Males evolved from the dominant isogametic mating type.
Explore the source record for details and available documents.
Algal Proteins↗
Biomedical subjects
Toshiyuki Mori
Publications and source records attributed to Toshiyuki Mori.
Species preferentiality of the pollen tube attractant derived from the synergid cell of Torenia fournieri.
The synergid cell of Torenia fournieri attracts pollen tubes by a diffusible but yet unknown chemical attractant. Here we investigated the species difference of the attractant using five closely related species in two genera, namely T. fournieri, Torenia baillonii, Torenia concolor, Lindernia (Vandellia) crustacea, and Lindernia micrantha. These five species have an exserted embryo sac, and ablation experiments confirmed that their synergid cells attracted the pollen tube. When ovules of T. fournieri and one of the other species were cultivated together with pollen tubes of each species, pollen tubes were significantly more attracted to synergid cells of the corresponding species. The attraction was not affected by the close proximity of embryo sacs of different species. This suggests that the attractant is a species-preferential molecule that is likely synthesized in the synergid cell. The calcium ion, long considered a potential attractant, could not serve as the sole attractant in these species, because elevation of the calcium ion concentration did not affect the observed attraction. In vivo crossing experiments also showed that the attraction of the pollen tube to the embryo sac was impaired when pollen tubes of different species arrived around the embryo sac, suggesting that the species preferentiality of the attractant may serve as a reproductive barrier in the final step of directional control of the pollen tube.
Biological Factors↗
RETRACTED: Photocatalytic activity of Bi-doped TiO(2) in the degradation of monocrotophos in aqueous solution.
This article has been retracted consistent with Elsevier Policy on Article Withdrawal. Please see . The Publisher apologizes for any inconvenience this may cause.
Journal Article↗
Characterization and catalytic performances of three-dimensional mesoporous FeSBA-1 catalysts.
Iron substituted cubic cage type mesoporous molecular sieves (FeSBA-1) were synthesized for the first time in a highly acidic media using cetyltriethylammonium bromide as a template. The amount of Fe incorporation in SBA-1 can easily be controlled by the simple adjustment of the molar hydrochloric acid-to-silicon ratio. All the materials were unambiguously characterized by AAS, XRD, N2 adsorption, UV-Vis DRS, XPS, and ESR spectroscopy. The results from AAS, XRD, and N2 adsorption reveal that the iron atom can be incorporated in the framework of SBA-1 matrix without altering the structural order and the textural parameters. The nature and the coordination of iron atoms were extensively studied by XPS spectroscopy, and the results revealed that most of the iron atoms in FeSBA-1 are in +3 coordination state. UV-Vis DRS and ESR studies confirmed that the majority of the Fe atoms in FeSBA-1 exist in a tetrahedral coordination environment (most probably occupying framework positions). tert-Butylation of phenol employing tert-butanol as the alkylation agent was carried out over FeSBA-1 catalysts with different iron content and the results are compared with one-dimensional mesoporous catalysts. The influence of various reaction parameters such as reaction temperature, reactant feed ratio, weight hourly space velocity, and time-on-stream affecting the activity and selectivity of FeSBA-1 were also studied. Under the optimized reaction conditions, the FeSBA-1(36) catalyst showed superior catalytic performance for the tert-butylation of phenol as compared to the uni-dimensional mesoporous catalysts.
Catalysis↗
Interaction of human lactoferrin with cell adhesion molecules through RGD motif elucidated by lactoferrin-binding epitopes.
Lactoferrin (LF) is an iron-binding secretory protein, which is distributed in the secondary granules of polynuclear lymphocytes as well as in the milk produced by female mammals. Although it has multiple functions, for example antimicrobial, immunomodulatory, antiviral, and anti-tumor metastasis activities, the receptors responsible for these activities are not fully understood. In this study, the binding epitopes for human LF were first isolated from a hexameric random peptide library displayed on T7 phage. Interestingly, two of the four isolated peptides had a representative cell adhesion motif, Arg-Gly-Asp (RGD), implying that human LF interacts with proteins with the RGD motif. We found that human LF bound to the RGD-containing human extracellular matrix proteins, fibronectin and vitronectin. Furthermore, human LF inhibited cell adhesion to these matrix proteins in a concentration-dependent manner but not to the RGD-independent cell adhesion molecule like laminin or collagen. These results indicate that a function of human LF is to block the various interactions between the cell surface and adhesion molecules. This may explain the multifunctionality of LF.
