Intratumor microbiota: Occult participants in the microenvironment of multiple myeloma

More recently, microbiota was detected in several tumorous tissues including multiple myeloma (MM), but the roles of which is still under-studied as paucity of research on tumor biology. Moreover, we also detected the presence of microbiota in the bone marrow of patients with MM by 2bRAD-M sequencing technology, which is an incurable hematological malignancy characterized by accumulation of abnormal plasma cells in the bone marrow. However, the roles of intratumor microbiota in tumor disease remains poorly understood. In this review, we critically reviewed recent literature about microbiota in the tumorigenesis and progression of MM. Importantly, we proposed that the emergence of microbiota in the microenvironment of multiple myeloma may be attributed to microbial dysbiosis and impaired intestinal barrier, due to the increased prevalence of MM in patients with obesity and diabetes, of which the characteristic phenotype is gut microbial dysbiosis and impaired intestinal barrier. When the intestinal barrier is damaged, dysbiotic microbiota and their metabolites, as well as dysregulated immune cells, may participate in the reshaping of the local immune microenvironment, and play pivotal roles in the tumorigenesis and development of multiple myeloma, probably by migrating to the bone marrow microenvironment from intestine. We also discuss the emerging microbiological manipulation strategies to improve long-term outcomes of MM, as well as the prospective of the state-of-the-art techniques to advance our knowledge about the biological implication in the microbiome in MM.

Light at the end of the tunnel: Clinical features and therapeutic prospects of KRAS mutant subtypes in non-small-cell lung cancer

Lung cancer is one of the most common causes of cancer-related deaths, and non-small-cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. Kirsten rat sarcoma virus (KRAS), one of the three subtypes of the RAS family, is the most common oncogene involved in human cancers and encodes the key signaling proteins in tumors. Oncogenic KRAS mutations are considered the initiating factors in 30% of NSCLC cases, accounting for the largest proportion of NSCLC cases associated with driver mutations. Because effective inhibition of the related functions of KRAS with traditional small-molecule inhibitors is difficult, the KRAS protein is called an “undruggable target.” However, in recent years, the discovery of a common mutation in the KRAS gene, glycine 12 mutated to cysteine (G12C), has led to the design and synthesis of covalent inhibitors that offer novel strategies for effective targeting of KRAS. In this review, we have summarized the structure, function, and signal transduction pathways of KRAS and discussed the available treatment strategies and potential treatment prospects of KRAS mutation subtypes (especially G12C, G12V, and G12D) in NSCLC, thus providing a reference for selecting KRAS mutation subtypes for the treatment of NSCLC.

Prognostic significance of CD56 antigen in newly diagnosed multiple myeloma: A real-world retrospective study

The prognostic value of plasma cell CD56 expression of patients with multiple myeloma (MM) has been reported in many studies, but the results are controversial. This study aimed to examine the prognostic significance of CD56 in MM patients. Eighty seven patients with newly diagnosed MM were enrolled in this study, and their clinical characteristics, immunophenotypes, and cytogenetics were retrospectively analyzed to explore the prognostic significance of CD56 expression. Multiparameter flow cytometry was used to detect MM in bone marrow samples from all patients. Patients were divided into 2 groups based on whether they expressed CD56: CD56 + group and CD56 - group. After 4 cycles of chemotherapy, the overall response rate of the CD56 - patients was lower than that of the CD56 + patients (60.0% vs 81.1%, P = .036). Survival analysis showed that the median progression-free survival (PFS) was 10 months for the CD56 - group and 27 months for the CD56 + group (P = .007). The median overall survival (OS) of patients for the CD56 - group was 25 months versus not reached in the CD56 + group (P = .010). In addition, among the high-risk patients detected by fluorescence in situ hybridization (FISH), the median PFS was 4 months for the CD56 - group and 16 months for the CD56 + group (P = .012). The median OS of the CD56 + group and CD56 - group was 36 months and 15 months, respectively, with statistically significant differences (P = .017). Our study confirmed that CD56 - patients with MM had a worse prognosis than that of CD56 + patients with MM. Among the patients with ≥ 2 high-risk cytogenetics, the existence of the CD56 negativity can further identify MM patients with poor PFS and OS.

