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At least 217 records · Page 12Linked to original sources
PubMed1994

[Total esophagoplasty using a double pedicled free graft from the jejunum: the last resort].

After repeated failures of classic oesophagoplasties (gastroplasty and coloplasty) a last chance reconstruction could rely on a free jejunal transplant. We report an exceptional and original case where digestive tract was re-established between the orostoma and the epigastric antrum. The patient has four neoplasms in the throat, thoracic oesophagus. After circular pharyngolarynectomy and total oesophagectomy, all the usable vascularized plasties had necrosed. The ultimate reconstruction was performed with a free jejunal transplant carrying two vascular bundles revascularized with the cervical vessels and the internal thoracic vessels. Several recommendations are proposed: Save as much of the digestive tube as possible; preserve the physiological gastroduodenal circuit; redissect the residual plasty in order to raise the new one as high as possible; perform a sub-cutaneous insertion of the residual plasties and the jejunal transplant; and if the loss of digestive substance is greater than 30 cm, a long free jejunal transplant with two vascular bundles should be used.

Adult↗
PubMed1985

Nodules are induced on alfalfa roots by Agrobacterium tumefaciens and Rhizobium trifolii containing small segments of the Rhizobium meliloti nodulation region.

Regions of the Rhizobium meliloti nodulation genes from the symbiotic plasmid were transferred to Agrobacterium tumefaciens and Rhizobium trifolii by conjugation. The A. tumefaciens and R. trifolii transconjugants were unable to elicit curling of alfalfa root hairs, but were able to induce nodule development at a low frequency. These were judged to be genuine nodules on the basis of cytological and developmental criteria. Like genuine alfalfa nodules, the nodules were initiated from divisions of the inner root cortical cells. They developed a distally positioned meristem and several peripheral vascular bundles. An endodermis separated the inner tissues of the nodule from the surrounding cortex. No infection threads were found to penetrate either root hairs or the nodule cells. Bacteria were found only in intercellular spaces. Thus, alfalfa nodules induced by A. tumefaciens and R. trifolii transconjugants carrying small nodulation clones of R. meliloti were completely devoid of intracellular bacteria. When these strains were inoculated onto white clover roots, small nodule-like protrusions developed that, when examined cytologically, were found to more closely resemble roots than nodules. Although the meristem was broadened and lacked a root cap, the protrusions had a central vascular bundle and other rootlike features. Our results suggest that morphogenesis of alfalfa root nodules can be uncoupled from infection thread formation. The genes encoded in the 8.7-kilobase nodulation fragment are sufficient in A. tumefaciens or R. trifolii backgrounds for nodule morphogenesis.

Conjugation, Genetic↗
PubMed2005

Three-dimensional reconstruction of the mouse nephron.

Renal function is crucially dependent on renal microstructure which provides the basis for the regulatory mechanisms that control the transport of water and solutes between filtrate and plasma and the urinary concentration. This study provides new, detailed information on mouse renal architecture, including the spatial course of the tubules, lengths of different segments of nephrons, histotopography of tubules and vascular bundles, and epithelial ultrastructure at well-defined positions along Henle's loop and the distal convolution of nephrons. Three-dimensional reconstruction of 200 nephrons and collecting ducts was performed on aligned digital images, obtained from 2.5-mum-thick serial sections of mouse kidneys. Important new findings were highlighted: (1) A tortuous course of the descending thin limbs of long-looped nephrons and a winding course of the thick ascending limbs of short-looped nephrons contributed to a 27% average increase in the lengths of the corresponding segments, (2) the thick-walled tubules incorporated in the central part of the vascular bundles in the inner stripe of the outer medulla were identified as thick ascending limbs of long-looped nephrons, and (3) three types of short-looped nephron bends were identified to relate to the length and the position of the nephron and its corresponding glomerulus. The ultrastructure of the tubule segments was identified and suggests important implications for renal transport mechanisms that should be considered when evaluating the segmental distribution of water and solute transporters within the normal and diseased kidney.

Animals↗
PubMed1998

[Possibilities for revascularization in early and late stage lunate malacia].

