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PubMed1995

[Microvascular decompression of the trigeminal nerve: electrophysiological changes].

In a 67-year-old woman with trigeminal neuralgia, pressure on the trigeminal nerve of vascular bundle and arachnoidal adhesions was relieved by microsurgery. Short-latency, brainstem, trigeminal evoked-potentials were continuously recorded throughout the operation. The initial response was characterized by prolonged latency, low amplitude and distorted shape. Immediately after decompression the response attained normal latency, amplitude and shape. Pain disappeared within less than 24 hours. Power spectrum analysis showed wide frequency range in the initial evoked potentials, consistent with desynchronization of the afferent impulses. The range of frequencies was reduced to normal as soon as the trigeminal nerve was decompressed.

Aged↗
PubMed1997

[Long-term results of condylar reconstruction using patella as vascularized graft].

PURPOSE OF THE STUDY: In 1966, R. Merle d'Aubigné published 4 cases of unicondylar destructions (due to trauma or tumor) reconstructed with the patella replacing the joint surface. Since this time the same technique has been used in 6 other cases. The results of these 10 patients are studied. MATERIAL AND METHOD: Six of the examined patients were treated initially for a giant cell tumor, 1 for a low-grade osteosarcoma, and 3 for post traumatic arthritis. The patellar transplant remains vascularized by it's supero-medial vascular bundle. The femoral condyle was affected in 9 cases, the tibial plateau in one. RESULTS: The long term follow-up of these 10 patients revealed unexpected satisfactory results. None of the operated knees was clinically "excellent", due to instability or axial deterioration, but function remained correct, with a good range of motion, active professional possibilities, and, often, regular practice of some sports, like skiing or tracking. Function was not correlated with radiological aspect. The arthritic remodeling of the knee was obvious in all of the cases, and regularly increasing. Five of the 10 knees had to be reoperated (one or several times): 3 during the first months of follow-up (1 for sepsis, 2 for supracondylar fractures), 5 during the first years, to improve function (2 arthrolysis, 2 valgus osteotomies, 1 loose bodies removal). Three patellar plasties had to be converted into a total knee prosthesis, after 8, 27 and 40 years. The follow-up of the 7 patients still walking on their patellar plasty is of 2, 4, 17, 19, 24, 24 and 25 years. DISCUSSION AND CONCLUSION: Condylar reconstruction using a vascularized patellar transplant is mechanically speaking an approximative, obsolete and rather rough procedure. Nowadays one would prefer a knee prosthesis, with or without auto or allografts, preserving the patella. The immediate functional result would certainly be better, but the future remains uncertain. The patellar plasty can delay for 10, 20 years or even more the time of a prosthesis. This technique might also be useful in countries where prosthetic implants are not easily available.

Arthroplasty, Replacement, Knee↗
PubMed2003

Ovules and seeds in Acalyphoideae (Euphorbiaceae): structure and systematic implications.

Acalyphoideae, the largest subfamily of Euphorbiaceae, are investigated with respect to ovule and seed structure on the basis of 172 species of 80 genera in all 20 tribes of Acalyphoideae sensu Webster. All species of Acalyphoideae examined have bitegmic ovules with a non-vascularized inner integument. However, noticeable differences exist among and sometimes within the genera in the thickness of the inner and outer integument, the presence or absence of vascular bundles in the outer integument, whether ovules are pachychalazal or not, the presence or absence of an aril, seed coat structure (in terms of the best-developed mechanical cell-layer), and the shape of cells constituting the exotegmen. For the latter two characters, two different types of seed coat (i.e., "exotegmic" and "exotestal") and three different types of exotegmic cell (i.e., palisadal, tracheoidal and ribbon-like) were distinguished. Comparisons showed that three tribes Clutieae, Chaetocarpeae and Pereae are distinct from the other Acalyphoideae as well as from the other Euphorbiaceae in having an exotestal seed coat with a tracheoidal exotegmen. The tribe Dicoelieae is also distinct from the other Acalyphoideae in having an exotegmic seed that is composed of ribbon-like cells of exotegmen (i.e., cells both longitudinally and radially elongated, sclerotic and pitted). The tribe Galearieae, which should be treated as a distinct family Pandaceae, is also distinct from the other Acalyphoideae in having an exotegmic seed with a tracheoidal exotegmen (i.e., cells longitudinally elongated, sclerotic and pitted). The remaining genera of Acalyphoideae always have an exotegmic seed with a palisadal exotegmen (i.e., cells radially elongated, sclerotic and pitted). The shared palisadal exotegmen supports the close affinity of Acalyphoideae (excluding five tribes) with Crotonoideae and Euphorbioideae. Within the remaining genera of Acalyphoideae, a significant diversity is found in ovule and seed morphology with respect to the thickness of the inner and outer integument, the size of chalaza, vascularization of an outer integument and an aril.