Research and application of a new multilevel fuzzy comprehensive evaluation method for cold stress in dairy cows

Effective and comprehensive evaluation of cold stress is critical for healthy dairy cow breeding in the winter. Previous studies on dairy cow cold stress have considered thermal environmental factors but not physiological factors or air quality. Therefore, this study aimed to propose a multilevel fuzzy comprehensive evaluation (FCE) method for cold stress in dairy cows based on the analytic hierarchy process (AHP) and a genetic algorithm (GA). First, the AHP was used to construct an evaluation index system for cold stress in dairy cows from 3 dimensions: thermal environment (temperature, relative humidity, wind speed, and illumination), physiological factors (respiratory rate, body surface temperature), and air quality [NH₃, CO₂, inhalable particulate matter (PM₁₀)]. Second, the consistency test of the judgment matrix was transformed into a nonlinear constrained optimization problem and solved using the GA. Next, based on fuzzy set theory, the comment set and membership function were established to classify the degree of cold stress into 5 levels: none, mild, moderate, high, and extreme. Then, the degree of cold stress in cows was obtained using multilevel fuzzy comprehensive judgment. To investigate the effect of illumination indicators on cold stress in dairy cows, 24 prelactation cows from the south and north sides were selected for a 117-d comprehensive cold stress evaluation. The results showed that the mean mild cold stress durations were 605.3 h (25.22 d) and 725.5 h (30.23 d) and the moderate cold stress durations were 67.2 h (2.8 d) and 96 h (4.0 d) on the south and north sides, respectively. Simultaneously, generalized linear mixed model showed that there were significant correlations between the daily cold stress duration and milk yield, feeding time, lying time, and active steps in the cows on both sides. This method can reasonably indicate cow cold stress conditions and better guide cold protection practices in actual production.

CD103-CD23+ classical hair cell leukemia: A case report and review of the literature

INTRODUCTION

This case report is presented to improve our understanding of the atypical immunophenotype of hairy cell leukemia.

PATIENT CONCERNS

A 58-year-old woman presented to our department with fatigue for >10 days.

DIAGNOSIS

The patient was diagnosed with an increased proportion of abnormal lymphocytes in peripheral blood and bone marrow smear, positive for CD11c, CD19, CD20, CD22, CD25, CD123, CD200, and Kappa, partial expression of CD23, but no expression of CD103, positive for BRAF V600E mutation.

INTERVENTIONS AND OUTCOMES

Cladribine combined with rituximab achieved complete remission of minor residual disease negativity.

CONCLUSION

Hairy cell leukemia is rare, and the diagnosis and differential diagnosis should be made by combining the patient's medical history, clinical manifestations, immunophenotype, gene detection, and other means. Purine nucleoside analogs are the first-line treatments.

Successful treatment using immunotherapy in combination with chemotherapy for metastatic squamous cell carcinoma of unknown primary origin with bulky abdominal mass: A case report

RATIONALE

Cancer of unknown primary (CUP) means that the primary focus cannot be found after preliminary clinical evaluation. It accounts for 2.3% to 5% of newly diagnosed cancer cases. Due to the lack of standard treatment, CUP is usually associated with poor prognosis and is the third to fourth most common cause of cancer-related deaths.

PATIENT CONCERNS

We report the case of a 42-year-old female patient who was admitted to the hospital for intermittent right abdominal pain and abdominal distension. Abdominal computed tomography (CT) showed a large abdominal mass of unknown origin, which was difficult to resect due to its close relationship with surrounding tissues. Twenty days later, the patient had enlarged left supraclavicular lymph nodes, and percutaneous biopsy revealed squamous cell carcinoma. In addition, next-generation sequencing (NGS) of tissue and blood samples showed immune-related mutations and PD-L1 expression.

DIAGNOSES

The patient was diagnosed with metastatic squamous cell carcinoma of unknown primary origin, with a bulky abdominal mass.

INTERVENTIONS

The patient was treated with carboplatin, albumin-binding paclitaxel, and immune checkpoint inhibitor (carilizumab). After 6 cycles, the patient was switched to maintenance treatment with carilizumab.

OUTCOMES

The general condition of the patient improved, and the lesion was significantly reduced. The treatment efficacy was assessed as partial remission according to Response Evaluation Criteria in Solid Tumors. The patient benefited from immunotherapy combined with chemotherapy.

LESSONS

There is no recommended standard treatment for most CUPs, which leads to their poor prognoses. By performing NGS for patients and targeting immune-related positive predictors, immunotherapy combined with chemotherapy may prolong the overall survival of patients. This case report suggests that immunotherapy combined with chemotherapy is feasible and effective in patients with CUP.

Latest evidence on immunotherapy for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a type of aggressive tumor that involves the intrahepatic, perihilar and distal biliary tree, and is usually diagnosed at an advanced stage. The standard first-line systemic therapy for patients with advanced CCA is a combination of gemcitabine and cisplatin; targeted therapies and angiogenesis inhibitors are not widely used clinically at present. However, with the development of precision medicine, immunotherapy has started to play a more important role. Programmed cell death protein 1 inhibitors are now considered a good therapeutic option for CCA. Treatments using chimeric antigen receptor T cells, bispecific antibodies, oncolytic viruses and cancer vaccines have also achieved satisfactory results. In addition, combinations of immunotherapy with a variety of conventional therapies have shown some efficacy, and several studies have provided insights into their use in antitumor therapy. Although there are numerous challenges in the treatment of advanced CCA, immunotherapy remains a noteworthy breakthrough. The current evidence on the immunotherapy of CCA is discussed in the present review.

