scholarly journals The Transverse Veins of the Wheat Leaf

1972 ◽  
Vol 25 (4) ◽  
pp. 721 ◽  
Author(s):  
J Kuo ◽  
TP O'brien ◽  
S-Y Zee
Keyword(s):  
Vessel Wall ◽  
Sieve Tube ◽  
Triticum Aestivum L ◽  
Wall Thickening ◽  
Tracheary Elements ◽  
Mestome Sheath ◽  
Vascular Elements ◽  
Parenchyma Cells ◽  
Wheat Leaf ◽  
Vascular Parenchyma

The histology and fine structure of the transverse veins that connect the longitudinal veins in the leaf of wheat (Triticum aestivum L. cv. Heron) are illustrated and discussed. The transverse veins consist of a single sieve tube and vessel, and two files of vascular parenchyma cells. They lack the mestome sheath and parenchyma sheath that is present around longitudinal veins except where they make connection with longitudinal veins. The vascular elements of the transverse veins are connected to metaxylem and metaphloem of the longitudinal veins and these connections are illustrated in sections. The tracheary elements have an unusual pattern of wall thickening. Experiments with ferric chloride solutions reveal that the vessel wall may severely restrict passage of solutes from the transpiration stream to the free space of the mesophyll.

Leaf structure of Cananga odorata (Annonaceae) in relation to the collection of photosynthate and phloem loading: morphology and anatomy

1990 ◽  
Vol 68 (2) ◽  
pp. 354-363 ◽  
Author(s):  
David G. Fisher
Keyword(s):  
Sieve Tube ◽  
Type I ◽  
Type Ii ◽  
Tracheary Elements ◽  
Minor Vein ◽  
Type Iv ◽  
Parenchyma Cells ◽  
Vascular Parenchyma ◽  
Sieve Tubes ◽  
Cananga Odorata

Four distinct anatomical types of minor veins occur in Cananga odorata leaves. In order of decreasing size, they are (i) type I, with tracheary elements, fibers, vascular parenchyma cells, companion cells, and mostly nacreous-walled sieve-tube members; (ii) type II, with the same cell types except that the sieve-tube members have walls that usually lack nacreous thickenings; (iii) type III, with only vascular parenchyma cells and tracheids; and (iv) type IV (vein endings), with tracheary elements only. The proportions of the total minor vein length occupied by each are type I, 15.1%; type II, 27.2%; type III, 24.4%; and type IV, 33.3%. Thus about 60% of the minor vein network lacks sieve tubes. The average interveinal distance for all minor veins is 121 μm, but the average for veins containing sieve-tubes is 329 μm. Other salient features include vascular parenchyma cells up to 130 μm long, bundle-sheath cells whose lateral protuberances into the mesophyll increase extensively with decreasing vein size, and five layers of horizontally oriented spongy parenchyma cells. These features may facilitate transport of assimilate to the relatively small proportion of the minor vein network that contains sieve tubes.

Vascular System of the Stem of the Wheat Plant .II. Development

1972 ◽  
Vol 20 (1) ◽  
pp. 65 ◽  
Author(s):  
JW Patrick
Keyword(s):  
Vascular System ◽  
Wheat Plant ◽  
Sieve Tube ◽  
Triticum Aestivum L ◽  
Leaf Primordia ◽  
Vascular Differentiation ◽  
Vascular Elements ◽  
A Site ◽  
Further Development ◽  
Main Tiller

The sequence of vascular differentiation in the shoot of the main tiller of Triticum aestivum L. was reconstructed from seriai transverse sections of shoot apices made at various stages of development. The pattern of initiation and development of the pro- cambial strands was confirmed. The provascular bundles of the pith plexus arose independently and developed acropetally from the base of the future node. Early dif- ferentiation of proto-phloem and -xylem in the main procambial strands proceeded bidirectionally up the leaf primordia and down the stem from a site of initiation isolated from other differentiated vascular elements. Further development was basipetal from the tip of the primordia, and the rate of differentiation of the sieve elements was sufficient to maintain phloem continuity across the intercalary meristems of the laminae, sheaths, and internodes. Within the developing nodes sieve tube differentiation in the cross-linking strands lagged behind that of the leaf traces they interconnected, and this may influence the movement of photoassimilate from a recently expanded leaf to the apex.

