Turn-off enzyme activity of histidine-rich peptides for the detection of lysozyme.

An assay that integrates histidine-rich peptides (HisRPs) with high-affinity aptamers was developed enabling the specific and sensitive determination of the target lysozyme. The enzyme-like activity of HisRP is inhibited by its interaction with a target recognized by an aptamer. In the presence of the target, lysozyme molecules progressively assemble on the surface of HisRP in a concentration-dependent manner, resulting in the gradual suppression of enzyme-like activity. This inhibition of HisRP's enzyme-like activity can be visually observed through color changes in the reaction product or quantified using UV-visible absorption spectroscopy. Under optimal conditions, the proposed colorimetric assay for lysozyme had a detection limit as low as 1 nM and exhibited excellent selectivity against other nonspecific interferents. Furthermore, subsequent research validated the practical applicability of the developed colorimetric approach to saliva samples, indicating that the assay holds significant potential for the detection of lysozymes in samples derived from humans.

Spatiotemporal Organization of Functional Cargoes by Light-Switchable Condensation in Escherichia coli Cells.

Biomolecular condensates are dynamic subcellular compartments that lack surrounding membranes and can spatiotemporally organize the cellular biochemistry of eukaryotic cells. However, such dynamic organization has not been realized in prokaryotes that naturally lack organelles, and strategies are urgently needed for dynamic biomolecular compartmentalization. Here we develop a light-switchable condensate system for on-demand dynamic organization of functional cargoes in the model prokaryotic Escherichia coli cells. The condensate system consists of two modularly designed and genetically encoded fusions that contain a condensation-enabling scaffold and a functional cargo fused to the blue light-responsive heterodimerization pair, iLID and SspB, respectively. By appropriately controlling the biogenesis of the protein fusions, the condensate system allows rapid recruitment and release of cargo proteins within seconds in response to light, and this process is also reversible and repeatable. Finally, the system is demonstrated to dynamically control the subcellular localization of a cell division inhibitor, SulA, which enables the reversible regulation of cell morphologies. Therefore, this study provides a new strategy to dynamically control cellular processes by harnessing light-controlled condensates in prokaryotic cells.

The Prognostic Value of Neutrophil-to-Lymphocyte Ratio in Patients With Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis of Observational Studies.

The neutrophil-to-lymphocyte ratio (NLR), as an essential systemic inflammation factor, has been widely used as a prognostic indicator in various diseases, such as malignant tumors, cardiovascular disease, and intracranial hemorrhage. An increasing number of studies have believed that NLR is a valuable predictor of prognosis for patients with aneurysmal subarachnoid hemorrhage (aSAH). However, these results remain controversial. In the current study, we planned to carry out a systematic review and meta-analysis to investigate the association between NLR and poor outcome, and the occurrence of delayed cerebral ischemia (DCI). We carried out a comprehensive search for published literatures on PubMed, EMBASE, Cochrane Library, and Web of Science databases from inception to April 1, 2021. We conducted an assessment of all included studies based on the principles proposed in the Newcastle-Ottawa Quality Assessment Scale (NOS). Poor outcome and the occurrence of DCI were considered as the main outcome measure. We calculated the pooled odds ratio (OR) and corresponding 95% confidence interval (CI) to examine the strength of the association of NLR with poor outcome or the occurrence of DCI. We strictly selected a total of 10 studies comprising 4,989 patients. Nine studies reported the association between NLR and poor outcome, and five studies reported the association between NLR and the occurrence of DCI. The pooled results indicated higher NLR was significantly associated with both poorer outcomes (OR = 1.32, 95%CI 1.11-1.57; P = 0.002, I 2 = 87%), and the occurrence of DCI (OR = 1.72, 95%CI 1.22-2.41; P = 0.002, I 2 = 82%) in aSAH patients. The NLR is a valuable indicator of inflammation to independently predict poor outcome and occurrence of DCI after aSAH, where a higher NLR is significantly associated with poor outcomes and occurrence of DCI. These findings suggest that the NLR can help clinicians evaluate the prognosis and identify potentially severe patients early, which may contribute to better management and improve poor prognosis of aSAH patients.