Femtosecond laser-induced size reduction and emission quantum yield enhancement of colloidal silicon nanocrystals: effect of laser ablation time

Colloidal silicon (Si) nanocrystals (NCs) with different sizes were successfully prepared by femtosecond laser ablation under different laser ablation time (LAT). The mean size decreases from 4.23 to 1.42 nm by increasing the LAT from 30 to 120 min. In combination with structural characterization, temperature-dependent photoluminescence (PL), time-resolved PL and PL excitation spectra, we attribute room-temperature blue emissions peaked at 405 and 430 nm to the radiative recombination of electron-hole pairs via the oxygen-deficient centers related to Si-C-H₂ and Si-O-Si bonds of colloidal Si NCs prepared in 1-octene, respectively. In particular, the measured PL quantum yield of colloidal Si NCs has been enhanced significantly from 23.6% to 55.8% by prolonging the LAT from 30 to 120 min.

Correlation between luminescence and structural evolution of colloidal silicon nanocrystals synthesized under different laser fluences

We present a detailed investigation of the structural evolution and photoluminescence (PL) properties of colloidal silicon (Si) nanocrystals (NCs) synthesized through femtosecond laser ablation at different laser fluences. It is shown that the mean size of colloidal Si NCs increases from ∼0.97-2.37 nm when increasing laser fluence from 1.0-2.5 mJ cm^-2. On the basis of structural characterization, temperature-dependent PL, time-resolved PL, and PL excitation spectra, we identify that the size-dependent spectral shift of violet emission is attributed to the quantum confinement effect. The localized excitons' radiative recombination via the oxygen-related surface states on the surface of the colloidal Si NCs is employed to explain the origin of the blue emission.

Infrared single photon detector based on optical up-converter at 1550 nm

High performance single photon detector at the wavelength of 1550 nm has drawn wide attention and achieved vast improvement due to its significant application in quantum information, quantum key distribution, as well as cosmology. A novel infrared up-conversion single photon detector (USPD) at 1550 nm was proposed to work in free-running regime based on the InGaAs/ InP photodetector (PD)- GaAs/AlGaAs LED up-converter and Si single photon avalanche diode (SPAD). In contrast to conventional In_0.53Ga_0.47As SPAD, the USPD can suppress dark count rate and afterpulsing efficiently without sacrificing the photon detection efficiency (PDE). A high PDE of ~45% can be achieved by optical adhesive coupling between up-converter and Si SPAD. Using a developed analytical model we gave a noise equivalent power of 1.39 × 10⁻¹⁸ WHz^1/2 at 200 K for the USPD, which is better than that of InGaAs SPAD. This work provides a new single photon detection scheme for telecom band.

Origin of blue photoluminescence from colloidal silicon nanocrystals fabricated by femtosecond laser ablation in solution

We present a detailed investigation into the origin of blue emission from colloidal silicon (Si) nanocrystals (NCs) fabricated by femtosecond laser ablation of Si powder in 1-hexene. High resolution transmission electron microscopy and Raman spectroscopy observations confirm that Si NCs with average size 2.7 nm are produced and well dispersed in 1-hexene. Fourier transform infrared spectrum and x-ray photoelectron spectra have been employed to reveal the passivation of Si NCs surfaces with organic molecules. On the basis of the structural characterization, UV-visible absorption, temperature-dependent photoluminescence (PL), time-resolved PL, and PL excitation spectra investigations, we deduce that room-temperature blue luminescence from colloidal Si NCs originates from the following two processes: (i) under illumination, excitons first form within colloidal Si NCs by direct transition at the X or Γ (Γ25 → Γ'2) point; (ii) and then some trapped excitons migrate to the surfaces of colloidal Si NCs and further recombine via the surface states associated with the Si-C or Si-C-H2 bonds.

Realization of improved efficiency on nanostructured multicrystalline silicon solar cells for mass production

We report the realization of both excellent optical and electrical properties of nanostructured multicrystalline silicon solar cells by a simple and industrially compatible technique of surface morphology modification. The nanostructures are prepared by Ag-catalyzed chemical etching and subsequent NaOH treatment with controllable geometrical parameters and surface area enhancement ratio. We have examined in detail the influence of different surface area enhancement ratios on reflectance, carrier recombination characteristics and cell performance. By conducting a quantitative analysis of these factors, we have successfully demonstrated a higher-than-traditional output performance of nanostructured multicrystalline silicon solar cells with a low average reflectance of 4.93%, a low effective surface recombination velocity of 6.59 m s(-1), and a certified conversion efficiency of 17.75% on large size (156 × 156 mm(2)) silicon cells, which is ∼0.3% higher than the acid textured counterparts. The present work opens a potential prospect for the mass production of nanostructured solar cells with improved efficiencies.

