Computational Insights into SARS-CoV-2 Main Protease Mutations and Nirmatrelvir Efficacy: The Effects of P132H and P132H-A173V.

Nirmatrelvir, a pivotal component of the oral antiviral Paxlovid for COVID-19, targets the SARS-CoV-2 main protease (Mpro) as a covalent inhibitor. Here, we employed combined computational methods to explore how the prevalent Omicron variant mutation P132H, alone and in combination with A173V (P132H-A173V), affects nirmatrelvir's efficacy. Our findings suggest that P132H enhances the noncovalent binding affinity of Mpro for nirmatrelvir, whereas P132H-A173V diminishes it. Although both mutants catalyze the rate-limiting step more efficiently than the wild-type (WT) Mpro, P132H slows the overall rate of covalent bond formation, whereas P132H-A173V accelerates it. Comprehensive analysis of noncovalent and covalent contributions to the overall binding free energy of the covalent complex suggests that P132H likely enhances Mpro sensitivity to nirmatrelvir, while P132H-A173V may confer resistance. Per-residue decompositions of the binding and activation free energies pinpoint key residues that significantly affect the binding affinity and reaction rates, revealing how the mutations modulate these effects. The mutation-induced conformational perturbations alter drug-protein local contact intensities and the electrostatic preorganization of the protein, affecting noncovalent binding affinity and the stability of key reaction states, respectively. Our findings inform the mechanisms of nirmatrelvir resistance and sensitivity, facilitating improved drug design and the detection of resistant strains.

Extraction and characterization of anti-virus anthraquinones from Nicotiana tabacum-derived Aspergillus oryzae YNCA1220.

In this study, seven novel anthraquinones (1-7) and four described anthraquinones (8-11) were purified from Nicotiana tabacum-derived Aspergillus oryzae YNCA1220. It is worth noting that only analogs of 4 and 5 have been reported as natural products to date, while the nuclei of compounds 1-3, 6 and 7 were isolated for the first time in nature. Among them, compounds 1-3 bear an unusual anthra[2,3-b]furan-9,10-dione nucleus, 4 and 5 possess a rare 3-methyl-1H-pyrrol-2-yl substituent, and 6 and 7 are new framework anthraquinones bearing a 6-methyl-1,7-dihydro-2H-azepin-2-one ring. Interestingly, the in vivo assays indicated that 1, 4 and 5 had inactivation effects against tobacco mosaic virus (TMV) with inhibition rates of 41.6%, 55.4% and 38.6%, respectively, at a concentration of 50 µg/mL, which were better than that of the positive control agent, ningnanmycin (33.8%). Compounds 1, 4 and 5 also had protective effects with inhibition rates of 48.7%, 60.2% and 43.5% at the same concentration, while 4 had a better curative effect than ningnanmycin at a concentration of 100 µg/mL. In addition, mechanistic studies also revealed that a potent direct effect on TMV, the induction of SAR in tobacco plants, and the effective regulation of defense enzymes, defense genes, and defense hormones may be the reasons for the significant effects of 4 against TMV. At the same time, downregulation of the expression of total NtHsp70 protein by inhibiting the related Hsp70 genes may also be involved in tobacco resistance to TMV. To evaluate whether compounds have broader antiviral activities, the antirotavirus activities of new isolates were also evaluated and found to be highly effective with a therapeutic index (TI) value ranging from 11.6 to 17.7. This study suggests that the above anthraquinone compounds, particularly 4, have broad spectrum antiviral activities. The successful isolation and structure identification of the above anthraquinones provide new materials for the screening of anti-TMV agents and contribute to the improved utilization of N. tabacum-derived fungi.

An efficient TILLING platform for cultivated tobacco.

