Motility of Mugil cephalus L. spermatozoa in coelomic fluid, seminal fluid and saline media

The aim of this study was to assess the motility duration of Mugil cephalus when exposed to seminal fluid, coelomic fluid and saline media. Hypo-osmotic activation medium (distilled water containing bovine serum albumin 10 or 30 mg ml⁻¹) did not trigger sperm motility. Saline solution containing 500 m m NaCl, 3.1 m m KCl, 0.2 m m Tris, 3.4 m m CaCl₂, pH 7.5 initiated the sperm activation and the motility lasted for more than 2 min. Coelomic fluid showed an inhibitory effect for triggering the motility of spermatozoa. Higher salinity increases the motility duration of sperm. The optimum motility duration was shown in salinity 32 psu.     

Amino acid composition and proteolytic generated domains of higher plant tubulin

The molecular architecture of tubulin from higher plant remains unknown. In this report we have made an attempt to identify higher plant tubulin domains using total and limited proteolysis of Haemanthus endosperm tubulin. The tubulin was previously purified and characterized (Picquot and Lambert 1988). The amino acid composition revealed a high content of basic residues, such as arginine and lysine. Tubulin domains were probed by tryptic and chymotryptic cleavage and analyzed by immunoblotting using specific monoclonal antibodies against alpha or beta subunits. These data shed light on specific properties of the higher plant tubulin.     

In vitro augmentation of mesenchymal stem cells viability in stressful microenvironments: In vitro augmentation of mesenchymal stem cells viability

Mesenchymal stem cells (MSCs) are under intensive investigation for use in cell-based therapies because their differentiation abilities, immunomodulatory effects, and homing properties offer potential for significantly augmenting regenerative capacity of many tissues. Nevertheless, major impediments to their therapeutic application, such as low proliferation and survival rates remain as obstacles to broad clinical use of MSCs. Another major challenge to evolution of MSC-based therapies is functional degradation of these cells as a result of their exposure to oxidative stressors during isolation. Indeed, oxidative stress-mediated MSC depletion occurs due to inflammatory processes associated with chemotherapy, radiotherapy, and expression of pro-apoptotic factors, and the microenvironment of damaged tissue in patients receiving MSC therapy is typically therapeutic not favorable to their survival. For this reason, any strategies that enhance the viability and proliferative capacity of MSCs associated with their therapeutic use are of great value. Here, recent strategies used by various researchers to improve MSC allograft function are reviewed, with particular focus on in vitro conditioning of MSCs in preparation for clinical application. Preconditioning, genetic manipulation, and optimization of MSC culture conditions are some examples of the methodologies described in the present article, along with novel strategies such as treatment of MSCs with secretome and MSC-derived microvesicles. This topic material is likely to find value as a guide for both research and clinical use of MSC allografts and for improvement of the value that use of these cells brings to health care.     

Improvement of acetone,butanol, and ethanol production from woody biomass using organosolv pretreatment

Bioprocess and Biosystems Engineering - A suitable pretreatment is a prerequisite of efficient acetone–butanol–ethanol (ABE) production from wood by Clostridia. In this study,...     

Computed tomography analysis of knee pose and geometry before and after total knee arthroplasty

Using a three-dimensional (3D) modality to image patients' knees before and after total knee arthroplasty (TKA) allows researchers and clinicians to evaluate causes of pain after TKA, differences in implant design, and changes in the articular geometry as a result of surgery. Computed tomography (CT) has not been fully utilized to date for evaluating the knee after TKA due to metal artifacts obscuring part of the image. We describe an accurate, validated protocol, which has been implemented in vivo, that improves visibility of the patellofemoral joint, matches implant models automatically in 3D, segments preoperative bone semi-automatically, detects and sets coordinate systems automatically, determines the six degrees of freedom of knee pose and geometry, and allows for multiple other measurements that are clinically relevant. Subjects are imaged at 0° and 30° knee flexion, while pushing on a custom-made knee rig to provide partial loadbearing. With some modifications, the protocol can be adopted by any group with access to a CT scanner and image analysis software, allowing for the investigation of numerous clinical and biomechanical questions.     

Quinazolinone exposure induces apoptosis and changes expressions of Fas/FasL and C-Flip in embryonic mice testicles

Quinazolinones represent a class of sedative and anticancer drugs. Quinazolinones-based compounds have ability to suppress prostate tumor growth via apoptosis. Apoptosis is very common in embryos and adults of normal and injured mammalian testes. Effects a new derivative of quinazolinone (4(3H) quinazolinone-2-ethyl-2-phenyl ethyl (QEPE)), on the testis of Balb/C mice embryos were investigated. QEPE was able to reduce number of germ cells and diameter of seminiferous tubules. TUNEL assay analysis indicated that reduction correlated with an increase in the number of apoptotic cell. Furthermore, electron microscope observations confirmed typical apoptotic morphologies characterized by chromatin fragmentation. Finally, RT-PCR analysis showed QEPE increases the levels of Fas/Fasl and decreases C-Flip mRNAs in the testis of exposed embryos.     

