Odorant-binding protein (OBP) genes affect host specificity in a fig-pollinator mutualistic system

The interaction between figs and their pollinating wasps is regarded as a model system for studying specialized co-evolved mutualism. Chemoreception of fig wasps plays an important role in this interaction, and odorant-binding proteins (OBP) function in the first step of odorant detection. The OBP repertoire of the fig wasp Ceratosolen solmsi is reported to be one of the smallest among insects; however, it is unknown how these OBPs are related to the complicated mating process occurring within the fig cavity and the extreme host specificity of the species. In the present study, we combined a structural analysis of the conserved cysteine pattern and motif order, a phylogenetic analysis, and previous studies on ligand-binding assays to deduce the function of OBPs. We also quantified the expression of OBP genes in different life stages of female and male fig wasps by using real-time quantitative PCR, which can help to predict the function of these genes. The results indicated that CsolOBP1 and CsolOBP2 (or CsolOBP5) in males may bind to pheromones and play important roles in mate choice, whereas CsolOBP4 and CsolOBP5 may primarily function in host localization by females through binding of volatile compounds emitted by receptive figs.

Values of gastroscopy and endoscopic ultrasonography in diagnosis and treatment of esophageal papilloma

AIM: To explore the value of gastroscopy and endoscopic ultrasonography in diagnosis and treatment of esophageal papilloma.

METHODS: Forty nine cases with esophageal papilloma confirmed by pathological examination underwent gastroscopy and 24 of them underwent endoscopic ultrasonography. Then their manifestations of gastroscopy and endoscopic ultrasonography as well as the relationship between the pathologic and clinical characteristics were analyzed.

RESULTS: On gastroscopy, most lesions of EP cases were located at the middle or distal esophagus (89.8%), assuming feather-like or corpora mammillaria-like bulge, with floccular or fine granular-like surface and grayish-white color, and most of the EP was single with diameter ranging from 0.3-0.6 cm. Of 24 cases undergoing endoscopic ultrasonography, 17 were diagnosed as EP (70.8%), and 6 were diagnosed as inflammatory proliferation or polypus (25%). The classic endosonographic characteristics were even iso-echoic with clear boundary originating from mucosa layer, protruding into the lumen.

CONCLUSION: Esophageal papilloma is well displayed on endoscopic ultrasonography, which could be used to determine indications of endoscopy.

One-case analysis of esophageal superficial mucosal exfoliation

Esophageal superficial mucosal exfoliation is a quite rare disease in clinical practice. We report a young female who vomited out a strip of pale soft tissue like a strand with one end in the mouth and the other free with a little blood after taking food. After being admitted, the patient was given conventional therapies such as fasting and acid-suppression by proton pump inhibitor. Six days later, the patient was discharged with liquid diet. After a 2-mo to 1-year following up, no abnormal findings were observed under endoscope after two months and one year later.

Maxizyme-mediated specific inhibition on mutant-type p53 in vitro

AIM: To evaluate the specific inhibition of maxizyme directing against mutant-type p53 gene (mtp53) at codon 249 in exon 7 (AGG→AGT) in vitro.

METHODS: Two different monomers of anti-mtp53 maxizyme (maxizyme right MzR, maxizyme left MzL) and control mutant maxizyme (G⁵→A⁵) were designed by computer and cloned into vector pBSKU6 (pBSKU6MzR, pBSKU6MzL). After being sequenced, the restrictive endonuclease site in pBSKU6MzR was changed by PCR and then U6MzR was inserted into pBSKU6MzL, the recombinant vector was named pU6Mz and pU6asMz (mutant maxizyme). Mtp53 and wild-type p53 (wtp53) gene fragments were cloned into pGEM-T vector under the T7 promoter control. The ³²p-labeled mtp53 transcript was the target mRNA. Cold maxizyme transcripts were incubated with ³²p-labeled target RNA in vitro and radioautographed after denaturing polyacrylamide gel electrophoresis.

RESULTS: In cell-free systems, pU6Mz showed a specific cleavage activity against target mRNA at 37 °C and 25 mM MgCL₂. The cleavage efficiency of pU6Mz was 42%, while pU6asMz had no inhibitory effect. Wtp53 was not cleaved by pU6Mz either.

CONCLUSION: pU6Mz had a specific catalytic activity against mtp53 in cell-free system. These lay a good fundation for studying the effects of anti-mtp53 maxizyme in HCC cell lines. The results suggest that maxizyme may be a promising alternative approach for treating hepatocellular carcinoma containing mtp53.

Anti-HBV hairpin ribozyme-mediated cleavage of target RNA in vitro

AIM: To study the preparation and cleavage activity of HpRz directed against the transcript of HBV core gene in vitro.

METHODS: HpRz gene designed by computer targeting the transcript of HBV core gene was cloned into the vector p1.5 between 5’-cis-Rz and 3’-cis-Rz. ³²p-labeled HpRz transcript proved whether the vector fit for the preparation of hairpin ribozyme in vitro. ³²p-labeled pKC transcript containing HBV core region as target-RNA was transcribed using T₇ RNA polymerase and purified by denaturing PAGE. Cold HpRz transcript was incubated with ³²p-labeled target-RNAs under different conditions and radio autographed after denaturing polyacrylamide gel electrophoresis.

RESULTS: HpRz has the specific ability of cleavage of target RNA at 37 °C and 12 mM MgCl₂. K_m = 26.31 nmol/L, K_cat = 0.18/min. These results revealed that the design of HpRz was correct.

CONCLUSION: HpRz prepared in this study possesses specific catalytic activity from the identification of cleavage activity. These results indicate that hairpin ribozyme may intracellularly inhibit the replication of HBV, therefore it may become a novel potent weapon for the treatment of hepatitis B.

Optoelectronic butterfly interconnection architecture of modified signed-digit arithmetic systems: fully parallel adder and subtracter

The carry-free property of modified signed-digit addition is discussed, and a space-position-logic-encoding scheme is proposed, which not only makes best use of the convenience of binary (0, 1) logic operation but is also suitable for the trinary (1, 0, 1-) property of modified signed-digit digits. Based on the spaceposition-logic-encoding scheme, a fully parallel modified signed-digit adder and subtracter is built by use of optoelectronic switch modules and butterfly interconnections; thus an effective combination of a parallel algorithm and a parallel architecture is implemented. The effectiveness of this architecture is verified by both simulation and experimental results.

Butterfly interconnection networks and their applications in information processing and optical computing: applications in fast-Fourier-transform-based opticalinformation processing

As modern optical information processing has developed, research on massive and parallel rapid computing and processing has attracted more attention. In this paper, butterfly networks and a variety of types of optical information processing are studied and discussed. For a basis, one- and twodimensional butterfly interconnection networks are studied in constructions, and the relationship and the transformation between them are provided. Algorithms for both the one- and two-dimensional fast Fourier transforms are analyzed, one- and two-dimensional butterfly networks for implementing the algorithms are built, and computer-simulation results are attained. Finally, an underlying optical network system is suggested and studied in respect to its architecture and advantages; it is a new optical butterfly network hardware system consisting of two-dimensional binary phase diffraction gratings, which perform a variety of types of fast-Fourier-transform-based optical information processing.