Weight-dependent Fluorescence Lifetime Imaging for Viscosity Detection in Glycerol-water Mixtures / 生物化学与生物物理进展

ObjectiveBased on fluorescence lifetime imaging technology, a novel method for viscosity detection is proposed and the capability of different weighting of fluorescence lifetimes in distinguishing the viscosity of glycerol-water mixtures is evaluated, aiming to enhance the accuracy and reliability of viscosity differentiation. MethodsThis approach incorporates the principles of electronic weighting, introducing both amplitude-weighted average fluorescence lifetime (τm) and intensity-weighted average fluorescence lifetime (τi). Viscosity changes in glycerol-water mixtures are detected through τm and τi. τm Reflects the relationship between fluorescence signal amplitude and time, while τi focuses on the time-varying characteristics of fluorescence signal intensity. ResultsThe results of both τm and τi mutually corroborate each other, not only enhancing the reliability in detecting viscosity changes in glycerol-water mixtures but also revealing their unique roles in the detection process. Although τm plays a crucial role in capturing changes in fluorescence signal amplitude, τi exhibits higher accuracy in viscosity detection when considering the time-varying characteristics of fluorescence signal intensity. It is particularly noteworthy that, due to τi’s greater sensitivity, microenvironment viscosity detection can be directly analyzed using τi. This provides a more convenient approach for real-time, highly sensitive microfluidic viscosity monitoring. Therefore, through the comprehensive utilization of τm and τi, a more thorough and accurate understanding of the viscosity information in glycerol-water mixtures can be obtained, and specific parameters can be selected for in-depth analysis based on specific needs. ConclusionThe combination of amplitude weighting and intensity weighting allows for a more sensitive identification of subtle changes in viscosity under different conditions. The innovation of this method lies in its simultaneous consideration of multiple parameters, enhancing sensitivity and distinguishability to variations in viscosity. Therefore, this weighted-dependent fluorescence lifetime imaging technique not only introduces a novel approach for viscosity detection in glycerol-water mixtures but also provides a powerful analytical tool for various fields, including microfluidics, rheology, and research on novel functional materials.

The acute and long-term outcome of patients with ST segment elevation myocardial infarction concurrent with chronic total occlusion / 中华心血管病杂志

Objective: To evaluate the acute and long-term outcome of patients with ST segment elevation myocardial infarction (STEMI) concurrent with chronic total occlusion (CTO) undergoing primary percutaneous coronary intervention (PCI). Methods: 11 905 STEMI patients from the China Acute Myocardial Infarction Registry were enrolled in this study and divided into CTO group and non-CTO group according to the angiography results of primary PCI. 1∶3 propensity score matching was used to match the patients between the two groups. The primary endpoint was in-hospital mortality and mortality at 1-year post PCI. The secondary endpoint was major adverse cardiovascular events (MACE) including death, re-myocardial infarction, revascularization, heart failure associated readmission, stroke and major bleeding at 1-year post PCI. Results: There were 931 CTO patients (7.8%) in this cohort (male=755 (81.1%), mean age (62.2±11.4 years)). The rest 10 974 patients were STEMI without CTO (male=8 829 (80.5%),mean age (60.0±11.8) years). After propensity score matching, 896 patients were enrolled in CTO group and 2 688 in non-CTO group. In-hospital mortality was significantly higher in the CTO group than in non-CTO group (4.2% vs. 2.4%, P=0.006). The ratio of all cause death, cardiac death, and MACE at 1-year follow up was also significantly higher in the CTO group than in non-CTO group (8.5% vs. 4.4%, P<0.001, 5.3% vs. 2.6%, P=0.001, 35.1% vs. 23.3%, P<0.001, respectively). Multiple regression analysis showed that CTO (HR=1.54, 95%CI 1.06-2.22, P=0.022), advanced age (HR=1.06, 95%CI 1.04-1.08, P<0.001), and previous heart failure history (HR=4.10, 95%CI 1.90-8.83, P<0.001) were independent risk factors of 1-year mortality. Conclusions: The in-hospital and 1-year mortality increased significantly in STEMI patients concurrent with CTO. CTO, advanced age and history of heart failure are independent risk factors of 1-year death among STEMI patients.

