scholarly journals Seasonal morphological variation of the vas deferens of scorpion mud turtle (Kinosternon scorpioides)

2014 ◽  
Vol 14 (3) ◽  
Author(s):  
Diego Carvalho Viana ◽  
Leandro Almeida Rui ◽  
Amilton Cesar dos Santos ◽  
Maria Angélica Miglino ◽  
Antônio Chaves de Assis Neto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rainy Season ◽  
Vas Deferens ◽  
Microscopic Analysis ◽  
Lipid Vesicles ◽  
Dry Season ◽  
Transmission Electron ◽  
Cellular Debris ◽  
Mud Turtle ◽  
Dry Seasons

This study aimed to characterize the morphology of the vas deferens ofKinosteron scorpioides by macroscopic and microscopic analysis. Were used 20 adult male jurarás collected at regular intervals during the year and divided into four experimental groups in the rainy and dry seasons, being processed for light microscopy, scanning electron microscopy and transmission electron microscopy. Morphometry for tubular and luminal diameters and epithelial height were also performed. On rainy season, vas deferens presented pseudostratified epithelium with cylindrical cells, spermatozoids and milky fluid in the lumen, with cytoplasmic organelles and lipid vesicles. On dry season, epithelium was pseudostratified with cuboid cells, with cellular debris and no spermatozoids. There was significant variation (p<0,05) for morphometry of vas deferens, with lower values of tubular and luminal diameters on rainy season, and higher epithelial height on dry season.

Bridging the Resolution Gap: Correlated 3D Light and Electron Microscopic Analysis of Large Biological Structures

1999 ◽  
Vol 5 (S2) ◽  
pp. 526-527
Author(s):  
Maryann E. Martone
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Surface Area ◽  
Light Microscope ◽  
Microscopic Analysis ◽  
Electron Microscopic Analysis ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Biological Structures ◽  
Ganglion Neurons

One class of biological structures that has always presented special difficulties to scientists interested in quantitative analysis is comprised of extended structures that possess fine structural features. Examples of these structures include neuronal spiny dendrites and organelles such as the Golgi apparatus and endoplasmic reticulum. Such structures may extend 10's or even 100's of microns, a size range best visualized with the light microscope, yet possess fine structural detail on the order of nanometers that require the electron microscope to resolve. Quantitative information, such as surface area, volume and the micro-distribution of cellular constituents, is often required for the development of accurate structural models of cells and organelle systems and for assessing and characterizing changes due to experimental manipulation. Performing estimates of such quantities from light microscopic data can result in gross inaccuracies because the contribution to total morphometries of delicate features such as membrane undulations and excrescences can be quite significant. For example, in a recent study by Shoop et al, electron microscopic analysis of cultured chick ciliary ganglion neurons showed that spiny projections from the plasmalemma that were not well resolved in the light microscope effectively doubled the surface area of these neurons.While the resolution provided by the electron microscope has yet to be matched or replaced by light microscopic methods, one drawback of electron microscopic analysis has always been the relatively small sample size and limited 3D information that can be obtained from samples prepared for conventional transmission electron microscopy. Reconstruction from serial electron micrographs has provided one way to circumvent this latter problem, but remains one of the most technically demanding skills in electron microscopy. Another approach to 3D electron microscopic imaging is high voltage electron microscopy (HVEM). The greater accelerating voltages of HVEM's allows for the use of much thicker specimens than conventional transmission electron microscopes.

scholarly journals The invertebrate colonization during decomposition of Eichhornia azurea kunth in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir (São Paulo, Brazil)

2002 ◽  
Vol 62 (2) ◽  
pp. 293-310 ◽  
Author(s):  
N. de L. STRIPARI ◽  
R. HENRY
Keyword(s):  
Decomposition Rate ◽  
Rainy Season ◽  
Dry Season ◽  
Material Loss ◽  
Litter Bags ◽  
Eichhornia Azurea ◽  
Mouth Zone ◽  
Dry Seasons ◽  
Invertebrate Colonization

The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1st, 3rd, 7th, 14th, 28th, 56th and 72nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60ºC) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW--1) on the remaining detritus of Eichhornia azurea was recorded in the 56th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW--1. In the rainy season, higher density was found in the 28th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW--1. Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7th and 14th days in the rainy and dry seasons, respectively.