Modified thalamocortical model: A step towards more understanding of the functional contribution of astrocytes to epilepsy

It is evident that the cortex plays a primary role in seizure generation. At the same time, various experimental results clearly confirm that thalamic neurons are also actively involved in seizure generation and spreading. On the other hand, recent neurophysiologic findings suggest that astrocytes regulate dynamically the synaptic activity in neuronal networks. Therefore, in the present study, the thalamocortical neural population model (TCPM) is modified by embedding into the model the functional role of astrocytes in the regulation of synaptic transmission. Using the modified TCPM (MTCPM) we examined the hypothesis that one of the possible causes of neural hypersynchronization is the dysfunction of astrocytes in the regulatory feedback loop. Then, two MTCPMs are coupled via excitatory synapses and the astrocytes are also coupled together through gap junctions. Utilizing the MTCPM and CMTCPM, the transition from normal to malfunctioned states is analyzed using a dynamical system approach. In this way, the hypothesis is investigated and it is demonstrated that the healthy astrocytes provide feedback control to regulate neural activity. That is, the astrocytes compensate to a large extent variations in the coupling between neural populations and maintain the balance between the excitation and inhibition levels. However, the malfunctioned astrocytes are no longer able to regulate and/or compensate the excessive increase of the inter-population coupling strength. As a consequence, disruption of the signaling function of astrocytes could contribute to the neuronal hyperexcitability and generating epileptiform activity. These results suggest that astrocytes might be one of the potential targets for the treatment of epilepsy.     

A new RAPD marker for beet necrotic yellow vein virus resistance gene in Beta vulgaris

RAPD markers linked to beet necrotic yellow vein virus (BNYVV) resistance genes were identified in two Beta vulgaris accessions Holly-1-4 and WB42 using bulked segregant analysis. The polymorphism revealed by the RAPD markers in the F₂ generations of WB42 was higher than that of Holly-1-4. The segregation distortion at marker loci was slightly lower in the B. vulgaris × B. maritima cross than in the B. vulgaris × B. vulgaris cross. For Holly-1-4, a RAPD marker was identified in a long distance from the resistance gene of Rz ₁ . However, a RAPD marker tightly linked with Rz ₂ gene in repulsion phase was detected with an approximate distance of 0.036 rf. This marker was not generation specific and showed high repeatability. The distance between Rz ₁ and Rz ₂ genes was estimated as 0.464 rf. After the Rz ₂ Rz ₂ and Rz ₂ rz ₂ genotypes were identified using ELISA values and repulsion phase RAPD markers, comparison of their ELISA means revealed lack of the gene dosage effects. Nevertheless, under the field or severe infection conditions, the difference between ELISA mean values of the Rz ₂ Rz ₂ and Rz ₂ rz ₂ genotypes might be more than that observed in this study and the gene dosage effects of Rz ₂ allele might be important.     

Seasonal inventory and status of flying insects, in Kihansi Gorge, Tanzania

Sampling of flying insects in Kihansi Gorge was conducted in six micro-habitats namely Lower, Upper, Main, Mid-Gorge and Mhalala Spray Wetlands and adjacent forest. The four traps used were, malaise, pitfall, light and artificial substrate sampler, besides sweep netting and beating. In the wet season, 65,549 flying insects (65.13%) were recorded when compared to 35,633 flying insects (34.87%) in dry season. At its peak, 29,783 flying insects (29.15%) were recorded at the start of wet season (December 2004). The abundance value was significant ( χ ² = 1794.98, d.f. = 5, P  ≤ 0.001). The favourable weather condition at the beginning of the wet season might have triggered emergence of high numbers of winged insects like ants, to facilitate migration through dispersal and reproduction, and some aquatic insects (Plecoptera, Odonata and Trichoptera) moulted and entered into terrestrial life to raise terrestrial abundance. No association was recorded between abundance of flying insects and amphibians (Kihansi Spray Toad; Nectophynoides asperginis ), for Mid-Gorge and Main Spray Wetlands (r = −0.71, n = 4, P  = 0.147 and r = −0.69, n = 5, P  = 0.201) respectively.     

Assessment of ability of endangered Caspian brown trout, <Emphasis Type="Italic">Salmo trutta caspius</Emphasis> (Salmonidae) in production of semen with desirable quality

To assay the effects of stripping frequency on semen characteristics of Caspian brown trout, Salmo trutta caspius, the chemical composition of seminal fluid, sperm production (semen volume, sperm density, spermatocrit,) and sperm motility characteristics (percentage and duration of motility) were investigated over four times stripping during the spawning season. According to data, semen volume, sperm density, osmolality and the concentrations of Na⁺, Cl⁻, K⁺, Ca²⁺, Mg²⁺ and total protein gradually decreased by increasing of stripping frequency. The values of glucose and triglyceride had no significant changes over four times stripping. Also, the values of semen pH, the percentage (5 s after activation) and duration of motility were statistically stable until third stripping but a decrease was recorded for these parameters in the fourth stripping. As well as, significant positive correlations were found for sperm density vs. K⁺, Cl⁻, Na⁺, Ca²⁺, Mg²⁺, total protein, spermatocrit; the percentage of motile spermatozoa vs. Ca²⁺, Mg²⁺, K⁺, Cl⁻, Na⁺, total protein, and also the duration of motility vs. K⁺, Cl⁻, total protein and pH. In text, specific objectives of this study have been expressed.