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PubMed1987

Changes in the levels of major sulfur metabolites and free amino acids in pea cotyledons recovering from sulfur deficiency.

Changes in levels of sulfur metabolites and free amino acids were followed in cotyledons of sulfur-deficient, developing pea seeds (Pisum sativum L.) for 24 hours after resupply of sulfate, during which time the legumin mRNA levels returned almost to normal. Two recovery situations were studied: cultured seeds, with sulfate added to the medium, and seeds attached to the intact plant, with sulfate added to the roots. In both situations the levels of cysteine, glutathione, and methionine rose rapidly, glutathione exhibiting an initial lag. In attached but not cultured seeds methionine markedly overshot the level normally found in sulfur-sufficient seeds. In the cultured seed S-adenosylmethionine (AdoMet), but not S-methylmethionine, showed a sustained rise; in the attached seed the changes were slight. The composition of the free amino acid pool did not change substantially in either recovery situation. In the cultured seed the large rise in AdoMet level occurred equally in nonrecovering seeds. It was accompanied by 6-fold and 10-fold increases in gamma-aminobutyrate and alanine, respectively. These effects are attributed to wounding resulting from excision of the seed. (35)S-labeling experiments showed that there was no significant accumulation of label in unidentified sulfur-containing amino compounds in either recovery situation. It was concluded from these results and those of other workers that, at the present level of knowledge, the most probable candidate for a ;signal' compound, eliciting recovery of legumin mRNA level in response to sulfur-feeding, is cysteine.

Journal Article↗
PubMed2002

The TRANSPARENT TESTA16 locus encodes the ARABIDOPSIS BSISTER MADS domain protein and is required for proper development and pigmentation of the seed coat.

Screening for seed pigmentation phenotypes in Arabidopsis led to the isolation of three allelic yellow-seeded mutants, which defined the novel TRANSPARENT TESTA16 (TT16) locus. Cloning of TT16 was performed by T-DNA tagging and confirmed by genetic complementation and sequencing of two mutant alleles. TT16 encodes the ARABIDOPSIS BSISTER (ABS) MADS domain protein. ABS belongs to the recently identified "B-sister" (B(S)) clade, which contains genes of unknown function that are expressed mainly in female organs. Phylogenetic analyses using a maximum parsimony approach confirmed that TT16/ABS and related proteins form a monophyletic group. TT16/ABS was expressed mainly in the ovule, as are the other members of the B(S) clade. TT16/ABS is necessary for BANYULS expression and proanthocyanidin accumulation in the endothelium of the seed coat, with the exception of the chalazal-micropylar area. In addition, mutant phenotype and ectopic expression analyses suggested that TT16/ABS also is involved in the specification of endothelial cells. Nevertheless, TT16/ABS apparently is not required for proper ovule function. We report the functional characterization of a member of the B(S) MADS box gene subfamily, demonstrating its involvement in endothelial cell specification as well as in the increasingly complex genetic control of flavonoid biosynthesis in the Arabidopsis seed coat.

Amino Acid Sequence↗
PubMed2003

Dual regulated RNA transport pathways to the cortical region in developing rice endosperm.

Prolamine and glutelin RNAs are localized to two subdomains of the cortical endoplasmic reticulum (ER), the protein body ER and the cisternal ER, in developing rice seeds. The addition of nearly full-length prolamine sequences at the 3' untranslated region of a reporter RNA redirects its localization from the cisternal ER to the protein body ER. Deletion analysis of prolamine RNA sequences indicates the presence of two partially redundant cis elements required for protein body ER targeting. The addition of glutelin 3' untranslated region to protein body ER cis sequences, however, redirects RNA localization to the cisternal ER. These results indicate that there are at least two regulated RNA transport pathways as well as a constitutive pathway to the cortical ER.

3' Untranslated Regions↗
PubMed1991

Embryonic Lethals and T-DNA Insertional Mutagenesis in Arabidopsis.

T-DNA insertional mutagenesis represents a promising approach to the molecular isolation of genes with essential functions during plant embryo development. We describe in this report the isolation and characterization of 18 mutants of Arabidopsis thaliana defective in embryo development following seed transformation with Agrobacterium tumefaciens. Random T-DNA insertion was expected to result in a high frequency of recessive embryonic lethals because many target genes are required for embryogenesis. The cointegrate Ti plasmid used in these experiments contained the nopaline synthase and neomycin phosphotransferase gene markers. Nopaline assays and resistance to kanamycin were used to estimate the number of functional inserts present in segregating families. Nine families appeared to contain a T-DNA insert either within or adjacent to the mutant gene. Eight families were clearly not tagged with a functional insert and appeared instead to contain mutations induced during the transformation process. DNA gel blot hybridization with internal and right border probes revealed a variety of rearrangements associated with T-DNA insertion. A general strategy is presented to simplify the identification of tagged embryonic mutants and facilitate the molecular isolation of genes required for plant embryogenesis.

Journal Article↗
PubMed2004

Engineering of bypass conduits to improve patency.

