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1.
J Reconstr Microsurg ; 39(4): 295-300, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36150693

RESUMO

BACKGROUND: The anterolateral thigh flap is a versatile and dependable perforator flap and is a popular choice in the reconstruction of various body sites. The variable perforator anatomy suggests preoperative perforator imaging to improve safety and speed of dissection. An innovative perforator imaging technique is thermography, which lately gained attention in plastic surgery. METHODS: Thirty-two healthy participants were included in this randomized study. One thigh was examined with dynamic infrared thermography and consecutively with ultrasound, while the contralateral thigh was examined with ultrasound as standalone technology. RESULTS: The application of dynamic infrared thermography prior to ultrasound perforator identification significantly accelerated the ultrasound examination duration by 90 to 130 seconds. The mean duplex ultrasound examination duration correlated positively with the hotspot and perforator quantity per thigh. CONCLUSION: The addition of thermographic perforator mapping can accelerate color duplex ultrasound anterolateral thigh perforator imaging. Furthermore, thermography supplements color duplex ultrasound with crucial information on angiosome location.


Assuntos
Retalho Perfurante , Procedimentos de Cirurgia Plástica , Humanos , Termografia , Ultrassonografia Doppler em Cores/métodos , Ultrassonografia Doppler Dupla , Coxa da Perna/cirurgia , Retalho Perfurante/cirurgia
2.
Plant J ; 103(5): 1869-1884, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32530511

RESUMO

Cereal endosperm represents the most important source of the world's food; nevertheless, the molecular mechanisms underlying cell and tissue differentiation in cereal grains remain poorly understood. Endosperm cellularization commences at the maternal-filial intersection of grains and generates endosperm transfer cells (ETCs), a cell type with a prominent anatomy optimized for efficient nutrient transport. Barley HISTIDINE KINASE1 (HvHK1) was identified as a receptor component with spatially restricted expression in the syncytial endosperm where ETCs emerge. Here, we demonstrate its function in ETC fate acquisition using RNA interference-mediated downregulation of HvHK1. Repression of HvHK1 impairs cell specification in the central ETC region and the development of transfer cell morphology, and consecutively defects differentiation of adjacent endosperm tissues. Coinciding with reduced expression of HvHK1, disturbed cell plate formation and fusion were observed at the initiation of endosperm cellularization, revealing that HvHK1 triggers initial cytokinesis of ETCs. Cell-type-specific RNA sequencing confirmed loss of transfer cell identity, compromised cell wall biogenesis and reduced transport capacities in aberrant cells and elucidated two-component signaling and hormone pathways that are mediated by HvHK1. Gene regulatory network modeling was used to specify the direct targets of HvHK1; this predicted non-canonical auxin signaling elements as the main regulatory links governing cellularization of ETCs, potentially through interaction with type-B response regulators. This work provides clues to previously unknown molecular mechanisms directing ETC specification, a process with fundamental impact on grain yield in cereals.


Assuntos
Diferenciação Celular , Endosperma/crescimento & desenvolvimento , Histidina Quinase/metabolismo , Hordeum/metabolismo , Proteínas de Plantas/metabolismo , Divisão Celular , Polaridade Celular , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Endosperma/metabolismo , Regulação da Expressão Gênica de Plantas , Histidina Quinase/fisiologia , Hordeum/enzimologia , Hordeum/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia
3.
Int J Mol Sci ; 21(20)2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33066598

RESUMO

Some eukaryotes exhibit dramatic genome size differences between cells of different organs, resulting from programmed elimination of chromosomes. Here, we present the first transcriptome analysis of programmed chromosome elimination using laser capture microdissection (LCM)-based isolation of the central meristematic region of Aegilops speltoides embryos where B chromosome (B) elimination occurs. The comparative RNA-seq analysis of meristematic cells of embryos with (Bplus) and without Bs (B0) allowed the identification of 14,578 transcript isoforms (35% out of 41,615 analyzed transcript isoforms) that are differentially expressed during the elimination of Bs. A total of 2908 annotated unigenes were found to be up-regulated in Bplus condition. These genes are either associated with the process of B chromosome elimination or with the presence of B chromosomes themselves. GO enrichment analysis categorized up-regulated transcript isoforms into 27 overrepresented terms related to the biological process, nine terms of the molecular function aspect and three terms of the cellular component category. A total of 2726 annotated unigenes were down-regulated in Bplus condition. Based on strict filtering criteria, 341 B-unique transcript isoforms could be identified in central meristematic cells, of which 70 were functionally annotated. Beside others, genes associated with chromosome segregation, kinetochore function and spindle checkpoint activity were retrieved as promising candidates involved in the process of B chromosome elimination.