Realization of high performance silicon nanowire based solar cells with large size

We report the realization of high performance silicon nanowire (SiNW) based solar cells with a conversion efficiency of 17.11% and a large size of 125 × 125 mm(2). The key factor for success lies in an efficient approach of dielectric passivation to greatly enhance the electrical properties while keeping the advantage of excellent light trapping of the SiNW structure. The suppression of carrier recombination has been demonstrated through the combination of the SiO2/SiNx stack, which exhibits a good passivation effect on heavily doped SiNWs via reducing both the Shockley-Read-Hall recombination and near surface Auger recombination. We have examined in detail the effects of different passivations and SiNW lengths on the effective minority carrier lifetime, reflectance and carrier recombination characteristics, as well as cell performance. The proposed passivation techniques can be easily adapted to conventional industrial manufacturing processes, providing a potential prospect of SiNW based solar cells in mass production.

Light absorption engineering of hydrogenated nanocrystalline silicon by femtosecond laser

The light absorption coefficient of hydrogenated nanocrystalline silicon has been engineered to have a Gaussian distribution by means of absorption modification using a femtosecond laser. The absorption-modified sample exhibits a significant absorption enhancement of up to ∼700%, and the strong absorption does not depend on the incident light. We propose a model responsible for this interesting behavior. In addition, we present an optical limiter constructed through this absorption engineering method.

Long-range linear elasticity and mechanical instability of self-scrolling binormal nanohelices under a uniaxial load

Mechanical properties of self-scrolling binormal nanohelices with a rectangular cross-section are investigated under uniaxial tensile and compressive loads using nanorobotic manipulation and Cosserat curve theory. Stretching experiments demonstrate that small-pitch nanohelices have an exceptionally large linear elasticity region and excellent mechanical stability, which are attributed to their structural flexibility based on an analytical model. In comparison between helices with a circular, square and rectangular cross-section, modeling results indicate that, while the binormal helical structure is stretched with a large strain, the stress on the material remains low. This is of particular significance for such applications as elastic components in micro-/nanoelectromechanical systems (MEMS/NEMS). The mechanical instability of a self-scrolling nanohelix under compressive load is also investigated, and the low critical load for buckling suggests that the self-scrolling nanohelices are more suitable for extension springs in MEMS/NEMS.

Tunable nonlinear absorption of hydrogenated nanocrystalline silicon

Nonlinear absorption (NLA) of hydrogenated nanocrystalline silicon (nc-Si:H) has been investigated through the open aperture Z-scan method for the photon energy of the incident irradiance slightly less than the bandgap of the sample. NLA responses have been observed to be highly sensitive to the wavelength and intensity of the incident irradiance as well as to the bandgap of the sample, indicating greatly tunable NLA of nc-Si:H. The band tail of nc-Si:H appears to play a crucial role in such NLA responses.

Light absorption mechanism in single c-Si (core)/a-Si (shell) coaxial nanowires

We have carried out detailed investigations on the light absorption mechanism in single crystalline silicon (c-Si) (core)/amorphous Si (a-Si) (shell) coaxial nanowires (NWs). Based on the Lorenz-Mie light scattering theory, we have found that the light absorption in the coaxial NWs relies on the leaky mode resonances and that the light absorption can be optimized towards photovoltaic applications when the a-Si shell thickness is about twice the c-Si core radius. The photocurrent has been found to be enhanced up to ∼ 560% compared to c-Si NWs, and to be further enhanced up to ∼ 60% by coating the nonabsorbing dielectric shells.

Realization of effective light trapping and omnidirectional antireflection in smooth surface silicon nanowire arrays

We have successfully fabricated well-ordered silicon nanowire (SiNW) arrays of smooth surface by using a low-cost and facile Ag-assisted chemical etching technique. We have experimentally found that the reflectance can be significantly suppressed (<1%) over a wide solar spectrum (300-1000 nm) in the as-grown samples. Also, based on our bundled model, we have used rigorous coupled-wave analysis to simulate the reflectance in SiNW arrays, and found that the calculated results are in good agreement with the experimental data. From a further simulation study on the light absorption in SiNW arrays, we have obtained a photocurrent enhancement of up to 425% per unit volume of material as compared to crystalline Si, implying that effective light trapping can be realized in the as-grown samples. In addition, we have demonstrated experimentally and theoretically that the as-grown samples have an omnidirectional high-efficiency antireflection property.

The large diameter and fast growth of self-organized TiO2 nanotube arrays achieved via electrochemical anodization

We have carried out a detailed investigation of the effect of water content on the electrochemical anodization of Ti in electrolytes consisting of ammonium fluoride, water, and ethylene glycol. We have explored the possible growth of ordered TiO(2) nanotubes in the electrolyte with water concentrations from 1 to 100 vol% and the applied voltage from 10 to 150 V, where large diameter (approximately 600 nm) and fast growth rate (approximately 100 microm h(-1)) have been successfully realized for the self-organized TiO(2) nanotube arrays. The achievement benefits from the clear understanding of the effects of both the water content and the anodization voltage on the formation of TiO(2) nanotube arrays. We have further shown crystalline formation of TiO(2) nanotubes by simple thermal annealing. The mechanisms of the effect of the water content on the diameter and growth rate revealed here should establish a basis for further optimization of the TiO(2) nanotube geometries.

