Expression of basic fibroblast growth factor in human gastric carcinomas.

The expression of mRNA for the basic fibroblast growth factor (FGF) gene was examined in seven human gastric carcinoma cell lines and in tissue from 29 gastric carcinomas together with the adjacent normal mucosa. Among the seven gastric carcinoma cell lines, the MKN45 cell line expressed mRNA for the basic FGF gene. Basic FGF protein production was confirmed by flow cytometric analysis and immunohistochemistry. Among the surgical specimens, 16 (55%) of 29 gastric carcinomas showed higher levels of basic FGF mRNA than the normal mucosa. Interestingly, in scirrhous gastric carcinomas characterized by their fibrous stroma and rapid growth, 9 (69%) of 13, samples examined revealed higher levels of basic FGF mRNA than normal mucosa, whereas only 3 (33%) of the 9 well differentiated adenocarcinomas studied produced similar results. Immunohistochemically, basic FGF protein was localized in tumor cells. These results suggest that basic FGF produced by tumor cells may play an important role in producing fibrosis and angiogenesis in gastric carcinomas.     

Japanese Rice Wine can reduce psychophysical stress-induced depression-like behaviors and Fos expression in the trigeminal subnucleus caudalis evoked by masseter muscle injury in the rats

We determined if Japanese Rice Wine (Sake) had inhibitory effects on stress-induced enhancement of masseter muscle (MM) nociception in the rats. Male rats were subjected to the repeated forced swim stress (FS) or sham conditionings from Day ?3 to ?1. Daily administration of Sake or saline was conducted after each stress conditioning. At Day 0 the number of Fos positive cells, a marker for neural activity, was quantified at the trigeminal subnucleus caudalis (Vc) region by MM injury with formalin. FS increased MM-evoked Fos expression in the Vc region, which was inhibited by Sake compared to saline administration. Sake did not alter the number of Fos positive cells under sham conditions, indicating that inhibitory roles of Sake on neural activity in the Vc region were seen under FS conditions. These findings indicated that Sake had inhibitory roles on stress-induced MM nociception at the Vc region in our experimental conditions.     

Proteomic analyses of retina of excitatory amino acid carrier 1 deficient mice

Background  

Excitatory amino acid carrier 1 (EAAC1) is a glutamate transporter found in neuronal tissues and is extensively expressed in the retina. EAAC1 plays a role in a variety of neural functions, but its biological functions in the retina has not been fully determined. The purpose of this study was to identify proteins regulated by EAAC1 in the retina of mice. To accomplish this, we used a proteomics-based approach to identify proteins that are up- or down-regulated in EAAC1-deficient (EAAC1^-/-) mice.     

Multiple plastids collected by the dinoflagellate Dinophysis mitra through kleptoplastidy

Kleptoplastidy is the retention of plastids obtained from ingested algal prey, which may remain temporarily functional and be used for photosynthesis by the predator. We showed that the marine dinoflagellate Dinophysis mitra has great kleptoplastid diversity. We obtained 308 plastid rbcL sequences by gene cloning from 14 D. mitra cells and 102 operational taxonomic units (OTUs). Most sequences were new in the genetic database and positioned within Haptophyceae (227 sequences [73.7%], 80 OTUs [78.4%]), particularly within the genus Chrysochromulina. Others were closely related to Prasinophyceae (16 sequences [5.2%], 5 OTUs [4.9%]), Dictyochophyceae (14 sequences [4.5%], 5 OTUs [4.9%]), Pelagophyceae (14 sequences [4.5%], 1 OTU [1.0%]), Bolidophyceae (3 sequences [1.0%], 1 OTU [1.0%]), and Bacillariophyceae (1 sequence [0.3%], 1 OTU [1.0%]); however, 33 sequences (10.8%) as 9 OTUs (8.8%) were not closely clustered with any particular group. Only six sequences were identical to those of Chrysochromulina simplex, Chrysochromulina hirta, Chrysochromulina sp. TKB8936, Micromonas pusilla NEPCC29, Micromonas pusilla CCMP491, and an unidentified diatom. Thus, we detected >100 different plastid sequences from 14 D. mitra cells, strongly suggesting kleptoplastidy and the need for mixotrophic prey such as Laboea, Tontonia, and Strombidium-like ciliates, which retain numerous symbiotic plastids from different origins, for propagation and plastid sequestration.     

