Tyrosine phosphorylation of IRF3 by BLK facilitates its sufficient activation and innate antiviral response.

Viral infection triggers the activation of transcription factor IRF3, and its activity is precisely regulated for robust antiviral immune response and effective pathogen clearance. However, how full activation of IRF3 is achieved has not been well defined. Herein, we identified BLK as a key kinase that positively modulates IRF3-dependent signaling cascades and executes a pre-eminent antiviral effect. BLK deficiency attenuates RNA or DNA virus-induced ISRE activation, interferon production and the cellular antiviral response in human and murine cells, whereas overexpression of BLK has the opposite effects. BLK-deficient mice exhibit lower serum cytokine levels and higher lethality after VSV infection. Moreover, BLK deficiency impairs the secretion of downstream antiviral cytokines and promotes Senecavirus A (SVA) proliferation, thereby supporting SVA-induced oncolysis in an in vivo xenograft tumor model. Mechanistically, viral infection triggers BLK autophosphorylation at tyrosine 309. Subsequently, activated BLK directly binds and phosphorylates IRF3 at tyrosine 107, which further promotes TBK1-induced IRF3 S386 and S396 phosphorylation, facilitating sufficient IRF3 activation and downstream antiviral response. Collectively, our findings suggest that targeting BLK enhances viral clearance via specifically regulating IRF3 phosphorylation by a previously undefined mechanism.

[Cystic fibrosis primarily presenting with pseudo-Bartter syndrome: a report of three cases and literature review]. / 以假性Bartter综合征为主要表现的囊性纤维化患儿3ä¾‹å¹¶æ–‡çŒ®å¤ä¹ .

OBJECTIVES: To summarize the clinical characteristics and genetic variations in children with cystic fibrosis (CF) primarily presenting with pseudo-Bartter syndrome (CF-PBS), with the aim to enhance understanding of this disorder. METHODS: A retrospective analysis was performed on the clinical data of three children who were diagnosed with CF-PBS in Hunan Children's Hospital from January 2018 to August 2023, and a literature review was performed. RESULTS: All three children had the onset of the disease in infancy. Tests after admission showed hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis, and genetic testing showed the presence of compound heterozygous mutation in the CFTR gene. All three children were diagnosed with CF. Literature review obtained 33 Chinese children with CF-PBS, with an age of onset of 1-36 months and an age of diagnosis of 3-144 months. Among these children, there were 29 children with recurrent respiratory infection or persistent pneumonia (88%), 26 with malnutrition (79%), 23 with developmental retardation (70%), and 18 with pancreatitis or extrapancreatic insufficiency (55%). Genetic testing showed that c.2909G>A was the most common mutation site of the CFTR gene, with a frequency of allelic variation of 23% (15/66). CONCLUSIONS: CF may have no typical respiratory symptoms in the early stage. The possibility of CF-PBS should be considered for infants with recurrent hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis, especially those with malnutrition and developmental retardation. CFTR genetic testing should be performed as soon as possible to help with the diagnosis of CF.

Deactivation of the kinase IKK by CUEDC2 through recruitment of the phosphatase PP1.

Despite rapid progress in elucidating the molecular mechanisms of activation of the kinase IKK, the processes that regulate IKK deactivation are still unknown. Here we demonstrate that CUE domain-containing 2 (CUEDC2) interacted with IKKalpha and IKKbeta and repressed activation of the transcription factor NF-kappaB by decreasing phosphorylation and activation of IKK. Notably, CUEDC2 also interacted with GADD34, a regulatory subunit of protein phosphatase 1 (PP1). We found that IKK, CUEDC2 and PP1 existed in a complex and that IKK was released from the complex in response to inflammatory stimuli such as tumor necrosis factor. CUEDC2 deactivated IKK by recruiting PP1 to the complex. Therefore, CUEDC2 acts as an adaptor protein to target IKK for dephosphorylation and inactivation by recruiting PP1.