Efficacy and Safety of Tranexamic Acid in Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Tranexamic acid has been shown to reduce rebleeding after aneurysmal subarachnoid hemorrhage; however, whether it can reduce mortality and improve clinical outcomes is controversial. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of the tranexamic acid in aneurysmal subarachnoid hemorrhage. We conducted a comprehensive literature search of PubMed, Embase, Web of Science, and Cochrane Library from inception to March 2021 for randomized controlled trials (RCTs) comparing tranexamic acid and placebo in adults with aneurysmal subarachnoid hemorrhage. The risk of bias was evaluated using the Cochrane Handbook, and the quality of evidence was evaluated using the GRADE approach. This meta-analysis included 13 RCTs, involving 2,888 patients. In patients with aneurysmal subarachnoid hemorrhage tranexamic acid had no significant effect on all-cause mortality (RR = 0.96; 95% CI = 0.84-1.10, p = 0.55, I 2 = 44%) or poor functional outcome (RR = 1.04; 95% CI = 0.95-1.15, p = 0.41) compared with the control group. However, risk of rebleeding was significantly lower (RR = 0.59; 95% CI = 0.43-0.80, p = 0.0007, I 2 = 53%). There were no significant differences in other adverse events between tranexamic acid and control treatments, including cerebral ischemia (RR = 1.17; 95% CI = 0.95-1.46, p = 0.15, I 2 = 53%). At present, routine use of tranexamic acid after subarachnoid hemorrhage cannot be recommended. For a patient with subarachnoid hemorrhage, it is essential to obliterate the aneurysm as early as possible. Additional higher-quality studies are needed to further assess the effect of tranexamic acid on patients with subarachnoid hemorrhage.

Tuberous sclerosis complex presenting as primary intestinal lymphangiectasia: A case report.

BACKGROUND: Primary intestinal lymphangiectasia (PIL) is a rare congenital protein-losing enteropathy caused by dysplasia of the small intestinal lymphatics. The cause of the disease is unknown. Through a literature review, we found that PIL and tuberous sclerosis complex (TSC) have some common symptoms and molecular pathways. CASE SUMMARY: Here, we present the case of a patient with a three-year history of primary intestinal lymphangiectasia. The patient most recently visited the hospital with abdominal distension and swelling of the left leg. His mother told us that she was diagnosed with TSC one year previously, which alerted us because the patient had multiple regions of pigmentation. To evaluate the condition of the child and make a definite diagnosis, multiple imaging examinations were performed, as was TSC gene analysis. The results met the diagnostic criteria for TSC. The patient was discharged after symptomatic treatment. Through a review of the literature, it can be seen that changes at the molecular gene level of TSC can lead to abnormal lymphatic vessels. CONCLUSION: In summary, when patients with hypomelanotic macules or enamel hypoplasia are diagnosed with PIL, TSC gene screening may be important for further diagnosis.

Highly enantioselective synthesis of (R)-1,3-butanediol via deracemization of the corresponding racemate by a whole-cell stereoinverting cascade system.

BACKGROUND: Deracemization, the transformation of the racemate into a single stereoisomeric product in 100% theoretical yield, is an appealing but challenging option for the asymmetric synthesis of optically pure chiral compounds as important pharmaceutical intermediates. To enhance the synthesis of (R)-1,3-butanediol from the corresponding low-cost racemate with minimal substrate waste, we designed a stereoinverting cascade deracemization route and constructed the cascade reaction for the total conversion of racemic 1,3-butanediol into its (R)-enantiomer. This cascade reaction consisted of the absolutely enantioselective oxidation of (S)-1,3-butanediol by Candida parapsilosis QC-76 and the subsequent asymmetric reduction of the intermediate 4-hydroxy-2-butanone to (R)-1,3-butanediol by Pichia kudriavzevii QC-1. RESULTS: The key reaction conditions including choice of cosubstrate, pH, temperature, and rotation speed were optimized systematically and determined as follows: adding acetone as the cosubstrate at pH 8.0, a temperature of 30 °C, and rotation speed of 250 rpm for the first oxidation process; in the next reduction process, the optimal conditions were: adding glucose as the cosubstrate at pH 8.0, a temperature of 35 °C, and rotation speed of 200 rpm. By investigating the feasibility of the step-by-step method with one-pot experiment as a natural extension for performing the oxidation-reduction cascade, the step-by-step approach exhibited high efficiency for this cascade process from racemate to (R)-1,3-butanediol. Under optimal conditions, 20 g/L of the racemate transformed into 16.67 g/L of (R)-1,3-butanediol with 99.5% enantiomeric excess by the oxidation-reduction cascade system in a 200-mL bioreactor. CONCLUSIONS: The step-by-step cascade reaction efficiently produced (R)-1,3-butanediol from the racemate by biosynthesis and shows promising application prospects.