Assuntos
Aegilops/genética , Cromossomos de Plantas/genética , Regulação da Expressão Gênica de Plantas , Sementes/genética , Transcriptoma , Aegilops/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Meristema/genética , Meristema/metabolismo , Especificidade de Órgãos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
4.
Plant Cell ; 26(9): 3728-44, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25271242

RESUMO

Barley (Hordeum vulgare) grain development follows a series of defined morphological and physiological stages and depends on the supply of assimilates (mainly sucrose) from the mother plant. Here, spatio-temporal patterns of sugar distributions were investigated by mass spectrometric imaging, targeted metabolite analyses, and transcript profiling of microdissected grain tissues. Distinct spatio-temporal sugar balances were observed, which may relate to differentiation and grain filling processes. Notably, various types of oligofructans showed specific distribution patterns. Levan- and graminan-type oligofructans were synthesized in the cellularized endosperm prior to the commencement of starch biosynthesis, while during the storage phase, inulin-type oligofructans accumulated to a high concentration in and around the nascent endosperm cavity. In the shrunken endosperm mutant seg8, with a decreased sucrose flux toward the endosperm, fructan accumulation was impaired. The tight partitioning of oligofructan biosynthesis hints at distinct functions of the various fructan types in the young endosperm prior to starch accumulation and in the endosperm transfer cells that accomplish the assimilate supply toward the endosperm at the storage phase.


Assuntos
Frutanos/metabolismo , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Hordeum/genética , Radical Hidroxila/metabolismo , Íons , Metaboloma , Mutação/genética , Oligossacarídeos/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fatores de Tempo
5.
Proc Natl Acad Sci U S A ; 109(29): 11609-12, 2012 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-22753516

RESUMO

Molecular self-assembly has often been suggested as the ultimate route for the bottom-up construction of building blocks atom-by-atom for functional nanotechnology, yet structural design or prediction of nanomolecular assemblies is still far from reach. Whereas nature uses complex machinery such as the ribosome, chemists use painstakingly engineered step-by-step approaches to build complex molecules but the size and complexity of such molecules, not to mention the accessible yields, can be limited. Herein we present the discovery of a palladium oxometalate {Pd(84)}-ring cluster 3.3 nm in diameter; [Pd(84)O(42)(OAc)(28)(PO(4))(42)](70-) ({Pd(84)} ≡ {Pd(12)}(7)) that is formed in water just by mixing two reagents at room temperature, giving crystals of the compound in just a few days. The structure of the {Pd(84)}-ring has sevenfold symmetry, comprises 196 building blocks, and we also show, using mass spectrometry, that a large library of other related nanostructures is present in solution. Finally, by analysis of the symmetry and the building block library that construct the {Pd(84)} we show that the correlation of the symmetry, subunit number, and overall cluster nuclearity can be used as a "Rosetta Stone" to rationalize the "magic numbers" defining a number of other systems. This is because the discovery of {Pd(84)} allows the relationship between seemingly unrelated families of molecular inorganic nanosystems to be decoded from the overall cluster magic-number nuclearity, to the symmetry and building blocks that define such structures allowing the prediction of other members of these nanocluster families.