Targeting-induced local lesions in genomes (TILLING) is a powerful reverse-genetics tool that enables high-throughput screening of genomic variations in plants. Although TILLING has been developed for many diploid plants, the technology has been used in very few polyploid species due to their genomic complexity. Here, we established an efficient capillary electrophoresis-based TILLING platform for allotetraploid cultivated tobacco (Nicotiana tabacum L.) using an ethyl methanesulfonate (EMS)-mutagenized population of 1,536 individuals. We optimized the procedures for endonuclease preparation, leaf tissue sampling, DNA extraction, normalization, pooling, PCR amplification, heteroduplex formation, and capillary electrophoresis. In a test screen using seven target genes with eight PCR fragments, we obtained 118 mutants. The mutation density was estimated to be approximately one mutation per 106 kb on average. Phenotypic analyses showed that mutations in two heavy metal transporter genes, HMA2S and HMA4T, led to reduced accumulation of cadmium and zinc, which was confirmed independently using CRISPR/Cas9 to generate knockout mutants. Our results demonstrate that this powerful TILLING platform (available at http://www.croptilling.org) can be used in tobacco to facilitate functional genomics applications.

Genome-wide genetic variation and comparison of fruit-associated traits between kumquat (Citrus japonica) and Clementine mandarin (Citrus clementina).

KEY MESSAGE: The comprehensive genetic variation of two citrus species were analyzed at genome and transcriptome level. A total of 1090 differentially expressed genes were found during fruit development by RNA-sequencing. Fruit size (fruit equatorial diameter) and weight (fresh weight) are the two most important components determining yield and consumer acceptability for many horticultural crops. However, little is known about the genetic control of these traits. Here, we performed whole-genome resequencing to reveal the comprehensive genetic variation of the fruit development between kumquat (Citrus japonica) and Clementine mandarin (Citrus clementina). In total, 5,865,235 single-nucleotide polymorphisms (SNPs) and 414,447 insertions/deletions (InDels) were identified in the two citrus species. Based on integrative analysis of genome and transcriptome of fruit, 640,801 SNPs and 20,733 InDels were identified. The features, genomic distribution, functional effect, and other characteristics of these genetic variations were explored. RNA-sequencing identified 1090 differentially expressed genes (DEGs) during fruit development of kumquat and Clementine mandarin. Gene Ontology revealed that these genes were involved in various molecular functional and biological processes. In addition, the genetic variation of 939 DEGs and 74 multiple fruit development pathway genes from previous reports were also identified. A global survey identified 24,237 specific alternative splicing events in the two citrus species and showed that intron retention is the most prevalent pattern of alternative splicing. These genome variation data provide a foundation for further exploration of citrus diversity and gene-phenotype relationships and for future research on molecular breeding to improve kumquat, Clementine mandarin and related species.

Case report of ocular Kaposi's sarcoma.

BACKGROUND: Kaposi's sarcoma (KS) is generally considered a neoplastic disorder of vascular origin and occurs in patients with acquired immunodeficiency syndrome (AIDS) or who have received immunosuppressive treatments after an organ transplant (Soulier et al., Blood 86(4):1276-80, 1995; Viejo-Borbolla and Schulz, AIDS Rev 5(4):222-9, 2003; Schulz, J Antimicrob Chemother 45(Suppl T3):15-27, 2000; Aversa et al. Crit Rev Oncol Hematol 53(3):253-65, 2005; Mbulaiteye and Engels, Int J Cancer 119(11):2685-91, 2006; Tessari et al., Eur J Dermatol 16(5):553-7, 2006). Several Kaposi's sarcoma case reports involving eyelids and conjunctiva have been published (Bavishi et al., Int J STD AIDS 23(3):221-2, 2012; Baumann et al., Ger J Ophthalmol 4(4):239-45, 1995). CASE PRESENTATION: we report a 13 years old asian male patient rare case of ocular KS that was initiated from the sclera and progressed into the cornea and conjunctiva without an human Immunodeificiency Virus (HIV) or HHV-8 infection after a peripheral blood stem cells transplantation. In this case, anti- vascular endothelial growth factor (VEGF) therapy was attempted to stop the advance of ocular lesions and failed. Eventually, the KS was cured by a limbo-corneal lamellar graft, an amniotic membrane and scleral allograft transplantation plus intraoperative mitomycin C(MMC) after the complete excision of the tumors. CONCLUSION: A compete surgical excision combined with the intraoperative application of MMC, as well as grafts to repair the scleral, conjunctival, and corneal surfaces, could prevent a recurrence of KS.