Identification of a novel CHS1/LYST variant in a Chinese pedigree affected with Chediak-Higashi syndrome / 中华医学遗传学杂志

OBJECTIVE@#To detect pathological variant in two patients with Chediak-Higashi syndrome (CHS) from a consanguineous family and to explore its genotype-phenotype correlation.@*METHODS@#Clinical data was collected for this pedigree. Genomic DNA was prepared from probands' peripheral leukocytes and their relatives' fingernail. Whole exome sequencing and Sanger sequencing were carried out to detect potential variant of the LYST gene.@*RESULTS@#The proband presented with partial oculocutaneous albinism, immunodeficiency and acidophilic inclusion body in bone marrow and blood smears. A novel homozygous nonsense variant c.8782C>T (p.Gln2928*) was identified in exon 34 of the LYST gene in the sib pair. The same variant was found to be in heterozygous status in 6 unaffected individuals from the pedigree.@*CONCLUSION@#Above result enriched the mutational spectrum of CHS and provided a basis for genetic counseling and prenatal diagnosis for this pedigree.

Flurbiprofen axetil promotes neuroprotection by activation of cerebral peroxisome proliferator-activated receptor gamma after focal cerebral ischemia in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Our previous papers indicate that flurbiprofen axetil (FA), a cyclooxygenase inhibitor, is a promising therapeutic strategy for cerebral ischemia in rats. This study aimed to investigate whether FA could promote a neuroprotective effect by activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) after focal cerebral ischemia in rats.</p><p><b>METHODS</b>Totally 48 male Sprague-Dawley (SD) rats were randomly assigned into six groups (n = 8 in each group): animals in group ischemia/reperfusion (I/R) only received 120-minute transient middle cerebral artery occlusion (tMCAO); animals in group I/R + FA were administered FA (10 mg/kg) by caudal vein just after 120-minute tMCAO; animals in group I/R + FA + GW9662 were administered GW9662 (a PPAR-γ inhibitor, 1 mg/kg) intraperitoneally 30 minutes before cerebral ischemia onset and FA (10 mg/kg) by caudal vein just after 120-minute tMCAO; animals in group I/R + GW9662 were administered GW9662 (1 mg/kg) intraperitoneally 30 minutes before cerebral ischemia onset; animals in group I/R + DMSO were administered 3% DMSO (vehicle of GW9662, 1 ml/kg) intraperitoneally 30 minutes before cerebral ischemia onset; animals in sham group experienced the identical surgery apart from the insertion of the nylon filament. The neurologic deficit score (NDS) were performed at 72 hours after reperfusion, and then mean brain infarct volume percentage (MBIVP) was determined with 2,3,5-triphenyltetrazolium chloride (TTC) 10 g/L staining.</p><p><b>RESULTS</b>NDS was significantly increased in group I/R + FA (12.0 (10.0 - 15.0)), group I/R + FA + GW9662 (10.0 (8.0 - 12.0)), and in group I/R + FA + DMSO (12.0 (9.0 - 14.0)) at 72 hours after reperfusion compared with those in group I/R (7.5 (6.0 - 10.0)). NDS was conspicuously different between group I/R + FA (12.0 (10.0 - 15.0)) and group I/R + FA + GW9662 (10.0 (8.0 - 12.0)). MBIVP in group I/R ((45.82 - 8.83)%) was significantly greater than that in group I/R + FA ((23.52 - 9.90)%), group I/R + FA + GW9662 ((33.17 - 7.15)%); MBIVP in group I/R + FA ((23.52 - 9.90)%) was significantly smaller than that in group I/R + FA + GW9662 ((33.17 - 7.15)%).</p><p><b>CONCLUSIONS</b>FA confers the neuroprotective effect on tMCAO in rats and the selective PPAR-γ antagonist GW9662 attenuates the effect of FA. FA could promote a neuroprotective effect by, or in part, activation of PPAR-γ after focal cerebral ischemia in rats.</p>