Assuntos
Engenharia Química/métodos , Modelos Químicos , Nanoestruturas/química , Nanotecnologia/métodos , Paládio/química , Espectrometria de Massas , Água/química
6.
J Exp Bot ; 65(18): 5291-304, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25024168

RESUMO

In cereal grains, the maternal nucellar projection (NP) constitutes the link to the filial organs, forming a transfer path for assimilates and signals towards the endosperm. At transition to the storage phase, the NP of barley (Hordeum vulgare) undergoes dynamic and regulated differentiation forming a characteristic pattern of proliferating, elongating, and disintegrating cells. Immunolocalization revealed that abscisic acid (ABA) is abundant in early non-elongated but not in differentiated NP cells. In the maternally affected shrunken-endosperm mutant seg8, NP cells did not elongate and ABA remained abundant. The amounts of the bioactive forms of gibberellins (GAs) as well as their biosynthetic precursors were strongly and transiently increased in wild-type caryopses during the transition and early storage phases. In seg8, this increase was delayed and less pronounced together with deregulated gene expression of specific ABA and GA biosynthetic genes. We concluded that differentiation of the barley NP is driven by a distinct and specific shift from lower to higher GA:ABA ratios and that the spatial-temporal change of GA:ABA balances is required to form the differentiation gradient, which is a prerequisite for ordered transfer processes through the NP. Deregulated ABA:GA balances in seg8 impair the differentiation of the NP and potentially compromise transfer of signals and assimilates, resulting in aberrant endosperm growth. These results highlight the impact of hormonal balances on the proper release of assimilates from maternal to filial organs and provide new insights into maternal effects on endosperm differentiation and growth of barley grains.


Assuntos
Ácido Abscísico/metabolismo , Giberelinas/metabolismo , Hordeum/metabolismo , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia
7.
Injury ; : 111573, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38679560

RESUMO

INTRODUCTION: Hypernatremia is a common problem among patients with severe burn injuries and seems to be associated with an unfavorable clinical outcome. The current study was designed to evaluate the impact of antibiotics with a high proportion of sodium on this phenomenon. METHODS: All admissions to our burn center from 01/2017 till 06/2023 were retrospectively screened. All patients aged >18 years which suffered from at least 20 % total body surface burned area (TBSA) 2nd degree burn injuries or more than 10 % TBSA when including areas of 3rd degree burn injuries were included. The course of the serum Na-level was analyzed from two days before till two days after the start of the antibiotic treatment. Ampicillin/sulbactam, cefazoline and piperacillin/tazobactam were classified as high-dose sodium antibiotics (HPS), meropenem and vancomycin as low-dose sodium antibiotics (LPS). RESULTS: 120 patients met the inclusion criteria. A significant increase of the serum Na was detectable in the HPS group on day 1 and 2 after initiating the antibiotic treatment (n = 64, day 1: 2,1 (SD 4,18) mmol/l, p < 0,001; day 2: 2,44 (SD 5,26) mmol/l, p < 0,001) while no significant changes were detectable in the LPS group (n = 21, day 1: 0,18 (SD 7,45) mmol/l, p = 0,91; day 2: -0,27 (SD 7,44) mmol/l, p = 0,87). This effect was further aggravated when analyzing only the HPS patients with a TBSA ≥30 % (n = 33; day 1: 2,93 (SD 4,68) mmol/l, p = 0,002; day 2: 3,41 (SD 5,9) mmol/l, p = 0,003). CONCLUSION: The amount of sodium in antibiotics seems to have a relevant impact on the serum Na during the early stages of severe burn injury. Therefore, this aspect should be taken into account when searching for the most appropriate antibiotic treatment for patients with severe burn injury, especially when being at acute risk for a clinical relevant hypernatremia.

