Circular Nucleus Research Articles

Hybrid (femtolaser) phacoemulsification: technical aspects and functional results

This article summarizes scientific and practical results of hybrid femtosecond laser-assisted phacoemulsification (HFE) including study of clinical and technical aspects of the intervention and evaluation of post-surgical functional state of the eye on the basis of clinical, morphological and biomechanical data. The HFE technology should be considered the method of choice for microinvasive phaco surgery, its main advantage being the possibility of controlled handling of such important surgical stages as anterior circular continuous capsulorhexis and nucleus fragmentation on a closed eyeball, which significantly reduces the risk of complications and decreases of effective ultrasound time.

Ultrastructure of the Midgut Adult, Trachyderma philistina (Coleoptera: Tenebrionidae)

In the anterior part of the midgut adult Trachyderma philistina, the apical part showed microvilli in the form of membrane with folds and also microvilli appeared slender and uniform. Between these folds of microvilli appeared a lot of ribosomes and rough endoplasmic reticulum. Secretory vesicles are discharged from part of midgut. A well-developed oval nucleus appeared in the cytoplasm near the apical part of the cell. The nucleus is surrounded by a lot of free ribosomes and rough endoplasmic reticulum. Mitochondria appeared near the apical part of the cell. A well-developed thick basement membrane appeared in the basal part of the anterior midgut of adult beetle Trachyderma philistina. In the middle part of the midgut, a very thick well-developed brush border microvilli appeared. Mitochondria and numerous tracheae appeared through cytoplasm. Rough endoplasmic reticulum appeared throughout the cytoplasm. A lot of secretory vacuoles were observed directed apically. A well-developed oval and circular nucleus appeared near the basal part of the cell and surrounded by numerous rough endoplasmic reticulum A well-developed muscle fiber appeared apically and basally. A very thin basement membrane appeared in the basal part of the cell. The peritrophic membrane is absent in the midgut of adult stage Trachyderma philistine while regenerative cells appeared in the basal part of the middle midgut cell. In the posterior part of the midgut, microvilli appeared in the form of membranes due to the presence of numerous organelles that are discharging into the lumen. Lipid spheres and aggregations of glycogen are present throughout the cell. A thin basement membrane was observed.

The accessory magnocellular neurosecretory system of the rostral human hypothalamus.

The morphology and neurophysin expression of the magnocellular accessory neuroendocrine system located in the rostral human hypothalamus is investigated in a series of brains obtained at autopsy. The hypothalami were fixed in formalin and embedded in paraffin, or after cryoprotection, frozen for cryostat sectioning. Paraffin sections were either stained with Luxol Fast blue or immunoreacted for neurophysin I or neurophysin II, the precursor molecule for oxytocin and vasopressin. Further, 50-μm-thick serial cryostat sections were immunoreacted with the same antibodies. Both the paraventricular and supraoptic nuclei as well as the hypothalamo-hypophysial tracts exhibited strong immunoreactivity for the neurophysin antibodies. In addition, large collections of immunoreactive accessory magnocellular nuclei and single scattered neurophysin-positive neurons were located in the preoptic region between the paraventricular and supraoptic nucleus among the hypothalamo-hypophysial nerve fibers. In addition, smaller collections of neurophysin-immunoreactive neurons were located in the basal part of this region. Among the accessory magnocellular nuclei, the classical circular nucleus was identified. Accessory magnocellular neurons were often located along the blood vessels and projections of some of these neurons penetrated the vascular endothelium. The accessory magnocellular cell bodies expressed either neurophysin I or neurophysin II immunoreactivity. Summarizing, the accessory magnocellular system in the human brain is large and differs in morphology compared to the system seen in other vertebrates. The neurons of this system contain both vasopressin and oxytocin. Some neurons of the accessory neuronal systems might secrete vasopressin or oxytocin directly into the blood stream.