Cosserat curve model for superelasticity of helices

Superelasticity behavior of helices has been the focus of recent research in micro-/nano-engineering, while the traditional Kirchhoff rod model restricts itself in the bending and torsion conditions. With the aid of the concept of a Cosserat curve, a novel theoretical basis has been established for statics and dynamics of helices with essential extension and shear, which is able to quantitatively analyze the superelastic mechanical properties. Except for a good agreement with the experimental observation, numerical solutions have shown that we cannot only predict two important properties of the superelasticity characteristics: the breaking force and the stretch of the coil wire under the axial loading, but also precisely describe and explain the Hooke's constant and torque in the entire stretching and breaking processes. The present work has provided useful information for the future experimental investigation on superelasticity as well as its application in meta-/quantum devices.

The fabrication and characteristics of indium-oxide covered porous InP

Uniform and vertical indium-oxide nanotube (IONT) arrays embedded well in n-type InP single crystal have been successfully prepared in situ by porous InP-template-assisted chemical vapor deposition (CVD). This IONT/InP nanostructure reveals high sensitivity to humidity at room temperature, which is ascribed to the ultrahigh surface-to-volume ratio of this nanostructure and the large number of oxygen defected states in IONTs. Such a nanostructure of IONT arrays embedded in a III-V semiconductor substrate could be expected to have potential applications, such as superior gas sensors. This work provides a novel approach for fabricating low-melting metal oxide semiconductor nanotubes.

Interface modification of the InGaN/GaN quantum wells: the strain pre-relief effect

Interface modification by inserting an ultrathin low-temperature GaN layer prior to the growth of high-temperature GaN barriers followed by an annealing process was employed to improve the properties of the InGaN/GaN quantum wells. By detailed studies and comparisons of the surface morphology, photoluminescence and the surface compositions of the InGaN/GaN quantum wells at different growth stages with and without the interface modification, we find that with the interface modification the surface morphology was significantly improved with better smoothness, and smaller and shallower pits of lower density compared with that without interface modification; further, the indium aggregation and phase separation were suppressed. The physical phenomena are attributed to the 'strain pre-relief effect' by the formation of quasi-dots (approximately 20 nm in diameter) prior to temperature ramping and growth of high-temperature GaN barriers. Furthermore, the ultrathin low-temperature GaN layers have a good protection property as confirmed by PL and XPS measurements.

An InGaN/GaN single quantum well improved by surface modification of GaN films

Surface modification of GaN films by in situ droplet homoepitaxy of thin GaN layers was employed for improvement of the surface/interface qualities characterized by atomic smoothness, low defect density and surface chemistry being close to stoichiometry. We find that, with surface modification of the GaN films the surface morphology of the subsequently grown InGaN/GaN single quantum well (SQW) was improved with less density of surface pits and indium-rich inclusions. The improvement in surface smoothness and InGaN/GaN surface/interface qualities is desirable for the growth of high-quality multiple QWs (MQWs) structures and fabrication of high-performance and reliable LEDs. PL results show that with surface modification the QW luminescence was significantly enhanced by more than 50% than that without surface modification.

Synthesis of hierarchical pure ZnO nanostructures with controllable morphology

Hierarchical pure ZnO nanostructures with controllable morphology were synthesized by two-step oxygen-controlled thermal evaporation method without any catalyst. Zn nanowires with little oxidation were deposited firstly on Si substrates located at the low temperature area at step one. The morphology of hierarchical ZnO nanostructures can be effectively modulated at step two by oxygen flow rate, taking advantage of the controllable oxidation rate of Zn and concentration of ZnO(x) under various oxygen supplies. Transmission electron microscope images and corresponding selected area electron diffraction patterns suggest that low oxygen supplementation causes the epitaxial growth of nanorods from the surface of the Zn nanowire, while high oxygen flow rate will lead to the preferential growth of nanorods along the [001] orientation. Room-temperature photoluminescence measurements demonstrate that the variety of nanostructures can cause the variation of the ultraviolet to green peak intensity ratio, suggesting that the controlled morphologies can be used to modulate the optical properties of ZnO nanostructures.

Identification and control of the origin of photoluminescence from silicon quantum dots

We present a detailed investigation into the origin of photoluminescence (PL) from silicon quantum dots in hydrogenated amorphous silicon nitride annealed in oxygen ambient. On the basis of structural characterization, temperature-dependent PL, time-resolved PL, and PL excitation spectra, we identify that the luminescence of the oxidized samples originates from the localized exciton radiative recombination via the surface states related to Si-N or Si-O-Si bonds. In combination with the results due to annealing in argon and hydrogen environments, we have further shown that control of the origin of the PL can be realized by modifying the radiative defect density through annealing treatment.

