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1.
J Nematol ; 56(1): 20240020, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38737094

RESUMO

Plant-parasitic nematodes (PPN) are an understudied pathogen group in the Oregon cool-season grass seed cropping system. In this survey, the PPN associated with annual ryegrass, bentgrass, fine fescue, orchardgrass, perennial ryegrass, and tall fescue were determined. Thirty-seven fields were sampled in the 2022 or 2023 growing season by collecting 10 soil cores in each of six 100-m transects for nematode extraction and visual identification. PerMANOVA testing indicated significant differences in PPN community composition across grass host and sampling time. Pratylenchus and Meloidogyne were the most commonly encountered nematodes, with maximum population densities of 1,984 and 2,496 nematodes/100 g soil, respectively. Sequencing of the COX1 gene region indicated the presence of P. crenatus, P. fallax, P. neglectus, P. penetrans, and P. thornei, with some of these species being detected for the first time on these grass hosts. The only Meloidogyne sp. found in these grasses was M. nassi, based upon sequencing of the ITS gene region. This first-of-its-kind survey indicates the need for further assessment of the impact of these PPNs on yield and stand longevity in cool-season grass seed fields in Oregon.

2.
Heliyon ; 10(3): e25311, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38327446

RESUMO

Since Mine Action's inception at the end of the 1980s, operators have collected limited data on the Victim Operated Explosive Devices (VOEDs) they clear. This includes not only data on the explosive ordnance itself but data on how they were found, where they were found and how they were processed and ultimately destroyed. In a context where detection of mines, boobytraps and certain Victim Operated Improvised Explosive Devices (VOIEDs) is an ongoing humanitarian and military challenge, significantly expanded operational data collection provides an achievable way to facilitate enhanced operational risk management. Risk decisions inherent in the clearance of VOEDs are better if made on the basis of extensive operational data. In the absence of a technological solution to detect and positively discriminate VOEDs from false positive indications, the collection of operational data offers the best prospect for "managing" if not "solving" the problem.

3.
Heliyon ; 8(3): e09135, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35846450

RESUMO

Managing environmental risk is essential to ensure organisations minimise their impact on the environment, comply with environmental legislation and maintain their reputation in an increasingly environmentally aware society. Organisations frequently use management systems to plan and execute routine environmental assessments, however environmental impacts may still arise from routine activities or accidents that could be avoided by effective environmental management. Currently there is no method for an organisation to assess the level of awareness their employees have of activities that may lead to an environmental impact, or the level of uptake of environmental management processes. Therefore, the Environmental Management Performance Assessment (EMPA) process was developed to enable organisations to self-assess existing environmental management processes by survey of their employees. The EMPA process was aligned to key phases of the Deming Cycle and involves development and distribution of a survey to organisation employees. The responses are then used to recognise areas for improvement by progression through a bespoke flow chart integrated with the initial survey. This enables demonstration of how particular hazards arise from insufficient awareness at different stages in the Deming Cycle and how these hazards can have wider, reputational, economic, and legislative consequences. The process was trialled by surveying academic researchers on the environmental management processes in their laboratories as a sample set.

4.
Heliyon ; 7(5): e06990, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34036190

RESUMO

Modern era combat helmets have different iterations and configurations to offer greater protection from blunt impact or ballistic penetration to suit the theatre of operation, although there are currently no standards for blast protection. Moreover, incorporation of blast protection into the same constrained mass-volume envelope is extremely challenging as there is very little space for a material to absorb or dissipate the shockwave. Foam padding is fitted in contemporary combat helmet designs for comfort and standoff purposes. Examples were subjected to blastwaves generated from an air-driven shocktube, along with open cell polyurethane foam specimens of varying pores per inch and thicknesses to. Whilst the range of samples tested did not afford any superior blast mitigation behaviour over the foam already present in helmets, they exhibited comparable performance with a lower mass. There also appears to be positive correlation between increased mass and increased impulse transmitted through the foam. The literature suggests that multiple mechanisms of damage for blast induced mild Traumatic Brain Injury (bTBI) can be caused by the helmet itself, therefore additional protection from a blunt or ballistic impact may increase the risk of damage from a blast insult.

