Cellulose synthesizing complexes in some giant marine algae

1990 ◽  
Vol 95 (2) ◽  
pp. 309-319
Author(s):  
TAKAO ITOH
Keyword(s):  
Plasma Membrane ◽  
Marine Algae ◽  
Wide Distribution ◽  
Cellulose Microfibrils ◽  
Individual Species ◽  
Random Arrangement ◽  
Cell Wall Development ◽  
The Mean ◽  
Chaetomorpha Aerea ◽  
Dictyosphaeria Cavernosa

The structure of putative cellulose synthesizing complexes (TCs) has been studied in giant marine algae and is discussed in relation to the assembly of cellulose microfibrils. Including previous work, 14 species belonging to nine genera in the Siphonocladales and two species in the Cladophorales are known to have linear TCs on both E- and P-fracture faces of the plasma membrane. Species studied in the present paper included Boodlea composita, Dictyosphaeria cavernosa, Ernodesmis verticillata, Siphonocladus tropicus, Struvea elegans, Valoniopsis pachynema and Chaetomorpha aerea. Contrary to their fairly consistent width (30–36 nm), TCs have a ‘wide distribution of length among individual species and at various stages of development in the same species. Most of the TCs have a random arrangement of subunits, but sometimes they are arranged in three rows. The mean TC length is greater during secondary wall synthesis than in primary ‘wall synthesis in all of the following species: Boodlea composita, Dictyosphaeria cavernosa, Siphonocladus tropicus, Valonia macrophysa, Valonia ventricosa and Chaetomorpha aerea. These results support previous results suggesting that the linear TCs increase their length during cell wall development. The size of TC subunits, ranging from 7.3 to 8.9 nm, was smaller than the structural membrane particles on the plasma membrane in all of the species examined. It is suggested that the spacing between individual glucan chains will be reduced to half after crystallization of cellulose microfibrils, on the basis of evidence that the width of microfibrils is as wide as that of TC. The width of microfibrils ranged from 11.2 to 23.6 nm, while most of the species had microfibrils with a width in the range 14 to 16 nm. The width of microfibrils in Boergesenia was the largest among the giant marine algae. The formation of TCs from subunits, which are transmembrane particles, is characteristic of Siphonocladales in spite of their varying cell morphology.

Desmosomes in hamster cheek pouch epithelium: their quantitative characterization during epithelial differentiation

1984 ◽  
Vol 66 (1) ◽  
pp. 411-429
Author(s):  
F.H. White ◽  
K. Gohari
Keyword(s):  
Plasma Membrane ◽  
Surface Area ◽  
Cheek Pouch ◽  
Unit Surface Area ◽  
Granular Cells ◽  
Hamster Cheek Pouch ◽  
Average Cell ◽  
Membrane Area ◽  
The Mean ◽  
Granular Layers

Desmosomes in stratified squamous epithelia appear to exhibit quantitative alterations during differentiation. In this work we use stereological and other morphometric methods to quantify these structures in epithelial cells from defined basal, spinous and granular strata. Hamster cheek pouch mucosa from five animals was processed for electron microscopy using strictly standardized techniques and a stratified random sampling procedure was used to obtain micrographs of cells from basal, spinous and granular layers. Stereological intersection counting techniques were used to determine for each layer the relative surface area of plasma membrane occupied by desmosomes (Ss), the number of desmosomes per unit surface area of plasma membrane (Ns), the mean individual desmosomal diameter (delta) and the mean individual desmosomal surface area (s). In addition, estimates of nuclear volume were obtained by direct measurement of nuclear profiles and volume-to-surface ratios were obtained by a combination of point and intersection counting, which enabled estimates for the volume (Vcell) and plasma membrane surface area (SPM) of the ‘average’ cell within each stratum to be acquired. Using this information, it was then possible to calculate both the total surface area (S) and the number (N) of desmosomes on the plasma membranes of average cells. The parameters Ss and Ns showed progressive increases between basal and granular layers, whereas values for delta and s were lower in granular cells when compared with basal and spinous cells. The parameters Vcell, SPM, S and N all increased progressively and significantly during differentiation. Between basal and granular layers, the mean cell volume and surface area had each increased approximately threefold, whereas the surface area and number of desmosomes on the average cell plasma membrane had increased approximately seven- and eleven-fold, respectively. Granular cells thus possess more numerous desmosomes, which occupy a greater proportion of the plasma membrane area but which are individually smaller, when compared with basal and spinous layers.