Immunohistochemical profiling of estrogen-related receptor gamma in rat brain and colocalization with estrogen receptor alpha in the preoptic area

Estrogen-related receptor (ERR) is a member of the nuclear receptor superfamily that has strong homology with estrogen receptor (ER) α. Despite the lack of endogenous ligands, ERR serves as transcription factors through their constitutively active structure with or without interaction with ERα. Among the three subtypes of ERR (α, β, and γ), ERRγ is highly expressed in brain, but the distribution of ERRγ is poorly characterized. Therefore, we investigated ERRγ immunoreactivity throughout the rostro-caudal axis in rat brain. Immunohistochemistry revealed localization of ERRγ protein in the cell nucleus, and a ubiquitous distribution of ERRγ in brain regions including the olfactory bulb, cerebrum, brain stem, and cerebellum. Selective intense immunoreactivity was observed in the reticular thalamic nucleus, zona incerta, circular nucleus, interpeduncular nucleus, pontine nucleus, and parasolitary nucleus. Most ERRγ-immunoreactive (ir) regions were also positive for ERα and/or ERβ, which suggests that ERRγ is involved in modulation of estrogen signaling in adult rat brain. Double immunofluorescence demonstrated colocalization of ERRγ with ERα within the anteroventral periventricular nucleus of the preoptic area (AVPV) and medial preoptic nucleus (MPO), which are major target sites for estrogen action. The results of this study suggest that ERRγ function in the brain is affected by estrogens through an interaction with ERα. The findings also provide basic information on brain region-specific ERRγ function.

Gyrator transform of four-petal Gaussian beam and generation of rectangular hollow beam

Four-petal Gaussian beam is a special type of Gaussian beam, and its propagation properties are widely used in micro optics, optical communication and splitting technology. Recently, the generations and the properties of different types of hollow beams have become a hot research topic, such as research on hollow optical vortex beams. The Gyrator transform can be used to fulfill the mode conversion of laser beam. In this paper, based on the Gyrator transform, the analytical expression of four-petal Gaussian beam passing through such a transform system is derived, and the intensity distribution and the corresponding phase distribution associated with the transforming four-petal Gaussian beam are analyzed by numerical simulations. It is found that the four-petal Gaussian beam can be transformed into rectangular hollow beam by Gyrator transform, under the appropriate conditions of the beam order, the beam parameter, the transform angle of Gyrator transform, and the waist width. For the beam order n=m=3, the transform angle of Gyrator transform = 0.4133, the beam parameter K=30, and the waist width = 0.9, the rectangular hollow optical vortex beams can be obtained. Under such conditions, the maximum intensities appear in the four corners, and they are almost uniform on the four sides. The effects of the beam parameters, the transform angle, and the beam order on the distributions of intensity and phase of the rectangular hollow beam are analyzed in detail. The numerical results show that for the beam parameter K10, the rectangular hollow beam always is obtained, and for a lager beam parameter, the intensity distribution of the rectangular hollow beam is more uniform. Different beam order generates different type of hollow beam. For example, for n=m = 2, = 1.2, K = 30, and = 0.5409, a new strange circular hollow beam with solid circular nucleus can be obtained. The transform angle of Gyrator transform has a significant effect on the energy distribution of the hollow beam. When the transform angle changes in a small range, the uniformity of the intensity distribution of the rectangular hollow beam is lost. The bigger the transform angle change, the more serious the loss of uniformity of the hollow beam intensity is. The size of the hollow beam bright ring is determined by the waist width of the four-petal Gaussian beam: the larger the waist width, the smaller the bright ring is. The results further enriches the applications of Gyrator transform system and the four-petal Gaussian beam in the beam shaping.

English

This present work describe the peripheral blood cell morphology from Chelonoids carbonaria . To do this were used ten animal specimens clinically healthy, six female and four male, submitted to peripheral blood collect by jugular vein. Blood was collected to prepare blood smears, without the use of anticoagulants. The slides were stained and analyzed microscopically to describe the cell morphology. The mature erythrocytes had an ellipsoid shape and a grain-free nucleus; immature ones were circular. The leukocytes, granulocytes and agranulocytes were also circular. The heterophils had cytoplasmic granules with various elongated shapes, and the eosinophils had a uniform round shape. The basophils had highly dense basophilic granules, stained in blue; the granules were irregularly arranged and also inside the nucleus. The lymphocytes were circular with a large circular nucleus. The thrombocytes were small, with basophilic staining and a small cytoplasm (the nucleus occupied almost the entire cell). The morphological results found in this study are consistent with cell types of other chelonians.