MiR-200a and miR-200b restrain inflammation by targeting ORMDL3 to regulate the ERK/MMP-9 pathway in asthma.

BACKGROUND: Asthma is one of the most frequent and serious diseases worldwide. Inflammation has been reported to correlate with airway remodeling, which is critical for the progression of asthma. Better understanding of novel molecules modulating asthma and the underlying mechanism will benefit explorations of new treatments. Method: To explore the role of miR-200a and miR-200b in asthma, miR-200a mimics/inhibitor and miR-200b mimics/inhibitor were employed in A549 cells, respectively. Expression levels of inflammatory cytokines, including TNF-α, IL-4, IL-5, IL-13 and IL-1ß, were measured by quantitative real time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). A dual luciferase reporter assay was performed to identify whether miR-200a/200b directly bound to Orosomucoid 1-like 3 (ORMDL3). ERK, p-ERK and MMP-9, involved in downstream pathways of ORMDL3, were detected using qRT-PCR and western blotting. Results: MiR-200a/200b silencing significantly increased the expression of inflammatory cytokines, including TNF-α, IL-4, IL-5, IL-13 and IL-1ß, in A549 cells. ORMDL3 was the target gene of miR-200a/200b, with high expression levels in miR-200a inhibitor and miR-200b inhibitor groups. MiR-200a and miR-200b played synergistic roles in the regulation of the inflammatory effect in A549 cells. Expression levels of p-ERK and MMP-9 were significantly increased in miR-200a inhibitor and miR-200b inhibitor groups and were rescued by ERK inhibitor and MMP-9 inhibitor, respectively. Conclusion: These findings suggest that miR-200a and miR-200b are required to regulate asthma inflammation. Reduction in miR-200a/200b promotes the development of asthma inflammation by targeting ORMDL3 to activate the ERK/MMP-9 pathway. Therefore, elevating miR-200a and miR-200b and decreasing ORMDL3 might be potential strategies for inhibition of the asthma process.

[Different effects of long-term and short-term repeated restraints on the hematopoietic stem cells in mice].

Humans with chronic psychological stress are prone to develop multiple disorders of body function including impairment of immune system. Chronic psychological stress has been reported to have negative effects on body immune system. However, the underlying mechanisms have not been clearly demonstrated. All immune cells are derived from hematopoietic stem cells (HSC) in the bone marrow, including myeloid cells which comprise the innate immunity as a pivotal component. In this study, to explore the effects of chronic psychological stress on HSC and myeloid cells, different repeated restraint sessions were applied, including long-term mild restraint in which mice were individually subjected to a 2 h restraint session twice daily (morning and afternoon/between 9:00 and 17:00) for 4 weeks, and short-term vigorous restraint in which mice were individually subjected to a 16 h restraint session (from 17:00 to 9:00 next day) for 5 days. At the end of restraint, mice were sacrificed and the total cell numbers in the bone marrow and peripheral blood were measured by cell counting. The proportions and absolute numbers of HSC (Lin-CD117+Sca1+CD150+CD48-) and myeloid cells (CD11b+Ly6C+) were detected by fluorescence activated cell sorting (FACS) analysis. Proliferation of HSC was measured by BrdU incorporation assay. The results indicated that the absolute number of HSC was increased upon long-term mild restraint, but was decreased upon short-term vigorous restraint with impaired proliferation. Both long-term mild restraint and short-term vigorous restraint led to the accumulation of CD11b+Ly6C+ cells in the bone marrow as well as in the peripheral blood, as indicated by the absolute cell numbers. Taken together, long-term chronic stress led to increased ratio and absolute number of HSC in mice, while short-term stress had opposite effects, which suggests that stress-induced accumulation of CD11b+Ly6C+ myeloid cells might not result from increased number of HSC.

Acute and chronic pain affects local field potential of the medial prefrontal cortex in different band neural oscillations.