Chemical conversion synthesis and optical properties of metal sulfide hollow microspheres

A facile chemical conversion method has been demonstrated to prepare various metal sulfide hollow microspheres. The present strategy utilizes the large difference in solubility between ZnS and other metal sulfides (Ag2S, PbS, CuS, Cu2S, Bi2S3, and Sb2S3) for the effective transformation and shows mild growth conditions and good reproducibility. The morphology, structure, and composition of the yielded hollow nanostructures have been confirmed by transmission electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction measurements. The optical properties of the metal sulfide hollow microspheres have been systematically investigated by absorption, micro-Raman, and photoluminescence spectroscopy. The results demonstrate that these metal sulfide hollow microspheres possess good optical quality with tunable band gaps and luminescence properties, which indicate their broad potential applications. This simple chemical conversion technique can be further extended to the synthesis of other semiconductors with various morphologies.

[Molecular mechanisms of Glanzmann thrombasthenia caused by alphaII b P126H mutation: an in vitro experiment]

OBJECTIVE

To explore the molecular mechanisms of Glanzmann thrombasthenia caused by alpha IIb P126H mutation.

METHODS

Eukaryotic vector of alpha IIb P126H was constructed by PCR site-directed mutagenesis and then co-transfected with eukaryotic vector PCDM8 II a expressing the subunit beta3 into human renal epithelial cells of the line 293& and Chinese hamster ovarian cancer cells of the line CHO after sequencing. The membrane expression of alpha IIb P126H mutant was analyzed by flow cytometry and the whole expression was confirmed by Western blotting. The alpha IIb P126H mutant subcellular localization was determined by laser confocal scanning microscopy.

RESULTS

The 293T cells cotransfected with cDNAs of mutated alpha IIb and wild-type beta3 failed to express alpha II bbeta3 on the cell surface as shown by FACS. Western blotting of the cell lysate showed no detectable mature alpha IIb. Immunofluorescence studies demonstrated proa II bbeta3 complex colocalized with an endoplasmic reticulum (ER) marker, but showed minimal colocalization with an Golgi marker.

CONCLUSION

The P126H mutation in alpha IIb prevents transport of the pro-alpha II bbeta3 complex from ER to the Golgi body, thus hindering its maturation and surface expression. The impaired alpha II bp33 transport is responsible for the thrombasthenia.

Formation of uniform and square nanopore arrays on (100) InP surfaces by a two-step etching method

Uniform and square single-crystal InP nanopore arrays have been successfully fabricated on a (100) n-InP surface by a two-step etching method. The characteristic of slow etching rates in four equivalent crystalline (011) facets of (100) n-InP in a mixture of pure HCl and pure H(3)PO(4) has been found, which is the main reason for the formation of square single-crystal InP nanopores. The distribution of nanopores can be closely associated with the distribution of carriers in the semiconductor during the electrochemical etching process. An oscillating behaviour of current has been observed, which can probably be attributed to the oscillations in concentration of the electrolyte at the pore tips caused by diffusion of the electrolyte in the nanopore channels.

Integration of single-crystalline nanocolumns into highly ordered nanopore arrays

The arrangement of nanostructures into desired well-ordered architectures is crucial for the realization of functional nanodevices and has been the focus of current nanotechnology. Existing physical and chemical approaches have the ability to assemble nanostructures, but it is still a challenge to arrange basic nanostructures into a highly ordered designed pattern. Here, we report a novel method to integrate tin-doped indium oxide single-crystalline nanocolumns into highly ordered two-dimensional nanopore patterns through radio-frequency magnetron sputtering by the aid of porous alumina membranes (PAMs). We have further demonstrated that the morphology of the assembled nanopore arrays is controllable by adjusting either the PAM configurations or sputtering conditions. Our present method provides the possibility of a general approach for nanounit integration, and these assembled regular nanopore arrays pave the way for the application of novel filters and sensors.

Mitogenic activity of edible mushroom lectins

A special group of lectins were isolated from three popular Asian edible mushrooms: Volvariella volvacea, Pleurotus flabellatus and Hericium erinacium, and their mitogenic activities towards mouse T cells were compared to the extensively investigated Agaricus bisporus lectin (ABL) and the Jack bean lectin, Concanavalin A (Con A). Among the four mushroom lectins tested, V. volvacea lectin (VVL) exhibited strong mitogenic activity as demonstrated by 3H-thymidine incorporation, which was at least 10-fold more effective than that of Con A, and the other mushroom lectins did not exhibit any proliferative activity. Treatment with VVL and ABL resulted in activation of the protein tyrosine kinase, p56lck, and expression of early activation markers, CD69 and CD25, but only VVL induced intracellular calcium influx while ABL triggered cell death. The calcium influx was sensitive to calcium channel antagonists such as nifedipine and verapamil. The P. flabellatus lectin (PFL) and H. erinacium lectin (HEL) did not stimulate p56lck expression and cell proliferation. Neither of these lectins interfered with Con A-mediated lymphocyte proliferation, which further indicated that both PFL and HEL were non-mitogenic. Taken all results together, VVL induced mitogenesis through T cell receptors and the subsequent calcium signaling pathway.