The Role of miRNAs in Cartilage Homeostasis.

Osteoarthritis (OA) is an age-related disease with poorly understood pathogenesis. Recent studies have demonstrated that miRNA might play a key role in OA initiation and development. We reviewed recent publications and elucidated the connection between miRNA and OA cartilage anabolic and catabolic signals, including four signaling pathways: TGF-ß/Smads and BMPs signaling, associated with cartilage anabolism; and MAPK and NF-KB signaling, associated with cartilage catabolism. We also explored the relationships with MMP, ADAMTS and NOS (NitricOxide Synthases) families, as well as with the catabolic cytokines IL-1 and TNF-α. The potential role of miRNAs in biological processes such as cartilage degeneration, chondrocyte proliferation, and differentiation is discussed. Collective evidence indicates that miRNAs play a critical role in cartilage degeneration. These findings will aid in understanding the molecular network that governs articular cartilage homeostasis and in to elucidate the role of miRNA in the pathogenesis of OA.

[Effect of Tibetan medicine zuotai on the activity, protein and mRNA expression of CYP1A2 and NAT2].

To study the effect of Tibetan medicine Zuotai on the activity, protein and mRNA expression of CYP1A2 and NAT2, three different doses (1.2, 3.8 and 12 mg x kg(-1)) of Zuotai were administrated orally to rats once a day or once daily for twelve days, separately. Rats were administrated orally caffeine (CF) on the second day after Zuotai administration, and the urine concentration of CF metabolite 5-acetylamino-6-formylamino-3-methyl-uracil (AFMU), 1-methyluric acid (1U), 1-methylxanthine (1X), 1, 7-dimethylxanthine (17U) at 5 h after study drug administration was determined by RP-HPLC. The activity of CYP1A2 and NAT2 was evaluated by the ratio of metabolites (AFMU+1X+1U)/17U and the ratio of AFMU/(AFMU+1X+1U), respectively. The protein and mRNA expression of CYP1A2 and NAT2 were determined by ELISA and RT-PCR method, respectively. After single administration of Zuotai 3.8 mg x kg(-1) and repeated administration of Zuotai 3.8 and 12 mg x kg(-1), the activity of CYP1A2 and NAT2 decreased significantly compared with control group and there was no significant difference between other dose group and control group. The protein expression of CYP1A2 was significant lower than that in control group after repeated administration of Zuotai 12 mg x kg(-1), and the mRNA expression of CYP1A2 decreased significantly compared with that of control group after single administration of Zuotai 3.8 mg x kg(-1) and repeated admistration of Zuotai 12 mg x kg(-1), separately. The protein expression of NAT2 decreased significantly compared with that of control group after single and repeated administration of Zuotai 3.8 mg x kg(-1), respectively, and the mRNA expression of CYP1A2 decreased significantly compared with control group after single administration of Zuotai 3.8 mg x kg(-1). This study found that Tibetan medicine Zuotai had significant effect on the activity, protein and mRNA expression of CYP1A2 and NAT2.

Morphological characterization and distribution of antennal sensilla of Spodoptera frugiperda (Lepidoptera: Noctuidae) using scanning electron microscopy.