There are various biomechanical procedures for the treatment of lunate necrosis in the literature, but only a few deal with the possible revascularisation of the bone. We used the second dorsal metacarpal vascular bundle implantation technique in different stages of Kienböck's disease. Since 1990, twelve patients were treated by this method. In stage I-II according to Lichtman, we implanted the vessels in the lunate after excochleation and cancellous bone grafting, in stage III we used a modified form of the Graner operation and revascularised the proximalised part of the capitate. In the first group, six patients, we observed significant improvement in five cases clinically, radiologically confirmed stagnation of the process in four cases. In the second group of six patients, the clinical symptoms improved in four cases, three patients had to change work and one patient developed a pseudarthrosis between the capitate and corticocancellous block, but the proximalised part of capitate survived in all cases. Vascular bundle implantation can be a helpful method in early stages of lunate necrosis, helping to slow or to stop the progression of the disease.

Adolescent↗
PubMed2003

Changes in the expression pattern of the plasma membrane H+-ATPase in developing Ricinus communis cotyledons undergoing the sink/source transition.

The plasma membrane (PM) H+-ATPase is thought to play a key role in generating the proton motive force used to drive the uptake and accumulation of solutes in plant cells. Changes in its expression pattern were studied in the Ricinus communis L. cotyledon as it changed from a sink to a source organ. Expression was monitored in 3-, 10- and 14-day-old cotyledons using an antibody to the maize PM H+-ATPase. The antibody labelled a 100-kDa protein in membrane fractions prepared from cotyledons and this protein occurred at higher levels in the PM-enriched fractions compared to those enriched in intracellular membranes. Immunostaining of tissue sections of 3-day-old Ricinus cotyledons (sinks) with this antibody demonstrated that the PM H+-ATPase was highly expressed in the lower epidermal cells and also in the vascular bundles, particularly the phloem. The high expression in the epidermis suggests that these cells may be important in the initial active uptake of solutes from the endosperm. A similar distribution was observed in the 10-day-old seedlings but, in addition, larger, more spherical cells (idioblasts) had developed in the lower and upper epidermal layers and these were also labelled. In 14-day-old seedlings the cotyledons are no longer reliant on nutrients from the endosperm (which has totally degraded) and they are functioning as source organs. This is reflected in a decrease in PM H+-ATPase expression in the lower epidermal cells, apart from idioblasts and stomatal guard cells. The latter were also observed in the upper epidermis. Expression remained high in the vascular bundles of 14-day-old seedlings with strong staining in the phloem.

Cell Membrane↗
PubMed2005

Maladaptive role of IL-6 in ischemic acute renal failure.

The role of IL-6 was investigated in murine ischemic acute renal failure. The renal pedicles were clamped for 17 min, and the mice were studied at various times after reperfusion. We found that serum IL-6 increased after murine ischemic renal injury. This increase was associated with increased IL-6 mRNA in the ischemic kidney but not in the contralateral kidney or the liver. Maximal IL-6 production occurred at 4 to 8 h and decreased to baseline by 24 h. Reperfusion of the kidney was required for IL-6 production. In situ hybridization and immunohistochemistry showed that macrophages infiltrated areas adjacent to the vascular bundles in the outer medulla within hours of reperfusion and showed that these macrophages produced IL-6 mRNA. For understanding how macrophages were stimulated to produce IL-6, an in vitro model in which S3 proximal tubular cells were injured by reactive oxygen species was set up. These injured cells released molecules that activated macrophages to produce IL-6 in vitro. IL-6 that was produced in response to renal ischemia was maladaptive because transgenic knockout of IL-6 ameliorated renal injury as measured by serum creatinine and histology. IL-6 transgenic knockout mice were lethally irradiated, and their bone marrow was reconstituted with wild-type IL-6 cells. Such bone marrow transfers abolished the protective effects of transgenic IL-6 knockout. It is concluded that macrophages infiltrate the area of the vascular bundles of the outer medulla, these macrophages produce IL-6, and this IL-6 exacerbates ischemic murine acute renal failure.

Acute Kidney Injury↗
PubMed2003

Enzymes of jasmonate biosynthesis occur in tomato sieve elements.