scholarly journals Values of Selected Haematological Indicators in Six Species of Feathered Game

2010 ◽  
Vol 79 (9) ◽  
pp. S3-S8 ◽  
Author(s):  
Eva Straková ◽  
Pavel Suchý ◽  
Romana Kábelová ◽  
František Vitula ◽  
Ivan Herzig
Keyword(s):  
Blood Cell ◽  
Total Concentration ◽  
Haemoglobin Concentration ◽  
Individual Species ◽  
Neutrophil Granulocytes ◽  
Corpuscular Haemoglobin ◽  
Mean Corpuscular Haemoglobin Concentration ◽  
Mean Corpuscular Haemoglobin ◽  
The Mean ◽  
Corpuscular Haemoglobin Concentration

The present paper extends the knowledge of selected blood indicators in six species of feathered game such as helmeted guineafowl (Numida meleagris), common pheasant (Phasianus colchicus), Japanese quail (Coturnix coturnix japonica), chukar (Alectoris chucar), grey partridge (Perdix perdix) and wild turkey (Meleagris gallopavo), reared in the Czech Republic and Europe. The red blood cell (RBC) values in individual species of feathered game ranged as follows: the mean RBC counts varied in a range of 2.10 - 2.58 T/l; haematocrit values were in a range of 0.33 - 0.39 1/1; haemoglobin concentration varied in a range of 101.20 - 129.13 g/l; mean corpuscular haemoglobin concentration (MCHC) ranged from 28.63 to 35.44%; mean corpuscular haemoglobin (MCH) varied in a range of 46.15 - 62.07 pg and the mean corpuscular volume (MCV) was 147.66 - 178.20 fl. Except for the total concentration of haemoglobin and the mean corpuscular haemoglobin concentration, no significant differences were found between the mean values of RBC values in individual species of feathered game. However, some differences between species were found in white blood cell (WBC) values, ranging as follows: the total WBC count ranged from 13.55 to 26.90 G/l, basophil granulocytes from 0.011 to 0.110 G/l, eosinophil granulocytes from 0.011 to 0.593 G/l, neutrophil granulocytes from 1.868 to 6.661 G/l, lymphocytes from 10.937 to 20.922 G/l and monocytes from 0.034 to 0.199 G/l. Most values showed significant (P ⪬ 0.05) to highly significant (P ⪬ 0.01) interspecies differences. The main goal of the study was to investigate selected haematological indicators in six major species of feathered game.

Structure of oak wood from the Swedish warship Vasa revealed by X-ray scattering and microtomography

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Kirsi Svedström ◽  
Ingela Bjurhager ◽  
Aki Kallonen ◽  
Marko Peura ◽  
Ritva Serimaa
Keyword(s):  
Cellular Structure ◽  
Short Range ◽  
Average Length ◽  
Cellulose Microfibrils ◽  
Crystalline Cellulose ◽  
Oak Wood ◽  
X Ray ◽  
X Ray Scattering ◽  
The Mean ◽  
Ray Scattering

Abstract The degradation of oak wood of the historical warship Vasa was studied, focusing on cellular structure by X-ray microtomography (μCT) and on the nanostructure of the cell wall by wide- and small-angle X-ray scattering (WAXS, SAXS). Solid samples [polyethylene glycol (PEG)-, impregnated and PEG-extracted] were submitted to X-ray analysis and the results compared to those of recent oak. The cellular structure of the Vasa oak was surprisingly well preserved at the micrometer level, according to the μCT images. As revealed by WAXS, the fraction of crystalline cellulose was lower in the Vasa samples compared with recent oak, but the average length and width of cellulose crystallites (25±2 nm and 3.0±0.1 nm, respectively), and the mean microfibril angles (4–9°), showed no significant differences. Accordingly, the crystalline parts of cellulose microfibrils are well preserved in the Vasa oak. The SAXS results indicated a declined short-range order between the cellulose microfibrils and a higher porosity of the Vasa oak compared with recent oak, which may be explained by modification of the hemicellulose-lignin matrix.

scholarly journals The spatial distribution of shallow-water (<150 m) black corals (Cnidaria: Antipatharia) in the Hawaiian Archipelago

2015 ◽  
Vol 8 ◽  
Author(s):  
Daniel Wagner
Keyword(s):  
Spatial Distribution ◽  
Coral Species ◽  
Individual Species ◽  
Hawaiian Archipelago ◽  
Black Coral ◽  
Ecological Features ◽  
Black Corals ◽  
Single Category ◽  
The Mean ◽  
Hard Substrates