Amino Acid Motifs↗
Structure, function and evolution of the mitochondrial division apparatus.
Mitochondria are derived from free-living alpha-proteobacteria that were engulfed by eukaryotic host cells through the process of endosymbiosis, and therefore have their own DNA which is organized using basic proteins to form organelle nuclei (nucleoids). Mitochondria divide and are split amongst the daughter cells during cell proliferation. Their division can be separated into two main events: division of the mitochondrial nuclei and division of the matrix (the so-called mitochondrial division, or mitochondriokinesis). In this review, we first focus on the cytogenetical relationships between mitochondrial nuclear division and mitochondriokinesis. Mitochondriokinesis occurs after mitochondrial nuclear division, similar to bacterial cytokinesis. We then describe the fine structure and dynamics of the mitochondrial division ring (MD ring) as a basic morphological background for mitochondriokinesis. Electron microscopy studies first identified a small electron-dense MD ring in the cytoplasm at the constriction sites of dividing mitochondria in the slime mold Physarum polycephalum, and then two large MD rings (with outer cytoplasmic and inner matrix sides) in the red alga Cyanidioschyzon merolae. Now MD rings have been found in all eukaryotes. In the third section, we describe the relationships between the MD ring and the FtsZ ring descended from ancestral bacteria. Other than the GTPase, FtsZ, mitochondria have lost most of the proteins required for bacterial cytokinesis as a consequence of endosymbiosis. The FtsZ protein forms an electron transparent ring (FtsZ or Z ring) in the matrix inside the inner MD ring. For the fourth section, we describe the dynamic association between the outer MD ring with a ring composed of the eukaryote-specific GTPase dynamin. Recent studies have revealed that eukaryote-specific GTPase dynamins form an electron transparent ring between the outer membrane and the MD ring. Thus, mitochondriokinesis is thought to be controlled by a mitochondrial division (MD) apparatus including a dynamic trio, namely the FtsZ, MD and dynamin rings, which consist of a chimera of rings from bacteria and eukaryotes in primitive organisms. Since the genes for the MD ring and dynamin rings are not found in the prokaryotic genome, the host genomes may make these rings to actively control mitochondrial division. In the fifth part, we focus on the dynamic changes in the formation and disassembly of the FtsZ, MD and dynamin rings. FtsZ rings are digested during a later period of mitochondrial division and then finally the MD and dynamin ring apparatuses pinched off the daughter mitochondria, supporting the idea that the host genomes are responsible for the ultimate control of mitochondrial division. We discuss the evolution, from the original vesicle division (VD) apparatuses to VD apparatuses including classical dynamin rings and MD apparatuses. It is likely that the MD apparatuses involving the dynamic trio evolved into the plastid division (PD) apparatus in Bikonta, while in Opisthokonta, the MD apparatus was simplified during evolution and may have branched into the mitochondrial fusion apparatus. Finally, we describe the possibility of intact isolation of large MD/PD apparatuses, the identification of all their proteins and their related genes using C. merolae genome information and TOF-MS analyses. These results will assist in elucidating the universal mechanism and evolution of MD, PD and VD apparatuses.
Animals↗
T7 lytic phage-displayed peptide libraries exhibit less sequence bias than M13 filamentous phage-displayed peptide libraries.
We investigated whether the T7 system of phage display could produce peptide libraries of greater diversity than the M13 system of phage display due to the differing processes of lytic and filamentous phage morphogenesis. Using a bioinformatics-assisted computational approach, collections of random peptide sequences obtained from a T7 12-mer library (X(12)) and a T7 7-mer disulfide-constrained library (CX(7)C) were analyzed and compared with peptide populations obtained from New England BioLabs' M13 Ph.D.-12 and Ph.D.-C7C libraries. Based on this analysis, peptide libraries constructed with the T7 system have fewer amino acid biases, increased peptide diversity, and more normal distributions of peptide net charge and hydropathy than the M13 libraries. The greater diversity of T7-displayed libraries provides a potential resource of novel binding peptides for new as well as previously studied molecular targets. To demonstrate their utility, several of the T7-displayed peptide libraries were screened for streptavidin- and neutravidin-binding phage. Novel binding motifs were identified for each protein.
