Water uptake dynamics in soybean seeds: influence in seeds performance and DNA integrity / Dinâmica de absorção de água em sementes de soja: influência no desempenho de sementes e integridade do DNA

ABSTRACT: Relationships among water uptake rate and temperatures were investigated in five soybean seeds lots cv. M 6410 IPRO. Germination, field emergence and electrical conductivity tests were applied to determine seed performance after fast (complete immersion in water), control (moist substrate) and slow (moist atmosphere) imbibitions both at 20 °C and 30 °C. The fresh weight increment over time in soybean seeds during imbibition was recorded. In parallel, analysis of the DNA integrity of seedlings obtained from such seeds was performed in gel electrophoresis. Absorption pattern of soybean seeds were similar among temperatures, but absorption characteristics vary with time progress according to the way of water entrance into the seeds. Upon fast imbibition seeds germinated lower than non-fast-imbibed seeds, besides loss of seed performance. In contrast, slow-imbibed seeds showed high germination, low abnormal seedlings and maintenance of seeds performance. DNA isolation from fast imbibed seeds was highly degraded; although, some considerably degraded samples were reported in controlled imbibed seeds and the best preserved DNA was found in slow-imbibed seeds. The pattern of DNA degradation is typically passive or non programmed cell death. Our results showed it is important to consider the water uptake rate during germination test, since DNA integrity plays a critical role during seed imbibition, preserving soybean seed performance.

RESUMO: As relações entre a taxa de embebição em água e temperaturas foram estudadas em cinco lotes de sementes de soja cv. M 6410 IPRO. Testes de germinação, emergência a campo e condutividade elétrica foram aplicados para avaliar o desempenho das sementes após rápida embebição (imersão direta em água), controlada (substrato úmido) e lenta (atmosfera úmida), ambos a 20 °C e 30 °C. O incremento no peso fresco das sementes durante a embebição foi registrado. Paralelamente, a integridade do DNA de plântulas oriundas das sementes foi avaliado em gel por eletroforese. O padrão de embebição das sementes de soja foi similar entre as temperaturas, mas houve variações com o tempo de acordo com o modo de entrada de água nas sementes. Após a embebição rápida, as sementes apresentam menor germinação e desempenho que as sementes submetidas aos demais métodos de embebição. O DNA isolado a partir de sementes que embeberam rapidamente encontrava-se degradado, embora em sementes que foram hidratadas de forma controlada também fosse encontrada degradação do DNA. O DNA mais preservado foi encontrado em sementes que embebem lentamente. O padrão de degradação do DNA é típico de morte passiva ou não programada de células. Os resultados indicam que é importante considerar a taxa de embebição em água durante o teste de germinação, pois a integridade do DNA desempenha uma função importante durante a embebição, preservando o desempenho das sementes de soja.

Freeing the brake: Proliferation needs primary cilium to disassemble

Primary cilia are non-motile, microtubule-based, antennae-like organelle that protrude out from the cell surfaceand perform sensory function or transduce physiological signals in majority of the vertebrate cells. Cilia areassembled on basal bodies that are transformed centrioles. The assembly-disassembly of primary cilia maypose an additional measure on regulating cell cycle in vertebrate cells. While primary cilia are commonly foundin differentiated or quiescent cells that are not cycling, disassembly of primary cilia may promote re-entry ofthese cells into the mitotic cycle, and support proliferation. Many cancer tissues or cancer-derived cells exhibitloss of primary cilia. However, primary cilia may also promote tumorigenesis in some contexts throughgrowth-promoting signalling. This review will shed light on recent advancements of temporal coordination ofciliary disassembly and cell cycle progression, with a focus on how cilia loss may support tumorigenesis invarious epithelial cancers

D-Tryptophan governs biofilm formation rates and bacterial interaction in P. mendocina and S. aureus

Biofilm genesis by Pseudomonas and Staphylococcus sp is associated with biofouling in natural settings. D-Tryptophan (DTrp) inhibits bacterial biofilms and have been proposed for biofouling control applications. In this study, D-Trp significantlyinhibited Pseudomonas mendocina and Staphylococcus aureus cell attachment (biofilm formation) rates on polystyrene96-well microtiter plates in comparison with L-Tryptophan (L-Trp) and mixtures of D-/L-Tryptophan (D-/L-Trp). Theinhibitory effect was greater on P. mendocina, where the rate of cell adherence was declined to 8.7 9 105 cells/h from8.0 9 106 cells/h (control) in P. mendocina. In S. aureus it was declined to 4.2 9 107 cells/h from 9.2 9 107 cells/h(control) at 1 mM concentration. It hindered the intracellular communication and adherence in both the strains, as confirmed by SEM and real time PCR analysis. Addition of D-Trp to preformed biofilms also caused partial disassembly. Intraand interbacterial aggregation were decreased subsequently upon treatment with D-Trp. It repressed the genes involved incell–cell communication, which could be responsible for the diminished biofilm formation of the selected strains. HenceD-Tryptophan has proved to be an effective strategy to control biofilm and may support in the development of surfacecoating technologies.

