Neurons of the superficial tectal gray an intracellular HRP-study on the kitten superior colliculus in vitro

Summary An en bloc preparation of the mammalian superior colliculus in vitro has been used to study neurons of the superficial gray layer (SGS) with intracellular recording and HRP-technics. Electrophysiological data from kittens at 4–19 days of age suggest that at this stage SGS-neurons possess multiple spike trigger zones which can be activated by synaptic depolarization and are probably located on dendrites. In response to intratectal stimulation SGS-neurons generate EPSP-IPSP sequences or IPSPs. IPSPs are found in all penetrated cells as early as the 4th postnatal day. Ascending projection cells (APCs) and inter-layer cells (ILCs) have been identified based on antidromic activation and/or intracellular labeling with HRP. The extended dendritic arbor of APCs and ILNs (dorsal spread up to 10–20 m below surface, horizontal spread up to 1100–1500 m) enables these cells to sample visual information from a wide area of the visual field. Recurrent collaterals, in conjunction with potent inhibitory mechanisms, could contribute to the formation of receptive field properties of superficial tectal neurons. ILCs establish collateral connections with the intermediate gray layer.     

Developmental competence of oocytes showing increased cytoplasmic viscosity

BACKGROUND: The objective of the study was to investigate the developmental fate of oocytes with increased cytoplasmic viscosity as assessed by the persistence of the injection funnel after withdrawal of the ICSI pipette. METHODS: For this purpose, 1008 oocytes showing a characteristic injection funnel during ICSI were subdivided into two groups according to the oocyte's ability to restore its spherical shape within 2-3 min after ICSI. Fertilization and further development was evaluated in both groups. In addition, implantation and pregnancy rates were analysed. RESULTS: In the funnel positive cohort (group 1) significantly fewer oocytes degenerated after injection (P < 0.01) compared with oocytes without persistent funnel (group 2). However, at zygote stage, presence of a halo (P < 0.05) and a optimal pronuclear pattern 0 (P < 0.01) was increased in group 2. In addition, significantly fewer poor quality embryos were found in this group (P < 0.01). The number of good quality blastocysts but not blastocyst formation was increased in group 2 (P < 0.05). This resulted in an increased clinical pregnancy rate if embryos which derived exclusively from funnel negative oocytes were transferred (P < 0.05). CONCLUSIONS: Our data suggest that cytoplasm of higher viscosity delays development up to cleavage stage and impairs optimal development. Injection funnel persistence was found to be a negative prognostic marker of preimplantation development.     

Monomorphic (Basal Cell) Salivary Adenoma of Ovary: Report of a Case

A pregnant 26-year-old woman presented with an asymptomatic 10-cm left ovarian mass diagnosed at 19 weeks gestation. On removal, the tumor was shown to be a cribriform variant of basal cell salivary adenoma with no other teratomatous or germ cell tumor elements present. The pregnancy continued uneventfully to term and the patient remains symptom-free 10 months after diagnosis. Tissues of salivary type are occasionally observed within mature cystic teratomas of the ovaries and are presumed to have given rise to the present lesion, which is thought to be the first reported case of a neoplasm of salivary type arising in the ovaries.     

Mechanoelectric Feedback in a Model of the Passively Inflated Left Ventricle

Mechanoelectric feedback has been described in isolated cells and intact ventricular myocardium, but the mechanical stimulus that governs mechanosensitive channel activity in intact tissue is unknown. To study the interaction of myocardial mechanics and electrophysiology in multiple dimensions, we used a finite element model of the rabbit ventricles to simulate electrical propagation through passively loaded myocardium. Electrical propagation was simulated using the collocation-Galerkin finite element method. A stretch-dependent current was added in parallel to the ionic currents in the Beeler–Reuter ventricular action potential model. We investigated different mechanical coupling parameters to simulate stretch-dependent conductance modulated by either fiber strain, cross-fiber strain, or a combination of the two. In response to pressure loading, the conductance model governed by fiber strain alone reproduced the epicardial decrease in action potential amplitude as observed in experimental preparations of the passively loaded rabbit heart. The model governed by only cross-fiber strain reproduced the transmural gradient in action potential amplitude as observed in working canine heart experiments, but failed to predict a sufficient decrease in amplitude at the epicardium. Only the model governed by both fiber and cross-fiber strain reproduced the epicardial and transmural changes in action potential amplitude similar to experimental observations. In addition, dispersion of action potential duration nearly doubled with the same model. These results suggest that changes in action potential characteristics may be due not only to length changes along the long axis direction of the myofiber, but also due to deformation in the plane transverse to the fiber axis. The model provides a framework for investigating how cellular biophysics affect the function of the intact ventricles. © 2001 Biomedical Engineering Society. PAC01: 8716Uv, 8719Nn, 8719Hh, 8719Rr, 8718Bb, 8710+e, 0270Dh, 8717Aa     

Development of a novel electrophoretic system for the isolation of human spermatozoa

BACKGROUND: Optimization of assisted conception outcomes involves the development of rapid, safe, effective techniques for the isolation of functional human spermatozoa free from significant DNA damage. In this study we describe a novel electrophoretic sperm isolation technique that achieves these objectives. METHODS: The separation system consisted of a cassette comprising two 400 mul chambers separated by a polycarbonate filter containing 5 micromol/l pores and bounded by a 15 kDa polyacrylamide membrane to allow the free circulation of buffer. Semen was introduced into one chamber, current applied (75 mA at variable voltage) and within seconds a purified suspension of spermatozoa could be collected from the adjacent chamber. These cells were assessed for their count, viability, motility, morphology and DNA integrity. RESULTS: The suspensions generated by the electrophoretic separation technique contained motile, viable, morphologically normal spermatozoa and exhibited low levels of DNA damage. Moreover, these cell suspensions were free from contaminating cells, including leukocytes. The technique was comparable to discontinuous gradient centrifugation except that it took a fraction of the time and generated cells with significantly less DNA damage. CONCLUSION: Electrophoretic separation represents a highly effective, novel approach for the isolation of spermatozoa for assisted conception purposes.     