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a globally significant agricultural pest, causing severe damage to corn production in China. Chemical odor-based trapping is a major approach for FAW control, making it essential to understand the FAW antennal sensillum types to enhance development of effective chemical odor attractants. In this study, we comprehensively examined the antennal sensilla types of FAW, identifying eight types and two subtypes, including Böhm's bristles, sensilla trichoidea, sensilla chaetica (I and II), sensilla coeloconica, sensilla styloconica, sensilla squamiformia (I and II), sensilla auricillica, and sensilla basiconica. Sensilla chaetica II, and sensilla squamiformia II are reported for the first time for FAW in this study. Detailed low-voltage field emission scanning electron microscope (LVSEM) images and descriptions are provided for each sensillum type. This study provides the morphological information to aid in conducting antennal sensillum neurophysiological tests on FAW. RESEARCH HIGHLIGHTS: The types of sensilla of fall armyworm were examined, identifying eight types and two subtypes, including Böhm's bristles, sensilla trichoidea, sensilla chaetica (I and II), sensilla coeloconica, sensilla styloconica, sensilla squamiformia (I and II), sensilla auricillica, and sensilla basiconica. Detailed low-voltage field emission scanning electron microscope images and descriptions were provided for each sensillum type.

An unprotected vulnerable relict subtropical conifer-Keteleeria evelyniana: Its forests, populations, growth and endangerment by invasive alien plant species in China.

Relict subtropical coniferous forests in China face severe fragmentation, resulting in declining populations, and some are under significant threat from invasive alien species. Despite the crucial importance of understanding forest dynamics, knowledge gaps persist, particularly regarding the impact of invasive plants on vulnerable natives like Keteleeria evelyniana. In this study, we investigated the impact of invasive plants on the regeneration of forests dominated by K. evelyniana, a subtropical relict species in southwestern China. For this purpose, we characterized forest dynamics of 160 forest plots featuring K. evelyniana as the primary dominant species and determined whether the presence of invasive plants was correlated with regeneration of K. evelyniana. We identified four distinct forest types in which K. evelyniana was dominant. We found that radial growth of K. evelyniana trees is faster in younger age-classes today than it was for older trees at the same age. The population structure of K. evelyniana in each forest type exhibited a multimodal age-class distribution. However, three forest types lacked established saplings younger than 10 years old, a situation attributed to the dense coverage of the invasive alien Ageratina adenophora. This invasive species resulted in a reduction of understory species diversity. Additionally, our analysis uncovered a significant negative correlation in phylogenetic relatedness (net relatedness index) between native and invasive alien plant species in eastern Yunnan. This suggests closely related invasive species face heightened competition, hindering successful invasion. Taken together, our findings indicate that successful establishment and habitat restoration of K. evelyniana seedling/saplings require effective measures to control invasive plants.

Prognostic significance of USP22 as an oncogene in papillary thyroid carcinoma.

Ubiquitin-specific protease 22 (USP22), a novel deubiquitinating enzyme, has been associated with metastasis, therapy resistance, and cell cycle progression. The purpose of this study was to investigate the expression level of USP22 in papillary thyroid carcinoma (PTC) samples and to evaluate its clinical significance in PTC patients. USP22 expression was examined in 30 fresh PTC tissues and paired adjacent noncancerous tissues by real-time quantitative RT-PCR. Immunohistochemistry for USP22 was performed on additional 156 PTC tissues. The clinical significance of USP22 expression was analyzed. We found that the expression levels of USP22 mRNA and protein in PTC tissues were both significantly higher than those in noncancerous tissues. Clinicopathological analysis showed that USP22 expression was significantly correlated with tumor size (p=0.036), extracapsular invasion (p=0.012), multifocality (p=0.014), lymph node metastasis (p=0.022), distant metastasis (p=0.005), and TNM stage (p=0.002). The Kaplan-Meier survival curves revealed that USP22 expression was associated with poor prognosis in PTC patients. USP22 expression was an independent prognostic marker of overall patient survival in a multivariate analysis. Our findings suggest that USP22 is an independent predictor of poor prognosis of PTC patients.

Bloodletting Acupuncture at Jing-Well Points Alleviates Myocardial Injury in Acute Altitude Hypoxic Rats by Activating HIF-1α/BNIP3 Signaling-Mediated Mitochondrial Autophagy and Decreasing Oxidative Stress.