5.
Plant Dis ; 104(1): 121-128, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31730414

RESUMO

Aureobasidium pullulans is used as a biocontrol agent for fire blight protection in organic apple and pear production. We assessed colonization of pome flowers by A. pullulans in orchards located near Corvallis, OR and Wenatchee, WA. Blossom Protect, a mix of A. pullulans strains CF10 and CF40, and its citrate-based companion, Buffer Protect, were sprayed at 70% bloom. Later in bloom, the population size of putative A. pullulans on flowers was estimated by dilution plating; plate scrapings of putative A. pullulans were then sampled and subjected to a PCR analysis. Sequenced PCR amplicons of the internal transcribed spacer region and the elongase gene confirmed the presence of A. pullulans, whereas a multiplex PCR with primers specific to CF10 and CF40 was used to determine the presence of the introduced strains. At Corvallis, a wet spring environment, A. pullulans, was recovered from most (>90%) Bartlett pear and Golden Delicious apple flowers sampled from experimental trees, regardless of whether the trees were treated with Blossom Protect. Nevertheless, population size estimates of A. pullulans on the flowers were correlated with the number of times Blossom Protect was sprayed on the trees. At Wenatchee, an arid spring environment, A. pullulans was detected on most flowers from trees treated with Blossom Protect, but only on a minority of flowers from nontreated controls. In both locations, the combined incidence of strains CF10 and CF40 on flowers averaged 89% on Blossom Protect-treated trees, but only 27% on adjacent, nontreated trees. During subsequent trials, the efficacy of Blossom Protect for fire blight control was compared with alternative yeast isolates, with each applied with Buffer Protect; local isolates of A. pullulans and Cryptococcus neoformans and a postharvest biocontrol strain of Cystofilobasidium infirmominiatum were used All yeast strains suppressed fire blight to a degree; however, in each of four trials, the level of suppression was highest with Blossom Protect, and it was significantly superior (P ≤ 0.05) to other yeast isolates in two of the trials. Because A. pullulans strains CF10 and CF40 were detected primarily on flowers on trees treated with Blossom Protect, and because they were detected much less frequently on nearby nontreated tress, we recommend treating every tree row with Blossom Protect at least once for organic fire blight suppression.


Assuntos
Ascomicetos , Frutas , Malus , Pyrus , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , DNA Fúngico/genética , Frutas/microbiologia , Malus/microbiologia , Interações Microbianas , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase , Pyrus/microbiologia
6.
Sci Total Environ ; 690: 730-738, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302539

RESUMO

The environmental risks from explosive manufacturing and testing activities are usually evaluated using a qualitative process such as environmental impact prioritisation as recommended by legislation and guidance. However, standard environmental management system (EMS) guidance rarely provides detailed information on how to objectively assess the significance of the environmental impacts based on a rational scientific evidence. Quantitative exposure and eco-toxicity assessments are frequently used in combination with environmental threshold limit guidelines, but these omit important environmental impacts such as physical damage to land, nuisance and contribution to climate change. These impacts are particularly relevant to the explosives industry where noise nuisance and physical damage are given high priority. In addition, contamination from explosive compositions may comprise mixtures of multiple legacy and new generation explosives such as 1,3,5-trinitro-1,3,5-triazinane (RDX), 2,4,6-trinitrotoluene (TNT), 5-nitro-1,2,4-triazol-3-one (NTO), 2,4-dinitroanisole (DNAN) and nitroguandine (NQ), which may have combined impacts not captured by conventional eco-toxicity assessments. Further, threshold limits for energetic materials in soil and water have not been established for most nations. Additionally, in the explosive industry wider concerns such as legislative compliance and stakeholder concerns may help to provide a more broadly applicable assessment of environmental impact. Therefore in this study a novel decision framework was developed to integrate empirical data with business risks to enable rational decision making for the environmental management of explosive manufacturing facilities. The application of the framework was illustrated using three case studies from the explosive manufacturing industry to demonstrate how the framework can be used to justify environmental management decision making. By linking the environmental impacts to business risks, we demonstrate that manufacturers are able to assess a wide spectrum of issues that might not be identified in the initial environmental assessment such as non-toxic pollution incidents, breaches in legislation and stakeholder perceptions.