Subdigital Setae of Narrow‐Toed Geckos,Including a Eublepharid (Aeluroscalabotes felinus)

Subdigital adhesive setae have previously been documented in all legged gecko families except the Eublepharidae. I present evidence that members of Aeluroscalabotes felinus, the only arboreal eublepharids, possess subdigital setae up to 9 μm in length. This discovery suggests that the conditions leading to adhesive setae were probably present in the ancestors of all geckos, rather than arising multiple times within Gekkota. The digits and setae of Aeluroscalabotes resemble those of other climbing, bent‐toed geckos. I describe the setal morphology of the following bent‐toed species: Cyrtodactylus peguensis, Gonatodes albogularis, and Pristurus rupestris. The presence of subdigital setae is highly correlated with an arboreal lifestyle across geckos and other lizards such as anoles and skinks. Although relatively simple in form, these setae likely confer additional traction that significantly benefits climbing species. Further developmental and biomechanical studies comparing these species with more agile climbers like the Tokay will improve our understanding of the evolutionary processes leading to adhesive setae, and consequently inform engineers attempting to fabricate effective artificial gecko setae. Anat Rec, 291:869‐875, 2008. © 2008 Wiley‐Liss, Inc.     

Quantitative changes in testicular structure and function in rat exposed to mobile phone radiation

The possible effects of the electromagnetic fields (EMF) generated by mobile phones on reproductive functions have been discussed in recent years. The aim of this study was to evaluate the effects of EMF emitted from mobile phones on the rat testis morphology and histopathology using stereological techniques. We also investigated cortisol, testosterone, FSH and LH levels. A total of thirty‐two (n = 32) male Wistar albino rats were used in this study. Animals were randomly divided into four groups as control (C, n = 8), sham (Sh, n = 8), mobile phone speech (Sp, n = 8) and mobile phone standby (ST by). Morphometric measurements were made with the help of a computer‐assisted stereological analysis system. The testis weight and volume were significantly lower in the EMF exposed groups. The mean volume fraction of interstitial tissue was higher, but the volume fraction of tubular tissue was lower in the EMF‐exposed groups. The mean tubular and germinal tissue volume, seminiferous tubule diameter and germinal epithelium height were also lower in EMF exposed groups. The cortisol levels in the EMF‐exposed groups were significantly higher. In conclusion, the EMF created by mobile phones caused morphologic and histological changes by the affecting germinal epithelium tissue negatively.     

Comparison of ex vivo and in vivo micro‐computed tomography of rat tibia at different scanning settings

The parameters of a micro‐computed tomography (μCT) scan, including whether a bone is imaged in vivo or ex vivo, determine the quality of the resulting image. In turn, this impacts the accuracy of the trabecular and cortical outcomes. The absolute impact of μCT scanning at different voxel sizes and whether the sample is imaged in vivo or ex vivo on the morphological outcomes of the proximal tibia in the rat is unknown. The right proximal tibia of 6‐month‐old Sham‐control and ovariectomized (OVX) rats (n = 8/group) was scanned using μCT (SkyScan 1176, Bruker, Kontich, Belgium) using three sets of parameters (9 μm ex vivo, 18 μm ex vivo, 18 μm in vivo) to compare the trabecular and cortical outcomes. Regardless of scan protocols, differences between Sham and OVX groups were observed as expected. At a voxel size of 18 μm, scanning in vivo or ex vivo had no effect on any of the outcomes measured. However, compared to a 9 μm voxel size scan, imaging at 18 μm resulted in significant underestimation of the connectivity density (p < 0.05) of the trabecular bone and a significant overestimation (p < 0.05) of the trabecular indices (trabecular thickness, degree of anisotropy) and of the cortical indices (cortical bone area, cortical area fraction, cortical thickness) in both Sham and OVX rats. These results suggest the benefit to scanning the proximal tibia of rats at a voxel size as low as 9 μm, although considerations must be made for the increased acquisition time, anesthesia, animal welfare, and radiation exposure associated with lower voxel size in vivo scanning. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1690–1698, 2017.

     

Diagnosis of orbital mass lesions: clinical,radiological, and pathological recommendations

The orbit can harbor mass lesions of various cellular origins. The symptoms vary considerably according to the nature, location, and extent of the disease and include common signs of proptosis, globe displacement, eyelid swelling, and restricted eye motility. Although radiological imaging tools are improving, with each imaging pattern having its own differential diagnosis, orbital mass lesions often pose a diagnostic challenge. To provide an accurate, specific, and sufficiently comprehensive diagnosis, to optimize clinical management and estimate prognosis, pathological examination of a tissue biopsy is essential. Diagnostic orbital tissue biopsy is obtained through a minimally invasive orbitotomy procedure or, in selected cases, fine needle aspiration. The outcome of successful biopsy, however, is centered on its representativeness, processing, and interpretation. Owing to the often small volume of the orbital biopsies, artifacts in the specimens should be limited by careful peroperative tissue handling, fixation, processing, and storage. Some orbital lesions can be characterized on the basis of cytomorphology alone, whereas others need ancillary molecular testing to render the most reliable diagnosis of therapeutic, prognostic, and predictive value. Herein, we review the diagnostic algorithm for orbital mass lesions, using clinical, radiological, and pathological recommendations, and discuss the methods and potential pitfalls in orbital tissue biopsy acquisition and analysis.