Euphorbiaceae↗
PubMed1998

[Blood supply of wrist and forearm after exclusion of radial vascular fascicle of all length from blood stream].

The arm and forearm are commonly used in plastic and reconstructive surgery as a donor site for harvesting free microsurgical revascularized autografts, which include not only soft tissues, but when necessary, a fragment of radial bone as well. The radial autograft is taken together with radial vascular bundle, the radial artery is so being excluded from participation in hand and forearm blood flow. Until now there are no common opinion of expedient reconstruction of the radial artery because there are no evidence of visible blood flow disturbances in the hand. There are no convincing data on the functional status of the hand in long-term postoperative period and on the ways and degree of compensation of circulation. It is very important that evaluation of the ways and degree of blood flow compensation may play a great part in the problem of hand replantation, that is to determine the influence of the extent of blood flow restoration not only on hand viability, but on the long-term functional outcome as well. This investigation has revealed impaired blood supply and metabolism in hand soft tissues and bones by using the forearm as a donor site for taking free microsurgical revascularized autografts by radionuclide and ultrasound methods.

Blood Flow Velocity↗
PubMed1994

Transport of sodium and urea in outer medullary descending vasa recta.

We dissected and perfused outer medullary vasa recta (OMVR) from vascular bundles in the rat. Permeabilities of sodium (PNa) and urea (Pu) were simultaneously determined from the lumen-to-bath efflux of 22Na and [14C]urea. PNa and Pu were also measured by in vivo microperfusion of descending (DVR) and ascending vasa recta (AVR) at the papillary tip of Munich-Wistar rats. In some OMVR PNa was indistinguishable from zero. The mean +/- SE of PNa (x 10(-5), cm/s) in OMVR was 76 +/- 9. Pu in OMVR was always very high (x 10(-5), cm/s), 360 +/- 14. There was no correlation between OMVR PNa and Pu. Inner medullary AVR and DVR had PNa of 115 +/- 10 and 75 +/- 10, respectively, and Pu of 121 +/- 10 and 76 +/- 11, respectively. PNa and Pu in papillary vasa recta were always nearly identical and highly correlated. Transport of [14C] urea in OMVR was reversibly inhibited by addition of unlabeled urea or phloretin to the bath and lumen, providing evidence for carrier-mediated transport. These data suggest that sodium and urea might traverse the wall of inner medullary vasa recta by a paracellular pathway while urea also crosses by a transcellular route in OMVR. Electron microscopic examination of seven in vitro perfused OMVR revealed no fenestrations and exposure of these vessels to 10 microM calcium ionophore A23187 or 1 nM angiotensin II resulted in reversible contraction, suggesting that in vitro perfused OMVR are DVR only.

Angiotensin II↗
PubMed2002

Tubulovascular nitric oxide crosstalk: buffering of angiotensin II-induced medullary vasoconstriction.