Late Onset Disassembly of a Modular Neck-stem Component after Cementless Hip Replacement without Dislocation: A Case Report and Review of Literatures / 대한고관절학회지

Modular femoral prostheses are characterized by a second neck-stem junction. This modularity provides many clinical benefits including hip offset restoration, intraoperative leg length and anteversion adjustment. Although, this extra junction in modular femoral prostheses can contribute to catastrophic consequences like fracture, cold welding, corrosion and fretting of the modularity. However, only few complications related to the modularity itself have been reported in the literature. We report a unique case of neck-stem component dissociation without dislocation of the R-120PC™ Modular Stem (DJO Surgical). Our 71-year-old obese female patient underwent cementless hip replacement 5 years ago. Following radiographic confirmation of neck-stem dissociation open reduction was performed and wiring fixation was applied to secure the neck to the stem. After reduction and fixation, hip joint was stable, and our patient returned to her daily routine 2.5 months postoperatively. The last follow up was at 12 months after surgery with excellent radiographic and clinical evaluation.

Molecular flexibility of Mycobacterium tuberculosis ribosome recycling factor and its functional consequences: An exploration involving mutants.

Internal mobility of the two domain molecule of ribosome recycling factor (RRF) is known to be important for its action. Mycobacterium tuberculosis RRF does not complement E. coli for its deficiency of RRF (in the presence of E. coli EF-G alone). Crystal structure had revealed higher rigidity of the M. tuberculosis RRF due to the presence of additional salt bridges between domains. Two inter-domain salt bridges and one between the linker region and the domain containing C-terminal residues were disrupted by appropriate mutations. Except for a C-terminal deletion mutant, all mutants showed RRF activity in E. coli when M. tuberculosis EF-G was also co-expressed. The crystal structures of the point mutants, that of the C-terminal deletion mutant and that of the protein grown in the presence of a detergent, were determined. The increased mobility resulting from the disruption of the salt bridge involving the hinge region allows the appropriate mutant to weakly complement E. coli for its deficiency of RRF even in the absence of simultaneous expression of the mycobacterial EF-G. The loss of activity of the C-terminal deletion mutant appears to be partly due to the rigidification of the molecule consequent to changes in the hinge region.

Traumatic Disassembly of a Bipolar Hip Prosthesis: A Case Report

We report a rare case of a complete disassembly of the inner head from the bipolar cup without polyethylene wear and locking system failure. An 84-year-old man who had a femur neck fracture of the right hip underwent a replacement of the bipolar prosthesis 4 months ago. He fell down from a height of a chair and felt a sudden sharp pain in the right hip. Roentgenograms revealed that the inner head was dislocated from the outer cup; subsequently, a revision surgery was carried out. When the outer head was removed from the acetabulum, the bearing insert and locking ring were not deformed. Because there was no evidence of loosening of the femoral stem, identicallysized bipolar cup and metal head replacement was performed. At a 6 months follow-up, he had mild hip pain but had returned fully to daily living.

Disassembly of Polyethylene Liner in Cementless Metal-Backed Cup: A case report / 대한정형외과학회잡지

In 1971, for purpose of reduction of peak stress occuring in cement and trabecular bone of the acetabulum, Harris reported a series of metal-backed acetabular components with removable polyethylene liners that could be replaced if excessive wear occured. Modular designs of hip prostheses have become popular recently, but they introduce the risk of disassembly of the components postoperatively. And introduce of loosening and infection of femoral or acetabular components by debris of polyethylene liner. We report a case of mechanical disassembly of polyethylene liner in cementless metal backed cup, and review previously reported articles.

Environmental Pollution by Dioxin-like PCBs around a Disassembly of Obsolete Solid Waste / 环境与健康杂志

Objective To investigate the distribution and environmental pollution of dioxin-like polychlorinated biphenyls(PCBs) in a place of disused transformer and other electronic waste disassembled. Methods The ambient air, aerosol, water, soil and vegetable samples were collected to analyze the dioxin-like PCBs level with isotope internal standards and HRGC-HRMS techniques. Results The concentration of dioxin-like PCBs in ambient air was 4 031.77-4 942.34 pg/m3(namely 1.832-2.666 pg TEQ/m3), while in aerosol it was 325.45-3 499.77 pg/m3(0.370 9-1.536 3 pg TEQ/m3). In the soil sample, the value was 2 316.59-19 100.30 pg/g(1.358-15.264 pg TEQ/g) dry weight. In water it was 5.731-237.640 ng/L(2.585-73.046 pg TEQ/L). In vegetable it was 1 078.45-1 620.04 pg/g(0.778 3-1.126 2 pg TEQ/g) wet weight. In all air, aerosol, soil, water and vegetable samples, the content of PCB-118 was the most. PCB-126 had the highest TEQ value. In non-ortho PCBs, PCB-77 was of maximum content. In mono-ortho PCBs, PCB-118 was the most, and the followings were PCB-105, PCB-156 and PCB-167. All the 12 kinds of PCBs were investigated in all samples except PCB-169 absent in ambient air. Conclusions The investigated area around the disassembly of obsolete solid waste has been badly contaminated by dioxin-like polychlorinated biphenyls(PCBs), and PCBs already exist in the vegetables. According to the results of the present paper, some further studies should be carried out to evaluate the toxic effects on food and people health.