Transmission Electron Microscopy of Lipid Vesicles for Drug Delivery: Comparison between Positive and Negative Staining

2010 ◽  
Vol 16 (4) ◽  
pp. 456-461 ◽  
Author(s):  
Valentina Bello ◽  
Giovanni Mattei ◽  
Paolo Mazzoldi ◽  
Nicoletta Vivenza ◽  
Paolo Gasco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Transmission Electron Microscopy ◽  
Iron Oxide ◽  
Osmium Tetroxide ◽  
Lipid Vesicles ◽  
Negative Staining ◽  
Transmission Electron ◽  
Compositional Characterization

AbstractLipid-containing nanostructures, in the form of solid lipid nanoparticles or iron oxide nanoparticles (NPs) coated with a lipid shell, were used as case studies for assessing and optimizing staining for transmission electron microscopy structural and compositional characterization. These systems are of paramount importance as drug delivery systems or as bio-compatible contrast agents. In particular, we have treated the systems with a negative (phospshotungstic acid) or with a positive (osmium tetroxide) staining agent. For iron-oxide NPs coated with the lipid shell, negative staining was more efficient with respect to the positive one. Nevertheless, in particular cases the combination of the two staining procedures provided more complete morphological and compositional characterization of the particles.

scholarly journals Biofilm Formation by Neisseria gonorrhoeae

2005 ◽  
Vol 73 (4) ◽  
pp. 1964-1970 ◽  
Author(s):  
L. L. Greiner ◽  
J. L. Edwards ◽  
J. Shao ◽  
C. Rabinak ◽  
D. Entz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Neisseria Gonorrhoeae ◽  
Continuous Flow ◽  
Microscopic Analysis ◽  
Growth Conditions ◽  
Acetylneuraminic Acid ◽  
Maackia Amurensis ◽  
Transmission Electron ◽  
Epithelial Cell Layer ◽  
Cervical Cells

ABSTRACT Studies were performed in continuous-flow chambers to determine whether Neisseria gonorrhoeae could form a biofilm. Under these growth conditions, N. gonorrhoeae formed a biofilm with or without the addition of 10 μM sodium nitrite to the perfusion medium. Microscopic analysis of a 4-day growth of N. gonorrhoeae strain 1291 revealed evidence of a biofilm with organisms embedded in matrix, which was interlaced with water channels. N. gonorrhoeae strains MS11 and FA1090 were found to also form biofilms under the same growth conditions. Cryofield emission scanning electron microscopy and transmission electron microscopy confirmed that organisms were embedded in a continuous matrix with membranous structures spanning the biofilm. These studies also demonstrated that N. gonorrhoeae has the capability to form a matrix in the presence and absence of CMP-N-acetylneuraminic acid (CMP-Neu5Ac). Studies with monoclonal antibody 6B4 and the lectins soy bean agglutinin and Maackia amurensis indicated that the predominate terminal sugars in the biofilm matrix formed a lactosamine when the biofilm was grown in the absence of CMP-Neu5Ac and sialyllactosamine in the presence of CMP-Neu5Ac. N. gonorrhoeae strain 1291 formed a biofilm on primary urethral epithelial cells and cervical cells in culture without loss of viability of the epithelial cell layer. Our studies demonstrated that N. gonorrhoeae can form biofilms in continuous-flow chambers and on living cells. Studies of these biofilms may have implications for understanding asymptomatic gonococcal infection.

scholarly journals CARMUSTINE LOADED NANOSIZE LIPID VESICLES SHOWED PREFERENTIAL CYTOTOXICITY AND INTERNALIZATION IN U87MG CELL LINE ALONG WITH IMPROVED PHARMACOKINETIC PROFILE IN MICE: A STRATEGY FOR TREATMENT OF GLIOMA