Studies were designed to determine the source of NO responsible for buffering of the angiotensin II (Ang II)-mediated decrease of blood flow in the renal medulla. Intracellular Ca2+ concentration ([Ca2+]i) and NO production ([NO]i) of pericytes and endothelium of the vasa recta were independently measured with the use of fura 2-AM and 4,5-diaminofluorescein diacetate (DAF-2DA), respectively, in microtissue strips of the vascular bundles of the outer medullary vasa recta. Disruption of the endothelium of the vasa recta by perfusion with latex microspheres enabled imaging of the pericytes. Ang II (1 micromol/L) produced an increase of [NO]i of 19+/-6 U in pericytes of the vasa recta when the vessels were adjacent to medullary thick ascending limbs (mTALs). Pericytes of isolated vasa recta without surrounding mTALs showed a rapid peak increase in [Ca2+]i of 248+/-107 nmol/L, with a sustained elevation of 107+/-75 nmol/L, but did not show an increase in [NO]i to either Ang II (1 micromol/L) or the Ca2+ ionophore 4-bromo-A23187 (5 micromol/L). These observations indicated the lack of Ang II and Ca2+-sensitive NO production in pericytes of the vasa recta. In isolated vasa recta with intact endothelium, Ang II reduced [Ca2+]i from 128+/-28 to 62+/-13 nmol/L and failed to increase [NO]i. However, the Ca2+ ionophore did increase [NO]i in the endothelium (47+/-8 U), indicating the presence of Ca2+-sensitive NO production. Significant increases of [NO]i were observed in single isolated mTALs in response to both Ang II (33+/-6 U) and the Ca2+ ionophore (51+/-18 U). We conclude that Ang II increases [Ca2+]i in pericytes of the descending vasa recta as part of its constrictor action and that this vasoconstriction is buffered by the NO from the surrounding tubular elements, such as mTALs.

Angiotensin II↗
PubMed1981

The ultrastructure of the thin limbs of Henle in Kidneys of the desert heteromyid (Perognathus penicillatus).

The thin limbs of both long- and short-looped nephrons in Perognathus kidneys were studied with transmission and scanning electron microscopy. The superficial nephrons have a short thin limb located in the vascular bundles of the outer medulla and are characterized by a simple, low-lying epithelium (0.4 +/- 0.1 mu thickness). In contrast, the first descending part of the thin limb of the majority of midcortical and juxtamedullary nephrons has a relatively thick epithelium (1.7 +/- 0.6 mu in thickness) with marked lateral and basal interdigitation and a dense surface covering of microvilli. The remaining part of the long descending thin limb is relatively simple with a low-lying epithelium (0.6 +/- 0.1 mu in thickness), decorated on its surface by sparse microplicae. The bend of the loop and the ascending limb are covered by a very simple low-lying epithelium (0.6 +/- 0.2 mu in thickness) with relatively little surface modification. The extreme urine-concentrating ability of Perognathus does not appear to be due to the development of a unique thin loop epithelium but rather to the extensive length of the inner and outer medulla.

Animals↗
PubMed1989

Renal anatomy of the manatee, Trichechus manatus, Linnaeus.

The manatee kidney is composed of several closely apposed lobes. These are formed by cortical folds (plicae corticales) that completely isolate the medullae, except where the medullae of adjacent lobes are partially fused. The cortex is continuous; its folds usually are separated, but only partially, by interlobar septa extending from the renal capsule. The cortex makes up approximately 57% of renal mass in adults and 68% in the calf. There are about 3 million glomeruli per kidney. The average is somewhat less than that expected of an adult eutherian of equal mass. The glomeruli, however, are large; they form 7.38% +/- 1.33 of cortical mass, which is above that for at least ten unrelated adult eutherians. The number of glomeruli per gram of cortex is considerably greater in the calf than in the adult. The medullae are about 43% of renal mass. The cortico-medullary thickness ratio is 0.08 to 0.24. All terminal collecting ducts open at a crater (cratera cribrosa) of varying depth. Hair-pin loops occur at all levels of medulla, and apparently all loops bend at their thick segment. Cortical loops occur in the medullary rays. Vascular bundles were evident at the cortico-medullary border and thin tubules extended into the medulla from the central ends of the medullary rays (cortical) in seven out of the nine kidneys. The renal pelvis is separated from the central ends of the cortical folds by delicate fascia through which pass the interlobar vessels. There are no fornices and no infundibula. The collagenous tissue of the pelvic wall extends across most of the pelvic surface of the outer medulla.