For patients with severe coronary artery and distal peripheral vascular disease not amenable to angioplasty and lacking sufficient autologous vessels there is a pressing need for improvements to current surgical bypass options. It has been decades since any real progress in bypass material has reached mainstream surgical practice. This review looks at possible remedies to this situation. Options considered are methods to reduce prosthetic graft thrombogenicity, including endothelial cell seeding and developments of new prosthetic materials. The promise of tissue-engineered blood vessels is examined with a specific look at how peptides can improve cell adhesion to scaffolds.

Blood Vessel Prosthesis↗
PubMed1975

Maize alpha-glucan phosphorylase.

The major isozyme of alpha-glucan phosphorylase from developing maize seeds has been purified to homogeneity as verified by gel electrophoresis, ultracentrifugation and immunoprecipitation. The enzyme appears to be dimeric and has an estimated molecular weight of 223000 +/- 10000 based on ultracentrifugation, dodecylsulfate gel electrophoresis, and pyridoxal phosphate content. Adenosine diphosphoglucose appears to be a physiologically important inhibitor and interacts with the enzyme to give sigmoid kinetics when glucose 1-phosphate is the variable substrate. There are no properties of the enzyme which distinguish it from other phosphorylases as having a primarily synthetic role.

Adenosine Diphosphate Glucose↗
PubMed2025

The homeostasis of β-alanine is key for Arabidopsis reproductive growth and development.

β-Alanine, an abundant non-proteinogenic amino acid, acts as a precursor for coenzyme A and plays a role in various stress responses. However, a comprehensive understanding of its metabolism in plants remains incomplete. Previous metabolic genome-wide association studies (mGWAS) identified ALANINE:GLYOXYLATE AMINOTRANSFERASE2 (AGT2, AT4G39660) linked to β-alanine levels in Arabidopsis under normal conditions. In this study, we aimed to deepen our insights into β-alanine regulation by conducting mGWAS under two contrasting environmental conditions: control (12 h photoperiod, 21°C, 150 μmol m-2 sec-1) and stress (harvested after 1820 min at 32°C and darkness). We identified two highly significant quantitative trait loci (QTL) for β-alanine, including the AGT2 locus associated in both environments and ALDEHYDE DEHYDROGENASE6B2 (ALDH6B2, AT2G14170) associated only under stress conditions. A coexpression-correlation network revealed that the regulatory pathway involving β-alanine levels, AGT2, and ALDH6B2 connects the branched chained amino acid (BCAA) degradation through the propionate pathway. Metabolic profiles of AGT2 overexpression (OE) and knock-out (KO) lines (agt2) across various organs and developmental stages established the critical role of AGT2 in β-alanine metabolism. This work underscores the importance of β-alanine homeostasis for proper growth and development in Arabidopsis.

Arabidopsis↗
PubMed2006

Corridors increase plant species richness at large scales.

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Biodiversity↗
PubMed1994

Isolation of a Bacterial Culture That Degrades Methyl t-Butyl Ether.

We have isolated a mixed bacterial culture (BC-1) which is capable of degrading the gasoline oxygenate methyl t-butyl ether (MTBE). BC-1 was developed from seed microorganisms present in a chemical plant biotreater sludge. This enrichment culture has been maintained in continuous culture treating high concentrations of MTBE (120 to 200 mg/liter) as the sole carbon source in a simple feed containing NH(4), PO(4), Mg, and Ca nutrients. The unit had a stable MTBE removal rate when maintained with a long cell retention time (ca. 80 to 90 days); however, when operated at a </=50-day cell waste rate, loss of MTBE-degrading activity was observed. The following three noteworthy experimental data show that MTBE is biodegraded extensively by BC-1: (i) the continuous (oxygen-sparged) culture was able to sustain a population of autotrophic ammonia-oxidizing bacteria which could nitrify influent NH(4) concentrations at high rates and obtain CO(2) (sole carbon source for growth) from the metabolism of the alkyl ether, (ii) BC-1 metabolized radiolabeled either (CH(3)O-MTBE) to CO(2) (40%) and C-labeled cells (40%), and (iii) cell suspensions of the culture were capable of degrading (substrate depletion experiments) MTBE to t-butyl alcohol, a primary metabolite of MTBE. BC-1 is a mixed culture containing several bacterial species and is the first culture of its kind which can completely degrade an alkyl ether.

Journal Article↗
PubMed1962

Growth of Streptococcus faecalis var. liquefaciens on plants.

The proliferation of Streptococcus faecalis var. liquefaciens on two varieties of beans, and on corn, rye, and cabbage was investigated. Comparisons were made with growth patterns on these same plants exhibited by S. lactis and Lactobacillus plantarum. The ability of each of the bacteria to multiply and to spread to new plant parts as they developed from seed was studied under several environmental conditions. Plants were grown aseptically in glass culture and in sterilized and non-sterilized soil in the greenhouse. Quantitative estimations of increase in bacterial numbers were made. S. faecalis established commensal growth on each of five plants, although selectivity was noted for some plant parts. The organism increased in numbers on the plants equally as well as did the control bacteria, both alone, and in competition with the control bacteria and the microflora of the soil.