Perkinsus sp. (Alveolata, Perkinsidae) a Parasite of the Clam Meretrix meretrix (Veneridae) from Arabian Gulf: Ultrastructural Observations of the Trophozoites and the Cellular Response of the Host

Genus Perkinsus Levine, 1978 (Alveolata, Perkinsidae) an intracellular pathogenic parasite is described from the mantle and gill filaments of a commercially important clam, Meretrix meretrix, collected from the Arabian Gulf, Saudi Arabia. This genus contains currently seven named species: P. marinus, P. olseni (P. atlanticus), P. chesapeaki (P. andrewsi), P. mediterraneus, P. honshuensis, P. beihaiensis and P. qugwadi. Meanwhile, some unnamed Perkinsus sp. have been described in wide variety of mollusc species. Ultrastructural features of Perkinsus sp. trophozites and the host reaction are described. The different developmental stages of trophozoites appeared as single or grouped cells surrounded by amorphous material that constituted cysts or nodules randomly distributed throughout the connective tissue of the mantle. The early trophozoites were generally spherical to ellipsoidal with a circular nucleus containing a prominent central nucleolus. The cytoplasm had several small vacuoles which coalesce to form a great vacuole in the later trophozoites and the nucleus becomes eccentric. Some lomosomes were observed between the wall and the plasmalemma of trophozoites. A large number of degraded and pyknotic cell and several cellular structure with lysed aspects were encountered in the surrounding area near the cysts. Ultrastructural data showed that the lysed granular cells and the coalescence of the granules result in the cyst that encapsulates various trophozoites. In the current study, we describe for the first time the presence of Perkinsus sp. as well as the host reaction in clams from the Saudi Arabian coasts.

TRANSPORT EFFICIENCY OF PASSIVE DIFFUSION OF VIRAL CARGOS IN BIOLOGICAL CELLS

Using in silico experiments, we isolate the effects of geometry on the efficiency of passive diffusion transport, PS, of viral cargos to the nuclear region. We model the cell as an elliptical 2D structure (eccentricity e) containing a circular nucleus with radii R (semi-minor) and r, respectively. The cargos move in isotropic random walk inside the cell. PS is estimated as the ratio of the number of cargos that reach the nuclear region and of cargos released. We show that PS decreases with the total distance traveled but increases with r/R. Shifting the nuclear position inside circular cells (e = 0) produce probability distribution functions of total distance traveled that shifts to shorter modes as one side becomes closer to the cell membrane. On the contrary, cargos in more elongated cells (e = 0) have preserved PS-values even for longer distances of travel inside the cell. Finally, an optimum r/R exists due to a trade-off between increased efficiency of transport to the nucleus and high cytoplasmic area. This work could contribute in elucidating the reason why some viruses induce asymmetry in their host cells.

A novel method for procuring a large quantity of mature murine eosinophils in vivo

Eosinophils are rare hematopietic cells that normally constitute only 1 ~ 3% of peripheral blood leukocytes. It would be of help for the purpose of research to obtain a large quantity of eosinophils. In this study, we wanted to develop a novel strategy to induce massive expansion of murine eosinophils in vivo, based on the observation showing that treatment of IL-33 induces eosinophilia in mice. We generated an EL-4 lymphoma cell line (herein named EL-4-IL-33) that was engineered to secrete an active form of IL-33. We found that Siglec-F + granulocyte numbers increased by 1850-fold in the peritoneal cavity 10 days after inoculation with 1 × 10 7 EL-4-IL-33 cells. This number corresponds to 74-fold increase, as compared with the number of Siglec-F + granulocytes in mice that received wild-type EL-4 cells. Siglec-F + granulocytes expanded by IL-33 had the circular nucleus and expressed eosinophil-specific genes. They also showed some functional characteristics of eosinophils in that they had the ability to respond to IL-5 for survival and eotaxin-1 for chemoattaxis and to produce bioactive eosinophil peroxidase, suggesting that these cells are genuine eosinophils. Our results indicate that sustained secretion of IL-33 by lymphoma cells in the peritoneal cavity is highly effective in increasing peritoneal eosinophil numbers. Therefore, our simple method to obtain eosinphils on a large scale might be of value for eosinophil studies.