Arsenic trioxide induces autophagic degradation of the FLT3-ITD mutated protein in FLT3-ITD acute myeloid leukemia cells.

The prognosis of acute myeloid leukemia (AML) with FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutations is poor. Some studies, including our previous study, have indicated that arsenic trioxide (ATO) exhibited significant anti-carcinogenic activity in FLT3-ITD AML cells and explored the possibility of targeting the FLT3-ITD protein for degradation as a therapy. Autophagy is a critical mechanism of the anti-leukemic effects of ATO. In this study, we explored the therapeutic efficacy of ATO treatment in a mouse model bearing FLT3-ITD AML and found that ATO significantly reduced the leukemic burden in bone marrow and spleen. We also found that autophagy was responsible for, at least in part, the degradation of the FLT3-ITD protein by ATO. After ATO treatment, MV4-11 cells showed complete autophagic flux. The autophagy inhibitor bafilomycin A or down-regulation of the key autophagy genes Atg5 and Atg7 reversed the FLT3 degradation induced by ATO. We also found that p62/SQSTM1 delivered FLT3-ITD proteins to the lysosome, where they were subsequently degraded. These results indicate that ATO can induce autophagic degradation of the FLT3-ITD mutated protein in FLT3-ITD AML.

Arsenic trioxide and all-trans-retinoic acid selectively exert synergistic cytotoxicity against FLT3-ITD AML cells via co-inhibition of FLT3 signaling pathways.

FLT3-ITD mutations occur in approximately 30% of acute myeloid leukemia (AML) and are associated with a poor outcome. Currently available FLT3 inhibitors have in vitro but limited clinical activity in FLT3-ITD AML. Reports have shown that an arsenic trioxide (ATO)/all-trans-retinoic acid (ATRA) combination improves prognosis in acute promyelocytic leukemia, especially with FLT3-ITD, and ATO or ATRA alone enhances apoptosis in FLT3-ITD AML cells treated with FLT3 inhibitors, providing a rationale to investigate the role of ATO/ATRA in FLT3-ITD AML. Here, we demonstrate that an ATO/ATRA combination selectively exerts synergistic cytotoxicity against FLT3-ITD AML cell lines (MV4;11/MOLM-13). The signaling pathways affected by ATO/ATRA include FLT3/STAT5/MYC, FLT3/STAT5/E2F1, FLT3/ERK/ATF5 and FLT3/AKT/ATF5.ATF5 may function as an oncogene in FLT3-ITD AML. Our findings provide experimental evidence that supports further exploration of ATO/ATRA in FLT3-ITD AML in vivo and warrants a clinical evaluation of regimens comprising an ATO/ATRA combination.

Interference of a pair of symmetric partially coherent beams.

We study theoretically and experimentally the interference of light produced by a pair of mutually correlated Schell-model sources. The spatial distributions of the fields produced by the two sources are inverted with respect to each other through their common center in the source plane. When the beams are in phase, a bright spot appears in the center of the spatial distribution of the beam intensity. When the beams have a phase shift phi= pi, a dark spot appears in the center of the spatial distribution of the beam intensity. Experimental results that illustrate these results are included. Both bright and dark spots diverge more slowly with the increasing distance from the sources than the beam itself.

An observation chamber for studying temperature-dependent and drug-induced events in live neurons using fluorescence microscopy.