Animals↗
PubMed1984

Blood supply and drainage of the outer medulla of the rat kidney: scanning electron microscopy of microvascular casts.

Blood supply and drainage of the outer medulla of the rat kidney were studied by scanning electron microscopy of vascular casts, using both arterial (n = 10) and venous (n = 10) injections of resin. Both outer and inner stripes of the outer medulla were supplied through different arterial capillary networks arising from efferent arterioles and arterial (descending) vasa recta. In contrast to previous studies using silicone rubber and light microscopy, a rich arterial capillary network supplying the outer stripe was demonstrated. Capillaries in the outer stripe and outer part of the inner stripe drained into venous vasa recta between vascular bundles, while capillaries in the inner part of the inner stripe drained into venous vasa recta within the bundles. The results indicate that each zone in the outer medulla is supplied through separate capillary networks. The demonstration of a rich capillary network in the outer stripe of the outer medulla suggests that the predilection of this zone for tubular necrosis with ischemic or toxic injury is not related to a sparse capillary blood supply.

Animals↗
PubMed2004

Anatomy and function of sensory hepatic nerves.

Vagal and spinal afferent innervation of the portal hepatic area has not been studied as thoroughly as the innervation of other important organs. It is generally agreed that unlike noradrenergic sympathetic efferent nerve fibers, sensory nerve fibers of either vagal or dorsal root/spinal origin do not directly innervate hepatocytes, but are restricted to the stroma surrounding triades of hepatic vasculature and bile ducts, and to extrahepatic portions of the portal vein and bile ducts. For vagal afferent innervation, retrograde and anterograde tracing studies in the rat have clearly shown that only a minor portion of the common hepatic branch innervates the liver area, while the major portion descends in the gastroduodenal branch toward duodenum, pancreas, and pylorus. Hepatic paraganglia, bile ducts, and portal vein receive the densest vagal afferent innervation. Calretinin may be a relatively specific marker for vagal afferent innervation of the portal-hepatic space. Calcitonin gene-related peptide (CGRP) is a specific marker for dorsal root afferents, and CGRP-immunoreactive fibers are mainly present near the intrahepatic vascular bundles and bile ducts, and in the same extrahepatic compartments that contain vagal afferents. Because of the specific anatomical organization of hepatic nerves, selective hepatic denervation, whether selective for the vagal or sympathetic division, or for efferents and afferents, is nearly impossible. Great caution is therefore necessary when interpreting functional outcomes of so-called specific hepatic denervation studies.

Animals↗
PubMed2005

Evaluation of two-dimensional electrophoresis and liquid chromatography--tandem mass spectrometry for tissue-specific protein profiling of laser-microdissected plant samples.

Laser microdissection (LM) allows the collection of homogeneous tissue- and cell-specific plant samples. The employment of this technique with subsequent protein analysis has thus far not been reported for plant tissues, probably due to the difficulties associated with defining a reasonable cellular morphology and, in parallel, allowing efficient protein extraction from tissue samples. The relatively large sample amount needed for successful proteome analysis is an additional issue that complicates protein profiling on a tissue- or even cell-specific level. In contrast to transcript profiling that can be performed from very small sample amounts due to efficient amplification strategies, there is as yet no amplification procedure for proteins available. In the current study, we compared different tissue preparation techniques prior to LM/laser pressure catapulting (LMPC) with respect to their suitability for protein retrieval. Cryo-sectioning was identified as the best compromise between tissue morphology and effective protein extraction. After collection of vascular bundles from Arabidopsis thaliana stem tissue by LMPC, proteins were extracted and subjected to protein analysis, either by classical two-dimensional gel electrophoresis (2-DE), or by high-efficiency liquid chromatography (LC) in conjunction with tandem mass spectrometry (MS/MS). Our results demonstrate that both methods can be used with LMPC collected plant material. But because of the significantly lower sample amount required for LC-MS/MS than for 2-DE, the combination of LMPC and LC-MS/MS has a higher potential to promote comprehensive proteome analysis of specific plant tissues.