Histology and ultrastructure of Aedes albopictus larval midgut infected with Bacillus thuringiensis var. israelensis

Histological and ultrastrucutural alterations in the midgut of Aedes albopictus larvae infected with Bacillus thuringiensis var. israelensis (Bti) were observed by light and transmission electron microscopy (TEM). Two formulations of Bti were used: granulated and powder, with 0.2% active ingredient in 90 larvae of Ae. albopictus distributed in three containers containing 30 larvae each (one control group and two test groups). The midgut epithelium of the control group presented flattened and elongated cells with mace-shape with a narrow base. Midgut epithelium cells' surface was convex and had a large circular nucleus located in the median-apical portion of the cell. These cells also presented a basal lamina with a small accumulation of extracellular fibrous matrix, thus characterizing a basal membrane, with a muscle layer and a peritoneal membrane more externally. After Bti ingestion, the larvae stopped/slowed their natural movements down in 5 min. After 30 min approximately, the swimming movements stopped completely. Internally, the intestinal cells showed a disorganization of the basal processes, dilatation and fragmentation of the rough endoplasmic reticulum, with intense cytoplasmic vacuolization. There were concentric dense laminas accumulated in the cytoplasm, and these residual membranous bodies were seen greatly increased in size after 60 min. Mitochondria, fragments of rough endoplasmic reticulum and other remainder organelles were surrounded and segregated from the cytoplasm by exocytosis. This article reports the histopathological alterations in the midgut of Ae. albopictus after infection with Bti and contributes to a better understanding of the mode of action of this bacterial strain used as bioinsecticide against mosquito larvae.

Zolpidem, a selective GABA A receptor α 1 subunit agonist, induces comparable Fos expression in oxytocinergic neurons of the hypothalamic paraventricular and accessory but not supraoptic nuclei in the rat

Functional activation of oxytocinergic (OXY) cells in the hypothalamic paraventricular (PVN), supraoptic (SON), and accessory (ACC) nuclei was investigated in response to acute treatment with Zolpidem (a GABA A receptor agonist with selectivity for α 1 subunits) utilizing dual Fos/OXY immunohistochemistry. Zolpidem was administered intraperitoneally in dose 10 mg/kg of BW and 60 min later the animals were sacrificed by transcardial perfusion with fixative. The Fos/OXY co-labelings were analyzed on 40 μm thick serial coronal sections using computerized light microscopy. Zolpidem elicited a concordant Fos/OXY staining in all four PVN sub-areas investigated, including the anterior (15.71 ± 2.35%), middle (14.52 ± 2.53%), dorsal (13.34 ± 2.61%), and periventricular (18.21 ± 4.75%) ones, however, had no significant stimulatory effect on OXY cells in the SON. In response to Zolpidem, statistically significant activations were also seen in certain groups of accessory structures including the circular nucleus (13.99 ± 3.43%), small clusters of accessory neurons (10.55 ± 1.94%), and the lateral hypothalamic perivascular nucleus (9.42 ± 2.74%). Between the naive and vehicle controls, the dual Fos/OXY labelings did not elicit any significant differences. Our data provide insight into the topographic patterns of brain activity within the clusters of magnocellular OXY cells in the hypothalamus associated with stimulation of GABA A benzodiazepine receptors and for the first time illustrate the triggering contemporaneousness within the cells of the principal and accessory magnocellular nuclei in response to Zolpidem treatment. The present study provides a comparative background that may help in the further understanding of a possible extend of Zolpidem effect on the brain.

A criterion for the formation of stacking faults at incoherent spheroidal precipitates and application to silicon oxide in silicon

The formation of stacking faults (SF) at incoherent precipitates is modelled assuming that the SF formation is triggered by a sudden release of strain accumulated in the precipitate during its thermal history. This strain release occurs by emission of intrinsic point defects and leads to a high local supersaturation of intrinsic point defects that condense into a circular SF nucleus by the Bardeen–Herring mechanism. Expressions are derived allowing to calculate the critical precipitate size leading to SF formation as well as the size of the associated SF nucleus. The theoretical results are illustrated for silicon oxide precipitates in silicon and compared with experimental data. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The phase-field theory applied to CO 2 and CH 4 hydrate

A phase-field theory is applied to model the growth of carbon dioxide hydrate and methane hydrate from a supersaturated solution in water. Temperature- and pressure-dependent thermodynamics for the two systems are accounted for. Simulations of the growth of a planar hydrate film and a circular hydrate nucleus are presented and the interface velocity has been extrapolated from the results to experimental time scales. We discuss how pressure and temperature affects the growth rate and argue that the governing process for the dynamics is the chemical diffusion of the guest molecule in the aqueous solution. We also present results from anisotropic simulations and outline how this will affect the growth.