The allene oxide cyclase (AOC) is a plastid-located enzyme in the biosynthesis of the signaling compound jasmonic acid (JA). In tomato, AOC occurs specifically in ovules and vascular bundles [Hause et al. (2000) Plant J. 24; 113]. Immunocytological analysis of longitudinal sections of petioles and flower stalks revealed the occurrence of AOC in companion cells (CC) and sieve elements (SE). Electron microscopic analysis led to the conclusion that the AOC-containing structures of SE are plastids. AOC was not detected in SE of 35S::AOCantisense plants. The enzymes preceding AOC in JA biosynthesis, the allene oxide synthase (AOS) and the lipoxygenase, were also detected in SE. In situ hybridization showed that the SE are free of AOC-mRNA suggesting AOC protein traffic from CC to SE via plasmodesmata. A control by in situ hybridization of AOS mRNA coding for a protein with a size above the exclusion limit of plasmodesmata indicated mRNA in CC and SE. The data suggest that SE carry the capacity to form 12-oxo-phytodienoic acid, the unique precursor of JA. Together with preferential generation of JA in vascular bundles [Stenzel et al. (2003) Plant J. 33: 577], the data support a role of JA in systemic wound signaling.

Cyclopentanes↗
PubMed1990

[Transplantation of the meniscus in dogs--preliminary report].

A preliminary investigation of the allogenic transplantation of the meniscus without the vascular bundle was carried out in 4 adult dogs with 8 knees. In one operation session on 2 dogs at 2 operative tables and with two operative teams an identical surgical procedure in general anaesthesia was done. A medial parapatellar incision of the knee was used, the medial capsule and the collateral ligament near its proximal insertion were severed. Explanted medial menisci were exchanged and the meniscus from the other dog was put in position of the explanted one and fixed with 3 tangentially placed sutures (posterior, medial and anterior) which were taken out through the capsule and teid extra-articularly; there was no immobilisation, and after 3 weeks the identical operation was done on the other knee. The animals were sacrificed 4-5 months after the operation, the knees were dissected and observed. In all 8 knees transplanted menisci were completely healed around their periphery, however their appearance was rather changed. They were narrower, thinner, and of different colour and consistency. The transplanted menisci were removed and conserved in 10% (formalin) for the further investigation. It is concluded that the allogenic meniscal transplantation without the vascular bundle is possible and that the further investigation of this problem is justified.

Animals↗
PubMed2006

Abscisic acid is a key inducer of hydrogen peroxide production in leaves of maize plants exposed to water stress.

The histochemical and cytochemical localization of water stress-induced H(2)O(2) production in the leaves of ABA-deficient vp5 mutant and wild-type maize (Zea mays L.) plants were examined, using 3,3-diaminobenzidine and CeCl(3) staining, respectively, and the roles of endogenous ABA in the production of H(2)O(2) induced by water stress were assessed. Water stress induced by polyethylene glycol resulted in the accumulation of H(2)O(2) in mesophyll cells, bundle-sheath cells and vascular bundles of wild-type maize leaves, and the accumulation was substantially blocked in the mutant maize leaves exposed to water stress. Pre-treatments with several apoplastic H(2)O(2) manipulators abolished the majority of H(2)O(2) accumulation induced by water stress in the wild-type leaves. The subcellular localization of H(2)O(2) production was demonstrated in the cell walls, xylem vessels, chloroplasts, mitochondria and peroxisomes in the leaves of wild-type maize plants exposed to water stress, and the accumulation of H(2)O(2) induced by water stress in the cell walls and xylem vessels, but not in the chloroplasts, mitochondria and peroxisomes, was arrested in the leaves of the ABA mutant or the ABA biosynthesis inhibitor (tungstate)-pre-treated maize plants. Pre-treatments with the apoplastic H(2)O(2) manipulators also blocked the apoplastic but not the intracellular H(2)O(2) accumulation induced by water stress in the leaves of wild-type plants. These data indicate that under water stress, the apoplast is the major source of H(2)O(2) production and ABA is a key inducer of apoplastic H(2)O(2) production. These data also suggest that H(2)O(2) generated in the apoplast could not diffuse freely into subcellular compartments.

Abscisic Acid↗
PubMed1994

Temporal and Spatial Expression Pattern of Sucrose Synthase during Tomato Fruit Development.