OBJECTIVE: To explore the protective effect and possible mechanisms of bloodletting acupuncture at Jing-well points (BAJP) pre-treatment on acute hypobaric hypoxia (AHH)-induced myocardium injury rat. METHODS: Seventy-five rats were randomly divided into 5 groups by a random number table: a control group (n=15), a model group (n=15), a BAJP group (n=15), a BAJP+3-methyladenine (3-MA) group (n=15), and a BANA (bloodletting at nonacupoint; tail bleeding, n=15) group. Except for the control group, the AHH rat model was established in the other groups, and the corresponding treatment methods were adopted. Enzyme-linked immunosorbent assay (ELISA) was used to detect creatine kinase isoenzyme MB (CK-MB) and cardiac troponins I (CTnI) levels in serum and superoxide dismutase (SOD) and malondialdehyde (MDA) levels in myocardial tissue. Hematoxylin-eosin (HE) staining was used to observe myocardial injury, and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining was used to observe cell apoptosis. Transmission electron microscopy detection was used to observe mitochondrial damage and autophagosomes in the myocardium. The mitochondrial membrane potential of the myocardium was analyzed with the fluorescent dye JC-1. Mitochondrial respiratory chain complex (complex I, III, and IV) activities and ATPase in the myocardium were detected by mitochondrial respiratory chain complex assay kits. Western blot analysis was used to detect the autophagy index and hypoxia inducible factor-1α (HIF-1α)/Bcl-2 and adenovirus E1B 19k Da-interacting protein 3 (BNIP3) signaling. RESULTS: BAJP reduced myocardial injury and inhibited myocardial cell apoptosis in AHH rats. BAJP pretreatment decreased MDA levels and increased SOD levels in AHH rats (all P<0.01). Moreover, BAJP pretreatment increased the mitochondrial membrane potential (P<0.01), mitochondrial respiratory chain complex (complexes I, III, and IV) activities (P<0.01), and mitochondrial ATPase activity in AHH rats (P<0.05). The results from electron microscopy demonstrated that BAJP pretreatment improved mitochondrial swelling and increased the autophagosome number in the myocardium of AHH rats. In addition, BAJP pretreatment activated the HIF-1α/BNIP3 pathway and autophagy. Finally, the results of using 3-MA to inhibit autophagy in BAJP-treated AHH rats showed that suppression of autophagy attenuated the treatment effects of BAJP in AHH rats, further proving that autophagy constitutes a potential target for BAJP treatment of AHH. CONCLUSION: BAJP is an effective treatment for AHH-induced myocardial injury, and the mechanism might involve increasing HIF-1α/BNIP3 signaling-mediated autophagy and decreasing oxidative stress.

Bloodletting Acupuncture at Jing-Well Points on Hand Induced Autophagy to Alleviate Brain Injury in Acute Altitude Hypoxic Rats by Activating PINK1/Parkin Pathway.