7.
Sci Total Environ ; 668: 184-192, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-30852196

RESUMO

Explosive contamination is commonly found at military and manufacturing sites (Hewitt et al., 2005; Clausen et al., 2004; Walsh et al., 2013). Under current environmental legislation the extent of the contamination must be characterized by soil sampling and subsequent separation of the explosive contaminants from the soil matrix by extraction to enable chemical analysis and quantification (Dean, 2009). It is essential that the extraction method can consistently recover explosive residue from a variety of soil types i.e. all materials that have not degraded or irreversibly bound to the matrix, so that any resultant risk is not underestimated. In this study, five different soil types with a range of organic content, particle size and pH, were spiked with a mixture of RDX, DNAN, NQ and NTO at 50 mg/kg and were extracted using one of four one-step extraction methods: stirring, shaking, sonication, and accelerated solvent extraction (ASE). Analysis of the extraction efficiencies of the four methods found that they were broadly successful for the extraction of all IHE constituents from all five soils (an average of 84% ±â€¯14% recovery across 80 extractions). However, soils with high organic content (Total Organic Content (TOC) ≥ 2%) were found to significantly affect extraction efficiency and reproducibility. NTO and DNAN were the least consistent in extraction efficiency with poorest recovery of NTO as low as 37% ±â€¯2%. Of the four tested methods shaking was found to be the most reproducible, though less efficient than stirring (64%-91%). ASE was found to have the most variable results for extraction of IHE constituents suggesting that ASE was the most affected by the different soil types. Therefore, it is recommended that the efficiency and reproducibility of the selected extraction method should be validated by extracting known concentrations of the IHE from the soil of interest and that any required correction factors are reported.

8.
Sci Total Environ ; 625: 1264-1271, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29996423

RESUMO

Contamination of military ranges by the use of explosives can lead to irreversible environmental damage, specifically to soil and groundwater. The fate and effects of traditional explosive residues are well understood, while less is known about the impact of Insensitive High Explosives (IHEs) that are currently being brought into military service. Current research has focussed on the investigation of individual constituents of IHE formulations, which may not be representative of real-world scenarios when explosive residues will be deposited together. Therefore, this study investigated the fate and transport of the combined IHE constituents 2,4-dinitroanisole (DNAN), 1-nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO) in two UK soil types. Static experiments ran for 9weeks to determine the fate of the combined explosive constituents in soil by monitoring the rate of degradation. Transport was examined by running soil column experiments for 5weeks, with a watering regime equivalent to the average yearly UK rainfall. Both static and soil column experiments confirmed that DNAN and NTO started to degrade within twenty-four hours in soil with high organic content, and were both completely degraded within sixty days. NQ was more stable, with 80% of the original material recovered after sixty days. The major degradation product of DNAN in the test soils was 2-amino-4-nitroanisole (2-ANAN), with trace amounts of 4-amino-2-nitroanisole. NTO was rapidly degraded in soil with high organic content, although no degradation products were identified. Results supported work from literature on the individual constituents DNAN, NQ and NTO suggesting that the three explosives in combination did not interact with each other when in soil. This study should provide a useful insight into the behaviour of three combined Insensitive High Explosive constituents for the predication of soil and water contamination during military training.

9.
Chemosphere ; 169: 604-608, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27907880

RESUMO

Polymer-bonded explosives (PBX) fulfil the need for insensitive munitions. However, the environmental impacts of PBX are unclear, even though it is likely that PBX residues from low-order detonations and unexploded ordnance are deposited on military training ranges. The release of high explosives from the polymer matrix into the environment has not been studied in detail, although as polymers degrade slowly in the environment we anticipate high explosives to be released into the environment. In this study, PBXN-109 (nominally 64% RDX) samples were exposed to variable UK climatic conditions reproduced in the laboratory to determine the effects of temperature, UV irradiation and rainfall on the release of RDX from the polymer binder. The most extreme conditions for spring, summer and winter in the UK were artificially reproduced. We found that up to 0.03% of RDX was consistently released from PBXN-109. The rate of RDX release was highest in samples exposed to the summer simulation, which had the lowest rainfall, but the highest temperatures and longest UV exposure. This was confirmed by additional experiments simulating an extreme summer month with consistently high temperatures and long periods of sunlight. These results probably reflect the combination of polymer swelling and degradation when samples are exposed to higher temperatures and prolonged UV irradiation.