scholarly journals Pathological anatomy of the upper taproot and stems of alfalfa afflicted with crown rot induced by Phoma medicaginis Malbr. Roum. var. medicaginis Boerema

1969 ◽  
Vol 89 (3-4) ◽  
pp. 243-250
Author(s):  
Rocío del P. Rodríguez
Keyword(s):  
Secondary Xylem ◽  
Crown Rot ◽  
Common Symptom ◽  
Tracheary Elements ◽  
Woody Tissue ◽  
Vascular Elements ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Different Types ◽  
Internal Necrosis

Internal necrosis in the upper taproot and in the stems is a common symptom associated with Phoma crown rot of alfalfa. Necrotic tissues were examined by using histological and histochemical techniques in permanent and semi-permanent preparations. Necrosis occurred in the woody tissue only, affecting the vascular elements, fibers, and ray parenchyma. In the upper taproot, tissues at the center of the stele were completely degraded with hyperplasia occurring in some parenchyma cells. Occlusion with wound gums and pectin occurred in elements of the secondary xylem. Wound periderm surrounded the infected areas, limiting radial but not longitudinal colonization by the pathogen. In the stems, different types of occlusions were observed, likely of composition similar to that found in the upper taproot. Hyphae were observed within tracheary elements. 

Abstract WMP55: Vessel Wall Characteristics using High Resolution Magnetic Resonance Imaging in Reversible Cerebral Vasoconstriction Syndrome and Central Nervous System Vasculitis

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Russell Cerejo ◽  
Seby John ◽  
Tariq Hammad ◽  
Emmanuel C. Obusez ◽  
Rula Hajj-ali ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Central Nervous System ◽  
Vessel Wall ◽  
Clinical Presentation ◽  
Wall Thickening ◽  
Resonance Imaging ◽  
Cns Vasculitis ◽  
Cerebral Vasoconstriction ◽  
Intracranial Vessel ◽  
Vessel Stenosis

Introduction: Reversible cerebral vasoconstriction syndrome (RCVS) and central nervous system (CNS) vasculitis often have similar initial clinical presentation, laboratory findings and imaging features creating a diagnostic dilemma. High-resolution-3-Tesla Magnetic Resonance Imaging with Gadolinium contrast (HR-MRI) is a non-invasive method to look at intracranial vessel wall characteristics. Methods: A retrospective analysis of all patients with a diagnosis of RCVS or CNS vasculitis that underwent HR-MRI at our institution was performed. Inclusion criteria for RCVS were clinical presentation, no aneurysmal subarachnoid hemorrhage, normal cerebrospinal fluid and reversible multifocal intracranial vessel stenosis whereas criteria for CNS vasculitis were cases with positive brain biopsy or typical clinical presentation, course and laboratory markers with rheumatology and stroke neurology agreement in diagnosis. Demographics, clinical presentation, laboratory testing, imaging studies and outcomes were collected. Results: Eleven patients with RCVS [10 (90.9%) females, mean age 45.2] and 8 with CNS vasculitis [6 primary CNS vasculitis, 6 (75%) males, mean age 43.5] were included in the study. No abnormal vessel wall enhancement or thickening was seen in any of the RCVS patients in areas of vessel stenosis. Six (75%) of CNS vasculitis patients had vessel wall thickening or enhancement (p=0.001 for comparison to RCVS) and the remaining 2 patients had HR-MRI performed 6 and 10 years after diagnosis and chronic treatment. All RCVS patients who had follow up HR-MRI demonstrated resolution of the multifocal stenosis. Two out of 4 CNS vasculitis patients with subsequent HR-MRI imaging had decrease in vessel wall thickening and enhancement after immunosuppressive therapy. Conclusion: In acute stages of presentation, HR-MRI may be useful in differentiating RCVS from CNS vasculitis. It may also be useful in following the disease course to look for resolution of intracranial vessel stenosis in RCVS or treatment response in vasculitis. Further studies are needed to confirm the utility of HR-MRI in diagnosis and disease progression in RCVS and vasculitis.

scholarly journals Analysis of placental pathology and fetal outcome

2018 ◽  
Vol 7 (4) ◽  
pp. 1322
Author(s):  
Amrutha Ramachandran
Keyword(s):  
Vessel Wall ◽  
Perinatal Death ◽  
Neonatal Morbidity ◽  
Fetal Outcome ◽  
Careful Examination ◽  
Wall Thickening ◽  
P Value ◽  
Placental Pathology ◽  
Exact Test ◽  
Tertiary Teaching