Sucrose synthase is proposed to play an important role in the early stages of tomato fruit (Lycopersicon esculentum Mill.) growth. In this work, the temporal and spatial expression patterns of sucrose synthase during tomato fruit development were investigated. Fruit contained the majority of the sucrose synthase protein and mRNA relative to other organs. Only trace levels of sucrose synthase protein and mRNA were detected in the stem, petiole, and roots. Sucrose synthase mRNA was detected in pistils prior to anthesis, reached peak levels in fruit 5 to 7 d after anthesis (DAA), and was not detectable after 35 DAA. Sucrose synthase protein levels reached a maximum at 20 to 25 DAA and then declined to nondetectable levels after 45 DAA. The lack of coordination between protein and mRNA levels suggests that sucrose synthase expression may be controlled at the levels of both transcription and translation. Sucrose synthase mRNA was differentially localized in the fruit, being most abundant in the mesocarp cells adjacent to the placenta, the columella, and the cells surrounding the vascular bundle. Except around the vascular tissue, the localization of sucrose synthase mRNA positively correlates with starch granule accumulation at the cellular level.

Journal Article↗
PubMed1998

Localization of expression of three cold-induced genes, blt101, blt4. 9, and blt14, in different tissues of the crown and developing leaves of cold-acclimated cultivated barley

Tissues expressing mRNAs of three cold-induced genes, blt101, blt14, and blt4.9, and a control gene, elongation factor 1alpha, were identified in the crown and immature leaves of cultivated barley (Hordeum vulgare L. cv Igri). Hardiness and tissue damage were assessed. blt101 and blt4.9 mRNAs were not detected in control plants; blt14 was expressed in control plants but only in the inner layers of the crown cortex. blt101 was expressed in many tissues of cold-acclimated plants but most strongly in the vascular-transition zone of the crown; blt14 was expressed only in the inner layers of the cortex and in cell layers partly surrounding vascular bundles in the vascular-transition zone; expression of blt4.9, which codes for a nonspecific lipid-transfer protein, was confined to the epidermis of the leaf and to the epidermis of the older parts of the crown. None of the cold-induced genes was expressed in the tunica, although the control gene was most strongly expressed there. Thus, the molecular aspects of acclimation differed markedly between tissues. Damage in the vascular-transition zone of the crown correlated closely with plant survival. Therefore, the strong expression of blt101 and blt14 in this zone may indicate a direct role in freezing tolerance of the crown.

Journal Article↗
PubMed1993

Activity of a chimeric promoter with the doubled CaMV 35S enhancer element in protoplast-derived cells and transgenic plants in maize.

A reproducible and efficient transformation system has been developed for maize that is based on direct DNA uptake into embryogenic protoplasts and regeneration of fertile plants from protoplast-derived transgenic callus tissues. Plasmid DNA, containing the beta-glucuronidase (GUS) gene, under the control of the doubled enhancer element (the -208 to -46 bp upstream fragment) from CaMV 35S promoter, linked to the truncated (up to -389 bp from ATG) promoter of wheat, alpha-amylase gene was introduced into protoplasts from suspension culture of HE/89 genotype. The constructed transformation vectors carried either the neomycin phosphotransferase (NPTII) or phosphinothricin acetyltransferase (PAT) gene as selective marker. The applied DNA uptake protocol has resulted at least in 10-20 resistant calli, or GUS-expressing colonies after treatment of 10(6) protoplasts. Vital GUS staining of microcalli has made possible the shoot regeneration from the GUS-stained tissues. 80-90% of kanamycin or PPT resistant calli showed GUS activity, and transgenic plants were regenerated from more than 140 clones. Both Southern hybridization and PCR analysis showed the presence of introduced foreign genes in the genomic DNA of the transformants. The chimeric promoter, composed of a tissue specific monocot promoter, and the viral enhancer element specified similar expression pattern in maize plants, as it was determined by the full CaMV 35S promoter in dicot and other monocot plants. The highest GUS specific activity was found in older leaves with progressively less activity in young leaves, stem and root. Histochemical localization of GUS revealed promoter function in leaf epidermis, mesophyll and vascular bundles, in the cortex and vascular cylinder of the root. In roots, the meristematic tip region and vascular tissues stained intensively. Selected transformants were grown up to maturity, and second-generation seedlings with segregation for GUS activity were obtained after outcrossing. The GUS-expressing segregants carried also the NPTII gene as shown by Southern hybridization.