Amino Acid Sequence↗
Preoperative endoscopic pancreatic stenting for prophylaxis of pancreatic fistula development after distal pancreatectomy.
BACKGROUND AND OBJECTIVE: Pancreatic fistula is a common complication of distal pancreatectomy (DP). Although various surgical procedures have been proposed for DP in an attempt to decrease the high incidence of pancreatic fistula, the prevention of pancreatic fistula remains a major problem in DP. Endoscopic pancreatic stenting for the treatment or prophylaxis of such a fistula has been rarely described. METHODS: We reviewed 9 patients who underwent preoperative endoscopic pancreatic stenting for the prophylaxis of pancreatic fistula development after DP. RESULTS: Preoperative endoscopic pancreatic stenting was successfully performed with a 7F stent in all the 9 patients. Two patients, both with intraductal papillary mucinous tumor, developed mild acute pancreatitis after the stent placement. None of the 9 patients developed pancreatic fistula. The pancreatic stent was removed from 8 to 28 days (mean 11 days) postoperatively. CONCLUSIONS: Preoperative endoscopic pancreatic stenting may be an effective prophylactic measure against pancreatic fistula development following DP in selected patients.
Adenocarcinoma, Mucinous↗
Anatomic study of the superior right colic vein: its relevance to pancreatic and colonic surgery.
BACKGROUND: This study was designed to describe the precise anatomic venous tributaries of the superior mesenteric vein with special emphasis on the superior right colic vein (SRCV), which is seldom mentioned in the literature. METHODS: Nine adult cadavers were dissected to define the venous tributaries of the superior mesenteric vein. The SRCV, middle colic vein, and right colic vein (RCV) were defined as those that drained from the marginal vein of the right flexure of the colon, the transverse colon, and the ascending colon, respectively. RESULTS: The SRCV was observed to drain from the right flexure of the colon to the confluence of the right gastroepiploic and superior pancreaticoduodenal veins and present the gastrocolic trunk of Henle (GTH) in 8 of 9 cases. The RCV terminated into the GTH in 4 cases. The SRCV, the RCV, and the middle colic vein formed a confluence and entered into the GTH in 1 case. CONCLUSIONS: The SRCV exits and drains from the right colonic flexure to the GTH in 89% of cases.
Adult↗
Gallstone disease: Management of intrahepatic stones.
Hepatolithiasis (oriental cholangiohepatitis) has reportedly been endemic only in East Asia. The disease is now occasionally recognized in Western societies, especially in people who have lived in the Orient. Hepatolithiasis is characterized by its intractable nature and frequent recurrence, requiring multiple operative interventions, which is in distinct contrast to gallbladder stones. In addition to frequent cholangitis and chronic sepsis, it is widely known that longstanding intrahepatic stones lead to intrahepatic cholangiocarcinoma. Symptoms of hepatolithiasis include abdominal pain, jaundice and cholangitis. Pyogenic cholangitis due to strictures and hepatolithiasis tends to recur, and sometimes patients may present with liver abscesses. Radiological studies and percutaneous procedures are keys in the diagnosis and treatment of hepatolithiasis. Non-invasive imaging modalities such as ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) accurately depict the normal anatomy and presence of intrahepatic stones. It should be stressed that each modality has its pros and cons, and imaging studies should be performed on the basis of understanding the pathophysiology. As the diagnostic role of magnetic resonance cholangiopancreatography (MRCP) evolves, the roles of both endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC), and their most significant advantage, is primarily therapeutic with their ability to extract stones, biopsy intraductal lesions, and place stents easily. The primary goals of treatment are to eliminate attacks of cholangitis and to stop the progression of the disease (which leads to biliary cirrhosis). Surgery has a primary role in hepatolithiasis because hepatolithiasis tends to recur, so that multiple sessions of the endoscopic approach (i.e. two or three times a year) are often required. PTC is an alternative when surgical resection of the affected lobe is difficult. Techniques for lithotripsy, including shockwave and laser, can be applied in endoscopic sessions, offering a better chance of clearing the stones.