8.
Cureus ; 16(5): e60380, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38883017

RESUMO

Introduction Managing open lower extremity fractures is challenging, with potential complications such as amputation and infection. The aim of the study was to determine whether the time delay and initial treatment of the patients treated in a non-specialized hospital before being transferred to a dedicated level I trauma center led to a worse outcome. Methods Retrospective data from 44 patients (37 males and seven females) undergoing free tissue transfer for lower extremity open fractures from January 2017 to December 2022 were analyzed. Group A received primary care externally and was later transferred for definitive treatment (n=17, 38.6%), while group B received initial care at a level I trauma center (n=27, 61.4%). Surgical outcomes, complications, the duration of the hospital stay, and assessment times were compared. Various demographic variables, co-morbidities, prior interventions, and flap types were analyzed.  Results Average age (A: 55.1±16.7; B: 38.7±19.8 years; p=0.041), overall hospitalization (A: 55.7±22.8; B: 42.8±21.3 days; p=0.041), and time to soft tissue reconstruction differed significantly between groups (A: 30.7±12.2; B: 18.9±9.3 days; p=0.013). Overall, 31.8% had multiple injuries without statistical differences between groups A and B (29.4% vs. 33.3%; p>0.05). There were no statistical differences between the groups in terms of major and minor complications and bone healing characteristics. Limb salvage was successful overall in 93.2% (A: 94.1%; B: 92.6%; P>0.05). Major complications occurred in 9.1%; three patients underwent major amputation (A: n=2; B: n=1). Minor complications were observed in 43.2% of patients (partial flap necrosis, wound dehiscence and non-union; A: 41.2%; B: 44.4%; p>0.05). Overall, 65.9% of patients (A: 64.7%; B: 66.7%; p>0.05) experienced uneventful bone healing, while 18.2% of patients (A: 23.5%; B: 14.8%; p>0.05) experienced delayed healing. Flaps used were mostly musculocutaneous (71.7%). Various assessed demographic characteristics, including age and presence of polytrauma, showed no significant influence on complications (p>0.05). Conclusion  Although there is a significant difference in the time course of externally treated patients with open fractures, prolonged treatment is not associated with a higher complication rate or compromised bone healing outcome. Despite the findings, it is important to avoid delays and strive for interdisciplinary collaboration.

9.
Plant J ; 71(4): 639-55, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22487146

RESUMO

Barley endosperm cells differentiate into transfer cells (ETCs) opposite the nucellar projection. To comprehensively analyse ETC differentiation, laser microdissection-based transcript and metabolite profiles were obtained from laser microdissected tissues and cell morphology was analysed. Flange-like secondary-wall ingrowths appeared between 5 and 7 days after pollination within the three outermost cell layers. Gene expression analysis indicated that ethylene-signalling pathways initiate ETC morphology. This is accompanied by gene activity related to cell shape control and vesicle transport, with abundant mitochondria and endomembrane structures. Gene expression analyses indicate predominant formation of hemicelluloses, glucuronoxylans and arabinoxylans, and transient formation of callose, together with proline and 4-hydroxyproline biosynthesis. Activation of the methylation cycle is probably required for biosynthesis of phospholipids, pectins and ethylene. Membrane microdomains involving sterols/sphingolipids and remorins are potentially involved in ETC development. The transcriptional activity of assimilate and micronutrient transporters suggests ETCs as the main uptake organs of solutes into the endosperm. Accordingly, the endosperm grows maximally after ETCs are fully developed. Up-regulated gene expression related to amino acid catabolism, C:N balances, carbohydrate oxidation, mitochondrial activity and starch degradation meets high demands for respiratory energy and carbohydrates, required for cell proliferation and wall synthesis. At 10 days after pollination, ETCs undergo further differentiation, potentially initiated by abscisic acid, and metabolism is reprogrammed as shown by activated storage and stress-related processes. Overall, the data provide a comprehensive view of barley ETC differentiation and development, and identify candidate genes and associated pathways.


Assuntos
Endosperma/citologia , Endosperma/genética , Endosperma/metabolismo , Hordeum/citologia , Hordeum/genética , Ácido Abscísico/metabolismo , Aminoácidos/metabolismo , Diferenciação Celular , Proliferação de Células , Forma Celular/genética , Parede Celular/genética , Endosperma/crescimento & desenvolvimento , Etilenos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hordeum/metabolismo , Microdissecção , Polinização , Esfingolipídeos/metabolismo , Esteróis/metabolismo
10.
Plants (Basel) ; 12(8)2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37111818

RESUMO

Endosperm development in barley starts with the formation of a multinucleate syncytium, followed by cellularization in the ventral part of the syncytium generating endosperm transfer cells (ETCs) as first differentiating subdomain, whereas aleurone (AL) cells will originate from the periphery of the enclosing syncytium. Positional signaling in the syncytial stage determines cell identity in the cereal endosperm. Here, we performed a morphological analysis and employed laser capture microdissection (LCM)-based RNA-seq of the ETC region and the peripheral syncytium at the onset of cellularization to dissect developmental and regulatory programs directing cell specification in the early endosperm. Transcriptome data revealed domain-specific characteristics and identified two-component signaling (TCS) and hormone activities (auxin, ABA, ethylene) with associated transcription factors (TFs) as the main regulatory links for ETC specification. On the contrary, differential hormone signaling (canonical auxin, gibberellins, cytokinin) and interacting TFs control the duration of the syncytial phase and timing of cellularization of AL initials. Domain-specific expression of candidate genes was validated by in situ hybridization and putative protein-protein interactions were confirmed by split-YFP assays. This is the first transcriptome analysis dissecting syncytial subdomains of cereal seeds and provides an essential framework for initial endosperm differentiation in barley, which is likely also valuable for comparative studies with other cereal crops.