2020 ◽  
pp. 240-248
Author(s):  
BHABANI SANKAR SATAPATHY ◽  
JNANRANJAN PANDA
Keyword(s):  
Electron Microscopy ◽  
Cell Line ◽  
Drug Loading ◽  
Lipid Vesicles ◽  
Pharmacokinetic Profile ◽  
In Vitro Cytotoxicity ◽  
Pharmacokinetic Data ◽  
Transmission Electron

Objective: Successful treatment of glioma still remains a tough challenge. The present study aims at the development and evaluation of carmustine loaded nanosize phospholipid vesicles (CNLVs) for the treatment of glioma. Methods: The experimental NLVs were developed by conventional lipid layer hydration technique and were characterized by different in vitro tools such as diffraction light scattering (DLS), zeta potential, field emission scanning electron microscopy (FESEM), cryo-transmission electron microscopy (cryo-TEM), in vitro drug loading capacity, drug release study etc. In vitro cytotoxicity and cellular uptake of the optimized drug-loaded NLVs were carried out in U87MG human glioblastoma cell line. In vivo pharmacokinetic study was conducted in Swiss albino mice. Results: DLS data showed an average vesicle diameter of 92 nm with narrow size distribution. Optimized CNLVs were spherical in shape with a smooth surface as depicted from FESEM data. Cryo-TEM study confirmed formation of unilamellar vesicles with intact outer bilayer. A reasonable drug loading of 7.8 % was reported for the optimized CNLVs along with a sustained release of CS over a 48 h study period. In vitro cytotoxicity assay revealed a considerable higher toxicity of CNLVs than free drugs in the U87MG cells. Confocal microscopy showed a satisfactory internalization of the optimized drug-loaded NLVs in the tested cell line. Pharmacokinetic data demonstrated an enhanced mean residence time of optimized CNLVs in blood than free drug. Conclusion: Results depicted the potential of experimental CNLVs for the treatment of glioma after further in vivo tests.

A Comparative Study of Pathological Nanomineral Aggregates with Distinct Morphology in Human Aortic Atherosclerotic Plaques

2021 ◽  
Vol 21 (1) ◽  
pp. 547-554
Author(s):  
Yuan Li ◽  
Changqiu Wang ◽  
Anhuai Lu ◽  
Kang Li ◽  
Xiao Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Microscopic Analysis ◽  
Atherosclerotic Plaques ◽  
Carbonate Hydroxyapatite ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Precursor Phase ◽  
Exact Difference

Calcification exists in atherosclerotic plaques in the form of nanomineral aggregates and is closely related to the development of atherosclerosis. Spheroidal and massive calcification are two major types of calcification found in atherosclerotic tissue. However, the exact difference between these two types of calcification is still not clear. Samples composed entirely of spheroidal calcifications and massive calcifications were isolated from aortic atherosclerotic plaques and tested using both bulk and microscopic analysis techniques. Scanning electron microscopy and transmission electron microscopy showed that spheroidal calcifications had a core–shell structure. Massive calcifications were composed of randomly arranged nanocrystals. Synchrotron radiation X-ray diffraction, Raman spectroscopy and selected area electron diffraction showed amorphous calcium phosphate, whitlockite and carbonate hydroxyapatite all existing in spheroidal calcification, while massive calcification only consisted of carbonate hydroxyapatite. We conclude that amorphous calcium phosphate may act as a precursor phase of spheroidal calcifications that eventually transforms into a crystalline phase, while whitlockite in lesions could aggravate the progression of atherosclerosis.

scholarly journals Seasonal morphological variability in an in situ Cyanobacteria monoculture: example from a persistent Cylindrospermopsis bloom in Lake Catemaco, Veracruz, Mexico

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Owen Lind ◽  
Laura Dávalos-Lind ◽  
Carlos López ◽  
Martin López ◽  
Juli Dyble Bressie
Keyword(s):  
Rainy Season ◽  
Morphological Variability ◽  
Morphological Diversity ◽  
Dry Season ◽  
Transient Condition ◽  
Dry Seasons ◽  
Trichome Morphology ◽  
Determining Factor