The medial prefrontal cortex is involved in the process of sensory discrimination. In this study, we examined the local field potential activity response to the different stages of pain in the prelimbic cortex (PrL) which is a sub-region of the medial prefrontal cortex. Recent studies revealed extensive information about neural oscillations, but there is limited information on the local field potential profiles for acute or chronic pain, particularly in freely moving animals. This study showed that acute mechanical pain increases alpha oscillation and decreases beta and gamma oscillations before spared nerve injury surgery. Delta oscillation was decreased by chronic pain and gamma oscillation varied with time. However, acute mechanical pain stimulus had no effects on local field potential in rats under mechanical allodynia. Together, our findings provide novel insights into the role of medial prefrontal cortex local field potential activity response to pain stimulus.

BLK positively regulates TLR/IL-1R signaling by catalyzing TOLLIP phosphorylation.

TLR/IL-1R signaling plays a critical role in sensing various harmful foreign pathogens and mounting efficient innate and adaptive immune responses, and it is tightly controlled by intracellular regulators at multiple levels. In particular, TOLLIP forms a constitutive complex with IRAK1 and sequesters it in the cytosol to maintain the kinase in an inactive conformation under unstimulated conditions. However, the underlying mechanisms by which IRAK1 dissociates from TOLLIP to activate TLR/IL-1R signaling remain obscure. Herein, we show that BLK positively regulates TLR/IL-1R-mediated inflammatory response. BLK-deficient mice produce less inflammatory cytokines and are more resistant to death upon IL-1ß challenge. Mechanistically, BLK is preassociated with IL1R1 and IL1RAcP in resting cells. IL-1ß stimulation induces heterodimerization of IL1R1 and IL1RAcP, which further triggers BLK autophosphorylation at Y309. Activated BLK directly phosphorylates TOLLIP at Y76/86/152 and further promotes TOLLIP dissociation from IRAK1, thereby facilitating TLR/IL-1R-mediated signal transduction. Overall, these findings highlight the importance of BLK as an active regulatory component in TLR/IL-1R signaling.

Migration of dorsal aorta mesenchymal stem cells induced by mouse embryonic circulation.

Mesenchymal stem cells (MSCs) represent powerful tools for regenerative medicine for their differentiation and migration capacity. However, ontogeny and migration of MSCs in mammalian mid-gestation conceptus is poorly understood. We identified canonical MSCs in the mouse embryonic day (E) 11.5 dorsal aorta (DA). They possessed homogenous immunophenotype (CD45(-)CD31(-)Flk-1(-)CD44(+)CD29(+)), expressed perivascular markers (α-SMA(+)NG2(+)PDGFRß(+)PDGFRα(+)), and had tri-lineage differentiation potential (osteoblasts, adipocytes, and chondrocytes). Of interest, MSCs were also detected in E12.5-E13.5 embryonic circulation, 24 hr later than in DA, suggesting migration like hematopoietic stem cells. Functionally, E12.5 embryonic blood could trigger efficient migration of DA-MSCs through platelet-derived growth factor (PDGF) receptor-, transforming growth factor-beta receptor-, but not basic fibroblast growth factor receptor-mediated signaling. Moreover, downstream JNK and AKT signaling pathway played important roles in embryonic blood- or PDGF-mediated migration of DA-derived MSCs. Taken together, these results revealed that clonal MSCs developed in the mouse DA. More importantly, the embryonic circulation, in addition to its conventional transporting roles, could modulate migration of MSC during early embryogenesis.

LncRNA NEAT1 regulates MMP-16 by targeting miR-200a/b to aggravate inflammation in asthma.