11.
J Am Chem Soc ; 134(11): 5243-61, 2012 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-22303894

RESUMO

Two series of oligorotaxanes R and R' that contain -CH(2)NH(2)(+)CH(2)- recognition sites in their dumbbell components have been synthesized employing template-directed protocols. [24]Crown-8 rings self-assemble by a clipping strategy around each and every recognition site using equimolar amounts of 2,6-pyridinedicarboxaldehyde and tetraethyleneglycol bis(2-aminophenyl) ether to efficiently provide up to a [20]rotaxane. In the R series, the -NH(2)(+)- recognition sites are separated by trismethylene bridges, whereas in the R' series the spacers are p-phenylene linkers. The underpinning idea here is that in the former series, the recognition sites are strategically positioned 3.5 Å apart from one another so as to facilitate efficient [π···π] stacking between the aromatic residues in contiguous rings in the rotaxanes and consequently, a discrete rigid and rod-like conformation is realized; these noncovalent interactions are absent in the latter series rendering them conformationally flexible/nondiscrete. Although in the R' series, the [3]-, [4]-, [8]-, and [12]rotaxanes were isolated after reaction times of <5-30 min in yields of 72-85%, in the R series, the [3]-, [4]-, [5]-, [8]-, [12]-, [16]-, and [20]rotaxanes were isolated in <5 min to 14 h in 88-98% yields. It follows that while in the R' series the higher order oligorotaxanes are formed in lower yields more rapidly, in the R series, the higher order oligorotaxanes are formed in higher yields more slowly. In the R series, the high percentage yields are sustained throughout, despite the fact that up to 39 components are participating in the template-directed self-assembly process. Simple arithmetic reveals that the conversion efficiency for each imine bond formation peaks at 99.9% in the R series and 99.3% in the R' series. This maintenance of reaction efficiency in the R series can be ascribed to positive cooperativity, that is, when one ring is formed it aids and abets the formation of subsequent rings presumably because of stabilizing extended [π···π] stacking interactions between the arene units. Experiments have been performed wherein the dumbbell is starved of the macrocyclic components, and up to five times more of the fully saturated rotaxane is formed than is predicted based on a purely statistical outcome, providing a clear indication that positive cooperativity is operative. Moreover, it would appear that as the R series is traversed from the [3]- to the [4]- to the [5]rotaxane, the cooperativity becomes increasingly positive. This kind of cooperative behavior is not observed for the analogous oligorotaxanes in the R' series. The conventional bevy of analytical techniques (e.g., HR-MS (ESI) and both (1)H and (13)C NMR spectroscopy) help establish the fact that all the oligorotaxanes are pure and monodisperse. Evidence of efficient [π···π] stacking between contiguous arene units in the rings in the R series is revealed by (1)H NMR spectroscopy. Ion-mobility mass spectrometry performed on the R and R' series yielded the collisional cross sections (CCSs), confirming the rigidity of the R oligorotaxanes and the flexibility of the R' ones. The extended [π···π] stacking interactions are found to be present in the solid-state structures of the [3]- and [4]rotaxanes in the R series and also on the basis of molecular mechanics calculations performed on the entire series of oligomers. The collective data presented herein supports our original design in that the extended [π···π] stacking between contiguous arene units in the rings of the R series of oligorotaxanes facilitate an essentially rigid rod-like conformation with evidence that positive cooperativity improves the efficiency of their formation. This situation stands in sharp contrast to the conformationally flexible R' series where the oligorotaxanes form with no cooperativity.