<p>The phrase <em>cyanobacteria bloom</em> implies a transient condition in which one to few species dominates communities. In this paper we describe a condition in which the <em>bloom</em> is of multi-year duration consisting of different morphologies of a single cyanobacteria species. Lake Catemaco, Veracruz, México maintained a year-round massive (10<sup>8</sup> trichomes L<sup>-1</sup>) population of potentially toxin-producing cyanobacteria, <em>Cylindrospermopsis spp.</em> The trichomes are present as straight and coiled morphotypes.  The relative trichome morphology abundance varied with rainy (June – October) and dry seasons (November – May), but total trichome abundance did not vary.  Coiled trichomes and heterocytes (occurring only on coiled trichomes) were significantly more abundant, both absolutely and relatively, during the dry season. Both coiled trichome and heterocyte mean volumes were significantly smaller during the rainy season than during the dry season.  Biovolumes were largest in January when water temperature was 5º C cooler suggesting buoyancy as a morphology-determining factor. However, with a more than three-fold lower TIN concentration during the dry season, we hypothesized that the coiled morphotype became abundant primarily because it formed heterocytes, which the straight morphotype did not. Spatial trichome and heterocyte abundance differences were small among the 15 lake sites (average CV for all dates = 20%). However, there was a pattern of increased heterocyte and coiled trichome abundance from lake inflow, as a nitrogen source, to outflow during the rainy season. The total volume of heterocytes per litre of lake water increased progressively four-fold from a minimum early in the rainy season to a maximum at the end of the dry season. Morphological diversity, as seen in Lake Catemaco, can partially compensate for the lack of species diversity in determination of community structure.</p>

Filaments of surfactant protein A specifically interact with corrugated surfaces of phospholipid membranes

1999 ◽  
Vol 276 (4) ◽  
pp. L631-L641 ◽  
Author(s):  
Nades Palaniyar ◽  
Ross A. Ridsdale ◽  
Stephen A. Hearn ◽  
Yew Meng Heng ◽  
F. Peter Ottensmeyer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Protein A ◽  
Lipid Vesicles ◽  
Surfactant Protein ◽  
Uranyl Acetate ◽  
Lipid Vesicle ◽  
Transmission Electron

Pulmonary surfactant, a mixture of lipids and surfactant proteins (SPs), plays an important role in respiration and gas exchange. SP-A, the major SP, exists as an octadecamer that can self-associate to form elongated protein filaments in vitro. We have studied here the association of purified bovine SP-A with lipid vesicle bilayers in vitro with negative staining with uranyl acetate and transmission electron microscopy. Native bovine surfactant was also examined by transmission electron microscopy of thinly sectioned embedded material. Lipid vesicles made from dipalmitoylphosphatidylcholine and egg phosphatidylcholine (1:1 wt/wt) generally showed a smooth surface morphology, but some large vesicles showed a corrugated one. On the smooth-surfaced vesicles, SP-As primarily interacted in the form of separate octadecamers or as multidirectional protein networks. On the surfaces of the striated vesicles, SP-As primarily formed regularly spaced unidirectional filaments. The mean spacing between adjacent striations and between adjacent filaments was 49 nm. The striated surfaces were not essential for the formation of filaments but appeared to stabilize them. In native surfactant preparations, SP-A was detected in the dense layers. This latter arrangement of the lipid bilayer-associated SP-As supported the potential relevance of the in vitro structures to the in vivo situation.

scholarly journals Effects of Depth and Seasons on the Physicochemical and Bacteriological Quality of Selected Well Water Samples in Awka Urban, Anambra State, Nigeria

2020 ◽  
pp. 1-28
Author(s):  
M. U. Orji ◽  
S. C. Onuorah ◽  
M. O. Ifemeje ◽  
O. R. Umeh
Keyword(s):  
Water Samples ◽  
Rainy Season ◽  
Salmonella Typhi ◽  
Dry Season ◽  
Well Water ◽  
Frequency Of Occurrence ◽  
Proteus Vulgaris ◽  
Anambra State ◽  
Dry Seasons