Background: A careful examination of placenta along with microscopic study may frequently point to the cause of perinatal death. The American College of Pathologists has provided guidelines for the examination of placenta. Aim of this study was to illustrate the gross and histopathological changes in placenta in certain normal and abnormal pregnancies and to analyse the relationship of placental pathology with fetal outcome.Methods: A prospective study of 120 deliveries at a tertiary teaching centre in India. Each placenta was studied macroscopically and sent to the pathology department for histological examination.  The study included placentas of normal pregnancies and those with maternal high-risk features. The placenta was fixed in formalin and 6 sections were taken. The paraffin sections were studied for vessel wall thickening, infarction, villitis, chorioangiosis, calcification and intervillous hemorrhage. The primary outcome variables were fetal and neonatal morbidity. Abnormal fetal /neonatal events in each histological group were compared with the normal group using Ψ2 test for homogeneity. For cell frequencies less than 5, Fischer exact test was used.Results: Vessel wall thickening was demonstrated in 54/120 patients (45%). 7 out of 54 (12.96%) fetuses were still born in this group compared to 2/30 (6.67%) with normal histology (p value <0.05). Infarcts were demonstrated in 15/120 (12.5%). The occurrence of abnormal neonatal events in this group was significant p <0.01.Conclusions: Placental histological features of vessel wall thickening, and infarction is associated with abnormal fetal and neonatal outcome. Larger studies are required to establish the inference.

scholarly journals Laser Scanning Confocal Microcopy for Arabidopsis Epidermal, Mesophyll, and Vascular Parenchyma Cells

BIO-PROTOCOL ◽  
2017 ◽  
Vol 7 (5) ◽  
Author(s):  
Christian Elowsky ◽  
Yashitola Wamboldt ◽  
Sally Mackenzie
Keyword(s):  
Laser Scanning ◽  
Parenchyma Cells ◽  
Vascular Parenchyma

scholarly journals Comparison of alternate preparative techniques on wall thickness in coronary artery bypass grafts: the HArVeST randomised controlled trial

2021 ◽  
Author(s):  
Gianni Angelini ◽  
Tom Johnson ◽  
Culliford Lucy ◽  
Gavin Murphy ◽  
Tracy Harris ◽  
...  
Keyword(s):  
High Pressure ◽  
Coronary Artery ◽  
Wall Thickness ◽  
Vessel Wall ◽  
Controlled Trial ◽  
Artery Bypass ◽  
Low Pressure ◽  
Wall Thickening ◽  
Pressure Testing ◽  
Randomised Controlled

Background: The success of coronary artery bypass grafting surgery (CABG) is dependent on long-term graft patency, which is negatively related to early wall thickening. Avoiding high-pressure distension testing for leaks and preserving the surrounding pedicle of fat and adventitia during vein harvesting may reduce wall thickening. Methods: A single-centre, factorial randomised controlled trial was carried out to compare the impact of testing for leaks under high versus low pressure and harvesting the vein with versus without the pedicle in patients undergoing CABG. The primary outcomes were graft wall thickness, as indicator of medial-intimal hyperplasia, and lumen diameter assessed using intravascular ultrasound after 12 months. Results: 96 eligible participants were recruited. With conventional harvest, low-pressure testing tended to yield a thinner vessel wall compared to high-pressure (mean difference MD (low minus high) -0.059mm, 95%CI -0.12, +0.0039, p=0.066). With high pressure testing, veins harvested with the pedicle fat tended to have a thinner vessel wall than those harvested conventionally (MD (pedicle minus conventional) -0.057mm, 95%CI -0.12, +0.0037, p=0.066, test for interaction p=0.07). Lumen diameter was similar across groups (harvest comparison p=0.81; pressure comparison p=0.24). Low pressure testing was associated with fewer hospital admissions in the 12 months following surgery (p=0.0008). Harvesting the vein with the pedicle fat was associated with more complications during the index admission (p=0.0041). Conclusions: Conventional saphenous vein graft preparation with low pressure distension and harvesting the vein with a surrounding pedicle yielded similar graft wall thickness after 12 months, but low pressure was associated with fewer adverse events.