OBJECTIVE: To explore the protective effect of bloodletting acupuncture at twelve Jing-well points on hand (BAJP) on acute hypobaric hypoxia (AHH)-induced brain injury in rats and its possible mechanisms. METHODS: Seventy-five Sprague Dawley rats were divided into 5 groups by a random number table (n=15), including control, model, BAJP, BAJP+3-methyladenine (3-MA), and bloodletting acupuncture at non-acupoint (BANA, tail tip blooding) groups. After 7-day pre-treatment, AHH models were established using hypobaric oxygen chambers. The levels of S100B, glial fibrillary acidic protein (GFAP), superoxide dismutase (SOD), and malondialdehyde (MDA) in serum were measured by enzyme-linked immunosorbent assay. Hematoxylin-eosin staining and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method were used to assess hippocampal histopathology and apoptosis. Transmission electron microscopy assay was used to observe mitochondrial damage and autophagosomes in hippocampal tissues. Flow cytometry was used to detect mitochondrial membrane potential (MMP). The mitochondrial respiratory chain complexes I, III and IV activities and ATPase in hippocampal tissue were evaluated, respectively. Western blot analysis was used to detect the protein expressions of Beclin1, autophagy protein 5 (ATG5), microtubule-associated protein 1 light chain 3 beta (LC3B), phosphatase and tensin homolog induced kinase 1 (PINK1), and Parkin in hippocampal tissues. The mRNA expressions of Beclin1, ATG5 and LC3-II were analyzed by quantitative real-time polymerase chain reaction. RESULTS: BAJP treatment reduced hippocampal tissue injury and inhibited hippocampal cell apoptosis in AHH rats. BAJP reduced oxidative stress by decreasing S100B, GFAP and MDA levels and increasing SOD level in the serum of AHH rats (P<0.05 or P<0.01). Then, BAJP increased MMP, the mitochondrial respiratory chain complexes I, III and IV activities, and the mitochondrial ATPase activity in AHH rats (all P<0.01). BAJP improved mitochondrial swelling and increased the autophagosome number in hippocampal tissue of AHH rats. Moreover, BAJP treatment increased the protein and mRNA expressions of Beclin1 and ATG5 and LC3-II/LC3-I ratio in AHH rats (all P<0.01) and activated the PINK1/Parkin pathway (P<0.01). Finally, 3-MA attenuated the therapeutic effect of BAJP on AHH rats (P<0.05 or P<0.01). CONCLUSION: BAJP was an effective treatment for AHH-induced brain injury, and the mechanism might be through reducing hippocampal tissue injury via increasing the PINK1/Parkin pathway and enhancement of mitochondrial autophagy.

Dispersal Behavior Characters of Spodoptera frugiperda Larvae.

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a major pest of corn worldwide. FAW larval dispersal is an important life strategy that influences FAW population distribution in corn fields and subsequent plant damage. We studied FAW larval dispersal in the laboratory with sticky plates placed around the test plant and a unidirectional airflow source. Crawling and ballooning were the main dispersal means of FAW larvae both within and between corn plants. All larval instars (1st-6th) could disperse by crawling, with crawling being the only dispersal mechanism for 4th-6th instars. By crawling, FAW larvae could reach all aboveground parts of a corn plant as well as adjacent corn plants where leaves overlapped. Ballooning was used primarily by 1st-3rd instar larvae, and the proportion of these larvae that used ballooning decreased with age. Ballooning was largely governed by the larva's interaction with airflow. Airflow influenced the direction and distance of larval ballooning. With an airflow speed of about 0.05 m/s, 1st instars could travel up to 196 cm from the test plant, indicating that long-distance FAW larval dispersal depends on ballooning. These results increase our understanding of FAW larval dispersal and provide scientific information for the development of FAW monitoring and control strategies.

Forest characteristics, population structure and growth trends of threatened relict Pseudotsuga forrestii in China.

Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China. P. forrestii tree numbers have greatly decreased due to deforestation, over-utilization and habitat degradation. Here we clarify P. forrestii community types, structure, species diversity, seedling recruitments and growth trends. We identified four P. forrestii community types: (1) Pseudotsuga forrestii - Quercus guyavifolia - Acer davidii evergreen coniferous and broad-leaved mixed forest; (2) Pseudotsuga forrestii - Pinus yunnanensis - Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest; (3) Pseudotsuga forrestii evergreen coniferous forest; (4) Pseudotsuga forrestii - Abies georgei var. smithii evergreen coniferous forest. P. forrestii forests are characterized by both warm temperate and temperate affinities. Simpson diversity, Pielou evenness, Shannon-Wiener diversity indices ranged from 0.75 to 0.76, 0.74-0.81, and 1.62-1.93, respectively, with no significant differences among the four forest types. The forest stratification was multilayered. The canopy layer was generally 10-25 m tall, with the emergent layer reached 25-42 m. DBH and age structures of P. forrestii showed multimodal distributions. Its maximum age P. forrestii was 570 years with a DBH of 143 cm. The growth of annual ring width of P. forrestii was slow, and generally decreased with age, whereas the basal area at the breast height increased with age. Established seedlings/saplings were mainly found in unstable micro-habitats. Regeneration of P. forrestii depends on moderate natural disturbances. Finally, we provide recommendations for P. forrestii conservation.