Enterococcus faecalis↗
PubMedDate not supplied

Primary glioblastoma multiforme in younger patients: a single-institution experience.

AIMS AND BACKGROUND: To report our experience of patients with primary glioblastoma multiforme of young age by evaluating the characteristics, prognostic factors, and treatment outcomes. PATIENTS AND METHODS: Seventy patients with primary glioblastoma multiforme (GBM) treated at our department between 1996 and 2004 were studied. The male-female ratio was 2.6:1. The median age was 53 (16-74). Sixty-eight patients (97%) were operated on before radiotherapy and 2 patients (3%) underwent only stereotactic biopsy. All patients received radiotherapy. Postoperative chemotherapy as an adjuvant to radiotherapy was given to 9 patients (12%). The patients were divided into 2 groups according to their age (group A < or = 35 years, n = 21 vs group B > 35 years, n = 49). Survival was determined with the Kaplan-Meier method and differences were compared using the log-rank test. Cox regression analysis was performed to identify the independent prognostic factors. Karnofsky performance status (> or = 70 vs < 70), age (< or = 35 vs > 35 years), gender, tumor size (< or = 4 vs > 4 cm), number of involved brain lobes (1 vs more than 1), type of surgery (total vs subtotal), preoperative seizure history (present vs absent), radiotherapy field (total cranium vs partial), total radiotherapy dose (60 vs 66 Gy), and adjuvant chemotherapy (present vs absent) were evaluated in univariate analysis. RESULTS: The median survival was 10.3 months in the whole group, 19.5 months in the younger age group and 5.7 months in the older age group. During follow-up re-craniotomy was performed in 2 patients (3%), and 1 patient (1%) developed spinal seeding metastases and was given spinal radiotherapy. In univariate analysis younger age vs older age: median 19.5 months vs 5.27 months (P = 0.0012); Karnofsky performance status > or = 70 vs < 70: median 15.3 months vs 2.67 months (P < 0.0001), and external radiotherapy dose 60 Gy vs 66 Gy: median 11.6 months vs 3 months (P = 0.02) were found as significant prognostic factors for survival. In regression analysis a worse performance status (KPS <70) was found to be the only independent factor for survival (P = 0.014, 95% CI HR = 0.0043 [0.0001-0.15]). CONCLUSIONS: Younger patients with primary glioblastoma multiforme had a relatively long survival (median, 19.5 months, with a 2-year survival rate of 30%) compared to older patients. This was due particularly to their better performance status.

Adolescent↗
PubMed2006

Promoting healthy people 2010 through small grants.

The Department of Health and Human Services initiated a pilot "microgrant" or small grants program in 2001 to promote Healthy People 2010 (HP 2010) implemented by the Yale-Griffin Prevention Research Center. This article describes the 103 agencies funded under this initiative and 67 control group agencies. It evaluates the HP 2010 focus areas targeted and the effectiveness of promoting HP 2010 objectives through microgrants. Forty-four percent of the grant recipients and 79% of the control group agencies indicated low levels of familiarity with HP 2010 goals. Changes in knowledge of HP 2010 goals for the microgrant group increased significantly from 5.24 +/- 3.67 to 7.83 +/- 1.86 (p < .05). The results suggest that microgrants can be a useful mechanism to plant the seeds for developing community and organizational capacity to define local health priorities, practice and test new initiatives or expand existing programs and promote knowledge about HP 2010.

Connecticut↗
PubMed2003

VWF73, a region from D1596 to R1668 of von Willebrand factor, provides a minimal substrate for ADAMTS-13.

ADAMTS-13 was recently identified as a new hemostatic factor, von Willebrand factor (VWF)-cleaving protease. Either congenital or acquired defects of the enzymatic activity lead to thrombotic thrombocytopenic purpura (TTP). ADAMTS-13 specifically cleaves a peptidyl bond between Y1605 and M1606 in the A2 domain of VWF. Here, we determined the minimal region recognized as a specific substrate by ADAMTS-13. A series of partial deletions in the A2 domain flanked with N- and C-terminal tags were expressed in Escherichia coli and affinity-purified. These purified proteins were incubated with human plasma, subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analyzed by Western blot. Judging from mobility shifts, all constructs except one were cleaved at the expected site. Data suggested that a minimal region as a functional substrate consisted of 73 amino acid residues from D1596 to R1668 of VWF, designated VWF73, and that further deletion of the E1660-R1668 region led to the loss of cleavage by ADAMTS-13. VWF73 was not cleaved by plasma from patients with congenital or acquired TTP, but cleaved by plasma from patients with hemolytic uremic syndrome, suggesting that VWF73 is a specific substrate forADAMTS-13. Thus, VWF73 will be a useful seed to develop a new rapid assay to determine ADAMTS-13 activity.

ADAM Proteins↗