Assuntos
Substâncias Explosivas/química , Polímeros/química , Triazinas/análise , Poluentes Químicos da Água/análise , Tempo (Meteorologia) , Adipatos/química , Butadienos/química , Elastômeros/química , Temperatura
10.
Plant Dis ; 97(3): 423, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30722395

RESUMO

Utah sweetvetch (Hedysarum boreale Nutt.) is a native American perennial nitrogen fixing legume used mainly in rangeland reclamation, soil rejuvenation, and erosion control. In June 2011, a field of Utah sweetvetch grown for seeds in central Oregon had approximately 15% of the plants exhibiting chlorosis, defoliation, stunting, wilting, and/or death. Dissection of the crown of symptomatic plants revealed discolored pinkish brown vascular tissue. Symptomatic tissues from six random plants were surface sterilized, placed on acidified potato dextrose agar (PDA) medium, and cultured for 7 days at room temperature, which allowed six fungal isolates (SS1 through SS6) to be collected. On PDA, all six isolates had rapid, creamy white colored growth. Based on observations of 1-week-old isolates, microconidia were oval to kidney shaped, single celled, 8 to 10 × 2.5 to 4 µm, and formed at the tips of long unbranched monophialides. Macroconidia were three to four septate, cylindrical to slightly curved, with characteristic foot shaped basal cell and blunt apical cell, 37 to 49 × 4.4 to 5.3 µm. Chlaymydospores observed were 8.5 to 11 × 7.6 to 9 µm. Based on fungal references (1,2,3), the isolates were identified as Fusarium solani (Mart.) Sacc. Identification of the isolates at the molecular level was determined by amplification of the internal transcribed spacer (ITS) region using PCR and amplicon sequencing. Botrytis cinerea and F. graminearum cultures were used as controls for the extraction, amplification, and sequencing steps. Genomic DNA was extracted from mycelia using protocols of the MOBIO Ultraclean Soil DNA Isolation Kit (MO-BIO Laboratories Inc, Carlsbad, CA, USA). PCR was performed using ITS1/ITS4 primers and resulted in 563- to 573-bp amplicons, which were sequenced. Analysis of the ITS sequences (GenBank Accession Nos. JX524018 to JX524023) for the six fungal isolates using BLASTn revealed a 99% sequence identity with F. solani strains (AB470903, AB513851, AJ608989, EF152426, EU029589, and HM214456). Pathogenicity was confirmed on Utah sweetvetch plants in the greenhouse. Seeds of Utah sweetvetch were first plated on acidified PDA for germination; healthy seedlings were then selected and transplanted into pots with sterilized soil after 2 weeks of growth. The plants were kept in a greenhouse at Central Oregon Agricultural Research Center, Madras, Oregon. Ten 40-day-old healthy vetch plants were inoculated by drenching with a mixed conidial suspension (107 conidia/ml) of the six F. solani isolates. Ten plants drenched with sterile distilled water were included as controls. Symptoms of chlorosis and stunting similar to those in the commercial field were observed within 30 days of inoculation on 8 of 10 inoculated plants, while control plants were symptomless. Fungal isolates identical to F. solani were reisolated from the symptomatic plants. To our knowledge, this is the first report of F. solani on Utah sweetvetch plants. References: (1) C. Booth. The Genus Fusarium. CMI, Kew, Surrey, UK, 1971. (2) P. E. Nelson et al. Fusarium species: An illustrated manual for identification. The Pennsylvania State University Press, USA, 1983. (3) H. I. Nirenberg. A simplified method for identifying Fusarium spp. occurring on wheat. Can. J. Bot. 59:1599, 1980.

11.
Phytopathology ; 99(2): 128-38, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19159304

RESUMO

As a prerequisite to infection of flowers, Erwinia amylovora grows epiphytically on stigmas, which provide a conducive habitat for bacterial growth. Stigmas also support growth of several other bacterial genera, which allows for biological control of fire blight; although, in practice, it is very difficult to exclude E. amylovora completely from this habitat. We investigated the dynamics of growth suppression of E. amylovora by comparing the ability of virulent and avirulent strains of E. amylovora to compete with each other on stigmas of pear, apple, and blackberry, and to compete with a co-inoculated mixture of effective bacterial antagonists. When strains were inoculated individually, virulent E. amylovora strain Ea153N attained the highest population size on stigmas, with population sizes that were approximately double those of an avirulent hrpL mutant of Ea153 or the bacterial antagonists. In competition experiments, growth of the avirulent derivative was suppressed by the antagonist mixture to a greater extent than the virulent strain. Unexpectedly, the virulent strain enhanced the population size of the antagonist mixture. Similarly, a small dose of virulent Ea153N added to inoculum of an avirulent hrpL mutant of Ea153 significantly increased the population size of the avirulent strain. A pathogenesis-gene reporter strain, Ea153 dspE::gfp, was applied to flowers and a subset of the population expressed the green fluorescent protein while growing epiphytically on stigmas of apple. These results are consistent with the hypothesis that virulent E. amylovora modifies the epiphytic habitat presented by the stigma through a pathogenesis-related process, which increases host resources available to itself and, coincidentally, to nonpathogenic competitors. Over nine orchard trials, avirulent Ea153 hrpL significantly suppressed the incidence of fire blight four times compared with six for the antagonist mixture. The degree of biological control achievable with an avirulent strain of E. amylovora likely is limited by its inability to utilize the stigmatic habitat to the same degree as a virulent strain.