The secondary phloem of Austrobaileya scandens

1970 ◽  
Vol 48 (2) ◽  
pp. 341-359 ◽  
Author(s):  
Lalit M. Srivastava
Keyword(s):  
Tannic Acid ◽  
Cross Sections ◽  
Significant Proportion ◽  
Sieve Tube ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Sieve Cells ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Definition Of

The origin of sieve elements and parenchyma cells in the secondary phloem of Austrobaileya was studied by use of serial cross sections stained with tannic acid – ferric chloride and lacmoid. In three important respects, Austrobaileya phloem recalls gymnospermous features: it has sieve cells rather than sieve-tube members; a significant proportion of sieve elements and companion cells arise independently of each other; and sieve areas occur between sieve elements and companion cells ontogenetically unrelated to each other. The angiospermous feature includes origin of most sieve elements and parenchyma, including companion cells, after divisions in phloic initials. In these instances companion cells show a closer ontogenetic relationship to sieve elements than do other parenchyma cells. The combination of gymnospermous and angiospermous features makes phloem of Austrobaileya unique when compared to that of all those species that have been investigated in detail. It is further suggested that the term albuminous cells is inappropriate and should be replaced by companion cells but that the ontogenetic relationship implicit in the definition of companion cells is too restrictive and should be abandoned.

Uncovering the ultrastructure of ramiform pits in the parenchyma cells of bamboo [Phyllostachys edulis (Carr.) J. Houz.]

Holzforschung ◽  
2020 ◽  
Vol 74 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Caiping Lian ◽  
Shuqin Zhang ◽  
Xianmiao Liu ◽  
Junji Luo ◽  
Feng Yang ◽  
...  
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Type I ◽  
Aperture Diameter ◽  
Parenchyma Cells ◽  
Vascular Parenchyma ◽  
Function Relationship ◽  
Relationship Of ◽  
Important Evidence

AbstractPits are the main transverse channels of intercellular liquid transport in bamboo. Ramiform pits are a special type of simple pit with two or more branches. However, little is known about the morphology and physiological functions of ramiform pits. The anatomy of plants can provide important evidence for the role of cells. To better understand the ultrastructure and the structure-function relationship of ramiform pits, their characteristics need to be investigated. In this study, both qualitative and quantitative features of ramiform pits were studied using field-emission environmental scanning electron microscopy (FE-ESEM). The samples included the native structures and the replica structures obtained by resin castings. The results show that the ramiform pits have a diverse morphology that can be divided into main categories: type I (the primary branches) and type II (the secondary branches). The distribution of ramiform pits is different in ground parenchyma cells (GPCs) and vascular parenchyma cells (VPCs). The number, the pit aperture diameter and the pit canal length of ramiform pits in the VPCs were, respectively, greater (3-fold), larger (2–3-fold) and shorter (1.3-fold) than those in the GPCs.

Effect of Picloram on Organogenesis in Detached Leaves ofEcheveria elegansBgr.

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 175-182 ◽  
Author(s):  
M. V. S. Raju ◽  
R. Grover
Keyword(s):  
Root Elongation ◽  
Shoot Organogenesis ◽  
Tracheary Elements ◽  
Vascular Differentiation ◽  
Root Primordia ◽  
Low Concentrations ◽  
Parenchyma Cells ◽  
Callus Production ◽  
Detached Leaves ◽  
Apical Organization

The effect of picloram (4-amino-3,5,6-trichloropicolinic acid) on regeneration of detached leaves ofEcheveria elegansBgr. was studied. Picloram stimulated callus production at all concentrations. Low concentrations of 1 to 15 ppmw picloram did not affect shoot organogenesis and the same, however, stimulated rhizogenesis. Inhibition of both root- and shoot-organogenesis was noticeable at concentrations below 20 ppmw and above. Roots increased in number at all picloram concentrations below 40 ppmw, the maximum number being at concentration of 15 to 20 ppmw of the herbicide. Observations indicated that root elongation was considerably suppressed. Picloram-induced callus contained mature parenchyma cells devoid of contents and considerable amount of tissue disruption was noticed. Irregular vascular differentiation and obliteration of tissues particularly in the region of tracheary elements, were obvious. Although normal apical organization was lacking in root primordia and in arrested short roots, these elongated normally into mature roots when they were transferred to water, thus indicating that apical meristems were not severely affected by picloram.

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