Aminobutyrates↗
PubMed1998

Rotation plasty for osteosarcoma of the femur.

A 20-year-old female with right femoral osteosarcoma noted severe pain and swelling of the right thigh, and was transferred to the authors' hospital after suffering a pathologic fracture of the right femur. Plain x-ray disclosed a tumor shadow extending from the pathologic fracture of the distal portion of the femur to the center of the diaphysis. MRIs showed a broad lesion and hematoma, and invasion to the femoral vascular bundle was suspected. Angiograms revealed vascularization coincidental to the tumor, and an irregular vascular wall of the femoral artery, which was shifted posteriorly. After consultation with the patient and her family, rotation plasty was performed. The sciatic nerve was isolated and preserved; major vessels were sectioned proximally and distally because of tumor tissue invasion to the femoral artery and vein. After wide excision of the tumor, the leg was rotated outward 180 degrees, and osteosynthesis was performed between the remaining femur and the tibia, followed by microsurgical anastomosis of vessels. Five years postoperatively, no local recurrence or metastasis has been observed. The patient has excellent functional recovery without pain, and no other complications.

Adult↗
PubMed1977

Comparison of vegetative anatomy of piperales. I. Juvenile xylem of twigs.

Medullary bundles of Piperaceae resemble those of Ranunculaceae. The nature of tracheary elements of primary xylem suggests that Houttuynia cordata (Saururaceae), Piper cubeba (Piperaceae) and Chloranthus officinalis (Chloranthaceae) are of lower evolutionary status than others. Among these three, P. cubeba shows stratification of secondary xylem, a specialized character. Lateral wall of metaxylem tracheary elements and distribution of bundles of Peperomia, suggest their primitive status and distinctness, supporting separation of "Peperomiacea:" (of NOVAK). Piper cubeba, Houttuynia and Chloranthus bear one important Ranunculaceous character: scalariform perforation in primary vessels. Primitive species of Peperomia carry probably another Ranunculaceous character, i.e., many circles of medullary bundles. Shape and pattern of vascular bundles of Piper cubeba, Houttuynia and Chloranthus are similar. Other species of Piper show modifications. Peperomia represents another distinct pattern.

Plants↗
PubMed1991

The caudal gluteal vessels: a suitable recipient bundle for free bone grafting in the canine femur.

The caudal gluteal vascular bundle was analyzed in the dog to determine its suitability as a recipient area for free vascularized bone grafts in the femur. The anatomy of the caudal gluteal artery and vein, as well as the arterial blood flow, were studied. This bundle was also used to revascularize 50 free vascularized rib grafts for proximal and femoral shaft reconstruction. The pedicle was constant, long (6.12 +/- 1.85 cm), and easily accessible via a lateral approach. It was large enough (artery: 1.74 +/- 0.46 mm, vein: 2.27 +/- 0.69 mm) and had an adequate blood flow (99 +/- 8 ml/mn) for microvascular techniques. Due to the existence of three anastomotic vascular rings with both the superficial and deep femoral bundles, these vessels had a bidirectional blood flow. In all the free vascularized rib grafts the caudal gluteal vessels were distally based (reversed blood flow) and provided a sufficient blood supply to the grafted bone. These results suggest that the caudal gluteal vessels are excellent recipient vessels for research in the field of free vascularized bone grafts using the canine femur.

Animals↗
PubMed2001

Two Arabidopsis thaliana genes, KOR2 and KOR3, which encode membrane-anchored endo-1,4-beta-D-glucanases, are differentially expressed in developing leaf trichomes and their support cells.