Development and application of ultrasonic surgical instruments

In this paper, a new approach for designing ultrasonic surgical instruments (USI) is presented. These medical instruments convert an ultrasonic signal into a mechanical vibration by utilizing a magnetostrictive method and have been found to be very useful for various medical procedures. The implemented system consists of an ultrasonic generator, a transducer, and waveguide instruments. The generator produces a high-current ultrasonic signal. The transducer converts this signal into a mechanical vibration. By use of the waveguide instrument, the vibration can be propagated and amplified. This new type of USI possesses a comprehensive ability to stop bleeding, cut bone tissues, regulate frequency automatically, control temperature, etc. The results from animal experiments and from human clinical operations show that the developed USI has the advantages in various aspects over the conventional equipment.

Immunohistochemical studies of GABA and parvalbumin in the developing human cerebellum

The localization of GABA and parvalbumin was studied in the developing cerebellum of human fetuses from 16 to 28 weeks of gestation. The avidin-biotin complex immunohistochemical method combined with silver staining were used to reveal the presence of GABA- and parvalbumin-positive neurons and nerve fibres. As early as the 16th week of gestation, GABA immunopositivity was observed in the cerebellar cortex and the deep nuclei. GABA-positive neurons included Purkinje cells, stellate and basket cells of the cerebellar cortex and neurons in the deep nuclei. The gradient of immunoreactivity increased with the maturing cells, being weak at 16 weeks and becoming markedly pronounced at 28 weeks of gestation. GABA-immunopositive mossy fibres were observed in the granular cell layer at 16 weeks, and by 28 weeks, a robust fibre network was present in the cortex and deep nuclei. Immunohistochemical localization for parvalbumin indicates that weak immunoreactivity was observed in Purkinje cells, stellate and basket cells at 16 weeks of gestation, increasing in intensity with advancing age, notably in the Purkinje cells which had acquired an elaborate arbor of neurites at 28 weeks of gestation. In the deep nuclei, parvalbumin-positive cells and nerve fibres were observed throughout the 16 to 28 week period. These results indicate that GABA- and parvalbumin-positive neurons and fibres appeared as early as 16 weeks of gestation, expressing a high degree of immunoreactivity by the 28 week of fetal age.

Tyrosine hydroxylase- and dopamine-beta-hydroxylase-positive neurons and fibres in the developing human cerebellum--an immunohistochemical study

Six human fetuses of gestational ages 16-28 weeks were employed. The immunocytochemical avidin-biotin-peroxidase complex method combined with the silver Bodian technique was used to evaluate the presence of tyrosine hydroxylase and dopamine-beta-hydroxylase neurons and afferent and efferent fibres in the cerebellum during development. Our results illustrated that by 16-18 weeks, immunoreactivity of the Purkinje cells and the granule cells was evident. By 23 weeks, the positive Purkinje cells were tightly packed together and the perinuclear granules began to extend into the processes. The positive cells next to Purkinje cells were the basket cells and stellate cells. By 26-28 weeks, all positive cells increased in number and size. Mossy and climbing fibres appeared early in development (16-18 weeks of gestation) and were seen synapsing with the positive granule cells. At the same time, some parallel fibres were observed. At later stages, the tyrosine hydroxylase- and dopamine-beta-hydroxylase-positive Purkinje cells were surrounded by abundant climbing fibres, while parallel fibres were also evident in the molecular layer. In the deep cerebellar nuclei, positive tyrosine hydroxylase and dopamine-beta-hydroxylase neurons were present by 16-18 weeks of development. Those in the dentate nucleus were more polymorphic but smaller in size. Some afferent fibres were also spotted around 16-18 weeks of gestation and their numbers increased later. Positive efferent fibres were present by 26 weeks. All these observations point to an early presence of tyrosine hydroxylase and dopamine-beta-hydroxylase components in cerebellar development.

Distribution of neuropeptide Y in the developing human spinal cord

The distribution of neuropeptide Y at different levels of the spinal cord of 23 human fetuses aged from 10-41 weeks of gestation was studied using immunocytochemical staining. Neuropeptide Y-immunoreactive neurons were identified at all levels of the spinal cord examined as early as 10 weeks of gestation. These cells were localized in the superficial layers (laminae I and II of Rexed) of the dorsal gray matter. As the age of the fetuses increased, their cell number increased and the region containing positive neurons extended from the superficial to deep layers (laminae III and VI). Immunoreactive fibers started to appear in fetuses at 10 weeks of gestation. They were found not only in the gray and white matters, but also in the pia mater lining the spinal cord. As the fetuses aged, the neuropeptide Y-immunoreactive fibers became mostly concentrated in the intermediate zones of the thoracic and sacral segments corresponding to the developing autonomic centers. Our results suggest that neuropeptide Y may play a role in the early development of the autonomic system.