12.
Cancers (Basel) ; 14(14)2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35884441

RESUMO

Soft tissue sarcomas (STSs) are tumors that are challenging to treat due to their pathologic and molecular heterogeneity and their tumor biology that is not yet fully understood. Recent research indicates that dysregulation of cyclin-dependent kinase (CDK) signaling pathways can be a strong driver of sarcogenesis. CDKs are enzyme forms that play a crucial role in cell-cycle control and transcription. They belong to the protein kinases group and to the serine/threonine kinases subgroup. Recently identified CDK/cyclin complexes and established CDK/cyclin complexes that regulate the cell cycle are involved in the regulation of gene expression through phosphorylation of critical components of transcription and pre-mRNA processing mechanisms. The current and continually growing body of data shows that CDKs play a decisive role in tumor development and are involved in the proliferation and growth of sarcoma cells. Since the abnormal expression or activation of large numbers of CDKs is considered to be characteristic of cancer development and progression, dysregulation of the CDK signaling pathways occurs in many subtypes of STSs. This review discusses how reversal and regulation can be achieved with new therapeutics and summarizes the current evidence from studies regarding CDK modulation for STS treatment.

13.
Biomedicines ; 10(8)2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-36009423

RESUMO

The rat median nerve model is a well-established and frequently used model for peripheral nerve injury and repair. The grasping test is the gold-standard to evaluate functional recovery in this model. However, no comprehensive review exists to summarize the course of functional recovery in regard to the lesion type. According to PRISMA-guidelines, research was performed, including the databases PubMed and Web of Science. Groups were: (1) crush injury, (2) transection with end-to-end or with (3) end-to-side coaptation and (4) isogenic or acellular allogenic grafting. Total and respective number, as well as rat strain, type of nerve defect, length of isogenic or acellular allogenic allografts, time at first signs of motor recovery (FSR) and maximal recovery grasping strength (MRGS), were evaluated. In total, 47 articles met the inclusion criteria. Group I showed earliest signs of motor recovery. Slow recovery was observable in group III and in graft length above 25 mm. Isografts recovered faster compared to other grafts. The onset and course of recovery is heavily dependent from the type of nerve injury. The grasping test should be used complementary in addition to other volitional and non-volitional tests. Repetitive examinations should be planned carefully to optimize assessment of valid and reliable data.

14.
J Am Chem Soc ; 133(15): 5947-54, 2011 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-21446750

RESUMO

The process of osmotically driven crystal morphogenesis of polyoxometalate (POM)-based crystals is investigated, whereby the transformation results in the growth of micrometer-scale tubes 10-100 µm in diameter and many thousands of micrometers long. This process initiates when the crystals are immersed in aqueous solutions containing large cations and is governed by the solubility of the parent POM crystal. Evidence is presented that indicates the process is general to all types of POMs, with solubility of the parent crystal being the deciding parameter. A modular approach is adopted since different POM precursor crystals can form tubular architectures with a range of large cationic species, producing an ion-exchanged material that combines the large added cations and the large POM-based anions. It is also shown that the process of morphogenesis is electrostatically driven by the aggregation of anionic metal oxides with the dissolved cations. This leads to the formation of a semi-permeable membrane around the crystal. The osmotically driven ingress of water leads to an increase in pressure, and ultimately rupture of the membrane occurs, allowing a saturated solution of the POM to escape and leading to the formation of a "self-growing" microtube in the presence of the cation. It is demonstrated that the growth process is sustained by the osmotic pressure within the membrane surrounding the parent crystal, as tube growth ceases whenever this pressure is relieved. Not only is the potential of the modular approach revealed by the fact that the microtubes retain the properties of their component parts, but it is also possible to control the direction of growth and tube diameter. In addition, the solubility limits of tube growth are explored and translated into a predictive methodology for the fabrication of tubular architectures with predefined physical properties, opening the way for real applications.