Live-cell imaging chambers are used in a wide range of cell biology research. Recently, chambers capable of taking high-resolution and time-lapse images of live cells have been developed and become commercially available. However, because most of these chambers are designed to maintain a thermally stable environment for the cells under study, it is usually very difficult to use them to study temperature-dependent cellular events. Here we report the development of a chamber that is able to be used for the continuous monitoring of live neurons under most commercially available upright epifluorescence and confocal microscopes and in which the temperature and composition of the medium surrounding the neurons can be changed rapidly and reversibly. This live-cell observation chamber has been used successfully with cultured rat hippocampal neurons to study temperature-dependent changes in the dynamics of the microtubule cytoskeleton using fluorescence recovery after photobleaching (FRAP) together with the localization of alpha-tubulin in the dendritic spines. The success of these observations demonstrates the usefulness and applicability of the live-cell observation chamber described here to a wide range of cell biology experiments.

Cold-induced exodus of postsynaptic proteins from dendritic spines.

Dendritic spines are small protrusions on neuronal dendrites and the major target of the excitatory inputs in mammalian brains. Cultured neurons and brain slices are important tools in studying the biochemical and cellular properties of dendritic spines. During the processes of immunocytochemical studies of neurons and the preparation of brain slices, neurons were often kept at temperatures lower than 37 degrees C for varied lengths of time. This study sought to investigate whether and how cold treatment would affect the protein composition of dendritic spines. The results indicated that upon cold treatment four postsynaptic proteins, namely, alpha,beta-tubulins, calcium, calmodulin-dependent protein kinase IIalpha, and cytoplasmic dynein heavy chain and microtubule-associated protein 2, but not PSD-95 or AMPA receptors, exited from the majority of dendritic spines of cultured rat hippocampal neurons in a Gd(3+)-sensitive manner. The cold-induced exit of tubulins from dendritic spines was further found to be an energy-dependent process involving the activation of Gd(3+)-sensitive calcium channels and ryanodine receptors. The results thus indicate that changes in temperature, calcium concentration, and energy supply of the medium surrounding neurons would affect the protein composition of the dendritic spines and conceivably the protein composition of the subcellular organizations, such as the postsynaptic density, in the cytoplasm of dendritic spines.

Reconstruction of a one-dimensional surface from inverse transmission.

An optimization algorithm for the reconstruction of a surface profile is presented. This algorithm uses the far-field transmitted intensity to retrieve the surface profile of a thin film. We approach the inverse transmission problem as a constrained optimization problem. A mathematical representation of the surface based on B-spline curves and an optimum profile search with the self-adaptation evolutionary strategy (ES) are adopted. As the input data for the ES algorithm for surface inversion, the transmitted intensity has been measured by both a laser bidirectional reflectometer instrument and an in-line digital speckle camera system. The reconstructed 1D surfaces are compared with the profile measured by an atomic force microscope.

[Effect of Kunyining capsule on reproductive endocrine-immune functions in ovariectomized rats].

OBJECTIVE: To study the therapeutic mechanism of Kunyining (KYN) on the climacteric syndrome and provide the pharmacodynamic basis. METHOD: Ovariectomized rats were used as model to observe the effect of KYN on weight and the index of the organ of OVX rats. The concentration of E2, FSH, LH, PRL, BGP and IL-2 in serum were measured by competitive radio-immunological methods. RESULT: KYN could obviously increase the index of uterus and adrenal gland in OVX rats, and enhance the contents of E2, IL-2 and BGP. The level of FSH, LH, PRL in serum were decreased. CONCLUSION: KYN can regulate beneficially the unbalanced reproductive endocrine-immune network, which is the pharmacological basis of KYN treating climacteric syndrome.

Dendritic spines of developing rat cortical neurons in culture.