Diffusion characteristics of subcortical structures in patients with subcortical ischemic vascular disease and its correlation to cognitive function / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the diffusion-tensor imaging (DTI) characteristics of normal-appearing white matter (NAWM) and normal-appearing gray matter (NAGM) on conventional magnetic resonance imaging (MRI) in patients with subcortical ischemic vascular disease (SIVD) and examine the relation of such features with the general cognitive function of the patients.</p><p><b>METHODS</b>DTI was performed in 46 SIVD patients and 34 age-matched control subjects with normal MRI findings. The apprarent diffusion coeeficient (ADC) and fractional anisotropy (FA) were measured within the regions of white matter lesions (WMLs), NAWM and NAGM. All the subjects were examined by neurologists with MMSE and clinical neurologic examination.</p><p><b>RESULTS</b>Compared with normal controls, SIVD subjects showed increased ADC values in the subcortical NAGM and NAWM in anterior periventricular and centrum semiovale, with decreased FA values in the caudate nucleus, thalamus and centrum semiovale. An increased severity of the WMLs was associated with increased ADC and decreased FA in the NAWM of SIVD patients. After controlling for age, the ADC in the NAWM of the posterior periventricular, NAWM and WMLs in the centrum semiovale, caudate nucleus and thalamus showed significant inverse correlations to MMSE; FA values in NAWM of the anterior periventricular and WMLs of the centrum semiovale were positively correlated to MMSE.</p><p><b>CONCLUSION</b>In SIVD patients, the NAWM and NAGM regions shown by MRI contain diffusion abnormalities, and these abnormalities shown by DTI are significantly correlated to the general cognitive function of the patients.</p>

Proton magnetic resonance spectroscopy of the thalamus and hypothalamus in patients with first-episode depression / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the presence of abnormal metabolism in the thalamus and hypothalamus in patients with first-episode depression.</p><p><b>METHODS</b>Thirty drug-naive patients with first-episode depression and 30 age-matched controls were scanned with proton magnetic resonance spectroscopy ((1)H-MRS) for Naa, Cho, Cr and mI.</p><p><b>RESULTS</b>Compared with the control group, the patients showed significantly reduced mI and mI/Cr of the hypothalamus, reduced mI/Cr of the left thalamus, and lowered Cho, ml, and ml/Cr of the right thalamus (P<0.05).</p><p><b>CONCLUSION</b>Patients with first-episode depression may have myo-inositol and phosphoric acid metabolism disorder in the thalamus and hypothalamus with malfunction of cellular osmotic pressure adjustment mechanism. Abnormal mI/Cr in the thalamus and hypothalamus may represent an important biochemical change in advanced patients with depression.</p>

Therapeutic time window of flurbiprofen axetil's neuroprotective effect in a rat model of transient focal cerebral ischemia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The neuroprotective effect of the cyclooxygenase (COX) inhibitor has been demonstrated in acute and chronic neurodegenerative processes. But its function under cerebral ischemic conditions is unclear. This study was designed to evaluate the neuroprotective efficacy of emulsified flurbiprofen axetil (FA, COX inhibitor) and its therapeutic time window in a model of transient middle cerebral artery occlusion (MCAO) in rats.</p><p><b>METHODS</b>Forty-eight male SD rats were randomly assigned into six groups (n = 8 in each group); three FA groups, vehicle, sham and ischemia/reperfusion (I/R) groups. Three doses of FA (5, 10 or 20 mg/kg, intravenous infusion) were administered just after cerebral ischemia/reperfusion (I/R). The degree of neurological outcome was measured by the neurologic deficit score (NDS) at 24, 48 and 72 hours after I/R. Mean brain infarct volume percentage (MBIVP) was determined with 2, 3, 5-triphenyltetrazolium chloride (TTC) staining at 72 hours after I/R. In three other groups (n = 8 in each group), the selected dosage of 10 mg/kg was administrated intravenously at 6, 12 and 24 hours after I/R.</p><p><b>RESULTS</b>The three different doses of FA improved NDS at 24, 48 and 72 hours after I/R and significantly reduced MBIVP. However, the degree of MBIVP in the FA 20 mg/kg group differed from that in FA 10 mg/kg group. Of interest is the finding that the neuroprotective effect conferred by 10 mg/kg of FA was also observed when treatment was delayed until 12 - 24 hours after ischemia reperfusion.</p><p><b>CONCLUSION</b>COX inhibitor FA is a promising therapeutic strategy for cerebral ischemia and its therapeutic time window could last for 12 - 24 hours after cerebral ischemia reperfusion, which would help in lessening the initial ischemic brain damage.</p>