Asthma is a common respiratory disease which is characterized by persistent airway inflammation. Abnormal expression of long non-coding RNAs (lncRNAs) is observed in asthma. However, whether lncRNA nuclear-enriched abundant transcript 1 (NEAT1) regulates asthmatic inflammation and its mechanism still needs to be further investigated. The expression levels of inflammatory factors (tumour necrosis factor (TNF)-α, interleukin (IL)-4, IL-13, and IL-10) were detected using reverse transcription quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). MTT and flow cytometry assays were employed to determine cell proliferation and apoptosis, respectively. Dual luciferase reporter assay was performed to verify the relationship between miR-200a/b and MMP-16 or NEAT1. NEAT1 silencing markedly reduced TNF-α, IL-4, and IL-13 levels, while elevated IL-10 expression, suppressed cell proliferation, and promoted cell apoptosis. However, NEAT1 overexpression elicited the opposite effects on cell proliferation and inflammation cytokines secretion. What is more, NEAT1 negatively regulated miR-200a/b expression, and MMP16 was a target gene of miR-200a/b. miR-200a/b overexpression suppressed inflammation, cell proliferation, and enhanced cell apoptosis through regulation of MMP16. Moreover, MMP-16 overexpression or miR-200a/b inhibition abolished the regulatory effect of sh-NEAT1 on cell inflammation and apoptosis in BEAS-2B cells. NEAT1 acted as the role of sponge for miR-200a/b to regulate MMP-16 expression, thereby promoting asthma progression, suggesting that NEAT1 might have great potential as therapeutic target for asthma.

Lasting antibody and T cell responses to SARS-CoV-2 in COVID-19 patients three months after infection.

The dynamics, duration, and nature of immunity produced during SARS-CoV-2 infection are still unclear. Here, we longitudinally measured virus-neutralising antibody, specific antibodies against the spike (S) protein, receptor-binding domain (RBD), and the nucleoprotein (N) of SARS-CoV-2, as well as T cell responses, in 25 SARS-CoV-2-infected patients up to 121 days post-symptom onset (PSO). All patients seroconvert for IgG against N, S, or RBD, as well as IgM against RBD, and produce neutralising antibodies (NAb) by 14 days PSO, with the peak levels attained by 15-30 days PSO. Anti-SARS-CoV-2 IgG and NAb remain detectable and relatively stable 3-4 months PSO, whereas IgM antibody rapidly decay. Approximately 65% of patients have detectable SARS-CoV-2-specific CD4+ or CD8+ T cell responses 3-4 months PSO. Our results thus provide critical evidence that IgG, NAb, and T cell responses persist in the majority of patients for at least 3-4 months after infection.

Interleukin-3 promotes hemangioblast development in mouse aorta-gonad-mesonephros region.

BACKGROUND: The hemangioblast is a bi-potential precursor cell with the capacity to differentiate into hematopoietic and vascular cells. In mouse E7.0-7.5 embryos, the hemangioblast can be identified by a clonal blast colony-forming cell (BL-CFC) assay or single cell OP9 co-culture. However, the ontogeny of the hemangioblast in mid-gestation embryos is poorly defined. DESIGN AND METHODS: The BL-CFC assay and the OP9 system were combined to illustrate the hemangioblast with lymphomyeloid and vascular potential in the mouse aorta-gonad-mesonephros region. The colony-forming assay, reverse transcriptase polymerase chain reaction analysis, immunostaining and flow cytometry were used to identify the hematopoietic potential, and Matrigel- or OP9-based methods were employed to evaluate endothelial progenitor activity. RESULTS: Functionally, the aorta-gonad-mesonephros-derived BL-CFC produced erythroid/myeloid progenitors, CD19(+) B lymphocytes, and CD3(+)TCRbeta(+) T lymphocytes. Meanwhile, the BL-CFC-derived adherent cells generated CD31(+) tube-like structures on OP9 stromal cells, validating the endothelial progenitor potential. The aorta-gonad-mesonephros-derived hemangioblast was greatly enriched in CD31(+), endomucin(+) and CD105(+) subpopulations, which collectively pinpoints the endothelial layer as the main location. Interestingly, the BL-CFC was not detected in yolk sac, placenta, fetal liver or embryonic circulation. Screening of candidate cytokines revealed that interleukin-3 was remarkable in expanding the BL-CFC in a dose-dependent manner through the JAK2/STAT5 and MAPK/ERK pathways. Neutralizing interleukin-3 in the aorta-gonad-mesonephros region resulted in reduced numbers of BL-CFC, indicating the physiological requirement for this cytokine. Both hematopoietic and endothelial differentiation potential were significantly increased in interleukin-3-treated BL-CFC, suggesting a persistent positive influence. Intriguingly, interleukin-3 markedly amplified primitive erythroid and macrophage precursors in E7.5 embryos. Quantitative polymerase chain reaction analysis demonstrated declined Flk-1 and elevated Scl and von Willebrand factor transcription upon interleukin-3 stimulation, indicating accelerated hemangiopoiesis. CONCLUSIONS: The hemangioblast with lymphomyeloid potential is one of the precursors of definitive hematopoiesis in the mouse aorta-gonad-mesonephros region. Interleukin-3 has a regulatory role with regards to both the number and capacity of the dual-potential hemangioblast.