The Arabidopsis KOR gene encodes a membrane-anchored endo-1,4-beta-D-glucanase involved in cell wall assembly. To obtain a more detailed knowledge of the small gene family encoding membrane-anchored endo-1,4-beta-D-glucanases in Arabidopsis thaliana, we have characterized two additional membrane-anchored endo-1,4-beta-D-glucanase genes. Sequence comparison indicates that KOR2 is distantly related to KOR and other plant membrane-anchored endo-1,4-beta-D-glucanases. The expression of KOR2 and KOR3 was followed by the beta-glucuronidase (gusA) reporter-gene method. While the KOR gene is most often expressed throughout the plant, KOR2::gusA and KOR3::gusA are active only in restricted cell types. We demonstrate that KOR2::gusA is expressed very early in the development of root hairs within the root differentiation zone (specialization zone) but not in the root-hair-bearing epidermal cells at the root/shoot junction (transition zone). Furthermore, KOR2::gusA is expressed in the proximal parts of leaves and floral organs (rosette and cauline leaves, sepals, petals and stamens), and in trichomes, as they develop at the tip of young leaves and later in more basal regions of the leaf blade. The KOR3::gusA construct is expressed in the trichome support cells that form a ring at the base of each trichome and in the bundle sheath cells which surround the vascular bundle within the leaf mesophyll tissue. Reverse transcription-polymerase chain reaction of Arabidopsis RNA confirmed the expression of KOR2::gusA and KOR3::gusA. In conclusion, although KOR2 and KOR3 have more restricted expression patterns than the previously characterized KOR gene, they are expressed in cell types at time points where cell wall assembly is likely to occur and, interestingly, differentially expressed in leaf trichomes and their support cells.

Arabidopsis↗
PubMed1995

Red/far-red and blue light-responsive regions of maize rbcS-m3 are active in bundle sheath and mesophyll cells, respectively.

Leaves of the C4 plant maize have two major types of photosynthetic cells: a ring of five large bundle sheath cells (BSC) surrounds each vascular bundle and smaller mesophyll cells (MC) lie between the cylinders of bundle sheath cells. The enzyme ribulose bisphosphate carboxylase/oxygenase is encoded by nuclear rbcS and chloroplast rbcL genes. It is not present in MC but is abundant in adjacent BSC of green leaves. As reported previously, the separate regions of rbcS-m3, which are required for stimulating transcription of the gene in BSC and for suppressing expression of reporter genes in MC, were identified by an in situ expression assay; expression was not suppressed in MC until after leaves of dark-grown seedlings had been illuminated for 24 h. Now we have found that transient expression of rbcS-m3 reporter genes is stimulated in BSC via a red/far-red reversible phytochrome photoperception and signal transduction system but that blue light is required for suppressing rbcS-m3 reporter gene expression in MC. Blue light is also required for the suppression system to develop in MC. Thus, the maize gene rbcS-m3 contains certain sequences that are responsive to a phytochrome photoperception and signal transduction system and other regions that respond to a UVA/blue light photoperception and signal transduction system. Various models of "coaction" of plant photoreceptors have been advanced; these observations show the basis for one type of coaction.

Gene Expression Regulation, Plant↗
PubMed1998

[Neurovascular infrahyoidal myofascial flap. Anatomic and topographic study of the innervation and blood supply].

The neurovascular infrahyoidal myofascial flap: An anatomical and topographical study of the innervation and blood supply. 15 cadavers had bilaterally been examined for the topography of the upper thyroid artery and vein and of the lower cervical ansa, as an axial bundle of vessels and nerves for the infrahyoidal myofascial flap. With the injection of methylene blue the vascular territories of the upper thyroid artery had been demonstrated. The upper thyroid artery and vein could be found in all cases. This artery was deriving in 47% from the external carotid artery, in 30% from the bifurcation and in 23% from the common carotid artery. The vein flowed in 43% into the facial vein and in 37% into the internal jugular vein. In the remaining 20% several segmental veins were found, which flowed into the jugular vein separately. In case of a far caudally situated vascular bundle the radius of rotation can be limited in cranial direction. The voluntary innervation of the muscles of this flap is derived from the lower cervical ansa. The upper radix of the ansa can be found 1 cm in latero-cranial direction of the greater horn of the hyoid bone, where it is separating from the hypoglossal nerve. The upper thyroid artery is supplying the infrahyoidal musculature in the whole extension from the hyoid bone to the sternum. Therefore it is possible to develop a myofascial flap of 3.5 cm x 11.5 cm in size, which is pedicled at an upper vascular and nerval bundle. Depending on the radius of rotation defects of the floor of mouth, of the tongue and of the oro- and hypopharynx can well be covered with this new neurovascular myofascial flap.

Arteries↗