The Hawaiian Archipelago contains some of the best surveyed black coral populations on the globe; however, most previous surveys have grouped all black coral species into a single category. As a result, the unique ecological features of individual species have not been identified. This study mapped the spatial distribution of eight antipatharian species (Antipathes griggi,Antipathes grandis,Cirrhipathescf.anguina,Stichopathes echinulata,Stichopathes?sp.,Aphanipathes verticillata,Acanthopathes undulataandMyriopathescf.ulex) found in shallow-waters (&lt;150 m) along the Hawaiian Archipelago, and compared data on substrate type, depth and temperature among species. All black coral species were exclusively recorded on hard substrates and were generally widely distributed along the Hawaiian Islands. Additionally, antipatharian species were found at overlapping depths and temperatures, although there were significant differences in the mean depths and temperatures between most species. In cases where species did not have significant differences in mean depths, the overlapping species had different colony and polyp morphologies, which may serve to minimize competition by allowing species to grow most efficiently under particular current regimes. This study represents one of the first to map the spatial distribution of sympatric antipatharian species, and indicates that individual species exploit unique environments in terms of depth and temperature or have unique morphologies to avoid overlap.

scholarly journals Roles of Proliferation and Angiogenesis in Locally Aggressive Biologic Behavior of Ameloblastoma versus Ameloblastic Fibroma

2022 ◽  
Author(s):  
Amr Ibrahim ◽  
Emad Elqalshy ◽  
Ahmed El-Mohamadi ◽  
Kamal Abd El-Rahman ◽  
Magdy Alazzazi
Keyword(s):  
Protein Expression ◽  
Wide Distribution ◽  
Vascular Density ◽  
Image Analyzer ◽  
Tissue Sections ◽  
Formalin Fixed Paraffin ◽  
Ameloblastic Fibroma ◽  
Formalin Fixed Paraffin Embedded ◽  
Embedded Blocks ◽  
The Mean

Background: The present study was carried out to evaluate the roles of proliferation and angiogenesis in locally aggressive biologic behavior of ameloblastoma versus ameloblastic fibroma; Methods: 30 formalin-fixed paraffin embedded blocks (15 cases of ameloblastoma &amp; 15 cases of ameloblastic fibroma) were used. To evaluate the proliferation, the tissue sections were stained with AgNORs stain. CD105 was used as immunohistochemical marker of angiogenesis. Quantitative evaluations of AgNORs were performed. The mean vascular density was evaluated as a measure for CD105 protein expression by using image analyzer computer system; Results: The mean number of AgNORs dots per nucleus was significantly higher in ameloblastoma as compared to ameloblastic fibroma. Also, the protein level of CD105 showed positive expression and wide distribution that the mean vascular density was significantly higher in ameloblastoma as compared to ameloblastic fibroma; Conclusion: Quantitative evaluation of AgNORs stain &amp; the mean vascular density utilizing CD105 protein expression may reflect a higher proliferative activity and a more locally aggressive biologic behavior of ameloblastoma when compared to ameloblastic fibroma, that other factors may be involved in biologic behavior of ameloblastic fibroma.

scholarly journals Initial responsiveness to darbepoetin alfa and its contributing factors in non-dialysis chronic kidney disease patients in Japan

2020 ◽  
Author(s):  
Terumasa Hayashi ◽  
Hideki Kato ◽  
Kenichiro Tanabe ◽  
Masaomi Nangaku ◽  
Hideki Hirakata ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Darbepoetin Alfa ◽  
Iron Supplementation ◽  
Initial Response ◽  
Wide Distribution ◽  
Renal Outcome ◽  
Contributing Factors ◽  
Modifiable Factors ◽  
The Mean

