteric third-order small arteries and middle cerebral arteries isolated from 3-day simulated microgravity (SUS), countermeasure (STD, daily 1 h of -G(x) gravitation), and control (CON) groups of rats were studied. The following mechanical parameters were calculated: the overall stiffness parameter of passive vessels (beta), circumferential stress (sigma(theta))-strain (epsilon(theta)) relationship, and pressure-dependent incremental elastic modulus (E(inc,p)) of both active and passive vessels, and vascular smooth muscle (VSM) activity-dependent incremental modulus (E(inc,a)). Results from the analysis of active biomechanical properties revealed the contribution of vascular smooth muscle (VSM) tone during the early adaptation to microgravity: (1) For mesenteric small arteries, active circumferential sigma(theta) -epsilon(theta) curve of SUS group was comparable with that of the passive vessels, indicating that the function of VSM to restore the normal stress distribution is compromised; however, this mal-adaptation was fully prevented by the countermeasure of daily 1 h of -G(x) gravitation; (2) For the middle cerebral arteries, active circumferential sigma(theta) -epsilon(theta) relation of SUS group was shifted to the left side of the passive curve and epsilon(theta) was kept at a nearly constant level with the corresponding sigma(theta) being at its normal range; furthermore, the enhanced myogenic tone responsiveness was not prevented by daily short-duration -G(x). Analysis of the passive biomechanical properties has suggested remodeling changes in matrix components of different types of vessels, which might be significant if the exposure duration was further prolonged. In brief, studies of vascular biomechanics are of particular importance in elucidating the mechanisms underlying vascular adaptation to microgravity and its gravity-based countermeasure.

Detection of specific interferon-gamma-secreting T cell response to Mycobacterium tuberculosis RD1-encoded antigens in pleural effusions, ascites, and cerebrospinal fluid / 中国医学科学院学报

<p><b>OBJECTIVE</b>To detect Mycobacterium tuberculosis RD1-encoded antigens-specific, interferon-gamma (INF-gamma)-secreting T cells in pleural effusions, ascites, and cerebrospinal fluid.</p><p><b>METHOD</b>The early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) peptides-specific T cells in peripheral blood mononuclear cell (MC), ascites MC, pleural effusions MC, and cerebrospinal fluid MC were detected using enzyme-linked immunospot assay (ELISPOT) for INF-gamma.</p><p><b>RESULTS</b>ESAT-6 or CFP-10 peptides-specific, INF-gamma-secreting T cells were detected in peripheral blood, ascites, pleural effusions, and cerebrospinal fluid, which marked the presence of tuberculosis infection. Patients with positive ELISPOT results of INF-gamma-release assay were all diagnosed as active tuberculosis. Spot forming cells in ascites and pleural effusions were much higher than those in peripheral blood (up to 6.4 and 31.9 times).</p><p><b>CONCLUSION</b>Detection of RD1-encoded antigens-specific, INF-gamma-secreting T cells in pleural effusions, ascites, and cerebrospinal fluid provides a new way to diagnose tuberculosis infection.</p>

Sensitivity of interferon-gamma release assay T-SPOT. TB in diagnosing extrapulmonary tuberculosis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the sensitivity of an interferon-gamma release assay T-SPOT. TB in the diagnosis of bacteriologically or histologically confirmed extrapulmonary tuberculosis.</p><p><b>METHOD</b>Totally 31 patients with bacteriologically or histologically confirmed extrapulmonary tuberculosis in Peking Union Medical College Hospital received T-SPOT. TB assay to detect early secreting antigen target 6 or culture filtrate protein 10 peptides-specific T cells in the peripheral blood mononuclear cells (PBMCs).</p><p><b>RESULTS</b>T-SPOT. TB assay showed positive results in 29 patients with extrapulmonary tuberculosis and the sensitivity was 93.5% (95% CI 84.8% - 100%). The median of spot forming cells (SFCs) in response to early secreting antigen target 6 peptides was 196/10(6) PBMCs (interquartile range, 72-532/10(6) PBMCs), the median of SFCs in response to culture filtrate protein 10 peptides was 276 SFCs/10(6) PBMCs (interquartile range, 72-568/10(6) PBMCs), and the median of the incorporate SFCs was 612/10(6) PBMCs (interquartile range, 192-1 152/10(6) PBMCs).</p><p><b>CONCLUSION</b>T-SPOT. TB is highly sensitive in diagnosing extrapulmonary tuberculosis.</p>