Bilateral retinal responses during the acute phase (4-14 days) after traumatization of a single eye in the mouse

The infiltration of T lymphocytes and macrophages was examined in the retinae of traumatized and non-traumatized contra-lateral eyes of mice. Traumatization was produced by channeling a small hole in the limbic region of a single eye in each animal while it was under Nembutal anesthesia and a small piece of iron wire was inserted into the eye. After the T lymphocytes and macrophages were made apparent by immuno-histochemistry, they were counted on sectioned strips of the peripheral retinae 250 micrometer in length in both traumatized and non-traumatized eyes. During the first two weeks after the induced disturbance, both the retinae of the traumatized and non-traumatized eyes showed infiltration of T lymphocytes and macrophages. Although this increase in T lymphocyte infiltration was observed in both damaged eye and the undamaged one, the former displayed an enhanced increase. The contrary was noticed for macrophages infiltrating the undamaged eye. A bilateral response was therefore evident through the cellular infiltration in the traumatized and un-traumatized eyes. Morphometrical observations also revealed nuclear size changes in the retina during this acute phase of traumatization.

Immunohistochemical localization of enkephalin and substance P in the nucleus caudalis of the spinal trigeminal V in the medulla oblongata of the human fetus

The distribution of enkephalin-positive neurons, substance P-positive and enkephalin-positive fibers was studied in the nucleus caudalis of the trigeminal spinal V in the medulla oblongata regions of developing humans (12 weeks gestation to 40 weeks gestation). Enkephalin-positive neurons were identified in all the subnuclei of the nucleus caudalis as early as 12 weeks of gestation and increased in number as the fetus aged. Substance P-positive neurons were absent in this area throughout development. On the other hand, substance P-positive and enkephalin-positive fibers were present in all the subnuclei, again commencing as early as 12 weeks of gestation. These fibers tended to be linked to each other in the different subnuclei and to the reticular formation in this area and to increase significantly in quantity by the latter quarter of pregnancy. These results show the early presence of these neurons and fibers in the first trimester of development.

The cholinergic system in retinal transplants in rats

Retinas from embryonic day 13 or 14 Sprague-Dawley albino rats were transplanted to the brainstem of newborn rats with unilateral eye enucleation at birth. Two months after the transplantation, the activity and distribution of acetylcholinesterase and choline acetyltransferase were studied using histochemical and immunocytochemical methods respectively. Results obtained showed that the staining patterns of these two cholinergic enzymes in the retinal transplants were essentially the same as those observed in the retinas of normal rats and in the control retinas of the recipient animals. The similarities in the distribution of these two cholinergic enzymes in these retinas suggest that the cholinergic system in the retinal transplants is likely to be functional.

Localization of acetylcholinesterase positive neurons and substance P and enkephalin positive fibers by histochemistry and immunohistochemistry in the sympathetic intermediate zone of the developing human spinal cord

Localization of acetylcholinesterase positive neurons and substance P and enkephalin fibers were studied by histochemistry and immunohistochemistry in the intermediate sympathetic zone of the spinal cords of 39 human embryos/fetuses from gestation ages five to 40 weeks. Acetylcholinesterase positive neurons were observed in the nucleus intermediolateralis pars principalis as early as the fifth week of gestation. By the ninth to 13th weeks of gestation, positive neurons were also seen in the nuclei intermedialis pars funicularis, intercalatus spinalis and intercalatus pars paraependymalis. Increase in amount of these positive acetylcholinesterase neurons was demonstrated till term. Substance P and enkephalin fibers were initially observed by the eighth gestation week in the intermediolaterlis pars principalis nucleus and positive fibers were then detected in the nucleus intermedialis pars funicularis as well as the nucleus intercalatus spinalis by the 14th week of gestation. By the 26th week of gestation, all the major nuclei intermediolateralis par principalis, intermedialis pars funicularis, intercalatus spinalis and intercalatus pars paraependymalis has substance P and enkephalin fibers. Initial demonstration of acetylcholinesterase positive neurons appeared to be at an earlier stage than that of our substance P and enkephalin positive fibers.

Immunohistochemical studies on the development of 5-HT (serotonin) neurons in the nuclei of the reticular formations of human fetuses

5-HT-positive neurons were detected by the PAP immunohistochemical methods in different nuclei of the reticular formations of human fetuses as early as 10 weeks of gestation. The majority of positive 5-HT cells were located in dorsal raphe and central superior nuclei, and there was a reduction of these neurons per 40-microns section as the fetus aged.