Search results for " shape"
showing 10 items of 298 documents
Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex
2016
This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph) with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively). Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P < 0.001) although with impo…
Sudden sensorineural hearing loss: is there a relationship between routine haematological parameters and audiogram shapes?
2016
Objective: To investigate the relationship between haematological routine parameters and audiogram shapes in patients affected by sudden sensorineural hearing loss (SSNHL). Design: A retrospective study. All patients were divided into four groups according to the audiometric curve and mean values of haematological parameters (haemoglobin, white blood cell, neutrophils and lymphocytes relative count, platelet count, haematocrit, prothrombin time, activated partial thromboplastin time, fibrinogen and neutrophil-to-lymphocite ratio) of each group were statistically compared. The prognostic role of blood profile and coagulation test was also examined. Study sample: A cohort of 183 SSNHL patient…
Foreword to
2016
Early in his investigations, Leeuwenhoek (1670s)1 deduced that spermatozoa were alive and an integral part of semen, rather than artifacts or parasites. He eventually observed spermatozoa in the semen of men, dogs, horses, birds, fishes, amphibians, molluscs, and many insects, and concluded that they must be a universal feature of male reproduction. The huge differences in sperm form among species have been discussed in relation to evolutionary changes dictated by the egg and its investments.2 Spallanzani (1800s)1 was the first scientist to develop successful methods for artificial insemination, first with amphibians and later with dogs. With these experiments, he showed that physical conta…
Sperm kinematic, head morphometric and kinetic-morphometric subpopulations in the blue fox (Alopex lagopus)
2016
This work provides information on the blue fox ejaculated sperm quality needed for seminal dose calculations. Twenty semen samples, obtained by masturbation, were analyzed for kinematic and morphometric parameters by using CASA-Mot and CASA-Morph system and principal component (PC) analysis. For motility, eight kinematic parameters were evaluated, which were reduced to PC1, related to linear variables, and PC2, related to oscillatory movement. The whole population was divided into three independent subpopulations: SP1, fast cells with linear movement; SP2, slow cells and nonoscillatory motility; and SP3, medium speed cells and oscillatory movement. In almost all cases, the subpopulation dis…
Is Autophagy Altered in the Leukocytes of Type 2 Diabetic Patients?
2015
It is unknown whether autophagy is altered in the leukocytes of type 2 diabetes (T2D) patients and whether oxidative and endoplasmic reticulum (ER) stresses regulate this mechanism. We studied anthropometric and metabolic parameters and evaluated oxidative stress, chromatin condensation, ER stress, and autophagy parameters in leukocytes of 103 T2D patients versus 109 sex- and age-matched controls. Patients showed increases in glucose, insulin, homeostasis model assessment of insulin resistance, and glycated hemoglobin (HbA1c) compared with controls (p < 0.001). Leukocytes displayed enhanced total and mitochondrial reactive oxygen species (ROS), reduced mitochondrial mass, and increased chro…
17β-Estradiol Reduces Nitric Oxide Production in the Guinea Pig Cochlea
2013
Intense noise exposure and the application of ototoxic substances result in increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO). In order to reduce the free NO concentration in the inner ear under pathological conditions, the use of natural cytoprotective substances such as 17β-estradiol is a promising therapeutic concept. In male guinea pigs the organ of Corti and the lateral wall were isolated from the cochlea and afterwards incubated for 6 h in cell-culture medium. 17β-Estradiol was adjusted in 2 concentrations to organ cultures of the right ears (12 animals per concentration). The left ears were used as controls. The NO produc…
Puma (Puma concolor) epididymal sperm morphometry
2016
The Andean puma (Puma concolor) has not been widely studied, particularly in reference to its semen characteristics. The aim of the present study was to define the morphometry of puma sperm heads and classify their subpopulations by cluster analysis. Samples were recovered postmortem from two epididymides from one animal and prepared for morphological observation after staining with the Hemacolor kit. Morphometric data were obtained from 581 spermatozoa using a CASA-Morph system, rendering 13 morphometric parameters. The principal component (PC) analysis was performed followed by cluster analysis for the establishment of subpopulations. Two PC components were obtained, the first related to …
Unbaffled, Stirred Bioreactors for Animal Cell Cultivation
2017
One of the main features of animal cell bioreactors is that the cultured cells lack a strong membrane and are therefore more prone to shear damage. It is widely accepted that animal cell damage in aerated bioreactors is mainly related to burst bubbles at the air–liquid interface. A viable alternative to sparged bioreactors, aimed at minimizing cell damage, may be represented by uncovered, unbaffled, stirred tanks, which are able to provide sufficient mass transfer through the deep free surface vortex that takes place under agitation. As a consequence the need for bubble formation and subsequent bursting accompanied by cell damage is conveniently avoided. In this chapter, mass transfer perfo…
Optical Forging of Graphene into Three-Dimensional Shapes
2017
Atomically thin materials, such as graphene, are the ultimate building blocks for nanoscale devices. But although their synthesis and handling today are routine, all efforts thus far have been restricted to flat natural geometries, since the means to control their three-dimensional (3D) morphology has remained elusive. Here we show that, just as a blacksmith uses a hammer to forge a metal sheet into 3D shapes, a pulsed laser beam can forge a graphene sheet into controlled 3D shapes in the nanoscale. The forging mechanism is based on laser-induced local expansion of graphene, as confirmed by computer simulations using thin sheet elasticity theory. peerReviewed
Fibrin-chitosan composite substrate for in vitro culture of chondrocytes
2013
The aim of this study was to develop a biocompatible monolayer substrate based on fibrin and chitosan for in vitro culture of chondrocytes. Fibrin-chitosan composite substrates combined the proved cell adhesion properties of fibrin with the hydrophilicity and poor adhesion capacity of chitosan. Chitosan microspheres were produced by coacervation method, agglomerated within a fibrin network and subsequently crosslinked with genipin. The composite substrate was stable for 28 days of culture due to the high crosslinking density. Human chondrocytes cultured on the composite substrate were viable during the culture period. At the end of culture time (28 days) the composite substrate showed low c…