The characteristic of an anti-human DR5 antibody A6.

The efficacy of many cancer treatments is due to their ability to induce apoptosis. DR5 can activate apoptosis pathway after binding with its natural ligand, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L). Both TRAIL and agonistic anti-DR5 monoclonal antibody are currently being explored for cancer therapy. The mechanisms of cytotoxicity of our previously prepared monoclonal antibody A6 against DR5 were investigated here. A6 could cause viability loss of Jurkat cells in both time- and dose-dependent manner which could be attributed to the activation of apoptosis pathway. Caspases 3, 8 and 9 were activated in Jurkat cells and the caspase specific inhibitors, such as broad caspases inhibitor Z-VAD-FMK, caspase 8 specific inhibitor Z-IETD-FMK and caspase 9 specific inhibitor Z-LEHD-FMK could recover the viability loss caused by A6. The function and molecular mechanism of TRAIL-mediated apoptosis were also investigated and compared with those of A6. Although A6 and TRAIL recognize a different epitope, they could induce a similar reaction in Jurkat cells.

Gabapentin regulates dopaminergic neuron firing and theta oscillation in the ventral tegmental area to reverse depression-like behavior in chronic neuropathic pain state.

PURPOSE: Ventral tegmental area (VTA) dopamine system plays an important role in depression and is also involved in pain experience. In this study, we investigated the VTA dopaminergic (DA) neuron firing and local field potential (LFP) in pain-related depression, and we try to explore the underlying relationship between pain and depression. MATERIALS AND METHODS: We used neuropathic pain model [spare nerve injury (SNI)] to induce pain-related depression. The Dixon up-down method was used to test mechanical hypersensitivity. Behavioral changes like open field test, sucrose preference test, and forced swim test were used to test depression-like behaviors. Gabapentin (GBP) was used to explore the chronic analgesic treatment that could reverse pain-related depression. To investigate the in vivo variations of VTA DA neuron firing and LFP, multichannel acquisition processor system was used. RESULTS: We used SNI to induce depression-like behaviors. Repeated GBP treatment reversed these behaviors after 14 days of injection. An in vivo electrophysiological analysis of the firing characteristics of VTA DA neurons and LFP revealed that SNI increased the firing rate of DA neurons, but not the burst firing activity. Surprisingly, chronic GBP reversed the firing rate of DA neurons and reduced the burst firing activity. Moreover, SNI increased the LFP power in delta and theta oscillation and decreased it in beta oscillation. Repeated administration of GBP significantly suppressed theta oscillation. Above all, chronic GBP altered these characteristics to reverse depression-like behaviors. CONCLUSION: The present study confirmed that the tonic firing activity of VTA DA neurons, but not the burst firing activity, was the key factor in peripheral neuropathy-induced depression. Chronic GBP regulated the firing pattern of DA neurons and decreased theta oscillation in VTA to treat pain-related depression. This variation tendency of electrophysiological characteristics of VTA DA neurons and theta oscillation in VTA might represent an attempt to cope with pain-related negative mood disorder.