The formation of spines and their association with synapses were examined in developing cultured rat cortical neurons using fluorescence labeling techniques. Small protrusions were found on the processes of cultured cortical neurons after seven days in vitro (DIV), and the density of protrusions almost halved during the second week in vitro, after which it remained unchanged throughout the third week in vitro. The proportion of protrusions associated with the accumulation of the presynaptic marker, synaptophysin, increased steadily from <5% at 7 DIV to approximately 50% at 21 DIV. Based on the absence or presence of an enlargement at the end, protrusions on processes were further divided into filopodia and spines, respectively. The percentage of protrusions that were classified as spines increased steadily from approximately 5% at 3-4 DIV to approximately 80% at 18-20 DIV. The percentage of spines associated with synaptophysin accumulation increased gradually as the cortical neurons developed in vitro, reaching a plateau of approximately 40% after two weeks. However, the percentage of filopodia associated with synaptophysin accumulation never exceeded 5% during the first three weeks in vitro. Double-label staining the microfilaments and beta-tubulin or phosphorylated neurofilament H of cultured neurons further revealed many spines without any nearby axon-like processes. These findings suggest that spines are the dominant form of protrusion on the processes of more mature cortical neurons, that spines are the preferential sites where synapses reside, and that maintaining constant contact with axons is not essential for the formation of spines in cultured cortical neurons.

Heavy chain of cytoplasmic dynein is a major component of the postsynaptic density fraction.

A protein with an apparent molecular size of 490 kDa was found in the postsynaptic density (PSD) fraction isolated from porcine cerebral cortices and rat forebrains, and this 490 kDa protein accounted for approximately 3% of the total protein of these samples. Matrix-assisted laser desorption ionization-time of flight mass spectrometric and Western blotting analyses consistently indicated that this 490 kDa protein consisted primarily of the heavy chain of cytoplasmic dynein (cDHC). Immunocytochemical analyses showed that cDHC was found in 92% and 89% of the phalloidin-positive protrusions that were themselves associated with discrete clusters of synaptophysin, a presynaptic terminal marker, and PSD-95, a postsynaptic marker, on neuronal processes, respectively. Quantitative Western blotting analyses of various subcellular fractions isolated from porcine cerebral cortices and rat forebrains further showed that not only the heavy but also the intermediate chains of dynein are enriched in the PSD fraction. Cytoplasmic dynein is a microtubule-associated motor protein complex that drives the movement of various cargos toward the minus ends of microtubules and plays many other diverse functions in the cell. Our results that cDHC is a major component of the PSD fraction, that both dynein heavy and intermediate chains are enriched in the PSD fraction and that cDHC is present in dendritic spines raise the possibilities that cytoplasmic dynein may play structural and functional roles in the postsynaptic terminal.

Effect of Kunyining capsule on reproductive endocrine-immune functions in ovariectomized rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the therapeutic mechanism of Kunyining (KYN) on the climacteric syndrome and provide the pharmacodynamic basis.</p><p><b>METHOD</b>Ovariectomized rats were used as model to observe the effect of KYN on weight and the index of the organ of OVX rats. The concentration of E2, FSH, LH, PRL, BGP and IL-2 in serum were measured by competitive radio-immunological methods.</p><p><b>RESULT</b>KYN could obviously increase the index of uterus and adrenal gland in OVX rats, and enhance the contents of E2, IL-2 and BGP. The level of FSH, LH, PRL in serum were decreased.</p><p><b>CONCLUSION</b>KYN can regulate beneficially the unbalanced reproductive endocrine-immune network, which is the pharmacological basis of KYN treating climacteric syndrome.</p>

Interference of a pair of symmetric Collett-Wolf beams.

We present a study of the interference of light produced by a pair of mutually correlated Gaussian Schell-model sources. The spatial distributions of the fields produced by these sources are symmetric with respect to a plane through their common center and differ by a phase factor exp(i phi). When phi = 0, the resulting radiation is a beam with an intensity distribution that displays a narrow bright line at its center. When the sources can be regarded as Collett-Wolf sources, the resulting bright line diverges much more slowly than the beam itself. When phi = pi the radiated beam has an intensity distribution with a narrow dark line at its center. The theoretical results are supported by experimental results obtained by use of a modified Michelson interferometer and suggest that the interference of a pair of correlated Collett-Wolf beams can be used to produce a pseudo-nondiffracting beam.

High-order correlations from rough-surface scattering.