Phosphatidylinositol‐Specific Phospholipase C (PI‐PLC) Cleavage of GPI‐Anchored Surface Molecules of Trypanosoma cruzi Triggers In Vitro Morphological Reorganization of Trypomastigotes

Trypanosoma cruzi trypomastigotes treated with phosphatidylinositol-specific phospholipase C (PI-PLC) in vitro are rapidly induced to differentiate into round forms. Using confocal microscopy, we were able to show that trypomastigotes treated with PI-PLC initiate the process of flagellum remodeling by 30 sec after contact with the enzyme and amastigote-like forms are detected as early as 10 min after PI-PLC treatment. Scanning and transmission electron microscopy indicate that trypomastigotes undergo a previously undescribed process of flagellum circularization and internalization. Analysis of the flagellar complex with monoclonal antibody 4D9 shows heterogeneous labeling among the parasites, suggesting a remodeling of these molecules. After PI-PLC treatment, parasites rapidly lose the surface marker Ssp-3 and 24 h post-treatment they begin to exhibit a circular nucleus and a rod-shaped kinetoplast. By flow cytometry analysis and confocal microscopy, the Ssp-4 amastigote-specific epitope can be detected on the parasite surface. This indicates that the release of trypomastigote GPI-anchored molecules by exogenous PI-PLC in vitro can trigger morphological changes.

Intracerebroventricular injection of senktide-induced Fos expression in vasopressin-containing hypothalamic neurons in the rat

Intracerebroventricular injection of senktide, a selective agonist for neurokinin B receptor (NK3), induced Fos expression in many neurons of the rat hypothalamus. Fos-positive neurons were predominantly present in the supraoptic and paraventricular hypothalamic nuclei, and some of them were seen in the lateral preoptic area, lateral hypothalamic area, arcuate nucleus, perifornical region, posterior hypothalamic area, circular nucleus, and along relatively large blood vessels (lateral hypothalamic perivascular nucleus) in the anterior hypothalamus. A double labeling study was performed to examine if vasopressin-containing neurons in the hypothalamus could be activated by the treatment. Neurons with both Fos-like immunoreactivity (-LI) and vasopressin-LI were found in the paraventricular nucleus, supraoptic nucleus, circular nucleus and lateral hypothalamic perivascular nucleus. In the supraoptic nucleus, about 87% of vasopressin-containing neurons exhibited Fos-LI, which corresponded to about 64% of Fos-positive neurons in the nucleus. In the paraventricular nucleus, about 80% of vasopressin-like immunoreactive neurons exhibited Fos-LI, which constituted about 51% of the total population of Fos-positive neurons in the region. The results suggest that NK3 receptor may be involved in the modulation of release of vasopressin from the hypothalamus in the rat.

Neurokinin B receptor (NK3)-containing neurons in the paraventricular and supraoptic nuclei of the rat hypothalamus synthesize vasopressin and express Fos following intravenous injection of hypertonic saline

Subnuclear localization of neurokinin B receptor (NK3) in the paraventricular and supraoptic nuclei of the hypothalamus was immunohistochemically investigated in the rat. In the paraventricular hypothalamic nucleus, intense neurokinin B receptor-like immunoreactivity was found in the posterior magnocellular part, moderate to weak neurokinin B receptor-like immunoreactivity was seen in the other parts. In the supraoptic nucleus, intense neurokinin B receptor-like immunoreactivity was distributed in its principal part, and a few neurons with neurokinin B receptor-like immunoreactivity were found in the retrochiasmatic part. Co-localization of neurokinin B receptor-like immunoreactivity with vasopressin-like immunoreactivity was examined through serial adjacent sections. Neurons with both neurokinin B receptor-like immunoreactivity and vasopressin-like immunoreactivity were primarily found in the supraoptic nucleus and posterior magnocellular part of the pavaventricular nucleus. A small number of neurons with neurokinin B receptor-like immunoreactivity and vasopressin-like immunoreactivity were also seen in the circular nucleus and the region surrounding blood vessel in the anterior hypothalamus. Many neurokinin B receptor-containing neurons in the paraventricular and supraoptic nuclei, as well as in circular nucleus and the region surrounding the blood vessel, expressed Fos-like immunoreactivity after intravenous injection of hypertonic saline. The present study demonstrated that a large proportion of neurokinin B receptor-like immunoreactive neurons in the paraventricular hypothalamic and supraoptic nuclei contained vasopressin-like immunoreactivity, and expressed Fos-like immunoreactivity after intravenous administration of hypertonic saline. The results suggest that neurokinin B receptor in the two nuclei may be involved in modulation of the release of vasopressin when the internal environment is disturbed.