Proteomic analysis of interleukin 6-induced differentiation in mouse myeloid leukemia cells.

Cytokine-induced differentiation of myeloid leukemia cells has important therapeutic implications, but the mechanism remains to be clarified. M1 cell, a mouse acute myeloid leukemia cell line, which underwent growth inhibition, terminal differentiation and apoptosis in response to IL-6, was selected as an experimental model to study on the molecular mechanisms of myeloid cell differentiation on a proteome-wide scale. Cell differentiation was evaluated by cell morphology and CD11b expression. With two-dimensional (2D) gel analyses, 17 protein spots showed obvious changes in quantity during the process of differentiation were found. With matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF-MS) or/and nano-electrospray ionization MS/MS (ESI-MS/MS) analysis, 15 protein spots were identified. The mRNA levels of these 15 proteins during differentiation were also examined using a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Except two proteins, the mRNA levels demonstrated similar expression patterns to what the proteomic analysis revealed. The identified proteins were known to be involved in different cellular functions, including protein synthesis, transcription, signal transduction, cell cycle control, cell rescue and defense, cellular organization, and metabolism. Notably, seven proteins were not described before to be involved in differentiation. Our data provide novel information for a better understanding of the mechanisms by which terminal differentiation of acute myeloid leukemia cells induced by IL-6.

Phosphatidylinositol(PI)-3 Kinase Contributes to the Activation of Stat3 in M1 Leukemia Cells Induced by IL-6.

Wortmannin, a specific inhibitor of PI-3 kinase, antagonized the inhibitory effect of IL-6 in M1 acute myeloid leukemia cells. Electrophoretic mobility shift assays revealed that wortmannin selectively reduced the IL-6-induced activation of Stat3, while Stat3 plays a central role in IL-6-induced growth-arrest and terminal differentiation of M1 cells. These results indicated that PI-3 kinase was involved in the signal transduction of IL-6 and contributed to the activation of Stat3.

Is gestational hypertension protective against perinatal mortality in twin pregnancies?

BACKGROUND: Pregnancy-induced or gestational hypertension is a common pregnancy complication. Paradoxically, gestational hypertension has been associated with a protective effect against perinatal mortality in twin pregnancies in analytic models (logistic regression) without accounting for survival time. Whether this effect is real remains uncertain. This study aimed to validate the impact of gestational hypertension on perinatal mortality in twin pregnancies using a survival analysis approach. METHODS: This was a retrospective cohort study of 278,821 twin pregnancies, using the U.S. 1995-2000 matched multiple birth dataset (the largest dataset available for multiple births). Cox proportional hazard models were applied to estimate the adjusted hazard ratios (aHR) of perinatal death (stillbirth and neonatal death) comparing gestational hypertensive vs. non-hypertensive pregnancies controlling for maternal characteristics and twin cluster-level dependence. RESULTS: Comparing births in gestational hypertensive vs. non-hypertensive twin pregnancies, perinatal mortality rates were significantly lower (1.20% vs. 3.38%), so were neonatal mortality (0.72% vs. 2.30%) and stillbirth (0.48% vs. 1.10%) rates. The aHRs (95% confidence intervals) were 0.34 (0.31-0.38) for perinatal death, 0.31 (0.27-0.34) for neonatal death, and 0.45 (0.38-0.53) for stillbirth, respectively. The protective effect of gestational hypertension against perinatal death became weaker over advancing gestational age; the aHRs in very preterm (<32 weeks), mild preterm (32-36 weeks) and term (37+ weeks) births were 0.29, 0.48 and 0.76, respectively. The largest risk reductions in neonatal mortality were observed for infections and immaturity-related conditions. CONCLUSIONS: Gestational hypertension appears to be beneficial for fetal survival in twin pregnancies, especially in those ending more prematurely or for deaths due to infections and immaturity-related conditions. Prospective studies are required to rule out the possibility of unmeasured confounders.