Bile Ducts, Intrahepatic↗
Domain-swapped structure of the potent antiviral protein griffithsin and its mode of carbohydrate binding.
The crystal structure of griffithsin, an antiviral lectin from the red alga Griffithsia sp., was solved and refined at 1.3 A resolution for the free protein and 0.94 A for a complex with mannose. Griffithsin molecules form a domain-swapped dimer, in which two beta strands of one molecule complete a beta prism consisting of three four-stranded sheets, with an approximate 3-fold axis, of another molecule. The structure of each monomer bears close resemblance to jacalin-related lectins, but its dimeric structure is unique. The structures of complexes of griffithsin with mannose and N-acetylglucosamine defined the locations of three almost identical carbohydrate binding sites on each monomer. We have also shown that griffithsin is a potent inhibitor of the coronavirus responsible for severe acute respiratory syndrome (SARS). Antiviral potency of griffithsin is likely due to the presence of multiple, similar sugar binding sites that provide redundant attachment points for complex carbohydrate molecules present on viral envelopes.
Algal Proteins↗
Distribution of lymphatic vessels in the neural plexuses surrounding the superior mesenteric artery.
OBJECTIVES: To investigate whether lymphatic vessels exist in the neural plexuses surrounding the superior mesenteric artery (SMA) and the ultrastructural relationship between neural plexuses and lymphatic vessels. METHODS: A total of 970 serial sections including the structure surrounding the SMA were obtained from 9 cadavers. They were subjected to conventional hematoxylin/eosin staining and immunostaining for the lymphatic marker D2-40. Epithelial membrane antigen and S100 were also immunostained to identify the perineurium and nerve bundles, respectively. RESULTS: Thin-walled, erythrocyte-free vessels staining with lymphatic markers (D2-40) were found in the neural plexuses surrounding the SMA along a full circumference. There seemed to be a distribution correlation between lymphatic vessels and neural plexuses. Lymphatic vessels were not identified within the nerve bundles. The plexuses contained no lymph nodes in any sections. CONCLUSIONS: To our knowledge we report the immunohistochemical visualization of lymphatic vessels in peri-SMA neural plexuses for the first time. Therefore, particular attention should be paid to the lymphatic vessels within neural plexuses as a possible route of invasion and the source of pancreatic cancer recurrence.
Aged↗
Pancreatic carcinoma that completely obstructs the Wirsung duct without dilatation of the main pancreatic duct.
BACKGROUND AND AIM: Pancreatic carcinomas in which the main pancreatic duct (MPD) is completely obstructed are almost always associated with dilatation of the upstream MPD. However, some carcinomas are not associated with MPD dilatation despite complete MPD obstruction. This paradoxical phenomenon has not been well documented. METHODS: The findings from endoscopic retrograde cholangiopancreatography in 207 cases of pancreatic head carcinomas were analyzed with special reference to this unique type of carcinoma. Twenty-five of the patients were found to exhibit no MPD dilatation on ultrasonography, computed tomography or magnetic resonance imaging. RESULTS: Pancreatography via the major papilla showed complete obstruction of the MPD (112 patients with MPD dilatation and 6 without), stenosis (70 and 10, respectively), or no abnormal findings (0 and 9, respectively). In all six patients with complete MPD obstruction but without upstream MPD dilatation, injection of the minor papilla revealed a non-dilated dorsal pancreatic duct. The size of the obstructive carcinomas with and without MPD dilatation was comparable. CONCLUSIONS: Some (3%) pancreatic head carcinomas are not associated with MPD dilatation despite complete obstruction of the Wirsung duct. In such cases, the Santorini duct drains the dorsal pancreatic duct, completely compensating for the obstructed Wirsung duct. Attention should be paid to this unique type of carcinoma in diagnosing pancreatic head carcinomas.
Adenocarcinoma↗
[Serous cystic tumor of the pancreas].
Explore the source record for details and available documents.
Cystadenoma, Serous↗
[A case of localized AL-type amyloidosis of the stomach].