It is proposed to apply an optical setup of a randomly weak rough dielectric film on a reflecting metal substrate for the measurement of high-order correlations from rough-surface scattering. The angular amplitude and intensity correlations are measured. Because of multiple scattering, when the input laser beam size is comparatively small or close to the travel pass length inside the film, C(2) and C(3) are measured by subtraction of the amplitude correlation from the intensity correlation.

[Relevant factors and management for patients with squamous carcinoma in tongue without clinical cervical lymphatic node metastasis].

OBJECTIVE: To discuss the treatment of cN(0) tongue carcinoma patients. METHODS: 185 cases of the mobile tongue carcinoma patients (male 102, female 83, aged 28 to 88) treated with surgery from 1988.5 to 1995.6 had been followed up and retrospectively analyzed. Extensive resection of the primary tumors and neck dissections were performed, and all the samples were pathological positive. RESULTS: The cervical lymphatic node metastasis rates for stage I-II, III-IV disease, grade I, II disease were 16.66%, 38.05%, 17.42% and 37.50% respectively. And the rates were 9.00%, 31.37% and 55.55% for submucous infiltration, muscle infiltration and perineural infiltration, respectively. The overall 5 year survival was 72.43%, and the 5 year specific survival rate was 44.44% and 83.96% for those having or not having cervical node metastasis. The levels of 29 patients with positive node metastasis for 148 cN(0) patients were submandibular and submental lymphatic nodes (22.64%), superior deep cervical lymphatic nodes (35.84%), middle deep cervical lymphatic nodes (26.41%), inferior deep cervical lymphatic nodes (15.09%), posterior neck lymphatic nodes (0.00%). The over all 5 year survival rates for selective neck dissection were 85.13% and 21.62% in therapeutic dissection (chi(2) = 29.73, P < 0.01). Patients performed selective neck dissection the rates were 68.96% and 89.07% respectively with or without lymphatic node metastasis. Comparably the 5-year rate was only 20.00% for the patients performed the therapeutic dissection with lymphatic node metastasis. CONCLUSIONS: (1) cN(0) patients should be observed carefully in stage I, and the selective dissection must be performed in stage II-IV. (2) Supraomohyoid ND is essential for T(2) patients, and functional ND is essential for T(3 - 4) patients. (3) There is correlation between cervical metastasis and the stage, grade or infiltration of tongue cancer (P < 0.05). The prognosis could be expected from these factors.

Development of excitatory synapses in cultured neurons dissociated from the cortices of rat embryos and rat pups at birth.

We studied the development of excitatory synapses in cultured neurons dissociated from the cortices of rat embryos at the 18th day of gestation (E18) and rat pups at birth (P0). Between 7 and 14 days in vitro (DIV), large increases in the amplitudes and frequencies of the spontaneous excitatory postsynaptic currents (EPSCs) of both cultured E18 and P0 neurons were observed. The EPSCs of E18 neurons were mediated primarily by alpha-amino-3-hydroxy-5-methyl-4-iso-xazole-propionic acid (AMPA) receptors at 7 DIV and by both N-methyl-D-aspartate (NMDA) and AMPA receptors at 14 DIV. Consistently, immunostaining indicated significant increases in the proportion of the clusters of NR1, an NMDA receptor subunit, which were associated with the accumulation of synaptophysin, a presynaptic marker, in cultured E18 neurons between 7 and 14 DIV. The proportion of NR1 clusters residing in synaptic regions and the proportion of synapses that colocalized with NR1 clusters in 7-day-old P0 neurons were not different statistically from those found in 7-day-old E18 neurons. However, cultured P0 neurons at 7 DIV displayed clear EPSCs mediated by NMDA receptors. Our results suggest that the targeting of NMDA receptors to synaptic regions lag behind the synaptic clustering of AMPA receptors during the in vitro development of cultured rat E18 cortical neurons. The results further suggest that the cortical neurons at P0 differ from those at E19 in certain cellular properties; as a result, the currents mediated by the synaptic NMDA receptors in 7-day-old P0 neurons are larger than those mediated by the synaptic NMDA receptors in 7-day-old E18 neurons.