Enhance the resolution of photonic crystal negative refraction imaging by metal grating.

The resolution of imaging is limited by the missing of high-frequencies information. The superlens employing negative refraction can compensate for these components. But for the directional coupling of Bloch waves and the low coupling efficiency of large-angle waves, the resolution of subwavelength imaging is not satisfactory. However, the subwavelength metallic grating can produce high-order diffracted waves carrying a lot of high-frequencies information. Therefore, this structure is used to inhibit the zero-order diffraction and enhance the high-order diffraction to achieve super-resolution.

Comparison of the pharmacokinetics of sulfamethoxazole in native Han and Tibetan male Chinese volunteers living at high altitude.

The aim of this study was to investigate the pharmacokinetics of sulfamethoxazole in native Han and Tibetan healthy Chinese subjects living chronically at high altitude. An open-labeled, controlled, prospective study was conducted in healthy Chinese male volunteers. Sulfamethoxazole 1,200 mg was administered orally to two groups: native Han and Tibetan volunteers living at high altitude (2,500-3,900 m [8,200-12,800 ft]). Blood samples were collected from an indwelling venous catheter into heparinized tubes before (baseline) study drug administration and at 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 12, 24, 36, and 48 h after study drug administration. Sulfamethoxazole in whole blood, plasma, and plasma water, and metabolite N (4)-acetyl-sulfamethoxazole in plasma were determined by HPLC. Tolerability was determined using blood chemistry testing, continuous 12-lead electrocardiogram, and blood pressure monitoring. The protein binding was significantly higher in the native Tibetan group (70.5 %) compared to the native Han group (67.3 %) (p < 0.05). The binding of sulfamethoxazole to red blood cells was 7.4 and 8.3 % in the native Han and native Tibetan groups, respectively. There was no significant difference between the two groups. The AUC(0-∞) was significantly lower in the native Tibetan group compared to the native Han group (p < 0.05), and other pharmacokinetics parameters were found to have no significant difference between the two groups. This study found little changes in the disposition of sulfamethoxazole in these native healthy Tibetan Chinese subjects living at high altitude in comparison to native healthy Han Chinese subjects living at high altitude.

[Effect of high altitude hypoxia on the activity and protein expression of CYP2C9 and CYP2C19].

This study is to investigate the effect of high altitude hypoxia on the activity and protein expression of CYP2C9 and CYP2C19. Rats from plain (P) and rats with acute middle altitude hypoxia (AMH), chronic middle altitude hypoxia (CMH), acute high altitude hypoxia (AHH) and chronic high altitude hypoxia (CHH) were administered orally phenytoin sodium (PHT) and omeprazole (OMZ) to evaluate the activity of CYP2C9 and CYP2C19, separately. The serum concentrations of PHT and metabolite 4'-hydroxyphenytoin (HPPH) at 12 h after treatment and the serum concentrations of OMZ and metabolite 5-hydroxy omeprazole (5-OHOMZ) at 3 h after treatment were determined by RP-HPLC. The activity of CYP2C9 and CYP2C19 was evaluated by the ratio of HPPH to PHT and the ratio of 5-OHOMZ to OMZ, respectively. The protein expressions of CYP2C9 and CYP2C19 were determined by ELISA method. The activities of CYP2C9 (HPPH/PHT) in P, AMH, CMH, AHH and CHH were 0.67 +/- 0.31, 0.75 +/- 0.29, 0.76 +/- 0.23, 0.79 +/- 0.31 and 0.75 +/- 0.18, respectively, and the activities of CYP2C19 (5-OHOMZ/OMZ) in P, AMH, CMH, AHH and CHH were 0.17 +/- 0.06, 0.20 +/- 0.10, 0.11 +/- 0.05, 0.37 +/- 0.13 and 0.19 +/- 0.05, respectively. The protein expressions of CYP2C9 in P, AMH, CMH, AHH and CHH were 4.20 +/- 1.27, 3.95 +/- 0.81, 3.93 +/- 1.11, 4.32 +/- 1.03 and 4.12 +/- 0.86 ng x g(-1), respectively, and the protein expressions of CYP2C19 in P, AMH, CMH, AHH and CHH were 3.91 +/- 1.82, 3.63 +/- 2.07, 2.55 +/- 0.85, 4.78 +/- 2.37 and 3.51 +/- 1.03 ng x g(-1), respectively. The activities and protein expressions of CYP2C9 in AMH, CMH, AHH and CHH were not significantly different with those of P. The protein expressions of CYP2C19 in AMH, CMH, AHH and CHH were not significantly different with those of P, but the activity of CYP2C19 in AHH was significantly higher than that of P. This study found significant changes in the activity of CYP2C19 under the special environment of acute high altitude hypoxia.