Ultrastructural studies on the post‐infection changes inIxora coccineainfected byalternaria alternata

The present study reports the post infection changes caused by Altemaria alternata (Fr) Keisler infection in Ixora coccinea L. var. bandhuca Roxb. The hyphae are intercellular and branched. The hyphal cytoplasm contains mitochondria, with narrow cristae, circular nucleus and ribosomes. Host cytoplasm contains hexagonal crystalline inclusions, mitochondria with sparse cristae and large ellipsoid lipid inclusions in the early infection stages. Mature stages of infection showed disorganization of entire cytoplasm leading to the agglutination of the organelles.

1 Functional cytology of the human testis

The seminiferous tubular compartment of the human testis occupies about two thirds of the volume of the organ and is supported by loose connective tissue containing the Leydig cells. Sertoli cells extend from the basal lamina to the lumen of the seminiferous tubule and provide structural and functional support to the germ cells which proliferate and mature through the complex process of spermatogenesis, lasting for approximately 70 days. Histological examination of the human seminiferous epithelium gives the impression of a very irregular pattern of germ cell development but recent cytological, ultrastructural and computer-modelling studies have shown that the arrangement of germ cells within the seminiferous tubules is in fact highly organized into a helical pattern based upon the geometry of concentric spirals. Thus the human spermatogenic cycle is precisely regulated in accordance with the more familiar ordered arrangements of germ cells seen in most non-human primates and other mammalian species. The population of Leydig cells in the adult human testis represents the third and final phase of their developmental history, preceded by distinct neonatal and, earlier, fetal Leydig cell generations. Human Leydig cells are irregular in outline, deeply staining with basophilic dyes and exhibit a characteristic circular or ovoid nucleus. The density of their cytoplasm is attributed to extensive domains of smooth endoplasmic reticulum, characteristic of steroidogenic tissue. Mitochondria are numerous and lipid droplets and lipfuscin inclusions accumulate with advancing age. Crystals of Reinke up to 30 microns in length are often noted in the Leydig cell cytoplasm although their function remains unknown. The intertubular tissue contains small calibre lymphatic vessels, fibroblasts, collagen, blood vessels and occasional macrophages. With increasing age, declining sperm production and lowered androgen levels are correlated with decreases in the numbers of Sertoli cells and Leydig cells although the mechanisms responsible for this attrition have not been defined. Continued collaboration between morphologists and physiologists is necessary if we are to understand fully the endocrine regulation of spermatogenesis and the factors contributing to disturbances of spermatogenic function.

Continuous circular capsulorhexis and nucleus delivery in planned extracapsular cataract extraction

A technique for nucleus delivery through a continuous circular capsulorhexis in planned extracapsular cataract extraction is presented. The concept of hydro- and viscoexpression of the nucleus is explained, and a strongly bent cannula specially designed for the procedure is introduced.

Statistical analysis of single silver nucleus growth on single crystal silver microelectrodes

The statistical analysis of a distribution of 2 D nucleation sites on single crystal silver microelectrodes has been carried out on a collection of experimental potentiostatic current-time transients of single nucleus growth. The transients were interpreted in terms of a geometric model for the growth of a circular nucleus on a circular electrode. It was found that the geometric model is an adequate one for interpreting the experimental data. The locations of the nucleation sites were determined from the shape of the current-time transients. There is quantitative evidence that about 24% of the total number of nuclei originated on preferred sites or active centres. Some preliminary results from an autocorrelation analysis are also presented.