Abstract Background Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with cardiovascular events and poor renal outcome in patients with chronic kidney disease (CKD). This study aimed to investigate the initial responsiveness to darbepoetin alfa (DA) and its contributing factors using the data from the BRIGHTEN. Methods Of 1980 patients enrolled at 168 facilities, 1695 were included in this analysis [285 patients were excluded mainly due to lack of hemoglobin (Hb) values]. The initial ESA response index (iEResI) was defined as a ratio of Hb changes over 12 weeks after DA administration per weight-adjusted total DA dose and contributing factors to iEResI were analyzed. Results The mean age was 70 ± 12 years (male 58.8%; diabetic nephropathy 27.6%). The median creatinine and mean Hb levels at DA initiation were 2.62 mg/dL and 9.8 g/dL, respectively. The most frequent number of DA administration during 12 weeks was 3 times (41.1%), followed by 4 (15.6%) times with a wide distribution of the total DA dose (15–900 μg). Remarkably, 225 patients (13.3%) did not respond to DA. Multivariate analysis showed that male gender, hypoglycemic agent use, iron supplementation, high eGFR, low Hb, low CRP, low NT-proBNP, and low urinary protein–creatinine ratio were independently associated with better initial response to DA (P =  < 0.0001, 0.0108, < 0.0001, 0.0476, < 0.0001, 0.0004, 0.0435, and 0.0009, respectively). Conclusions Non-responder to DA accounted for 13.3% of patients with non-dialysis CKD. Iron supplementation, low CRP, low NT-proBNP, and less proteinuria were predictive and modifiable factors associated with better initial response to DA.

Microtubules and cell wall development in differentiating protophloem sieve elements of Triticum aestivum L

1987 ◽  
Vol 87 (4) ◽  
pp. 595-607
Author(s):  
E. P. ELEFTHERIOU
Keyword(s):  
Cell Wall ◽  
Triticum Aestivum L ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
Wall Thickening ◽  
Sieve Elements ◽  
Material Deposition ◽  
Cellulose Microfibril Orientation ◽  
Cell Wall Development ◽  
Developing Area

The densities of microtubules (MTs) along the lateral walls of developing sieve elements in root protophloem of wheat have been investigated by electron microscopy. They increase gradually in the very young sieve elements to reach a maximum just before the initiation of wall thickening. During wall increment MTs remain at high densities (more than 10 MTs μm−1), but their number declines abruptly when wall material deposition ceases. Cell wall thickening is not uniform: broad ridges alternate with narrow depressions, the latter occupied by plasmodesmata. During wall material deposition MTs overlie the thickenings only, being entirely absent from the non-thickened areas. The orientation of MTs reflects that of the currently deposited cellulose microfibrils in the cell wall, all being perpendicular to the direction of cell expansion. Numerous vesicles, apparently of Golgi apparatus origin, are encountered amongst the cortical arrays of MTs. Though the least spacing between the contiguous MTs is much smaller than the diameter of even the smallest vesicles, the latter were seen amongst the MTs, indicating that MTs do not prevent the vesicles from passing between them towards the developing area. All results favour the suggestion that MTs in sieve elements are involved in cell wall pattern development, cellulose microfibril orientation, and presumably in cell elongation.

Temperature effects on the non-parasitic phase of Amblyomma parvum (Acari: Ixodidae)

2021 ◽  
Author(s):  
João Luiz Horacio Faccini ◽  
Tatiane Kawamura de Almeida ◽  
Isabella Chaves Sousa ◽  
Livio Martins Costa Junior ◽  
Hermes Ribeiro Luz
Keyword(s):  
Abiotic Factors ◽  
Wide Distribution ◽  
Distribution Range ◽  
Egg Mass ◽  
Egg Hatching ◽  
Wide Range ◽  
Amblyomma Parvum ◽  
The Mean ◽  
C 32 ◽  
Parasitic Phase

The tick Amblyomma parvum has a wide distribution in the Central and South America. Therefore, throughout its distribution range, populations of this tick are exposed to different abiotic factors (e.g., Temperature and humidity). Here, we assess the effect of five temperatures, 18°C, 21°C, 24°C, 27°C, 32°C and 80 ± 10% RH on non-parasitic phases of A. parvum under controlled conditions of laboratory. Our results show that temperature affects all parameters of the non-parasitic phases of A. parvum. Mean periods of premolt and molting of immatures, and mean periods of pre-oviposition, oviposition and incubation of females decreases as temperature increases from 18 °C to at 32 °C. Conversely, the molting success of larvae increased from 18 °C to 32 °C but the percentages were statistically non-significant under 21°C, 24°C and 27°C. The molting success of nymphs was higher than 95% under all temperatures. Mean percentages of egg mass and EPE increases as temperature increase from 18 °C to 27°C, then both decrease at 32 °C. The mean percentage of egg hatching was higher than 90% from 21 to 32 °C. The total non-parasitic phase of A. parvum was completed in an average of 223.4, 150.9, 114.7, 90.2 and 69.0 days, respectively, under temperatures of 18°C, 21°C, 24°C, 27°C and 32°C. The effect of five temperatures studied in this experiment suggest that populations of A.parvum can exhibit different biological and ecological behaviors throughout its distribution range, as expected to occur in ticks with wide range distribution.

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