[The pathological basis of the argument in the treatment of melanoma of the uveal tract].

Melanoma of the uveal tract is most common primary intraocular cancer in adults. Approximately 50% of patients with uveal melanoma died from metastasis, irrespective of the type of treatment. Enucleation was the primary form of treatment and the best option. Whether the enucleation of the eye containing uveal melanoma accelerates metastatic death has long been a controversial topic. The combination of pathological and some experimental studies in progress concerning this contentious topic is discussed in the current article.

Subwavelength imaging by a graded-index photonic-crystal flat lens in a honeycomb lattice.

The left-handed behavior of a photonic-crystal flat lens with a graded index in a honeycomb lattice is proposed and theoretically studied. The performance of the flat superlens imaging of this structure has been demonstrated by finite-difference time-domain simulations. The full width at half-maximum of the image decreases to 62% compared to that of the image of a photonic-crystal slab without a graded index. The evanescent waves can be amplified and propagate to the far-field range. The image is not limited to be near the interface. The canalization effect of this structure is analyzed, and the tolerance of the edge cut of the graded-index structure is pretty good.

Macrophages acquire fibroblast characteristics in a rat model of proliferative vitreoretinopathy.

PURPOSE: Our aim was to establish a rat model of proliferative vitreoretinopathy (PVR) induced by macrophages and investigate whether macrophages can be a cell origin of fibroblast-like cells present in PVR. METHODS: One eye of each rat received an intravitreal injection of macrophages. Clinical examination was performed to evaluate the development of PVR. Histological study was carried out to observe the pathological progression. Immunohistochemical staining with vimentin (VIM), glial fibrillary acidic protein (GFAP), α-smooth-muscle actin (α-SM actin), cytokeratin (CK) and CD68 characterized the cell types within the PVR membranes. The distribution, morphological change of prelabeled macrophages, as well as their colocalization with CD68, VIM, GFAP, α-SM actin and CK, were observed on days 3, 14 and 28 after injection. RESULTS: In response to intravitreal injection of macrophages, 90% of the experimental rats developed PVR from postoperative day 7. The histological progression of PVR was characterized by the sequential appearance of inflammatory cell invasion, fibroblast proliferation and scar formation. The dominating cells comprising the proliferative membranes at the advanced stage were fibroblasts. Injected macrophages retained round shape and positive staining with CD68 on day 3. On day 28, they acquired elongated/spindle shape combined with intense staining of VIM but absence of CD68, GFAP, α-SM actin and CK, and became the primary constituent of fibrocellular membranes. CONCLUSIONS: Macrophages effectively and reproducibly induce the development of proliferative fibrocellular membranes in rats. In this PVR model, macrophages acquire fibroblast-like cell phenotype and contribute to fibrocellular membranes directly, suggesting that macrophages may be a cell origin of fibroblast-like cells involved in PVR.