[Hyperactivation of c-Jun NH(2)-terminal protein kinase contributes to the proliferation of B lymphoma cells].

This study was purposed to explore the effect of hyperactivation of c-Jun NH(2)-terminal protein kinase (JNK) on the proliferation of B lymphoma cells. The human B lymphoma cell lines Daudi and Raji were chosen as research objects. The expression of JNK protein was determined by Western blot. The subcellular localization of JNK protein was detected by immunofluorescence. The cell cycle was analyzed by flow cytometry. The suppressive effect of JNK inhibitor SP600125 on the proliferation of Daudi and Raji cells was assayed by ATPLite method. The results demonstrated that hyperactivation of JNK has been found in Daudi and Raji cells. Immunofluorescence confirmed the aberrant subcellular localization of JNK protein in Daudi and Raji cells. Cell cycle assay revealed that Daudi and Raji cells underwent G(2)-M arrest in the presence of SP600125. Furthermore, Daudi and Raji cells showed significant increase in sub-G(1) population, an indicator of apoptotic cells, with the treatment of JNK inhibitors. These data suggested that JNK inhibitors suppressed the growth of B lymphoma cells via cell cycle arrest and apoptosis. Daudi and Raji cells treated with different concentrations of JNK selective inhibitor SP600125 showed dose-dependent reduction in the growth of Daudi and Raji cells. It is concluded that hyperactivation of JNK enhance the proliferation of Daudi and Raji cells. The aberrant subcellular localization of JNK protein may facilitate the nuclear accumulation of basal JNK activity, which made JNK to be a potential target to treat human B lymphoma.

Calibration error on the measurement of back vertex power for contact lenses with method using focimeter with manual focusing.

PURPOSE: The International Standard ISO 9337-1, which sets forth the method for measuring back vertex power of contact lenses with manually focusing focimeters, specifies that test lenses conforming to ISO 9342 may be used to calibrate focimeters on its spectacle lens support, and correction values obtained in this way can be used directly in measuring contact lenses on its contact lens support. This study was conducted because of concern that the method mentioned in ISO 9337-1 is not good enough for the calibration of focimeters used to measure contact lenses. METHODS: To test the validity of this method, a research group from China National Institute of Metrology (NIM) studied it theoretically and carried out a series of comparison experiments, respectively, with the conventional test lenses conforming to ISO 9342 and test lenses made at NIM (with an expanded uncertainty of 0.025 D). RESULTS: The results show that the measurement error between the two calibration methods will exceed 0.50 D if the specification described in ISO 9337-1 is adopted. This error also exceeds allowable tolerances for focimeters and for contact lenses themselves. Experiments and theoretical calculations done by the NIM group show that these errors mainly come from spherical aberration. Vertex error induced by the lens support is not negligible. CONCLUSION: When focimeters are calibrated to find correction values with the method specified in ISO 9337-1, measurement error will not be eliminated if these correction values are used in measuring contact lenses, and the resulting deviation is too large to be ignored. Therefore, special test lenses should be used to calibrate focimeters to find correction values when these focimeters are used to measure back vertex power of contact lenses because contact lenses are a special product being used to correct human vision.

Comparison of IL-6-induced STAT1 activation in different responsive cells.

AIM: To investigate the activation status of signal transducer and activator of transcription 1 (STAT1) induced by interlerkin-6 (IL-6) in different responsive cells. METHODS: Immunoblot analysis was performed with antibodies against STAT1 and tyrosine-phosphorylated STAT1. RESULTS: It's found that IL-6 had growth-promoting effects on 7TD1 and TF1 cells but had little effect on the tyrosine-phosphorylation of STAT1. On the other hand, IL-6 activated STAT1 in a dose and time-dependent manner in M1, R2 and U937 cells which underwent growth arrest and macrophage differentiation upon IL-6 induction. CONCLUSION: These results suggest that IL-6-induced STAT1 activation might be associated with growth-inhibitory effects, and our data might help to explain why IL-6 exerts distinct biological effects in different target cells.