Relevance of exocytotic glutamate release from retinal glia

Glial cells release molecules that influence brain?development, function, and disease. Calcium-dependent exocytosis has been proposed as potential release mechanism in astroglia, but the physiological relevance of "gliotransmission" in?vivo remains controversial. We focused on the impact of glial exocytosis on sensory transduction in the retina.?To this end, we generated transgenic mice to block exocytosis by Cre recombinase-dependent expression of the clostridial botulinum neurotoxin serotype?B light chain, which cleaves vesicle-associated membrane protein 1-3. Ubiquitous and neuronal toxin expression caused perinatal lethality and?a reduction of synaptic transmission thus validating transgene function. Toxin expression in Müller cells inhibited vesicular glutamate release and impaired glial volume regulation but left retinal histology and visual processing unaffected. Our model to study gliotransmission in?vivo reveals specific functions of exocytotic glutamate release in retinal glia.     

The structure of beta-carbonic anhydrase from the carboxysomal shell reveals a distinct subclass with one active site for the price of two

CsoSCA (formerly CsoS3) is a bacterial carbonic anhydrase localized in the shell of a cellular microcompartment called the carboxysome, where it converts HCO(3)(-) to CO(2) for use in carbon fixation by ribulose-bisphosphate carboxylase/oxygenase (RuBisCO). CsoSCA lacks significant sequence similarity to any of the four known classes of carbonic anhydrase (alpha, beta, gamma, or delta), and so it was initially classified as belonging to a new class, epsilon. The crystal structure of CsoSCA from Halothiobacillus neapolitanus reveals that it is actually a representative member of a new subclass of beta-carbonic anhydrases, distinguished by a lack of active site pairing. Whereas a typical beta-carbonic anhydrase maintains a pair of active sites organized within a two-fold symmetric homodimer or pair of fused, homologous domains, the two domains in CsoSCA have diverged to the point that only one domain in the pair retains a viable active site. We suggest that this defunct and somewhat diminished domain has evolved a new function, specific to its carboxysomal environment. Despite the level of sequence divergence that separates CsoSCA from the other two subclasses of beta-carbonic anhydrases, there is a remarkable level of structural similarity among active site regions, which suggests a common catalytic mechanism for the interconversion of HCO(3)(-) and CO(2). Crystal packing analysis suggests that CsoSCA exists within the carboxysome shell either as a homodimer or as extended filaments.     

Nutritional significance of the selective ingestion of Albizia zygia gum exudate by wild chimpanzees in Bossou, Guinea

The selective ingestion of plant gum exudates by chimpanzees has been frequently observed at various study sites. At Bossou, Guinea, chimpanzees also frequently ingest Albizia zygia gum exudate. A functional explanation for this behavior is lacking, so we evaluated its possible contribution of energy in the form of short-chain fatty acids (SCFA) as well as minerals. An in vitro fermentation study of A. zygia gum using the fecal bacteria of a Bossou chimpanzee showed that carboxylic acids were produced with a 6-hr lag phase up to 44 mmol/l by 18 hr of incubation. Acetate was the most abundant acid produced, followed by lactate and propionate. The energy supplied from the fermentation of a piece of gum exudate (20-30 g) was negligible in comparison with the estimated daily energy requirements of chimpanzees in the wild. However, A. zygia gum exudate (20-30 g) can supply sufficient amounts of calcium, manganese, magnesium, and potassium to fulfill the daily requirements for these minerals in chimpanzees.     

T wave alternans in an in vitro canine tissue model of Brugada syndrome

Macroscopic T wave alternans (TWA) associated with increased occurrence of ventricular arrhythmias has been reported in patients with Brugada syndrome. However, the mechanisms in this syndrome are still unclear. We evaluated the hypothesis that TWA in Brugada syndrome was caused by the dynamic instability and heterogeneity of action potentials (APs) in the right ventricle. Using an optical mapping system, we mapped APs on the epicardium or transmural surfaces of 28 isolated and arterially perfused canine right ventricular preparations having drug-induced Brugada syndrome (in micromol/l: 2.5-15 pinacidil, 5.0 terfenadine, and 5.0-13 pilsicainide). Bradycardia at cycle length (CL) of 2,632 +/- 496 ms (n = 19) induced alternating deep and shallow T waves in the transmural electrocardiogram. Compared with the shallow T waves, deep T waves were associated with epicardial APs having longer durations and larger domes. Adjacent regions having APs with alternating domes, with constant domes, and without domes coexisted simultaneously in the epicardium and caused TWA. In contrast to the alternating epicardial APs, midmyocardial and endocardial APs did not change during TWA. Alternans could be terminated by rapid (CL: 529 +/- 168 ms, n = 7) or very slow (CL: 3,000 ms, n = 7) pacing. The heterogeneic APs during TWA augmented the dispersion of repolarization both within the epicardium and from the epicardium to the endocardium and caused phase 2 reentry. In this drug-induced model of Brugada syndrome, heterogeneic AP contours and dynamic alternans in the dome of right ventricular epicardial, but not midmyocardial or endocardial, APs caused TWA and heightened arrhythmogenicity in part by increasing the dispersion of repolarization.