Arabidopsis↗
PubMed1990

The early nodulin transcript ENOD2 is located in the nodule parenchyma (inner cortex) of pea and soybean root nodules.

A pea cDNA clone homologous to the soybean early nodulin clone pGmENOD2 that most probably encodes a cell wall protein was isolated. The derived amino acid sequence of the pea ENOD2 protein shows that it contains the same repeating pentapeptides, ProProHisGluLys and ProProGluTyrGln, as the soybean ENOD2 protein. By in situ hybridization the expression of the ENOD2 gene was shown to occur only in the inner cortex of the indeterminate pea nodule. The transcription of the pea ENOD2 gene starts when the inner cortical cells develop from the nodule meristem. In the determinate soybean nodule the ENOD2 gene is expressed in the inner cortex as well as in cells surrounding the vascular bundle that connects the nodule with the root central cylinder. The term 'nodule inner cortex' is misleading, as there is no direct homology with the root inner cortex. Therefore, we propose to consider this tissue as nodule parenchyma. A possible role of ENOD2 in a major function of the nodule parenchyma, namely creating an oxygen barrier for the central tissue with the Rhizobium containing cells, is discussed.

Amino Acid Sequence↗
PubMed2000

Characterization of two novel defense peptides from pea (Pisum sativum) seeds.

A fraction that possesses antifungal activity against Aspergillus niger has been isolated from seeds of the pea (Pisum sativum) by ammonium sulfate fractionation followed by gel filtration on Sephadex G-75. On further purification by reverse-phase high performance liquid chromatography, two small cysteine-rich polypeptides were obtained (Psd1 and Psd2). They are localized primarily in vascular bundles and epidermis tissues of pea pods and exhibit high antifungal activity toward several fungi, displaying IC(50) values ranging from 0.04 to 22 microg/ml. This inhibitory activity decreases when A. niger growth medium is supplemented with cations such as Ca(2+), Mg(2+), Na(+), and K(+). Although the primary sequence of both Psd1 and Psd2 shows homology with other plant defensins, they cannot easily be assigned to any established group.

Amino Acid Sequence↗
PubMed2001

Microscopic imaging of slow flow and diffusion: a pulsed field gradient stimulated echo sequence combined with turbo spin echo imaging.

In this paper we present a pulse sequence that combines a displacement-encoded stimulated echo with rapid sampling of k-space by means of turbo spin echo imaging. The stimulated echo enables the use of long observation times between the two pulsed field gradients that sample q-space completely. Propagators, constructed with long observation times, could discriminate slowly flowing protons from diffusing protons, as shown in a phantom in which a plug flow with linear velocity of 50microm/s could clearly be distinguished from stationary water. As a biological application the apparent diffusion constant in longitudinal direction of a transverse image of a maize plant stem had been measured as a function of observation time. Increasing contrast in the apparent diffusion constant image with increasing observation times were caused by differences in plant tissue: although the plant stem did not take up any water, the vascular bundles, concentrated in the outer ring of the stem, could still be discerned because of their longer unrestricted diffusional pathways for water in the longitudinal direction compared to cells in the parenchymal tissue. In the xylem region of a tomato pedicel flowing water could be distinguished from a large amount of stationary water. Linear flow velocities up to 0.67 mm/s were measured with an observation time of 180 ms.

Algorithms↗
PubMed2002

Developmental genetics and evolution of symbiotic structures in nitrogen-fixing nodules and arbuscular mycorrhiza.