15.
BMC Plant Biol ; 11: 48, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21406103

RESUMO

BACKGROUND: Seed metabolism is dynamically adjusted to oxygen availability. Processes underlying this auto-regulatory mechanism control the metabolic efficiency under changing environmental conditions/stress and thus, are of relevance for biotechnology. Non-symbiotic hemoglobins have been shown to be involved in scavenging of nitric oxide (NO) molecules, which play a key role in oxygen sensing/balancing in plants and animals. Steady state levels of NO are suggested to act as an integrator of energy and carbon metabolism and subsequently, influence energy-demanding growth processes in plants. RESULTS: We aimed to manipulate oxygen stress perception in Arabidopsis seeds by overexpression of the non-symbiotic hemoglobin AtHb1 under the control of the seed-specific LeB4 promoter. Seeds of transgenic AtHb1 plants did not accumulate NO under transient hypoxic stress treatment, showed higher respiratory activity and energy status compared to the wild type. Global transcript profiling of seeds/siliques from wild type and transgenic plants under transient hypoxic and standard conditions using Affymetrix ATH1 chips revealed a rearrangement of transcriptional networks by AtHb1 overexpression under non-stress conditions, which included the induction of transcripts related to ABA synthesis and signaling, receptor-like kinase- and MAP kinase-mediated signaling pathways, WRKY transcription factors and ROS metabolism. Overexpression of AtHb1 shifted seed metabolism to an energy-saving mode with the most prominent alterations occurring in cell wall metabolism. In combination with metabolite and physiological measurements, these data demonstrate that AtHb1 overexpression improves oxidative stress tolerance compared to the wild type where a strong transcriptional and metabolic reconfiguration was observed in the hypoxic response. CONCLUSIONS: AtHb1 overexpression mediates a pre-adaptation to hypoxic stress. Under transient stress conditions transgenic seeds were able to keep low levels of endogenous NO and to maintain a high energy status, in contrast to wild type. Higher weight of mature transgenic seeds demonstrated the beneficial effects of seed-specific overexpression of AtHb1.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Hemoglobinas/genética , Sementes/metabolismo , Arabidopsis/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Óxido Nítrico/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , Oxigênio/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , RNA de Plantas/genética , Sementes/genética , Estresse Fisiológico
16.
Handchir Mikrochir Plast Chir ; 53(6): 552-555, 2021 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-34875706

RESUMO

Microsurgical dissection and suturing techniques require persistent practice and perseverance. Rookies in particular often practice on the "dry model" in order to achieve a smooth transition to the application on the patient in the surgical theatre. Whether surgical glove, pig heart, with magnifying glasses, as a virtual reality tool, rat model with or without a training microscope - many different exercise models are described. For a number of years, self-made devices with smartphone cameras as a magnifying aid have also been known and are sometimes used. There is now a new commercial system from the US which allows the trainee to learn basic microsurgical techniques at any time and almost anywhere, or to perfect advanced knotting techniques such as the "through-the-loop" knot relatively easily and inexpensively. For this purpose, a conventional smartphone can be clamped in a 3 D swivel arm and anastomoses can be practiced on various vessel lumens. The smartphone therefor mimics a surgical microscope. There are prefabricated "cards" with built-in small plastic tubes of various diameters (1-3 mm) that can be used for practice.We believe that in the future such training kits can be part of the standard reporting in microsurgical training for interns and students in microsurgical centers.


Assuntos
Microcirurgia , Smartphone , Animais , Competência Clínica , Humanos , Ratos , Estudantes , Técnicas de Sutura , Suínos
17.
Front Surg ; 8: 743571, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34977137

RESUMO

Hyperbilirubinaemia has been shown to compromise wound healing in severely burned patients. The therapy options for patients with impairment of wound healing and subsequent severe liver dysfunction are limited. A novel extracorporeal treatment, CytoSorb® (CytoSorbents Corp, USA), is a whole blood adsorber composed of highly biocompatible and porous polystyrene divinylbenzene copolymer beads covered in a polyvinylpyrrolidone coating. It is capable of extracting mainly hydrophobic middle-sized (up to 55 kDa) molecules from blood via size exclusion, including cytokines and bilirubin. We performed therapy with CytoSorb® on a severely burned (48% Total Body Surface Area-TBSA) patient with secondary sclerosing cholangitis (SCC) to promote the wound healing process by reducing bilirubin concentrations and to bridge the time to spontaneous liver regeneration or eventually to liver transplantation after two skin transplantations had failed to provide wound closure. In the first 6 days the cartridge was changed on a daily basis and later after every 2-4 days. The therapy with six adsorbers decreased a total bilirubin concentration from 14.02 to 4.29 mg/dl. By maintaining a stable bilirubin concentration under 5 mg/dl, debridement of abdomen and upper extremities with autologous skin grafting and, 4 weeks later, autologous skin grafting of the back from scrotum and lower extremities were performed successfully. After wound healing had been achieved, the CytoSorb therapy was discontinued after 57 days and 27 adsorber changes. CytoSorb therapy can be a promising support of wound and skin graft healing in patients with severe burns and liver dysfunction due to a significant reduction of total bilirubin concentration.