Combined application of enzyme-linked immunospot assay, positron emission tomography, and gene chip assay in the diagnosis of a case of chronic disseminated tuberculosis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To highlight the clinical features and diagnosis of chronic disseminated tuberculosis, with emphasizing the usefulness of several recently available diagnostic technologies in this setting.</p><p><b>METHOD</b>We presented a case of chronic disseminated tuberculosis diagnosed with the combined application of interferon-gamma release assay T-SPOT. TB, 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET), and gene chip assay.</p><p><b>RESULTS</b>A 53-year-old gentleman who had chronic cough for 7 years and fever for 2 weeks was referred to our hospital for further evaluation. 18F-FDG-PET/CT scan showed increased FDG uptake in multiple lesions involving bilateral lungs, supraclavicular, mediastinal and intro-abdominal lymph nodes and bones, mimicking metastatic malignancy. T-SPOT. TB assay revealed significant responses [ early secreting antigen target 6 (ESAT-6): 3 908 spot forming cells (SFCs)/10(6) peripheral blood mononuclear cells (PBMCs), culture filtrate protein (CFP-10): 3 400 SFCs/10(6) PBMCs]. Subsequent biopsy of supraclavicular lymph node, lung, and ilium revealed granulomas, while culture of the obtained tissue yeilded mycobacteria. Gene chip testing identified M. tuberculosis sensitive to isoniazid and rifampin. After 10 weeks of treatment for tuberculosis, the patient's condition was improved and a second T-SPOT. TB assay showed significantly reduced responses (ESAT-6: 1528 SFCs/10(6) PBMCs; CFP-10: 1460 SFCs/10(6) PBMCs).</p><p><b>CONCLUSIONS</b>Timely diagnosis of chronic disseminated tuberculosis requires high index of suspicion. T-SPOT. TB assay, PET/CT, and gene chip assay may provide valuable information that facilitates further diagnostic procedures and treatment decision.</p>

Advances in clinical applications of T-SPOT. TB for interferon-gamma release assay in the immunodiagnosis of tuberculosis / 中国医学科学院学报

T-SPOT. TB is an interferon-gamma release assay to detect T-cell response to early secreting antigen target 6 and culture filtrate protein 10 peptides by enzyme-linked immunospot assay for tuberculosis diagnosis. It is highly sensitive and specific, and will not be affected by the subject's immune status and Bacillus Calmette-Guerin vaccination. This assay has been licensed for in-vitro diagnosis in Europe and the United States. Its potential roles in distinguishing active tuberculosis from latent tuberculosis infection and predicting active tuberculosis among individuals with latent tuberculosis have been increasingly studies. This article reviews the advances in the clinical application of T-SPOT. TB.

Spectral analysis of blood pressure signal in conscious rats released from simulated microgravity / 生理学报

The aim of the present study was to examine whether there are changes in systolic and diastolic blood pressure (SBP and DBP) and heart rate (HR) and their spectral indices in conscious free-moving rats after tail-suspension for 28 d. The tail-suspended hindlimb-unloaded (HU) rat model was used to simulate the cardiovascular effect of microgravity and the post-spaceflight cardiovascular dysfunction. The auto- and cross-spectral analysis of SBP variability (SBPV) and HR variability (HRV) were performed by the method based on the autoregressive model (AR), and the auto-spectral results was compared with the results from the classical periodogram method. The baroreceptor-heart rate reflex sensitivity (BRS) was estimated using transfer function analysis from SBP to HR. The results indicated that auto-spectral results based on the two methods were comparable, while smoother power spectral curves with distinguished peaks were trained by the AR method. The means of SBP, DBP, and HR, the main spectral indices of SBPV and HRV, and the mean average gain of transfer functions computed at low- and high-frequency ranges (0.25-0.8 Hz and 0.8-2.4 Hz) did not show significant changes before and after release from suspension. Furthermore, the main spectral indices of SBPV and HRV at different time points did not show significant differences between the control and suspension groups. However, the means of SBP, DBP, and HR at different time points were significantly higher in simulated weightless rats than those in the control rats. The findings of the present study suggest that a mid-term simulated microgravity might induce hypertension and tachycardia upon removal from the suspension which reflects a general sympathetic hyperactivity. We speculated that the sympathetic hyperactivity might be a compensatory mechanism activated in the intact animal to counteract HU-induced hypo-responsiveness of resistance vessels. In addition, lack of clear and distinct changes in HRV and BRS have also been reported in some recent space and ground-based human studies.