Genetic and molecular mechanisms of development are compared for two major plant-microbe endosymbioses: N(2)-fixing nodules (with rhizobia or actinomycetes Frankia) and arbuscular mycorrhiza (with Glomales fungi). Development from the primordia formed de novo in root tissues is common for all known types of N(2)-fixing nodules. However, their structure varies greatly with respect to: (i) tissue topology (location of vascular bundles is peripherical in legumes or central in non-legumes); (ii) position of nodule primordium (inner or outer cortex in legumes, pericycle in non-legumes); (iii) stability of apical meristem (persistent in the indeterminate nodules, transient in the determinate ones). In addition, legumes vary in ability to form compartments harboring endosymbiotic rhizobia and located intercellularly (infection threads) and intracellularly (symbiosomes). Using pea (Pisum sativum) symbiotic mutants, the nodule developmental program is dissected into a range of spatially and temporarily differentiated steps comprising four sub-programs (development of endosymbiotic compartments; nodule histogenesis; autoregulation of nodulation; bacteroid differentiation). The developmental mutations are suggested in some cases to reverse the endosymbiotic system into the morphologically simpler forms some of which may correspond to the ancestral stages of nodule evolution. The origin of legume-rhizobial and actinorhizal symbioses is suggested to be based on a set of preadaptations many of which had been evolved in angiosperms during coevolution with arbuscular mycorrhizal fungi (e.g., inter- and intracellular maintenance of symbionts, their control via defence-like reactions and recognition of chitin-like molecules). An analysis of parallel morphological variation in symbiotic mutants and wild-growing legume species enables us to reconstruct the major stages of evolution for N(2)-fixing symbioses.

Actinomycetales↗
PubMed1991

Transgenic rice cell lines and plants: expression of transferred chimeric genes.

Cell suspension-derived rice (Oryza sativa L.) protoplasts were transformed by direct gene uptake. PEG-mediated transformation was more efficient than electroporation. Plasmid DNA containing a hygromycin phosphotransferase (HPT) gene (which confers hygromycin resistance) driven by the CaMV 35S promoter and a beta-D-glucuronidase (GUS) gene under control of the 1', 2' double promoter of the mannopine synthase (mas) locus of Agrobacterium tumefaciens was introduced into rice protoplasts. Southern analysis of DNA from transformed cell lines showed that the HPT and GUS genes were present intact. Both genes were expressed in transgenic cell suspensions. GUS activity was detected by histochemical staining of the cells and by enzyme assays. During a 12-day culture period the proportion of stained cells rose to a maximum and then decreased again. Considerably higher numbers of blue-stained cells were obtained when the transgenic cell lines were grown in the presence of 5-azacytidine. Transcripts of the GUS gene could not be detected, in contrast with the HPT gene. Plantlets were regenerated from one transgenic cell line. GUS activity was found in both leaf and root tissues of these plants, particularly, but not exclusively, in vascular bundles. A mouse dihydrofolate reductase coding sequence (DHFR), conferring methotrexate resistance, fused to the CaMV 35S promotor and the wild-type nopaline synthase (NOS) gene of A. tumefaciens were also introduced into rice protoplasts. Stable integration of both genes was confirmed by Southern analysis. Expression of the DHFR gene was demonstrated by high levels of resistance to methotrexate of the transgenic cell suspensions and by the presence of DHFR transcripts. Expression of the NOS gene at enzyme or RNA level was not detected. Southern analysis suggests that this gene was probably either methylated or scrambled in these lines.

Amino Acid Oxidoreductases↗
PubMed1995

Expression patterns of three genes in the stem of lucerne (Medicago sativa).

We have identified three stem abundantly expressed genes in lucerne (alfalfa, Medicago sativa). A cDNA library, constructed from lucerne stem polyadenylated RNA, was screened by differential hybridization. From this screening, cDNA clones that correspond to genes which are preferentially, or specifically, expressed in the stem were isolated. MsaS1 encodes an unidentified protein, MsaS2 encodes an S-adenosyl-homocysteine hydrolase and MsaS3 encodes an extensin-like protein. Northern blot analysis of RNA isolated from individual stem internodes indicated that the three corresponding genes show differing developmental patterns of expression. The expression of MsaS1 was confined to the youngest stem tissue and may be regulated by sucrose. In stem tissue the level of RNA for the three genes decreased in response to wounding. Tissue print hybridization analysis was used to localize the expression of the genes to the xylem side of vascular bundles in lucerne stems.

Adenosylhomocysteinase↗