Assuntos
Erwinia amylovora/patogenicidade , Flores/microbiologia , Controle Biológico de Vetores/métodos , Doenças das Plantas/microbiologia , Rosaceae/microbiologia , Virulência
12.
Plant Dis ; 90(10): 1331-1336, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30780941

RESUMO

We evaluated epiphytic growth of the fire blight bacterium, Erwinia amylovora, on flowers of plant species common to landscapes where pears and apples are grown. The plants were from genera regarded as important nectar and pollen sources for pollinating insects: Acer, Amelanchier, Brassica, Cytisus, Populus, Prunus, Rubus, Salix, Taraxacum, Trifolium, and Symphoricarpos. Floral bouquets were inoculated with E. amylovora and incubated in growth chambers at 15°C for 96 h. Regardless of their susceptibility to fire blight, all species from the rose family except Prunus domestica (European plum) supported epiphytic populations of E. amylovora that exceeded 1 × 106 CFU/flower with relative growth rates for the populations that averaged 7% per hour. Nonrosaceous plants were generally poor supporters of epiphytic growth of the fire blight pathogen with relative growth rates averaging <4% per hour. In two seasons of field inoculations, the rosaceous non-disease-host plants, Prunus avium (sweet cherry) and Rubus armeniacus (Himalayan blackberry), yielded mean population sizes of E. amylovora that exceeded 1 × 106 CFU/flower; in contrast, at 8 days after inoculation, mean population sizes of the pathogen were in the range of 5 × 103 to 5 × 104 CFU/flower on Cytisus scoparius (Scotch broom) and <1 × 102 CFU on Acer macrophylum (big leaf maple). Because vectors of E. amylovora, principally bees, visit many kinds of flowers in landscape areas between pear and apple orchards, flowers of rosaceous, non-disease-host species could serve as potential sites of inoculum increase during their periods of bloom.

14.
J Pediatr Orthop ; 16(6): 734-40, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8906644

RESUMO

Thirty-one patients with cerebral palsy and neuromuscular scoliosis underwent instrumentation with a unit rod fixed with sublaminar wires and posterior spine fusion. The mean curve measured 79 degrees preoperatively, 19 degrees immediately postoperatively, and 18 degrees at final follow-up of 2.8 years, excluding two patients who died and four who were lost to follow-up after < 12 months. The preoperative pelvic obliquity was 25 degrees, which was initially corrected to 3 degrees and remained unchanged at 4 degrees at final follow-up. Twenty-four patients underwent a one-stage posterior fusion, and seven patients underwent both anterior and posterior fusions. Complications included one acute deep-wound infection and one late deep-wound infection seeded from the urinary tract. No pseud-arthroses or hardware failures have occurred to date. Seven children with open triadiate cartilages had a posterior spinal fusion only and were followed up to skeletal maturity with a 3 degrees loss of correction of the scoliosis and a 0 degree loss of correction of pelvic obliquity. Questionnaires filled out by primary caretakers demonstrated that the objective of improving the child's ability to sit more comfortably was accomplished for the majority (65%) of patients. Spinal fusion was recommended for other children by 86% of interviewed caretakers.


Assuntos
Paralisia Cerebral/complicações , Cifose/cirurgia , Escoliose/cirurgia , Adolescente , Adulto , Perda Sanguínea Cirúrgica , Pinos Ortopédicos , Criança , Feminino , Humanos , Fixadores Internos , Cifose/etiologia , Masculino , Complicações Pós-Operatórias/etiologia , Cuidados Pré-Operatórios , Estudos Retrospectivos , Escoliose/etiologia , Fusão Vertebral/métodos , Resultado do Tratamento
15.
J Pediatr Orthop ; 16(3): 332-5, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8728632

RESUMO

This study was undertaken to determine the impact of spinal bracing on curve pattern and the rate of progression of neuromuscular scoliosis in children with cerebral palsy. Twenty-one patients were treated with a Wilmington custom-molded orthosis with 23 h a day brace wear for a mean bracing period of 67 months (range, 22-173). Twenty-two patients had a similar follow-up to spinal fusion but had no bracewear. Patients who were braced had a scoliosis that reached a magnitude of 50 degrees at a mean 12.5 years, compared with a mean age of 14 years for those who were not braced (p > 0.05). Spinal orthotics had no impact on scoliosis curve, shape, or rate of progression in spastic quadriplegic patients who were followed-up on fusion. Apical vertebral rotation > 2 (Nash and Moe criteria) is an indicator of impending rapid progression of the scoliosis curve.