Intercellular imaging by a polyarginine derived cell penetrating peptide labeled magnetic resonance contrast agent, diethylenetriamine pentaacetic acid gadolinium / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The cellular plasma membrane represents a natural barrier to many exogenous molecules including magnetic resonance (MR) contrast agent. Cell penetrating peptide (CPP) is used to internalize proteins, peptides, and radionuclide. This study was undertaken to assess the value of a new intracellular MR contrast medium, CPP labeled diethylenetriamine pentaacetic acid gadolinium (Gd-DTPA) in molecular imaging in vitro.</p><p><b>METHODS</b>Fluorescein-5-isothiocyanate (FITC) and Gd-DTPA respectively labeled with CPP (FITC-CPP, Gd-DTPA-CPP) were synthesized by the solid-phase method. Human hepatic cancer cell line-HepG2 was respectively stained by FITC-CPP and FITC to observe the uptake and intracellular distribution. HepG2 was respectively incubated with 100 nmol/ml Gd-DTPA-CPP for 0, 10, 30, 60 minutes, and imaged by MR for studying the relationship between the incubation time and T(1)WI signal. The cytotoxicity to NIH3T3 fibroblasts cells was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide reduction assay (MTT).</p><p><b>RESULTS</b>The molecular weights of CPP labeled imaging agents, which were determined by MALDI mass spectrometry (FITC-CPP MW = 2163.34, Gd-DTPA-CPP MW = 2285.99), were similar to the calculated molecular weights. Confocal microscopy suggested HepG2 translocated FITC-CPP in cytoplasm and nucleus independent with the incubation temperature. MR images showed HepG2 uptaken Gd-DTPA-CPP had a higher T(1) weighted imaging (T(1)WI) signal, and that the T(1)WI signal intensity was increasing in a time-dependent manner (r = 0.972, P = 0.001), while the signal intensity between the cells incubated by Gd-DTPA for 60 minutes and the controlled cells was not significantly different (P = 0.225). By MTT, all concentrations from 50 nmol/ml to 200 nmol/ml had no significant (F = 0.006, P = 1.000) effect on cell viability of mouse NIH3T3 fibroblasts, compared with the control group.</p><p><b>CONCLUSIONS</b>The newly constructed CPP based on polyarginine can translocate cells by carrying FITC and MR contrast agent Gd-DTPA, and the intracellular concentrations are readily detectable by MR imaging, suggesting a new way for MR molecular imaging.</p>

The endoscopically assisted forehead lift using skull cortical tunnel fixation--a report of 19 cases / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the effect of the fixation on skull and thorough mobilization of the brow area on the results of the endoscopically assisted subperiosteal forehead lift.</p><p><b>METHODS</b>The operation procedure included adequate subperiosteal dissection, especially at the frontotemporal transition area; complete mobilization of the brow area and fixation of the incised scalp to the skull through a cortical tunnel without tension. 19 patients received the operation.</p><p><b>RESULTS</b>Long-term follow-up showed that all the 19 patients were satisfied with the surgical results. A transient frontal branch paresis happened in one case, which resolved in 3 months spontaneously without sequelae.</p><p><b>CONCLUSIONS</b>Cortical tunnel fixation well keeps the brows at a lifted position and achieves persistent rejuvenation of the forehead.</p>