18.
J Am Chem Soc ; 131(12): 4180-1, 2009 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19275232

RESUMO

The framework materials [W(72)Mn(II/III)(12)O(268)X(7)](52-/40-) undergo heteroatom (X)-controlled reversible SC-SC redox reactions whereby the Ge-templated framework reduction is fast and reoxidation is slow. The opposite trend is set for the Si-templated framework, and these processes can be followed optically, spectroscopically and crystallographically.

19.
Planta ; 230(1): 205-13, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19415324

RESUMO

The nucellar projection (NP)/endosperm transfer cell (ETC) complex represents the link between maternal and filial seed tissues in barley and mediates nutrient transfer into the endosperm. Cells of NP function as metabolic interface to precondition amino acid supply of the endosperm. The organ displays a top-down gradient of differentiation, with mitotically active, differentiating/elongating as well as disintegrating cells, characterized by proteolysis and nitrogen remobilization. To understand metabolism, interconversion and transfer of amino acids at the maternal-filial boundary, we applied a combined transcriptome and metabolite approach based on laser-assisted microdissection. Results suggest that amino acid degradation observed in NP largely occurs within mitochondria, consistent with their role in controlling amino acid homeostasis and metabolism. Differentially expressed genes and free amino acid levels associated with glutamate and glutamine metabolism indicate concerted action of glutamine dehydrogenase, glutamine synthetase and alanine:glyoxylate aminotransferase 2 within a hypothetical cycle for glutamine and alanine degradation and re-synthesis of the preferred transport form glutamine. Stimulation of gene expression involved in methionine metabolism in NP suggests a pathway of regulated synthesis of S-methylmethionine and a possible mechanism for the transfer of reduced sulphur from maternal tissues into the endosperm. Thus, the established micromethods revealed strategies in NP of young barley grains for mobilization and metabolism of transient N and S reserves and transfer into the endosperm.


Assuntos
Aminoácidos/metabolismo , Hordeum/metabolismo , Sementes/metabolismo , Regulação da Expressão Gênica de Plantas , Glutamato-Amônia Ligase/genética , Glutamato-Amônia Ligase/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Homeostase , Hordeum/citologia , Hordeum/genética , Redes e Vias Metabólicas , Metabolômica/métodos , Microdissecção/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/citologia , Sementes/genética
20.
Methods Mol Biol ; 1723: 397-409, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29344874

RESUMO

Spatiotemporal patterning throughout the plant body depends to a large degree on cell- and tissue-specific expression of genes. Subsequently, for a better understanding of cell and tissue differentiation processes during plant development it is important to conduct transcript analyses in individual cells or tissue types rather than in bulk tissues. Laser capture microdissection (LCM) provides a useful method for isolating specific cell types from complex tissue structures for downstream applications. Contrasting to mammalian cells, the texture of plant cells is more critical due to hard, cellulose-rich cell walls, large vacuoles, and air spaces which complicates tissue preparation and extraction of macromolecules, like DNA and RNA. In particular, developing barley seeds (i.e. grains) depict cell types with differences in osmomolarity (meristematic, differentiating and degenerating tissues) and contain high amounts of the main storage product starch. In this study, we report about methods allowing tissue-specific transcriptome profiling by RNA-seq of developing barley grain tissues from low-input RNA amounts. Details on tissue preparation, laser capture microdissection, RNA isolation, and linear mRNA amplification to produce high-quality samples for Illumina sequencing are provided. Particular emphasis was placed on the influence of the mRNA amplification step on the transcriptome data and the fidelity of deduced expression levels obtained by the developed methods. Analysis of RNA-seq data confirmed sample processing as a highly reliable and reproducible procedure that was also used for transcriptome analyses of different tissue types from barley plants.


Assuntos
Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Hordeum/genética , Microdissecção e Captura a Laser/métodos , Proteínas de Plantas/genética , RNA de Plantas/genética
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