A 78-year-old woman was admitted to our hospital for treatment of liver cirrhosis and an esophageal varix. Endoscopy revealed a protruding nodular lesion with a transparent smooth surface proximal to the pylorus, which was accompanied by a partly yellow-whitish spot. A depressed lesion with an even edge was found. Histologically, the protruding lesion and depressed lesion showed amyloid deposits, mainly in the mucosal layer. The lesions were found to correspond to AL type amyloidosis by immunochemical analysis. General examination showed no other amyloid deposits. Thus, we diagnosed localized amyloidosis of the stomach.
Aged↗
GENERATIVE CELL SPECIFIC 1 is essential for angiosperm fertilization.
The double fertilization process in angiosperms is based on the delivery of a pair of sperm cells by the pollen tube (the male gametophyte), which elongates towards an embryo sac (the female gametophyte) enclosing an egg and a central cell. Several studies have described the mechanisms of gametophyte interaction, and also the fertilization process - from pollination to pollen tube acceptance. However, the mechanisms of gamete interaction are not fully understood. Cytological studies have shown that male gametes possess distinct cell-surface structures and genes specific to male gametes have been detected in cDNA libraries. Thus, studies of isolated gametes may offer clues to understanding the sperm-egg interaction. In this study, we identified a novel protein, designated GCS1 (GENERATIVE CELL SPECIFIC 1), using generative cells isolated from Lilium longiflorum pollen. GCS1 possesses a carboxy-terminal transmembrane domain, and homologues are present in various species, including non-angiosperms. Immunological assays indicate that GCS1 is accumulated during late gametogenesis and is localized on the plasma membrane of generative cells. In addition, Arabidopsis thaliana GCS1 mutant gametes fail to fuse, resulting in male sterility and suggesting that GCS1 is a critical fertilization factor in angiosperms.
Amino Acid Sequence↗
Recombinant production of anti-HIV protein, griffithsin, by auto-induction in a fermentor culture.
Griffithsin (GRFT) is a novel anti-HIV protein isolated from the red alga Griffithia sp. The potent anti-viral activity of GRFT against both laboratory and primary isolates of HIV at picomolar concentrations makes this protein an attractive candidate microbicide to prevent sexual transmission of HIV. Here, we describe the recombinant production and purification of a biologically active hexa-histidine-tagged GRFT (His-GRFT) from Escherichia coli. To facilitate a large-scale production of recombinant His-GRFT, we tested different expression conditions to optimize the expression in the cytoplasm of E. coli to increase the overall production of soluble His-GRFT. Attempts to express His-GRFT in shake flask cultures resulted in a modest yield of soluble His-GRFT, with a large accumulation of the protein in inclusion bodies. The use of a fermenter and of a rich, auto-inducing medium allowed the total amount of His-GRFT per liter to be increased by about 45-fold, with approximately 70% of the protein expressed in the soluble fraction. N-terminal sequencing and MALDI-TOF analyses of the recombinant His-GRFT confirmed that the initial methionine residue was cleaved off. Recombinant His-GRFT showed equivalent activity with natural GRFT, both in respect to gp120-binding characteristics as well as anti-HIV activity. Size-exclusion chromatography analysis showed that both native GRFT and recombinant His-GRFT existed as homodimers in solution. The expression system described in this work provides a basis for the mass production of GRFT to allow further studies of the protein and investigation of therapeutic and preventive strategies against HIV.
Algal Proteins↗
Role of Krüppel-like factor 15 in PEPCK gene expression in the liver.
Regulation of hepatic gene expression is important for energy homeostasis. We now show that hepatic expression of the gene for the transcription factor Kruppel-like factor 15 (KLF15) is increased by food deprivation and reduced by feeding in mice. Expression of the KLF15 gene in mouse liver was also down-regulated by a euglycemic-hyperinsulinemic clamp and was increased by inhibition of phosphatidylinositol 3-kinase. In cultured rat hepatocytes, KLF15 gene expression was induced by dexamethasone and a non-hydrolyzing analog of cAMP, and this effect was inhibited by insulin in a manner dependent on phosphatidylinositol 3-kinase signaling. Forced expression of KLF15 in cultured hepatocytes increased both the expression and the promoter activity of the gene for phosphoenolpyruvate carboxykinase (PEPCK). These results suggest that insulin and its counteracting hormones regulate the hepatic expression of KLF15, and that this transcription factor contributes to the regulation of PEPCK gene expression in the liver.
Animals↗