Background: The people of Awka urban show an increasing trend of using well water resulting to unreliable and quality-compromised water supply. Aim: Effects of depth and seasons on the physicochemical and bacteriological quality of selected well water samples in Awka urban, Anambra State was conducted to determine their quality and suitability for domestic uses. A total of thirty shallow and deep well water samples were collected during the rainy and dry seasons. Methods: Physicochemical analysis was carried out using standard analytical methods. The total bacterial count was determined by dilution method. Results: Some of the physicochemical parameters (PH, dissolved oxygen, nitrate, cadmium, lead and arsenic) exceeded the World Health Organization maximum containment levels indicating that the samples were unfit for domestic uses. The bacterial counts ranged from 2.66 to 3.26 logcfu/ml during the rainy season and 2.54 to 3.20 logcfu/ml during the dry season. The total coliform counts also exceeded the W.H.O levels. Citrobacter freundii, Shigella flexneri, Serratia marcescens, Proteus vulgaris, Vibrio cholerae, Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Bacillus subtilis were isolated during both seasons and identified using standard analytical procedures. The bacterium that had the highest frequency of occurrence during the rainy season was Citrobacter freundii (16.55%) while Salmonella typhi had the highest frequency of occurrence during the dry season (17.69%) respectively. Proteus vulgaris had the least frequency of occurrence 5.41% and 4.62% during the rainy and dry seasons respectively. The results were analyzed statistically using two-way analysis of variance. Higher bacterial counts were recorded in rainy season and shallow wells than dry season and deeper wells. Conclusion: The presence of these bacteria above admissible limits showed that the water lacked proper water management services and may be harmful to humans. There is therefore a need to monitor the well water quality by employing better sanitary practices and subjecting the waters through various forms of water treatments before use to help prevent disease outbreak.

scholarly journals Pediatric infectious diseases admissions: Sex differences and seasonal variations

2021 ◽  
Vol 015 (02) ◽  
pp. 049-058
Author(s):  
Samuel Olorunyomi Oninla ◽  
Michael Olaniyan Onigbinde ◽  
Akinyemi Olaleye Fadugbagbe ◽  
Emmanuel Olaseinde Bello ◽  
Omolayo Adebukola Olubosede
Keyword(s):  
Sex Differences ◽  
Infectious Diseases ◽  
Seasonal Variations ◽  
Rainy Season ◽  
Malaria Incidence ◽  
Relevant Information ◽  
Dry Season ◽  
Incidence And Mortality ◽  
Significant Difference ◽  
Dry Seasons

Objective: This study set out to assess sex differences and seasonal variations in Pediatric Infectious Diseases (PID) admissions. Methods: One year retrospective study of PID admissions was conducted among children aged one month to 15 years. Relevant information retrieved from patients’ hospital records were dates of admission and discharge, age, sex, final PID diagnoses and outcome. Results: Of 1,035 patients’ records assessed, 603 (58.3%) were males and 432 (41.7%) females (p<0.001). Males in ages 1-12 and 13-59 months contributed largely to the gender difference. Over the 12 months period, PID admissions mean was 86.25±21.92, with rainy and dry seasons means of 92.57±20.7 and 77.4±20.9, respectively (p<0.001). Ages 13-19, 60-119 and ≥120 months had significantly higher admissions mean during the rainy season (p<0.001 in each group), while higher admissions occurred among ages 1-12months in dry season (p<0.001). Top six PID managed were malaria, gastroenteritis, pneumonia, septicemia, meningitis and typhoid, and males had higher incidence in all except for typhoid, with only malaria having significant difference (p<0.001). Malaria, septicemia and typhoid incidence were higher significantly during the rainy season, while gastroenteritis occurred more in the dry season. Overall fatality rate was 4.6%; females and males rates were 6.3% and 3.5%, respectively (p=0.661). Rainy and dry seasons mortality means were 5±1.77 and 2.6±0.8, respectively (p<0.001). Conclusion: Male children were more vulnerable to PID, with significant higher malaria incidence among them than females. PID incidence and mortality were significantly higher during the rainy season than dry. Malaria and gastroenteritis occurred significantly in rainy and dry seasons, respectively.

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