Assuntos
Paralisia Cerebral/complicações , Aparelhos Ortopédicos , Escoliose/fisiopatologia , Escoliose/terapia , Adolescente , Criança , Progressão da Doença , Feminino , Humanos , Recém-Nascido , Masculino , Aparelhos Ortopédicos/efeitos adversos , Prognóstico , Radiografia , Fatores de Risco , Escoliose/etiologia , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/fisiopatologia
17.
Lab Invest ; 48(3): 263-8, 1983 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6827806

RESUMO

Because of the importance of renal basement membrane glycoproteins in normal and abnormal tubular and glomerular morphogenesis, structure, and function, the sequential development of fibronectin, GP-2, and entactin was studied in vivo and in a newly developed, serum-free mouse metanephric organ culture system. The organ culture system permits advanced tubular differentiation and glomerular epithelial development of whole metanephros without perfusion or urine formation. Affinity-purified antibodies and immunohistologic techniques were used, and the ontogeny of basement membrane glycoproteins was characterized in vivo and in vitro. It was thus possible to characterize the pattern of normal renal basement membrane glycoprotein production and to comparatively study renal glomerular and tubular basement membrane formation in the presence and the absence of endothelial and/or mesangial influences. Both in vivo and in vitro undifferentiated mesenchyme expressed fibronectin but not GP-2 or entactin. Further, both in vivo and in vitro, all three glycoproteins developed in the basement membranes of the earliest recognizable tubular and glomerular forms. Because of the sharp parallel between in vivo and in vitro basement membrane glycoprotein production we conclude that the whole organ metanephric culture system is a useful model for the study of renal basement membrane development. Further, based on the pattern of in vitro basement membrane production, it may be concluded that tubular and glomerular epithelial cells are capable of producing basement membrane glycoproteins in the absence of endothelial or recognizable mesangial cells following initial embryonic induction.


Assuntos
Membrana Basal/metabolismo , Glicoproteínas/fisiologia , Rim/ultraestrutura , Glicoproteínas de Membrana , Animais , Feto/fisiologia , Fibronectinas/biossíntese , Glicoproteínas/biossíntese , Glicoproteínas/metabolismo , Rim/crescimento & desenvolvimento , Rim/metabolismo , Glomérulos Renais/crescimento & desenvolvimento , Túbulos Renais/crescimento & desenvolvimento , Laminina , Camundongos , Técnicas de Cultura de Órgãos
18.
In Vitro ; 18(8): 675-82, 1982 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7129481

RESUMO

A new mouse metanephric organ culture system has been developed to study mammalian renal development. The system permits in vitro organotypic differentiation in a serum-free, hormone supplemented medium consisting of Dulbecco's minimal essential medium (MEM) and Ham's F12 medium supplemented with insulin, 5 microgram/ml; PGE1, 25 ng/ml; T3, 3.2 pg/ml; hydrocortisone, 5 microgram/ml; and transferrin, 5 microgram/ml. In this system, metanephric development continues morphologically beyond the S-shaped tubule stage. A well differentiated proximal tubule forms with a well defined brush border, specialized intercellular connections, and an apical endocytic network. In addition, a unique devascularized glomerulus, with highly differentiated podocytes surrounding areas of basement membrane, forms entirely from epithelial elements. The present organ culture model goes beyond the limitations of previously described systems in that it does not require separation of nephrogenic blastema from ureteric bud, nor require animal serum or nonspecific tissue extracts for metanephric development. The model is thus suited for morphological, biochemical, and endocrinological study of normal and abnormal renal organogenesis.


Assuntos
Rim/embriologia , Animais , Meios de Cultura , Feminino , Idade Gestacional , Túbulos Renais/embriologia , Camundongos , Técnicas de Cultura de Órgãos , Gravidez , Fatores de Tempo
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